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Biomedical subjects

L Meunier

Publications and source records attributed to L Meunier.

At least 91 records · Page 5Linked to original sources
PubMed1988

[Does plasma exchange have a place in the treatment of necrotizing angiodermatitis?].

Necrotizing angiodermatitis is of characteristic clinical expression and is often difficult to treat. It is associated with microcirculatory disorders of hypertensive or diabetic origin. A particularly long course (m = 8 months) in 8 patients with necrotic angiodermatitis (of hypertensive origin in 6 cases and diabetes in 2) resulted in treatment by plasma exchange, two other patients with immunological angiodermatitis being treated similarly because of very similar symptomatology. The 10 patients (3 men, 7 women age range 55 to 80 years) received between 4 and 18 small volume plasma exchanges over 2 to 12 weeks. Results were evaluated from pain and duration of healing, absence of pain being reported by 7 patients and a beneficial effect on healing by 6 patients. No correlation existed between ESR and hematocrit values during treatment and the clinical course. The question arises as to whether the mode of action of plasma exchange in angiodermatitis is related to the purifying of serum factors or a rheological role.

Aged↗
PubMed1987

New in vitro procedures for experimental studies on the development of 11-day mouse embryo forelimb buds.

A new method has been developed for culturing 11-day mouse forelimb buds in vitro. In cultures performed with conventional procedures, skeletal pieces frequently appeared distorted and reduced in size. Moreover, forelimb buds explanted from embryos younger than a stage corresponding to 50 pairs of somites developed narrow hand plates devoid of radiated autopods. By contrast, in the new procedure using media supplemented with fetal calf serum and growth factors and enhancing distal feeding with carrier implants of catgut, enlarged pads were obtained that exhibited at least 4 digital rays in buds explanted from embryos with 40-44 pairs of somites. Compared with conventional procedures, the mean value of DNA content per limb bud was twice as great with use of our improved method. The ability of limb bud cells to proliferate and differentiate when cultured either in classical or in modified conditions, and the importance of the technical procedures, are discussed in the new prospect of in vitro developmental studies.

Animals↗
PubMed1986

[Systemic scleroderma. Contribution of esophageal manometry].

Oesophageal motor function was studied by oesophageal manometry in 48 patients with progressive systemic sclerosis: 25 with proximal scleroderma and 23 with diffuse scleroderma. Oesophageal lesions were noted in 70% (74% in diffuse scleroderma; 64% in proximal scleroderma). Classical manometric signs of scleroderma were found in only 31% of patients. Peristaltic modifications might begin at the junction of the two muscular coats, since a four centimeter long aperistaltic suspended area was noted in that region in 20% of patients, especially in the proximal scleroderma group. Oesophageal motility and low lower oesophageal sphincter pressure account for the gastro-oesophageal reflux and may compromise respiratory function, as suggested by the high frequency of concurrent oesophageal and respiratory dysfunction in diffuse scleroderma. Systematic prevention of gastro-oesophageal reflux should perhaps be advocated as soon as abnormalities in oesophageal motility are diagnosed.

Adolescent↗
PubMed1986

Chondrogenesis in mouse limb buds in vitro: effects of dibutyryl cyclic AMP treatment.

We studied the effects of dibutyryl cyclic AMP (dbcAMP) on mouse limb-bud chondrogenesis at three stages of embryonic development. After 24 h of culture, limb buds with or without a covering of ectoderm were treated with 1 mM dbcAMP for 48 h and were then compared with untreated cultured limb buds. Treatment with dbcAMP enhanced cartilaginous differentiation in organ cultures of stage-17 and -19 (according to Theiler's) limb buds, although the presence of ectoderm reduced the level of dbcAMP stimulation. By stage 20, treatment with dbcAMP irreversibly inhibited cartilaginous differentiation. These results suggest that the responsiveness of mesenchymal limb-bud cells to dbcAMP is stage related. The results of histological studies as well as of analyses of DNA content and sulphated glycosaminoglycan accumulation supported the hypothesis that dbcAMP treatment induces recruitment of initially non-chondrogenic cells whose commitment explains the enhancement of cartilaginous differentiation. Limb-bud competence for chondrogenesis throughout the three developmental stages studied is also discussed.

Animals↗
PubMed1986

[Chronic herpes of the pyodermatitis vegetans type in chronic cutaneous lymphoid leukemia].

