Search PubMed⌕ Search

Biomedical subjects

D Y Wang

Publications and source records attributed to D Y Wang.

At least 19 recordsLinked to original sources
PubMed1992

A prospective study of obesity, lipids, apolipoproteins and ischaemic heart disease in women.

The aim of the study was to examine the relationships of obesity, lipids and apolipoproteins with the risk for subsequent ischaemic heart disease in middle-aged women, using a case-control study nested within a cohort study. A total of 3634 women aged 26-88 were recruited in Guernsey between 1977 and 1985 and followed until June 1986 by abstraction of their general practitioners' records. Fifty-one cases of incident ischaemic heart disease (11 myocardial infarction, 40 angina) were identified. For each case up to 4 controls were selected, matched for age and date at recruitment. Odds ratios for the development of ischaemic heart disease in the middle and upper thirds of the distribution for each variable in the controls, relative to the lowest third (and two-sided P-values for linear trends), were: 3.0, 2.6 (0.015) for Quetelet's index; 3.3, 5.1 (0.003) for total cholesterol; 0.5, 0.6 (0.102) for apolipoprotein A-I; 1.8, 2.4 (0.015) for apolipoprotein B; 1.3, 2.1 (0.155) for apolipoprotein(a). The increased risks associated with increased Quetelet's index and total cholesterol were independent of each other and these variables were more strongly related to myocardial infarction than to angina. The relationships of risk with serum cotinine, fatty acids, dehydroepiandrosterone sulphate and sex hormone binding globulin were weak and did not approach statistical significance.

Adult↗
PubMed1992

Regulation of ciliary neurotrophic factor expression in myelin-related Schwann cells in vivo.

Adult rat sciatic nerve is known to express high levels of ciliary neurotrophic factor (CNTF) mRNA and protein. Here we examine the cellular localization of CNTF protein and mRNA in peripheral nerve and the regulation of CNTF expression by peripheral axons. In intact nerve, CNTF immunoreactivity is found predominantly in the cytoplasm of myelin-related Schwann cells. After axotomy, CNTF immunoreactivity and mRNA levels fall dramatically and do not recover unless axons regenerate. This behavior is similar to the pattern of myelin gene expression in these nerves. We conclude that the expression of CNTF in Schwann cells depends on axon-Schwann cell interactions.

Animals↗
PubMed1992

Effect of physiotherapy on the auditory evoked response of paralysed, sedated patients in the intensive care unit.

Auditory evoked response (AER) was recorded before, during and after physiotherapy in 11 paralysed (atracurium 0.56 (SD) 0.13 mg kg-1 h-1), sedated (propofol 2.2 (1.0) mg kg-1 h-1; fentanyl 4.4 (2.3) micrograms kg-1 h-1) and critically ill patients undergoing ventilation in the intensive care unit (ICU). The latency of the negative wave, NB, was reduced by physiotherapy (mean 44.8 (SD) 7.9 ms before, 41.0 (6.8) ms during (P less than 0.01, non-parametric Friedman test) and 45.6 (6.3) ms after physiotherapy); NB amplitude showed no consistent change (-0.81 (1.4) microV, -0.81 (1.5) microV and -0.71 (1.3) microV, respectively). NB latency responded to patient arousal at constant levels of sedation and this requires further evaluation as a means of monitoring sedation in paralysed patients in the ICU.

Adult↗
PubMed1992

Relationship of blood prolactin levels and the risk of subsequent breast cancer.

