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D Fellmann

Publications and source records attributed to D Fellmann.

At least 91 records · Page 5Linked to original sources
PubMed1986

[In vitro semi-automated morphometry of preserved human corneal endothelium].

Cellular morphometry allows us to quantify the structural alterations of the corneal endothelium. Our study was a semi-automatized in vitro analysis of fresh and preserved corneal endothelium (MK medium cryopreservation). The equipment used was the Quantimeter 720 connected to a Digital PDP1123 computer. Nineteen corneas were studied and the following cellular parameters were established: perimeter, surface area, form factor and polymorphism coefficient. The computer program used was the SPSS/PC (Statistical Package for the Social Sciences) and the principal statistical tests were the Bartlett test and variance analysis. The statistical computerized study allowed us to compare the four cellular parameters and to establish the incidence rate of the conservation process on endothelial morphometry. The statistical and morphometry methods have proved to be reproducible and reliable and carry a supplementary quantitative element to analyse the influence of the conservation process.

Adult↗
PubMed1985

Immunohistochemical demonstration of a new neurone system in rat brain using antibodies against human growth hormone-releasing factor (1-37).

An antiserum raised against the 1-37 N-terminal sequence of the human growth hormone-releasing factor (GRF) stains two distinct neurone systems in rat brain: the somatocrinin neuroglandular system in the infundibulum and a large, hitherto unknown population of interneurones, the perikarya of which are chiefly distributed in the lateral hypothalamus. Their projections are abundant in several hypothalamic and limbic areas. These interneurones contain high amounts of a substance, probably a new neuropeptide, sharing an epitope with the 29-37 sequence of the human GRF.

Animals↗
PubMed1985

Anatomical and ontogenetic studies of the human paraventriculo-infundibular corticoliberin system.

In human fetus, newborn, infant and adult hypothalami, antibodies to ovine corticoliberin-41 stain a paraventriculo-infundibular neuroglandular pathway. The perikarya are located in the paraventricular nucleus, they mainly project to the ventral and lateral areas of the median eminence. Eminential corticoliberin-positive fibres appear during the 16th week of fetal life, and increase in number during the following weeks. Perikarya were first revealed in the 19th week. In some areas of the median eminence, corticoliberin-, vasopressin- or [Met]enkephalin-immunoreactive terminals are similarly distributed. Sequential stainings or staining comparison of contiguous semi-thin sections failed to prove the coexpression of corticoliberin and [Met]enkephalin immunoreactivities in fibres, but indicated that corticoliberin and vasopressin immunoreactivities may be coexpressed in a few fibres. Those methods enabled us to observe, in the paraventricular nucleus, perikarya revealed by corticoliberin and vasopressin antisera. Our results suggest a possible release of corticoliberin in portal vessels of the median eminence beginning in the 16th week of fetal life, i.e. 8 weeks later than appearance of the corticotrophs in the pituitary. Establishment of a corticoliberin hypothalamic control of pituitary corticotrophs at mid gestation agrees with previous physiological and teratological studies. Abundance, as well as immunostaining intensity of the corticoliberin processes, in the infant and adult median eminence attest to the physiological importance of this system. Close vicinity of corticoliberin, vasopressin and [Met]enkephalin fibres, in some eminential areas and coexpression of corticoliberin and vasopressin immunoreactivities in some neurons, are morphological correlates of functional relations which were reported.

Adult↗
PubMed1985

Immunodetection of bovine chorionic somatomammotrophin (bCS).

Bovine chorionic somatomammotrophin (bCS) was detected in the bovine placenta by using an immunoenzymatic procedure. This hormone appears mainly located in the binucleate cells of the foetal cotyledons and to a lesser extent in some localized superficial areas of the foetal and maternal epithelium. These areas may correspond to foetal binucleate cells migrating into the maternal caruncles.

Animals↗
PubMed1985

[Phenotype of periparasitic hepatic infiltrating mononuclear cell in human alveolar echinococcosis].

Phenotypic analysis with monoclonal antibodies showed that OKT8+ T cells represent the main cell population of the periparasitic mononuclear cell infiltrate in the liver of 7 patients with alveolar echinococcosis. A significant decrease of the OKT8+ subpopulation had been previously demonstrated in the peripheral blood mononuclear cells of these patients. The results obtained in this study suggest an intrahepatic homing for these particular T cells. However, functional analysis of these cells is required in order to assess the physiopathological significance of these observations.

