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Biomedical subjects

J E Scoble

Publications and source records attributed to J E Scoble.

80 records · Page 5Linked to original sources
PubMed1985

Calcium transport in canine renal basolateral membrane vesicles. Effects of parathyroid hormone.

The effects of parathyroid hormone were studied on Ca2+ fluxes in canine renal proximal tubular basolateral membrane vesicles (BLMV). Efflux of Ca2+ from preloaded BLMV was found to be stimulated by an external Na+ gradient, and this was inhibited by the Na+ ionophore, monensin, and enhanced by intravesicular negative electrical potentials, which indicated electrogenic Na+/Ca2+ exchange activity. There was a Na+ gradient independent Ca2+ flux, but membrane binding of Ca2+ was excluded from contributing to the Na+ gradient-dependent efflux. The Na+ gradient-dependent flux of Ca2+ was very rapid, and even 2- and 5-s points may not fully represent absolute initial rates. It was saturable with respect to the interaction of Ca2+ and Na+ with an apparent (5 s) Km for Na+-dependent Ca2+ uptake of 10 microM, and an apparent (5 s) Vmax of 0.33 nmol/mg protein per 5 s. The Na+ concentration that yielded half maximal Ca2+ efflux (2 s) was 11 mM, and the Hill coefficient was two or greater. Both Na+ gradient dependent and independent Ca2+ efflux were decreased in BLMV prepared from kidneys of thyroparathyroidectomized (TPTX) dogs, and both were stimulated by parathyroid hormone (PTH) infusion to TPTX dogs. BLMV from TPTX dogs exhibited significantly reduced maximal stimulation of Na+ gradient-dependent Ca2+ uptake with an apparent (5 s) Vmax of 0.23 nmol/mg protein per 5 s, but the apparent Km was 8 microM, which was unchanged from normal. The Na+ gradient independent Ca2+ uptake was also reduced in BLMV from TPTX dogs compared with normal. Thus, PTH stimulated both Na+/Ca2+ exchange activity and Na+ independent Ca2+ flux. In vivo, the latter could result in an elevation of cytosolic Ca2+ by PTH, and this might contribute to the observed decrease in solute transport in the proximal tubule.

Adenosine Triphosphate↗
PubMed1983

The diagnostic value of urinary enzyme measurements in hypertension.

N-Acetyl-beta-D-glucosaminidase (NAG), beta-D-galactosidase, alkaline phosphatase (ALP) and leucine aminopeptidase (LAP) were assayed in the urine of 100 normal and 112 hypertensive subjects. Age-related urinary activities for these enzymes in the normotensive control subjects are presented. A new procedure for the assay of urinary ALP using 2-methoxy-4-(2'-nitrovinyl)phenyl (MNP) phosphate is described. Thirty-five of the hypertensive patients were considered to have primary renal disease. The urinary activity of NAG was increased in 27 (77%) of these patients and the detection of primary renal disease was not enhanced by measurements of the other urinary enzymes. Testing the urine both for NAG activity and protein, led to the detection of 91% of these patients. The assay procedures described are simple to perform and can be carried out in outpatient clinics. The measurement of urinary NAG activity is a cheap and reliable method for detecting renal disease in hypertensive patients but maximum diagnostic yield is achieved when proteinuria is determined as well.

Acetylglucosaminidase↗
PubMedDate not supplied

Laudable pus - lardaceous kidneys.

Amyloidosis frequently affects the kidney leading to proteinuria and loss of function. In cases of AA (reactive/inflammatory) amyloidosis, it is sometimes possible to quench the stimulus to chronic inflammation and by so doing stop further elaboration and deposition of amyloid fibrils. We describe the case of a man with a long-standing empyema who developed nephrotic syndrome and renal impairment. The empyema was resected and shortly afterwards proteinuria disappeared and renal function improved. Strenuous efforts are mandatory to locate and definitively treat underlying inflammatory foci in AA amyloidosis.

Amyloidosis↗
PubMedDate not supplied

Atheroembolic disease.

Atheroembolism is becoming an increasingly common cause of renal failure in people with widespread atheromatous disease. It remains a diagnosis that is often missed, or made only at postmortem. An awareness of risk factors and a high index of suspicion will allow it to be recognized more often.

Embolism, Cholesterol↗