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Biomedical subjects

S J Lan

Publications and source records attributed to S J Lan.

At least 37 records · Page 2Linked to original sources
PubMed1993

Prevalence and characteristics of areca nut chewers among junior high school students in Changhua county, Taiwan.

Some studies indicate that betel quid and its ingredients chewing can produce cell mutagenicity and tumorigenicity. In Taiwan studies, betel quid chewing is the main cause of submucous fibrosis and oral cancer. Understanding the distribution and characteristics of the areca nut chewing population is one of the first steps in the effort to prevent these oral diseases. A stratified cluster random sample of 2442 junior high school students in Changhua county, Taiwan, were surveyed for the habit of areca nut chewing. Significantly more male students chewed areca nut than female students (9.2% vs 0.9%). The proportion of students who were chewing areca nuts increased with increasing (seventh to ninth) grades. Areca nut was used by junior high school students at a higher rate in village (rural) areas as compared to town (semi-urban) and city (urban) areas (6.4%, 3.7% and 3.0%, respectively). More students in the ordinary achievement classes were chewing areca nuts than those in the high achievement classes (8.4% vs 1.6%). Areca nut chewing students tended to have users in their families. Cigarette smoking and alcohol drinking were positively associated with areca nut chewing. More than half (53.6%) of the areca nut chewing students first experimented with this habit with a family member, most often the father or grandfather.

Adolescent↗
PubMed1993

Tobacco smoking and other factors in relation to serum alpha-1-antitrypsin.

Serum levels of alpha-1-antitrypsin were measured by radial immunodiffusion, and phenotypes were determined by electrofocusing in acrylamide gel in 160 subjects who were used as controls in a case-control study of hepatocellular carcinoma (HCC). The results were studied in relation to age, sex, diagnostic category, tobacco smoking, consumption of alcoholic beverages, presence of hepatitis B surface antigen (HBsAg), and serum levels of alphafetoprotein (AFP) by modeling the data through multiple regression. There was no relation of serum alpha-1-antitrypsin values with sex, HBsAg, AFP, consumption of alcoholic beverages, and diagnostic category (p > 0.25). By contrast, there were statistically significant dose-dependent positive associations of serum alpha-1-antitrypsin with age and tobacco smoking (p < 0.01 in both instances). The positive association of serum alpha-1-antitrypsin with tobacco smoking and the previously reported excessive elevation of serum alpha-1-antitrypsin in hepatitis B-negative tobacco-related cases of HCC suggest that alpha-1-antitrypsin is intimately related to the pathogenetic process linking tobacco smoking to HCC.

Age Factors↗
PubMed1993

[An investigation on public awareness, attitude and behavior toward drinking water quality in Taiwan].

The objective of this study was to investigate the public awareness, attitude and behavior toward drinking water quality. The results showed that (1) Overall, 80.6% of those responding to the survey rated their local drinking water quality as above average or better. (2) Even though most people were happy with the present quality of their drinking water, 79.2% of the public characterized themselves as concerned about encountering substances in drinking water in their lifetime that could lead to bad health effect or death. (3) 73.8% of the survey respondents never examined the water facilities for their own use.

Adult↗
PubMed1993

[Workplace risk factors associated with eye syndrome in office workers].

Four large sealed office buildings were investigated to determine the relationship between the prevalence of sick building syndrome and the indoor air quality. Questionnaires were distributed to all building occupants. Respondents suffered from upper airway, eye, lower airway and many less specific complaints. Multivariate logistic regression analyses were conducted to assess workplace risk factors associated with eye syndrome. Working with visual display terminals, glare, use of desk lamp, fabric-covered partitions, new carpet, too dim, too bright and lack of openable windows correlated significantly with the prevalence of eye syndrome.

Adult↗
PubMed1992

Twin membership and breast cancer risk.

Pregnancy estrogens are substantially elevated in twin pregnancies and are likely to be more so in the case of dizygotic twins. If levels of pregnancy estrogens were positively related to breast cancer risk in the offspring, female twin members would be expected to be at slightly higher risk. Data from an international case-control study were utilized to assess this hypothesis. The analysis was based on 870 cases with breast cancer and 2,641 hospital controls from two sites: Glamorgan, Wales (1965-1967), and Boston, Massachusetts (1965-1966). Seventeen cases were members of twin pairs, and 8 of them had a twin brother; 33 controls were members of twin pairs and 14 had a twin brother. Among all women, the odds ratios for breast cancer were as follows: for twins with brothers, 1.54 (95% confidence interval (CI) 0.64-3.71); for twins with sisters, 1.30 (95% CI 0.58-2.92); and for all twins, 1.40 (95% CI 0.77-2.55). The odds ratios were higher among premenopausal women. These findings are not conclusive, but they are compatible with the hypothesis that pregnancy estrogens may affect the risk of breast cancer in the offspring.

