Search PubMed⌕ Search

Biomedical subjects

T Stevenson

Publications and source records attributed to T Stevenson.

At least 19 recordsLinked to original sources
PubMed2004

Force platform feedback for standing balance training after stroke.

BACKGROUND: Standing balance deficits are common in individuals after stroke. One way to address these deficits is to provide the individual with feedback from a force platform while balance activities are performed. The feedback can take visual and/or auditory form. OBJECTIVES: To determine if visual or auditory force platform feedback improves the clinical and force platform standing balance outcomes in clients with stroke. SEARCH STRATEGY: We searched the Cochrane Stroke Group trials register (last searched December 2003), and the following electronic bibliographic databases: the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2003), MEDLINE (1966 to May 2003), EMBASE (1974 to May 2003), CINAHL (1982 to May 2003), PEDro (May 2003), CIRRIE (May 2003) and REHABDATA (May 2003). Reference lists of articles were reviewed and manufacturers of equipment were contacted. SELECTION CRITERIA: Randomized controlled trials comparing force platform with visual feedback and/or auditory feedback to other balance treatments. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trials for inclusion, methodological quality, and data extraction. Trials were combined for meta-analysis according to outcome and type of feedback. MAIN RESULTS: We included seven trials (246 participants). Force platform feedback did not improve clinical measures of balance when moving or walking (Berg Balance Scale and Timed Up and Go). Significant improvements in laboratory force platform indicators of stance symmetry were found for regimens using visual feedback (standardised mean difference (SMD) -0.68, 95% confidence interval (CI) -1.31 to -0.04, p = 0.04) and the concurrent visual and auditory feedback (weighted mean difference (WMD) -4.02, 95% CI -5.99 to -2.04, p = 0.00007). There were no significant effects on laboratory postural sway indicators, clinical outcomes or measures of function at follow-up assessment. REVIEWERS' CONCLUSIONS: Force platform feedback (visual or auditory) improved stance symmetry but not sway in standing, clinical balance outcomes or measures of independence.

Biofeedback, Psychology↗
PubMed2000

The role of microbiological testing in systems for assuring the safety of beef.

The use of microbiological testing in systems for assuring the safety of beef was considered at a meeting arranged by the International Livestock Educational Foundation as part of the International Livestock Congress, TX, USA, during February, 2000. The 11 invited participants from industry and government research organizations concurred in concluding that microbiological testing is necessary for the implementation and maintenance of effective Hazard Analysis Critical Control Point (HACCP) systems, which are the only means of assuring the microbiological safety of beef; that microbiological testing for HACCP purposes must involve the enumeration of indicator organisms rather than the detection of pathogens; that the efficacy of process control should be assessed against performance criteria and food safety objectives that refer to the numbers of indicator organisms in product; that sampling procedures should allow indicator organisms to be enumerated at very low numbers; and that food safety objectives and microbiological criteria are better related to variables, rather than attributes sampling plans.

Animals↗
PubMed2000

HIV, hepatitis C and risk behaviour in a Canadian medium-security federal penitentiary. Queen's University HIV Prison Study Group.

In a voluntary anonymous HIV and hepatitis C serology screen in a Canadian male medium security federal penitentiary, 68% of 520 prisoners volunteered a blood sample and 99% of those giving a blood sample completed a risk behaviour questionnaire which was linked numerically to the blood sample. Compared to previous screenings for HIV (4 years earlier), and hepatitis C (3 years earlier) in the same institution, HIV seroprevalence had risen from 1% to 2% and hepatitis C seroprevalence from 28% to 33%. The overwhelming risk association for hepatitis C was with drug use outside prison, although there was a small group of men who had only ever injected drugs inside prison, over half of whom had been infected with hepatitis C. The proportion of prisoners who had injected drugs in prison rose from 12% in 1995 to 24% in 1998. The proportion of surveyed individuals sharing injection equipment at some time in prison was 19%, and while HIV rates in the prison are currently low, HIV prevalence amongst Canadian street i.v. drug users is rising rapidly, underlining the need for urgent preventative measures in prisons.

HIV Seropositivity↗
PubMed1999

Hydrolysis of peptide hormones by endothelin-converting enzyme-1. A comparison with neprilysin.

