Ecological study of association between Helicobacter pylori infection and gastric cancer in Taiwan

The association between Helicobacter pylori infection and gastric cancer remains controversial. A community-based serosurvey was carried out in Taiwan to investigate the association. Serum IgG antibodies against Helicobacter pylori were examined in 728 subjects randomly selected from three townships with different gastric cancer mortality rates. The overall seropositivity of Helicobacter pylori was 54.7% (398/728) with no gender difference (males: 54.5%; females: 54.8%). The seroprevalence of Helicobacter pylori progressively increased with age in all three study townships. The age-specific seropositivity of Helicobacter pylori correlated well with age-adjusted gastric cancer mortality in the three townships. The difference in seropositivity was more profound in younger age groups. The ecological study in Taiwan suggests an association between Helicobacter pylori infection and gastric cancer. Helicobacter pylori infection in early childhood may be a key issue; in addition, a long induction time appears to be required for gastric carcinogenesis.

Abnormal peripheral microcirculation in seemingly normal subjects living in blackfoot-disease-hyperendemic villages in Taiwan

Blackfoot disease (BFD) is an endemic peripheral arterial disease confined to the southwestern coast of Taiwan. The cause of the disease has been ascribed to the high-arsenic artesian well water. The purpose of this study was to examine the possible association between the long-term exposure to artesian well water and the change in microvascular circulation in the absence of peripheral arterial insufficiency. A total of 45 men living in the BFD-hyperendemic villages and another 51 age- sex- body-mass index-matched men who lived in nonendemic villages nearby were recruited into this study. All subjects were free from peripheral vascular disease (resting ankle-brachial index > 1.00), clinical claudication, cigarette smoking, diabetes mellitus, hypertension, ischemic heart disease, cerebral infarction and obesity. Laser Doppler flowmetry was used to measure the peripheral microcirculation on the big toes both at 36 degrees C (basal perfusion, Pb) and after a hyperthermic test at 42 degrees C (Ph). The time required to reach Ph (T), and the average rate (R) of increase from Pb to Ph measured by (Ph-Pb)/T were also calculated. Results showed that those living in the BFD-hyperendemic area had a lower Pb [32.8 +/- 6.0 perfusion units (PU) vs. 67.0 +/- 4.3 PU, p < 0.001], a lower Ph (193.2 +/- 13.6 vs. 231.1 +/- 6.3 PU, p < 0.005), a longer T (3.04 +/- 0.19 vs. 1.31 +/- 0.08 min, p < 0.001) and a slower rate of increase from Pb to Ph (48.0 +/- 4.8 vs. 76.2 +/- 5.4 PU/min, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple risk factors associated with arsenic-induced skin cancer: effects of chronic liver disease and malnutritional status

In order to evaluate the prevalence and multiple risk factors of arsenic-induced skin cancer among residents in Taiwanese villages in which chronic arseniasis is hyperendemic, a total of 1571 subjects aged 30 or more years were recruited between September 1988 and March 1989. All of them were interviewed personally by a public health nurse using a structured questionnaire, and 1081 interviewed study subjects, including 468 men and 613 women, participated in physical examination, giving a participation rate of 68.8%. The overall prevalence of skin cancer was as high as 6.1%, showing an increase with age in both men and women. There was a significant dose-response relation between skin cancer prevalence and chronic arsenic exposure as indexed by duration of residence in the endemic area, duration of consumption of high-arsenic artesian well water, average arsenic exposure in parts per million (p.p.m.) and cumulative arsenic exposure in p.p.m.-years. Chronic carriers of hepatitis B surface antigen with liver dysfunction had an increased prevalence of skin cancer. Undernourishment, indexed by a high consumption of dried sweet potato as a staple food, was also significantly associated with an increased prevalence of arsenic-induced skin cancer. All these risk factors remained statistically significant in the multiple logistic regression analysis. Consistent with animal experiments, the findings imply that liver function and nutritional status may affect the metabolism of inorganic arsenic and the development of subsequent skin cancers.

Increased prevalence of hypertension and long-term arsenic exposure

To examine the association between long-term exposure to inorganic arsenic and the prevalence of hypertension, we studied a total of 382 men and 516 women residing in villages where arseniasis was hyperendemic. Hypertension was defined as a systolic blood pressure of 160 mm Hg or greater, a diastolic blood pressure of 95 mm Hg or greater, or a history of hypertension treated regularly with antihypertensive drugs. The long-term arsenic exposure was calculated from the history of artesian well water consumption obtained through standardized interviews based on a structured questionnaire and the measured arsenic concentration in well water. Residents in villages where long-term arseniasis was hyperendemic had a 1.5-fold increase in age- and sex-adjusted prevalence of hypertension compared with residents in nonendemic areas. Duration of artesian well water consumption, average arsenic concentration in drinking water, and cumulative arsenic exposure were all significantly associated with hypertension prevalence. The higher the cumulative arsenic exposure, the higher the prevalence of hypertension. This dose-response relation remained significant after adjustment for age, sex, diabetes mellitus, proteinuria, body mass index, and serum triglyceride level. The results suggest that long-term arsenic exposure may induce hypertension in humans.

Synthesis and characterization of oligomeric nido-carboranyl phosphate diester conjugates to antibody and antibody fragments for potential use in boron neutron capture therapy of solid tumors

Antibodies conjugated to oligomeric carboranyl compounds have a high potential as target species for boron neutron capture therapy (BNCT) of solid tumors. As a first step toward developing conjugates with BNCT capabilities, an oligomeric nido-carboranyl phosphate diester (Kane, R. R., Dreschel, K., and Hawthorne, M.F. (1993) J. Am. Chem. Soc. 115, 8853-8854), CB10 (10 nido-carboranes containing 90 boron atoms) with a pseudo-5'-terminal amino group, was conjugated to the anticarcinoembryonic antigen antibody T84.66 and its F(ab') fragment. The homobifunctional linker disuccinimidyl suberate (DSS) was coupled to CB10 via its 5'-terminal amino group followed by removal of excess linker with organic solvent extraction and conjugation with intact antibody. Similarly, the heterobifunctional linker, m-maleimidobenzoyl-N-hydroxysuccinimide (MBS), was coupled to CB10 and conjugated to the hinge region sulfhydryl of the F(ab') fragment of T84.66. The extent of reaction was monitored by the mobility shift of CB10-antibody conjugate on native polyacrylamide gels and the increased susceptibility of the CB10-antibody conjugate to staining with silver nitrate. CB10 was also labeled with radioiodine (131I) in a solid phase reaction with iodogen and used in double-label studies with 125I-labeled antibody. Although free CB10 bound very tightly to gel filtration media such as Sephadex G-25, the CB10-antibody conjugate passed through freely. After separation of CB10-antibody conjugate from free CB10 on Sephadex G-25, molar incorporations of CB10 were calculated. At a molar ratio of 10:1 (CB10:T84.66), greater than 90% of T84.66 and 30% of its F(ab)' fragment were conjugated to CB10.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous biliary stone removal under fluoroscopy

BACKGROUND

Bile duct stone is a common biliary tract disease in Taiwan. Surgery and choledochoscopy are the current methods of treatment. This is a retrospective review of 65 cases who were admitted with postoperative biliary residual stones, or cholangitis secondary to the biliary stones. Percutaneous biliary stone removals under fluoroscopy were attempted.

