ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Inorganic Chemistry  (7,274)
  • Cell & Developmental Biology  (4,158)
  • 2015-2019  (5)
  • 1980-1984  (6,178)
  • 1975-1979  (5,249)
Collection
Keywords
Publisher
Years
Year
  • 101
    Electronic Resource
    Electronic Resource
    Morphology and histology of the alimentary tracts of ambassidae (Cuvier) (Teleostei) in relation to feeding (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 182 (1984), S. 295-305 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The gross morphology and histology of the alimentary tracts of three species of glassy perchlet; Ambassis productus, A. natalensis, and A. gymnocephalus from estuaries on the southeast coast of Africa were investigated. The anatomy of the digestive tracts in all three species was found to be similar. Well-developed dentition and pharyngeal teeth together with a distensible stomach and a low relative gut length (RGL) suggest a predatory and carnivorous habit for all three species.The relative gut lengths of Ambassis species from different estuarine systems are compared‥ Differences in RGL for A. productus and A. natalensis from the Kosi and St Lucia systems with fish from Mdloti estuary are discussed. It is suggested that decreased RGL for fish at Mdloti is attributable to decreased food availability and not to a lack in the calorific content of their diet.Histological investigation revealed the presence of the following regions: a pharynx; an oesophagus; a stomach differentiated into cardiac and pyloric regions; a duodenum or upper intestine; an ileum or lower intestine; and a rectum. Pyloric and rectal sphincters are present. The tunics of the above regions are described. The epithelium of the oesophagus contains taste buds and numerous mucus cells, and varies from stratified anteriorly to simple columnar posteriorly. The muscularis comprises dorsally and ventrally located inner muscle bundles and an outer circular layer. Both layers consist of striated fibres.Gastric glands are present in the mucosa of the cardiac stomach but are absent in the pylorus. Columnar absorbing cells and goblet cells are present in the epithelium of the upper and lower intestine. The rectum is distinguished from the intestine by the proliferation of mucous-secreting cells which are thought to aid defecation.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051820305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 102
    Electronic Resource
    Electronic Resource
    Growth and metamorphosis of the rectus abdominis muscle in Rana pipiens (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 182 (1984), S. 317-337 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cross sections through the middle segment of the anuran rectus abdominis muscle were analyzed morphometrically at nine stage of development, from early larval life through full maturity. The numbers, sizes, and relative distributions of twitch and slow muscle fibers, newly differentiated fibers, degenerating fibers, and satellite cells were determined at each stage. The data indicate that the muscle increases slowly in size and fiber content during early larval life. New fibers appear to form primarily along the medial margin of the muscle. During mid-larval stages, when thyroid hormone levels are rising, new fibers form throughout the medial portion of the muscle. At a slightly later stage, fibers in the lateral region of the muscle begin to degenerate. Structurally normal presynaptic elements are present on both degenerating fibers and the empty basal laminae of fibers that had been removed by phagocytes. Both fiber formation and fiber loss slow during midmetamorphic climax, at the time when thyroid hormone levels reach a peak in anurans and begin to decline. Degenerating fibers appear within the body of the muscle at the end of metamorphosis. By the end of the second postmetamorphic month, neither degenerating nor newly differentiated fibers are present. The muscle continues to grow through adult life primarily by fiber hypertrophy.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051820307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 103
    Electronic Resource
    Electronic Resource
    Adrenergic innervation of the gills of brown and rainbow trout, Salmo trutta and S. gairdneri (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 182 (1984), S. 307-316 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The adrenergic innervation of structures in the gills of brown and rainbow trout was studied with catecholamine fluorescence histochemistry.In the arterio-arterial vascular pathway, there was an innervation of the afferent and efferent lamellar arterioles, but the afferent and efferent filamental arteries and the secondary lamellae were devoid of any fluorescent nerve fibres. In S. trutta only, there was an additional innervation of the afferent and efferent branchial arteries and the base of the efferent filamental artery.The innervation of the arterio-venous vascular pathway was similar in both trout species. Many fluorescent nerve fibres were found on nutritive arterioles in the gill arch and interbranchial septum, and in the core of each filament between the surface epithelium and the wall of the filament venous sinus. No fluorescent nerve fibres were observed at the origins of the capillaries arising from the efferent filamental artery.The sympathetic nerve supply is provided to the gills mainly through the posttrematic nerve, with an occasional small contribution through the pretrematic nerve.The presence of adrenergic nerves in the gills is discussed in relation to the regulation of blood flow through the arterio-arterial and arterio-venous pathways.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051820306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 104
    Electronic Resource
    Electronic Resource
    Morphometric diffusing capacity and functional anatomy of the book lungs in the spider Tegenaria spp. (Agelenidae) (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 182 (1984), S. 339-354 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The presence of both book lungs and a tracheal system in many spiders raises the question of the functional significance of this double respiratory system. The present physiological and morphometric study of the house spider (Tegenaria spp.) reveals that the diffusing capacity (Dto2) of the lungs alone suffices during rest and following exercise to meet measured rates of oxygen consumption (\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm.} $\end{document}o2) at driving pressures (ΔPto2) similar to those calculated for vertebrate lungs. During moulting ΔPto2 may rise to more than double the vertebrate values, implying the possible insufficiency of book lungs during this critical life phase. Resting \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm .} $\end{document}o2 is greatest (92 mm3/h · g) during the early morning and lowest (66 mm3/h · g) near midday: during moulting \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm .} $\end{document}o2 rises to 278.7 mm3/h · g. In spiders recovering from exercise \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm V}\limits^{\rm .} $\end{document}o2 is consistently greater than during rest: neither value is significantly reduced by blockage of the tracheal stigmas. Regression calculations of morphometric values for a hypothetical 100-mg Tegenaria yield a total lung volume of 0.578 mm3, a pulmonary surface area of 69.8 mm2, and a surface-to-volume ratio of 120.89 mm2/mm3. In spite of the similar thickness of the chitinous and hypodermal components of the air-hemolymph barrier (each ca. 0.2 μm in nonmoulting animals), the low permeability of chitin for oxygen makes this layer the greater barrier to diffusion. For a 100-mg specimen Dto2 is 3.5 mm3/h · torr: similar to that of a turtle (Pseudemys) on a gram-body weight basis.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051820308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 105
    Electronic Resource
    Electronic Resource
    Ultrastructural studies on oogenesis in the shrew (Crocidura russula): I. The preantral follicle (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 59-71 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Ultrastructural analysis of the ovarian follicle prior to antrum formation in the shrew, Crocidura russula, shows gradual differentiation of mitochondria, endoplasmic reticulum, Golgi complexes, vesicles, and multivesicular bodies correlated with the growth of the oocyte from primordial to tertiary follicle and the development of the follicular wall. The growth rate of the follicle in relation to that of the oocyte was found to be biphasic.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 106
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 107
    Electronic Resource
    Electronic Resource
    Styletogenesis in nemertean worms: The ultrastructure of organelles involved in intracellular calcification (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 119-134 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ultrastructure of cellular organelles involved in stylet formation is examined in six species of nemertean worms by transmission electron microscopy (TEM). Stylets are nail-shaped structures containing calcium phosphate that are assembled intracellularly in large uninucleate cells, called styletocytes. Each stylet develops within a membrane-bound vacuole in the styletocyte cytoplasm. Well developed arrays of Golgi bodies are typically found in the vicinity of developing stylet vacuoles, and fully formed vacuoles are filled with PAS+ material that appears to be derived from the smooth endoplasmic reticulum. At the onset of styletogenesis, a conical sliver of organic material differentiates on the inner surface of the vacuolar membrane. This material displays a species-specific banding pattern in decalcified sections, and apparently acts as a template during calcification of the stylet shaft. After the organic core of the shaft is formed, mitochondria aggregate around the stylet vacuole and presumably help accumulate the calcium used in mineralization of the stylet. A knob-shaped proximal piece is subsequently assembled on the base of the shaft. The proximal piece contains a nonbanded matrix and has electron-dense material at its surface that may help in correctly orienting this region toward the basis during replacement of the central stylet.
    Additional Material: 35 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 108
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 109
    Electronic Resource
    Electronic Resource
    Ultrastructural observations on the embryonic development of the integument of Lacerta muralis (Lacertilia, Reptilia) (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 203-228 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Integumentary development on the dorsal and ventral aspects of the body of 14, 21, 26, 33, and 40-day incubated embryos of the European Wall Lizard (Lacerta muralis) is described. While the earliest stages of epidermal differentiation resemble those reported for other tetrapods, precocious differentiation of dermal collagen more resembles that of anamniotes than that of birds and mammals. Anchoring complexes comprising cellular components, anchor filaments, and collagen are described, and their possible relationship to the formation of scale anlagen is discussed. The first embryonic epidermal generation differentiates beneath the periderm; most features of its histogenesis resemble those that have been described for the epidermis of adult squamates, but certain previously ignored organelles, including possible earlier β-keratin precursors, are reported. Different strategies regarding in ovo peridermal loss and posthatching shedding behavior are described and discussed in light of presently available data concerning control of cell differentiation in the squamate epidermis.
    Additional Material: 26 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 110
    Electronic Resource
    Electronic Resource
    Ultrastructure of the male reproductive system and of spermatogenesis in the viviparous brittle-star, Amphipholis squamata (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 243-262 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The fine structure of the male reproductive system of the hermaphroditic brittle-star, Amphipholis squamata, has been studied in specimens from both the Pacific coast (Washington) and the Atlantic coast (New Hampshire). Each testis is a small (100-μm) sphere and is attached to the internal wall of the bursa by peritoneal suspensor cells. Occasional flagellated cells are found on the external surface of the testis. The testicular wall of A. squamata is a multilayered structure, similar to that of other ophiuroids, but the hemal sinus is PAS negative in this species. Germinal cells are surrounded throughout their development by the filopodia of interstitial cells. Adjacent interstitial cells are interconnected, and thus form a structural network within the testis. Positionally and functionally, the interstitial cells resemble Sertoli cells; however, their origin, behavior and ultrastructure are different in many ways.Spermatogenesis includes a series of cyclical changes (aspermatogenic phase, proliferative phase, differentiative phase, and evacuative phase). Within a single testis, the resulting production of sperm is in short pulses, but if all 10 testes are taken together, sperm are produced continuously throughout the year. The events of spermiogenesis closely follow those that have been described in other echinoderms. However, we have provided new information on the release of excess cell membranes and the fusion process of mitochondria.The mature spermatozoa of A. squamata are flagellated and motile, and have “primitive” structural features, in spite of the fact that they fertilize the eggs inside the genital bursae. The spermatozoa do not, as was previously thought, enter the bursa by rupture of the adjacent walls. Instead, they are ejaculated through a gonoduct into the rapid incurrent flow of water entering the bursa. The locomotion of the spermatozoa is in eccentric spirals, due to the unusually large angle at which the flagellum is inserted into the base of the sperm.
    Additional Material: 33 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 111
    Electronic Resource
    Electronic Resource
    List of reviewers for the journal of morphology, 1983 (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 180 (1984), S. 1-2 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051800102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 112
    Electronic Resource
    Electronic Resource
    The larval nephridia of the brackish-water polychaete, Nereis diversicolor (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 273-289 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The larval nephridia of the brackish-water polychaete Nereis diversicolor are described for the first time, and have been studied to determine if their times of development and structural characteristics are consistent with a role in the osmotic regulation of the larva. As shown in serial paraffin sections and by interference-contrast optics, the nephridia of the three-setiger larva consist of a single pair of very large metanephridia, arising in the 3rd larval setiger, but with their elongated terminal ducts and coiled ciliated tubules pushed forward into the 2nd setiger; their open metanephrostomes and anterior anchoring filaments lie dorsal to the 2nd set of setae. In contrast, the definitive or juvenile metanephridia, arising in the 4th and subsequently formed setigerous segments, have short terminal ducts and coiled ciliated tubules confined to the segments on which their external nephropores open; their nephrostomes are ventrally located and open into the rear of the next anterior segment. These findings are in contrast to the claims of Edouard Meyer (1887), who described two pairs of closed protonephridia in the 2nd and 3rd larval setigers of Perinereis cultrifera. Although it is not excluded that the single larval pair of metanephridia of N. diversicolor may arise as protonephridia, Meyer's claim of two pairs of larval protonephridia was an observational error. The larval nephridia of the marine Platynereis dumerilii resemble in form, but are considerably smaller than, those of N. diversicolor. It is concluded that the hypertrophied pair of larval metanephridia of N. diversicolor is an evolutionary adaptation to existence in habitats of low and unpredictably varying salinity. Their development occurs irrespective of the prevailing salinity; hence, it must be genetically determined.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 113
    Electronic Resource
    Electronic Resource
    Movements of the mandibles and tongue during mastication and swallowing in Pteropus giganteus (Megachiroptera): A cineradiographical study (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 95-114 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Quantitative lateral and dorsoventral cineradiography shows that the masticatory movements of the mandible, condyles, tongue, and hyoid of Pteropus giganteus (Chiroptera) move along highly regular paths that are characteristic for each of the three food types tested.Mandibular movements are predominantly orthal, although a small forward translation occurs early in opening and small lateral deflections occur in both opening and closing phases. These deflections are related to the existence of active (bolus bearing) and balancing sides of the jaws, chewing being not truly bilateral. The deflections are associated with a shift of both condyles toward one side. In consequence the active condyle is located in a lateral part of the associated fossa, the inactive condyle in a medial part. Food transfer from side to side involves a reversal of the chewing direction during opening. Such reversals are especially frequent near the end of a chewing sequence.The fore, middle, and hind parts of the tongue differ in their movement patterns. Movements of the fore part, and to a lesser extent of the middle part, follow the open-close movements of the lower jaw. The hind part of the tongue moves predominantly dorsally during slow closing and ventrally during fast opening and fast closing. All three parts move forward during slow closing and slow opening, and backward during fast opening and fast closing. Movements of the hyoid are closely synchronized with those of the hind part of the tongue. Furthermore, tongue and hyoid movements are synchronized with jaw movements. All cycles of Pteropus giganteus are transport cycles, and the synchrony appears to reflect the consistency of the food (soft pulp, juices). Food consistency also accounts for the high swallowing rate and the absence of any significant difference between nonswallowing and swallowing cycles.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 114
    Electronic Resource
    Electronic Resource
    A Golgi study of anterior dorsal ventricular ridge in the alligator, Alligator mississippiensis (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 153-174 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The anterior dorsal ventricular ridge was examined in the American alligator, Alligator mississippiensis, with cresyl violet and Golgi-Kopsch preparations. Four cytoarchitectonic areas (lateral dorsolateral, medial dorsolateral, intermediolateral, and lateral) can be distinguished by variations in the density of neurons and their tendency to form clusters of neurons with apposed somata. Three distinct types of neurons are distributed throughout these areas. Juxtaependymal neurons lie near the ventricular surface and have dendritic fields paralleling the ependymal layer. Their dendrites bear a moderate density of spines. Spiny neurons all have stellate shaped dendritic fields and dendrites that bear dendritic spines, but they vary greatly in the density of spines and the thickness of their dendrites. A very spiny variety has a high spine density and relatively thick dendrites. A moderately spiny variety has a moderate spine density and thin dendrites. A sparsely spiny variety has a low spine density and thick dendrites. Aspiny neurons have a relatively large number of dendrites that form a gnarled dendritic field and lack spines.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 115
    Electronic Resource
    Electronic Resource
    Phagocytosis in the spleen of the sunfish Lepomis spp. (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 175-195 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A histological investigation of the filtering function of the spleen of the sunfish Lepomis spp. was conducted by light, scanning, and transmission electron microscopy. The parenchyma of the organ is predominantly red pulp, a system of splenic cords and sinuses. The white pulp consists of loose lymphoid tissue which forms a cuff around the pulp arteries. Filtering of particulate matter from the blood occurs in the red pulp by phagocytes of the pulp cords and ellipsoids (periarterial macrophage sheaths). The ellipsoids are pale-staining cuffs of macrophages and reticular cells in a framework of reticular fibres surrounding the arterial capillaries. Destruction of effete blood cells (especially erythrocytes) is confined to the pigment nodules; particulate matter is not taken up by the nodules. These yellow-brown bodies are dispersed throughout the red pulp and are bounded by a reticular capsule. They contain masses of phagocytes and have the appearance of a morula. They are associated with blood vessels and are surrounded by sinusoids. Prussian Blue stain shows the presence of haemosiderin within their phagocytes. The phagocytes of the pigment nodules are filled with inclusions such as residual bodies, siderosomes, and fragments of erythrocytes. The early filtering of particulate matter by the phagocytes of the pulp cords and ellipsoids may allow for a more efficient phagocytosis of erythrocytes by the pigment nodules, followed by storage and reutilization of iron-containing compounds uncontaminated by other phagocytosed material.
