PubMed Health⌕ Search

Biomedical subjects

B Morrison

Publications and source records attributed to B Morrison.

At least 19 recordsLinked to original sources
PubMed2001

How can action research apply to health services?

The authors ask whether and how action research can apply to health services research, given action research's claim to be radically different from mainstream research. They analyze the key tenets of an idealized version of action research, comparing them with those of the approach characteristic of mainstream research. The authors conclude, firstly, that action research deserves all credit for pioneering flexible and imaginative ways of working. Yet, there is nothing in the fundamental logic of the mainstream approach to preclude it from adopting some of these. Action researchers therefore need to reconsider their critical stance toward mainstream research. Conversely, mainstream researchers need to reconsider their critical stance toward the ways of working pioneered by action research and to adopt them as appropriate.

Delivery of Health Care↗
PubMed2000

A randomized trial of the efficacy and tolerability of the COX-2 inhibitor rofecoxib vs ibuprofen in patients with osteoarthritis. Rofecoxib/Ibuprofen Comparator Study Group.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). It is not known whether a specific inhibitor of COX-2 will provide efficacy in osteoarthritis (OA) comparable with NSAIDs. Therefore, we compared the efficacy and safety of the rofecoxib, which specifically inhibits COX-2, with those of the NSAID ibuprofen in patients with OA. OBJECTIVE: To compare the clinical efficacy and tolerability of rofecoxib (12.5 and 25 mg once daily) with ibuprofen (800 mg 3 times daily). METHODS: A randomized, double-blind trial of 809 adults with OA was conducted. Patients with OA in whom the knee or hip was the primary source of pain were randomized to 1 of 4 treatment groups on demonstration of disease activity: placebo; rofecoxib, 12.5 or 25 mg once daily; or ibuprofen, 800 mg 3 times daily. Clinical efficacy and safety were monitored during a 6-week treatment period. RESULTS: Both doses of rofecoxib demonstrated efficacy clinically comparable with ibuprofen as assessed by 3 primary end points (pain walking on a flat surface [Western Ontario and McMaster Universities Osteoarthritis Index], patient global assessment of response to therapy, and investigator global assessment of disease status) according to predefined comparability criteria. Both rofecoxib doses and the ibuprofen dose provided significantly (P<.001) greater efficacy than placebo on all primary end points. Results from secondary end points were consistent with those of the primary end points. All treatments were well tolerated; the overall incidence rates of clinical adverse experiences were not significantly different (P>.05) among the treatment groups. CONCLUSION: Rofecoxib was well tolerated and provided clinical efficacy comparable with a high dose of the NSAID ibuprofen.

Aged↗
PubMed2000

Traumatic injury induces differential expression of cell death genes in organotypic brain slice cultures determined by complementary DNA array hybridization.

The expression of a large panel of selected genes hypothesized to play a central role in post-traumatic cell death was shown to be differentially altered in response to a precisely controlled, mechanical injury applied to an organotypic slice culture of the rat brain. Within 48 h of injury, the expression of nerve growth factor messenger RNA was significantly increased whereas the levels of bcl-2, alpha-subunit of calcium/calmodulin-dependent protein kinase II, cAMP response element binding protein, 65,000 mol. wt isoform of glutamate decarboxylase, 1beta isoform of protein kinase C, and ubiquitin messenger RNA were significantly decreased. Because the expression levels of a number of other messenger RNAs such as the neuron-specific amyloid precursor protein, beta(2) microglobulin, bax, bcl(xl), brain-derived neurotrophic factor, cyclooxygenase-2, interleukin-1beta, interleukin-6, tumor necrosis factor-alpha, receptor tyrosine kinase A, and receptor tyrosine kinase B were unaffected, these selective changes may represent components of an active and directed response of the brain initiated by mechanical trauma. Interpretation of these co-ordinated alterations suggests that mechanical injury to the central nervous system may lead to disruption of calcium homeostasis resulting in altered gene expression, an impairment of intracellular cascades responsible for trophic factor signaling, and initiation of apoptosis via multiple pathways. An understanding of these transcriptional changes may contribute to the development of novel therapeutic strategies to enhance beneficial and blunt detrimental, endogenous, post-injury response mechanisms.

