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Biomedical subjects

R Stewart

Publications and source records attributed to R Stewart.

At least 91 records · Page 5Linked to original sources

Topical anaesthesia of intact skin: liposome-encapsulated tetracaine vs EMLA.

In this randomized, double-blind study, we have compared the ability of 5% liposome-encapsulated tetracaine (amethocaine) (LET) vs 5% eutectic mixture of local anaesthetics (EMLA) to produce local anaesthesia of intact skin in 40 healthy volunteers. Volunteers had both preparations applied to their forearms under an occlusive dressing for 1 h. Superficial anaesthesia was measured by a total of nine 1-mm pinpricks on each arm. Deeper anaesthesia was assessed by single insertion of a sterile 22-gauge needle to a depth of 3 mm and pain was reported on a visual analogue scale (VAS). If the volunteer perceived greater than four of the 1-mm pinpricks, the 3-mm insertion was not performed. Results showed that the number of pinpricks perceived was significantly less (P < 0.01) for LET (median 1.0; range 0-9) vs EMLA (1.5; 0-9). In volunteers who had deeper anaesthesia assessed, there was no significant difference (P = 0.065) in VAS scores for LET (mean 1.5 (SD 1.4); n = 34) vs EMLA (2.4 (2.1); n = 28). Overall anaesthetic effect, as ranked by all of the subjects, was significantly better for LET compared with EMLA (P = 0.024). We have demonstrated that when applied in equal volumes, 5% LET produced better superficial local anaesthesia than EMLA.

Administration, Cutaneous↗

The changing role of the regional tier of the NHS.

Reviews the past role of regional health authorities in the the British NHS and gives details of the recent changes to regions associated with the functions and responsibilities paper. Goes on to give details of the research project in which we are currently involved and reports on our interim findings (as of April 1996). In a final discussion section, reflects on those findings in terms of the evolving problems of influence and control in a national service operating in a devolved quasi-market.

Decision Making, Organizational↗

H.M. revisited: relations between language comprehension, memory, and the hippocampal system.

Three studies tested the claim that H.M. exhibits a "pure memory deficit" that has left his ability to comprehend language unimpaired relative to memory-normal controls. In Study 1, H.M. and memory-normal controls of comparable intelligence, education, and age indicated whether sentences were ambiguous or unambiguous, and H. M. detected ambiguities significantly less often than controls. In Study 2, participants identified the two meanings of visually presented sentences that they knew were ambiguous, and relative to controls, H.M. rarely discovered the ambiguities without help and had difficulty understanding the first meanings, experimenter requests, and his own output. Study 3 replicated these results and showed that they were not due to brain damage per se or to cohort effects: Unlike H.M., a patient with bilateral frontal lobe damage detected the ambiguities as readily as young and same-cohort older controls. These results bear on two general classes of theories in use within a wide range of neurosciences and cognitive sciences: The data favor "distributed-memory theories" that ascribe H.M.'s deficit to semantic-level binding processes that are inherent to both language comprehension and memory, over "stages-of-processing theories," where H.M.'s defective storage processes have no effect on language comprehension.

Adult↗

Oral analogue scale as an outcome measure after displaced intra-articular calcaneal fractures.

Functional outcome measures of displaced intra-articular calcaneal fractures have been documented using general health surveys (SF36) and disease-specific health surveys (Visual Analogue Scale). A simple oral analogue scale (OAS) was collected on 115 patients with 124 displaced intra-articular calcaneal fractures at 2 years or more after fractures. There was a high correlation (r = 0.72, P < 0.0001) between the verbal OAS and the written Visual Analogue Scale. We believe that the OAS may assist in follow-up outcome assessment and management in this difficult trauma patient population. Outcomes may be accomplished verbally rather than in written form.

Calcaneus↗

Heterogeneity of macrophage and T cell subpopulations in peripheral nerves from HIV infected individuals: A preliminary study.

GOAL: To determine the heterogeneity of surface marker expression of macrophages in peripheral nerve of patients who died with AIDS. BACKGROUND: Peripheral neuropathy occurs in 20%-40% of AIDS patients. There is evidence that activated macrophages may be involved in the neural damage associated with HIV-1 infection. We studied the expression of macrophage surface markers CD14, CD11c, CD68, and HLA-DR and also T cell surface markers CD3, CD4, and CD8 in peripheral nerves of AIDS patients. METHODS: Three levels of peripheral nerves (sciatic, tibial, or sural) were examined from a limited number of subjects consisting of 4 HIV-seropositive and 5 HIV-seronegative individuals. Standard immunohistochemical technique utilized alkaline phosphatase conjugate and fuchsin substrate. RESULTS: Surface antigen expression was significantly (p < .0025 increased in HIV-positive tissues compared with HIV-negative controls for CD14 and CD4 in sciatic nerves, CD68 and CD4 in tibial nerves, and CD68 in sural nerves. There were trends for increased expression of HLA-DR, CD3, and CD8 in sciatic nerves, CD11c and CD14 in tibial nerves, and CD14, HLA-DR, and CD4 in sural nerves in HIV-positive tissues compared with HIV-negative controls. CONCLUSION: During the course of AIDS there may be an involvement of all three levels of peripheral nerves suggesting that HIV-related neuropathy is a multifocal process.

