Cytochrome P4501A1 polymorphism as a susceptibility factor for breast cancer in postmenopausal Chinese women in Taiwan

The incidence of breast cancer has been greatly increasing in Taiwan over the past two decades. Since cytochrome P4501A1 (CYP1A1) is involved in the metabolism of environmental carcinogens or oestrogen, we hypothesized that CYP1A1 genetic polymorphism may be a susceptibility factor for breast cancer. This hypothesis was evaluated in this case control study of 150 breast cancer patients and 150 healthy controls among Chinese women. Two CYP1A1 polymorphisms were studied, one containing a new Msp1 site and the other located in axon 7 and resulting in the replacement of an isoleucine (Ile) residue by a valine (Val). After simultaneously considering the known or significant risk factors for breast cancer, including the age of study participants, positive family history of breast cancer, early menarche (< or = 13 years), nulliparity and late first full-term pregnancy (> or = 30 years), hormone replacement therapy and smoking, the CYP1A1 Msp1 polymorphism was found to be a significant factor in determining the risk of breast cancer. The homozygous variant was the most susceptible genotype with an adjusted odds ratio of 1.98 (95% confidence interval (CI) = 1.01-3.99) compared with the non-homozygous variants (the homozygous wild-type and the heterozygous variant). In contrast, the CYP1A1 Ile/Val polymorphism was not significantly associated with breast cancer development (adjusted OR = 1.07, 95% CI = 0.64-1.78). Interestingly, the Msp1 polymorphism was especially significant in postmenopausal women, but not in premenopausal women. Further stratification analysis in postmenopausal women who were non-smokers and with no history of hormone replacement therapy showed the cancer risk due to the Msp1 variant to be more significant in women with early menarche. We conclude that CYP1A1 polymorphism is a susceptibility factor for breast cancer in postmenopausal Chinese women in Taiwan. Further study with a large sample size should be considered to address issues of interactions between CYP1A1 and other risk factors.

Association between N-acetyltransferase 2 (NAT2) genetic polymorphism and development of breast cancer in post-menopausal Chinese women in Taiwan, an area of great increase in breast cancer incidence

The incidence of breast cancer has increased greatly in Taiwan over the past 2 decades. Increased exposure to environmental carcinogens, including aryl aromatic amines, as a result of the economic boom, is suspected to be one factor contributing to this increase. The enzyme N-acetyltransferase 2 (NAT2) determines the rate of metabolism of aryl aromatic amines, and therefore the NAT2 slow acetylator genotype is associated with an increased risk of cancer. Our present case-control study of 150 breast cancer patients and 150 healthy controls in Taiwan was performed to explore the association between NAT2 genetic polymorphism and individual susceptibility to breast cancer. A structured questionnaire was used to collect relevant information regarding all known or suspected risk factors of breast cancer. The NAT2 genotype was determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay in 139 cases and 133 controls, and 28.8% and 21.1%, respectively, were found to have slow acetylator genotypes. Multivariate analysis, simultaneously considering other risk factors, including age at menarche, nulliparity or age at first full-term pregnancy, body mass index (BMI), hormone replacement therapy (HRT) and smoking status, showed that the NAT2 slow acetylator genotype was associated with an increased risk with borderline significance (Odds Ratio, 1.81; 95% CI, 1.01-3.31). Interestingly, this association was not significant in premenopausal women, but was significant in post-menopausal women. Further stratification of our study subjects based on different risk factor status showed that the increased risk for an NAT2 slow acetylator was more marked in post-menopausal women who were not using HRT or who had a lower BMI. Our findings suggest that NAT2 polymorphism is a susceptibility factor for breast cancer in Taiwanese women, and that NAT2-metabolized carcinogens are probably present in the environment and may be associated with induction of breast cancer.

Frequent aberration of the transforming growth factor-beta receptor II gene in cell lines but no apparent mutation in pre-invasive and invasive carcinomas of the uterine cervix

