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  • Articles  (225)
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  • Springer  (225)
  • Macmillan Magazines Ltd.
  • Oxford University Press
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  • 1
    ISSN: 1573-0832
    Keywords: ELISA ; Endodermis ; H. annosum ; Immunocytochemistry ; Root rot ; Vascular tissues
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Vascular disintegration mainly of medulla rays of spruce roots is of major significance in root rot disease of spruce caused byH. annosum. Using seedling roots as an experimental model, the possible routes and initial host reactions preceding invasion of vascular tissues was investigated. Transmission electron microscopy showed that penetration through the endodermis was an obvious route but not without host resistance. Using antibodies againstH. annosum hyphal materials, some labelling of vascular tissues remote from sites of fungal colonization suggest the release of fungal secretory products partly active in tissue disintegration. Similarly, intense labelling was also observed in severely colonized host tissues at late stages of infection. Strong labelling recorded at 3 d p.i. mainly on fungal hyphae and scant gold particles on invaded host tissues could imply that induction of host antifungal metabolites may have been a late event. A correlation was found between total antigenic material in root homogenates measured by ELISA, density of tissue labelling by immunocytochemistry and severity of disease symptoms. The importance of this in relation to diagnosis of biotic root rot diseases in the field is discussed.
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  • 2
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    Calcified tissue international 27 (1979), S. 33-40 
    ISSN: 1432-0827
    Keywords: Chick embryo ; Bone ; Organ culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The study describes the ultrastructure of the mineralized portion of chick tibiae from 10 days in ovo to 2 days post-hatch. At 10 days a single mineralized cylinder surrounds the diaphysis. On its outer surface columnar trabeculae join to form ridges parallel to the long axis of the bone. These ridges are covered by another cylinder and form the haversian canals. At 11 days vascular invasion of the marrow cavity occurs and resorption of the endosteal surface begins. This type of periosteal deposition and endosteal resorption is repeated during and subsequent to embryonic development. The mineralized portion of 10-day chick tibiae cultured for 2 days in modified BGJ medium was compared with 10-, 11-, and 12-day tibiae in ovo. Cultured tibiae were similar in length and calcium content to 11-day tibiae in ovo. The form of mineral deposited in ovo and in culture was the same, namely, aggregates of spherical mineral clusters. Differences in culture included the following: (a) few concentric cylinders were deposited as compared with tibiae in ovo; (b) trabeculae were not arranged in rows and ridges in culture; (c) osteocytic lacunae were restricted to bases of trabeculae rather than uniformly distributed as in ovo; and (d) the endosteal surface of tibiae in culture appeared etched.
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  • 3
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    Calcified tissue international 26 (1978), S. 237-241 
    ISSN: 1432-0827
    Keywords: Epiphyseal chondrocytes ; Freezefracture ; Scanning electron microscopy ; Cell processes ; Membrane particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Chondrocytes in epiphyseal cartilage were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using freeze-fracture techniques. Freeze-fracture replicas showed large numbers of fingerlike, 0.11–0.15 μm diameter, projections from the chondrocyte surface, with numerous 95–180 Å diameter intramembranous particles associated with both the cell membrane surface and these projections. With SEM, these cytoplasmic projections were also obvious, but appeared collapsed into clusters of globular-shaped projections on the surface of the chondrocytes. With freeze-fracture techniques, in which shrinkage artifacts were essentially eliminated, the cytoplasmic projections were often seen in intimate contact with the extracapsular matrix. However, with chondrocytes prepared by both SEM and conventional TEM, there was evidence of shrinkage, the cytoplasmic projections having little contact with the extracapsular matrix. These findings show that the cytoplasmic processes are not artifacts of tissue processing and provide morphological evidence in support of the hypothesis that matrix vesicles are of cellular origin.
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  • 4
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    Calcified tissue international 25 (1978), S. 75-83 
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
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  • 5
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    Calcified tissue international 24 (1977), S. 223-229 
    ISSN: 1432-0827
    Keywords: Enamel-cementum-morphology ; Immunocytochemistry ; Biochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The continuously erupting rabbit incisor tooth is normally thought of as having an enamel covered “crown” on its labial surface and a cementum covered “root” on its lingual surface. We have examined both surfaces of continuously erupting rabbit incisor teeth taken from near term embryos by a variety of means, including transmission and scanning electron microscopy, biochemical fractionation, and immunohistochemistry. In all cases, we could detect no qualitative difference in the early extracellular matrices taken from the labial and lingual surfaces of the teeth. Both matrices were shown to be composed of dentin and enamel, although the thickness and geometry of the enamel matrix on the lingual surface was somewhat different from that on the labial surface.
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  • 6
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    Cell & tissue research 200 (1979), S. 223-227 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Lacertilian reptiles ; Vasotocin neurons ; Mesotocin neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hypothalamic magnocellular neurosecretory system of lizards was studied with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique at the light microscopic level. It was shown that vasotocin and mesotocin are synthesized in separate neurons. The vasotocinergic as well as the mesotocinergic perikarya are of different sizes. Both cell types occur in close juxtaposition, but without a distinct pattern of distribution. The external zone of the lacertilian median eminence contains numerous immunoreactive vasotocinergic fibers and only few immunoreactive mesotocinergic fibers. The general organization of the hypothalamic magnocellular neurosecretory system of lizards, as revealed by immunocytochemistry, is essentially similar to that revealed with unspecific staining methods.
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  • 7
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Ecdysteroids ; Prothoracic gland ; Insect hormones ; Galleria mellonella
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fixation of prothoracic glands of Galleria mellonella with a solution containing saponin permits immunocytochemical staining of the entire gland. By this means ecdysteroids were demonstrated electron microscopically to be present in the hyaloplasm and microtubules.
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  • 8
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    Cell & tissue research 176 (1977), S. 493-504 
    ISSN: 1432-0878
    Keywords: Pancreas ; Acinar cells ; Cell surface ; Dissociation ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pancreatic acinar cell surfaces have been studied by SEM with a dissection technique and correlated with results obtained by TEM. The SEM results demonstrate characteristic arrangement of microplicae which in some areas are densely packed. In many areas, the microplicae are distributed in such a manner that they create zones with typical geometrical shapes and show a relatively smooth surface. These smooth areas may coincide, as indicated by correlated TEM results, with the limits of intimate contact between adjacent acinar cells which, in turn, represent part of the junctional complex. Another aspect revealed by these SEM preparations concerns the presence of groups of densely packed microplicae, arranged in regular rows and distributed along some grooves and/or infoldings of the cellular surface. On the basis of SEM and TEM information, it is likely that these structures correspond to intercellular (and possibly, in some cases, intracellular) canaliculi which topographically form a kind of extensive microlabyrinthine arrangement running along all the cell sides. One final point revealed by fractured samples concerns the finding of spherical zymogen droplets within the vesicles of the Golgi complex. Because in many scanning images these vesicles appear connected by small openings, it is suggested that they may represent a system of intercommunicating chambers (vacuoles) through which the zymogen droplets can be continuously accumulated and discharged into the acinar lumen.
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  • 9
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    Cell & tissue research 177 (1977), S. 307-316 
    ISSN: 1432-0878
    Keywords: Third ventricle ; Mature monkeys ; Scanning electron microscopy ; Ependyma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Surface features of the ependymal lining of the third ventricle in mature male and female monkeys have been investigated with scanning electron microscopy (SEM). Broad aspects of third ventricular morphology from three species of monkey are similar regardless of sex. The lateral walls are heavily ciliated whereas the ventral floor and most ventral parts of the lateral walls are not. Clumps of cilia on the lateral walls are so dense that underlying surface details are usually obscured. There is a transition zone between the ciliated lateral wall and nonciliated ventral floor. The floor and lower part of the lateral walls of the third ventricle exhibit a characteristic polygonal pattern upon which surface specializations such as microvilli, blebs and polymorphous membrane protrusions are superimposed. Ependyma of the choroid plexus of the third ventricle also display membrane specializations. Supraependymal cells are more visible in nonciliated regions.
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  • 10
    ISSN: 1432-0878
    Keywords: Enkephalin neurons ; Vasotocin neurons ; Isotocin neurons ; Immunocytochemistry ; Goldfish (Carassius)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Our immunocytochemical investigation of the magnocellular neuroendocrine system in the goldfish hypothalamus reveals enkephalin (ENK)-containing neurons interspersed among the vasotocin (VT)- and isotocin (IT)-containing neurons of the preoptic nucleus. The perikarya of the ENK, VT, and IT neurons do not show distinct morphological differences at the level of light microscopy and are not located preferentially within the nucleus. Separate ENK, VT and IT fibers course laterally and ventrally through the hypothalamus as they descend toward the pituitary gland. All three fiber types form terminals around blood vessels in the neurohypophysis.
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  • 11
    ISSN: 1432-0878
    Keywords: Pancreatic polypeptide (PP) ; Neurones ; Central nervous system ; Peripheral nervous system, gut ; Immunocytochemistry ; Mammals ; Birds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pancreatic polypeptide (PP) is a candidate hormone of unknown physiological significance. It is produced by a population of endocrine cells in the pancreas. In the present study a PP-like peptide was found to occur in the mammalian and avian central and peripheral nervous systems. Immunoreactive nerve fibres and nerve cell bodies were widely distributed in the brain. Dense accumulations of nerve fibres occurred in the following areas: nucleus accumbens, interstitial nucleus of the stria terminalis, para- and periventricular hypothalamic nuclei, and medial preoptic area. In addition, nerve fibres were regularly seen in cortical areas. Immunoreactive perikarya were observed in the following regions: cortex, nucleus accumbens, neostriatum and septum. In the gut, immunoreactive nerve fibers were distributed in the myenteric plexus, in smooth muscle, around blood vessels, and in the core of the villi. Immunoreactive perikarya occurred in the submucosal and myenteric plexus, suggesting that PP immunoreactive nerves are intrinsic to the gut. In the species examined, the neuronal PP-like peptide could be demonstrated with an antiserum raised against avian PP, but not with those raised against bovine or human PP. Thus, neuronal PP is distinct from the PP that occurs in pancreatic endocrine cells.
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  • 12
    ISSN: 1432-0878
    Keywords: Pituitary ; Dexamethasone ; ACTH ; Autoradiography ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 3H-Dexamethasone (10 μg/kg) was injected intravenously in adrenalectomized rats and after survival times of 5, 30, 60, and 180 min its uptake within the pituitary was studied by autoradiography. Radioactivity was concentrated in cell nuclei in the pars nervosa and pars distalis. Within the pars intermedia, only cells of the marginal zone were labeled. In the pars distalis, some cells showed a weak nuclear accumulation of radioactivity as early as 5 min after injection. The tissue radioactivity was nearly maximal at 5 min, and the proportion of radioactivity in nuclei reached a maximum of 60–70% by 30 min. In competition experiments, non-radioactive steroids (1 mg/kg) were injected 5 min before 3H-dexamethasone and sacrifice was 30 min later. Dexamethasone markedly diminished the nuclear accumulation in the pars distalis, but corticosterone and progesterone did not. In the pars nervosa, corticosterone and progesterone competed for nuclear uptake of 3H-dexamethasone, although less effectively than dexamethasone itself. Different cell types in the pars distalis were characterized by treating autoradiograms with an immuno-peroxidase bridge procedure. Cells treated with anti-ACTH 17–39 had the greatest nuclear concentration of radioactivity, and those stained with anti-TSH were least heavily labeled. Cells treated with antisera to GH, PRL, and hCG were moderately labeled.
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  • 13
    ISSN: 1432-0878
    Keywords: Blood vessels ; High voltage electron microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The luminal surface features and Junctional complexes from developing blood vessels in the rat central nervous system have been studied by high-voltage electron microscopy and scanning electron microscopy. Developing blood vessels exhibit three types of luminal projections; marginal folds or ridges at Junctional complexes, ridges not at Junctional complexes and microvilli. Both types of ridges are associated with troughs or depressions in the luminal surface of the endothelial cell. Those ridges not associated with Junctional complexes take part in the production of enclosed tunnels in the endothelial cell cytoplasm. Fusion of the external leaflets of Junctional complexes between adjacent endothelial cells occurred, initially, near the luminal surface of the blood vessel with other small fusion sites forming in the direction of the basal lamina secondarily. Further fusion activity to produce the zonula occludens type junction appeared to spread outwards from the smaller fusion sites.
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  • 14
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    Cell & tissue research 178 (1977), S. 17-38 
    ISSN: 1432-0878
    Keywords: Myosin ; Immunocytochemistry ; Adrenal medulla ; Exocytosis ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Myosin was isolated in high purity from the bovine adrenal medulla by gel filtration and ion exchange chromatography. The purified myosin was analyzed by electrophoresis in gels containing SDS and found to contain a 200,000 molecular weight heavy chain and major light chains of molecular weights 20,000 and 17,000 in a 1∶1∶1 molar ratio. At high ionic strength the myosin had high Ca-ATPase and K-EDTA-ATPase activities and low Mg-ATPase activity. At low ionic strength, the Mg-ATPase was activated to a low level by rabbit muscle actin. The myosin was found to decorate F-actin in the absence, but not the presence of ATP. In low ionic strength solutions, the myosin assembled into characteristic bipolar filaments. The distribution of this myosin in the adrenal medulla and of cross-reacting myosin in several other bovine tissues was determined with the use of antimedullary myosin immunoglobulin G as a specific stain that was detected by direct and indirect immunofluorescence. In the medulla strong staining was seen between the chords of chromaffin cells indicating the presence of a highly muscular vasculature that may perform functions analogous to those of the myoepithelium of exocrine glands. The chromaffin cells showed weak positive staining around the nuclei and in a pattern radiating toward adjacent blood vessels. Cells of the inner zone of the adrenal cortex showed strong staining in the peripheral cytoplasm while cells in the intermediate and outer zones did not stain. In a blood smear, platelets and the cytoplasm of leukocytes stained strongly while erythrocytes did not stain. In striated muscle and the gray and white matter of the cerebrum only the capillaries and larger vessels stained. In the liver the phagocytic cells bordering vascular sinuses stained strongly while the hepatocytes were separated from one another by a 2 micron trilaminar band possibly representing the microfilament web surrounding the bile canaliculi and associated with junctional complexes. The results suggest that myosin is present in several highly differentiated, non-motile tissue cells where it may play a role in secretion or other specialized functions.
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  • 15
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    Cell & tissue research 200 (1979), S. 29-33 
    ISSN: 1432-0878
    Keywords: Magnocellular neurosecretory system ; Activation ; Rat ; Vasopressinergic neurons ; Oxytocinergic neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The activated hypothalamic magnocellular neurosecretory system of the rat was studied in tissue sections, double stained with the unlabeled antibody peroxidase-antiperoxidase complex (PAP) technique. The results indicate that in animals with an activated hypothalamic magnocellular neuroendocrine system, as well as in normal animals, vasopressin and oxytocin are exclusively synthesized in separate vasopressinergic and oxytocinergic neurons.
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  • 16
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    Cell & tissue research 200 (1979), S. 409-423 
    ISSN: 1432-0878
    Keywords: Human placenta ; Classification of villi ; Histology ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The classification of human placental villi was reviewed on the basis of material prepared by means of special methods. The material from in situ normal-term placentae was biopsied by aspiration into glutaraldehyde. The classification was made on the basis of light-microscopic observations of semithin sections, reconstructions from serial sections, and scanning-electron micrographs. The peripheral villous tree is roughly divided into stem (ramuli), intermediate and terminal villi. The intermediate villi may be further subdivided as mature and immature types, which are found between the stem and terminal villi. Some of the terminal villi possess a local specialization described as the neck region. The histological characteristics and the branching pattern of each type are described, and the basis of the proposed classification is discussed.
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  • 17
    ISSN: 1432-0878
    Keywords: Pineal organ ; Uroloncha domestica (Aves, Passeriformes) ; Photoreceptor-like cells ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the pineal organ of the lovebird, Uroloncha domestica, bulbous, cup-shaped and elongated outer segments of photoreceptor-like pinealocytes are demonstrated by scanning electron microscopy. These scarce outer segments, 4–11 μm in length, extend into the pineal lumen. The present structural observations speak in favor of photosensitive pinealocytes in the pineal organ of Uroloncha domestica. The relation of the photoreceptor-like pinealocytes to acetylcholinesterase-positive nerve cells and a nervous connection between the pineal and the brain indicate that the pineal organ of this passeriform species may be the site of neuroendocrine and photoreceptive functions.