Endothelins are peptide hormones with a potent vasoconstrictor activity that are also known to function as intercellular signaling molecules. The final step in the biosynthesis of endothelins is the proteolytic processing of precursor peptides by endothelin-converting enzymes (ECEs). ECE-1 is a zinc metalloendopeptidase related in amino acid sequence to neprilysin, a mammalian cell-surface peptidase involved in the metabolism of numerous biologically active peptides. Despite apparent structural similarities, ECE-1 and neprilysin have been considered to differ significantly in substrate specificity. In this study we have examined the activity of recombinant ECE-1 against a collection of biologically active peptides. ECE-1, unlike neprilysin, was found to have minimal activity against substrates smaller than hexapeptides, such as Leu-enkephalin. Larger peptides such as neurotensin, substance P, bradykinin, and the oxidized insulin B chain were hydrolyzed by ECE-1 as efficiently as big endothelin-1, a known in vivo substrate. Identification of the products of hydrolysis of six peptides indicates that ECE-1 has a substrate specificity similar to that of neprilysin, preferring to cleave substrates at the amino side of hydrophobic residues. The data indicate that ECE-1 possesses a surprisingly broad substrate specificity and is potentially involved in the metabolism of biologically active peptides distinct from the endothelins.

Amino Acid Sequence↗
PubMed1999

Glycosal: the first rapid, point-of-care test for the determination of hemoglobin A1c in patients with diabetes.

BACKGROUND: Glycosal is a rapid, point-of-care test using the established method of affinity chromatography for the quantitative determination of hemoglobin A1c (HbA1c). Glycosal enables the measurement of HbA1c to be performed in the diabetic clinic or doctor's office during a normal consultation, within minutes. The Glycosal test cartridge integrates with HaemaQuant, a compact spectrophotometric analyser equipped with a light emitting diode (LED) photo-optic detection system. An interactive liquid crystal display (LCD) provides the operator with an intuitive guide through the test procedure with the final result being expressed as HbA1c. Glycosal has a linear working range of at least 3%-18% HbA1c, requires approximately 10 microL of whole blood and generates a result in approximately 4 minutes. Glycosal has a mean coefficient of variation of less than 5% across its linear range. METHODS: Glycosal was evaluated in the clinical environment by means of comparison to two routine HbA1c autoanalyser methods used in the Clinical Chemistry Department of the Malmo University Hospital, Sweden. The Variant (BioRad) and the Mono-S (Pharmacia) systems are both cation exchange high-performance liquid chromatography (HPLC) systems specifically measuring HbA1c. Fresh (< 2 days) EDTA anticoagulated blood samples were randomly selected from the routine diabetic clinic (n = 54) along with nondiabetic samples from consenting volunteers (n = 8). RESULTS: The Variant and Mono-S HPLC methods showed excellent agreement compared to each other (correlation coefficient [r] > 0.99). The agreement between Glycosal and Variant (r = 0.98) and Glycosal and Mono-S (r > 0.98) HPLC methods were almost equally as significant. A further final evaluation of a 10 sample series (4%-10% HbA1c) of the hospital's HbA1c reference materials by Glycosal produced very strong agreement (r > 0.99) against the Mono-S HPLC. CONCLUSIONS: The Glycosal rapid test is proven to be comparable to two high-precision cation exchange HPLC autoanalyzers and constitutes a low-cost, HbA1c measurement system for the management of individuals suffering from diabetes mellitus at the point-of-care.

Chromatography, Affinity↗
PubMed1996

Berg balance test.

Explore the source record for details and available documents.

Accidental Falls↗
PubMed1996

Early results from the Euromir 95 experiment programme.

A total of 41 experiments were conducted in the context of the Euromir 95 mission, in the categories of life sciences, materials science, astrophysics and technology (Table 1). First results were presented recently at a post-flight Investigator Working Group Meeting at the European Astronauts Centre in Cologne, Germany. This article summarises all but those of the life-sciences experiments, which will be published separately at a later date.

Aerospace Medicine↗
PubMed1996

Exclusion of epidermal growth factor and high-resolution physical mapping across the Rieger syndrome locus.

