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Biomedical subjects

R S Lin

Publications and source records attributed to R S Lin.

At least 73 records · Page 4Linked to original sources
PubMed1991

A non-invasive monitoring of exposure to an industrial organic solvent, dimethylformamide.

A urinary metabolite, N-hydroxymethyl-N-methyl formamide (DMF-OH) was measured by a colorimetric method in Wistar and Sprague-Dawley rat urine after a single exposure to N,N-dimethyl formamide (DMF). A linear relationship was found between the total excretion of DMF-OH in 2 days versus the exposure ranging from 1 to 20% of the LD50 of DMF i.e. 47.2 to 944 mg DMF per kg b. wt. This is proposed to be a non-invasive biological method for monitoring exposure to DMF.

Animals↗
PubMed1990

Age-period-cohort analysis of pancreatic cancer mortality in Taiwan, 1971-1986.

Interest has recently emerged about the increasing trend of pancreatic cancer mortality in Taiwan, particularly in the elderly. The mortality data of pancreatic cancer over the period 1971-1986 for males and females aged 40-84 in Taiwan were analysed using a log-linear Poisson model to examine the effects of age, calendar period of death, and birth cohort. This age-period-cohort model provides a summary guide for the reading and interpretation of cancer mortality trends. Age is the strongest factor in predicting pancreatic cancer mortality according to the models; the oldest age group 80-84 years old has 14.5 times the risk of the youngest age group 40-44. The cohort effect is also of particular interest because the generation at greatest risk for pancreatic cancer in both sexes, is the one born between 1917 and 1926, and a declining trend is observed thereafter for more recent cohorts. Parameters of the period factor show no observable trend before 1975, followed by a significantly increasing risk in the subsequent time period. However, the drop of pancreatic cancer mortality over all age groups between 1985-86 is puzzling and a further study to monitor the secular trends in the following years is warranted.

Adult↗
PubMed1985

Occupational exposure to electromagnetic fields and the occurrence of brain tumors. An analysis of possible associations.

To explore the association between occupation and the occurrence of brain tumor, an epidemiologic study was conducted using data from the death certificates of 951 adult white male Maryland residents who died of brain tumor during the period 1969 through 1982. Compared with the controls, men employed in electricity-related occupations, such as electrician, electric or electronic engineer, and utility company serviceman, were found to experience a significantly higher proportion of primary brain tumors. An increase in the odds ratio for brain tumor was found to be positively related to electromagnetic (EM) field exposure levels. Furthermore, the mean age at death was found to be significantly younger among cases in the presumed high EM-exposure group. These findings suggest that EM exposure may be associated with the pathogenesis of brain tumors, particularly in the promoting stage.

Adult↗
PubMed1981

A multifactorial model for pancreatic cancer in man. Epidemiologic evidence.

In the past 30 years, the incidence of pancreatic cancer has increased substantially. The disease now causes more deaths than all other malignant neoplasms, except those of the colorectal region, lung, and breast. A study in over 115 hospitals in five metropolitan areas showed that males with pancreatic cancer were more often employed in the dry cleaning business or in occupations involving close exposure to gasoline, increasing the risk for pancreatic cancer up to five times. Females at risk for pancreatic cancer were more likely to smoke cigarettes, to have uterine myomas, and to have undergone oophorectomy or spontaneous abortions. Generally, these patients were of higher social class and drank more wine and decaffeinated coffee than demographically similar controls. Assessment of the effects of several factors showed that relative risks increased 34-fold among females and nearly sixfold among males. While no single factor accounts for the preponderance of pancreatic cancer, a combination of factors--each associated with a relatively small risk enhancement--may very well do so.

Adolescent↗
PubMed1976

Influence of certain dietary fibers on serum and tissue cholesterol levels in rats.

Pectin, carragheenan, agar gum arabic, cellulose and wheat bran were each fed to rats at a level of 5 to 7% to examine their effect on serum, liver and tissue cholesterol levels. Diets (casein-sucrose diet containing 10-15% soybean oil, or skim milk-wheat flour diet containing 10-15% soybean oil) supplemented with either 0, 0.2, or 0.5% cholesterol were used to test the possibly dietary interactions. Among the fibers tested, pectin displayed the most hypocholesterolemic effect. In some experiments, pectin lowered the level of cholesterol in the serum, liver, and aorta, but it elevated body cholesterol levels. Carragheenan was inconsistent in lowering serum cholesterol levels and tended to increase liver and carcass cholesterol levels. These results probably suggest that pectin and carragheenan can affect the distribution of cholesterol within the body. Gum arabic and agar did not lower serum cholesterol levels and in one case gum arabic elevated them. Furthermore, in some experiments they elevated liver body cholesterol levels. It appears that feeding of gum arabic and agar probably resulted in an expansion of the whole body cholesterol pool. Feeding of wheat bran or cellulose had no significant effect on either serum or liver cholesterol levels. The study indicates that the effect of dietary fiber is dependent on the composition of the diet. Furthermore, while some fibers such as pectin may exhibit a hypocholesterolemic effect in rats, other fibers such as gum arabic and agar may actually elevate serum or tissue cholesterol levels.

