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Biomedical subjects

K Hunt

Publications and source records attributed to K Hunt.

At least 73 records · Page 4Linked to original sources
PubMed1990

Social class and health in youth: findings from the west of Scotland twenty-07 study.

The assumption that social class inequalities in health are a persistent feature of the life-course has been questioned in a recent issue of this journal. On the evidence of mortality and chronic illness, the pattern in youth in Britain appears to be characterised by the lack of class differentials, a striking contrast to early adulthood where the familiar picture of health inequalities is observed. The possibility that this finding of relative equality in youth is a consequence of the limited, and potentially inappropriate, health indicators used has now been tested on a cohort of 15-year-olds in the West of Scotland. On a range of indicators, from subjective assessments to objective physical measures, very little evidence of class variation in health is found. The possible transience of the youth pattern is, however, indicated by findings from a cohort of 35-year-olds in the same study, among whom marked class gradients in health are apparent. Possible explanations for the transformation of a pattern of relative class equality in youth into one of inequalities in adulthood are discussed.

Adolescent↗
PubMed1990

Predicting contraceptive method usage among women in west Scotland.

Users of the six major methods of contraception are compared across a broad range of variables using data from a community sample. Differences between the groups were apparent for a range of socioeconomic and reproductive variables, and current users of the various methods also differed in their past use of contraception. Users of barrier methods fared particularly well. Few differences were observed for current health status or for the sociocultural variables examined, although users of natural methods differed from all others in their religious affiliation and commitment. Discriminant analysis showed that the most predictive variables distinguishing women who had opted for permanent methods of contraception (female sterilization and vasectomy) were the woman's stated reason for using her current method and her past contraceptive patterns; the inclusion of social, health and reproductive indicators did little to improve the prediction. It is argued that heightened expectations for contraceptive efficacy in the face of increasing concerns about long-term health consequences have contributed to the increased use of permanent methods.

Adult↗
PubMed1990

Mortality in a cohort of long-term users of hormone replacement therapy: an updated analysis.

OBJECTIVE: To reexamine the mortality experience of a cohort of long-term users of hormone replacement therapy (HRT) in comparison with that reported previously for the same cohort of women, paying particular attention to cardiovascular mortality, deaths from breast and endometrial cancer, and deaths attributed to suicide or suspected suicide. DESIGN: Longitudinal cohort of 4544 long-term users of HRT amongst whom mortality is being monitored prospectively in comparison with expected rates in the female population of England and Wales (taking account of age and calendar period). SUBJECTS: 4544 women, all of whom were recruited from specialist menopause clinics around Britain and had taken at least one year's continuous HRT at the time of recruitment to the study. MAIN OUTCOME MEASURES: All cause mortality, cardiovascular mortality, deaths from female cancers, deaths attributed to suicide or suspected suicide. RESULTS: Overall mortality (based on 236 deaths over the entire study period from recruitment to December 1988) remained significantly lower than expected on the basis of national rates (relative risk (RR) 0.56, 95% confidence limits (CL) 0.47-0.66). When specific causes were considered, the only mortality ratios greater than unity were for injury, poisoning and violence (1.54, 95% CL 1.02-2.06), and for suicide and suspected suicide ('suicide') (2.40, 95% CL 1.68-3.11). Comparison of the ratios for the 112 additional deaths with those obtained in our previous analysis revealed that one of the few ratios to show any increase was that for breast cancer mortality. This rose from a significant deficit of 0.55 (95% CL 0.28-0.96) in the earlier period to 1.00 (95% CL 0.55-1.45) in the later period. There was also a suggestion of an increase in breast cancer risk with increasing duration since first use of HRT. Most of the other cause-specific ratios were very similar over the two periods. The ratio of death from all circulatory diseases was notably lower in the later analysis (RR 0.37, 95% CL 0.15-0.58) than in the earlier analysis (0.51, 95% CL 0.36-0.69), as were all of the subcategories of cardiovascular death. The mortality ratio for cancer of the ovary and uterine adnexa fell from 1.12 in the previous analysis to 0.63 (95% CL 0-1.41). The mortality ratio for 'suicide' also decreased, but was only slightly lower in the later period. As before, however, there was evidence of a relatively high prevalence of prior psychiatric problems amongst the recent 'suicide' deaths, suggesting that the excess of deaths from 'suicide' may be a manifestation of selection. CONCLUSION: These data are consistent with a beneficial effect of HRT on cardiovascular diseases, although updated information comparing progestogen-opposed and -unopposed treatment is not available. The increase in breast cancer mortality contrasts with the pattern for all other specific causes examined; taken together with the suggestion of an increase in breast cancer mortality with increasing interval since first exposure to HRT, this finding is somewhat worrying.

Breast Neoplasms↗
PubMed1989

Comparison of two early season anthelmintic programmes on a commercial beef farm.

