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Biomedical subjects

J Murray

Publications and source records attributed to J Murray.

At least 253 records · Page 14Linked to original sources
PubMed1994

Comparison of seat pressures on three bowel care/shower chairs in spinal cord injury.

Pressure, positioning, and postural support are critical aspects in the design of a new bowel care/shower chair for persons with spinal cord injuries (SCI). The purpose of this evaluation was to evaluate seating pressures on three existing bowel care/shower chairs commonly used by persons with spinal cord injuries. A pressure mapping device, the Force Sensing Array, was used to measure seat pressure, position and postural support. Three seated subjects with spinal cord injuries were evaluated on each of the following three bowel care/shower chairs: Lumex, TRAUM-AID and E&J. The results of this evaluation will be briefly presented. This study is part of a larger study to design a bowel care/shower chair that uniquely meets the needs of persons with spinal cord injury.

Baths↗
PubMed1993

Herpes simplex virus type 1 ribonucleotide reductase large subunit: regions of the protein essential for subunit interaction and dimerization.

We have constructed a series of random N-terminal deletions of the large subunit (R1) of the herpes simplex virus type 1 ribonucleotide reductase. Deletions extended throughout the R1 gene open reading frame and, in total, 31 different truncated polypeptides were expressed in Escherichia coli using the T7 expression system. N-Terminal truncations were analyzed for their interaction with the small subunit (R2) of ribonucleotide reductase using a sensitive enzyme-linked immunosorbent assay (ELISA) method and for their ability to complement R2 in ribonucleotide reductase assays. Truncated proteins were also tested for homodimerization using gel-filtration chromatography. The results identified a region of R1 between amino acids 349 and 373 which was essential for subunit interaction. Proteins lacking up to 348 amino-terminal residues associated with R2 and complemented R2 in ribonucleotide reductase assays. Proteins commencing at amino acid 373 and beyond did not interact with R2 and were inactive in enzyme assays. Using a plasmid which expressed an N-terminal deleted protein commencing at amino acid 247, we constructed two defined C-terminal deletions to give proteins comprising amino acids 247-434 and 247-996 of R1. Neither of these truncated proteins bound R2 and we concluded that a second region between amino acids 996 and 1137 (the C-terminus) is required for interaction with R2. Gel-filtration studies indicated that deletion of the first 420 amino acids from R1 did not affect dimerization. However, deletions of 457 amino acids and larger gave proteins which existed as monomers.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Correlation between radiological and pathological diagnosis of silicosis: an autopsy population based study.

The radiological findings for the profusion of rounded opacities were compared to pathological findings for parenchymal silicosis in 557 gold miners who had, on average, 2.7 years between the radiological and pathological examination. Three readers read the radiographs, and ILO category 1/1 or more was defined as a positive diagnosis of silicosis. The sensitivity values were 0.393, 0.371, and 0.236, and the specificity values were 0.987, 0.965, and 0.978, for the three readers, respectively. The sensitivity of the readers improved with increasing degree of autopsy silicosis, but a large proportion of those with a moderate and marked degree of silicosis were not diagnosed radiologically. The diagnostic sensitivity of the radiological test could be improved by using category 0/1 as a cutoff point for workers exposed to a high average concentration of respirable silica dust. The diagnostic specificity of radiology could be improved by using category 1/0 or 1/1 as a cutoff point for a positive diagnosis for workers exposed to a low average concentration of respirable silica dust.

Autopsy↗
PubMed1993

The topographic organization of repetitive DNA in the human nucleolus.

