Biomedical subjects

W F Tsoi

Publications and source records attributed to W F Tsoi.

At least 19 recordsLinked to original sources

PubMed2001

Immune related genetic polymorphisms and schizophrenia among the Chinese.

Genetic association studies were conducted among two independent cohorts of Chinese ethnicity. The samples consisted of cases and unrelated controls, ascertained from Guangzhou, China, and Singapore. The studies were prompted by our earlier report of an association between schizophrenia and HLA DQB1 alleles (HLA DQB1*0602 and HLA DQB1*0303) in the Singapore sample. Polymorphisms of HLA DQB1 and flanking markers on chromosome 6p21.3 were investigated in the first part of the study. A significant negative association with HLA DQB1*0402 was detected in the Guangzhou sample (Odds ratio, OR 0.26, 95% confidence intervals, CI 0.1, 0.6; p < 0.02, corrected for multiple comparisons). Additional analysis of the Guangzhou and Singapore samples revealed associations at three other anonymous markers flanking HLA DQB1. In the second part of the study, three polymorphisms at the Interleukin-1 gene cluster (IL-1, chromosome 2q13-q21) were investigated in both cohorts, since associations with schizophrenia have been reported in another sample. Persuasive evidence for an association at IL-1 was not detected in either sample. Our results suggest a susceptibility locus for schizophrenia in the HLA region among the Chinese, but further clarification is necessary.

Adult↗

PubMed1996

Acute phase proteins in male Chinese schizophrenic patients in Singapore.

Changes in the concentration of some serum acute phase proteins (alpha 1-antitrypsin, alpha 2-macroglobulin, complement C3, haptoglobin, ceruloplasmin, transferrin, albumin and hemopexin), thyroxine-binding globulin, retinol-binding globulin, plasminogen and Gc-globulin are reported in two separate series of Chinese, male schizophrenic patients and healthy controls. In the first series, 41 healthy blood donors and 98 schizophrenic patients in different stages of the disease were investigated. The second series consists of a random sample of 50 acutely ill schizophrenic patients and a second group of healthy subjects. The concentrations of these serum proteins were measured by rocket immunoelectrophoresis in agarose gel. Increased levels of serum alpha 1-antitrypsin, alpha 2-macroglobulin, haptoglobin, ceruloplasmin, and thyroxine-binding globulin were observed in both series of patients when compared to their respective controls. Albumin, transferrin and retinol-binding protein levels were reduced in patients in both series. Hemopexin levels were increased only in the acutely ill patients while complement C3 was decreased in the chronically ill patients. No changes were observed in the Gc-globulin levels of all groups of patients. With the exception of complement C3, the changes observed in the levels of these serum proteins were appropriate for that of an acute phase response.

Acute Disease↗

PubMed1996

Insomnia in the community.

This study is the first to document the prevalence of insomnia in Malays and Chinese in a Singapore community. The overall rate of insomnia was low at 15.3% with females and Malays at higher risk. Patients with insomnia had significantly higher sleep latency, awakenings at night, as well as a report of not feeling fresh throughout the day. There was an association between insomnia patients with increased stress levels, especially at home, and a higher rate of co-morbid minor psychiatric disorder. However, most patients do not seek medical help, and even less resort to sleeping pills.

Adolescent↗

PubMed1995

Further evidence for an association between schizophrenia and the HLA DQB1 gene locus.

A case-control study was conducted in Singapore, in order to examine a proposed association between schizophrenia and the HLA DQB1 gene locus. The probands were male inpatients of Chinese ethnicity with schizophrenia (ICD-10 criteria, n = 102) and the controls were adults matched for gender and ethnicity (n = 111). Polymorphisms of the HLA DQB1 gene were examined using molecular typing by reverse dot-blotting (MTRB), a novel PCR based method. Among the patients, a positive association with HLA DQB1*0303 (odds ratio 4.46, C.I. 1.63, 12.17), as well as a negative association with HLA DQB1*0602 (odds ratio 0.22, C.I. 0.18, 0.83) was detected.

Adult↗

PubMed1995

A controlled double-blind trial of moclobemide and imipramine in the treatment of depression.

The aim of this study is to compare the antidepressant efficacy and side effects of moclobemide with imipramine (a standard antidepressant). Moclobemide is a reversible inhibitor of monoamine-oxidase-A (RIMA) with selectivity for the MAO type A isoenzyme. Thirty-two patients who met DSM-3R criteria for major depressive episode or dysthymia were randomly assigned to receive either moclobemide or imipramine in a double-blind prospective study. The results indicated no difference in antidepressive efficacy between the two drugs, but imipramine had more anticholinergic side-effects. Neither drug had significant effects on pulse rate, blood pressure, weight changes or blood chemistry. These results were confirmed by previous studies.

Adult↗

PubMed1995

Follow-up study of female transsexuals.

