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Biomedical subjects

S Thomas

Publications and source records attributed to S Thomas.

At least 361 records · Page 20Linked to original sources

The perception and judgment of senior baccalaureate student nurses in clinical decision making.

This descriptive, exploratory study sought to validate Brooks's theory of intrapersonal perceptual awareness, a middle-range theory derived from King's interacting systems framework and to extend King's work by making perception (sensory and intuitive), judgment (cognitive and affective), and decision making explicit concepts in the personal system. The results supported the theory's central premise and clarified the interaction between perception and judgment but did not support bringing perception, judgment, and decision making into the personal system as proposed. Self emerged as the core concept, and the results are used to recommend a proposed reconceptualization of King's personal system as self.

Decision Making↗

Is it worth the wait? A survey of patients' satisfaction with an oncology outpatient clinic.

Increasing numbers of cancer survivors and the tradition of long-term follow-up in the outpatient clinic has resulted in overcrowded oncology clinics and long waiting times. Little is known about patients' perceptions of their clinic attendance. This survey of 252 oncology patients investigated patients' satisfaction with the clinic, anxiety associated with clinic attendance and the strengths and weaknesses of the oncology service. Results demonstrated high levels of satisfaction. Far from being perceived as anxiety-provoking, the clinic was looked upon as a valuable source of reassurance, 92% of patients reporting they were 'always' or 'usually' reassured as a consequence of their visit. Qualitative data showed that clinic staff were the most important source of satisfaction. Waiting was overwhelmingly the worst aspect of the clinic, described by 27% of patients as 'excessively long'. One-fifth of the total sample had attended the clinic for 10 years or more and over a third of this group reported they would be worried at the prospect of being discharged to the care of their general practitioners. Despite disadvantages associated with long waits, the clinic was perceived as providing a valuable source of reassurance which a proportion of patients were clearly reluctant to be without.

Adult↗

Cerebral white matter changes (leukoaraiosis), stroke, and gait disturbance.

OBJECTIVES: Leukoaraiosis, a radiological change of cerebral white matter thought to be caused by ischemia, is associated with gait disturbance. However, because of concomitant stroke and cerebral atrophy, the clinical relevance of leukoaraiosis is uncertain. We, therefore, sought to determine if leukoaraiosis is a predictor of gait disturbance after accounting for cerebral atrophy and stroke in patients with a high prevalence of cerebrovascular disease. DESIGN: Cross-sectional observational study. SETTING: Neurology service (inpatient and outpatient) of a Department of Veterans Affairs Hospital. PARTICIPANTS: Consecutive sample of 130 patients, 127 men and three women. MEASUREMENTS: The findings of a gait scale were correlated to vascular risk factors, neurological examination as quantified by the NIH stroke scale and supplemental motor scale, and to brain CT findings. Brain CT scans were rated for leukoaraiosis, cerebral infarction, and cerebral atrophy. RESULTS: Gait disturbance was more frequent and more severe in subjects with leukoaraiosis, of whom 31% had mild and 49% moderate/severe gait disturbance compared with 27% with mild and 12% with moderate/severe gait disturbance in subjects without leukoaraiosis (P < .001). Leukoaraiosis, cerebral atrophy, a history of multiple strokes, and weakness and ataxia of the legs were independent predictors of gait disturbance. The proportion and severity of leukoaraiosis increased with increasing gait disturbance in subgroups without leg deficit (P < .001) and without multiple strokes (P < .001), but no association with leukoaraiosis was shown in patients with leg deficit or a history of multiple strokes (P = .037 and P = .186, respectively). Gait disturbance was more severe when both leukoaraiosis and cerebral atrophy were present (P = .019). CONCLUSION: In our Veteran population, leukoaraiosis is an independent predictor of gait disturbance after accounting for stroke and cerebral atrophy. Although leukoaraiosis is a form of cerebrovascular disease, it appears to be most closely associated to gait disturbance in the absence of symptomatic stroke or leg deficit.

Adult↗

Single-dose pharmacokinetics of thalidomide in human immunodeficiency virus-infected patients.

The pharmacokinetics of thalidomide in nine human immunodeficiency virus-infected patients were studied. Single doses of thalidomide were well absorbed, with mean peak concentrations (+/- standard deviations) of 1.17 +/- 0.21 and 3.47 +/- 1.14 microg/ml in the 100- and 300-mg dosing groups, respectively, and the mean elimination half-life was approximately 6 h. Adverse effects were mild, with drowsiness being reported for seven of nine patients.

Adult↗

Modification of IgH PCR clonal analysis by the addition of sucrose and cresol red directly to PCR reaction mixes.

Diagnostic immunoglobulin (Ig) polymerase chain reaction (PCR) clonality analyses need to be simple, reproducible, and rapid. Sucrose and cresol red (gel loading buffer reagents) were added to a routine IgH PCR reaction mix to obviate the need for adding gel loading buffer separately after PCR amplification. Not only did this decrease the time spent after PCR analysis but also gave similar or enhanced IgH PCR product intensity compared with normal IgH PCR conditions on polyacrylamide gel electrophoresis. This procedure was easily adapted to routine PCR analysis without the need for further manipulations or optimisation of the PCR reaction mix, and it increased the reproducibility and specificity of the IgH PCR products.

Clone Cells↗

Influence of altered plasma membrane fatty acid composition on cesium transport characteristics and toxicity in Saccharomyces cerevisiae.

