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Biomedical subjects

Y Wong

Publications and source records attributed to Y Wong.

At least 37 records · Page 2Linked to original sources
PubMed2001

Pulmonary cryptococcosis: a case report and review of the Asian-Pacific experience.

Pulmonary cryptococcosis is a very rare form of pneumonia, which is seldom seen among immunocompetent patients. We report the case of a 36-year-old man who presented with indolent pneumonia that was subsequently diagnosed to be pulmonary cryptococcosis without other systemic involvement. Contrary to formal belief, there was evidence of residual lung fibrosis 12 months after initial presentation. The features of pulmonary cryptococcosis reported in the Asian Pacific region are also reviewed.

Adult↗
PubMed2001

Macrophage migration inhibitory factor is an important mediator in the pathogenesis of gastric inflammation in rats.

BACKGROUND & AIMS: Macrophage migration inhibitory factor (MIF) has been shown to play a pivotal role in inflammatory and immune-mediated diseases. This study investigates the role of MIF in gastric inflammation. METHODS: Expression of MIF was examined in a rat gastric ulcer model induced by acetic acid, and the functional role of MIF in acute gastric ulcer was investigated by administration of a neutralizing anti-MIF antibody. RESULTS: MIF messenger RNA and protein were markedly up-regulated in acute gastric ulcer, which correlated with the accumulation of macrophages (P < 0.001) and neutrophils (P < 0.05) at the site of inflammation. Macrophages, like neutrophils, were the major inflammatory cells infiltrating the ulcer base and they strongly expressed inducible nitric oxide synthase. However, macrophages, not neutrophils, were a rich source of MIF production in acute gastric ulcer. In vivo and in vitro blockade of MIF with the neutralizing anti-MIF antibody significantly inhibited the marked up-regulation of MIF, tumor necrosis factor alpha, inducible nitric oxide synthase, and intercellular adhesion molecule-1. This was associated with the marked inhibition of macrophage (70% reduced) and neutrophil (60% reduced) accumulation and activation, thus reducing ulcer sizes and attenuating ulceration. CONCLUSIONS: This study has shown that MIF was markedly up-regulated during acute gastric ulcer. Inhibition of acute gastric ulcer by blockade of MIF indicates that MIF is a key inflammatory mediator and plays a pathogenic role in gastric inflammation.

Acetic Acid↗
PubMed2001

Sex differences in investigation results and treatment in subjects referred for investigation of chest pain.

OBJECTIVE: To evaluate differences in investigation results and treatment between men and women referred for diagnostic treadmill exercise testing and coronary arteriography. DESIGN: Cohort study. SETTING: Tertiary cardiology centre. SUBJECTS: 1522 subjects referred by primary care physicians to an open access chest pain clinic for initial investigation of chest pain, of whom 485 were subsequently referred for coronary arteriography; and a similar cohort of 107 subjects referred directly by secondary care physicians for diagnostic coronary arteriography. MAIN OUTCOME MEASURES: Rates of positive exercise tests and rates for referral for arteriography and revascularisation according to sex. RESULTS: Overall, women were less likely to be referred for arteriography and revascularisation than men. However, men were more likely to have positive exercise tests, and for various exercise test diagnostic end points men were also more likely to have significant coronary artery disease. After taking this into account, there was no sex difference in referral rates for arteriography or revascularisation. CONCLUSIONS: There was no evidence of a sex bias resulting in inappropriate underinvestigation or undertreatment of women. However, the positive predictive value of treadmill exercise testing is low for women and further research is needed into how best to investigate women with chest pain.

Aged↗
PubMed2001

Soy protein hydrolyzate with bound phospholipids reduces serum cholesterol levels in hypercholesterolemic adult male volunteers.

This study was done to evaluate the effects of soy protein hydrolyzate with bound phospholipids (c-SPHP), on the serum cholesterol levels in hypercholesterolemic subjects over a three-month period. Subjects were Taiwanese adult male volunteers whose serum total cholesterol levels were above 220 mg/dl. Twenty-one subjects were divided into three groups randomly, and each group was given c-SPHP zero, 3, or 6 g per day. Test diets were orally administered in a powdered drink form that contained c-SPHP or casein hydrolyzate (placebo). The subjects were given the test diet four times daily. The study consisted of a two-week pre-feeding period, a three-month feeding period, followed by a two-week post-feeding period. After 3 months of c-SPHP administration, 3 g per day, serum total cholesterol decreased significantly from the initial level (15.0%, p<0.01) and compared with the placebo group (p<0.05). Furthermore, LDL-cholesterol decreased significantly (27.7%, p<0.01) and the LDL/HDL ratio also decreased significantly (47.4%, p<0.01) from the initial levels. These effects of c-SPHP were dose-dependent. This study suggests that c-SPHP has remarkable improving effects on the serum cholesterol levels in hypercholesterolemic subjects.

