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Biomedical subjects

M K Chan

Publications and source records attributed to M K Chan.

At least 73 records · Page 4Linked to original sources
PubMed1990

Sustained-release bezafibrate corrects lipid abnormalities in patients on continuous ambulatory peritoneal dialysis.

A study was undertaken in 24 Chinese patients on maintenance continuous ambulatory peritoneal dialysis, using bezafibrate in its sustained-release form to correct lipid abnormalities. Six patients who received 400 mg/day developed severe muscle weakness with grossly elevated creatine phosphokinase activities within 3 weeks. The drug was discontinued and the symptoms disappeared. The remaining 18 patients received 400 mg/week for 8 weeks. There was a significant decrease in serum triglyceride (2.74 +/- 0.33 to 1.86 +/- 0.17 mmol/l at the 4th week and 1.65 +/- 0.4 mmol/l at the 8th week). Concomitantly, serum total cholesterol decreased. Serum high-density lipoprotein cholesterol increased significantly (from 1.18 +/- 0.082 to 1.36 +/- 0.060 mmol/l at the 4th week and 1.40 +/- 0.103 mmol/l at the 8th week). Post-heparin lipoprotein and hepatic lipases were measured by a substrate-specific method. The former increased significantly (p = 0.000) after bezafibrate treatment while the latter did not change. All parameters of lipid metabolism returned towards baseline 4 weeks after discontinuation of therapy. The drug was well tolerated at 400 mg/week and there was no significant rise in serum creatine phosphokinase.

Adolescent↗
PubMed1990

Clinical experience with pefloxacin in patients with urinary tract infections.

A total of 27 patients, 21 of them females, with a median age of 56 were treated with pefloxacin for urinary tract infections. Some 74% of these infections were associated with upper tract symptoms, and Escherichia coli was the most common causative micro-organism (75% of cases). Fifteen patients had co-existent diseases with/without urological abnormalities. All strains of E coli were sensitive to pefloxacin; Actinobacter and one strain of Klebsiella and Streptococcus faecalis were resistant. Two patients who defaulted and one who had an initial negative bacterial culture were excluded from the analysis of the outcome. The overall bacteriological cure rate at four to eight weeks was 87.5% (21/24). The incidence of possible side-effects was high, occurring in 59% of the patients. Nausea, dizziness and vomiting were the most common. These were mild and did not require termination of treatment. Peripheral neuropathy, which disappeared four weeks after stopping pefloxacin, occurred in one patient.

Adolescent↗
PubMed1990

The value of cytologic examination for nasopharyngeal carcinoma.

Cytologic examination is useful in the diagnosis of NPC. The actual yield in exfoliative cytologic diagnosis can be improved by a better designed applicator. Metastatic NPC in lymph node FNA shows certain features that are diagnostic. Detection of EBNA can be done with smears from fine-needle aspirates and may help to exclude NPC from the diagnosis if they are negative.

Biopsy, Needle↗
PubMed1990

Newcastle bone disease in Hong Kong: a study of aluminum associated osteomalacia.

We measured serum aluminum concentrations in 104 haemodialysis patients from 3 centres in Hong Kong. We found that the 52 patients dialyzed in unit A had much higher mean aluminium levels (100 micrograms/L) than those from the other two units (61 and 39 micrograms/L respectively). In unit A, where water treatment by reverse osmosis had been introduced only recently, 30.8% of patients had fractures/looser zones, 46.2% had rugger-jersey spine and 28.8% had skeletal erosions. When these patients were divided into two groups according to whether their serum aluminium concentration was below or above 100 micrograms/l, the latter patients had significantly lower alkaline phosphatase, serum phosphate, and higher total prescribed dose of aluminium hydroxide. It was concluded that both dialysate aluminium and oral aluminium intake seemed to have contributed to the high incidence of osteomalacic fractures among Unit A patients. In eight of these patients serum aluminium increased by more than 150 micrograms/L after four weeks of receiving 1.5 g desferrioxamine twice weekly. Serial X-rays showed that the mean time after dialysis for the appearance of fractures/Looser zones was 72 months. Three patients developed fractures/Looser zones after successful renal transplantation; and it was postulated that the prompt excretion of aluminium permitted increased osteoclastic activity, resulting in fractures in these patients.

Adult↗
PubMed1990

Minimal change glomerulopathy in two patients after thymectomy.

Two myasthenia gravis patients developed nephrotic syndrome due to minimal change glomerulopathy 3 to 14 years after thymectomy for malignant thymoma. Impaired cellular and humoral immunity has been documented in patients with thymoma and persists after thymectomy. The occurrence of minimal change disease lends support to the hypothesis that the glomerulopathy is secondary to T-cell dysfunction, resulting in production of a lymphokine which increases glomerular basement membrane permeability.

Adult↗
PubMed1990

N-acetyl-beta-glucosaminidase in the localization of the site of urinary tract infections.

