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Biomedical subjects

M Richards

Publications and source records attributed to M Richards.

At least 55 records · Page 3Linked to original sources
PubMed2001

Fatigue in patients with cancers of the breast or prostate undergoing radical radiotherapy.

To determine the prevalence, severity, and correlates of fatigue among patients with cancers of the prostate or breast receiving high dose radiotherapy with curative intent, a prospective, questionnaire-based study evaluated a convenience sample of 62 patients who were about to start a course of radiotherapy. Patients were assessed immediately prior to treatment, and again within a week of finishing. Fatigue was assessed using the Fatigue Severity Scale (FSS) and the Bidimensional Fatigue Scale (BFS). Quality of life was assessed using the European Organisation for Research and Treatment of Cancer 30-item Quality of Life Questionnaire (EORTC QLQc30). Psychological distress was assessed using the Hospital Anxiety and Depression Scale (HADS). Personality Traits were assessed using the Eysenck Personality Inventory (EPI). Fatigue severity increased significantly on 3 out of the 5 assessment instruments used. Radiotherapy was associated with a decline in global quality of life, role, cognitive and social functioning, and an increase in nausea/vomiting, pain, insomnia, diarrhea, and financial difficulty. At baseline, 39% of the variation in fatigue scores among the patients could be explained by a combination of measures of their global quality of life and physical functioning. A combination of fatigue and anxiety scores at baseline was able to predict 54% of the variation in fatigue scores at the completion of radiotherapy. These data indicate that fatigue is a significant problem for patients receiving radical radiotherapy, although its severity is relatively modest.

Adult↗
PubMed2001

Vascular risk and cognitive impairment in an older, British, African-Caribbean population.

OBJECTIVES: In an older, British, African-Caribbean population with high prevalence rates of hypertension and diabetes mellitus, we ascertained clinical vascular disease (stroke or ischemic heart disease) and vascular risk (including hypertension, diabetes, and lipid profile) and investigated their associations with cognitive impairment. DESIGN: Cross-sectional community-based study. SETTING: The sample was drawn from registration lists for seven primary care services in south London, United Kingdom. PARTICIPANTS: 278 individuals, age 55 to 75, who were born in a Caribbean nation. MEASUREMENTS: Participants were interviewed and examined for cardiovascular risk factors, including a blood test for lipid profile and fibrinogen. A battery of 11 psychometric tests was administered blind to medical status. Cognitive impairment was defined on the basis of a composite measure derived from individual test scores. RESULTS: Seventy-nine (28%) subjects were classified as having relative cognitive impairment and were compared with the remainder of the sample. Marked differences were seen between low and normal/high educational levels in the strength of associations between measures of vascular risk and cognitive impairment. Hypertension, diabetes, and raised triglycerides were significant factors in those with lower levels of education. Low fibrinogen (negatively associated), high cholesterol, and manual occupation were significant factors in those with normal/high levels of education. Physical exercise was negatively associated with cognitive impairment: an association that persisted after adjustment for age, occupation, depression, and physical disability and after excluding subjects with the most severe imipairment. CONCLUSION: Measures of vascular risk were associated with relative cognitive impairment in this population. These associations were modified by previous educational attainment. Physical activity was negatively associated with cognitive impairment.

Black or African American↗
PubMed2001

Air pollution and birth weight in Britain in 1946.

Recent studies suggested that air pollution might be related to low birth weight. We tested this hypothesis on data from the British 1946 birth cohort. We found a strong association between birth weight and an air pollution index based on coal consumption. Babies born in the most polluted areas were on average 87 grams lighter than those born in the areas with the cleanest air. Adjustment for a number of sociodemographic factors did not change these estimates. While confounding by unmeasured factors cannot be ruled out, these historical data support the hypothesis that birth weight could be affected by air pollution.

Air Pollution↗
PubMed2001

C-type natriuretic peptide expression in olfactory regions of rat brain is modulated by acute water deprivation, salt loading and central angiotensin II.

