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Biomedical subjects

A Morin

Publications and source records attributed to A Morin.

At least 91 records · Page 5Linked to original sources
PubMed1984

Inhibition of human IL 2 production by MDP and derivatives.

In the present study, well-defined immunomodulatory synthetic glycopeptides were used to investigate putative regulatory mechanisms of in vitro IL 2 production by normal human peripheral blood mononuclear cells. MDP (muramyl dipeptide) and two of its structural analogs, murabutide and MDP-DD, were shown to inhibit the in vitro PHA-induced IL 2 production in a majority of normal individuals tested. Involvement of prostaglandins in such an inhibitory effect was suggested by the fact that indomethacin completely abrogated the MDP-induced suppression. There was, however, some evidence indicating that the inhibition induced by the synthetic glycopeptides and that induced by PGE2 were somewhat different. Indeed, although the PGE2-induced suppression of IL 2 production was completely reversed by preirradiation of PBMNC, this was not observed for the MDP-dependent inhibition. In addition, PMA was able to abrogate the suppression induced by MDP, whereas it increased that of PGE2. From these data we propose that at least two independent pathways in the regulation of human IL 2 production exist: a one-signal pathway already described in which PGE2 directly triggers a radiosensitive suppressor T cell subset; and a second pathway with two signals, one given by PGE2 and a second one given by agents such as muramyl peptides. These two signals are required to activate a radioresistant suppressor cell subset.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1984

[Congenital anomalies of the origin and/or distribution of coronary arteries originating from the aorta. Angiographic study of 39 cases].

39 cases of congenital anomalies in the origin and/or in the distribution of the coronary arteries arisen from the aorta, without associated cardiac abnormality, seen in the course of 6 525 selective coronary arteriographies in adults, are reported and integrated into a general classification of coronary arteries abnormalities. The clinical correlation of these anomalies is specified. The authors emphasize the importance of their diagnosis in the surgery of valve replacement or of myocardial revascularization.

Adult↗
PubMed1984

[The cloverleaf skull. Anatomical presentation of a case].

We report the case of a still-born baby girl who had a rare craniostenosis known as the "clover leaf skull syndrome". The 125 previously reported cases were reviewed allowing us to better define the principal features of this condition.

Female↗
PubMed1984

Regulation by muramyl dipeptide (MDP) of the lymphoproliferative responses and polyclonal activation of human peripheral blood mononuclear cells.

The ability of muramyl dipeptide (MDP), its adjuvant inactive stereoisomer, MDP(D-D), and the non-pyrogenic, adjuvant active analogue, MDP-butyl ester (MDP-BE), to induce in vitro proliferation and/or polyclonal activation (PA) of peripheral blood mononuclear cells (PBMNC) from normal volunteers, was studied. MDP, as well as its two analogues, were incapable of inducing 3H-thymidine uptake or immunoglobulin synthesis in PBMNC cultures from the majority of the individuals tested. However, these muramyl peptides were capable of regulating the in vitro proliferative responses of some individuals to concanavalin A and to soluble antigens of Candida albicans. At the same time, enhancement of the pokeweed mitogen-induced IgA and IgM but not IgG PA was observed with MDP, its adjuvant active analogue MDP-BE, but not with the adjuvant inactive stereoisomer MDP(D-D). Results are discussed with relation to a possible genetic restriction of the responsiveness to MDP.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1983

Inverse control of prolactin and growth hormone gene expression: effect of thyroliberin on transcription and RNA stabilization.

