Search PubMed⌕ Search

Biomedical subjects

R Stewart

Publications and source records attributed to R Stewart.

At least 73 records · Page 4Linked to original sources
PubMed1999

Wilms' tumor: a 25-year review of the role of preoperative chemotherapy.

PURPOSE: This 25-year population based, single institution review was conducted to investigate the impact of preoperative chemotherapy on surgical and histological staging in patients with Wilms' tumors. RESULTS: Forty-nine patients under the age of 15 years were identified from case notes to have had histologically verified Wilms' tumors over the 25-year period from January 1972 to December 1996. Twenty-six patients were treated initially with preoperative chemotherapy, 23 with immediate surgery. Eleven had treatment randomized within the UKCCSG WT9101 trial (UKWT3), and the remainder received initial treatment according to unit policy. Surgical stages in the two groups (preoperative chemotherapy and immediate surgery) were respectively, stage 1:14(28.5%) and 11 (22.5%), stage II: one (2%) and eight (16.3%), stage III: 11 (22.5%) and four (8.2%). Seven patients had clinical stage IV disease at presentation. Histology results were favorable in 45 patients and unfavorable in four. All patients received chemotherapy during treatment, whereas 25 (51%) also received radiotherapy. No significant difference was evident in the two groups with respect to treatment-related morbidity. Five patients relapsed, three of whom died within the period of review, but a fourth has since died. CONCLUSIONS: This study suggests that the use of preoperative chemotherapy does not put the patient at increased risk of postoperative morbidity or reduced survival. The distribution of surgical stages suggests that limited tumor downstaging may have occurred as a result of preoperative chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Efficacy and safety profile of ketorolac 0.5% ophthalmic solution in the prevention of surgically induced miosis during cataract surgery.

This multicenter, double-masked, randomized, parallel study compared the efficacy and safety profile of ketorolac tromethamine 0.5% ophthalmic solution with that of its vehicle in the maintenance of pupillary mydriasis during cataract surgery. A total of 176 adult patients scheduled to undergo unilateral extracapsular cataract extraction and posterior-chamber intraocular lens implantation received either ketorolac tromethamine 0.5% (n = 89) or vehicle (n = 87), starting 2 hours before surgery. One drop of study medication was instilled every 30 minutes for a total of 4 drops. No epinephrine was used in the intraoperative irrigating solution. Pupil diameter was measured with a caliper at 3 time points during surgery. To ensure participant safety, biomicroscopy, ophthalmoscopy, intraocular pressure, adverse events, and preoperative and postoperative visual acuity and refractive error were also monitored. The mean change in horizontal and vertical pupil diameter from the time of the first incision to after cortical irrigation and aspiration was significantly less with active ketorolac than with vehicle (P < or = 0.014). Consequently, mean pupil diameter after cortical irrigation and aspiration was significantly greater with ketorolac than with vehicle (P < or = 0.030). No significant between-group differences were observed in the change in pupil diameter between the end of surgery and postoperative administration of a miotic agent, safety variables, or occurrence of adverse events. In this study, ketorolac tromethamine 0.5% ophthalmic solution provided effective and well-tolerated inhibition of surgically induced miosis during cataract surgery.

Aged↗
PubMed1999

Vascular risk factors and Alzheimer's disease.

OBJECTIVE: We aim to summarise the recent and accumulating epidemiological research which suggests that cardiovascular disease and vascular risk factors play an important role as risk factors for Alzheimer's disease (AD) in later life. METHOD: The epidemiological literature is summarised in considering the evidence for such an association, focusing on optimally designed population-based studies. Potential mechanisms of association are considered, drawing on relevant findings from neuroscience. RESULTS: Cardiovascular disease and vascular risk disorders appear to be important factors in the aetiology of AD. However, there is a paucity of prospective studies with an adequate duration of follow-up to investigate the apparent age- and time-dependent nature of these associations. CONCLUSIONS: Vascular disorders represent potentially preventable risk factors with an important population impact due to their high prevalence in developed countries. The concept of AD and vascular dementia as clearly distinguishable disorders clinically or aetiologically is becoming increasingly tenuous. A better understanding of the relationship between AD and vascular disorders will depend on a more flexible diagnostic and conceptual framework.

Aged↗
PubMed1999

Type 2 diabetes mellitus, cognitive impairment and dementia.

