Search PubMed⌕ Search

Biomedical subjects

D Fellmann

Publications and source records attributed to D Fellmann.

At least 73 records · Page 4Linked to original sources
PubMed1990

[Study of the bronchoalveolar lavage in ankylosing spondylarthritis].

The study of the broncho-alveolar lavage (BAL) has been carried out in 15 consecutive (13 B27) ankylosing spondylarthritis (AS), compared to 17 test subjects. There is no modification of the number of cells, of the percentage of lymphocytes, of the CD4/CD8 ratio, of the beta-2-microglobulin or the conversion enzyme in the BAL liquid between the AS group and the test group. The IgA level of the BAL is lower and the IgA deposits in the bronchial mucosa are more frequent in the AS group (but not in a significant way). Unlike other inflammatory diseases, it seems that there is no subclinical alveolitis in the course of AS.

Adult↗
PubMed1989

Cloning of cDNAs encoding a rat neuropeptide immunologically related to salmon melanin-concentrating hormone.

In order to identify the neuropeptide related to melanin-concentrating hormone (MCH) synthetized by neurons of the posterior hypothalamus in the mammals, we have screened rat hypothalamus and rat brain cDNA expression libraries using MCH antiserum. We isolated 5 distinct immunopositive recombinants with cross-hybridizing cDNA inserts. One of them hybridized to RNAs exclusively located in neurons stained by the same antiserum, as seen by successively performing in situ hybridization and then an immunocytochemical technique on the same section. Sequencing of this MCH-like cDNA is in progress.

Animals↗
PubMed1989

Human hypothalamic neuronal system revealed with a salmon melanin-concentrating hormone (MCH) antiserum.

An antiserum raised against synthetic salmon melanin-concentrating hormone (MCH) reveals an extensive neuronal system in the posterior lateral areas of the human hypothalamus. These neurons correspond to those previously described in the rat, which are characterized by expression of MCH-like, alpha-melanotropin-like and human growth hormone-releasing factor (1-37)-like immunoreactivities.

Adult↗
PubMed1989

Coexistence of acetylcholinesterase-, human growth hormone-releasing factor(1-37)-, alpha-melanotropin- and melanin-concentrating hormone-like immunoreactivities in neurons of the rat hypothalamus: a light and electron microscope study.

Using an antiserum (AS) raised against rat cerebral acetylcholinesterase (AChE), we revealed a neuron population in lateral and dorsal areas of the posterior rat hypothalamus. These neurons were previously described using antibodies to human growth hormone-releasing factor(1-37) (GRF-37), alpha-melanotropin (alpha-MSH) and melanin-concentrating hormone (MCH). Different intracytoplasmic distributions of the immunodeposits were observed depending on the used serum. Ultrastructural investigations demonstrated that AChE-AS labeled rough endoplasmic reticulum and nuclear envelope in control rats. MCH-AS stained Golgi apparatus in control animals and secretory granules in colchicine-injected rats. GRF-37-AS always revealed secretory granules, and alpha-MSH-AS gave the same staining only after colchicine injection.

Acetylcholinesterase↗
PubMed1989

[Specific hybridization of a synthetic oligonucleotide in rat hypothalamic neurons immunoreactive to immune serum against salmon melanin-concentrating hormone].

An oligonucleotide probe corresponding to the 9 C-terminal residues encoded by a complementary DNA of a rat peptide related to salmon melanin concentrating hormone (MCH) was synthetized. It specifically hybridized to the neurons stained by antisera to MCH in the rat posterior hypothalamus, as seen by coupling in situ hybridization and immunocytochemical methods. This result validates our sequence determination. This oligonucleotide will be useful to establish the complete sequence of the rat MCH precursor molecule. It will also constitute a valuable tool to study physiological or experimentally-induced changes in the expression of the rat MCH gene.

Animals↗
PubMed1989

[Cloning of the cDNA, while encoding a hypothalamic neuropeptide in the rat, related to the melanin-concentrating hormone in the salmon].

In order to identify the neuropeptide related to salmon melanin-concentrating hormone (MCH) synthetized by neurons of the posterior hypothalamus in the mammals, we have screened rat hypothalamus and rat brain cDNA expression libraries using MCH antiserum. Five recombinants were isolated, which cDNAs were amplified using the polymerase chain reaction. One of them hybridized to RNAs exclusively located in hypothalamic neurons stained by the same antiserum, as seen by performing in situ hybridization and immunocytochemical techniques on the same section. The sequence analysis showed that this cDNA corresponds to the end of the open reading frame encoding a MCH-like peptide and to the 3' untranslated region. The rat MCH is very similar to salmon MCH (greater than 85% homologies in the 14C-terminal residues).

