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Biomedical subjects

M K Chan

Publications and source records attributed to M K Chan.

At least 55 records · Page 3Linked to original sources
PubMed1993

Nutritional status of Kadazan children in a rural district in Sabah, Malaysia.

The nutritional status of 896 Kadazan children below 6 years of age from 23 villages of Tambunan District were studied. When stunting and wasting were defined as those who were below two standard deviations of height-for-age and weight-for-height (Waterlow et al, 1977) and based on the National Center for Health Statistics reference population, 67.6% of boys and 66.8% of girls were stunted while 12.3% of boys and 8.3% of girls were wasted. Weaning foods and toddler feeding practices were unsatisfactory. The role of health education on child care and feeding practices is emphasized.

Anthropometry↗
PubMed1992

Cytodiagnosis of lesions presenting as salivary gland swellings: a report of seven cases.

The cytologic and histologic findings of seven cases presenting clinically as salivary gland swellings are described. These included two cases of pilomatrixoma of skin in the parotid region, two cases of neurilemmoma in the submandibular area, a case of Kimura's disease in the peri-mandibular gland lymphoid tissue, a case of Castleman's disease in intraparotid lymph node, and a case of branchial cleft cyst in the parotid region. It is important to recognize lesions that masquerade as salivary gland tumors so that misdiagnosis and overdiagnosis on smears can be avoided and the patients can be treated appropriately.

Adolescent↗
PubMed1992

The impact of donor and recipient hepatitis B surface antigen status on liver disease and survival in renal transplant recipients.

Ninety-eight renal transplant recipients who had been followed for 1-6.5 years (median 3.2 years) were reviewed to determine the effect of donor and recipient hepatitis B surface antigen status on the incidence of hepatitis and on patient survival. The cumulative risk of developing hepatitis posttransplant was significantly higher in hepatitis B surface antigen-positive versus hepatitis B surface antigen-negative patients (P = 0.001). Nine (60%) of 15 patients who were hepatitis B surface antigen-positive prior to transplantation, 3 (75%) of 4 patients who became hepatitis B surface antigen-positive after transplantation, and 17 (22%) of 79 patients who were persistently hepatitis B surface antigen-negative developed hepatitis posttransplant. Five hepatitis B surface antigen-negative patients received allografts from hepatitis B surface antigen-positive donors. None of the five, including one who was initially seronegative, became hepatitis B surface antigen-positive posttransplant. Of the four patients who became HBsAg-positive posttransplant, three received kidneys from donors of unknown HBsAg status in China, while one was transplanted with a kidney from a HBsAg-negative donor. In summary, we found that the risk of developing hepatitis after renal transplantation was significantly higher in hepatitis B surface antigen-positive patients. However, both patient and graft survival were similar in hepatitis B surface antigen-positive and hepatitis B surface antigen-negative patients. The transplantation of kidneys from HBsAg-positive donors to HBsAg-negative patients did not result in clinically significant hepatitis or chronic HBsAg carriage. De novo hepatitis B infection may arise from sources other than the kidney itself.

Adult↗
PubMed1992

Amino-aciduria and enzymuria in patients with artificial heart valves.

Fifteen patients with artificial heart valves and evidence of chronic intravascular haemolysis were studied for proximal tubular dysfunction. Three patients had haemosiderinuria and haemoglobinuria; 2 had haemoglobinuria alone. Increased urinary amino acid nitrogen occurred in 8, raised fractional beta 2-microglobulin excretion in 2, hypophosphataemia in 4, renal glycosuria in 1 and enhanced fractional urate excretion in 1. Urinary N-acetyl-beta-glucosaminidase (NAG) excretion increased in 7; the mean urinary NAG/creatinine ratio was raised to twice the upper limit of the normal range. Renal haemosiderosis due to chronic intravascular haemolysis could cause tubular injury.

Acetylglucosaminidase↗
PubMed1991

Focal sclerosing glomerulopathy. Risk factors of progression and optimal mode of treatment.

