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M Jeffreys

Publications and source records attributed to M Jeffreys.

16 recordsLinked to original sources
PubMed2006

Breast composition measurements using retrospective standard mammogram form (SMF).

The standard mammogram form (SMF) representation of an x-ray mammogram is a standardized, quantitative representation of the breast from which the volume of non-fat tissue and breast density can be easily estimated, both of which are of significant interest in determining breast cancer risk. Previous theoretical analysis of SMF had suggested that a complete and substantial set of calibration data (such as mAs and kVp) would be needed to generate realistic breast composition measures and yet there are many interesting trials that have retrospectively collected images with no calibration data. The main contribution of this paper is to revisit our previous theoretical analysis of SMF with respect to errors in the calibration data and to show how and why that theoretical analysis did not match the results from the practical implementations of SMF. In particular, we show how by estimating breast thickness for every image we are, effectively, compensating for any errors in the calibration data. To illustrate our findings, the current implementation of SMF (version 2.2beta) was run over 4028 digitized film-screen mammograms taken from six sites over the years 1988-2002 with and without using the known calibration data. Results show that the SMF implementation running without any calibration data at all generates results which display a strong relationship with when running with a complete set of calibration data, and, most importantly, to an expert's visual assessment of breast composition using established techniques. SMF shows considerable promise in being of major use in large epidemiological studies related to breast cancer which require the automated analysis of large numbers of films from many years previously where little or no calibration data is available.

Algorithms↗
PubMed2006

Lifecourse weight patterns and adult-onset diabetes: the Glasgow Alumni and British Women's Heart and Health studies.

OBJECTIVE: To examine the association between body weight measures across the lifecourse and the risk of adult-onset diabetes. METHODS: We analysed data from the Glasgow Alumni Cohort and the British Women's Heart and Health Study (BWHHS). The former included 5,571 men and women who had height and weight measured at university, and reported birthweight, mid- and later-life weight in a postal questionnaire. The BWHHS analysis included 4,280 women who had height and weight measured in later adulthood and recalled their birthweight and early adult height and weight. Adult-onset diabetes was defined as doctor-diagnosed disease after age 30, either self-reported or abstracted from medical records. RESULTS: Thirty nine women and 209 men (Glasgow Alumni study) and 314 women (BWHHS) had diabetes. Those with diabetes had lower mean birthweight than those without, although the differences were small. Individuals with diabetes were also shorter and heavier at all ages than those without diabetes. Being overweight during at least one time period in adult life was associated with an increased risk of diabetes, compared to those who were never overweight. While there was no age at which being overweight was particularly detrimental, the risk associated with being overweight was cumulative across the lifecourse. CONCLUSIONS: Being overweight at any point during life is associated with an increased risk of adult-onset diabetes. The cumulative nature of this association reinforces the need to prevent the development of excess weight at an early age to reduce diabetes prevalence in coming decades.

Adolescent↗
PubMed2006

Association between sibship size and allergic diseases in the Glasgow Alumni Study.

BACKGROUND: Recent epidemiological studies consistently report an inverse association between sibship size and allergic disease, but evidence from individuals born before the 1980s is inconsistent. As information on relative permanence of this finding may offer clues to its biological explanation, the association between sibship size and allergic disease in individuals born between 1918 and 1952 was investigated. METHODS: Cross sectional surveys conducted by the Student Health Service at the University of Glasgow (1948-68) provided data on 14 140 men and women aged 16-30 years at the time of examination. The main outcome measures studied were self-reported asthma, eczema-urticaria, and hay fever. RESULTS: A total of 1677 individuals (11.9%) provided a positive history of at least one of the three allergic diseases: 457 (3.2%) asthma, 594 (4.2%) eczema-urticaria, and 885 (6.3%) hay fever. Compared with those without siblings (reference odds ratio = 1), the odds ratios (95% confidence intervals) for having any allergic disease among those with one, two or three siblings were 0.86 (0.75 to 0.99), 0.80 (0.69 to 0.93), and 0.70 (0.60 to 0.83), respectively (p(trend)<0.001). Increasing birth order and low socioeconomic position in childhood were associated with a lower risk of allergy. Adjustment for birth order, year of birth, age, sex, socioeconomic position in childhood, and family history of allergy did not materially alter the results. CONCLUSIONS: There is a robust inverse association between sibship size and allergic disease even among people born in the first half of the 20th century. These results favour relatively time-independent explanations for this phenomenon (such as the hygiene hypothesis or parity related changes in the intrauterine environment) over new environmental exposures.

Adolescent↗
PubMed2006

Initial experiences of using an automated volumetric measure of breast density: the standard mammogram form.