Amino Acid Sequence↗
PubMed1989

[Cloning and sequence analysis of cDNA of common precursors of three hypothalamic neuropeptides immunologically related to human somatocrinin 1-37, alpha melanotropin and salmon melanin-concentrating hormone].

We have cloned and sequenced DNAs complementary to the mRNA encoding the precursor of the rat melanin-concentrating hormone. This allowed us to elucidate the primary structure of the 96 C-terminal residues of this precursor. It contains three possible sites for enzymatic cleavage enabling the generation of MCH and of two additional neuropeptides. These three peptides can bind one of our antisera raised against human somatocrinin 1-37, alpha-melanotropin and salmon melanin-concentrating hormone, which immunocytochemically stain the same neuron population in the hypothalamus.

Amino Acid Sequence↗
PubMed1988

Dopaminergic neurons of the substantia nigra modulate preproenkephalin A gene expression in rat striatal neurons.

The messenger RNA coding for preproenkephalin A (PPA) was detected by in situ hybridization in striatal neurons in normal rats and in rats having had the right substantia nigra destroyed by an injection of 6-hydroxydopamine or by electrolysis. Animals were killed 15, 30, 45 and 70 days following the lesion. A double-stranded PPA cDNA and a single-stranded PPA cRNA labeled with 32P or 35S were used as probes to detect the PPA mRNA in brain sections. The controls demonstrated the specificity of the labeling. The darkening of X-ray film in contact with the striatum was appraised, the optical density was measured, and the density of the cells expressing the PPA gene in sections was calculated using an image analyzer. The mean number of silver grains per labeled cell (reflecting the number of PPA mRNA copies per cell) was also calculated using an image analyzer. The 6-hydroxydopamine lesion which destroyed all dopaminergic neurons in the right substantia nigra, provoked a large increase in the number of PPA mRNA copies in enkephalin neurons of the right striatum, and decreased the number of cells expressing the PPA mRNA in the left striatum. These variations substantia nigra provoked similar variations, but less intense.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[Peripheral distribution of a neuropeptide recognized by an antiserum raised against the mammalian CRF41, in the mollusc Helix pomatia].

Immunocytochemical methods using an antiserum raised against ovine corticoliberin revealed perikarya and processes in the central and peripheral nervous system of the Pulmonate Gastropod Helix pomatia. The coexistence of immunoreactive nerve fibres and primary sensory neurons in the intestinal wall and in the tentacles appeared particularly significant. The distribution of this peptide suggests that it could act as a sensory neurotransmitter at the central and peripheral levels.

Animals↗
PubMed1987

Anatomical study of enkephalin gene expression in the rat forebrain following haloperidol treatment.

The effect of haloperidol treatment on preproenkephalin A (PPA) gene expression in the rat forebrain was anatomically studied by using an in situ hybridization procedure. The PPA mRNA was detected in sections of control rats and of rats having received an i.p. injection of haloperidol for 14 or 21 days. Sections were incubated with rat PPA cDNA labeled with 32P or 35S, exposed with X-ray film and dipped in Ilford K-5 emulsion. The results showed that haloperidol treatment did not modify the number of cells expressing the PPA gene in the caudate-putamen, the nucleus accumbens, the septum and the olfactory tubercle. In contrast, the PPA mRNA content was increased in the neurons of the caudate-putamen and nucleus accumbens, but unchanged in other areas. These results demonstrate that haloperidol acts by increasing PPA mRNA content selectively in striatal neurons already expressing the PPA gene.

Animals↗
PubMed1987

Unrelated peptide immunoreactivities coexist in neurons of the rat lateral dorsal hypothalamus: human growth hormone-releasing factor1-37-, salmon melanin-concentrating hormone- and alpha-melanotropin-like substances.

Antisera raised against 3 unrelated synthetic neuropeptides - salmon melanin-concentrating hormone, human growth hormone-releasing factor1-37, and alpha-melanotropin - stained the same extensive neuron population in lateral and dorsal areas of the posterior hypothalamus. Controls for specificity have shown that these 3 antisera bind 3 different epitopes. Differences in intracellular staining patterns suggest that these epitopes could be borne by distinct peptides.

Animals↗
PubMed1987

Human corticoliberin hypothalamic neuroglandular system: comparative immunocytochemical study with anti-rat and anti-ovine corticotropin-releasing factor sera in the early stages of development.

