PubMed Health⌕ Search

Biomedical subjects

K K Cheng

Publications and source records attributed to K K Cheng.

At least 55 records · Page 3Linked to original sources
PubMed2000

Effect of anti-inflammatory drugs on overall risk of common cancer: case-control study in general practice research database.

OBJECTIVE: To examine whether anti-inflammatory drug treatment protects against the commoner cancers in the United Kingdom. DESIGN: Case-control study using the general practice research database. SETTING: Practices throughout United Kingdom providing data to the database. SUBJECTS: Patients who had a first diagnosis of five gastrointestinal (oesophagus, stomach, colon, rectum, and pancreas) cancers and four non-gastrointestinal (bladder, breast, lung, and prostate) cancers in 1993-5 for whom prescription data were available for the at least the previous 36 months. Each case was matched for age, sex, and general practice with three controls. MAIN OUTCOME MEASURE: Risk of cancer. RESULTS: In 12 174 cancer cases and 34 934 controls overall risk of the nine cancers was not significantly reduced among those who had received at least seven prescriptions in the 13-36 months before cancer diagnosis (odds ratio 0.98, 95% confidence interval 0.89 to 1.07). Findings were nevertheless compatible with protective effects from anti-inflammatory drugs against cancers of the oesophagus (0.64, 0. 41 to 0.98), stomach (0.51, 0.33 to 0.79), colon (0.76, 0.58 to 1. 00), and rectum (0.75, 0.49 to 1.14) with dose related trends. The risk of pancreatic cancer (1.49, 1.02 to 2.18) and prostatic cancer (1.33, 1.07 to1.64) was increased among patients who had received at least seven prescriptions, but the trend was dose related for only pancreatic cancer. CONCLUSIONS: Anti-inflammatory drugs may protect against oesophageal and gastric cancer as well as colon and rectal cancer. The increased risks of pancreatic and prostatic cancer could be due to chance or to undetected biases and warrant further investigation.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

A case-control study of oesophageal adenocarcinoma in women: a preventable disease.

The incidence of adenocarcinoma of the oesophagus in British women is among the highest in the world. To investigate its aetiology, we conducted a multi-centre, population based case-control study in four regions in England and Scotland. We included 74 incident cases in women with histologically confirmed diagnoses of adenocarcinoma of the oesophagus, and 74 female controls matched by age and general practice. High body mass index (BMI) around the age of 20 years (highest vs lowest quartile, adjusted odds ratio (OR) = 6.04, 95% confidence interval (CI) 1.28-28.52) and low consumption of fruit (highest vs lowest quartile, adjusted OR = 0.08, 95% CI 0.01-0.49) were associated with increases in risk. Breastfeeding by women was associated with reduced risk of their subsequently developing this cancer (ever vs never, adjusted OR = 0.41, 95% CI 0.20-0.82) and there was a significant dose-response effect with total duration of breastfeeding. The summary population attributable risk from these three factors was 96% (90% if breastfeeding is excluded). We conclude that high BMI in early adulthood and low consumption of fruit are important risk factors for adenocarcinoma of the oesophagus. Breastfeeding may confer a protective effect but this needs confirmation. This cancer is a largely preventable disease in women.

Adenocarcinoma↗
PubMed1999

Nitric oxide signaling pathway mediates the L-arginine-induced cardiovascular effects in the nucleus tractus solitarii of rats.

We have previously demonstrated that L-arginine produces profound cardiovascular effects when microinjected into the nucleus tractus solitarii (NTS) of the rat. The present study extended our earlier work and examined further the underlying mechanisms of action of L-arginine in the NTS. Our results showed that intra-NTS microinjection of L-arginine (0.1-10 nmol) elicited dose-dependent depressor and bradycardic effects that were not significantly evoked by equivalent doses of D-arginine. The effects of L-arginine were blocked by pre-injection of 7-nitroindazole (0.02-1 nmol), a neuronal nitric oxide synthase inhibitor. Additionally, application of the calmodulin inhibitor W-7 (0.01-0.33 nmol) reduced cardiovascular responses to L-arginine (10 nmol) in a dose-dependent manner. Pre-injections of soluble guanylyl cyclase inhibitors, LY83583 (0.01-0.33 nmol) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 0.03-1 pmol) both suppressed the L-arginine-induced depressor and bradycardic effects. Finally, the cardiovascular effects of L-arginine in the NTS were attenuated by HA1004 (0.1-1 nmol), a cGMP-dependent protein kinase inhibitor, but not by the protein kinase C inhibitor H-7 (1 nmol). Taken together, the results indicate that the cardiovascular effects produced by L-arginine in the NTS are inhibited by pharmacological interventions that block nitric oxide production and cGMP-PKG signaling pathway within the nucleus.