Animals↗
PubMed2000

Dynamic mechanical stretch of organotypic brain slice cultures induces differential genomic expression: relationship to mechanical parameters.

Although the material properties of biological tissues are reasonably well established, recent studies have suggested that the biological response of brain tissue and its constituent cells may also be viscoelastic and sensitive to both the magnitude and rate of a mechanical stimulus. Given the potential involvement of changes in gene expression in the pathogenic sequelae after head trauma, we analyzed the expression of 22 genes related to cell death and survival and found that a number of these genes were differentially regulated after mechanical stretch of an organotypic brain slice culture. Twenty-four hours after stretch, the expression of BDNF, NGF, and TrkA was significantly increased, whereas that of bcl-2, CREB, and GAD65 was significantly decreased (MANOVA followed by ANOVA, p < 0.05). Expression of CREB and GAD65 was negatively correlated with strain, whereas expression of APP695 was negatively correlated with strain rate (all p < 0.05). This study demonstrates that a subset of genes involved in cell death and survival are differentially regulated after dynamic stretch in vitro and that the expression of specific genes is correlated with mechanical parameters of that stretch.

Analysis of Variance↗
PubMed1999

Pilot trial of infusional 5-fluorouracil, interleukin-2, and subcutaneous interferon-alpha for advanced renal cell carcinoma.

The authors developed an outpatient, three-drug combination regimen for advanced renal cell carcinoma. Treatment was administered for 5 days each week for 4 weeks, followed by 2-week rests. Each weekly treatment consisted of 5-fluorouracil 1,750 mg/m2 continuous intravenous infusion for 24 hours followed by interleukin-2 6 mIU/m2 per day continuous intravenous infusion for 4 days, and interferon-alpha2b 6 mU/m2 subcutaneously on days 1, 2, and 5. This trial was undertaken to assess tolerability to this regimen and obtain a preliminary assessment of its effectiveness. Most patients required some dose adjustments (especially of cytokines), treatment interruptions, or both. Toxicities were as would be expected from individual drug profiles with only mild to moderate hematologic toxicities. Among 16 patients with renal cell carcinoma treated, four had major (clinical partial response) responses, one of which was demonstrated to be a pathologic clinical response after surgical resection of a residual mass. Estimated median survival time of all patients was 93 weeks. Response and survival were correlated with known clinical risk factors. Responding patients were noted to be significantly older in age (X = 61.75 years) than nonresponders (X = 48.92 years). There was no correlation between age and other clinical risk factors, treatment tolerance, or survival. The authors conclude that this three-drug regimen is a practical, tolerable, and promising regimen for further study in renal cell carcinoma.

Adult↗
PubMed1999

Commissioning health services research: an iterative method.

The standard linear method of commissioning research involves many stages, some lengthy. While assessment criteria are usually explicit, their weighting and interaction are not. Output is assessed on completion. This method is suitable where the research question is clear-cut. However, it has drawbacks when the research question and the form and scope of the research are not clear at the outset, as is often the case with research on the delivery and organisation of services. Also, it does not encourage potential users of the research to develop a sense of ownership. An alternative method is proposed by which the scope, form and content of research are not specified in advance but are developed iteratively. A programme director, advised by a group of potential users and research commissioners, has devolved authority to commit funding for the stages of the work as it unfolds, predicated on evolving need. There are foreseeable but avoidable risks of the group over-identifying with the researchers, of research management becoming cumbersome, and of unproductive friction between research groups when they are required to work together. The iterative method, being new and untried, is itself an organisational change requiring evaluation. However, from our local experience, it provides for productive dialogue between research commissioners, researchers and potential users.

Health Services Research↗
PubMed1999

Effect of specific COX-2 inhibition in osteoarthritis of the knee: a 6 week double blind, placebo controlled pilot study of rofecoxib. Rofecoxib Osteoarthritis Pilot Study Group.

