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Biomedical subjects

A Mitchell

Publications and source records attributed to A Mitchell.

At least 19 recordsLinked to original sources
PubMed2007

[Female patients with arterial hypertension].

In Germany, more women than men die from cardiovascular causes. Women account for more than two thirds of the patients who die as a direct consequence of high blood pressure. Although arterial hypertension is a major risk factor for cardiovascular disease, and many drugs are available for hypertension treatment, less than 30% of hypertensive patients in Germany are controlled. There is a striking age-dependent development of blood pressure values in women compared to men. Blood pressure is lower in younger women than in men, a fact that likely contributes to the reduced cardiovascular risk in younger women. Hormonal changes that occur with menopause are thought to lead to an increase in cardiovascular risk in postmenopausal women to match that of men in the same age-group. To date, women and men are treated according to the same guidelines, since large studies have established a reduction in cardiovascular endpoints as a result of hypertension treatment. The database on putative differences in the effects and side-effects, as well as the effectiveness of the various classes of antihypertensive drugs dependent on gender is limited but growing.

Age Distribution↗
PubMed2006

Dietary determinants of post-menopausal bone loss at the lumbar spine: a possible beneficial effect of iron.

INTRODUCTION: Previous studies suggesting different effects of diet on post-menopausal bone loss may have given conflicting results because they sometimes failed to exclude confounding conditions or used imprecise methodology. DESIGN: To identify dietary determinants of bone loss from the lumbar spine after menopause in women not taking hormone replacement who developed no evidence of spondylotic or sclerotic degenerative disease, forty-three women were followed with repeated (mean = 12) measurements of bone mineral density (BMD) at L2-4 for 11-14 years. Eleven developed evidence suggestive of degenerative disease and were excluded. Diet was assessed at the beginning of the study and 2.5 years later using 3-day and 7-day periods of weighed intakes. Nutrients estimated were: carbohydrate, fat, protein, fibre, calcium, magnesium, iron, phosphorus, copper, zinc and six vitamins. We tested the ability of diet to predict post-menopausal bone loss using stepwise regression. RESULTS: Each woman's BMD change was described by a single coefficient after log transformation of the BMD data. The best model for BMD loss including dietary factors alone had two significant determinants: daily energy or protein (p=0.0003) intake was adverse, while dietary iron (p=0.002) was predictive of bone maintenance, an effect that persisted if iron was expressed as a ratio to energy intake. Adding body mass index to the model increased the goodness of fit (R (2)adj rose from 0.33 to 0.42) without affecting the statistical significance of the dietary determinants. CONCLUSIONS: Diet may influence bone loss after menopause, with dietary iron (or an associated factor) possibly having a protective effect on bone at the spine.

Body Mass Index↗
PubMed2006

No increase in human cases of Mycobacterium bovis disease despite resurgence of infections in cattle in the United Kingdom.

A resurgence of Mycobacterium bovis infections in cattle in the United Kingdom since the 1980s has raised concern about risks to human health. Enhanced surveillance data for England, Wales and Northern Ireland between 1993 and 2003 of culture-positive human M. bovis cases identified 315 M. bovis infections; the mean annual number of cases was 28 (range 12-41). The most frequently reported exposures were consumption of unpasteurized dairy products 41/83 (49%) and exposure to cattle 45/123 (37%). Of all cases, 249 (83%) were born before 1960. Of 50 cases born after 1960, only 14 were born in the United Kingdom. Over the same time period the annual number of new herd infections increased from 332 to 1749 as derived from the UK State Veterinary Service database. In conclusion, despite a more than fivefold increase in cattle herd infections during the 1990s, there was no increase in reported human cases.

Adult↗
PubMed2006

Status of Eldana saccharina (Lepidoptera: Pyralidae), its host plants and natural enemies in Ethiopia.