Antibodies, Monoclonal↗
PubMed1985

[Coexpression of immunoreactivity with an anti-corticoliberin immune serum and immunoreactivity with an anti-vasopressin immune serum in human hypothalamic neurons].

Confrontations of immuno-stainings as well as sequential stainings with corticoliberin and vasopressin antisera were performed on contiguous sections of human median eminence (ME) or hypothalamic paraventricular nucleus (PVN). Results show that a double immunoreactivity to both IS is expressed in some parvicellular PVN perikarya, and suggest that such a double immunoreactivity can be possible in some ME fibers. Similar results had been previously obtained in animals only under experimental conditions.

Corticotropin-Releasing Hormone↗
PubMed1985

[Immunocytochemical localization of alpha-melanotropin in bovine placenta].

The immunocytochemical study of the bovine placenta has demonstrated the presence of cells containing alphamelanotropic hormones, in the decidual epithelium, since the 4th month of pregnancy. The number and the staining intensity of those cells grow up with the placental development. Since the 6th month, we observed the immunoreactional presence of cells in the foetal chorionic epithelium.

Amnion↗
PubMed1984

Corticoliberin neurons: cytophysiology, phylogeny and ontogeny.

In the rat hypothalamus, antibodies to ovine CRF41 stain neurons of a paraventriculo-infundibular neuroglandular pathway. CRF like immunoreactivity (CLI)-containing perikarya are mostly packed in the parvocellular division of the paraventricular nucleus. Their morphology and topography differ from that of other peptidergic neurons. However a few CLI perikarya are also stained with vasopressin antibodies. CLI neurons project massively to the external layer of the median eminence (ELME). Adrenalectomy induced a total depletion of ELME CLI 12 to 24 h after surgery, followed by a secondary accumulation already conspicuous 5 days later. This biphasic evolution, identical to that of ELME vasopressin, is totally prevented by a replacement therapy with dexamethasone. Reserpine also induces an acute depletion of ELME CLI and vasopressin, that can be prevented by a monoamine oxidase inhibitor pretreatment. These results indicate the involvement of CLI neurons in the corticotropic axis, suggesting that they are indeed corticoliberin neurons. Among the extrahypothalamic locations of CLI neurons their abundance in the amygdala central nucleus is of interest since it is involved in the corticotropic axis. A similar pattern of CLI was noticed in several mammalian brains and also in lower vertebrates (birds, reptiles, amphibians, fishes). Species adaptations of CLI neurons were observed: CLI neurons are of the cerebrospinal fluid contacting type in the turtle. CLI fibres terminate close to corticotrophs in the fish pituitary. This suggests a direct excitosecretory role of CRF on these cells and concurs with a CRF function of CLI peptide even in fishes. CLI processes and terminals appear in the human fetal ELME at the 16th week of development and increase in number during the following weeks. Perikarya are seen at 19 weeks. In the rat CLI fibers and perikarya were detected as early as the 18th day of fetal development. Thus, paraventriculo-infundibular CLI system develops later than corticotrophs. This chronology perfectly concurs with the results of previous physiological and experimental studies.

Adrenalectomy↗
PubMed1984

The CRF neuron: immunocytochemical study.

In the central nervous systems of several species belonging to different vertebrate classes, immunocytochemical stainings with an antiserum to ovine CRF 41 show multiple location of CRF perikarya and various areas containing CRF fibres and terminals. These stainings reflect species and interspecies functional adaptations of the CRF neurones which constitute a prominent hypothalamo-infundibular system involved in pituitary gland control, and also interneurone systems as attested to by extrahypothalamic perikarya and by CRF perisomatal endings in several brain areas. Perikarya of the hypothalamo-infundibular system are mainly packed in the paraventricular nucleus (mammals, birds) or in homologous areas, e.g.: paraventricular organ (turtle) where they are CSF-contacting neurones and preoptic nucleus (amphibians, fishes). In all species but fish, CRF fibres end in the median eminence (ME) against portal vessels. In fish, CRF processes terminate in the peripheral areas of proadenohypophyseal neurodigitations, close to corticotrophs. In all species these stainings are abolished by preabsorption of the serum by CRF. In fishes, reptiles and amphibians they are also suppressed by urotensin I, which is thought to be the teleost's CRF. Adrenalectomy experiments in the rat provided evidence for a corticosteroid regulation of ME CRF: short term (12-24 hr) adrenalectomy induces a complete depletion of CRF immunoreactivity followed by a secondary accumulation (5-20 days). This biphasic evolution is prevented by a dexamethasone replacement therapy. Inhibitory role of catecholamines on CRF release was indicated by: disappearance of ME CRF, induced by a single reserpine injection and suppression of this effect by monoamineoxidase inhibitor (pargyline or tranylcypromine) pretreatment. CRF fibres were first observed in the ME at the 16th week of fetal development in the human, and at the 18th day in the rat fetus. Thus, immunoreactive CRF system develops later than pituitary corticotrophs.

