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Biomedical subjects

J F Moorhead

Publications and source records attributed to J F Moorhead.

At least 127 records · Page 7Linked to original sources
PubMed1982

Plasma LCAT activities in renal allograft recipients.

Plasma LCAT activities were measured in 51 renal allograft recipients as well in 18 patients before and after successful renal transplantation. The mean plasma LCAT activity of the 51 patients did not differ significantly from that of 27 normal subjects. When the patients were separated into two groups according to whether they had normal or impaired renal function, there was no significant difference in their mean LCAT activities. Plasma LCAT activities correlated significantly with total cholesterol and total triglyceride concentrations. The sequential study demonstrates that the low plasma LCAT activities in uraemic patients rose towards normal after successful transplantation. At the same time, total cholesterol and HDL-cholesterol concentrations also increased. The increase in LCAT activity after renal transplantation is due to increased concentrations of the enzyme and probably reflects increased turnover of triglyceride-rich lipoproteins.

Adult↗
PubMed1982

Hypophosphataemia after parathyroidectomy in chronic renal failure.

Out of 24 patients receiving haemodialysis who were subjected to parathyroidectomy, 13 developed hypophosphataemia; this persisted for 3-52 weeks (mean 10.6 weeks). Before operation these 13 patients had had significantly higher plasma alkaline phosphatase activities (p less than 0.01) and significantly higher values in iliac crest bone biopsy samples for active resorption surface and active formation surface (p less than 0.05 in each case) than the group who remained normophosphataemic. Significantly more of the patients who remained normophosphataemic had shown periarticular calcification in preoperative skeletal radiographs (p less than 0.001). Hypophosphataemia may result from reduced mobilisation of phosphate from bone or its increased accretion into bone, and resorption of phosphate from periarticular mineral deposits may protect against development.

Adult↗
PubMed1982

Plasma lecithin-cholesterol acyltransferase activities in uraemic patients.

Plasma lecithin-cholesterol acyltransferase (LCAT) activity was measured in 43 haemodialysis and 15 peritoneal dialysis (CAPD) patients. LCAT activities in both groups of patients were significantly lower than those of normal subjects and did not correlate with any of the other biochemical parameters studied. The effect of intravenous administration of 100 U/kg of heparin on LCAT activity was examined in 21 haemodialysis patients and 19 normal subjects. Heparin inhibited LCAT activity by increasing plasma free fatty acid concentrations. LCAT remained inhibited throughout a dialysis session and returned towards pre-dialysis levels an hour after haemodialysis was discontinued. The cause of the low LCAT activities in the patients was not certain, but did not appear to be due to the presence of inhibitors in the uraemic plasma. The significance of these findings is discussed.

Adult↗
PubMed1982

Rejection encephalopathy. An acute neurological syndrome complicating renal transplantation.

Fifteen episodes of encephalopathy have been studied in 13 renal transplant recipients. All episodes of encephalopathy occurred during an acute rejection crisis. Clinical and biochemical features were recorded during rejection crises associated with encephalopathy and in an equal number of uncomplicated rejection episodes in the same patients. Encephalopathy was related to the severity of the rejection crisis and not to other features such as blood pressure, fever, steroid therapy or plasma electrolytes. The definition of the syndrome of rejection encephalopathy and its relation to the severity of the rejection has important therapeutic implications. Steroid therapy should not be withdrawn or reduced because of acute neurological features. Control of hypertension, fluid overload and electrolyte imbalance, in addition to treatment of the rejection episode, are necessary to reverse the encephalopathy. The prognosis of this syndrome is excellent with no long-term sequelae.

Acute Disease↗
PubMed1982

Glycosylated haemoglobin in chronic renal failure and after renal transplantation.

