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Biomedical subjects

P Mitchell

Publications and source records attributed to P Mitchell.

At least 577 records · Page 32Linked to original sources
PubMedDate not supplied

Changes in nutrient intakes of elementary school children following a school-based intervention: results from the CATCH Study.

BACKGROUND: Twenty-four-hour recalls were used to assess the change in nutrient intake among elementary-age school children exposed to the Child and Adolescent Trial for Cardiovascular Health (CATCH). The purpose of this paper is to compare changes in nutrient intakes between treatment groups, sexes, ethnic groups, and the four CATCH sites. METHODS: Twenty-four-hour recalls were administered to a subsample of the CATCH cohort at baseline in third grade and following the intervention in fifth grade (n = 1,182). Changes in nutrient levels for total energy, dietary cholesterol, and dietary fiber and changes in the proportion of energy from fat, protein, carbohydrate, and fatty acids were studied looking at differences by treatment group, sex, ethnicity, and site. Mixed-model analysis of variance was used to examine the change in nutrient intake, defined as intake at follow-up minus intake at baseline. RESULTS: Students in the intervention schools showed statistically significant differences in the changes in total energy and proportion of energy from total fat, saturated fat, protein, and monounsaturated fat compared with students in the control group. Students in the intervention group decreased their total fat intake from 32.7% of energy to 30.3% of energy and saturated fat from 12.8% of energy to 11.4% of energy. There were no significant differences in intervention effects by ethnic group, sex, or site. Differences in nutrient change between the school-only and the school-plus-family intervention groups were nonsignificant. CONCLUSION: The results show that a school-based intervention can positively influence children's intakes of total fat and saturated fat, suggesting that population-based approaches for reducing cardiovascular risk factors in children are feasible and effective. The results are also important in showing that the intervention was effective in Caucasian, African-American, and Hispanic students, in boys and girls, and across four regions of the United States.

Analysis of Variance↗
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Impact of fat reduction on micronutrient density of children's diets: the CATCH Study.

BACKGROUND: The purpose of this study was to examine the impact of fat reduction on vitamin and mineral density in the diets of groups of children who participated in the CATCH school-based intervention study for 2 1/2 years. METHODS: Twenty-four-hour dietary recalls were collected on 1,182 children residing in four states and with diverse ethnic backgrounds, at baseline when they were in third grade and again at follow-up when they were in fifth grade. RESULTS: With a 2.4% reduction in total fat intake from baseline levels in the intervention group, mean changes in vitamin and mineral intakes per 1,000 kcal of this group were small yet significant compared with the control group. As mean fat intake decreased, the nutrient density of most vitamins and minerals increased; the sole exceptions were vitamin E and sodium. Mean intake of all vitamins and minerals studied exceeded 2/3 of the RDA at both baseline and follow- up for both the intervention and the control groups. No significant differences were noted between treatment groups for the percentages of children meeting 2/3 or more of the RDA at both baseline and follow-up periods. CONCLUSIONS: CATCH was successful in maintaining mean vitamin and mineral intakes of intervention group children when total dietary fat was reduced.

Adolescent↗
PubMedDate not supplied

Osmochemistry of solute translocation.

The main aim of this brief contribution is to suggest that our understanding of the general principles of osmochemistry may provide useful insights into the type of mechanism by which solute-translocating catalysts work. In particular, I would like to encourage a more widespread and explicit recognition of the special merits of the mobile barrier type of mechanism (Mitchell, 1957, 1987), not as a panacea, but to explain the translocation of the characteristically hydrophilic and somewhat bulky solutes that are the main substrates of solute porters and of some osmoenzymes in bacterial membranes.

Bacteria↗
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The influence of anxiety as a risk to early onset major depression.

OBJECTIVE: we seek to identify and quantify any risk provided by several expressions of "anxiety" to major depression overall, and to separate melancholic and non-melancholic sub-types. METHOD: a sample of 269 patients with a current major depressive episode was assessed for rates of separate formalised anxiety disorders, both for lifetime and prior to the initial depressive episode. We also sought for evidence of familial anxiety and, early childhood expression of anxiety forerunners, measured both state and trait anxiety levels as well as anxiety at a "personality" level, and assessed use of anxiolytic medications. Depressive sub-typing was undertaken using DSM-IV criteria, while "early onset" (EO) depression was defined as an initial onset at 25 years or less, and subsequently re-examined with a cut-off age of 20 years or less. RESULTS: overall. 42% of our sample were assigned as having EO depression, with there being a higher representation of non-melancholic than melancholic EO subjects (i.e., 51% vs. 29%), arguing for sub-type status being respected in the analyses. For both melancholic and non-melancholic subjects two trait anxiety items ("tense"; "keyed up/on edge") were over-represented, suggesting that such a tense anxiety style may provide an antecedent risk to depression (of either sub-type) or be a consequence of depression. Specificity was most evident in the non-melancholic sub-sample, where EO depression was associated with a family history of anxiety, early childhood expressions of anxiety and with two lifetime anxiety disorders (social phobia and obsessive-compulsive disorder). Broadly similar results were returned when "EO" definition was reduced to 20 years or less. CONCLUSIONS: our study is consistent with previous research in identifying anxiety in the form of social inhibition or social avoidance as being particularly likely to precede and perhaps be a conduit to early onset non-melancholic major depression. This conclusion both sharpens risk factor research and indicates an important fulcrum that could be used to assist primary prevention of the depressive disorders.