To elucidate the central role of c-type natriuretic peptide (CNP), levels of CNP mRNA in control rat brain were compared with levels following acute water deprivation, salt loading and central administration of angiotensin II (AII), using Northern blot and in situ hybridisation. Rats with water deprivation (WD) had no access to water for 48 h, rats with salt loading (SL) had access to 2% saline for 48 h, and control rats had free access to water. Both WD and SL significantly raised plasma sodium (Na). Levels of CNP mRNA in olfactory regions were significantly decreased in WD and increased in SL. In the medulla, WD and SL both increased CNP mRNA, but levels of CNP mRNA elsewhere in the brain were not significantly altered. Intracerebroventricular AII (500 ng) increased water intake, and induced a significant increase in CNP expression at 4 h in olfactory regions, but not in other brain sites. In summary, CNP expression is regulated in olfactory regions of the rat brain in response to acute challenges to water and salt balance and by central AII.

Angiotensin II↗
PubMed2001

Stroke, vascular risk factors and depression: Cross-sectional study in a UK Caribbean-born population.

BACKGROUND: Stroke, hypertension and diabetes are common in older Caribbean-born populations in the UK who may be at risk of depression secondary to vascular disease. AIMS: We examined the association between stroke, vascular risk factors and depression in a community-based Caribbean-born population aged 55-75 years. METHOD: Vascular risk factors were identified by interview, examination and blood tests. Depression was categorised using the Geriatric Depression Scale. Disablement was assessed as a potential mediating factor. RESULTS: Physical illness and disablement were strongly associated with depression, independent of disablement. Previous stroke was associated with depression, independent of disablement. No vascular risk factors were associated with depression. CONCLUSIONS: The risk of depression associated with stroke was not explained by disablement. However, the hypothesis that vascular risk factors are important in the genesis of depression was not supported.

Age Distribution↗
PubMed2001

Long-term affective disorder in people with mild learning disability.

BACKGROUND: Increased risk of affective disorder in learning disability has been reported, although the extent to which this is due to adverse social and material circumstances is uncertain and there have been potential limitations in the measurement of affective disorder. AIMS: To determine risk of affective disorder in those classified with mild learning disability in the British 1946 birth cohort and to investigate whether this risk was accounted for by disadvantage in childhood and adulthood. METHOD: Learning disability was defined as the equivalent of an IQ < or =69 at age 15 years. The Present State Examination at age 36 years and the Psychiatric Symptom Frequency Scale at age 43 years provided psychiatric outcome measures. RESULTS: Learning disability was associated with a fourfold increase in risk of affective disorder, not accounted for by social and material disadvantage or by medical disorder. CONCLUSIONS: Learning disability is strongly associated with risk of affective disorder, persisting well into midlife.

Adolescent↗
PubMed2001

Fast trains, slow boats, and the ancestry of the Polynesian islanders.

The question of the origins of the Polynesians has, for over 200 years, been the subject of adventure science. Since Captain Cook's first speculations on these isolated Pacific islanders, their language affiliations have been seen as an essential clue to the solution. The geographic and numeric centre of gravity of the Austronesian language family is in island Southeast Asia, which was therefore originally seen as their dispersal homeland. However, another view has held sway for 15 years, the 'out of Taiwan' model, popularly known as the 'express train to Polynesia'. This model, based on the combined evidence of archaeology and linguistics, proposes a common origin for all Austronesian-speaking populations, in an expansion of rice agriculturalists from south China/Taiwan beginning around 6,000 years ago. However, it is becoming clear that there is, in fact, little supporting evidence in favour of this view. Alternative models suggest that the ancestors of the Polynesians achieved their maritime skills and horticultural Neolithic somewhere between island Southeast Asia and Melanesia, at an earlier date. Recent advances in human genetics now allow for an independent test of these models, lending support to the latter view rather than the former. Although local gene flow occurring between the bio-geographic regions may have been the means for the dramatic cultural spread out to the Pacific, the immediate genetic substrate for the Polynesian expansion came not from Taiwan, but from east of the Wallace line, probably in Wallacea itself.

Anthropology, Cultural↗
PubMed2001

Depression, APOE genotype and subjective memory impairment: a cross-sectional study in an African-Caribbean population.