Between 1968 and 1976 a total of 5162 women volunteers were enrolled into a prospective study conducted on the Island of Guernsey. Up to February 1990 145 women subsequently developed breast cancer. Blood samples were taken at the time of enrollment and prolactin levels were known for 85% of the volunteers. In calculating the relationship between blood prolactin levels and subsequent breast cancer risk, women were excluded if they had a hysterectomy or an oophorectomy or had cancer at any site before enrollment. The final analysis was based on 2596 premenopausal and 1180 naturally postmenopausal women and, of these respectively, there were 71 and 40 volunteers who subsequently developed breast cancer. The total follow-up for these two groups was 49,941 and 22,360 woman-years, respectively. In assessing the relationship between blood prolactin levels and risk of subsequent breast cancer the cohort was divided into quintiles according to prolactin concentration and relative risks (RR) were estimated. In calculating these values possible confounding by age at entry, age at menarche, parity, age at first birth, years since menopause, body build, history of benign breast disease and family history of breast cancer were taken into consideration. There was no significant relation between risk of breast cancer and prolactin in either pre- or postmenopausal women. Hence prolactin appears not to be an important determinant of breast cancer risk.

Adolescent↗
PubMed1992

Endogenous plasma sex hormones in pre- and postmenopausal women with breast cancer: results from a case-control study in Moscow.

Plasma sex hormone-binding globulin (SHBG), testosterone, total oestradiol (E2) and proportion of E2 not bound to blood proteins (percentage free E2) have been measured in a case-control study to test whether any of these factors are related to the risk of breast cancer. The cases studied were 27 premenopausal and 34 postmenopausal women with newly diagnosed localized breast cancer who were admitted to the All-Union Cancer Research Centre, Moscow. The controls were an equivalent number of women from the same neighbourhood. These were matched for age (within 2 years) and menopausal status. The average levels of E2 in cases were significantly higher than controls (p = 0.004 and p < 0.001 for pre- and postmenopausal groups, respectively). Percentage free E2 was significantly raised only in premenopausal cases (p = 0.019). The plasma concentrations of testosterone and SHBG were similar for both pre- and postmenopausal groups. Raised E2 or percentage free E2 was associated with an increased relative risk of breast cancer. However, only E2 levels (crude or adjusted for body build) were significantly related to risk in the two menopausal sets (p = 0.022 and p = 0.002, respectively). High percentage free E2 was associated with almost a threefold increase in the risk of breast cancer in premenopausal women; however, this increase was not statistically significant (p = 0.083). The levels of SHBG or testosterone, crude or adjusted for body build and E2 concentration, were not related to risk of breast cancer.

Adult↗
PubMed1992

Advanced breast cancer in Egyptian women: clinical features and response to endocrine therapy. The Anglo-Egyptian Health Agreement Collaborative Study.

Response to endocrine therapy and its relationship to the clinical features of the disease were studied in 84 Egyptian patients with inoperable, locally advanced or metastatic breast cancer. Twenty-four premenopausal patients were treated by oophorectomy with or without concurrent prednisolone. Only one of 20 evaluable patients achieved an objective response. Median time to progression for premenopausal patients was 3 months. Sixty postmenopausal patients received tamoxifen 10 mg twice daily either alone or with prednisolone. Fourteen of 57 (25%) evaluable patients achieved an objective response (four complete remission, 10 partial remission). Median duration of response was 13 months and median time to progression for all postmenopausal patients was 5 months (range 1-30 months). The outcome for postmenopausal patients was similar to that found in a parallel study at Guy's Hospital, London. The response rate for premenopausal Egyptian patients was, however, disappointing and lends support to the claim that breast cancer in Egyptian women is particularly aggressive.

Adult↗
PubMed1991

Serum hormone levels in British and rural Chinese females.

The comparison of blood levels of oestradiol, testosterone, prolactin, and sex-hormone binding globulin (SHBG) was made of 3250 rural Chinese and 300 British women, aged 35 to 64. To reduce the number of assays performed the blood samples were combined so as to form 390 and 30 pools, respectively. The Chinese had significantly less oestradiol and testosterone. Prolactin levels were similar in both races. SHBG was significantly lower in postmenopausal British women. In the Chinese women, testosterone was positively and prolactin negatively correlated with breast cancer mortality.

Adult↗
PubMed1991

Blood concentrations of estradiol and sex hormone-binding globulin in relation to age at menarche in premenopausal British and Japanese women.

