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Biomedical subjects

J Bauer

Publications and source records attributed to J Bauer.

At least 649 records · Page 36Linked to original sources
PubMed1976

Kidney and plasma renin in human renovascular hypertension.

Renin activities were determined in plasma and in single, microdissected juxtaglomerular apparatus in 19 patients with unilateral renal artery stenosis. The mean juxtaglomerular apparatus renin concentration in the stenosed kidneys was 5.5 +/- 1.2 (SEM) mug.l-1.h-1 which is about ten times that of the suppressed renin concentration in the contralateral kidneys (0.6 +/- 0.05 mug.l-1.h-1). On the affected side a positive correlation was found between intrarenal and renal venous renin concentration (r = 0.93; p less than 0.001). Both intrarenal and renal venous renin concentrations of the stenosed kindeys were positively correlated to renin secretion rates, as calculated from renin analysis in plasma from the vena cava and renal veins. No relationship could be demonstrated between intrarenal or renal venous renin concentration and the degree of blood pressure elevation or transstenotic pressure gradient. However, a positive correlation was evident between peripheral plasma renin activity and diastolic blood pressure (r = 0.88; p less than 0.001). Comparative enzyme kinetic analyses of renin from the juxtaglomerular apparatus and renal venous plasma were performed using sheep substrate. The lowest apparent Km-values of renin were found in renal venous plasma from the stenosed kidneys (198 +/- 13 mug/l) compared with the contralateral side (301 +/- 20 mug/l; p less than 0.001). Mean apparent Km-values of juxtaglomerular apparatus renin in the stenosed (270 +/- 36 mug/l) and contralateral (292 +/- 37 mug/l) kidneys did not differ. No significant differences were found between mean apparent Km-values for renin in peripheral plasma of renovascular hypertensive patients and control subjects using either homologous human or heterologous sheep renin substrate. The results suggest that, in addition to the renin concentration other factors are relevant to chronic high blood pressure in renovascular hypertension.

Adult↗
PubMed1976

Thrombin-induced oxygen consumption, malonyldialdehyde formation and serotonin secretion in human platelets.

The relationship of a thrombin-induced burst in O2 consumption to lipid peroxidation in washed human platelets was investigated by measuring malonyldialdehyde, a by-product of endoperoxide degradation in platelets. The ratio of O2 consumed by malonyldialdehyde produced was approximately 7:1. Acetylsalicylate blocked the formation of malonyldialdehyde completely and partially inhibited the O2 burst induced by thrombin. 5,8,11,14-Eicosatetraynoic acid inhibited the O2 burst as well as the malonyldialdehyde formation completely. The release of [14C]serotonin was not affected by either inhibitor.

Blood Platelets↗
PubMed1975

Comparison of visually guided reaching in normal and deprived infant monkeys.

A stump-tailed macaque, deprived of sight of its hands and body since shortly after birth, appears to be deficient in the accuracy and precision of its visually guided reaching. These deprived monkeys quickly develop adequate reaches if they are allowed to view their hands. To assess the deficit, we developed a method of open-loop testing (no sight of the reaching limb) for use on both an experimental group deprived of sight of limbs and a control group raised under identical restraints but allowed sight of limbs. The results show that the deprived monkeys can learn to reach a given visible target, but the learned reach is not as precise in the training condition or as precise to new target directions as it is for controls. Furthermore, there is little intermanual transfer of reaching skill for the experimentals but nearly 100% transfer for the controls. Finally, experimentals show a loss of precision in retention testing following a lack of practice, but controls do not. We conclude that the differences in visually guided reaching behavior of the two groups is evidence that the normal accuracy results from unconstrained vision of the hands which produces a mapping of the coordinates of motor response onto the space of vision.

Animals↗
PubMed1975

Diabetes insipidus secondary to penetrating thoracic trauma.

Three cases of diabetes insipidus following non-cranial trauma are presented. They are believed to be the first of their kind reported. The etiology, pathogenesis and differential diagnosis of diabetes insipidus are discussed. The literature if briefly reviewed and similarities between patients with DI due to long bone trauma with fat embolism, post open heart surgery hypotension, Sheehan's syndrome following postpartum hemorrhage, DI and our own patients are discussed. It is concluded that the diabetes insipidus is caused by selective disruption of posterior pituitary circulation due to fat globules, thrombi and hypovolemia resulting in hypoxia and tissue necrosis.

Adolescent↗