The hypothalamic tripeptide thyroliberin (TRH) regulates prolactin (PRL) and growth hormone (GH) synthesis inversely by modulating the levels of their specific mRNA. Changes in mRNA levels could involve both transcriptional and posttranscriptional events. To examine further these possibilities, we have investigated the effect of TRH on the biosynthesis and degradation of PRL and GH RNA in a rat pituitary tumor cell line. Newly synthesized PRL and GH RNA sequences were quantified in nuclear and cytoplasmic fractions by hybridization of 3H-labelled RNA to immobilized plasmid DNA containing either PRL or GH cDNA sequences. Steady-state levels of specific RNA were estimated by RNA blot hybridization. The results indicate that TRH increases in a rapid but transient manner the transcription of the PRL gene, and suggest that it does not alter the processing and the transport to the cytoplasm. In contrast, after a lag-time, TRH seems to induce a long-lasting inhibition on GH, as well as on overall gene transcription. Furthermore, we observed an effect of TRH on mRNA stability. TRH significantly increases the half-life of PRL mRNA. Our results also support the hypothesis that TRH decreases the half-life of GH mRNA. Such post-transcriptional action of TRH amplifies and prolongs the regulations exerted at the transcriptional level.

Animals↗
PubMed1983

Effect of monensin on secretory pathway in GH3 prolactin cells. A cytochemical study.

The effects of the carboxylic ionophore monensin have been studied on a rat prolactin cell line (GH3 cells) under basal conditions or after acute stimulation by thyrotropin-releasing hormone (TRH). It was found that 1) monensin induces a rapid dilatation of Golgi elements in these endocrine cells; 2) secretory product, prolactin, is localized by electron microscope immunocytochemistry attached to the inner face of the membrane of these dilated vacuoles; 3) monensin induces preferentially a dilatation of the cis face of the Golgi zone, since the "GERL" complex identified by acid phosphate cytochemistry is disorganized or fragmented rather than vacuolized; and 4) monensin decreases strongly the basal release of prolactin in the culture medium but does not prevent the stimulating effect of TRH on this release. This suggests that monensin blocks preferentially the pathway of release of secretory product under basal conditions in GH3 cells but that another pathway less sensitive to monensin is involved under acute stimulation by TRH.

Acid Phosphatase↗
PubMed1982

Effect of isoprinosine on in vitro proliferative responses of human lymphocytes stimulated by antigen.

Isoprinosine, a synthetic purine derivative, did not significantly interfere with the thymidine uptake of triggered normal lymphocytes, nor exhibit a detectable mitogenic activity. Isoprinosine was able to significantly enhance specific proliferative responses of human lymphocytes from sensitized donors to soluble antigens. Isoprinosine did not alter the early interaction of human mononuclear cells with 125I-labelled antigen, nor the expression of their membrane receptors for immunoglobulin Fc fragments. The agent could not replace the accessory rôle of adherent cells in proliferative responses to antigens. The enhancing effect of isoprinosine on antigen specific responses of T-cells was observed upon adding the compound on any one of the seven days of culture. Isoprinosine partially restored the inhibited proliferation of lymphocytes cultured in the presence of deoxyadenosine and deoxycoformycin. Data suggest that metabolic changes involving purines may account for the effect of isoprinosine on the expression of T-cell responses.

Adult↗
PubMed1982

Inhibitors of Neisseria gonorrhoeae produced in liquid medium by Bacteroides fragilis and Eubacterium limosum.

Indigenous micro-organisms of the urogenital flora including anaerobes can inhibit the in vitro growth of Neisseria gonorrhoeae. Bacteroides fragilis and Eubacterium limosum strains known to inhibit the gonococcal growth on solid medium have been shown to produce their antigonococcal activities in liquid medium. Concentrations of individual short-chain fatty acids produced by E. limosum strains were lower than the inhibitory concentrations reported for N. gonorrhoeae. B. fragilis strains produced propionic acids in amounts known to be inhibitory to the gonococcus. Furthermore, studies with E. limosum (Ps11A) cultures incubated at 29 degrees C (200 ml, 50 l) and at 37 degrees C (200 ml) have shown that short-chain fatty acids were not the inhibitors since no correlation between the short-chain fatty acids and the antigonococcal activity was found throughout the growth of the cultures. Moreover, the observed inhibitory activity of E. limosum was not due to pH change or to nutrient depletion of the medium. These observations coupled with the specificity of the antigonoccal activity produced by E. limosum suggest that it is different from previously reported gonococcal inhibitors of bacterial origin.

Anti-Bacterial Agents↗
PubMed1980

Rapid temperature programmed gas-liquid chromatography of volatile fatty acids (C1-C7) for the identification of anaerobic bacteria.