    Additional Material: 30 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 116
    Electronic Resource
    Electronic Resource
    Pigment cell differentiation in the fire-bellied toad, Bombina orientalis. I. Structural, chemical, and physical aspects of the adult pigment pattern (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 179 (1984), S. 229-242 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Wild-collected adults of Bombina orientalis are bright green dorsally and red to red-orange ventrally. As a prelude to an analysis of the differentiation of pigment cells in developing B. orientalis, we describe structural and chemical aspects of the fully differentiated pigment pattern of the “normal” adult.Structurally, differences between dorsal green and ventral red skin are summarized as follows: (1) Dorsal green skin contains a “typical” dermal chromatophore unit comprised of melanophores, iridophores, and xanthophores. Red skin contains predominantly carotenoid-containing xanthophores (erythrophores), and skin from black spot areas contains only melanophores. (2) In ventral red skin, there is also a thin layer of deep-lying iridophores that presumably are not involved in the observed color pattern. (3) Xanthophores of red and green skin are morphologically distinguishable from each other. Dorsal skin xanthophores contain both pterinosomes and carotenoid vesicles; ventral skin xanthophores contain only carotenoid vesicles. Carotenoid vesicles in dorsal xanthophores are much larger but less electron dense than comparable structures in ventral xanthophores.The presence of carotenes in ventral skin accounts for the bright red-orange color of the belly of this frog. Similar pigments are also present in green skin, but in smaller quantities and in conjunction with both colored (yellow) and colorless pteridines. From spectral data obtained for xanthophore pigments and structural data obtained from the size and arrangement of reflecting platelets in the iridophore layer, we attempt to explain the phenomenon of observed green color in B. orientalis.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051790303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 117
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 180 (1984) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051800101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 118
    Electronic Resource
    Electronic Resource
    Intercellular bridges in ovaries of the newborn gerbil (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 180 (1984), S. 29-35 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This study describes intercellular bridges in the ovaries of neonatal gerbils. Electron microscopy has revealed the presence of true intercellular bridges, connecting oogonia or oocytes, in ovaries of newborn gerbils. The cytoplasm of the intercellular channels is similar to that of the connected cells, with mitochondria, smooth and rough endoplasmic reticulum, and free ribosomes present. Lysosomes are also occasionally present in the intercellular bridges and they may be involved in early waves of oocyte atresia. An electrondense substance, 350-500 Å thick, is located immediately beneath the unit membrane of the intercellular bridges. Accumulation of electron-dense material increases the thickness of the walls of the intercellular bridges, supporting and maintaining the patency of the channels. It is suggested that the intercellular channels probably allow the interchange of nutrients, organelles, and possibly regulatory materials as well.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051800105
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 119
    Electronic Resource
    Electronic Resource
    Organization of interstitial tissue in the testis of the salamander Necturus maculosus (Caudata: Proteidae) (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 181 (1984), S. 87-95 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In Necturus maculosus the organization of the interstitial tissue varies according to the stage of spermatogenesis. Leydig cells at various stages of differentiation and myoid cells are always present in this tissue. The Leydig cells are undifferentiated at all phases of germ cell activity and only hypertrophy following spermiation and degeneration of Sertoli cells. These Leydig cells are structurally analogous to mammalian Leydig cells. They do not form part of the lamina propria of the seminiferous lobules and hence cannot be referred to as lobule-boundary cells previously described in the urodele testis (Lofts, '74). When the Leydig cells hypertrophy, numerous unmyelinated axons appear in the interstitial tissue. These axons, often devoid of Schwann-cell cytoplasm, occur in close proximity to Leydig cells. Because the levels of both Substance P and neurotensin increased in the testis of Necturus maculosus as Leydig cells differentiated, we concluded that these neural elements may regulate Leydig-cell function locally, through the release of neuropeptides.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051810108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 120
    Electronic Resource
    Electronic Resource
    The venous system of the terrestrial crab Ocypode cordimanus (Desmarest 1825) with particular reference to the vasculature of the lungs (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 181 (1984), S. 133-142 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The respiratory system of Ocypode cordimanus consists of seven pairs of gills, modified for aerial gas exchange, and a single pair of lungs. Each lung is formed from the inner surface of the branchiostegite and the thoracic wall of the branchial chamber. The branchiostegal surface is increased by a fleshy infolding, the branchiostegal shelf, whilst the surface area of the thoracic lung wall is enhanced by a large flaplike fold.The anatomy of the major sinus systems and the vascular supply to the lungs were investigated. Venous hemolymph is supplied to the lungs potentially from all the major body sinuses. The dorsal, ventral, hepatic, and infrabranchial sinuses are all connected anteriorly to the two eye sinuses which distribute hemolymph to the lungs. Each eye sinus gives off five branches to the branchiostegal lung surface and one to the thoracic lung wall. These afferent vessels are highly branched and interdigitate closely with efferent vessels. The two systems are connected by flat lacunae lying just beneath the respiratory epithelium and these are believed to be the site of gas exchange. The efferent vessels empty into two pulmonary veins on each side, one serving the branchiostegal lung wall and the other the thoracic wall. The two vessels on each side fuse before joining the pericardial cavity as a single trunk on each side.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051810202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 121
    Electronic Resource
    Electronic Resource
    Head skeleton of the marine catfish Arius tenuispinis day (Osteichthyes: Siluriformes, Ariidae) (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 181 (1984), S. 221-238 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The osteology of the head skeleton of marine catfish Arius tenuispinis is described in detail. The skeletal elements of the different regions are dealt with categorically. Bones of the ethmoidal, orbitotemporal, auditory, and occipital regions of the cranium; and the upper jaw, lower jaw, hyoid arch, hypobranchial, and opercular series of the visceral skeleton are described in detail. Identity of the ectopterygoid, mesopterygoid, and metapterygoid is established in accordance with the current nomenclature and accepted homologies. The shelving bone of the epiotic is found to be large, having articulation with the parapophyses of the complex vertebra. The head skeleton of A. tenuispinis conforms to the normal siluroid pattern.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051810208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 122
    Electronic Resource
    Electronic Resource
    Cellular and ultrastructural features of the adult and the embryonic eye in the marine gastropod, Ilyanassa obsoleta (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 181 (1984), S. 205-220 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Light and electron microscopic techniques show that the eye of the marine prosobranch gastropod, Ilyanassa obsoleta, is composed of an optic cavity, lens, cornea, retina, and neuropile, and is surrounded by a connective tissue capsule. The adult retina is a columnar epithelium containing three morphologically distinct cell types: photoreceptor, pigmented, and ciliated cells. The retina is continuous anteriorly with a cuboidal corneal epithelium. The neuropile, located immediately behind the retina, is composed of photoreceptor cell axons, accessory neurons, and their neurites. The embryonic eye is formed from surface ectoderm, which sinks inward as a pigmented cellular mass. At this time, the eye primordium already contains presumptive photoreceptor cells, pigmented retinal cells, and corneal cells. Several days later, just before hatching, the embryonic eye remains in intimate contact with the cerebral ganglion. It has no ciliated retinal cells, neuropile, optic nerve, or connective tissue capsule and its photoreceptor cells lack the electron-lucent vesicles and multivesicular bodies of adult photoreceptor cells. As the eye and the cerebral ganglion grow apart, the optic nerve, neuropile, and connective tissue capsule develop.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051810207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 123
    Electronic Resource
    Electronic Resource
    Morphological basis of the feeding mechanics in the shingle-back lizard Trachydosaurus rugosus (Scincidae, Reptilia) (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 181 (1984), S. 271-295 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: This report details certain morphological aspects of the feeding system of the lizard Trachydosaurus rugosus, an opportunistic omnivore, as a first step toward a functional characterization of its masticatory system. The skull is relatively solid and internally well braced; its anterodorsal elements are tightly tied to the integument and covering osteoderms. There is potential for intracranial kinesis and streptostyly. At small gapes, mandibular movements seem to be restricted to relatively simple, hingelike actions by a series of mechanical stops. The dentition features a progression of smaller to larger teeth posteriorly along the tooth row. The jaw adductor musculature is massive; other jaw muscles are relatively simple. The external adductor mass is particularly noteworthy in that it is subdivided into four mechanical units by a complex internal tendon tract (the coronoid aponeurosis). The internal adductor is composed of two separate gross muscles, pseudotemporalis (PST) and pterygoideus (PT). Each of these is subdivided into two main units by aponeurotic sheets, the PST by parts of the coronoid aponeurosis and the PT by a separate series. The form of the aponeurotic system in Trachydosaurus confounds the separation and identification of the adductor muscles and their component parts along the lines of traditional nomenclature, and underscores the need for separating criteria based on homology from those reflecting morphological and possibly functional divisions.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051810303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 124
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 182 (1984) 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051820101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 125
    Electronic Resource
    Electronic Resource
    Cholesterogenesis and related enzymes in isolated rat hepatocytes during pre- and postnatal life (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 62-66 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cholesterogenesis pathway during pre- and postnatal development was studied in isolated rat hepatocytes. No modified activity of cytosol acetoacetyl coenzyme A (CoA), thiolase, or 3-hydroxy-3-methylglutaryl CoA (HMGCoA) synthase was detectable at the different stages examined. Minimal levels of 114C-acetate incorporation into cholesterol and HMGCoA reductase activity were present at 16 days of fetal development in newborn and suckling rats, whereas both parameters increased rapidly before birth. The pattern of NaF nonsuppressible reductase activity showed a different activation state of the enzyme, suggesting the appearance of a modulation state, probably related to the development of some short-term regulatory mechanisms.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 126
    Electronic Resource
    Electronic Resource
    Cultured mouse marrow cell lines: Interactions between fibroblastoid cells and monocytes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 143-152 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Continuous cell lines were derived from primary cultures of adherent bone marrow cells from SJL/J, BALB/c, C3H/eb, RF, and nude-ICR mice. All these lines readily assumed a pure fibroblastoid appearance with the exception of the BALB/c line (MBA-14), which retained both fibroblastoid and monocytoid cells. This particular line could promote the proliferation of myeloid progenitors (CFU-C) in short-term bone-marrow cultures. The two cell types that composed the MBA-14 cell line were successfully isolated and grown separately; the monocytes as the 14M and 14M1 cell lines and the fibroblastoid cells as the 14F clones. The latter were found to be preadipocytes and accumulated fat in the absence of added hydrocortisone, in medium supplemented with fetal calf serum. Growth of the monocyte lines (14M and 14M1) was dependent upon the mononuclear phagocyte stimulator CSF-1. In the parent MBA-14 cell line the growth of monocytes seemed to depend upon stimulating factor(s) produced by the fibroblastoid cells. The 14M1 monocytes were able to process and degrade antigen as efficiently as primary macrophages. Furthermore, processed antigen produced by 14M1 cells evoked proliferative response by antigen-primed lymph-node cells. In addition to these immunological functions the 14M1 cells were capable of modulating the colony-stimulating activity and degree of adipogenesis exhibited by the fibroblastoid cells. These interactions between monocytes and fibroblastoid cells may constitute part of the mechanism controlling the activity of the hematopoietic microenvironment.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 127
    Electronic Resource
    Electronic Resource
    Interaction of T lymphocytes and macrophages with cultured vascular endothelial cells: Attachment, invasion, and subsequent degradation of the subendothelial extracellular matrix (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 169-178 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Circulating macrophages and T lymphocytes can invade the vascular endothelium and migrate from the circulatory system to an extravascular compartment such as inflammatory organs. In an in vitro model system we have examined the capacity of murine T lymphocytes and peritoneal macrophages to attach and invade a confluent vascular endothelial cell monolayer and to degrade sulfated proteoglycans in the subendothelial extracellular matrix.Concanavalin A and antigen-specific (egg albumin) activated T lymphocytes labeled with [3H]thymidine attached to the apical surface of the vascular endothelium in a time-dependent manner. A subsequent invasion of the endothelial cell monolayer was observed by scanning electron microscopy. Both activated T lymphocytes and murine macrophages degraded the [35S]O4=-containing fragments in a process which required cell-matrix contact but was not dependent on serum proteases.Sulfated glycosaminoglycan chains produced from matrix proteoglycans by treatment with papain or alkaline borohydride were 3-4 times larger than the cell-mediated degradation fragments. This suggests that both macrophages and T lymphocytes elaborate upon stimulation an endoglicosidase capable of cleaving glycosaminoglycans specifically and releasing heparan sulfate-rich fragments. The ability of activated cells of the immune system to attach and invade the vascular endothelium and to degrade sulfated proteoglycans is very similar to that reported for highly metastatic tumor cells.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180209
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 128
    Electronic Resource
    Electronic Resource
    Growth factor-induced proliferation of human fibroblasts in serum-free culture depends on cell density and extracellular calcium concentration (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 203-210 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Human neonatal skin fibroblasts plated sparsely in MCDB 105 traversed a complete cell cycle in the absense of serum or serum-derived proteins. Addition of pure PDGF did not significantly increase entrance into S phase as revealed by 3H-thymidine labeling index or clonal growth on palladium islands. In subphysiologic Ca2+ concentrations or in the presence of a calmodulin inhibitor, W7, proliferation in the absence of growth factors ceased and PDGF became mitogenic. In contrast, confluent fibroblast cultures were stimulated by PDGF in physiologic Ca2+ concentrations. This was also the case with sparse adult skin fibroblast cultures while a fetal strain entered S in the absence of PDGF even in low extracellular Ca2+ concentrations. EGF gave similar results as PDGF in all experiments performed. This proposes a similar role for the two growth factors in the cell cycle. However, a difference in the mechanisms of action of PDGF and EGF is indicated by the fact that PDGF and EGF were additive at optimal concentrations when maximal growth response by a single growth factor was restricted by a subphysiologic extracellular Ca2+ concentration.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 129
    Electronic Resource
    Electronic Resource
    Selection of mouse macrophage-like sublines that differ in leukemogenic potential and characterization (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 105-112 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The murine macrophage-like cell line (Mm-1), which is nonleukemogenic to syngeneic SL mice, was originally derived from spontaneously differentiated cells of a clonal line of mouse myeloid leukemia cells (M1). In the present experiment, variant cell lines with a high (Mm-A), moderate (Mm-P), and little or no (Mm-Sl and Mm-S2) leukemogenic potential were obtained from the Mm-1 cells. The mean survival times of syngeneic SL mice inoculated i.p. with 5 × 106 Mm-A and Mm-P cells were 17 and 33 days, respectively, whereas almost all the mice inoculated with Mm-S1 or Mm-S2 cells survived for more than 90 days. These variant cell lines did not lose their macrophage-like characteristics in vitro. These variant cell lines phagocytized latex beads and sensitized sheep erythrocytes, produced lysozyme, and adhered to culture dishes. The four variant cell lines showed no significant difference in porliferation rates in vitro in liquid medium containing 10% calf serum, but Mm-A cells could grow both in soft agar medium in the absence of ascitic fluid containing colony-stimulating factor (CSF) and in liquid medium containing 1% serum, whereas Mm-P cells could grow in the liquid medium but not in soft agar medium without ascitic fluid, and Mm-S1 and Mm-S2 cells could not grow in either medium. The ratio of the nuclear area to the cell area (NCR) of Mm-A cells was a high (51%) but those of Mm-Sl and Mm-S2 cells were low (40-41%), and that of Mm-P cells was intermediate (44%). The leukemogenicity of Mm-1 cell lines was roughly correlated with their NCR. The possibility that interactions between Mm-1 variant cells and host immune cells might be involved in the mechanisms of their different leukemogenicities was not supported by results on the in vitro susceptibilities of Mm-1 variant cells to the cytostatic actions by normal macrophages and spleen cells and on leukemogenicities of the Mm-1 variant cells in athymic nude mice. A possible method of control of the leukemogenicity of Mm-1 variant cells is discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 130
    Electronic Resource
    Electronic Resource
