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Biomedical subjects

G Welch

Publications and source records attributed to G Welch.

33 records · Page 2Linked to original sources
PubMed1990

The replicable dimensions of the Beck Depression Inventory.

Numerous studies have focused on the factor structure of the Beck Depression Inventory (BDI) because its underlying structure, once identified, may improve our conceptualizations of the cognitive processes in depression. These studies have produced a wide range of interpretations for the BDI, yet the replicability of these factor solutions across independent samples has not been demonstrated. In this study, a series of factor analyses were conducted that involved the use of a new factor matching procedure (FACTOREP), and both depressed patient and normal population samples. The results supported the presence of a large general factor only, which suggests that the items of the BDI are tapping a general construct of depressive symptoms rather than the variety of more specific constructs suggested by previous researchers.

Adult↗
PubMed1989

The reliability and discriminant validity of three potential measures of bulimic behaviours.

There is currently a need for a reliable and valid self-report measure of bulimic behaviours that is brief and economical to administer and that can be used to assess response to treatment and to investigate correlates of bulimic symptoms. Three potential screening measures of bulimic behaviours (the Bulimia Test, the Conroy-Healy Eating Questionnaire and the Bulimia subscale of the Eating Disorder Inventory) were evaluated using internal consistency analysis and Receiver (or Relative) Operating Characteristic curve analysis, to determine their internal reliability and ability correctly to identify bulimic patients seen at an eating disorders outpatients clinic. The results showed that the three measures examined were all good discriminators of bulimic and non-bulimic patients. However, the results showed that the Bulimia Test was clearly the most reliable measure, apparently because of its greater length. It is suggested that further investigations be conducted to establish the sensitivity of the Bulimia Test to changes in the severity of bulimic behaviours in patients, since this will increase knowledge of its utility as a measure of response to treatment.

Adult↗
PubMed1988

The factor structure of the eating disorders inventory.

The Eating Disorders Inventory (EDI) is a promising new measure of the cognitive and behavioral characteristics of anorexia nervosa and bulimia, although the replicability of its eight subscales has not been evaluated. Therefore, a factor analysis of the EDI was carried out that used the FACTOREP procedure. The results, using non-patient responses, did not confirm the original eight subscales, but did show three clear and replicable factors to exist. It was suggested that these may be of clinical value as preliminary screening measures or as indices of response to treatment, although further validation would be required to establish their utility.

Adult↗
PubMed1986

Mitochondrial DNA of two independent oligomycin-resistant Chinese hamster ovary cell lines contains a single nucleotide change in the ATPase 6 gene.

We have determined the nucleotide sequence of the URF A6L and ATPase 6 genes of the mitochondrial DNA of wild-type Chinese hamster ovary (CHO) cells and of two independently isolated, cytoplasmically inherited CHO mutant cell lines that are resistant to oligomycin, an inhibitor of the mitochondrial ATP synthase (ATPase) complex. Comparison of the nucleotide sequences of the mutants with that of their parental cell line revealed a single nucleotide difference, a G-to-A transition at nucleotide 433 of the ATPase 6 gene. This single base pair change predicts a nonconservative amino acid change, with a glutamic acid residue being replaced by a lysine residue at amino acid 145 of the ATPase 6 gene product in the mutants. This glutamic acid residue and several others in the surrounding amino acid sequence are conserved among all species examined to date. Analyses of several of the biochemical properties of the oligomycin-resistant CHO mutants indicate that the glutamic acid residue at position 145 of subunit 6 of the mitochondrial ATP synthase complex is important for the binding of oligomycin to the enzyme complex, but is not essential for proton translocation.

Adenosine Triphosphatases↗
PubMed1986

Investigation of 'weight pathology' of 58 mothers of anorexia nervosa patients and 204 mothers of schoolgirls.

'Weight pathology'--defined by Kalucy et al. (1977) as 'deviations in weight, shape, eating behaviour and activity'--has been hypothesized to be unduly common in families with anorexia nervosa. It was investigated in this study by means of questionnaires evaluating both weight history and attitudes towards weight-related matters in 58 mothers of anorexia nervosa patients and 204 mothers of schoolgirls of similar age and socioeconomic status (SES). No support was found for the hypothesis. A family history of aberrant weight and mother's current weight and past weight histories showed no significant differences between the groups. 142 other mothers of schoolchildren and 446 attenders at Weight Watchers also completed the questionnaire on attitudes towards weight-related matters. Mothers of patients showed a lower concern on all scales than did all other groups. The findings are discussed in relation to earlier controlled studies of family factors in anorexia nervosa.

