Search PubMed⌕ Search

Biomedical subjects

C Hayes

Publications and source records attributed to C Hayes.

At least 127 records · Page 7Linked to original sources
PubMed1990

Sexual partners of injecting drug users: the risk of HIV infection.

The sexual mediation of HIV infection by injecting drug users to the heterosexual population has become a major issue in AIDS prevention. Infection that is acquired through sharing contaminated injecting equipment can be passed on to non-injecting drug using partners and to non-drug using partners through sexual intercourse. A study of risk behaviour among injecting drug users in the North West of England focused, inter alia, upon aspects of their sexual activity and attitudes that have relevance for HIV transmission. It was found that in those respondents with regular partners, the level of sexual activity was related to the partner's use of drugs. The use of condoms was low in the sample as a whole, including those who reported having casual sexual contacts and sharing others' injecting equipment. These data confirm the need for concern and the advisability of targetting safer-sex education on drug users.

Adult↗
PubMed1990

AIDS-related risk behaviour, polydrug use and temazepam.

In a study of AIDS-related risk behaviour among injecting drug users in the north west of England it was found that 90% were polydrug users, and 28% were using temazepam. A third of all polydrug users had regularly used more than three drugs in addition to their preferred drug in the previous year. Statistical analysis revealed that the use of temazepam and extensive polydrug use were associated with sharing injecting equipment. Significant associations were also found with indices of sexual risk behaviour. It was concluded that multiple drug use and the use of temazepam were associated with behaviour that could increase exposure to HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Rehospitalization after initial rehabilitation for acute spinal cord injury: incidence and risk factors.

Many acute spinal cord injury (SCI) patients require rehospitalization after discharge from initial rehabilitation. Previous studies of rehospitalization for these patients have been cross-sectional with respect to time since injury (in years), and have not allowed for comparison of patients with equal exposure to the risk of medical complications once they have reentered the community. To examine the incidence, cause, and monetary cost of rehospitalizations during the first year after discharge from initial rehabilitative care (day 365), the medical records of 88 consecutive, acute SCI patients who completed initial rehabilitation at a regional model SCI care system were reviewed. Cases were excluded from the study if the patient was lost to follow-up before day 365. All readmissions to the regional SCI care system during the follow-up period were reviewed for primary diagnosis, length of stay (LOS), and hospital charges incurred. Thirty-four patients (39%) were readmitted at least once by day 365. There was a total of 47 readmissions; mean LOS was 11.9 +/- 2.1 days per admission (+/- 1SE), and mean hospital charge per admission was $9,683. Univariate comparisons between the characteristics of patients who were readmitted vs those who were not indicated that the readmitted group was less educated (11.8 +/- 2.1 years vs 12.9 +/- 0.3 years, p less than 0.05) and had a substantially longer initial rehabilitation LOS (88.9 +/- 6.6 days vs 72.9 +/- 5.1 days, p less than 0.05). Readmissions were less common among patients who were discharged at Frankel class C or D (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Tissue selenium levels in selenium-supplemented rats and their relevance in mammary cancer protection.

The present study was designed to investigate whether there is any correlation between the anticarcinogenic efficacy of selenium (Se) compounds and tissue Se retention under high levels of supplementation. With the use of the dimethylbenz[a]anthracene-induced mammary tumor model in chemoprevention experiments, our data showed that selenomethionine was not as active as selenite over a graded dose range from 1 to 5 p.p.m. Se. Tissue Se concentrations in blood, liver, kidney and skeletal muscle were always higher in rats given selenomethionine compared with those given selenite at each of the three levels tested (1, 3 and 5 p.p.m. Se). The difference was only minimal in blood, but became more pronounced in the liver and kidney, and was quite dramatic in the skeletal muscle. Thus a high tissue concentration or total body burden of Se is not necessarily an indicator of reduced susceptibility to carcinogenesis. The bioavailability of the Se pool in maintaining liver glutathione peroxidase activity during a period of Se deprivation, following excess selenite or selenomethionine loading, was also assessed. The half-life of decay of the enzyme was calculated to be 4.2 and 9.1 days respectively, in those rats that had already been exposed to 3 p.p.m. Se as either selenite or selenomethionine. From a nutritional viewpoint, selenomethionine may be superior to selenite, especially with respect to maintenance of glutathione peroxidase during periods of Se inadequacy, but the reverse seems to be true in terms of anticarcinogenic potency under high levels of Se supplementation. These results suggest that the nutritional and anticarcinogenic efficacies of a given Se compound may not be parallel to each other.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1989