    Homologous and heterologous mitogenic desensitization of Swiss 3T3 cells to phorbol esters and vasopressin: Role of receptor and postreceptor steps (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 133-142 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Prolonged treatment of Swiss 3T3 cells with phorbol 12,13 dibutyrate (PDB) rendered the cells refractory to subsequent mitogenic stimulation by both PDB and vasopressin. In contrast, the cells retained full responsiveness to a wide variety of other mitogens. An early response to vasopressin and phorbol esters, inhibition of (125l)-labeled epidermal growth factor [(125l)-EGF] binding, was also substantially decreased in PDB pretreated cells. The cross desensitization was not produced by vasopressin; this ligand induced homologous but not heterologous desensitization. Exposure of Swiss 3T3 cells to PDB caused a down regulation of (3H)-PDB receptors but did not reduce the binding of vasopressin to refractory cells. The time-course (t1/2 = 7 h) and dependence on PDB concentration (half maximal at 20 nM) for this phorbol ester receptor loss paralleled the induction of the mitogenic desensitizations to both PDB and vasopressin. However, the time-course of recovery revealed an important dissociation between receptor presence and mitogenic response.When Swiss 3T3 cultures, which had been pretreated with PDB, were washed to remove this ligand and incubated in its absence for 24 h, both (3H)-PDB receptors and PDB or vasopressin inhibition of (125l)-EGF binding were almost completely restored to control levels. However the homologous and heterologous mitogenic desensitizations showed a very different reversal time. After a 24-h recovery period PDB-treated refractory cells were still unable to synthesize DNA in response to PDB or vasopressin. The mitogenic desensitizations were however completely reversible; after a 48-h incubation in the absence of PDB the cells responded fully to the mitogenic actions of PDB or vasopressin. This finding suggests that a further postreceptor step was also desensitized by prolonged PDB treatment. The presence of a low level of cycloheximide during the PDB pretreatment blocked induction of this postreceptor refractoriness. We propose that this refractory postreceptor step selectively blocks both PDB and vasopressin stimulation of DNA synthesis and may represent the point at which the mitogenic pathways of phorbol esters and vasopressin converge.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180205
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 131
    Electronic Resource
    Electronic Resource
    A new assay for factors that regulate the synthesis of granulocyte differentiation proteins in vitro (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 161-168 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Morphological and molecular aspects of granulocyte differentiation can be studied concomitantly using liquid cultures of immature granulocytes in conjunction with a newly developed high-performance liquid chromatographic (HPLC) assay for differentiation proteins. Immature granulocytes, isolated from guinea pig bone marrow by Ficoll density centrifugation, were placed in liquid cultures and incubated for periods up to 1 week. In the presence of 10% dialyzed, normal guinea pig serum, these cells were almost all converted to mature granulocytes, whereas at serum concentrations below 1% mostly macrophages were formed. Cell multiplication does not appear to be necessary for granulocyte maturation in this culture system. The data also show that morphological maturation in vitro is accompanied by the formation of all the major membrane and secondary granule differentiation proteins detected by the HPLC assay in extracts of mature granulocytes formed in vivo. The techniques described here should facilitate the isolation and purification of the factors in normal serum that control the induction of synthesis of these differentiation markers.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 132
    Electronic Resource
    Electronic Resource
    A kinetic and clonal analysis of heterogeneity in K562 cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 186-192 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Expression of markers of differentiation was measured in a clone of the continuous cell line K562, derived originally from the cells of a patient with leukemia. Three of the markers were lineage specific, R18 for erythropoiesis and 80H.5 and My-1 for granulopoiesis. The fourth marker was the self-renewal capacity of clonogenic cells. The markers were measured as a function of time in pooled colonies from day 2 to day 12, and at a point of time in individual colonies. Evidence of an orderly pattern of marker appearance and disappearance was not seen. Rather, their expression appeared to occur at random during growth.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180211
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 133
    Electronic Resource
    Electronic Resource
    Colchicine prevents the translation of mRNA molecules transcribed immediately after proliferative activation of hepatocytes in regenerating rat liver (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 179-185 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A dual-labelling technique has been used to establish that partial hepatectomy has no effect on the degradation of poly (A)+ mRNA and confirms that the increased incorporation of precursor into mRNA during early prereplicative development reflects an actual increase in mRNA biosynthesis. Simultaneous studies on the changes in nuclear RNA metabolism support the conclusion that an increase in gene transcription does occur. Colchicine, at concentrations known to disrupt microtubules, has no effect on this increase in gene transcription but prevents the translation of the gene products by promoting polysome disaggregation transiently during a critical stage of prereplicative development. Studies with mefenamic acid and hydrocortisone, specific inhibitors of prostaglandin metabolism, have ruled out any involvement of prostaglandins in the induction of prereplicative mRNA synthesis.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 134
    Electronic Resource
    Electronic Resource
    Hexose transport derepressed and refractory to purine regulation in NAD(H)-depleted Nil cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 218-224 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Nil hamster fibroblasts depleted of NAD(H) by growth in medium devoid of nicotinamide (NAm-MEM) exhibit up to 2-3-fold higher rates of glucose transport. Derepression of glucose transport is observed only when Nil cells have become severely depleted of both intracellular NAD(H) and ATP, despite the continued presence of 5.5 mM D-glucose in the growth medium. Neither the initial rate of transport, approximated from 3-O-methylglucose uptake, nor accumulation of D-glucose itself is repressed upon restoring nicotinamide to the medium. Exposure of the cells to NAD+ (10-5 M), however, leads to a sharp curtailment of transport within 2 to 3 hours. The purines, hypoxanthine and guanine, that sharply reduce glucose transport capacity of normal cells, have no significant effect upon transport activity of NAD(H)-depleted cells.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 135
    Electronic Resource
    Electronic Resource
    Localisation of Alanine uptake by cultured renal epithelial cells (LLC-PK1) to the basolateral membrane (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 211-217 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Alanine uptake by LLC-PK1 cells has previously been demonstrated to be almost exclusively sodium dependent. We here confirm that when the cells are grown on an impermeable substratum there is a marked fall in uptake as confluence is reached. By applying an autoradiographic technique to visualize transported alanine, it is clear, however, that even in subconfluent cultures there is marked cellular inhomogeneity with regard to uptake, which takes place predominantly in those cells at the periphery of growing islands and not those at the interior. In contrast, when cells are grown on permeable substrata, a uniform distribution of silver grains is found. In two other types of experiment, we found that when confluent cell monolayers on an impermeable support were treated briefly with a chelating agent or suspended by mechanical treatment, there was a marked increase per cell in sodium-dependent alanine uptake and in ouabain-sensitive potassium uptake. We conclude that the apparent fall in alanine uptake as cells reach confluence on an impermeable support is due to masking of transport sites, which are predominantly, if not exclusively, located at the basolateral membrane.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 136
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984) 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 137
    Electronic Resource
    Electronic Resource
    Delayed and reduced cell replication and diminishing levels of DNA polymerase-α in regenerating liver of aging mice (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 225-232 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Kinetics of cell replication was compared in regenerating livers of Mus musculus at ages ranging between 6 and 32 months. Incorporation of [3H]-thymidine into DNA and autoradiographic analysis showed that the maximal extent of DNA replication following partial hepatectomy became delayed with age. Furthermore, the total fraction of parenchymal and nonparenchymal cells in S phase at different intervals during regeneration diminished as mice aged. The specific activity of DNA polymerase-α, the putative replicative enzyme, declined progressively during aging. The specific activity of DNA polymerase-β, the purported repair enzyme, declined to an appreciably lesser extent during the lifespan of the mouse. No evidence was found for the appearance of a specific inhibitor of polymerase-α in senescent mouse liver. Also, the bulk of the activities of both hepatic DNA polymerase-α and -β remained localized in the cell nucleus throughout the lifetime of the animal and were mainly associated with chromatin.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 138
    Electronic Resource
    Electronic Resource
    Prolactin regulation of cryptic prolactin receptors in cultured rat mammary tumor cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 247-252 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Rat mammary tumors contain a unique class of cryptic cell-surface prolactin receptors that can be unmasked by depleting the cells of energy. These cryptic receptors, which are found in mammary tumors and nonlactating normal mammary cells but not in differentiated mammary tissue, are continuously inserted and rapidly removed from the cell surface. In this report we demonstrate that prolactin regulates the level of cryptic receptors. Treatment of primary cultures of rat mammary tumor cells with prolactin at concentrations between 0.1 and 0.5 ng/ml caused cryptic receptor levels to increase within 24 h, and this increase was maintained for up to 6 days. At prolactin concentrations of 10-50 ng/ml, receptor levels were the same as in cells incubated without hormone, while a decrease in the steady-state level of cryptic receptors was induced within 24 h by 100-500 ng prolactin/ml. Concentrations of 1,000-5,000 ng prolactin/ml caused a rapid, dose-dependent down regulation of cryptic receptor sites. Down regulation at 5,000 ng prolactin/ml was (1) complete (84 ± 5% reduction) in 1 h; (2) specific for lactogenic hormones; (3) completely reversed within 10 h after prolactin removal; (4) energy dependent; and (5) not blocked by the cytoskeleton active agents cytochalasin B and colchicine or by NH4CI, which inhibits hormone degradation. We conclude that rat mammary tumor cells have the capacity to auto-regulate cryptic prolactin receptors, a property that supports our notion that such receptors play a role in regulating prolactin responsiveness. The observed pattern of cryptic receptor autoregulation in response to prolactin concentration and time of exposure suggests that a pool of cryptic sites provides these cells with the capacity to respond to prolactin concentrations from pg to μg/ml, a range well beyond the Kd for the receptor itself. Since prolactin receptors in mammary tumors are not down regulated unless prolactin concentrations are well beyond the saturation point, these cells may have a selective growth advantage over cells in normal mammary tissue.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180305
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 139
    Electronic Resource
    Electronic Resource
    Prereplicative changes in the soluble calmodulin of isoproterenol-activated rat parotid glands (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 257-261 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cells of rat parotid glands were maximally stimulated to initiate DNA synthesis by injecting into the animal a single dose of 25 to 150 mg of isoproterenol/ kg of body weight. During the 18- to 21-hr prereplicative period following injection of the highest dose of the drug, there were two predominant and transient redistributions of calmodulin from the bound to the soluble form, which tripled the level of soluble calmodulin at 3 hr and again at 18 hr just before the initiation of DNA synthesis. A small (50%) increase in total calmodulin was observed only during the early (3-h) prereplicative surge of soluble calmodulin. The late, pre-DNA-synthetic surge of soluble camodulin and the initiation of DNA synthesis were both prevented in rats that lacked their parathyroid-thyroid gland complex and had been hypocalcemic for 48 or 72 hr. Unlike the effect of high doses of isoproterenol, low doses (e.g., 25 mg/kg body weight) of the β-adrenergic drug could maximally stimulate DNA synthetic activity without the later pre-DNA-synthetic surge of soluble calmodulin, suggesting that any apparent correlation between the level of calmodulin and DNA synthesis may be spurious and that an actual increase in the level of soluble calmodulin just before the onset of DNA synthesis was not a prerequisite for DNA synthetic activity in parotid cells.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 140
    Electronic Resource
    Electronic Resource
    Coordinate regulation of polypeptide chain initiation and elongation in rabbit reticulocytes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 267-276 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Under normal conditions, reticulocytes synthesize α- and β-globin polypeptides at equal rates. Incubation in the absence of hemin or under anoxia or hypertonic stress (100 mM excess NaCl) reduces the rate of protein synthesis to 30-50% of control levels. However, only hemin deprivation causes a reduction in polyribosome size and preferential inhibition of α-globin synthesis consistent with specific reduction in the rate of polypeptide chain initiation. Polyribosomal profiles are unaffected by anoxic or hypertonic stress and the ratio of α:β globin synthesis remains close to unity. Measurement of ribosome transit time indicates that anoxic or hypertonic stress causes a decrease in the rate of polypeptide chain elongation that varies with the degree of inhibition of protein synthesis. Ribosomes isolated from stressed cells exhibit a reduced ability to bind 35S-met-tRNAf, suggesting that the ability to form initiation complexes is also impaired. These results suggest that reticulocytes, unlike nucleated cell lines, can coordinately reduce rates of initiation and elongation in response to certain physiological stresses.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 141
    Electronic Resource
    Electronic Resource
    Dependence of HL-60 myeloid cell differentiation on continuous and split retinoic acid exposures: Precommitment memory associated with altered nuclear structure (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 277-286 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cell differentiation of HL-60 human leukemic promyelocytes along the myeloid pathway due to various continuous and distributed exposures to retinoic acid was studied. HL-60 myeloid differentiation was a continuously driven process; significant terminal cell differentiation occurred only after a minimum exposure to inducer of two division cycles. Cells so committed to differentiation retained a heritable, finite memory of differentiation commitment over a further division cycle. Prior to becoming committed, cells acquired precommitment memory of exposure to inducer. Precommitment memory abbreviated the subsequent exposure to inducer needed for commitment to differentiation. Precommitment memory was semistable. It was heritable, but was lost after four division cycles. The acquisition and loss of precommitment memory correlated with alterations in nuclear architecture detected by narrow angle light scatter using flow cytometry. The altered nuclear architecture first occurred before any overt cell differentiation or growth arrest. It was thus an early event in the induced program of terminal cell differentiation. Alterations in relative abundances of cytoplasmic proteins also occurred prior to overt cell differentiation or growth arrest. One of these was a 17 kdalton, anionic, probably Ca2+ binding, protein. Retinoic acid thus induced early cellular changes, including cytoplasmic and nuclear alterations, within one cell cycle when cell differentiation was not yet apparent.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180310
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 142
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 119 (1984) 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041190101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 143
    Electronic Resource
    Electronic Resource
    Intravesicular pH and iron uptake by immature erythroid cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 225-232 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The intravesicular pH of intact rabbit reticulocytes was measured by two methods; one based on the intracellular:extracellular distribution of DMO (5, 5, dimethyl + oxazolidin-2,4-dione), methylamine, and chloroquine and the other by quantitative fluorescence microscopy of cell-bound transferrin. The latter method was also applied to nucleated erythroid cells from the fetal rat liver. A pH value of approximately 5.4 was obtained with both methods and in both types of cells. Treatment of the cells with lysosomotrophic agents, metabolic inhibitors, and ionophores elevated the intravesicular pH and inhibited iron uptake from transferrin. When varying concentrations of NH4Cl were used, a close correlation was observed between the inhibition of iron uptake and elevation of the intravesicular pH. At pH 5.4 iron release from rabbit iron-bicarbonate transferrin in vitro was much more rapid than from iron-oxalate transferrin. The bicarbonate complex donates its iron to rabbit reticulocytes approximately twice as quickly as the oxalate complex. It is concluded that the acidic conditions within the vesicles provide the mechanism for iron release from the transferrin molecule after its endocytosis and that the low vesicular pH is dependent on cellular metabolism.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200217
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 144
    Electronic Resource
    Electronic Resource
    The relationship between purines, pyrimidines, nucleosides, and glutamine for fibroblast cell proliferation (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 233-241 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous studies indicate that glutamine is a critical requirement for cell proliferation in vitro. We recently showed that depletion of glutamine from the cuture medium supporting growing cells significantly reduced the proportion of cells undergoing DNA synthesis. Similarly glutamine depletion significantly reduced the stimulatory response of quiescent cells to 10% serum. This study shows that the inhibitory effects of depletion of glutamine - in either of these two situations - can be overcome by the addition of adenine or adenosine. Adenine was the only nitrogen base and adenosine was the only nucleoside for which this effect was observed. Such effects could, however, also be achieved by addition of the purine metabolites hypoxantine and inosine. Furthermore, it was found that glutamine (or adenine/adenosine) is only required during a limited interval coinciding with the late part of the G1-phase and the beginning of S-phase. These data suggest the possibility that glutamine exerts its main regulatory effects on cell proliferation by acting as a precursor for adenine and adenosine.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200218