In a cross-sectional study, serum estradiol (E2) and sex hormone-binding globulin (SHBG) concentrations were not significantly related to age at menarche in premenopausal British women in the luteal or follicular phases of the cycle. In Japanese subjects in the luteal phase, a marginally higher concentration of E2 was observed in those who had undergone an early rather than a late menarche. In British women, previous oral contraceptive users had significantly lower luteal phase E2 concentrations than never users.

Adult↗
PubMed1991

Selenium in human mammary carcinogenesis: a case-cohort study.

In a prospective study conducted on the island of Guernsey a cohort of 5162 ostensibly healthy women was enrolled between 1967 and 1976. Blood samples were drawn from each participant, who also completed a questionnaire, which provided information on established risk indicators in human mammary carcinogenesis. Plasma selenium levels were measured in 46 breast cancer cases diagnosed a mean of 11 (S.D. 4) years after entry into the study cohort and in an age-stratified sample of 138 women drawn from the study base. Plasma selenium level in the cases was 109 (28) micrograms/l and in the base sample 103 (22) micrograms/l (95% confidence interval for the overall difference, -2 to 14 micrograms/l). The adjusted relative risk of developing breast cancer in the different quartiles of the selenium distribution was 0.80, 0.79, 0.72 and 1.00, respectively. Thus, in the present study selenium was not a strong indicator of human breast cancer risk.

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↗
PubMed1991

Autocrine production of insulin-like growth factor II using an inducible expression system results in reduced estrogen sensitivity of MCF-7 human breast cancer cells.

An inducible expression vector, utilizing the metal response elements from the human metallothionein IIA promoter and encoding human prepro-insulin-like growth factor II (IGF-II), was transfected into MCF-7 McG cells, an MCF-7 subline which exhibits an estrogen dependent phenotype in vitro and does not express detectable levels of IGF-II mRNA. Two stably transfected clones, designated MI5 and MI7, which expressed IGF-II mRNA in a Zn2+ regulated manner, were isolated. Clone MI5 did not secrete detectable levels of IGF-II activity, as determined by radioimmunoassay of conditioned medium, but clone MI7 secreted high levels of IGF-II activity in a Zn2+ inducible fashion. Clone MI5 and control clones transfected with the selection plasmid pSV2 neo and the control plasmid pSP65 continued to display an estrogen dependent phenotype in vitro. However, under both anchorage dependent and anchorage independent growth conditions, clone MI7 cells exhibited an estrogen responsive, rather than dependent, phenotype. Moreover, when grown in the presence of inducing concentrations of Zn2+, MI7 cells were either virtually (for anchorage dependent growth) or completely (anchorage independent growth) unresponsive to estradiol. Both the basal growth rate in the absence of metal ions and the Zn2+ induced increases in cell proliferation could be inhibited by the monoclonal antibody alpha-IR3, which blocks the binding site of the IGF-I receptor. The antiestrogens tamoxifen and 4-hydroxytamoxifen were found to enhance the growth stimulation resulting from Zn2+ induced IGF-II production in MI7 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1991

Fiberoptic examination of the nasal cavity and nasopharynx in children.

A flexible fiberoptic nasolaryngoscope with color video camera was used to study the nasal cavity and nasopharynx in 243 pediatric patients. The size of the adenoid tissue was judged by endoscopy and classified into three types according to the distance from the vomer to the adenoid tissue. The condition of the nasopharyngeal orifice of the Eustachian tube was also classified into three types relating to the condition of adenoid tissue. Assessment was performed by correlating these measurements with the type of tympanogram, lateral X-ray and clinical complaints. The authors conclude that: (1) Fiberoptic examination allows direct visualization of the size and condition of the adenoid tissue, as well as of the condition of the nasopharyngeal orifice of the Eustachian tube. (2) The size of the adenoid tissue correlates very well with the nasal obstruction complaint as well as with the type of tympanogram. (3) The condition of the nasopharyngeal orifice of the Eustachian tube significantly corresponds with the type of tympanogram. (4) For the indication of adenoidectomy, fiberscopy gives more accurate information than standard X-ray. (5) With a correct choice of premedication and local anesthesia, it is a minor invasive technique which is very well tolerated by children. It is possible in all cases provided it is performed by a skilled endoscopist and preceded by careful explanation to the child. (6) Finally, thanks to the possibility of direct visualization of the fiberscopic image via a monitor, it allows a better explanation of the indication for adenoidectomy to the child's parents.