Reexamination of London, England, mortality in relation to exposure to acidic aerosols during 1963-1972 winters.

Air pollution epidemiology since the 1950s has been able to demonstrate that increases in daily mortality in London, England, were associated with elevated concentrations of index air pollutants, i.e., British Smoke (BS) and sulfur dioxide (SO2). In this work, we reanalyze that portion of the 1958-1972 winter mortality-pollution record for which daily direct acid aerosol measurements were made at a central site in London (St. Bartholomew's Medical College). The purposes of these exploratory analyses are to examine the dataset for indications of a relationship between acid aerosol pollution and human mortality and to compare any noted associations with those for other pollution variables. It is found that the log of acid aerosol concentrations is more strongly associated with raw total mortality in bivariate analyses than is BS or SO2, despite the fact that acid data are available from only one central site (versus seven disperse sites for BS and SO2). The logarithmic nature of the exposure side of the H2SO4-mortality relationship implies a saturation model of pollution effects, possibly due to multiday pollution harvesting influences on a susceptible subpopulation. Moreover, mortality-pollution cross-correlation analyses indicate that mortality effects usually follow pollution in time, supporting a causal relationship between the two. The apparent advantage of H2SO4 over BS in predicting total raw mortality is consistent with the hypothesis that it is the portion of particulate mass of greater health significance and may also allow the development of London mortality results which are more easily transferable to other environments than is the case for existing BS results.

Acid Rain↗
PubMed1988

Effects of ambient ozone on respiratory function in active, normal children.

Respiratory functions were measured on a daily basis by spirometry over a period of 4 wk at a summer camp at Fairview Lake in northwestern New Jersey. Fifty-three boys and 38 girls 8 to 15 yr of age participated in the study on at least 7 days; 37 children were in residence for 4 wk, 34 for the first 2 wk only; and 20 for the last 2 wk. There were 72 whites, 15 blacks, 3 Asians, and 1 Hispanic in the study group. Multiple regression analyses indicated that the O3 concentration in the previous hour, the cumulative daily O3 exposure during the hours between 9 A.M. and the function measurement, ambient temperature, and humidity were the most explanatory environmental variables for daily variations in function, with the 1 - h O3 concentration having the strongest influence. Linear regressions were performed for each child between O3 concentration and function, and all average slopes were significantly negative (p less than 0.05) for FVC, FEV1, PEFR, and FEF25-75 for all children, and for boys and girls separately. Comparable results were obtained in data subsets (i.e., children studied during the first or second 2 wk only, and for data sets truncated at O3 less than 80 and O3 less than 60 ppb). The average regression slopes (+/- SE) for FVC and FEV1, respectively, were -1.03 +/- 0.24 and -1.42 +/- 0.17 ml/ppb, whereas for PEFR and FEF25-75 they were -6.78 +/- 0.73 and -2.48 +/- 0.26 ml/s/ppb.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Effects of ambient ozone on respiratory function in healthy adults exercising outdoors.