Adult↗
PubMedDate not supplied

'Acting out' and 'acting in' behavioural stress responses: the relevance of anxiety and personality style.

OBJECTIVE: To look for links between 'acting out' and 'acting in' behavioural stress responses with anxiety and disordered personality function. METHOD: Depressed patients completed a self-report measure of behavioural responses to stress 1 year after baseline assessment of anxiety levels, personality functioning and other study variables. RESULTS: Patients were assigned to four factorial groups on the basis of variable 'acting out' and 'acting in' scale scores, and effects of individual scale scores also examined. 'Acting in' styles were indicative of high trait anxiety, disordered personality functioning and, in particular, a Cluster C personality disorder style. 'Acting out' was linked most clearly with a Cluster B personality disorder style. CONCLUSIONS: We demonstrate links between behavioural stress responses and anxiety levels and disordered personality functioning. Assessing behavioural stresses responses may shape the clinical expression of some depressive disorders and inform the clinician about the likely salience of anxiety and personality styles.

Acting Out↗
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Do early adverse experiences establish a cognitive vulnerability to depression on exposure to mirroring life events in adulthood?

BACKGROUND: We pursue a 'lock and key' hypothesis which posits that early adverse events ('locks') create an increased vulnerability to depression in the face of mirroring life events ('keys') in adulthood. Here we examine whether any such vulnerability links are cognitively mediated. METHODS: We study a sample of 96 clinically depressed patients who reported an identifiable 'cognitive schema' being activated when depressed. We examine for significant associations between early adverse events and later precipitants to the patients' depression, and then assess the extent to which any identified links are cognitively mediated. RESULTS: Qualitative analyses suggested quite strong associations between early childhood experiences and identified schemas, while the quantitative analyses identified few links. LIMITATIONS: These contrasting results may present a challenge to the hypothesis or reflect methodological limitations, and we therefore detail some of the complexities involved in identifying cognitive schemas.

Adaptation, Psychological↗
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Factors associated with use of glaucoma medications in a population of older people: The Blue Mountains Eye Study.

PURPOSE: To examine factors associated with use of glaucoma medications in a population of older people. METHODS: The Blue Mountains Eye Study examined 3654 people aged 49-97 years. Participants completed an interviewer-administered questionnaire which included information on current medication use. Open-angle glaucoma (OAG) was diagnosed if matching glaucomatous visual field defects and optic disc cupping were present. Ocular hypertension (OH) was diagnosed in subjects without glaucomatous disc and field changes who had an intraocular pressure (IOP) of > or = 22 mmHg in either eye or who had lower IOP levels but reported treatment with glaucoma medication. RESULTS: Use of glaucoma medication was reported by 3.3% of persons in this population (119/3644), including 44% of OAG and 28% of OH cases. Among newly diagnosed OAG and OH cases, 30% had never visited an ophthalmologist. Factors associated with a previous diagnosis of OAG or OH in a multivariate model included use of one or more general medications (OR 7.5; 95% CI 2.5-22.9), a history of other eye disease (OR 3.4; 95% CI 1.9-6.2) and first-degree family history of glaucoma (OR 3.6; 95% CI 1.8-7.2). CONCLUSIONS: Glaucoma screening may need to target individuals with OAG risk factors who are less likely to visit a general practitioner or ophthalmologist.

Adrenergic beta-Antagonists↗
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Carrots, carotene and seeing in the dark.

Should older people eat more carrots, or at least increase their carotene intake to prevent loss of night vision? Participants in the Blue Mountains Eye Study were asked about their ability to see in the dark. Nutrient and food intake were estimated from a food frequency questionnaire. Associations between self-reported poor night vision and estimated nutrient intake were investigated using logistic regression. Poor night vision among women was associated with higher beta-carotene (P for trend = 0.03) and total vitamin A intake (P for trend = 0.048). Increased consumption of carrots, but no other food high in beta-carotene, was associated with significant increased reporting of poor night vision among women (P for trend = 0.04). While carrot intake may protect against difficulty in seeing at night, it is probable that people attributing poor driving ability to their vision may be eating more carrots in the hope of reversing this decline.