The aim of this study was to examine the social and sexual adjustments of Singapore female transsexuals following sex reassignment surgery. All female transsexuals who were operated on since 1989 were interviewed. There were a total of 17 transsexuals with a mean age of 29 years (range, 20 to 41 years) at the time of inception. Before surgery, all were single. After surgery, 6 out of 11 subjects had married abroad. Before surgery, some had problems with identity cards, passports, travelling and work which were resolved with surgery. They were better accepted and had better sexual adjustment after surgery. All were satisfied with the change in sex, but only 65% were satisfied with the surgery. Only 59% said they were willing to undergo the operation again. After a test case in court, they were unable to marry in Singapore. Their primary motive to undergo sex reassignment surgery was to become a member of the opposite sex, so that they could be recognised socially and legally.

Adult↗

PubMed1995

Fluoxetine in the treatment of depression in Asian (Chinese and Indian) patients in Singapore.

The aim of this paper is to study the efficacy and side-effects of fluoxetine. Fluoxetine is a specific serotonin reuptake inhibitor. Nineteen Asian (Chinese and Indian) patients who satisfied the DSM-3R criteria for major depressive episode were treated with fluoxetine 20 mg daily for 12 weeks. They were monitored two weekly. The results showed that during the period of treatment there was significant improvement in depressive symptoms and no serious side-effects. There were no significant changes in weight, temperature, blood pressure and pulse rate throughout the 12 weeks. This study showed that fluoxetine was well-tolerated and relieved the symptoms of depression effectively. Most of the results are supported by other studies.

Adult↗

PubMed1994

Lack of association of the dopamine D3 receptor gene polymorphism (BalI) in Chinese schizophrenic males.

Dopamine receptors have been implicated in the aetiology of schizophrenia and mode of action of antipsychotic drugs. A finding of increased homozygosity at the D3 receptor gene (BalI locus) has recently been reported. We have investigated the distribution of D3 receptor gene polymorphism (BalI) in 137 schizophrenic Chinese males and 125 healthy matched controls. The frequency of the rare allele was 0.30 and 0.31 in the patient and the control series. The distribution of genotypes in the patient series did not deviate significantly from Hardy-Weinberg equilibrium in the present series.

Adult↗

PubMed1993

Season, climate and suicide in Singapore.

In Singapore, an island city state in the tropics, climatic variables like sunlight, windspeed, temperature, rainfall and humidity are significantly correlated with subgroups of suicidal subjects such as Malays, young adults and youths. In the young age group (0-19 years) the relationship between meteorological factors and suicide appear to be greater than in the other two groups.

Adolescent↗

PubMed1993

First admission schizophrenia: clinical manifestation and subtypes.

This paper describes the clinical manifestations and classification of schizophrenia in Singapore. The subjects were all first admission to Woodbridge Hospital in 1975. They were followed up 5, 10 and 15 years later. There were 423 patients. Of these, 17% had no delusions or hallucinations and 14% presented with only negative and withdrawn behaviour. They can be subdivided into four subtypes: paranoid, hebephrenic, "catatonic" and simple. Follow-up study showed that the percentage of full, partial and no recovery remained the same at around 30%, 30% and 40% at the end of 5, 10 or 15 years. The paranoid subtypes had best outcome and the simple had the worst outcome. Bleuler's criteria and his subtypes of schizophrenia are accepted by most psychiatric textbooks. These criteria did not include behavioural disturbances which are the commonest manifestations in this study. Other follow-up studies confirmed that paranoid patients have the best long-term outcome.

Adult↗

PubMed1993

Follow-up study of transsexuals after sex-reassignment surgery.

INTRODUCTION: This is a follow-up study of 45 male and 36 female sex reassigned transsexuals. METHOD: The subjects were interviewed before and 1 to 8 years following sex reassignment surgery. RESULTS: When first seen the males (mean age 23.8 years) were slightly younger than females (mean age 24.9 years). The males had less education and held lower level jobs. They started their sexual life about 1-2 years earlier, but they cross-dressed 4-7 years later than the females. The follow-up results showed that 35% were married and all of them had no problems adjusting to their new life. The overall results were 56% very good and 44% good. There is no pre-operative variables that can predict good adjustments for female transsexuals. For male transsexuals, earlier age of transsexual manifestation was related to good post-operative adjustments. DISCUSSION: The females were less satisfied with the surgery, but they adjusted well as the males. The results were comparable with those from previous studies.

Adult↗

PubMed1992

The effects of centrally acting drugs on the EEG correlates of meditation.

The present study investigated the effects of three centrally acting drugs on the significant increase in the intermediate alpha frequency of the electroencephalogram (EEG) that accompanied meditation in a male volunteer. When compared to the EEG recorded before each of the three drugs was administered, naloxone tended to enhance the increase in the power of the intermediate alpha EEG (9.4-10.4 Hz), while diazepam tended to spread the increase to the slow (7.4-9.4 Hz) alpha EEG, and flumazenil was without much effect on the overall EEG pattern. However, these EEG changes when compared to similar changes obtained with saline administration were not significantly different from the latter. Thus, it is unlikely that the EEG correlates of meditation are causally related to the rise or fall of endogenous opioid peptides or benzodiazepinelike substances in the brain.