Focal sclerosing glomerulopathy and especially focal segmental glomerulosclerosis (FSGS) have been recognized as a distinct clinical entity, however, there still exist controversies in terms of prognostic risk factors of progression and optimal mode of treatment. A total of 32 patients (2 with focal global sclerosis; FGS, the remainder with FSGS) were followed up for a mean period of 82 months (3-240 months). Fourteen presented with nephrotic syndrome and 18 had proteinuria with or without hypertension. Thirteen patients, all of whom except 1 were nephrotic, received steroid treatment with or without other immunosuppressive agents (cyclophosphamide/cyclosporin A/azathioprine). Three of the steroid-treated remained stable in complete remission; 5 nephrotic non-responders had renal death. The mean slope of 1/creatinine versus time for steroid-treated and non-treated groups was -0.23 and -0.043, respectively (p = 0.04), suggesting that nephrotic range proteinuria might be prognostically important. However, for the population of FSGS/FGS as a whole, only the initial serum creatinine predicted renal survival (p = 0.001 by Cox's regression model). Hypertension and hypercholesterolaemia were not important variables by themselves. Nevertheless, we found that the 9 patients treated with antihyperlipidaemics (gemfibrozil/probucol/cholestyramine/maxEPA) fared better, mean slope being -0.023 versus -0.103 for non-treated, though not reaching statistical significance (p = 0.96). Controlled prospective study involving a larger number of patients might be worthwhile.

Adolescent↗
PubMed1991

Amelioration of gentamicin nephrotoxicity by phospholipids.

The effect of phospholipids on gentamicin-induced nephrotoxicity was studied in Sprague-Dawley rats. Group 1a (5 rats) were given daily intraperitoneal injections of 100 mg/kg of gentamicin and sacrificed on day 7. Group 1b (10 rats) were similarly treated but were sacrificed on day 14. Group 2a (5 rats) were given 30 mg/kg of phospholipids for 6 days and sacrificed on day 7, serving as phospholipid controls. Group 2b (5 rats) were similarly treated, and from day 7 onwards daily intraperitoneal injections of 100 mg/kg of gentamicin were given while oral phospholipids were continued until the rats were sacrificed 7 days after gentamicin treatment. Group 2c (10 rats) were treated in the same manner as group 2b but the animals were sacrificed on day 28 after gentamicin treatment. Group 3 (10 rats) were given 30 mg/kg of phospholipids concurrently with intraperitoneal gentamicin injections and were sacrificed on day 28. Protein concentrations, N-acetyl-beta-glucosaminidase (NAG) activities and creatinine were measured in 24-h urine samples. Serum creatinine concentrations were measured in blood samples and 24-h creatinine clearance calculated. Gentamicin concentrations were determined in kidney tissues from which sections were also taken for light- and electron-microscopy. Results showed that gentamicin induced a marked increase in NAG and protein excretion, and a marked decrease in creatinine clearance with six rats succumbing to uraemia. Phospholipid treatment, whether started before or concurrently with gentamicin injections, reduced gentamicin-induced nephrotoxicity. The rats did not lose weight. Urinary excretion of NAG and protein was significantly reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1991

The physical state of human papillomavirus type 16 DNA in cervical carcinomas of Hong Kong Chinese.

The presence of human papillomavirus (HPV) in 15 cervical carcinoma specimens obtained from Hong Kong Chinese patients was analyzed by Southern blot hybridization studies. In nine (60%) of them, HPV 16 genomes were detected, while two others (13.3%) were found to harbor HPV DNA of unknown type closely related to HPV 16. All of them were classified as squamous cell carcinomas according to WHO guidelines. In addition, the presence of HPV 18 was shown in another two (13.3%) squamous cell carcinoma samples. Among the nine tumors harboring HPV 16, four specimens (44.4%) have HPV in integrated forms, while four others (44.4%) have HPV in episomal forms. The simultaneous presence of both episomal and integrated forms was demonstrated in the remaining tissue sample (11.2%). The result obtained here indicates a strong association between HPV infection and cervical carcinogenesis in Hong Kong Chinese, with HPV 16 prevalent in squamous cell carcinoma. Moreover, the persistence of HPV 16 episomes in some of the tumor specimens suggests that extrachromosomal HPV DNA, possibly acting synergistically with other oncogenic factors, is also capable of inducing cervical cancer.

Blotting, Southern↗
PubMed1991

Effects of prenatal cocaine exposure on perinatal morbidity and postnatal growth in the rabbit.