Acacia↗
PubMedDate not supplied

Sexual activity of women in Taiwan.

In this paper, we calculate a base line of statistical data on the frequency of sexual activity at various ages of Taiwanese women. A cross-sectional study using questionnaires administered during personal interviews was conducted on more than seventeen thousand women who attended family planning clinics in the Taipei metropolitan area in 1991 and 1992. Of the women surveyed, 2.8 per cent were sexually inactive in the previous month, 83.67 per cent had intercourse one to nine times in the previous month, and 13.56 per cent had intercourse ten times or more. The mean frequency of sexual activity was 6.8 times a month. Age-specific mean coital frequencies for the age groups of less than 25 years, of 25-34 years, and of 35-44 years were 10.3, 7.3, and 6.6 times per month, respectively. Increased sexual frequency was associated with the following factors: young age, unmarried, lower educational level, fewer years of marriage and being on the pill. When logistic regression was used to control for confounding variables, we found that a woman's age is the most significant factor in predicting her sexual frequency.

Adolescent↗
PubMedDate not supplied

Prolonged bleeding time in cirrhotic patients: relationship to peripheral vasodilation and severity of cirrhosis.

A prolonged bleeding time (> 540 s), measured with a Simplate single template device, was found in 0% of 50 patients with chronic hepatitis and 38% of 154 cirrhotic patients. Cirrhotic patients with a prolonged bleeding time (n = 59) had lower platelet counts (P < 0.001) and a longer prothrombin time (P < 0.001) and activated partial thromboplastin time (P < 0.001) compared with cirrhotic patients with a normal bleeding time (n = 95). A weak but significant negative correlation existed between the bleeding time and platelet count in cirrhotic patients (n = 154, r = -0.3668, P < 0.001). Patients with decompensated cirrhosis had a longer bleeding time in comparison to patients with compensated cirrhosis (621 +/- 39 vs 478 +/- 27 s, respectively, P < 0.01). The prolonged bleeding time was also discovered in 25% of 83 cirrhotic patients with a platelet count > 80 x 10(9)/L and a prothrombin time < 17 s (usually taken as safe limits for invasive procedures). Twenty-seven of the 83 cirrhotic patients received a haemodynamic study by Swan-Ganz catheterization. A lower systemic vascular resistance was found in cirrhotic patients with an abnormal bleeding time than in cirrhotic patients with a normal bleeding time (844 +/- 57 vs 1171 +/- 60 dyne.s.cm-5, respectively, P < 0.001), whereas both groups had similar hepatic venous pressure gradient (16.2 +/- 1.2 vs 18.1 +/- 1.4 mmHg, respectively, P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Bleeding Time↗
PubMedDate not supplied

Risk assessment of active smoking: smoking-attributable mortality and years of potential life lost in Taiwan, 1980 and 1992.

Anti-smoking programs have been advocated by the government and other private organizations for decades in Taiwan, especially in the past ten years. We conducted an analysis to assess the effectiveness of anti-smoking programs by examining the changes in active smoking attributable mortality (ASAM) and active smoking attributable years of potential life lost (ASAYPLL) between 1980 and 1992. This analysis also evaluated the present health impact due to active smoking. Total estimated ASAM was 12,765 for 1980 and 14,764 for 1992, representing 34.9% and 31.8% of all deaths from smoking-related causes for each year, respectively. Our results suggested a progress of anti-smoking efforts contributed by the government and other private anti-smoking organizations. By comparing the figures between 1980 and 1992, a reduction in all dimensions has been observed. The overall smoking prevalence rate decreased from 31.7% to 29.5% and the ASAM rate declined from 121.8/10(5) to 91.5/10(5). Additionally, the ASAYPLL rate declined from 513.4/10(5) to 406.9/10(5). Furthermore, the ratio of ASAM from cardiovascular diseases (CVD) to all ASAM decreased from 56.3% in 1980 to 46.7% in 1992, while the ratio of ASAM from cancer to all ASAM increased from 22.9% in 1980 to 34.9% in 1992. Our analysis also found that active smoking seemed to be a more important risk factor for smoking-related causes of death in people aged 41-65 than in people of other age group. Although the anti-smoking programs seemed effective over the past 13 years, active smoking still contributed to an estimated number of 14,764 deaths and 63,743 economically productive years lost in 1992. More efforts should be devoted to further reduce the high smoking prevalence in men and particularly to hamper the increasing smoking trend in adolescents and young women. This remains a challenge for the government of Taiwan.

Adolescent↗
PubMedDate not supplied

Risk of childhood leukemia in areas passed by high power lines.

