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Biomedical subjects

A Gavin

Publications and source records attributed to A Gavin.

17 recordsLinked to original sources

Immunology: Toll-like receptors and antibody responses.

Microbial components, such as lipopolysaccharides, augment immune responses by activating Toll-like receptors (TLRs). Some have interpreted this to mean that TLR signalling might not only help to initiate the adaptive immune response, but may also be required for it. The expanded view is shared by Pasare and Medzhitov, who conclude from an analysis of mice deficient in MyD88 (a TLR-signalling adaptor protein) that the generation of T-dependent antigen-specific antibody responses requires activation of TLRs in B cells. However, we show here that robust antibody responses can be elicited even in the absence of TLR signals. This appreciable TLR-independence of immune responses should be taken into account in the rational design of immunogenic and toleragenic vaccines.

Adaptor Proteins, Signal Transducing↗

Spironolactone reduces brachial pulse wave velocity and PIIINP levels in hypertensive diabetic patients.

AIMS: To assess whether spironolactone has beneficial effects on blood pressure (BP), N-terminal propeptide of type III procollagen (PIIINP) and pulse wave velocity (PWV) in hypertensive, type II diabetics. METHODS: Ten patients with type II diabetes and hypertension were enrolled in a randomized, double-blind crossover study comparing 4 months' treatment with spironolactone and placebo with a 4-week washout phase. BP, PIIINP and carotid-radial PWV were measured at the end of each treatment phase. RESULTS: Compared with placebo, spironolactone reduced systolic BP by 15.6 +/- 46.1 mmHg (P = 0.005, 95% CI 2.7-28.5 mmHg), PIIINP by 0.6 +/- 0.3 microg l(-1) (P = 0.04, 95% CI 0.02-1.1 microg l(-1)) and PWV by 0.6 +/- 0.2 m s(-1) (P = 0.008, 95% CI 0.18-1.02 m s(-1)). CONCLUSIONS: Spironolactone is effective at reducing systolic BP and brachial artery stiffness as indicated by PWV. It also reduces PIIINP in type II diabetic patients with hypertension.

Aged↗

Spectrum of cardiac abnormalities associated with long QT in stroke survivors.

OBJECTIVES: To find out what spectrum of cardiac abnormalities are found in those stroke survivors who can be deemed to be at high cardiac risk by their having long QT. METHODS: 202 patients with good recovery from a cerebrovascular event occurring at least one month previously were recruited into a prospective epidemiological study. These stroke survivors underwent a battery of cardiac investigations including 12 lead ECG, echocardiography, myocardial perfusion scanning, and heart rate variability assessment. The ECGs were digitised by a single observer blinded to the blood pressure and other investigations of the patients. The maximum heart rate corrected QT interval (QTc max) in the 12 lead ECG was derived by Bazett's formula. RESULTS: Prolonged QTc max significantly correlated with increasing blood pressure, left ventricular mass index, and depressed heart rate variability. As the number of cardiac abnormalities increased, QTc max became more prolonged. CONCLUSIONS: Long QT is significantly associated with left ventricular mass index even after adjustment for both systolic and diastolic blood pressures. Long QT was also associated with the total cardiac disease burden. These two observations may explain why stroke survivors with long QTc max were at greater risk of cardiac death.

Adult↗

Recent trends in cervical cancer mortality in Britain and Ireland: the case for population-based cervical cancer screening.

This study used published mortality data and regression techniques to look at time trends in cervical cancer mortality between 1970 and 2000 in the UK and the Republic of Ireland. Mortality from cancer of the cervix has been declining in the UK for at least the past 30 years. The rate of decrease has been greatest in England, Wales and Scotland and has accelerated in these countries since the reorganisation of screening services in the late 1980s. Mortality in Northern Ireland is also decreasing, but at a lesser rate and without significant change over the same period. In contrast, cervical cancer mortality in the Irish Republic, which, unlike the UK, does not have comprehensive population-based screening, has been increasing by an average of 1.5% per year since 1978. The mortality rate, which was half of that in the UK in the late 1970s, now exceeds that in any of the region of the UK. The absence of population-based screening for cervical cancer in the Republic of Ireland is the most plausible explanation for these differences in trend.

Adult↗

Evidence of prostate cancer screening in a UK region.

