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Biomedical subjects

M Janier

Publications and source records attributed to M Janier.

At least 91 records · Page 5Linked to original sources
PubMed1990

Noninvasive quantification of muscarinic receptors in vivo with positron emission tomography in the dog heart.

The in vivo quantification of myocardial muscarinic receptors has been obtained in six closed-chest dogs by using positron emission tomography. The dogs were injected with a trace amount of 11C-labeled methylquinuclidinyl benzilate (MQNB), a nonmetabolized antagonist of the muscarinic receptor. This was followed 30 minutes later by an injection of an excess of unlabeled MQNB (displacement experiment). Two additional injections of unlabeled MQNB with [11C]MQNB (coinjection experiment) and without [11C]MQNB (second displacement experiment) were administered after 70 and 120 minutes, respectively. This protocol allowed a separate evaluation of the quantity of available receptors (B'max) as well as the association and dissociation rate constants (k+1 and k-1) in each dog. The parameters were calculated by using a nonlinear mathematical model in regions of interest over the left ventricle and the interventricular septum. The average value of B'max was 42 +/- 11 pmol/ml tissue, the rate constants k+1, k-1, and Kd were 0.6 +/- 0.1 ml.pmol-1.min-1, 0.27 +/- 0.03 ml.pmol-1.min-1, and 0.49 +/- 0.14 pmol.ml-1, respectively, taking into account the MQNB reaction volume estimated to 0.15 ml/ml tissue. Although [11C]MQNB binding would appear irreversible, our findings indicate that the association of the antagonist is very rapid and that the dissociation is far from negligible. The dissociated ligand, however, has a high probability of rebinding to a free receptor site instead of escaping into the microcirculation. We deduce that the positron emission tomographic images obtained after injecting a trace amount of [11C]MQNB are more representative of blood flow than of receptor density or affinity. We also suggest a simplified protocol consisting of a tracer injection of [11C]MQNB and a second injection of an excess of cold MQNB, which is sufficient to measure B'max and Kd in humans.

Animals↗
PubMed1990

A case of cicatricial pemphigoid with circulating IgA and IgG antibodies directed against 280 kD, 165 kD and 120-130 kD epidermal antigens.

A case of subepidermal autoimmune blistering disease in an 86-year-old woman is reported. Clinical features were those of a cicatricial pemphigoid, with prominent mucosal involvement leading to conjunctival and nasal scarring. Direct immunofluorescence findings were consistent with either cicatricial pemphigoid or linear IgA dermatosis, since both IgG and IgA linear deposits were found at the basal membrane zone. Immunoelectron microscopy of perilesional skin revealed IgA deposits within the lamina lucida and immunoblotting of the patient's serum disclosed IgA and IgG antibodies directed against epidermal antigens of 280, 165 and 120-130 kD.

Aged↗
PubMed1990

[Oxatomide: review of pharmacodynamic effects and clinical effects in dermatology].

Oxatomide is a new anti-allergy drug, derived from benzamidazole, which has shown original pharmacological properties at different stages of the degranulation of mastocytes and basophils, inhibition of the increase of intracellular calcium, inhibition of histamine release and of the synthesis of leukotrienes and prostaglandins. In addition, it has an antagonistic action on the histamine H1 receptors and inhibits the effects of serotonin and SRSA leukotrienes. Clinical trials have shown the clinical efficacy of oxatomide on chronic urticaria and atopic dermatitis, double blind against placebo. Also its action is quicker than certain reference molecules with which it was compared. The product seems to have excellent tolerance. Oxatomide is a molecule of which the pharmacological properties are coupled with clinical efficacy on allergic dermatoses.

Animals↗
PubMed1990

Endothelial cells: target for the HIV1 virus?

