PubMed Health⌕ Search

Biomedical subjects

K C Lam

Publications and source records attributed to K C Lam.

At least 19 recordsLinked to original sources
PubMed1983

Clear cell carcinoma of liver. An ultrastructural study.

A light microscopic and ultrastructural study of ten consecutive cases each of the clear cell type and nonclear cell type of hepatocellular carcinoma (HCC) showed important differences between the two groups which may help to explain their different biological behavior. The clear cells contained substantial quantities of glycogen and lipid which partly substitute the usual cytoplasmic constituents. An analogy was made between these tumor cells with clear cytoplasm and the clear cells which occurred in the intermediary stages of hepatocellular carcinogenesis in animals in an attempt to explain the better outcome of clear cell HCC.

Adenocarcinoma↗
PubMed1983

Sitosterol and cholesterol metabolism in a patient with coexisting phytosterolemia and cholestanolemia.

Sitosterol and cholesterol metabolism were studied in a patient with coexisting phytosterolemia and cholestanolemia, and in a control subject, both on similar diets containing about 170 mg cholesterol and 135 mg phytosterols per day. The turnover of 22,23-3H-sitosterol and 4-14C-cholesterol, given intravenously, were followed for up to 372 days. The specific activity-time curves for both sterols were resolved into two exponentials and fitted into a two-pool model. The half-lives of both exponential curves for sitosterol, in the patient, were abnormally long. Equilibration of the tracer between the two pools, in the patient, occurred at about 30 days as compared to 10-15 days in the control subject. The daily turnover of sitosterol in the patient was estimated to be 10 times greater than that in the control subject. The patient's total body exchangeable pool of sitosterol was 9.6 g or about 80 times the amount found in the control. The patient's plasma phytosterol levels fell by 25% when he went on a diet containing only 10 mg phytosterols per day. During this period the specific activity of his plasma sitosterol with respect to an equilibrated dose of 3H-labeled tracer remained constant; this was compatible with the absence of endogenous synthesis. Cholesterol turnover in the patient showed prolonged half-lives for both exponential curves and reduced fractional daily loss from the fast-exchanging pool. The patient's xanthoma sterols underwent 16% and 55% exchange with plasma sitosterol and cholesterol, respectively, on day 60, indicating the presence of a third exchangeable pool.

Adult↗
PubMed1983

Ranitidine does not affect gonadal function in man.

We studied the effect of ranitidine on gonadal function in 20 male subjects with chronic duodenal ulcer. Eleven were treated with ranitidine 150 mg twice daily for 3 months and 150 mg at night for 9 months, nine with placebo for 3 months. Similar to placebo, treatment with ranitidine did not influence basal serum concentrations of testosterone (T), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL). No significant changes were found in sperm concentration, motility or morphology. Ranitidine does not affect gonadal function in man.

Adolescent↗
PubMed1982

Spontaneous regression of hepatocellular carcinoma: a case study.

A Chinese patient with documented hepatocellular carcinoma (HCC) satisfied the criteria of Everson and Cole for spontaneous regression of malignant tumors. Subsequently he survived a tumor-free period of at least 13 years. During the period of regression, shrinkage of liver coincided with a rise of SGOT to a level comparable to that reported for patients with liver cancer during hepatic arterial ligation and cytotoxic therapy. Postregression liver biopsy from the site of the previous tumor revealed relatively uninflamed HBsAg-positive tissue without dysplasia. The case provided the positive end of the survival spectrum in HCC, evidence that regression of HCC might occur by involution rather than maturation, and histologic data suggesting that regressed HCC might be replaced by surrounding tissue instead of leaving behind dysplasia.

Aspartate Aminotransferases↗
PubMed1982

Effect of cimetidine on gonadal function in man.

1 To study the effect of cimetidine on gonadal function in man, eleven male subjects with chronic duodenal ulcer were given cimetidine orally at a dosage of 1000 mg per day 3 months and 400 mg nocte for the subsequent 3 months. 2 Testosterone levels were found to be elevated during therapy when compared to pre- and post-treatment periods. Serum LH remained unchanged but FSH was increased during therapy. In five out of eleven subjects serum PRL levels were increased. Mean sperm count was lower during cimetidine therapy when compared with that after drug withdrawal. The motility and morphology of the spermatozoa were not affected.

Adult↗
PubMed1982

Hepatitis B virus and cigarette smoking: risk factors for hepatocellular carcinoma in Hong Kong.

One hundred seven Chinese patients with primary hepatocellular carcinoma (PHC) were compared with 107 hospital controls for the presence of hepatitis B surface antigen and smoking, drinking, and dietary habits. Eighty-two % of PHC cases were hepatitis B surface antigen positive compared to 18% of controls (relative risk, 21.3; 95% confidence limits, 10.1 and 45.9). Prior history of jaundice was significantly related to PHC, independent of hepatitis B surface antigen status. There was a significant association between cigarette smoking and PHC negative for hepatitis B surface antigen. The relative risk of hepatitis B surface antigen-negative PHC for heavy smokers (20 + cigarettes/day) was 3.3 compared to light smokers and nonsmokers (95% confidence limits, 1.0 and 13.4). Our data indicated that infection by the hepatitis B virus and cigarette smoking were independent risk factors for PHC.

Carcinoma, Hepatocellular↗
PubMed1982

Analytical epidemiology of primary liver carcinoma in the Pacific Basin.

