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Biomedical subjects

S H Lai

Publications and source records attributed to S H Lai.

29 records · Page 2Linked to original sources
PubMed1988

Oral contraceptives and premenopausal breast cancer in nulliparous women.

Characteristics of women with potential for modifying the relationship between use of oral contraceptives (OCs) and the risk of premenopausal breast cancer were investigated using data from the Cancer and Steroid Hormone study, a population-based, case-control study conducted in eight geographic areas of the United States. Cases consisted of 2945 women who were premenopausal and 20-54 years of age when breast cancer was diagnosed between December 1, 1980, and December 31, 1982; controls consisted of 2646 women with no history of breast cancer who were also premenopausal and 20-54 years of age when selected during the same period. Results are presented with the cases and controls divided into eight groups on the basis of age at diagnosis on selection (20-44, 45-54), parity (0, greater than or equal to 1), and age at menarche (less than 13, greater than or equal to 13). Among nulliparous women who experienced menarche before age 13, the relative risk of developing breast cancer in the age interval 20-44 years is estimated to be 1.0 for never-users of OCs (reference), 1.3 for greater than 0-3 years of use (95% confidence intervals 0.7-2.4), 1.3 for 4-7 years (95% CI 0.7-2.6), 2.7 for 8-11 years (95% CI 1.2-6.3), and 11.8 for 12 years or longer (95% CI 1.4-95.7). OC use is not significantly related to the risk of breast cancer among women in any of the other seven groups. These findings suggest that prolonged OC use may accelerate the onset of breast cancer for a small group of susceptible women while having no appreciable impact on overall risk. The findings should be regarded as tentative, however, since they are based upon numerous comparisons and because age of menarche was stratified at 13 years to highlight the concentration of breast cancer risk apparent in our data.

Adult↗
PubMed1987

Breast cancer risk in relation to type of estrogen contained in oral contraceptives.

We report analyses designed to address the recent hypothesis that women who use combination-type OCs containing ethinylestradiol (EE) are at increased risk of breast cancer before age 45, if use of such OCs occurs prior to first term pregnancy (FTP). Our findings, based on data from 1679 cases and 1689 controls, 20-44 years of age, from the population-based Cancer and Steroid Hormone Study, are against the hypothesis. The relative risk of breast cancer by duration of exclusive use prior to FTP of OCs containing EE is estimated to be 1.0 (1-12 months EE use), 1.2 (13-48 months EE use), and 0.9 (49+ months EE use). There was no evidence of a latent effect. Among parous women with 49+ months exclusive use prior to FTP of EE-containing OCs, the relative risk of breast cancer was estimated as 0.9 (0-4 years after FTP) and 0.6 (5-9 years after FTP). Among nulliparous women with 49+ months exclusive use of EE-containing OCs, the relative risk of breast cancer was estimated as 1.0 (0-4 years since first use), 0.7 (5-9 years since first use), and 1.1 (10-14 years since first use). With regard to exclusive use of OCs containing mestranol, parous women who used such preparations long-term before their FTP showed no alteration of breast cancer risk, even 15 years or more after pregnancy. Nulliparous women with exclusive use of ME-containing OCs did show elevations in breast cancer risk, but the magnitude of risk in relation to duration of use and latent interval shows no pattern that suggests a cause-effect relationship.

Adult↗
PubMed1986

Relationship between salt excretion and blood pressure in various regions of China: Part 2.

Overnight urine samples were collected on three consecutive days from 2483 persons in 12 regions of China and the mean 9-hour overnight sodium and potassium levels subsequently determined. Analysis of the data by univariate regression, simple correlation, and multiple regression indicated that there was a positive correlation between the mean level of sodium in urine and blood pressure.

Adult↗
PubMed1986

Cantonese-style salted fish as a cause of nasopharyngeal carcinoma: report of a case-control study in Hong Kong.

Two hundred fifty incident cases of nasopharyngeal carcinoma under age 35 years in Hong Kong Chinese and an equal number of age- and sex-matched friend controls were interviewed. Mothers of cases and controls were interviewed also, if available, to obtain information on childhood events concerning the study subjects. Consumption of Cantonese-style salted fish during all time periods was significantly associated with nasopharyngeal carcinoma; the association was especially strong during childhood. The relative risk for having Cantonese-style salted fish as one of the first solid foods during weaning was 7.5 (95% confidence limits, 3.9, 14.8), and the relative risk for consuming the food at least once a week compared to less than once a month at age 10 years was 37.7 (95% confidence limits, 14.1, 100.4). It is estimated that over 90% of young nasopharyngeal carcinoma cases in Hong Kong Chinese can be attributed to consumption of this food during childhood.