Limitations of area based measures of breast density have led several research groups to develop volumetric measures of breast density, for use in predicting risk and in epidemiological research. In this paper, we describe our initial experiences using an automated algorithm (standard mammogram form, SMF) to estimate the volume of the breast that is dense from digitized film mammograms. We performed analyses on 3816 mammograms of 626 women, who were part of the Glasgow Alumni Cohort and had mammograms taken within the Scottish Breast Screening Programme between 1989 and 2002. Absolute volume of dense breast tissue (SMF volume) and the percentage of the volume of the breast that is dense (SMF%) were calculated. The median (interquartile range) of SMF volume was 66 cm3 (48 to 98), and of SMF% was 23.4% (18.6 to 29.7). SMF%, but not SMF volume, was positively related to a six category classification (SCC) of visually assigned area-based breast density (increase in ln(SMF%) per category increase in SCC: 0.04% (95% CI: 0.03-0.05). The SMF algorithm produced lower SMF volume for craniocaudal (CC) compared with mediolateral oblique (MLO) views, but CC/MLO differences for SMF% were small. The mean right/left difference for ln(SMF volume) was -0.027 cm3 (95% confidence interval (CI) -0.044 to -0.009) and of ln(SMF%) was 0.005% (95% CI -0.008% to 0.019%). We present these initial data as a background for future analytical work using SMF.

Absorptiometry, Photon↗
PubMed2005

Acne in adolescence and cause-specific mortality: lower coronary heart disease but higher prostate cancer mortality: the Glasgow Alumni Cohort Study.

Androgen level or androgen activity is implicated in several health outcomes, but its independent role remains controversial. This study investigated the association between history of acne in young adulthood, a marker of hormone activity, and cause-specific mortality in the Glasgow Alumni Cohort Study. Male students who attended Glasgow University between 1948 and 1968 and participated in voluntary health checks reported history of acne (n = 11,232). Vital status has been traced, and risk factors in adulthood are known for about 50% of the participants. Those with a history of acne were more often nonsmokers while university students and tended to be from a lower socioeconomic position. The two groups did not differ in other adolescent (height, body mass index, blood pressure, and number of siblings) or in most adult risk factors. Students who reported a history of acne had a lower risk of all-cause (hazard ratio = 0.89, 95% confidence interval (CI): 0.76, 1.04) and coronary heart disease (hazard ratio = 0.67, 95% CI: 0.48, 0.94) mortality but had some evidence of a higher risk of prostate cancer mortality (hazard ratio = 1.67, 95% CI: 0.79, 3.55). This study shows that androgen activity during adolescence may protect against coronary heart disease but confer a higher risk of prostate cancer mortality.

Acne Vulgaris↗
PubMed2003

Body mass index in early and mid-adulthood, and subsequent mortality: a historical cohort study.

BACKGROUND: The aim of this study was to investigate the associations between body mass index (BMI) in early and mid-adulthood, and BMI change between these ages, and mortality. METHODS: Historical cohort study of 629 men, who had height and weight measured at the Student Health Service of the University of Glasgow in 1948-1949 (median age 22 y) and who reported their weight in a postal questionnaire in 1963-1966 (median age 38 y). The participants were followed up until April 2002 (mean follow-up: 35 y). During this time, 124 men died, 68 of cardiovascular disease (CVD) and 33 of cancer. FINDINGS: Mean BMI increased from 21.4 kg/m(2) (standard deviation (s.d.): 2.2 kg/m(2)) in early adulthood to 24.2 kg/m(2) (s.d.: 3.0 kg/m(2)) in mid-adulthood. All-cause mortality was associated with being overweight (BMI> or =25 kg/m(2)) at age 22 but not at age 38, adjusted hazard ratio (HR): 1.85 (95% confidence interval (CI) 1.09-3.13) and 1.05 (95% CI: 0.73-1.52), respectively. BMI at age 22 y was more strongly associated with CVD mortality than was BMI at age 38 y, adjusted HR(22 y): 2.41 (95% CI: 1.26-4.60) and HR(38 y): 1.33 (95% CI: 0.82-2.16). There was no clear relationship between cancer mortality and BMI at either age: HR(22 y): 0.68 (95% CI: 0.16-2.91), HR(38 y): 0.90 (95% CI: 0.44-1.84), although relatively few men died of cancer in the follow-up period. Similar patterns were seen for obesity (BMI> or =30 kg/m(2)) as for being overweight. Analyses of weight patterns indicated particularly detrimental effects of overweight persisting from early to mid-adulthood. CONCLUSIONS: BMI in early adulthood is positively related to CVD mortality in later life in men. The risk associated with early adulthood adiposity appeared to be greater than that in mid-adulthood. We did not demonstrate an association between weight gain and later mortality. These results reinforce the need to stem the obesity epidemic in children and young adults.

Adult↗
PubMed2003

Breast density: agreement of measures from film and digital image.

Mammographic density, in particular density from digital images, is increasingly used in breast cancer research. We investigated the concordance between density assigned by the same radiologist to a mammogram film and a digital image of the same mammogram. Two density measures were investigated, Wolfe parenchymal patterns and a six category classification (SCC) system of density. Included in the study were 78 women, 528 mammograms. Crude and weighted Kappa statistics were used to estimate agreement between the density assigned from the film and the image. Kappa for Wolfe measures was 71%, p<0.001 and for SCC measures was 54%, p<0.001. Weighted Kappa values were 79%, p<0.001 and 77%, p<0.001, respectively. There was some evidence to suggest that the digitized image may be assigned a higher Wolfe but not numerical category than the original film, and the magnitude of these differences was small. Neither age nor mammogram view (craniocaudal or mediolateral oblique) were related to the likelihood of agreement of the two density measurements. This evidence justifies the use of digital images in the visual assessment of breast density in research studies.

