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Biomedical subjects

J Sim

Publications and source records attributed to J Sim.

At least 55 records · Page 3Linked to original sources
PubMed1997

Desensitization of the P2X(2) receptor controlled by alternative splicing.

P2X receptors are ion channels gated by extracellular ATP. We report here cloning of a P2X(2) receptor splice variant (P2X(2-2)) carrying a 207 bp deletion in the intracellular C-terminus and the analysis of the corresponding genomic structure of the P2X(2) gene. P2X(2-2) is as highly expressed as the original P2X(2) sequence in various tissues. ATP-activated currents mediated by heterologous expressed P2X(2) or P2X(2-2) receptors showed significant differences in desensitization time constants and steady-state currents in the continuous presence of ATP. These results imply functional differences between cells differentially expressing these P2X(2) isoforms.

Adenosine Triphosphate↗
PubMed1996

Attitudes and beliefs within the Sikh community regarding organ donation: a pilot study.

The current shortage of organs for transplantation is a matter of considerable concern in the United Kingdom (U.K.). Whilst issues of histocompatibility create particular problems in this respect for the Asian population in the U.K., it is sometimes suggested that there is also a resistance to the idea of organ transplantation among this community. To explore this issue, a small-scale interview study was conducted in Coventry among members of the Sikh community. A judgemental sample of 22 individuals, from different strata of the local Sikh community, were interviewed either in one-to-one interviews or in a focus group. These interviews had two broad aims: to determine the prevailing attitudes towards organ transplantation, and to gauge the impact and acceptability of the current Department of Health campaign literature. It was found that, whilst there were a number of misgivings to do with notions of mutilation and reincarnation, and anxieties as to technical or clinical aspects of the transplantation process, the prevailing view was supportive of transplantation, and organ donation was seen as a highly appropriate means of exhibiting the altruistic tradition within Sikhism. Such barriers that exist to the idea of transplantation seem to have more to do with knowledge and understanding than with cultural or religious factors. Concerning the campaign literature, informants identified a number of shortcomings, and indicated ways in which the impact of the leaflets and posters might be enhanced. Although the generalizability of these findings is limited, and despite possible threats to the validity of the data collected, this study has produced findings with significant implications for future policy in this area.

Ethnicity↗
PubMed1996

The admission of Asian patients to intensive therapy units and its implications for kidney donation: a preliminary report from Coventry, UK.

OBJECTIVE: To determine the relative admission rates of Asian and non-Asian patients to intensive therapy units (ITUs) in Coventry and to explore the implications of these rates for the transplantation of organs to Asian people. DESIGN: Examination of 1991 census data and a retrospective review of ITU admissions books. Data were collected on ethnic background, presenting diagnosis, and clinical outcome for each admission. SETTING: The three ITUs in Coventry. PATIENTS: All admissions to the ITUs from 1990-93 inclusive. RESULTS: Asian patients were admitted to ITUs disproportionately to their numbers in the Coventry population. Members of the Asian community were less than half as likely to be admitted to an ITU (p < 0.001) and more likely to die while there (p = 0.007) than members of the non-Asian population in Coventry. The proportions of patients referred to the transplant unit and the rates of subsequent donation do not seem to differ significantly for Asian and non-Asian patients (p = 0.26 in both cases). CONCLUSIONS: There are clear implications for the availability of cadaveric kidney transplantation to Asian patients, given that few kidneys from non-Asian donors are histocompatible with Asian recipients. Indeed, in Asians, promotion of living related donation may be more effective in countering the organ shortfall than efforts to increase consent to cadaveric transplantation. However, it may be valuable to investigate any patterns of morbidity or social or cultural factors that might explain the initial low admissions rates to ITUs for Asian patients.

Asia↗
PubMed1995

Use of denaturing gradient electrophoresis to determine the distributions of polymorphisms in entire genes in natural populations.

