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Biomedical subjects

M K Chan

Publications and source records attributed to M K Chan.

At least 91 records · Page 5Linked to original sources
PubMed1989

Optimal reuse of cuprammonium rayon hollow-fibre dialyzers.

The optimal number of times a hollow-fibre cuprammonium rayon (Terumo TAF) dialyzer could be used was determined in twelve patients. Each dialyzer was reused six times. There was a highly significant decrease in neutrophil count (46.9 +/- 6.9%, mean +/- s.e.m.), platelet count (9.6 +/- 3.8%, mean +/- s.e.m.) and serum C3 concentration (10.25 +/- 2.4%, mean +/- s.e.m.) 30 minutes after the commencement of dialysis The intensity of these changes decreased with the re-use of the dialyzers up to the fourth time. There was a small, but significant increase in serum beta 2-microglobulin concentrations after a 6-hour dialysis. The difference between pre- and post-dialysis serum beta 2-microglobulin concentrations appeared to be greater during the 5th and the 6th use (18.8% and 20.5% vs 5.0% during the first use). The clearance rates of urea and creatinine showed a trend to decrease from the fourth use onwards and the ultrafiltration coefficient was significantly reduced from the third use (8.5 +/- 4.0 mean +/- s.e.m.) onwards so that at the sixth use it was only 75.8 +/- 4.8%, (mean +/- s.e.m.) of the value at the first use. It is concluded that the optimal number of uses a cuprammonium rayon hollow-fibre dialyzer can be put to is four.

Biocompatible Materials↗
PubMed1989

A double-blind controlled trial of norfloxacin versus cotrimoxazole in the treatment of urinary tract infections.

A double-blind controlled trial of norfloxacin versus cotrimoxazole in the treatment of urinary tract infections was conducted. Eighty-eight patients were recruited but data from 80 patients were analysed. Norfloxacin cured 93 per cent of the infections while the cure rate achieved by cotrimoxazole was only 70 per cent (p = 0.03, Fisher's exact test). The difference was attributable to a higher incidence of resistance to cotrimoxazole among the bacterial isolates. Escheria coli was the commonest pathogen and together with klebsiella accounted for 78 per cent of all isolates. Fifteen per cent of E coli and 15 per cent of klebsiella isolates were resistant to cotrimoxazole while all were sensitive to norfloxacin. Side effects were minimal and consisted mainly of nausea and non-specific dizziness.

Adult↗
PubMed1989

Climatic factors and peritonitis in CAPD patients.

From March 1983 to December 1987 the relation of the occurrence of all episodes of peritonitis in CAPD patients to climatic factors, such as temperature and relative humidity was examined. Altogether 389 episodes were recorded in 239 patients. Peritonitis due to Staphylococcus epidermidis, Gram-negative organisms and culture-negative episodes was most frequent during the hot months of the year, June to October. The occurrence of peritonitis due to Staphylococcus aureus was uniformly distributed throughout the year. Relative humidity did not seem to affect the frequency of peritonitis.

Climate↗
PubMed1989

The role of soluble immune response suppressor lymphokine in the prediction of steroid responsiveness in idiopathic nephrotic syndrome.

The role of serum soluble immune response suppressor (SIRS) lymphokine in the prediction of steroid responsiveness in idiopathic nephrotic syndrome was investigated. Serum SIRS was detected by its capacity to suppress the induction of plaque forming cells in pokeweed mitogen-stimulated in vitro lymphocyte culture in a dose dependent manner, and specificity was determined by the ability of monoclonal anti-SIRS coated beads to specifically absorb the suppressor activity. Serum SIRS was present in 7 of 18 patients with steroid responsive nephrotic syndrome and in 1 of 6 patients with nephrotic syndrome who were resistant to steroid treatment. It was also found in 2 of 4 patients with nephrotic syndrome which would be expected to be resistant to steroid treatment, in 2 of 10 patients with steroid responsive nephrotic syndrome in remission and in 2 of 8 normal healthy controls but was absent in 8 patients with non-nephrotic proteinuria secondary to a variety of renal disease. It was concluded that, although serum SIRS was present more often in patients with steroid responsive nephrotic syndrome, it is not a sensitive enough assay for predicting the response to treatment.

Humans↗
PubMed1988

Primary glomerulonephritis in Hong Kong.

