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Biomedical subjects

H Yuen

Publications and source records attributed to H Yuen.

17 recordsLinked to original sources
PubMed2005

Comparison of olanzapine and risperidone in 367 first-episode patients with non-affective or affective psychosis: results of an open retrospective medical record study.

INTRODUCTION: Previous studies comparing olanzapine (OLZ) and risperidone (RIS) have tended to focus on multiple-episode patients, with no studies examining their comparative efficacy in a non-selective sample of first-episode psychosis. METHODS: The Early Psychosis Prevention and Intervention Centre in Australia had admitted 786 first-episode psychosis (FEP) patients between 1998-2000. Data were collected from the medical records (MR) of 367 patients, which met inclusion criteria. The primary objective was to evaluate the efficacy of OLZ vs. RIS as measured by CGI-S, CGI-BP (symptomatic level), GAF and SOFAS (functioning level). RESULTS: 367 FEP patients were entered into the study, 278 in the RIS- (2.7 mg/day) and 89 in the OLZ group (10.2 mg/day). No between-group differences were found in non-affective FEP (n = 273). In affective FEP patients (n = 94), mainly treated for acute mania (86.7 %), OLZ treatment was related to better response on the symptomatic (CGI-S; p = .002), but not on the functioning level (GAF and SOFAS; ns). There were trends in the OLZ group towards a higher rate of remission of positive symptoms ( p = .054) and a shorter treatment duration to reach this remission in affective FEP patients ( p = .077). More extrapyramidal side effects ( p <.001) were related to RIS and more weight gain to OLZ-treatment ( p <.001). DISCUSSION: Despite the limitations of a retrospective MR design, study results suggest equal therapeutic efficacy of OLZ and RIS in non-affective FEP and some therapeutic advantages of OLZ compared to RIS in affective FEP patients, especially in those with acute mania. Results may serve as hypotheses for future randomised controlled trials.

Adolescent↗
PubMed2005

The impact of substance use disorders on clinical outcome in 643 patients with first-episode psychosis.

OBJECTIVE: Studies investigating the impact of comorbid substance use disorders (SUD) in psychosis have tended to focus on cross-sectional data, with few studies examining the effects of substance use course on clinical outcome. The main aim of the present study was to assess the impact of baseline SUD and course of SUD on remission of positive symptoms. METHOD: The Early Psychosis Prevention and Intervention Centre admitted 786 first-episode psychosis (FEP) patients between 1998 and 2000. Data on SUD and clinical outcome were collected from patients' medical records (MR) of 643 patients who met inclusion criteria. RESULTS: Lifetime prevalence of SUD was 74%, with 62% having a SUD at baseline. This reduced to 36% in those patients who completed 18 months of treatment at the EPPIC program. A Cox regression analysis indicated that a decrease or cessation of substance use significantly increased the probability of remission, whilst persistent SUD substantially reduced the likelihood. In addition, patients who reduced use appeared to have better outcomes at 18 months than those patients who had never used substances. Baseline SUD was not found to have any significant influence on symptom remission. CONCLUSION: Patients presenting with FEP have high rates of SUD. Effective management of psychosis within a specialized service is associated with reductions in SUD over the course of treatment, although persistent substance use is associated with non-compliance, treatment drop-out and poor remission rates. As such, young people with FEP and comorbid substance use should be offered integrated treatment that addresses both disorders.

Adult↗
PubMed2003

An Asia-Pacific, double blind, placebo controlled, randomised study to evaluate the efficacy, safety, and tolerability of tegaserod in patients with irritable bowel syndrome.

BACKGROUND: Tegaserod has been shown to be an effective therapy for the multiple symptoms of irritable bowel syndrome (IBS) in Western populations. However, little information is available regarding the use of tegaserod in the Asia-Pacific population. AIMS: To evaluate the efficacy, safety, and tolerability of tegaserod versus placebo in patients with IBS from the Asia-Pacific region. PATIENTS: A total of 520 patients from the Asia-Pacific region with IBS, excluding those with diarrhoea predominant IBS. METHODS: Patients were randomised to receive either tegaserod 6 mg twice daily (n=259) or placebo (n=261) for a 12 week treatment period. The primary efficacy variable (over weeks 1-4) was the response to the question: "Over the past week do you consider that you have had satisfactory relief from your IBS symptoms?" Secondary efficacy variables assessed overall satisfactory relief over 12 weeks and individual symptoms of IBS. RESULTS: The mean proportion of patients with overall satisfactory relief was greater in the tegaserod group than in the placebo group over weeks 1-4 (56% v 35%, respectively; p<0.0001) and weeks 1-12 (62% v 44%, respectively; p<0.0001). A clinically relevant effect was observed as early as week 1 and was maintained throughout the treatment period. Reductions in the number of days with at least moderate abdominal pain/discomfort, bloating, no bowel movements, and hard/lumpy stools were greater in the tegaserod group compared with the placebo group. Headache was the most commonly reported adverse event (12.0% tegaserod v 11.1% placebo). Diarrhoea led to discontinuation in 2.3% of tegaserod patients. Serious adverse events were infrequent (1.5% tegaserod v 3.4% placebo). CONCLUSIONS: Tegaserod 6 mg twice daily is an effective, safe, and well tolerated treatment for patients in the Asia-Pacific region suffering from IBS and whose main bowel symptom is not diarrhoea.