Breast Neoplasms↗
PubMed2000

The meme metaphor.

Explore the source record for details and available documents.

Cultural Evolution↗
PubMed1996

The heart rate response to carotid artery massage in a sample of healthy elderly people.

Carotid artery massage was carried out in a cross-section of 95 healthy elderly subjects (51 men and 44 women, mean age of 74 years) to assess the heart rate response and associated symptoms. These subjects were drawn from a larger group of randomly selected healthy elderly people living in Southampton. They had no history of myocardial infarction or stroke and were not taking any drugs that might enhance the carotid sinus reflex. A continuous distribution of response to carotid artery massage was seen with a median percent change in RR interval of 11.6% (IQR 22.9%); 66% had a percent change in RR interval of < 20%, 90% had a change of < 50%, and 9.5% a change of > 100%. Carotid sinus hypersensitivity (sinus arrest > 3 s) was found in 4 previously asymptomatic subjects; a prevalence of 4.2% (95% CI 1.2%-10.4%), and this was associated with dizziness in 2 of these 4 subjects. Dizziness also occurred in one other subject who had a change in RR interval of 178%. The definition of an abnormal carotid sinus reflex is arbitrary given the continuous RR interval response to carotid artery massage. In diagnosing carotid sinus syndrome, the RR interval response to carotid artery massage alone is not sufficient, as this maneuver must also reproduce the patient's presenting symptoms.

Aged↗
PubMed1991

A population survey of cardiovascular disease in elderly people: design, methods and prevalence results.

A cross-sectional survey of an age- and sex-stratified random sample of the elderly population living in Southampton was undertaken with the object of measuring the frequency of cardiovascular disease by questionnaire and examination, and assessing cardiac anatomy and physiological function by noninvasive methods. The response rate was 64% and 259 men and women aged between 65 and 95 years were interviewed and examined and had a twelve-lead ECG and chest radiograph. Forty per cent of men and 47% of women reported a diagnosis of one or more cardiovascular diseases, of which high blood pressure 33%, coronary heart disease 14% (angina pectoris 11% and myocardial infarction 8%), peripheral arterial disease of the lower limbs 7%, and cerebrovascular disease 6% occurred most frequently. With the exception of high blood pressure, which women reported more frequently than men (40% vs 27%), the prevalence of these diagnoses by sex was similar. The self-administered WHO questionnaires gave point prevalence estimates for angina pectoris of 13%, possible myocardial infarction 7% and intermittent claudication 5%, which were similar to reported prevalences of these diseases, although disagreement in the classification of individuals for each disease was common. When comparing the WHO chest pain questionnaire with the doctors' independent diagnosis of angina pectoris in this population, the sensitivity of the WHO questionnaire was 79%, with a specificity of 98% and a predictive value of 88%. For each sex the sensitivity of the WHO chest pain questionnaire was similar but specificity and predictive value were both lower for women.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1978

The effects of DL-5-hydroxytryptophan on ethanol consumption by rats.

Rats were offered access to either distilled water or a 12% v/v solution of ethanol as their only fluid during a one hour period daily. After daily fluid consumption has achieved a stable baseline, either distilled water or DL-5-hydroxytryptophan (5HTP) in doses of 50, 100 or 200 mg/kg was injected intraperitoneally one hour prior to the drinking session. While each of the three doses of 5HTP caused a significant reduction in ethanol intake, distilled water had no effect. Water consumption was unaffected by 5HTP or distilled water injections. Varying the pretreatment interval from 0.5, 1, 4 to 8 hours for the 100 mg/kg 5HTP dose resulted in a significant decrease in ethanol consumption at 0.5 and 1 hour pretreatment intervals only. In approximately 25% of the rats tested, 5HTP resulted in a prolonged rejection of ethanol so severe that it resulted in death. Selected rats offered water during this ethanol rejection period readily drank it and survived.

5-Hydroxytryptophan↗
PubMed1971

B.M.A. Planning Unit survey of general practice 1969.

A postal survey of 776 principals representative of general practice in Britain is described. Doctors working in health centres are compared both with colleagues in other group practices and with doctors who have no group practice allowance. Young doctors are mainly in group practice, especially health centres; the proportion of doctors who are not in groups is diminishing steadily, and they are mainly older. With some notable exceptions health centres provide most space, equipment, and staff; group practitioners in privately-owned premises spend more of their money on their practices, more often use appointment systems, and tend to make more efficient use of premises and staff. Overall, however, the picture is still one of general practice geared to the needs of practitioners working alone. Premises with space for sophisticated organization and for future teaching needs are unusual.Scotland, the North of England, and Wales have fewer young doctors. Average lists are higher in the North of England, and less money is invested in practice premises.Young doctors look for modern premises and the tools and staff for the job. If their career expectations are to be met the tremendous improvements made in some practices must be extended rapidly to the remainder.

Age Factors↗