The type II transforming growth factor-beta (TGF-beta) receptor (RII) gene located at 3p22 plays an important role in regulating growth and differentiation of epithelium, including that of the uterine cervix. Loss-of-function mutations of RII have frequently been found in gastrointestinal cancers, with a replication-error (RER) phenotype characterized by the presence of microsatellite instability (MI). In this study, genomic PCR, SSCP and DNA sequencing were conducted to investigate the coding sequences of the RII gene in cell lines (n = 5) and tissues (n = 15) of squamous carcinomas of the uterine cervix. Intragenic deletions were noted in 2 of 5 cervical-cancer cell lines (ME180 and HeLa cells). However, no mutation, other than DNA polymorphisms, was found in 15 cervical cancers with either alleleic loss at 3p22 (n = 11) or MI (n = 4). Further analysis of squamous intraepithelial lesions (SIL) with (n = 12) or without (n = 4) MI for the (A)10 change, a prototypic mutation found in over 90% of RER-positive colon cancers, also showed no aberration. Our study concludes that the RII gene is frequently disrupted in cervical-cancer cell lines, but is rarely mutated in CC and SIL tissues, including those showing MI or alleleic loss at 3p22. The underlined mechanism of genomic instability in CC and SIL may thus differ from that of colorectal cancer. The allelic loss at 3p22-24 in CC does not involve the coding sequence of the RII gene. The non-coding sequence of RII or an unidentified gene may be responsible for it.

Monoclonality and surface lesion-specific microsatellite alterations in premalignant and malignant neoplasia of uterine cervix: a local field effect of genomic instability and clonal evolution

Invasive squamous carcinoma of the uterine cervix (CC) arises from sequential progression of low-grade (L) and high-grade (H) squamous intraepithelial lesions (SILs). In clinical observations, these lesions are frequently found as synchronous multiple foci. The nature and evolutionary mechanism of these lesions are largely unknown. We have performed allelotyping of three 3p markers (at 3p14, 3p22-24, and 3p25) on 22 LSILs and 15 HSILs microdissected from patients with multiple (n = 21) or uniform (n = 6) cervical lesions. The results were analyzed together with our previous allelotyping of 57 deeply invasive CCs. Loss of heterozygosity at one of the three markers was observed in 23%, 27%, and 31 % of LSILs, HSILs, and CCs, respectively. Frequent and early allelic loss was noted (in 30% of LSILs and 50% of HSILs) at 3p14, which may harbor tumor suppressor genes involved in early stages of cervical carcinogenesis. A high frequency of microsatellite alteration (MA) was found in LSIL (41%) and HSIL (67%) but not in CC (5.3%). In particular, MA was more frequently found in low-grade lesions in association with invasive cancers (75%, 6/8) than in those associated with SILs (29%, 4/14) (P < 0.05). Together with the finding of a monoclonal origin of premalignant and malignant cervical lesions, the present results allow us to propose a model of local field effect of genomic instability that progressively affects the clonal evolution of SIL of uterine cervix.

Sentinel surveillance for enterovirus 71, Taiwan, 1998

Outbreaks of enterovirus 71 have been reported around the world since 1969. The most recent outbreak occurred in Taiwan during April-July 1998. This hand, foot, and mouth disease epidemic was detected by a sentinel surveillance system in April at the beginning of the outbreak, and the public was alerted.

Allelic loss of the BRCA1 and BRCA2 genes and other regions on 17q and 13q in breast cancer among women from Taiwan (area of low incidence but early onset)

We have examined the role of the breast cancer susceptibility genes BRCA1 and BRCA2 and other loci in the vicinity of these 2 genes on the long arms of chromosomes 17 and 13 (17q and 13q) for the presence of genomic deletions in breast cancer among Taiwanese women. Breast cancer in Taiwan is particularly characterized by its low incidence rate and its early age of tumor onset. Twelve microsatellite markers spanning the region 17q12-21 and 8 microsatellite markers spanning the region 13q12-14 were analyzed for allelic loss or loss of heterozygosity (LOH) in 90 patients with primary infiltrating ductal carcinoma. Compared with the background LOH level (10-12%) estimated by LOH at 4 unrelated loci, 17 markers (11 at 17q and 6 at 13q) demonstrated a significantly increased frequency (21-42%) of allelic loss (p < 0.05). Subsequent construction of deletion maps based on LOH at these significant loci localized the 6 smallest regions of overlap, including those harboring BRCA1, BRCA2, the retinoblastoma gene and 3 novel regions (the 1st located approximately 0.5 to 1 cM telomeric to BRCA1, the 2nd centromeric to BRCA1 flanked by D17S857/D17S846 and the 3rd closely adjacent to BRCA2), suggesting sites of susceptibility genes. Allelic loss at BRCA1 and BRCA2 was specifically associated with poorly differentiated tumors.

