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Biomedical subjects

B Hall

Publications and source records attributed to B Hall.

At least 55 records · Page 3Linked to original sources
PubMed1996

Antisense acid invertase (TIV1) gene alters soluble sugar composition and size in transgenic tomato fruit.

Invertase (beta-fructosidase, EC 3.2.1.26) hydrolyzes sucrose to hexose sugars and thus plays a fundamental role in the energy requirements for plant growth and maintenance. Transgenic plants with altered extracellular acid invertase have highly disturbed growth habits. We investigated the role of intracellular soluble acid invertase in plant and fruit development. Transgenic tomato (Lycopersicon esculentum Mill.) plants expressing a constitutive antisense invertase transgene grew identically to wild-type plants. Several lines of transgenic fruit expressing a constitutive antisense invertase gene had increased sucrose and decreased hexose sugar concentrations. Each transgenic line with fruit that had increased sucrose concentrations also had greatly reduced levels of acid invertase in ripe fruit. Sucrose-accumulating fruit were approximately 30% smaller than control fruit, and this differential growth correlated with high rates of sugar accumulation during the last stage of development. These data suggest that soluble acid invertase controls sugar composition in tomato fruit and that this change in composition contributes to alterations in fruit size. In addition, sucrose-accumulating fruit have elevated rates of ethylene evolution relative to control fruit, perhaps as a result of the smaller fruit size of the sucrose-accumulating transgenic lines.

Aging↗
PubMed1996

Breaking the silence on elder abuse.

Elder abuse has been described as the silent crime-silent, but not insignificant. The magnitude of the problem for Canadians was revealed in a national survey of 2,000 randomly selected seniors residing in private dwellings: four per cent of respondents reported some form of abuse. The perpetrators were usually people in positions of trust, such as family members or caregivers.

Aged↗
PubMed1995

Localization of the mouse lissencephaly-1 gene to mouse chromosome 11B3, in close proximity to D11Mit65.

Lissencephaly is a human brain malformation manifested by a smooth cerebral surface and severe mental retardation. Some of the patients have been shown to have deletions in chromosome 17p13.3, and recently, LIS-1 has been proposed to be the disease-associated gene. We have now mapped the mouse homolog of LIS-1 to mouse chromosome 11B3 by using fluorescence in situ hybridization to metaphase chromosomes. The analysis of yeast artificial chromosome clones placed Lis-1 in close proximity to the microsatellite marker D11Mit65.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1995

Net uptake of plasma homocysteine by the rat kidney in vivo.

Hyperhomocysteinemia is a common finding in dialysis-dependent end-stage renal disease (ESRD) patients, but its etiology and refractoriness to standard homocysteine-lowering B-vitamin therapy are poorly understood. In the absence of actual in vivo data, it has been hypothesized that loss of normal renal parenchymal uptake and metabolism of homocysteine is an important determinant of hyperhomocysteinemia in ESRD, given that urinary homocysteine excretion by healthy kidneys is trivial. We assessed net renal uptake and metabolism of homocysteine using an established rat model for measuring arteriovenous amino acid differences across the rat kidney, along with simultaneous determination of renal plasma flow, urine flow, and urinary homocysteine concentration. Substantial homocysteine uptake and metabolism by normal rat kidneys was demonstrated, and we also confirmed that urinary homocysteine excretion is minimal. These data suggest that loss of the sizable homocysteine metabolizing capacity of the intact kidneys may be an important determinant of the refractory, potentially atherothrombotic hyperhomocysteinemia frequently observed in ESRD.

Animals↗
PubMed1995

Repeat callers and the Samaritan telephone crisis line--a Canadian experience.

Telephone crisis lines are increasingly providing a much needed service in the community to the lonely, the depressed, and the suicidal. The Samaritan volunteer crisis line discussed here is open to any person at any time, day or night. The instant availability of such an anonymous service attracts callers who use the line inappropriately; these people are often referred to as repeat callers. The Samaritans discovered that repeat callers were creating serious problems for both staff and volunteers. The difficult task was to develop a policy to restrict the repeat callers, but at the same time ensuring that the mandate of the crisis line was offered to them. This article examines the characteristics of repeat callers, and makes suggestions about the management of the chronic caller.

Behavior Therapy↗
PubMed1995

Neutrophil-rich, Ki-1-positive anaplastic large-cell malignant lymphoma.

The presence of neutrophils, in the absence of necrosis, is uncommon in malignant lymphoma (ML). We identified a subgroup of Ki-1-positive anaplastic large cell ML (Ki-1 ALCL) in which neutrophils were a prominent component. Six of 20 cases of Ki-1 ALCL had a significant neutrophil infiltrate that varied from 5 to 10% to > 50% of cells per high power field. Neutrophils were not seen in 100 cases of other types of ML reviewed. Patients were first seen with skin lesions (four), localized lymphadenopathy (three), generalized lymphadenopathy (one), and localized extranodal disease (one). All had primary disease. Two patients had peripheral neutrophilia. Three of six patients had clinical stage IV disease. Four patients are currently in clinical remission; one died of recurrent disease; and one patient with acquired immunodeficiency syndrome (AIDS) died of Pneumocystis carinii pneumonia. Four cases demonstrated a T-cell phenotype, one of which arose in a patient with AIDS. Two had a B-cell phenotype. All cases were positive for CD30 (Ki-1). These observations expand the morphologic spectrum of Ki-1 ALCL to include a neutrophil-rich variant. We conclude that the presence of neutrophils is another morphologic feature shared by some cases of Ki-1 ALCL, lymphomatoid papulosis, and Hodgkin's disease, which suggests a possible pathogenetic link among them.

