PubMed Health⌕ Search

Biomedical subjects

S Brun

Publications and source records attributed to S Brun.

10 recordsLinked to original sources
PubMed1991

Venous occlusion and chronic cigarette smoking: dose-dependent decrease in the measurable release of tissue-type plasminogen activator and von Willebrand factor.

This study was aimed at examining the effect of chronic cigarette smoking on a venous occlusion test. Two groups of young healthy men, a control group of 20 non-smoking subjects and a group of 21 smoking subjects having an average consumption of 17.6 packages.day-1.years (SD 8.6) were studied. Venous occlusion performed in smokers did not induce a significant measurable release of von Willebrand factor (vWF). The release of tissue-type plasminogen activator (t-PA) was significantly weaker for the smokers than for the control group (P less than 0.02). An inverse correlation was found between the cumulative parameter of tobacco consumption and the measurable amount of t-PA Ag or vWF Ag released during venous occlusion (r' = -0.994 and r' = -0.889). Cigarette smoking is thus associated with disturbances of the biological response to this venous occlusion test.

Adult↗
PubMed1991

[Risk factors of vertebral osteoporosis. Results of a study of 2279 women referred to a menopause clinic].

The principal clinical risk factors of osteoporosis were correlated with vertebral bone density measured by biphoton absorptiometry in 2,279 women referred to a menopause clinic. Age, age at puberty, the menopause and how long ago it had occurred, smoking and past history of osteoporosis were negatively and independently correlated with bone density. Early onset of the menopause significantly increased the risk of a low bone density as compared with a natural or surgical menopause occurring after the age of 45. In contrast, estrogen replacement therapy and excess weight decreased this risk after the menopause. Osteoarthrosis and 25 (OH) vit. D3 levels were positively correlated with bone density. These variables taken together in a multiple linear regression model were able to explain only 25 per cent of the variations in bone density between individuals, suggesting the predominant role of other factors not taken into account in our study, notably of a genetic and environmental nature. Before the menopause, none of the factors studied enabled prediction of the risk defined by a low bone density. Among women with one or more clinical risk factors correlated with bone density, 29 per cent in fact had low bone density, as compared with 20 per cent in the absence of such factors. In contrast, 54 per cent of women with a low bone density had no risk factor. The results of this study show that the exception of secondary causes of osteoporosis, the majority of so-called "risk" factors which can be assessed by history have only a minimal influence on bone density.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1990

Study of quantitative modifications of the plasma protein S system components in non-acute inflammatory syndromes.

Thrombosis frequently accompanies inflammatory disease. There are numerous and frequent modifications of haemostasis parameters during inflammatory disease. Deficiencies in protein S, a protein C cofactor, are predisposing factors for thromboses. In 43 patients with biological inflammatory syndromes (ESR above 80 mm in the first hour found twice in a three-day period and disturbances of other biological inflammatory markers) we studied the variations of the protein S system: total antigenic protein S, free antigenic protein S, C4b BP, all antigenic fractions being assayed by electro-immuno diffusion. The results show an increase in free protein S (mean 114.3%, range 25%-180%, P less than 0.005), the biologically active fraction of protein S. They also evidence the expected increase in C4b BP (mean 188.3%, range 41%-335%, P less than 10(-5]. There is an increase in total protein S Ag (mean 145.3%, range 56%-220%, P less than 10(-5]. The results show a high positive correlation between the increased free protein S Ag and total protein S Ag (r' = 0.78, P less than 0.01), between total protein S and C4b BP (r' = 0.8, P less than 0.01) and between free protein S and C4b BP (r' = 0.73, P less than 0.01). C4b BP concentrations are correlated with haptoglobin (r' = 0.59, P less than 0.01), orosomucoid (r' = 0.53, P less than 0.01), C3 complement component (r' = 0.80, P less than 0.01), C4 (r' = 0.39, P less than 0.02) and platelet count (r' = 0.51, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Prevention of cisplatin nephrotoxicity in cancer: adjusting the dosage with a computerized chrono-pump].

Platinum and its derivates are particularly efficient in treatment of ovarian and testis carcinomas. Nevertheless, the high nephrotoxicity of these drugs limits their use. It is known that nephrotoxicity appears when platinum plasmatic concentrations are higher than 1.5 mg/l. Moreover, the wide variability between patients and between cures, emphasizes the difficulties of utilization. Using a computerized pump and a program for individual dosage regimen, an efficient prevention of plasmatic overdosages have been realised and nephrotoxicity accidents have been avoided.

Aged↗
PubMed1989

[Torsade de pointes during an atropine sulfate test in a patient with congenital long QT syndrome].