Age Factors↗
PubMed1992

Age at first establishment of chronic hepatitis B virus infection and hepatocellular carcinoma risk. A birth order study.

It is frequently assumed that the risk of hepatocellular carcinoma related to hepatitis B virus is higher when chronic hepatitis B virus infection is acquired early in life. This hypothesis has never been directly evaluated. However, firstborn and secondborn children are exposed to common infections after their school enrollment, whereas laterborn children are exposed much earlier, through their older siblings. The authors analyzed sibship size and birth order data from a large case-control study of patients admitted to Athens, Greece, hospitals between April 1976 and October 1984. The analyses included 185 patients with hepatocellular carcinoma, 35 patients with metastatic liver cancer, and 432 other hospital controls. There was a tendency for cases of hepatocellular carcinoma to concentrate at higher birth orders. When the analysis was restricted to cases and controls who were positive for hepatitis B surface antigen, this tendency was even more notable. These results are compatible with the hypothesis that establishment of chronic hepatitis B virus infection at an early age increases the risk of hepatocellular carcinoma substantially more than does chronic infection with this virus established at a later age.

Age Factors↗
PubMed1992

Evidence of prenatal influences on breast cancer risk.

Intrauterine exposure to high concentrations of endogenous pregnancy oestrogens may be important in the aetiology of breast cancer. In a nested case-control study we have assessed the relation between breast cancer risk and indicators of pregnancy oestrogen concentrations; pre-eclampsia/eclampsia is negatively related and measures of fetal size are positively related to oestrogen concentrations. Standard records for women born at Uppsala University Hospital between 1874 and 1954 were linked with records of invasive breast cancer cases, identified through their unique national registration numbers in the Swedish Cancer Registry during 1958-90. For each breast cancer case, we selected as potential controls female offspring of the first three mothers admitted to the hospital after the case's mother; only controls still living in Sweden and free from breast cancer when it was diagnosed in the case were finally included. Conditional logistic regression analysis was done for 458 breast cancer cases and 1197 matched controls. Pre-eclampsia/eclampsia was associated with a breast cancer rate ratio of 0.24 (95% confidence interval 0.09-0.70, p = 0.01). Linear trends for breast cancer incidence with increasing birth weight, birth length, and placental weight were positive but not significant. Thus, prenatal factors are important in breast carcinogenesis. Concentrations of pregnancy oestrogens may be one such factor, but other prenatal or perinatal factors cannot be excluded.

Adult↗
PubMed1992

Beyond simple pooling for HIV screening.

We discuss some theoretical features underlying the successful uses of pooling in testing HIV seroprevalence. In particular it is shown that there is a scaling relation for the distribution of positive sera among the pools. A multi-stage pooling method consisting of repeatedly halving the positive pools is proposed. Concentrating on the number of tests required for screening all positive individuals the method is shown to be highly efficient in low prevalence situations.

Biometry↗
PubMed1992

A case-control study of coronary heart disease in Athens, Greece.

A case-control study of coronary heart disease (CHD) was conducted in Athens, Greece. The case series consisted of 329 patients with electrocardiographically confirmed coronary infarct or a diagnostic coronary arteriogram, or both, who were admitted during a 16-month period to a major teaching hospital. Controls were 570 patients admitted to the same hospital just before or after the CHD cases for minor surgery; eye, ear, nose or minor urological problems; or chest problems definitely shown to be unrelated to CHD. All cases and controls were interviewed in the hospital wards and selected laboratory data were abstracted. The main analysis was done by modelling through multiple logistic regression, controlling for demographic variables as well as for the mutual confounding effects of the investigated risk factors. Obesity, hypertension, diabetes mellitus, elevated blood cholesterol and excessive coffee intake were significant (P < 0.02) independent risk factors with relative risk estimates in the 2- to 3-fold range. Non-significant positive associations were found with respect to tobacco smoking and modest coffee consumption, whereas non-significant negative associations were noted with respect to alcohol intake and regular exercise. A negative association with duration of afternoon siesta was of borderline statistical significance.