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 145
    Electronic Resource
    Electronic Resource
    Anion requirement and effect of anion transport inhibitors on the response of vero cells to diphtheria toxin and modeccin (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 119 (1984), S. 7-14 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The anion requirement for toxic action of diphtheria toxin and modeccin was studied. In Cl--free Hepes buffer made isotonic with mannitol, cells were insensitive to diphtheria toxin and modeccin. Just 2 mM NaCl was sufficient to obtain full toxic activity of modeccin, whereas 140 mM NaCl was required for maximal intoxication with diphtheria toxin. Br- could substitute for Cl-. NO3-, I- and ClO3- were less efficient than Cl-, whereas SO42- and SCN- were unable to replace Cl-. Cl- deprivation both reduced the ability of cells to bind diphtheria toxin and prevented bound toxin from intoxicating the cells. The binding of modeccin was not reduced. SITS (4-acetamide-4′-isothio-cyano-stilbene-2,2′-disulfonic acid), an inhibitor of Cl- entry, protected against diphtheria toxin and modeccin, indicating that Cl- transport is required for intoxication.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041190103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 146
    Electronic Resource
    Electronic Resource
    Altered methionine metabolism occurs in all members of a set of diverse human tumor cell lines (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 119 (1984), S. 29-34 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Methionine dependence is a metabolic defect found thus far only in transformed and malignant cells. The defect is manifested as the inability of cells to grow in media in which methionine (Met) is replaced by its immediate precursor homocysteine (Hcy). We have termed this Met - Hcy + media. We demonstrate here that methionine-dependent cells derived from human tumors, compared to normal methionine-independent cells, have low levels of free Met, low levels of S-adenosylmethionine (AdoMet) and elevated levels of S-adenosylhomocysteine (AdoHcy) when incubated in Met - Hcy + medium. Methionine-independent human tumor cells also have very low levels of free Met compared to normal cells but generally have levels of AdoMet and AdoHcy comparable to normal cells in Met - Hcy+ medium. All tumor cell types incorporate amounts of Met into protein similar to normal methionine-pindependent human fibroblasts when incubated in Met - Hcy+ medium, thereby indicating apparently normal levels of Met synthesis in the tumor cells. The methionine-independent tumor cell lines in Met - Hcy+ medium seem able to regulate their AdoMet/AdoHcy ratios normally despite this defect in having very low levels of free Met. Thus, in a diverse set of human tumor cell lines, all are defective in at least one aspect of Met metabolism, giving rise to the possibility of a general metabolic defect in cancer.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041190106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 147
    Electronic Resource
    Electronic Resource
    Verapamil enhances the toxicity of conjugates of epidermal growth factor with Pseudomonas exotoxin and antitransferrin receptor with pseudomonas exotoxin (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 271-279 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Verapamil, a clinically important calcium channel blocker, has been found to cause a 40-fold enhancement of killing of the human KB cell line by a cytotoxic conjugate of epidermal growth factor with Pseudomonas exotoxin (EGF-PE). Synergistic effects of verapamil and EGF-PE are also seen on HeLa D98 cells and a human epidermal carcinoma cell line, A431. Verapamil also potentiates the effect of a toxic conjugate formed between Pseudomonas exotoxin and a monoclonal antibody to the human transferrin receptor (anti-TFR-PE) and enhances the effect of Pseudomonas exotoxin (PE) alone. Two other calcium antagonists were tested. Diltiazem enhances the cytotoxic effect of EGF-PE, but nifedipine does not. Verapamil does not affect the binding and uptake of 125I-EGF by KB cells, but it significantly delays the disappearance of internalized 125I-EGF from the cells. Density gradient fractionation studies using cell homogenates suggest that 125I-EGF accumulates in an undegraded form in lysosomes when cells are treated with verapamil. By immunofluorescence microscopy using an antibody to PE, EGF-PE was found to accumulate in lysosomes; by electron microscopy the lysosomes had an abnormal appearance. The effects of verapamil on toxicity of EGF-PE and lysosomal function appear to be related. However, it is not known whether the enhanced toxicity of EGF-PE in the presence of verapamil is due to its delayed degradation in lysosomes or some more general effect of verapamil on membrane permeability.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200303
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 148
    Electronic Resource
    Electronic Resource
    Cystamine augments the stimulation of DNA synthesis by peptide growth factors and microtubule-disrupting agents in cultures of 3T3 mouse fibroblasts (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 303-308 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cystamine together with colchicine markedly enhanced the uptake of [3H]-thymidine into DNA of quiescent cultures of insulin-stimulated Swiss 3T3 mouse fibroblasts. Flow cytofluorometric analyses showed an increased rate of transition of cells from G0/G1 → S + G2 in response to combinations of insulin, colchicine, and cystamine. Cystamine, the most effective of several thiol compounds, gave maximal augmentation at 200 μM and was toxic at 300-500 μM. Amplification of DNA synthesis by cystamine was also obtained with epidermal growth factor, vasopressin, and 0.5% fetal bovine serum. Combinations of cystamine and other microtubule-disrupting agents such as nocodazole, maytansine, and podophyllotoxin enhanced DNA synthesis in insulin-stimulated cells. In experiments involving sequential addition of agents, significant enhancement of DNA synthesis was observed when the addition of colchicine to cystamine-treated cells was delayed or conversely when the addition of cystamine to colchicine-treated cultures was delayed. This reciprocal interaction between cystamine and colchicine suggests that a prereplicative intermediate accumulates in response to the action of these dissimilar compounds. We consider the possibility that cystamine may act by forming mixed disulfides with thiol groups of unknown protein(s) that regulate DNA replication.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200307
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 149
    Electronic Resource
    Electronic Resource
    Structural determinants of the capacity of heparin to inhibit the proliferation of vascular smooth muscle cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 315-320 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous work from our laboratory has demonstrated that both anticoagulant and nonanticoagulant heparin species can inhibit the proliferation of vascular smooth muscle cells in vivo and in vitro. In this communication, we report studies on the structure-function relationships of heparin to its antiproliferative effect on vascular smooth muscle cells. These structure-function studies were carried out by preparing discrete sizes of heparin fragments and by chemically modifying heparin. The compounds were tested for their ability to inhibit rat and calf aortic smooth muscle cell growth. The minimum fragment size which retains some growth inhibitory activity is a hexasaccharide; maximal antiproliferative activity was obtained with dodecasaccharide and larger fragments. Both O-sulfation and N-substitution were found to be important for the growth inhibitory effect. Comparison of the antiproliferative and anticoagulant activities of the different heparin species has allowed us to identify several heparin molecules which have lost their anticoagulant properties, but retain antiproliferative activity.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200309
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 150
    Electronic Resource
    Electronic Resource
    An antibody that inhibits fibronectin-independent adhesion of fibroblasts to extracellular matrix material (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 329-334 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Chinese hamster ovary (CHO) fibroblasts adhere to the extracellular matrix by both fibronectin-dependent and -independent mechanisms (Harper and Juliano, 1981a,b). Previous studies have suggested that a trypsin-sensitive, 265,000-dalton membrane glycoprotein (gp265) is involved in the fibronectin-independent adhesion process. Using a polyclonal antibody against soluble products obtained from trypsin-treated CHO cells, we have been able to further analyze this involvement. This antibody immunoprecipitates a trypsin-sensitive 265,000-dalton protein from detergent-solubilized cells. Incubation of AdvF11, a variant cell line that does not utilize fibronectin for adhesion, with this antibody blocks their adhesion to extracellular matrix material (ECM). The immunoglobulin fraction will also partially block adhesion of the parental cell line to ECM particularly when the ECM is first treated with an antifibronectin antibody. Taken together these results add support for the involvement of gp265 in fibronectin-independent adhesion and provide a methodology for further characterization.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200311
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 151
    Electronic Resource
    Electronic Resource
    Adenosine-resistant chinese hamster fibroblast variants with hyperactive adenosine-deaminase: An analysis of the protection against exogenous adenosine afforded by increased activity of the deamination pathway (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 321-328 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The activity of purine salvage and interconversion enzymes was examined in two sublines of Chinese hamster cells-RA11 and RA41-isolated on the basis of their resistance to adenosine concentrations toxic to wild-type CCL39 cells. Adenosine deaminase (ADA) activity was found to be two times higher in RA11 and three times higher in RA41 than in CCL39. Inhibition of ADA activity by coformycin reduced the level of adenosine resistance but did not restore wild-type sensitivity, indicating that a second defect contributes to the adenosine-resistant phenotype of these variants; evidence was indeed obtained for the presence in both lines of additional alterations protecting them against the lethal depletion of phosphoribosylpyrophosphate (Ishii and Green, 1973) imposed by adenosine to wild-type cells. To gain better insight into the influence of ADA hyperactivity on adenosine resistance, a procedure was developed for the specific isolation of variants with increased levels of ADA activity. Cell lines with 3-5 times and then 100-500 times the wild-type ADA activity were stepwise recovered. These investigations confirmed that amplification of ADA can efficiently contribute in protecting cells against high concentrations of exogenous adenosine. The variants isolated by this procedure again manifested, in addition to amplification of ADA activity, another alteration decreasing their sensitivity to adenosine. A possible mechanism accounting for the frequent isolation of variants that coexpress ADA hyper-activity and a second defect contributing protection against adenosine toxicity are considered.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200310
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 152
    Electronic Resource
    Electronic Resource
    Kinetics of clonogenic melanoma cell proliferation and the limits on growth within a bilayer agar system (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 114-124 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Accurate descriptions of the kinetics of cell growth in semi-solid agar clonogenic systems have been difficult because the number of cells in colonies of different sizes is largely unknown. We stained and removed tumor cell colonies from agar, directly counted their cells, and established equations to quantitate the number of cells within colonies of different sizes. We used these equations to quantitate, in terms of cell number and volume, the total amount and kinetics of clonogenic cell proliferation from biopsies of human melanoma and cell lines of several different tumor types. Daily observations of cells in agar and serial photography indicated a 0- to 4-day delay in the onset of proliferation in agar followed by rapid growth and then abrupt cessation of proliferation. We quantified the extent of proliferation of cells from melanoma biopsies of seven patients and 11 cell lines after they were allowed to proliferate in agar until they stopped. Approximately 10% of cells divided one to five times while only 0.01% divided six to nine times. The total number of cells within the colonies at the end of growth was different while the total volume of cells within the colonies per plate was similar; approximately 109 μm3 cellular volume per plate represents an upper limit for proliferation within the closed, nonrefed bilayer agar system. Previous replating studies using the same biopsy cells have shown that clonogenic melanoma cells can self-renew and have more proliferative capacity than that expressed during primary colony formation. Thus, the clonogenic assay only measured initial proliferative capacities. Furthermore, variable delays in the onset of proliferation may contribute to the heterogenity of colony size within clonogenic assays.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 153
    Electronic Resource
    Electronic Resource
    Amino acid activation of amino acid transport system N early in primary cultures of rat hepatocytes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 133-138 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: System N, a neutral amino acid transport system characterized in rat hepatocytes, shows significant changes in activity during the first 24 hr of primary culture (Weissbach, L., Handlogten, M.E., Christensen, H.N., and Kilberg, M.S. [1982] J. Biol. Chem. 257:12006-12011). Experiments presented in the present report demonstrate that during the first 12 hr of primary culture System N can be stimulated by individual amino acids in the culture medium by a cycloheximide-insensitive mechanism. This enhanced activity results from an elevation in the Vmax of the transport system, and the magnitude of the increase is related to the concentration of the amino acid in the culture medium. Nonsubstrates as well as substrates of System N are effective, and trans-stimulation does not appear to play a role in this phenomena. Transport by Systems ASC, Gly, and L is enhanced by the presence of amino acids in the culture medium, but these systems are significantly less sensitive than System N. The results suggest that amino acids act at a posttranslational step to activate System N activity.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210116
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 154
    Electronic Resource
    Electronic Resource
    Temperature-dependent transmembrane potential changes in cells infected with a temperature-sensitive moloney sarcoma virus (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 139-142 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Normal rat kidney cells (NRK) infected with the temperature-sensitive (ts) transformation mutant of Moloney murine sarcoma virus yielded a clone of cells, 6m2, that exhibited a transformed morphology at 33°C and a normal morphology at 39°C. Transmembrane potential (Em) was measured fluorometrically using a cyanine dye diS-C3-(5). Fluorescence was inversely correlated with Em. Cells at 33°C had lower Em. Em changes were recorded within 15 minutes of temperature shift from 33°C to 39°C in both directions, increasing in the 33°C to 39°C direction and decreasing in the 39°C to 33°C direction. Uninfected NRK cells when shifted under the same condition exhibited small fluorescence changes in the 33°C to 39°C direction. Shifting from 39°C to 33°C resulted in Em changes similar to those in 6m2 cells. Also studied was a cell line infected with a spontaneous revertant of the ts mutant, designated 54-5A4; it was transformed at both temperatures. Shifting from 33°C to 39°C in both directions yielded small changes. Transmembrane potential changes in 6m2 cells precede other transformation-specific changes that occur after a temperature shift.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210117
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 155
    Electronic Resource
    Electronic Resource
    Collagen degradation in human lung fibroblasts: Extent of degradation, role of lysosomal proteases, and evaluation of an alternate hypothesis (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 152-158 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Experiments were conducted to determine the extent and variability of collagen degradation in human fetal lung fibroblasts. Cells were incubated with [14C]proline, and degradation was measured by determining the hydroxy[14C]proline in a low molecular weight fraction relative to total hydroxy[14C]proline. Average (basal) degradation in stationary phase HFL-1 cells incubated for 8 h was 16 ± 3%, and substantial alterations in the composition of the labeling medium, e.g., omitting serum and varying pH between 6.8 and 7.8, had no effect. Organic buffers slightly lowered degradation in a manner that was independent of pH. Collagen degradation in two other lung cell lines, Wl-38 and IMR-90, did not differ from the level in HFL-1. Degradation was significantly higher (23 ± 5%) in HFL-1 cultures labeled for 24 h rather than 8 h, and pulse-washout experiments showed that the rate of degradation was not uniform: after an 8-h pulse, 11% of the hydroxy [14C]proline in the medium was in the low molecular weight fraction, but 31% was in this fraction after a 16-h washout. The lack of effect of either serum deprivation or elevated pH suggests that lysosomal proteases have no direct role in basal degradation; however, NH4Cl decreased the enhanced degradation observed in ascorbate deficiency to basal level, indicating that abnormal molecules synthesized under those conditions are degraded by lysosomal proteases. The appearance of small hydroxy[14C]proline-containing molecules was inhibited by αα′dipyridyl and cycloheximide in a dose-dependent and reversible manner, demonstrating that their production depends on enzymatic hydroxylation of proline and protein synthesis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210119
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 156
    Electronic Resource
    Electronic Resource
    2,3,7,8-Tetrachlorodibenzo-p-dioxin: Examination of biochemical effects involved in the proliferation and differentiation of XB cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 143-151 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: XB, a cell line derived from a mouse teratoma, differentiates into stratified squamous epithelium when incubated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). To examine the possible biochemical mediators of this response, we compared the effects produced by TCDD to those elicited by other compounds which stimulate epidermal proliferation and/or differentiation in mice. XB/3T3 cultures keratinize when incubated with cholera toxin, epidermal growth factor (EGF), or TCDD, but not 12-0-tetradecanoylphorbol-13-acetate (TPA). Incubation of XB cells with TCDD (10-9M) for 48 hours produces a 20% increase in thymidine incorporation, a response which is neither as large nor as rapid as that produced by cholera toxin, TPA, or EGF. Although both cholera toxin and TCDD stimulate differentiation and thymidine incorporation in XB/3T3 cultures, cholera toxin increases cAMP 30-fold in these cells, while TCDD does not affect cAMP accumulation at any of the times studies (15 min to 120 hours). Inhibitors of arachidonic acid metabolism, which block epidermal proliferative responses to TPA in vivo, do not prevent the differentiation of XB cell in response to TCDD. In XB/3T3 cultures, TPA stimulates arachidonic acid release at all times tested (1, 6, and 24 hours) and increases the incorporation of 32Pi into total phospholipids and phosphatidylcholine after 3 hours. In contrast, TCDD affects neither arachidonic acid release nor the turnover of phosphatidylinositol or phosphatidylcholine at any of the times tested. Although we examined biochemical effects which have been suggested as part of the mechanism of TCDD and which are produced by other epidermal proliferative compounds in XB cells, no mediator of the TCDD-produced differentiation of XB/3T3 cultures was observed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210118