Two early season suppressive anthelmintic programmes, ivermectin given three, eight and 13 weeks after turn out and a morantel sustained release bolus administered at turn out, were compared on a commercial farm. The morantel treated cattle grew significantly faster than the ivermectin treated group during the period of treatment, on average at 0.80 kg/day compared with 0.71 kg/day (P less than 0.01). In the second half of the grazing season (13 to 25 weeks after turn out) the ivermectin treated group grew faster than the morantel treated group although the difference was not statistically significant. Over the entire grazing season there was no significant difference in average growth rate between the morantel treated group which grew at 0.80 kg/day and the ivermectin treated group which grew at 0.77 kg/day. These results were related to pasture larval counts, faecal egg counts and plasma pepsinogen levels throughout the grazing period. It was concluded that the morantel sustained release bolus allowed growing cattle to reach their production potential during the period of treatment. However, its efficacy in maintaining production throughout the grazing season was reduced by the 90 day treatment period which failed to give the level of control of gastrointestinal nematode parasites achieved by the 105 day period of treatment in the ivermectin programme.

Animals↗
PubMed1989

Changes in the spatial distribution of pulmonary blood flow during the fetal/neonatal transition: an in vivo study in the rabbit.

The spatial distribution of pulmonary blood flow was investigated in term fetal and neonatal rabbit littermates, using the plasma tracer fluorescein-isothiocyanate bovine serum albumin (FITC-BSA). A tracer bolus was injected intravenously and allowed 2 minutes to circulate in vivo, prior to arrest of the circulation and tissue preparation. In the fetus, fluorescence was only present in 43% of the lung volume, contained within discrete regions of "lobules." Some 57% of lung volume received no tracer inflow at all (during 2 min). In the fetal lung, the size of the potential airspaces in the perfused regions was 1.5 times larger than those in the nonperfused regions. In the fetus, a high pulmonary vascular resistance (PVR) is maintained. It is generally accepted that pulmonary blood flow in the fetus is evenly distributed to the entire vascular bed. Our results show that fetal pulmonary blood flow is distributed to discrete "lobules," while (over a 2 min period) the majority of "lobules" receive no flow at all. Thus, by directing flow to a lesser proportion of the vasculature, greater flow rates are achieved, and the risk of blood sludging and stasis is reduced. Alternation of perfusion with nonperfusion in each "lobule," perhaps regulated by the lobular arterioles, would permit both maintenance of the high fetal PVR and uniform lung development. In the neonatal lung, the plasma tracer was distributed uniformly to the entire vascular bed. This suggests that some of the reduction in PVR at birth is due to recruiting 50-60% of lung vasculature.

Animals↗
PubMed1988

Perceived value of treatment among a group of long-term users of hormone replacement therapy.

There have been many epidemiological studies on the effects of long-term use of hormone replacement therapy, but women's own views of this type of treatment have rarely been investigated. This paper presents data on experiences and perceptions of hormone replacement therapy from 3117 British women receiving the therapy who were attending a specialist menopause clinic, and in whom mortality and cancer incidence were being monitored. Almost 90% of the women claimed to have found the therapy helpful overall, although ascribed benefits for specific ;menopausal' symptoms were often much more equivocal. Data are also presented on women's sources of information about treatment options. More women identified the mass media or a personal contact (48%) than a health professional (41%) as their first source of information, and over 20% indicated that they had exerted pressure on their general practitioner to obtain the therapy. These data point to the key role that general practitioners can play in managing ;menopausal' symptoms once a woman has made the decision to consult.

Consumer Behavior↗
PubMed1987

The completeness of cancer registration in follow-up studies--a cautionary note.

In Britain the National Health Service Central Registers (NHSCRs) provide the facility for a study population to be 'flagged', initiating a system of notification to investigators of deaths and cancers that occur in the population. This system of notification is an invaluable resource for epidemiological research. A comment on its efficiency is provided here by a comparison of the system with an independently ascertained series of breast cancers. Fifty verified breast cancer cases were identified during a study of a flagged cohort of British women taking hormone replacement therapy. At the time of analysis (May 1985), some 2.5 years after diagnosis of the most recent case, twenty-eight of the 50 cases had not been notified to the investigators by the NHSCRs. Of these, fourteen had not been registered. Eight had been duly registered, but had not yet been recorded at the NHSCRs. Five of the remaining six cases were in the process of being notified. The implications of these findings for cancer researchers are discussed. The potential for omission and delay between the diagnosis of cancers in a flagged population and their notification to the investigators must be taken into account, if underestimation of the true level of cancer risk is to be avoided.

Breast Neoplasms↗
PubMed1987

Long-term surveillance of mortality and cancer incidence in women receiving hormone replacement therapy.

