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Biomedical subjects

D Fellmann

Publications and source records attributed to D Fellmann.

At least 127 records · Page 7Linked to original sources

Immunocytochemical demonstration of somatostatin-containing neurons in the hypothalamus of the domestic mallard.

In the hypothalamus of the adult domestic mallard, small to medium-sized perikarya are stained specifically with rabbit antiserum against cyclic somatostatin (PAP technique of Sternberger). The somatostatin-immunoreactive material is located in neurons different from those containing immunoreactive LHRH, vasotocin or mesotocin. Somatostatin-containing perikarya are observed 1) in a chain-like arrangement extending from the area of the median division of the supraoptic nucleus to the caudal end of the paraventricular nucleus; 2) as single cells in the preoptic region; and 3) as a conspicuous formation in the optic tract division of the supraoptic nucleus. In the rostral portion of the median eminence, somatostatin-immunoreactive axons penetrate into the external zone. Fine accessory fiber bundles project to the neural lobe.

Animals↗

[Antigenic determinants of beta-LPH, beta-MSH, alpha-endorphin, ACTH and alpha-MSH revealed by anti-beta-endorphin in neurons of the human infundibular nucleus].

Comparison of adjacent serial sections of the tubero-infundibular region of Human adult hypothalamus demonstrates that the same perikarya, axons and terminals are stained both with anti-beta-endorphin and anti 17-39 ACTH antisera. The most immunoreactive of these neurons are also revealed with anti alpha-endorphin, anti alpha and beta-MSH, anti-1-24 ACTH and anti beta-LPH. These results suggest that neurons of the infundibular nucleus can store and probably secrete peptide similar to propiocortin or fragment(s) of this molecule.

Adrenocorticotropic Hormone↗

[Description of neurons immunoreactive to anti-beta-endorphin immune serum present in the infundibular nucleus in man].

Neurons containing peptide (s) immunologically related to beta-endorphin have been detected by immunochemistry in human adult and fetal hypothalami. Their perikarya are located in the infundibular nucleus. Some fibres terminate close to vessels in the median eminence, others form pericellular baskets around perikarya of non-immunoreactive neurons of the infundibular nucleus. These results suggest that the central nervous system elaborates beta-endorphin or immunologically related peptides.

Adult↗

[Immunocytological studies of C cells with anti-calcitonin or antisomatostatin immunoserums in rats treated with vitamin D, thyroxine or benzyl-thiouracil].

In rats treated with vitamin D3, thyroxin or BTU alone or with associations of vitamin D3 + BTU or vitamin D + thyroxin, immunocytochemical studies with an anti-human calcitonin serum show a stimulating effect of vitamin D and of thyroxin and an inhibiting effect of BTU on the C cells of the thyroïd. These results are in agreement with the existence of functional relations between follicular and C cells. A few calcitonin-containing cells are immunoreactive to an anti-somatostatin serum. All the C cells contain both calcitonin and somatostatin when they are grouped in a single big interfollicular cluster.

Animals↗

[Comparative immunocytological study of prolactin and somatotropin cells in Alytes obstetricans (Laur.) tadpoles raised in groups or isolated].

In the anterior pituitary of Alytes obstetricans Tadpoles in premetamorphic stages, two cell types were localized by cytoimmunological techniques: orangeophilic cells secreting a prolactin-like hormone in the anterior and median region and erythrosinophilic cells secreting growth hormone in a more caudal situation. Both cells are more numerous and stimulated in grouped Tadpoles than in isolated ones.

Animals↗

[Immuno-cytologic study of hypothalamic LH-RH neurons of the human fetus].

The immunocytological study of LH-RH producing neurons was carried out on 3 newborns and 14 fetuses (from 10 to 36 weeks of age). Perikarya and fibers which were immunoreactive to anti-LH-RH IS were revealed by IF or IE in all the hypothalamus beginning with the 13th week. Important variations in neurons staining may translate "physiological" differences in their LH-RH charge but can be also the result of the diverse technical conditions. In three 16-week-old female fetuses, the large number of neurons (more than 150 per hypothalamus) permitted a good topographical and morphological study of them. They are scattered in vast areas of the anterior hypothalamus (lamina terminalis (LT) and septum), mediobasal and premammillary hypothalamus. The fibers which are particularly immunoreactive in semi-thin sections form a large hypothalamo-infundibular contingent in the posterior lip of the ME where they give rise to collaterals that terminate in contact with the capillaries of the mantelplexus, this taking place both before and after the apparition of the intra-eminential loops at the 16th week. Numerous in the LT, they terminate around the deep capillaries of the vascular organ or in contact with the ependymal epithelium. Some extra hypophyseal fibers go towards the epithalamus and the mesencephalon. To conclude, very early, in the human fetus the peptidergic LH-RH system resembles that described in adult primates; its role in the maturation and control of the gonadotropic cells is evoked.