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 157
    Electronic Resource
    Electronic Resource
    Acetylcholine receptors in monkey and rabbit oocytes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 415-418 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Membrane potential responses to acetylcholine (ACh, 10-7-10-3 M) were investigated in monkey and rabbit ovarian oocytes. In monkey oocytes ACh most commonly elicited a short-latency hyperpolarization concomitant with a decreased membrane input resistance (Rin). Under voltage-clamp short-latency ACh currents had an equilibrium potential of approximately -40 mV. In rabbit oocytes responses to ACh consisted of an increase in Rin or of a depolarization with an equilibrium potential of approximately -15 mV. Curare, hexamethonium, and atropine (10-5-10-3 M) did not block these ACh responses. Thus, the oocyte membrane in the rabbit contains ACh receptors that cannot be classified as either muscarinic or nicotinic.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210220
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 158
    Electronic Resource
    Electronic Resource
    Treatment of lymphoblastoid cells with interferon decreases insulin binding (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 437-441 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Lymphoblastoid Daudi cells, which are highly sensitive to growth inhibition by interferon (IFN), can be grown in a defined serum-free medium containing insulin, transferrin, and albumin as the only proteins. We examined whether the growth inhibition by IFN could be in part due to a change in receptors for insulin or transferrin. Cells treated for at least 2 days with 100 units/ml of IFN-α2 bound less 125I-insulin and after 3 days of treatment this binding was reduced by more than 50%. No change in the binding of 125I-transferrin was observed. Treatment with IFN of Raji cells, which are resistant to growth inhibition by IFN, resulted in a similar decrease in 125I-insulin binding. Growth inhibition of Daudi cells by serum deprivation had no effect on 125I-insulin binding. Therefore, the IFN-induced loss of insulin binding sites is not a consequence of growth inhibition.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210224
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 159
    Electronic Resource
    Electronic Resource
    Detection of intranuclear clusters of Sm antigens with monoclonal anti-Sm antibodies by immunoelectron microscopy (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 449-451 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: It has been shown that small nuclear RNA (snRNA) species U1, U2, U4, U5, and U6 are found in the nucleus in the form of small nuclear ribonucleoprotein particles (snRNPs), and that anti-Sm antibodies react with snRNP polypeptides, which are associated with all five snRNAs. We report here a novel intranuclear complex, denoted “Sm cluster,” detected by immunostaining with monoclonal anti-Sm antibodies in HeLa cells.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210226
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 160
    Electronic Resource
    Electronic Resource
    Masthead (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984) 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210301
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 161
    Electronic Resource
    Electronic Resource
    Stimulation of DNA-mediated transformation by UV irradiation of recipient (mouse FM3A) cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 453-457 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: DNA-mediated transformation for thymidine autotrophs (Tk+) was stimulated severalfold when the recipient (mouse FM3A) (Tk-) cells were preirradiated by UV light. The effect was most prominently seen with the cells irradiated 12-16 hours prior to DNA addition. A similar stimulatory effect was observed when the cells were treated with novobiocin or mitomycin C. The effect, however, was blocked when cycloheximide was present during postirradiation period, suggesting that de novo protein synthesis is required for producing the effect. Most of the Tk+ transformants arised from the UV-irradiated cells carried the donor DNA sequences in their chromosomes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 162
    Electronic Resource
    Electronic Resource
    Junctional competence in clones of mammary epithelial cells, and modulation by conditioned medium (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 174-183 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Colony-forming epithelial cells exfoliated in human milk have been examined by immunofluorescence using antibodies to cytokeratins (tonofilaments), and to high molecular weight desmosomal core proteins. The cells may be classified by their ability to form junctional complexes with their neighbours. Those deficient in desmosomal junctions, called D - cells, grow into colonies of noncontiguous cells without desmosomes, and with a perinuclear network arrangement of cytokeratins. Junction forming, or D + cells, grow as contiguous cell sheets with abundant desmosomes and well developed bundles of tonofilaments. D - cells may also segregate D + cells among their progeny yielding mixed clones, and a gradual increase in the overall number of D + cells during culture. Established D + cells have surface markers characteristic of mammary epithelium and are presumably derived by exfoliation of luminal cells of the alveoli or ducts which contain desmosomal junctions. D - cells also possess mammary epithelial cell markers, but their origin is unknown. Medium conditioned by the Nil 8 line of hamster cells contains a junction-promoting activity that accelerates the rate, or frequency, of segregation of D + cells from D - cells, so that milk cells grown in this medium predominently give closed colonies of D + cells. Medium conditioned by the MRC5 strain of human embryo lung cells, however, contains a junction-inhibiting activity, which prevents new junction formation and probably destroys existing junctions, so that cells in this medium mostly grow as open colonies of cells with D - phenotype. It is hoped that studies with this experimental system will assist in the better understanding of normal and abnormal regulation of desmosomal junctions and their role in tissue integrity.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 163
    Electronic Resource
    Electronic Resource
    The role of increased proteolysis in the atrophy and arrest of proliferation in serum-deprived fibroblasts (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 189-198 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When cultured fibroblasts are deprived of serum, the degradation of long-lived proteins and RNA increases, the cells stop proliferating, and they decrease in size. To determine the role of the increased protein catabolism in these responses, we studied the effects of inhibitors of intralysosomal proteolysis in Balb/c 3T3 cells. When these cells were placed in serum-deficient medium (0.5% serum), the rate of degradation of long-lived proteins increased about twofold within 30 min. This increase was reduced by 50-70% with inhibitors of lysosomal thiol proteases (Ep475 and leupeptin) or agents that raise intralysosomal pH (chloroquine and NH4Cl). By contrast, these compounds had little or no effect on protein degradation in cells growing in 10% serum. Thus, in accord with prior studies, lysosomes appear to be the site of the increased proteolysis after serum deprivation. When 3T3 cells were deprived of serum for 24-48 hours, the rate of protein synthesis and the content of protein and RNA and cell volume decreased two- to fourfold. The protease inhibitor, Ep475, reduced this decrease in the rate of protein synthesis and the loss of cell protein and RNA. Cells deprived of serum and treated with Ep475 for 24-48 hours had about twice the rate of protein synthesis and two-to fourfold higher levels of protein and RNA than control cells deprived of serum. The Ep475-treated cells were also about 30% larger than the untreated cells. Thus, the protease-inhibitor prevented much of the atrophy induced by serum deprivation. The serum-deprived fibroblasts also stopped proliferating and accumulated in the G1 phase of the cell cycle. The cells treated with Ep475 accumulated in G1 in a manner identical to untreated serum-deprived cells. Other agents which inhibited protein breakdown in serum-deprived cells also did not prevent the arrest of cell proliferation. Thus the enhancement of proteolysis during serum deprivation appears necessary for the decrease in size and protein synthesis, but probably not for the cessation of cell proliferation. When cells deprived of serum in the presence or absence of Ep475 were stimulated to proliferate by the readdition of serum, the larger Ep475-treated cells began DNA synthesis 1-2 hours later than the smaller untreated cells. Thus, after treatment with Ep475, the rate of cell cycle transit following serum stimulation was not proportional to the cell's size, protein, or RNA content, or rate of protein synthesis.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210124
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 164
    Electronic Resource
    Electronic Resource
    Sodium orthovanadate stimulation of DNA synthesis in nakano mouse lens epithelial cells in serum-free medium (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 199-205 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Quiescent cultured Nakano mouse lens cells incubated for 40 hours with sodium orthovanadate incorporated 3H-thymidine at an accelerated rate; the greatest response occurred at 20 μM vanadate, whereas by 2 μM an incorporation rate equivalent to unstimulated cells was noted. Microscopic examination of the cells revealed that those exposed to concentrations of vanadate greater than 100 μM had lysed by the end of the 40-hour incubation. Reduction in vanadate exposure time to 1 hour caused the cells to incorporate the greatest amount of 3H-thymidine at a vanadate concentration of 200 μM to 500 μM. Half-maximum incorporation of 3H-thymidine (after a 40-hour incubation) was induced by a 2-hour incubation with 20 μM vanadate. Studies with insulin showed that while 20 ng/ml insulin alone did not increase 3H-thymidine incorporation, 20 ng/ml insulin in combination with 20 μM vanadate resulted in a significant increase in 3H-thymidine uptake over cells exposed to only vanadate. Insulin alone will increase cell number and insulin with vanadate are synergistic in the stimulation of DNA synthesis, but the two together show no further increase in cell number over that produced by insulin alone. Thus, vanadate can increase progression from G1/G0 to S-phase, but cannot stimulate cells to divide. Studies designed to detect DNA damage and repair rather than S-phase DNA synthesis demonstrated that vanadate was not causing increased 3H-thymidine uptake by damaging DNA. Cell counts revealed that vanadate, while able to induce DNA synthesis, does not induce mitosis. Autoradiography and equilibrium sedimentation experiments demonstrated that gene amplification was not occurring. A known vanadate exchange inhibitor blocked the ability of vanadate to increase 3H-thymidine incorporation which is consistent with the idea that cellular internalization of vanadate is required for this effect to be seen. 86Rb+ uptake experiments demonstrate that the vanadate concentration inducing 50% inhibition of (Na+, K+)ATPase is nearly two orders of magnitude more concentrated that vanadate concentrations shown capable of inducing 3H-thymidine uptake. This strongly suggests that (Na+, K+)ATPase inhibition is not the central mechanism by which DNA synthesis is stimulated by vanadate.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210125
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 165
    Electronic Resource
    Electronic Resource
    Effects of temperature on aggregation and the mitogen-induced exit of lymphocytes from the resting state (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 206-214 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have determined the temperature dependence of the kinetics of entry into the first S phase of phytohemagglutinin-stimulated lymphocytes under conditions varying the stability of substrata over which the cells have settled. An exponential model was used to characterize entry into S phase. This model yields as parameters duration of lag period, t0, apparent first order rate constant for entry, k, and the number of cells committed to enter the first S phase, NA(t0). Values of t0 and NA(t0) show a 1.5-fold and 2.0-fold decrease and increase, respectively, over a 4°C temperature range and are independent of variation in substrate stability. The temperature dependence of the apparent first-order rate constant, k, however, is strongly influenced by stability. The observed activation energy increases from 3.0 kcal to 37 kcal when the substratum is agitated. This correlates well with reduced adherence of multicellular aggregates in agitated samples. The temperature dependencies for these three parameters are all numerically different, indicating that these parameters are determined by different rate-limiting processes. We propose that the mechanism mirrored by k is linked to the adherence of multicellular aggregates to the substratum.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210126
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 166
    Electronic Resource
    Electronic Resource
    An acellular human amnionic membrane model for in vitro culture of type ii pneumocytes: The role of the basement membrane in cell morphology and function (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 215-225 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: To determine whether a preformed basement membrane contributes to the maintenance of morphology and function of type II pneumocytes, we cultured isolated adult rat type II pneumocytes on the basement membrane and stromal surfaces of an acellular human amnionic membrane and on plastic. The presence of lamellar bodies on transmission electron microscopy and epithelial morphology in culture and a characteristic phospholipid profile after incubation with 3H-acetate identified the cells as type II. When type II cells were cultured on a preexisting basement membrane, they formed a well-organized monolayer with polarity, centrally located surface microvilli, and more basally located nuclei. Individual cells maintained a cuboidal morphology for 8-10 days. Intracellularly, there were numerous mitochondria, endoplasmic reticulum (ER), and lamellar bodies. The cells secreted a new basal lamina of their own. When cultured on the stromal side of the amnion, the cells became flattened within 48-60 hours, formed small lamellar bodies, and had scanty surface microvilli; they formed clumps and appeared less ordered. These cells did not secrete a visible basement membrane, and the majority detached from the stromal surface after 7-8 days in culture. In addition, culture on the basement membrane aspect of the amnion prevented the rapid decline in the percentage of 3H-acetate label incorporated in phosphatidylcholine after 72 hours of culture. We conclude that a preformed basement membrane influences the function and morphology of type II pneumocytes, organizes them into a monolayer in culture, and influences deposition of a visible basal lamina. Thus, the acellular human amnion provides an excellent model for the systematic study of basement membrane influence on the biology and pathology of these cells.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210127
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 167
    Electronic Resource
    Electronic Resource
    Maturation involves suppression of voltage-gated currents in the frog oocyte (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 576-588 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Voltage- and time-dependent currents having slow kinetics have been studied in plasma membranes of immature oocytes of the european frog, Rana esculenta. Ik, corresponding to an outward flow of K+, is activated at potentials more positive than about -40 mV, and subserves outward rectification; llr, corresponding to an outward flow of Cl-, is activated at potentials more negative than about -80 mV and subserves inward rectification. Such currents can act as negative feedback mechanisms in the control of membrane potential in the immature oocyte and limit to a somewhat restricted range its possible deviations from resting values. Besides lk, membrane depolarizations to potentials more positive than about + 30 mV are capable of activating lNa, corresponding to outflow of Na+. By contrast, the frog mature egg-cell has a single voltage- and time-dependent current, lM, activated at potentials more positive than +30 mV, with properties similar to lNa. The disappearance of lk and llr along with remarkable reduction in leakage lowers impedance in the egg membrane. It seems reasonable to suggest that the observed changes in membrane permeability reflect changes which have taken place along the maturation process and are of importance for successful fertilization.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210317
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 168
    Electronic Resource
    Electronic Resource
    Apparent desensitization of swiss 3T3 cells to the mitogens FGF and vasopressin (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 547-557 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The growth factors FGF and vasopressin were found to have only a transient effect on confluent quiescent monolayers of Swiss 3T3 cells. Whether measured as cumulative entry into S-phase by autoradiography, or as cell division by time-lapse filming, the elevated rate of cell proliferation was maintained only over 10-15 hr. Several trivial or artifactual explanations for this transience were ruled out, including toxicity of 3H-thymidine; exhaustion or degradation of medium components, nutrients or growth factors (although some medium depletion was observed); and the generation during quiescence of cells incapable of division. We have also eliminated heritable variation in the capacity to respond to individual growth factors. However, unstable phenotypic heterogeneity in growth factor requirements between cells may play some part, as found elsewhere for the response to low concentrations of serum (Brooks et al, 1984). Cell populations that had ceased to respond to vasopressin recovered their sensitivity after 2-3 days' incubation in conditioned medium lacking vasopressin. The phenomenon thus resembles the mitogen-induced desensitization described by Collins and Rosengurt (1982, 1983). However, in our case, the loss of sensitivity was not selective for vasopressin but applied also to epidermal growth factor (EGF) and to prostaglandin F2α. Furthermore, changes in responsiveness to vasopressin with time were associated with changes in cell density. Although some element of selective desensitization has not been ruled out, the transient response in our experiments can be accounted for in terms of unstable heterogeneity in growth factor requirements and/or in terms of density-dependent regulation of growth.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 169
    Electronic Resource
    Electronic Resource
