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  • Life and Medical Sciences
  • 1990-1994
  • 1980-1984  (49)
  • 1965-1969  (10)
  • 1940-1944
  • 1915-1919
  • 1981  (49)
  • 1969  (10)
Collection
Keywords
Publisher
Years
  • 1990-1994
  • 1980-1984  (49)
  • 1965-1969  (10)
  • 1940-1944
  • 1915-1919
Year
  • 1
    Electronic Resource
    Electronic Resource
    Inhibition of the metabolism of ram spermatozoa by derivatives of α-chlorohydrin (1981)
    New York, NY : Wiley-Blackwell
    Gamete Research 4 (1981), S. 203-217 
    Details
    ISSN: 0148-7280
    Keywords: α-chlorohydrin ; antifertility agent ; ram ; sperm metabolism ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The effects of the male antifertility agent, α-chlorohydrin, six of its derivatives, and glycidol were studied on the metabolism of washed ram spermatozoa in vitro with fructose as substrate. The α-chlorohydrin derivatives were the amino, the phosphorylated, and four glycol-bridge (ketal) compounds. All compounds except glycidol, in a concentration between 0.1 and 100 mM, reduced the aerobic glycolsis and/or oxidation of fructose. However, there was not a high correlation between the ability of these compounds to inhibit the metabolism of ram spermatozoa in vitro and their antifertility activity when administered to male rats. Other factors are clearly involved in their antifertility activity, eg, the concentration of the compounds in the epididymis and their conversion of either more or less spermicidal compounds in the body.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrd.1120040305
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  • 2
    Electronic Resource
    Electronic Resource
    A crustacean statocyst with only three hairs: Light and scanning electron microscopy (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 21-28 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Standard histological and SEM techniques have been used to examine the pair of statocyst organs located in the telson of the isopod, Cyathara polita. Each organ is formed as an invagination of the dorsal cuticle of the telson. The invagination narrows to form a stalk between the statocyst and dorsal surface. A canal courses longitudinally through this stalk and forms a continuous channel between the lumen of the cyst and the external environment. On the luminal floor of each statocyst, there are three pits; each correlates with a nodule protruding from the ventro-medial wall. From each pit, a single, bifurcating hair projects dorsally to contact the single concretion within the statocyst lumen. No other static organs have been found in this animal. Thus, maintenance of equilibrium in this species appears to be under the control of but six hairs, three in each statocyst. Innervation of each statocyst is provided by a branch of a nerve which connects anteriorly with the last abdominal ganglion.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051690103
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  • 3
    Electronic Resource
    Electronic Resource
    Form and function of protein assemblies (1969)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 74 (1969), S. 239-240 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Assemblies of protein molecules represent a fundamental level of biological organization. The dynamic behavior of these systems-including both the assembly process and functional rearrangements-may be accounted for by the specificity of the protein interactions, which depend on environmental conditions. Analysis of the self-assembly of virus particles has established that the design of an ordered structure can be built into the specific bonding properties of the constituent proteins. Any structure which can change its state of organization is, by definition, polymorphic. The distinctive aspect of polymorphism in protein structures, contrasted with nonliving states of matter, is that the molecular design has been selected to carry out a function and that this function is part of an integrated system. The differences in molecular conformation and arrangement in all polymorphic structures-for example, allosteric enzymes or ice crystals-depend on the intrinsic interaction properties of the molecules themselves. The structures of ice and water illustrate relations between specificity and polymorphism which are relevant to the form and function of protein assemblies.Two types of polymorphism can be distinguished: modal polymorphism, which is externally moderated, as in phase transitions between different crystals forms; and positional polymorphism, which is internally moderated, as in the different disposition of identical molecules within a single crystal lattice. Positional polymorphism, exemplified by the quasi-equivalent bonding of icosahedral virus coat proteins and the different arrangement of myosin and paramyosin at the center and polar portions of the bipolar filaments, results from specific interactions that are not compatible with a strictly equivalent packing of identical molecules. The structural rearrangements in muscle contraction and the switching between the oxy and deoxy forms of hemoglobin represent the formation of different structures in response to altered external conditions. The different structural states of many protein assemblies are characterized by conserved connections which may be regarded as providing the framework for functional rearrangements. The types of polymorphism displayed by hemoglobin, virus, and muscle proteins demonstrate the relevance of the simple view that the function of a protein is determined by the potential structures it can form.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040740427
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  • 4
