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Biomedical subjects

J Wilson

Publications and source records attributed to J Wilson.

At least 289 records · Page 16Linked to original sources
PubMed1996

Effect of profound ischaemia on human muscle: MRI, phosphorus MRS and near-infrared studies.

A pressure cuff was applied to the legs of two human volunteers in order to stop any blood supply for a period of about 30 min. The affected muscle was monitored using proton magnetic resonance imaging (MRI), phosphorus magnetic resonance spectroscopy (MRS) and near infrared (NIR) spectroscopy before, during and after this procedure. The internal temperature of the tissue was also measured. The phase of water protons in muscle showed changes that were not accounted for by the measured temperature, but which correlated with the large increase in deoxyhaemoglobin and deoxymyoglobin observed with NIR as well as the decrease in PCr and increase in Pi observed with MRS. Little or no change was found in proton density or T2*. These results show that in vivo measurements of temperature using the chemical shift method may be confounded by changes in tissue oxygenation. They also show that T2* is an insensitive measure of changes in tissue oxygenation.

Constriction↗
PubMed1996

MELAS associated with a mutation in the valine transfer RNA gene of mitochondrial DNA.

We describe a patient with the mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS) phenotype in whom initial investigations in skeletal muscle failed to show any histochemical or biochemical defect. Subsequent analysis of the mitochondrial genome identified a new heteroplasmic mutation in the valine transfer RNA gene, the first described in this region.

Adolescent↗
PubMed1996

Changes in ventilation related to changes in electromyograph activity during repetitive bouts of isometric exercise in simulated sailing.

This study examined the control of ventilation during repetitive bouts of isometric exercise in simulated sailing. Eight male sailors completed four successive 3-min bouts of similar isometric effort on a dinghy simulator; bouts were separated by 15-s rest intervals. Quadriceps muscle integrated electromyograph activity (iEMG) was recorded during each bout and expressed as a percentage of activity during maximal voluntary contraction (%iEMGmax). From the first to the fourth bout, the 3-min mean averages for ventilation and for %iEMGmax increased from 19.8 (SEM 1.1) to 37.5 (SEM 3.0) l.min-1 and from 31 (SEM 4) to 39 (SEM 4)% respectively; also, ventilation and %iEMGmax over each minute throughout the four bouts were significantly correlated (r = 0.85; P < 0.05). Progressive hyperventilation reduced the mean end-tidal partial pressure of carbon dioxide from 5.0 (SEM 0.3) kPa during bout 1 to 4.3 (SEM 0.4) kPa during bout 4 [37.7 (SEM 2.0) to 32.4 (SEM 3.0) mmHg]. From the first to the fourth bout the end-of-bout blood lactate concentration did not increase significantly although the concentration from the third bout onwards was significantly greater than at rest. The results suggested that the development of muscle fatigue, which was enhanced by the insufficiency of recovery during the 15-s intervals and mirrored in the progressive increase in iEMG, was linked with stimuli causing progressive hyperventilation. Though these changes in ventilation and iEMG could not be associated with changes in blood lactate concentration, they could both have been related to accumulating metabolites within the muscles themselves.

Adult↗
PubMed1996

Ataxia associated with increased plasma concentrations of pristanic acid, phytanic acid and C27 bile acids but normal fibroblast branched-chain fatty acid oxidation.

Investigations of peroxisomal function were undertaken in an 8-year-old girl who developed motor difficulties at the age of 3.5 years and went on to develop a progressive ataxia and dysarthria. There were no other neurological abnormalities and she was of normal intelligence. Analysis of plasma very long-chain fatty acids revealed a normal C26 concentration and normal C24/C22 and C26/C22 ratios. Analysis of branched-chain fatty acids showed an elevated plasma phytanic acid concentration of 60 mumol/L (normal < 15) and a considerably elevated pristanic acid concentration of 50 mumol/L (normal < 2). Plasma concentrations of the C27 bile acids 3 alpha, 7 alpha-dihydroxycholestanoic acid (DHCA) and 3 alpha, 7 alpha, 12 alpha-trihydroxycholestanoic acid (THCA) and of the C29-dicarboxylic acid were also increased. We postulated that these results might be due to deficiency of the peroxisomal branched-chain acyl-CoA oxidase, but when oxidation of branched-chain fatty acids was studied in cultured skin fibroblasts it was found to be normal. Alternative explanations for the accumulation of branched-chain substrates for peroxisomal beta-oxidation are discussed. Treatment with a low-phytanic acid diet arrested the progression of the ataxia and led to a slight improvement.