    The in vitro cell culture age and cell density of articular chondrocytes alter sulfated-proteoglycan biosynthesis (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 558-568 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of cell culture age and concomitant changes in cell density on the biosynthesis of sulfated-proteoglycan by rabbit articular chondrocytes in secondary monolayer culture was studied. Low density (LD, 2 d), middle density (MD, 5-7 d), and high density (HD, 12-15 d) cultures demonstrated changes in cellular morphology and rates of DNA synthesis. DNA synthesis was highest at LD to MD densities, but HD cultures continued to incorporate [3H]-thymidine. LD cultures incorporated 35SO4 into sulfated-proteoglycans at a higher rate than MD or LD cultures. The qualitative nature of the sulfated-proteoglycans synthesized at the different culture ages were analyzed by assessing the distribution of incorporated 35SO4 in associative and dissociative CsCI density gradients and by elution profiles on Sepharose CL-2B. Chondrocytes deposited into the extracellular matrix (cell-associated fraction) 35SO4-labeled proteoglycan aggregate. More aggregated proteoglycan was found in the MD and HD cultures than at LD. A 35SO4-labeled aggregated proteoglycan of smaller hydrodynamic size than that found in the cell-associated fraction was secreted into the culture medium at each culture age. The proteoglycan monomer (A1D1) of young and older cultures had similar hydrodynamic sizes at all cell culture ages and cell densities. The glycosaminoglycan chains of A1D1 were hydrodynamically larger in the younger LD cultures than in the older HD cultures and consisted of only chondroitin 6 and 4 sulfate chains. A small amount of chondroitin 4,6 sulfate was detected, but no keratan sulfate was measured. The A1D2 fractions of young LD cultures contained measurable amounts of dermatan sulfate; no dermatan sulfate was found in older MD or HD cultures. These studies indicated that chondrocytes at LD synthesized a proteoglycan monomer with many of the characteristics of young immature articular cartilage of rabbits. These results also indicated that rapidly dividing chondrocytes were capable of synthesizing proteoglycans which form aggregates with hyaluronic acid. Culture age and cell density appears primarily to modulate the synthesis of glycosaminoglycan types and chain length. Whether or not these glycosaminoglycans are found on the same or different core proteins remains to be determined.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 170
    Electronic Resource
    Electronic Resource
    Mechanism of action of leukotriene B4: Intracellular calcium redistribution in rabbit neutrophils (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 13-18 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The possible involvement of membrane-bound calcium in the mechanism of action of leukotriene B4 was examined using the fluorescent chelate probe, chlortetracycline. Leukotriene B4 was found to cause a rapid release of membrane-bound calcium at physiologically relevant concentrations. This effect of leukotriene B4 is stereospecific and its magnitude is decreased upon the transformation of leukotriene B4 into its ω-hydroxy and ω-carboxy metabolites. The pool of calcium affected by leukotriene B4 appears to be the same as that released by other chemotactic factors such as formyl-methionyl-leucyl-phenylalanine (f-Met-Leu-Phe). Similarly, preincubation with f-Met-Leu-Phe results in a decreased responsiveness of the cells to the addition of leukotriene B4. These results extend further the analogy between the mechanism of action of peptidic and lipid chemotactic factors, and emphasize the central role of the intracellular redistribution of calcium, as inferred and monitored by chlortetracycline fluorescence and steady-state isotopic flux studies, in neutrophil activation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 171
    Electronic Resource
    Electronic Resource
    Calcium stimulates ornithine decarboxylase activity in cultured mammalian epithelial cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 39-44 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Ornithine decarboxylase (ODC) activity usually rises to a peak a few hours after a trophic stimulus. The stimulation of ODC has been shown to depend on extracellular calcium in several in vitro eukaryotic systems. We have investigated the effect of calcium concentration on ODC activity and have found that ODC is stimulated when CaCl2 alone is added to calcium-deprived cells. Epithelial cells from calf esophagus were cultured and grown until stratified. Replacement of medium with fresh serum-free medium resulted in stimulation of ODC activity, which peaked at 4 hours and declined to basal level by 10 hours. Subsequent depletion of Ca2+ either by addition of ethylene glycol bis (β-aminoethyl ether) N, N′-tetraacetic acid (EGTA) or by replacement of medium with Ca2+-free medium, resulted in obliteration of ODC activity 4 hours later. Conversely, cultures in which medium was replaced with Ca2+-free medium and at 10 hours were repleted with Ca2+ (either by addition of CaCl2 or by replacement of medium with Ca2+-containing medium) exhibited a pronounced elevation of ODC activity 4 hours later. ODC activity peaked at 6 hours after the addition of CaCl2 and declined by 8 hours. The effect was elicited by a wide range of concentrations of added Ca2+ from 0.1 mM to 4.0 mM, but was maximal at 1.0 mM. ODC activity was totally abolished if either cycloheximide (10 μg/ml) or putrescine (10 mM) was added to cultures immediately prior to Ca2+ addition. Actinomycin D (2, 5, or 10 μg/ml) added 30 minutes before Ca2+ did not prevent the stimulation of ODC by added Ca2+. Stimulation by Ca2+ is dependent on (1) absence of Ca2+ during the initial 10-hour incubation and (2) duration of incubation in Ca2+-free medium prior to Ca2+ replenishment. The results indicate that Ca2+ can increase ODC in epithelial cells exposed to Ca2+-depleted medium and that the increase in ODC depends on protein synthesis but is not inhibited by actinomycin D.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 172
    Electronic Resource
    Electronic Resource
    Rapid changes in bidirectional K+ fluxes preceding DMSO-induced granulocytic differentiation of HL-60 human leukemic cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 83-90 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When grown in medium containing 5 mM potassium and 140 mM sodium, HL-60, a human promyelocytic cell line, maintained a steady-state intracellular K+ concentration of 145 mmol/L cells and a steady-state intracellular Na+ concentration of 30 mmol/L cells. Nearly 90% of the unidirectional 42K+ influx could be inhibited by the cardiac glycoside ouabain with a Ki of 5 × 10-8 M. This ouabain-sensitive component of influx rose as a saturating function of the extracellular K+ concentration with a K1/2 of 0.85 mM. The component of 42K+ influx resistant to ouabain inhibition was a linear function of the extracellular K+ concentration and was insensitive to inhibition by the diuretic furosemide. Unidirectional K+ efflux followed first order kinetics with a half-time of 55 min. Addition of 1.5% dimethyl sulfoxide (DMSO) to a culture of HL-60 cells allowed two population doublings followed by the cessation of growth without an impairment of cell viability. Beginning 2 to 3 days after DMSO addition, the cells underwent a dramatic reduction in volume (from 925 μm3 to 500 μm3) and began to take on the morphological features of mature granulocytes. Throughout this process of differentiation there was no change in the intracellular sodium or potassium concentration. However, immediately following the addition of DMSO to a culture of cells, there began an immediate, coordinated reduction in bidirectional K+ flux. The initial rate of the ouabain-sensitive component of K+ influx fell with a half-time of 11 h to a final rate, at 6 days induction, equal to one ninth that of the uninduced control, and over the same period, the rate constant for K+ efflux fell with a half-time of 14 h to a final value one fourth that of the uninduced control. The rapidity with which these flux changes occur raises the possibility that they play some role in the control of subsequent events in the process of differentiation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 173
    Electronic Resource
    Electronic Resource
    Hydrocortisone stimulates fibronectin synthesis in cultured fibroblasts (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 103-107 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effect of hydrocortisone on fibronectin synthesis was investigated in cultured skin fibroblasis. Confluent cells were treated with hydrocortisone (10-7 M to 10-5 M) for 2 days and labeled with [3H]proline for 24 h. Fibronectin levels in both the culture medium and the cell layer were studied by gelatin-Sepharose affinity chromatography and SDS-polyacrylamide gel electrophoresis. In control cultures of human fetal skin fibroblasts, fibronectin constituted 8% of the total labeled proteins in the medium. The proportion of fibronectin increased to 13.1% at 10-7 M hydrocortisone, 15.5% at 10-6 M and to 19.4% at 10-5 M. The proportion of fibronectin associated with the cell layer remained at 2-3% of total [3H]prolne-labeled proteins and did not increase with hydrocortisone exposure. The stimulating effect of hydrocortisone on medium fibronectin was also demonstrated in cultured human newborn foreskin fibroblasts and in rabbit skin fibroblasts.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 174
    Electronic Resource
    Electronic Resource
    Aluminum lons stimulate DNA synthesis in quiescent cultures of Swiss 3T3 and 3T6 cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 298-304 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Micromolar concentrations of Al3+ are shown to be strongly mitogenic for quiescent cultures of Swiss 3T3 and 3T6 cells. Al3+ caused a striking shift in the dose-response curve for the effect of fetal bovine serum on 3H-thymidine incorporation. In the absence of serum the mitogenic effect of aluminum was greatly potentiated by insulin or cholera toxin, but not epidermal growth factor or 12-0-tetradecanoyl-phorbol-13-acetate. The stimulation of DNA synthesis was maximal by 15-20 μMM Al3+. Al3+ at 100 μMM had no inhibitory effect on DNA synthesis. Al3+ had no significant effect on cellular cyclic adenosine monophosphate in the presence or absence of insulin or an inhibitor of cyclic nucleotide phosphodiesterases.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180313
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 175
    Electronic Resource
    Electronic Resource
    Differential sensitivity of fibroblasts to epidermal growth factor is related to cyclic AMP concentration (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 291-297 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The differential sensitivity of various cell lines to the mitogenic effects of epidermal growth factor (EGF) was investigated. Two lines of evidence suggest that cellular capacity to respond proliferatively to EGF is related to intracellular cyclic AMP concentration. First, the ability of three density-arrested cell lines to synthesize DNA in response to EGF was directly proportional to the basal cyclic AMP level of the cells at quiescence. Second, treatment of cultures with various agents known to promote intracellular cyclic AMP accumulation increased the sensitivity of all three cell lines to EGF. The mechanism whereby cyclic AMP modulates EGF responsiveness is not known; cholera toxin did not affect the cellular capacity to bind or internalize and process EGF. Although platelet-derived growth factor (PDGF) had no effect on cyclic AMP levels, transient treatment of quiescent cultures with this polypeptide also enhanced EGF sensitivity. In agreement with previous data and in contrast to cholera toxin, PDGF induced the down-regulation of EGF receptors in the three cell lines. These data suggest that the capacity of various cell types to respond to EGF is subject to both intracellular regulation by cyclic AMP and extracellular modulation by factors such as PDGF which can affect EGF receptor activity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 176
    Electronic Resource
    Electronic Resource
    The role of Protein breakdown in growth, quiescence, and starvation of vascular smooth muscle cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 317-323 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Protein accumulation in growing cells may be due in part to a reduction in the rate of protein breakdown. Previous studies of the relation of cell proliferation to protein degradation often produced growth arrest by conditions that may involve nutritional deprivation. However, nutrient lack can itself accelerate proteolysis and produce negative protein balance. We therefore reexamined the relation between growth and protein breakdown using a more selective method for limiting cell growth. We produced quiescent cell cultures using a chemically defined, serum-free medium supplemented with hormones and nutrients. Such media can maintain viability and near neutral protein balance in cultured vascular smooth muscle cells, in part because of reduced breakdown of cellular protein. We then compared rates of protein degradation in these quiescent but not starving cells, to those of cultures stimulated to grow by addition of mitogenic substances. Platelet-derived growth factor, fibroblast growth factor, or fetuin added to insulin-containing medium stimulated growth of smooth muscle cells, but further reduced protein breakdown only slightly. Contrary to the implications of certain previous studies, our results show that proliferating cells can accumulate protein without an appieciable reduction in the rates of protein breakdown. Thus, while accelerated proteolysis appears to be an important adaptation to adverse nutritional conditions, growth of smooth muscle cells does, not require changes in overall protein breakdown, but occurs primarily through an increase in protein synthesis.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 177
    Electronic Resource
    Electronic Resource
    Calmodulin antagonists sensitize cells to pseudomonas toxin (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 119 (1984), S. 15-22 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: L cells and mouse 3T3 cells, which are very sensitive to Pseudomonas aeruginosa exotoxin A (PEA), were protected with weak bases and low concentrations of monensin. BHK cells and a number of other cell lines which are much less sensitive to PEA were much less protected under these conditions. Trifluoperazine, dansylcadaverine, and several other calmodulin antagonists strongly sensitized BHK cells to the toxin whereas they did not affect the sensitivity of the mouse 3T3 and L cells. The sensitization of the BHK cells was counteracted by treatment with weak bases or low concentrations of monensin. Calmodulin antagonists also sensitized cells to toxin which had become inaccessible to antitoxin, indicating that the effect of the calmodulin antagonists is exerted on a process taking place after the toxin is endocytosed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041190104
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 178
    Electronic Resource
    Electronic Resource
    Endocytosis and exocytosis of protein in capillary endothelium (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 157-162 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The transport of proteins across continuous capillary endothelium is believed to be mediated by micropinocytic vesicles which shuttle molecules between the lumenal and abluminal plasma membrane. We have studied the ability of capillary endothelial cells isolated from rat epididymal fat to endocytose fluorescently labelled ovalbumin within micropinocytic vesicles. Net association of fluorescent ovalbumin with endothelial cells reaches an equilibrium after 40 minutes of incubation. This equilibrium is presumably due to a balance between endocytosis and subsequent exocytosis of this protein. Capillaries equilibrated with fluorescent ovalbumin exhibited rapid exocytosis of this protein when it was removed from the external medium. The rate of endocytosis was concentration dependent and obeyed the kinetics expected for adsorptive phase endocytosis. High concentrations of ovalbumin stimulated the ingestion of 14C-sucrose, a marker of fluid endocytosis, suggesting that protein can affect the movement of vesicles within the endothelial cytoplasm. These results imply that capillary endothelium isolated from rat epididymal fat exhibits the ability to endocytose and subsequently exocytose protein. This demonstrates that the two components of endothelial vesicular transport or transcytosis can be observed and studied in a system of isolated capillary endothelium.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 179
    Electronic Resource
    Electronic Resource
    Adenosine inhibits cell division and promotes neurite extension in PC12 cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 188-196 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Low concentrations (10-50 μM) of adenosine (EC50 = 17 μM) or chloroadenosine (EC50 = 23 μM) prevent the division of PC12 cells. This inhibition is not mimicked by guanosine, inosine, 3′,5′ dideoxyadenosine, phenylisopropylad-enosine, or adenylylimidodiphosphate. The growth inhibition is not relieved by addition of uridine or deoxycytidine, nor is it potentiated by homocysteine thiolactone. Inhibition of adenosine uptake does not inhibit adenosine-de-pendent growth arrest. PC12 variants that are deficient in adenosine kinase are as sensitive as wild-type cells to the growth-inhibitory effects of adenosine. These experiments suggest that adenosine prevents cell division at an adenosine receptor rather than acting after being metabolically altered. The adenosine receptor that inhibits cell division does not appear to be the adenosine receptor that stimulates adenylate cyclase for these reasons: (1) phenylisopropyladenosine, which is a potent agonist of this receptor, does not inhibit cell division; (2) 3′,5′ dideoxyadenosine does not antagonize the effect of adenosine on cell division; and (3) theophylline does not affect growth inhibition by adenosine. Thus, these experiments suggest the existence of a second adenosine receptor that can inhibit cell division.Adenosine also promotes the morphological differentiation of PC12 cells. In the presence of the adenosine deaminase inhibitor, erythro-9-(2-hydroxy-3-nonyl)adenosine (EHNA), adencsine causes the formation of short neurites (one-half to one and one-half cell diameters in length). Adenosine also increases the rate of neurite formation of both long and short neurites in response to NGF.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200212
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 180
    Electronic Resource
    Electronic Resource
    Induction of cytochrome P-450 isozymes in rat hepatoma-derived cell cultures (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 169-180 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have investigated the responsiveness of established rat hepatocyte cell cultures to inducers of cytochrome P-450. One Reuber hepatoma-derived line (Fu5-C8), which under normal culture conditions produces no detectable cytochrome P-450(MC) or cytochrome P-450(PB) - the major cytochrome P-450 isozymes induced by 3-methylcholanthrene and phenobarbital, respectively- was tested for the ability to accumulate either cytochrome P-450 isozyme in response to treatment with various xenobiotics. By immune-precipitation from [35S]-methionine-labeled cell extracts, using monospecific anticyto-chrome P-450(MC) antybody or monoclonal anticytochrome P-450(PB) antibody, it was demonstrated that these cells possess the capability to synthesize cytochrome P-450(MC) in response to 3-methylcholanthrene treatment, while none of the drug treatments caused the synthesis of detectable quantities of cytochrome P-450(PB). RNA extracted from Fu5-C8 cells directed the in vitro synthesis of immune-precipitable cytochrome P-450(MC) only after treatment of the cells with 3-methylcholanthrene Kinetic analysis of the response of these cells to 3-methylcholanthrene induction revealed detectable levels of immune-precipitable cytochrome P-450(MC) 2 h after drug treatment with maximal induction occurring between 12 and 16 h of exposure. Another cell line (HF 1.5), obtained originally by hybridization of Fao X H5 variants of a Reuber H35 hepatoma, produces cytochrome P-450(MC) and also cytochrome P-450(PB) constitutively, as determined by specific immune-precipitation from labeled cell extracts. Exposure of confluent monolayers to either phenobarbital or 3-methylcholanthrene resulted in an induction of cytochrome P-450(PB) or cytochrome F-450(MC), respectively. Double-labeling immunofluorescence studies indicate that all cells in the culture produce albumin and most of the cells produce cytochrome P-450(MC), but only a subset of cells synthesize cytochrome P-450(PB). Our results demonstrate that some continuously dividing hepatocyte cell cultures retain the capacity to respond to xenobiotics, including phenobarbital, a response which is typically exhibited by fully differentiated liver cells. Such established hepatocyte cell cultures should prove useful for investigating the mechanism of induction of cytochrome P-450(PB).
