Biomedical subjects

J W Lau

Publications and source records attributed to J W Lau.

22 records · Page 2Linked to original sources

PubMed1996

Urinary 6 beta-hydroxycortisol excretion in Hong Kong Chinese patients with hepatocellular carcinoma and other chronic liver diseases.

BACKGROUND: The biotransformation of xenobiotics into toxic metabolites by cytochrome P-450 has been implicated in carcinogenesis. This study investigated CYP3A4 activity, which metabolically activates procarcinogens such as aflatoxin B1, by measuring the urinary 6 beta-hydroxycortisol (6 beta OHF) to free cortisol (F) ratio in patients with hepatocellular carcinoma (HCC) and other chronic liver diseases. METHODS: One hundred forty-three controls and 150 patients with different liver diseases, including chronic liver disease (due to alcoholism and/or chronic hepatitis B virus infection), cirrhosis (any cause), and resectable and nonresectable HCC, were recruited. Twenty-four hour urine samples were collected for measurement of 6 beta OHF and free cortisol by an enzyme-linked immunosorbent assay (ELISA) and a radioimmunoassay, respectively. RESULTS: Patients with nonresectable HCC showed a significant increase in 6 beta OHF excretion as well as their 6 beta OHF/F ratio (P < 0.05) when compared with the controls and other liver disease groups including patients with resectable HCC. The nonresectable HCC group showed a bimodal distribution in the 6 beta OHF/F ratio. Using a ratio of 9 or more in all HCC patients, the sensitivity and specificity of using the 6 beta OHF/F ratio to predict nonresectability of HCC was 48.8% and 92.6%, respectively. CONCLUSIONS: Our results show an increase in mean CYP3A4 enzyme activity, reflected as an increase in the 6 beta OHF/F ratio, in Hong Kong Chinese with nonresectable HCC compared with those with resectable HCC and other liver diseases. Although the role of increased CYP3A4 activity in the aetiology of HCC is not known, our specificity and sensitivity estimates suggest that a high 6 beta OHF/F ratio indicates probable inoperability. However, a normal level is a poor predictor of resectability.

Adolescent↗

PubMed1994

Crohn's disease in the Chinese population. An experience from Hong Kong.

PURPOSE: Crohn's disease was extremely rare among Chinese. We reviewed all cases diagnosed as having Crohn's disease during a five-year period. METHODS: A diagnosis of Crohn's disease was made only if all of the following criteria were fulfilled: 1) clinical symptom(s) and sign(s) compatible with chronic inflammatory bowel disease; 2) exclusion of intestinal infection by repeated stool cultures; 3) macroscopic features of small and/or large intestinal inflammation with skip lesion, stricture, and fistula formation; 4) histologic features of Crohn's disease, i.e., focal lymphoid aggregate, focal cryptitis, and granuloma formation; 5) clinical response to conventional therapy for inflammatory bowel disease. RESULTS: Fifteen ethnic Chinese patients were diagnosed as having Crohn's disease in this period. All patients had colitis, whereas small intestine inflammation was documented in only 47 percent of patients. Extraintestinal manifestations were uncommon except for arthropathy: ankylosing spondylitis (2), sacroiliitis (1), juvenile rheumatoid arthritis (1), and colitic arthritis (1). The majority of our patients responded to medical therapy. Surgery was undertaken in 33 percent of patients. CONCLUSION: Although there is a general increased incidence of Crohn's disease in the Western world, we too are beginning to see more cases in the Far East. Nevertheless, gastrointestinal infection with bacteria and/or parasites should still be carefully excluded in these countries.

Adolescent↗

PubMed1994

Laparoscopic cholecystectomy: results of first 300 cases in Hong Kong.

Prospective analysis of the first three hundred patients who underwent laparoscopic cholecystectomy was carried out in three surgical centres of Hong Kong. Over a 20-month period, 300 consecutive patients were recruited, including elective and emergency cases. The indications for laparoscopic cholecystectomy were symptomatic gallstones (78%), cholangitis (6%), pancreatitis (5%) and cholecystitis (11%). Patients with common duct stones (12) had preoperative endoscopic sphincterotomy and stone extraction prior to cholecystectomy. Laparoscopic cholecystectomy was accomplished successfully in 287 patients. Thirteen patients (4.3%) required conversion to open cholecystectomy. The reasons for conversion were: inability to identify cystic duct and common bile duct clearly (6); bleeding (5); Mirizzi syndrome (1); and slippage of cystic duct clip (1). The median operation time was 80 min with a range of 28-270 min. The median hospital stay was 3 days. Seventy-five per cent of patients required only a single dose of pethidine injection. None of the patients required blood transfusion. The overall complication rate was 7%. These included mild cellulitis of the subumbilical wound (3%) and postoperative chest infection (3%). One patient developed subphrenic abscess which resolved on percutaneous drainage under ultrasound guidance. Iatrogenic injury to the common bile duct was seen in one patient who had an impacted stone at Hartmann's pouch. With adequate training laparoscopic cholecystectomy can be performed safely. The advantages over open cholecystectomy are less wound pain, better cosmesis and shorter convalescence.

Cholecystectomy↗

PubMedDate not supplied

Congenital hypertrophy of the retinal pigment epithelium and APC mutations in Chinese with familial adenomatous polyposis.

Mutations in the adenomatous polyposis coli gene (APC) often cause both congenital hypertrophy of the retinal pigment epithelium (CHRPE) and familial adenomatous polyposis (FAP). To investigate the relationship between APC mutations, CHRPE and FAP, all FAP patients at the Prince of Wales Hospital, Hong Kong, were asked to participate in a study. Ten Chinese patients from 6 kindreds and their family members volunteered, along with 12 healthy control subjects selected among hospital visitors and staff. All were examined for dilated fundus by indirect ophthalmoscopy. Mutations in APC coding exons were detected by sequencing. In one FAP patient, a novel A insertion at codon 1023 was detected. Three previously reported mutations were detected in 6 FAP patients: a deletion of ACAAA at codon 1061, and 2 truncating point substitutions at codons 216 and 283. In 3 FAP patients, no APC mutation was found, suggesting that mutations in APC coding regions are not the sole cause of FAP or CHRPE. A total of 64 CHRPE lesions were found in FAP patients and some relatives with and without APC mutations. Contrary to most reports, APC mutations before exon 9 did cause CHRPE lesions, albeit relatively few.

Adenomatous Polyposis Coli↗