METHODS

Either a T-tube tract or percutaneous transhepatic cholangial drainage tract or both were used for stone removal. Angiographic superselective catheterization technique was applied for superselective cholangiography to identify the location of stones and to deliver basket and electrohydraulic lithotripsy probe to the site of the stones. Balloon dilation was applied for biliary stricture.

RESULTS

Most of the cases needed multiple sessions (four, on an average) to remove all stones. There were 52% of the cases who needed balloon dilation for associated biliary strictures, and 7.7% of the cases had residual stones at the end of the procedure, because of technical difficulties. Chills and fever, pancreatitis, hepatic arterial injury and perforation of the common bile duct were procedure-related complications. In follow-up studies, 15% of the cases had recurrent biliary stones and 4.6% of the patients expired from malignant biliary tumors.

CONCLUSIONS

Percutaneous biliary stone removal under fluoroscopy is beneficial for direct visualization of the location and number of the stones, and the architectural changes of the bile ducts. Superselective catheterization and balloon dilation were responsible for the high success rate (92.5%) here.

Arsenic-related Bowen's disease and paraquat-related skin cancerous lesions show no detectable ras and p53 gene alterations

We have investigated point mutations of codons 12, 13, and 61 in H-, K-, and N-ras oncogenes as well as p53 tumour suppressor gene exon 5 through exon 9 by PCR-SSCP analysis in 26 skin biopsy tissues from 16 arsenic-related Bowen's disease patients and 6 skin samples from 4 paraquat manufacturing workers. No mutation was found. These results are different from findings with UV associated skin cancers. Interestingly, a silent change at codon 27 of H-ras in one allele was detected in all 4 paraquat manufacturing workers and in 2 of 16 arsenic-related Bowen's disease patients. It is likely that the molecular mechanisms involved in arsenic and paraquat induced skin cancers differ from sunlight-related skin malignancies.

Correlations of chronic hepatitis B virus infection and cigarette smoking with elevated expression of neu oncoprotein in the development of hepatocellular carcinoma

To investigate the potential role of neu oncogene expression in hepatocarcinogenesis, a nested case-control study was conducted within a cohort of 9691 male adults in Taiwan. Blood samples of study subjects were collected during 1984-1986 and frozen at -30 degrees C until subsequent analysis. The neu oncoprotein level in the stored serum was measured by an enzyme-linked immunosorbent assay for 27 cases of newly developed hepatocellular carcinoma (HCC), 12 liver cirrhosis cases, and 40 healthy controls. The mean level of neu oncoprotein was significantly higher in HCC and liver cirrhosis cases than in controls. The risk of HCC increased significantly with increasing serum level of neu oncoprotein (trend test, P = 0.02). The proportion of subjects having an elevated serum level of neu oncoprotein, defined as a level greater than the mean level of all controls, was significantly higher among asymptomatic HBsAg carriers than noncarriers (P = 0.05), showing a multivariate-adjusted odds ratio of 4.0. Among HCC cases, a strong association was observed between cigarette smoking and elevated prediagnostic serum level of neu oncoprotein. The association remained highly significant (P = 0.017) even when adjustment was made for potential confounders. The multivariate-adjusted odds ratio of having an elevated serum level of neu oncoprotein, defined as a level greater than the mean plus 1 SD of control levels, for HCC cases who smoked more than 10 cigarettes a day was as high as 386.5 compared with the cases who smoked less than 10 cigarettes a day or nonsmoking cases. The results suggest that both HBsAg carrier status and cigarette smoking are related to the increased expression of neu oncogene, and cigarette smoking seems to play a significant role in the latter stages of hepatocarcinogenesis. There was no association between alcohol drinking and serum neu oncoprotein level.

Characteristics of patients with bleeding peptic ulcer requiring emergency endoscopy and aggressive treatment

OBJECTIVES

Patients with an ulcer and active bleeding or a nonbleeding, visible vessel are high-risk for further bleeding and should receive aggressive therapy. In this study, we tried to identify clinical parameters that predict these high-risk groups.

METHODS

Over a 7-month period, 16 clinical parameters were analyzed prospectively in 316 patients with bleeding peptic ulcer. A multivariate analysis was used to find the independent predictors for the high-risk patients.

RESULTS

A total of 114 patients (36%) was found to have a spurting hemorrhage (eight patients), oozing hemorrhage (27 patients), or a nonbleeding visible vessel (79 patients). Using an univariate analysis, a statistically significant predictor was the appearance of coffee ground fluid or blood from the nasogastric tube. This predictor also emerged as an independent factor (odds ratio, 0.4333; 95% confidence interval, 0.263-0.714).

CONCLUSIONS

Patients with bleeding peptic ulcer who have coffee ground fluid or blood from the nasogastric tube should receive an emergency endoscopy and aggressive treatment.

Mortality in diabetic patients after lower extremity amputations

This study evaluates the prognostic factors and causes associated with mortality in Chinese diabetic patients after lower extremity amputations. Medical records of all diabetic patients admitted to the National Taiwan University Hospital for leg amputations from 1982 to 1991 were reviewed. Demographic data, medical history, amputation levels and admission routines, including fasting plasma glucose, cholesterol, triglycerides, blood urea nitrogen, creatinine, urine protein and electrocardiograms, and bacterial culture done during the admission period were recorded. The vital status of the patients was followed by personal contact and mortality was ascertained from government computer records. The causes of death were recorded according to the death certificates. Univariate analysis and multivariate Cox's proportional hazards model were used to identify the prognostic factors associated with mortality. A total of 87 diabetic amputees, of whom 34 died, were found within this 10-year period. Cerebral infarction, infection and diabetes mellitus were the most commonly reported causes of death. Their calculated mortality was 5.95 times higher than the mortality rate of the age-comparable population in Taiwan. A history of hypertension and coronary heart disease were found to be the best indicators for predicting a fatal outcome with rate ratios of over two-fold. This study shows that post-amputational mortality is high in diabetic patients and that the major cause of death is cerebral infarction. The major cause of death in this study differs from that reported for Caucasians, for whom cardiovascular disease is the most important cause of death.

Assessment of immunocytochemical and histochemical stainings in the distinction between reactive mesothelial cells and adenocarcinoma cells in body effusions

BACKGROUND

The accumulation of fluid in body cavities is a common event in both neoplastic and non-neoplastic diseases. However, the distinction between cells of reactive process and those of malignancy in cytology is not always possible. It is especially difficult when reactive mesothelial cells and adenocarcinoma cells are encountered. The aim of the present study was to find out the most accurate or reliable immunocytochemical and histochemical stains to distinguish reactive mesothelial cells from adenocarcinoma cells, and to serve as a standard method in the future when dealing with equivocal cases.