OBJECTIVE: To examine the pattern of use of prostate-specific antigen (PSA) testing in a UK region, where National Health Service policy does not recommend screening for prostate cancer. SUBJECTS AND METHODS: Data were collected on all PSA tests in Northern Ireland between 1990 and 1999. Annual rates of PSA testing were calculated by age, GP Practice and year. RESULTS: In all, 165 862 PSA tests were performed on 84 669 men, and over a third of men aged > or = 50 years had at least one PSA test. Men aged < 50 years accounted for 12.9% of first tests. The proportion of tests from primary care increased from 47.2% in 1993 to 67.0% in 1999. The mean age of men tested once decreased from 65.6 to 61.9 years (P trend < 0.001) and the proportion with an elevated PSA level also declined during the period. Repeat testing increased with PSA level (P < 0.001) but 29.4% of men with a PSA level of < or = 4 ng/mL also had repeat testing. Raised PSA values were more common from hospital than primary care (32.4% vs 20.6%, P < 0.001) and in older men. Test rates varied 100-fold across general practices, a finding not explained by sociodemographic factors, but one which reflects differential adherence to national guidelines, suggesting that general practitioners are key targets for attempting to rationalise the use of the PSA test. CONCLUSION: These findings suggest that PSA screening is taking place against evidence-based advice and has resulted in over 20 000 men being designated as having a raised PSA level, creating a need for further assessment.

Adult↗

Knowledge, attitudes and behaviour in the sun: the barriers to behavioural change in Northern Ireland.

To inform future health promotion programmes, we studied the knowledge, attitudes and behaviour of the Northern Ireland population to sun care. An interviewer-administered questionnaire was applied to one adult per household from a random sample of 1242 addresses. Lower levels of knowledge were found among respondents who were male, aged under 25 years or over 65 years, in a manual occupation or living in the west where health promotion activity on this topic was less active than in the east. Younger adults, females and professional groups were more likely to indicate that a suntan was important, healthy or attractive. Use of high factor sunscreen was inversely proportional to perceived importance of a suntan. Sunburn was more common in younger adults but more men reported multiple episodes of burning. Regular skin checks were uncommon and self-assessment of skin type was unrealistic indicating that sun care advice based on self assessment should be avoided in this population. Future campaigns should target appropriate messages at specific population subgroups. The study highlights the importance of collecting baseline information before implementing health promotion programmes and suggests that repeat monitoring is essential to ensure that key messages remain relevant. This study also indicates that Care in the Sun campaigns here impacted on general awareness in the population even with limited resources. There is, therefore, potential for greater impact with high funding levels.

Adolescent↗

Association of early life factors and acute lymphoblastic leukaemia in childhood: historical cohort study.

In a historical cohort study of all singleton live births in Northern Ireland from 1971-86 (n=434,933) associations between early life factors and childhood acute lymphoblastic leukaemia were investigated. Multivariable analyses showed a positive association between high paternal age (> or =35 years) and acute lymphoblastic leukaemia (relative risk=1.49; 95% confidence interval (CI)=0.96--2.31) but no association with maternal age. High birth weight (> or =3500 g) was positively associated with acute lymphoblastic leukaemia (relative risk=1.66; 95% CI=1.18--2.33). Children of mothers with a previous miscarriage or increased gestation (> or =40 weeks) had reduced risks of ALL (respective relative risks=0.49; 95% CI=0.29--0.80, and 0.67; 95% CI=0.48--0.94). Children born into more crowded households (> or =1 person per room) had substantially lower risks than children born into less crowded homes with also some evidence of a lower risk for children born into homes with three adults (relative risks=0.56; 95% CI=0.35-0.91 and 0.58; 95% CI=0.21-1.61 respectively). These findings indicate that several early life factors, including living conditions in childhood and maternal miscarriage history, influence risk of acute lymphoblastic leukaemia in childhood.

Abortion, Spontaneous↗

Use of complementary/alternative medicine by breast cancer survivors in Ontario: prevalence and perceptions.

