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M Simon

Publications and source records attributed to M Simon.

At least 37 records · Page 2Linked to original sources
PubMed1992

Comparative study of nitroimidazoles on the bioelectric properties of frog skin as a membrane model.

The effects of misonidazole (MISO) and two other nitroimidazoles (5-NO2 and 4,5-NO2) on the bioelectric parameters of ion transport (potential difference and short circuit current) across frog skin as a membrane model, were studied in vitro. The nitroimidazoles investigated caused structure dependent effects on the sodium transport function of the membrane. MISO induced a biphasic action following administration on the external side of the membrane: after an initial enhancement, the potential difference and short circuit current signals both decreased. The other imidazole derivatives, 5-NO2 and 4,5-NO2, showed only one phase, whether administered on the external or internal membrane surface. All the nitroimidazoles investigated decreased sodium transport after internal or external surface administration. It was found that the 4,5-NO2 imidazole derivative irreversibly decreased the bioelectric membrane parameters.

Animals↗
PubMed1992

Autoradiographic characterization of angiotensin receptor subtypes in fetal and adult human kidney.

To better understand the action of angiotensin II (ANG II) and angiotensin receptor antagonists (ARA) in human kidney, ANG II receptors were characterized by in vitro autoradiography in fetal and adult human renal tissue using 125I-[Sar1-Ile8]ANG II (125I-ANG II), a potent ANG II antagonist. Binding was inhibited with the ARAs DuP 753 and PD 123177, respectively. In adult kidneys (n = 5), binding of 125I-ANG II showed the following characteristics: arterial vessels had dissociation constant (Kd) = 387.6 +/- 29.1 (SD) pM and maximal binding (Bmax) = 41.4 +/- 3.6 fmol/mg tissue equivalent (TE); glomeruli had Kd = 885.7 +/- 217.1 pM and Bmax = 35.5 +/- 8.1 fmol/mg TE; and outer medulla had Kd = 142.1 +/- 52.5 pM and Bmax = 7.7 +/- 2.3 fmol/mg TE. PD 123177 effectively displaced 125I-ANG II only in large preglomerular vessels [half-maximal inhibitory concentration (IC50) = 0.22 +/- 0.1 nM, type 2 receptor (AT2)], whereas DuP 753 displaced only the labeled ligand in glomeruli (IC50 = 0.28 +/- 0.11 nM) and outer medulla (IC50 = 0.39 +/- 0.11 nM, AT1). In fetal kidneys (n = 4), a diffuse 125I-ANG II binding was demonstrated in the medulla (Kd = 36.6 +/- 7.1 pM; Bmax = 25 +/- 3.8 fmol/mg TE) and in the cortex (Kd = 19.5 +/- 8 pM; Bmax = 7.2 +/- 2.2 fmol/mg TE). Both cortical (IC50 = 0.039 +/- 0.019 nM) and medullary binding (IC50 = 0.076 +/- 0.039 nM) could only be displaced by PD 123177.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Impairment of some granulocyte functions in Sweet's syndrome.

Chemotaxis, phagocytic and intracellular killing activities of polymorphonuclear leukocytes (PMNL) were investigated in vitro in 7 patients suffering from the acute phase of Sweet's syndrome. A moderate but consistent impairment of neutrophilic chemotactic activity (NCA) was revealed in all patients. Intracellular killing of blastospores of Candida albicans was diminished in 5/7 patients. Phagocytosis and oxidase activities were within normal levels. These results point to an alteration of some PMNL functions in the acute phase of Sweet's syndrome.

Candida albicans↗
PubMed1992

Expression of beta-2 integrin molecules on human keratinocytes in cytokine-mediated skin diseases.

Integrins are cell surface molecules of importance in a wide variety of cellular functions, including morphogenesis, cell migration and cell matrix interactions. The beta-2 (B2) integrin (leukocyte integrin, CD11/CD18) subfamily comprising three members, each consisting of a shared beta subunit (CD18) non-covalently associated with unique alpha subunits (CD11a, CD11b, CD11c). In the present study, we have analysed the expression pattern of B2 integrins on the surface of human keratinocytes (HKs) in biopsies obtained from healthy volunteers, from positive tuberculin skin tests and from patients with acute urticaria (AU), lichen planus (LP), psoriasis vulgaris (PV), mycosis fungoides (MF) or purpura pigmentosa chronica (PPC). In biopsies obtained from positive tuberculin tests and from the clinically involved skin of patients with LP, PV, MF or PPC, a multifocally occurring, suprabasal peroxidase-positive reaction was observed on the membranes of the HKs when the monoclonal antibodies (MABs) Dako CD11a, Dako-p150, 95 or Dako CD18 were used. In contrast, no specific staining of the HKs was observed with the same MABs in biopsies from healthy volunteers, from patients with AU and in the uninvolved skin specimens obtained from the other patients. The HKs from PV, LP, MF, PPC and AU patients and those from the healthy subjects failed to give a positive reaction when the MAB against CD11b (OKM1) was used. Our present findings provide further evidence that HKs may be actively involved in cell adhesion processes.

Antigens, CD↗
PubMed1992

Modulation of presynaptic sympathetic activity by kinins and related compounds: influence of converting enzyme inhibition.