OBJECTIVE: To determine the efficacy and safety of the cyclooxygenase 2 (COX-2) specific inhibitor, rofecoxib in patients with osteoarthritis (OA) of the knee. METHODS: Rofecoxib, 25 mg or 125 mg once daily, was compared with placebo in a 6 week, double blind, parallel group, randomized, multicenter study of 219 patients with knee OA. RESULTS: Both doses of rofecoxib produced clinically significant improvement as assessed by primary (e.g., WOMAC Pain Subscale 0-100 mm, decrease from baseline: placebo: 7.1 mm; rofecoxib 25 mg: 28.1 mm, rofecoxib 125 mg: 28.0 mm; p < 0.001 rofecoxib vs placebo) and secondary efficacy (p < 0.05) criteria compared with placebo. Clinical improvement with the 25 mg dose was similar to that with the 125 mg dose. Both rofecoxib doses were generally well tolerated. CONCLUSION: Specific inhibition of COX-2 by 25 and 125 mg rofecoxib, administered once daily, resulted in clinically meaningful improvements in patients with OA. This study confirms that COX-2 derived prostanoids are important clinical mediators of pain and other symptoms of knee OA and that inhibition of COX-1 is not required to provide clinical benefit.

Adult↗
PubMed1998

SPring-8 in-vacuum undulator beam test at the ESRF.

Before the commissioning of SPring-8, the in-vacuum hybrid undulator developed at SPring-8 had been brought to the ESRF for the first beam test in the summer of 1996. The purpose of this test was to investigate the influence of the in-vacuum undulator on the beam and check its vacuum system. However, heating by the resistive wall impedance turned out to be a critical issue for the in-vacuum undulators.

Journal Article↗
PubMed1998

In vitro central nervous system models of mechanically induced trauma: a review.

Injury is one of the leading causes of death among all people below the age of 45 years. In the United States, traumatic brain injury (TBI) and spinal cord injury (SCI) together are responsible for an estimated 90,000 disabled persons annually. To improve treatment of the patient and thereby decrease the associated mortality, morbidity, and cost, several in vivo models of central nervous system (CNS) injury have been developed and characterized over the past two decades. To complement the ability of these in vivo models to reproduce the sequelae of human CNS injury, in vitro models of neuronal injury have also been developed. Despite the inherent simplifications of these in vitro systems, many aspects of the posttraumatic sequelae are faithfully reproduced in cultured cells, including ultrastructural changes, ionic derangements, alterations in electrophysiology, and free radical generation. This review presents a number of these in vitro systems, detailing the mechanical stimuli, the types of tissue injured, and the in vivo injury conditions most closely reproduced by the models. The data generated with these systems is then compared and contrasted with data from in vivo models of CNS injury. We believe that in vitro models of mechanical injury will continue to be a valuable tool to study the cellular consequences and evaluate the potential therapeutic strategies for the treatment of traumatic injury of the CNS.

Adult↗
PubMed1997

Differences in resistance to herpes simplex virus type 1 (HSV-1) among oligodendroglia derived from different strains of mice are determined after viral adsorption but prior to the expression of immediate early (IE) genes.

The nature of an innate cellular resistance to HSV-1 of cultured murine oligodendrocytes (OLs) in three strains of mice (C57BL/6J, Balb/cByJ and A/J) was investigated. The expression of immediate early (ICP4), early (ICP8) and late (gC) antigens in primary OL cultures was studied using an indirect immunofluorescence (IF) technique. HSV-1 infected OLs from C57BL/6J mice showed no viral antigens at 24 h post infection (p.i.) but rather a marked delay in antigen expression beginning at 60 h p.i. In contrast all three proteins were expressed in A/J OLs at 24 h p.i. while Balb/cByJ OLs showed an intermediate protein expression pattern. These results suggest that the innate cellular resistance to HSV-1 is determined prior to the expression of immediate early viral antigens. To further study these differences, the adsorption capacity between the three mouse strains was compared using dextran purified, [3H]thymidine labelled virus. No differences in HSV-1 adsorption were identified. Results from viral penetration studies approached statistical significance suggesting that penetration may be impaired in C57BL/6J and Balb/cByJ OLs when compared to A/J OLs and is likely fusion independent. The selective differences in HSV-1 resistance mediated by OLs, reflect differences in virus host cell interactions, that likely contribute to differences in mortality, viral spread, and the ability of virus to induce central nervous system (CNS) demyelination.