METHODS

Ninety-nine cases of malignant epithelial effusion were collected from 755 cases of effusion obtained from 3 large body cavities in the past one-year period. Among them, 71 cases were histologically as adenocarcinoma and 13 cases as non-adenocarcinoma. The other 15 cases were carcinoma proved by image as well as clinical symptoms and signs. These 99 cases, plus 10 cases of non-malignant effusion, underwent immunocytochemical and histochemical stainings. Five common commercial antibodies used in this immunocytochemical study were epithelial membrane antigen (EMA), carcinoembryonal antigen (CEA), cytokeratin, vimentin and Leu-M1. The histochemical study included periodic acid-Schiff diastase (D-PAS) and mucicarmine stains.

RESULTS

The immunocytochemical study showed that EMA had a high frequency of positive staining with malignant epithelial cells and a negative staining with mesothelial cells. Cytokeratin always stained with malignant epithelial cells but it also stained with mesothelial cells. Almost all the proved adenocarcinomas expressed CEA which was not expressed in the proved non-adenocarcinomas. However, CEA occasionally stained mesothelial cells. Leu-M1 showed a low frequency of staining with the proved adenocarcinoma cells, but it did not stain proved non-adenocarcinoma cells and mesothelial cells. On the contrary, vimentin stained with all mesothelial cells but occasionally with malignant epithelial cells, especially the proved adenocarcinoma cells. In the histochemical study, both mucicarmine and D-PAS showed a low sensitivity but high specificity in detecting the adenocarcinoma cells.

CONCLUSIONS

No single marker is absolutely reliable to distinguish exfoliated, reactive mesothelial cells from adenocarcinoma cells in effusions. However, a panel of 3 antibodies containing EMA, CEA and vimentin, together with D-PAS and mucicarmine stains may help solve this problem.

Modeling of soliton-dragging logic gates with gain

Islam [Ultrafast Fiber Switching Devices and Systems (Cambridge U. Press, Cambridge, 1992)] and Islam and co-workers [in Digest of Integrated Photonics Research (Optical Society of America, Washington, D.C., 1992)] have proposed adding a lumped gain to soliton dragging logic gates in order to relax the timing constraints. Three reduced models are used to study the dragging gate with discrete gain and are compared with complete simulations. The most accurate of these methods, the variational method with chirp, predicts the time shift of the control pulse with an accuracy within 12% at all initial separations of the control and signal pulses. This method also predicts an increase by a factor of 2 in the timing window, a result that is consistent with complete simulations and experiments.

Age-period-cohort analysis of pulmonary tuberculosis mortality in Taiwan: 1961 to 1990

The specific aim of this study was to examine the effects of age, calendar period of death, and birth cohort in pulmonary tuberculosis (TB) mortality in Taiwan during the period 1961 to 1990. A log-linear Poisson regression model modified from the method of Osmond and Gardner was used and 79,881 deaths (58,025 males and 21,856 females) were included in the analysis. Birth cohort is the most significant predictor of pulmonary TB mortality according to the model. The earliest birth cohort from 1891 had a pulmonary TB mortality 17,327 and 6,186 times those born from 1986 for males and females, respectively. There was also a significant age effect. The youngest age group of zero to four years had a pulmonary TB mortality 7.10 and 5.87 times those for the age group of five to nine years for males and females, respectively. The oldest age group of 70 to 74 years had a risk of pulmonary TB mortality 2.89 and 1.88 times those for the five- to nine-year age groups for males and females, respectively. Parameters of the period factor showed a decreasing pulmonary TB mortality from 1961 to 1990 that was less significant than those of age or cohort. In addition to the improvement in medical measures that influenced the effect of calendar year on TB mortality, year of birth is an important determinant in the trend of TB mortality in Taiwan. The result shows that the major focus for TB mortality in Taiwan is in the age groups born between 1891 and 1921.

Effect of chronic cocaine on reproduction in female house mice

The effect of chronic cocaine exposure on the reproductive success of juvenile female house mice was studied. We followed two generations of female mice to examine the consequence of cocaine treatment on developmental and reproductive parameters such as weight gain, first estrus, impregnation, fertility, and maternal success. Twenty-two-day-old female mice were given cocaine at a daily total of 40 mg/kg body weight, delivered by two SC injections of 20 mg/kg each, until they were mated and inseminated by experienced males. The treatment attenuated weight gain and delayed puberty in the females but had no discernible effect on their pups. Administration of cocaine to lactating mothers decreased the weaning weight of their pups. Juvenile females previously nursed by mothers receiving cocaine and receiving 40 mg/kg cocaine daily themselves were impregnated at older ages than controls. Nevertheless, once these juveniles reached puberty, they mated successfully and their reproductive parameters did not differ from those of control mice. Thus, chronic cocaine treatment of juvenile female mice slows body growth and development but has little effect on the offspring produced later when they reached adulthood.

Atherosclerotic risk factors for peripheral vascular disease in non-insulin-dependent diabetic patients

The purpose of this study was to evaluate risk factors associated with peripheral vascular disease (PVD) in patients with non-insulin-dependent diabetes mellitus (NIDDM). A group of 100 patients (50 men and 50 women) aged 50 years or over with PVD and another group of 200 age-sex-matched patients (100 men and 100 women) without PVD were studied. The mean +/- standard error of ages for subjects with and without PVD were 60.8 +/- 0.6 years and 59.7 +/- 0.3 years, respectively. Doppler ultrasound was used to measure the systolic pressures of the brachial, posterior tibial and dorsal pedal arteries bilaterally. The diagnosis of PVD was made by an ankle-brachial index (ABI) < 0.90 and the diagnosis of non-PVD by an ABI > 1.00. The association of PVD with diabetic duration, body mass index (BMI), cerebral infarction (CI), coronary heart disease (CHD), proteinuria, diabetic retinopathy, neuropathy, hypertension, and cigarette smoking was evaluated. In addition, biochemical data including fasting plasma glucose, hemoglobin (HD)Alc, cholesterol, triacylglycerol, high- and low-density lipoprotein cholesterol, uric acid, blood urea nitrogen (BUN) and creatinine (Cr) were studied. In univariate analysis, PVD was associated with an increased level of systolic blood pressure (SBP), BUN and Cr, cigarette smoking, CI, CHD, proteinuria and retinopathy. In stepwise logistic regression analysis, the level of SBP, cigarette smoking and CI remained statistically significant. The log odds of PVD could be expressed as: -2.834 + 0.013 (SBP in mmHg) + 0.577 (cigarette smoking) + 1.320 (CI). PVD is the result of aggregation of atherosclerotic risk factors; among those factors noted in this study, SBP, cigarette smoking and CI are important.

