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Biomedical subjects

R Guillet

Publications and source records attributed to R Guillet.

At least 55 records · Page 3Linked to original sources
PubMed1987

Brain oxidative phosphorylation following alteration in head position in preterm and term neonates.

An alteration in head position, which effects cerebral blood flow, may increase the risk for intraventricular hemorrhage in the critically ill infant. The purpose of this study was to evaluate in vivo cerebral oxidative metabolism as an index of tissue oxygen delivery reflecting brain blood flow, in healthy preterm and term infants following a change in head position. Cerebral phosphoenergetics using 31 phosphorus nuclear magnetic resonance spectroscopy were measured in 10 preterm and eight term infants following three different head positions: neutral, prone, and supine. All infants were clinically stable at the time of study. The phosphocreatine to inorganic phosphate ratio, an indicator of bioenergetic reserve, was determined. The mean +/- SD for phosphocreatine to inorganic phosphate ratio in the neutral position in preterm and term infants was 1.08 +/- 0.15 and 1.12 +/- 0.21, respectively, and did not change significantly following head turning. These data suggest that any alteration in cerebral blood flow as a result of a change in head position in the healthy neonate may be compensated by physiological and biochemical regulations so that no changes in brain oxidative phosphorylation are measurable.

Brain↗
PubMed1987

Aggregation of red blood cells studied by ultrasound backscattering.

The erythrocyte aggregation phenomenon is an important factor in capillary circulation. This phenomenon can be evaluated by a number of methods (microscopic observations, viscometry, light measurements) which cannot be applied simply to in vivo measurements. In contrast, ultrasound which propagates through soft tissues allows measurement of the mechanical properties of red blood cell (RBC) suspensions which depend on the aggregation phenomenon. We devised an apparatus in order to measure in vitro the ultrasonic backscattering intensity of RBC suspensions. First, with latex particles of different sizes, the ultrasonic backscattering coefficient has been measured in order to evaluate the apparatus response. Then, the ultrasonic backscattering coefficient of different aggregated erythrocyte suspensions has been measured and correlated with the erythrocyte sedimentation rate. Finally, the size of RBC aggregates of different suspensions has been evaluated.

Blood Sedimentation↗
PubMed1981

[Uterine and sigmoid perforations following voluntary interruption of pregnancy by aspiration. A case report (author's transl)].

A recent case of mixed uterine and colic perforations associated with generalized peritonitis is reported, the lesions developing within the context of the digestive complications of the method known as aspiration for voluntary interruption of pregnancy. The frequency, severity, and treatment of these lesions are described, urgent laparotomy being necessary to correct both abdominal digestive tract and genital lesions. Prevention of these complication technique. Coelioscopy is essential if a perforation is suspected, and must be followed by a laparotomy if its presence is confirmed.

Abortion, Induced↗
PubMed1980

[Traumatic recto-vesical wounds (author's transl)].

The authors report a case of a traumatic recto-vesical wound: such cases are rare and serious. The importance of an early diagnosis, which is not usually difficult, allows quick reparative treatment by the trans vesical route associated with a colostomy higher up which is later closed.

Adolescent↗
PubMed1978

Corticotropin responsiveness in the neonatal rat.

Plasma ACTH concentrations were determined in neonatal rats 1, 7, 14, and 21 days old, subjected to treatment with either a median eminence extract with corticotropin releasing factor (CRF) activity or to ether exposure. 'CRF' injection elevated plasma ACTH levels on all days tested. Ether exposure elevated ACTH levels on days 14 and 21, but not on days 1 or 7. These results indicate: (1) that there is no diminution of responsiveness of the pituitary to direct stimulation by CRF as a function of age, and (2) that the mediators of the stress response above the level of the pituitary are not functionally mature until approximately day 14. Correlations with previous studies also indicate that there is a delay in the return of adrenal responsiveness until some time after these mediators attain maturity.

Adrenal Cortex↗