Adsorption↗
PubMed1994

Level and distribution of employee exposures to total and respirable wood dust in two Canadian sawmills.

Personal respirable (N = 230) and total (N = 237) dust measurements were made in two coastal British Columbia sawmills using a sampling strategy that randomly selected workers from all jobs in the mills over two seasons. Information about job title, department, season, weather conditions, location of the job relative to wood-cutting machines, and control measures also was collected at the time of sampling. Only 16 respirable wood dust samples were above the detection limit of 0.08 mg/m3; all 16 had levels < or = 0.20 mg/m3. Total wood dust concentrations were also low (36% less than the detection limit), with a mean of 0.51 mg/m3, and ranging from < 0.08 to 52 mg/m3. Measurements of exposure taken close to chippers, planers, and multiple saws had the highest total wood dust levels. Sawmill department and booth enclosures also were associated with wood dust concentrations, while local exhaust ventilation and weather conditions were not. Wood dust levels in this study were generally lower than in other studies of this industry, but most sawmill investigations report mean wood dust concentrations lower than those measured in the furniture and cabinetmaking industries, where concerns about wood dust exposures initially were raised.

British Columbia↗
PubMed1994

Respiratory syncytial virus subgroup B dominance during one winter season between 1987 and 1992 in Vancouver, Canada.

A subgroup analysis of 613 specimens submitted to the British Columbia's Children's Hospital from 1987 to 1992 revealed that subgroups A and B of respiratory syncytial virus (RSV) were both circulating in our community, with some predominance for subgroup A during the period from October 1987 to September 1988 (the 1987-88 season) (64%), 1990-91 (60%), and 1991-92 (62%). During 1989-90 subgroup A represented the majority of isolates (80%). Subgroup B predominated during only one season, 1988-89 (94%). No microheterogeneity within subgroups was apparent as judged by the monoclonal antibody reactivity pattern. More male than female children were affected overall, but no sex-related difference between subgroup infections could be detected (P = 0.28). The majority of patients were less than 1 year of age, and no significant association between age and subgroup was detected after stratifying for year (P = 0.64). This is, to our knowledge, the first comprehensive longitudinal RSV subgroup prevalence study from the Pacific Northwest and from Canada.

Adolescent↗
PubMed1993

Clomipramine, fluoxetine, and behavior therapy in the treatment of obsessive-compulsive disorder: a meta-analysis.

The most common effective treatments for obsessive-compulsive disorder include clomipramine, fluoxetine, and exposure-based behavior therapy. A meta-analysis was conducted on the results from 25 appropriate treatment studies (1975-1991). All three treatments were significantly effective for most of the outcome variables (overall severity, anxiety, depression). Exposure was not significantly effective for reducing depressed mood. More treatment outcome studies are needed before a clearly superior treatment or combination of treatments can be statistically determined.

Behavior Therapy↗
PubMed1993

Reproducibility of transcranial Doppler ultrasound examinations of the ophthalmic artery flow velocity.

Transcranial Doppler ultrasound measurements of ophthalmic artery velocity were made on 88 patients predominantly suffering from glaucoma. Of the four observed parameters, peak velocity, mean-enveloped velocity, diastolic velocity, and resistivity index, the latter was found to be the most reproducible (CV = 5.2%). The variability between patients was approximately twice that of the variability between consecutive measurements. Measurement error appeared to decrease as the operator gained experience.

Blood Flow Velocity↗