The nucleolus is a highly specialized nuclear domain where ribosomal DNA (rDNA) is transcribed and preribosomes are assembled. We investigated the molecular organization of the human lymphocyte nucleolus by fluorescence in situ hybridization and confocal laser scanning microscopy and found that transcribed rDNA and nontranscribed ribosomal intergenic spacer (IGS) sequences colocalized to discrete regions frequently on the nucleolar periphery of phytohemagglutinin-stimulated cells. The 5S rDNA gene cluster located on the long arm of chromosome 1 was not regularly associated with the nucleolus. Short interspersed (SINE) Alu elements detected by BLUR 11 were distributed diffusely throughout the nucleus but were severely underrepresented in the nucleolus, whereas an Alu element subcloned from the IGS detected sequences enriched in the nucleolus but sparsely represented in the remainder of the nucleus. In contrast, long interspersed (LINE) Kpn elements, which were located at the nucleolus, were not found in rDNA but were identified outside the ribosomal gene complex on the short arm of at least one acrocentric chromosome. A human chromosome 21-derived alphoid sequence that hybridized to the centromere was localized outside but near the nucleolus, and nonribosomal DNA consisting of a tandemly repeated simple sequence cluster derived from the short arm of chromosome 15 was organized in a compact fashion in the nucleolus. Our study provides new insight into the content and structure of the human nucleolus and illustrates that the unique organization of repetitive DNA on the acrocentric chromosome short arms is reflected in the topographic organization of the nucleolus.

Blotting, Southern↗
PubMed1993

Alternative or additional medicine? An exploratory study in general practice.

In a South London general practice a substantial proportion of patients in some age groups (35 and 45 yr) had tried alternative treatment. Satisfaction with the outcome was limited. The use of alternatives was associated with higher general practice consultation rates, especially among women. Qualitative interviews with users suggested that rapid cures for chronic conditions were rarely expected; rather, an alternative explanation for health problems was sought and a greater sense of autonomy in dealing with them. Negative attitudes towards modern medicine arose from perceptions of excessive technological intervention and iatrogenic disorders arising from long term drug treatment.

Adult↗
PubMed1993

Coping with the uncertainty of uncontrolled epilepsy.

Parents of children with uncontrolled epilepsy experience chronic uncertainty in relation to their child's condition. In this study the author sought to explore the levels and dimensions of uncertainty experienced by parents of children with Lennox-Gastaut syndrome; the relationship between parental uncertainty and stress; and the range of cognitive and behavioural coping responses employed by parents. The population is drawn from a self-help group for parents of children with L.G.S. coordinated by the author. Data was collected through questionnaires as well as in-depth interviews with parents. The findings revealed five key dimensions of uncertainty: in respect to (1) diagnosis, (2) aetiology, (3) seizure activity, (4) treatment, and (5) prognosis. The study highlights the importance of information, contact with other parents of children with uncontrolled epilepsy and diary writing as aids to reducing uncertainty and enhancing coping for parents. The paper concludes by calling for a re-evaluation of the role of parents of children with epilepsy which moves away from the notion of parents as a source of pathology for their children to parents as part of a family unit attempting to cope as best it can with a chronic illness.

Adaptation, Psychological↗
PubMed1993

Neurologic complications of critical medical illnesses.

OBJECTIVES: To identify the neurologic complications of critical medical illnesses, and to assess their effect on mortality rates and on medical ICU and hospital lengths of stay. DESIGN: Prospective clinical evaluation of all medical ICU admissions for 2 yrs. SETTING: A 14-bed, general medical intensive and coronary care unit in a large university hospital. PATIENTS: Patients (n = 1,850) admitted to the hospital, of whom 92 were admitted for primarily neurologic problems. Of the remaining 1,758 patients, 217 (12.3%) experienced a neurologic complication. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients developing a neurologic complication while in the medical ICU demonstrated an increased risk of inhospital mortality when compared with patients who did not suffer such problems (45.7% vs. 26.6%; p < .00001). Patients with neurologic complications experienced 2.5-fold longer medical ICU stay times (p < .001) and almost two-fold longer hospital stay times (p < .001). Metabolic encephalopathy, seizures, hypoxic-ischemic encephalopathy, and stroke were the most common complications. Sepsis was the most frequent cause of encephalopathy, and cerebrovascular lesions were the most common cause of seizures. Formal neurologic consultations were requested in only 36% of these patients. CONCLUSIONS: Neurologic complications are associated with increased mortality rates and longer medical ICU and hospital lengths of stay. These conditions are probably underrecognized at present. ICUs have the potential to serve as environments for neurologic teaching and research.

