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Biomedical subjects

J Thomas

Publications and source records attributed to J Thomas.

At least 163 records · Page 9Linked to original sources
PubMed2000

Investigation of thermoelectric silicide thin films by means of analytical transmission electron microscopy

The microstructure of rhenium silicide thin films and its progress by annealing were investigated by means of analytical transmission electron microscopy. Sputtered amorphous films were characterised by analysis of the radial distribution function (RDF). The position of the first maximum of RDF represents the most probable distance between neighbouring atoms and decreases from 2.75 to 2.62 A in films with an increasing Si-content from 60 to 75 at%. This decrease correlates with the change of the temperature coefficient (TC) of the electrical resistivity. During in situ annealing, the formation of nanocrystals in films with different Si-contents was observed. In thin films with 64 at% the quantity of nanocrystals increases after 1 h at 900 K whereas their sizes remain unchanged. The crystallisation in Re-rich thin films proceeds lower and produces larger crystals than in films near to the ReSi1.75 stoichiometry. Sputtered epitaxial ReSi1.75 films on Si (1 0 0) consist of crystals with nanometer size and an azimuthal torsion of 45 degrees.

Journal Article↗
PubMed2000

Health promotion and the role of the school nurse: a systematic review.

This paper describes findings from a systematic review of the literature on the effectiveness of school nurses in promoting the health of school children. The paper gives a brief account of the background to the study and the search strategy adopted. Some key findings are presented and discussed. The brief for the review was to seek evidence of effectiveness in the practice of school nurses. The results of the review were disappointing, in that little research of acceptable quality was found and little could be said about effectiveness. The result is therefore a more diffuse review that gives a summary of descriptive research and current views and opinions, although it does also present some pointers for future research. The study was funded by Health Promotion Wales.

Child↗
PubMed2000

Managers forum

Explore the source record for details and available documents.

Journal Article↗
PubMed2000

Methionine adenosyltransferase I/III deficiency: novel mutations and clinical variations.

Methionine adenosyltransferase (MAT) I/III deficiency, caused by mutations in the MAT1A gene, is characterized by persistent hypermethioninemia without elevated homocysteine or tyrosine. Clinical manifestations are variable and poorly understood, although a number of individuals with homozygous null mutations in MAT1A have neurological problems, including brain demyelination. We analyzed MAT1A in seven hypermethioninemic individuals, to provide insight into the relationship between genotype and phenotype. We identified six novel mutations and demonstrated that mutations resulting in high plasma methionines may signal clinical difficulties. Two patients-a compound heterozygote for truncating and severely inactivating missense mutations and a homozygote for an aberrant splicing MAT1A mutation-have plasma methionine in the 1,226-1,870 microM range (normal 5-35 microM) and manifest abnormalities of the brain gray matter or signs of brain demyelination. Another compound heterozygote for truncating and inactivating missense mutations has 770-1,240 microM plasma methionine and mild cognitive impairment. Four individuals carrying either two inactivating missense mutations or the single-allelic R264H mutation have 105-467 microM plasma methionine and are clinically unaffected. Our data underscore the necessity of further studies to firmly establish the relationship between genotypes in MAT I/III deficiency and clinical phenotypes, to elucidate the molecular bases of variability in manifestations of MAT1A mutations.

Adolescent↗
PubMed2000

Quality of life in schizophrenia: a comparison of instruments. Department of Veterans Affairs Cooperative Study Group on Clozapine in Refractory Schizophrenia.

Health-related quality of life in schizophrenia can be assessed by direct patient response or by a rating based on a structured interview. This study compares both types of instruments using a series of five standards: (1) sensitivity to change over time, (2) sensitivity to treatment effect, (3) correlation with symptom severity, (4) correlation with global clinical ratings, and (5) correlation with other measures of health-related quality of life. Four hundred and twenty-three inpatients with schizophrenia participating in a clinical trial comparing clozapine and haloperidol (VA Cooperative Study in Health Services #17) were evaluated using multiple measures of health-related quality of life (Lehman Quality of Life Interview; Heinrichs-Carpenter-Hanlon Quality of Life Scale; Strauss-Carpenter Level of Function scale, and clinical response.) The Quality of Life Interview showed less sensitivity to change and treatment effect, as well as lower correlations with all other measures than the Quality of Life Scale and the Level of Function scale. The latter scales showed high sensitivity to both change and treatment effect, and moderate-high correlations with other measures and with each other. The Quality of Life Scale and the Level of Function scale rater assessments appeared to be substantially more sensitive to subtle change and treatment effects than the patient-reported Quality of Life Interview for clinical trials. Health-related quality of life in schizophrenia is a more heterogeneous concept than previously appreciated.

Adult↗
PubMed2000

Serum inhibin, activin and follistatin in postmenopausal women with epithelial ovarian carcinoma.