The influence of altered plasma membrane fatty acid composition on cesium uptake and toxicity was investigated in Saccharomyces cerevisiae. Detailed kinetic studies revealed that both the Vmax and Km values for Cs+ transport increased (by approximately twofold in the latter case) when S. cerevisiae was grown in medium supplemented with the polyunsaturated fatty acid linoleate. In addition, Cs+ uptake by linoleate-enriched cells was considerably less sensitive to the competitive effects of other monovalent cations (K+, Rb+, and NH4+) than that by unsupplemented cells. Stimulation of Cs+ uptake in the presence of certain K+ and Rb+ concentrations was only evident in linoleate-enriched S. cerevisiae. At 100 mM CsCl, the initial rate of Cs+ uptake was greater in linoleate-supplemented cells than in unsupplemented cells and this was reflected in a more rapid displacement of cellular K+. However, little difference in net Cs+ accumulation between linoleate-supplemented and unsupplemented cells was evident during prolonged incubation in buffer or during growth. Thus, Cs+ toxicity was similar in linoleate-supplemented and unsupplemented cells. The results were consistent with the Cs+ (K+) transport mechanism adopting an altered conformational state in linoleate-enriched S. cerevisiae.

Biological Transport↗

Local Delivery of an Ultra-short-acting Nitric Oxide-releasing Compound, DMHD/NO, Is Highly Effective in Inhibiting Acute Platelet-Thrombus Formation on Injured Arterial Strips.

BACKGROUND: Nitric oxide (NO) plays an important role in modulating platelet-vessel wall interaction following vascular injury. We exampled the effects of local infusion of an ultra-short-acting NO-releasing compound: NO adduct of N, N'-dimethylhexanediamine (DMHD/NO), sodium nitroprusside, intravenous nitroglycerin, and aspirin on acute platelet-thrombus formation under conditions of high-shear blood flow in a rabbit extracorporeal perfusion model. MATERIALS AND METHODS: Strips of porcine aortic media were perfused in a Badimon chamber with arterial blood from 20 New Zealand White rabbits for 10 minutes at a shear rate of 1700 s(-1). Thrombus formation was quantified by morphometric analysis of thrombus area. Effects on collagen-induced platelet aggregation, blood pressure, bleeding time, and activated clotting time were also examined. RESULTS: DMHD/NO inhibited thrombus area and platelet aggregation in a dose-dependent manner with a 90% reduction in thrombus area (0.018 +/- 0.039 vs 0.215 +/- 0.085 mm(2)/mm control, P <.001) and a 50% reduction in platelet aggregation (4.8 +/- 4.4 vs 9.9 +/- 4.1 Omicron control, P =.04) at the highest dose of 1.0 nM/kg and 100 µM/L, respectively, without any effects on blood pressure, bleeding time, or activated clotting time. In contrast, equimolar concentrations of sodium nitroprusside and intravenous nitroglycerin had significantly reduced effects on thrombus area compared to DMHD/NO and were associated with significant reductions in blood pressure and prolongation of bleeding time. Aspirin had no effect on thrombus area at 1 µM/kg but reduced thrombus area and prolonged bleeding time at 2 and 5 µM/kg. CONCLUSIONS: Local delivery of DMHD/NO produced a 90% inhibition of experimental acute platelet-thrombosis under high-shear flow conditions without producing adverse systemic hemodynamic or hemostatic effects. Thus, inhibition of thrombus formation by local delivery of a rapidly acting NO donor may be an effective strategy for prevention of arterial injury-induced thrombosis.

Journal Article↗

A guide to dressing selection.

An update on the characteristics of different types of chronic wounds and the wound-related criteria for selecting the appropriate types of dressing.

Bandages↗

A study to compare two film dressings used as secondary dressings.

Dressings manufactured from adhesive polymeric films have been used extensively in wound management for about 20 years. This report describes the results of a trial designed to compare the performance of two such dressings, used as secondary dressings, in a multi-centre randomised controlled community study involving 100 patients. Independent analysis of the study data revealed that, after adjusting for other effects, no genuine difference was demonstrated between the dressings in terms of their ability to resist wrinkling or prevent maceration (the primary outcome variable).

Adult↗

A comparison of two dressings in the management of chronic wounds.

A hydropolymer dressing (Tielle) and a hydrocolloid dressing (Granuflex) were compared in a randomised controlled clinical study involving 100 patients with leg ulcers and 99 patients with pressure sores in the community. Statistically significant differences in favour of the hydropolymer dressing were detected for dressing leakage and odour production, but no statistically significant differences were recorded in the number of patients with either leg ulcers or pressure sores who healed in each treatment group.

Aged↗

Proliferation potential and histological features in neurofibromatosis 2-associated and sporadic meningiomas.

The authors compared the histological appearance and proliferation potential of 35 meningiomas in patients with neurofibromatosis 2 (NF2) and 30 sporadic meningiomas in age- and gender-matched patients without NF2. The NF2 meningiomas showed more mitotic figures (p < 0.001) and nuclear pleomorphism (p = 0.003) than the sporadic meningiomas; however, the incidence of meningothelial, fibroblastic, and transitional subtypes occurred equally in both groups. The proliferation potential was significantly higher in the 35 meningiomas removed from 23 patients with NF2 than in the 30 sporadic meningiomas removed in the 30 patients without NF2 (mean MIB-1 labeling indices: 2.5 vs. 1.75, p = 0.0147). The higher proliferation potential of the NF2 meningiomas may reflect differences in molecular biology between sporadic and NF2 meningiomas and may be related to an earlier onset, multiplicity, and more aggressive behavior of NF2 tumors.

Adolescent↗

Our journey.

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Canada↗