There has been an emerging concern about possible health risks posed by exposure to extremely low frequency electromagnetic fields (EMF). The incidence of childhood leukemia near high-power transmission lines has only rarely been investigated. A total of 67 cases of childhood leukemia (aged 0-14 years) were reported to the Cancer Registration Center in Taiwan between 1979 and 1988 from the five districts in the Taipei Metropolitan Area, where at least one elementary school campus is passed over by a high power transmission line (69-345 KV). The standardized incidence ratio (SIR) of childhood leukemia in the five districts was found to be significantly elevated (SIR = 1.49, 95% confidence interval: 1.16-1.91). Younger children seemed more susceptible to EMF exposure as indicated by the fact that children aged 0-4 years in two of the five districts showed significantly elevated SIRs compared to older ones. The unusually high SIRs for children of age 5-9 and 10-14 years in one of these districts (SIR = 4.38 and 3.68 respectively) deserves further investigation.

Adolescent↗
PubMedDate not supplied

Age-period-cohort analysis of breast cancer mortality.

The objective of this study is to develop a hypothesis about the carcinogenesis of breast cancer from a descriptive analysis. This study is an application of the age-period-cohort model (APC model) on the mortality rate of breast cancer in Taiwan over the period from 1964 to 1991. Age-specific and age-adjusted mortality rates are described and then age, period, and cohort effects are separately analysed. (Female) breast cancer mortality data in Taiwan from 1964 to 1991 were abstracted from the annual reports of the Taiwan Provincial Department of Health. The population data in Taiwan from 1964 to 1991 were abstracted from the demographic data in Taiwan compiled by the Ministry of Interior, R.O.C. The results show that both age-adjusted and age-specific mortality rates of breast cancer are increasing over the study period and with birth cohorts. The bimodal pattern becomes more apparent in later periods. The Clemmensen's hook is five years later both in the descriptive study and the APC analysis. The findings suggest a possible role of later life overnutrition as the major period effed (promoter) and a change in reproductive behavior as the cohort effect (initiator). The application of the APC model also denotes the possible role of later life overnutrition and a change in reproductive behavior after the birth cohort of 1929. These findings may help us develop hypotheses of carcinogenesis of breast cancer.

Adult↗
PubMedDate not supplied

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.

Adult↗
PubMedDate not supplied

Geographic variation of breast cancer in Taiwan: international and migrant comparison.

BACKGROUND: Breast cancer is increasing rapidly in Taiwan. A geographic variation, international comparison and migrant study has become essential for the development of hypotheses to account for this. MATERIALS AND METHODS: Age-adjusted mortality rates of breast cancer patients from all precincts and townships of Taiwan were calculated for a geographic variation study, and summarized for an international comparison. Age-specific and adjusted incidence rates of breast cancer in Taipei City were used for a migrant study. RESULTS: Age-adjusted mortality from breast cancer was highest in the Taipei and lowest in aboriginal areas. Oriental countries have significantly lower mortality rates from breast cancer but the incidence of breast cancer among Chinese women, and the difference between younger and older age groups has increased together with the degree of westernization in residential areas. Chinese women were found to have lower incidence rates than white women of the same area. We concluded that diet, reproductive behavior, and hereditary factors are involved in the development of breast cancer.

Asian People↗
PubMedDate not supplied

A validity analysis of residential magnetic fields estimated from high-voltage transmission lines.

Between November 1994 and May 1995, indoor power frequency magnetic fields of 407 residences in northern Taiwan were assessed by short-term on site measurements and by modeling computerized power lines information from high-voltage transmission lines. The study residences were selected according to the distance from the transmission lines with cutoff points of 50 meters (m), 100 m, and 150 m, which gave rise to four categories of residences. The analysis showed that the measured magnetic fields were higher than the calculated magnetic fields for most residences, especially for those with lower measured magnetic fields. The measured and calculated magnetic fields showed an agreement of 0.93 (intra-class correlation coefficient, [ICC] = 0.93) for the residences within 50 m of the transmission lines. The ICC declined with the distance from the transmission lines with a lowest ICC of 0.42 for the residences located more than 149 m away from power lines. When both measured and calculated magnetic fields were categorized into three levels with cutoff points of 1 milligauss (mG) and 2 mG, the indices of agreement were very similar for the three residential categories within 149 m of the lines with Kappa (K) between 0.51 and 0.55. The K for the residences more than 149 m from the lines was low at 0.29. The ICC and K observed from a reduced sample of 114 residences presumably representative of all residences in northern Taiwan with respect to the distribution of household magnetic fields was 0.90 and 0.64, respectively. Our data show that using exclusively computerized power lines information to assess residential magnetic fields exposure entails a certain degree of exposure misclassification, but in the absence of direct measurement, this way of doing provides reasonable estimates of magnetic fields exposure within 100 m of transmission lines.

Air Pollution, Indoor↗