Ataxia↗
PubMed1996

Neurological sequelae of the dancing eye syndrome.

UNLABELLED: Fifty-four patients with dancing eye syndrome (DES), presenting over a 25-year period, were reviewed retrospectively. One third of them were on active follow up at the time of the study. Malignancy was uncommon, diagnosed in only 4 patients, neuroblastoma in 3 cases and acute lymphoblastic leukaemia (ALL) in 1. An intercurrent illness preceded onset of DES in 51% of the children and was of equivocal significance. There was no clear temporal relationship to immunization. The acute phase of the illness was severe and caused total immobilization in 88% of patients. A favourable initial response to treatment with prednisolone or corticotrophin gel was observed in all patients. Although corticotrophin seemed to produce a more rapid response, overall improvement was similar with both treatments. Long-term neurological morbidity was a major problem with 91% of children suffering either persisting symptoms or repeated relapses. A persisting disability was found in 88% and was considered severe in 61% of patients. No features prognostic of neurological severity or outcome were identified. CONCLUSION: Demonstrable malignancy is uncommon in the dancing eye syndrome. The neurological legacy of DES is often evident well into adult life.

Brain Damage, Chronic↗
PubMed1996

Gene transfer by adenovirus in smooth muscle cells.

We report adenovirus-mediated gene transfer into airway smooth muscle cells in cultured cells and organ-cultured tracheal segments. Incubation of cultured rat tracheal myocytes with virus (5 x 10(8) pfu/ml) for 6 h resulted in beta-galactosidase expression in 94.8 +/- 2.5% of cells (n = 4). Following incubation of thin (less than 200 microns diameter) equine trachealis muscle segments with virus in organ culture (5 x 10(8)-5 x 10(10) pfu/ml) the average expression of the Lac Z gene was approximately 19 +/- 10% (n = 9). Expression was markedly improved, however, in segments from neonatal rats (13-21 days). In two experiments in which the mucosa and serosa were removed, nearly all cells expressed beta-galactosidase, whereas in a third experiment in which the tissue was not dissected, about 40% of cells were stained. Viral infection had no effect on tension development of strips following organ culture. In vitro gene transfer may provide a useful method to alter protein expression and examine the effect of this alteration on excitation/contraction coupling in smooth muscle.

Adenoviridae↗
PubMed1996

Evaluation of monoclonal antibody-mediated anti-acute myeloid leukemia immunotherapy in a SCID/hu model.

The therapeutic potential of the IgM complement-fixing murine monoclonal antibody (mAb) PM-81 (anti-CD15) against acute myeloid leukemia (AML) was assessed in a SCID/hu leukemia model. Intraperitoneal (i.p.) injection of NB4 leukemia cells resulted in aggressive growth of leukemia cells in the peritoneal cavity of irradiated SCID/CB-17 mice. Flow cytometric analysis of human CD15, 33 and 45 expression, as well as cytologic examination, revealed that leukemia cells disseminated into the peripheral blood and multiple tissues of the mice. The approximately linear relationship between the injected leukemia cells and the subsequent leukemia cell proliferation provided a reliable model for monitoring the therapeutic effects of immunotherapy. Intraperitoneal injection of the mAb PM-81 markedly suppressed leukemia cell growth in this SCID/leukemia model. Most of the untreated mice died within 35-50 days of leukemia cell inoculation. Four weeks after inoculation of NB4 cells, five of nine mAb PM-81 treated mice had no solid tumor growth and six of nine had no detectable peritoneal exudate leukemia cells as determined by flow cytometry. In contrast, 100% of the mice in the untreated or control mAb groups were found to have both solid and peritoneal leukemia growth. In further experiments designed to evaluate the effects of therapy on survival, 50% (4/8) of PM-81 treated mice survived to 150 days, and had no detectable solid or suspension leukemia cells detectable at necropsy. In contrast, the median survival of untreated or negative control antibody-treated mice was 40 days (comparison to PM-81 treated; p = 0.006 and p = 0.03, respectively). The mechanism of leukemia cell suppression is not likely due to complement fixation since we could not demonstrate in vitro any cytotoxicity mediated by SCID mouse plasma. Further study is required to understand the mechanism of the antileukemia effect of PM-81 in this model.

