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Biomedical subjects

M K Chan

Publications and source records attributed to M K Chan.

At least 163 records · Page 9Linked to original sources
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

Hepatitis B and the dialysis and renal transplantation unit.

Different facets of hepatitis B infections are encountered in a renal unit. The viral antigens are implicated in the pathogenesis of some cases of glomerulonephritis. Hepatitis B surface (HBs) antigenaemia frequently persists in dialysis patients who contract the virus and presents a significant health hazard to the attendant staff. Persistent HBs antigenaemia does not jeopardise renal allograft survival. The effect of anti-HBs antibodies is not clear. Transplantation can reactivate latent hepatitis B infections and render patients HBs antigen (HBsAg)-positive. Hepatic malignancies have been observed and increased patient mortality reported in HBsAg-positive renal allograft recipients. The effect of immunosuppression and maternal viral infection on the fetus is open to speculation.

Cross Infection↗
PubMed1981

The role of multiple pharmaco-therapy in the pathogenesis of hyperlipidemia after renal transplantation.

A study was undertaken in 54 renal allograft recipients to evaluate the multiple factors contributing to the pathogenesis of hyperlipidemia after renal transplantation. Serum triglyceride concentrations were found to correlate positively with the cummulative prednisolone dose, and with abdominal skin fold thickness. Serum cholesterol concentrations correlated significantly with serum creatinine concentrations. Patients on beta adrenergic blocking agents had lower plasma free fatty acid concentrations and patients on diuretics had higher serum triglyceride concentrations. The implication of these findings are discussed.

Adolescent↗
PubMed1981

The effects of vitamin A toxicity on calcium and lipid metabolism in chronic renal failure.

Serum vitamin A levels were high in haemodialysis patients, and were found to correlate with plasma calcium, triglyceride, cholesterol and insulin levels. Vitamin A containing multivitamin supplements were found to contribute to increased serum vitamin A levels, and their withdrawal in seven patients caused a significant decrease in serum vitamin A and calcium levels, with no effect on lipid levels. Vitamin A containing preparations should therefore be prescribed with caution in these patients.

Adult↗
PubMed1980

Fat clearance before and after heparin in chronic renal failure--haemodialysis reduces post-heparin fractional clearance rates of intralipid.

The effect of heparin on the kinetics of fat removal was studied in 15 subjects and it became apparent that the fat tolerance test could be performed after the administration of heparin. Therefore, fractional clearance rates of Intralipid were determined before and after heparin in three groups of patients: 18 in chronic renal failure, 11 on peritoneal dialysis and 17 on haemodialysis. Patients on peritoneal dialysis and on haemodialysis had similar serum triglyceride concentrations and comparable fractional clearance rates of Intralipid before heparin was given. However, the latter had significantly smaller increases in fractional rates of Intralipid clearance after the administration of heparin. Either gradual diminution of releasable releasable enzymes by regular heparinisation or activator concentrations becoming rate-limiting could be responsible for the low post-heparin fractional clearance rates observed in haemodialysis patients.

Acute Kidney Injury↗
PubMed1980

Nocturnal polyuria and saluresis in renal allograft recipients.

The evolution of nocturnal polyuria and saluresis in renal allograft recipients was studied by comparing the day to night (D:N) ratios of urine volume and sodium excretion in 15 patients who had undergone transplantation less than one year previously (recent-transplant group) with those in 11 patients who had undergone transplantation at least one year previously. Eleven patients with chronic renal failure and 12 normal subjects served as controls. Patients in the recent-transplant group had significantly lower D:N ratios of urine volume and sodium excretion than the patients who had undergone transplantation at least a year before, while the ratios in this last group did not differ significantly from those in the normal subjects. Nocturnal polyuria and saluresis gradually subsided in five patients studied for three months. Chronic renal failure and uraemic autonomic neuropathy were unlikely causes of the nocturia. The patients in the recent-transplant group had significantly lower D:N ratios of urine volume than the controls with chronic renal failure, and the mean Valsalva ratio in eight of them was not significantly different from that in the normal subjects. An undue sensitivity of renal allografts to postural influences was proposed.

Creatinine↗
PubMed1980

HDL cholesterol and intravenous fat tolerance in dialysis patients.

Serum cholesterol, triglyceride, HDL cholesterol and HDL triglyceride concentrations were determined in 27 dialysis patients and the same number of control subjects. Fat tolerance tests were performed in all dialysis patients and repeated 15 minutes after 100U/kg of heparin given intravenously in haemodialysis patients. Dialysis patients had higher serum triglyceride, lower HDL cholesterol, higher HDL triglyceride concentration, and lower fractional clearance rates of Intralipid than the control subjects.

Adult↗