A gas liquid chromatography method for the separation of 10 volatile fatty acids (C1-C7 and isomers) has been improved by using oven temperature programmed conditions. In our conditions, the proprietary stationary phase SP 1220 introduced by Supelco Inc., gave sharp separation of volatile fatty acids in less than 8 min. This method was suitable for analyses with both thermal conductivity and flame ionization detectors.

Anaerobiosis↗
PubMed1980

[Production of human type I interferon by lymphocytes in contact with cells infected by herpesvirus and fixed with glutaraldehyde].

Type I interferon was released from human lymphocytes cultured on cells infected with Herpesvirus and fixed with glutaraldehyde. This process of interferon induction did not involve histocompatibility antigens nor the Herpes immunity of the lymphocyte donors. Type I interferon can also be induced after interaction between lymphocytes and other intranuclear replicating virus infected cells.

Adult↗
PubMed1980

In vitro inhibition of Neisseria gonorrhoeae growth by strict anaerobes.

Thirty two anaerobic bacterial strains were screened for their in vitro inhibitory activity toward 21 Neisseria gonorrhoeae strains, including two penicillin-resistant strains. From this screening, six anaerobic bacteria belonging to the genera Bacteroides, Peptostreptococcus, and Eubacterium were selected for their large antigonococcal spectrum of activity. The inhibitory activity of these six strains appears to be specific to the gonococcus as a variety of anaerobes and aerobes were not generally inhibited by these strains. The antigonococcal effect was not due to pH change or nutrient depletion of the media.

Bacteroides↗
PubMed1977

[Arterial vascularization of the os coxae].

Study of the arterial vascularization of the coxal bone by microangiographic methods. Nutritive and periosteal blood-vessels come from Iliaca interna and Iliaca externa arteries. The ilium is vascularized by the Ilio-lumbalis artery which is a nutritive blood vessel. A eriosteal vascularization also exists. Ischium and pubis have a periosteal vascularization. Blood vessels are oriented toward the sus-acetabulum area where many anastomoses exist.

Angiography↗
PubMed1977

[Human celosomias].

Definition and nomenclature of celosomia are based on a historical review which provides a system of classification. Morphology and organogenesis of celosomia were studied on 64 embryonic and foetal bodies. The anatomical study of 6 cases of human celosomia provided a definition of the characteristics of major celosomia, by showing the constant elements of the syndrome (particularly the parietal malformation) and the anomalies frequently found in each of the different types:--anterior (or superior) celosomia;--middle celosomia, including laparoschisis;--posterior (or inferior) celosomia, among which exstrophy of the bladder may be either one of the constant elements of the syndrome, or a limited form of the inferior celosomia;--total celosomia, of which one case was studied for this report, and of which the major forms, the schistosomia, chelinosomia and strophosomia types, seem to constitute forms of transition with other types of monstruosity. With improved knowledge of anatomy and organogenesis the possibilities of treatment have improved over the past few years, but still remain limited in the more monstrous forms of celosomia.

Abdomen↗
PubMed1975

Effect of thyreotrope-releasing hormone (TRH) on prolactin turnover in culture.

A kinetic study of the influence of thyreotrope-releasing hormone (TRH) on prolactin turnover and synthesis by a new rat pituitary prolactin cell line (SD1) has been performed by means of pulse-chase experiments. After a 10-min [3H]leucine pulse, the chase was carried out in the presence or absence of TRH (54 nM), cycloheximide (3.6 X 10(-5)M) and/or [14C]-proline. The prolactin content of the cells in the medium was estimated using a radioimmunoassay technique. The specific radioactivity of prolactin in the medium was estimated after its isolation by disc gel electrophoresis. This kinetic study demonstrated, firstly, a rapid intracellular transit of newly synthesized prolactin (15 + 10 min or less); secondly, the existence of at least two intracellular prolactin pools; thirdly, a rapid effect of TRH on release of stored prolactin, which is independent of de novo protein synthesis, and fourthly, a delayed stimulating effect of TRH on prolactin synthesis.

Cell Line↗