Prenatal cocaine (CC) exposure may result in increased fetal loss, growth retardation, altered neurodevelopment, and sudden infant death syndrome (SIDS). We sought to establish an animal model for prenatal cocaine exposure which (1) would allow us to distinguish the direct effects from the indirect and nutritional effects of the drug, and (2) might be used to address questions of cocaine's toxicity, specifically to the developing respiratory control system. The study design included 38 New Zealand White rabbit does among CC, pair-fed (PF), and free-fed (FF) groups. Miniosmotic pumps were implanted in each doe on day 10 of timed gestation providing continuous subcutaneous administration of either 30 mg/kg/day of cocaine HCl in H2O (CC) or sterile H2O alone (PF and FF). Mean (SEM) plasma cocaine concentration was 1.71 +/- 0.21 mumol/l (519.4 +/- 64.4 ng/ml). Pregnancy outcome compared for incidence of stillbirth, maternal death, spontaneous abortion, and gross malformation among 211 pups was significant only for increased stillbirths among CC pups (18%, p less than 0.04) as compared to PF (6%) and FF pups (7%). External and renal malformation and postnatal weight, crown-rump length, and snout-occiput head circumference for pups aged 4 and 5 days of age did not differ among groups. The direct effects of prenatal cocaine evaluated in our model do not reproduce the altered perinatal outcome observed among humans. However, our results do not determine if physiologic function has been altered. Investigation of the physiologic and pathologic abnormalities that are relevant to this human condition, specifically to the developing respiratory control system, should add clarity to the mechanism of action of cocaine during pregnancy.

Abortion, Spontaneous↗
PubMed1991

Correction of anemia in patients on continuous ambulatory peritoneal dialysis with subcutaneous recombinant erythropoietin twice a week: a long-term study.

Subcutaneous recombinant human erythropoietin (rHuEPO) was given for 12 months twice weekly to 10 patients on continuous ambulatory peritoneal dialysis (CAPD) with anemia (hemoglobin less than 9.0 mg/dl). All patients responded to a median weekly dose of between 37.5 to 100 (mean 55 to 105) units/kg and reached a target hemoglobin of 10-12 mg/dl in a mean of 11.7 weeks (range 5-24). Serum iron, iron saturation and ferritin were significantly lower and serum potassium was significantly higher than the pre-treatment level from 1 month onwards. Five patients without pre-treatment iron overload required oral iron supplement and 3 required oral potassium-binding resin. No significant change in other serum biochemical parameters was observed. Blood pressure remained stable during the treatment period but additional or increased dosage of antihypertensive drugs was required in 5 patients. Peritoneal small solute clearance and ultrafiltration and residual renal clearance did not change significantly after correction of anemia. The incidence of peritonitis and exit site infection was similarly unaffected. One patient developed a severe headache which was not associated with hypertension and responded to withdrawal of rHuEPO treatment. Most of the remaining patients showed improvement in subjective well-being. It was concluded that the subcutaneous route twice a week is a safe, convenient and cost-effective way to administer rHuEPO to patients on CAPD.

Adult↗
PubMed1990

Urinary tract infections in post-renal transplant patients.

The overall incidence of urinary tract infections (UTIs) in our renal transplant population was 30.9%, i.e. 0.15 episode per patient-year. UTIs occurred more often within the first 3 months (60%) of transplantation. Fifty per cent of UTIs were asymptomatic. Recurrences were common. Acute tubular necrosis and cellular rejections were important associations. UTIs had little effect on graft function and survival up to 3 years post-transplant.

Adolescent↗
PubMed1990

Haematological changes after renal transplantation: differences between cyclosporin-A and azathioprine therapy.

Haematological changes after renal transplantation in 76 patients were reviewed and the differences observed between patients treated with cyclosporin-A and prednisolone and those treated with azathioprine and prednisolone were compared. Erythrocytosis defined as haemoglobin concentration equal to or exceeding 17 g/dl occurred in 25% of patients treated with cyclosporin-A and in 11.4% of patients treated with azathioprine. Only one patient, who received cyclosporin-A, had clinical evidence of thrombosis. Eight patients treated with cyclosporin-A and five treated with azathioprine had therapeutic venesections. There was no difference in the incidence of putative risk factors for post-transplant erythrocytosis between the two groups.

Adolescent↗
PubMed1990

Comparison of captopril and enalapril in the treatment of hypertension in patients with non-insulin dependent diabetes mellitus and nephropathy.

Eighteen patients with non-insulin dependent diabetes mellitus (NIDDM), hypertension and nephropathy were randomized to receive captopril or enalapril for 6 months. Two patients with serum creatinine of greater than 400 mumol/l had to be excluded from the study because of rapidly deteriorating renal function after starting treatment. Of the remaining patients, 7 received captopril and 9 received enalapril. Blood pressure control was achieved in about 50% of patients with either drug alone. Serum creatinine and creatinine clearance were unchanged in both groups but there was a greater tendency for the former to increase in patients with higher pretreatment values. Proteinuria was reduced at 1 month only in the enalapril group which also showed a significant elevation of serum potassium after treatment. Captopril and enalapril have only a modest antihypertensive action in patients with NIDDM and nephropathy. Their use in patients with renal insufficiency must be balanced against the risk of further aggravating the deterioration of renal function.