Adult↗
PubMed1992

Strategies for blood screening for the hepatitis C virus and for the human immunodeficiency virus in high risk groups.

For many infectious agents, seroprevalence rate is low but has serious consequences and must therefore be kept out of donated blood supplies. However, screening to ensure the safety of blood supplies has an associated very high cost. For example, in blood banks, detection of all the harmful items in a large number of samples is an expensive and tedious process. The laboratory and statistical approaches to obtain significant savings by the pooling method were discussed from 1943, recently, there have been further discussions of pooling sera as a means to determining the HIV seroprevalence rate in the general population or the weed out all HIV-positive individuals in blood screening. Here we describe a simple mathematical method to weed out all HIV, and HCV seropositive units. The method is designed to maximize possible savings. Two examples illustrate the application of this method in determining the number to be pooled in each stage, and the resulting savings. When the prevalence rate is lower than 2 percent. our method offers savings of over 80 percent.

Blood Donors↗
PubMed1992

[Risk factors related to the use of amphetamines in adolescent students].

The prevalence of amphetamine abuse among school children was studied by asking 3548 adolescent students (aged 12-15, response rate 98.6%) to complete a questionnaire anonymously, which was developed and evaluated by the authors. A complete set of data was collected for 3200 (90.2%) students. Eighty-five (2.7%) of them who admitted that they had used amphetamines constituted the case group. Non-users with negative urine tests formed the control group. Six independent factors were found to be related to amphetamine use when the answers were analyzed by stepwise logistic regression. The prevalence odds ratio estimation was elevated in: males compared females, students who did not live with both parents compared to those who lived with both parents, students with amphetamine-user friends compared to those with no-user friends, smokers compared to non-smoker, betel nut chewers compared non-chewers, and in students with positive attitudes compared to those with negative attitudes. The average starting age for smoking was 12.5 +/- 0.1 years; later this was followed by alcohol abuse, chewing of betel-nuts, and use of amphetamines. The average age of starting to use amphetamines was 13.5 +/- 0.2 years; a common reason given for using amphetamines was curiosity (65.4%). Many students (54.2%) obtained the amphetamine from their friends and most of them (85.2%) used it six months before responding to the questionnaire.

Adolescent↗
PubMed1991

[The prevalence of amphetamine use in adolescent students: self-reported and urine analysis].

The prevalence of amphetamine use was studied using an anonymous questionnaire given to 3548 adolescent students aged 12--15, with a response rate of 98.6%. This questionnaire was developed and evaluated by the authors. A complete set of data was collected on 3200 subjects, making up 90.2% of all students surveyed. Eighty-five (2.7%) students admitted that they had used amphetamines; that is, 64 of the 1,584 male (4.0%), and 21 of the 1,616 female (1.3%) respondents. The life-time prevalence odds ratio estimation was elevated in male (POR = 3.2, 95% CI 1.9--5.3), as compared to female students. The life-time prevalence rates increased with age only among male students (P trend = 0.01). Seven hundred and twenty four male students were randomly tested for the presence of amphetamines in their urine using thin layer chromatography and fluorescence polarization immunoassay. Of six students who tested positive, five asserted that they had not used amphetamines. The point prevalence rate of amphetamine use based on the urine tests was 0.9% among the 652 students who had completed questionnaires. This rate was higher than on self-reported use of amphetamines (rate difference 0.9%, 95% CI 0.2--1.6%). In this group, 27 (4.1%) admitted that they had used amphetamines. The estimated overall life-time prevalence rate was at least 4.9% (32/652), with 95% CI between 3.2% and 6.6%.

Adolescent↗
PubMed1991

[The study of Apgar score and infant birth weight in the central Taiwan].

The objective of this study was to assess the relationship between birth weight and the Apgar Score. We collected data on the birth weights and the 1 min and 5 min Apgar Score of new born infants between 1982 and 1987 at a teaching hospital in Central Taiwan. Compared to babies with normal Apgar Score, infants with low Apgar Scores were found to born with low and very low birth weights. In the 1 min of life test, the relative risks of low birth weights among infants with Apgar Scores of 0 to 3 and 4 to 6 were 115.0 and 5.9 times higher than those of normal infants, respectively. In the very low birth weight category, the relative risks of the above score were 252.5 and 51.1, in this order. In the 5 min of life test, the relative risks of the above scores were 16.2 and 12.1 in the low birth weight category, respectively. However, among babies of very low birth weight, the relative risks of the same scores were 121.2 and 84.9, in this order. In conclusion, the 5 min Apgar Score might be a useful prognostic index for the relationship between health and birth weight of new born infants.