Since converting enzyme and kininase II are identical enzymes and probably influences both, the biosynthesis of Ang II and the metabolism of bradykinin we investigated the effects of bradykinin, desArg-bradykinin and some bradykinin antagonists (desArg[9]-Leu[8]-bradykinin, HOE S 890307) on the sympathetic outflow of pithed SHR or Brown-Norway-Rats before and after acute or chronic inhibition of the converting enzyme by ramipril. bradykinin increased dose dependently the noradrenaline and adrenaline release in particular when the converting enzyme was inhibited. DesArg-bradykinin caused a dose-dependent increase in adrenaline release only after converting enzyme inhibition. The bradykinin-antagonists led to an increase in adrenaline release during ramipril administration. The weak but significant stimulation of adrenaline release by the bradykinin antagonists after converting enzyme inhibition might be due to unspecific actions on the adrenal medulla possibly induced by histamine release from mast cells.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

[Ilizarov techniques of leg lengthening. Problems and results].

Leg lengthening procedures have developed rapidly in the last 20 years, especially distraction epiphyseolysis and corticotomy. We have used both methods since 1977 and carried out 22 distraction epiphyseolyses (20 patients) and 33 corticotomies (28 patients). The average lengthening distance was 8.25 cm and 7.8 cm respectively (minimum 4 cm, maximum 18 cm). The time per cm lengthening (lengthening index) was 45.8 days/cm for epiphyseolysis and 52.2 days/cm for corticotomy. The complication rates were similar in both methods (1.18 and 1.21 pro lengthening procedure). Both techniques are preferably performed by a well trained team of physicians, nurses and physiotherapists for correction of leg length discrepancies.

Achondroplasia↗
PubMed1979

Serum ferritin as a possible marker of the hemochromatosis allele.

To determine whether a correlation exists between the biochemical expression of hemochromatosis and the HLA genotype, we studied 174 family members of 32 persons with the disease. Persons who shared both HLA haplotypes with the proband (and presumably having two hemochromatosis alleles) differed significantly from those who shared only one haplotype (and presumably having one hemochromatosis allele) in terms of serum iron (P less than 0.001 for both sexes), unsaturated iron-binding capacity (P less than 0.01 for female and P less than 0.0001 for male subjects) and serum ferritin (P less than 0.0001 for female and P less than 0.00001 for male subjects). The only significant difference between relatives having one hemochromatosis allele and age and sex-matched controls was related to serum ferritin values in male subjects (P less than 0.05, despite considerable overlap). In our hands, serum ferritin was the best indicator of disordered iron metabolism and was elevated among most homozygous but among few heterozygous family members.

Adolescent↗
PubMed1979

[Biological properties of immunocompetent cells].

Inflammation is characterized by the combined reaction of living tissue of the target organ and various types of white blood cells recruited from the circulation and platelets, which tend to eliminate the injurious agent and to repair the damaged tissue. Much of the current knowledge of the functions and characteristics of human white blood cells has been derived from studies of lymphoid cells from patients with various diseases. The results of recent studies (17, 19, 28) have pointed to the diagnostic importance of the immunocompetent cells. The various characteristics of cells involved in immune mediated reactions of various organs and in circulation in man may lead to a better understanding of immune reactions and finally to effective therapeutic modalities.

Antibody-Producing Cells↗
PubMed1979

[Idiopathic haemochromatosis. Pathogenic and genetic aspects. Detection and prevention (author's transl)].

The basic disorder of iron metabolism in idiopathic haemochromatosis finds expression on at least two levels: the intestinal mucosa (increased iron absorption) and the liver. Its exact nature, however, remains obscure. The role of iron overload in the pathogenesis of the disorder seems clear. Lysosome disruption has recently been proposed as a possible pathogenic factor. Phenotypic family studies have lent considerable weight to the hypothesis of a recessive transmission of idiopathic haemochromatosis. Demonstration of a close link between the disease and the HLA antigen A3 and haplotype A3, B14 has made it possible: to remove all doubt as to the hereditary nature of the disease; identify the underlying gene as located on chromosome 6 near the A locus of the HLA system; demonstrate a recessive mode of transmission; and achieve the early detection of individuals at risk in the family of a patient with the disease. Thanks to this possibility of early detection, the feasability of preventive measures is greatly enhanced.

Alleles↗
PubMed1979

[Idiopathic haemochromatosis. I. Clinical, biological and therapeutic aspects (author's transl)].

Over the last few years the study of idiopathic haemochromatosis has not brought to light any basic change in the overall pattern of organic and metabolic damage produced by the disease and comprising altered skin pigmentation, liver disease, diabete mellitus, heart disease, endocrine dysfunction, bone and joint disease. Nevertheless, certain facets of the clinical picture have been described and progress has been made in understanding the signs of the disease. Although the desferrioxamine test is no without merit, especially if performed after vitamin C administration, for measuring the extent of iron overload, two methods seem better equipped: serum ferritin radioimmunoassay and measurement of iron concentration in a liver biopsy specimen. The HLA antigen A3 and, more especially, haplotype A3, B14, are markers for the genetic basis of the disease. Repeated phlebotomy therapy generally brings about symptomatic improvement and a significant increase in survival.

Bloodletting↗
PubMed1979

[Demonstration by iron overloading study and HLA genotyping of recessive transmission of idiopathic haemochromatosis in two pseudodominant pedigrees (author's transl)].

We studied iron overloading and HLA genotype in two families with overt forms of idiopathic haemochromatosis in two successive generations. In each family the spouse of the patient with overt haemochromatosis in the first generation had clinical and laboratory signs of moderate iron overload and a HLA haplotype A3, B14 and A3, B7 respectively--which is frequently associated with the haemochromatosis gene. This specific HLA haplotype had been transmitted to the second generation patient with overt disease, which thus could be considered as having received a haemochromatosis gene from each parent. Although the finding of cases of overt disease in successive generation firstly suggests a dominant transmission the genetical analysis of these families lead to further strong argument in favour of recessive inheritance of idiopathic haemochromatosis.

Adolescent↗