AIMS: We set out to examine the evidence for an association between cognitive impairment or dementia and the presence of Type 2 diabetes mellitus (DM). We also sought evidence of potential mechanisms for such an association. METHODS: A literature search of three databases was performed and the reference lists of the papers so identified were examined, using English language papers only. RESULTS: We found evidence of cross-sectional and prospective associations between Type 2 DM and cognitive impairment, probably both for memory and executive function. There is also evidence for an elevated risk of both vascular dementia and Alzheimer's disease in Type 2 DM albeit with strong interaction of other factors such as hypertension, dyslipidaemia and apolipoprotein E phenotype. Both vascular and non-vascular factors are likely to play a role in dementia in diabetes. CONCLUSIONS: Current classification structures for dementia may not be adequate in diabetes, where mixed pathogenesis is likely. Further research into the mechanisms of cognitive impairment in Type 2 DM may allow us to challenge the concept of dementia, at least in these patients, as an irremediable disease.

Case-Control Studies↗
PubMed1999

Promoting group empowerment and self-reliance through participatory research: a case study of people with physical disability.

PURPOSE: Despite the growing popularity of the empowerment construct among social scientists, relatively few empowerment studies involving groupwork with people with physical disabilities exist. This article accordingly describes and analyses the organic development of the empowerment process within a spinal cord injury self-help group, set against the backdrop of policy imperatives for disability in post-apartheid South Africa. METHOD: The treatise on the group empowerment process is located within the context of a group evaluation conducted within a participatory research framework. Key variables informing the research approach included: quality of participation, control over resources and decision-making, shift in critical consciousness and understanding, malleability of roles within the group and role of the health professional. RESULTS: Group members assumed ownership of group management and decision-making and shifted from a professionally-led to a peer-led self-help group. Group objectives changed from providing mutual support to community education and outreach activities. The role of the health professional shifted from group facilitator to invited consultant. CONCLUSIONS: This case study demonstrates how group participation, promoted by a critically informed therapeutic and research praxis, can unlock the inherent potential for self-reliance and empowerment of socially marginalized collectives. It offers important insights with regard to group process, participatory research and the role of the health professional in creating opportunities for empowerment and self-reliance of people with disability.

Adolescent↗
PubMed1999

Comparison of three commercial systems for identification of yeasts commonly isolated in the clinical microbiology laboratory.

We evaluated three commercial systems (RapID Yeast Plus System; Innovative Diagnostic Systems, Norcross, Ga.; API 20C Aux; bioMerieux-Vitek, Hazelwood, Mo.; and Vitek Yeast Biochemical Card, bioMerieux-Vitek) against an auxinographic and microscopic morphologic reference method for the ability to identify yeasts commonly isolated in our clinical microbiology laboratory. Two-hundred one yeast isolates were compared in the study. The RapID Yeast Plus System was significantly better than either API 20C Aux (193 versus 167 correct identifications; P < 0.0001) or the Vitek Yeast Biochemical Card (193 versus 173 correct identifications; P = 0.003) for obtaining correct identifications to the species level without additional testing. There was no significant difference between results obtained with API 20C Aux and the Vitek Yeast Biochemical Card system (P = 0.39). The API 20C Aux system did not correctly identify any of the Candida krusei isolates (n = 23) without supplemental testing and accounted for the major differences between the API 20C Aux and RapID Yeast Plus systems. Overall, the RapID Yeast Plus System was easy to use and is a good system for the routine identification of clinically relevant yeasts.

Candida↗
PubMed1999

Smallest detectable difference in outcome variables related to painful restriction of the temporomandibular joint.

The smallest detectable difference is the smallest statistically significant change in measurement results. In the field of temporomandibular disorders, the smallest detectable difference is not a commonly used concept. Most outcome studies are based on comparisons of group means, although this does not provide information about individual changes or about the clinical relevance thereof. The smallest detectable difference for maximal mouth opening was calculated from previously published reliability coefficients and the standard deviations of different samples of healthy subjects and patients with complaints of the temporomandibular joint. The smallest detectable difference of pain intensity measured with different visual analogue scales was calculated from the reliability coefficients and standard deviations of a heterogeneous group of pain patients. The smallest detectable difference of function impairment was calculated for a group of patients with complaints of the temporomandibular joint. For maximal mouth opening in healthy subjects, the smallest detectable difference was 5 mm. Repeated measurements improved it to 3 mm. The smallest detectable difference on a visual analogue scale was 28 mm for actual pain intensity and 22 mm for minimal pain as well as for maximal pain intensity. For total function impairment of patients with complaints of the temporomandibular joint, the smallest detectable difference was 8 units on a 0 to 68 scale.