Excretion of N-acetyl-beta-glucosaminidase was measured in 57 patients with urinary tract infections and in 19 normal subjects. The normal range was 0.17 to 1.16 iu/mmol creatinine. The mean NAG/creatinine ratio was 3.11 in 28 patients with upper, and 1.14 in 21 patients with lower urinary tract infection (p = 0.0006). However, even among those clinically defined as having lower urinary tract infections, 18% had NAG/creatinine ratios above the normal range. The mean NAG/creatinine ratio of 8 patients with lower urinary tract symptoms who had underlying uronephrological diseases/systemic diseases capable of causing nephropathy was intermediate between the value obtained in patients with upper, and that observed in patients with lower urinary tract infections.

Acetylglucosaminidase↗
PubMed1989

Gemfibrozil improves abnormalities of lipid metabolism in patients on continuous ambulatory peritoneal dialysis: the role of postheparin lipases in the metabolism of high-density lipoprotein subfractions.

Twenty-five CAPD patients were given gemfibrozil in increasing doses for a total of 14 weeks. Parameters of lipid metabolism including serum total cholesterol, LDL cholesterol, HDL cholesterol, HDL2 cholesterol, HDL3 cholesterol triglyceride, apolipoprotein A-1, apolipoprotein B, postheparin lipoprotein lipase, and hepatic lipase activities were measured before the commencement, at every increment in the dose of gemfibrozil and 4 weeks after discontinuation of therapy. Gemfibrozil normalized the deranged parameters of lipid metabolism. Thus, with treatment, serum triglyceride, and total cholesterol, LDL cholesterol and apo B decreased, whereas serum HDL cholesterol, HDL2, and HDL3 (predominantly the latter subfraction), hepatic lipoprotein lipase activities increased. Apo A-1 did not change significantly. Even in normotriglyceridemic patients serum HDL cholesterol increased. The side effects consisted of muscle aches and a significant rise in serum CPK. Gemfibrozil produced a significant decrease in gamma-GT activities. A possible mechanism for the interconversion between HDL2 and HDL3 that resulted in a preferential increase in the latter was discussed. It was concluded that gemfibrozil, in a dose not exceeding 300 mg twice a day favorably improved the risk factor for ischemic heart disease in CAPD patients.

Adult↗
PubMed1989

Mesangial IgA nephropathy with steroid-responsive nephrotic syndrome: disappearance of mesangial IgA deposits following steroid-induced remission.

This report describes the clinical features and renal biopsy pathology in two patients with immunoglobulin A (IgA) nephropathy and nephrotic syndrome before and after steroid-induced remission. Apart from confirming the frequently relapsing course and mild glomerular changes observed in patients with IgA nephropathy and steroid-responsive nephrotic syndrome (SRNS), we were able to show that mesangial expansion and mesangial IgA deposits disappeared or were greatly reduced in repeat renal biopsies following steroid-induced remission. Because mesangial IgA deposits usually persist in repeat biopsies obtained from patients with typical IgA nephropathy, their resolution in our patients following steroid remission would support the proposal that the association of IgA nephropathy and SRNS may represent a distinct clinical syndrome. It is postulated that the presence of mesangial IgA deposits during nephrotic presentation and their disappearance following steroid-induced remission may result from increased mesangial sequestration of IgA circulating immune complexes (CIC) during the period of enhanced glomerular permeability and that the increased load of IgA CICs may reflect a common defect in mucosal immunity or immunoregulation in these patients.

Adult↗
PubMed1989

Hepatitis B infection and renal transplantation: the absence of anti-delta antibodies and the possible beneficial effect of silymarin during acute episodes of hepatic dysfunction.

The incidence of hepatitis B infection among renal transplant recipients was reviewed. Among 90 patients, 13 were HBsAg positive prior to renal transplantation. Episodes of hepatic dysfunction were seen in eight and one died of fulminating hepatitis and disseminated tuberculosis. Silymarin, a herbal extract, appears to confer some benefits in ameliorating hepatic dysfunction. Antibodies to the delta agent were not detected during any of these episodes. One patient contracted hepatitis B after transplantation and rapid reduction in steroid dose was associated with deterioration of liver function. He developed antibodies and cleared the virus. Four HBsAg-negative patients received kidneys from HBsAg positive donors without becoming HBsAg positive.

Adult↗
PubMed1989

Tuberculous peritonitis complicating long-term peritoneal dialysis. Report of 5 cases and review of the literature.