Adult↗
PubMed2001

Perspective: cell differentiation theory may advance early detection of and therapy for lung cancer.

Many of these deaths could be prevented if there were better screening methods to uncover the disease when it is limited and most responsive to intervention. Novel biomarkers of early-stage disease are therefore needed. By applying the principle of "oncology recapitulates ontogeny", we have discovered three homeobox (HOX) genes that are inappropriately expressed in the majority of lung tumors. Understanding the role of these inappropriately expressed genes in lung epithelial cell carcinogenesis may not only augment early detection, but may also offer new avenues of treatment of this disease.

Cell Differentiation↗
PubMed2000

Chlamydia pneumoniae infection and mortality from ischaemic heart disease: large prospective study.

OBJECTIVE: To determine whether there is an independent association between infection with Chlamydia pneumoniae and ischaemic heart disease. DESIGN: Prospective study using a nested case-control design. SETTING: Medical centre in London run by BUPA, a private medical organisation. PARTICIPANTS: 21 520 professional men aged 35-64 who attended for a medical examination in London between 1975 and 1982. MAIN OUTCOME MEASURE: Death from ischaemic heart disease. RESULTS: The distributions of concentrations of IgG and IgA antibodies to C pneumoniae were similar in the 647 men who subsequently died of ischaemic heart disease and in 1294 age matched controls who did not. There was no material association with heart disease irrespective of the cut-off point chosen to define seropositivity. At a cut-off point that defines 15% of controls as positive, for example, the odds ratios were 1.26 (95% confidence interval 0.95 to 1.68) for IgG and 1.09 (0.82 to 1.43) for IgA. CONCLUSIONS: No material association was found between infection with C pneumoniae and ischaemic heart disease. The size and prospective design of the study and the socioeconomic homogeneity of the cohort minimise both random and systematic error.

Adult↗
PubMed2000

Chlamydia pneumoniae IgG titres and coronary heart disease: prospective study and meta-analysis.

OBJECTIVE: To examine the association between coronary heart disease and serum markers of chronic Chlamydia pneumoniae infection. DESIGN: "Nested" case-control analysis in a prospective cohort study and an updated meta-analysis of previous relevant studies. SETTING: General practices in 18 towns in Britain. PARTICIPANTS: Of the 5661 men aged 40-59 who provided blood samples during 1978-80, 496 men who died from coronary heart disease or had non-fatal myocardial infarction and 989 men who had not developed coronary heart disease by 1996 were included. MAIN OUTCOME MEASURES: IgG serum antibodies to C pneumoniae in baseline samples; details of fatal and non-fatal coronary heart disease from medical records and death certificates. RESULTS: 200 (40%) of the 496 men with coronary heart disease were in the top third of C pneumoniae titres compared with 329 (33%) of the 989 controls. The corresponding odds ratio for coronary heart disease was 1.66 (95% confidence interval 1.25 to 2.21), which fell to 1.22 (0.82 to 1.82) after adjustment for smoking and indicators of socioeconomic status. No strong associations were observed between C pneumoniae IgG titres and blood lipid concentrations, blood pressure, or plasma homocysteine concentration. In aggregate, the present study and 14 other prospective studies of C pneumoniae IgG titres included 3169 cases, yielding a combined odds ratio of 1. 15 (0.97 to 1.36), with no significant heterogeneity among the separate studies (chi(2)=10.5, df=14; P>0.1). CONCLUSION: This study, together with a meta-analysis of previous prospective studies, reliably excludes the existence of any strong association between C pneumoniae IgG titres and incident coronary heart disease. Further studies are required, however, to confirm or refute any modest association that may exist, particularly at younger ages.

Adult↗
PubMed1999

Novel 2,2-bipyridine ligand for palladium-catalyzed regioselective carbonylation.

[reaction: see text] A palladium-catalyzed highly regioselective one-step carbonylation of 2,5-dibromo-3-methylpyridine is reported. A range of alkyl esters and amides can be prepared in good yield with better than 95:5 regioselectivity via this method. Key to the high regioselectivity for the formation aromatic amides is the introduction of a novel nonphosphine-based 2,2-bipyridine ligand. This novel reaction was scaled up smoothly in the plant to a 130-kg batch size and facilitated the delivery of bulk material for the clinical trials of Sch 66336, a candidate for oncologic treatments.

