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Biomedical subjects

M Nowicki

Publications and source records attributed to M Nowicki.

At least 55 records · Page 3Linked to original sources

The influence of hyperinsulinaemia on calcium-phosphate metabolism in renal failure.

BACKGROUND: Patients with renal failure are characterized by impaired insulin-mediated glucose uptake. Insulin plays a major role in the maintenance of phosphate homeostasis but it remains to be determined whether in uraemia insulin-dependent renal and extrarenal phosphate disposal is also affected. METHODS: The effect of hyperinsulinaemia on serum concentrations of phosphate, ionized calcium and intact PTH as well as renal excretion of calcium and phosphate was studied under euglycaemic conditions (glucose clamp technique) in patients with advanced renal failure and in healthy subjects. Fifteen patients with renal failure (mean serum creatinine 917 micromol/l) and 12 control subjects were included. All subjects underwent a 3-h euglycaemic clamp with constant infusion of insulin (50 mU/m2/min) following a priming bolus. The urine was collected for 3 h before and throughout the clamp. RESULTS: The tissue insulin sensitivity (M/I) was lower in patients with renal failure than in control subjects (5.3+/-2.4 vs 6.7+/-1.8mg/kg/min per mU/ml, P= 0.001) but the phosphate lowering action of insulin was larger in patients with renal failure than in control subjects. Urinary calcium excretion increased (P < 0.05) and phosphate excretion did not change during the clamp in both groups. Despite a decrease of serum ionized calcium in the group of patients with renal failure and no change in the control group, plasma PTH fell significantly in both groups but this effect was still significant after 180 min only in the renal failure group. A significant correlation was observed between changes in serum phosphate and PTH induced by hyperinsulinaemia (r = 0.48, P < 0.01 ) CONCLUSIONS: Phosphate-lowering effect of insulin is well preserved in severe renal failure despite the resistance to insulin-stimulated glucose uptake. The decrease of serum PTH observed during hyperinsulinaemia appears to be independent of serum ionized calcium.

Adult↗

Do healthcare managers have an ethical duty to admit mistakes?

Historically, healthcare organizations have been reluctant to admit mistakes because of potential legal liability. Admitting mistakes and taking corrective and compensatory action may reduce the likelihood of a lawsuit and, if a lawsuit is lost, may reduce the punitive damage award. Financial consequences involve admitting mistakes and incurring the associated compensatory costs or not admitting mistakes and incurring associated compensatory and punitive damages for the mistakes that are discovered later. Ethical consequences revolve around managers' duty to patients, the healthcare organization, and themselves and their families.

Ethics, Institutional↗

Partial regression of advanced cyclosporin-induced gingival hyperplasia after treatment with azithromycin. A case report.

Gingival hyperplasia is a well recognised complication of cyclosporin A therapy. Although its pathogenesis is still debated in several recent reports a second generation macrolide antibiotic-azithromycin induced partial or even complete regression of hyperplasia. We present a patient after kidney transplantation treated with cyclosporin who developed very advanced gigival overgrowth (stage 3+). The patient received a 3-day treatment with azithromycin which was repeated after 3 months. The first course of the drug caused a partial regression of gingival hyperplasia during following months but the repeated treatment did not provide a further regression of the changes.

Adult↗

Changes in plasma phosphate levels influence insulin sensitivity under euglycemic conditions.

The euglycemic clamp technique is a useful tool to evaluate insulin-mediated glucose uptake. The plasma phosphate concentration decreases during euglycemic clamp studies. Because insulin-dependent glucose uptake is closely related to phosphate uptake, we investigated whether modulation of plasma phosphate levels in the range observed during clamp studies influences insulin sensitivity. We studied 11 healthy (phosphate-replete) male volunteers (mean age, 27.5 +/- 1.8 yr;, mean body mass index, 23.9 +/- 1.6 kg/m2) in a double blind placebo-controlled cross-over study. The volunteers received in random order on two occasions either an infusion of sodium chloride (sham infusion) or an infusion of sodium phosphate. Insulin sensitivity was assessed under euglycemic conditions (clamp technique). The mean plasma phosphate concentration decreased with sham infusion from 1.09 +/- 0.17 to 0.64 +/- 0.13 mmol/L, whereas it increased with phosphate infusion from 1.06 +/- 0.19 to 1.32 +/- 0.13 mmol/L. In all volunteers except one the glucose disposal rate (M-value) was higher after phosphate infusion (mean M-value, 10.4 +/- 1.5 mg/kg.min) than that after sham infusion (mean M-value, 9.4 +/- 1.5 mg/kg.min; P < 0.01, by Wilcoxon's test for paired samples). There were no significant differences in mean plasma glucose, sodium, insulin, or arterialized standard bicarbonate levels with the two infusion protocols. Mean plasma calcium, albumin-corrected calcium, and potassium levels, however, were all significantly (P < 0.05) lower after phosphate infusion than after sham infusion. The mean PTH level decreased with sham infusion from 28 +/- 9 to 20 +/- 6 ng/L, whereas it increased with phosphate infusion from 26 +/- 9 to 36 +/- 8 ng/L, whereas it increased with phosphate infusion from 26 +/- 9 to 36 +/- 8 ng/L. The difference between the two infusion protocols was statistically significant (P < 0.01). The data presented illustrate that plasma phosphate (and calcium) levels may be confounders that should be at least monitored, and possibly controlled for, when performing euglycemic clamp studies.

