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Biomedical subjects

D J Hunter

Publications and source records attributed to D J Hunter.

At least 235 records · Page 13Linked to original sources
PubMed1994

Commissioning and public health.

Improving the nation's health is a major challenge. It has a long history within the specialty of public health medicine, with is commitment to knowledge and actions. But achieving a balance between these activities has been a source of considerable tension within the specialty. The commissioning function, with its related dimensions of purchasing and contracting, provides the best chance for decades of aligning public health knowledge with the action that can produce health improvement. The concept of public health management seeks to bridge knowledge and action, drawing on a range of skills. But there is a long way to go before the necessary skills and capacities are demonstrated in practice. The organizational and personal development agenda remains very large. Yet, what is occurring in the NHS has not been achieved anywhere in the world. Describes one practical approach to strategic health development and commissioning. But it will require sustained commitment if it is to succeed.

Contract Services↗
PubMed1994

Vitamin A and cancers of the breast, large bowel, and prostate: epidemiologic evidence.

In this review we have examined epidemiological data from a variety of sources to assess the relation between vitamin A intake and cancer risk. The potential for recall bias in case-control studies makes their interpretation difficult, particularly if we are searching for modest associations. Prospective data are preferable, but sparse. Studies of blood levels of carotenoids may be informative if the blood is stored at ultra-low temperatures; however, studies of blood retinol levels are largely uninformative as an index of dietary intake because blood retinol is not well correlated with intake except in vitamin A-deficient populations. We have also reviewed the evidence for an influence of vitamin A intake on the incidence of cancer at the three major cancer sites accounting for a substantial portion of cancers in developed countries. The available data are compatible with a modest inverse association between intake of vitamin A and breast cancer, although it is not clear whether this effect may be due to preformed vitamin A, carotenoids, or both. The evidence that vitamin A protects against colon cancer is unconvincing. In the case of prostate cancer, early suggestions that vitamin A may increase incidence have not been confirmed by subsequent studies. Fortunately, prospective data from a number of large ongoing cohort studies in the United States and Europe should be available within the next 5 years or so. These data will permit further assessment of potential correlations between vitamin A and cancer at various sites by analysis of much larger numbers of cases than are presently available.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The genomic instability associated with integrated simian virus 40 DNA is dependent on the origin of replication and early control region.

DNA rearrangements in the form of deletions and duplications are found within and near integrated simian virus 40 (SV40) DNA in nonpermissive cell lines. We have found that rearrangements also occur frequently with integrated pSV2neo plasmid DNA. pSV2neo contains the entire SV40 control region, including the origin of replication, both promoters, and the enhancer sequences. Linearized plasmid DNA was electroporated into X1, an SV40-transformed mouse cell line that expresses SV40 large T antigen (T Ag) and shows very frequent rearrangements at the SV40 locus, and into LMtk-, a spontaneously transformed mouse cell line that contains no SV40 DNA. Stability was analyzed by subcloning G-418-resistant clones and examining specific DNA fragments for alterations in size. Five independent X1 clones containing pSV2neo DNA were unstable at both the neo locus and the T Ag locus. By contrast, four X1 clones containing mutants of pSV2neo with small deletions in the SV40 core origin and three X1 clones containing a different neo plasmid lacking SV40 sequences were stable at the neo locus, although they were still unstable at the T Ag locus. Surprisingly, five independent LMtk- clones containing pSV2neo DNA were unstable at the neo locus. LMtk- clones containing origin deletion mutants were more stable but were not as stable as the X1 clones containing the same plasmid DNA. We conclude that the SV40 origin of replication and early control region are sufficient viral components for the genomic instability at sites of SV40 integration and that SV40 T Ag is not required.

Animals↗
PubMed1994

Appropriate indications for prostatectomy in the UK--results of a consensus panel.