HPV-associated cervical cancers show frequent allelic loss at 3p14 but no apparent aberration of FHIT mRNA

The genetic aberration involved in the loss of heterozygosity (LOH) at 3p14 has recently been attributed to the disruption of the FHIT gene in many cancers. This study analyzed HPV DNA and allelic status of 5 microsatellite markers spaning 3p13-3p25 in 57 cases of cervical cancer. With no homozygous deletion found in any case, a 39% overall frequency of LOH was noted. The presence of tumorigenic HPV DNA (91%) did not correlate with the allelic loss at any marker, including THRB (3p22-24) and D3S1228 (3p14) which were found with high LOH rates of 43% (12/28) and 37% (11/30), respectively. Further analysis of FHIT mRNA in 29 cancers by reverse transcription (RT)-PCR showed a full-length transcript in all cases. However, additional minor transcripts were occasionally observed in cancer tissues (9/29) as well as in normal tissues (12/31) by nested PCR of the RT products. Sequence analysis of these transcripts showed exclusive internal exon deletions, suggesting a source of minor splicing variants. No apparent mutation of the mRNA sequences was found in 8 transcripts examined, except for a silent polymorphism and a site of alternative splicing. The results suggest that, although frequently reported to be abrogated in several cancers, the mRNA of FHIT remains intact in cervical cancer. Other genes closely linked to FHIT may be responsible for frequent LOH at 3p14 observed in cervical cancer.

Surveillance of noise-induced hearing loss in Taiwan, ROC: a report of the PRESS-NHL results

BACKGROUND

To understand the extent of noise-induced hearing loss (NIHL) among noise-exposed workers, an ongoing public health surveillance system (Program to Reduce Exposure by Surveillance System or PRESS-NIHL) was established in Taiwan in 1995 to monitor the prevalence of NIHL.

METHODS

A total of 9,535 noise-exposed (> 85 dBA) workers were recruited into PRESS-NIHL from January to June 1995. Each received a periodic annual audiometric examination at 1 of 73 well-qualified audiometric examination rooms in accredited hospitals. Among those examined, 9,463 audiograms were acceptable for evaluation to determine the severity of NIHL at 4K Hz.

RESULTS

The mean hearing threshold at 4K Hz was 36.8 dB among male workers and 29.7 dB among female workers. The mean hearing loss at 4K Hz of male workers was higher than that of female workers. Among both men and women, hearing ability was found to decrease with increasing age. A total of 3,216 (34.0%) workers were found to have NIHL, with a hearing threshold higher than 40 dB (NIHL) in either one or both ears. Among these workers, 1,886 (19.9%) had mild NIHL (hearing threshold between 40 and 55 dB) and 1,330 (14.1%) had severe NIHL (hearing threshold above 55 dB) in either one or both ears. The proportion of severe NIHL was higher in certain industries, including construction (38.6%), ship building/repairing (19.2%), and weapon manufacturing (13.6%).

CONCLUSION

This surveillance system for NIHL is on of the first surveillance systems in the world established to monitor and control NIHL in the setting of industrial hygiene and occupational disease prevention. Our finding of a high prevalence of NIHL in certain industries will trigger immediate actions to control noise hazard, which in turn will provide better protection for noise-exposed workers.

Reducing lead exposure by surveillance system: the Taiwan experience

To evaluate the performance of a lead-surveillance program in reducing blood lead levels of workers in Taiwan, the authors conducted prospective and cross-sectional studies. A total of 6 905 workers, whose job titles indicated a direct exposure to lead in 1995, were included in this surveillance system. In this study, the authors compared the mean blood lead levels in 1994 (i.e., year of onset of surveillance) with that in 1995 in workers of major industries. Lead-exposed workers had a statistically significant decrease (i.e., average of 1.8 microg/dl) in blood lead levels during this 1-y period. The decrease was particularly obvious in individuals who worked in chemical products manufacturing, ship building/repairing, and plastic products manufacturing. The significant decreases in blood lead levels in these workers indicated that this surveillance system was effective. Surveillance, combined with control measures, might be an important means by which occupational lead exposure can be reduced.

Allelic loss at BRCA1, BRCA2, and adjacent loci in relation to TP53 abnormality in breast cancer

Cells with abnormal TP53 lose cell cycle checkpoints, resulting in genomic instability and neoplastic transformation. However, the evidence linking the tumor-specific targets of genomic alteration to an abnormal TP53 is limited. The present study tested the hypothesis that TP53 abnormalities are correlated with an increased frequency of deletion of breast cancer susceptibility loci (17q and 13q) in breast carcinomas. Tumors from 90 patients were examined for TP53 abnormality and loss of heterozygosity (LOH) at 11 loci on 17q (17q11.2-21) and 13q (13q12-14), including the loci for BRCA1 and BRCA2. A higher frequency of LOH was consistently found at 17q or 13q loci in tumors with an abnormal TP53. The increased LOH in relation to TP53 abnormality was statistically significant at the BRCA1, D17S588, and D13S267 loci (P < 0.05) but not at the locus for BRCA2 (P = 0.64). These observations imply a possible link between an abnormal TP53 and specific genomic deletions of breast cancer susceptibility loci, which may provide clues to the role of TP53 during breast tumorigenesis.