The effect of exposure to ozone (O3) in ambient air on respiratory function was studied in 30 healthy adult nonsmokers engaged in a regular daily program of outdoor exercise in Tuxedo, NY during the summer of 1985. Each subject did the same exercise each day, but exercise intensity and duration varied widely between subjects, with minute ventilation ranging from 20 to 153 L and duration ranging from 15 to 55 min. Spirometry was performed immediately before and after each exercise period. O3 concentrations during exercise ranged from 21 to 124 parts per billion (ppb). All measured functional indexes showed significant (p less than 0.01) O3-associated mean decrements with FVC at -2.1 ml/ppb, FEV1 at -1.4 ml/ppb, PEFR at -9.2 ml/s/ppb, FEF25-75 at -6.0 ml/s/ppb, and FEV1/FVC at -0.038%/ppb. Mean decrements were smaller for 10 subjects with minute ventilations greater than 100 L than for 10 other subjects with minute ventilations between 60 and 100 L or for the 10 subjects with minute ventilations below 60 L. Overall, the functional decrements were similar in magnitude to those we have seen in children engaged in supervised recreational programs in summer camps. For 10 subjects with minute ventilations comparable to those used in controlled 1- and 2-h exposures to O3 in purified air in chambers (50 to 80 L), the effects were about twice as large as those reported for the chamber studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Socioenvironmental characteristics associated with the onset of decline of ischemic heart disease mortality in the United States.

The relation of community socioenvironmental characteristics to timing of the onset of decline of ischemic heart disease (IHD) mortality was investigated among the 507 State Economic Areas of the continental United States. Onset of decline was measured using data for White men aged 35-74 and classified as early (1968 or before) vs late (after 1968). Ten socioenvironmental characteristics derived from US Census Bureau data were strongly related to onset of decline. Areas with the poorest socioenvironmental conditions were two to 10 times more likely to experience late onset than those areas with the highest levels. We found that income-related characteristics could account for most of the difference in onset of decline of IHD between metropolitan and non-metropolitan places. We conclude that community socioenvironmental characteristics provide the context for changes in risk factors and medical care.

Adult↗
PubMed1988

Obstetric practice in St Kitts and the Homerton Hospital, London.

Corinne Hayes and Karen Walker won 1000 pounds in last year's Student Elective Award competition for the protocol of their project. Here, they give an account of their work, the aims of which were to compare the incidence of low birthweight (less than 2.5 kg) and very low birthweight (less than 1.5 kg) babies in the UK and the Caribbean, to assess the outcome of these babies and to compare obstetric practice and the incidence of risk factors for low birthweight in the two populations.

Black People↗
PubMed1987

Changes in pituitary growth hormone cells prepared from rats flown on Spacelab 3.

Anterior pituitaries from "small" (250 g) and "large" (400 g) rats flown on the 7-day Spacelab 3 mission were pooled and trypsinized into two single-cell suspensions. Compared with ground-based controls, flight cells appeared to contain more intracellular growth hormone (GH) but release less GH over a 6-day culture period. After implantation into hypophysectomized rats, both sets of flight cells released only 50% of the GH compared with the control cells. Glands from large flight rats contained 44% somatotrophs compared with 37% for controls; small animals showed no difference. There were no striking differences in somatotroph ultrastructure between cells in the four groups. Western blot analysis indicated that there were no major differences in immunoactive GH variants. High-performance liquid chromatography fractionation of culture media indicated that small flight cells released much less of a high-molecular weight variant rich in GH bioactivity. The results suggest that GH cells from rats exposed to microgravity may experience secretory dysfunction. The possibility that this occurs directly at the pituitary cell level is discussed.

Animals↗
PubMed1987

Invasive squamous cell carcinoma of the vagina: a 14-year study.

A retrospective review was conducted of patients with squamous cell carcinoma of the vagina managed at one institution over a 14-year period. The 28 cases of squamous cell vaginal carcinoma constituted 3.1% of all female genital tract cancers. Forty-six percent of the patients had undergone a previous hysterectomy for benign disease or for cervical intraepithelial neoplasia; 14.2% had had irradiation. Disease of stage III or greater occurred in 43% of the study group. The majority of patients were treated by radiation therapy. The overall survival was 42.8%. This review indicates that patients who have had a previous hysterectomy should remain under close surveillance.