The authors report a case of chronic herpes virus infection of the face which developed in a 70-year old man already affected with chronic lymphocytic leukaemia of the B-cell type (CLL-B) with specific cutaneous localisations. Immunodepression was indicated only by marked hypogammaglobulinaemia. Cell-mediated immunity was preserved. The cutaneous lesions of the face were chronic and presented as pyodermatitis vegetans. A one-week course of acyclovir administered by intravenous infusion in doses of 5 mg/kg three times a day resulted in rapid and dramatic cure, but this result proved transient, since the virus infection relapsed 2 1/2 months later. The new episode also was successfully treated with a second course of acyclovir. The herpes virus infection had developed only on those skin areas that were specifically affected by the leukaemia; after treatment and eradication of the virus, massive lymphocytic infiltration of the dermis persisted in these areas. Involvement of the skin is rare in CLL-B and has been reported mainly in CLL-T. The lesions most frequently encountered are tuberous and papular lesions and infiltrated plaques on the forehead and ears. The pyodermatitis vegetans presentation is unusual. The reasons why viral skin lesions develop on those caused by leukaemia are unknown.

Acyclovir↗
PubMed1985

[Chondrogenesis in mouse limb bud in vitro. I. Effect of the ectoderm].

The role of the ectoderm in the chondrogenesis of mouse limb bud mesoderm was investigated in vitro at several developmental stages by analysis of the evolution of DNA content, the accumulation of sulfated glycosaminoglycans and histochemical procedures. Young limb buds or the undifferentiated apex of older buds (stages 17 and 19 of Theiler's table) from which the ectoderm had been removed with trypsin treatment initiated a large chondrogenesis but not morphogenesis. When the ectoderm was present, these limb buds showed a polarized proximal to distal outgrowth and differentiated skeletal primordia. Mesodermal cells of stage 20 limb bud apex were able to differentiate autopodial skeletons with or without the presence of the ectoderm: cartilaginous areas of the limb skeleton seem determined at this developmental stage. These results, which show the importance of the ectoderm in limb bud morphogenesis, are compared with results obtained using other methods with mouse or bird buds.

Animals↗
PubMed1976

[Substitutive treatment of hemopjolia A using a new factor VIII concentrate].

Thirty children with classical hemophilia were treated with an intermediate-purity factor VIII concentrate prepared according to Newman. The average factor VIII concentration was 21 U/ml. Thirty five injections ranging from 3 to 55 U/kg of body weight were given. The clinical efficacy was satisfactory, no side effects were observed. In vivo factor VIII recovery was initially very high, decreased rapidly until the 4th hour post infusion and then slowed according to a biological half-life of 11.3 +/- 3.1 hours. A satisfactory correlation between the dose injected and the factor VIII in vivo recovery was observed only after four hours post injection. The commercially available concentrate contains in average 25 U of factor VIII per ml, 13 U/mg of fibrinogen and 2.03 U/mg of proteins. It can be injected with a seringe and is therefore adapted to home care treatment. In addition, it is convenient for prolonged treatment with high doses of factor VIII as required by surgical procedure of treatment of patients with an inhibitor, avoiding limitations caused by hypervolemia or hyperfibrinogenemia.

Adolescent↗
PubMed1975

Performances of an artificial reagent for the one-stage factor IX assay.

A mixture of adsorbed normal human plasma and chicken plasma was prepared as reagent for factor IX measurement using a one-stage method. The substrate was found to be specific for factor IX. Its performances tested on samples displaying factor IX activity ranging from less than 1%-2,000% compared favorably with those obtained when using the plasma of severe haemophilia B patients as substrate.

Animals↗
PubMed1974

Enhancement activity of homologous anti-staphylococcal sera in experimental staphylococcal synovitis of chicks: a possible role of immune adherence antibodies.

Homologous anti-staphylococcal sera passively potentiated the development of experimental staphylococcal synovitis infection of chickens. These antisera obtained from chickens hyperimmunized with live Staphylococcus aureus were selected according to their immune adherence and agglutinating properties. While the agglutinins rose steadily for 11 weeks during the hyperimmunization schedule, the immune adherence antibody titers reached a peak at 8 weeks and dropped to almost zero 2 to 4 weeks later. The enhancement activity of these antisera was associated with a relatively high level of immune adherence antibodies and seemed not to be correlated with their agglutinin titers.

Animals↗
PubMedDate not supplied

Optimized conditions to couple two water-soluble biomolecules through alkylamine thiolation and thioetherification.

A simple method for introducing, in buffered saline, a reactive sulfhydryl group on water-soluble molecules bearing an alkyl-amino group is described. This method is based on the use of two water-soluble reagents: 2-iminothiolane and 6,6'-dithiodinicotinic acid. The first one is open upon reaction with an amino group, and the generated thiol group is immediately protected by action of the second reagent. The optimal conditions were determined by taking into account the stability and the reactivity of both reagents with regards to pH and temperature. This method was validated through two applications, the substitution of bovine serum albumin with a bromoacetyl peptide and the substitution of an amino link at the 5' end of an oligonucleotide by reaction with either a fluorescent tag, iodoacetamidofluorescein, or a bromoacetyl peptide, upon reduction of the protected disulfide bridge with a third water-soluble reagent, namely tris(2-carboxyethyl)phosphine.

Amino Acid Sequence↗