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  • 18
    ISSN: 1432-0878
    Keywords: Somatostatin ; Somatostatin cells ; Rat stomach ; Paracrine action ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Somatostatin cells in the stomach of the rat have a characteristic shape and distribution. In the antral mucosa they occur together with gastrin cells and enterochromaffin cells at the base of the glands. In the oxyntic mucosa they are scattered along the entire glands with some predominance in the zone of parietal cells. Throughout the gastric mucosa the somatostatin cells possess long and slender processes that emerge from the base of the cell and end in clublike swellings. Such processes appear to contact a certain proportion of neighbouring gastrin cells in the antral mucosa and parietal cells in the oxyntic mucosa. Exogenous somatostatin given by intravenous infusion to conscious rats counteracted the release of gastrin stimulated by feeding, elevated antral pH or vagal excitation. Gastrin causes parietal cells to secrete HCl and endocrine cells in the oxyntic mucosa to mobilise and synthesise histamine. Somatostatin is known to block the response of the parietal cells to gastrin. In contrast, somatostatin did not block the response of the histamine-storing endocrine cells to gastrin, perhaps because these endocrine cells lack receptors to somatostatin. Conceivably, somatostatin in the gastric mucosa has a paracrine mode of action. The observations of the present study suggest that somatostatin may affect some, but not all of the various cell types in the stomach. Under physiological conditions this selectivity may be achieved in the following ways: 1) Communication may be based on direct cell-to-cell contact. 2) Only certain cell types are supplied with somatostatin receptors.
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  • 19
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    Cell & tissue research 186 (1978), S. 399-412 
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Dog ; Pars distalis ; Thyrotropin (TSH) ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using the immunoperoxidase technique and antisera to the specific beta (β) subunits of bovine and rat TSH1, selective immunocytochemical staining was localized in a specific cell population in the pars distalis of the dog pituitary gland. These TSH cells were found to be positive to aldehyde fuchsin, alcian blue, periodic acid-Schiff (PAS) and aniline blue. With the performic acidalcian blue (pH 0.2) -PAS-orange G procedure these cells stained blue-purple, demonstrating FSH/LH cells (blue or turquoise), ACTH/MSH cells (redpurple) and PRL cells (orange-red). The TSH cells were further differentiated from other functional cell types of the pars distalis on the basis of their typical cytological features, intraglandular distribution and by immunocytochemical double staining. In the pars distalis of adult male dogs the TSH cells were mostly shown to be smaller in size and less numerous than in bitches in the anestrous phase of the sexual cycle. Moreover, cytological alterations in the immunoreactive thyrotrophs in the pituitary of male and female dogs generally paralleled the spontaneous changes in thyroid function associated with thyroid atrophy and/or pituitary insufficiency, and thyroid hyperplasia or goiter. In conclusion, because of their specificity and high potency, the antisera to the β-subunits of bovine and rat TSH represent an effective tool for the selective immunocytochemical localization of TSH in the dog pituitary. This allows the study of the morphology and function of TSH cells under different physiological, pathological and experimental conditions.
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  • 20
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    Cell & tissue research 187 (1978), S. 525-534 
    ISSN: 1432-0878
    Keywords: Salivary glands ; Insects ; Innervation ; Light microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the salivary gland of the cockroach Nauphoeta cinerea (Olivier) has been investigated with the use of light and scanning electron microscopy. Light microscopy of methylene blue stained glands reveals the presence of a dual innervation arising from the ventral nerve cord and the stomodeal nervous system; the principal innervation is that from the ventral nerve cord which passes to the gland via the reservoir ducts. Branches of these nerves form a plexus on the acinar surface, the axons of which exhibit swelling at irregular intervals. The presence of this surface plexus and the axonal swellings was confirmed by scanning electron microscopy both in normal glands and in those in which the basal lamina had been removed by means of an HCl-collagenase digestion method. No acinar plexus was seen to be formed by branches of the stomatogastric nerve that were associated with the gland. However, other branches of this nerve were clearly connected with a complex network of multipolar neurones on the surfaces of the anterior regions of both salivary reservoirs.
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  • 21
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    Cell & tissue research 188 (1978), S. 99-106 
    ISSN: 1432-0878
    Keywords: LHRH-neurosecretion ; Avian hypothalamus ; Vasotocin neurosecretion ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A fluorescent technique applying specific LHRH and vasotocin antisera was used for the immunocytochemical localization of the respective neurosecretory systems in the hypothalamus of gonadectomized, testosteronetreated and/or serotonin injected male domestic ducks. An immunoreactive (IR) LHRH-producing system, with perikarya located in the preoptic nucleus, could be traced through the ventral hypothalamus down to the external layer of the rostral and caudal ME, in close vicinity to the hypophysial portal system. An IR-vasotocin system originating in the paraventricular and supraoptic nuclei ran through the ventral hypothalamus, but terminated in (i) the external layer of the rostral ME, and (ii) in the posterior lobe of the hypophysis.
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  • 22
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    Cell & tissue research 188 (1978), S. 119-132 
    ISSN: 1432-0878
    Keywords: Neurophysin ; Paraventricular nucleus ; Supraoptic nucleus ; Sheep ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An antiserum cross-reactive against ovine neurophysins-I-II and -III has been used in conjunction with the immunoperoxidase histochemical procedure to localize the cells of the sheep paraventricular (PVN) and supraoptic nuclei (SON). In order to describe the topographical distribution of the SON and PVN a study was made on the serial sections cut (a) transversely from rostral to caudal positions and (b) sagittally from lateral to medial positions of the hypothalamus. The cells of the SON, when examined in the transverse aspect, extended approximately 1900 μ caudally and when examined in the sagittal plane were contained within a lateral-medial distance of 4830 μ. In each case the SON cells lay adjacent to the optic chiasm. As sections were cut transversely, the cells of the PVN first appeared in a rostral position defined as 0 μ and close to the ventral lining of the third ventricle. This general ventral and ventro-lateral distribution of cells maintained up to a caudal distance of approximately 840 μ. From positions 1260–2310 μ there was a dramatic dorsal shift of the PVN cells which by this time had also extended laterally. The total rostral-caudal distance occupied by the PVN cells was 3150 μ. That the lateral-medial distance occupied by the PVN was small (1050 μ) was determined on examining the magnocellular nuclei in sagittal section.
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  • 23
    ISSN: 1432-0878
    Keywords: Teleost ; Pars intermedia ; Immunocytochemistry ; PAP-technique ; MSH ; ACTH ; Endorphin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pars intermedia of S. mossambicus contains two different endocrine-cell types. The predominant cell type is lead-haematoxyline-positive and assumed to synthesize MSH and related peptides. The second cell type is PAS positive and its function and product(s) are unknown. Staining of light-microscopic and ultrathin sections with antisera against α-MSH, ACTH 1–24 and human β-endorphin revealed that only the lead-haematoxyline-positive cells of the pars intermedia react with these antisera, and that the secretory granules of these cells contain compounds that were immunoreactive to all three antisera. These findings are in line with the hypothesis that α-MSH, ACTH and endorphins are derived from the same precursor molecule. No specific reaction with one of the antisera could be detected in the PAS positive cells.
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  • 24
    ISSN: 1432-0878
    Keywords: Digestive tract ; Fish ; Gastrin-immunoreactive cells ; Pancreatic polypeptide-immunoreactive cells ; Somatostatin-immunoreactive cells ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gastrin, pancreatic polypeptide and somatostatin immunoreactive cells in the gut of two fish with stomachs (perch and catfish) and a stomachless fish (carp) were studied by immunocytochemistry. In the gastric mucosa of perch and catfish, cells showing gastrin and somatostatin-like immunoreactivity are found, scattered among the surface mucous cells and mucous neck cells. No pancreatic polypeptide (P.P.) immunoreactive cells are detected in the gastric mucosa. Cells showing gastrin and P.P.-like immunoreactivity are observed in the intestinal mucosa of perch, catfish and carp. In this location no somatostatin immunoreactive cells are found.
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  • 25
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    Cell & tissue research 189 (1978), S. 409-433 
    ISSN: 1432-0878
    Keywords: Rete testis ; Human ; Histophysiology ; Chordae retis ; Scanning electron microscopy ; Transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The human rete testis was examined with regard to 1) the number and distribution of entrances of seminiferous tubules, 2) the light microscopic topography and 3) details of the passages as revealed by scanning and transmission electron microscopy. In a newborn 1474 entrances were counted, approximately 50 % entering from the right and 50 % from the left of the central long axis. Three major subdivisions of the rete were distinguished and described: a septal (or interlobular) part represented by tubuli recti, a tunical (or mediastinal) part which is a true network of channels, and an extratesticular part characterized by dilatations (up to 3 mm wide) which we have called bullae retis. In SEM, cylindrical strands running from wall to wall in the tunical and extratesticular rete spaces are a prominent feature. We have called these chordae retis. They are covered by epithelium and are 5–40 μm wide and 15 to more than 100 μm long. They contain a peculiar tissue consisting of central myoid cells in a fibroelastic matrix. The smaller chordae are avascular. In the light of these findings the rete is interpreted as a highly complex myoelastic sponge. Its function is discussed.
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  • 26
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    Cell & tissue research 191 (1978), S. 539-548 
    ISSN: 1432-0878
    Keywords: Frog skin ; Respiratory capillaries ; Capillary networks ; Microcorrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Microcorrosion casts of blood vessels in the skin of Rana esculenta L. were examined by means of scanning electron microscopy with particular reference to the subepidermal network of respiratory capillaries. Due to the fact that arteries and veins lie in the deeper layers of the stratum spongiosum of the corium, the respiratory vessels form a morphologically homogeneous network. Functionally, however, this network is subdivided into small areas with a centripetal direction of blood flow. The deep capillary net, situated at the base of the stratum compactum of the corium, is not so dense as the respiratory network and does not directly communicate with it. Alveolar glands of the skin have no effect on the distribution of capillaries in the two networks.
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  • 27
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    Cell & tissue research 204 (1979), S. 147-153 
    ISSN: 1432-0878
    Keywords: Granulocytes ; Lymphocytes ; Monocytes ; Scanning electron microscopy ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Polymorphonuclear leukocytes, e.g., neutrophilic granulocytes, were enriched from heparinized blood by a Ficoll-step-gradient centrifugation procedure. Scanning electron microscopy (SEM) revealed a surface morphology of narrow ridge-like profiles and small ruffles with occasional microprocesses. Mononuclear leukocytes were isolated by centrifugation over a Ficoll-Metrizoat gradient. The lymphocytes showed varying numbers of microvilli of different length, size and shape. B lymphocytes, characterized by their capability of “sheep red blood cell (SRBC)-rosette formation”, displayed a similar surface morphology. Completely smooth lymphocytes, described in the literature as T lymphocytes, could not be detected, although many lymphocytes with few microprocesses were observed. Thus, SEM is not a useful tool for distinguishing between B and T lymphocytes in the peripheral blood of chickens. Monocytes were characterized by prominent membrane-like ruffles, but in some cases they closely resembled granulocytes. An influence of the various separation media on the surface morphology of the isolated cells could not be detected when compared with cells isolated by the buffy-coat method.
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  • 28
    ISSN: 1432-0878
    Keywords: α- and β-Endorphins ; Met-enkephalin ; Brain ; Immunocytochemistry ; Rana temporaria (Amphibia, Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the brain of Rana temporaria, two distinct systems reactive with α- and β-endorphin antisera, respectively, and with a met-enkephalin antiserum, have been detected immunohistochemically. Neurons reacting with α- and β-endorphin antisera are located (1) in the preoptic nucleus, and (2) in the pars ventralis of the tuber cinereum. Immunoreactive nerve fibres of both groups of perikarya end in the infundibular floor near the capillaries and the preoptico-hypophysial tract. Control reactions have shown that the immunoreactivity is suppressed by the corresponding antigens, but also by β-LPH. In view of these results the immunoreactive systems examined correspond to an α/β-endorphin system or a lipotropinergic system. Neurons reacting with the met-enkephalin antiserum are located in the paraventricular organ. Intense immunofluorescence was observed in the infundibular floor. Controls show that the labelling by met-enkephalin antiserum is exclusively suppressed by met-enkephalin. In the pituitary gland, on the other hand, α- and β-endorphin antisera reveal: 1) the MSH/ACTH-like cells of the pars intermedia and 2) the ACTH-like cells of the pars distalis.
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  • 29
    ISSN: 1432-0878
    Keywords: Oxytocin ; Neurophysin ; Vasotocin ; Mesotocin ; Suprachiasmatic nucleus ; Medial nucleus of the infundibular recess ; Immunocytochemistry ; Natrix maura (Serpentes) ; Mauremys caspica (Chelonia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The probable presence of oxytocin in the hypothalamo-hypophysial system of two reptilian species, the snake Natrix maura and the turtle Mauremys caspica, was re-investigated. A high-pressure liquid chromatographic analysis of the turtle neural lobe revealed the existence of vasotocin, mesotocin, and a third compound co-eluting with oxytocin. Brains from both species were fixed by vascular perfusion with Bouin's fluid. Adjacent paraffin sections were immunostained using antisera against the following substances: (1) bovine oxytocin-neurophysin; (2) a mixture of bovine oxytocin-neurophysin and vasopressin-neurophysin; (3) dogfish neurophysins; (4) oxytocin; (5) arginine-vasotocin; (6) mesotocin; (7) somatostatin. Immunoreactivity against oxytocin was found in parvocellular neurons of the snake suprachiasmatic nucleus and cerebrospinal-fluid contacting neurons of the medial nucleus of the infundibular recess of both species, the latter immunoreactivity being much more conspicuous in the turtle. Numerous fibers containing immunoreactive oxytocin extended between the medial nucleus of the infundibular recess, and the internal region of the medium eminence and the neural lobe. The oxytocin-immunoreactivity in all locations was completely abolished by preabsorption of the anti-oxytocin serum with three different oxytocin preparations. None of the neurons of the suprachiasmatic and medial nucleus of the infundibular recess, including the oxytocin-immunoreactive elements, reacted with either the antineurophysin sera used, or the anti-vasotocin or anti-mesotocin antibodies. The possible existence of a reptilian oxytocin-neurophysin is discussed. The alternative that, in the reptilian hypothalamus, neurons synthesize a compound closely related to, but different from oxytocin is also considered.
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  • 30
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Gonadotropin ; Subunits ; Gonadotropes ; Immunocytochemistry ; Immunoblotting ; Oncorhynchus mykiss (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Salmon gonadotropin (GTH II) is a heterodimeric glycoprotein hormone (α and IIβ subunits), serving as a maturational GTH, and is produced in a specific gonadotropic cell-type (GTH II-cells) containing small granules and large globules. In trout GTH II-cells, double immunolabeling for the α- and IIβ-subunits shows that colocalization of the α- and IIβ-immunolabeling is confined to the small granules, indicating storage of functional GTH II. On the other hand, α-immunolabeling is absent in the large globules, even though IIβ labeling is abundant throughout the period of seasonal gametogenesis. The α-specific antiserum recognizes the intact α-subunit as well as the reduced and deglycosylated α-subunits by immunoblotting. These results indicate that an accumulation of the IIβ-subunit is specifically generated in the large globules of these cells. In fact, with sexual maturity, the quantity of IIβ-subunits becomes elevated in the trout pituitary due to a marked increase in GTH II-cells containing many large globules. However, the derivation and function of the large globules and the fate of their contained IIβ-subunits remains unknown.
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  • 31
    ISSN: 1432-0878
    Keywords: Trans-differentiation ; Proliferation ; Bromodeoxyuridine ; Immunocytochemistry ; Regeneration ; Ciona intestinalis (Tunicata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In this study, we use three monoclonal antibodies that recognise antigens present in the central nervous system of the ascidian Ciona intestinalis to study regeneration and post-metamorphic development of the neural ganglion. We have also used bromodeoxyuridine labelling to study generation of the neuronal precursor cells. The first antibody, CiN 1, recognises all neurones in the ganglion, whereas the second, CiN 2, recognises only a subpopulation of the large cortical neurones. Western blotting studies show that CiN 2 recognises two membrane-bound glycoproteins of apparent Mr 129 and 100 kDa. CiN 1 is not reactive on Western blots. Immunocytochemical studies with these antibodies show that CiN 1-immunoreactive neurone-like cells are present at the site of regeneration as early as 5–7 days post-ablation, a sub-population of CiN 2-immunoreactive cells being detected by 9–12 days post-ablation. The third antibody, ECM 1, stains extracellular matrix components and recognises two diffuse bands on Western blots of whole-body and ganglion homogenates. The temporal and spatial pattern of appearance of CiN 1 and CiN 2 immunoreactivity both during post-metamorphic development and in regeneration occurs in the same sequence in both processes. Studies with bromodeoxyuridine show labelled nuclei in some neurones in the regenerating ganglion. Plausibly these originate from the dorsal strand, an epithelial tube that reforms by cell proliferation during the initial phases of regeneration. A second population of cells, the large cortical neurones, do not incorporate bromodeoxyuridine and thus must have been born prior to the onset of regeneration. This latter finding indicates a mechanism involving trans-differentiation of other cell types or differentiation of long-lived totipotent stem cells.