OBJECTIVE: To investigate the role of serum inhibin A, inhibin pro-alphaC immunoreactivity, activin A, and follistatin in postmenopausal women with epithelial ovarian cancer. DESIGN: Case-control study. SAMPLE: e Serum samples from 27 postmenopausal women with epithelial ovarian cancer and 54 controls from the general population participating in an ovarian cancer screening trial. RESULTS: Women with epithelial ovarian cancer had significantly higher serum levels of pro-alphaC immunoreactivity (P = 0.03), activin A (P = 0.004) and follistatin (P = 0.04), but not inhibin A (P = 0.13). Using the 90th centile in the control group as the cut off, pro-alphaC levels were elevated in 41% of women with epithelial ovarian cancer, while inhibin A was elevated in only 15%. Using the 95th centile as the cut off, serum pro-alphaC was elevated in only 11% of women with epithelial ovarian cancer (3/27), while activin A was elevated in 48% (11/23). Follicle stimulating hormone levels were significantly lower in women with epithelial ovarian cancer (P = 0.01). Although, inhibin-related peptides can modulate follicle stimulating hormone levels, there was no correlation between inhibin A, pro-alphaC immunoreactivity, activin A or follistatin and follicle stimulating hormone. CONCLUSION: These data demonstrate that though there is preferential secretion of precursor forms of the alpha subunit rather than dimeric inhibin A by epithelial ovarian cancer, pro-alphaC is unlikely to be a useful tumour marker. Activin A is more commonly elevated in postmenopausal women with epithelial ovarian cancer and its role as a tumour marker in the diagnosis and screening of epithelial ovarian cancer warrants further evaluation.

Activins↗
PubMed2000

Predictive value of MRI-identified mesial temporal sclerosis for surgical outcome in temporal lobe epilepsy: an intent-to-treat analysis.

PURPOSE: Magnetic resonance imaging (MRI) accurately identifies mesial temporal sclerosis (MTS), but prediction of successful surgical outcome ranges from 62% to 96% in published studies. Prior investigations only used patients who had received anterior temporal lobectomy (ATL), potentially overestimating the predictive value of MRI-identified MTS (MRI-MTS). METHODS: The authors performed an intent-to-treat analysis of 90 consecutive patients assessed for possible ATL, including 13 who did not undergo ATL because of inconclusive intracranial ictal EEG. Four (31%) of these 13 patients had unilateral mesial temporal abnormalities on their MRIs. RESULTS: The positive predictive value of MRI-MTS for seizure cessation decreased from 0.69 to 0.63 after adjustment for these additional false positive results. Four previous studies had revealed a positive predictive value of 0.75 (0.72 after similar adjustment). CONCLUSIONS: The authors conclude that the predictive value of MRI-MTS for outcome from ATL may be overestimated by small retrospective studies of highly selected postoperative patients.

Adolescent↗
PubMed2000

Automatic extraction of protein interactions from scientific abstracts.

This paper motivates the use of Information Extraction (IE) for gathering data on protein interactions, describes the customization of an existing IE system, SRI's Highlight, for this task and presents the results of an experiment on unseen Medline abstracts which show that customization to a new domain can be fast, reliable and cost-effective.

Abstracting and Indexing↗
PubMed2000

Normal values of regional left ventricular endocardial motion: multicenter color kinesis study.

Our goal was to establish normal values for quantitative color kinesis indexes of left ventricular (LV) wall motion over a wide range of ages, which are required for objective diagnosis of regional systolic and diastolic dysfunction. Color-encoded images were obtained in 194 normal subjects (95 males, 99 females, age 2 mo to 79 yr) in four standard views. Quantitative indexes of magnitude and timing of systolic and diastolic function were studied for age- and gender-related differences. Normal limits of all ejection and filling indexes were in a narrow range (< or =25% of the mean), with no major gender-related differences. Despite invariable ejection fractions, both peak filling and ejection rates decreased with age (30 and 20%, correspondingly) with a concomitant increase in mean filling and ejection times, resulting in five- and twofold increases in the late to early filling and ejection ratios, correspondingly. Diastolic asynchrony increased with age (from 4.7 +/- 2.0 to 6.4 +/- 3.2 from the 2nd to 7th decade). The normal values of color kinesis indexes should allow objective detection of regional LV systolic and diastolic dysfunction.

Adolescent↗
PubMed2000

Psychometric analysis of racial differences on the Maudsley Obsessional Compulsive Inventory.

Black university students scored significantly higher than White students on the Maudsley Obsessional Compulsive Inventory (MOCI). They tended to endorse more Cleaning and Checking subscale items in the pathological direction. Subsequent analyses examined whether this finding is a reflection of valid group differences in the prevalence of OCD or a psychometric artifact. Structured interviews were conducted to determine the correspondence of MOCI scores with OCD diagnoses. The race difference in endorsement frequency on the MOCI did not extend to OCD diagnoses. The MOCI scores showed modest predictive validity in Whites, but they did not predict interview-based diagnoses in Blacks. Multivariate item response theory was then employed to examine race differences in the Cleaning and Checking subscales. Equivalent item discrimination parameters fit the data for Black and White participants for both subscales. A more restrictive model in which relative item difficulties were also constrained to be equal for Black and White participants did not fit. This interaction between race and item difficulty suggests that the items do not have equivalent psychometric properties in Blacks and Whites.