Adult↗

PubMed1992

Male and female transsexuals: a comparison.

The aim of this study is to describe and compare the characteristics of 320 male and 130 female transsexuals in Singapore. The subjects were given a semistructured psychiatric interview. The results showed that the males were slightly younger, had less education and held lower level jobs. Their occupational preferences were reversed. The male transsexuals started petting, sexual intercourse and having partners about one to two years earlier, but they cross-dressed four to seven years later. Both males and females were homosexually orientated. Other studies showed that late maternal age was associated with homosexuality, but not with transsexualism. These studies also confirmed that transsexualism had its onset in early childhood, and that cross-dressing was an early feature. The Singapore 'transsexuals went through a "homosexual" and a "transvestite" phase before they became a transsexual. Western transsexuals exhibited both homosexual and heterosexual behaviour, and some were married to the opposite sex partners. Male prostitution was reported in many studies.

Adolescent↗

PubMed1992

Predicting the outcome of schizophrenia ten years later.

A total of 407 new admissions to Woodbridge Hospital, Singapore in 1975 with a diagnosis of schizophrenia were examined 10 years later to determine which variables were predictive of outcome. Useful predictors were marital status, duration of illness and Feighner's diagnostic criteria. Fairly useful predictors were age, sex and educational status. Race, family history, suicidal behaviour, thought disorder, affective blunting, delusions and hallucinations were not useful for predicting long term prognosis.

Adolescent↗

PubMed1991

A 15-year follow-up study of Chinese schizophrenic patients.

A cohort of 330 Chinese schizophrenic patients below age 40 were interviewed 5, 10 and 15 years later to determine which variables could predict their outcome. There were 189 males (57%) and 141 females (43%). At the end of 15 years, 48 (15%) died (34 (10%) from suicide). At the end of 5, 10 and 15 years, the percentages of patients still able to work were 55%, 54% and 48%, and still receiving treatment were 45%, 41% and 45% respectively. The patients who were well in 1990 had fewer readmissions. The only variables that consistently predicted outcome was duration of illness. Age and education level were fairly useful in predicting outcome. Sex, family history, work status, marital status, alcohol, drug and suicide history, and such symptoms as thought disorder, affective blunting, depression, delusions and hallucinations were not useful in predicting outcome.

Adolescent↗

PubMed1991

Insomnia: drug treatment.

This is a review and update on hypnotics. Insomnia is a symptom of many underlying conditions which have to be evaluated before resorting to medication. Hypnotics are useful for short term treatment. The benzodiazepines have replaced the barbiturates which have a low therapeutic index. The action of benzodiazepines depends on their absorption rate, lipophilicity, half-life and metabolites. They induce sleep, prolonged sleep time and reduced night wakenings. They increase stage 2 sleep, and reduce stage 1, 3, 4 and REM (Rapid Eye Movement) sleep. Flurazepam, triazolam and midaolam are described. The benzodiazepines suffer from many unwanted effects which include tolerance, dependence, withdrawal symptoms, rebound insomnia, hang over effect, alteration of memory process and synergism with ethanol. The ideal hypnotic should be free from these drawbacks. Three new generation hypnotics quazepam, zopiclone and zolpidem are described. Drugs suitable for long term hypnotic medication include antipsychotics, antidepressants and antihistamines.

Antidepressive Agents↗

PubMed1991

Suicide and schizophrenia in Singapore--a fifteen year follow-up study.

This is a prospective follow-up study of 482 schizophrenic patients. At the end of 15 years, 41 had died of suicide and 30 had died of natural causes, giving a suicide rate of 567 per 100,000 per year. Suicide patients were significantly younger and experienced less delusion at the time of their first presentation. There were otherwise no significant differences in the socio-demographic or clinical variables between the suicide group and the controls (surviving patients). Jumping from height was the commonest method of suicide and our rate of suicide for schizophrenia is comparable to those reported in the literature.

Adolescent↗

PubMed1991

New admissions to a psychiatric ward in a general hospital.

A study of 343 new patients in the first psychiatric department in a general hospital in Singapore revealed a large proportion (40%, n = 137) of neurotic patients, especially neurotic depressives (n = 76). The next largest group is the non-organic psychoses 35% (n = 120), most of which were schizophrenic psychoses (n = 73). The other major diagnostic groups were adjustment or acute stress reactions, alcohol or drug dependence and personality disorders. The neurotic patients were generally older than the psychotic patients at the time of admission (p less than 0.02). More of them were married (62.7%) compared with the psychotics of whom 51.5% remained unmarried (p less than 0.02). Comparison between neurotic depressives and manic-depressive psychotics should have no difference in sex ratio and marital status. However, the duration of admission for the latter was longer.

Adolescent↗