Antigens, CD↗

Factors influencing long-term primary cadaveric kidney transplantation--importance of functional renal mass versus avoidance of acute rejections--the Toronto Hospital experience 1985-1997.

1. The 5-year actuarial graft, patient and functional graft survival rates were analyzed in 743 consecutive primary cadaveric kidney transplants from The Toronto Hospital between January 1985-December 1997. 2. Recipient age > or = 55 years, male recipient sex, recipient diabetes mellitus, CIT > 36 hours and delayed graft function were found to significantly decrease patient survival. 3. Recipient age > or = 55 years, sensitization to HLA antigens (peak PRA > 50%), donor/recipient HLA antigen mismatches, CIT > 36 hours, delayed graft, function and 6-month SCr > 200 mumol/L were found to significantly decrease graft survival. 4. Acute rejection episodes had no significant impact on overall 5-year patient or graft survival. 5. The observation that serum creatinine > 200 mumol/L had a major adverse influence on long-term outcome reflects the importance of functional renal mass on graft survival.

Adult↗

'Two-component' ethylene signaling in Arabidopsis.

The Arabidopsis ETR1 gene codes for an ethylene hormone receptor that has striking sequence similarity with bacterial two-component regulators. This finding predicts that the ETR1 receptor transduces the ethylene signal through the phosphotransfer mechanisms established for a number of the bacterial regulators. To test this hypothesis, we have performed in vitro assays for ETR1 autokinase activity as well as for transfer of phosphate to the ETR1 receiver. So far, we have not detected either of these activities. Another question we are focusing on is the identity of protein substrates of the ETR1 receptor. Using the yeast two-hybrid system, we have obtained several clones to be subsequently characterized as potential interactors with ETR1.

Arabidopsis↗

Integrating technology with compassionate care: withdrawal of ventilation in a conscious patient with apnea.

This case was atypical because the patient was conscious and apneic. The usual responses that indicate a patient's distress during terminal weaning would not have been evident in this patient. Introducing noninvasive monitoring of end-tidal CO2 and SpO2 and using BIS allowed the weaning to progress with confidence that the patient was as comfortable as possible. We think we kept our commitment to HD to honor his wishes by using the most humane method we could devise, and to address his family's needs at the same time.

Aged↗

Control of ocular inflammation after cataract extraction with rimexolone 1% ophthalmic suspension.

PURPOSE: To assess the efficacy and safety of rimexolone 1% ophthalmic suspension in controlling intraocular inflammation after cataract extraction. SETTING: Twelve independent investigational centers in the United States METHODS: This study comprised 197 patients who had cataract extraction. Postoperatively, patients were randomized to a 2 week regimen of rimexolone 1% ophthalmic suspension or a placebo. Efficacy was analyzed by monitoring total anterior chamber cells and flare, other parameters of inflammation, and treatment failures. Safety was evaluated by monitoring treatment-related adverse events and intraocular pressure (IOP). RESULTS: Rimexolone 1% was clinically and statistically more effective in suppressing cell and flare than the placebo (P < .02). The overall discontinuation rate for treatment-related adverse events was 5.3% in the rimexolone group and 22.2% in the placebo group. There were no between-group differences in IOP. CONCLUSION: Rimexolone 1% ophthalmic suspension was safe and significantly more effective than a placebo in controlling intraocular inflammation after cataract extraction when used four times daily and continued for 2 weeks.

Administration, Topical↗

Expression of avrPphB, an avirulence gene from Pseudomonas syringae pv. phaseolicola, and the delivery of signals causing the hypersensitive reaction in bean.

Protein production encoded by the avirulence gene avrPphB from Pseudomonas syringae pv. phaseolicola was examined. Incorporation of [35S]-labeled methionine into the AvrPphB protein indicated processing of the full-length peptide in Escherichia coli to give a major 28-kDa product. The 28-kDa native peptide was isolated from E. coli following over-expression of avrPphB and found not to elicit the hypersensitive response (HR) after infiltration into bean leaves. Antiserum raised to the 28-kDa peptide allowed expression of avrPphB and processing of AvrPphB protein to be examined in P. syringae pv. phaseolicola; immunoreactive peptides of both 35 and 28-kDa were detected in races 3 and 4 (which contain avrPphB) only after induction in minimal medium + 10 mM sucrose. Antiserum raised to a synthetic peptide, derived from the sequence of the 62 amino acids found to be cleaved from the full-length AvrPphB protein, revealed the accumulation of peptides corresponding to the smaller cleavage products, in both E. coli and P. syringae pv. phaseolicola. Biochemical localization experiments showed that all AvrPphB peptides were cytoplasmic in P. syringae pv. phaseolicola. No AvrPphB peptides were produced in a hrpL mutant unless expression of the gene was directed by a strong vector promoter; induction kinetics similar to wild type were observed in a hrpY- strain, although it also failed to cause a confluent HR. Growth of P. syringae pv. phaseolicola under inducing conditions removed the requirement for rifampicin-sensitive mRNA synthesis by bacteria to allow HR development (the induction time) in bean and lettuce leaves. Constitutive expression of hrpL reduced but did not remove the induction time. Expression of the hrp gene cluster of P. syringae pv. phaseolicola from plasmid pPPY430 in E. coli enabled phenotypic expression of avrPphE (also carried by pPPY430) and avrPphB (if over-expressed from pPPY3031). Despite constitutive expression of the hrp and avr genes in E. coli, a protein synthesis dependent induction time was still required for development of the HR in bean genotypes with matching resistance genes. The significance of processing for the function of AvrPphB peptides and the delivery of elicitors of the HR are discussed.

