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Biomedical subjects

H G Hwu

Publications and source records attributed to H G Hwu.

At least 37 records · Page 2Linked to original sources
PubMed1997

Suggestive evidence for linkage of schizophrenia to markers on chromosome 13 in Caucasian but not Oriental populations.

Previously we reported suggestive evidence for linkage of schizophrenia to markers on chromosome 13q14.1-q32. We have now studied an additional independent sample of 44 pedigrees consisting of 34 Taiwanese, 9 English and 1 Welsh family in an attempt to replicate this finding. Narrow and broad models based on Research Diagnostic Criteria or the Diagnostic and Statistical Manual of Mental Disorders, third edition, revised, were used to define the schizophrenia phenotype. Under a dominant genetic model, two-point lod scores obtained for most of the markers were negative except that marker D13S122 gave a total lod score of 1.06 (theta = 0.2, broad model). As combining pedigrees from different ethnic origins may be inappropriate, we combined this replication sample and our original sample, and then divided the total sample into Caucasian (English and Welsh pedigrees) and Oriental (Taiwanese and Japanese pedigrees) groups. The Caucasian pedigrees produced maximized admixture two-point lod scores (A-lod) of 1.41 for the marker D13S119 (theta = 0.2, alpha = 1.0) and 1.54 for D13S128 (theta = 0, alpha = 0.3) with nearby markers also producing positive A-lod scores. When five-point model-free linkage analysis was applied to the Caucasian sample, a maximum lod score of 2.58 was obtained around the markers D13S122 and D13S128, which are located on chromosome 13q32. The linkage results for the Oriental group were less positive than the Caucasian group. Our results again suggest that there is a potential susceptibility locus for schizophrenia on chromosome 13q14.1-q32, especially in the Caucasian population.

Asian People↗
PubMed1997

Lack of allelic association between 102T/C polymorphism of serotonin receptor type 2A gene and schizophrenia in Chinese.

Recent studies have reported an association between a 102T/C polymorphism of serotonin receptor type 2A gene (5-HT2A) and schizophrenia. In addition, an association was detected between a 102T/C polymorphism of the 5-HT2A receptor gene and drug response to clozapine in the treatment of schizophrenic patients. These studies suggest an important role of the 5-HT2A gene in schizophrenia. To study the possible involvement of the 5-HT2A gene in the pathogenesis of schizophrenia, a case-control association study was carried out in a Chinese population from Taiwan. No significant differences of genotype distributions, allele frequencies and homozygosity were detected between schizophrenic patients (n = 177) and nonpsychiatric controls (n = 98). When subjects were divided into subgroups according to sex, still no differences of allele frequencies or genotype distributions were noted between patients and controls. Our data do not support an allelic association between the 102T/C polymorphism of the 5-HT2A receptor gene and schizophrenia in Chinese population.

Alleles↗
PubMed1996

Identification of a BglI polymorphism of catechol-O-methyltransferase (COMT) gene, and association study with schizophrenia.

Several linkage studies suggested chromosome 22q11-13 may harbor susceptible genes for schizophrenia. Catechol-O-methyl-transferase (COMT), which is involved in the metabolism of catecholamines, was mapped to 22q11 and is considered a possible candidate gene for schizophrenia. Recently, we identified a polymorphic marker, a single nucleotide C insertion at the 3' untranslated region of the COMT gene, which obliterates a BglI site. Using this BglI polymorphism, we conducted a case-control association study in Chinese patients with schizophrenia. No significant differences of allele and genotype frequencies were noted between patients (N = 177) and controls (N = 99). When patients were subgrouped according to sex, no significant differences of genotype and allele frequencies were noted in either male or female patients compared to normal controls. Our results do not support an association between the BglI polymorphism of COMT gene and schizophrenia.

Catechol O-Methyltransferase↗
PubMed1996

Lack of association between TaqI A1 allele of dopamine D2 receptor gene and alcohol-use disorders in atayal natives of Taiwan.

Association studies between the A1 allele of the dopamine D2 receptor (DRD2) gene TaqI A polymorphism and alcoholism remain controversial. A recent study from Japan demonstrated that the A1 allele is associated with severe alcoholism in the Japanese population. We were interested in knowing if this association also exists in the Atayals of Taiwan, who were found to have a higher prevalence of alcohol-use disorders than the Han Chinese in Taiwan. Genotype and allele frequencies were determined in alcohol-abusing, alcohol-dependent, and nonalcoholic control Atayal natives in Taiwan. A1 allele frequencies in alcohol-dependent, alcohol-abusing, and normal control Atayals were 0.39, 0.42, and 0.39, respectively. No difference in A1 allele frequency was found among these three groups. Our data do not support the hypothesis that the A1 allele of the TaqI A polymorphism of the DRD2 gene increases susceptibility to alcohol-use disorders in the Atayals of Taiwan.