    Electronic Resource
    Electronic Resource
    Chronic exposure to 60-Hz electric fields: Effects on pineal function in the rat (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 371-380 
    Details
    ISSN: 0197-8462
    Keywords: electric fields ; 60 Hz ; pineal gland ; circadian rhythm ; melatonin ; 5 methoxytryptophol ; acetyl transferase ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: As a component of studies to search for effects of 60-Hz electric field exposure on mammalian endocrine function, concentrations of melatonin, 5-methoxytryptophol, and serotonin-Nacetyl transferase activity were measured in the pineal glands of rats exposed or sham-exposed at 65 kV/m for 30 days. In two replicate experiments there were statistically significant differences between exposed and control rats in that the normal nocturnal increase in pineal melatonin content was depressed in the exposed animals. Concentrations of 5-methoxytryptophol were increased in the pineal glands of the exposed groups when compared to shamexposed controls. An alteration was also observed in serotonin-N-acetyl transferase activity, with lower levels measured in pineal glands from exposed animals.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020408
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  • 5
    Electronic Resource
    Electronic Resource
    Growth and metabolism of rodents exposed to 60-Hz electric fields (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 2 (1981), S. 381-390 
    Details
    ISSN: 0197-8462
    Keywords: 60-Hz electric fields ; body weight ; oxygen consumption ; rat ; mouse ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: There have been a number of reports in the literature concerning growth-related changes in various animal species exposed to high-strength electric fields. Many of the laboratories reporting such effects have not documented and controlled for the secondary factors that are associated with generating high-strength electric fields (ie, corona, ozone, harmonic distortion, cage vibration, spark discharge). We have designed an exposure system in which we eliminated or minimized these secondary factors, therefore enabling us to examine only the effects of electric fields per se. Sprague-Dawley rats and Swiss-Webster mice were exposed to 60-Hz electric fields at kV/m for up to four months. In 17 individual experiments, we found a greater number of experiments in which the exposed rats had lower body weights than controls. This trend was not evident in data obtained from 14 individual mouse experiments. In more exhaustive growth studies, we found no significant differences in body weights, organ weights, or O2 consumption between exposed and sham-exposed controls. Our failure to detect any major changes in growth was probably the result of eliminating or minimizing the secondary factors associated with electric field exposure.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250020409
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  • 6
    Electronic Resource
    Electronic Resource
    Influence of homoeotic genes on the aldehyde oxidase pattern in imaginal discs of Drosophila melanogaster (1981)
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 2 (1981), S. 75-87 
    Details
    ISSN: 0192-253X
    Keywords: Drosophila melanogaster ; homoeosis ; imaginal discs ; aldehyde oxidase ; pattern formation ; compartments ; selector genes ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In a study of the regulation of enzyme patterns in imaginal discs the aldehyde oxidase pattern was determined for some homoeotic mutations of D. melanogaster. Earlier indications that suggested that this pattern follows the determinitive state of compartments within imaginal discs were confirmed by the aldehyde oxidase (AO) pattern of both the wing and haltere discs from en1; bx3, en1; pbx, and en1; bx3 pbx larvae and the antennal discs from Antp73b and ssa larvae.We additionally analyzed whether AO activity depended on the determinative state of an entire compartment or was expressed autonomously in clones. Homozygous engrailed clones were induced by mitotic recombination. From the AO clones found in normally negative areas of the posterior compartment it was concluded that enzyme activity depended upon the determinative state of the cells and was not a function of the compartment as a whole.The results are described with reference to a scheme in which compartmental and subcompartmental selector genes are thought to determine a binary code on which AO patterns depend.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/dvg.1020020107
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  • 7
    Electronic Resource
    Electronic Resource
    Tentacular and oral-disc regeneration in the sea anemone, Aiptasia diaphana. I. Sequential morphological events in distal-end restitutionThis work was supported by National Science Foundation grant GB-5045 and National Institutes of Health Bio-Medical Sciences Support grant to NYU. (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 373-381 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The complete regeneration of a new oral-disc and tentacles has been observed and described for Aiptasia diaphana. These structures are regenerated quite rapidly: seven to ten days at 20°C. At three days post-amputation, the new primary, secondary, and tertiary tentacle buds begin to develop in direct association with the underlying primary, secondary, and tertiary septae (respectively) of the column, suggesting that the latter organize the form of the regenerating oral-disc. Two days after amputation, the zooxanthellae of the presumptive oral disc arrange themselves into a ring which quite precisely