BACKGROUND: Subjective memory impairment (SMI) is common in older populations but its aetiology and clinical significance is uncertain. Depression has been reported to be strongly associated with SMI. Associations with objective cognitive impairment are less clear cut. Other factors suggested to be associated with SMI include poor physical health and the apolipoprotein E (APOE) epsilon4 allele. Studies of SMI have been predominantly confined to white Caucasian populations. METHOD: A community study was carried out in a UK African-Caribbean population aged 55-75, sampled from primary care lists. Twenty-three per cent were classified with SMI. Depression was defined using the 10-item Geriatric Depression Scale. Other aetiological factors investigated were education, objective cognitive function, APOE genotype, disablement and vascular disease/risk. The principal analysis was restricted to 243 participants scoring > 20 on the Mini-Mental State Examination (85%). A second analysis included all 290 participants. RESULTS: Depression, self-reported physical impairment and APOE epsilon4 were associated with SMI. The association between SMI and physical impairment was not explained by depression, vascular disease/risk, or disability/handicap. The association between epsilon4 and SMI increased as MMSE scores decreased and was particularly strong in those with depression. The epsilon4 allele was present in 69% (95% CI 41-89%) of those with depression and SMI compared with 28% (20-36%) of those with neither. CONCLUSIONS: Depression may not be a sufficient explanation for subjective memory complaints. Memory complaints in the presence of depression are associated with high prevalence of epsilon4 and therefore, presumably, a raised risk of subsequent dementia.

Aged↗
PubMed2000

Tracing European founder lineages in the Near Eastern mtDNA pool.

Founder analysis is a method for analysis of nonrecombining DNA sequence data, with the aim of identification and dating of migrations into new territory. The method picks out founder sequence types in potential source populations and dates lineage clusters deriving from them in the settlement zone of interest. Here, using mtDNA, we apply the approach to the colonization of Europe, to estimate the proportion of modern lineages whose ancestors arrived during each major phase of settlement. To estimate the Palaeolithic and Neolithic contributions to European mtDNA diversity more accurately than was previously achievable, we have now extended the Near Eastern, European, and northern-Caucasus databases to 1,234, 2, 804, and 208 samples, respectively. Both back-migration into the source population and recurrent mutation in the source and derived populations represent major obstacles to this approach. We have developed phylogenetic criteria to take account of both these factors, and we suggest a way to account for multiple dispersals of common sequence types. We conclude that (i) there has been substantial back-migration into the Near East, (ii) the majority of extant mtDNA lineages entered Europe in several waves during the Upper Palaeolithic, (iii) there was a founder effect or bottleneck associated with the Last Glacial Maximum, 20,000 years ago, from which derives the largest fraction of surviving lineages, and (iv) the immigrant Neolithic component is likely to comprise less than one-quarter of the mtDNA pool of modern Europeans.

DNA, Mitochondrial↗
PubMed2000

Cognitive function in UK community-dwelling African Caribbean and white elders: a pilot study.

In recent years there has been interest in risk of cognitive impairment and dementia in populations of African origin. Little is known about this risk in older African Caribbean residents in the UK. One difficulty is lack of consensus over an adequate cognitive test battery for this community. Forty-five African Caribbean and 45 age and gender matched white community residents were recruited by household enumeration of an inner London electoral ward. These participants were administered the MMSE during a screening interview. Where possible, this was followed up by tests from the CERAD and CAMCOG neuropsychological batteries, a medical examination, and a structured interview with an informant. Based on these data, a psychiatrist blind to ethnicity independently rated 86 of these participants (41 of the African Caribbeans, all 45 of the whites) as cognitively normal, cognitively impaired, or demented. Of 41 African Caribbeans, 18 (44%) were rated as cognitively normal, 9 (22%) were rated as cognitively impaired, and 14 (34%) were rated as demented. Of the 45 whites, 39 (87%) were rated as cognitively normal, 4 (9%) were rated as cognitively impaired, and 2 (4%) were rated as demented. African Caribbeans scored significantly lower than whites in most cognitive test scores, which was not accounted for by their lower educational and occupational attainment, or their higher frequency of cardiovascular risk factors. African Caribbean elders in the UK appear to be at high risk of cognitive impairment and dementia. However, the influence of potential confounding factors such as socio-economic position and ill-health, and the effect of cultural test bias, cannot be ruled out.

Aged↗
PubMed2000

Median networks: speedy construction and greedy reduction, one simulation, and two case studies from human mtDNA.