Alcoholism↗
PubMed1996

No association of dopamine D2 receptor molecular variant Cys311 and schizophrenia in Chinese patients.

A serine-to-cysteine mutation of dopamine D2 receptor at codon 311 (Cys311) was found to have higher frequency in schizophrenic patients than in normal controls in Japanese by Arinami et al. [1994: Lancet 343: 703-704]. The Cys311 allele was found to be associated with patients with younger age-of-onset, positive family history, and more positive symptoms. To investigate the possible involvement of Cys311 in schizophrenia in the Chinese population, 114 unrelated Taiwanese Chinese schizophrenic patients with positive family history and 88 normal controls were genotyped for Cys311. Four patients and 5 normal controls were heterozygotes of Ser311/Cys311; no homozygotes of Cys311 were identified in either group. The allele frequencies of Cys311 in Chinese schizophrenic patients and normal controls were 2% and 3%, respectively. No significant difference was detected between the two groups. Our results do not support the argument that the Cys311 allele of DRD2 poses a genetic risk for certain types of schizophrenia in Chinese populations.

Adult↗
PubMed1996

Excess mortality of psychiatric inpatients in Taiwan.

The 6-year mortality rate of a nation-wide cohort of Taiwanese psychiatric inpatients admitted during the 1-year period from 1987 to 1988 was examined via record linkage. The psychiatric care system in Taiwan is mainly hospital-based. Of the 13,385 patients studied (9309 men and 4076 women), 2039 (1720 men and 319 women) had died by the end of 1993. The standardized mortality ratio (SMR) in this sample (3.10 for men and 4.83 for women) was as high as those reported in western industrialized countries during the pre-deinstitutionalization era. We also examined the relationship between the excess mortality of patients and age, sex, causes of death, diagnostic categories, and length of hospital stay. In general, the SMR was greatest for the youngest age group, women, unnatural deaths, substance use disorders, and in the first year after admission. Although the main cause for the excess mortality was unnatural deaths, there was also an excess mortality due to natural causes across all diagnostic categories. Several recommendations for the improvement of psychiatric care in Taiwan are made on the basis of these findings.

Adolescent↗
PubMed1996

Month of birth and schizophrenia in Taiwan: effect of gender, family history and age at onset.

Schizophrenic patients have been shown to have a moderate excess of winter births in the areas where seasonal variations in weather are large. In this report, we examined the seasonality of schizophrenic births in Taiwan, which has a subtropical climate. Using nationwide hospitalization data (2429 male and 1320 female schizophrenic patients), we applied the life table method to compare the risk of schizophrenia among 12 cohorts of month-of-birth for males and females, respectively. Differences among the risks of the 12 cohorts were tested using the logrank test. The samples were further stratified by family history and age at onset. There was a significant association between the risk of being admitted as a schizophrenic and month of birth for both males and females. The cohorts born in November and January had the highest risks. After stratification, the association was significant only for non-familial, male, and early onset schizophrenic patients. The results indicate that seasonally varying factors might increase the risk of schizophrenia, especially in those without a family history of the disease. Men are more vulnerable to such factors than women, and the schizophrenics resulting from such insults tend to be early onset.

Adolescent↗
PubMed1996

Major depressive disorder in Taiwan defined by the Chinese diagnostic Interview Schedule.

The lifetime prevalence rate of major depressive disorder (MDD), as defined by the Chinese Diagnostic Interview Schedule, is 1.14% in Taiwan. This is significantly lower than the lifetime prevalence rates reported in Western studies and similar to other studies in the Chinese population using similar methods for assessing cases of MDD. Epidemiological data from 136 MDD cases were analyzed to provide possible explanations for this difference in lifetime prevalence rates. The low rate of broken families in Chinese culture, low comorbidity rate, and older age of onset of MDD may suggest a reality of low lifetime prevalence rates of MDD in Taiwan.

Adult↗
PubMed1995

Negative symptoms at discharge and outcome in schizophrenia.

BACKGROUND: The clinical significance in schizophrenia of positive and negative symptoms at discharge was assessed. METHOD: Of schizophrenic patients fulfilling DSM-III criteria, 113 were recruited for this study. Personal, social and psychopathological data were collected and all cases were followed up at one and two years after discharge. RESULTS: The presence of positive symptoms (64 cases), without concomitant negative symptoms, did not predict the follow-up social function and positive symptom score. Conversely, the presence of negative symptoms (31 cases) predicted worse social functioning (P < 0.05 to P < 0.005) and higher positive symptom scores (P < 0.01) at follow-up using MANOVA: Eighteen cases (15.9%) had neither positive nor negative symptoms and had the best clinical outcome. CONCLUSIONS: Negative, but not positive, symptoms assessed at discharge are an important predictor of poor outcome. In addition, negative symptoms may themselves expose a biological vulnerability to the presence of positive symptoms.