Adult↗
PubMed2003

How would schools step up public health measures to control spread of SARS?

The severe acute respiratory syndrome (SARS) is a rapidly progressive, and sometime fatal disease with more than 1800 patients in over a dozen countries in Asia, Europe, and North America (including the United States and Canada) within two months. On 12 March 2003, the World Health Organisation (WHO) issued a global alert about SARS so it became a global challenge. Strengthening the public health measures at schools would protect children as well as providing the students an opportunity to learn about infectious disease control through life event approach. The public health measures at schools include two important components: basic understanding of the disease so schools would put on high alert on caution cases, and the measures to improve environmental hygiene at schools and preventive measures to stop infectious disease transmission. This will help to empower the whole community the readiness to deal with other outbreaks in the future.

Communicable Disease Control↗
PubMed2001

Biliary tract disease and acute non-A-E hepatitis in Hong Kong: prospective study.

OBJECTIVE: To investigate the role of biliary tract disease in patients with acute non-A-E hepatitis. DESIGN: Prospective study. SETTING: Infectious diseases unit, government hospital, Hong Kong. PATIENTS: Sixty-one consecutive patients, admitted with the diagnosis of acute hepatitis and negative hepatitis serology for hepatitis A, B, C, D, and E virus. MAIN OUTCOME MEASURES: Abdominal ultrasound and endoscopic retrograde cholangiopancreatography findings; clinical outcome. RESULTS: Ultrasonographic abnormalities indicating biliary tract disease were found in 30% (18/61) of patients. Endoscopic retrograde cholangiopancreatography performed in 78% (14/18) of patients with abnormal ultrasound finding(s) confirmed the presence of biliary tract disease. Age, sex, serum alanine aminotransferase level, and serum albumin level were independent predictors of biliary tract disease in the patients studied. CONCLUSION: Biliary tract diseases were found in 20% of patients with acute non-A-E hepatitis. Serum amylase and abdominal ultrasonography should be performed for all patients presenting with acute non-A-E hepatitis. Endoscopic retrograde cholangiopancreatography is indicated for those with apparent gallstones or abnormal biliary tract findings.

Acute Disease↗
PubMed1998

Delayed mid-ileal perforation secondary to acute-on-chronic ischaemia after a diagnostic colonoscopy.

Perforation occurring at a remote site of the bowel after diagnostic colonoscopy is rare. A 61-year-old man presenting with bloody diarrhoea underwent colonoscopy. A dynamic ileus developed in less than 1 day, and mid-ileal perforation occurred 7 days after the procedure. It is suggested that high air pressure during colonoscopy further compromised the reduced blood flow in the mid-ileum, which had underlying chronic ischaemia, leading to perforation. Our patient constitutes the first reported case of small-bowel perforation after colonoscopy due to pre-existent ileal ischaemia.

Acute Disease↗
PubMed1997

Haemolysis complicating acute viral hepatitis in patients with normal or deficient glucose-6-phosphate dehydrogenase activity.

Haemolytic anaemia as a complication of acute hepatitis has been reported in up to 23% of patients. However, the incidence may rise up to 70-87% in patients who have glucose-6-phosphate dehydrogenase (G6PD) deficiency. Massive intravascular haemolysis with renal failure, hepatic encephalopathy and even death have been reported. In our retrospective study of patients with acute viral hepatitis, the overall incidence of acute haemolysis was 4% (17/434). Only 53% (9/17) of them had G6PD deficiency. Patients with acute haemolysis had a significantly higher peak bilirubin level and required more prolonged hospitalization. Since hepatitis A virus vaccination, unlike hepatitis B virus vaccination, is not yet recommended for routine immunization, we suggest subjects who are G6PD-deficient should be vaccinated against hepatitis A. In endemic areas of hepatitis A virus infection, universal immunization remains the definitive answer.