Genomic deletion and p53 inactivation in cervical carcinoma

The tumor-suppressor gene p53 acts as "the guardian of the genome", sensing DNA damage and initiating protective responses. To examine the hypothesis that p53 abnormality leads to increased genomic alterations in primary tumor cells, our study utilized 51 primary tumors of cervical carcinoma and 10 microsatellite markers. These markers were mapped to the short arms of chromosomes 3 and 5, covering the regions 3p13-25 and 5p15.1-15.3. Genomic deletion on 3p and 5p was correlated with genetic or epigenetic p53 inactivation pathways, including p53 mutation, genetic deletion of p53 and cervical infection with human papillomavirus. The proportion of abnormal p53 was found to be significantly higher in the cases exhibiting loss of heterozygosity (LOH) on 5p (p < 0.001), supporting the hypothesis of the presence of a p53-dependent pathway to cervical tumorigenesis. In contrast, however, LOH on 3p was found to be independent of p53 inactivation. A common deletion region, 3p22-24, was identified in 44% of informative cases, and genomic loss at this specific region was correlated with early tumorigenic onset and poor grade of tumor differentiation. Diversity within the patterns of genomic alteration in the same form of cancer suggests different sets of risk/tumorigenic profiles, molecular pathogenesis, as well as prognosis and outcome.

The epidemiology and surveillance of blood lead in Taiwan (ROC): a report on the PRESS-BLL project

To monitor the lead hazards in industries and to investigate the prevalence of elevated blood lead levels (BLLs) in lead-exposed workers, a lead surveillance system (PRESS-BLLs) has been established and operated in Taiwan, Republic of China, since July 1993. A cohort of lead-exposed workers who received a periodic annual health examination at 55 accredited hospital laboratories was constructed. A total of 9807 separate BLL measurements were reported to the system in 1994. The mean BLL was 15.8 micrograms/dl in male workers and 11.6 micrograms/dl in female workers. The mean BLL of lead-exposed workers was significantly (P < 0.05, z-test) higher than that of the general Taiwanese population (8.6 micrograms/dl for males and 6.7 micrograms/dl for females). In addition, the BLLs of 983 (10.0%) workers exceeded the regulatory action level (40 micrograms/dl for males; 30 micrograms/dl for females). The workplaces and homes of 57% of the workers with elevated BLLs were thoroughly investigated to determine the sources of lead contamination. These actions identified the causes of elevated BLLs and set up strategies to reduce workers' lead exposure. The establishment of this occupational lead surveillance system represents a method for monitoring of lead hazards from occupational and environmental settings to prevent lead poisoning. The information acquired from the system can help in the setting up of a priority of prevention and the development of control measures. It is also useful for further monitoring of changes in the BLLs of the lead-exposed cohort. The Health Department of Taiwan can use this information to evaluate the effectiveness of current industrial hygiene practice. Subjects with elevated BLLs have been medically treated and placed on long-term follow-up for sequelae.

Novel patterns of p53 abnormality in breast cancer from Taiwan: experience from a low-incidence area

Among 114 breast cancers in Taiwan, the prevalence of p53 mutation (22.8%) and p53 accumulation (38.3%) was similar to that in high-incidence areas. However, novel patterns of p53 abnormalities, including unique sites or types of mutation (i.e. an excessive proportion of G:C to A:T transition at CpG site), and accumulation of wild-type p53 either within nuclear or cytoplasmic compartments were noted. These may have relevance to breast cancer in Taiwan, a low-incidence area.

A study of the relationship between ambient lead and blood lead among lead battery workers

OBJECTIVE

To examine the relationship between ambient lead levels and blood lead levels and to explore the modifiers of the relationship between ambient lead and blood lead.

METHOD

A cross-sectional study was conducted in two lead battery factories. Blood lead level and ambient lead concentration were measured for each participant concurrently. A structured questionnaire was administered to collect sociodemographic characteristics and occupational history.

