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Biomedical subjects

P Cherin

Publications and source records attributed to P Cherin.

At least 37 records · Page 2Linked to original sources
PubMed1997

Interleukin-1 expression in inflammatory myopathies: evidence of marked immunoreactivity in sarcoid granulomas and muscle fibres showing ischaemic and regenerative changes.

The most frequent autoimmune adult inflammatory myopathies are dermatomyositis, polymyositis, inclusion body myositis, and sarcoid myopathy. Interleukin-1 (IL-1) is a pleiotropic molecule, implicated in the inflammatory process, but also in tissue protection and remodelling. We evaluated the immunocytochemical expression of [L,-1alpha and beta in frozen muscle biopsy specimens from patients with dermatomyositis (15 cases), polymyositis (five cases), inclusion body myositis (five cases) and sarcoid myopathy (five cases). Positive immunoreactivities, were observed in both inflammatory cells and muscle fibres. Specificity of the immunostaining was assessed by Western blot experiments. IL-1 positive inflammatory cells were rare in polymyositis and inclusion body myositis, moderately abundant in dermatomyositis, and prominent in sarcoid myopathy granulomas. In sarcoid myopathy, 24.6 +/- 4.1% inflammatory cells were IL-1alpha-positive and 45.2 +/- 2.6% were IL-1beta-positive. IL-1 positive muscle fibres were mainly observed in dermatomyositis, usually remote from inflammatory infiltrates. Positive immunostaining for IL-1 was observed in fibres showing ischaemic punched-out vacuoles, that correspond to areas of myosinolysis, in atrophic perifascicular fibres, and in fibres located within healing microinfarcts. All NCAM-positive regenerating fibres were IL-1 positive. We conclude that: (i) IL-1 is expressed in granulomas of sarcoid myopathy, which is in keeping with the role ascribed to IL-1 in the formation of granulomas: (ii) IL-1 is expressed by muscle fibres undergoing ischaemic damage: and (iii) IL-1 expression by muscle fibres is associated with myofibrillar protein breakdown and regeneration.

Adult↗
PubMed1996

Mechanisms of lysis by activated cytotoxic cells expressing perforin and granzyme-B genes and the protein TIA-1 in muscle biopsies of myositis.

OBJECTIVE: Polymyositis (PM) and cermatomyositis (DM) are inflammatory muscle diseases of autoimmune origin. A chronic mononuclear cell infiltrate is always present around PM and DM muscle damage. In PM, the predominant cells are activated cytotoxic cells, natural killer, and CD8+ T lymphocytes. Cytotoxic cells can kill the target cells via 2 mechanisms. Both pathways induce target cell death by releasing the molecules (granule exocytosis) perforin (PF), which attacks the target cell membrane and causes cell death by necrosis, and TIA-1 protein and granzyme-B (GZB), possibly responsible for apoptosis. We studied the mechanisms of lysis in muscle biopsies of myositis. METHODS: We used a panel of monoclonal antibodies to determine the phenotypes of reactive lymphocyte subsets, in situ hybridization to study the expression of PF and GZB genes, and immunohistochemistry to evaluate TIA-1 protein production in muscle biopsies from 14 patients with myositis (11 PM/3 DM). Results were compared to those obtained from muscle biopsies of 12 control patients with muscle weakness, including patients with muscle dystrophy and vasculitis, but without myositis. RESULTS: Abundant CD8+ cells, especially in endomysial sites in PM, formed the predominant phenotype. The predominant mononuclear cells observed in DM were CD4+ T cells and CD22+ B lymphocytes, in perivascular sites. The GZB and PF genes and the TIA-1 protein were expressed simultaneously in muscle samples from patients with myositis. GZB, PF, and TIA-1 positive cells were predominantly located in endomysial sites of PM, in the nonnecrotic muscle fibers. In DM, these positive cells were rare. CONCLUSION: In myositis, especially PM, cytotoxic cells may cause muscle damage and muscle cell necrosis and/or apoptosis by releasing several proteins (PF, GZB, and TIA-1 proteins) responsible for the lysis of these stimulating target cells. Some drugs (prednisone and cyclosporine) inhibit the release of GZB and PF. Their efficacy may be due in part to this inhibitory effect.

Adult↗
PubMed1995

Dystrophinopathies and related disorders.

Muscular dystrophies primarily affect skeletal muscle and are characterized by progressive muscle wasting and weakness. Although these diseases have been clinically recognized for some time, genetic defects in a number of muscular dystrophies only recently have been identified. One of the most important advances in understanding the molecular genetics of neuromuscular diseases has been the cloning of the gene encoding dystrophin, the protein that is absent in the muscle of patients with Duchenne and Becker muscular dystrophy. Several dystrophin-associated proteins have been identified. Components of the dystrophin-glycoprotein complex are being characterized, and evidence indicates that proteins of this complex may be responsible for other forms of muscular dystrophy.

Dystrophin↗
PubMed1994

Hyperchloremic acidosis during grand mal seizure lactic acidosis.