Aged↗
PubMedDate not supplied

Diabetes, fasting blood glucose and age-related maculopathy: The Blue Mountains Eye Study.

PURPOSE: As diabetes is associated with other causes of visual loss (cataract, glaucoma) and elevated plasma fibrinogen, a risk factor for age-related maculopathy (ARM), our aim was to assess whether an association existed between diabetes and ARM. METHODS: After exclusions, 3228 persons aged 49-97 years were studied. Diabetes was assessed from history or fasting glucose > or = 7.0mmol/L. Early and ate ARM were graded from stereoscopic photographs. RESULTS: Late ARM (neovascular AMD or geographical atrophy) was found in 61 subjects (1.9%) while early ARM (large soft drusen and/or retinal pigment changes) was found in 171 (5.2%) subjects. Diabetes was present in 276 subjects (8.6%). Late ARM was present in 3.3% of subjects with and in 1.8% without diabetes. However, after adjusting for ARM risk factors, this difference was not statistically significant (OR 2.0; CI 0.9-4.6). Geographic atrophy was significantly associated with diabetes (OR 4.0; CI 1.6-10.3), but no association was found with either exudative ARM (OR 1.2; CI 0.4-3.5) or early ARM (OR 1.0; CI 0.5-1.8). No ARM associations were found with impaired fasting glucose. CONCLUSIONS: This study has found no consistent relationship between diabetes and ARM, apart from a statistically significant association with geographical atrophy alone.

Aged↗
PubMedDate not supplied

Renal impairment and anaemia in a population-based study of older people.

BACKGROUND: Established renal failure is a known cause of anaemia. However, the association between more modest levels of renal impairment and anaemia is unclear. AIMS: The aim of the present study was to investigate the association between mild renal impairment and anaemia in the general population. METHODS: A population-based, cross-sectional study was conducted in the general community in an urban area of the Blue Mountains, just west of Sydney, Australia. The study included 3222 people aged > or =49 years (mean age 65 years). Serum creatinine and haemoglobin were measured using standard laboratory techniques. Creatinine clearance was estimated from serum creatinine, body weight, sex and age. RESULTS: Two hundred and seventy subjects (8.4%) had serum creatinine levels > or =125 micromol/L and estimated -creatinine clearances were <0.84 mL/s (50 mL/min) in 894 subjects (27.7%) and <0.50 mL/s (30 mL/min) in 120 subjects (3.7%). There was a strong association between reduced renal function and anaemia. Compared to those with serum creatinine <125 micromol/L, the age-adjusted relative risk (RR) of anaemia in women (haemoglobin <12.0 g/dL) with serum creatinine > or =125 micromol/L was 5.5 (95% confidence interval (CI) 2.9-10.7) and the RR of anaemia in men (haemoglobin < 13.0 g/dL) was 3.1 (95% CI 1.6-6.0). Estimated -creatinine clearance <50 mL/min was associated with a three-fold increased risk of anaemia in women and a five-fold increased risk in men. CONCLUSIONS: The results of the present study suggest that even modestly impaired renal function is associated with anaemia in older men and women. The possibility of renal impairment should be considered in the diagnosis and management of anaemia in people aged>50 years.

Age Factors↗
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Cladribine followed by autologous stem-cell transplantation in progressive multiple sclerosis.

We studied the safety of autologous peripheral blood stem-cell transplantation (PBSCT) in four patients with progressive multiple sclerosis. Clinical and magnetic resonance imaging outcomes were secondary end-points. Cladribine administration preceded filgrastim-primed PBSC collection, aiming for lymphocyte depletion. Conditioning was with antithymocyte globulin and cyclophosphamide. The procedure was well tolerated, but without obvious clinical benefit. The study was terminated when other therapeutic options with lower morbidity became available.

Adult↗
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Idiopathic macular hypoplasia: a report of four cases and refinement of the phenotype of so-called ateliotic macula.