Animals↗
PubMed1996

Women's satisfaction with traditional and reduced antenatal visit schedules.

OBJECTIVE: to ascertain: (i) which demographic, obstetric, maternity care, practical and attitudinal variables, and which variables relating to social support and life problems predict satisfaction with traditional antenatal visit schedules; and (ii) which of these variables predict satisfaction with reduced antenatal visit schedules. DESIGN: a secondary analysis of data from the Antenatal Care Project (a randomised controlled trial comparing two schedules of routine antenatal visits). SETTING: three hospitals and their community sites in south-east London. PARTICIPANTS: 1882 pregnant women, that is all those who took part in the Antenatal Care Project, on whom maternity record data were available, and who returned their antenatal questionnaire. INTERVENTION: participants were randomly allocated to follow either the traditional schedule of 13 routine antenatal visits, or a reduced schedule of seven visits for nulliparous women and six visits for multiparous women. MEASUREMENTS: a questionnaire developed specifically for the Antenatal Care Project. Also some data extracted from women's maternity records. FINDINGS: women satisfied with reduced schedules were more likely to live in rented accommodation, and to have a caregiver who both listened and encourage them to ask questions than women not satisfied with reduced schedules. Women satisfied with the reduced schedules were less likely to be depressed in pregnancy than those not satisfied with reduced schedules. Women satisfied with the traditional schedule were more likely to have their general practitioner involved in their antenatal care, and to receive social support from relatives than those not satisfied with the traditional schedule. Initial preferences and expectations were also associated with satisfaction. KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: (i) groups most likely to be satisfied with traditional or reduced antenatal visit schedules cannot be easily identified. It is therefore necessary to talk to women individually, and tailor care to their particular preferences; (ii) social support for depressed women needs to be safeguarded if reduced schedules are to be introduced; (iii) improving the psychosocial quality of antenatal care may be a good strategy for making reduced visit schedules more acceptable to pregnant women.

Adult↗
PubMed1996

Reflective practice: a guide.

Reflective practice is an important concept to the development of nursing as a profession. Nurses need to become reflective practitioners, especially within the current changeable climate. Many practitioners however, find reflective practice confusing and feel unsure how to proceed. This paper attempts to remove some of the mystery surrounding this issue. The skills needed for reflection are identified from a review of the literature. These include self-awareness, critical analysis, synthesis and evaluation. A suggested activity for developing reflective skills is provided as well as a format for keeping a learning diary.

Clinical Competence↗
PubMed1996

Screening for peripheral arterial disease.

Peripheral arterial disease (PAD) is an age-dependent condition that limits ambulation and compromises quality of life in an estimated two million Americans. Early detection and treatment is essential for minimizing the signs and symptoms of PAD. Using a methodology developed by the National Council on the Aging, a noninvasive screening program was conducted for this disease in a population of 1,092 elderly ambulatory Rhode Island residents. Possible PAD was detected in 17.7% of the subjects, while 42% were identified as being at high risk for the disease.

Aged↗
PubMed1996

Prevalence of the eaeA gene in verotoxigenic Escherichia coli strains from dairy cattle in Southwest Ontario.

This study determined the prevalence of the eaeA gene and its relationship to serotype and type of verotoxin produced in a collection of 432 verotoxigenic Escherichia coli (VTEC) obtained from the faeces of healthy cows and calves in a systematic random survey involving 80 dairy farms in Southwest Ontario. A PCR amplification procedure involving primer pairs which target the conserved central region of the O157:H7 eaeA gene showed that 151 (35.2%) strains were positive for the eaeA gene. All isolates (9-21 for each O group) of O groups 5, 26, 69, 84, 103, 111, 145 and 157 were positive, whereas all isolates (7-34 for each O group) of O groups 113, 132, and 153 and serotype O156:NM (38 isolates) were negative for eaeA. Seventy-three percent of 130 isolates of eaeA-positive serotypes produced VT1 only compared with 20% of 253 isolates of eaeA-negative serotypes. We conclude that there is a strong association between certain O groups and the eaeA gene, that serotypes of eaeA-positive and eaeA-negative VTEC implicated in human and cattle disease are present at high frequency in the faeces of healthy cattle, that VT1 is more frequently associated with eaeA-positive than with eaeA-negative serogroups, and that the eaeA gene is more frequently found in VTEC from calves compared with VTEC from adult cattle.