We show here that the method of genomic denaturing gradient electrophoresis (gDGGE) can be used to examine any gene that has been previously cloned and sequenced, and to detect and approximately localize within the gene the majority of its polymorphisms. By using pooled-DNA gDGGE, many different samples can be scanned on a single gel. Further, the patterns on the gels and results from sequencing of some of the alleles shows that a variety of different kinds of polymorphism, ranging from single base changes to more substantial allelic differences, can be distinguished. The extramacrochaetae (emc) gene of Drosophila melanogaster exhibits no polymorphism in its ORF that can be detected by this method, although a rearrangement polymorphism was detected in the 3' downstream region of the gene. The suppressor-of-hairless (Su(H)) gene of D. melanogaster, however, exhibits a variety of polymorphisms in its ORF. Some are small deletions or insertions in a glutamine-rich part of the gene product that would not have been detectable by ordinary screening methods. Many of the polymorphisms detected in this preliminary survey are likely to have an impact on the function of the Su(H) gene product.

Animals↗
PubMed1995

Optimizing conditions for the growth of Lactobacillus casei YIT 9018 in tryptone-yeast extract-glucose medium by using response surface methodology.

This study was undertaken to find optimum conditions of tryptone, yeast extract, glucose, Tween 80, and incubation temperature for the growth of Lactobacillus casei YIT 9018 and to assess the effects of these factors by use of response surface methodology. A central composite design was used as an experimental design for allocation of treatment combinations. A second-order polynomial regression model, which was used at first for analysis of the experiment, had a significant lack of fit. Therefore, cubic and quartic terms were incorporated into the regression model through variable selection procedures. Effects involving incubation temperature, yeast extract, glucose, and tryptone were significant, whereas the only significant effect involving Tween 80 was the interaction effect between temperature and Tween 80. It turned out that growth of L. casei YIT 9018 was most strongly affected by the incubation temperature. Estimated optimum conditions of the factors for growth of L. casei YIT 9018 are as follows: tryptone, 3.04%; yeast extract, 0.892%; glucose, 1.58%; Tween 80, 0%; incubation temperature, 35 degrees C.

Bacteriological Techniques↗
PubMed1995

Moral rights and the ethics of nursing.

This paper explores the nature of rights, and their implications for the ethics of nursing. A right is seen as an entitlement which is justified on moral and/or legal grounds, and which may take the form of a right of action or a right of recipience, or both; in either case, correlative duties are generally imposed on others. Some of the conflicts which can occur among two or more conflicting rights are examined through three hypothetical scenarios, and approaches to their resolution are suggested. The question of whether nurses, as nurses, possess rights is then considered, and it is suggested that they do not. In conclusion, it is argued that, if rights are to be a helpful concept, they must be carefully defined and analysed, and their relationship to one another, and to duties, must be clarified.

Beneficence↗
PubMed1994

Molecular mechanisms of resistance to heat and oxidative damage.

Spore heat resistance can be predicted within reasonable limits from knowledge of optimal growth temperature of the sporeformer, the temperature of sporulation, water content of the spore protoplast, cortex size, total mineralization and specific mineralization. The molecular mechanisms by which dehydration and mineralization act to stabilize spores against heat damage are unknown. A major need for further progress is to identify the principal targets for lethal damage. In this review the hypothesis was explored that heat killing may be related to oxidative killing. The proposed common denominator for the two is the formation of radicals able to react with, and irreversibly damage, spore polymers such as proteins or DNA.

Hot Temperature↗
PubMed1993

Measurement validity in physical therapy research.

This article considers the role of measurement validity within physical therapy research. The concept of measurement validity is identified as a component of internal validity, and it is differentiated from the notion of reliability; these concepts are related to systematic and random sources of error, respectively. Using examples from physical therapy and rehabilitation, four main types of validity are reviewed: face validity, criterion-related validity, content validity, and construct validity. The differing implications of these types of validity for quantitative and qualitative research are discussed. Three principal areas of concern are then addressed, based on a critical discussion of selected examples from the literature. First, it is argued that validity is often poorly distinguished from the allied concept of reliability and that purported claims for validity often only demonstrate reliability. Second, it is claimed that validity is too often neglected in favor of reliability, and specific examples relating to gait analysis are put forward to support this argument. Third, some of the methodological difficulties that may occur when attempts are made to demonstrate validity are considered. The article concludes with a plea for a closer focus on the issue of measurement validity within physical therapy research.