After a brief revision about the long QT syndrome, we report the case of a 52 year old man admitted to hospital for a syncopal attack. His electrocardiogram was considered normal: sinus bradycardia and U waves were recorded. The echocardiogram revealed anterior mitral leaflet redundancy and possible tricuspid prolapse. During the atropine test, after a normal increment of sinus frequency, 2 runs of self-limited torsade de pointes appeared. The electrocardiogram showed lesion wave at first, and then prolonged QT. During the intracavitary study, premature ventricular stimulation caused torsade de pointes. After propranolol iv it was no more possible to induce major ventricular arrhythmias anymore. Coronarography was normal. Nadolol therapy was begun. On 6 months follow-up the patient is asymptomatic.

Arrhythmias, Cardiac↗
PubMed1979

[Quantitative determination of drugs by in situ spectrophotometry of chromatograms for pharmacokinetic studies. I. Sulpiride and other benzamides, vincamine, naftazone (author's transl)].

Assays are proposed for sulpiride and other benzamides, vincamine and naftazone in plasma (or blood) and urine with direct UV reflectance spectrophotometry on this are applied directly on TLC along with a calibration curve on each plate. Plasma (or total blood) samples are extracted, and an internal standard is added before aplication; slopes of the obtained calibration curves do not change significantly from plate to plate, thus allowing several determinations on the same plate. The sensitivity is 2 microgram in a 1-ml sample (amount applied 30 ng) for sulpiride and related compounds and about the same for vincamine. Naftazone is determined in plasma with simultaneous reflectance and transmittance spectrophotometric measurements at 520 nm on chromatoplates sprayed with lead acetate, the sensitivity reached is 10 ng in a 1-ml sample (amount applied 0.5 ng). For all drugs studied, the proposed techniques are specific, reliable and sensitive enough and can be used to perform pharmacokinetic studies in human or in animal after administration of doses in the therapeutic range.

Animals↗
PubMed1978

[Automatic determination of the alcohol level of dry wines].

An automated technique for the alcoholometric grade determination based upon measurement of dilution heat of ethanol in wine and appropriate reagent was tested. Interferences with wine other components was studied along with methods to minimize them. Two sets of determinations on more than 100 samples of various qualities (red wines, roses wines, white wines) and various geographical sources were performed and they were compared with the pycnometric reference technique. It is shown than this comparative study that for almost 95 p. 100 of the samples the alcoholometric grade can be determined with this automated technique with an accuracy better than 0,1 p. 100.

Autoanalysis↗
PubMed1978

[Styrene migration into wine contained in polyester resin tanks].

The use of polyester resins in wine tanks manufacture or coating has widely spread during the past five years; this type of material has been and is still the source of organoleptic damage due to non polymerized sytrene migration into urine. Sytrene is a solvant often used in resin polymerization: it act as a reticulation agent of insaturated linear polyester. Polymerization at room temperature is allowed gy additives but has to be completed in warm air or in steam. An excess of styrene is often used for a polymerisation as complete as possible and remains on a free form. Then it migrates from the tank walls into the wine. For a better understanding of the styrene migration mechanism studies were performed on two levels: from small containers (4 l) kept in the laboratory and from tanks (30 hl) set up in an I.N.R.A. wine estate in all conditions usually realized in practice. Influence of time, temperature and alcohol content were studied. Styrene migration was interpreted as a diffusion phenomenom and styrene diffusion coefficients were calculated for several temperatures. Knowledge of these coefficients and of styrene content of the tank walls allow the prediction of a tank behaviour in time. Other substances that styrene were detected in wine and in tank walls, they are impurities either from resins like ethylbenzene, or from the catalyst like mesityl oxide. The lattest has never been mentioned in the litterature. From the results obtained it is possible to give some advices to manufacturers and users of polyester resin tanks, about the quality of raw materials, resins and additives along with the conditions carried and for their use and about the control of monomer styrene content in the walls of just manufactured tank.

Food Contamination↗
PubMed1977

Quantitative determination of thiourea in citrus fruits.

A quantitative method for thiourea determination in orange peels is proposed, with direct reflectance spectrometric measurements on chromatoplates. Thiourea is separated on a silica gel plate with methanol-chloroform (10 + 90), and the spots are characterized with 2,6-dichloroquinone chloroimide; this colorimetric reaction is unstable, so thiourea is quantitated on the chromatogram by direct ultraviolet reflectance spectrometric measurements at 240 nm. Comparison between this method and the AOAC colorimetric method shows interferences and higher results in the colorimetric assay. By slightly modifying the extraction technique, such as purifying the extract on an alumina column, it is possible to decrease these interferences and to avoid erroneous results with the AOAC colorimetric method. For both methods, colorimetry in solution and reflectometry on chromatoplates, applied after the proposed extraction technique, the sensitivity is about 1 ppm and the reliabilities are similar.

Citrus↗