The clinical presentation and natural history of 428 patients with biopsy-proven primary glomerulonephritis were reviewed. Minimal change glomerulonephritis presented with the nephrotic syndrome and followed a benign course. Membranous glomerulonephritis took a slow downhill course. HBs antigenaemia was present in 30% of patients with membranous glomerulonephritis. Mesangiocapillary glomerulonephritis often presented with mixed nephritic-nephrotic syndrome and had a bad prognosis. No type II variant was detected. Mesangial IgA glomerulonephritis commonly presented with abnormal urinary sediments although 2.5% of adults presenting with the nephrotic syndrome without glomerular insufficiency had mesangial IgA disease. Mesangial IgA glomerulonephritis was an important cause of end-stage renal failure in Hong Kong.

Adolescent↗
PubMed1988

Peritoneal eosinophilia in patients on continuous ambulatory peritoneal dialysis: a prospective study.

A prospective study on peritoneal eosinophilia was conducted in 23 continuous ambulatory peritoneal dialysis (CAPD) patients for a mean period of 7.9 months. Peritoneal eosinophilia as defined by peritoneal eosinophil count exceeding 100/mm3 was found in 60.8% of patients. Most developed peritoneal eosinophilia within 3 months of the initiation of dialysis, although the phenomenon could occur as early as one day or as late as 6 months after dialysis. Fifty-seven percent of those with peritoneal eosinophilia also had peripheral blood eosinophilia. Although most peritoneal eosinophilic episodes subsided in a month, in one patient the process grumbled on for 150 days. The number of peritonitis episodes was not significantly different between patients with peritoneal eosinophilia and those without. The only distinction between the two groups of patients was that those who developed peritoneal eosinophilia had a significantly (P = .002) higher serum IgE concentration initially as well as throughout the period of observation.

Adolescent↗
PubMed1988

Transmission dynamics and estimates of malaria vectorial capacity for Anopheles balabacensis and An. flavirostris (Diptera: Culicidae) on Banggi island, Sabah, Malaysia.

Holoendemic malaria transmission in two small isolated forest communities and a coastal village was studied by (1) all night human bait collections of Anopheles species from inside and outside houses and (2) buffalo-biting and CDC light-trapping catches during March and November 1984. During the same period thick and thin blood films were collected from the human population, and spleen rates were determined in children from two to nine years of age. Using both the immunoradiometric assay (IRMA) and the dissection technique, more sporozoite-positive infections were detected in An. balabacensis and An. flavirostris in November than in March. IRMA confirmed the presence of Plasmodium falciparum sporozoites. An average of 76.2% of the An. balabacensis population lived long enough to have reached a point where infectivity with P. falciparum was possible in November. Although fewer than five adult females bit humans per night at any time, a resident could theoretically have received more than 160 infective bites in one year. A high frequency of feeding on humans, coupled with increased anopheline life expectancy, contributed to high estimates of falciparum malaria vectorial capacity (number of infections distributed per case per day); for An. balabacensis (1.44-7.44 in March and 9.97-19.7 in November) and for An. flavirostris (0.19-5.14 in March and 6.27-15.8 in November). These high values may explain the increased malaria parasite rates obtained from at least two forest communities. Correlation between actual and calculated rates of gametocytaemia was poorest in Kapitangan due to inadequate sampling of the human population. In Banggi island, malaria is stable and holoendemic, and the population enjoys a high degree of immunity.

Animals↗
PubMed1988

Oral treatment of peritonitis in CAPD patients with two dosage regimens of ofloxacin.

Two open studies of oral treatment of peritonitis in CAPD patients with ofloxacin are described. The first study included 10 episodes of peritonitis treated with ofloxacin 400 mg followed by 200 mg daily for a total of seven days. In the second study of 18 peritonitis episodes, the treatment was ofloxacin 400 mg followed by 300 mg daily for a total of ten days. The cure rate was 50% in the first study and 83% in the second. There was significant accumulation of ofloxacin in the serum but the mean serum trough level with the second treatment regimen plateaued at 6 mg/l on day 10. Peritoneal effluent ofloxacin levels correlated well with the prevailing serum concentrations of the antibiotic and, except on day 1, the mean peritoneal effluent ofloxacin levels all exceeded 3 mg/l with the second dosing scheme. Side effects were mainly nausea and dizziness.