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  • 32
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    Cell & tissue research 280 (1995), S. 541-548 
    ISSN: 1432-0878
    Keywords: Key words: Musle ; striated ; skeletal ; Regeneration ; Myosin ; Immunocytochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Indirect immunofluorescence was used to localize embryonic myosin heavy chains in soleus, adductor longus, tibialis anterior, plantaris, and extensor digitorum longus muscles of 6-month-old rats. A monoclonal antibody (2B6), specifically recognizing rat embryonic myosin, was applied to unfixed, transverse, frozen sections. The number of embryonic myosin-positive (EMP) extrafusal fibers was expressed as a percentage of the total number of fibers. EMP extrafusal fibers were only seen in the soleus and adductor longus muscles, both postural muscles. Approximately 1% of the soleus muscle fibers appeared positively stained for embryonic myosin. The majority of such fibers had a small diameter (〈500 μ2), appeared intensely fluorescent, and typically contained central nuclei. Re-expression of embryonic myosin due to spontaneous fiber denervation is not a likely factor in this study, since alpha-bungarotoxin and N-CAM localization were restricted to the motor end-plate region of EMP fibers. Since embryonic myosin was shown to disappear in all normal-sized myofibers by 2 to 3 months of age, the results suggest that the EMP extrafusal fibers seen in postural muscles of 6 to 12-month-old animals are regenerating myofibers. We speculate that a small number of muscle fibers may be regenerating in normal, adult postural muscles, in response to fiber damage possibly caused by excessive recruitment or overloading.
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  • 33
    ISSN: 1432-0878
    Keywords: Key words: Melanin-concentrating hormone ; Immunocytochemistry ; Development ; ontogenetic ; Sparus auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The development of the hypothalamic melanin-concentrating hormone (MCH) system of the teleost Sparus auratus has been studied by immunocytochemistry using an anti-salmon MCH serum. Immunoreactive perikarya and fibers are found in embryos, larvae, and juvenile specimens. In juveniles, most labeled neurons are present in the nucleus lateralis tuberis; some are dispersed in the nucleus recessus lateralis and nucleus periventricularis posterior. From the nucleus lateralis tuberis, MCH neurons project a conspicuous tract of fibers to the ventral hypothalamus; this penetrates the pituitary stalk and reaches the neurohypophysis. Most fibers end close to the cells of the pars intermedia, and some reach the adenohypophysial rostral pars distalis. Immunoreactive fibers can also be seen in extrahypophysial localizations, such as the preoptic region and the nucleus sacci vasculosi. In embryos, MCH-immunoreactive neurons first appear at 36 h post-fertilization in the ventrolateral margin of the developing hypothalamus. In larvae, at 4 days post-hatching, perikarya can be observed in the ventrolateral border of the hypothalamus and in the mid-hypothalamus, near the ventricle. At 26 days post-hatching, MCH perikarya are restricted to the nucleus lateralis tuberis. The neurohypophysis possesses MCH-immunoreactive fibers from the second day post-hatching. The results indicate that MCH plays a role in larval development with respect to skin melanophores and cells that secrete melanocyte-stimulating hormone.
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  • 34
    ISSN: 1432-0878
    Keywords: Key words: Neuropeptide Y ; Gastroenteropancreatic (GEP) endocrine system ; Development ; ontogenetic ; Vitellointestinal duct ; Pancreas ; exocrine ; Pancreas ; endocrine ; Immunocytochemistry ; Scyliorhinus torazame (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. This immunocytochemical study was carried out to elucidate the ontogenetic development of neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system of the cloudy dogfish, Scyliorhinus torazame. Immunostained cells first appeared in the pancreas of the embryo at the 15-mm stage, and were also detected in the vitellointestinal duct of the yolk stalk at the 20-mm stage. These cells were polymorphic, with occasional processes that were sometimes directed toward the vascular wall or into the cavity of the vitellointestinal duct. At the 34-mm stage, immunostained cells could also be found in the proximal part of the spiral intestine and, by the 74-mm stage, immunopositive cells were present in the gastric mucosa. In the gut and pancreas, the cells gradually increased in number with development, whereas in the vitellointestinal duct and internal yolk sac, they decreased and seemed to disappear following hatching. Thus, in juveniles, the distribution of the neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system had attained that of adults. Electron-microscopic immunocytochemistry demonstrated that, in the labeled cells of the vitellointestinal duct, the neuropeptide Y-like antigen was located in cytoplasmic granules, as in the cells of the gut and pancreas.
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  • 35
    ISSN: 1432-0878
    Keywords: Key words: Esophagus ; Epithelial cells ; Intestinal lectin ; L-36 ; RI-H fragment ; Immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Using an affinity purified antibody raised against the RI-H fragment of rat intestinal lectin L-36, the latter protein has been identified within the esophageal epithelium by means of ultracryotomy followed by immunogold labeling. The epithelium consists of 4 morphologically distinct cell-types, namely, the basal, spiny, granular and squamous cells, and each of these exhibits a different immunolabeling pattern. The basal cells form a layer on the basal lamina, and in these a diffuse cytoplasmic staining is observed. This basal cell layer is overlaid by spiny cells that extend many cell processes into wide intercellular spaces. In these cells, immunogold particles are found only on small granular inclusions consisting of an electron-lucent homogeneous substance. The granular cells form a third layer over the spiny cells, and are characterized by a number of large granular inclusions with an electron-dense core rimmed by a less electron-dense substance. Immunogold labeling is found on these granules, both on the core and peripheral region. Squamous cell-types constitute the most superficial layer of the epithelium. They are without granular inclusions, and immunogold labeling is confined to the cytoplasmic surface of the thickened plasma membrane. These findings suggest that L-36 is produced in the basal cells as free cytosolic protein, then becomes progressively aggregated into the granular inclusions of the spiny and granular cells, and is eventually transferred onto the cytoplasmic surface of the squamous cell plasma membrane where it may interact with complementary glycoconjugate(s) located at this site. The membrane lining substance thus formed may play a role in stabilizing the squamous cell membranes, thereby maintaining the structural integrity of the epithelium against mechanical stress coming from the esophageal lumen.
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  • 36
    ISSN: 1432-0878
    Keywords: Key words Estrogen receptor ; Progesterone receptor ; Gonadotropin-releasing hormone ; Preoptic area ; Hypothalamus ; Immunocytochemistry ; Mink (Mustela vison)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The distribution of gonadal steroid (estrogen, progesterone) receptors in the brain of the adult female mink was mapped by immunocytochemistry. Using a monoclonal rat antibody raised against human estrogen receptor (ER), the most dense collections of ER-immunoreactive (IR) cells were found in the preoptic/anterior hypothalamic area, the mediobasal hypothalamus (arcuate and ventromedial nuclei), and the limbic nuclei (amygdala, bed nucleus of the stria terminalis, lateral septum). Immunoreactivity was mainly observed in the cell nucleus and a marked heterogeneity of staining appeared from one region to another. A monoclonal mouse antibody raised against rabbit uterine progesterone receptor (PR) was used to identify the PR-IR cells in the preoptic/anterior hypothalamic area and the mediobasal hypothalamus (arcuate and ventromedial nuclei). This study also focused on the relationship between cells containing sex-steroid receptors and gonadotropin-releasing hormone (GnRH) neurons on the same sections of the mink brain using a sequential double-staining immunocytochemistry procedure. Although preoptic and hypothalamic GnRH neurons were frequently in close proximity to perikarya containing ER or PR, they did not themselves possess receptor immunoreactivity. The present study provides neuroanatomical evidence that GnRH cells are not the major direct targets for gonadal steroids and confirms for the first time in mustelids the results previously obtained in other mammalian species.
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  • 37
    ISSN: 1432-0878
    Keywords: Key words Immunochemistry ; Chromatography ; Immunocytochemistry ; PACAP ; VIP ; CGRP ; NOS ; GRP ; Gastointestinal tract ; Capsaicin ; Denervation ; Rat (Sprague Dawley ; Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The expression of pituitary adenylate cyclase activating polypeptide (PACAP) was studied in the gastrointestinal tract (GI-tract) of normal rats using radioimmunoassay, chromatography, immunocytochemistry, and in situ hybridization. PACAP-38, PACAP-27, and PACAP-related peptide were demonstrated in all parts of the GI-tract, PACAP-38 being the predominant form confirmed by chromatography. PACAP-immunoreactive nerve fibers and nerve cell bodies were found in the myenteric ganglia throughout the GI-tract. PACAP-containing nerve cell bodies were also demonstrated in the submucous ganglia of the small and large intestine. The synthesis of PACAP in intrinsic neurons was confirmed by in situ hybridization. Double immunostaining showed that PACAP is present in calcitonin gene-related peptide-containing sensory nerve fibers as well as in vasoactive intestinal polypeptide (VIP)- or VIP/gastrin-releasing peptide (GRP)-containing (intramural) nerve fibers in the upper GI-tract and in anally projecting, intrinsic VIP-and VIP/nitric oxide syntase-containing nerve cell bodies and nerve fibers in the small and large intestine. Neonatal treatment with capsaicin significantly reduced the concentration of PACAP-38 in the esophagus, stomach, and colon. Extrinsic denervation decreased the PACAP-38 concentration in the stomach, while no change was observed in the small intestine. These results indicate that PACAP- immunoreactive nerve fibers in the GI-tract originate from both intrinsic (enteric) and extrinsic (presumably sensory) sources suggesting that PACAP may have diverse gastrointestinal functions.
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  • 38
    ISSN: 1432-0878
    Keywords: Key words: Leu-callatostatins ; Callatostatins ; Allatostatins ; Neuropeptides ; Peptide purification ; Immunocytochemistry ; Myoinhibition ; Codling moth ; Cydia pomonella (Tortricidae: Lepidoptera) (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. A neuroendocrine peptide of the Leu-callatostatin family, LPVYNFGL-NH2, has been isolated from tissue extracts of 5th instar larvae of the codling moth, Cydia pomonella (Lepidoptera). It is identical to a peptide previously isolated from the blowfly, Calliphora vomitoria (Diptera). The distribution of this peptide within the tissues of C. pomonella has been mapped by immunocytochemistry using antisera raised against LPVYNFGL-NH2. Midgut endocrine cells contain Leu-callatostatin immunoreactivity, as do several paired Leu-callatostatin neurones in the brain and ventral nerve cord. Within the visceral nervous system, the frontal ganglion contains four Leu-callatostatin neurones. Axons from these cells combine with others originating from neurones in the brain and project within the nervi cardiostomatogastrici to innervate the tissues of the foregut. In particular, the oesophageal valve has a prominent ring of Leu-callatostatin-immunoreactive fibres. The synthetic peptide, LPVYNFGL-NH2, has a potent reversible inhibitory effect in vitro on all visible forms of spontaneous contractile activity of the foregut, including closure of the oesophageal valve. Complete myoinhibition is observed at peptide concentrations from 10−10 to 10−16 M. These results, in conjunction with the results of similar studies on cockroaches, crickets and flies, suggest that the Leu-callatostatins are a ubiquitous family of insect neuroendocrine peptides with an important role in the control of gut motility.
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  • 39
    ISSN: 1432-0878
    Keywords: Key words: Pineal organ ; Pinealocytes ; Pineal photoreceptors ; Sensory structures ; Photopigment ; Pinopsin ; Immunocytochemistry ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Pinopsin is a photoreceptive molecule cloned from the chicken pineal organ. An antibody highly specific for pinopsin was applied in light- and electron-microscopic immunocytochemical studies of the pineal organ of 1 to 2-month-old chickens. Intense immunoreactivity was found in the follicular lumen at the light-microscopic level. In addition, small immunoreactive spherical or fibrous structures were diffusely distributed at the parafollicular aspect of the pineal organ. To identify immunoreactive elements precisely, we used pre-embedding immunoelectron microscopy. These studies revealed immunoreactive outer segments of pinealocytes arranged closely side by side in the follicular lumina. The thin initial portion of the outer segment arose from a basal body located in the inner segment. Immunoreactive pear-shaped outer segments occupied small lumina. Follicular lumina displayed immunonegative arrays of whorl-like lamellar membranes. Occasionally, these immunonegative structures were surrounded by immunoreactive concentric lamellar complexes. In the parafollicular pineal parenchyma, long slender cilium-like structures or enlarged cilia and concentric lamellar arrays showed intense immunoreactivity. All immunoreactive structures observed in this study were considered to represent outer segments of pinealocytes of the chicken pineal organ.
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  • 40
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    Cell & tissue research 289 (1997), S. 265-274 
    ISSN: 1432-0878
    Keywords: Key words: Retina ; Amacrine cells ; Neurotransmitters ; Immunocytochemistry ; Tyrosine hydroxylase ; Dopamine ; Ichthyophis kohtaoensis (Gymnophiona)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Ichthyophis kohtaoensis, a member of the limbless Gymnophiona, has a specialized subterranean burrowing mode of life and a predominantly olfactory-guided orientation. The only visually guided behavior seems to be negative phototaxis. As these animals possess extremely small eyes (only 540 μm in diameter in adults), functional investigations of single retinal cells by electrophysiological methods have so far failed. Therefore, the content and distribution of retinal transmitters have been investigated as indications for a functioning sense organ in an animal that is supposed to be blind. In this study, the organization and development of the dopaminergic system have been examined in the retinae of embryonic, larval, and adult I. kohtaoensis, by using an antiserum against tyrosine hydroxylase, the rate-limiting enzyme in the catecholamine synthetic pathway, and an antiserum against dopamine itself. Labeled somata are situated in the inner nuclear layer and in the ganglion cell layer. Dopamine-positive fibers form a dense diffuse plexus, that covers the whole inner plexiform layer, whereas tyrosine hydroxylase-immunoreactive processes show a tendency to arborize in a stratified manner. Tyrosine-hydroxylase-immunolabeled fibers can occasionally be observed in the optic nerve head of larval stages. During ontogenesis and larval development, the distribution of transmitter-expressing cells changes and their number decreases, but no general degeneration of the visual system is detectable. Adult Ichthyophis still have retinal transmitters, indicating that the eyes, although obviously playing a minor role in a subterranean ecological niche, retain all the elements of functioning sense organs.
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  • 41
    ISSN: 1432-0878
    Keywords: Key words: Intracardiac neurones ; Innervation ; Heart ; Neuropeptide Y ; Immunocytochemistry ; Electron microscopy ; Rat (Sprague Dawley) ; Guinea-pig (Dunkin Hartley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Intrinsic neuropeptide Y-containing neurones in rat and guinea-pig hearts were studied at the ultrastructural level by the pre-embedding peroxidase-antiperoxidase immunocytochemical technique. Intracardiac neuronal cell bodies were often weakly or moderately immunostained, and the labelling was usually pronounced in the Golgi complex, multivesicular bodies, some cisterns of granular endoplasmic reticulum and large granular vesicles. Neuropeptide Y-immunoreactive nerve fibres were also observed in association with intracardiac neurones. A subpopulation of neuropeptide Y-immunoreactive granule-containing cells in the rat heart are described for the first time and were very heavily labelled; other granule-containing cells were non-immunoreactive, but were contacted by neuropeptide Y-containing nerves. Preterminal regions of nerve fibres that were located in nerve bundles were only weakly neuropeptide Y-immunoreactive, in contrast to the heavy labelling observed in varicosities that contained many synaptic vesicles. Many neuropeptide Y-immunoreactive nerve fibres were associated with the coronary vasculature and were particularly prominent in the walls of small arteries and arterioles where labelled nerve varicosities were present close to the smooth muscle cells. Immunoreactive nerves were also seen in the myocardium, usually near to capillaries. In axonal varicosities, the central core of large granular vesicles was immunolabelled, and electron-dense immunoreactive material outlined the membranes of small and large clear vesicles. The significance of neuropeptide Y-immunoreactive intracardiac neurones and granule-containing cells and the origin of associated labelled nerve fibres in the heart are discussed.
