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Biomedical subjects

G Simon

Publications and source records attributed to G Simon.

At least 199 records · Page 11Linked to original sources
PubMed1987

Reduced sodium concentration and increased sodium-potassium pump activity of erythrocytes in human hypertension.

Erythrocyte Nai, Nai/Ki and ouabain-sensitive and ouabain-insensitive 86Rb uptake (K transport) were measured in whole blood of 16 normotensive and 19 hypertensive white male subjects, within seconds or minutes after withdrawal of blood. Erythrocyte Nai and Nai/Ki were reduced (p less than 0.05), and ouabain-sensitive 86Rb uptake was increased (p less than 0.01) in hypertensive subjects. In a separate group of hypertensive white male subjects, an inverse correlation was found between erythrocyte Nai/Ki and ouabain-binding sites per erythrocyte (r = 0.85, p less than 0.01, n = 9). The abnormalities of erythrocyte cation fluxes in hypertensive subjects are similar to those induced by aldosterone in vascular smooth muscle cells and by glucocorticoid administration in the erythrocytes of human subjects, suggesting similarities in pathogenesis.

Binding Sites↗
PubMed1987

[Left ventricular function and cardiovascular adaptation to exercise in young sportsmen].

In order to find out whether the expression "sports heart" can be used in children and if so, to give an objective definition of it, we studied a group of 40 young people (mean age 12.2 +/- 1.6 years) subjected to intensive training and practising sports regularly, i.e. about 12 hours of physical activity per weeks on average. The sports practised were mainly tennis among boys and ice-skating among girls. A group of 40 subjects with similar characteristics but no particular physical training was studied simultaneously and served as control. These 80 young people had normal heart structure. All underwent routine cardiovascular examinations (physical, radiological, electrocardiographic), complete one - and two - dimensional echocardiography to evaluate left ventricular function and an exercise-test on ergometric bicycle. No difference was found between the left ventricle of sportsmen and that of controls; in particular, there was neither dilatation nor parietal thickening in sportsmen, so that all functional values were the same. During exercise-tests sportsmen performed better than controls, with significantly longer duration of effort and greater maximal oxygen consumption. However, heart rate at rest, then during exercise and recovery, and variations in systolic blood pressure during exercise and in the 10 minutes which followed were identical in both groups. The only notable difference was a deeper fall in diastolic blood pressure in sportsmen, indicating a better opening of the peripheral vascular bed during exercise. It is concluded that there are few cardiovascular differences between trained sporting children and children with normal physical activity, probably because the relatively short training undergone does not leave sufficient time for most of the adaptation systems to become established.

Adolescent↗
PubMed1987

[Echocardiographic contractility reserve and invasive hemodynamics in physical stress in probands with healthy hearts and patients with dilated cardiomyopathy].

In the present study, 17 patients with angiographically proven dilative cardiomyopathy (CM) were investigated simultaneously by both invasive right heart catheter and 1D/2D echocardiography at rest (R) and during bicycle exercise (E) stress test. They were compared with 14 normal subjects (N). The echocardiographic contractility reserve was determined as an increase in the systolic pump function (shortening fraction-SF, ejection fraction - EF) and compared with pulmonary capillary wedge pressure during exercise. 14/17 echocardiograms of dilative cardiomyopathy and all echocardiograms of normal subjects at rest as well as during exercise could be accepted. In N, echocardiographic parameters of systolic function significantly increased during exercise, whereas dilative cardiomyopathy showed decreased contractility reserve with no increase in pump function (for CM patients, at rest SF: 21.3% +/- 8%; EF: 41.6% +/- 14%; exercise SF: 21.3 +/- 9%; EF: 40.7% +/- 15%). Hemodynamic investigation in CM showed no increase in stroke volume accompanied by a pathologic increase in pulmonary wedge pressure, ranging from x = 16.4 mmHg at rest, up to 30.0 mm Hg in exercise (p less than 0.001), whereas in normal subjects, no pathologic increase in pressure was present (from 10.3 mm Hg at rest to 13.7 mm Hg during exercise). There were closed relations between invasive and non-invasive data. The relative alteration of stroke volume during E showed in N and in CM good correlation with echocardiography (N + 19%, CM -2%) and invasive data (N + 18%, CM + 2%). FSe during stress and PCPm showed a closed inverse correlation during exercise (p less than 0.001; r = 0.8). The lower the contractility in echocardiogram, the higher PCPm was in exercise.

