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Biomedical subjects

B S Thomas

Publications and source records attributed to B S Thomas.

At least 19 recordsLinked to original sources
PubMed1992

Patterns of alcohol and other drug use in an Iowa community.

From a baseline survey of high school students in two school systems, information was obtained to describe patterns of alcohol and other drug (AOD) use and adverse consequences of use, compare indices of AOD use and consequences for grade level and gender differences, and examine relationships of indices to selected individual, family-related, and social competence/adjustment-related risk factors. Though use of illicit drugs was reported at low levels, prevalence of drinking and incidence of binge drinking were relatively high. Increases in AOD use and adverse consequences with age and grade level were found, but gender differences were not found. Relationships of AOD use and adverse consequences to selected individual, family, and social risk factors were consistent with a substantial body of prior work but exceptions were found. Strongest correlations to both indices were found for risk taking, sense of mastery, family management/cohesion, peer pressure, and social/school adjustment.

Adolescent↗
PubMed1992

The affective outcomes of course work on computer technology in nursing.

At the University of Iowa, nursing students are introduced to computer technology as one unit in a course designed to explore nursing as a profession. A single group, pretest/posttest design was used to evaluate changes in attitudes associated with the course work. Relationships of attitudes scores and eight background variables were studied. Posttest attitudes scores were significantly higher than pretest scores. The attitudes scores were positively related to skills scores at a statistically significant level of .05, with no significant relationship between attitudes scores and knowledge base scores. Four of the eight background factors were related to the attitudes scores at a statistically significant level of .05.

Adult↗
PubMed1991

Cigarette smoking and steroid hormones in women.

Epidemiological evidence has suggested that cigarette smoking has an anti-oestrogenic effect in women, but the effects of smoking on steroid hormone metabolism are not fully understood. We compared serum concentrations of oestradiol, progesterone (luteal phase) and dehydroepiandrosterone sulphate (DHEA-S), and urinary excretion rates of six steroids of predominantly adrenal origin, in healthy premenopausal and postmenopausal female smokers and non-smokers. Serum concentrations of oestradiol, progesterone and DHEA-S did not differ between smokers and non-smokers by greater than 5%, and none of these differences was statistically significant. Mean urinary excretion rates of androsterone, aetiocholanolone, DHEA, 11-keto-aetiocholanolone, 11-hydroxyandrosterone and 11-hydroxyaetiocholanolone were very similar in smokers and non-smokers in premenopausal women, but were from 2-44% higher in smokers than non-smokers in postmenopausal women. The difference was statistically significant only for 11-hydroxyandrosterone. These results confirm previous reports that cigarette smoking does not affect serum oestradiol in premenopausal or postmenopausal women, but provide only weak evidence to support previous findings of increased levels of some adrenal steroids in postmenopausal women smokers. The mechanism for the apparent anti-oestrogenic effect of cigarette smoking remains unclear.

Adult↗
PubMed1990

Erythrocyte membrane stearic acid: oleic acid ratios in colorectal cancer using tube capillary column gas liquid chromatography.

Erythrocyte fatty acids were measured in 32 patients with colorectal cancer (four with recurrent disease), four patients with large colorectal adenomas, and 42 hospitalised patients without cancer. No significant differences were found with respect to any of the fatty acids between these groups. In particular there was no difference between the erythrocyte stearic acid: oleic acid ratios (mean +/- SD) between the cancer cases (1.07 +/- 0.31) and the control cases (1.09 +/- 0.31, 2-tailed Mann-Whitney U test). No difference in this ratio was observed with respect to age or sex and in the case of colorectal cancer, to the Dukes' stage, degree of tumour differentiation, or recurrence. A significant correlation was found between stearic acid concentrations in plasma and erythrocytes from fasting individuals (r = 0.477, n = 24, P less than 0.05). This study provides further evidence that the erythrocyte stearic acid: oleic acid ratio is of no value for diagnosing primary or recurrent colorectal cancer.

Aged↗
PubMed1989

Hormones are ambiguous risk factors for breast cancer.

Women with breast cancer whose blood and urinary androgens are at the lower end of the normal range have an early age at diagnosis, a rapid recurrence rate after mastectomy and tumours that are unresponsive to endocrine therapy. The most plausible explanation for these results is that the androgens are not involved in tumour initiation but control tumour growth rates after the malignant transformation has occurred. If this is so, endocrine case/control studies in which growth rates are not measured are an inefficient way of studying the endocrinology of breast cancer. It is suggested that the oestrogens and androgens should be considered as a single functional unit in future research.

Adult↗
PubMed1988

Erythrocyte membrane stearic and oleic acid ratios in breast cancer.

A case control study has been conducted to determine the value of stearic/oleic acid ratios in the erythrocyte membranes of women at the time of presentation with breast cancer. No difference was found between the stearic/oleic acid ratio of cases and that of controls with benign breast condition or normal volunteers. Furthermore, within clinical stages of breast cancer, no differences were detected. This ratio does not appear to be of value as a marker of malignancy, or of tumour burden.

Breast Neoplasms↗
PubMed1988

Urinary epidermal growth factor excretion and breast cancer risk.