A nested case-control study on association between hepatitis C virus antibodies and primary liver cancer in a cohort of 9,775 men in Taiwan

Most studies on the association between antibodies against hepatitis C virus (anti-HCV) and primary liver cancer (PLC) were limited to case-series, or cross-sectional case-control studies leaving a controversy on causal temporality. A nested case-control study on 38 newly-developed PLC patients and 152 matched controls selected from a cohort of 9,775 men in Taiwan recruited from September, 1984, to February, 1986, was carried out to examine the relation between HCV infection and PLC. Case-control pairs were matched on age (+/- 1 year), residence, and the date at recruitment. Serum samples collected from study subjects at the initial recruitment were examined for anti-HCV by enzyme immunoassay and hepatitis B surface antigen (HBsAg) by reverse passive hemagglutination assay combined with radioimmunoassay. History of cigarette smoking, alcohol consumption, vegetable consumption, vegetarian habit, and chronic liver diseases were also obtained through standardized interviews according to a structured questionnaire at the recruitment. After adjusting for HBsAg status and other risk factors, the anti-HCV was significantly associated with the development of PLC showing a multivariate-adjusted relative risk of 88.24. The results suggest that HCV infection may play an important role in the etiology of human PLC in Taiwan.

Correlates and predictive models for blood pressure values in residents of two communities in Taiwan

Factors predicting systolic blood pressure (SBP) and diastolic blood pressure (DBP) were extensively studied in residents aged 18 years and above from 10 villages in two Taiwanese communities. In women, the associated factors identified included age, body mass index, waist/hip ratio (not selected as a factor for DBP), plasma uric acid, plasma chloride, urinary sodium/creatinine ratio, urinary calcium/creatinine ratio, education level, ancestral origin, parental hypertension status, and marital status. In men, the factors were age, body mass index, plasma triglyceride concentration, urinary sodium/creatinine ratio, smoking status, alcohol drinking status, parental hypertension status (not selected for DBP), and marital status (not selected for DBP). The degree of BP variation which could be significantly explained by the measured factors differed between SBP and DBP, and differed between men and women: 18% in men and 39% in women for SBP variation; 15% in men and 27% in women for DBP variation. Factors other than those included in the models should be explored, particularly for men. This study identifies, for Chinese populations, predictive factors of BP well-known in Western societies (BMI, urinary sodium, plasma uric acid, alcohol consumption) and factors less emphasized in other studies (plasma triglyceride and marital status). A positive association between BP and urinary Na, a lack of association between BP and urinary K, and opposite findings in the relationship between BP and the education level for men (positive relation) and women (negative relation) are worth noting.

Clinicopathologic study of 208 patients with early gastric cancer in Taiwan: a comparison between Eastern and Western countries

To investigate whether there are any differences between the clinicopathologic characteristics of early gastric cancer (EGC) patients in Eastern and Western countries, 208 Taiwanese patients with EGC were reviewed between 1964 and 1992. The incidence of cancer has increased slightly over the 29-year period. Men were diagnosed with EGC frequently than women, and their mean age was 56 years. Epigastralgia (58.2%) was the most common symptom, whereas 5.8% of cancers were incidentally detected by endoscopy. Physical signs and laboratory tests were of limited value in making the diagnosis. Endoscopy was a better diagnostic aid than radiology. Tumours were frequently located in the lower third (53.2%) and middle third (43.3%) of the stomach. Cancers of the elevated type (17.8%) were less frequent than the depressed type (82.2%). Type IIc (31.2%) was the most common macroscopic type. The frequency of mucosal carcinoma (51.0%) was similar to submucosal carcinoma (49.0%). Mucosal carcinoma had less lymph node metastases (3.1%) than submucosal carcinoma (12.2%; P < 0.05), with an overall frequency of metastases of 7.5% (14/186). The 5-year survival rate was 90.8%. The clinicopathologic characteristics of EGC in Taiwan were similar to those of Western countries and other Eastern countries. Improvement of diagnostic examinations and endoscopic surveillance of asymptomatic subjects may lead to early diagnosis and thus ensure a more favourable outcome.

Discrimination of airborne radioactivity from radon progeny

Naturally occurring radon and thoron progeny are the most interfering nuclides in the aerosol monitoring system. The high background and fluctuation of natural radioactivity on the filter can cause an error message to the aerosol monitor. A theoretical model was applied in the simulation of radon and thoron progeny behavior in the environment and on the filter. Results show that even a small amount of airborne nuclides on the filter could be discriminated by using the beta:alpha activity ratio instead of gross beta or alpha counting. This method can increase the sensitivity and reliability of real-time aerosol monitoring.

Ten-year clinical analysis of diabetic leg amputees

The clinical characteristics of 234 amputees admitted to the National Taiwan University Hospital during a 10-year period were analyzed. Diabetes mellitus accounted for 37.2% (87 cases) of the amputations and was the most commonly associated disease. Malignancy was the second cause of amputation (16.2%). Traffic accidents and atherosclerosis (without diabetes mellitus) each accounted for about 13% of the amputations. Below-knee amputation was the most commonly performed procedure among the diabetics, while above-knee, below-knee and ray amputations were roughly equally performed among non-diabetic patients. Reamputations were done in 16 diabetic and 12 non-diabetic patients, mostly within a short period of time after the first amputation. Four of the diabetic reamputations and nine of the non-diabetic reamputations were performed on the same side as the first amputation. The mean +/- standard error of admission days and total expenses for each episode of amputation were 36.2 +/- 2.7 days and 116.5 +/- 1.7 thousand New Taiwan dollars for the non-diabetics and 41.3 +/- 4.0 days and 134.0 +/- 16.0 thousand New Taiwan dollars for the diabetics, respectively. We concluded that: 1) diabetes mellitus was the main cause of amputation; 2) diabetes mellitus was associated with a higher rate of reamputations of the contralateral legs; and 3) a multidisciplinary foot-care team is essential for the management of lower leg amputations.

Seroprevalence and associated risk factors of Helicobacter pylori infection in Taiwan

In order to estimate the seroprevalence and explore multiple risk factors associated with Helicobacter pylori infection among residents in Taiwan, a total of 823 subjects randomly selected from one metropolitan precinct and three townships were studied. Serum samples were tested for IgG antibodies against H. pylori by enzyme-linked immunosorbent assay using commercial kits. The overall seropositive rate was 54.4% with no gender difference (53.7% for males and 55.2% for females). There was a significant geographical variation with the highest seropositive rate (63.4%) in rural area where aborigines live, and where the age-adjusted stomach cancer mortality is highest and the lowest (40.5%) in urban area where Hakkas live, and where the stomach cancer mortality is lowest. There was also an increasing seropositive rate with age from 27.1% for children younger than 10 years old to 72.3% for adults aged more than 40 years old. Age-specific seroprevalence in Taiwan is higher than that in United States, France, Finland and Australia, and lower than that in Algeria, Ivory Coast and India. No association with H. pylori seropositivity was observed for drinking water source, toilet type, family income and educational level after adjusting for age and area. A dose-response relation between H. pylori seropositivity and sibship size was found. Upon further analysis of seroprevalence for children aged 16 or younger, a positive association was observed for birth order and current number of children in family; there was also an inverse association for current number of adults in family. The early childhood transmission among siblings seems an important determinant of H. pylori seropositivity in Taiwan.