Cardiac Output↗
PubMed1986

Application of a technique for serogrouping Clostridium difficile in an outbreak of antibiotic-associated diarrhoea.

A severe outbreak of Clostridium difficile antibiotic-associated diarrhoea (AAD) in an orthopaedic surgical unit is reported. Thirty-seven cases and eight relapses were observed. The 45 related strains together with another 13 strains of C. difficile isolated during the same period in other wards of the same hospital were typed by detection of cytotoxin production, determination of sorbitol fermentation and serogrouping by agglutination with six rabbit antisera defining the serogroups A, B, C, D, F and G. All the strains from the outbreak belonged to serogroup C, were toxigenic and fermented sorbitol. In contrast, four different patterns were observed in seven isolates from cases of AAD in other wards. Finally, six strains isolated from four asymptomatic adults, one adult suffering from shigellosis and one child with salmonellosis demonstrated two patterns different from that of the epidemic isolates. The data strongly suggest nosocomial spread of this micro-organism.

Adult↗
PubMed1986

Transdermal nitroglycerin as a step 3 antihypertensive drug.

The antihypertensive effect of transdermal nitroglycerin was tested in 11 men with hypertension (mean age 60 years) whose diastolic blood pressure exceeded 90 mm Hg while receiving a diuretic and a beta-adrenergic blocker. In a double-blind, randomized crossover trial the subjects received weekly increments of placebo or nitroglycerin (5, 10, 20, and 30 cm2) for 4 weeks each. The final dose of nitroglycerin was 22.5 cm2 (mean). During week 4 of nitroglycerin dosing, sitting and standing systolic blood pressures were reduced (P less than 0.05). Diastolic blood pressures and heart rates did not change during the study. In the five subjects with systolic hypertension (greater than or equal to 150 mm Hg), the mean reduction in systolic blood pressure was 24 mm Hg (P less than 0.01). Further studies are needed to determine if transdermal nitroglycerin has a role in the treatment of systolic hypertension.

Administration, Topical↗
PubMed1986

In vivo erythrocyte sodium concentration in human hypertension is reduced, not increased.

The level of intracellular sodium concentration in hypertension is of theoretical interest. Using extensive in vitro manipulations, previous investigators have reported increased erythrocyte sodium content in human hypertension. In the present study, erythrocyte sodium (Nai) and potassium (Ki) concentrations were measured within seconds after venopuncture by centrifuging whole blood over oil to separate the erythrocytes from plasma. Labelled 125I-albumin and 57Co-EDTA were used to estimate plasma trapping. The presence of white cells and platelets in the cell pellets had no detectable effect on erythrocyte cation measurements. Twenty-eight white male hypertensives and 25 normotensive control subjects were studied. In hypertensive subjects, Nai was reduced and Ki was increased. Erythrocyte sodium and sodium: potassium ratio (Nai:Ki) of hypertensive subjects correlated inversely with their pressor responses to intravenous norepinephrine. The findings suggest increased erythrocyte Na, K-pump activity in human hypertension. Assuming that erythrocyte cation concentrations reflect those of vascular muscle, enhanced transmembrane sodium gradient does not preclude pressor hyper-responsiveness in hypertension.

Angiotensin II↗
PubMed1986

Different cation transport inhibitor in benign and malignant experimental renal hypertension.

The role of circulating humoral agents in the pathogenesis of abnormal vascular wall cation composition in benign and malignant renal hypertension was investigated. Male F344 rats with chronic benign (n = 38) and malignant (n = 44) one-kidney, one clip (1K1C) hypertension and normotensive control rats (n = 63) were studied. Malignant hypertension developed spontaneously and was characterized by failure to thrive, weight loss, oedema, renal insufficiency, anaemia or haemoconcentration and hyperkalaemia. For bio-assay, monolayers of quiescent vascular smooth muscle cells from F344 rats were incubated in plasma or plasma extracts of normotensive and hypertensive rats for measurement of labelled rubidium (86Rb) uptake in the presence and absence of 2 mmol/l ouabain and/or 1 mmol/l furosemide. Compared with controls, ouabain-sensitive Rb uptake of cells was reduced in plasma extracts but not in whole plasma of rats with benign hypertension. Ouabain-sensitive Rb uptake was unchanged and ouabain-insensitive Rb uptake was reduced in both plasma and plasma extracts of rats with malignant hypertension. The latter was due to a reduction in furosemide-sensitive Rb uptake. In malignant hypertension, the increased sodium (Na) content of the aorta which characterizes benign hypertension was reversed and bladder wall Na content was reduced. The findings suggest that in malignant hypertension a circulating, furosemide-like inhibitor of ouabain-insensitive cation transport is the cause of vascular wall Na depletion and of diuresis and natriuresis that trigger the syndrome.