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  • 42
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    Cell & tissue research 201 (1979), S. 315-325 
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Post-natal development ; Neurohypophysial peptides ; Magnocellular and parvocellular neurons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunocytochemical localization of vasopressin (VP), oxytocin (OXY) and neurophysins I and II (NI and NII) in the hypothalamus of growing rats revealed several new features. Hormones and neurophysins were present in magnocellular neurons of newborn rats: VP and NII in a first neuronal population, OXY and NI in a second neuronal population. For the first three days after birth, the ratio of detected VP to detected NII increased whereas the ratio of detected OXY to detected NI appeared constant. It was obvious that maturation of the OXY/NI magnocellular system occurred later than maturation of the VP/NII magnocellular system. During the first three weeks of development, VP/NII fibres in the median eminence were separated into two distinct groups: the hypothalamo-neurohypophysial tract in the internal part of the median eminence, and pericapillary endings heavily loaded with VP and NII in the external part of median eminence. OXY/NI fibres did not show this particular distribution. Therefore, during this post-natal period, loading of infundibular VP endings was related to the increase of ACTH synthesis demonstrated by various authors. Therefore, we suppose that simultaneous participation of VP and corticotropin-releasing hormone does not only appear during experimental and chronic stimulation of ACTH synthesis (after adrenalectomy, for example) but that it also exists during physiological stimulation of corticotropic function. At birth, parvocellular suprachiasmatic neurons were devoid of VP and NIL A slight immunological reactivity appeared in 6-to 10-day-old rats and it became equivalent to the immunological staining in the adult rat during the third post-natal week. Thus, the appearance of suprachiasmatic VP preceded the differentiation of the rhythmic activity of the pituitary adrenal axis. These chronological relationships suggest the involvement of the suprachiasmatic VP-related-peptide in the circadian periodicity of the corticotropic function.
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  • 43
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    Cell & tissue research 201 (1979), S. 349-359 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Rat ; Somatostatin-containing neurons ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rat hypothalamus was studied at the light microscopic level with the use of single and double immunocytochemical staining methods. It was shown that the rat supraoptic and paraventricular hypothalamic nuclei, and their accessory neurosecretory nuclei, do not contain magnocellular somatostatin neurons. The distribution of the hypothalamic parvocellular somatostatin cells is described. The parvocellular component of the rat hypothalamic paraventricular nucleus is, at least partly, composed of somatostatin cells: they form a fairly well circumscribed periventricular cell mass. The rat suprachiasmatic nuclei contain separate somatostatin neurons and vasopressin neurons. Scattered somatostatin cells are present in the entire arcuate nucleus. In addition to the periventricular somatostatin cells located in the preopticanterior hypothalamic area and in the arcuate nucleus, the rat hypothalamus also contains numerous scattered somatostatin cells located distant from the third ventricle.
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  • 44
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Vasopressin ; Oxytocin ; Somatostatin ; Luteining hormone releasing hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hypothalamic hormones arginine-vasopressin (AVP), oxytocin (OXT), somatostatin (SOM), and luteinizing hormone-releasing hormone (LHRH) were localized in the rat neurohypophysis by the use of semithin serial sections and the unlabeled antibody enzyme method. Clusters of AVP fibres are present within the central region of the neural lobe, clusters of OXT fibres mainly in the peripheral part. The AVP fibres enter bilaterally into the neural lobe. The results call into question previous reports on the presence of AVP on receptors in the pars intermedia cells, since incubation with anti-AVP resulted in similar staining in the pars intermedia of the Wistar and homozygous Brattleboro rat, a mutant strain deficient in AVP. The same intermediate lobe cells are stained after incubation of serial sections with anti-AVP and anti-α-melanocyte-stimulating hormone (α-MSH). This staining of anti-AVP could be removed by solid phase absorption to α-MSH and is thus most probably due to cross reaction with α-MSH. SOM fibres appear to be present in the peripheral parts of the proximal neurohypophysial stalk and mainly lateral in its more distal parts. In the neural lobe they rapidly decrease in number, although some fibres continue into the distal part of the neural lobe, running bilaterally and situated adjacent to the pars intermedia. The SOM staining within magnocellular elements, which has been reported in the literature, can most probably be explained by cross reaction of anti-SOM with neurophysins. LHRH fibres are very scarce in the neurohypophysial stalk and absent in the neural lobe.
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  • 45
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; ACTH ; Lymnaea stagnalis ; Neurohormone ; Neurotransmitter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two giant neurons (diameter 130 μm) were identified immunocytochemically by means of the unlabeled antibody enzyme technique with anti ACTH 1–39 and 1–24 in the pond snail Lymnaea stagnalis. The cells are located in the visceral and the right parietal ganglion, respectively. They contain moderately electron dense elementary granules (diameter 150–160 nm). By means of the intracellular horseradish peroxidase injection technique it was shown that the cells send fibres into the neuropiles of various ganglia and into nerves. Synapses occur on the fine fibre branches in the neuropile. Synapse-like structures were found on the cell bodies and on the major fibres. The giant neurons are electrotonically coupled. With toluidine blue staining for small peptides it was demonstrated that in the central nervous system of the pond snail numerous peptidergic neurons occur in addition to those identified with the classical staining methods for neurosecretion.
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  • 46
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    Cell & tissue research 187 (1978), S. 105-113 
    ISSN: 1432-0878
    Keywords: Mesonephros ; Lamprey ; Renal corpuscle ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The renal corpuscle of the lamprey mesonephros was studied under the scanning electron microscope. Bowman's capsules with individual spaces are chockshaped sacs closely packed together along a medial artery. The lateral walls of the capsules are apposed to those of neighbouring capsules. Glomerular capillaries from the medial artery extend radially between the apposed walls of neighbouring Bowman's capsules. Bulgings of capillaries into the capsular space are associated with mesangial folds of the capsular epithelium. The transitional zone of the visceral layer with podocytes and the parietal layer of squamous epithelium is bounded by linearly arranged rod-shaped epithelial cells. Apertures of the urinary tubule are lined by cells equipped with a fascicle of cilia.
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  • 47
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    Cell & tissue research 188 (1978), S. 375-388 
    ISSN: 1432-0878
    Keywords: Urinary bladder ; Skin ; Toad, frog ; Water flow ; Na transport ; Vasopressin ; Cytochalasin B ; Microfilaments ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A morpho-functional study of the effects of cytochalasin B (CB) on Na and water transport was made in amphibian epithelia. The functional studies confirmed the dissociation of the natriferic and hydrosmotic effects of vasopressin in toad urinary bladders exposed to CB and showed in addition that the block of the hydrosmotic effect was reversible and could still be induced in epithelia maximally stimulated with the hormone. Scanning electron microscopy revealed that CB, per se, did not alter the apical surface of the bladders. An almost total loss of microvilli of granular cells was seen, however, if CB was associated with vasopressin and an osmotic gradient. The results suggest two points: a) the block of the hydrosmotic flow induced by CB is due to factors beyond the apical membrane; b) microfilaments may be important mechanochemical transducers in the chain of events leading to the hydrosmotic effect of vasopressin.
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  • 48
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Biologically active peptides ; Lymnaea stagnalis ; Neurohormone ; Neurotransmitter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Perikarya and nerve fibers were immunocytochemically identified in the central nervous system of the pond snail Lymnaea stagnalis by means of the unlabelled antibody enzyme method with antisera to 15 biologically active peptides of vertebrates: vasopressin, vasotocin, oxytocin, α-melanocyte stimulating hormone (α-MSH), met-enkephalin, somatostatin, glucagon, insulin, glucose-dependent insulinotropic peptide (GIP), vaso-active intestinal polypeptide (VIP), gastrin, secretin, pancreatic polypeptide (PP), Substance P, calcitonin. No immunostaining was obtained with antisera to β-endorphin, cholecystokinin (CCK), neurophysin I and II. Particular neurons could be identified with two antisera (anti-vasopressin/vasotocin, anti-α-MSH/metenkephalin, anti-substance P/PP, anti-PP/gastrin). Apparently this indicates that populations of cells identified with a given antiserum may consist of more than one cell type. Only a few of the new peptidergic cells appeared to be identical with classical neurosecretory cells. Thus the growth hormone producing Light Green Cells stained with anti-somatostatin and the axon terminals of the ovulation hormone producing Caudo-Dorsal Cells with anti-met-enkephalin. Whether this indicates structural identity of the growth hormone with somatostatin and of the ovulation hormone with met-enkephalin remains to be investigated. Just like the classical neurosecretory cells a number of the new peptidergic cells (anti-glucagon, -insulin, -met-enkephalin, -somatostatin, and -PP positive cells) send their axons to the peripheries of commissures, connectives or nerves. Thus these cells can be considered as probably neuroendocrine. The classical neurosecretory cells release their products into the haemolymph from these sites. Other new peptidergic cells (e.g., anti-vasopressin, -vasotocin, -oxytocin and -GIP positive cells) have axons that terminate, probably synaptically, on other neurons, indicating that they are “more conventional” neurons, their products being neurotransmitters/neuromodulators. It can also not be excluded that some cells of a population containing a given peptide are neuroendocrine and others make contact with other neurons.
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  • 49
    ISSN: 1432-0878
    Keywords: Key words: Epididymis ; Efferent ducts ; Cell culture ; Immunocytochemistry ; Immunoprecipitation ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The way in which the human epididymis modifies spermatozoa during their sojourn in this structure might be clarified by knowledge of the nature of its secretions. We have examined the presence of several lysosomal hydrolases in human epididymal tissue and fluids, and their synthesis and secretion by monolayer cultures. Tissues were obtained from men undergoing orchidectomy for prostatic carcinoma. The enzymes cathepsin D and acid α-glucosidase were localised in the lysosomes of epithelial cells from the corpus epididymidis, by an immunocytochemical technique. Cathepsin D was also found in epithelial cells of the efferent ducts within lysosomes, apical vesicles and multivesicular bodies. No immunolocalisation of acid glucosidase in the efferent ducts or on the microvilli of the corpus was demonstrable. Cathepsin D, β-hexosaminidase (N-acetylglucosaminidase) and α-glucosidase were measurable in the luminal fluid from the human corpus epididymidis; β-hexosaminidase was secreted into the culture medium by confluent monolayers of epididymal and efferent duct cells. Immunoprecipitation of cell extracts and culture medium of these cultures incubated with 35S-methionine revealed that the precursors of cathepsin D and β-hexosaminidase were synthesized and secreted by such monolayers. Thus, active lytic enzymes are secreted by the human epididymis and could modify sperm membranes.
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  • 50
    ISSN: 1432-0878
    Keywords: Compound eye ; Photoreceptor cells ; Ion pumps ; Polarity ; Immunocytochemistry ; Manduca sexta (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunohistochemical and physiological studies on various insect photoreceptors have demonstrated that the Na,K-ATPase (sodium pump) is restricted to the nonreceptive nonmicrovillar area of the plasma membrane. Here, we examined the distribution of the Na,K-ATPase in photoreceptor cells of the superposition-type compound eye in the moth Manduca sexta. Using immunofluorescent and immunogold cytochemistry, we show that the Na,K-ATPase is localized to both the nonmicrovillar and the microvillar parts of the plasma membrane. Manduca photoreceptors thus deviate from the common concept that the sodium pump and the molecular components of the photoreceptive machinery reside on different domains of the plasma membrane.
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  • 51
    ISSN: 1432-0878
    Keywords: Neurohemal areas ; Neuropeptides ; Monoamines ; Immunocytochemistry ; Nervous system, insect ; Gryllus bimaculatus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The morphology and position of putative neurohemal areas in the peripheral nervous system (ventral nerve cord and retrocerebral complex) of the cricket Gryllus bimaculatus are described. By using antisera to the amines dopamine, histamine, octopamine, and serotonin, and the neuropeptides crustacean cardioactive peptide, FMRFamide, leucokinin 1, and proctolin, an extensive system of varicose fibers has been detected throughout the nerves of all neuromeres, except for nerve 2 of the prothoracic ganglion. Immunoreactive varicose fibers occur mainly in a superficial position at the neurilemma, indicating neurosecretory storage and release of neuroactive compounds. The varicose fibers are projections from central or peripheral neurons that may extend over more than one segment. The peripheral fiber varicosities show segment-specific arrangements for each of the substances investigated. Immunoreactivity to histamine and octopamine is mainly found in the nerves of abdominal segments, whereas serotonin immunoreactivity is concentrated in subesophageal and terminal ganglion nerves. Immunoreactivity to FMRFamide and crustacean cardioactive peptide is widespread throughout all segments. Structures immunoreactive to leucokinin 1 are present in abdominal nerves, and proctolin immunostaining is found in the terminal ganglion and thoracic nerves. Codistribution of peripheral varicose fiber plexuses is regularly seen for amines and peptides, whereas the colocalization of substances in neurons has not been detected for any of the neuroactive compounds investigated. The varicose fiber system is regarded as complementary to the classical neurohemal organs.
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  • 52
    ISSN: 1432-0878
    Keywords: Interleukin ; Stellate reticulum ; Immunocytochemistry ; Epidermal growth factor ; Interleukin-1 receptor type I messenger RNA ; Tooth eruption ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunolocalization of interleukin-1α in the first mandibular molars of rats from day 0–12 postnatally showed that the protein was localized in the epithelial stellate reticulum adjacent to the dental follicle. Staining of the stellate reticulum was most prominent in the early days postnatally and was absent by postnatal day 11. Injection of epidermal growth factor into rats at day 0 greatly increased the intensity of the staining for interleukin-1α in the stellate reticulum. Epidermal growth factor (EGF) enhanced the gene expression of interleukin-1α in stellate reticulum cells in vitro, and this study suggests there is enhanced translation of interleukin-1α messenger RNA in the stellate reticulum following EGF injection. In turn, the interleukin-1α may exert its effect on the dental follicle cells adjacent to the stellate reticulum because EGF also enhanced expression of the interleukin-1 receptor type I messenger RNA in cultured dental follicle cells as well as enhancing its expression in vivo. In view of the fact that injection of EGF will stimulate precocious eruption of teeth, its stimulus of interleukin-1α synthesis in the stellate reticulum may be the mechanism by which EGF initiates a cascade of molecular events to signal the onset of tooth eruption.
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  • 53
    ISSN: 1432-0878
    Keywords: Key words: Galectin ; β-Galactoside-binding lectin ; Human ; Skin ; Immunocytochemistry ; Immunohistochemistry ; Hybridization ; in situ ; Langerhans cell ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The localization of an endogenous 14-kDa β-galactoside-binding lectin (galectin) and its pattern of gene expression were examined in normal human skin by light- and electron microscopy. Under the light microscope, immunostaining of 14-kDa galectin was observed in the cell membrane of cells in the basal and spinous layers of the epidermis. Galectin was also found in the Langerhans cells, as shown by double labeling using anti-14-kDa galectin and anti-CD1a antibodi es. In the dermis, immunostaining for the 14-kDa galectin was positive in the extracellular matrix and fibroblasts. At the electron-microscopic level of resolution, galectin was located primarily along the plasma membrane of keratinocytes, and in both the cytoplasm and nucleus of Langerhans cells in the epidermis, whereas in the dermis it was detected in the extracellular matrix and in both the nucleus and cytoplasm of fibroblasts. The gene expression of 14-kDa galectin was visualized by the HRP-staining me thod following in situ hybridization techniques. The expression was detected in the cytoplasm of cells in the basal and spinous layers of the epidermis; whereas, in the dermis, it was detected in the cytoplasm of fibroblasts. Moreover, SDS-polyacrylamide gel electrophoresis and lectin-blot analysis revealed that this galectin bound to glycoproteins of approximately 17, 62, and 72 kDa in the epidermis and to those of 29, 54, and 220 kDa in the dermis. The present study indicates that 1) normal human skin produces the β-galactoside-binding 14-kDa galectin, and 2) this galectin is located in both the epidermis, particularly in the keratinocytes and Langerhans cells, and in the dermis. These results suggest that galectin is important for cell-cell contact and/or adhesion in the epidermis and for cell-extracellular matrix interaction in the dermis.