Administration, Oral↗
PubMed1988

Glomerulonephropathy of Laurence-Moon-Biedl syndrome.

A patient with Laurence-Moon-Biedl syndrome and nephrotic range proteinuria is presented. Radiological investigation of the urinary tract revealed clubbed calyces but no evidence of obstruction or vesicoureteric reflux. Renal biopsy revealed occasional sclerotic glomeruli, extensive foot-process fusion and segmental glomerular basement membrane abnormalities with negative immunofluorescence for immunoglobulins and complement. Nephrotic proteinuria responded to steroid therapy but mild proteinuria persisted. The findings were consistent with minimal change nephropathy superimposed on the glomerular lesions of Lawrence-Moon-Biedl syndrome.

Adult↗
PubMed1988

Living-related renal transplantation in a patient with nail-patella syndrome.

Living-related renal transplantation was performed successfully in a patient with nail-patella syndrome. Graft biopsy 18 months post-transplantation showed normal glomerular basement membrane by electron microscopy. Dystrophic nails of both index fingers had also regrown, suggesting the donor kidney might replenish deficient factors.

Child↗
PubMed1988

The effect of diethylcarbamazine citrate on incidence and recovery rates of Brugia malayi microfilaremia in Sabah, Malaysia.

Mass drug administration via 3 modes of delivery reduced the incidence and prevalence rates and intensity of Brugia malayi infection in 3 rural villages in the Bengkoka Peninsula, Sabah, in 1982-1983. A dosage of 6 mg diethylcarbamazine citrate (DEC-C)/kg body weight was administered either daily or weekly (total of 6 doses, 36 mg/kg body weight), and impact on B. malayi cases were comparable in the 3 villages. A total of 384 people participated in the DEC-C regimens, and all pregnant women and children under 2 years were excluded from the study. Bekessy's method of estimation of incidence and recovery rates was applied to data on B. malayi microfilaremia before drug administration. Treatment with DEC-C by any of the 3 modes of delivery drastically reduced the number of episodes of patent microfilaremia, incidence and prevalence, and median microfilarial density. Reduction was sustained for at least 18 to 24 months after treatment.

Adolescent↗
PubMed1988

Treatment of urinary tract infections in Hong Kong: a comparative study of norfloxacin and co-trimoxazole.

The study compared the efficacy and safety of norfloxacin to those of co-trimoxazole in the treatment of urinary tract infections (UTI). A total of 172 adults, 42 men and 130 women were recruited and randomly allocated to norfloxacin or co-trimoxazole using a double-blind study design. Patients with lower UTI received norfloxacin 200 mg or co-trimoxazole (160 mg of trimethoprim plus 800 mg of sulphamethoxazole) b.i.d. for seven days. In patients with upper UTI, the norfloxacin dose was 400 mg b.i.d. for seven days. Eleven to 14 days after treatment, the bacteriological cure rates were 96.8% and 83.3% and the clinical cure rates were 96.9% and 89.9% for norfloxacin and co-trimoxazole, respectively. A few patients complained of gastrointestinal symptoms but there were few other side-effects and the treatments were well tolerated. In conclusion, both norfloxacin and co-trimoxazole were well tolerated but norfloxacin gave higher cure rates.

Adult↗
PubMed1988

Oral treatment of peritonitis in CAPD patients with ofloxacin.

Eighteen episodes of peritonitis in 16 CAPD patients were treated with oral ofloxacin 400 mg initially, followed by 300 mg daily for a total of 10 days. The culture-positive rate was 72.2% with Staphylococcal species as the most frequent isolates. The overall cure rate as defined by negative cultures 1 and 2 months after discontinuation of antibiotics was 83.3%. The time taken for the peritoneal effluent to clear completely was 5 days. With such a dosing regime, there was a significant increase in the mean serum trough level of ofloxacin from 2.28 mg/l on day 1 to 5.83 mg/l on day 10 (P less than 0.001). There was no significant difference in the serum levels attained whether or not phosphate binders were concurrently given. Side-effects were nausea and non-specific dizziness. No patients had to discontinue treatment because of side-effects. Ofloxacin appeared to diffuse from the blood into the peritoneal fluid, and a highly significant correlation existed between simultaneous blood and peritoneal effluent ofloxacin levels (r = 0.88, P less than 0.0001).

Administration, Oral↗