The amount of urinary epidermal growth factor (EGF) excreted was determined in 350 normal women of whom 37 subsequently developed breast cancer. These were a group of women selected on a case-control basis from 5000 volunteers who had participated in a prospective epidemiological study. Urinary EGF excretion was not correlated with known risk factors such as age at menarche or menopause, age at first or last full-term child or parity. Neither was it associated with day or length of menstrual cycle, breast mammographic parenchymal pattern or the blood concentration of prolactin, dehydroepiandrosterone or its sulphate ester. Univariate analysis indicated that the amount of urinary EGF was significantly correlated with urinary creatinine (P less than 0.001), age (P less than 0.001), urinary androsterone (P less than 0.02) or aetiocholanolone (P less than 0.02), height (P less than 0.05) and weight (P less than 0.05). However, multivariate analysis showed that the amount of urinary EGF was correlated only with creatinine excretion (P less than 0.001) and age (P less than 0.001) and that the significance of the other correlations were probably due to the confounding influence of creatinine.

Adult↗
PubMed1988

An autoimmune aetiology for hypothyroidism following interferon therapy for breast cancer.

Alpha-interferon has been administered as an adjuvant treatment for women with loco-regional relapse of breast cancer. During the course of treatment 5/10 (50%) of women receiving interferon developed de novo thyroid autoantibodies. Three patients became clinically myxoedematous, with biochemical evidence of hypothyroidism which responded to thyroxine replacement therapy. The leucocyte alpha-interferon preparations used in the trial enhanced Class I but not Class II MHC antigens on thyrocytes in vitro. These data strongly suggest that patients receiving alpha-interferon therapy should be closely monitored for the possible development of thyroid dysfunction and that thyroid antibody determination can greatly help to predict overt thyroid clinical abnormalities.

Autoantibodies↗
PubMed1988

A prospective study of the relationship between serum vitamins A and E and risk of breast cancer.

In an 8 year prospective study (1977-1985) on breast cancer, blood was taken from 5,086 women resident in Guernsey, and the serum stored at -20 degrees C. During this period 30 women developed the disease and their serum samples were analysed for vitamins A and E, and for retinol-binding protein (RBP). A further 288 age-matched control sera (up to 10 per pre-cancer case) were similarly analysed. No relationship was found between any of these substances and subsequent development of breast cancer. A significant correlation between increasing age and vitamin A (r = 0.46, P less than 0.001) and RBP (r = 0.36, P less than 0.001) concentrations was observed. There was also a trend for increased blood concentrations of vitamin E with age, but this was not significant. Serum RBP and vitamin A concentrations were highly correlated (r = 0.91, P less than 0.0001).

Adult↗
PubMed1988

Sex hormone-binding globulin and the natural history of breast cancer.

Low concentrations of SHBG in the blood appear to be related to rapid tumour growth rates whereas normal values are associated with slower rates. The inferences drawn from these and other experimental results are as follows: 1. It is no longer necessary to postulate that an abnormal endocrine environment is related to the risk of breast cancer. 2. Variation within the normal range of endocrine function may be sufficient to account for marked differences in the growth rates of transformed cells. 3. It is suggested that women whose tumours arise in an environment characterised by SHBG concentrations at the lower end of the normal range (and, hence, non-SHBG-bound oestradiol levels at the top end of the range) will tend to have an earlier age at diagnosis, a lower frequency of oestrogen-receptor positive tumours and a lower proportion of hormone responsive tumours than women with SHBG levels at the top of the range. 4. Case/control studies in which growth rates are not taken into account may be difficult to interpret.

Adult↗
PubMed1986

Thyroid function and the incidence of breast cancer in Hawaiian, British and Japanese women.

Serum-free thyroxine (FT4) concentrations are lower in Hawaiian and Hawaiian Caucasian women than in Hawaiian Japanese, Hawaiian Filipino, Hawaiian Chinese, and English and Japanese mainland women. There is a high inverse correlation between FT4 and risk of breast cancer in these ethnic groups. Thyroid-stimulating hormone (TSH) concentrations, which are inversely correlated with FT4, generally show the same relationship.

Adult↗
PubMed1986

Instructional computing in American nursing programs.

This paper summarizes more than a decade of progress on computing in nursing education and reports the results of a two-phase study of instructional computing in American nursing programs. The study reveals an enormous range of activity in nursing education, the importance of various barriers to growth and use of computers and the perceptions of deans and directors of potential remedies and the feasibility of each.

Computer-Assisted Instruction↗
PubMed1986

Identification of women at high risk of breast cancer.

Prospective studies of risk factors for breast cancer have been carried out since 1961 on a normal population which now comprises some 15,000 women. Classical (anamnestic) factors such as ages at menarche, menopause, or at first child, post-menopausal weight and high parity are not strong determinants of risk. Measurements of various aspects of endocrine function are more successful in identifying women at risk, as is assessment of mammographic parenchymal patterns but, again, these variables are not effective enough to make an intervention strategy imperative. However, the combination of classical, endocrinological, and radiological factors appears to achieve this aim. A substantial sub-set of women who have a four-fold risk of breast cancer may be identifiable.

Adult↗