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Biomedical subjects

J Hunter

Publications and source records attributed to J Hunter.

At least 145 records · Page 8Linked to original sources
PubMed1990

The effect of steering on the physiological energy cost of wheelchair propulsion.

Previous studies of the energy cost of wheelchair propulsion have used ergometers or tracks requiring little steering. We have measured minute ventilation (VE), oxygen consumption (VO2), carbon dioxide output (VCO2) and heart rate (HR) during exercise in a two arm, hand-rim propulsion wheelchair on a treadmill, and on three tracks of increasing tortuosity in eight able-bodied subjects. During propulsion at 0.6 m/sec, VE, VO2, and VCO2 were significantly greater on the track with the maximal steering component than on that with the minimal steering component, or on the treadmill with no steering component. Heart rate was significantly higher on the maximal compared to minimal steering component track. Exercise at speeds varying from 0.2 to 1.0 m/sec showed that VO2 and VCO2 were significantly higher on the medium steering component track than on the treadmill at speeds of 0.6 m/sec and above. We conclude that the effort of steering contributes significantly to the energy cost of wheelchair propulsion particularly at higher speeds.

Adult↗
PubMed1990

Autoimmune thyroiditis after bone marrow transplantation.

We describe the transfer of autoimmune thyroiditis by bone marrow transplantation. The male recipient developed compensated hypothyroidism 3 years after transplantation, and progressed to thyroid failure 1 year later. The female sibling had compensated hypothyroidism when screened 4 years after marrow donation. The donor, the recipient, and an older male sibling were HLA DR4, 5; the father was presumed homozygous for DR4 and the mother for DR5. Only the donor and recipient had abnormal thyroid function and positive antithyroid antimicrosomal antibodies. The most probable mechanism for the organ specific autoimmune dysfunction is the transfer of abnormal B and T cell clones from the donor. Radiation damage to the thyroid prior to transplantation, the mild graft-versus-host disease immediately following transplantation, and the general immune dysregulation seen in the first several years after marrow engraftment may have contributed to an acceleration of the autoimmune destruction of the recipient's thyroid.

Asthma↗
PubMed1990

Health perceptions of the homeless: a survey of Buffalo's City Mission.

Several faculty members at the State University of New York at Buffalo School of Nursing were interested in developing a nursing center in Western New York to serve the homeless population. The City Mission in Buffalo was selected as a site to conduct a survey to identify the demographic characteristics of one group of homeless subjects and their perceived needs. One hundred and twenty-four questionnaires were completed and analyzed statistically. The profile of the respondents was that of a young, single, Protestant white male from the Buffalo area with a history of local residence. A large proportion of the subjects perceived themselves as experiencing health problems. Both disease prevention and health promotion needs were recognized. The findings of this study were consistent with those of earlier studies including those completed in Boston, Massachusetts (1984). These data have served as a base for the provision of primary nursing interventions for this population within a nursing center model.

Attitude to Health↗
PubMed1989

Bacterial chemotactic oligopeptides and the intestinal mucosal barrier.

Intestinal absorption and enterohepatic circulation of N-formyl-methionyl-leucyl-125I-tyrosine, a bioactive synthetic analog of the bacterial chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine has been investigated in the rat. In ileum and proximal and distal colon, dithiothreitol, which increases mucosal permeability, increased peptide absorption and biliary recovery fourfold, 70-fold, and 20-fold over control values, respectively. When dithiothreitol was combined with d-l-benzyl succinate, a potent inhibitor of intestinal carboxypeptidase, absorption and biliary recovery from ileal loops increased markedly to 40-fold over control, whereas there was no further increase in absorption from colon loops. There was a strong correlation between biliary N-formyl-methionyl-leucyl-125I-tyrosine recovery and intestinal absorption of 51Cr-ethylenediaminetetraacetate, a marker of passive mucosal permeability (r = 0.97). We conclude that in the ileum both enzymic degradation and restricted mucosal permeability contribute to the intestinal barrier to luminal bacterial formyl oligopeptides. In the colon, however, enzymic mechanisms are less active and restricted mucosal permeability is the major factor. Abnormalities of the intestinal mucosal barrier to proinflammatory bacterial peptides could play a role in inflammatory disorders of the gut.