Bias↗
PubMed1993

Sports medicine: some ethical issues.

The ethical aspects of sports medicine have hitherto received little scrutiny, in contrast to its legal implications, which have recently been subject to much greater discussion. However, the differences that are apparent between sports medicine and 'mainstream' areas of clinical practice can shed new light on a number of the central issues within health-care ethics. By means of hypothetical case studies, this paper seeks to examine some of these issues within a sports medicine context. Specific attention will be paid to the concepts of autonomy and paternalism, issues to do with truthfulness, and the question of conflicting professional loyalties. It is suggested that the ethics of sports medicine warrant further and more detailed examination.

Adolescent↗
PubMed1992

AIDS, nursing and occupational risk: an ethical analysis.

This paper examines the notion of risk assessment in relation to nursing patients with HIV infection or AIDS. Risk assessment consists in examining three features of a given hazard; its magnitude, its probability, and its acceptability. In relation to the last of these, an 'acceptability threshold' can be identified. If contact with HIV-infected patients is perceived to pass this threshold, nurses may seek to abrogate the usual 'duty to treat'. Rather than endeavour to pinpoint this threshold, the paper explores some of the factors which may either raise or lower it, and their ethical implications. In particular, the consequences of setting a high threshold, and thereby limiting or avoiding contact with patients infected with HIV, are examined. In this debate, the burden of proof is seen as resting firmly on nurses themselves, not on the patients at risk of being deprived of care.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Preferential accumulation of n-3 fatty acids in the brain of chicks from eggs enriched with n-3 fatty acids.

Docosahexaenoic acid (DHA) is the major polyunsaturated fatty acid in the phospholipids of brain tissue. The extent to which maternal dietary n-3 fatty acid may influence the n-3 fatty acid composition of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) fractions of brain and liver tissue of progeny was investigated. Hens were fed diets containing n-9, n-3, or n-6 fatty acids. The brain tissue of the chicks from eggs enriched with n-3 fatty acids contained higher DHA, resulting in an increased C22:6 n-3:C20:4 n-6 ratio compared with chicks from eggs enriched with n-9 or n-6 fatty acids. Incorporation of C22:5 n-3, and C22:6 n-3 was mainly in the PE fraction as compared with the PC fraction of the chick brain. For chicks hatched from eggs enriched with n-9, n-3, and n-6 fatty acids, the total n-3 fatty acids in the brain PE fraction were 29.3, 41.3, and 21.9% compared with 6.7, 8.8, and 4.0% in the brain PC fraction. In contrast, the n-3 fatty acids increased evenly in phospholipid PC and PE fractions. Total amounts of PE in the brain lipids of chicks from eggs enriched with n-3 and n-6 fatty acids were 40.8 and 41.9% compared with 33.1% for chicks from eggs enriched with n-9 fatty acids. Analyses of the remaining yolk sac revealed a preferential absorption of DHA from the egg PE fraction by the developing chick.

Animals↗
PubMed1991

An ethical analysis of physical therapists' duty to treat persons who have AIDS: homosexual patients as a test case.

A possible abrogation of the health professional's usual duty to treat sometimes is suggested in regard to patients with acquired immunodeficiency syndrome (AIDS). The issue first arose and continues to be discussed in regard to those patients who have contracted AIDS through homosexual encounters, though there are now additional populations of patients with AIDS to whom the issue is being directed as well. We examine three lines of reasoning that may be advanced to support this view: the argument from morality, the argument from responsibility, and the argument from the alleged danger to others. We show logical and ethical shortcomings in each view and suggest how the physical therapist's duty to treat all patients who have AIDS can be realized in a safe and supportive environment.

Acquired Immunodeficiency Syndrome↗