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Biomedical subjects

S Booth

Publications and source records attributed to S Booth.

32 records · Page 2Linked to original sources
PubMed1997

Functional conservation of HTLV-1 rex balances the immune pressure for sequence variation in the rex gene.

Naturally occurring mutations in Human T-cell Leukemia Virus Type 1 (HTLV-1) Tax protein lead to loss of recognition by cytotoxic T-lymphocytes. Most of these mutations also abolish or severely impair the transactivation function of Tax. Ninety percent of the rex gene, which encodes the viral regulator of mRNA splicing (Rex), overlaps with the tax gene. In this paper, we report that four previously described point mutations in tax that abolished CTL recognition and activity did not alter either the dimerisation function or the ability to export viral mRNA of the corresponding Rex proteins. Rex proteins containing two other amino acid changes were likewise functional. However, five Rex deletion mutants, predominantly but not exclusively found in HAM/TSP patients, had all lost these functions. We conclude that, although the Tax protein is subject to strong CTL-mediated selection, there are stronger functional constraints on amino acid variation in Rex. This may limit the variation in the tax/rex nucleotide sequence which results in immune evasion.

Cells, Cultured↗
PubMed1996

Does oxygen help dyspnea in patients with cancer?

Dyspnea in patients with advanced cancer is a common symptom that is difficult to treat. This study investigated whether oxygen helps to relieve rest dyspnea in patients with advanced cancer. In a single-blind controlled trial, oxygen and air were administered in random order to hospice patients reporting dyspnea at rest. Measurements of arterial oxygen saturation, lung function, and dyspnea (using a visual analogue scale [VAS] and Borg score) were made before and after each gas had been given for 15 min. Data from 38 patients were used: analysis of variance revealed that mean VAS levels during baseline conditions, breathing room air (59 mm), were significantly reduced after administration of either air (48 mm; p < 0.001) or oxygen (45 mm; p < 0.001); there was no significant difference for the mean VAS scores between oxygen and air administration. There was no statistically significant order of treatment effect. There was no difference in the response to oxygen or air in patients with a history of cardiopulmonary disease. The improvement in dyspnea with oxygen could not be predicted from a subject's initial level of hypoxia. Results suggested that benzodiazepines may potentiate the effect of oxygen. The overall conclusion is that oxygen and air can have a significant effect in reducing dyspnea at rest in patients with advanced cancer.

Aged↗
PubMed1993

Factors influencing self-diagnosis and treatment of perceived helminthic infection in a rural Guatemalan community.

Changes in the diagnosis and treatment of helminthic infection were examined during a longitudinal study in a rural community in Guatemala. Self-diagnosis was predominant, with an increase in perceived helminthic infection during an economic crisis within the community. Allium sativum L. and Chenopodium ambrosoides L. were used as anthelmintics, often in conjunction with commercial drugs. During the economic crisis the use of plants as treatment for perceived infection increased whereas use of commercial helminthic medicine decreased. Dietary modifications were observed during periods of perceived infection, but were not consistent in the food items modified or the nature of the modification. Within the community individuals exhibited considerable heterogenity in their approaches to treatment.

Adolescent↗
PubMed1989

The effects of small plate osteosynthesis on postoperative radiotherapy.

Small plate osteosynthesis is becoming increasingly popular in reconstruction following ablative surgery for oral malignancies. In those cases where postoperative radiotherapy is to be included in the treatment it has been suggested that these plates may cause problems such as dose enhancement and tumour shielding and should therefore be removed prior to the radiotherapy. A physical method is described to assess the anticipated radiation dose changes at the tissue/plate interface both behind and in front of the plate. As a result of this assessment certain recommendations are made.

Bone Plates↗
PubMed1987

Particulate contaminants of intravenous medications and infusions.

Particulate contamination in small volume parenteral medications has been studied and compared with that found in a selection of large volume infusions. Particle counts in 39 commonly used small volume medications and 7 large volume infusions were performed by an automated light blockage method (HIAC) or by optical microscopy. Based on these results and a random survey of drug therapy of intensive care patients, it is concluded that the contribution of intravenous medications to the total particle load received by such patients is likely to be many times greater than from infusion fluids. Until firm evidence regarding the harmful systemic effects of drug particles is available and the manufacturing regulations adjusted appropriately, final in-line filtration of infusions immediately proximal to the intravenous cannula should be considered when drugs are being given intravenously.

Drug Contamination↗
PubMed1985

The elasticity of spectrin-actin gels at high protein concentration.