We have evaluated the 4q25-4q26 region where the autosomal dominant disorder Rieger syndrome has been previously mapped by linkage. We first excluded epidermal growth factor as a candidate gene by carrying out SSCP analysis of each of its 24 exons using a panel of seven unrelated individuals with Rieger syndrome. No evidence for etiologic mutations was detected in these individuals, although four polymorphic variants were identified, including three that resulted in amino acid changes. We next made use of two apparently balanced translocations, one familial and one sporadic, to identify a narrow physical localization likely to contain the gene or to be involved in regulation of gene function. Somatic cell hybrids were established from individuals with these balanced translocations, and these hybrids were used as a physical mapping resource for, first, preliminary mapping of the translocation breakpoints using known sequence tagged sites from chromosome 4 and then, after creating YAC and cosmids contigs encompassing the region, for fine mapping of those breakpoints. A cosmid contig spanning these breakpoints was identified and localized the gene to within approximately 150 kb of D4S193 on chromosome 4. The interval between the two independent translocations is approximately 50 kb in length and provides a powerful resource for gene identification.

Chromosome Mapping↗
PubMed1992

Empowering school students in developing strategies to increase bicycle helmet wearing.

This paper outlines a 2 year community-based action research program to develop strategies for increasing bicycle helmet wearing by children from a rural town in Queensland, Australia. The results of six program components are provided: student observations, focus groups (n = 50), baseline survey (n = 565), student workshops (n = 80), meeting with student representatives (n = 4) and helmet trialing program (n = 17). The children were encouraged to become active participants in the research and to develop practical strategies to increase helmet wearing. The main barriers to helmet wearing reported were poor design and peer group derision. The majority of children never wore a helmet and only 7% wore one whenever bicycle riding. Strategies suggested to make helmets more acceptable were: develop more comfortable and fashionable designs, and lower helmet costs. Students taking part in the baseline survey and workshops disagreed that helmet wearing should be compulsory; however, in later workshops and focus groups students said this was the only sure way of getting students to wear helmets. The program was not evaluated because of the non-interventionist strategy recommended by the students and the introduction of compulsory helmets. However, the project demonstrated that action research can be successfully used with children.

Adolescent↗
PubMed1991

Developmental variation in copper, zinc and metallothionein mRNA in brindled mutant and nutritionally copper deficient mice.

The concentrations of copper, zinc and metallothionein-I (MT-I) mRNA were determined in the liver, kidney and brain of the brindled mutant mouse from birth until the time of death. Despite accumulation of copper in the kidney of the mutant, MT-I mRNA concentrations were normal. There was no difference between the MT-I mRNA in the brain of mutant and normal in the first 10 days of life, but after day 10 metallothionein mRNA levels were increased in the mutant. The concentration of copper was very low in the liver of the mutant, and on day 6 after birth the metallothionein mRNA was also reduced by about 50%. This reduction was not seen in copper-deficient 6-day-old pups, despite very low hepatic copper levels. This suggests that the lower hepatic MT-I mRNA in the day 6 brindled mouse was not simply due to the reduction in hepatic copper and also that hepatic copper is not regulating metallothionein gene expression the liver of neonatal mice. After day 12 hepatic MT-I mRNA levels were elevated in mutant and in copper deficient mice, both of which die at 14 to 16 days. These increases and the increase in brain MT-I mRNA in older mutant mice are likely to be caused by stress. Overall the results support the conclusions that the brindled mutation does not cause a constitutive activation of the metallothionein genes, and that the differences in metallothionein mRNA between mutant and normal are most probably secondary consequences of the mutation.

Animals↗
PubMed1983

Mutations in humans and animals which affect copper metabolism.

Various inherited disorders of copper metabolism in man and animals are reviewed. Emphasis is placed on the use of cultured cells from mutants to determine the primary molecular defects and to acquire basic knowledge of normal copper metabolism. This allows better diagnostic tests and possible treatment of the disorders. Menkes' disease in humans and mottled mouse mutants are discussed in detail, as they illustrate these approaches.

Animals↗
PubMed1981

Copper induction of translatable metallothionein messenger RNA.

Copper chloride injection of rats resulted in a 4.5- to 9-fold increase in translatable metallothionein messenger RNA in the liver. Metallothionein in the translation products was identified on the basis of high cysteine and serine incorporation and absence of leucine incorporation as well as comigration with authentic zinc-induced rat-liver metallothionein on SDS-polyacrylamide gels.

Animals↗
PubMed1980

An outpatient approach to female sterilization with methylcyanoacrylate.

MCA is a tissue adhesive which can be delivered transcervically to the Fallopian tubes by means of the FEMCEPT device. In the patients treated with this system, both prior to hysterectomy and on an ambulatory basis, there have been no significant complications or side effects. In the most recent series of ambulatory patients treated with the REMCEPT-MCA system, the bilateral tubal closure rate was 78%.

Ambulatory Care↗