Adolescent↗
PubMed1977

Response of cultured mammalian cells to accelerated krypton particles.

One of the more interesting observations made in early studies with heavy ions is that the cross-section of the radiosensitive area in mammalian cells increases with LET of HZE particles. It is not certain, however, whether this radiosensitive area is limited to the nuclear area of cells. The successful acceleration of krypton ions to 8.5 MeV/amu at the HILAC Lawrence Berkeley Laboratory, has provided an opportunity to gain more information on this question. Cultured human kidney cells (T-1), growing in exponential phase, were exposed to 3 MeV/amu krypton particles and their colony-forming ability studied. The survival curve was found to be exponential with a mean lethal dose D0=720 rad. A calculation of the cross-section of the radio-sensitive area from the data obtained gives a value of about 145 micrometers2. Present results suggest that the inactivation cross-section stays about the same for heavy ions that have LET greater than 20,000 MeV cm2 g-1, that the nucleus is the only sensitive site for high LET radiation and that a single hit of a heavy ion with very high LET in the nuclear region of the cell can lead to lethal effects. Such particles are therefore extremely dangerous to proliferating living cells.

Cell Line↗
PubMed1976

Effects of high-LET particles (40A) on the brain of Drosophila melanogaster.

To investigate the effects of galactic heavy particles on nervous tissue, Drosophila melanogaster flies were exposed to 40A from the Super-HILAC accelerator at the Lawrence Berkeley Laboratory. The energy of the particles reaching the Drosophila neurons was 4-8 MeV/nucleon, and the fluence ranged from 6 X 10(4) to 8 X 10(7) particles/cm2. Thirty-five days after irrdiation at the higher fluences, extensive tissue fragmentation and cysts were found. At fluences as low as one hit/two cell bodies (about 5 X 10(6)) and one hit/90 cell bodies (about 9 X 10(4) particles/cm2 or 21 rad average dose) swelling of neuronal cytoplasm and focally fragmented membranes were noted; at fluences ranging from one hit/six to one hit/135 cell bodies, there was frequently a marked increase in glial lamellae around nerve-cell processes, which often had degenerative features. These findings support the view that single hits by heavy particles may injure nervous tissue.

Animals↗
PubMedDate not supplied

CT detection of occult pneumothorax in multiple trauma patients.

Chest injuries are the cause of death in 25% of trauma fatalities, and a major contributing factor in an additional 50%. Pneumothorax, the second most common chest injury, may often be initially overlooked. Administration of anesthesia and mechanical ventilation may produce enlargement of a pneumothorax and clinical deterioration. We reviewed 90 trauma patients who had been admitted with a diagnosis of pneumothorax or who had developed pneumothoraces after hospital admission. In 35 cases (38.8%), initial supine chest x-ray study failed to detect a pneumothorax, and the diagnosis was made on CT scan of the chest or abdomen performed within 2 hours of admission. In 15 of these cases (42.8%), identification of the pneumothorax on CT scan resulted in alterations in management, including chest tube placement in 10 patients and intensified monitoring in 5 patients. Failure to identify pneumothoraces in trauma patients may lead to deterioration and significant complications in patients requiring anesthesia or mechanical ventilation. CT scan may facilitate identification in these cases.

Adolescent↗
PubMedDate not supplied

Nitric oxide and its role in the cardiovascular system.

Nitric oxide (NO) is a ubiquitous, naturally occurring molecule found in a variety of cell types and organ systems. In the cardiovascular system, NO is an important determinant of basal vascular tone, prevents platelet activation, limits leukocyte adhesion to the endothelium, and regulates myocardial contractility. NO may also play a role in the pathogenesis of common cardiovascular disorders, including hypotension accompanying shock states, essential hypertension, and atherosclerosis. In this review, we discuss the biochemistry of NO and focus on its biology and pathophysiology in the cardiovascular system.

Animals↗
PubMedDate not supplied

The association of lifetime psychiatric illness and increased retinopathy in patients with type I diabetes mellitus.

Forty-nine patients with Type I diabetes mellitus were assessed to examine the relationship between lifetime prevalence of psychiatric illness and retinopathy severity. The subjects with a history of psychiatric illness had significantly worse retinopathy than the subjects without psychiatric illness. Eighty-nine percent of the subjects with severe nonproliferative retinopathy or proliferative retinopathy had a history of psychiatric illness, predominantly affective illness. In addition, the subjects with a history of psychiatric illness had significantly higher current glycohemoglobin levels than those with no psychiatric history. This study's findings suggest that psychiatric illness may be a risk factor for development of retinopathy in Type I diabetic patients.

Adaptation, Psychological↗