Seroepidemiology of rubella virus infection among female residents on the offshore islets of Taiwan

Although rubella vaccination was introduced in Taiwan in 1986 several outbreaks have occurred since then. In order to examine the epidemiological characteristics of rubella virus infection on the offshore islets of Taiwan, the Pescadore (Penghu) Islets and Orchid (Lan-Yu) Islet, the female residents of the islets aged 2-83 years were chosen as the study population. A community-based survey was carried out in three townships randomly selected through stratified sampling. Serum specimens of 677 healthy girls and women randomly sampled from the study areas were screened for the rubella antibody by a latex agglutination test and confirmed by a solid-phase immunoassay. A total of 415 subjects were antibody-positive giving a prevalence of 61.3%. The mean +/- standard deviation of rubella IgG index was 2.84 +/- 0.32. The seropositive rate increased with age in all three townships. The age pattern indicated that the regular ten-year rubella epidemic cycle ceased after 1978. A higher prevalence was observed in Orchid Islet than in the Pescadores. The overall seronegative rate was 48.7% (191/392) for females less than 20 years of age and 32.0% (48/150) for reproductive women between the ages of 20 and 35 years. With such a high proportion susceptible among females of child-bearing ages on the offshore islets of Taiwan, a mass rubella vaccination programme should be enforced in order to prevent possible outbreaks of congenital rubella syndrome in the future.

p53 gene mutations in brain tumors in Taiwan

Mutations of the p53 gene were investigated in 116 surgically removed primary brain tumor tissues by PCR-SSCP analysis. The mutations did not follow a random distribution among the various different subtypes, but occurred in 21.0% (13/62) of astrocytomas, 13.0% (3/23) of oligodendrogliomas and 35% (7/20) 35% (7/20) of PNETs. No mutation was found in the ependymomas. The majority of mutations identified in this study were G:C to A:T or C:G to T:A transitions (56.0%, 14 of 25) and occurred most frequently (56.0%, 14 of 25) at sites of CpG dinucleotides. Interestingly, codon 158 is a new hot spot which occurred with a frequency of 16.0% (4 of 25) in the samples analyzed.

Age-period-cohort analysis of lung cancer mortality in Taiwan, 1966-1990

The specific aim of this study was to examine the effects of age, calender period of death, and birth cohort in lung cancer mortality in Taiwan over the period 1966-1990. A log-linear model modified from the method of Osmond and Gardner was used. Age is the most important predictor of lung cancer mortality according to the model. The oldest age group of 75-79 years old had a lung cancer mortality 185.3 and 79.2 times those for the youngest age group of 30-34 for males and females, respectively. There was also a significant cohort effect. The birth cohorts at the highest risk of lung cancer death were those born around 1931 for males and 1921 for females. A leveled off or declined trend of lung cancer mortality was observed for more recent cohorts. Parameters of the period factor showed an increasing lung cancer mortality from 1966 to 1990. In addition to the adverse effect of cigarette smoking, dietary and environmental factors should be taken into consideration in interpreting the results.

[Family influence on cancer screening participation in seven communities in Taiwan]

Cancer is the leading cause of death in Taiwan. Since there is no definitive method for cancer prevention, early detection play a major role in fighting cancer. Factors that affect people's willingness to participate cancer screening have been discussed widely except for those relating to the family. The family's role in motivation & influencing its members to participate in an invited cancer-screening program was studied in seven Taiwanese communities. 5% of participants in each area for both genders were chosen by stratified random sampling, and matched with teice-informed nonparticipants who were chosen by sex, age, and neighborhood. By means of a home visit and structured questionnaire, 729 of the 987 eligible cases were interviewed (73.9%). The main findings were that the response was higher among people with higher education, nonsmokers, and those who felt the scheduled time and place of attendance was suitable and convenient. Moreover, in the 6 variables related to family (family structure, family life cycle, cancer history in family and friends, family APGAR, family support about health problems, and family's opinion about cancer screening), the last 4 variables were found to be significantly related by chi-square analysis to the attendance. Finally, a logistic regression analysis adjusted by age, sex, education, smoking habits, time available and traffic factors was used to analyze how family factors affect attendance. The result was cancer history in family and friends (odd ratio = 2.42) and family's encouragement (odd ratio = 1.85) had a positive association.

Seroepidemiology of human T-lymphotropic virus type I infection among intravenous drug abusers in Taiwan

In order to assess seroprevalence of human T-lymphotropic virus type I (HTLV-I) infection among intravenous drug abusers in Taiwan, serum samples were collected from 858 male study subjects. Antibodies against HTLV-I (anti-HTLV-I) in sera were tested by enzyme-linked immunosorbent assay and confirmed by Western blotting. The overall prevalence of anti-HTLV-I (2.3%) in drug abusers was significantly higher than that in the general population in Taiwan with a relative risk of 4.9, but it was only slightly higher than that in prostitutes (1.9%). There was a statistically significant increase in prevalence with age. Drug abusers engaged in prostitution had a significantly higher prevalence (18.2%) than those who were not (2.1%). No significant association with anti-HTLV-I positivity was observed with marital status and educational level. Tatooed abusers had an increased prevalence (2.7%) compared with the untattooed (1.4%). Drug abusers tattooed before 1980 had a significantly higher prevalence (3.5%) than those tattooed after 1980 (0.8%). Anti-HTLV-I prevalence was higher for those who had been blood transfused (4.5%) than untransfused abusers (2.0%).

Ingested inorganic arsenic and prevalence of diabetes mellitus

To examine the association between ingested inorganic arsenic and prevalence of diabetes mellitus, in 1988, the authors studied 891 adults residing in villages in southern Taiwan where arseniasis is hyperendemic. The status of diabetes mellitus was determined by an oral glucose tolerance test and a history of diabetes regularly treated with sulfonylurea or insulin. The cumulative arsenic exposure in parts per million-years was calculated from the detailed history of residential addresses and duration of drinking artesian well water obtained through standardized interviews based on a structured questionnaire and the arsenic concentration in well water. The body mass index was derived from body height and weight measured according to a standard protocol, while the physical activity at work was also obtained by questionnaire interviews. Residents in villages where the chronic arseniasis was hyperendemic had a twofold increase in age- and sex-adjusted prevalence of diabetes mellitus compared with residents in Taipei City and the Taiwan area. There was a dose-response relation between cumulative arsenic exposure and prevalence of diabetes mellitus. The relation remained significant after adjustment for age, sex, body mass index, and activity level at work by a multiple logistic regression analysis giving a multivariate-adjusted odds ratio of 6.61 and 10.05, respectively, for those who had a cumulative arsenic exposure of 0.1-15.0 and greater than 15.0 ppm-year compared with those who were unexposed. These results suggest the chronic arsenic exposure may induce diabetes mellitus in humans.

Seroprevalence study of Helicobacter pylori infection in patients with gastroduodenal diseases

To investigate Helicobacter pylori (H. pylori) infection in subjects with and without gastroduodenal diseases in Taiwan, IgG antibodies to H. pylori were examined in 136 healthy volunteers, 101 patients with non-ulcer dyspepsia, 122 gastric ulcers, 119 duodenal ulcers, and 161 gastric adenocarcinomas. The seropositivity was highest in duodenal ulcers (87.4%) (p < 0.001, as compared to healthy volunteers), followed by gastric ulcers (76.2%) (p < 0.01, as compared to healthy volunteers), but similar among gastric adenocarcinomas (60.3%), healthy volunteers (58.8%), and patients with non-ulcer dyspepsia (55.5%). Higher acquisition of H. pylori in younger patients with duodenal and gastric ulcers suggests a strong association with H. pylori. No ulcer characteristics, including number, location, and activity, were significantly statistically associated with the seropositivity of H. pylori in gastric and duodenal ulcers. Similarly, the location, extent of invasion, and histology of gastric adenocarcinoma was not significantly statistically associated with the seropositivity of H. pylori.