Animals↗
PubMed1989

Development of a realistic method to assess wheelchair propulsion by disabled people.

Most wheelchair users cannot achieve the steady state of cardio-respiratory performance necessary for standard physiological testing of wheelchair propulsion on ergometers or treadmills. Furthermore "real life" wheelchair utilisation involves short bursts of energy expenditure around furniture and other obstacles. We have developed a method of measuring wheelchair mobility on a test circuit of varying tortuosity and report here our preliminary experience. The parameters of mobility measured included distance; time taken; resting, maximum and final pulses (using a portable monitor); time to recover to stable resting pulse; and perceived exertion using the Borg Scale. Average speed and physiological cost of wheelchair propulsion (PCWP) (the difference between maximum and resting pulse divided by average speed) were calculated. The reproducibility of the components of the method was demonstrated in studies on normal volunteers. The test was also shown to be suitable for use by a sample of disabled people and was used in comparative studies of conventional and a novel arm crank wheelchair in normal volunteers. The method described appears to be an accurate and objective method of assessing wheelchair propulsion suitable for use by disabled people. It can also form the basis of comparative studies of different methods of propulsion of wheelchairs.

Adult↗
PubMed1989

Cross-validation of short forms of the WISC-R in two British samples.

Short forms of the WISC-R were computed by multiple linear regression on two samples of British children aged 6 to 12 years. The predictive validity of each short form was assessed both within the sample on which it was developed and cross-validated on the other sample. The empirically determined loss of power of prediction was found to be less than expected on a priori grounds. Predictions of individual scores at the lower end of the IQ distribution were less acceptable. It is concluded that short forms are robust and of value in research and for screening purposes, but cannot be recommended for clinical purposes.

Child↗
PubMed1989

Bone marrow transplantation for children with severe aplastic anemia: use of donors other than HLA-identical siblings.

Eighty-five percent of untransfused and 70% of transfused patients with severe aplastic anemia (SAA) are cured with bone marrow transplants from histocompatible sibling donors. Use of partially matched family donors or unrelated donors has been relatively unsuccessful because of high incidences of graft rejection and graft-versus-host disease (GVHD). Thirteen children with SAA received marrow grafts from alternative donors (sibling 4, parent 5, unrelated 4). The first three patients were pretreated with cyclophosphamide (CYCLO) +/- irradiation and received methotrexate for GVHD prophylaxis. Subsequent children were pretreated with CYCLO + high-dose cytosine arabinoside + methylprednisolone + total body irradiation, had monoclonal antibody T-cell depletion of the donor marrow, and received cyclosporine for GVHD prophylaxis. Three heavily transfused patients with haploidentical-related donors failed to engraft and died. All 10 patients with more closely matched donors engrafted. Acute GVHD was grade II in only one patient (non-T-depleted); this patient is the only one with severe chronic GVHD. Three engrafted patients died (Pneumocystis pneumonia, systemic parainfluenza, venocclusive disease). Seven children are alive 33+ to 2,692+ days. Donors for the survivors were siblings 3, parent 1, unrelated 3. These data suggest that bone marrow transplantation from closely matched donors other than histocompatible siblings can be effective therapy for SAA if an intensive conditioning regimen is used. These results must be confirmed with larger numbers and longer follow-up.

Adolescent↗
PubMed1989

Secondary flexor tendon reconstruction.

Staged flexor tendon reconstruction using silicone rods is a technique that can be successfully used to salvage severely injured digits. Refinements in the technique have led to the development of an active tendon prosthesis which is under clinical investigation. Attention to technical details and a well-supervised rehabilitation program are necessary to obtain satisfactory results.

Adolescent↗
PubMed1988

Work of a rehabilitation medicine service.