Antineoplastic Agents↗
PubMed1999

Relation between direct detection of Chlamydia pneumoniae DNA in human coronary arteries at postmortem examination and histological severity (Stary grading) of associated atherosclerotic plaque.

BACKGROUND: Numerous studies have suggested a link between Chlamydia pneumoniae infection, atherosclerosis, and coronary artery disease. However, it is still unclear whether C pneumoniae plays a causal role in the pathogenesis of these conditions. Accordingly, we have performed a systematic dissection of the 3 coronary arteries on 33 postmortem subjects and studied the relationship in individual artery segments between the presence of C pneumoniae DNA and the severity of associated atherosclerosis. METHODS AND RESULTS: The prevalence of C pneumoniae DNA in arterial segments was determined by polymerase chain reaction (PCR) after controlling for the presence of PCR inhibitors. Atherosclerosis in each arterial segment was graded histologically with the Stary classification. C pneumoniae was detected by PCR in 78.8% of subjects, but there was no association between the presence of this DNA and cause of death or grade of atherosclerosis. When paired mild and severe atherosclerotic lesions within subjects were compared, mild lesions were as likely to be positive for C pneumoniae as severe lesions. CONCLUSIONS: This study demonstrates that C pneumoniae can frequently be detected in atheromatous plaques in coronary arteries. However, its distribution did not correlate with severity or extent of disease.

Aged↗
PubMed1999

The prevalence of Chlamydia pneumoniae in atherosclerotic and nonatherosclerotic blood vessels of patients attending for redo and first time coronary artery bypass graft surgery.

OBJECTIVES: To determine if Chlamydia pneumoniae (C. pneumoniae) is more prevalent in atherosclerotic compared with normal blood vessels of patients requiring redo and first time coronary artery bypass graft surgery (CABG). BACKGROUND: Serological and pathological studies have associated atherosclerosis with C. pneumoniae infection. As atherosclerosis is one of the causes of graft failure following CABG, then it may be expected that the prevalence of the organism in failed grafts and diseased native vessels should be greater than in the new grafts. METHODS: Endarterectomy specimens and failed and new grafts were collected from 49 patients with late graft failure. Endarterectomy specimens and new grafts were also collected from nine patients having first time CABG. The presence of C. pneumoniae DNA was then checked for using a nested polymerase chain reaction. RESULTS: The prevalence of C. pneumoniae DNA in failed venous grafts (38.2%) was similar to that in endarterectomy specimens from native coronary arteries (38.5%) and greater than that in new saphenous vein grafts (11.8%). However, it was similar to that in new internal mammary artery grafts (30.0%). Also, the interval between surgery in redo patients was the same regardless of whether C. pneumoniae was present or not. CONCLUSIONS: Cross sectional studies cannot determine whether C. pneumoniae is a cause of atherosclerosis since they do not show whether infection precedes or follows its development. However, our results suggest that the organism is not an important factor in graft failure or atherosclerosis.

Aged↗
PubMed1999

Obesity concerns, weight satisfaction and characteristics of female dieters: a study on female Taiwanese college students.

OBJECTIVE: This study was designed to obtain baseline data regarding desired body weight, weight satisfaction, self-perceived weight categories, approaches to weight loss of female college students in Taiwan. The characteristics of subjects who are dieting were also assessed. METHODS: One thousand, fifty-seven female college students participated in this study. Written questionnaires were used for data collection. Students' height and weight were also measured. Simple frequency and one-way analysis of variance (ANOVA) were used to analyze data. Post hoc analyses were performed with the LSD test when the F ratio for the ANOVA was significant at p<0.05. RESULTS: In general, subjects perceived themselves as being heavier than their actual weight categories. The percentage of subjects who perceived they were overweight or obese was much higher than the percentage of subjects who were actually in these categories (51.4% vs. 16.2%). Above 20% of subjects in both severely underweight and underweight categories use some methods to lose weight. More than 60% of subjects in acceptable weight categories still want to lose weight. A higher percentage of subjects chose exercise than dieting as the major weight-loss method. Subjects in the DS/D (dissatisfied/dieting) group did not score higher points for knowledge and attitude in nutrition, and they tended to measure their body weight more frequently (p<0.05), spent more time for exercise (p<0.05) and for reading nutrition information (p<0.05); they also skipped lunch (p<0.05) more frequently than others. CONCLUSIONS: The results indicate that risk factors leading to eating disorders are common among Taiwanese college females. Dietitians, physicians and other health professionals should be on the alert to identify patients with eating disorders.

Adolescent↗
PubMed1999

Weight satisfaction and dieting practices among college males in Taiwan.