Amino Acid Sequence↗

Effect of intrathecal baclofen delivered by an implanted programmable pump on health related quality of life in patients with severe spasticity.

OBJECTIVES: To compare clinical effectiveness and health related quality of life in patients with severe spasticity who received intrathecal baclofen or a placebo. METHODS: In a double blind, randomised, multicentre trial 22 patients were followed up during 13 weeks and subsequently included in a 52 week observational longitudinal study. Patients were those with chronic, disabling spasticity who did not respond to maximum doses of oral baclofen, dantrolene, and tizanidine. After implantation of a programmable pump patients were randomly assigned to placebo or baclofen infusion for 13 weeks. After 13 weeks all patients received baclofen. Clinical efficacy was assessed by the Ashworth scale, spasm score, and self reported pain, and health related quality of life by the sickness impact profile (SIP) and the Hopkins symptom checklist (HSCL). RESULTS: At three months the scores of the placebo and baclofen group differed slightly for the spasm score (effect size=0.20) and substantially for the Ashworth scale (effect size=1.40) and pain score (effect size=0.94); health related quality of life showed no significant differences. Three months after implantation the baclofen group showed a significant, substantial improvement on the SIP "physical health", "mental health", "mobility", and "sleep and rest" subscales and on the HSCL mental health scale; patients receiving placebo showed no change. After one year of baclofen treatment significant (P<0.05) improvement was found on the SIP dimensions "mobility" and "body care and movement" with moderate effect sizes. Improvement on the SIP subscale "physical health" (P<0.05; effect size 0.86), the SIP overall score (without "ambulation"), and the "physical health" and overall scale of the HSCL was also significant, with effect sizes >0.80. Changes in health related behaviour were noted for "sleep and rest" and "recreation and pastimes" (P<0.01, P<0.05; effect size 0.95 and 0.63, respectively). Psychosocial behaviour showed no improvement. CONCLUSIONS: Intrathecal baclofen delivered by an implanted, programmable pump resulted in improved self reported quality of life as assessed by the SIP, and HSCL physical health dimensions also suggest improvement.

Adult↗

Female circumcision: implications for North American nurses.

1. Female circumcision is a centuries-old tradition that continues today and directly involves nursing practice and care of these patients. 2. Aside from traditional rites, female circumcision may be performed for economic factors, sexual control, and beliefs of its positive effects on childbirth. 3. Laws in North America and Europe ban the practice, but many children are sent abroad to have female circumcision performed.

Africa↗

Dichotomous pattern of coronary atherosclerosis 1 to 9 years after transplantation: insights from systematic intravascular ultrasound imaging.

OBJECTIVE: The aim of this study was to evaluate the extent and distribution of coronary atherosclerosis after transplantation. BACKGROUND: Transplant coronary artery disease is an important cause of death after cardiac transplantation. Unlike coronary angiography, intravascular ultrasound is a sensitive tool for detection and quantitation of this disease. METHODS: We performed intravascular ultrasound imaging in 132 (106 men, 50 +/- 10 years) patients, 1 to 9 years after transplantation using a 30-MHz ultrasound catheter. RESULTS: All three coronary arteries were visualized in 49, two in 62 and one in 21 patients. Of the 1,188 coronary artery segments, 706 were imaged (74% proximal, 64% mid- and 40% distal). At least one site with atherosclerosis (intimal thickness > or = to 0.5 mm) was found in 83% of patients. Atherosclerosis was noted in 64% of proximal, 43% of mid- and 26% of distal segments. Disease was diffuse in 48% and focal in 52%, circumferential in 66% and noncircumferential in 34%. Focal atherosclerosis was more common in proximal (59%) than mid- (48%) and distal segments (27%) (p=0.001). Noncircumferential plaques were more common in the proximal (42%) than mid- (28%) and distal segments (12%) (p=0.001). This pattern of focal and noncircumferential disease proximally, diffuse and circumferential disease distally, was observed irrespective of the time from transplantation. CONCLUSION: Atherosclerosis was detected in more than 80% of patients, with proximal segments most frequently involved. Diffuse and circumferential atherosclerosis was more common in mid- and distal segments. However, focal and noncircumferential involvement was more frequent proximally, a similar pattern to native atherosclerosis. These findings suggest that transplant coronary artery disease has a dual etiology based on the dichotomous pattern of atherosclerosis seen by intravascular ultrasound.

Chi-Square Distribution↗