Female↗

[Somatostatin-containing fibers and neurophysin-containing fibers in the median eminence of the fox, as seen with a double staining cytoimmunoenzyme technique].

In the external layer of the median eminence of the fox, the somatostatin-containing fibers and neurophysin-containing fibers of the hypothalamo-infundibular tract are located in distinct areas. In the neural lobe, somatostatin-positive areas are simultaneously neurophysin-positive. Outside the SON and PVN, some somatostatin-positive and neurophysin-negative perikarya are scattered close to the third ventricle. These facts suggest the existence of two somatostatin systems: a hypothalamo-infundibular (neurophysin-negative) one and a hypothalamo-neurohypophyseal (neurophysin-positive) one.

Animals↗

[Immunocytological study of the gonadotrophic and thyrotrophic cells of the rat adenohypophysis].

On paraffin or semi-thin sections various anti-LH or anti-TSH sera stain indifferently all the thyrotrophs and the gonadotrophs. Inversely anti-beta-TSH, anti-beta-LH or anti-beta-FSH purified sera permit the discrimination of these two cell populations. The constancy of fixation of the anti-beta-LH and anti-beta-FSH sera on all the gonadotrophs gives evidence of their ability to produce both FSH and LH. However in a few female rats the central gonadotrophs are stained more weakly by anti-beta-FSH serum than by anti-beta-LH serum. The purification of the antisera by adjunction of hormonal antigens (alpha subunits or heterologous hormone) does not enable, with the PAP technique on thin sections, a selective staining of the secretory granules of the thyrotrophs or of the gonadotrophs.

Animals↗

[Cyto-immunologic location of alpha-MSH and ACTH in the lead-hematoxylin (HPb)-stainable pituitary cells, in the eel].

The lead-haematoxylin positive cells of the pars intermedia react with anti-alpha-MSH and anti-1-24ACTH or anti-17-39ATCH; those of the rostal pars distalis are only revealed with antisera anti-1-24ACTH and anti-17-39ACTH. Intensity of cytoimmunological staining, which is modified after various experimental treatments (reserpine, metyrapon, pimozid, cortisol...) and during black or white background adaptaiton, corresponds essentially to that of the PbH staining.

Adrenocorticotropic Hormone↗

[Cytoimmunological study of the corticotrophic and corticomelanotrophic cells in the adenohypophysis of Boops salpa L. (marine teleost) in different experimental conditions (variation of salinity and of background color)].

The cytoimmunological study of the adenohypophysis of Boops salpa (marine Teleost), in different experimental conditions confirmed that the MacConaill's hematoxyline-positive cells contain: 1. ACTH (Corticotrophic Hormone) in the pars distalis, 2. MSH (Melanocyte-Stimulating Hormone) and ACTH in the pars intermedia.

Adaptation, Physiological↗

[Cytoimmunological demonstration of LH-RH neurons in the human fetus].

Neurons and axons were characterized by means of an antiserum against LH-RH in hypothalamus of human faetuses from the 13th week of gestation until birth. The morphology and the elective localization of neurons and axons in the mediobasal hypothalamus, premamillary area and in lamina terminalis, and the termination of axons, particularly those of the tubero-infundibular tract, are described. The results obtained permit discussion of hypothalamic control of gondotropic secretion in the human faetus from the 13th week.

Axons↗

[Cyto-immunological study of the anterior pituitary somatotropin cells of male and female adult Peking, Barbary and hybrid (from crossing male Peking X female Barbary) ducks and of male ducklings of the 3 races)].

The anti-human-STH immunserum applied on hypophysis sections of adults males and females Peking (Anas platyrhynchos L.) Barbary (Cairina moschata L.) and Hybrid (from the mating male Peking X female Barbary) ducks, marks orangeophils, oval- or round shaped, PAS negative cells exclusively localized in the caudal lobe of the pars distalis. In the males ducklings of the three races this immunserum reveals numerous and partially exhausted cells. The authors conclude that the acidophils alpha cells observed in the caudal lobe of the duck are somatotrophic cells.

Age Factors↗