Surveys for sugarcane stem borers were undertaken in Ethiopia to determine the prevalence and distribution of these and their natural enemies in crops and indigenous host plants. Eldana saccharina Walker was not recovered from sugarcane, but was present in three indigenous wetland sedges, Cyperus papyrus, C. fastigiatus and C. dives in the southern, central and northern part of the country. The latter indigenous host plant was present in waterways adjacent to sugarcane on the commercial sugar estates. The tachinids Schembria eldanae Barraclough and Actia sp. were common parasitoids of E. saccharina larvae in these indigenous sedges. The braconid Dolichogenidea sp. was recovered from E. saccharina larvae in C. dives. Pathogens comprising Beauveria bassiana, Bacillus thuringiensis and Entomophthora sp., were found to be important mortality factors of E. saccharina larvae in the indigenous sedges. The occurrence of E. saccharina in Ethiopia is reported for the first time, and the host plant preferences of the borer and its indigenous natural enemies found during the surveys are recorded. In addition, its potential threat to sugarcane production in Ethiopia is discussed.

Animals↗
PubMed2005

Radiation dose reduction without compromise of image quality in cardiac angiography and intervention with the use of a flat panel detector without an antiscatter grid.

OBJECTIVE: To test the hypothesis that replacing the antiscatter grid with an air gap will reduce patient radiation exposure without significant compromise of image quality. METHODS: 457 patients having either uncomplicated diagnostic studies or a single vessel angioplasty (percutaneous transluminal coronary angioplasty (PTCA)) on a flat plate system (GE Innova) were studied. For two months their total dose-area product score was recorded on standard gridded images and then for two months on images made with the grid out, with an air gap used to reduce scatter. Detector magnification was reduced one step when an air gap was used to achieve the same final image size. A sample set of studies was reviewed blind by five observers, who scored sharpness and contrast on a non-linear scale. RESULTS: The average dose-area product was significantly reduced, both in the diagnostic group (n = 276), from a mean (SD) of 26.2 (14.7) Gy.cm2 with the grid in to 16.1 (12) Gy.cm2 with the grid out (p = 0.01), and in the PTCA group (n = 181), from 48.2 (36.2) to 37 (27.5) (p = 0.01). The mean image quality scores of the gridless cohort were not significantly different from those of the gridded cohort. CONCLUSION: With the use of a flat plate detector, air gap gridless angiography reduces the radiation dose to the patient and, in consequence, to the operator without significantly affecting image quality. It is proposed that gridless imaging should be the default technique for adults and children and in most installations.

Cohort Studies↗
PubMed2005

Cattle movements and bovine tuberculosis in Great Britain.

For 20 years, bovine tuberculosis (BTB) has been spreading in Great Britain (England, Wales and Scotland) and is now endemic in the southwest and parts of central England and in southwest Wales, and occurs sporadically elsewhere. Although its transmission pathways remain poorly understood, the disease's distribution was previously modelled statistically by using environmental variables and measures of their seasonality. Movements of infected animals have long been considered a critical factor in the spread of livestock diseases, as reflected in strict import/export regulations, the extensive movement restrictions imposed during the 2001 foot-and-mouth disease outbreak, the tracing procedures after a new case of BTB has been confirmed and the Government's recently published strategic framework for the sustainable control on BTB. Since January 2001 it has been mandatory for stock-keepers in Great Britain to notify the British Cattle Movement Service of all cattle births, movements and deaths. Here we show that movements as recorded in the Cattle Tracing System data archive, and particularly those from areas where BTB is reported, consistently outperform environmental, topographic and other anthropogenic variables as the main predictor of disease occurrence. Simulation distribution models for 2002 and 2003, incorporating all predictor categories, are presented and used to project distributions for 2004 and 2005.

Agriculture↗
PubMed2005

The use of denial in an ethnically diverse British cancer population: a cross-sectional study.