PURPOSE: To refine the phenotype of idiopathic macular hypoplasia, also referred to as ateliotic macula, by describing a series of cases with this diagnosis. METHODS: A review of the clinical characteristics of four patients as documented in medical records with regard to refractive error, visual acuity, anterior segment examination, retinal findings, and ancillary tests such as electroretinography (ERG). RESULTS: All patients had oval circumscribed or diffuse areas in the posterior pole where the retina appeared not to have developed normally; the fovea was involved in three patients with reduced visual acuity, and one patient had parafoveal lesions with preserved visual acuity. There were three males and one females. Patients' age ranged from 4 to 16 years. Errors of refraction ranged from severe myopia to hypermetropia and mild astigmatism. The anterior segment was normal in all patients. Three patients had strabismus and two had nystagmus. ERG was normal in the one patient in whom it was performed. One patient was mosaic for trisomy of chromosome 9. CONCLUSIONS: The term idiopathic macular hypoplasia can be applied to a spectrum of abnormalities in which a localized area of the posterior pole has a primordial or underdeveloped appearance. Lesions involving the fovea result in poor acuity. Generalized retinal dysfunction is absent. At least one of the genes involved in macular development may be located on chromosome 9.

Adolescent↗
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En-ticements.

Explore the source record for details and available documents.

Humans↗
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Professional development: a guide to profiling and portfolios.

Portfolio development and self-profiling are the subject of a current debate in nursing. Nurses at all levels have become increasingly aware of the need to document and record their professional achievements. This article discusses what is involved in the profiling process and how to compile a portfolio.

Documentation↗
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Serious and fatal firearm injuries among children and adolescents in Alaska: 1991-1997.

STUDY OBJECTIVE: To describe demographics, causal factors, intent, and incident locations of serious and fatal firearm injuries among children and adolescents in Alaska, for the years 1991 through 1997. METHODS: Data from the Alaska Trauma Registry plus Vital Statistics death certificates were reviewed for a seven-year period (1991-1997). Data elements included are: intent (ICD 9-CM E-Codes and narratives); age group; region of incident; place of occurrence; alcohol or drug involvement; type of firearm used; and perpetrator. RESULTS: During the seven-year study period, 222 children and adolescents ages 0-19 years were admitted to a hospital for a non-fatal firearm injury, plus 165 others received fatal firearm injuries. Of these 387 serious and fatal injuries, 34.9% (135) were determined to be unintentional, 36.4% (141) were suicides or suicide attempts, 23.3% (90) were homicide/assaults, 0.5% (2) were legal intervention, and for 4.9% (19) intent was unknown. Rates of serious and fatal firearm injuries per 100,000 youth for the six-year study period ranged from 14 in the Fairbanks North Star Borough and the Kenai Peninsula Borough to 105 in the Yukon-Kuskokwim Region. The statewide average for this period was 27.1 per 100,000 children and adolescents. CONCLUSIONS: Firearm injuries are a leading cause of serious and fatal injuries to children and youth in Alaska. This study suggests that many children and adolescents in Alaska who were injured by firearms, or who caused injury to other children or youth by firearms, had easy access to them. Efforts should be made to convince adults not to let children or at risk teenagers have unsupervised access to firearms, and to promote safe storage of firearms.

Accidents↗
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Mannan mucin-1 peptide immunization: influence of cyclophosphamide and the route of injection.

The mucin MUC1 is greatly increased in breast cancer and is a potential target for immunotherapy. In mice, MUCI conjugated to oxidized mannan (MUC1-mannan fusion protein [M-FP]) targets the mannose receptor and induces a high frequency of cytotoxic T lymphocytes and anti-tumor responses. On this basis, three phase I trials were performed in patients with adenocarcinoma to evaluate the toxicity and the immunologic responses to mannan MUCI. Forty-one patients with metastatic or locally advanced carcinoma of the breast (trial 1), colon (trial 2), and various adenocarcinomas (trial 3) received increasing doses of M-FP (1 to 300 microg). The immunizations were given at weekly intervals (weeks 1 to 3) and repeated in weeks 7 to 9. Cyclophosphamide (to increase cellular immunity) was given on weeks 1 and 4. M-FP was given intramuscularly in trial 1 and intraperitoneally in trial 2. No toxic effects occurred, and delayed-type hypersensitivity responses were present only as a microscopic lymphocytic infiltration. Overall, approximately 60% of the patients had high-titer MUC1 immunoglobulin G1 antibody responses, with the intraperitoneal route yielding approximately 10-fold higher responses. Cellular responses (proliferation, cytotoxic T cells, or CD8 T cells secreting tumor necrosis factor-alpha alphand interferon-gamma in response to MUC1 stimulation in vitro) were found in 28% of the patients, which was similar to that seen without cyclophosphamide. In most patients, disease progressed, but in five it remained stable. In addition, there were no objective responses. M-FP is not toxic and induces immune responses that were amplified by the intraperitoneal route of immunization. Cyclophosphamide was of no benefit.

Adenocarcinoma↗