This paper reports the preliminary results of a cohort study of 4544 British women receiving hormone replacement therapy (HRT). These women were recruited at 21 specialist menopause clinics around Britain. Up to the end of June 1983, the mean duration of HRT use per woman was 67 months of which, on average, 43% was 'opposed' use. In general, however, both the amount of progestogen given and the number of days per cycle for which it was given was less than would have been the case if the women had been receiving modern opposed therapy. The major focus of the study was to monitor mortality and cancer incidence in the cohort. The mortality results were broadly reassuring: overall mortality was significantly lower than expected on the basis of national rates (relative risk 0.58) and mortality ratios were below unity for all specific causes of death examined apart from cancer of the ovary (relative risk 1.43, 95% confidence limits 0.62-2.82) and suicide or suspected suicide (relative risk 2.53, 95% confidence limits 1.26-4.54). The most likely explanation for the latter finding is selection bias--thus at least 7 of the 11 women who died from suicide or suspected suicide had a psychiatric history before receiving HRT. The cancer incidence results were less reassuring, although they should be interpreted with some caution because cancer registry rates were used for comparative purposes. With this proviso, endometrial cancer risk was significantly elevated (relative risk 2.84, 95% confidence limits 1.46-4.96); many of the women concerned had taken therapy which was predominantly or entirely opposed although only one woman had received an opposed regimen which would now be considered adequately protective to the endometrium. Breast cancer incidence was also significantly increased (relative risk 1.59, 95% confidence limits 1.18-2.10); detailed analysis suggested that the use of unopposed ethinyl-oestradiol in particular might have undesirable effects on the breast.

Breast Neoplasms↗
PubMed1987

Long-term effects of postmenopausal hormone therapy.

Short-term use of hormone replacement therapy is potentially useful in alleviating menopausal symptoms. Some people have suggested that it may also have a role in preventing certain other conditions. This could mean large numbers of women taking this therapy for quite long periods. Do we know enough about the long-term effects to recommend such use? In this article we review the recent evidence.

Breast Neoplasms↗
PubMed1986

Dental metric assessment of the omo fossils: implications for the phylogenetic position of Australopithecus africanus.

The discovery of Australopithecus afarensis has led to new interpretations of hominid phylogeny, some of which reject A. africanus as an ancestor of Homo. Analysis of buccolingual tooth crown dimensions in australopithecines and Homo species by Johanson and White (Science 202:321-330, 1979) revealed that the South African gracile australopithecines are intermediate in size between Laetoli/hadar hominids and South African robust hominids. Homo, on the other hand, displays dimensions similar to those of A. afarensis and smaller than those of other australopithecines. These authors conclude, therefore, that A. africanus is derived in the direction of A. robustus and is not an ancestor of the Homo clade. However, there is a considerable time gap (ca. 800,000 years) between the Laetoli/Hadar specimens and the earliest Homo specimens; "gracile" hominids from Omo fit into this chronological gap and are from the same geographic area. Because the early specimens at Omo have been designated A. afarensis and the later specimens classified as Homo habilis, Omo offers a unique opportunity to test hypotheses concerning hominid evolution, especially regarding the phylogenetic status of A. africanus. Comparisons of mean cheek teeth breadths disclosed the significant (P less than or equal to 0.05) differences between the Omo sample and the Laetoli/Hadar fossils (P4, M2, and M3), the Homo fossils (P3, P4, M1, M2, and M1), and A. africanus (M3). Of the several possible interpretations of these data, it appears that the high degree of similarity between the Omo sample and the South African gracile australopithecine material warrants considering the two as geographical variants of A. africanus. The geographic, chronologic, and metric attributes of the Omo sample argue for its lineal affinity with A. afarensis and Homo. In conclusion, a consideration of hominid postcanine dental metrics provides no basis for removing A. africanus from the ancestry of the Homo lineage.

Animals↗
PubMed1986

A bone marrow transplant with an acquired anti-Le(a): a case study.

A patient with aplastic anemia received an ABO incompatible bone marrow transplant (BMT) from an HLA identical sibling. Weekly HLA antibody screens were performed as part of the BMT protocol. At the time of transplant, a hemolytic anti-Le(a) was detected in the Le (a-b-) donor. The Le (a-b+) recipient had no red cell or LCT antibody. A hemolytic anti-Le(a) was detected in the recipient on day 8, but no LCT reactivity was noted at this time. On day 15, the LCT panel demonstrated reactivity with 9 of 50 panel cells without apparent HLA specificity. Graft vs. host disease (GVHD) was present on the skin at this time. The dose of cyclosporin A was increased, but by day 20 the GVHD worsened and the LCT titers increased to 8. This strong reactivity was noted only in the Le (a+) panel members (12/50) and was neutralized with commercial Lewis substance. On day 34 there was no evidence of GVHD, but the lymphocytotoxic anti-Lea continued to be present. The patient began experiencing renal and gastrointestinal difficulties by day 48, and expired on day 60. In renal transplants the kidneys retain their Lewis type and secrete Lewis substance in the urine. In our experience BMT patients retain their Lewis type regardless of the type of the donor. The Lewis system has been linked to renal allograft rejection, and Lewis antigens may function as transplantation antigens in BMT patients as well. In addition, lymphocytotoxic Lewis antibodies can mask other significant HLA antibodies and must be identified when screening patients in need of plateletpheresis products.

Anemia, Aplastic↗