Animals↗
PubMed1986

[The new migratory deal in Southern Europe].

The author examines migration patterns in Southern Europe during the 1970s and early 1980s, noting particularly the reduction in migration northward from this region. It is noted that "departure potential remains sizable in certain areas of Portugal, Spain, Southern Italy, and most particularly, of Turkey and Yugoslavia. Transoceanic migrations have by no means ceased, as new flows of skilled labor have, since 1974, gone towards Arab states endowed with petrol (oil) revenues. And yet, the paramount fact is most surely the emergence and the proliferation in Greece, Spain, and (especially) in Italy, of basically clandestine (illegal) immigration. This movement is due to the convergence of several factors: economic and demographic disparities between northern and southern shores of the Mediterranean Sea, the sealing-off of borders in Northwestern Europe and the 'carry-over' effect upon nations of 'transit', the extent of the flow of refugees, and--most particularly--the appeal provided by the development, in these new employer countries, of an underground economy accompanied by the extension into industry of the practice of 'undeclared' work. And notwithstanding the series of rules lastly drawn up in Spain and in Greece, such forms of clandestine (unauthorized) migration appear highly likely--to say the least--to persist." (SUMMARY IN ENG AND SPA)

Africa↗
PubMed1986

Cell growth and sodium content in the serum of uninephrectomized and renal hypertensive dogs.

The long-term cellular metabolic effects of serum factors from renal hypertensive and uninephrectomized normotensive dogs were investigated. Mouse fibroblastic L cells were cultured in M199 tissue culture medium supplemented (to 15%) with serum obtained from dogs before and after the induction of one-kidney one wrapped hypertension or with serum obtained from normotensive dogs before and after unilateral nephrectomy. At confluency, the protein, water (3-O-methyl-14C-D-glucose space), Na, K, and Mg content and 3H-thymidine uptake of cells were measured. Growth curves were derived for cells growing in serum obtained before and after uninephrectomy from normotensive and hypertensive dogs. Postnephrectomy serum from both normotensive and hypertensive dogs resulted in increased recovery of protein, increased water, K, and Mg content of cells, and increased cell numbers. 3H-thymidine uptake at confluency in postnephrectomy serum was the same as in prenephrectomy serum. The one important qualitative difference between postnephrectomy serum from normotensive and hypertensive dogs was the reduced Na content and concentration of cells cultured in the serum of hypertensive dogs. The growth-promoting serum factor in postnephrectomy blood was detected for up to 8 weeks after uninephrectomy; therefore, it did not appear to be renotropin. In experimental renal hypertension, there appear to be previously unidentified serum factors that enhance transmembrane Na gradient.

Animals↗
PubMed1985

Case report: human cutaneous alternariosis.

A case of human cutaneous alternariosis caused by Alternaria alternata on the right toe of a man is described and illustrated. Predisposing, debilitating diseases were not detectable. The alternariosis diagnosis was based on the visualization of Alternaria elements in the KOH-preparates and on the repeated successful cultivation of Alternaria alternata. Following local therapy the skin lesion healed.

Alternaria↗
PubMed1985

[Mathematical approach to bacterial identification].

The identification of Enterobacteriaceae is examined in the context of the recent field of research assisted by multi-criteria decisions. In particular, the authors discuss the limitations of two approaches of assisted identification based on completely different mathematical concepts: the calculation of the probabilities (used in commercial centres) and the aggregation of pre-orders by a model of assisted decision such as Electra II. In order to reduce the errors of interpretation inherent in the use of any model, the authors propose the use of computer assisted systems of bacterial identification in bacteriology laboratories.

Bacteriological Techniques↗