M

Mehmet Acker

Inserm

Publishes on Lysosomal Storage Disorders Research, Vitamin D Research Studies, Effects and risks of endocrine disrupting chemicals. 3 papers and 273 citations.

3Publications
273Total Citations

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Cytokines in Gaucher's disease.
Cited by 172

Gaucher's disease (GD) is characterized by hepatosplenomegaly, bone marrow infiltration, osteonecrosis, which may all be associated with the presence of pathological macrophages that contain undegraded glycosphingolipids. Levels of serum cytokines, which are soluble products of mononuclear phagocytes (MNP), were evaluated in 24 GD patients. Levels of interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1Ra), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and soluble interleukin-2 receptor (sIL-2R) in GD patients were significantly higher than in normal controls. We attempted to correlate cytokine levels with disease severity. Type I GD patients with more severe clinical manifestations had significantly higher levels of IL-1beta, IL-1Ra and IL-6, relative to type I patients with milder disease. Three patients homozygous for the 1448C mutation with neuropathic type III disease, had significantly higher levels of sIL-2R than type I patients or controls. We speculate that cytokine over-expression may relate to the pathophysiology of some of the clinical manifestations of GD. Thus, the elevated IL-1beta, TNF-alpha and IL-6 levels may induce the bone manifestations, the neutrophil chemotaxis and the increased incidence of hyper-gammaglobulinemia present in GD patients.

In Rat Uterus 17<i>β</i>-Estradiol Stimulates a Calcium-Binding Protein Similar to the Duodenal Vitamin D-Dependent Calcium-Binding Protein
Anne Delorme, Jean-Louis Danan, Mehmet Acker et al.|Endocrinology|1983
Cited by 77

A calcium-binding protein (CaBP) similar to rat duodenal vitamin D-dependent CaBP was identified in rat uterus. Uterine CaBP and duodenal CaBP had the same mol wt (9,000-10,000), exhibited the same calcium-dependent electrophoretic mobility, and were immunologically identical. The localization of CaBP in the rat uterus was explored using indirect immunoperoxidase methods, and by CaBP RIA in the endometrium and myometrium after enzyme separation. In the endometrium CaBP was found in the cytoplasm of the stroma cells but not in the epithelium or in the glandular cells. In the myometrium, it was located inside the smooth myometrial fibers. Hormonal regulation of CaBP was shown to differ in the uterus and duodenum. Duodenal CaBP concentrations increased in response to 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and were not influenced by ovariectomy or sex steroids administration. By contrast, CaBP synthesis fell drastically in the uterus of ovariectomized rats, but was greatly enhanced by low physiological doses of 17 beta-estradiol. This effect of 17 beta-estradiol on uterine CaBP was dose dependent. Medroxyprogesterone and more especially 1,25(OH)2D3 exerted no such stimulating effect on uterine CaBP. In vitamin D-deficient ovariectomized rats, administration of 17 beta-estradiol alone restored the uterine CaBP concentrations to normal and this potency contrasted with the apparent inability of 1,25(OH)2D3 to affect the uterine CaBP concentrations. Our data suggest that, unlike duodenal CaBP regulation, the expression of the CaBP gene in rat uterus is predominantly controlled by 17 beta-estradiol.

VITAMIN E DEFICIENCY DUE TO INCREASED CONSUMPTION IN β‐THALASSEMIA AND IN GAUCHER'S DISEASE*
Eliezer A. Rachmilewitz, Abraham Kornberg, Mehmet Acker|Annals of the New York Academy of Sciences|1982
Cited by 24

Plasma vitamin E levels were found to be decreased (less than 0.5 mg) in thalassemia and in 17 out of 20 patients with Gaucher's disease, where the levels were two standard deviations below the normal mean value. In the latter, the decrease in vitamin E levels correlated with the severity of the clinical expression of the disease and correlated inversely with the degree of hepatosplenomegaly and serum tartrate-resistant acid phosphatase activity. In both diseases, there was no evidence for intestinal malabsorption of the lipid-soluble vitamin. In spite of the different etiology, pathophysiology, and clinical expression, severe vitamin E deficiency could result in both diseases by a common mechanism. In thalassemia, rapid consumption of vitamin E occurs while neutralizing oxidative damage in the pathological erythrocyte membranes and in other tissues. In Gaucher's disease, lysosomal accumulation of glucocerebroside may stimulate phagocytes into a maintained "respiratory burst" with excessive production of oxygen free radicals, resulting in increased utilization and eventual deficiency of vitamin E. Efficacy of antioxidant therapy was evaluated by administration of vitamin E with and without canthaxanthin, which has similar antioxidant properties to beta-carotene, to patients with beta-thalassemia. The results showed increased serum vitamin E levels and a decrease in the extent of erythrocyte lipid membrane peroxidation, while no significant changes occurred in hemoglobin levels and in transfusion requirements.