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  • 54
    ISSN: 1432-0878
    Keywords: Galectin ; β-Galactoside-binding lectin ; Human ; Skin ; Immunocytochemistry ; Immunohistochemistry ; Hybridization, in situ ; Langerhans cell ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The localization of an endogenous 14-kDa β-galactoside-binding lectin (galectin) and its pattern of gene expression were examined in normal human skin by light- and electron microscopy. Under the light microscope, immunostaining of 14-kDa galectin was observed in the cell membrane of cells in the basal and spinous layers of the epidermis. Galectin was also found in the Langerhans cells, as shown by double labeling using anti-14-kDa galectin and anti-CD1a antibodies. In the dermis, immunostaining for the 14-kDa galectin was positive in the extracellular matrix and fibroblasts. At the electron-microscopic level of resolution, galectin was located primarily along the plasma membrane of keratinocytes, and in both the cytoplasm and nucleus of Langerhans cells in the epidermis, whereas in the dermis it was detected in the extracellular matrix and in both the nucleus and cytoplasm of fibroblasts. The gene expression of 14-kDa galectin was visualized by the HRP-staining method following in situ hybridization techniques. The expression was detected in the cytoplasm of cells in the basal and spinous layers of the epidermis; whereas, in the dermis, it was detected in the cytoplasm of fibroblasts. Moreover, SDS-polyacrylamide gel electrophoresis and lectin-blot analysis revealed that this galectin bound to glycoproteins of approximately 17, 62, and 72 kDa in the epidermis and to those of 29, 54, and 220 kDa in the dermis. The present study indicates that 1) normal human skin produces the β-galactoside-binding 14-kDa galectin, and 2) this galectin is located in both the epidermis, particularly in the keratinocytes and Langerhans cells, and in the dermis. These results suggest that galectin is important for cell-cell contact and/or adhesion in the epidermis and for cell-extracellular matrix interaction in the dermis.
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  • 55
    ISSN: 1432-0878
    Keywords: Defence mechanisms ; Encapsulation ; Granulocytes ; Immunocytochemistry ; Parasitism ; Perkinsus sp. (Protozoa) ; Tapes semidecussatus (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Parasitosis by the trophozoite protozoan Perkinsus sp. (Apicomplexa, Perkinsea) induces in the gill filaments of the clam Tapes semidecussatus (Mollusca, Bivalvia) a cellular reaction, which is constituted by infiltrated granulocytes. This cellular reaction has characteristics of those of a holocrine gland, since the parasites are encapsulated by the secretion product of the granulocytes after cell death. An enriched fraction of prezoosporangia and their associated capsule was obtained after culture of the parasitized gills in fluid thioglycollate medium. Specific polypeptides from this fraction were separated by SDS-PAGE and isolated for rabbit immunizations. The serum obtained against an Mr 225 kDa polypeptide, revealed its exclusive localization in the capsule and in the granules of the infiltrated granulocytes, thus indicating that this polypeptide is synthesized by these cells and secreted, in a polarized way, around the trophozoites resulting in their encapsulation. Selective deglycosylation of the polypeptide, by Endo H and alkaline β-elimination, did not show an effect on its molecular weight or antibody recognition. Furthermore, the absence of the 225 kDa band in the Western-blots of non-parasitized gills indicated the specific association of this polypeptide with the parasitosis. Finally, this is the first tissue-specific factor described in molluscs in relation to defence mechanisms.
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  • 56
    ISSN: 1432-0878
    Keywords: Oocyte ; Yolk granules ; Ribonuclease ; Immunocytochemistry ; Bullfrog, Rana catesbeiana (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract To determine the localization of the pyrimidine-guanine sequence-specific ribonuclease in Rana catesbeiana (bullfrog) oocytes, the RNase was first isolated and used to prepare a specific rabbit antiserum. Only one protein of similar molecular size to the RNase was immunoprecipitated from ovary homogenate by the antiserum, but two bands were observed by Western blotting analysis. These two proteins were shown by further purification of antibody and Western blotting analysis to have similar antigenicity. Immunoprecipitation and Western blotting of tissue homogenates showed that the RNase was found predominantly in the ovary, but not in other tissues. The specific localization of the RNase was determined by immuno-electron microscopy of oocyte sections incubated with the specific antiserum; the yolk granules, but not other organelles, were found to contain the RNase. Most of the RNase was evenly distributed in the lateral amorphous area of the yolk granule but not in the central yolk crystal area which contains stored vitellogenin proteins. Our results indicate that the RNase is compartmentalized in the yolk granules of oocytes, which might prevent damage to cellular RNAs.
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  • 57
    ISSN: 1432-0878
    Keywords: Esophagus ; Epithelial cells ; Intestinal lectin, L-36 ; RI-H fragment ; Immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Using an affinity purified antibody raised against the RI-H fragment of rat intestinal lectin L-36, the latter protein has been identified within the esophageal epithelium by means of ultracryotomy followed by immunogold labeling. The epithelium consists of 4 morphologically distinct cell-types, namely, the basal, spiny, granular and squamous cells, and each of these exhibits a different immunolabeling pattern. The basal cells form a layer on the basal lamina, and in these a diffuse cytoplasmic staining is observed. This basal cell layer is overlaid by spiny cells that extend many cell processes into wide intercellular spaces. In these cells, immunogold particles are found only on small granular inclusions consisting of an electron-lucent homogeneous substance. The granular cells from a third layer over the spiny cells, and are characterized by a number of large granular inclusions with an electron-dense core rimmed by a less electron-dense substance. Immunogold labeling is found on these granules, both on the core and peripheral region. Squamous cell-types constitute the most superficial layer of the epithelium. They are without granular inclusions, and immunogold labeling is confined to the cytoplasmic surface of the thickened plasma membrane. These findings suggest that L-36 is produced in the basal cells as free cytosolic protein, then becomes progressively aggregated into the granular inclusions of the spiny and granular cells, and is eventually transferred onto the cytoplasmic surface of the squamous cell plasma membrane where it may interact with complementary glycoconjugate(s) located at this site. The membrane lining substance thus formed may play a role in stabilizing the squamous cell membranes, thereby maintaining the structural integrity of the epithelium against mechanical stress coming from the esophageal lumen.
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  • 58
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    Cell & tissue research 281 (1995), S. 101-108 
    ISSN: 1432-0878
    Keywords: Somite ; Intergin ; Extracellular matrix, structures ; Embryo ; Laminin ; Immunocytochemistry ; Macaca fascicularis (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of integrin subunits α6 and β1, and the α6β1 integrin ligand, laminin, was examined during somitogenesis in developmental stages 11, 13, and 16 in the long-tailed macaque, using peroxidase immunocytochemistry. Within differentiating somites in stage 11, α6 expression was observed in the sclerotome, basal surface of dermamyotomal cells adjacent to the basal lamina and on scattered cells throughout the dermamyotome. In further advanced somites in stages 13 and 16, α6 immunoreactivity become restricted to the myotome, α6 was expressed on mesenchymal core cells within the myocele of undifferentiated epitheliod somites and the ventromedial wall of somites commencing differentiation at each stage. β1 distribution resembled that of α6 in stage 11 somitic tissue, however, it remained present on myotome and sclerotome cells in the later stages, and was also expressed on dermatomal cells in stage 16. Laminin immunoreactivity, while more intense and prevalent than α6 and β1 in each stage examined, occurred on the same somite cell populations as the 2 integrin subunits. These results show a defined distribution of α6 on somitic tissue, and suggest this integrin is involved in somite differentiation. They also support a possible role for α6 in myoblast formation and migration. Overlapping of β1 and laminin immunoreactivity with that of α6 further suggests that α6 paris with β1 as a functional heterodimer for laminin in defined somitic regions.
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  • 59
    ISSN: 1432-0878
    Keywords: Key words: Gap junction ; Intercellular junction ; Insect ; Arthropod ; Immunocytochemistry ; Heliothis virescens (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Gap junction-enriched fractions were prepared from larvae of the tobacco budworm Heliothis virescens using the NaOH procedure in the presence or absence of protease inhibitors and were analyzed by SDS-PAGE, immunoblotting and EM immunocytochemistry. Protease inhibitor fractions contained a 48-kDa protein in addition to the ∼10 proteins in fractions with and without inhibitors. Three polyclonal antibodies were used as probes for gap junction plaques and proteins: R16, against an ∼40-kDa candidate gap junction protein from Drosophila melanogaster; R17, against the 40-kDa candidate gap junction protein from H. virescens; and R18AP, an affinity purified antibody against a consensus sequence of N-terminal amino acids 2–21 of the H. virescens 40-kDa protein. R16, R17, and R18AP stain the 40- and 48-kDa proteins, R16 and R18AP stain a 64-kDa protein, and R16 stains an ∼30-kDa protein in the absence of inhibitors. Inclusion of protease inhibitors had no effect on gap junction ultrastructure. R16 and R17 label gap junction plaques in crude membrane and NaOH fractions, whereas R18AP exhibits only a low level of reactivity with gap junctions in crude membrane fractions and none with gap junctions in NaOH fractions. The results show that the 30-, 40-, 48- and 64-kDa proteins are immunologically related and are associated with gap junctions in H. virescens, the N-terminus of the 40-kDa protein is relatively inaccessible or easily lost, and the 48-kDa protein is protease-sensitive.
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  • 60
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    Cell & tissue research 281 (1995), S. 507-515 
    ISSN: 1432-0878
    Keywords: Microtubules ; Isoforms ; Nervous system ; Locomotion ; Cilia ; Immunocytochemistry ; Western blotting ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunocytochemistry and Western blotting techniques demonstrated that the nervous system and foot of the pond snail Lymnaea stagnalis are rich sources of tubulin, which can be extracted and assembled in vitro in the presence of taxol. Various broad-spectrum antibodies raised against α-tubulin and β-tubulin yielded qualitatively similar results. One monoclonal antibody to trypanosome α-tubulin, however, labelled α-tubulin more strongly on both probed sections and Western blots. Cytochemistry and immunoblotting revealed that tyrosinated tubulin constitutes a large proportion of total α-tubulin in locomotor cilia of the foot and in axons of the nervous system. Detyrosinated tubulin also appeared to be abundant in the foot cilia but only a very faint band of detyrosinated tubulin was found on protein blots extracted from the central ganglia, and staining was barely detectable in central ganglia or peripheral nerves. Similarly, acetylated tubulin appeared to be abundant in foot cilia, but Western blotting indicated only low levels of acetylated tubulin in the nervous system. Immunocytochemistry indicated that, while most neurons possessed little or no acetylated tubulin, a small number of axons contained significant amounts of this isoform. Thus, while a large amount of tubulin was expected in the nervous system and locomotor cilia of L. stagnalis, the observed distribution of isoforms was unanticipated. Specifically, neurons of other organisms have generally been reported to contain substantial amounts of both detyrosinated α-tubulin and acetylated α-tubulin. Our results indicate that such findings cannot be generalized across all species. L. stagnalis, with its well studied nervous system and unusual distribution of tubulin isoforms, may prove to be particularly useful for studying the roles of tubulin isoforms in microtubule function and cell activity.
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  • 61
    ISSN: 1432-0878
    Keywords: Circadian rhythm ; Colocalization ; Immunocytochemistry ; Brain (CNS), invertebrate ; Optic lobe ; Pigment-dispersing hormone, insect ; Leucophaea maderae (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Several lines of evidence suggest that pigment-dispersing hormone-immunoreactive neurons with ramifications in the accessory medulla are involved in the circadian system of insects. The present study provides a detailed analysis of the anatomical and neurochemical organization of the accessory medulla in the brain of the cockroach Leucophaea maderae. We show that the accessory medulla is compartmentalized into central dense nodular neuropil surrounded by a shell of coarse fibers. It is innervated by neurons immunoreactive to antisera against serotonin and the neuropeptides allatostatin 7, allatotropin, corazonin, gastrin/cholecystokinin, FMRFamide, leucokinin I, and pigment-dispersing hormone. Some of the immunostained neurons appear to be local neurons of the accessory medulla, whereas others connect this neuropil to various brain areas, including the lamina, the contralateral optic lobe, the posterior optic tubercles, and the superior protocerebrum. Double-label experiments show the colocalization of immunoreactivity against pigment-dispersing hormone with compounds related to FMRFamide, serotonin, and leucokinin I. The neuronal and neurochemical organization of the accessory medulla is consistent with the current hypothesis for a role of this brain area as a circadian pacemaking center in the insect brain.
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  • 62
    ISSN: 1432-0878
    Keywords: Neuropeptide Y ; Gastroenteropancreatic (GEP) endocrine system ; Development, ontogenetic ; Vitellointestinal duct ; Pancreas, exocrine ; Pancreas, endocrine ; Immunocytochemistry ; Scyliorhinus torazame (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract This immunocytochemical study was carried out to elucidate the ontogenetic development of neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system of the cloudy dogfish, Scyliorhinus torazame. Immunostained cells first appeared in the pancreas of the embryo at the 15-mm stage, and were also detected in the vitellointestinal duct of the yolk stalk at the 20-mm stage. These cells were polymorphic, with occasional processes that were sometimes directed toward the vascular wall or into the cavity of the vitellointestinal duct. At the 34-mm stage, immunostained cells could also be found in the proximal part of the spiral intestine and, by the 74-mm stage, immunopositive cells were present in the gastric mucosa. In the gut and pancreas, the cells gradually increased in number with development, whereas in the vitellointestinal duct and internal yolk sac, they decreased and seemed to disappear following hatching. Thus, in juveniles, the distribution of the neuropeptide Y-like-immunoreactive cells in the gastroenteropancreatic endocrine system had attained that of adults. Electron-microscopic immunocytochemistry demonstrated that, in the labeled cells of the vitellointestinal duct, the neuropeptide Y-like antigen was located in cytoplasmic granules, as in the cells of the gut and pancreas.
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  • 63
    ISSN: 1432-0878
    Keywords: Key words: Circadian rhythm ; Colocalization ; Immunocytochemistry ; Brain (CNS) ; invertebrate ; Optic lobe ; Pigment-dispersing hormone ; insect ; Leucophaea maderae (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Several lines of evidence suggest that pigment-dispersing hormone-immunoreactive neurons with ramifications in the accessory medulla are involved in the circadian system of insects. The present study provides a detailed analysis of the anatomical and neurochemical organization of the accessory medulla in the brain of the cockroach Leucophaea maderae. We show that the accessory medulla is compartmentalized into central dense nodular neuropil surrounded by a shell of coarse fibers. It is innervated by neurons immunoreactive to antisera against serotonin and the neuropeptides allatostatin 7, allatotropin, corazonin, gastrin/cholecystokinin, FMRFamide, leucokinin I, and pigment-dispersing hormone. Some of the immunostained neurons appear to be local neurons of the accessory medulla, whereas others connect this neuropil to various brain areas, including the lamina, the contralateral optic lobe, the posterior optic tubercles, and the superior protocerebrum. Double-label experiments show the colocalization of immunoreactivity against pigment-dispersing hormone with compounds related to FMRFamide, serotonin, and leucokinin I. The neuronal and neurochemical organization of the accessory medulla is consistent with the current hypothesis for a role of this brain area as a circadian pacemaking center in the insect brain.
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  • 64
    ISSN: 1432-0878
    Keywords: Key words: Quinolinic acid ; Interferon-γ ; Kynurenine ; Electron microscopy ; Immunocytochemistry ; Excitotoxicity ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract.  Quinolinate (QUIN), a tryptophan-derived excitotoxin, was localized ultrastructurally in human peripheral blood monocytes/macrophages (MØ) by immuno-electron microscopy. A combined carbodiimide/glutaraldehyde/paraformaldehyde-based fixation procedure was developed for optimal retention of QUIN in the cell as well as minimal loss of ultrastructure; a silver-enhanced colloidal gold detection system was used for electron-microscopic analysis. Gold particles representing QUIN immunoreactivity were associated with the inner side of the plasma membrane in normal MØ. The number of gold particles increased significantly when QUIN levels were elevated by treatment with its precursor kynurenine, but location of the gold particles remained essentially the same under this condition. Treatment with interferon-γ increased the number of Golgi bodies, vacuoles and pseudopodia, reflecting the activated state of the cell. Significantly increased numbers of gold particles representing QUIN were detectable in approximately the same location as in the case of kynurenine treatment. Combined treatment with kynurenine and interferon-γ maximally increased the number of gold particles at the periphery of the cell. The pseudopodia were intensely stained with gold particles, while they were not detectable in the inner part of the cytoplasm or in any other organelle even under this activated condition. The significance of the specific location of QUIN revealed in the present study and its relation to the release and subsequent actions of QUIN are discussed.