Adult↗

Acute failure of the transplanted kidney--pathophysiology, diagnosis and prevention.

Acute failure of the transplanted kidney is a major problem in the early posttransplant phase and is recognized as a major cause of graft loss. Early renal transplant dysfunction is mainly due to ischemic damage (acute tubular necrosis), rejection, infection, and cyclosporin A toxicity. Less common causes include bleeding, ureteral obstruction, urinary leak, venous thrombosis, and stenosis or occlusion of the renal transplant artery. Recent advances in both invasive (renal biopsy) and non-invasive (imaging and biochemical) techniques have improved specificity and sensitivity of the diagnosis of the acute renal failure. Several procedures which aim to prevent the kidney transplant failure have recently been introduced. Although they were shown to reduce the incidence of early allograft failure, their influence on the long-term graft survival remains to be proven.

Acute Disease↗

Effect of moxonidine on urinary electrolyte excretion and renal haemodynamics in man.

Moxonidine and related compounds have been recently introduced into antihypertensive therapy. It is thought that these drugs exert their blood pressure lowering effect through interaction with non-adrenergic receptors in the central nervous system, i.e. imidazoline receptors, although the contribution of specific interaction with alpha 2-receptors is still under debate. Imidazoline receptors have recently been documented in the renal proximal tubule. In experimental studies, interaction of imidazolines with these receptors decreased the activity of the Na+/H+ antiporter and induced natriuresis. To quantitate the effect of the imidazoline receptor agonist moxonidine on renal sodium handling and renal haemodynamics in man, we examined ten healthy normotensive males (age 25 +/- 4 years) in a double blind placebo-controlled study using a crossover design. Subjects were studied on a standardized salt intake (50 mmol per day). On the 7th and 10th study day they were randomly allocated to receive either i.v. placebo or i.v. 0.2 mg moxonidine. Urinary electrolyte excretion, lithium clearance (as an index of proximal tubular sodium handling), glomerular filtration rate (GFR), effective renal plasma flow (ERPF), renal vascular resistance (RVR), mean arterial blood pressure (MAP), plasma renin activity (PRA) and plasma noradrenaline (NA) levels were assessed. Injection of moxonidine did not increase fractional sodium excretion or lithium clearance. Specifically, antinatriuresis was not observed after injection of moxonidine despite a significant decrease in MAP from 91 to 85 mmHg and a significant increase in PRA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The effect of dietary salt on insulin sensitivity.

Acute reduction of salt intake causes an increase in serum lipid and insulin levels in healthy volunteers and patients with essential hypertension, suggesting induction of insulin resistance by salt restriction. Direct measurements of insulin sensitivity using the euglycaemic clamp showed no significant change after 7 days of salt restriction. Our previous study showed a time dependent course of dyslipidaemia after institution of a low salt diet. We therefore assessed insulin sensitivity (M-value) under euglycaemic conditions (clamp technique) at discrete time points using a parallel group design. Two groups of healthy males were examined on high (200 mmol d-1) and low (20 mmol d-1) salt intake. One group (n = 7, 25 +/- 3 years, BMI 22.4 +/- 2.1 kg m-2) received high and low salt diet in random order each for 7 days. The other group (n = 7, 26 +/- 3 years, 22.1 +/- 1.9 kg m-2) received the respective diet in random order for 3 days. A significantly (P < 0.01) different mean M-value was noted in the group receiving the diets for 3 days, i.e. after low salt intake it was 7.4 +/- 1.2 mg kg-1 min-1 and after high salt intake 8.6 +/- 1.1 mg kg-1 min-1. In contrast, the mean M-value was similar after low and high salt periods in the group of individuals who had been studied after 7 days on either salt take (7.8 +/- 1.8 on low salt vs. 7.6 +/- 1.3 mg kg-1 min-1 on high salt).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