DESIGN

Biological and personal environmental measurements of 219 lead-exposed workers were analyzed by both simple and multiple linear regression. A regression model was selected for interpretation.

RESULTS

A high correlation (r = 0.62) between ambient lead (PbA) and blood lead (PbB) was observed. In addition, numerous factors, including age, sex, alcohol consumption, personal hygiene practice and type of lead exposure, were also found to influence blood lead levels. Although PbB was highly correlated with PbA, blood lead level may not be effectively lowered by reducing ambient lead level. Based on the regression coefficients, improvement of hygienic practice was more effective at lowering PbB than reducing ambient lead level. Good hygienic practice may be the preferential way to reduce lead exposure in current conditions.

CONCLUSION

Education of correct work practice may be more important than engineering control in the developing countries to lower blood lead levels in lead battery factories.

A case-control study of breast cancer in Taiwan--a low-incidence area

To investigate risk factors for breast cancer in Taiwan, a low-incidence area, a case-control study was conducted. This comprised 244 subjects with diagnosed and pathologically confirmed breast cancer (age range 20-80 years) and 450 female ophthalmology outpatients as controls. Univariate and multiple logistic regression analysis suggests that breast cancer in Taiwan is aetiologically similar to breast cancer in high to moderate-incidence areas. A family history of breast cancer appears to be the most important factor contributing to the risk of breast cancer (odds ratio = 4.69). The effect of reproductive hormones (represented by the years of history of menses in premenopausal women, odds ratio = 3.35; or the age at menarche in post-menopausal women, odds ratio = 2.67) plays a significant role in tumorigenesis. Breast feeding appears to be a particularly important protective factor in Taiwanese women (odds ratio = 0.57).

Olpitrichum tenellum as a biotrophic contact mycoparasite

Olpitrichum tenellum was shown to be a biotrophic mycoparasite, contacting but not penetrating its host hyphae by means of hook-shaped contact cells, which apparently absorb nutrients and growth factors from living host cells. The known hosts are Fusarium moniliforme, Alternaria alternata, and Cladosporium sp. The hyperparasite failed to grow in the absence of the host on glucose – yeast extract medium unless a water extract of the host was added. Keywords: Olpitrichum tenellum, mycoparasite, axenic culture, hyperparasite.

Establishment of a work-related diseases surveillance system in Taiwan, Republic of China

BACKGROUND

The occurrence of occupational illness and injury has been seriously underestimated in Taiwan, which subsequently contributes to difficulties in performing effective control of occupational hazards and implementing intervention programs for protecting workers.

METHODS

Based on the successful experience of the nationwide blood lead level surveillance program, the Department of Health, the Executive Yuan, Taiwan, Republic of China, has established a work-related diseases surveillance system. This government-administered system requests practicing physicians to report the suspected cases suffering from six categories of work-related disorders.

RESULTS

An occupational illness and injury surveillance program in Taiwan has been in operation since June of 1995.

CONCLUSION

Background information of work-related diseases obtained from this surveillance system will be useful for providing better management of available resources for occupational medicine, for preventing hazards, and for enforcing occupational diseases prevention programs. Our experience in establishing this surveillance system will be used in other countries and settings.

Microwave distillation-solid phase adsorbent trapping device for the determination of off-flavors, geosmin and methylisoborneol, in catfish tissue below their rejection levels

Described is a rapid microwave-mediated steam distillation device for determining two predominant off-flavor compounds, geosmin and methylisoborneol, in catfish tissue. A microwave on-time of 10 min is needed to efficiently remove these off-flavor compounds from the sample matrix and trap them on a solid phase adsorbent. A minimal amount of organic solvent is used to elute the trapped compounds. The extract is then analyzed by gas chromatography with ion trap detection in the selective ion storage mode. Detection limits in the sub-parts-per-billion range are obtained with this method.

Occupational lead exposure and blood pressure

BACKGROUND

To assess the relation between occupational lead exposure and elevated blood pressure with consideration of a possible confounding effect by noise exposure.

MATERIALS AND METHOD

Some 112 male and 110 female workers at two lead battery manufacturing factories were recruited for this 1992 study in Taiwan. Study participants received regular physical examinations, including standard measurement of blood pressure, body height/weight. Current occupational exposures to lead and noise were measured by a personal sampling scheme and instruments, and included individual ambient lead/noise exposure and blood lead level.