PURPOSE: To determine the prevalence of use of complementary/alternative medicine (CAM) by breast cancer survivors in Ontario, Canada, and to compare the characteristics of CAM users and CAM nonusers. PATIENTS AND METHODS: A questionnaire was mailed to a random sample of Ontario women diagnosed with breast cancer in 1994 or 1995. RESULTS: The response rate was 76.3%. Overall, 66.7% of the respondents reported using CAM, most often in an attempt to boost the immune system. CAM practitioners (most commonly chiropractors, herbalists, acupuncturists, traditional Chinese medicine practitioners, and/or naturopathic practitioners) were visited by 39.4% of the respondents. In addition, 62.0% reported use of CAM products (most frequently vitamins/minerals, herbal medicines, green tea, special foods, and essiac). Almost one half of the respondents informed their physicians of their use of CAM. Multiple logistic regression analysis determined that support group attendance was the only factor significantly associated with CAM use. CONCLUSION: CAM use is common among Canadian breast cancer survivors, many of whom are discussing CAM therapy options with their physicians. Knowledge of CAM therapies is necessary for physicians and other health care practitioners to help patients make informed choices. CAM use may play a role in the positive benefits associated with support group attendance.

Attitude↗

Breast cancer survivors' perceptions of complementary/alternative medicine (CAM): making the decision to use or not to use.

The study described in this article explored breast cancer survivors' perceptions and experiences as they decided whether to use a variety of complementary/alternative therapies. Six focus groups were conducted composed of women who had been diagnosed with breast cancer. Each 2-hour session was audiotaped and transcribed verbatim. In this article, the process by which the participants made the decision to use or not to use complementary/alternative therapies, including their discovery and investigation of complementary/alternative medicine (CAM) and their experiences using or not using CAM, are described. Barriers to using CAM included cost, access, and time. Family and friends generally supported the decision to use CAM; however, the participants described health care practitioners' reactions as mixed.

Adult↗

The Northern Ireland Cancer Registry.

The Northern Ireland Cancer Registry was evaluated using a 5% sample of all cancers diagnosed histologically in 1983 as the standard for comparison. The overall registration rate was low. Two years following histological diagnosis only 63% of the cancers were registered and 19% of these were notified solely by the Registrar General's office. In a subgroup of patients who were known to have died by the time of the study, only 49% of the cancers were registered while the patient was alive. A further 30% of cases were registered only after death and 21% of cases went unregistered. There was no significant variation in registrations by area, by hospital or by age group. There was a considerable variation in registration rate by disease group. A low level of awareness among hospital doctors about the Northern Ireland Cancer Registry was postulated as a reason for the low levels of registrations received. This was investigated through a postal questionnaire. A response rate of 51% was achieved after two postings. Both the response rate and level of knowledge varied by grade and specialty of the doctor. Only 43% of responders knew of the existence of the cancer registry and only 2% registered patients more often than once a year. Possible methods for improving the system are discussed.

Data Interpretation, Statistical↗

Metabolic and organ mass responses to selection for high growth rates in the domestic chicken (Gallus domesticus).

Evolutionary hypotheses suggest that higher rates of postembryonic development in birds should either lower the resting metabolic rate (RMR) in a trade-off between the costs of growth and maintenance or increase RMR because of a buildup of metabolic machinery. Furthermore, some suggest that higher rates of postembryonic development in birds should reduce peak metabolic rate (PMR) through delayed tissue maturation and/or an increased energy allocation to organ growth. We studied this by comparing metabolic rates and organ sizes of fast-growing meat-type chickens (broilers) with those of birds from a laying strain, which grow much slower. During the first week of life, despite growing six times faster, the RMR of the broiler chickens was lower than that of birds of the laying strain. The difference between strains in RMR disappeared thereafter, even though broilers continued to grow twice as fast as layers. The differences between strains in growth rate during the first week after hatching were not reflected in similar differences in the relative masses of the heart, liver, and small intestine. However, broilers had heavier intestines once they reached a body mass of 80 g. In contrast, broilers had relatively smaller brains than did layers. There was a positive correlation, over both strains, between RMR and the masses of leg muscles, intestine, and liver. Furthermore, despite delayed maturation of muscle tissue, broilers exhibited significantly higher PMR. We hypothesize that a balance between the larger relative muscle mass but lower muscle maturation level explains this high PMR. Another correlation, between leg muscle mass and PMR, partly explained the positive correlation between RMR and PMR.

Analysis of Variance↗