Plasmatic levels of endothelial markers [von Willebrand's factor (VWF), fibronectin (FN), and angiotensin converting enzyme (ACE)] were measured in patients at various stages of evolution of HIV1 infection. VWF levels were elevated at all stages, while other markers were significantly altered only for the most advanced stages. These results can be interpreted as indicating an endothelial involvement during HIV infection and VWF being the most sensitive marker. Endothelial markers, mainly VWF, could be used as prognosis marker of the infection. Capillary density was measured in the dermis of uninvolved skin showing a significant angiogenesis associated with the HIV1 infection. These biochemical and histological results however do not indicate whether these changes are directly linked to endothelial infection by the virus or to an indirect effect. The endothelial cell being an immunocompetent cell what is its involvement in the genesis of the immuno deficiency syndrome?

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Microbiological study of male genital ulcers. Apropos of 75 cases].

Between November 1986 and June 1987, the microbial aetiology of genital ulcers was assessed in 75 male patients attending the Sexually Transmitted Disease (STD) clinic in Hôpital Saint-Louis, Paris. Evidence of Haemophilus ducreyi was found in 18 patients (24%), Herpes simplex virus in 19 (25.3%). Syphilis was diagnosed on the basis of dark field microscopy and/or positive serology test in 19 patients (25.3%). Lymphogranuloma venereum was not diagnosed in any patient. Primary pathogens were not identified from the remaining 19 (25.3%) men. Neisseria gonorrhoea was isolated in five patients, from the ulcer in three cases, from the urethra in two. Asymptomatic urethral carriage of Chlamydia trachomatis was culture proven in seven cases. The presence of IgM antibodies to C. trachomatis at a titre greater than 40 found in 17 patients was a indication of a current chlamydial infection. Three patients (4%) were discovered to be HIV-1 positive.

Adolescent↗
PubMed1990

Crossover study of thalidomide vs placebo in severe recurrent aphthous stomatitis.

A multicentric crossover randomized trial of 100 mg of thalidomide vs placebo each for 2 months was conducted in patients with severe aphthous stomatitis of more than 6 months' duration. Seventy-three patients were included. Complete remission was obtained in 32 patients who received thalidomide and in 6 patients who received placebo. The confidence interval of the difference between the two treatments ranged from 25% to 53%. Most of the patients who did not achieve a complete remission had a dramatic improvement with regard to the number of aphthae when they were receiving thalidomide. Thirteen of 17 patients who had a complete remission while they were receiving thalidomide had a recurrence with placebo, 19 +/- 9 (mean +/- SD) days after stopping this drug. Side effects were significantly more frequent with thalidomide, especially drowsiness and constipation. We concluded that thalidomide in a dosage of 100 mg/d is an effective treatment of severe aphthous stomatitis but is not without some risk.

Adult↗
PubMed1989

Chronic urticaria and macroglobulinemia (Schnitzler's syndrome): report of two cases.

Two cases of chronic urticaria associated with macroglobulinemia are reported, and the characteristics of 13 other cases are reviewed. This entity was described by Schnitzler in 1974 and has the following characteristics: chronic nonpruritic urticaria with leukocytoclastic vasculitis, bone pains with hyperostosis, intermittent fever, and a monoclonal IgM gammopathy. Liver, lymph node, and spleen enlargement may occur. Criteria for the diagnosis of Waldenström's disease are lacking (IgM level less than 10 gm/L, no overt lymphoid proliferation in bone marrow). Other immunologic findings (complement, C1 inhibitor, cryoglobulin, rheumatoid factor, antinuclear antibodies) are negative or normal. Evolution is long-term with a long follow-up period. In one case a lymphoplasmocytic lymphoma developed. No adequate treatment has yet been found. Pathogenesis is unclear but seems to be caused by skin deposits of the IgM paraprotein, as attested to by the direct cutaneous immunofluorescent findings in some cases.

Bone Diseases↗
PubMed1989

Multiple subcutaneous abscesses due to Mycobacterium tuberculosis in an immunocompetent host.

A 58-year-old immunocompetent man presented with a 9-month history of several disseminated subcutaneous ulcerative nodules, fever and weight loss. Histopathological changes were not specific. X-ray of the chest disclosed a large right hilar density highly suggestive of a lung carcinoma. All these manifestations eventually proved to be caused by Mycobacterium tuberculosis, which grew from sputum and skin. We report this case because of its striking clinical features.

Abscess↗