Mutational analysis of delta antigen: effect on assembly and replication of hepatitis delta virus

Hepatitis delta virus requires a helper function from hepatitis B virus for packaging, release, and infection of hepatocytes. The assembly of large delta antigen (HDAg) is mediated by copackaging with the small surface antigen of hepatitis B virus (HBsAg), and the assembly of small HDAg requires interactions with large HDAg. To examine the molecular mechanisms by which small HBsAg, large HDAg, and small HDAg interact, we have established a virion assembly system in COS7 cells by cotransfecting plasmids encoding the small HBsAg, the small HDAg, and large HDAg mutants. Results indicate that sequences within the C-terminal 19-amino-acid domain flanking the Cxxx isoprenylation motif are important for the assembly of large HDAg. In addition, a large HDAg mutant bearing extra sequences separating the C-terminal 19-amino-acid domain from the common regions of the small and large HDAgs is capable, like the wild-type large HDAg, of copackaging with small HBsAg. The ability of assembly is also demonstrated for a large HDAg mutant from which nuclear localization signals have been removed. Furthermore, a cryptic signal within the N-terminal 50 amino acid residues other than the putative N-terminal coiled-coil structure and a subdomain between amino acid residues 50 and 65 of the large HDAg are important for the assembly of small HDAg as well as the trans-dominant negative regulation of large HDAg in hepatitis delta virus replication.

Influence of smoking on Graves' disease with or without ophthalmopathy and nontoxic nodular goiter in Taiwan

The effect of smoking habits on Graves' disease with or without ophthalmopathy and nontoxic nodular goiter has been discussed for more than 10 years in Western countries, but there are no published reports from Oriental countries, where the prevalence of cigarette smoking among women is lower than in Western women. The purpose of this study was to determine the relationship between smoking and Graves' ophthalmopathy, Graves' disease without ophthalmopathy, and nontoxic nodular goiter in Taiwan. The study included 349 patients with thyroid disease from endocrinologic clinics, including 116 patients with Graves' ophthalmopathy (92 women, 24 men), 108 patients with Graves' disease but without ophthalmopathy (96 women, 12 men), and 125 patients with nontoxic nodular goiter (114 women, 11 men). Information on smoking habits at the time of onset of the disease was obtained by a self-administered structured questionnaire. Since women generally smoke less than men, female and male smoking habits were compared separately with those of controls matched with patients on the basis of age. There was a significantly higher prevalence of cigarette smoking in women with Graves' ophthalmopathy and nontoxic nodular goiter than for healthy female controls, showing an odds ratio of 8.15 and 6.48, respectively, despite a lower prevalence of cigarette smoking in Taiwan (7.6% in women with Graves' ophthalmopathy, 6.1% in women with nontoxic nodular goiter) than in the West (64.2% in women with Graves' ophthalmopathy, 30% in women with nontoxic nodular goiter). Men in these three disease groups and women with Graves' disease without ophthalmopathy showed no significant association with cigarette smoking.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of the human cytomegalovirus 65K tegument phosphoprotein in insect cells by baculovirus vectors

The gene encoding the 65K tegument phosphoprotein (pp65) of human cytomegalovirus (HCMV) was cloned into pAc373 to construct a recombinant baculovirus (Acpp65-3) expressing pp65 in insect Sf9 cells. A baculovirus that carried a fragment of the gene, corresponding to the first 442 amino acids of pp65, was also developed, using vector pVL941 (Acpp65-2). Recombinant proteins migrating in SDS-polyacrylamide gels with an M(r) of either 65K (Acpp65-3) or 56K (Acpp65-2) were detected in cytoplasmic and nuclear extracts of infected Sf9 cells. The 56K and 65K proteins were recognized in immunoblots by monoclonal antibodies (MAbs) 28-77 and 28-19, which are specific for pp65. The insect cell-expressed antigens were also analysed on Western blots using MAbs 4D11, 7D2, 8E3, 7B4 and 8E10, which recognize the HCMV antigen GP66 in immunoblots. The truncated pp65 antigen of Acpp65-2 was reactive with MAbs 4D11, 7D2, 8E10 and 7B4. The protein expressed by Acpp65-3 reacted only with MAb 4D11. The data proved that the epitopes recognized by MAbs 4D11, 7D2, 8E3 and 7B4 mapped in the region of pp65, comprising amino acids 1 to 442, and also that GP66 and pp65 represent the same HCMV antigen. Immunoblot analysis of human sera from individuals seropositive for HCMV showed that the recombinant pp65 products were as antigenic as the native 65K phosphoprotein produced in HCMV-infected human embryonic fibroblasts.

Increased sister chromatid exchange frequency in peripheral lymphocytes of nasopharyngeal carcinoma and cervical cancer patients

The specific aim of this study was to compare the frequency of sister chromatid exchange (SCE) in peripheral lymphocytes using it as a biomarker of integral exposures to carcinogens in 14 untreated newly-diagnosed nasopharyngeal carcinoma (NPC) patients, 16 untreated newly-diagnosed cervical cancer patients, and 30 healthy controls matched with patients on age, sex, cigarette smoking and alcohol drinking. Peripheral lymphocytes were cultured in RPMI 1640 medium containing 20% fetal calf serum and 6 microM phytohemagglutinin. After culture for 24 hours, 20 microM 5-bromo-2-deoxyuridine was added into the medium. Colcemid solution was further added after 70 hours. Harvested cells were stained with Hoesch 33258, illuminated, and restained with Giemsa. The SCE frequency was scored by two readers independently and blindly. The results showed a significantly increased SCE frequency in lymphocytes for NPC patients (mean +/- standard error = 14.7 +/- 1.7 SCEs/cell) compared with their matched controls (10.1 +/- 0.7 SCEs/cell) and for cervical cancer patients (12.0 +/- 0.9 SCEs/cell) compared with their matched controls (9.2 +/- 0.7 SCEs/cell). These results suggest that NPC and cervical cancer patients have a higher integral exposures to both viral and chemical carcinogens than matched controls.

Effect of cocaine on the production of puberty-accelerating pheromone by male mice

This study examined whether chronic cocaine exposure could reduce reproductive fitness of adult male mice by interfering with their production of the puberty-accelerating pheromone, an androgen-dependent urinary pheromone that accelerates puberty in juvenile female mice. Administered at a high dose of 60 mg/kg body weight/day, cocaine caused mortality, body weight loss, and suppression of circulating testosterone during the first week of treatment. However, at 40 mg/kg/day, it resulted in little adverse effect on these parameters. Animals showed habituation to repeated cocaine exposure by regaining part of the lost weight and reelevating suppressed testosterone level at later stages of treatment. Urine samples collected from animals receiving 60 mg/kg cocaine daly for 2 weeks lost the puberty-accelerating effect. However, neither a 3-day treatment of the same dose nor a lower dose of 40 mg/kg reduced the effectiveness. The diminished effect of cocaine-treated male mouse urine might reflect lowered testosterone levels with a lag of 10 to 15 days, similar to that of castrated male mouse urine. These results indicate that cocaine has no direct effect on the production of priming pheromone, and its metabolites in the urine did not affect the response of juvenile females to the pheromone.