Haemoglobin A1 (HbA1) was determined by ion-exchange chromatography in 37 normoglycaemic patients with chronic renal failure (CRF) and 26 with successful renal transplants. Blood glucose concentrations in patients with CRF were similar to those in controls, and there was a significant correlation between fasting blood glucose concentration and HbA1 in these groups. HbA1 in patients with CRF was, however, significantly lower than that in control subjects. Concentrations of HbA1 in patients on haemodialysis, peritoneal dialysis, and those with steady state CRF prior to dialysis were not significantly different from each other. Whereas patients with successful renal transplants of greater than 3 months' duration had HbA1 concentrations indistinguishable from controls, HbA1 in patients with transplants of shorter duration were significantly lower. These observations are suggestive of a shortened erythrocyte survival in CRF per se. Furthermore, these results indicate: (a) the inadequacy of HbA1 in monitoring the quality of diabetic control in patients with CRF, and (b) the absence of a specific effect of dialysis on HbA1, and the restoration to normal HbA1 after successful renal transplantation.

Adolescent↗
PubMed1982

Response patterns to DL-carnitine in patients on maintenance haemodialysis.

10 hypertriglyceridaemic hemodialysis patients were given dl-carnitine, 600 mg daily, for 8 weeks and then 1.2 g daily for 12 weeks. Serum total cholesterol, total triglyceride, high-density lipoprotein cholesterol and plasma free fatty acid (FFA), glucose, and immunoreactive insulin concentrations were measured at regular intervals during the treatment. Intravenous fat tolerance tests were performed in 9 patients. Plasma FFA concentrations fell and the post-heparin fractional clearance rate of Intralipid increased significantly after all-carnitine administration. While overall no clear-cut effect of dl-carnitine on serum lipids was found, two patterns of response to dl-carnitine could be distinguished: the 'paradoxic' response with a rise in serum triglyceride concentrations and the dual response to two different dosages of dl-carnitine.

Adult↗
PubMed1982

Hyperlipidemia in patients on maintenance hemo- and peritoneal dialysis: the relative pathogenetic roles of triglyceride production and triglyceride removal.

A study was undertaken in 76 patients on maintenance hemodialysis and 26 patients on maintenance peritoneal dialysis to elucidate the pathogenesis of hyperlipidemia in these patients. A high prevalence of hypertriglyceridemia and low concentrations of high density lipoprotein cholesterol was found. Hemodialysis patients had low or normal total cholesterol concentrations which were significantly lower than those on peritoneal dialysis. The length of treatment did not affect the prevalence of the lipid abnormalities. Both pre- and post-heparin fractional clearance rates of Intralipid were markedly reduced in both groups of dialysis patients and were correlated inversely with serum triglyceride concentrations. However, when compared with normal subjects with similar fractional clearance rates of Intralipid, both groups of dialysis patients had higher serum triglyceride concentrations, probably reflecting increased triglyceride production. Serum triglyceride concentrations in both groups of dialysis patients were positively correlated with plasma immunoreactive insulin levels. Furthermore, a significant inverse correlation was observed between plasma immunoreactive insulin levels and post-heparin fractional clearance rates of intralipid. It was concluded that insulin resistance probably caused the defective triglyceride removal, and that both decreased removal and increased production of triglycerides contributed to the hyperlipidemia in dialysis patients.

Adult↗
PubMed1981

Hyperlipidaemia in untreated nephrotic syndrome, increased production or decreased removal?

The relative importance of increased lipoprotein synthesis and decreased lipoprotein catabolism is examined in 13 patients with untreated nephrotic syndrome by the use of intravenous fat tolerance tests analysed in relation to other parameters of lipid metabolism. Increased lipoprotein synthesis in nephrotic patients was indicated by the fact that at a given fractional clearance rate of Intralipid (K2), nephrotic patients had higher serum TG concentrations than did control subjects. A defect in lipoprotein catabolism was also suggested by the frequent finding of intermediate density lipoproteins on electrophoresis and the marginally low (p = 0.05) mean K2 in nephrotic patients. A highly significant (p less than 0.001) positive correlation between HDL-cholesterol concentrations and postheparin fractional clearance rates (K'2) of Intralipid led to the speculation that in the severe nephrotic state (albumin less than 20 g/l) the loss of high density lipoproteins may contribute to the hyperlipidaemia.