delimits the area from which the tentacle buds will form. In spite of its suggestive proximity, this accumulation of algae plays no role in the induction of tentacle buds as was shown by studying regeneration in anemones which essentially lacked large quantities of these symbiotic algae.Cuts perpendicular to the longitudinal axis of the column result in an equal rate of tentacular regeneration around the entire circumference of the presumptive oral disc. Oblique amputations foster an asynchronous regeneration: the tentacle buds of the distal-most area of the severed column are larger and regenerate much sooner than those of the proximal region. Similar results were obtained by studying anemones which were cut perpendicular to their longitudinal axes at different levels along the column. The data suggest that an oral-aboral gradient exists concerning the time required for the initiation of tentacle budding and the rate of tentacle regeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270308
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  • 8
    Electronic Resource
    Electronic Resource
    Cell proliferation in Xenopus tissues: A comparison of mitotic incidence in vivo and in organ culture (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 363-372 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Using the Colcemid technique, the mitotic incidence (MI) was measured in the epidermis, lung, spleen, liver, kidney and ovarian follicular cells of metamorphosed, immature Xenopus laevis laevis. The MI was higher at 25°C than at 20°C, and there was a significant ranking correlation between organs in respect of the MI in different animals. With the exception of the liver and kidney, organ cultures showed good preservation for up to six days in vitro using a medium supplemented with 10% fetal calf serum, and values for MI comparable with or even higher than in vivo were obtained.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270307
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  • 9
    Electronic Resource
    Electronic Resource
    Comparative analysis of the development of the lizard, Liolaemus tenuis tenuis. II. A series of normal postlaying stages in embryonic development (1981)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 169 (1981), S. 337-349 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this work, we have completed a study of the development of the ovoviviparous lizard Liolaemus tenuis tenuis. Ovoviviparity in this lizard is a condition in which eggs are retained within the reproductive duct for about 60 days. During this period the phases of segmentation, gastrulation, neurulation, presomitic, and somitic embryos transpire. During the months of December and January the eggs are laid, and at this time the embryos are comparable to stage 27 Liolaemus gravenhorsti lizard embryos, or to stage 29 Calotes versicolor lizard embryos. Differentiation of the facial region occurs between Days 12 and 42 after egg laying. Limbs develop rapidly between the 8th and 23rd days. By 53 days the appendicular skeleton is completely formed. After 36 days the mesonephros begins to degenerate, and its function is gradually taken over by the developing metanephros. Newborn lizards do not possess an egg caruncle. During the period up to hatching, there is a great increase of liquid within the egg, presumably amniotic fluid. Cracks develop in the leathery shell shortly before hatching and are, perhaps, the first sign of the onset of hatching. Increase of liquid in the egg during postlaying development accounts for its increase in weight and change in shape. Weight of the embryo at hatching does not exceed 32% of the total weight of the egg.
    Additional Material: 27 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051690307
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  • 10
    Electronic Resource
    Electronic Resource
    Ultrastructure of human labial salivary glands. I. Acinar secretory cells (1969)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 127 (1969), S. 383-407 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structure of human labial salivary gland acini was studied by light and electron microscopy. Contrary to previous reports, these glands were pure mucous in nature; no serous elements were present. The acinar cells were found in all stages of maturation. Immature cells were characterized by an extensive and highly organized rough-surfaced endoplasmic reticulum. The Golgi complex was extremely prominent, consisting of stacks of flattened cisternae and swarms of small vesicles. Mucous droplets were almost completely absent. As secretory activity progressed, the endoplasmic reticulum involuted, while the Golgi cisternae became distended and formed many vacuoles. In mature mucous cells, the apical cytoplasm was filled with membrane-bounded mucous droplets, and the nucleus was displaced basally. The droplets frequently showed great variation in density from cell to cell, and even within the same cell they sometimes were quite heterogeneous. They were liberated from the acinar cells by an apocrine process, so that droplets with intact limiting membranes were often observed in the acinar lumen. These droplets soon lysed, their contents fusing into streams of mucus. Occasionally during apocrine secretion a mucous cell failed to reconstitute its apical surface, and its entire contents spilled into the acinar lumen.Unusual cytoplasmic inclusions were present in many of the acinar cells. These inclusions, which were surrounded by a single membrane, consisted of lipid droplets closely associated with bundles of fine filaments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051270402
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