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Biomedical subjects

C Stevens

Publications and source records attributed to C Stevens.

At least 127 records · Page 7Linked to original sources
PubMed1990

Characteristics of Trichomonas vaginalis isolates from women with and without colpitis macularis.

Colpitis macularis, the most specific clinical sign for diagnosis of trichomoniasis, was detected by colposcopy in 52 of 118 infected women. Patients with colpitis macularis had a mean (+/- SD) of 18 +/- 20 Trichomonas vaginalis organisms/field (x 400 magnification) compared with 7 +/- 17 in patients with colpitis macularis (P less than .003). To compare possible virulence markers in isolates from women with and without colpitis macularis, isolates were analyzed for hemolytic activity, abscess production in an animal model, and adherence to cells in tissue culture. The mean hemolytic activity (relative to complete hemolysis) was 84% for 22 isolates from women with and 78% for 29 isolates from women without colpitis macularis. After subcutaneous injections in mice, abscesses were produced by 70% of isolates from patients with and 68% from patients without colpitis macularis. After a 15-min exposure, 39% of radiolabeled isolates from women with or without colpitis macularis adhered to HeLa cell monolayers. Purulent discharge, the second most useful sign for clinical diagnosis, was associated with colpitis macularis and with the number of organisms per high-power field on wet mount (P less than .01 for each comparison) but was not correlated with any experimental assay. Thus, no experimental characteristic of T. vaginalis isolates was associated with colpitis macularis or purulent vaginal discharge.

Abscess↗
PubMed1990

Control of oxidative damage in rheumatoid arthritis by gold(I)-thiolate drugs.

The roles of anti-arthritic gold(I)-thiolate drugs such as disodium aurothiomalate ('Myocrisin') in the modulation or promotion of oxygen radical-mediated oxidative damage in vivo are reviewed. In particular, the precise molecular mechanisms by which these novel second-line agents exert their therapeutic effects are discussed in terms of (i) the direct and indirect control of enzymes involved in the generation or scavenging of reactive oxygen species (ROS) such as superoxide ion, hydrogen peroxide and hydroxyl radical, (ii) the protection of proteins and relevant enzyme systems against attack by ROS and (iii) their direct involvement in the production (at appropriate 'target' sites) or scavenging of ROS in vivo. In addition, the role of the orally-effective gold(I)-phosphine complex auranofin in the control of oxidative damage in rheumatoid arthritis is also discussed.

Antirheumatic Agents↗
PubMed1989

The influence of initial posture on the sit-to-stand movement.

Head movements, ground reaction forces and electromyographic activity of selected muscles were recorded simultaneously from two subjects as they performed the sit-to-stand manouevre under a variety of conditions. The influence of initial leg posture on the magnitude of the various parameters under investigation was examined first. A preferred initial leg posture resulted in smaller magnitudes of head movement and ground reaction forces. EMG activity in some muscles, trapezius and erector spinae, decreased, while in others, quadriceps and hamstrings, it increased in the preferred leg posture. The decreases seen correlate with reductions in head movement observed. The effect of inhibiting habitual postural adjustments of the head and neck, by comparing "free" and "guided" movements was also examined. In guided movements there are significant reductions in head movement, ground reaction forces and EMG activity in trapezius, sternomastoid and erector spinae. It would appear that both initial leg posture and the abolition of habitual postural adjustment have a profound influence on the efficiency of the sit-to-stand manouevre. This preliminary study high-lights the practical importance of head posture in the diagnosis and treatment of movement disorders, as well as in movement education.

Humans↗
PubMed1989

Non-shivering thermogenesis and obesity in adult diabetic Wistar fatty rats.

1. Characteristics of resting and of norepinephrine (NE)-stimulated thermogenesis, and the glycemic response to NE were determined in adult male Wistar Fatty rats. Rats were maintained on Purina chow No. 5001 until 22 weeks of age, and fed semisynthetic diets containing 54% carbohydrate, 20% protein, 16% mixed fats, plus essential vitamins, minerals, and non-nutritive fiber from 22 until 30 weeks of age. 2. Obese rats were 50% heavier than lean throughout the study. Phenotype effects (obese greater than lean) were present for retroperitoneal (RP) and dorsal (DOR) white fat depot weight, adipocyte number per depot, and adipocyte lipid content. Epididymal mass and cellularity were similar in both phenotypes. 3. Interscapular brown adipose tissue (IBAT) mass, adipocyte size, and adipocyte number were greater in obese than in lean. Resting metabolic rates (RMR) of obese rats were lower than in lean, and increased 79% in lean but only 33% in obese animals following NE (200 micrograms/kg BW, s.c.) stimulation. 4. The glycemic response to NE occurred normally in both phenotypes, and resulted in a 3-fold increment in plasma glucose in lean rats and a 5-6-fold increase in plasma glucose in obese rats. 5. The results of this study are consistent with hyperplasia and hypertrophy of IBAT, RP and DOR depots, and indicate that the capacity for non-shivering thermogenesis is impaired in the obese phenotype of this strain in spite of peripheral sensitivity to NE and greater mass and cellularity of brown adipose tissue.

Adipose Tissue↗