The results of the work of the Edinburgh Rehabilitation Medicine Service in one year were evaluated. Over 1400 new patients were seen, of whom 525 were in hospital at the time. Patients most often referred were those who had had cardiovascular accidents, back pain, lower limb amputations, and head injuries and those convalescing after heart surgery. Most patients had several problems. Many were referred so that they could obtain wheelchairs or other appliances, or for assessment of their ability to drive. Only 3% of the referrals were considered inappropriate. Of the inpatients, 455 (87%) returned home after treatment, but 13 (2%) did not respond satisfactorily to rehabilitation. Twelve per cent (18% of the inpatients) were referred from other health boards, suggesting a need for similar facilities elsewhere.

Persons with Disabilities↗
PubMed1988

Performance of the Hudson Multi-Vent oxygen mask.

The performance of the Hudson Multi-Vent oxygen mask was assessed by attaching it to a model of a head and generating varying inspiratory flows of oxygen through the mouth and nasal orifices. The oxygen concentration that was delivered by the mask varied with the inspiratory flow rate at all oxygen concentrations. This effect was proportionately similar at all levels of set oxygen concentration: about 50% of the increment of inspired oxygen was lost as the inspiratory flow rate increased from 20 L/min to 100 L/min. The performance of the mask was not affected by the route (oral or nasal) of inspiratory flow. Rotation of the mask in the coronal plane produced marked changes in delivered oxygen concentration; with the oxygen concentration set at 50%, and the inspiratory flow rate at 40 L/min, the delivered oxygen concentration was 45% when the mask was parallel to the coronal plane of the model, was 41% when it was angled 10 degrees towards the face, and was 27% when it was angled 10 degrees away from the face. The measurement of oxygen concentrations at different points inside the mask confirmed that the oxygen-enriched gas is directed in a localized stream in the centre of the mask, and that air is entrained through the large ports that are sited at the sides of the mask to satisfy inspiratory flow. The measurement of inspired oxygen concentrations in 12 hospital inpatients confirmed that the model reflected accurately the performance of the mask when used in a routine way. We conclude that, in clinical use, the Hudson Multi-Vent mask is unlikely to deliver the set oxygen concentration, and that the delivered oxygen concentration is not predictable.

Equipment Design↗
PubMed1988

Enterohepatic circulation of bacterial chemotactic peptide in rats with experimental colitis.

The association of hepatobiliary disorders with colonic inflammation is well recognized. Although the pathophysiology is obscure, increased permeation of toxic bacterial products across the inflamed gut to the portal circulation might be one mechanism. Potentially toxic metabolites include N-formylated chemotactic peptides that are produced by several species of intestinal bacteria and can be detected in colonic fluid in vivo. To investigate the metabolic fate of one of these low molecular weight proinflammatory peptides, N-formyl L-methionine L-leucine 125I-L-tyrosine was introduced into colon loops of healthy rats (n = 10) and rats with experimental colitis (n = 15) induced by rectal instillation of 15% (vol/vol) acetic acid. Gut, liver, and blood radioactivity were monitored by external gamma-counting and radioactivity in bile was measured by biliary catheter drainage into a well counter. Bile was processed by high-performance liquid chromatography to determine the amount of intact, bioactive peptide excreted over 3 h. After colonic instillation of 1 nmol of peptide, the mean (+/- SEM) biliary excretion of intact peptide was 6.4 +/- 2.0 pmol in normal rats and 49.0 +/- 20 pmol in rats with colitis (p less than 0.01). An enterohepatic circulation of synthetic N-formyl L-methionine L-leucine L-tyrosine has been demonstrated in the rat. Experimental colitis was associated with an eightfold increase in biliary excretion of this proinflammatory bacterial peptide. Proinflammatory bacterial peptides synthesized by colonic bacteria could be important in the pathophysiology of colon inflammation and its frequently associated hepatobiliary complications.

Acetates↗
PubMed1988

Human anti-PlE1 antibody recognizes epitopes associated with the alpha subunit of platelet glycoprotein Ib.