Animals↗
PubMed1996

Nerve conduction velocity in human limbs with late sequelae after local cold injury.

Cold-induced neuropathy may play a dominant role in the long-term sequelae with cold sensitivity after local cold injuries (LCIs). Somatosensory functions were assessed and nerve conduction velocity (NCV) and motor distal delay (MDD) were measured in the limbs of 31 Norwegian former soldiers with persistent cold intolerance 3-4 years after the primary LCI. NCV measurements were performed in 24 lower and 16 upper extremities. NCV was related to degree of overall subjective complaints quantified by means of a visual analogue scale (VAS). Motor (MNCV) and sensory conduction velocity (SNCV) in the lower extremities and SNCV in the hands were significantly decreased compared with controls. MDD was pathologically increased in the feet. NCV of the forearms ranged from normal to significant reduction. The more pronounced effect on the lower extremities may be caused by deeper cooling of the calves compared with forearms for several reasons. No significant associations were found between VAS and NCV except for the right median nerve. NCV measurements may provide objective findings in cold-injured patients and in those with few or no conspicuous clinical signs.

Adult↗
PubMed1996

High-dose cyclophosphamide, carboplatin, and etoposide with autologous stem cell rescue in patients with breast cancer.

This study was designed to establish the toxicity and response rates o observed with a combination of high-dose cyclophosphamide, carboplatin, and etoposide with stem cell rescue in patients with breast carcinoma. Eligibility criteria included metastatic or locally advanced breast carcinoma ; aged < or equal to 60 years; performance status Eastern Cooperative Oncology Group (ECOG) 0-1; and creatinine clearance > or equal to 65 ml/min. Chemotherapy consisted of cyclophosphamide 25 mg/kg i.v. X 4 days, etoposide 400 mg/m(2) i.v. X 4 days, and carboplatin 375 mg/m(2) X 4 days. Bone marrow or peripheral blood stem cells were reinfused 48 h after completion of chemotherapy. Seventeen patients were treated in this study. The major toxicity was gastrointestinal (grades I and II). Fevers associated with neutropenia were observed in all the patients, but no episodes of bacteremia were documented. Hematopoietic toxicities were acceptable. No toxic deaths were observed. Six patients had chemotherapy-sensitive disease at time of transplant, nine had refractory disease, and two were untested. A response rate of 62% with 18% complete response (CR) was achieved. Two patients are free of disease at +7 and +9 months after transplantation. The combination of high-dose cyclophosphamide, carboplatin, and etoposide is well tolerated with a response rate comparable to previously reported high-dose chemotherapy regimens. However, in a poor prognostic risk group, namely patients with chemoinsensitive disease, this therapeutic approach seems to be of no advantage over standard chemotherapy.

Adult↗
PubMed1996

Job satisfaction and perceptions of health.

Workers' perceptions of health have become one focus of research on the costs of health care, yet little is understood about the relationship between perceptions of health and perceptions of work. An exploratory cross-sectional study was conducted on a large southern university campus to determine if perceptions of select facets of work were related to perceptions of health. Results indicated that satisfactory perceptions of coworkers was the strongest predictor of current and future health perceptions, and the strongest predictor of perceptions of resistance to illness. Other significant job-facet predictors of health perceptions were autonomy, the work done on the present job, and pay. Satisfaction with supervision and opportunities for promotion were not predictive of health-perception measures. Implications for enhanced employee health include a greater emphasis on coworker relationships, especially in the current context of organizational change in business and industry.

Adult↗
PubMed1996

The incidence and level of Listeria monocytogenes contamination of food sources at primary production and initial processing.