Adult↗
PubMed1995

Laparoscopic assisted vaginal hysterectomy: an audit plus a word of caution.

Laparoscopic assisted vaginal hysterectomy (LAVH) performed in 109 cases has been reviewed. In this series the mean operative time was 89 minutes and mean inpatient hospitalization was 3.7 days. Throughout the review, 6 patients were considered to have major complications and each is discussed. The association of previous caesarean section and bladder damage is noted. LAVH widens the indications available for vaginal hysterectomy in younger women in whom the abdominal approach would previously be indicated, but extra caution is advised when this technique is first introduced to a gynaecological service.

Adult↗
PubMed1994

Learning from the experience of loss: people bereaved during intensive care.

In Hartlepool Intensive Therapy Unit (ITU) nurses have recently addressed the needs of relatives while they are visiting the department and afterwards during their bereavement. However in order to determine how best to improve nurses' service we decided to ask those people bereaved their opinions about their experience in order to meet their requirements in the most appropriate way. 16 recently bereaved relatives were interviewed concerning a variety of areas, including information they received in the ITU, support they were given by nurses, how they coped after their loss, and suggestions for improvements. Although this was a small study important areas for improvement were highlighted, and we have now been able to address these further in nursing service and make plans for future developments.

Adaptation, Psychological↗
PubMed1994

Pathways into the work force: antecedents of school and work force status.

OBJECTIVE: The study aim was to identify risk factors for specific pathways into the work force using data from the Ontario Child Health Study Follow-up. METHOD: Potential predictor variables were derived from data collected in 1983 on adolescents aged 13 to 16 years. The subjects were followed up 4 years later and the school/work force outcome was determined. Bivariate and multivariate statistical analyses were used to identify variables with a strong independent association with this outcome. RESULTS: Subjects in the work force were four times more likely than those attending school to have come from a low-income family and at least two times more likely to have a family background of low maternal education, to have failed a grade, or to have used substances heavily during early adolescence. Subjects with two or more of these risk factors were likely to be in part-time work or unemployed. CONCLUSIONS: Preventive interventions should be targeted at children from poor families, or who fail at school, or show early onset of substance abuse and other deviant behaviors. Studies are needed to further elucidate the relationship between these risk factors and pathways into the work force and beyond.

Adolescent↗
PubMed1994

Protein adsorption, lymphocyte adhesion and platelet adhesion/activation on polyurethane ureas is related to hard segment content and composition.

Segmented polyurethane ureas with different hard segment content and composition were synthesized using 4,4'-diphenylmethane diisocyanate and polytetramethylene glycols. Using polyols with different molecular weights, it was possible to synthesize polyurethane ureas with either: (i) a constant ratio of urethane to urea bonds; (ii) a constant urethane content; or (iii) a constant urea content. Bulk properties were assessed by dynamic mechanical analysis. Surface properties were estimated by contact angle measurements and streaming potential measurements. Haemocompatibility was evaluated in vitro by measuring the adsorption of human serum albumin (HSA) and fibrinogen (Fg), the adhesion of human peripheral blood lymphocytes (PBL), and the presence of activated platelets on the biomaterial surfaces. Enzyme immuno assays (EIA) have been specially developed for this purpose for the detection of antibody-recognizable plasma proteins and platelet surface membrane proteins. No simple correlation between chemical structure of the polymers and surface properties was found. Parameters of haemocompatibility correlated more closely with hard segment content and chemical composition than with the surface characteristics of the polymers. Adsorption of plasma proteins, adhesion of lymphocytes and the adhesion/activation of platelets were found to increase with increasing hard segment content of the polyurethane ureas. However, the monoclonal-antibody recognisable fibrinogen and the platelet activation were nearly constant with increasing hard segment content, if the urea content was kept constant.

Adsorption↗
PubMed1994

Efficacy of breathing and coughing exercises in the prevention of pulmonary complications after coronary artery surgery.

One hundred twenty patients undergoing coronary artery surgery completed a randomized controlled study designed to investigate whether prophylactic chest physiotherapy affected the incidence of postoperative pulmonary complications. Group 1 patients received no preoperative or postoperative chest physiotherapy. Group 2 patients received preoperative education and instruction in breathing and coughing exercises and postoperative supervision and assistance in performing the same. These exercises were supervised by a physiotherapist twice per day on the first 2 postoperative days and once per day on the 3rd and 4th postoperative days. Physiotherapy for group 3 patients was the same as for group 2 patients except that patients were seen by a physiotherapist 4 times per day on the first 2 postoperative days and twice per day on the 3rd and 4th postoperative days. Group 2 and 3 patients were instructed to practice breathing and coughing exercises every hour. Overall, an incidence of clinically significant postoperative pulmonary complications of 7.5 percent was demonstrated. In general, these patients demonstrated lower levels of preoperative pulmonary function and very low early postoperative oxygenation compared with those who did not develop pulmonary complications. There was no indication that the incidence or severity of fever, hypoxemia, chest roentgenologic abnormalities or clinically significant postoperative pulmonary complications was different between groups. These results suggest that the necessity for prophylactic chest physiotherapy after routine coronary artery surgery should be reviewed.