Aminoquinolines↗
PubMed1999

Cluster randomised controlled trial of expert system based on the transtheoretical ("stages of change") model for smoking prevention and cessation in schools.

OBJECTIVES: To examine whether a year long programme based on the transtheoretical model of behaviour change, incorporating three sessions using an expert system computer program and three class lessons, could reduce the prevalence of teenage smoking. DESIGN: Cluster randomised trial comparing the intervention to a control group exposed only to health education as part of the English national curriculum. SETTING: 52 schools in the West Midlands region. PARTICIPANTS: 8352 students in year 9 (age 13-14 years) at those schools. MAIN OUTCOME MEASURES: Prevalence of teenage smoking 12 months after the start of the intervention. RESULTS: Of the 8352 students recruited, 7444 (89.1%) were followed up at 12 months. The intention to treat odds ratio for smoking in the intervention group relative to control was 1.08 (95% confidence interval 0.89 to 1.33). Sensitivity analysis for loss to follow up and adjustment for potential confounders did not alter these findings. CONCLUSIONS: The smoking prevention and cessation intervention based on the transtheoretical model, as delivered in this trial, is ineffective in schoolchildren aged 13-14.

Adolescent↗
PubMed1999

Cancer incidence in the south Asian population of England (1990-92).

Cancer incidence among English south Asians (residents in England with ethnic origins in India, Pakistan or Bangladesh) is described and compared with non-south Asian and Indian subcontinent rates. The setting for the study was areas covered by Thames, Trent, West Midlands and Yorkshire cancer registries. The study identified 356 555 cases of incident cancer (ICD9:140-208) registered between 1990 and 1992, including 3845 classified as English south Asian. The main outcome measures were age specific and directly standardized incidence rates for all cancer sites (ICD9:140-208). English south Asian incidence rates for all sites combined were significantly lower than non-south Asian rates but higher than Indian subcontinent rates. English south Asian rates were substantially higher than Indian subcontinent rates for a number of common sites including lung cancer in males, breast cancer in females and lymphoma in both sexes. English south Asian rates for childhood and early adult cancer (0-29 years) were similar or higher than non-south Asian rates. English south Asian rates were significantly higher than non-south Asian rates for Hodgkin's disease in males, cancer of the tongue, mouth, oesophagus, thyroid gland and myeloid leukaemia in females, and cancer of the hypopharynx, liver and gall bladder in both sexes. The results are consistent with a transition from the lower cancer risk of the country of ethnic origin to that of the country of residence. They suggest that detrimental changes in lifestyle and other exposures have occurred in the migrant south Asian population.

Adolescent↗
PubMed1999

An assessment of the Nam Pehchan computer program for the identification of names of south Asian ethnic origin.

BACKGROUND: An assessment was made of the usefulness and accuracy of a computer program for the identification of the south Asian population through the classification of names on a disease register. METHODS: The computer program, Nam Pehchan, was used to classify names as either south Asian or non south Asian. The results were compared with a reference standard, which combined use of the program with visual inspection. The latter was facilitated by a computer-generated dictionary of common non south Asian names. The data set consisted of 356,555 cases of incident cancer (ICD9: 140-208) registered between 1990 and 1992 by Thames, Trent, West Midlands and Yorkshire cancer registries. RESULTS: Nam Pehchan classified 5506 cases as south Asian. Visual inspection identified 2024 false positives (36.8 per cent of all cases identified as south Asian by Nam Pehchan) and 363 false negatives (9.5 per cent of those identified by the reference standard). Compared with the reference standard, Nam Pehchan had a sensitivity of 90.5 per cent and a positive predictive value of 63.2 per cent. CONCLUSION: The Nam Pehchan program quickly identified a high proportion of the names classified as south Asian by the reference standard, but the high false positive rate means that the program alone is not an adequate single strategy. The time-consuming process of inspection of program negatives for large data sets can be substantially reduced by comparison with dictionaries of common non south Asian names.

Asia↗
PubMed1996

Nutrition and esophageal cancer.

Epidemiologic evidence on the relation between nutrition and esophageal cancer is reviewed. Results from ecologic, case-control, cohort, and intervention studies are included. Most of the findings pertain more to squamous cell carcinoma than adenocarcinoma of the esophagus. The protective effect of fruit and vegetable consumption is supported by a large body of evidence, especially from case-control studies. The effects of food groups and nutrients other than fruits and vegetables also have been examined, but the overall evidence is less convincing. Recent intervention studies in high incidence areas in China indicate that micronutrient supplements may have a modest effect in reducing risk, but the generalizability of this result is uncertain. Hot drinks are likely to increase the risk of esophageal cancer. On the other hand, the role of tea drinking, especially the use of green tea, remains to be defined better.

Adenocarcinoma↗