Adolescent↗
PubMed1997

Acute viral hepatitis in Hong Kong: a study of recent incidences.

Acute hepatitis patients admitted to a referral centre from January 1995 through December 1995 were studied to determine the seroprevalence of the hepatitis viruses and related risk factors. Of the 434 patients with acute viral hepatitis, the episodes due to hepatitis A, B, C, D, and non-A, non-B, non-C, (non-ABC) were 214 (49.3%), 163 (37.6%), 7 (1.6%), 0 (0%), and 50 (11.5%), respectively. Acute hepatitis A and non-ABC hepatitis commonly occur in late spring and early summer and are probably related to the intake of shellfish and travel to endemic areas. Approximately 60% of cases of symptomatic hepatitis B infection were acute exacerbations of chronic infection. Sexual exposure was the single most important risk factor for acute hepatitis B infection. The rarity of acute hepatitis C and D might be related to the low rate of intravenous drug use in our locality. Hepatitis E virus probably contributed significantly to the cases of non-ABC hepatitis. Further studies are needed to establish the importance of various causative agents of acute hepatitis in Hong Kong.

Journal Article↗
PubMed1996

Association of self-limited cytomegalovirus colitis and shigellosis in an immunocompetent patient.

Cytomegalovirus (CMV) infection of the colon has been rarely reported in immunocompetent patients. Patients with severe acute illness or disseminated CMV infection have high mortality. In contrast, the patients with local injury of the colon due either to other gastrointestinal infections or to anal intercourse, who are otherwise healthy, usually have self-limited disease. The CMV infection is believed to be the bystander and may be treated conservatively. Concomitant CMV colitis and other gastrointestinal infections occur exclusively in immunosuppressed patients. We report, to our knowledge, the first case of co-infection of the colon with CMV and Shigella in an immunocompetent patient. The hypothesis is that the mucosal damage caused by Shigella infection may predispose the colon to secondary CMV invasion.

Colitis↗
PubMed1988

Alkaline intra-oesophageal pH and gastro-oesophageal reflux in patients with peptic oesophagitis.

Simultaneous 22-h measurements of intra-oesophageal and intragastric pH were made in 22 patients with symptoms of gastro-oesophageal reflux (7 with peptic oesophagitis, 8 with peptic oesophageal stricture, and 7 with peptic oesophagitis and previous partial gastrectomy) to determine whether alkaline intra-oesophageal pH is a consequence of alkaline gastro-oesophageal reflux. In the three groups of patients intra-oesophageal pH was greater than 7 for 16.9 +/- 4.8%, 27.5 +/- 7.6%, and 21.0 +/- 7.7%, respectively, of total recording time (p = NS). Intragastric pH greater than 7 was recorded only in the patients with partial gastrectomy (10.3 +/- 5.3% of recording time; p less than 0.01 in comparison with the other groups). Elevations of intra-oesophageal pH to greater than 7 never occurred during episodes of alkalinization of intragastric pH. These results suggest that refluxed fluids are unlikely to be the cause of alkaline intra-oesophageal pH in patients with peptic oesophagitis.

Adult↗
PubMed1982

Morphine enhances the release of 3H-purines from rat brain cerebral cortical prisms.

In vitro experiments have shown that 3H-purines can be released from 3H-adenosine preloaded rat brain cortical prisms by a KCl-evoked depolarization. The KCl-evoked release of 3H-purines is dependent on the concentration of KCl present in the superfusate. At concentrations of 10(-7) approximately 10(-5)M morphine did not influence the basal release of 3H-purines from the prisms, although it enhanced the KCl-evoked release of 3H-purines. The enhancement of KCl-evoked 3H-purine release by morphine was concentration-dependent and was antagonized by naloxone, suggesting the involvement of opiate receptors. Uptake studies with rat brain cerebral cortical synaptosomes show that morphine is a very weak inhibitor of adenosine uptake. Comparisons with dipyridamole, a potent inhibitor of adenosine uptake, suggest that this low level of inhibition of the uptake did not contribute significantly to the release of 3H-purine by morphine seen in our experiments. It is therefore suggested that morphine enhances KCl-evoked 3H-purine release by an interaction with opiate receptors and that the resultant increase in extracellular purine (adenosine) levels may account for some of the actions of morphine.

Adenosine↗