A total of 82 Asian and 117 randomly selected white Caucasian patients at the Leicestershire Cancer Centre were assessed using measures of coping and adaption to cancer. On the Mental Adjustment to Cancer (MAC) scale, Asian patients were more fatalistic (P < 0.0001) and had more significant hopeless/helpless scores (P = 0.007). The two ethnic groups answered the three questions thought to assess denial differently. Caucasians were more likely not to dwell on their illness (73 vs 55.5%, P < 0.0001) and agree with the statement 'I have difficulty believing this is happening to me' (73 vs 60.5%, P < 0.0001). However, Asian patients were more likely to agree with the statement 'I don't really believe I have cancer' (48.2 vs 31.3%, P = 0.019). Within both groups there was an association with denial and anxious preoccupation (P < 0.001). On the Hospital Anxiety and Depression (HAD) scale, there was no difference in anxiety scores between either sexes or between the Asian and Caucasian groups. However, Asian patients were more depressed (P = 0.001). Although denial was significantly related to the presence of both depression (P < 0.0001) and anxiety (P = 0.001) in the entire patient population, there were different predictors of denial in each subgroup. On multiple regression analysis depression was linked with denial in Caucasians, whereas Fighting Spirit (minus helplessness/hopelessness) was linked with denial in Asian patients. There are definite differences in coping styles in British cancer patients according to ethnicity. While significant numbers in both groups employ denial in some form, Caucasian patients appear to adapt to the psychological pressures of cancer more successfully than Asian patients at a particular point in time. Further work is required to elucidate longitudinal relationships between denial and adaption to cancer.

Adaptation, Psychological↗
PubMed2005

Herd-level risk factors associated with tuberculosis breakdowns among cattle herds in England before the 2001 foot-and-mouth disease epidemic.

A case-control study of the factors associated with the risk of a bovine tuberculosis (TB) breakdown in cattle herds was undertaken within the randomized badger culling trial (RBCT). TB breakdowns occurring prior to the 2001 foot-and-mouth disease epidemic in three RBCT triplets were eligible to be cases; controls were selected from the same RBCT area. Data from 151 case farms and 117 control farms were analysed using logistic regression. The strongest factors associated with an increased TB risk were movement of cattle onto the farm from markets or farm sales, operating a farm over multiple premises and the use of either covered yard or 'other' housing types. Spreading artificial fertilizers or farmyard manure on grazing land were both associated with decreased risk. These first case-control results from the RBCT will be followed by similar analyses as more data become available.

Animals↗
PubMed2005

Reconstructing the evolutionary history of the Lorisidae using morphological, molecular, and geological data.

Major aspects of lorisid phylogeny and systematics remain unresolved, despite several studies (involving morphology, histology, karyology, immunology, and DNA sequencing) aimed at elucidating them. Our study is the first to investigate the evolution of this enigmatic group using molecular and morphological data for all four well-established genera: Arctocebus, Loris, Nycticebus, and Perodicticus. Data sets consisting of 386 bp of 12S rRNA, 535 bp of 16S rRNA, and 36 craniodental characters were analyzed separately and in combination, using maximum parsimony and maximum likelihood. Outgroups, consisting of two galagid taxa (Otolemur and Galagoides) and a lemuroid (Microcebus), were also varied. The morphological data set yielded a paraphyletic lorisid clade with the robust Nycticebus and Perodicticus grouped as sister taxa, and the galagids allied with Arctocebus. All molecular analyses maximum parsimony (MP) or maximum likelihood (ML) which included Microcebus as an outgroup rendered a paraphyletic lorisid clade, with one exception: the 12S + 16S data set analyzed with ML. The position of the galagids in these paraphyletic topologies was inconsistent, however, and bootstrap values were low. Exclusion of Microcebus generated a monophyletic Lorisidae with Asian and African subclades; bootstrap values for all three clades in the total evidence tree were over 90%. We estimated mean genetic distances for lemuroids vs. lorisoids, lorisids vs. galagids, and Asian vs. African lorisids as a guide to relative divergence times. We present information regarding a temporary land bridge that linked the two now widely separated regions inhabited by lorisids that may explain their distribution. Finally, we make taxonomic recommendations based on our results.

Animals↗
PubMed2005

Current indications for contrast echocardiography imaging.