Adult↗
PubMed1995

Haloperidol plasma concentrations in Taiwanese psychiatric patients.

Haloperidol and reduced haloperidol are interconverted. The plasma concentrations of these two butyrophenones have been suggested to be important factors in determining the clinical effect of haloperidol treatment. The steady-state plasma concentrations of haloperidol and reduced haloperidol were measured in 322 Taiwanese schizophrenic patients using high performance liquid chromatography. The daily doses of haloperidol varied from 5 to 200 mg (mean +/- SD, 35.3 +/- 34.6 mg). There was a positive correlation between plasma concentrations and doses, following the equation: haloperidol concentration (ng/mL) = 0.88 x dose (mg/day)-1.66. However, the interpatient variation in haloperidol concentrations was up to ten-fold even in patients receiving the same dose (20 mg/day, n = 88). The expected values were about 10% to 50% higher than those reported in Caucasian patients. The plasma reduced haloperidol concentrations were significantly lower than, and correlated with, those of haloperidol in patients with haloperidol levels lower than 25 ng/mL. However, once haloperidol exceeded 25 ng/mL, reduced haloperidol levels rapidly elevated and appeared significantly higher than haloperidol levels. While haloperidol could reach its steady state in about 1 week, reduced haloperidol needed at least 4 weeks to do so. Haloperidol doses of less than 30 mg/day and plasma concentrations lower than 25 ng/mL are recommended for most Chinese patients.

Adult↗
PubMed1994

Low frequency of the ADH2*2 allele among Atayal natives of Taiwan with alcohol use disorders.

Genetic variation at two polymorphic alcohol dehydrogenase loci, ADH2 and ADH3, and at the polymorphic mitochondrial aldehyde dehydrogenase locus, ALDH2, may influence the risk of developing alcoholism by modulating the rate of elimination of ethanol and the rate of formation and elimination of acetaldehyde. Populations differ in allele frequencies at these loci. We determined the genotypes at all three of these loci in Atayal natives of Taiwan. The frequencies of ADH2*2, ADH3*1, and ALDH2*1 alleles (0.91, 0.99, and 0.95, respectively) were significantly higher among the Atayal than among a predominantly Han Chinese population from Taiwan. Among the Atayal, the group with alcohol use disorders (alcohol dependence and alcohol abuse) had a significantly lower frequency of the ADH2*2 allele (0.82) than those without alcohol use disorders (0.91). The ADH2*2 allele encodes the beta 2 subunit; isozymes containing beta 2 subunits oxidize alcohol faster in vitro than the beta 1 beta 1 isozyme encoded by ADH2*1. Thus, the simplest explanation for these data is that individuals with a beta 2 isozymes have a higher rate of ethanol oxidation, which is a deterrent to alcohol abuse and dependence in some individuals. The Atayal with alcohol use disorders also had a lower frequency of ALDH2*2 than the controls; this allele is known to be responsible for the alcohol-flush reaction among Asians, and thereby deters drinking.

Adult↗
PubMed1994

The cross national epidemiology of obsessive compulsive disorder. The Cross National Collaborative Group.

Data on the epidemiology of psychiatric disorders from different parts of the world using similar methods and diagnostic criteria have previously not been available. This article presents data on lifetime and annual prevalence rates, age at onset, symptom profiles, and comorbidity of obsessive compulsive disorder (OCD), using DSM-III criteria, from community surveys in seven countries: the United States, Canada, Puerto Rico, Germany, Taiwan, Korea, and New Zealand. The OCD annual prevalence rates are remarkably consistent among these countries, ranging from 1.1/100 in Korea and New Zealand to 1.8/100 in Puerto Rico. The only exception is Taiwan (0.4/100), which has the lowest prevalence rates for all psychiatric disorders. The data for age at onset and comorbidity with major depression and the other anxiety disorders are also consistent among countries, but the predominance of obsessions or compulsions varies. These findings suggest the robustness of OCD as a disorder in diverse parts of the world.

Adolescent↗
PubMed1993

Plasma homovanillic acid and treatment response in a large group of schizophrenic patients.