STUDY OBJECTIVE: The use of formal consensus development to determine appropriate indications for prostatectomy and to identify factors underlying clinical decisions about appropriateness is described. DESIGN: A nominal group technique was used. SETTINGS: The study took place in an academic research institution. PARTICIPANTS: The panel consisted of six urologists and three general practitioners. MEASUREMENTS AND MAIN RESULTS: The panel identified agreed indications for prostatectomy, expressed in terms of different combinations of type of retention, type and severity of symptoms, and level of comorbidity. Agreement was reached for 67% of the indications considered. For acute on chronic retention, surgery is indicated, regardless of symptom severity, if life expectancy is greater than one year. For acute or chronic retention, surgery is generally indicated if symptoms are severe, or if symptoms are moderate and life expectancy is greater than five years. For patients with neither acute nor chronic retention, surgery is indicated if symptoms are severe, or if these are moderate and life expectancy is greater than five years. For chronic or acute retention surgery is inappropriate if symptoms are mild and life expectancy is less than one year, or if there is no retention and only mild symptoms. An "appropriateness score" was developed. This confirmed that in general the ratings were internally consistent, that the panel attached little weight to mild symptoms, that a combination of irritative and obstructive symptoms was no more indicative of surgery than obstructive symptoms alone, and that the type of symptom was less important than the other factors considered. CONCLUSIONS: The results provide a basis for population based surveys of the need for prostatectomy.

Acute Disease↗
PubMed1994

Urinary symptoms: prevalence and severity in British men aged 55 and over.

OBJECTIVE: To measure the prevalence and severity of urinary symptoms among men aged 55 and over in the British population. DESIGN: Cross sectional population survey using a postal questionnaire. SETTING: North West Thames health region. SUBJECTS: 1480 men aged 55 years and over randomly selected from 8 general practices. MAIN OUTCOME MEASURES: Self reported frequency and severity of urinary symptoms, their bothersomeness and previous prostate surgery. RESULTS: The response rate among eligible subjects was 78%. The prevalence of moderate and severe symptoms was 204 per 1000, rising from 160 per 1000 in the 55-59 age group to 259 per 1000 in the 70-74 age group and declining after the age of 80 to 119 per thousand in the 85+ age group. Twelve per cent of men reported previous prostate surgery, and the probability of having had surgery increases steadily with age. About a third of those undergoing surgery have recurrence or persistence of symptoms after surgery. Of men with moderate and severe symptoms, 27.9% reported that their symptoms were a medium or big problem, 36.9% reported that their symptoms interfered with their daily activities at least some of the time, and 43.1% were unhappy or 'felt terrible' about the prospect of a future with their current symptoms. CONCLUSION: The prevalence of urinary symptoms in men is lower than previously reported, although there is a substantial number of men who are bothered by, or who find their lives adversely effected by them.

Activities of Daily Living↗
PubMed1994

Contraceptive methods and the transmission of HIV: implications for family planning.

Heterosexual transmission is the predominant mode of spread of the Human Immunodeficiency Virus (HIV) in most of the world. Whether the use of hormonal contraceptives, IUDs and spermicides is associated with an increased or decreased risk for HIV acquisition remains controversial. Several mechanisms whereby contraceptive methods may influence the transmission of HIV have been proposed. As contraceptive use increases among women of reproductive age, the group most vulnerable to HIV infection, any associations between contraceptive method and HIV risk become even more important. The available studies of these associations are predominantly cross-sectional and give conflicting results. We review the published evidence for associations between HIV and individual contraceptive methods. At this time no definitive conclusions regarding these associations can be drawn. Further research, especially prospective epidemiological studies and basic biological research on mechanisms of heterosexual transmission and the effect of contraceptives on these mechanisms, is urgently needed.

Condoms↗
PubMed1994

Risk factors for gonorrhoea, syphilis, and trichomonas infections among women attending family planning clinics in Nairobi, Kenya.

OBJECTIVE: To identify the risk factors for gonorrhoea, syphilis, and trichomonas infections among low risk women in Nairobi, Kenya. METHOD: In a cross-sectional study, 4,404 women attending two peri-urban family planning clinics between 1989 and 1991 were interviewed using a structured questionnaire and examined for signs of sexually transmitted disease (STD) infection. Cervical cultures for gonorrhoea, PAP smear (including microscopy for trichomonas), RPR and HIV testing were done. RESULTS: Positive cervical cultures for gonorrhoea were found in 3.2% of women, positive syphilis serology in 1.9%, and positive trichomonas microscopy in 5.2%. Genital ulcers were found in 1.9% of women. Although unmarried status and reporting more than one sex partner in the previous year were both significantly associated with each disease in the crude analysis, these associations were attenuated after controlling for each other and for other risk factors. The population attributable risks (PARs) for these factors were low (7-16%) owing to the high proportion of cases who were married and monogamous. The majority of women with microbiological evidence of infection had normal pelvic examinations. Clinical diagnostic algorithms for STDs in this population had a low sensitivity and positive predictive value. Nevertheless, a strong association between HIV seropositivity and STDs was observed. CONCLUSION: The low population attributable risks found in this study suggest that behaviour change messages directed to women, particularly if they are married have a low potential for preventing STDs. The poor performance of clinical diagnostic algorithms illustrates the desirability of testing these algorithms in a variety of populations and reinforces the need for low-cost methods of microbiologic diagnosis if populations with relatively low prevalences of these infections are to be included in programmes to diagnose and treat STDs.