UNLABELLED: The assessment of regional ventricular function is dependent on good endocardial definition. Suboptimal images can be converted to diagnostic recordings in the majority of patients by contrast agents, which have become an indispensable aid in rest and stress echocardiography. In particular for stress echocardiography image quality is essential and contrast administration is of great importance. However this diagnostic procedure must be performed following the indications which reflect the risks of the procedure and consider the benefits of an accurate diagnosis on further patient management. The contraindications recently introduced in the use of the echo-contrast agent SonoVue for acute cardiac patients reflect the same contraindications which have been applied in stress echocardiography for several years. Clinical trials and post-marketing surveillance have demonstrated that this approach is safe with no fatalities reported. For all ultrasound contrast media, side effects have been reported but they are usually mild. However, rare allergic and potentially life threatening reactions may occur and the investigators have to be prepared for such an event with appropriate drugs stored in the echo department. In a recent retrospective analysis in 751 consecutive stress echocardiograms the use of contrast during dobutamine stress echocardiography was not associated with an increased risk of side effects. The incidence of side effects was very low and different in patients receiving Optison, SonoVue or without contrast agent. CONCLUSION: Ultrasound contrast agents are licensed for improvement of endocardial border definition. Data from clinical trials and wide clinical experience indicate an excellent risk/benefit ratio if the current contraindications are applied.

Echocardiography↗
PubMed2005

Assumptions about disease treatment challenged in a family health clerkship: views of first clinical year medical students.

CONTEXT: During a family health clerkship at the University of The West Indies, students are expected to acquire individual and community diagnosis skills and the ability to relate the two, as well as acquire knowledge of other community agencies involved in health care. OBJECTIVE: To determine the main assumptions related to disease treatment, which students have had to re-think after engaging in this clerkship. METHODS: End of clerkship assessments were carried out from two successive groups of third year medical students (n=64) at the University of West Indies, Jamaica. Students were asked to "list two assumptions regarding treating disease that have been challenged by your experience". A subsequent content analysis was done. RESULTS: Fifty-five students (86%) completed the assessment. All assumptions were listed (n=99) and similar issues were linked into emerging themes. Twenty-five groups of assumptions produced seven main themes: "Issues related to compliance" (27.3%),"Patient's treatment is mainly physical" (17.2%), " Superiority of western medicine over alternative" (15.2%), "Patients' health seeking behavior and attitudes" (12.1%), " The extent of the contribution of social factors on health" (12.1%) and "Patients' knowledge and understanding of health" (7.0%). CONCLUSION: The majority of students examined felt challenged on three themes: relating to issues of compliance, treating the "whole" patient not just the physical, and the superiority of western medicine over alternative. The three most popular individual assumptions were; patients have a mindset that favours compliance, medication affordability does not affect compliance and treatment is independent of social and environmental conditions.

Attitude of Health Personnel↗
PubMed2005

Evaluation of the broiler's ability to adapt to an early moderate deficiency of phosphorus and calcium.

We studied the ability of broiler chickens to adapt to early moderate P and Ca deficiencies by evaluating the impact of feeding different concentrations of P and Ca, from 1 to 18 d, on performance, bone characteristics, and nutrient absorption in the grower (Gr) period (18 to 32 d). Two starter (St) diets were fed from 1 to 18 d: a control (C) diet [0.45% nonphytate P (nPP) and 0.9% Ca] and a low (L) diet (0.30% nPP and 0.6% Ca). On d 19, half of the birds fed the St C diet were switched to a Gr C diet (0.40% nPP and 0.8% Ca), and the other half were switched to a Gr L diet (0.30% nPP and 0.6% Ca), whereas those fed the L diet in the St phase were fed the L diet in the Gr phase, resulting in a total of 3 treatments. Broiler chickens fed the St L diet weighed less (P < 0.05) than those fed the St C diet at 18 d; however, by 23 d they had they caught up to the C-C birds, and no BW differences (P > 0.05) were observed at 28 and 32 d. Feeding the St L diet resulted in decreased (P < 0.05) tibia ash at 18 d, but by 32 d their tibia ash was not different from that of birds fed the St C and Gr L diets. Broilers subjected to P and Ca restriction from hatch to 18 d absorbed more P and Ca during all times sampled than birds fed the St C and Gr C diets or those fed the St C and the Gr L diet. These results demonstrated that modern broilers exhibited a high adaptive capacity when they were exposed to early dietary P or Ca restrictions.

