The diagnosis of segmental transplant renal artery stenosis by captopril renography

The captopril renogram test has been shown to be a sensitive test for the diagnosis of renal artery stenosis in native and transplanted kidneys. Most reports have involved only stenosis of the main renal artery. Although segmental renal artery stenosis has been diagnosed successfully in native kidneys, it is not clear whether the captopril renogram test can diagnose segmental renal artery stenosis in a transplanted kidney. The authors report two cases of successful identification, by the captopril renogram test, of functionally significant stenosis in an intrarenal branch of a single transplant renal artery.

Serum parathyroid hormone suppression by intravenous 1,25-dihydroxyvitamin D3 in patients on maintenance haemodialysis

Secondary hyperparathyroidism in patients with end-stage renal disease is characterised by elevated circulating levels of parathyroid hormone, due to inadequate synthesis of calcitriol, the active metabolite of vitamin D. Recent studies suggest that administration of calcitriol may directly suppress parathyroid (PTH) secretion independent of changes in serum calcium. We have studied the effect of intravenous calcitriol administration on the PTH level in 14 patients on maintenance haemodialysis with serum PTH levels above 2,000 pmol/l over a 16-week period. There was a significant reduction in the PTH level (65%) and a rise of serum calcium to the normal range. There was a significant reduction in serum PTH levels before the serum calcium concentrations increased, suggesting that calcitriol directly inhibits PTH release. In conclusion, intravenous treatment with calcitriol is of clinical importance, because it suppresses hypersecretion of PTH in uraemic patients, with minimal side effects.

Acute Renal Failure due to Rhabdomyolysis Following Human Stampede

Acute renal failure (ARF) following rhabdomyolysis is a well known entity. In this paper, we present an unusual cause for trauma that resulted in rhabdomyolysis associated with renal failure. Rhabdomyolysis resulted from human stampede that occurred in a mountain tunnel on the occasion of The Pilgrimage to Makkah in 1990. To the best of our knowledge, human stampede as a cause of rhabdomyolysis has not been reported in the literature. A total of eight patients were referred to our center. Laboratory investigations revealed rhabdomyolysis as well as evidence of moderate to severe renal impairment in all patients. They were treated with forced alkaline diuresis, but three required hemodialysis. All patients recovered. Treatment with forced alkaline diuresis was found to be useful in the treatment of these patients and instituting such treatment is worthwhile even in those cases where renal failure is established.

Withdrawal of beta-blocking drugs

Our early observations indicated that when treatment was changed from propranolol to placebo, anginal patients experienced a higher incidence of chest pain during the first week of placebo treatment compared to the second week. Since then, there have been several reports of myocardial infarction and sudden death occurring when propranolol therapy has been stopped. However, more formal hospital studies have indicated that ischemia from propranolol withdrawal is relatively infrequent. Studies in normal subjects and hypertensive patients have shown an increase in beta-receptor sensitivity as suggested by increased responsiveness to isoprenaline after propranolol withdrawal. Some investigators have found an increase in free triiodothyronine levels. Catecholamine levels do not appear to be raised. Other relevant factors in ischemic patients might be a reversal of the favorable rightward shift of the oxyhemoglobin dissociation curve or a reversal of reduced platelet aggregation produced by propranolol. Last, propranolol withdrawal in patients who have received the drug for a considerable period might unmask a withdrawal in patients who have received the drug for a considerable period might unmask a progression of the disease process, so that in the absence of beta blockade oxygen supply is inadequate to meet the requirements of relatively ischemic areas even at rest. Whether all beta blockers are similar to propranolol in this regard is unknown. We are examining, in normal volunteers, the sensitivity of the beta receptor after the withdrawal of atenolol, pindolol, or propranolol, administered for at least 2 weeks after final dose adjustment to levels sufficient to produce maximum inhibition of exercise tachycardia. The sensitivity of the beta receptor is being assessed by the response of bolus injections of isoprenaline and the response to exercise tachycardia.

Two aminophylline preparations in nocturnal asthma

In a double-blind trial the effects of aminophylline suppositories and slow-release aminophylline tablets were compared with similar placebo preparations in nine patients whose complaint was asthma which woke them from sleep at night. Forced expired volume in one second (FEV1) was measured in each patient at three-hourly intervals from 1900 hours to 0700 hours on four separate nights, the preparation being administered immediately after the 2200 hour measurement. On the nights when a placebo was administered the FEV1 showed a statistically significant fall between 1900 and 0400 hours. Aminophylline had a statistically highly significant effect in reducing or preventing this fall, suppositories and tablets being equally effective in this single-dose study.