Adult↗
PubMed1999

Use of oral buprenorphine ('buprenorphine jello') for postoperative analgesia in rats--a clinical trial.

Buprenorphine (0.1, 0.2, 0.3 or 0.4 mg/kg) in a flavoured gelatin base was administered preoperatively to rats undergoing a flank laparotomy. A control group of animals underwent surgery and received only flavoured gelatin. Body weight loss was significantly greater in the group which received no analgesia than in any of the analgesic-treated groups (P < 0.01). Food consumption was reduced significantly in all groups except in those animals which received 0.3 mg/kg buprenorphine. Water consumption was significantly reduced in the control (no analgesia) group (P < 0.001), but was not significantly depressed in the analgesic-treated groups (P > 0.05). Between-group comparisons did not show any significant difference between the different dose rates of analgesia used on either the change in body weight or the reduction in food or water consumption. The results of this study support the use of buprenorphine jelly for post-surgical analgesia in rats. This route of delivery is easy to use, and causes a minimum of stress to the rats.

Administration, Oral↗
PubMed1999

Local low-dose IL-2 therapy.

Interleukin-2 (IL-2) is a powerful drug for treating cancer. However, it is only powerful if it is properly applied. That is, IL-2 should be applied at the tumor site, because at the transition of normal and malignant tissue are the tumor infiltrating cells. These should be activated by IL-2. Local application implies that IL-2 can be used in relatively low doses. It is becoming clear that even a single injection of IL-2 can cure cancer. IL-2 can also enhance the therapeutic effects of irradiation and Cisplatin. Locally applied IL-2 therapy is virtually non-toxic.

Animals↗
PubMed1998

Management theory. More art than science?

Evidence-based medicine can draw on more clear-cut research than that available for management. But it is still desirable to practise evidence-based management. Managers should encourage a research culture and a questioning approach. Developing a research culture requires at least one senior manager to act as a role model.

Decision Making, Organizational↗
PubMed1998

Morphometric analysis of the peripheral neuropathy of AIDS.

A morphometric study of the peripheral nervous system at autopsy was undertaken in 11 AIDS patients and 10 controls. The left L4, L5, and S1 dorsal root ganglia (DRG) and samples of the sciatic nerve at the buttock, tibial nerve at the knee, and sural nerve at the ankle were collected. Indices of neuronal/axonal degeneration and of segmental demyelination/ remyelination were measured at each level. The small number of cases and evidence of neuropathy in a number of the control cases resulted in statistical significance for only a limited number of comparisons. Nodules of Nageotte in the DRG were increased fivefold in AIDS cases compared with controls, and axonal degeneration in single-teased nerve fibers was increased 9-fold in the sciatic nerve, 28-fold in the tibial nerve, and 12-fold in the sural nerve. The ratios of AIDS to controls for the density of remaining DRG neurons and large myelinated axons were reduced to 0.71 in the DRG, 0.84 in the sciatic nerve, 0.84 in the tibial nerve, and 0.66 in the sural nerve. Axonal regeneration in single-teased nerve fibers was increased threefold at the sciatic nerve level in AIDS, but was markedly reduced at distal levels. Acute segmental demyelination in single-teased nerve fibers was present to a greater extent than in controls at all levels of the peripheral nerves in the AIDS cases. Remyelinating fibers were increased compared with controls only in the proximal sciatic nerve. No case showed the changes of cytomegalovirus infection. In a parallel immunohistochemical study of these AIDS peripheral nerves, T-cell and macrophage infiltration, with cytokine expression, was demonstrated. The pathological process in the neuropathy of terminal AIDS appears to be a multifocal immunologically mediated inflammatory disease, with increased density of macrophages and T cells at all levels of the peripheral nervous system, producing segmental demyelination and axonal degeneration. Reparative processes (axonal regeneration and remyelination) occurred only at the most proximal levels of the nerves.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Endothelial cell proliferation activity in benign prostatic hyperplasia and prostate cancer: an in vitro model for assessment.