OBJECTIVE: To obtain baseline data regarding body mass index (BMI), weight satisfaction and weight perception in male college students. Approaches used to lose weight and characteristics of dieters were also investigated. METHODS: Written questionnaires and height and weight measurements were used to collect data. Nine-hundred thirty male college students selected by multiple stage sampling among colleges in Taiwan participated in this study. Simple frequency and ANOVA were used to analyze data. Post hoc analyses were performed with the LSD test when the F ratio for the ANOVA was significant at p<0.05. RESULTS: The mean BMI for all subjects was 21.7. Males with a BMI < or =22.5 are considered thin by Taiwanese and world standards. Yet 34% of these males were attempting to lose weight and 14% percent perceived themselves as either overweight or obese. Exercise was the main approach to losing weight for subjects in all weight categories. Subjects in the dissatisfied/dieting group tended to measure body weight more frequently (p<0.05), spent more time exercising and reading nutrition information (p<0.05) and skipped breakfast and lunch more frequently (p<0.05) than non-dieters. Male dieters ate fewer vegetables and less meat than non-dieters. CONCLUSIONS: Male college students had frequent misconceptions and dissatisfaction with their body weight. Behavioral characteristics among those dissatisfied with their weight indicate they are at risk for developing eating disorders.

Adult↗
PubMed1999

Chronic infection with Helicobacter pylori, Chlamydia pneumoniae, or cytomegalovirus: population based study of coronary heart disease.

OBJECTIVE: To study possible associations between coronary heart disease and serological evidence of persistent infection with Helicobacter pylori, Chlamydia pneumoniae, or cytomegalovirus. DESIGN: Population based, case-control study, nested within a randomised trial. SETTING: Five general practices in Bedfordshire, UK. INDIVIDUALS: 288 patients with incident or prevalent coronary heart disease and 704 age and sex matched controls. RESULTS: High concentrations of serum IgG antibodies to H pylori were present in 54% of cases v 46% of controls, with corresponding results for C pneumoniae seropositivity (33% v 33%), and cytomegalovirus seropositivity (40% v 31%). After adjustments for age, sex, smoking, indicators of socioeconomic status, and standard risk factors, the odds ratios (95% confidence intervals) for coronary heart disease of seropositivity to these agents were: 1.28 (0.93 to 1.75) for H pylori, 0.95 (0.66 to 1.36) for C pneumoniae, and 1.40 (0.96 to 2. 05) for cytomegalovirus. CONCLUSIONS: There is no good evidence of strong associations between coronary heart disease and serological markers of persistent infection with H pylori, C pneumoniae, or cytomegalovirus. To determine the existence of moderate associations between these agents and disease, however, larger scale studies will be needed that can keep residual confounders to a minimum.

Adult↗
PubMed1999

Risk factors for coronary heart disease and persistent infection with Chlamydia pneumoniae or cytomegalovirus: a population-based study.

BACKGROUND: A large number of epidemiological and pathological studies have reported on associations between coronary heart disease and persistent infection with Chlamydia pneumoniae or cytomegalovirus, but relatively few have reported on possible relations between these infections and vascular risk factors. OBJECTIVE: To determine whether serum concentrations of immunoglobulin G antibodies to C. pneumoniae or cytomegalovirus are correlated to standard vascular risk factors, markers of inflammation and indicators of socioeconomic status. METHODS: We performed a cross-sectional sero-epidemiological study nested within a randomized trial involving five general practices in Bedfordshire, UK. We made measurements of a number of standard vascular risk factors, serum markers of systemic inflammation and other relevant characteristics in 704 individuals. RESULTS: There were significant associations between C. pneumoniae immunoglobulin G levels and male sex and cigarette smoking (2P < 0.01 for each) and between cytomegalovirus immunoglobulin G levels and age (2P < 0.001). Other factors were not significantly associated with serum antibodies to either persistent infection. CONCLUSIONS: Serological evidence of persistent infection with C. pneumoniae or cytomegalovirus in this population was not strongly associated with most standard vascular risk factors and other characteristics. The main implication is that such risk factors are not likely to be important confounders or mediators of the reported associations between coronary heart disease and these agents.

Adult↗
PubMed1999

Imaging features of focal intrahepatic extramedullary haematopoiesis.

The imaging findings of focal intrahepatic extramedullary haematopoiesis (EMH) in a 51-year-old woman with beta-thalassaemia intermedia are described with particular reference to MRI and CT. Bone marrow colloid scintigraphy was unhelpful in confirming the diagnosis, which was made from fine needle aspiration. This is the first description of stellate scars occurring in an EMH lesion. A review of the radiological appearances of this rare condition is presented.

Female↗