Listeria monocytogenes was isolated in low numbers from a variety of environmental samples associated with the primary production of food, including vegetation, faeces and meat. The organism was rarely detected on growing grass and vegetables prior to processing. The excretion of L. monocytogenes by farm animals was linked to their diet, with animals fed entirely on hay or manufactured diets not excreting detectable levels of Listeria (i.e. absence in 25 g). However, animals fed on silage, which is frequently contaminated with L. monocytogenes, commonly excreted the organism. Transport of live animals over long distances (> 100 km) significantly increased the level of excretion of Listeria, but the contamination of carcasses of sheep and cattle was not high. Pigs and poultry faeces were free of Listeria prior to slaughter and pig carcasses were not found to have Listeria present. Frozen and chilled chicken did show detectable levels reflecting the greater potential for contamination during poultry processing. Samples of minced beef were tested and 21 of 23 samples were positive for L. monocytogenes, demonstrating that processing significantly increases the level of contamination compared to whole carcasses. Multilocus enzyme electrophoresis of a representative selection of the isolates showed that there was a wide range of electrophoretic types present in the primary production environment, relatively few of which have been linked to cases of human listeriosis. However, these types do arise on farms and occasional contamination of food raw material by potentially virulent strains may be sufficient to allow adaptable strains to become established in the processing environment and thus be responsible for more widespread contamination of the food available to the consumer.

Abattoirs↗
PubMed1996

Patterns and costs of post-acute care: a longitudinal study of people aged 60 and over in Dubbo.

Declining length of stay of older people in hospital has caused concern about shifting of costs from acute to community care services. Because the two types of care are funded through different programs and from different jurisdictions, the coordination of acute and post-acute care has become the major issue. There is, however, little information available on patterns of use and costs of post-acute care either in Australia or elsewhere. In an existing longitudinal community study of older people in Dubbo, New South Wales, data on use of services by people aged 60 years and over for 12 months of hospitalisations was collected by linkage to the records of Home and Community Care providers. Only a quarter of older people received any type of Home and Community Care service in the 12 weeks after discharge and two-thirds of these received only one type of service. While less than 5 per cent received a service from an occupational therapist, physiotherapist or speech therapist, 78 per cent visited a general practitioner after discharge. The average cost of all Home and Community Care services received after hospital discharge was around $12.50 per week per person discharged. The predictors of higher costs of service use were: living alone, and the interactions of high levels of disability with owning a house. Results on service coordination, the identification of post-acute services, cost consequences of program funding, assessment and discharge planning are related to debates emerging from the Commonwealth Heads of Government.

Aftercare↗
PubMed1996

Neutralizing antibodies to Escherichia coli Vero cytotoxin 1 and antibodies to O157 lipopolysaccharide in healthy farm family members and urban residents.

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Escherichia coli O157 lipopolysaccharide (LPS) was developed with sera from 63 children with confirmed recent E. coli O157 infection and from 256 age-stratified urban controls. The median ELISA values for control and case sera were 0.05 (interquartile range, 0 to 0.20; mean +/- standard deviation [SD], 0.15 +/- 0.22) and 1.41 (interquartile range, 1.11 to 1.59; mean +/- SD, 1.41 +/- 0.53), respectively (P < 0.001). With a breakpoint of 0.59 (mean ELISA value of the control sera + 2 SDs), the assay had a sensitivity, specificity, and positive and negative predictive values of 95, 94, 80, and 98%, respectively, for recent E. coli O157 infection. The O157 LPS assay and Vero cytotoxin (VT) 1-neutralizing-antibody (NAb) assay were used to compare the relative frequencies of O157 LPS antibodies and VT1-NAbs in an age-stratified urban population from Toronto, Ontario, Canada, and in 216 healthy family members from dairy farm in southern Ontario. The frequency of O157 LPS antibodies was about threefold higher in dairy farm residents (12.5%) than in urban residents (4.7%) (P < 0.01). Similarly, the frequency of VT1-NAbs was about sixfold higher in dairy farm residents (42.0%) than in urban residents (7.7%) (P < 0.001). These findings are consistent with a greater level of exposure of dairy farm residents to VT-producing E. coli (VTEC) strains. The high rate of seropositivity to VT1 in farm residents probably reflects the booster effect of repeated VTEC exposures and argues against a sustained generalized immunosuppressive effect of VT1. Seroepidemiological studies may help in assessing the level of exposure of different populations to VTEC strains.

Adolescent↗