PURPOSE: Urinary excretion of several pro-angiogenic and antiangiogenic substances has been correlated with malignant tumor growth. The aim of this study was to assay angiogenic activity in urine from patients with cancer of the prostate and benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Urine specimens from 22 healthy male volunteers (control), 33 patients with BPH and 29 with organ confined prostate cancer were analyzed for angiogenic activity in a bovine capillary endothelial cell proliferation assay. In parallel the concentration of basic fibroblast growth factor and vascular endothelial growth factor was determined by enzyme immunoassay in the corresponding urine specimens. RESULTS: Urine samples from patients with BPH and prostate cancer increased bovine capillary endothelial cell proliferation by 13.1% and 15.1%, respectively, whereas urine from the control group showed a significantly lower angiogenic activity, increasing endothelial cell proliferation by only 0.7% (p = 0.001). Urinary basic fibroblast growth factor and vascular endothelial growth factor were highest in patients with BPH and lowest in the group with prostate cancer (p = 0.0001). CONCLUSIONS: Urine from patients with BPH and prostate cancer stimulates endothelial cell proliferative activity. The degree of endothelial cell stimulation does not correlate with the concentration of basic fibroblast growth factor or vascular endothelial growth factor. Whether the observed pro-angiogenic activity is due to an increased production or release of (an) other angiogenic factor(s) and/or loss of (an) angiogenesis inhibitor(s), deserves further investigation.

Adult↗
PubMed1998

Double-masked, placebo-controlled evaluation of loteprednol etabonate 0.5% for postoperative inflammation. Loteprednol Etabonate Post-operative Inflammation Study Group 1.

PURPOSE: To compare the efficacy and safety of loteprednol etabonate 0.5% with those of a placebo (vehicle) in controlling anterior chamber cell and flare reaction in patients having cataract surgery with intraocular lens (IOL) implantation. METHODS: This randomized, double-masked, placebo-controlled, parallel-group multicenter study comprised patients who exhibited a minimum anterior chamber inflammation (ACI) score (sum of cell and flare reaction) of 3 (0 to 9 scale) on the day after cataract removal with posterior chamber IOL implantation. All 227 patients received loteprednol etabonate 0.5% or the placebo 4 times a day in the operated eye for up to 14 days after surgery. Five patients without valid on-treatment follow-up visits were not evaluated for efficacy. RESULTS: By the final visit, the ACI had resolved in 64% (70/109) of patients in the loteprednol etabonate group and 29% (33/113) of those in the placebo group (P < .001). The resolution rate and mean change from baseline of the individual components of ACI (cell and flare), as well as other signs and symptoms, was better in the loteprednol etabonate group. Both treatments were well tolerated. Among the 53 patients who did not complete the study, 34 (29%) were placebo patients discontinued for inadequate anti-inflammatory effect. The treatment failure rate and the time course of failures were lower in the loteprednol etabonate group; the differences were clinically meaningful and statistically significant (P < .001). Three patients in the loteprednol etabonate group had an intraocular pressure elevation of 10 mm Hg or more over the preoperative screening value. CONCLUSION: Loteprednol etabonate 0.5% led to a clinically meaningful reduction in the signs and symptoms of postoperative ACI and had an acceptable safety profile when compared with a placebo.

Adult↗
PubMed1998

Effect of optical temperature feedback control on patency in laser-soldered microvascular anastomosis.

Feedback control has been postulated to improve the efficacy of laser welding in microsurgery, but alteration of outcome has not been clearly shown. The authors evaluated the ability of an optical closed loop temperature feedback control to improve patency, aneurysm rate, and to histologically limit thermal damage. Rat femoral artery anastomoses were performed under operating microscope magnification. One hundred and twenty-four anastomoses were performed in five groups using 1) free-hand (FH) 1.9-microm laser soldering without feedback; 2) temperature controlled (TC) 1.9-microm laser soldering with optical feedback; 3) FH 808 nm laser; 4) TC 808 nm laser soldering; and 5) 10-0 nylon suture control. In Groups 2 and 4, an optical feedback system controlling laser exposure to produce a preset temperature was used. Anastomotic time was significantly less for all laser groups (p < 0.05). Late patency for all 1.9-microm laser anastomoses was almost 0. Temperature controlled 808-nm anastomoses showed no significant difference from sutures in terms of patency (88 percent vs. 96 percent), bursting pressure, and aneurysm rate, while freehand 808-nm anastomoses had a significantly lower patency (71 percent) and more tissue damage (ANOVA, p < 0.05). The authors conclude that temperature control improves outcome in microvascular anastomosis by reducing transmural thermal injury caused by variations in surgeon technique.

Anastomosis, Surgical↗