Acoustic Impedance Tests↗
PubMed1990

The relationship of free fatty acids with the binding of oestradiol to SHBG and to albumin in women.

Free fatty acid concentration, sex hormone binding globulin (SHBG) concentration, % free oestradiol and % SHBG-bound oestradiol were measured in fasting and non-fasting serum samples from 48 women. Free fatty acids were 128% higher (P less than 0.001) and % SHBG-bound oestradiol was 11% lower (P = 0.001) in fasting than non-fasting samples, but these changes were not significantly correlated (r = -0.16, P = 0.287). Mean SHBG concentration and % free oestradiol did not differ significantly between fasting and non-fasting samples. Between subject correlations were calculated for measurements from 30 premenopausal women: % free oestradiol was inversely correlated with SHBG and free fatty acids and positively correlated with Quetelet's Index; % SHBG-bound oestradiol was positively correlated with SHBG but was not consistently or significantly related to free fatty acids or Quetelet's Index. It was concluded that physiological increases in free fatty acid concentrations do not increase % free oestradiol and that free fatty acids are less important than SHBG concentration and perhaps other variables in determining differences between individuals in oestradiol binding to SHBG.

Adult↗
PubMed1990

Sex hormones in women in rural China and in Britain.

Plasma concentrations of certain hormones linked to breast cancer risk were measured in age-pooled samples from 3,250 rural Chinese women in 65 counties, and 300 British women, all aged 35-64. In age-groups 35-44, 45-54 and 55-64 respectively, mean oestradiol concentrations were 36% (P = 0.043), 90% (P less than 0.001) and 171% (P = 0.001) higher in the British than in the Chinese women, and mean testosterone concentrations were 48% (P less than 0.001), 68% (P less than 0.001) and 53% (P = 0.001) higher in the British than in the Chinese women. The difference in testosterone concentrations between the two countries appeared to be due largely to the lower average body weight in the Chinese women. Sex hormone binding globulin did not differ significantly between the two countries in age groups 35-44 and 45-54, but was 15% (P = 0.002) lower in the British than in the Chinese women at ages 55-64. Prolactin concentrations did not differ significantly between the two countries in any age group.

Adult↗
PubMed1990

Effects of a monoclonal antibody against progesterone, on embryo transport, development and implantation in laboratory mice.

A monoclonal antibody against progesterone (11P27) given on Day 2 of pregnancy interrupted pregnancy in BALB/c mice but not in BCF1 mice. The reason for this strain difference remains unclear, although it may involve discrimination by the recipient's immune system. The effects in BALB/c mice were reversed by progestin treatment. A dose of 5 nmol, which completely blocked implantation, had no significant effects on embryo transport and development on Day 4. A dose of 10 nmol did not increase the proportion of abnormal embryos, even though it accelerated tubal transport and increased embryo loss. No tubal retention was evident; most remaining embryos reached the uterus at the normal time. The transformation of morulae to blastocysts was only slightly delayed in 11P27-treated mice, and transfer experiments showed no decrease in embryo viability. The antibody appeared to act by blocking actions of endogenous progesterone on the uterus: uteri of 11P27-treated mice failed to develop a decidual cell reaction to intrauterine oil, and embryos from untreated donors failed to implant in 11P27-treated recipients. Antagonism of progesterone by antibody treatment prevented implantation in BALB/c mice apparently by actions on the uterus rather than on the embryo.

Animals↗