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 181
    Electronic Resource
    Electronic Resource
    Thermal down-regulation of exportable rRNA in nuclei (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 211-218 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The export of rRNP particles from nuclei isolated from Tetrahymena was investigated after preincubating the nuclei at different temperatures under nonpermissive export-conditions. We observed a new phenomenon: Temperature elevation from the sublethal cells' growth temperature, 8°C, to the optimal temperature, 28°C, lead to a gradual down-regulation in the maximal proportion of rRNP particles subsequently exported from nuclei at 28°C. This thermal down-regulation is apparently not due to qualitative changes in the exported rRNP particles, a derangement in the gross nuclear organization, a degradation and/or nicking of the nuclear rRNA, a gross decomposition of the major nuclear proteins, a random cross-linking of nuclear components by disulfide bonds, or an elution of nuclear factors possibly required for rRNP export. Moreover, there is a corresponding thermal down-regulation in nuclear envelope-free nuclei. Our data indicate that nuclei possess a mechanism that regulates the number of potentially exportable rRNP particles at a level preceding the rRNP passage through the nuclear envelope.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 182
    Electronic Resource
    Electronic Resource
    Uptake of epidermal growth factor into a lysosomal enzyme-deficient organelle: Correlation with cell's mitogenic response and evidence for ubiquitous existence in fibroblasts (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 118 (1984), S. 305-316 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The internalization process following cell surface receptor binding by epidermal growth factor (EGF) was studied. It was found that EGF is taken up into a dense, membranous organelle. This organelle is deficient in lysosomal enzyme activity and is biochemically dissimilar to the major lysosomal fraction. The uptake of EGF by this organelle was demonstrated in three different cell types representing three different species. Each of these cell types is highly responsive to the mitogenic action of EGF. These results indicate that EGF is endocytosed and delivered to a dense, possibly nonlysosomal, organelle which is ubiquitous in fibroblasts. Furthermore, we demonstrate a close, positive correlation between EGF uptake into this fraction and the ability of cells to respond to the mitogen. A negative relationship between uptake into the subcellular fraction containing lysosomal enzymes and EGF-stimulated DNA synthesis was observed. Using numerous incubation conditions no exceptions to the correlation between EFG uptake into the lysosomal enzymedeficient fraction and EGF-induced DNA synthesis were observed. These results suggest a role for this dense organelle in the production of a mitogenic signal.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041180314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 183
    Electronic Resource
    Electronic Resource
    Compound 48/80 impairs cytokinesis in murine leukemiccells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 119 (1984), S. 1-6 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Compound 48/80 (poly-p-methoxyphenethylmethylamine), an agent commonly used to trigger degranulation of mast cells, at concentrations of 5-20 μg/ml suppresses the proliferation of L1210 and Friend leukemic cells in vitro, inducing the formation of giant cells, which are polykaryons. Both the proportion of polykaryons in cultures and their size (which reflects the number of nuclei per polykaryon) increase during growth in the presence of 48/80 up to 48 hr; thereafter, the cells lose viability. A predominant number of nuclei in these polykaryons contain a 4C, or higher DNA content. The data indicate that compound 48/80 impairs the cleavage (cytokinesis) and perhaps mitotic processes. Mechanisms by which compound 48/80 induces the described effects are unknown but may be related to the polycationic nature of the polymer and its interaction with the cell membrane. Certain attributes of compound 48/80 suggest that this or similar polymers may have value as research tools for the study of regulatory mechanisms involved in cell division.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041190102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 184
    Electronic Resource
    Electronic Resource
    Regulation of Na+, K+-ATPase activity in MDCK kidney epithelial cell cultures: Role of growth state, cyclic AMP, and chemical inducers of dome formation and differentiation (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 51-63 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Na+,K+-ATPase activity was monitored in MDCK kidney epithelial cell monolayers and in cell extracts as a function of cell density, cAMP elevation, and exposure to hexamethylene bisacetamide (HMBA) and dimethylsulfoxide (Me2SO). Ouabain-sensitive Na+,K+-ATPase and 86Rb+ uptake activities, and the number of [3H]-ouabain binding sites were maximal in subconfluent cultures and decreased accompanying the development of a confluent monolayer. A sodium pump density of 8 × 107 pumps/cell was estimated for subconfluent cultures, declining to 9 × 105 pumps/cell at confluence. Previous studies have shown that dibutyryl cyclic AMP (Bt2cAMP), 1-methyl-3-isobutylxanthine (IBMX), or the differentiation inducers HMBA and Me2SO, which also caused cAMP elevation, all stimulated dome formation, a visible manifestation of active transepithelial Na+ and water transport (Lever, 1979). In the present study, all of these inducers were found to elevate intracellular Na+ content, implicating this variable in control of induction of dome formation. Operationally, inducers could be divided into two classes. HMBA and Me2SO partially inhibited ouabain-sensitive 86Rb+ influx. Ouabain, at a concentration that caused partial sodium pump inhibition and increased intracellular Na+ content, was also effective as an inducer. The second class, exemplified by IBMX and Bt2cAMP caused a furosemide-sensitive increase in intracellular Na+ content. This class of inducers stimulated ouabain-sensitive 86Rb+ uptake, presumably by substrate effects due to increased Na+ levels. The Na+ or ATP activation of Na+,K+-ATPase activity assayed in cell-free extracts, the affinity of the transport system for Rb+ in intact cells and intracellular ATP levels were unchanged by inducer treatment. Elevation of intracellular Na+ concentration, either by cAMP-stimulated, furosemide-sensitive mechanisms or by partial inhibition of the sodium pump may stimulate the induction of dome formation in MDCK cells.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210108
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 185
    Electronic Resource
    Electronic Resource
    Serum and substratum-dependent coupled loss of differentiated and tumorigenic phenotypes in B16-conv melanoma cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 74-80 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Clonal B16 mouse melanoma conv cells are tumorigenic spindle-shaped cells (S-type cells) exhibiting tyrosinase activity and melanosomes under usual culture conditions. When the cells passaged on glass substratum were plated for colony formation on plastic substratum in Eagle's minimum essential medium (MEM) with 10% calf bovine serum, most of them converted to fibroblastlike cells (F-type cells) with the coupled loss of differentiated and tumorigenic phenotypes. However, they continued to be S-type cells provided that they were plated on glass substratum. The conversion from S- to F-type cell was not induced with high frequency even on plastic substratum when the concentration of calf serum in the medium was low (1-2%). These results indicate that both plastic substratum and serum factor are requisites for converting the phenotypic expression of the conv cells. Partial characterization of the serum factor indicates that it is adsorbable to plastic substratum, inactivated at 70°C for 10 min, salted out at 40% of saturated ammonium sulfate; in addition the factor seems to act on cells within 1 day after plating.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 186
    Electronic Resource
    Electronic Resource
    Induction of microvillar hydrolase activities by cell density and exogenous differentiation inducers in an established kidney epithelial cell line (LLC-PK1) (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 64-73 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Several hydrolase activities characteristic of the apical brush border membrane of renal proximal tubule, leucine aminopeptidase, γ- glutamyl transpeptidase, alkaline phosphatase, maltase, and trehalase, were identified in cultures of the LLC-PK1 kidney epithelial cell line. A coordinate increase in activities of these enzymes was observed upon development of a confluent cell density and functional membrane polarization. Further large progressive increases in individual hydrolase activities were induced after the addition of compounds known as differentiation inducers. Hexamethylene bisacetamide preferentially induced increased trehalase and maltase activities. Induced trehalase activity exhibited an increased Vmax but a similar Km compared with activity in control extracts. Induction required protein synthesis and was dependent on inducer concentration and exposure time. Treatment of confluent cultures with N,N′-dimethylformamide triggered an induction of maltase, trehalase, alkaline phosphatase, and γ-glutamyl transpeptidase activities, whereas dimethylsulfoxide induced trehalase and γ-glutamyl transpeptidase activities. Increased leucine aminopeptidase and maltase activities were observed after addition of the phosphodiesterase inhibitor 1-methyl-3-isobutylxanthine. Induction of trehalase activity by N,N′-dimethylformamide was reversible over a 4-day period after removal of inducer, but effects of hexamethylene bisacetamide were irreversible. These results suggest that the LLC-PK1 cell line reproducibly develops differentiation-specific characteristics under defined conditions in cell culture, which can be individually modulated by chemicals known as inducers of cell differentiation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 187
    Electronic Resource
    Electronic Resource
    Effect of hyperosmolarity on the activity of amino acid transport system L in avian fibroblasts (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 81-86 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The transport of selected neutral amino acids known as good substrates of amino acid transport System L has been studied in chick embryo fibroblasts exposed for 4 hours to hyperosmolar culture medium. The activity of the L system, as measured by initial rates of L-phenylalanine uptake, increased in hyperosmolarity treated cells when determined before any cell depletion of intracellular amino acids. This effect was lost after depletion but reappeared after reloading the cells with pertinent substrates of System L. This transport activity appeared to be related to the internal level of amino acids capable of exchange through System L. In hyperosmolarity-treated chick embryo fibroblasts a higher level of System L substrates was obtained during the reloading phase in comparison to control cells. This expanded amino acid pool reflected an increased activity of transport System A, an agency of amino acid mediation known to enlarge its capacity following a hyperosmolar treatment of chick embryo fibroblasts (see Tramacere et al., 1984). L-Methionine, a preferred substrate of both A and L systems, appeared to be involved in the coupling between the activity of amino acid transport Systems A and L in these cells.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 188
    Electronic Resource
    Electronic Resource
    The intracellular pH of quiescent and proliferating human and rat thymic lymphocytes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 87-95 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We compared the cytoplasmic pH (pHi) of quiescent and actively cycling thymic lymphocytes. Human and rat thymocyte suspensions were fractionated by centrifugation on one step albumin density gradients. The pellet was composed of small, quiescent cells and the interphase contained mostly larger, actively cycling cells with a high proliferation index. When measured using [14C]-dimethyloxazolidinedione (DMO), pHi in the large cells of both species was approximately 0.15 units more alkaline than in the small cells. However, these differences were not detectable when pHi was measured with carboxylated fluorescein derivatives generated in situ by cytoplasmic enzymes. This apparent discrepancy can be explained by compartmentation of DMO, which accumulates in the alkaline mitochondrial matrix. Comparison of the mitochondrial content of quiescent and cycling thymocytes by several methods showed that the latter contained over 2.5-fold more mitochondria per unit cell volume. Assuming a constant intramitochondrial pH, this difference can account for the observed accumulation of DMO (i.e., apparent cytoplasmic alkalinity) in the actively proliferating cells. Therefore, no evidence was found for the existence of differences in pHi between quiescent and proliferating lymphocytes. Moreover, caution must be exercised when comparing DMO partition data in cells with varying relative mitochondrial content.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 189
    Electronic Resource
    Electronic Resource
    Characterization of monovalent ion transport systems in an insect cell line (Manduca sexta embryonic cell line che) (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 125-132 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The monovalent ion transport systems of an immortalized insect cell line (CHE) have been investigated. These cells are unusual in that unlike most vertebrate cells, their normal extracellular environment consists of high potassium and low sodium concentrations. CHE cells maintained high intracellular [K+] through both a furosemide-inhibitable and a vanadate-inhibitable transport system. Intracellular exchangeable [Na+] was slightly lower than the extracellular [Na+] and was maintained at this level through a vanadate-sensitive transport system. Na+ uptake was also inhibited by furosemide: however, the stoichiometry of furosemide-sensitive Na+ uptake when compared with furosemide-sensitive K+ uptake indicated that these cations are not cotransported. 4,4′-Diisothiocyano-2,2′-disulfonic acid stilbene (DIDS) inhibited Na+, K+, and Cl- uptake. Vanadate and furosemide decreased cytoplasmimic pH, while cytoplasmic pH increased in the presence of DIDS. A model is presented explaining how Na+, K+, Cl-, H+ and HCO3 - fluxes are regulated in these cells.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 190
    Electronic Resource
    Electronic Resource
    The organization of microfilaments in spreading platelets: A comparison with fibroblasts and glial cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 96-113 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Platelets respond to stimulatory agents in general by the formation of long spikelike surface projections built up of tightly bundled microfilaments. During contact stimulation this is followed by a second phase when thin membrane lamellae grow out between the projections. This behaviour resembles that seen for instance in fibroblasts and glial cells, sending out microspikes and lamellipodia as a step in their advancement over solid substrata. Conditions, designed earlier for the preservation and visualization of the fragile organization of microfilaments and microtubules in the peripheral, highly motile parts (leading lamellae) of such cells (Höglund et al. (1980) J. Musc. Res. Cell Motility, 1:127-146), were used here to produce high-resolution images of the ultrastructural organization of platelets spreading on a solid substratum. This revealed an unexpected arrangement of actin filaments running parallel to the advancing edge, and small tufts of microfilaments on the outside of this edge-bundle. Cytochalasin D caused a regression of the spikelike projections as well as of both types of structures in the advancing platelet lamella and led to the appearance of a dense filamentous mat in juxtaposition to the plasma membrane. Analysis of the actin pools using the DNAase inhibition assay showed that the dramatic reorganizations of actin seen during the two phases of contact stimulation was reflected in a shift in the G/F-actin ratio only during the early phase.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 191
    Electronic Resource
    Electronic Resource