RESULTS

Among the 222 battery-factory workers, the average blood lead level was 56.9 +/- 25.5 micrograms/dl (mean +/- standard deviation), the average concentration of ambient lead exposure was 0.190 +/- 0.331 mg/m3, average noise exposure was 85.9 +/- 5.7 dBA, average systolic blood pressure was 125.2 +/- 14.9 mmHg, average diastolic pressure was 80.2 +/- 10.9 mmHg, and average mean arterial pressure was 95.2 +/- 11.1 mmHg. After considering all possible confounding variables, multivariate regression analyses demonstrated that current blood lead level was not a significant predictor for both systolic and diastolic blood pressures in either sex. In the final model, body mass index and years of working in the factory were the only two factors significantly associated with a change in blood pressure. No evidence of an effect of ambient lead exposure or noise exposure on blood pressure were found.

CONCLUSIONS

The present study suggests that short-term lead exposure, either ambient lead exposure or blood lead level, was not related to blood pressure change among workers who had been exposed at work to occupational lead. These results add to the body of evidence indicating that blood lead exposure does not adversely affect blood pressure.

Clinical response of tuberculous pericarditis to medical treatment: a retrospective survey

BACKGROUND

The prevalence of tuberculosis has declined with advanced antituberculous chemotherapy. However, the occurrence of subsequent constrictive pericarditis in tuberculosis has not reduced. Clinical progress of tuberculous pericarditis was investigated in patients receiving antituberculous chemotherapy.

METHODS

Thirteen patients with tuberculous pericarditis (11 men and 2 women aged 14 to 86 years [mean 60.0 +/- 17.0]), treated initially with antituberculous medications were analyzed. All patients underwent pericardiocentesis on admission following echocardiography.

RESULTS

Dyspnea was the most common clinical pictures. Bloody effusion fluids were noted in 10 patients. Moreover, the lymphocytic fluids were present in 78% of all patients. The neutrophilic fluids tended to have a bloody color, and there was progress to constrictive pericarditis even for those on anti-tuberculous chemotherapy. Five patients with subsequent constrictive pericarditis received pericardiectomy within 3.5 months of admission. Three of them received pericardiectomy later, despite pericardial window procedure.

CONCLUSIONS

Follow-up by echocardiogram is necessary within three months after commencing medical treatment because of the high incidence of progression constrictive pericarditis despite aggressive medical treatment. Pericardiectomy seems to be the only solution to the catastrophic outcome of constrictive pericarditis.

Alcoholism, hepatitis B and C viral infections, and impaired liver function among Taiwanese aboriginal groups

Viral hepatitis and alcoholism prevail in four major Taiwanese aboriginal groups. To study the relative importance of the acquisition of hepatitis B virus or hepatitis C virus infection and alcoholism to the presence of impaired liver function in these groups, the authors conducted a semistructured clinical interview for alcoholism and test for seromarkers for viral hepatitis among 993 cohort members enrolled in 1990-1992 in an ongoing prospective study (Taiwan Aboriginal Study Project). The subjects' blood specimens were tested for serum alanine aminotransferase/aspartate aminotransferase levels and for the presence of hepatitis B surface antigen and anti-hepatitis C virus antibody. The prevalence of a combination of an alanine aminotransferase level of > 35 IU/liter and an aspartate aminotransferase level of > 40 IU/liter, implying impaired liver function or advanced liver disease, was 4.3% overall. Univariate and multiple logistic regression analysis showed that, rather than chronic hepatitis B virus infection, hepatitis C virus infection and alcoholism were the two dominant risk factors that signalled the risk of liver damage among these Taiwanese aborigines. In addition, these two contributing factors were able to act synergistically to cause impaired liver function.

Prospective study of noise exposure during pregnancy on birth weight

To examine the effect of noise exposure during pregnancy on infant birth weight, a well-characterized cohort of 200 pregnant women in the first trimester participating in prenatal care clinics was followed throughout gestation (in Taiwan, 1991). Individual 24-hour noise exposure of all women was prospectively measured, and information regarding possible noise exposure from traffic and occupation was also obtained. Noise exposure during pregnancy was correlated with the birth weights of the women's babies. No association between personal noise exposure measured in decibels (less than 85 dBALeq during pregnancy) and birth weight was found. Possible occupational noise exposure (indicated by working in a manual job), traffic noise exposure (indicated by distance between the home and main streets), and a history of listening to amplified music and using personal listening devices during pregnancy also showed no effect on infant birth weight. Maternal weight, maternal weight gained during pregnancy, gestational age, and infant's sex were the four factors that correlated significantly with birth weight. The noise exposure experienced by women during pregnancy may not be great enough to affect their infants' birth weight.