Family factors affecting the outcome of tuberculosis treatment in Taiwan

Despite the progress of tuberculosis (TB) control, the failure of treatment mainly due to non-adherence to medical recommendations remains a major obstacle to the eradication of this disease in both industrialized and developing countries. We interviewed 397 active pulmonary TB cases (274 males and 123 females) in Taiwan and followed up their treatment outcomes. No significant differences were found between any of the groups of either sex on TB cognition scores. Positive correlations between cognition scores and compliance scores, between cognition scores and family apgar scores, and between compliance scores and family apgar scores were noted in this study. In males, the complete treatment group had a higher compliance score (mean +/- standard deviation = 13.45 +/- 2.80) and family apgar score (22.44 +/- 2.29) than the incomplete treatment group (11.61 +/- 3.21 and 14.77 +/- 3.92, respectively). In females, the complete treatment group had a higher cognition score (65.99 +/- 6.75), compliance score (13.65 +/- 2.55) and family Apgar score (22.78 +/- 2.30) than the incomplete treatment group (62.05 +/- 6.91, 11.70 +/- 3.04 and 14.84 +/- 3.80, respectively). In the logistic regression analysis, both the family Apgar score and compliance score were significantly related to the TB treatment outcomes. The subjects with a family Apgar score higher than 20 had a chance to complete treatment as high as 72-fold (95% confidence interval = 31.7-164.0) that of those with a score less than 20.(ABSTRACT TRUNCATED AT 250 WORDS)

Helicobacter pylori infection in early and advanced gastric adenocarcinoma: a seroprevalence study in 143 Taiwanese patients

The association between gastric adenocarcinoma and Helicobacter pylori infection remains controversial. A seroprevalence study of Helicobacter pylori infection in 143 patients with gastric adenocarcinoma and a control group of 823 subjects randomly selected from four areas in Taiwan, was carried out to elucidate the association. The overall seropositivity of Helicobacter pylori in gastric adenocarcinoma patients (62.9%) was higher than in controls (54.4%), but the difference was not statistically significant (p > 0.05). The seropositivity of early gastric adenocarcinoma (61.5%) was not significantly different from that of advanced gastric adenocarcinoma (63.2%). Various demographic factors such as sex, blood type, cigarette smoking, tumor histology and location were not associated with the seroprevalence of Helicobacter pylori. The age-specific seroprevalence of Helicobacter pylori tended to be higher in younger patients and decreased after the age of 60 years in gastric adenocarcinoma, in contrast to a stepwise increase of seropositivity in controls. This suggests that Helicobacter pylori infection in early life may be a contributory factor in gastric carcinogenesis.

Helicobacter pylori infection in a randomly selected population, healthy volunteers, and patients with gastric ulcer and gastric adenocarcinoma. A seroprevalence study in Taiwan

To investigate the association of Helicobacter pylori and gastric ulcer and adenocarcinoma, IgG antibodies against H. pylori were examined in 823 randomly selected subjects, 92 healthy volunteers, 117 patients with gastric ulcer, and 148 with gastric adenocarcinomas in Taiwan, where the prevalence of gastric adenocarcinoma is high. The seropositivity of this population in Taiwan was 54.4%. Gastric ulcer patients had a higher seropositivity (83.8%) than healthy volunteers (62.0%) and gastric adenocarcinoma patients (62.2%) (P < 0.001). Gender difference, blood type, and habit of smoking were not associated with the seroprevalence in any study groups. Gastric ulcer coexistent with duodenal ulcer had a higher seropositivity (94.7%) (P < 0.05). The seropositivity of H. pylori in gastric adenocarcinoma patients was higher than in healthy volunteers only in younger age and was not associated with histologic type, invasion, and location of major tumors. The results reemphasize the association of H. pylori infection with gastric ulcer but not with gastric adenocarcinoma in Taiwan.

Secular changes in the clinical manifestation and pathologic pattern of early gastric cancer in Taiwan

To investigate whether there has been a time trend change in the percentage of early gastric cancer to gastric cancer and the clinicopathologic features of early gastric cancer in Taiwan, we reviewed 208 patients diagnosed between 1964 and 1992. Patients were divided into group I from 1964-1980 (n = 106) and group II from 1981-1992 (n = 102). The percentage of early gastric cancer among total gastric resections in group II (14.7%) did not differ from group I (12.7%; p = 0.19). Epigastralgia (58.2%) was the most common complaint; 11.8% (12/102) of cancers in group II were incidentally detected by endoscopy. Endoscopy provided a better diagnostic aid than did radiology. Tumors were frequently located in the antrum (50.9%) with a mean diameter of 2.8 cm. Small cancers of less than 1 cm in diameter were more prevalent in group II (37.3%) than group I (10.4%; p < 0.001). Cancers of the elevated type (17.8%) were uncommon in contrast to depressed ones (82.2%; p < 0.001). The frequency of mucosal carcinoma (51.0%) was similar to submucosal carcinoma (49.0%). Mucosal carcinoma had less lymph node metastases (3.1%) than submucosal carcinoma (12.2%; p < 0.05) with an overall frequency of metastases of 7.5% (14/186). The five-year survival rate of group I (91.7%) was not statistically different from group II (94.6%). We concluded that, except for the symptomatology and the ability to diagnose, the clinicopathologic features of early gastric cancer were similar between these two time periods. Repeated investigation of suspicious lesions and endoscopic screening on asymptomatic subjects may increase the rate of detection and thus guarantee a favorable outcome.

Amplification and overexpression of cyclin D1 in human hepatocellular carcinoma

Amplification of the chromosome 11q13 region occurs in several types of human cancer including esophageal, breast, lung, bladder and hepatocellular carcinoma (HCC). The gene cyclin D1 maps to this region in close proximity to two proto-oncogenes hst-1 and int-2. We previously demonstrated that cyclin D1 was not only amplified but also overexpressed in about 30% of human esophageal cancers. To investigate the role of cyclin D1 in human hepatocellular carcinoma (HCC), DNA from 30 HCC and 5 control liver tissues from Taiwan and also the HCC cells lines HepG2 and Hep3B, were examined for amplification of the cyclin D1 gene. A 3 to 20-fold amplification was found in 4 of the 30 (13%) HCC samples but not in any of the 5 control tissues or the 2 cell lines. Immunohistochemical analysis of cyclin D1 indicated overexpression of this protein in tumors that displayed gene amplification. Weak or negative staining was observed in the other HCC samples as well as in the control tissues and cell lines. These data suggest that increased expression of cyclin D1 may play an important role in the development of a subset of human HCC, perhaps by perturbing normal control of the cell cycle.

