Biomedical subjects

M Ewing

Publications and source records attributed to M Ewing.

At least 19 recordsLinked to original sources

PubMed2001

A preliminary open label dose comparison using an antioxidant regimen to determine the effect on viral load and oxidative stress in men with HIV/AIDS.

OBJECTIVE: To investigate the effect of antioxidant supplementation on viral load and the antioxidant/reactive oxygen species system in people with HIV. DESIGN: Single centre, prospective, dose comparison study. SETTING: Outpatient clinic specializing in HIV care. SUBJECTS: Sixty-six participants were sequentially recruited by advertisement, and 48 subjects completed the study. INTERVENTIONS: A recommended dose antioxidant regimen (5,450 IU vitamin A as beta-carotene, 250 mg vitamin C, 100 IU vitamin E, 100 microg selenium, 50 mg coenzyme Q10) or a high-dose antioxidant regimen (21,800 IU vitamin A as beta-carotene, 1,000 mg vitamin C, 400 IU vitamin E, 200 microg selenium, 200 mg coenzyme Q10) for a 12 week period. RESULTS: Using repeated measures analysis of variance, the changes over treatment time were significant for selenium, glutathione, glutathione peroxidase and lipid peroxides (P < 0.03). Changes in allantoin, uric acid and viral load were not significant (P > 0.05). The main effects for group and the interaction effects were not significant for any of the parameters measured (P > or = 0.05). CONCLUSION: Antioxidant supplementation significantly improved some measures of oxidative defence. There was no benefit in using a high-dose supplement in this study.

Adult↗

PubMed1999

The Hassles Assessment Scale for Students in College: measuring the frequency and unpleasantness of and dwelling on stressful events.

Development of the Hassles Assessment Scale for Students in College, a new scale to measure students' stress, is described. In the scale, students rate each of 54 hassles for its frequency and unpleasantness in the past month and indicate the degree to which they dwelt or ruminated on it. Very high levels of internal consistency for the frequency, unpleasantness, and dwelling measures were found. Correlational analyses demonstrated the scale's criterion validity (scores were negatively correlated with the number of hours respondents reported engaging in physical exercise) and congruent validity (scores were positively correlated with scores on the Inventory of College Students' Recent Life Experience, an established scale for assessing student hassles). Exploratory factor analyses suggested the possibility that many items on the scale are independent, with each contributing some specific variance to the total variance of the item pool that is not shared with other items.

Adaptation, Psychological↗

PubMed1996

The occurrence of carboxymycobactin, the siderophore of pathogenic mycobacteria, as a second extracellular siderophore in Mycobacterium smegmatis.

Carboxymycobactin, in which the usual intracellular mycobactin siderophore is modified by possession of a carboxylic acid group, has been isolated as a second extracellular siderophore from culture filtrates of Mycobacterium smegmatis grown under iron-deficient conditions. (The primary siderophore is an exochelin which is a trihydroxamate, pentapeptide derivative). There may be up to 12 similar molecules produced with differing chain lengths that can be recognized by HPLC or HPTLC. The amount of carboxymycobactin is about 20 times higher when cultures are grown with glycerol instead of glucose. Formation is maximal with an initial pH of the medium of about 8.4. The proportion of carboxymycobactin to the total siderophore produced--mainly exochelins--is maximally 10% (usually 10-25 micrograms ml(-1)). Formation of both extracellular siderophores (exochelin and carboxymycobactin) and of the intracellular mycobactin is maximal at the same initial concentration of iron added to the medium, 0.05-0.1 micrograms Fe ml(-1), though exochelin is synthesized 24 h in advance of both carboxymycobactin and mycobactin.

Chromatography, High Pressure Liquid↗

PubMed1995

[Cytogenetics and molecular studies confirm the histopathologic diagnosis of chronic myeloproliferative diseases].

The histopathological classification of chronic myeloproliferative disorders can be supported by applying cytogenetics and molecular genetics to the analysis of bone marrow or blood cells, as demonstrated in 253 cases evaluated. The Philadelphia translocation (9;22) is the most important genetic parameter, being specific for chronic myeloid leukemia. Conventional methods for the detection of the t(9;22) are karyotyping and Southern blot analysis of the bcr gene. The newly established technique of fluorescence in situ hybridization (FISH) allows visualization of bcr-abl fusion even in non dividing cells. Molecular cytogenetics for t(9;22) yield results that are rapid and reliable as well as easily quantifiable.

Biopsy↗

PubMed1993

Soft tissue response to orthognathic surgery in persons with unilateral cleft lip and palate.

Individuals with cleft lip and palate often require orthognathic surgery to establish facial harmony and optimal occlusal function. Surgery to the skeletal components of the face can accomplish predictable alterations in jaw relations. The soft tissue response to those skeletal movements, however, is difficult to predict, as it is also for the noncleft individual. In addition there is the variability of the repaired cleft lip. The study included 30 persons with complete unilateral cleft lip and palate, operated for midface deficiency using a Le Fort I maxillary advancement at a mean age of 18.0 years. Some relapse occurred in the immediate postoperative period, but after 1 year the mean advancement of the maxilla was 4.9 mm (best fit of anterior maxilla) and 5.6 mm (incisal edge). Both skeletal and soft tissue changes were negligible after that time. The ratio of upper lip advancement to underlying incisor advancement was 0.65 to 1. Although the lip response was highly correlated to the underlying bony movement, the variation was sufficient to preclude accurate prediction. The upper lip thinned with maxillary advancement, but this was not related to the original lip thickness. Coincident mandibular surgery had no appreciable effect on upper lip movement.

Adolescent↗

PubMed1992

Soft tissue response to mandibular advancement and genioplasty.

Changes in facial esthetics after orthognathic surgery should be predictable if the results are to be satisfactory. The skeletal elements are moved in a planned and controlled manner, but the soft tissue drape is not as precisely managed. This study was on 31 patients who had undergone a mandibular advancement by means of a sagittal split osteotomy, 17 of whom had also received an advancement genioplasty and 6 received a maxillary impaction. The results showed a consistent 1:1 ratio of soft to hard tissue advancement at pogonion and B point, and that predictions could be accurate in both anteroposterior and vertical directions. When a genioplasty was added to the advancement, however, the results were much less consistent. The mean ratio was 0.9:1 of soft tissue to skeletal movement at pogonion, but the average difference between hard and soft tissue movement was +/- 2.6 mm. Thus the prediction of anteroposterior soft tissue changes was quite inaccurate. Changes in the vertical dimension were also more marked in the genioplasty group. The lower lip also showed a variable response, particularly in the genioplasty group, where the mean ratio was 0.5 mm lip advancement per 1.0 mm skeletal change, but again a range of 4.0 mm in either direction. There were no meaningful changes 1 year after surgery.

Adolescent↗

PubMed1991