    Growth requirements of low-density rabbit costal chondrocyte cultures maintained in serum-free medium (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 354-363 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The factors required for the active proliferation of low-density rabbit costal chondrocytes exposed to 9:1 (v/v) mixture of Dulbecco's modified Eagle's medium and Ham's F12 medium have been defined. Low-density primary cultures of rabbit costal chondrocytes proliferated actively when the medium was supplemented with high-density lipoprotein (300 μg/ml), transferrin (60 μg/ml), fibroblast growth factor (FGF) (1 ng/ml), hydrocortisone (10-6 M), and epidermal growth factor (EGF) (30 ng/ml). Insulin, although it slightly decreased the final cell density, was required for reexpression of the cartilage phenotype at confluence. Optimal proliferation of low-density chondrocyte cultures was only observed when dishes were coated with an extracellular matrix (ECM) produced by cultured corneal endothelial cells, but not on plastic. Furthermore, serum-free chondrocyte cultures seeded at low density and maintained on ECM-coated dishes gave rise to a homogeneous cartilage-like tissue composed of spherical cells. These chondrocytes therefore seem to provide a good experimental system for analyzing factors involved in supporting proliferation of chondrocytes and their phenotypic expression.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200314
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 192
    Electronic Resource
    Electronic Resource
    Characterization and partial purification of keratinocyte growth factor from the hypothalamus (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 377-383 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: An extract of bovine hypothalamus is known to be mitogenic for human keratinocytes in vitro. In order to identify the'responsible substance(s), biochemical characterization and subsequent bioassay of the extract in a serum-free culture system were performed. The keratinocyte growth-promoting activity of the hypothalamic extract was unaffected by heating (100 C, 10 min); acidification to pH 3.3; or by exposure to lipase, RNAase, or proteolytic enzymes; but was abolished by alkalinization to pH 11. An approximate molecular weight of 1,700 daltons was determined by elution on a calibrated Sephadex G-25 column, and an approximate pI of 3.5 was determined by isoelectric focusing. Optimal concentrations of the crude extract (150-300 μg/ ml) increased keratinocyte growth approximately 50-fold compared to control cultures lacking the extract. Partial purification resulted in a preparation biologically active at 30 ng/ml protein equivalent and was consistent with the presence of a single mitogen which we have termed keratinocyte growth factor (KGF). Mitogenic activity for human melanocytes, dermal fibroblasts, and endothelial cells, present in the crude hypothalamic extract, was lacking in heat-treated preparations that contained KGF. Optimal concentrations of purified epidermal growth factor and ethanolamine, the only remotely similar substances previously reported to augment keratinocyte growth in vitro, could not substitute for KGF in the serum-free culture system. Keratinocyte growth-promoting activity comparable to that observed in bovine hypothalamic extracts was present in human hypothalamic extracts prepared in the same manner.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200316
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 193
    Electronic Resource
    Electronic Resource
    Effects of sodium butyrate on growth and cell-cycle kinetics of cultured rabbit articular chondrocytes (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 384-390 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The sodium salt of n-butyric acid was found to inhibit the growth of asynchronous cultures of rabbit articular chondrocytes. This inhibitory effect was dose-dependent between 1 mM and 5 mM, reversible, and accompanied by volume enhancement and modification of cellular morphology. Flow-cytometric analysis showed that drug exposure led to a slowing-down of the cell-cycle progression; after 1 day's exposure, cells accumulated in G1, and after 2 or 3 days' treatment, in G2, without a blockage in M; the increase of cells in G2 was in fact due to an enhancement of binculeated cells. The treated cells had an increased RNA content. Articular chondrocytes seem to be target cells for sodium butyrate and therefore it represents a valuable biological tool for studying the mechanisms of their growth regulation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200317
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 194
    Electronic Resource
    Electronic Resource
    Evolution of cAMP phosphodiesterase activity in cultured myometrial cells: Effects of steroids and of successive subcultures (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 120 (1984), S. 391-396 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cyclic AMP phosphodiesterase (PDE) activity was characterized in culture of ewe myometrial cells and its sensitivity to steroid hormones was tested. Cultured myometrial cells were maintained from the first to the 20th subculture in the presence of 2% of serum in a medium supplemented with 1 μM of insulin. It was found that myometrial cells possess a PDE activity with atypical kinetics. The nonlinear responses in Lineweaver-Burke plots suggest the presence of high- and low-affinity PDE activities. In cell culture, apparent Km values were similar to those obtained from the original myometrium. Vmax values increased with successive subcultures, revealing an increase in the capacity of the cells to degrade cAMP; in parallel, the growth rate decreased. The PDE specific activity in cultured myometrial cells was inhibited by estra-diol or progesterone. When added together, no synergistic effect was obtained. The rate of inhibition for both steroids was constant during successive passages for both low- and high-affinity conditions. Results obtained in myometrial cell long-term culture were compatible with reports in other species in vivo. Considering the role of cAMP in the regulation of uterine functions, subcultured myometrial cells provided us a useful experimental system with which to study the cAMP metabolism process.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041200318
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 195
    Electronic Resource
    Electronic Resource
    Biochemical effects of 12-O-tetradecanoylphorbol-13-acetate, retinoic acid, phenobarbital, and 5-azacytidine on a normal rat liver epithelial cell line (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 1-6 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA), all trans-retinoic acid (RA), 5-azacytidine (5-AC), and phenobarbital (PB) on the activities of seven enzymes and/or isozymes of a diploid rat liver epithelial cell line have been studied. At 0.1 μg/ml, TPA depressed the specific activities of lactate dehydrogenase and gamma-glutamyl transpeptidase, whereas 2 mM PB depressed gamma-glutamyl transpeptidase and alkaline phosphatase. At 0.01 μg/ml, RA markedly depressed the activity of NADH-diaphorase and lactate dehydrogenase but enhanced the activity of alkaline phophatase. Only 2 μM 5-AC caused the most significant shift of lactate dehydrogenase isozyme toward the “muscle”-type isozyme. Histochemical studies revealed that PB and 5-AC induced focal areas of cells with glycogen deposits, but no significant changes in either ultrastructure or alpha-fetoprotein and albumin immunohistochemical staining pattern were observed to suggest hepatocytic differentiation. Although none of the enzymatic changes could be consistently correlated with the effects of these biological modifiers on the cellular growth rate, the effect of RA on NADH-diaphorase, lactate dehydrogenase, and alkaline phosphatase activities was the opposite of the changes observed during carcinogenesis of these rat liver epithelial cells by multiple treatments with N-methyl-N′-nitro-N-nitrosoguanidine. The depression of gamma-glutamyl transpeptidase activity by PB is contradictory to that observed histochemically in hepatocytes in vivo, but such discrepancy may be related to the differences in cell type, growth conditions, or duration of exposure.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 196
    Electronic Resource
    Electronic Resource
    Glucose metabolism in murine fetal cortical brain cells: Lack of insulin effects (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 45-50 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Glucose uptake and oxidation were markedly higher in cultured than in freshly isolated neural cells, prepared from murine fetal brain cortices. The hexose transport process-measured as 3-O-methyl-D-glucose uptake-appeared comparable in both conditions, and proceeded proportionally to the extracellular sugar concentration up to 6 mM. In contrast, glucose oxidation occurred independently of the prevailing glucose concentration from 1.4 mM on. Acute or chronic exposure to insulin exerted no effect upon cellular glucose uptake or oxidation. These results suggest that glucose handling by maturing fetal cortical cells is mainly determined by the rate of cellular glucose breakdown rather than by the rate of glucose transport into the cell; the marked rise in cellular glucose metabolism during culture might result from the synthesis and/or activation of a key enzyme in glucose catabolism. Our observations also indicate that the previously described neurotrophic effects of insulin are not mediated via enhanced glucose handling.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210107
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 197
    Electronic Resource
    Electronic Resource
    Integrated control of growth and differentiation of normal human prokeratinocytes cultured in serum-free medium: Clonal analyses, growth kinetics, and cell cycle studies (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 31-44 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The effects of growth factors, hormones, and calcium on the growth and differentiation of secondary cultures of normal human prokeratinocytes, i.e., proliferative keratinocytes, derived from adult or neonatal skin were determined by culture in serum-free basal medium, MCDB 153. Clonal growth was achieved when MCDB 153 was supplemented with either epidermal growth factor (EGF) or bovine pituitary extract (BPE), provided insulin was present. In the absence of insulin, however, both EGF and BPE were required for clonal growth. Using this assay, it was established that colony-forming efficiency is independent of calcium concentrations above 0.03 mM and averages 56%; colony size, however, was influenced by calcium and EGF concentrations. Optimal clonal growth occurred in medium containing 10 ng/ml EGF and 0.3 mM calcium. By contrast, differentiation was enhanced by the combination of low EGF (0.1 ng/ml) and high calcium (2 mM). This suggests that an inverse relationship exists between the growth response (extent of clonal growth) and the differentiation response (extent of differentiation). These results suggest that proliferation and differentiation are regulated in an integrated manner. Detailed kinetic studies and cytofluorimetric and autoradiographic analyses also showed that exponentially growing secondary cultures of adult and neonatal prokeratinocytes have a 24-hour cell generation time with G1, S, G2, and M phases of 12, 8, 3, and 1 hours, respectively. In addition, the data show that such cells can be growth arrested in medium that does not induce differentiation and that such a procedure significantly limits the cell's subsequent proliferative potential. Furthermore, prolonged culture of adult (〉 30 population doublings) and neonatal prokeratinocytes (〉 50 population doublings) is associated with senescence and the G1 arrest of noncycling cells.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210106
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 198
    Electronic Resource
    Electronic Resource
    Topography of protein kinases and phosphoproteins in the plasma membrane of 3T3 cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 357-367 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The plasma membrane of 3T3 cells contains at least two different endogenous cyclic AMP-dependent protein kinase systems. One catalyzes the phosphorylation of endogenous protein substrates, i.e., PP24 and PP14, whereas the other catalyzes the phosphorylation of exogenous substrates. In this paper the topography of these cyclic AMP-dependent phosphorylation systems is described. The results show that the kinases which phosphorylate only exogenous substrates are primarily localized to the outer plasma membrane surface whereas the endogenous cyclic AMP-dependent protein kinase and its two endogenous substrates are localized to the cytoplasmic plasma membrane surface. The data also establish that neither the cytoplasmically orientated kinase nor its substrates has a transmembrane orientation even though factors acting on the outer plasma membrane can affect these proteins. This suggests that functional modulation of the cytoplasmically localized cyclic AMP-dependent phosphorylation system can be mediated by a transmembrane regulatory mechanism. The importance of determining the topography of such plasma membrane phosphorylation systems is emphasized by recent studies which show that neoplastic transformation can be mediated at least in part by protein kinases and/or phosphoproteins which are localized on the cytoplasmic surface of the plasma membrane.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210213
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 199
    Electronic Resource
    Electronic Resource
    Characterization of the metabolic forms of 6-thioguanine responsible for cytotoxicity and induction of differentiation of HL-60 acute promyelocytic leukemia cells (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 383-390 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: HL-60 human acute promyelocytic leukemia cells that lack hypoxanthineguanine phosphoribosyltransferase (HGPRT) activity have been developed by mutagenization and selection. These cells exhibited markedly decreased sensitivity to the cytotoxic action of 6-thioguanine (TG) and, in contrast to parental HL-60 cells, had the capacity to undergo terminal granulocytic differentiation after treatment with this purine antimetabolite. Analysis of extracellular and intracellular metabolites of TG revealed negligible metabolism of TG in these HGPRT- HL-60 cells. These findings are consistent with the concept that inhibition of cellular replication requires generation of analog nucleotide and suggest that TG itself is capable of initiation of differentiation. 6-Thioguanosine (TGuo) had limited activity, while β-2′-deoxythioguanosine (dTGuo) was inactive, as an inducer of maturation of HGPRT- HL-60 cells. These cells converted relatively large amounts of the nucleosides to the free base TG; the simultaneous exposure of cells to 8-aminoguanosine (AGuo), an inhibitor of purine nucleoside phosphorylase activity, decreased the degradation of TGuo and dTGuo to TG and promoted the intracellular accumulation of TG nucleotides, presumably through the action of nucleoside kinase activities. In a double mutant deficient in both HGPRT and deoxycytidine kinase (DCK) activities, dTGuo was devoid of cytotoxicity and was an effective inducer of maturation. The potency of dTGuo as an inducer in this system was not significantly affected by the presence of AGuo. These results suggested that dTGuo itself was also an active initiator of maturation. Thus, induction of differentiation appeared to be due to the free base, TG, as well as its deoxynucleoside form, dTGuo, whereas the formation of TG nucleotides appeared to antagonize maturation and produce cytotoxicity.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210216
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 200
    Electronic Resource
    Electronic Resource
    Effects of 2′,3′-dideoxynucleosides on mammalian cells and viruses (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 121 (1984), S. 402-408 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous studies on the biological effects of the 2′,3′-dideoxynucleosides (ddNs) have shown that while ddAdo is lethal to E. coli, ddThd has minimal effects on the growth of mammalian cell lines and that it inhibits retrovirus infection of some cell lines but not others. Previous studies have also shown that the 5′-triphosphate of ddThd, ddTTP, selectively inhibits cellular DNA polymerases β and γ and retroviral reverse transcriptases. Cellular DNA polymerase α is relatively resistant to ddTTP. We have extended these findings to show that the 5′-triphosphates of the other 3 ddNs (ddATP, ddCTP, and ddGTP) affect cellular DNA polymerases α, β, and γ in the same fashion as does ddTTP. We also show that all four ddNs in concentrations up to 100 μM have negligible effects on the growth of NIH Swiss 3T3 cells. These negligible effects may be due to inefficient intracellular phosphorylation of each nucleoside to the triphosphate. We have determined that, in several different cell lines, ddThd is phosphorylated only at a very slow rate to ddTTP, and in the one cell line tested (monkey CV-1 cells), ddAdo and ddGuo are also poorly phosphorylated. Both ddAdo and ddGuo, and probably ddThd, are converted by CV-1 cells to additional unknown compounds which may have biological activity. The four ddNs display effects of different magnitudes on certain virus infections. Although 30 μM ddThd inhibits herpes simplex I infection of CV-1 cells by 50%, 30 μM ddAdo has no effect. Infection of NIH Swiss 3T3 cells by 334C murine leukemia virus is inhibited 70-80% by ddAdo, ddCyd, and ddThd at 50 μM, but inhibition by 50 μM ddGuo is 100%.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041210218
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...