Adolescent↗
PubMed1994

A prospective study of symptomatic gallstones in women: relation with oral contraceptives and other risk factors.

OBJECTIVE: To examine the relation between oral contraceptives (OCs), body mass index (BMI), weight change, alcohol use, parity, smoking, and symptomatic gallstones in women less than 45 years of age. METHODS: In this prospective study, associations between the various self-reported exposures and symptomatic gallstones were assessed in 96,211 female United States nurses with 425 cases of gallstones, using multiple logistic regression. RESULTS: We found little relation between ever-use of OCs and symptomatic gallstones (relative risk [RR] 1.2, 95% confidence interval [CI] 0.9-1.6), although there was a modest elevation in risk for long-term use (RR 1.5, 95% CI 1.0-2.2 for 10-14 years; RR 1.6, 95% CI 1.0-2.4 for 15 or more years). There was also an increased risk in current users of OCs (RR 1.6, 95% CI 1.1-2.4). The risk of symptomatic gallstones increased with increasing BMI and weight gain since age 18. Women with four or more births had an elevated risk of symptomatic gallstones (RR 2.0, 95% CI 1.3-3.2), and current cigarette smokers had a slightly higher risk than never-smokers (RR 1.3, 95% CI 1.0-1.7). The risk decreased with increasing alcohol intake. CONCLUSION: We found no substantial increase in the risk of symptomatic gallstones among ever-OC users, although current and long-term users had somewhat elevated risks. Body mass index remains the strongest predictor of symptomatic gallstones among young women.

Adult↗
PubMed1994

Risk factors for HIV infection among women in Dar-es-Salaam, Tanzania.

To identify risk factors for HIV infection among women not known to be members of high-risk groups in Dar-es-Salaam, Tanzania, and assess associations between contraceptive use and HIV infection, we conducted a cross-sectional case-control study at three representative family planning clinics. Between February 1991 and June 1992, we enrolled 2,285 women; women were interviewed using a structured questionnaire, and specimens were collected for laboratory diagnosis of HIV and other sexually transmitted diseases (STDs). The overall HIV prevalence was 11.5% (95% CI: 10.2-12.8). Other prevalent STDs included gonorrhea (4.2%), trichomoniasis (14.3%), candidiasis (11.5%), and syphilis (2.5%). HIV seroprevalence was significantly lower among younger women and women in nonpolygamous marriages. HIV risk increased with both women's education and male partner's education. Number of sex partners in the last 5 years was positively associated with HIV risk; however, among HIV-seropositive women, the median number of sexual partners was only two. For married women with only a single partner, their risk increased significantly if their husbands had other partners. The risk of HIV infection was higher among subjects with STDs, although only significantly so for gonorrhea (OR 1.95, 95% CI: 1.10-3.45). After controlling for known and potential risk factors, the risk of HIV infection was significantly increased among women who had ever used an intrauterine device (IUD) (OR 2.50, 95% CI: 1.35-4.64). Use of other contraceptives, including oral contraceptives, was not significantly associated with HIV infection. Our findings confirm that HIV and STDs are a major public health problem among women in Dar-es-Salaam.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Tubal ligation, hysterectomy, and risk of ovarian cancer. A prospective study.

OBJECTIVE: To assess whether tubal ligation and hysterectomy affect subsequent risk of ovarian cancer. DESIGN: Prospective cohort study with 12 years of follow-up. SETTING: United States, multistate. PARTICIPANTS: A total of 121,700 female registered nurses who were 30 to 55 years of age in 1976; the follow-up rate was 90% as of 1988. MAIN OUTCOME MEASURE: Ovarian cancer of epithelial origin confirmed by medical record review. RESULTS: We observed a strong inverse association between tubal ligation and ovarian cancer, which persisted after adjustment for age, oral contraceptive use, parity, and other ovarian cancer risk factors (multivariate relative risk [RR], 0.33; 95% confidence interval [CI], 0.16 to 0.64). The association was similar when we assessed tubal ligation status at the baseline questionnaire and excluded cases in the first 4 years to eliminate any possible short-term decrease in risk due to screening of the ovaries during ligation surgery. We noted a weaker inverse association between simple hysterectomy and ovarian cancer (RR, 0.67; 95% CI, 0.45 to 1.00). Neither vasectomy nor condom use by a partner was associated with risk of ovarian cancer. CONCLUSIONS: These data indicate that tubal ligation, and perhaps hysterectomy, may substantially reduce risk of epithelial ovarian cancer.

