Intact parathyroid hormone, ionized calcium and calcium infusion test in the evaluation of hyperparathyroidism in chronic renal failure

We studied the parathyroid function in patients with advanced renal failure by determining their plasma concentrations of ionized calcium (iCa), intact parathyroid hormone (PTH) and its inactive metabolites (PTH-MM). The suppressibility of the parathyroidism was studied with a calcium infusion test. The intact PTH values of the nondialysis and dialysis patients did not statistically differ from each other. The concentrations of PTH-MM were, however, higher in the dialysis patients than in the nondialysis patients (p less than 0.05). The ratio of PTH-MM to intact PTH was lowest in healthy reference subjects and highest in dialysis patients (p less than 0.01), and did not correlate with the degree of intact PTH elevation in the patient groups. The calcium infusion test was carried out on 15 patients. All showed suppression in the elevated plasma intact PTH concentration and in 6 the intact PTH value normalized. The PTH-MM value did not normalize in any of the patients. During oral calcium treatment the degree of intact PTH suppression at an achieved concentration of plasma iCa was predictable from the infusion test. Three patients were parathyroidectomized after the calcium infusion test. In 2 of these elevated intact PTH normalized within 24 h while in 1 no change took place. In this latter case on clinical improvement was noted. We conclude that the determination of plasma intact PTH concentration especially of combined with plasma iCa value is a reliable means of studying the hyperparathyroidism associated with chronic renal failure.     

The effect of atrial natriuretic peptide on human isolated resistance arteries.

1. The action of (1-28) alpha-human atrial natriuretic peptide (ANP) was studied on human isolated resistance arteries. 2. Renal, skeletal muscle, omental and subcutaneous resistance arteries were taken from tissue removed at surgery and isometric tension responses were measured with a myograph. 3. ANP (10(-9)-10(-6) M) relaxed precontracted segments of renal and skeletal muscle arteries in a concentration-dependent manner. ANP failed to relax isolated omental or subcutaneous arteries. 4. The effect of ANP on human isolated resistance arteries varies depending on the site of origin of the artery.     

Value of approach to the cervical spine by bilateral anterolateral route

The authors report their experience of anterolateral bilateral approach of cervical spine. They underline the advantages and inconvenience of this route and discuss the indications.     

Human glomeruli release fatty acids which stimulate thromboxane synthesis in platelets

The cell-free medium of isolated human glomeruli exhibited a procoagulant activity and stimulated thromboxane (TXB2) synthesis in human platelets in a dose-dependent manner. The amount of TXB2 measured was 16-fold higher than what could have been predicted (TXB2 synthesized by the platelets under control conditions plus TXB2 present in the glomerular supernatant). The lipid extract of the glomerular supernatant and its purified fraction including the fatty acids was still able to stimulate--although at a lesser degree--TXB2 synthesis in platelets. Stimulation was abolished after treatment of this fraction by charcoal or albumin. Gas chromatography/mass spectrometry analysis demonstrated the presence in the purified glomerular fraction of several long-chain saturated or monoenoic fatty acids at a total concentration of 80 microM with the following order of abundance: stearic, palmitic, myristic and oleic acids. Addition to human platelets of these same exogenous synthetic acids resulted in a dose-dependent stimulation of TX synthesis. It was maximum with three or four fatty acids tested in combination, but still present with myristic acid used separately. Arachidonic acid was absent in the glomerular supernatant. Thus the stimulation observed could not be related to a greater availability of substrate. Fatty acids did not act on platelets through a non-specific detergent effect since addition of high doses of detergents inhibited TXB2 formation in platelets. The combination of fatty acids from glomerular origin identified in the present study represents a novel factor involved in the control of intracapillary hemostasis, but different from the procoagulant activity common to many tissues.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spontaneous fractures of the lesser metatarsals secondary to an amputated hallux and peripheral neuropathy

A general overview of the literature concerning the development of diabetic neuropathic arthropathy is discussed. A case report is presented dealing with spontaneous fractures of the lesser metatarsal in a patient with an amputated hallux and peripheral neuropathy secondary to diabetes mellitus.     

Impaired insulin receptor binding and postbinding defects of adipocytes from normal and diabetic pregnant women

To evaluate the relative contribution of insulin binding and postbinding defects of glucose utilization in peripheral tissue during normal and diabetic pregnancy, we have studied the in vitro insulin action of isolated adipocytes from eight nondiabetic pregnant women and nine pregnant women with insulin-dependent diabetes mellitus who were undergoing cesarian section. The pregnant women were compared with a matched group of normal nonpregnant women undergoing gynecologic surgery. Insulin binding to adipocytes measured at tracer insulin concentration was reduced by 45% (P less than 0.01) in normal pregnant women and by 30% (P less than 0.02) in pregnant women with diabetes. In contrast, no changes were found between the three groups in insulin binding to pure monocytes and erythrocytes. The glucose transport system in fat cells from both groups of pregnant women was characterized by impaired maximal (P less than 0.05) and half-maximal (P less than 0.05) response to insulin. When fat cell glucose metabolism was studied, pregnant diabetic women exhibited decreased basal lipogenesis (P less than 0.05) and decreased maximal responses of lipogenesis and glucose oxidation to insulin stimulation (P less than 0.05). Similar but less pronounced abnormalities were seen in glucose metabolism of adipocytes from nondiabetic pregnant women. In conclusion, both in late normal and diabetic pregnancy, insulin binding to adipocytes is significantly reduced and accompanied by decreased insulin sensitivity and reduced maximal insulin responsiveness of glucose transport and by impaired basal and maximally insulin-stimulated glucose metabolism.