Adaptation, Physiological↗
PubMed2005

Is Post-Traumatic Stress Disorder a helpful concept for adults with intellectual disability?

BACKGROUND: Research using the concept of Post-Traumatic Stress Disorder (PTSD) with adults with intellectual disability (ID)assumes they perceive and react to traumatic events in a similar way to non-disabled adults. Reactions to trauma displayed by children may be relevant to adults with ID as well. METHODS: Two focus groups were held with professionals and practitioners to explore the relevance of criteria from child as well as adult literature to adults with ID who experience trauma. Descriptive thematic analysis was carried out. RESULTS: Abuse, parental bereavement, and having children removed were considered common sources of trauma. Similarities identified between disabled and non-disabled adults were flashbacks and nightmares; distressed by reminders; avoidance; hypervigilance and increased arousal. Differences were the frequent occurrence of multiple rather than single events, which were considered significant in generating chronic problems similar to those described as PTSD; also the occurrence of physical health problems and behavioural re-enactments. DISCUSSION AND CONCLUSIONS: Experienced professionals and practitioners considered most of the ideas from PTSD research with non-disabled adults to be relevant to adults with ID who experience trauma, but that some behaviour reported in research with children was also relevant. Topics and questions for use in clinical and research practice with individuals who have experienced trauma were proposed.

Diagnostic and Statistical Manual of Mental Disord↗
PubMed2004

Calcium phosphate-PEG-insulin-casein (CAPIC) particles as oral delivery systems for insulin.

An oral delivery system for insulin was developed and functional activity was tested in a non-obese diabetic (NOD) mice model. Calcium phosphate particles containing insulin was synthesized in the presence of PEG-3350 and modified by aggregating the particles with caseins to obtain the calcium phosphate-PEG-insulin-casein (CAPIC) oral insulin delivery system. Single doses of CAPIC formulation were tested in NOD mice under fasting or fed conditions to evaluate the glycemic activity. The blood glucose levels were monitored every 1-2h for 12h following the treatments using an ACCU CHECK blood glucose monitoring system. Orally administered and subcutaneously injected free insulin solution served as controls in the study. Based on the results obtained we propose that: (1). the biological activity of insulin is preserved in CAPIC formulation; (2). insulin in CAPIC formulations, but not the free insulin, displays a prolonged hypoglycemic effect after oral administration to diabetic mice; (3). CAPIC formulation protects insulin from degradation while passing through the acidic environment of the GI track until it is released in the less acidic environment of the intestines where it can be absorbed in its biologically active form; (4). CAPIC formulation represents a new and unique oral delivery system for insulin and other macromolecules.

Administration, Oral↗
PubMed2004

Incidence of hepatitis C virus infection and associated risk factors among Scottish prison inmates: a cohort study.

To gauge the incidence of hepatitis C virus (HCV) infection and associated risk factors among inmates during their imprisonment, the authors recruited adult males in a long-stay Scottish prison into a cohort study between April 1999 and October 2000. On two occasions (at 0 and 6 months), saliva was collected for anonymous HCV antibody testing and risk behavior data were obtained through a self-administered questionnaire. The participation rate was 85% at both initial recruitment (612/719) and follow-up (375/441; 171 men were ineligible for follow-up). For inmates who reported never having injected drugs, ever having injected drugs, having injected drugs during follow-up, and having shared needles/syringes during follow-up, HCV incidences per 100 person-years of incarceration risk were 1, 12, 19, and 27, respectively. Ever having injected drugs (relative risk = 13.0, 95% confidence interval: 1.5, 114.3) and having shared needles/syringes during follow-up (relative risk = 9.0, 95% confidence interval: 1.1, 71.7) were significantly associated with HCV seroconversion. The effectiveness of existing interventions, including the provision of bleach tablets for sterilizing injection equipment, was suboptimal. The development of methadone maintenance programs in prisons and the creation of drug courts to keep offending drug injectors out of prison might help to reduce transmission in this setting.

Adult↗