Apgar Score↗
PubMed1991

[Compressive radial nerve palsy induced by military shooting training--a case report].

A newly recruited soldier suffered a sudden onset of wrist-drop of left hand and numbness on the back of thumb after a military training course in target shooting. An examination disclosed decreased muscle power (0/5) in the left wrist dorsiflexion, disturbance of pain-temperature sensation on the radial side of left hand and absence of the deep tendon reflex of brachioradialis. Electrophysiological studies showed slowness of motor conduction velocity, delay of distal latency and reduced amplitude. EMG revealed fibrillation over the extensor digitorium communis (EDC) at rest, brachioradialis and prolongation of polyphasic MUAPs over EDC. Left radial nerve mononeuropathy induced by mechanical compression of the radial nerve on the spiral groove of humerus was conspicuous. We attempted to discuss the disease etiology, electrophysiological findings and treatment.

Adult↗
PubMed1991

Use of modified diets in nursing homes.

Randomly chosen medical charts of 212 elderly subjects in 11 nursing homes were reviewed to determine which characteristics of the subjects were most closely associated with their diet prescriptions. The chart reviews indicated that 104 (49.0%) of the 212 subjects had some type of nutrient-modified diet prescription. Eight patients who were tube fed were not included in subsequent analyses. Sodium restriction was the most common modification (60 [29.4%] of the remaining 204 patients) and calorie-controlled diets were also common (52 [25.5%] of the patients). Of the 55 patients with hypertension, 31 (56.4%) had no sodium restriction. Only 10% of all low-sodium diets limited sodium to 2 g per day. Of the 38 patients with diabetes, 7 (18.4%) had no prescription for calorie control, and there was no indication that increased dietary fiber was encouraged for diabetic patients. Only one of the 121 subjects with a diagnosis of coronary heart disease or atherosclerosis had a prescription for a cholesterol-lowering diet. Characteristics of the subjects not specifically related to diet or diagnosis, such as age, sex, duration of stay, and level of care, had no significant relationship to diet prescription. These findings suggest that the practitioners in our sample were not convinced of the efficacy of modified diets to control disease for most nursing home residents.

Aged↗
PubMed1991

Efficiency gains from the use of sample pooling technique: a theoretical example of dengue virus detection in vector.

Testing large numbers of specimens for viral antigens, antibodies, requires a great deal of manpower, time and money. Therefore it would be useful if testing could be performed with the specimens pooled. However, how to establish the optimal number of specimens to be pooled to achieve the maximum efficiency while maintaining both sensitivity and specificity is a question that needs to be answered. In this study, we developed a mathematical model and procedure to resolve this problem. We estimated a saving rate of over 98% for an assumed infection rate of 1/10000 by testing the sample in pools of 100-101 specimens. The saving rate decreases with increasing infection rates, until there is probably no efficiency gain achieved for infection rates greater than 30%. Tests of infection in pooled mosquitoes were assumed to be free of viruses other than the dengue virus to interfere with detection. Heads of Aedes mosquitoes were first pooled and squashed, and the extract obtained was injected by intrathoracic inoculation into Toxorhynchites amboinensis, a biological amplifier of dengue antigen. Sensitivity was not reduced. Therefore, this pooling technique is useful for determining the optimal number of specimens in a pool, calculating an exact infection rate, and for identifying specific infected specimens in tests of a large number of samples showing low rates of infection in our theoretical example.

Aedes↗
PubMed1991

[A study of weight and weight/birth at birth by gestational week].

A study of 35,919 live neonates was conducted from 1976 to 1987 (excluding 1980) at a teaching hospital in Central Taiwan. Our goal was to determine the proportions of low birth weight (LBW) and very low birth weight (VLBW) and birth weight/birth length ratios by gestational week. The results showed that LBW and VLBW neonates were 6.3% and 1.1%, respectively. In LBW neonates groups, there was a rapid decline after the 33rd gestational week, then as low as 6.9% by the 38th gestational week. After the 28th gestational week, there was a rapid decline in VLBW proportion, then a further decline to 9.3% at the 32nd gestational week. Birth weight/birth length ratios were 2.94 and 6.25 at the 28th and 39th gestational weeks, respectively. There were no differences in birth weight/birth length ratios between male and female babies. Based on the above findings, we tried to set a norm from birth weight/birth length ratios by gestational week.

Birth Weight↗