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Biomedical subjects

F Ruff

Publications and source records attributed to F Ruff.

97 records · Page 6Linked to original sources
PubMedDate not supplied

[Study of histamine in asthma].

Histamine is generally considered as the principal chemical mediator in experimental allergy of type I and anaphylaxis. However, its part in human bronchial asthma remains discussed, because neither the dosage of histamine in blood, nor the use of antihistaminics have furnished any real evidence. This study is dealing with two elements: the importance of local bronchopulmonary phenomena, and the associated mediators also liberated in asthma, such as SRSA. ECFA, kinines, prostaglandins and disorders of balance between, on one hand, alpha and beta-actions of the catecholamines, and on the other hand, between the two main types of cyclic nucleotides. These considerations should allow a better approach of the asthma etiopathology and perhaps an improvement of its treatment.

Animals↗
PubMedDate not supplied

Induction of hypertension and cardiac hypertrophy in guinea pig by DOCA salt.

Experimental hypertension can be induced in rats by uninephrectomy, administration of deoxycorticosterone acetate (DOCA) and sodium chloride. We developed this model in the guinea pig, because it presents an isoenzymic myosin pattern and calcium-induced calcium release similar to those of humans. Unilateral nephrectomy was performed in 33 guinea pigs, after which they were given DOCA (300 mg/kg pellets, s.c.; n = 11, or 10 mg, i.m.; n = 12, 5 days a week for 5 weeks). One week after surgery, drinking water was supplemented with NaCl 9 g/l and KCl 2 g/l for 5 weeks. Control guinea pigs (n = 10) were nephrectomized but not treated. Five weeks after surgery, hemodynamic measurements were recorded and the animals sacrificed to assess the degree of left ventricular hypertrophy. Left ventricular hypertrophy was considered significant if the ratio of left ventricular weight/body weight was > 2.3 and if the thickness of the left ventricle free wall was > 3.5 mm. Results showed that the systolic, diastolic and mean blood pressures of the treated groups were 36% higher than in the control group. Cardiac hypertrophy occurred within 5 weeks, and resulted in an increase in left ventricle weight and in left ventricular hypertrophy. The possibility of using the DOCA salt model of experimental hypertension in the guinea pig could help to elucidate the mechanisms responsible for hypertension and induced left ventricular hypertrophy, and thus improve prevention and treatment.

Analysis of Variance↗
PubMedDate not supplied

Pharmacokinetics of acipimox and of its N-deoxy metabolite following single and repeated oral administration to healthy volunteers.

The aim of the present study was to evaluate the plasma pharmacokinetics of acipimox and of its N-deoxy metabolite (5-methylpyrazine-2-carboxylic acid, MPCA) following single and repeated administration of 250 mg acipimox (thrice daily, for 6 days) to ten healthy volunteers. Mean maximum concentration, the corresponding time, area under the curve extrapolated to infinity and elimination half-life values of acipimox after single administration were equal to 5.74 micrograms/ml (range 2.56-8.38 micrograms/ml), 1.7 h (1-3 h), 16.99 micrograms/ml.h (11.28-22.17 micrograms/ml.h) and 1.15 h (0.79-1.48 h), respectively. Mean area under the curve over one dosing interval (8 h) and elimination half-life values of acipimox after repeated dosing were not significantly different from the corresponding values after the single dose. No significant accumulation was observed following the repeated treatment, since the mean accumulation ratio was 1.08 (range 0.74-1.52). The mean maximum concentration and corresponding time values in the 7 out of 10 subjects with detectable metabolite levels after the single dose were 0.19 microgram/ml (0.10-0.34 microgram/ml) and 6.7 h (3-12 h), respectively, whilst after the repeated treatment, detectable concentrations of the metabolite were observed in all subjects, the mean maximum concentration value being equal to 0.48 micrograms/ml (0.11-1.19 microgram/ml). The average ratio of the parent/metabolite area under the curve values (8 h) after repeated dosing was equal to 14 (range 2-56). Inter-subject variability in the extent of metabolite formation was very high.

Administration, Oral↗
PubMedDate not supplied

[Peripheral airway obstruction in the course of occupational exposure to asbestos].

Typically, the functional abnormalities in individuals exposed to asbestos dust take the form of a pulmonary fibrosis. Recently, several authors have stressed the early existence of small airways obstruction. In the present study, by measurement of closing volume, we have confirmed an obstructive factor in a certain number of exposed subjects, even if they were non-smokers, i.e. had no other apparent reason for small airways disease.

Airway Obstruction↗