Adult↗
PubMed1993

Smoking cessation in relation to total mortality rates in women. A prospective cohort study.

OBJECTIVE: To examine the temporal relationship between stopping smoking and total mortality rates among middle-aged women. DESIGN: Prospective cohort study with 12 years of follow-up. SETTING: Registered nurses residing in the United States. PARTICIPANTS: 117,001 female registered nurses, ages 30 to 55 years, who were free of manifest coronary heart disease, stroke, and cancer (except nonmelanoma skin cancer) in 1976. MAIN OUTCOME MEASURES: Total mortality, further categorized into deaths from cardiovascular diseases, cancers, and violent deaths. RESULTS: A total of 2847 deaths (933 among "never smokers," 799 among former smokers, and 1115 among current smokers) occurred during 1.37 million person-years of follow-up. The multivariate relative risks for total mortality compared with never smokers were 1.87 (95% CI, 1.65 to 2.13) for current smokers and 1.29 (CI, 1.14 to 1.46) for former smokers. Participants who started smoking before the age of 15 years had the highest risks for total mortality (multivariate relative risk, 3.15; CI, 2.16 to 4.59), cardiovascular disease mortality (relative risk, 9.94; CI, 5.15 to 19.19), and deaths from external causes of injury (relative risk, 5.39; CI, 1.84 to 15.78). Compared with continuing smokers, former smokers had a 24% reduction in risk for cardiovascular disease mortality within 2 years of quitting. The excess risks for total mortality and both cardiovascular disease and total cancer mortality among former smokers approached the level of that for never smokers after 10 to 14 years of abstinence. The health benefits of cessation were clearly present regardless of the age at starting and daily number of cigarettes smoked. CONCLUSIONS: The risk of cigarette smoking on total mortality among former smokers decreases nearly to that of never smokers 10 to 14 years after cessation.

Adult↗
PubMed1993

A prospective study of the intake of vitamins C, E, and A and the risk of breast cancer.

BACKGROUND: Although it has been hypothesized that large intakes of the antioxidant vitamins C, E, and A reduce the risk of breast cancer, few prospective data are available. METHODS: We prospectively studied 89,494 women who were 34 to 59 years old in 1980 and who did not have cancer. Their intakes of vitamins C, E, and A from foods and supplements were assessed at base line and in 1984 with the use of a validated semiquantitative food-frequency questionnaire. RESULTS: Breast cancer was diagnosed in 1439 women during eight years of follow-up. After multivariate adjustment for known risk factors, the relative risk among women in the highest quintile group for intake of vitamin C as compared with the risk among those in the lowest quintile group was 1.03 (95 percent confidence interval, 0.87 to 1.21); for vitamin E, after vitamin A intake had been controlled for, the relative risk was 0.99 (95 percent confidence interval, 0.83 to 1.19). In contrast, among women in the highest quintile group for intake of total vitamin A the relative risk was 0.84 (95 percent confidence interval, 0.71 to 0.98; P for trend = 0.001). Among women in the lowest quintile group for intake of vitamin A from food, consumption of vitamin A from supplements was associated with a reduced risk (P = 0.03). The significant inverse association of vitamin A intake with the risk of breast cancer was also found on study of data based on the 1984 questionnaire and four years of follow-up. CONCLUSIONS: Large intakes of vitamin C or E did not protect women in our study from breast cancer. A low intake of vitamin A may increase the risk of this disease; any benefit of vitamin A supplements may be limited to women with diets low in vitamin A.

Adult↗
PubMed1993

Family history, age, and risk of breast cancer. Prospective data from the Nurses' Health Study.