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  • 65
    ISSN: 1432-0878
    Keywords: Key words: Urothelium ; Tartrate-resistant acid phosphatase ; Nitric oxide synthase I ; Superoxide dismutase ; Immunocytochemistry ; Free radicals ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Three enzymes, viz., tartrate-resistant acid phosphatase (TRAP), nitric oxide synthase I (NOS-I), and superoxide dismutase (SOD), involved in the production and metabolism of free radicals or radical equivalents, were demonstrated by immunocytochemistry in the urothelium of the ureters of six patients of various ages. Two of these enzymes (TRAP and NOS-I) were colocalized in the most apical and lateral border of the superficial cells of the urothelium. In contrast, SOD showed a patchy or granular distribution within the supranuclear region of these cells. Intra- and subepithelial macrophages exhibited a weak TRAP, but no NOS-I or SOD, immune reaction. On the basis of the immunocytochemical findings, arguments in favor of a cytotoxic function of the superficial cells of the human urothelium are presented.
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  • 66
    ISSN: 1432-0878
    Keywords: Key words: Oxytocin ; Immunocytochemistry ; Paraventricular nucleus ; Superior cervical ganglion ; Spinal cord ; Sympathetic nervous system ; Retrograde tracing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The paraventricular nucleus of the hypothalamus is a major integrative nucleus for relaying information from the suprachiasmatic nucleus to the autonomic system. The precise pathway by which this information can influence autonomic functions, such as melatonin synthesis in the pineal gland, is not clear. In the present study, we used a retrograde tracer injected in the superior cervical ganglion to identify spinal preganglionic neurons. One of the main neurotransmitters present in descending projections of the paraventricular nucleus of the hypothalamus, oxytocin, was detected with immunocytochemistry to visualise possible contacts with the neurons located in the intermediolateral column of the spinal cord and projecting to the superior cervical ganglion. Although many appositions could be seen at the light-microscopic level, this abundance could not be confirmed at the electron-microscopic level. The implications of these observations for the overall timing message received by the spinal preganglionic neurons are discussed.
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  • 67
    ISSN: 1432-0878
    Keywords: Key words: Crustacean hyperglycaemic hormone ; Immunocytochemistry ; Neurohaemal organ ; Daphnia magna ; Artemia salina (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Crustacean hyperglycaemic hormone-immunoreactive neuronal systems are detected in the central and peripheral nervous systems of two entomostracan crustaceans, Daphnia magna and Artemia salina, by immunocytochemistry using specific antisera against crustacean hyperglycaemic hormones of the decapod crustaceans Orconectes limosus and Carcinus maenas. In D. magna, four small putative interneurones are detected in the brain. In the thorax, ten bipolar peripheral neurones are stained by both antisera. They are obviously segmental homologues with centrally projecting axons that form interdigitating varicose fibres and terminals in putative neurohaemal areas next to the surface of the anterior part of the thoracic ganglia. Similar immunopositive neurones occur both in the central and peripheral nervous systems of A. salina. A total of five groups of neurones occur in the protocerebrum, the deutocerebrum and the mandibular ganglion. Some of the protocerebral neurones are bipolar and project to the dorsal frontal organ. A single pair of peripheral multipolar neurones in the maxillary segment projects centrally into the ventral nerve cord and innervates unidentified somatic muscles and tissues in the maxillary and the first appendage segments. None of the brain neurones in both species show similarities to decapod X-organ sinus gland neurosecretory neurones. Chromatography of brain extracts of D. magna combined with immunodot blotting revealed two strongly immunoreactive fractions at retention times close to that of the crustacean hyperglycaemic hormone of crayfish. Moreover, preabsorption controls suggest that the cross-reacting peptides of D. magna and A. salina are structurally closely related to those of decapods.
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  • 68
    ISSN: 1432-0878
    Keywords: Key words: Allatostatin ; Immunocytochemistry ; In situ hybridization ; Hemocytes ; Inhibition of corpora allata ; Diploptera punctata (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Allatostatins are neuropeptides that inhibit the production, by the corpora allata, of a major insect hormone, juvenile hormone. These peptides are produced by cells of the brain and ganglia as well as by midgut endocrine cells. Transport from these sites may contribute to the allatostatin content in the hemolymph (insect blood). Using a monoclonal antibody against Diploptera punctata allatostatin I (A-P-S-G-A-Q-R-L-Y-G-F-G-L-NH2) and in situ hybridization with a digoxigenin-labeled cRNA probe generated from a portion of the allatostatin gene, it is demonstrated that allatostatin is present in and synthesized by granular hemocytes of D. punctata. About 5% of the hemocytes react with anti-allatostatin antibody and a similar number hybridize with a cRNA probe that detects allatostatin-specific mRNA. Electron micrographs showed that allatostatin-immunoreactive material occurs in membrane-bound, uniformly dense granules that frequently fill fusiform-shaped cells. Allatostatin in cell and plasma fractions of hemolymph quantified by enzyme-linked immunosorbent assay and by bioassay for inhibition of juvenile hormone synthesis in vitro indicated that about equal quantities (0.1–0.2 fmol/μl) are present in cell and plasma fractions. The production of allatostatin by hemocytes suggests that allatostatins may function as regulatory peptides in hemolymph activities in addition to their other known functions.
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  • 69
    ISSN: 1432-0878
    Keywords: Key words: Aquaporins ; AQPcic ; Filter chamber ; Homopteran insects ; Immunocytochemistry ; Cicadella viridis ; Euscelidius variegatus ; Scaphoideus titanus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In the Homopteran order of insects, the plant xylem feeders exhibit a highly differentiated part of their digestive tract known as the filter chamber. In this tissue, water crosses plasma membranes through a transepithelial osmotic gradient. In previous studies on the filter chamber of Cicadella viridis, we purified and characterized from the plasma membranes a 25 kDa protein that we demonstrated to be an aquaporin (or water channel, member of the major intrinsic protein family, a group of membrane channels for small solutes). We called this protein AQPcic for Cicadella aquaporin. In the present study, we used polyclonal antibody anti-AQPcic in Western blotting and immunocytochemical analysis of the intestinal tract of Cercopis sanguinolenta, Philaenus spumarius, Aphrophora alni (Cercopidae), Euscelidius variegatus, and Scaphoideus titanus (Jassidae). Western blotting experiments revealed that immunologically related AQPcic proteins are found in those species. The molecular weight of these proteins is 15–26 kDa. Immunocytochemical studies on ultrathin filter-chamber sections revealed that the anti-AQPcic antibody systematically labelled the membrane microvilli of epithelial cells. A good correlation thus exists between the physiology of these cells and the presence of aquaporin-related proteins in their membranes.
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  • 70
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    Cell & tissue research 199 (1979), S. 349-352 
    ISSN: 1432-0878
    Keywords: Spermatozoa ; Mitochondria ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary As seen by scanning electron microscopy, the mitochondrial helix in the developing midpiece of mouse testicular spermatozoa is dextral in direction and consists of spherical mitochondrial units arranged in an orderly array of four units per gyre: three appearing in face view and a fourth hidden from view at the back of the gyre. As the spermatozoa mature, the dextral helix is transformed into a sinistral helix. Its constituent spherical mitochondria either change direction abruptly without changing shape; or having first become semilunar or diamond-shaped, they change direction gradually. Mitochondrial division follows the change in helical pitch producing a double sinistral helix. The spherical (or semilunar/diamond-shaped) mitochondria presumably elongate to form the units of the mature midpiece.
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  • 71
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    Cell & tissue research 201 (1979), S. 129-135 
    ISSN: 1432-0878
    Keywords: Pineal body ; Freeze-fracturing ; Scanning electron microscopy ; Wistar rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The three-dimensional ultrastructure of the pineal body of the rat is described on the basis of freeze-fractured preparations. The pineal capsule consists of irregular cells with very flat and perforated processes. Through these openings, extremely branched canaliculi, extending to almost every pineal cell, communicate with the tissue compartment outside the organ. The pericapillary spaces contain, in juxtaposition with capillaries of the fenestrated type, nerve fibers as well as a flocculent granular and filamentous material of unknown origin and chemical nature.
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  • 72
    ISSN: 1432-0878
    Keywords: Isotocinergic neurons ; Immunocytochemistry ; Hypothalamus ; Intracellular recording ; Goldfish (Carassius)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Isotocinergic (IT) neurons show physiological and morphological characteristics that are similar to those of other preoptic neuroendocrine cells in the goldfish. Preoptic IT cells show resting membrane potentials of 20–55 mV, action potentials of up to 100mV, and physiological evidence of axonal branching. Dye-marked IT cells measure 14–56 μm, their dendrites projecting to the ependyma and into the hypothalamic neuropil, their multiple beaded axons projecting to the pituitary. Indirect immunofluorescence identifies these dyemarked cells as IT. By combining electrophysiological, dye-marking and immunocytochemical techniques we can now, for the first time, study single, antidromically-identified peptidergic neurons of a specific type in vertebrate and invertebrate species.
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  • 73
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    Cell & tissue research 188 (1978), S. 259-264 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Human fetus ; Oxytocin ; Neurophysin ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The use of antibodies against oxytocin or neurophysin enabled the detection by immunocytochemistry of oxytocin-neurophysin neurons in the hypothalamus in the human fetus. The perikarya of these neurons are located in the paraventricular and supraoptic nuclei. Immunoreactive neurons occur in the median eminence. The neurophysin immunoreactive neurons were more numerous than the oxytocin immunoreactive neurons. The specificity of the immunocytological reaction was controlled. The first oxytocin-neurophysin neurons are seen as early as the 14th week of gestation.
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  • 74
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Vasoactive intestinal polypeptide ; Radioimmunoassay ; Gut hormones ; Anura
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Immunocytochemical and radioimmunological techniques with region specific antisera have been used to identify a vasoactive intestinal polypeptide-like material in the anuran intestine. Seven species of Anura were investigated: Bombina bombina, Alytes obstetricans, Rana temporaria, Rana esculenta, Hyla arborea, Hyla crepitans and Bufo bufo. In five of the species (A. obstetricans, R. temporaria, H. arborea, H. crepitans and B. bufo) vasoactive intestinal polypeptide-like immunoreactive mucosal endocrine cells and nerve fibres in all layers of the gut wall, were detected by both immunofluorescence and peroxidase-antiperoxidase methods. In the other two species, R. esculenta and B. bombina, no mucosal endocrine cells were detected although the vasoactive intestinal polypeptide-immunoreactive nerve fibres were plentiful. Radioimmunoassay showed the presence of significant amounts of vasoactive intestinal polypeptide-immunoreactivity in intestinal extracts from all species. The highest quantities were present in those anurans with both immunostained cells and nerves. Gel permeation chromatography showed that most of the vasoactive intestinal polypeptide-like peptide eluted in a position identical to that of natural mammalian (porcine) vasoactive intestinal polypeptide. The results indicate that a vasoactive intestinal polypeptide-like peptide is well represented in the Anura and that it is immunologically very similar to the mammalian peptide.
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  • 75
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    Cell & tissue research 216 (1981), S. 647-654 
    ISSN: 1432-0878
    Keywords: Mast cells ; Regeneration ; Exocytosis ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cell-surface morphology of regenerating mast cells was followed over a period of 48 h after histamine release. Control cells (not stimulated to secrete) were characterized by anastomosing folds of membrane of equal depth and width. During exocytosis these folds disappeared and were replaced by deep cup-shaped flaps of membrane evident in cells incubated for 10 min. During the first hours of regeneration these flaps fused mutually or with the plasma membrane. This activity suggests membrane retrieval, maybe specifically recycling the granule-type patches of membrane. Membrane-fusion activity was observed to some degree also after extended incubation. After 48 h of incubation the regeneration process was still not completed, as indicated by the fact that holes leading to intracellular cavities could still be found.
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  • 76
    ISSN: 1432-0878
    Keywords: Epididymis ; Efferent ducts ; Cell culture ; Immunocytochemistry ; Immunoprecipitation ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The way in which the human epididymis modifies spermatozoa during their sojourn in this structure might be clarified by knowledge of the nature of its secretions. We have examined the presence of several lysosomal hydrolases in human epididymal tissue and fluids, and their synthesis and secretion by monolayer cultures. Tissues were obtained from men undergoing orchidectomy for prostatic carcinoma. The enzymes cathepsin D and acid α-glucosidase were localised in the lysosomes of epithelial cells from the corpus epididymidis, by an immunocytochemical technique. Cathepsin D was also found in epithelial cells of the efferent ducts within lysosomes, apical vesicles and multivesicular bodies. No immunolocalisation of acid glucosidase in the efferent ducts or on the microvilli of the corpus was demonstrable. Cathepsin D, β-hexosaminidase (N-acetylglucosaminidase) and α-glucosidase were measurable in the luminal fluid from the human corpus epididymidis; β-hexosaminidase was secreted into the culture medium by confluent monolayers of epididymal and efferent duct cells. Immunoprecipitation of cell extracts and culture medium of these cultures incubated with 35S-methionine revealed that the precursors of cathepsin D and β-hexosaminidase were synthesized and secreted by such monolayers. Thus, active lytic enzymes are secreted by the human epididymis and could modify sperm membranes.
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  • 77
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    Cell & tissue research 280 (1995), S. 541-548 
    ISSN: 1432-0878
    Keywords: Musle, striated, skeletal ; Regeneration ; Myosin ; Immunocytochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Indirect immunofluorescence was used to localize embryonic myosin heavy chains in soleus, adductor longus, tibialis anterior, plantaris, and extensor digitorum longus muscles of 6-month-old rats. A monoclonal antibody (2B6), specifically recognizing rat embryonic myosin, was applied to unfixed, transverse, frozen sections. The number of embryonic myosin-positive (EMP) extrafusal fibers was expressed as a percentage of the total number of fibers. EMP extrafusal fibers were only seen in the soleus and adductor longus muscles, both postural muscles. Approximately 1% of the soleus muscle fibers appeared positively stained for embryonic myosin. The majority of such fibers had a small diameter (〈500 ν), appeared intensely fluorescent, and typically contained central nuclei. Re-expression of embryonic myosin due to spontaneous fiber denervation is not a likely factor in this study, since alpha-bungarotoxin and N-CAM localization were restricted to the motor end-plate region of EMP fibers. Since embryonic myosin was shown to disappear in all normal-sized myofibers by 2 to 3 months of age, the results suggest that the EMP extrafusal fibers seen in postural muscles of 6 to 12-month-old animals are regenerating myofibers. We speculate that a small number of muscle fibers may be regenerating in normal, adult postural muscles, in response to fiber damage possibly caused by excessive recruitment or overloading.
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  • 78
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    Cell & tissue research 280 (1995), S. 549-560 
    ISSN: 1432-0878
    Keywords: Enteric nervous system ; Immunocytochemistry ; Calretinin ; Calbindin ; Bombesin ; Small intestine ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Light- and electron-microscopic studies were used to investigate connections between specific subgroups of neurons in the myenteric plexus of the guineapig small intestine. Inputs to two classes of calretinin-immunoreactive (IR) nerve cells, longitudinal muscle motor neurons and ascending interneurons, were examined. Inputs from calbindin-IR primary sensory neurons and from three classes of descending interneurons were studied. Electron-microscopic analysis showed that calbindin-IR axons formed two types of inputs, synapses and close contacts, on calretinin-IR neurons. About 40% of inputs to the longitudinal muscle motor neurons and 70% to ascending interneurons were calbindin-IR. Approximately 50% of longitudinal muscle motor neurons were surrounded by bombesin-IR dense pericellular baskets and 40% by closely apposed varicosities. At the electron-microscope level, the bombesin-IR varicosities were found to form synapses and close contacts with the motor neurons. Dense pericellular baskets with bombesin-IR surrounded 36% of all ascending interneurons, and a further 17% had closely apposed varicosities. Somatostatin-and 5-HT-IR descending interneurons provided no dense pericellular baskets to calretinin-IR nerve cells. Thus, calretinin-IR, longitudinal muscle motor neurons and ascending interneurons receive direct synaptic inputs from intrinsic primary sensory neurons and from non-cholinergic, bombesin-IR, descending interneurons.