Blood Pressure↗
PubMed1990

Lipid metabolism in renal failure.

Many patients with renal failure show abnormalities of lipid metabolism. Hypertriglyceridemia and low levels of high density lipoprotein (HDL) cholesterol are frequent abnormalities in uremic patients. The hypertriglyceridemia and low HDL cholesterol are thought to result from decreased lipoprotein lipase activity. The decreased levels of hepatic lipase observed in renal failure may account for the presence of intermediate density lipoproteins (IDL) and the high HDL2 subfraction. The risk factor for coronary artery disease expressed as the ratio of total cholesterol to HDL cholesterol is elevated in renal failure patients, especially in those with hypertriglyceridemia. Treatment of renal patients with gemfibrozil partially reverses many of the lipid abnormalities including the low HDL cholesterol. However, only the HDL3 subfraction increased while HDL2 remained unchanged.

Humans↗
PubMed1990

A randomized prospective trial of three different regimens of treatment of peritonitis in patients on continuous ambulatory peritoneal dialysis.

A randomized prospective study was undertaken in patients on continuous ambulatory peritoneal dialysis (CAPD) to evaluate the efficacy of three different antibiotic regimens for the treatment of peritonitis. There were 39 episodes in each treatment group. Patients were treated with intraperitoneal (IP) cephalothin (250 mg/L) and tobramycin (8 mg/L) in group 1, oral ofloxacin (400 mg loading followed by 300 mg daily) in group 2, and a combination of ofloxacin (400 mg followed by 300 mg daily) and rifampicin (300 mg daily). Treatment duration was 10 days. The average culture-positive rate was 75%. The overall cure rate was 80.6% with IP antibiotics, 78.4% with oral ofloxacin, and 81.1% with ofloxacin and rifampicin. After the exclusion of tunnel infections and episodes of peritonitis due to Pseudomonas and resistant organisms, the corresponding figures were 100%, 90.6%, and 93.7%, respectively. Side effects were minimal with IP treatment and with oral ofloxacin, but severe nausea and vomiting occurred in some cases with the combination of ofloxacin and rifampicin. It was concluded that oral ofloxacin is an acceptable first-line therapy for peritonitis in CAPD patients.

Administration, Oral↗
PubMed1990

Development of an automated human sperm quality system.

A computer-automated system, including hardware and software components, is developed for objective assessment of human sperm density and other characteristics, including morphological abnormalities and motility. The hardware component essentially consists of an IBM AT, a relatively low-cost image processing board and other inexpensive commercially available instruments. On the other hand, the software component is developed through the incorporation of image analysis, pattern recognition and modelling techniques with the knowledge of human reproduction from the available literature. The whole system is expected to produce a practical and cost-effective means for the routine assessment of human semen quality.

Computer Systems↗
PubMed1990

The effect of fish-oil dietary supplement on the progression of mesangial IgA glomerulonephritis.

The effect of fish-oil dietary supplement on the rate of progression of renal failure in 11 patients with IgA nephropathy was investigated by comparing the slope of the plot of reciprocal serum creatinine versus time before and after supplement. After supplement, the slope significantly decreased in two patients, increased in two, and was not significantly altered in the remainder. Before supplement, serum IgA, IgA circulating immune complexes, and in-vitro Ig production were not significantly different from normal controls. After supplement, urinary protein transiently increased, serum IgA circulating immune complexes decreased, and serum triglyceride and in-vitro platelet aggregation tended to decrease. Only the change in serum IgG and spontaneous in-vitro IgG production correlated with the change in the rate of renal functional deterioration. No clinical or biochemical parameters before supplement predicted the subsequent response. In patients with IgA nephropathy, non-immune factors probably contribute to progression of renal failure, and in these patients fish-oil dietary supplement has either no demonstrable or an unpredictable effect.

Adult↗
PubMed1990

Hypocalcemic heart failure in end-stage renal disease.

A 37-year-old woman presented with hypocalcemic heart failure complicating end-stage renal disease. Heart failure persisted despite conventional therapy but improved after correction of hypocalcemia. Continuous monitoring of left ventricular function by radionuclide study during calcium replacement showed dramatic improvement. Our case showed that hypocalcemia could be a rare but reversible cause of frank heart failure in uremic patients.

Adult↗