Human erythrocyte spectrin of high purity was studied alone and mixed with rabbit skeletal actin by dynamic rheometry as a function of protein concentration at pH 7.4 and 24 degrees C. Pure spectrin had a very low storage modulus, G', increasing slightly with increase in protein concentration (approximately 3 dynes/cm at 25 mg/ml). In contrast, unpurified cytoskeletal extracts containing spectrin, actin, and band 4.1 showed a marked concentration dependence for G', increasing to 150 dynes/cm at 20 mg/ml. Mixtures of purified spectrin and skeletal actin at a weight ratio of 4:1 also showed G' markedly dependent on concentration (approximately 150-200 dynes/cm at 20 mg/ml). Maximum elasticity of spectrin-actin gels occurred at a molar ratio of actin monomers to spectrin tetramers of 14:1. We conclude that the reconstituted in vitro spectrin-actin network consists of actin fibers cross-linked by spectrin tetramers at regular intervals. The gel is rapidly reformed after mechanical disruption or thermal collapse, indicating that the polymer fibers are in equilibrium with the constituent monomers.

Acetone↗
PubMed1985

Methylphenidate and children with attention deficit disorder. Dose effects on classroom academic and social behavior.

The short-term, dose-response effects of methylphenidate hydrochloride were evaluated on academic and social classroom measures in 29 children with attention deficit disorder. In a double-blind, cross-over design with order randomized, children received a placebo for two weeks and three doses of methylphenidate hydrochloride (0.15 mg/kg, 0.3 mg/kg, and 0.6 mg/kg) for one week each. Dependent measures included the output and accuracy of performance in grade-appropriate reading comprehension workbooks and arithmetic problems, spelling word acquisition, and observations of disruptive and on-task behavior. Beneficial drug effects and linear dose-response curves on all dependent measures were found. The results suggest that beneficial methylphenidate effects on classroom behavior may be accompanied by enhanced academic achievement in some hyperactive children.

Achievement↗
PubMed1982

Effect of recent food on estimation of high-density lipoprotein and total cholesterol in normal subjects.

Magnesium/phosphotungstic acid was confirmed as specific for precipitation of chylomicrons, low-density and very low density lipoprotein particles in serum from healthy volunteers who were either fasting or who had eaten egg yolks or a salmon sandwich containing Flora margarine 2 hours previously. In eight subjects who ate salmon sandwiches that contained butter or Flora margarine, neither the total cholesterol nor the high-density lipoprotein (HDL) cholesterol differed significantly from the fasting level over 7 hours. In eight subjects, egg yolks also did not alter significantly either the total serum cholesterol or the HDL cholesterol at 1/2, 1, 1 1/2, 2, 5, and 7 hours after eating. Patients may be screened for HDL cholesterol and total cholesterol estimation when not fasting. However, individual subjects showed variation in their total cholesterol and, particularly, HDL cholesterol over a three-month period. Replicate analysis of HDL cholesterol may be required for its complete assessment.

Adult↗
PubMedDate not supplied

Group training in communication skills for carers of adults with aphasia.

This study describes a communication skills group programme for four carers of adults with aphasia that ran once a week for 6 consecutive weeks. The content of the group was based on an approach previously not described in the literature in any detail. Conversation analysis (CA) was used to guide individualized advice that was incorporated into the group by the use of written advice sheets. Intervention was motivated by the results of a newly developed assessment tool--the Conversation Analysis Profile for People with Aphasia (CAPPA)--and a quantitative and qualitative analysis of collaborative repair. The CAPPA utilizes the methodology of conversation analysis (CA) as a means of both characterizing and comparing the relationship between the carers' perception of the aphasia and what is occurring in natural conversation. During the group, accurate perceptions and strategies that minimized the disruption to the conversation were reinforced, while inaccurate perceptions and strategies that appeared to impede interaction were discouraged. The use of the CAPPA results and a quantitative/qualitative analysis of repair management to measure change pre- and post-group was explored. The post-intervention analyses examined three questions in particular: (1) did the carers demonstrate more accurate perceptions of their relatives' aphasia?; (2) did the carers report a decrease in the problem severity of the aphasia?; and (3) was there a change in the time taken to repair a trouble source and was this attributable to a change in the management of repair by the carer? The study was essentially an investigation of whether this type of approach was beneficial to the carers involved. The results suggested that focusing on individualized advice and targeting conversation management in the group setting was a useful way of providing advice to carers. Furthermore, the CAPPA and a quantitative/qualitative analysis of repair management seem to have the potential for motivating the individualized advice and measuring the effectiveness of an intervention.

Aged↗