Together, a platelet-reactive antibody in the serum of a polytransfused patient (proband) and a platelet-reactive antibody in the serum of a mother of an infant with neonatal thrombocytopenia have served to establish the diallelic, platelet-specific alloantigen system, PlE. We now provide evidence that the platelet-specific antibody in the serum of the proband, anti-PlE1, recognizes epitopes associated with the alpha subunit of glycoprotein (GP) Ib. By 51Cr release, platelets from two of three patients with the Bernard-Soulier syndrome (BSS) responded sub-normally to anti-PlE1, and the apparently normal response of platelets from the last BSS patient was attributable to anti-HLA-A2 antibodies in the proband serum. These results suggested that the PlE1 antigen is associated with the GPIb complex (glycoproteins Ib kX) known to be absent from BSS platelets. This possibility was confirmed by ELISA using the purified GPIb complex or glycocalicin, the N-terminal fragment of GPIb alpha produced by proteolysis with endogenous platelet calpain, as solid-phase antigen. Anti-PlE1 antibody bound specifically to both the GPIb complex and glycocalicin. 3H-labelled platelet membrane glycoproteins with apparent molecular weights of 130k, 25k, and 21k (under reduced conditions) corresponding to GPIb alpha, GPIb beta, and GPIX were immunoprecipitated by anti-PlE1 plasma. Finally, at a titre of 1:16, anti-PlEl completely inhibited ristocetin-induced platelet agglutination, a property of platelets mediated by GPIb.

Antigens, Human Platelet↗
PubMed1988

Measurement of slowly exchanging 45Ca in rat aorta without using EGTA or lanthanum and its application to quantify the effects of the calcium entry blockers nifedipine and verapamil.

In rat aortic strips a method was developed to measure a fraction of slowly exchanging 45Ca, which correlates with contraction and the cytosolic Ca pool that is enhanced by K+-induced depolarization. In this method no EGTA or lanthanum are used, but the strips are washed for 45 min with a Tyrode solution at 4 degrees C. The K+ depolarization induced increase in 45Ca and contraction was concentration-dependently inhibited by verapamil and nifedipine. Since lanthanum and EGTA affect cellular membranes, this method may allow a more physiological approach to the measurements of slowly exchanging 45Ca.

Animals↗
PubMed1988

Partially matched bone marrow transplantation in patients with myelodysplastic syndromes.

Six patients with a myelodysplastic syndrome (MDS) were treated with bone marrow transplantation (BMT) using partially-matched related (3) or unrelated (3) donors. Patients' ages ranged from 7 to 31 years (median, 10 years). Bone marrow karyotype abnormalities were present in five patients included four with monosomy 7 and one with trisomy 8. One patient was in complete remission before transplant; the remaining five had excess of blasts or were undergoing leukemic transformation. Donor, and recipient were mismatched at the DR locus (2), A locus (2), B locus (1), or A and B loci (1). Conditioning included busulfan, cytarabine, cyclophosphamide, methylprednisolone, and total body irradiation. Cyclosporine was started on day -1. Marrows were T-cell depleted using a monoclonal antibody (MoAb) (CD3) and normal rabbit serum. Four patients engrafted routinely. One patient died of aspergillosis before engraftment (day 12) and one patient failed to engraft on first attempt, but engrafted following additional preparation. Median time to neutrophils greater than 500/microL and platelets greater than 25,000/microL were 16 and 19 days, respectively. Acute graft-v-host disease (GVHD) was less than or equal to grade II in all patients. One patient died with recurrent disease (day 257). One patient died at day 515 of pancreatitis and respiratory failure. Three patients are alive and disease-free at 240, 395, and 560 days post-BMT including two patients with unrelated donors. Partially matched T-depleted bone marrow from related or unrelated donors may be effective, and possibly curative therapy for patients with MDS who lack a histocompatibility locus antigen (HLA)-identical sibling donor.

Adolescent↗
PubMed1987

Mitral stenosis with free-floating left atrial thrombus and recurrent systemic embolisation. A case report.

A 64-year-old white woman with moderately severe rheumatic mitral stenosis complicated by atrial fibrillation and recurrent systemic embolisation to the brain was found at operation to have a large 'free-floating' left atrial thrombus, as well as multiple left atrial appendage thrombi. These had not been detected by echocardiography. She also had significantly reduced left ventricular contractility on cine angiography, and right coronary artery atherosclerosis. She underwent successful mitral valve replacement and excision of the left atrial appendage.

Atrial Fibrillation↗