Breathing Exercises↗
PubMed1994

Premedication reduces the incidence of systemic reactions during inhalant rush immunotherapy with mixtures of allergenic extracts.

BACKGROUND: Rush immunotherapy, while having many potential benefits, is associated with an increased incidence of systemic reactions. OBJECTIVE: To determine whether pretreatment with medications reduces the rate of systemic reactions during rush immunotherapy and to identify predictors of such reactions if possible. METHODS: We conducted a double-blind, placebo-controlled study of 22 allergic children ages 6 to 18 years who received rush immunotherapy. Active treatment consisted of a combination of H1 and H2 histamine antagonists and a corticosteroid in gelatin capsules given prior to administration of rush immunotherapy whereas placebo patients received lactose. Rush immunotherapy consisted of eight injections of increasing doses of a mixture of allergens to which each patient was skin-reactive over 1 1/2 days. Serial skin tests and peak expiratory flow rate measurements were performed during the procedure. Following the initial series of injections, patients were followed for 8 weeks and had blood drawn at 2-week intervals for measurements of specific IgG and IgE. RESULTS: Systemic reactions were observed in 3 (27%) active and 8 (73%) placebo patients (Fisher's exact test: P = .047). The mean time for systemic reactions was 63 minutes after a previous injection. The most common dose causing a systemic reaction was 0.3 mL of 1:1000 (wt/vol). The best predictors of development of a systemic reaction were degrees of skin sensitivity to the extract before and after premedication. Local reactions were not associated with subsequent systemic reactions. Specific IgG rose by 2 weeks while specific IgE did not change significantly during the 8-week follow-up period. Pretreatment did not change the number of systemic reactions seen with subsequent injections. CONCLUSIONS: Premedication significantly reduces the incidence of systemic reactions during rush immunotherapy and is therefore recommended. Degree of skin sensitivity to the injected extract may eventually prove to be a clinically useful predictor for the development of systemic reactions.

Adolescent↗
PubMed1993

Genetic and physical mapping of the Treacher Collins syndrome locus with respect to loci in the chromosome 5q3 region.

Treacher Collins syndrome is an autosomal dominant, craniofacial developmental disorder, and its locus (TCOF1) has been mapped to chromosome 5q3. To refine the location of the gene within this region, linkage analysis was performed among the TCOF1 locus and 12 loci (IL9, FGFA, GRL, D5S207, D5S210, D5S376, CSF1R, SPARC, D5S119, D5S209, D5S527, FGFR4) in 13 Treacher Collins syndrome families. The highest maximum lod score was obtained between loci TCOF1 and D5S210 (Z = 10.52; theta = 0.02 +/- 0.07). The best order, IL9-GRL-D5S207/D5S210-CSF1R-SPARC-++ +D5S119, and genetic distances among these loci were determined in the 40 CEPH families by multipoint linkage analysis. YAC clones were used to establish the order of loci, centromere-5'GRL3'-D5S207-D5S210-D5S376-CSF1R -SPARC-D5S119-telomere. By combining known physical mapping data with ours, the order of chromosome 5q3 markers is centromere-IL9-FGFA-5'GRL3'-D5S207-D5S210- D5S376-CSF1R-SPARC-D5S119-D5S209- FGFR4-telomere. Based on this order, haplotype analysis suggests that the TCOF1 locus resides distal of CSF1R and proximal to SPARC within a region less than 1 Mb in size.

Base Sequence↗
PubMed1993

An epilepsy needs document.

Services for epilepsy in the UK are poor in quality, fragmentary and poorly organized. We attempt to define and quantify the scope, content and standards of medical, paramedical and nursing services required, from primary health care to specialist centres. This document has been approved by the Joint Epilepsy Council of Great Britain and Ireland, representing all major patient organizations and care providers.

Cross-Sectional Studies↗
PubMed1993

Isolation of a partial candidate gene for Menkes disease by positional cloning.

Menkes disease is an X-linked recessive disorder of copper metabolism resulting in death in early infancy. The gene has been mapped to band Xq13 based, in part, on a translocation breakpoint in a female with the disease, which was found to lie within 300 kilobases (kb) of the PGK-1 locus, allowing the isolation of a YAC clone spanning the breakpoint. Phage subclones from the breakpoint region were isolated and used to screen cDNA libraries. cDNA clones were found which detect an 8 kb transcript from normal individuals but show diminished or absent hybridization in Menkes disease patients. Partial sequence of the cDNA shows a unique open reading frame containing putative metal binding motifs which have been found in heavy metal resistance genes in bacteria. This gene is a strong candidate for the Menkes disease gene.

Adenosine Triphosphatases↗