OBJECTIVE: To evaluate the prevalence and the mechanism of hyperchloremic acidosis component (HClA) during lactic acidosis secondary to grand mal seizures. DESIGN: Retrospective study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: 35 patients admitted for grand mal seizures with lactic acidosis (pH < 7.35, TCO2 < 20 mmol/l and PaCO2 < 8 kPa). MEASUREMENTS: HClA was defined by the ratio: excess anion gap/HCO3 deficit (delta AG/delta TCO2) < 0.8. A difference in the distribution space of protons and their accompanying anion, i.e., a displacement of chloride from cells by the entering lactate, was evaluated by the ratio natremia/chloremia (Na+/Cl-). RESULTS: Immediately after seizures, a profound lactic acidosis was observed (pH = 7.22 +/- 0.17 (mean +/- SD), AG: 23.8 +/- 7.1 mmol/l, TCO2 = 14.5 +/- 5.3 mmol/l, lactate: 14.6 +/- 6.9 mmol/. HClA was present on admission in 11 patients (31.5%). Its prevalence increased to 73% after recovery. delta AG/delta TCO2 ratios were unrelated to creatinine, level and PaCO2, but dependent on the ratio Na+/Cl- (r = 0.803; p < 0.001, delta AG/delta TCO2 = 6.4 x (Na+/Cl-)-7.9). These data demonstrate that HClA is not a respiratory or renal phenomenon and suggest differences in the distribution spaces of hydrogen ions and their accompanying anions. CONCLUSION: HClA component may be associated with lactic acidosis in grand mal seizures and appears to be secondary to a lactate antiport. This phenomenon could be an immediate physiological response to a sudden metabolic acidosis.

Acid-Base Equilibrium↗
PubMed1994

Intravenous gamma globulin as first line therapy in polymyositis and dermatomyositis: an open study in 11 adult patients.

OBJECTIVE: Polymyositis (PM) and dermatomyositis (DM) are inflammatory muscle diseases of presumed autoimmune origin. Many possible interventions are available to treat these patients: corticosteroids, immunosuppressive drugs, plasmapheresis, and total body irradiation. But these therapies are not always effective and may be responsible for certain serious side effects. Polyvalent intravenous immunoglobulin (IVIG) has been tried with success in inflammatory myopathies after failure of traditional treatment. An attempt was made to evaluate the efficacy of IVIG as first line therapy in patients with PM or DM. METHODS: Eleven Caucasian patients [6 women, 5 men, mean age 55.6 (SD 10.1) years], with active recent inflammatory myopathy, were treated by high doses of IVIG as first choice. The average duration of inflammatory myopathy before IVIG was 9.6 months (SD 10.2 months, with a range of 1 month to 3 years). Five patients had PM and 6 had DM. None had myositis associated with connective tissue disease. Two patients had a history of malignant disease: 1 lymphoma and 1 breast tumor with relapse of the malignancy during the study. One patient had a probable lung carcinoma and in another patient, ovarian carcinoma was diagnosed a few months after the onset of IVIG. We used preparations of polyvalent human i.v. gamma globulins with intact IgG. All patients received 1 g/kg daily for 2 days each month. The mean course of treatment was 4 months. RESULTS: Clinical assessment, evaluated by proximal muscle power and biochemical tests, was carried out before each treatment period. Significant clinical improvement was noted in only 3 of the 11 patients (one with acute coxsackie virus B infection, and one with possible drug induced myopathy). Mean muscle power estimated for the 11 patients before and after IVIG therapy was not significantly improved. Eight patients showed significant biochemical improvement (more than 50%). Mean CK levels for the 11 patients showed a statistically significant decrease during IVIG therapy (p < 0.01). Minor IVIG side effects were noted in one patient. CONCLUSION: IVIG therapy seems effective rarely as first therapy in patients with inflammatory myopathy but may be considered especially in viral or drug induced myopathy. IVIG therapy as the first treatment may also be tried in patients with contraindication for steroids, and in mild myopathy, especially in the elderly, to avoid steroid induced side effects.

Adult↗
PubMed1993

[Drugs and brief losses of consciousness in the elderly. Results of a case-control multicenter study].

To study the possible role of drugs intake in syncope in elderly patients, we conducted a multicentric case-control study in 588 cases and 1818 controls, controlling as an essential confounding variable the underlying cardiovascular diseases. The following class were in excess among the case: non tricyclic antidepressants (p < 0.0001, RR: 4.5), neuroleptic drugs (p < 0.05, RR: 1.8), and antiparkinsonian drugs (p < 0.02, RR: 2.7).

Aged↗
PubMed1993

Dermatomyositis and ovarian cancer: a report of 7 cases and literature review.

The relationship between malignancy and inflammatory myopathies is now statistically well established. However, the link between polymyositis (PM) or dermatomyositis (DM) and ovarian cancer (OC) has never been clearly emphasized. OC is the 6th most frequent malignancy, occurring in about 1% of the general female population. We describe 7 cases of DM associated with OC (proven in 6 patients, and very probable in a 7th), in a series of 140 adult inflammatory myopathies followed in our institution [84 PM and 56 DM (including 45 female)]. Twenty-four patients had associated malignancy (12 PM and 12 DM). Without considering the probable case, OC occurred in 13.3% (6/45) of the total female DM population, a much higher rate than the 1% observed in the general female population; and in 21.4% (6/28) of females aged over 40 with DM. In women over 40 with DM, ovarian cancer has a major position among associated internal malignancies, and has to be adequately looked for by physicians.

Adult↗
PubMed1991

[Recurrent thrombocytopenic thrombotic purpura associated to prostatic cancer. A case].

The association between thrombocytopenic thrombotic purpura (TTP) and infectious or multisystem disease, pregnancy, transplantation, drugs and toxins is well known. The onset of TTP in the course of neoplasm is rarely described. The authors report one case of TTP associated with prostatic tumor. TTP preceded the discovery of neoplasm by 12 months. Moreover, TTP showed an original course with four recurrences despite antiplatelet and hormonal therapies; the successive regressions were obtained with less and less effort, as TTP was discovered at an early stage.

Humans↗