Adult↗
PubMed1984

Relationship between salt excretion and blood pressure in various regions of China.

Overnight urine samples were collected on three consecutive days from 3105 persons in 12 regions of China, and analysed for levels of sodium and potassium. The mean 9-hour overnight urine sodium level ranged from 49.51 to 139.12 mmol, and urine potassium from 6.32 to 18.43 mmol. Univariate regression, simple correlation analysis, and multivariate ridge regression analysis were carried out on the data. A positive correlation between blood pressure and urine sodium or sodium/potassium ratio was found in each of the twelve regions. Urine potassium showed a negative correlation with blood pressure in three regions.

Adult↗
PubMed1980

Establishment of a cell line (NPC/HK1) from a differentiated squamous carcinoma of the nasopharynx.

A long-term cell culture epithelioid cell line was established from a recurrent squamous carcinoma of the nasopharynx of a Chinese male 17 1/2 years after radiation therapy. The cell line, designated NPC/HK1, has been passed 72 times over a period 1 year. The cells have been shown by light and electron microscopies to be of the squamous epithelial type. When they were transplanted subcutaneously into the back of athymic nude BALB/c (nu/nu) mice, tumors developed at the sites of inoculation, which on histological examination were shown to be well-differentiated squamous carcinomas, similar in morphology to the recurrent human tumor from which they were derived. Karyotypic analysis of cells from the cell line demonstrates an aneuploid human type with a modal chromosome number of 74 with both numerical and structural aberrations. Viral particles or Epstein-Barr viral nuclear antigen (EBNA) has not been demonstrated in the cells from the primary culture or several of the subcultures tested. The presence of EBNA in touch smears prepared from the biopsy tissue was inconclusive. Infection of the subcultured cells with EBV from P3HR1 and B95-8 cells was unsuccessful.

Adult↗
PubMedDate not supplied

Idiopathic pulmonary hemosiderosis in a child: report of one case.

Idiopathic pulmonary hemosiderosis (IPH) is uncommon in children. We report a 3-year-old girl who was presented with acute pale-looking appearance, hemoptysis, hematemesis and shortness of breath. This patient was confirmed to have pulmonary hemorrhage by the presence of hemosiderin-laden macrophages in the bronchoalveolar lavage fluid using a flexible bronchoscope. Other causes of PH including glomerular, cardiac and immunological disorder were excluded by normal laboratory studies. She was primarily treated by oral prednisolone, but due to recurrent hemoptysis, immunosuppressive agent was added for maintenance therapy. Pediatricians should consider PH in a patient who has recurrent dyspnea, hemoptysis and iron deficiency anemia.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Effect of hypocapnia in the first three days of life on the subsequent development of periventricular leukomalacia in premature infants.

Several etiologies for causing periventricular leukomalacia (PVL) in preterm infants have been investigated worldwidely. The aim of this study is to investigate whether hypocapnia plays a role in the pathogenesis of the subsequent development of PVL. From Jan. 1997 to June 1998, 91 premature infants (mean gestational age 28.8 +/- 2.5 weeks and birth body weight 1169 +/- 385 g) born in Chung Gung Children's Hospital requiring mechanical ventilation in the first 72 hrs were enrolled in our study. Serial neuorosonogram were followed on day 1, 3, 7 and then at least every 2 to 3 weeks until discharge. These infants were divided into two groups defined as the PVL group and non-PVL group. Variables comprising perinatal data were analyzed and compared between these two groups to screen out possible risk factors related to the development of PVL. There was no difference noted. As for the effect of PaCO2, we found the infants with PVL to have mean lower PaCO2 during the first 72 hours of life. (P = 0.004). Logistic regression model revealed that the incidence for PVL increased significantly when mean PaCO2 is lowered to less than 25 mmHg. Hypocapnia during the first three days of life seems to be an important etiological factor associated with the development of periventricular leukomalacia. Therefore, the ventilatory strategy in the care of the premature neonates should not only provide adequate ventilation but also careful avoidance of hypocapnia.

Carbon Dioxide↗