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Biomedical subjects

W C Chan

Publications and source records attributed to W C Chan.

At least 199 records · Page 11Linked to original sources
PubMed1982

Erythrocyte hemighosts: a hallmark of severe oxidative injury in vivo.

Erythrocyte hemighosts and ghosts were found in five patients: two with severe oxidant haemolysis caused by chemicals or drugs, and three G6PD deficient subjects with haemolysis triggered by infection and/or drugs. Scanning and transmission electron-microscopy showed that the hemighost consisted of a thinned-out part with antero-posterior apposition of the membrane and a thicker spheroidal part containing most of the haemoglobin. Heinz bodies were found in both parts of the cell close to the membrane. Large number of hemighosts (30-90%) is an ominous sign as three of our five affected patients died. The removal of these cells by exchange transfusion or the induction of forced diuresis probably saved the life of the other two patients. Experiments in rabbits showed that hemighosts were found only with severe oxidative injury induced by a large dose of acetylphenylhydrazine (50 mg/kg) and the spleen was not required for their formation. The marked congestion in the splenic sinusoids and other microcirculation results from sludging of these damaged rigid cells and is an important pathophysiological mechanism in severe oxidant injury.

Adult↗
PubMed1982

Studies on the epidemiology of subperiodic Brugia malayi in Malaysia: problems in its control.

The dynamics of the transmission of subperiodic Brugia malayi in a typical endemic area in Malaysia was studied over a period of 4 years. Mass chemotherapeutic control with diethylcarbamazine citrate was found to be inefficient, new cases being detected even after the fifth treatment cycle of 6 mg/kg X 6 days per cycle. This is in marked contrast to the situation in periodic b. malayi areas where mass treatment efficiently controlled the infection. The disparity in results in these two areas is attributed to zoonotic transmission of subperiodic B. malayi from non-human primates where a mean infection rate of 76.3% was found.

Animals↗
PubMed1981

A unique patient with coexisting cerebrotendinous xanthomatosis and beta-sitosterolemia.

An adult Chinese man presented with tendinous and tuberous xanthomatosis and severe atheromatous changes in the coronary arteries. In addition, he had chronic hemolytic anemia, with spherostomatocytic erythrocytes. Cerebrotendinous xanthomatosis was diagnosed on the basis of increased cholestanol levels in his plasma, red cells and xanthoma, changes in bile acid composition due to the defective synthesis of chenodeoxycholic acid. Coexisting beta-sitosterolemia was confirmed by the finding of large amounts of the plant sterols such as beta-sitosterol and campesterol. This is the first report of these two rare lipid storage disorders in the same patient.

Adult↗
PubMed1981

Clinical features and natural mortality of chronic active hepatitis in Hong Kong.

To study the clinical picture and survival of chronic active hepatitis (CAH) in Hong Kong, the records of 298 non-alcoholic patients with histologically proven CAH were reviewed. The male:female ratio was 3:1. The mean age (+/- SD) on presentation was 47.3 (+/- 13.1) years. The liver was shrunken and the mean mass (+/- SD) at autopsy was 887 gm (+/- 266) compared to 1343 gm (+/- 172) in cases without liver disease. The spleen was enlarged to 2 to 20 cm below the left costal margin in 98% of cases. The survival graph showed an annual mortality of approximately 13%, without a tendency to flatten out within ten years of diagnosis. Survival was best in patients presenting with splenomegaly alone, average in those presenting with ascites or gastrointestinal haemorrhage and worst in those presenting with hepatic decompensation. The modes of death were significantly correlated with the chief complaints on first presentation (p less than 0.001). The study documented the clinical aspects of CAH in Hong Kong and amplified the differences reported among CAH patients between Australia and Asia.

Adult↗
PubMed1980

Factors influencing the diagnostic sensitivity of the exercise test in coronary artery disease.