Adolescent↗
PubMed1986

Spontaneous lambda OR mutations suppress inhibition of bacteriophage growth by nonimmune exclusion phenotype of defective lambda prophage.

Survivor clones with defects in gene functions that participate in the replicative killing of thermally induced Escherichia coli constructs with integrated lambda N through P or cIII through P gene fragments were selected at a frequency of about 10(-6). Among the population of survivors, clones were identified that exhibited normal lambda immunity at 30 degrees C, as shown by their ability to prevent the plating of lambda wild type and to support the plating of a nearly identical heteroimmune bacteriophage lambda imm434. However, when placed at 42 degrees C to inactivate the cIts857 repressor, these survivor isolates excluded the plating of both lambda wild-type and lambda imm434 phages, a phenotype designated nonimmune exclusion (Nie). Spontaneous mutants of lambda wild type were isolated that overcame the Nie phenotype and would plaque at 42 degrees C on cell lawns of these isolates. The acquired lambda se mutations suppressed nonimmune exclusion, prevented lysogenization by interrupting repressor expression from PRM, and made the phage insensitive to replicative inhibition. The se mutations were genetically mapped and sequenced within the rightward lambda operator site.

Bacteriophage lambda↗
PubMed1986

Geographic variation in the onset of decline of ischemic heart disease mortality in the United States.

This report examines geographic variation in the onset of the decline of ischemic heart disease (IHD) mortality in white males aged 35-74 during the period 1968-78. Using a quadratic regression model, State Economic Areas (SEAs) were classified as experiencing onset of the decline in 1968 or earlier, 1969-72, or 1973 or later. In the United States as a whole, approximately one-third of SEAs experienced a late onset of the decline (after 1968). Metropolitan SEAs were in advance of non-metropolitan, and the Northeast and Pacific states showed earlier onset than the South and midsections of the country. The acceleration of the national decline after 1972 appears to be due to declines in areas in which rates had been increasing or in plateau until that time. Evidence about geographic variation in the onset of decline may provide clues about social and environmental factors responsible for the decline.

Adult↗
PubMed1986

Consolidated Omnibus Budget Reconciliation Act of 1985.

This article briefly describes the legislative history of the old-age, survivors, and disability insurance (OASDI) and supplemental security income (SSI) provisions, as well as related Medicare and Medicaid provisions, of the Consolidated Omnibus Budget Reconciliation Act of 1985 (Public Law 99-272). It includes a chronology outlining the interaction of the budget reconciliation process with the development of the OASDI minor and technical changes bill (H.R. 2005) and the development of other social security related legislation resulting in proposals that ultimately combined in the overall Consolidated Omnibus Budget Reconciliation Act of 1985. The article also provides a detailed summary of the provisions of the legislation.

Aged↗
PubMed1985

A longitudinal study of children exposed to sulfur oxides.

This study is a longitudinal comparison of the health of children exposed to markedly different concentrations of sulfur dioxide (SO2) and moderately different concentrations of particulate sulfate (SO4=). The four groups of subjects lived in two areas of one smelter town and in two other towns, one of which was also a smelter town. In the area of highest pollution, children were intermittently exposed to high SO2 levels (peak three-hour average concentration exceeded 2,500 micrograms/m3) and moderate particulate SO4= levels (average concentration was 10.1 micrograms/m3). When the children were grouped by the four gradients of pollution observed, the prevalence of cough (measured by questionnaire) correlated significantly with pollution levels (trend chi-square = 5.6, p = 0.02). No significant differences in the incidence of cough or other symptoms occurred among the groups of subjects over three years, and pulmonary function and lung function growth over the study were roughly equal among all the groups. These results suggest that intermittent elevations in SO2 concentration, in the presence of moderate particulate SO4= concentration, produced evidence of bronchial irritation in the subjects, but no chronic effect on lung function or lung function growth was detected.

Air Pollutants↗