In the Pacific Basin, the hepatitis B virus is closely associated with hepatocellular carcinoma in its geographic distribution and familial clustering, and its presence in liver tissues. The contribution of aflatoxin to the development of hepatocellular carcinoma in different regions varies from negligible to probably major. Neither the hepatitis B virus nor aflatoxin can account for the varied epidemiology of hepatocarcinogenesis in the Pacific Basin. Many potential carcinogens for the liver have been identified in food, drugs, industrial chemicals, and in the general environment, but their importance in hepatocarcinogenesis remains to be defined.

Aflatoxins↗
PubMed1981

Clinical features of hepatocellular carcinoma: review of 211 patients in Hong Kong.

A retrospective study of 211 patients with proven hepatocellular carcinoma (HCC) was made. The commonest symptoms were anorexia and malaise (73%). Five patients (2.5%) had near-normal biochemical tests despite the presence of massive tumors. Diagnostic yield from angiography, percutaneous peritoneoscopic biopsy, or scintiscanning was 87-98%. Three percent of the patients had resectable tumors. Median survival for patients with untreated disease was 3.5 weeks. Apart from histology, the total serum bilirubin level was the only factor of prognostic value. Only 12 patients had preexisting symptomatic cirrhosis. When compared with 80 patients with symptomatic postnecrotic cirrhosis without malignancy, patients with HCC had higher SGOT:SGPT ratio, Higher serum albumin levels, and higher platelet counts. There was only minimal overlap of patients with symptomatic postnecrotic cirrhosis and those with HCC. The authors conclude that their patients with HCC appeared late for treatment. A probable difference in the development of symptomatic postnecrotic cirrhosis and of HCC with asymptomatic postnecrotic cirrhosis is suggested.

Adolescent↗
PubMed1981

Deleterious effect of prednisolone in HBsAg-positive chronic active hepatitis.

To study the efficacy of corticosteroids in chronic active hepatitis (CAH) positive for hepatitis B surface antigen (HBsAg), we pair-randomized 51 patients to receive either 15 to 20 mg of prednisolone per day or a placebo. After initial remission, the maintenance dosage of prednisolone was 10 mg per day, and the patients were prospectively followed for up to 3 1/2 years. Prednisolone decreased serum bilirubin (P < 0.05) and globulin (P < 0.01) at three months; it delayed other biochemical remission occurring after the second month of medication (P < 0.001); it hastened biochemical relapse (P < 0.0001); and it increased the frequency of complications (P < 0.0001) and the death rate (P < 0.01). We conclude that prednisolone has an overall harmful effect in patients with HBsAg-positive CAH.

Adult↗
PubMed1981

Spontaneous portosystemic shunt: relationship to spontaneous encephalopathy and gastrointestinal hemorrhage.

This study examined the effect of large spontaneous portosystemic shunts on the incidence of variceal hemorrhage and hepatic encephalopathy. Twenty cases of chronic liver disease with large spontaneous shunts were compared with a group of patients with liver disease and with Cruveilhier-Baumgarten (C-B) murmurs and with a control group having liver disease and absence of large shunts on angiography. Gastrointestinal hemorrhage was present in similar proportions of patients in the three groups. Hepatic encephalopathy occurred more frequently in the spontaneous shunt group and C-B murmur group. The encephalopathy was spontaneous in 12 of 14 patients with large natural shunts whereas it was precipitated by events such as gastrointestinal bleeding, diuretics, or infection in 14 of 15 of the patients with C-B murmur and five of the seven controls. Therefore, spontaneous portosystemic shunts do not protect against gastrointestinal hemorrhage and are associated with an increased risk of spontaneous hepatic encephalopathy.

Adolescent↗
PubMed1981

Haemodynamic responses to intravenous cimetidine in subjects with normal lung function and in subjects with chronic airway obstruction.

1 The haemodynamic responses to a bolus intravenous injection of 400 mg cimetidine were studied in eight subjects with normal lung function and sixteen with chronic obstructive airway disease (COAD), under continuous systemic and pulmonary arterial monitoring. In all subjects there were significant immediate but transient (less than 10 min) drops in the systemic and pulmonary arterial pressures (both systolic and diastolic), the systemic vascular resistance and total pulmonary resistance. The percentage drops were significant more marked in the COAD group in the following: systemic arterial pressures (systolic and diastolic), systemic vascular resistance and total pulmonary resistance. The cardiac output showed no significant change in the group with normal lung function but rose significantly in the COAD group. None of the subjects had any symptoms associated with the haemodynamic changes. 2 These results can be explained by a generalized vasodilatory effect of cimetidine, but the relationship to its H2-receptor blocking effect is undetermined. Hypoxia and/or hypercapnia may sensitize an individual to the vasodilatory effect of cimetidine.

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

Prevalence of Toxoplasma gondii antibodies in the Chinese population of Hong Kong.

Sera from 2,499 randomly selected Chinese inhabitants of Hong Kong were tested for the presence of Toxoplasma gondii antibodies using the indirect fluorescent antibody test. The over-all prevalence was 9.8%. The prevalence was significantly higher in the 10 to 19 and 30 to 39 year age group and the highest level of titres was found in the 20 to 29 group. There was no significant difference in prevalence between the male and female population and between the rural and city dwellers. The distinctly low prevalence of toxoplasmosis in Hong Kong can probably be attributed to the absence of cats in most domestic households and the preference of the people to eat well-cooked meat (commonly beef and pork).

Adolescent↗