The characteristics of 5 patients who developed tuberculous peritonitis while receiving long-term peritoneal dialysis (PD) are presented. There were 2 males and 3 females. 3 patients were on intermittent and 2 were on continuous ambulatory peritoneal dialysis when tuberculous peritonitis was first diagnosed. None of the patients had recently received immunosuppression therapy or were diabetics. The clinical presentations were similar to other forms of peritonitis complicating PD except for a more insidious onset. As extraperitoneal involvement and peritoneal lymphocytosis were rarely present, the diagnosis was mainly dependent on the direct demonstration of Mycobacterium tuberculosis with smear (1 patient) and culture (4 patients). In 1 patient with a pleuroperitoneal communication, the diagnosis was made by pleural biopsy and a positive response to antituberculous therapy. All patients responded to treatment with a combination of three antituberculous drugs which included streptomycin, isoniazid, rifampicin and pyrazinamide. Two patients were transferred to hemodialysis. In 3 patients, peritoneal dialysis was continued. Peritoneal clearance and ultrafiltration capacity were unchanged for up to 16 months after treatment in 2 patients who continued peritoneal dialysis but was reduced by 30 and 50%, respectively, in the remaining patient. Only 1 patient died, but her death was not directly related to tuberculous peritonitis. It was concluded that with a high index of suspicion and early institution of treatment, tuberculous peritonitis complicating PD can be successfully treated with low mortality and without compromising the dialysis capacity of the peritoneal membrane.

Adult↗
PubMed1989

Pseudomonas peritonitis in CAPD patients: characteristics and outcome of treatment.

Twenty-five episodes of Pseudomonas peritonitis which occurred over a five-and-a-half-year period were reviewed. Pseudomonas peritonitis accounted for 25/516 (4.8%) of all episodes of peritonitis. Nine of the episodes were first infections in that the patient had not experienced peritonitis before. The rest were repeat peritonitis. There was no difference in any demographic factors between the first episodes and the repeat episodes except exit site infection which was more common among patients who had repeat infections. Overall cure rate of Pseudomonas peritonitis was 20/25 (80%). Five catheters had to be removed, all in patients who had to be transferred permanently to haemodialysis. In general, ceftazidime in combination with an aminoglycoside was an effective regimen. Oral ofloxacin was not useful despite in vitro sensitivity of the pathogen to the antibiotic.

Adult↗
PubMed1989

Fungal peritonitis complicating peritoneal dialysis: report of 27 cases and review of treatment.

The clinical features, treatment and outcome of 27 cases of fungal peritonitis were studied. Twenty-one cases occurred in patients receiving CAPD and six in patients on intermittent peritoneal dialysis. Twenty-five cases were due to Candida spp., one was due to Trichosporon spp. and in one, both Candida and Trichosporon and an unidentified acid-fast bacillus were isolated. Clinical features of fungal peritonitis and bacterial peritonitis were the same. A direct comparison with patients without fungal peritonitis failed to reveal an increased incidence of diabetes mellitus. However, a history of recent bacterial peritonitis and antibiotic treatment was frequently obtained. We found that the combination of oral ketoconazole and intraperitoneal miconazole is successful in treating fungal peritonitis complicating peritoneal dialysis but catheter removal and replacement is often necessary. Analysis of the relationship between clinical outcome and various treatment strategies in cases reported in the literature and in our own showed that an initial trial of antifungal drugs consisting of oral ketoconazole and i.p. 5-fluorocytosine or miconazole is warranted in most cases before contemplating catheter removal.

Adolescent↗
PubMed1989

Adult-onset mesangiocapillary glomerulonephritis: a disease with a poor prognosis.

A retrospective analysis of the records of 46 patients with adult-onset mesangiocapillary glomerulonephritis seen over a period of 15 years is reported. There were 28 males and 18 females with a mean age of 34 years. Mean observation period was 60 months. All patients had renal biopsies and characteristic changes, but no dense deposit variant was seen. HBsAg was positive in 20 per cent of the patients tested whereas in the general population it was about 10 per cent. Nephrotic syndrome was the commonest presentation. There was a mean delay of 8.5 months between the onset of symptoms and renal biopsy. Nineteen patients were given steroid/immunosuppressive therapy while 27 received no specific treatment. At the time of review, renal function was stable in 13 patients but progressively deteriorating in 33. In the latter, the slope of the graph of reciprocal of creatinine versus time could be accurately determined. Steroid/immunosuppressive therapy did not influence the rate of progression of renal failure but appeared to hasten and induce more partial remissions of the nephrotic state. There was no difference in cumulative renal survival between treated and untreated patients, and between HBsAg-positive and negative patients. Overall, 23 patients required dialysis/renal transplantation and an additional four had died of end-stage renal failure at the time of this review.

Adolescent↗
PubMed1989

Lupus nephritis patients on maintenance dialysis in Hong Kong.

Eleven patients with lupus nephritis required maintenance dialysis. Two were on haemodialysis (HD), 9 on continuous ambulatory peritoneal dialysis (CAPD). One was subsequently transplanted and recurrence of lupus nephritis occurred at 9 months posttransplant. One discontinued CAPD after 6 months; 4 died and the remaining 7 were fully rehabilitated. There was marked regression of extra-renal lupus activity post-dialysis.

Adult↗