Adrenalectomy↗
PubMed1984

Ontogeny of the neuroglandular system revealed with HPGRF 44 antibodies in human hypothalamus.

Using the indirect immunofluorescence technique, an antiserum to synthetic hpGRF 44 (the 44 residue peptide with high growth hormone releasing activity isolated from a human pancreatic tumor), antibodies of which interact with 40-44 C terminal amino acid sequence, stains a novel neuron system in the adult human hypothalamus. HpGRF-like immunoreactivity (GLI) containing neurons are different from previously known peptidergic systems. GLI perikarya are few in number and located mainly in the infundibular nucleus. In the median eminence, abundant GLI fibers terminate against portal capillaries in the same areas as somatostatin fibers which are morphologically different. No GLI staining was observed in hypothalami before 18 weeks of fetal development. GLI perikarya and intraeminential nerve terminals were simultaneously detected in 18-week-old fetuses attesting to a possible release of this peptide in the portal vessels as early as this stage. GLI neuron system was steadily revealed in 19- to 30-week-old fetuses. It was not detectable in 6 out of the 7 studied hypothalami from newborn infants. In most infant and adult hypothalami, it is well developed. Results presented here support the hypothesis (1) that hpGRF antiserum stains the neuron system producing the somatocrinin and (2) that this neuron system may begin in controlling pituitary somatotrophs at the 18th week of fetal development, which is in agreement with previous hypotheses.

Adult↗
PubMed1983

[Latent pituitary adenoma. Autopsy study].

The incidence of latent pituitary microadenoma is poorly known as few studies have as yet been carried out. To address this problem, microadenoma was systematically looked for during 100 random routine post-mortem examinations in subjects with no endocrine disorders. Microadenoma was found in ten cases. Immunocytochemical study demonstrated prolactinoma in 6 cases, somatotropic adenoma in 1, mixed adenoma in 1, and non-functional adenoma in 2. Microadenoma seems more prevalent between fifty and sixty years of age. Outcome is discussed: spontaneous resolution, growth with onset of clinical manifestations, or persistence without changes in size.

Adenoma↗
PubMed1983

Reserpine-induced depletion of corticoliberin (CRF)-like immunoreactivity in the zona externa of the rat median eminence.

An acute reserpine treatment has the same selective and marked depleting effect on corticoliberin-like immunoreactivity as on vasopressin-like immunoreactivity in the rat zona externa of the median eminence. Somatostatin and gonadoliberin immunoreactivities appear unmodified. Reserpine effect is blocked by pretreatment with monoamine oxidase inhibitors (pargyline or tranylcypromine). Present results support the notion of an inhibitory role of monoamines, particularly catecholamines, on the release of corticoliberin.

Animals↗
PubMed1983

Immunocytochemical demonstration of a novel peptidergic neurone system in the cat brain with an anti-growth hormone-releasing factor serum.

In 15-day-, 1-month- and 1.5-month- old cats an antiserum against hpGRF-44 stained a novel hypothalamo-infundibular neuroglandular system. Its intra-eminential processes present an important development between 15 and 30 days of age. Perikarya and nerve fibres, which are abundant in several brain areas as early as the 15th day, suggest that the peptide revealed by hpGRF-44 antibodies also acts as a neuromodulator.

Animals↗
PubMed1983

Changes in corticoliberin and vasopressin-like immunoreactivities in the zona externa of the median eminence in adrenalectomized rats. Immunocytochemical study.

The zona externa of the median eminence was found completely depleted of corticoliberin-like immunoreactivity (CLI) and of vasopressin-like immunoreactivity (VLI) 12-14 h and 22-24 h after bilateral adrenalectomy. Amount of CLI increased to the level of untreated rats 5 days after this operation while amount of VLI rose higher than in control animals. The same was found 20 days after surgery. These results emphasize the involvement of two infundibular neurosecretory systems--CLI and VLI--in the regulation of the pituitary--adrenal axis.

Adrenalectomy↗