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  • 79
    ISSN: 1432-0878
    Keywords: Laminin ; Nerve tracts ; Ontogenetic development ; Brain ; Immunocytochemistry ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Laminin, a large glycoprotein of the basement membrane that promotes the growth of nerve cell processes in vitro has also been detected in the brains of developing embryos in situ where it is postulated to promote or guide neural outgrowth. We have investigated the histological and developmental patterns of a receptor to a specific pentapeptide sequence in the A chain of the laminin molecule (PA22-2 or IKVAV) that has been identified as a neuron growth-promoting sequence. Standard immunocytochemical procedures were used to localize the receptor by means of a polyclonal antibody to affinity-purified receptor (MR=110 kDa) from mouse brains. Results for postnatal stages (P) stages (P 1,7,8,25,30,and adult) show that the 110 kDa receptor is localized in fibers in the cortex and hippocampus, in astroglial cells at the surface of the cortex, and in neuronal cell bodies in the hippocampus. In contrast, the A-chain ligand is localized in cell bodies in the same regions at P stages. For embryonic stages (E) (E 14 and E 16) the receptor is localized in bundles of fibers in the superficial and deep cortical layers, and in cell bodies in these regions at E 14 only. Staining for the A chain ligand of the receptor was first seen postnatally. We speculate that the inverse histological pattern of receptor and ligand with respect to cell bodies and fibers may reflect a role in controlling axon guidance during development or repair during regeneration.
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  • 80
    ISSN: 1432-0878
    Keywords: Dopamine ; Serotonin ; Tyrosine hydroxylase ; Immunocytochemistry ; Nervous system, insect-Gryllus bimaculatus (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The cellular localization of the biogenic amines dopamine and serotonin was investigated in the ventral nerve cord of the cricket, Gryllus bimaculatus, using antisera raised against dopamine, β-tyrosine hydroxylase and serotonin. Dopamine-(n〈-70) and serotonin-immunoreactive (n〈-120) neurones showed a segmental arrangement in the ventral nerve cord. Some neuromeres, however, did not contain dopamine-immunoreactive cell bodies. The small number of stained cells allowed complete identification of brain and thoracic cells, including intersegmentally projecting axons and terminal arborizations. Dopamine-like immunostaining was found primarily in plurisegmental interneurones with axons descending to the soma-ipsilateral hemispheres of the thoracic and abdominal ganglia. In contrast, serotonin-immunostaining occurred predominantly in interneurones projecting via soma-contralaterally ascending axons to the thorax and brain. In addition, serotonin-immunoreactivity was also present in efferent cells and afferent elements. Serotonin-immunoreactive, but no dopamine-immunoreactive, varicose fibres were observed on the surface of some peripheral nerves. Varicose endings of both dopamine-and serotonin-immunoreactive neurones occurred in each neuromere and showed overlapping neuropilar projections in dorsal and medial regions of the thoracic ganglia. Ventral associative neuropiles lacked dopamine-like immunostaining but were innervated by serotonin-immunoreactive elements. A colocalization of the two amines was not observed. The topographic representation of neurone types immunoreactive for serotonin and dopamine is discussed with respect to possible modulatory functions of these biogenic amines in the central nervous system of the cricket.
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  • 81
    ISSN: 1432-0878
    Keywords: Cathepsin E ; Aspartic proteinase ; Osteoclasts ; Immunocytochemistry ; Rat (WKA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The immunocytochemical localization of cathepsin E, a non-lysosomal aspartic proteinase, was investigated in rat osteoclasts using the monospecific antibody to this protein. At the light-microscopic level, the preferential immunoreactivity for cathepsin E was found at high levels in active osteoclasts in the physiological bone modeling process. Neighboring osteoblastic cells were devoid of its immunoreactivity. At the electron-microscopic level, cathepsin E was exclusively confined to the apical plasma membrane at the ruffled border of active osteoclasts and the eroded bone surface. Cathepsin E was also concentrated in some endocytotic vacuoles of various sizes in the vicinity of the ruffled border membrane, some of which appeared to be secondary lysosomes containing the phagocytosed materials. These results strongly suggest that this enzyme is involved both in the extracellular degradation of the bone organic matrix and in the intracellular breakdown of the ingested substances in osteoclasts.
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  • 82
    ISSN: 1432-0878
    Keywords: Key words: Laminin ; Nerve tracts ; Ontogenetic development ; Brain ; Immunocytochemistry ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Laminin, a large glycoprotein of the basement membrane that promotes the growth of nerve cell processes in vitro has also been detected in the brains of developing embryos in situ where it is postulated to promote or guide neural outgrowth. We have investigated the histological and developmental patterns of a receptor to a specific pentapeptide sequence in the A chain of the laminin molecule (PA22-2 or IKVAV) that has been identified as a neuron growth-promoting sequence. Standard immunocytochemical procedures were used to localize the receptor by means of a polyclonal antibody to affinity-purified receptor (MR=110 kDa) from mouse brains. Results for postnatal stages (P) stages (P 1,7,8,25,30,and adult) show that the 110 kDa receptor is localized in fibers in the cortex and hippocampus, in astroglial cells at the surface of the cortex, and in neuronal cell bodies in the hippocampus. In contrast, the A-chain ligand is localized in cell bodies in the same regions at P stages. For embryonic stages (E) (E 14 and E 16) the receptor is localized in bundles of fibers in the superficial and deep cortical layers, and in cell bodies in these regions at E 14 only. Staining for the A chain ligand of the receptor was first seen postnatally. We speculate that the inverse histological pattern of receptor and ligand with respect to cell bodies and fibers may reflect a role in controlling axon guidance during development or repair during regeneration.
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  • 83
    ISSN: 1432-0878
    Keywords: Key words: Trans-differentiation ; Proliferation ; Bromodeoxyuridine ; Immunocytochemistry ; Regeneration ; Ciona intestinalis (Tunicata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In this study, we use three monoclonal antibodies that recognise antigens present in the central nervous system of the ascidian Ciona intestinalis to study regeneration and post-metamorphic development of the neural ganglion. We have also used bromodeoxyuridine labelling to study generation of the neuronal precursor cells. The first antibody, CiN 1, recognises all neurones in the ganglion, whereas the second, CiN 2, recognises only a subpopulation of the large cortical neurones. Western blotting studies show that CiN 2 recognises two membrane-bound glycoproteins of apparent Mr 129 and 100 kDa. CiN 1 is not reactive on Western blots. Immunocytochemical studies with these antibodies show that CiN 1-immunoreactive neurone-like cells are present at the site of regeneration as early as 5–7 days post-ablation, a sub-population of CiN 2-immunoreactive cells being detected by 9–12 days post-ablation. The third antibody, ECM 1, stains extracellular matrix components and recognises two diffuse bands on Western blots of whole-body and ganglion homogenates. The temporal and spatial pattern of appearance of CiN 1 and CiN 2 immunoreactivity both during post-metamorphic development and in regeneration occurs in the same sequence in both processes. Studies with bromodeoxyuridine show labelled nuclei in some neurones in the regenerating ganglion. Plausibly these originate from the dorsal strand, an epithelial tube that reforms by cell proliferation during the initial phases of regeneration. A second population of cells, the large cortical neurones, do not incorporate bromodeoxyuridine and thus must have been born prior to the onset of regeneration. This latter finding indicates a mechanism involving trans-differentiation of other cell types or differentiation of long-lived totipotent stem cells.
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  • 84
    ISSN: 1432-0878
    Keywords: Key words: Choline acetyltransferase ; Cholinergic neuron ; Visual system ; Bolwig’s organ ; Immunocytochemistry ; In situ hybridization ; Drosophila melanogaster (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Choline acetyltransferase (ChAT) is the enzyme catalyzing the biosynthesis of acetylcholine and is considered to be a phenotypically specific marker for cholinergic neurons. We have examined the distribution of ChAT-expressing neurons in the larval nervous system of Drosophila melanogaster by three different but complementary techniques: in situ hybridization with a cRNA probe to ChAT messenger RNA, immunocytochemistry using a monoclonal anti-ChAT antibody, and X-gal staining of transformed animals carrying a reporter gene composed of 7.4  kb of 5′ flanking DNA from the ChAT gene fused to a lacZ reporter gene. All three techniques demonstrated ChAT-expressing neurons in the larval visual system. In embryos, the photoreceptor organ (Bolwig’s organ) exhibited strong cRNA hybridization signals. The optic lobe of late third-instar larvae displayed ChAT immunoreactivity in Bolwig’s nerve and a neuron close to the insertion site of the optic stalk. This neuron’s axon ran in parallel with Bolwig’s nerve to the larval optic neuropil. This neuron is likely to be a first-order interneuron of the larval visual system. Expression of the lacZ reporter gene was also detected in Bolwig’s organ and the neuron stained by anti-ChAT antibody. Our observations indicate that acetylcholine may be a neurotransmitter in the larval photoreceptor cells as well as in a first-order interneuron in the larval visual system of Drosophila melanogaster.
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  • 85
    ISSN: 1432-0878
    Keywords: Pituitary ; Gonadotrops ; Crinophagy ; Electron microscopy ; Enzyme cytochemistry ; Immunocytochemistry ; Autoradiography ; Catfish, Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The possible function of globules and irregular membrane-bound masses in the gonadotropin cells of the pituitary of Clarias gariepinus was studied. Strong secretory stimulation led to the disappearance of the secretory granules from gonadotropin cells but globules and irregular masses remained present. Acid phosphatase was detected enzyme-cytochemically in both globules and irregular masses. Radiolabelling with tritiated amino acids followed by autoradiography demonstrated that globules received radioactive material after secretory granules. The latter received radioactive material within 75 min of administration of radioactive amino acids but globules and irregular masses did not. Although some globules became radioactively labelled within 24 h of the administration of radioactive amino acids, irregular masses remained unlabelled during this period. Secretory granules reacted positively with antisera against α and β gonadotropin subunits, whereas globules and irregular masses only reacted with the antiserum against the β subunit. A moderate anti-7B2 immunoreactivity was demonstrated in secretory granules and globules, whereas irregular masses labelled strongly. The combined cytological results indicate that globules and irregular masses are degradative, possibly crinophagic structures which develop by fusional events from secretory granules to globules and then to irregular masses.
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  • 86
    ISSN: 1432-0878
    Keywords: Key words: Interleukin ; Stellate reticulum ; Immunocytochemistry ; Epidermal growth factor ; Interleukin-1 receptor type I messenger RNA ; Tooth eruption ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Immunolocalization of interleukin-1α in the first mandibular molars of rats from day 0–12 postnatally showed that the protein was localized in the epithelial stellate reticulum adjacent to the dental follicle. Staining of the stellate reticulum was most prominent in the early days postnatally and was absent by postnatal day 11. Injection of epidermal growth factor into rats at day 0 greatly increased the intensity of the staining for interleukin-1α in the stellate reticulum. Epidermal growth factor (EGF) enhanced the gene expression of interleukin-1α in stellate reticulum cells in vitro, and this study suggests there is enhanced translation of interleukin-1α messenger RNA in the stellate reticulum following EGF injection. In turn, the interleukin-1α may exert its effect on the dental follicle cells adjacent to the stellate reticulum because EGF also enhanced expression of the interleukin-1 receptor type I messenger RNA in cultured dental follicle cells as well as enhancing its expression in vivo. In view of the fact that injection of EGF will stimulate precocious eruption of teeth, its stimulus of interleukin-1α synthesis in the stellate reticulum may be the mechanism by which EGF initiates a cascade of molecular events to signal the onset of tooth eruption.
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  • 87
    ISSN: 1432-0878
    Keywords: Key words: Defence mechanisms ; Encapsulation ; Granulocytes ; Immunocytochemistry ; Parasitism ; Perkinsus sp. (Protozoa) ; Tapes semidecussatus (Mollusca
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Parasitosis by the trophozoite protozoan Perkinsus sp. (Apicomplexa, Perkinsea) induces in the gill filaments of the clam Tapes semidecussatus (Mollusca, Bivalvia) a cellular reaction, which is constituted by infiltrated granulocytes. This cellular reaction has characteristics of those of a holocrine gland, since the parasites are encapsulated by the secretion product of the granulocytes after cell death. An enriched fraction of prezoosporangia and their ass ociated capsule was obtained after culture of the parasitized gills in fluid thioglycollate medium. Specific polypeptides from this fraction were separated by SDS-PAGE and isolated for rabbit immunizations. The serum obtained against an Mr 225 kDa polypeptide, revealed its exclusive localization in the capsule and in the granules of the infiltrated granulocytes, thus indicating that this polypeptide is synthesized by these cells and secreted, in a polarized way, around the trophozoites resulting in t heir encapsulation. Selective deglycosylation of the polypeptide, by Endo H and alkaline β-elimination, did not show an effect on its molecular weight or antibody recognition. Furthermore, the absence of the 225 kDa band in the Western-blots of non-parasitized gills indicated the specific association of this polypeptide with the parasitosis. Finally, this is the first tissue-specific factor described in molluscs in relation to defence mechanisms.
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  • 88
    ISSN: 1432-0878
    Keywords: Key words: Pituitary ; Gonadotrops ; Crinophagy ; Electron microscopy ; Enzyme cytochemistry ; Immunocytochemistry ; Autoradiography ; Catfish ; Clarias gariepinus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The possible function of globules and irregular membrane-bound masses in the gonadotropin cells of the pituitary of Clarias gariepinus was studied. Strong secretory stimulation led to the disappearance of the secretory granules from gonadotropin cells but globules and irregular masses remained present. Acid phosphatase was detected enzyme-cytochemically in both globules and irregular masses. Radiolabelling with tritiated amino acids followed by autoradiography demons trated that globules received radioactive material after secretory granules. The latter received radioactive material within 75 min of administration of radioactive amino acids but globules and irregular masses did not. Although some globules became radioactively labelled within 24 h of the administration of radioactive amino acids, irregular masses remained unlabelled during this period. Secretory granules reacted positively with antisera against α and β gonadotropin subunits, whereas globules and irregular masses only reacted with the antiserum against the β subunit. A moderate anti-7B2 immunoreactivity was demonstrated in secretory granules and globules, whereas irregular masses labelled strongly. The combined cytological results indicate that globules and irregular masses are degradative, possibly crinophagic structures which develop by fusional events from secretory granules to globules and then to irregular masses.
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  • 89
    ISSN: 1432-0878
    Keywords: Melanin-concentrating hormone ; Immunocytochemistry ; Development, ontogenetic ; Sparus auratus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The development of the hypothalamic melanin-concentrating hormone (MCH) system of the teleost Sparus auratus has been studied by immunocytochemistry using an anti-salmon MCH serum. Immunoreactive perikarya and fibers are found in embryos, larvae, and juvenile specimens. In juveniles, most labeled neurons are present in the nucleus lateralis tuberis; some are dispersed in the nucleus recessus lateralis and nucleus periventricularis posterior. From the nucleus lateralis tuberis, MCH neurons project a conspicuous tract of fibers to the ventral hypothalamus; this penetrates the pituitary stalk and reaches the neurohypophysis. Most fibers end close to the cells of the pars intermedia, and some reach the adenohypophysial rostral pars distalis. Immunoreactive fibers can also be seen in extrahypophysial localizations, such as the preoptic region and the nucleus sacci vasculosi. In embryos, MCH-immunoreactive neurons first appear at 36 h post-fertilization in the ventrolateral margin of the developing hypothalamus. In larvae, at 4 days post-hatching, perikarya can be observed in the ventrolateral border of the hypothalamus and in the mid-hypothalamus, near the ventricle. At 26 days post-hatching, MCH perikarya are restricted to the nucleus lateralis tuberis. The neurohypophysis possesses MCH-immunoreactive fibers from the second day post-hatching. The results indicate that MCH plays a role in larval development with respect to skin melanophores and cells that secrete melanocyte-stimulating hormone.
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  • 90
    Electronic Resource
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    Cell & tissue research 280 (1995), S. 123-131 
    ISSN: 1432-0878
    Keywords: Differentiation ; 5′-Nucleotidase ; Immunocytochemistry ; PC12 cells ; Synaptophysin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract 5′-Nucleotidase hydrolyzes 5′-mononucleotides to their nucleosides but is also thought to have a function in neuronal differentiation and synapse formation. The distribution of the enzyme, a glycosyl-phosphatidylinositol-anchored sialoglycoprotein, was investigated in PC12 cells using immunofluorescence microscopy. 5′-Nucleotidase was located both in intracellular compartments and at the cell surface. There was no principal difference in the cellular distribution between undifferentiated cells and after neuritogenic differentiation by nerve growth factor. Intracellularly, 5′-nucleotidase often revealed a sickle-shaped perinuclear distribution and a dotted pattern throughout the cytoplasm, including that of neurites and growth cones. The intracellular distribution was clearly different from that of the synaptic vesicle protein synaptophysin. However, the dotted fluorescence resembled that obtained after uptake of the endosomal marker acridine orange. 5′-Nucleotidase was present on the entire cell surface including all neurites formed after differentiation. There was no increase in 5′-nucleotidase fluorescence at synapse-like contacts between the tips of neurites and other PC12 cells. Surfacelocated 5′-nucleotidase could no longer be detected after the application of glycosyl-phosphatidylinositol-specific phospholipase C to cultured cells. This treatment did not affect PC12 cell differentiation. Our results thus reveal 5′-nucleotidase both at the surface and within organelles and suggest that PC12 cells may be used as a model system for the study of the physiological function of 5′-nucleotidase in neural cells.