Bacterial Infections↗
PubMed1993

An experimental anti-idiotype vaccine mimicking lipopolysaccharide gives protection against Pasteurella multocida type A infection in mice.

An anti-idiotype strategy was employed which showed that polyclonal anti-idiotype antibodies could be produced which could mimic a linear Pasteurella multocida lipopolysaccharide (LPS) molecule. These antibodies when used as vaccine antigens, induced antibodies which recognised LPS and imparted acquired protection upon syngeneic vaccinates challenged with homologous organisms.

Animals↗
PubMed1993

Cor pulmonale and silicosis: a necropsy based case-control study.

The presence of cor pulmonale at death in relation to other factors such as emphysema, silicosis, and thromboembolism was analysed in a case-control study of 732 South African gold miners. Marked emphysema was the highest risk factor with an odds ratio of 21.32 (95% confidence interval (95% CI) 5.02-90.7), then extensive silicosis (OR 4.95, 95% CI 2.92-8.38) and thromboembolic disease (OR 1.92, 95% CI 1.37-2.69). Age and smoking were not significant predictors of cor pulmonale.

Aged↗
PubMed1993

Regulation of distal esophageal mucosal blood flow: the roles of nitric oxide and substance P.

BACKGROUND: An increase in esophageal mucosal blood flow (MBF) may be an important protective mechanism against mucosal injury from noxious agents that are ingested or refluxed. This study investigated the changes in MBF and the regulation thereof after intraluminal application of noxious chemical stimuli. The role, if any, of substance P (SP) and nitric oxide (NO), two potent vasodilatory substances, and the vascular distribution of SP in the distal esophagus were evaluated. METHODS: Esophageal MBF was measured in anesthetized dogs with a laser Doppler flow probe attached to manometry and pH probes. MBF was measured before and after topical application of HCl (2 ml; 1N) or capsaicin (2 ml; 0.5%) in the distal esophagus. The effects on MBF of intraarterial SP and bradykinin were also determined. Pharmacologic antagonists and denervation procedures were used to delineate the mechanisms that regulate MBF. RESULTS: Sequential luminal applications of hydrochloric acid (HCl) or a single application of capsaicin increased MBF (p < 0.01). Topical intraluminal lidocaine blocked the response to capsaicin (p > 0.2) but not to HCl (p < 0.05). Abrupt increases in MBF occurred with intraarterial SP or bradykinin (p < 0.01). Neither atropine nor truncal vagotomy blocked the increase in MBF from these peptides or noxious stimuli. The NO synthesis antagonist NG-nitro-L-arginine methyl ester (L-NAME) blocked the response to bradykinin and attenuated the response to HCl (p < 0.05). NG-nitro-L-arginine methyl ester did not affect the response to SP or capsaicin. A substance P antagonist blocked the effects of both capsaicin (p > 0.6) and SP (p > 0.1) but not that of HCl (p < 0.01) or bradykinin (p > 0.01). CONCLUSIONS: Intraluminal applications of HCl or capsaicin appear to stimulate increases in esophageal MBF by different mechanisms. HCl produces an adaptive response that appears dependent on the paracrine effect of NO. Capsaicin-sensitive neurons mediate vasodilation through SP neurotransmission, independent of extrinsic vagal or cholinergic innervation.

Animals↗
PubMed1993

Medical procedure classification in Canada--where are we going?

Various medical procedure classifications have been used in combination with disease classifications in Canada for decades. In anticipation of the introduction of the next revision of the International Classification of Diseases (ICD-10), a project has begun to revise the Canadian Classification of Diagnostic, Therapeutic, and Surgical Procedures (CCP) that will accompany it. Changes in health care delivery dictate that this revised classification have broader application than its predecessor. This report begins with some results of the consultation processes undertaken to prepare for the revision. The planned structure and scope of the revised classification system are explained. Progress of the revision project to date and its future directions are described. The report's authors solicit information and assistance from classification users and from potential users of data based on the classification.

Abstracting and Indexing↗