Adolescent↗
PubMed2000

Child maltreatment, other trauma exposure, and posttraumatic symptomatology among children with oppositional defiant and attention deficit hyperactivity disorders.

Consecutive child psychiatric outpatient admissions with disruptive behavior or adjustment disorders were assessed by validated instruments for trauma exposure and posttraumatic stress disorder (PTSD) symptoms and other psychopathology. Four reliably diagnosed groups were defined in a retrospective case-control design: Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), comorbid ADHD-ODD, and adjustment disorder controls. ODD and (although to a lesser extent) ADHD were associated with a history of physical or sexual maltreatment. PTSD symptoms were most severe if (a) ADHD and maltreatment co-occurred or (b) ODD and accident/illness trauma co-occurred. The association between ODD and PTSD Criterion D (hyperarousal/hypervigilance) symptoms remained after controlling for overlapping symptoms, but the association of ADHD with PTSD symptoms was largely due to an overlapping symptom. These findings suggest that screening for maltreatment, other trauma, and PTSD symptoms may enhance prevention, treatment, and research concerning childhood disruptive behavior disorders.

Adjustment Disorders↗
PubMed2000

Library resources and getting the best out of them.

Nurses are required to undertake professional updating, PREP (UKCC, 1994), and are increasingly under pressure to ensure that they provide evidence-based healthcare (DoH, 1996). Proliferation of the literature, the move from printed to electronic sources of information and shortage of time may all be seen as barriers to nurses who wish to gain access to information to support these activities. Libraries are important gateways to this information and this article is a brief guide to making the most of library resources.

Databases, Factual↗
PubMed2000

Reducing antipsychotic medication in people with a learning disability.

BACKGROUND: The use of antipsychotic drugs in people with learning disabilities is currently receiving intensified scrutiny and attempts are being made to reduce it. AIMS: A randomised controlled trial was designed to investigate factors influencing antipsychotic drug reduction among people with learning disabilities prescribed such medication for behavioural problems. METHOD: Thirty-six participants randomly allocated to the experimental group underwent four, monthly 25% drug reduction stages. There were no planned drug changes for the control group (n = 20). RESULTS: Twelve participants (33%) completed full withdrawal; a further seven (19%) achieved and maintained at least a 50% reduction. Drug reduction was associated with increased dyskinesia and higher activity engagement but not increased maladaptive behaviour. Some setting characteristics were associated with drug reinstatement. CONCLUSIONS: A substantial proportion of people with learning disability prescribed antipsychotic medications for behavioural purposes rather than for treating psychotic illness can have their drugs reduced or withdrawn.

Adult↗
PubMed2000

Preventing psychological trauma in soldiers: the role of operational stress training and psychological debriefing.

Armed conflict is associated with significant long-term psychiatric morbidity. Interventions to reduce the incidence of psychiatric disorder following psychological trauma may be classified into three categories. Primary prevention includes the selection, preparation and training of individuals likely to be exposed to potentially traumatizing events. Secondary prevention comprises a variety of brief psychological techniques immediately or shortly after traumatizing life events, the best known of which is Psychological Debriefing. Tertiary interventions comprise the treatment of established PTSD and others. Psychiatric morbidity was studied in 106 British soldiers returning from UN peace-keeping duties in the former Republic of Yugoslavia. All 106 soldiers received an Operational Stress Training Package prior to their deployment and a randomly selected group also received a post-operational PD. Very low rates of PTSD and other psychopathology were found overall and the Operational Stress Training Package may have contributed to this. Elevated CAGE scores suggestive of significant alcohol misuse were observed in both groups and chemical avoidance behaviours arising from this may have masked psychopathology. CAGE scores diminished significantly in the debriefed group by the end of the follow-up period suggesting that PD may have been of benefit despite the apparent absence of PTSD. This study also demonstrates that a high incidence of psychiatric morbidity is not an inevitable consequence of military conflict.

Adolescent↗
PubMed2000

Malignant teratoid medulloepithelioma in a llama.

A lesion was identified in the eye of a juvenile llama, and preliminary clinical findings included anterior uveitis and an exudative retinal detachment suggestive of infectious disease. However, histopathologic evaluation of the enucleated globe revealed an intraocular neoplasm composed of primitive neuroepithelium forming ribbons, cords, and rosettes, heteroplastic elements including spindle cells in a loose myxomatous matrix, and islands of well-differentiated hyaline cartilage. Immunohistochemically, neoplastic cells were positive for vimentin and neuron-specific enolase. Spindle cells were multifocally positive for desmin and muscle specific actin, indicating differentiation towards myofibers. These findings are consistent with a diagnosis of malignant teratoid medulloepithelioma, an extremely rare ocular neoplasm that affects children and young animals.

Animals↗