Current seroepidemiology of rubella virus infection among female residents in Taiwan

To examine the epidemiological characteristics of rubella virus infection on Taiwan Island and in Orchid and Pescadore islets, a community-based survey was carried out in 19 townships and metropolitan precincts randomly selected through stratified sampling. Serum specimens of 4,770 healthy girls and women randomly sampled from study areas were screened for the rubella antibody by passive latex agglutination testing and confirmed by enzyme-linked immunosorbent assay. A total of 2,934 subjects were antibody positive, giving a prevalence of 61.5%. The mean +/- standard deviation of rubella IgG index was 2.51 +/- 0.37. The seropositive rate increased with age in all residential areas and ethnic groups. The age pattern indicated that the regular 10-year cycle of rubella epidemic was no longer existent after 1978. A higher prevalence was observed in the eastern island and Orchid Islets compared with other areas. The highest seropositive rate was found in Orchid Islets. The overall seronegative rate was 62.9% for females < 20 years of age and 36.9% for women between the ages of 20 and 29 years. With such a high susceptible density among girls and women of child-bearing ages as well as the endemicity of rubella virus infection in Taiwan, mass vaccination against rubella should be enforced in order to prevent possible future outbreaks of the congenital rubella syndrome.

Risk factors of lung cancer by histological category in Taiwan

The relationship between various risk factors and lung cancer by different histological types was evaluated in a case-control study. A total of 72 adenocarcinoma patients and 59 squamous/small cell lung cancer patients, 262 hospital controls and 262 neighborhood controls were interviewed. Multiple conditional logistic regression analyses revealed that occupational exposures to asbestos and working as a cook were significant risk factors associated with adenocarcinoma of the lung. An inverse association between incense burning and the adenocarcinoma was noted. The squamous and small cell carcinomas of the lung were significantly associated with cigarette smoking, passive smoking exposure from friends at entertainment activities, the use of coal as cooking fuel, history of prior tuberculosis and chronic bronchitis, and occupational exposures to asbestos.

Endoscopic examination in patients with acquired immunodeficiency syndrome: Taiwan experience

Endoscopic experience in patients with acquired immunodeficiency syndrome (AIDS) has rarely been reported in Taiwan. We present our experience in 9 AIDS patients (8 male and 1 female, age from 26 to 63 years) with 12 examinations. The risk factor of these patients were bisexual in 3, homosexual in 2, hemophilia in 1, drug abuse in 1, and paid-sex in 2. Odynophagia or dysphagia was the major complaints. Oral ulcers or/and thrush were noted in 8 patients. Endoscopic findings included negative (6/12), candidiasis (3/12), erosions (1/12), ulcers (1/12) and ulcer scar (1/12) in esophagus; negative (8/12), gastritis (1/12), erosions (1/12), ulcers (1/12) and Kaposi's sarcoma (1/12) in stomach; and negative (11/12) and duodenitis (1/12) in duodenum. Patients with esophageal candidiasis always had oral thrush. Dysphagia was highly correlated with positive endoscopic findings in esophagus. It is important for an endoscopist to identify clinical symptoms and to examine patient's oral cavity before an endoscopic examination. The endoscopist must keep himself from being infected by exposure to contaminated blood and secretion and avoid dissemination of this horrible disease by undisinfected instruments.

Urinary aflatoxin levels, hepatitis-B virus infection and hepatocellular carcinoma in Taiwan

Using a urinary immunoassay to measure aflatoxin metabolites, we examined the associations between exposure to aflatoxin, chronic infection with the hepatitis-B virus (HBV) and background rates of hepatocellular carcinoma (HCC) mortality in a cross-sectional survey of 250 residents from 8 areas of Taiwan with a 4-fold variation in age-adjusted HCC mortality. Specimens of fasting blood and overnight urines were used to determine HBV carrier status and excretion of aflatoxin in the subjects surveyed. While the prevalence of hepatitis-B virus carriers showed moderate variability, there was a 500-fold range in urinary aflatoxin levels. Mean log-transformed levels of aflatoxin metabolites were similar in males and females and in HBV carriers and non-carriers. In the 8 townships, HCC mortality correlated positively with both area HBV carrier prevalence and mean aflatoxin levels. The primary analyses, however, were conducted at the individual level. Each subject's aflatoxin level was treated as the response variable in a multiple regression model, and the corresponding sex-specific area HCC rate was included as a predictor along with the individual's carrier status, age and sex; alcohol consumption and cigarette smoking were also considered. In these analyses, a significant association was again observed between the marker of aflatoxin exposure and the background rate of HCC mortality. In females, the slope of the regression line was somewhat steeper in HBV carriers, but this pattern was not seen in males and formal testing yielded no statistically significant evidence of an interaction. Our findings are consistent with the hypothesis that aflatoxin plays an independent role in hepatocellular carcinoma in Taiwan.

Radon exhalation rate from various building materials

Solid-state alpha-track detectors using cellulose nitrate films were used to measure the radon exhalation rates from building materials. The radon flux emitted from the surface of the building material was measured by placing an inverted cup on the top of the building material. Cellulose nitrate film was placed within the cup. Tracks due to alpha particles from radon that migrate from the building material into the air space in the cup were registered on the cellulose nitrate film. The films were etched in a solution consisting of 10(-3) m3 2.5 N NaOH solution. A spark counter or microscope was used to record the tracks appearing on the cellulose nitrate film. The average exhalation rate of radon was obtained by means of a simple mathematical approach that can be used to estimate the maximum possible radon concentration in a closed room due to building materials alone. Infiltration and ventilation effects were excluded in this work. This new technique and simple approach can be used to establish the data base for average radon exhalation rates from all available building materials and walls or floors. The maximum indoor radon concentration can be estimated from the measured average radon exhalation rate by using this simplified model.

Functional motifs of delta antigen essential for RNA binding and replication of hepatitis delta virus

The functions of delta antigens (HDAgs) in the replication of hepatitis delta virus (HDV) have been identified previously. The small HDAg acts as a transactivator, whereas the large HDAg has a negative effect on replication. To understand the molecular mechanisms involved in the control of HDV replication, we have established a replication system in Huh-7 cells by cotransfecting a monomeric cDNA genome of HDV and a plasmid encoding the small HDAg. We demonstrate that a leucine repeat in the middle domain of the small HDAg is involved in binding to the HDV genome and transactivation of HDV replication. When the leucine repeat was disrupted by a substitution of valine for leucine at position 115, both RNA-binding and transactivation activity of the small HDAg were abolished. In contrast, the binding and transactivation activities were not affected when Leu-37 and Leu-44 of the small HDAg were replaced by valines. In addition, small and large HDAgs can interact with each other to form protein complexes in vitro. The complex formation that may lead to the trans-dominant negative regulation of large HDAg in HDV replication is mediated by a cryptic signal located between amino acid residues 35 and 65 other than the putative N-terminal leucine zipper motif. Furthermore, an extra 21-amino-acid extension near the N terminus converts the small HDAg into a pseudo-large HDAg with negative regulation activity of HDV replication even though the extreme C-terminal residue is unchanged.