OBJECTIVE: To examine prospectively the risk of breast cancer as influenced by a maternal history of breast cancer, the mother's age at diagnosis, or a sister's history of breast cancer. DESIGN: Prospective cohort study with biennial follow-up. SETTING/PARTICIPANTS: 117,988 women in the Nurses' Health Study aged 30 to 55 years in 1976, followed up through 1988 (1.3 million person-years of follow-up). RESULTS: We identified 2389 incident cases of invasive breast cancer. Compared with women without a maternal history of breast cancer, the age-adjusted relative risk (RR) of breast cancer was highest among women whose mother was diagnosed before the age of 40 years (RR, 2.1 [95% confidence interval, 1.6 to 2.8]). The RR decreased with advancing maternal age at time of diagnosis to 1.5 (95% confidence interval, 1.1 to 2.2) for maternal diagnosis after the age of 70 years. Having a sister with a history of breast cancer also was related to increased risk; for women with one sister with breast cancer compared with those with one sister without such a history, the age-adjusted RR was 2.3 (95% confidence interval, 1.6 to 3.4). Women whose mother and sister both had a history of breast cancer had an RR of 2.5 (95% confidence interval, 1.5 to 4.2) compared with those without a family history. These associations did not differ appreciably when stratified by age; menopausal status; history of benign breast disease; body mass index; age at menarche; or parity or age at first birth of the women at risk. The results remained unchanged when we controlled for these risk factors in multivariate models. Despite slightly greater mammography surveillance and earlier detection of tumors among women with a family history of breast cancer, detection bias is unlikely to account for more than a small part of the observed association. CONCLUSIONS: Risk of breast cancer is approximately doubled among women whose mother had breast cancer diagnosed before the age of 40 years or who have a sister with breast cancer, and remains elevated even for those whose mothers were diagnosed with breast cancer at the age of 70 years or older. However, the risk associated with a mother or sister history of breast cancer is smaller than suggested by earlier retrospective studies. Overall, within this population of middle-aged women, only 2.5% of breast cancer cases are attributable to a positive family history.

Adult↗
PubMed1993

Influence of maternal insulin-dependent diabetes mellitus on neonatal morbidity.

OBJECTIVE: To compare the neonatal morbidity rates (corrected for gestational age at delivery and method of delivery) among infants of women with insulin-dependent diabetes mellitus and those of women without diabetes. DESIGN: Historical cohort analysis. SETTING: Tertiary care centre. PATIENTS: All liveborn infants of women with insulin-dependent diabetes mellitus (IDM group) born between Jan. 1, 1980, and Dec. 31, 1989, each matched for gestational age at delivery, method of delivery and year of birth with two newborns of women without diabetes (control group). MAIN OUTCOME MEASURES: Neonatal respiratory distress, jaundice, hypoglycemia, polycythemia, hypocalcemia, intraventricular hemorrhage, seizure and macrosomia. RESULTS: There were 230 infants in the IDM group and 460 in the control group. Compared with the control group the IDM group had significantly higher incidence rates of glucose infusion (odds ratio [OR] 5.38), birth weight above the 90th percentile (OR 4.15) and neonatal jaundice (OR 1.94). No significant difference was found in the incidence rate of respiratory distress, polycythemia or hypocalcemia. The maternal serum hemoglobin A (HbA) level was not significantly related to birth weight, and neither the serum HbA level nor the presence of macrosomia was predictive of neonatal morbidity. Nearly 25% of the infants in the IDM group were born before 37 weeks' gestation; 48.2% of these were delivered early because of maternal hypertension. CONCLUSIONS: Neonatal morbidity in infants of women with diabetes is determined more by gestational age at delivery than by the maternal diabetes. Within the limits obtained in this study the degree of control of the diabetes does not seem to affect neonatal morbidity.

Adult↗
PubMed1993

Tackling inequalities in health: the Australian experience.

Federal and state governments in Australia have embarked on a series of national initiatives which show a firm commitment to tackling social inequalities in health. The development of national goals and targets for health, for example, covers social and environmental conditions and sets differential targets for specific social groups with very poor health status. In a complementary initiative, a wide ranging analysis of the health care system--the National Health Strategy--has as one of its main objectives to improve the equitable impact of the health system. Where problems of access to and quality of services have been exposed, policies have been devised to deal with them. The exceptionally poor health of the Aboriginal community has elicited cross party support for action. Resources have been allocated to implement the National Aboriginal Health Strategy: to improve living and working conditions, education, and employment opportunities. Britain can glean much from the Australian experience.

Australia↗