Molecular data sets characterized by few phylogenetically informative characters with a broad spectrum of mutation rates, such as intraspecific control-region sequence variation of human mitochondrial DNA (mtDNA), can be usefully visualized in the form of median networks. Here we provide a step-by-step guide to the construction of such networks by hand. We improve upon a previously implemented algorithm by outlining an efficient parametrized strategy amenable to large data sets, greedy reduction, which makes it possible to reconstruct some of the confounding recurrent mutations. This entails some postprocessing as well, which assists in capturing more parsimonious solutions. To simplify the creation of the resulting network by hand, we describe a speedy approach to network construction, based on a careful planning of the processing order. A coalescent simulation tailored to human mtDNA variation in Eurasia testifies to the usefulness of reduced median networks, while highlighting notorious problems faced by all phylogenetic methods in this context. Finally, we discuss two case studies involving the comparison of characters in the two hypervariable segments of the human mtDNA control region in the light of the worldwide control-region sequence database, as well as additional restriction fragment length polymorphism information. We conclude that only a minority of the mutations that hit the second segment occur at sites that would have a mutation rate comparable to those at most sites in the first segment. Discarding the known "noisy" sites of the second segment enhances the analysis.

DNA, Mitochondrial↗
PubMed2000

Leptin-induced decrease in food intake in chickens.

The effect of intracerebroventricular (i.c.v.) injection of leptin was investigated using broiler and Single Comb White Leghorn (SCWL)-type chickens. These represent relatively fast- and slow-growing birds, respectively. The i.c.v. injection of leptin decreased food intake in both broilers and Leghorns in a dose-dependent manner. The most efficacious dose appeared to be 10 microg in both types of chickens. Water intake was generally not affected by leptin, indicating that this effect was not due to general malaise. It appears that leptin can act within the central nervous sytstem of birds to decrease food intake.

Aging↗
PubMed2000

Fatigue in patients with prostate cancer receiving hormone therapy.

The aim of this study was to determine the prevalence, severity and correlates of fatigue in a convenience sample of outpatients with prostate cancer prior to and following 3-months treatment with first-line hormone therapy (cyproterone acetate and goserelin). 'Severe fatigue' in the patients (n=62) was defined as a score on the Fatigue Severity Scale (FSS) greater than the 95th percentile of a group of elderly volunteers without cancer. Subjects also completed other questionnaires about fatigue and about quality of life, anxiety/depression and personality. Subjects underwent a nutritional assessment, tests of voluntary muscle function and attention. The prevalence of 'severe fatigue' at baseline was 8/58 (14%). Median FSS scores increased significantly after 3 months treatment. On multivariate analysis psychological distress explained 28% of the variance in fatigue scores. Treatment was associated with a reduction in voluntary muscle function, loss of muscle bulk, a decline in virility and potency, an improvement in pain and a reduction in nausea/vomiting. Fatigue is an important but under-recognised side-effect of hormone therapy.

Aged↗
PubMed2000

A study to investigate the prevalence, severity and correlates of fatigue among patients with cancer in comparison with a control group of volunteers without cancer.

BACKGROUND: Determining the prevalence of fatigue among cancer patients is complicated by the high prevalence of fatigue symptoms in the general population. The aim of this study was to determine the prevalence, severity and correlates of fatigue among both cancer patients and control subjects without cancer. PATIENTS AND METHODS: A total of 227 cancer patients and 98 control subjects were recruited to the study. They completed a number of questionnaires about fatigue, quality of life and psychological symptoms. The majority of subjects also underwent assessment of voluntary muscle function and nutritional status. Severe fatigue in the patients was defined as a score on the Fatigue Severity Scale in excess of the 95th percentile of the control group. RESULTS: The prevalence of severe fatigue was 15% among patients with recently diagnosed breast cancer, 16% among patients with recently diagnosed prostate cancer, 50% among patients with inoperable non small cell lung cancer and 78% among patients receiving specialist inpatient palliative care. In the patients a combination of dyspnoea, psychological distress, pain, and a measure of overall disease burden accounted for 56% of the variance in fatigue scores. CONCLUSIONS: Severe fatigue is a common problem among cancer patients, particularly those with advanced disease. Fatigue is significantly associated with the severity of psychological symptoms (anxiety and depression) and with the severity of pain and dyspnoea.

Adult↗