Plasma levels of homovanillic acid (pHVA), a metabolite of dopamine, were measured in ninety-five Chinese schizophrenic patients free of neuroleptics for at least four weeks. These patients were treated with classical antipsychotics for six weeks. Pretreatment pHVA was positively correlated with the subsequent clinical response (r = 0.408, p < 0.0001). Good responders (BPRS improvement > or = 50%, n = 47) had higher pretreatment pHVA levels than poor responders (BPRS improvement < 50%, n = 48) (15.7 +/- 8.4 ng/ml versus 9.9 +/- 3.7 ng/ml, p < 0.0001). A higher than 15 ng/ml pretreatment pHVA level was associated with a more consistent clinical response to the subsequent treatment. Using a pHVA level of 12 ng/ml as a demarcation point, 72% of patients (34 of 47) who had pHVA > or = 12 responded whereas 65% (31 of 48) who had < 12 did not respond (chi-square = 13.02, p < 0.0001). These results suggest that higher pretreatment pHVA levels may predict a better clinical response to antipsychotics. Based upon the pHVA findings, two hypothetical subtypes of schizophrenia are proposed.

Adolescent↗
PubMed1992

Comparison of haloperidol and reduced haloperidol plasma levels in four different ethnic populations.

1. Plasma haloperidol and reduced haloperidol concentration were measured in four ethnic populations. 2. Plasma samples were obtained under steady-state conditions and obtained 10-12 hours post bedtime dose and prior to the morning dose. 3. Haloperidol and reduced haloperidol plasma levels were assayed by radioimmunoassay and liquid chromatography. 4. A wide interpatient variability between haloperidol dose and plasma concentration was observed for each ethnic group. 5. The Chinese group differed from the other ethnic populations. 6. A nonlinear relationship was observed between haloperidol and reduced haloperidol plasma levels in each ethnic group. Further, the relationship of haloperidol to reduced haloperidol plasma levels differed for each ethnic group. These results suggest that various ethnic groups could metabolize haloperidol and reduced haloperidol differently.

Black or African American↗
PubMed1992

A typology of alcoholism in Taiwan aborigines: a study on evolving process of community cases.

Thirty-one habitual drinkers with a personal, familial, social complication were screened from a Taiwan aborigine community. Each was given an in-depth descriptive semistructured interview. The interview, recorded with audiotape, contained 4 aspects: (1) personal developmental history; (2) family structure and interaction; (3) developmental process and current state of drinking behavior, and (4) attitude toward drinking behavior. Based on the evolving process and current state of drinking behavior, three process patterns of alcoholism were defined: (1) social developmental type (67.7%); (2) deviant behavioral type (9.7%), and (3) special constitutional type (22.6%).

Adult↗
PubMed1991

Dose-dependent reduced haloperidol/haloperidol ratios in schizophrenic patients.

Plasma haloperidol (HAL) and reduced HAL (RHAL) concentrations were measured in 113 Chinese schizophrenic patients. Daily doses of HAL ranged from 8 to 65 mg. Samples were obtained under steady-state conditions and drawn 10-12 hours after the bedtime dose and before the morning dose. In all, 313 blood samples were collected. Multiple samples were obtained at the same doses in 63 patients and at two or three different doses in 31 patients. HAL and RHAL concentrations were assayed by high performance liquid chromatography. Interpatient variation in plasma HAL levels at a given dosage was up to sixfold. However, there was a high positive correlation between plasma levels and daily dosages with the equation of HAL plasma level (ng/ml) = 0.88 x dosage (mg/day) -0.56 or 46.0 x dosage (mg/day/kg) + 0.28. The expected values are about 15-55% higher than those obtained from non-Chinese patients as reported in the literature. The RHAL/HAL ratios were dose-dependent. The greater the dose used, the higher the ratio. An upper therapeutic limit of plasma HAL level is suggested to be 25 ng/ml, which can be achieved at dosages about 30 mg/day in most Chinese patients. Based upon the dose-dependent increase in RHAL/HAL ratios, the importance of RHAL in determining the therapeutic benefit of HAL treatment is discussed.

Adolescent↗
PubMed1991

Risk factors of alcoholism among Taiwan aborigines: implications for etiological models and the nosology of alcoholism.

The objective of this study was to explore possible risk factors of alcohol abuse (AA) and dependence (AD), as defined by DSM-III criteria, in Taiwan aborigines. The risk factors in a sample of 1555 Taiwan aborigines were analyzed by using the chi-square test and multivariate logistic regression statistics. The logistic regression showed that the risk factors of AD are being male, having relatively little education, being involved in a problem marriage, being a laborer, being part of a couple with a drinking problem, and having a positive family history of alcoholism. AA has the risk factors of ethnic subgroups dwelling in the main Taiwan Island, male, poor education, working people, and a drinking problem for the couple. Etiological models are proposed as social origins for AA, with interactional model for AD, in this aboriginal sample. Data on Chinese alcoholism is discussed, and a generalized hypothesis constructed that, for the same phenotypical subtype of alcoholism in different ethnic groups, the etiological models are different.

Adult↗