Development of the paraventriculo-infundibular corticoliberin system was studied by immunocytochemical analysis of human hypothalamic sections using antisera raised against rat or ovine corticotropin-releasing factor (CRF). This comparative study confirms the presence of a significant number of CRF-immunoreactive fibers in the median eminence during the 16th week of fetal development and suggests they may appear as early as the 14th week. Some hypothalamic peri- and paraventricular neurons, observed from the 12th week, are rat-CRF-immunoreactive but not ovine CRF-immunoreactive. There appears to be chronological differences concerning the ability of the two antisera to recognize hypothalamic structures during the early stage of development.

Animals↗
PubMed1987

Immunological study of the tissue expression of D-beta-hydroxybutyrate dehydrogenase, a ketone body-converting enzyme.

In rats, as in most mammal, ketone bodies are mainly produced in liver while they are metabolized in extrahepatic tissues. The expression of mitochondrial membrane-bound D-beta-hydroxybutyrate dehydrogenase (BDH), a ketone body-converting enzyme, has been estimated by two immunological techniques: immunohistofluorescence and Western blotting. The in situ labeling with anti-BDH antibody shows that the enzyme is expressed differently among the organs. Furthermore, within a given organ there are strong differences according to the cell type. The quantification of the enzyme by immunoblotting reveals that liver mitochondria have the highest content (more than 3% in protein mass). This content is 3,5 and 10 times lower in kidney, heart and brain mitochondria, respectively. Parallel D-beta-hydroxybutyrate dehydrogenase activity measurements on isolated mitochondria show differences in molecular activity of this enzyme according to the tissue origin. Due to the phospholipid requirement of this enzyme these differences in molecular activity are related to specific membrane lipid composition.

Animals↗
PubMed1987

[Contribution of immunocytochemistry to the study of the development of neuroglandular peptidergic systems in the human fetal hypothalamus].

Immunohistochemistry makes possible the in situ detection of neuropeptides in the cell bodies were they are synthesized, in the fibers that carry them, and in endings. Immunohistochemistry appears necessary to identify and map peptidergic neurons and to study their ontogeny. From 1975, we have carried the immunohistochemical study of several hypothalamic neuronal populations in the human fetus: LH-RH (1976), somatostatin (1977), pro-opiocortin (1978), vasopressin and oxytocin (1979), corticoliberin (1982), somatocrinin (1983), and hypothalamic neurons containing an unidentified peptide (1984). Comparative ontogenetical studies have also been performed in rats.

Animals↗
PubMed1987

[Ontogenetic data on the peptidergic interneuronal population in immunoreactivity of the GRF 37 type serum of the human posterolateral hypothalamus. Immunocytochemical studies using anti-GRF 37 and anti-MCH (melanin-concentrating hormone) immune sera].

Human posterolateral hypothalamic neurons are revealed with an anti GRF 37 serum as soon as the 7th week of fetal life. The same neuronal population can be observed in the adult brain even in hypothalami from old subjects, with the same distribution, and similar immunoreactivity than in fetal stages. These neurons are revealed using a melanin concentrating hormone (MCH) antiserum; the MCH immunoreactivity appears at the same stage of fetal development than GRF 37 immunoreactivity. The two antisera recognize two epitopes on one or two molecules. Those new facts agree with an hypothesis about the very important and permanent functional role of that new human hypothalamic interneuronal system.

Adult↗
PubMed1986

Coexpression of human growth hormone-releasing factor 1-37-like and alpha-melanotropin-like immunoreactivities in neurones of the rat lateral dorsal hypothalamus.

Antibodies recognizing the 29-37 sequence of the human somatocrinin specifically stain a large population of interneurones located in the lateral dorsal hypothalamus. Staining comparisons revealed that these perikarya also contain alpha-MSH-like immunoreactivity. The neurones exhibiting human GRF1-37-like immunoreactivity correspond to the system previously shown to present alpha-MSH-like and rat CRF-like immunoreactivities.

Animals↗
PubMed1986

[Ontogenesis in man, of a population of neurons in the dorsal and lateral hypothalamus, secretors of a peptide that has not yet been characterized].

A human GRF 1-37 antiserum demonstrates a new neuronal system in lateral perifornical areas of the human hypothalamus. The molecule that is revealed in those neurons cannot be somatocrinin. Perikarya are abundant. They are observed beginning with the 9th week of development. alpha-MSH-like immunoreactivity, which is showed in the analogous cells of the rat, is not yet established in human. The early differentiation of those neurons and their abundance during the fetal life attest to the important neurophysiological function of the unidentified peptide they secrete.

Fetus↗