Adolescent↗
PubMed1981

Fat clearances and hyperlipidaemia in renal allograft recipients--the role of insulin resistance.

The mechanism of hyperlipidaemia in renal allograft recipients was investigated in 19 patients randomly selected from a cohort of 54 patients with functioning renal allografts. Serum cholesterol, triglyceride and high-density lipoprotein cholesterol concentrations as well as plasma immunoreactive insulin levels were measured in fasting blood samples. Intravenous fat tolerance tests were performed before and 15 min after heparin administration. Renal allograft recipients had reduced fractional clearance rates of Intralipid and a positive correlation was demonstrated between plasma immunoreactive insulin levels and serum triglyceride concentrations. Plasma immunoreactive insulins also correlated inversely with fractional clearance rates of Intralipid. It was concluded that both increased production and decreased removal of lipoproteins contribute to the hyperlipidaemia and that insulin resistance due to corticosteroids was the centre of the problem.

Adult↗
PubMed1981

Three years' experience of continuous ambulatory peritoneal dialysis.

Patients on continuous ambulatory peritoneal dialysis (CAPD) were studied for three years. 29 of them who had been on CAPD for six months or more were compared with patients on intermittent peritoneal dialysis (IPD) and on haemodialysis (HD). CAPD patients had significantly higher levels of HDL-cholesterol than HD patients. Urea, potassium, phosphate, and urate levels were significantly lower, and haemoglobin levels significantly higher, than in the IPD and HD groups. 43 CAPD patients studied had a peritonitis rate of 2.22 episodes per patient-year. CAPD offers an alternative form of dialysis to those unsuitable for HD, but until peritonitis rates can be reduced CAPD cannot rival HD as a long-term treatment.

Adolescent↗
PubMed1981

Vitamin A toxicity and hypercalcaemia in chronic renal failure.

Serum vitamin A concentrations were measured in 38 patients undergoing haemodialysis, 24 of whom were taking multivitamin preparations containing vitamin A. Vitamin A concentrations were significantly higher in patients undergoing haemodialysis than in 28 normal controls (p less than 0.001). Patients taking vitamin A supplements had significantly higher vitamin A concentrations than those not taking them (p less than 0.05), and hypercalcaemic patients had higher concentrations than normocalcaemic patients (p less than 0.005). Withdrawal of vitamin A supplements in seven patients caused significant falls in serum vitamin A concentrations and plasma calcium concentrations (p less than 0.01 at two and three months in both cases) and in plasma alkaline phosphatase concentrations (p less than 0.01 at two months). Vitamin A toxicity can contribute to hypercalcaemia in patients undergoing haemodialysis, probably by an osteolytic effect. Multivitamin preparations containing vitamin A should therefore be prescribed with caution in these patients.

Adult↗
PubMed1981

Plasma hydroxyproline fractions in patients with dialysis osteodystrophy.

Plasma hydroxyproline fractions were measured in 17 normal subjects and in 54 patients on maintenance haemodialysis therapy (MHT) with various degrees of dialysis osteodystrophy. On the basis of both radiological and histological findings these patients were divided into three groups: radiologically normal, histologically normal and those with osteitis fibrosa. The mean total plasma hydroxyproline concentrations were significantly elevated in all groups of MHT patients. However, these increases were mainly due to peptide-bound and free hydroxyproline fractions. The highest values for these two fractions were found in patients with osteitis fibrosa. The free to peptide-bound hydroxyproline ratio was not significantly altered in the majority of patients on dialysis; the mean ratio was significantly lower in patients with osteitis fibrosa when compared with patients with no histological evidence of bone disease. This finding would suggest that there is no inhibition of hydroxyproline catabolism in patients on haemodialysis and the measurements of both free and peptide-bound hydroxyproline were equally sensitive in identifying patients with osteitis fibrosa.

Bone Diseases↗