A continuous multistage bicycle ergometer test was performed on 50 patients with coronary artery disease. Selective cinecoronary angiography and left ventriculography were performed within a week of the test in all patients. Overall, 62% had a positive ischemic response, defined as 1 mm or greater depression of the ST segment. Patients with 75% or greater stenosis in any vessel and those with triple-vessel involvement had a higher incidence of positive tests. Those with low systolic ejection fractions and areas of asynergy had fewer positive tests than patients with normal ejection fractions and normal or minimal segmental wall motion abnormalities. The level of exercise, location of arterial disease and the presence of collateral blood supply to the diseased vessels did not appear to influence the sensitivity of the exercise stress test.

Adult↗
PubMed1980

Do chronic urinary tract infections induce cancer in the rat fed nitrate and aminopyrine?

Seven out of one hundred male rats in the experimental group developed malignant tumours after 18 months, during which period they were given nitrate and aminopyrine in the drinking water and had chronic urinary tract infections induced by known strains of E. coli. In the control animals, no lesions were observed in the two un-infected groups given nitrosamine precursors in the drinking water or water alone. However, two out of fifty control animals in the infected group, not administered nitrosamine precursors, developed malignant lymphoma. All rats were maintained on Purina rat chow. Our data appear to suggest that chronic urinary tract infection did induce tumour production in the rat.

Adenocarcinoma↗
PubMed1979

Late onset chronic mucocutaneous candidiasis with lymphoma and specific serum inhibitory factor.

A patient with late onset chronic mucocutaneous candidiasis developed lymphocytic lymphoma. A specific inhibitor of in vitro lymphoproliferative responses to candidal antigen was detected in her serum which persisted following clinical remission of candidiasis after combined amphotericin-B and 5-Fluorocystosine therapy. It is unclear whether the combined therapy was exclusively anticandidal, nonspecific immunostimulant or cytotoxic affecting the underlying incipient lymphoma.

Amphotericin B↗
PubMed1979

Mycosis fungoides and Hodgkin's disease occurring in the same patient: report of three cases.

The patients with the typical clinical course and pathology of Mycosis Fungoides (MF) were found also to have Hodgkin's Disease (HD), nodular sclerosing type. In two cases, HD was diagnosed 2 years after the diagnosis of MF; in the third case, both diseases were diagnosed simultaneously. Previous claims of MF transforming into second lymphomas are reviewed. The possible significance of our observed association of MF and HD is discussed.

Hodgkin Disease↗
PubMed1979

Bronchial cancer in Hong Kong 1976-1977.

Bronchial cancer is a disease of high and increasing annual incidence in Hong Kong, especially in women, whose age-specific death rates from this cause are amongst the highest in the world. A case-control study of the relationship of bronchial cancer with smoking was carried out during 1976--77, taking particular note of the histological type of the tumour. Two hundred and eight male and 189 female patients were interviewed, covering about half the total number of cases of bronchial cancer registered as dead from the disease in Hong Kong during the period of the survey. The association with smoking was more evident in males than in females, and in squamous and small-cell types, as a group, than in adenocarcinoma. Forty-four per cent of the women with bronchial cancer were non-smokers, their predominant tumour being adenocarcinoma, and in them on association could be detected with place of residence or occupation. There was no strong evidence of an association with the use of kerosene or gas for cooking; 23 did not use kerosene. The cause of the cancer in these non-smoking women remains unknown.

Adenocarcinoma↗
PubMed1979

Tuberculoid cutaneous infection due to a niacin-positive Mycobacterium chelonei.

A case of cutaneous infection due to a niacin-positive Mycobacterium chelonei (previously called M. abscessus) on the dorsum of the hand of a professional cotton-classifier is reported from Hong Kong. The infection was probably directly acquired from handling contaminated raw cotton. The patient was successfully treated with combined anti-tuberculous drugs over a period of 1 year. Histologically, the skin lesion showed tuberculoid granulomas, in addition to abscesses.

Adult↗