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  • 91
    Electronic Resource
    Electronic Resource
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    Cell & tissue research 280 (1995), S. 123-131 
    ISSN: 1432-0878
    Keywords: Key words: Differentiation ; 5′-Nucleotidase ; Immunocytochemistry ; PC12 cells ; Synaptophysin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. 5′-Nucleotidase hydrolyzes 5′-mononucleotides to their nucleosides but is also thought to have a function in neuronal differentiation and synapse formation. The distribution of the enzyme, a glycosyl-phosphatidylinositol-anchored sialoglycoprotein, was investigated in PC12 cells using immunofluorescence microscopy. 5′-Nucleotidase was located both in intracellular compartments and at the cell surface. There was no principal difference in the cellular distrib ution between undifferentiated cells and after neuritogenic differentiation by nerve growth factor. Intracellularly, 5′-nucleotidase often revealed a sickle-shaped perinuclear distribution and a dotted pattern throughout the cytoplasm, including that of neurites and growth cones. The intracellular distribution was clearly different from that of the synaptic vesicle protein synaptophysin. However, the dotted fluorescence resembled that obtained after uptake of the endosomal marker acridine orange. 5′-Nucleotidase was present on the entire cell surface including all neurites formed after differentiation. There was no increase in 5′-nucleotidase fluorescence at synapse-like contacts between the tips of neurites and other PC12 cells. Surface-located 5′-nucleotidase could no longer be detected after the application of glycosyl-phosphatidylinositol-specific phospholipase C to cultured cells. This treatment did not affect PC12 cell differentiation. Our results thus reveal 5′ -nucleotidase both at the surface and within organelles and suggest that PC12 cells may be used as a model system for the study of the physiological function of 5′-nucleotidase in neural cells.
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  • 92
    ISSN: 1432-0878
    Keywords: Key words: Subcommissural organ ; Secretory glycoproteins ; Antibodies ; Immunochemistry ; Immunocytochemistry ; Dogfish ; Scyliorhinus canicula (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The subcommissural organ of the dogfish, Scyliorhinus canicula (L), has been investigated by use of antibodies and lectins applied to blots and tissue sections processed for light and electron microscopy. Antibodies have been raised against each of the bands that have previously been identified in immunoblots by the use of antisera raised against secretory glycoproteins extracted from the dogfish subcommissural organ, viz., the 600-kDa band and two gel regions including the 475 to 400-kDa and the 145-kDa bands obtained from preparative gels; they are referred to as Ab-600, Ab-475/400, and Ab-145. These antisera and the lectins concanavalin A and wheat germ agglutinin have been used for the staining of: (1) blots of extracts of the dogfish subcommissural organ and optic tectum; (2) tissue sections of the dogfish brain. The findings indicate that the bands of 600, 475 and 400 kDa contain compounds that should be regarded as secretory glycoproteins of the dogfish subcommissural organ. The 600-kDa and 400-kDa bands are labeled by concanavalin A; wheat germ agglutinin labels the 475-kDa band strongly and the other two weakly. Ab-600 reacts with the bands at 600, 475 and 400 kDa and stains materials stored in the rough endoplasmic reticulum and secretory granules of 200–600 nm in diameter. The 600-kDa compound is probably a precursor form. Ab-475/400 stains the same three bands revealed by Ab-600; immunocytochemically, it reacts with two types of secretory granules (200–600 and 800–1200 nm in diameter) but it does not label the rough endoplasmic reticulum. Ab-145 reveals the bands at 600, 475 and 400 kDa and a diffuse zone in the region of 145 kDa; in light-microscopic immunocytochemistry, it behaves as Ab-475/400. The 475-kDa and 400-kDa glycoproteins, and a compound of approximately 145 kDa thus probably correspond to processed forms. Ab-475/400 stains granules present in cell processes ending on local blood vessels and at the leptomeninges. Since this antiserum selectively labels secretory granules, this finding may be taken as evidence for a basal route of secretion.
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  • 93
    ISSN: 1432-0878
    Keywords: Key words: Sauvagine ; Corticotropin-releasing factor ; Immunocytochemistry ; Interrenal gland ; Rana catesbeiana (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Immunocytochemistry was used to investigate the presence of corticotropin-releasing factor-like peptides in the interrenal (adrenal) glands of the bullfrog Rana catesbeiana by using specific antisera raised against synthetic nonconjugated rat/human corticotropin-releasing factor, urotensin I, and sauvagine. From these three antisera, covering a broad range of corticotropin-releasing factor-like immunoreactivities, only the sauvagine antiserum gave positive immunoreactivity. Sauvagine immunoreactivity was found in cortical cells grouped into cords in the renal zone of the interrenal gland. The central and subcapsular cords were less stained. Tyrosine hydroxylase-positive chromaffin cells were not sauvagine-immunoreactive. The immunoreactivity was abolished, in all cases, by previous immunoabsorption of the sauvagine antiserum with synthetic sauvagine (0.1 μM), but it was not eliminated by sucker (Catostomus commersoni) urotensin I, sole (Hippoglossoides elassodon) urotensin I, sucker corticotropin-releasing factor, rat/human corticotropin-releasing factor, or ovine corticotropin-releasing factor (0.1–10 μM). In a sauvagine radioimmunoassay, interrenal extracts displaced 125I-sauvagine from antiserum only partially, and not in parallel with the sauvagine standard curve. The results suggest that the sauvagine immunoreactivity in the R. catesbeiana interrenal gland may represent a novel sauvagine-like peptide.
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  • 94
    ISSN: 1432-0878
    Keywords: Key words: Pituitary hormones ; Immunocytochemistry ; Morphometry ; Metamorphosis ; Bufo arenarum (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The development and dynamics of thyrotropin (TSH), adrenocorticotropic hormone (ACTH), prolactin (PRL), and growth hormone (GH) cells have been studied using immunocytochemical techniques and rabbit antisera, raised against the relevant human hormone, in the pars distalis of Bufo arenarum larvae at different stages of development. The four types of cells studied were identified in different zones of the pars distalis: TSH cells occurred mainly in the centro-ventral zone, ACTH cells in the rostral and dorsal zones, GH cells in the central and caudal zones, and PRL cells in the anterior two-thirds of the gland. This distribution pattern does not show significant changes with development. Morphometry and stereology were used to evaluate the changes observed in the volume of the pars distalis and the immunoreactive cells during development. The former increased during larval growth and decreased throughout the metamorphic climax. The results obtained on cell number, volume density, and total volume suggest that, during larval growth (pre-prometamorphosis) of B. arenarum, TSH, PRL, GH and ACTH cells show a proliferative period with storage of their hormones; a second period involving hormone release occurs at the metamorphic climax.
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  • 95
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    Cell & tissue research 281 (1995), S. 367-374 
    ISSN: 1432-0878
    Keywords: Placenta ; Amniochorion ; Cytotrophoblast cells ; Immunoglobulin G ; Immunocytochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Maternal immunoglobulin-G (IgG) is known to be transported across the placental syncytiotrophoblast during the period when the human fetus is incapable of manufacturing these defensive molecules. In this study we investigated the possible role of the amniochorion, that surrounds the amniotic cavity in which the fetus lies, in the transfer of immunoglobulin. Endogenous IgG was localised in the amniochorion by confocal immunofluorescence microscopy and by ultrastructural labelling of ultrathin frozen tissue sections using the protein A-gold technique. Immunoreactivity was identified in the extracellular matrix tissues and necrotic amniotic epithelial cells. Healthy amniotic epithelial cells and cytotrophoblast cells of the chorion laeve were devoid o endogenous IgG. These results suggest a possible non-specific paracellular transport pathway between cytotrophoblast cells, which may conceivably contribute to the acquisition of passive immunity by the fetus, and offer a rational explanation for the presence of small quantities of maternal IgG in the amniotic fluid.
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  • 96
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    Cell & tissue research 281 (1995), S. 507-515 
    ISSN: 1432-0878
    Keywords: Key words: Microtubules ; Isoforms ; Nervous system ; Locomotion ; Cilia ; Immunocytochemistry ; Western blotting ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Immunocytochemistry and Western blotting techniques demonstrated that the nervous system and foot of the pond snail Lymnaea stagnalis are rich sources of tubulin, which can be extracted and assembled in vi- tro in the presence of taxol. Various broad-spectrum antibodies raised against α-tubulin and β-tubulin yielded qualitatively similar results. One monoclonal antibody to trypanosome α−tubulin, however, labelled α-tubulin more strongly on both probed sections and Western blots. Cytochemistry and immunoblotting revealed that tyrosinated tubulin constitutes a large proportion of total α-tubulin in locomotor cilia of the foot and in axons of the nervous system. Detyrosinated tubulin also appeared to be abundant in the foot cilia but only a very faint band of detyrosinated tubulin was found on protein blots extracted from the central ganglia, and staining was barely detectable in central ganglia or peripheral nerves. Similarly, acetylated tubulin appeared to be abundant in foot cilia, but Western blotting indicated only low levels of acetylated tubulin in the nervous system. Immunocytochemistry indicated that, while most neurons possessed little or no acetylated tubulin, a small number of axons contained significant amounts of this isoform. Thus, while a large amount of tubulin was expected in the nervous system and locomotor cilia of L. stagnalis, the observed distribution of isoforms was unanticipated. Specifically, neurons of other organisms have generally been reported to contain substantial amounts of both detyrosinated α-tubulin and acetylated α-tubulin. Our results indicate that such findings cannot be generalized across all species. L. stagnalis, with its well studied nervous system and unusual distribution of tubulin isoforms, may prove to be particularly useful for studying the roles of tubulin isoforms in microtubule function and cell activity.
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  • 97
    ISSN: 1432-0878
    Keywords: Key words: Arginine ; Analogues ; Immunocytochemistry ; Nitric oxide ; Pituitary ; Retina ; Transport ; Rat (Wistar) ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Nitric oxide is formed by the action of nitric oxide synthase upon l-arginine. The efficacy of some exogenously applied arginine analogues in inhibiting nitric oxide synthase and thus nitrergic transmission indicates that neurons producing nitric oxide may possess an arginine transport system. To investigate whether arginine analogues are preferentially transported into nitric oxide-utilising cells or into cells making other neurochemicals, we have raised highly specific antisera against a number of arginine analogues including NG-methyl arginine, d-arginine, NGnitro-l-arginine, NG-nitro-l-arginine methyl ester and canavanine. Retinae were incubated in physiological media containing these analogues and rats were given intraperitoneal injections of the analogues to study the pituitary. Immunocytochemistry and NADPH-diaphorase histochemistry revealed that many of these analogues could be transported preferentially, but not exclusively, into nitric oxide-generating cells. However, some nitric oxide-producing cells apparently lacked the ability to take up some arginine analogues. We conclude that nitric oxide-generating cells in the retina and pituitary possess one or more arginine transporters. Other subsets of neurons that use GABA or glutamate as a neurotransmitter may also accumulate arginine analogues, possibly as a substrate for formation of these neurochemicals.
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  • 98
    ISSN: 1432-0878
    Keywords: Key words: Placental stem villi ; Perivascular contractile sheath ; Molecules of adhesion plaques ; Extracellular matrix molecules ; Immunocytochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In previous studies, we have shown that smooth muscle cells and myofibroblast subpopulations of the perivascular stem villous sheath of the human placenta contain focal adhesion plaques and talin immunoreactivity. The close association of these cells to elastic and collagen fibres have led to the assumption of a functional myofibroelastic unit within the perivascular stem villous sheath. Interactions between the extracellular matrix and smooth muscle cells depend on a variety of structural protein assemblies. In the present study, we examined, by immunocytochemistry, whether the molecular assembly of extracellular matrix proteins and molecules of focal adhesions, known to be essential for signal transduction in smooth muscle cells, are also found in smooth muscle cells of the perivascular stem villous sheath of the human placenta. Vascular and extravascular smooth muscle cells were immunoreactive for α-actinin, vinculin, paxillin and tensin, the integrin chains α1 and β1, and the basement membrane components laminin and heparan/-chondroitin sulfate proteoglycan perlecan. pp125FAK did not react. In the extracellular matrix of blood vessel walls and the perivascular stem villous sheath, we found immunoreactivity of fibronectin and collagen types I, VI and undulin (collagen type XIV). From our data we conclude that within the perivascular stem villous sheath, there exists a system of signal transduction molecules, indicating a cross talk between the smooth muscle cells of this sheath and their surrounding extracellular matrix.
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  • 99
    ISSN: 1432-0878
    Keywords: Key words: Parietal eye ; Pineal organ ; Retina ; Glutamate ; Aspartate ; Immunocytochemistry ; Electron microscopy ; Lacerta muralis ; Lacerta agilis ; Lacerta viridis (Lacertilia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The fine structure of the organ and the localization of the excitatory amino acids glutamate and aspartate were studied in the parietal eye of lizards by postembedding immunoelectron microscopy. The parietal eye contains cone photoreceptor cells, secondary neurons, and ependymal and lens cells. The photoreceptors form long inner and outer segments, some of them being paired as ”twin-photoreceptors” by zonulae adherentes. Perikarya of neurons bear sensory cilia (containing 9×2+0 pairs of tubules) extending into the intercellular space. No neurohormonal terminals are present in the parietal eye. A higher immunoreactivity to glutamate than to aspartate is found in the photoreceptors and in the secondary neurons of the parietal eye. Glutamate immunogold labeling is more intense in the axonal processes of photoreceptors and neurons and in most of the nerve fibers of the parietal nerve running to the brain stem. Weak aspartate and glutamate immunoreactivity can be detected in the ependymal and lens cells. A similar distribution of immunoreactive amino acids is found in the photoreceptors, secondary neurons, and ependymal glial elements of the pineal organ, and retina of the lateral eye of the same animals. Immunoreactive glutamate accumulates in the axons of photoreceptors and secondary neurons of the parietal eye suggesting that this excitatory amino acid acts as a synaptic mediator in the neural efferentation of the organ. Thus, the efferent light-conducting pathway of the parietal organ is similar to that of the pineal organ and lateral eye retina. As the Mullerian cells of the retina, the ependymal and lens cells of the parietal eye and the ependymal-glial cells of the pineal organ may play a role in the metabolism and/or elimination of excitatory amino acids released by photoreceptors.
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  • 100
    ISSN: 1432-0878
    Keywords: Key words: Ovary ; Vascularization ; Vascular corrosion casts ; Scanning electron microscopy ; Countercurrent mechanism ; Rabbit (New Zealand white)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Ovarian angioarchitecture was studied by scanning electron microscopy of vascular corrosion casts in estrous, pseudopregnant (stimulated with human chorionic gonadotropin) and pregnant rabbits. In all samples, the proper ovarian branch of the ovarian artery (ramus ovaricus) entered the ovarian hilus near the caudal pole of the organ and ran parallel to the major axis of the hilus. The extraovarian venous drainage was formed by several vessels emptying into a distal large vein. The ramus ovaricus exhibited various degrees of coiling and branched in the medulla. The coiling of the ramus ovaricus and its ramifications were maintained in all samples. A venous meshwork and/or flat vein branches closely enveloped the arterial coils found in the hilus and outer medulla. At this level numerous arteriovenous contacts were demonstrated in all samples. The coiled arteries, prior to entering the ovarian cortex, supplied several small peripheral follicles which were drained by the hilar veins. In the cortex the coiled arteries branched in numerous thin, straight or slightly undulated arterioles which supplied developing estrous follicles and pseudopregnant corpora lutea. The arterioles supplying the pregnant corpora lutea were long, large and tightly spiraled. The venous drainage followed the modifications of the arterial supply. These data demonstrate that ovarian cycle and pregnancy induced significant changes in the cortical vessels, which adapted their structure to the temporary functional needs of the recruited follicles or corpora lutea. Hilar and medullary vessels have permanent structures that may represent morphological devices for (a) a continuous control of the blood flow (spiral arteries) and (b) a local recirculation of endocrine products (arteriovenous contacts) comparable to the ”countercurrent mechanism” previously shown to operate in ovaries of other species, but not yet found in rabbits.
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