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Biomedical subjects

A Henderson

Publications and source records attributed to A Henderson.

At least 55 records · Page 3Linked to original sources
PubMed1998

Nursing's metaparadigm concepts: disimpacting the debates.

Theoretical advances in nursing have been complicated by polarization and extreme positions regarding nursing's approach to its main metaparadigm concepts: person, health, environment and nursing. In this paper, the authors deconstruct some of the central arguments that are used to further this polarization. Using a critical interpretive approach, they explain some of the logical implications imposed by various extreme positions for the larger project of nursing's health and social mandate, and consider the effects of such polarization. On the basis of an appreciation of the serious difficulties inherent in certain philosophical and theoretical positions currently evident within nursing's literature, the authors argue for a less extreme and more integrated reference point for nursing's theory and practice.

Disease↗
PubMed1998

Evaluating the effectiveness of two teaching strategies for patients diagnosed with hypertension.

This study investigated whether a structured patient-centred education programme was more effective than the normal ad hoc information that patients receive in improving their knowledge of hypertension whilst in hospital. Forty patients were assessed to determine their knowledge level regarding the management of risk factors related to hypertension. A pre-test was performed shortly after admission to hospital. Twenty patients in the test group received a structured education programme, and 20 patients in the control group received the usual ad hoc information. Two post-tests were performed, one at the time of discharge and the other approximately 8 weeks after discharge, to determine the change in knowledge levels. Comparison of the pre- and post-tests of the test group revealed a significant increase in knowledge level at the time of discharge from hospital. Patients were found to retain this new knowledge at 8 weeks and 1 year after discharge. No significant difference was found for the control group. This study has shown that a structured approach to health education is more effective in improving patients' knowledge about their condition than relying on the ad hoc information that patients traditionally receive during their hospitalization.

Adult↗
PubMed1998

Aneuploidy in male Indian muntjac cells is limited to the Y2 chromosome.

In untreated cell cultures of Indian muntjac (Munticus muntiacus vaginalis; 2n = 6 female, 7 male) we observed that spontaneous aneuploidy is limited primarily to the Y2 chromosome. We therefore treated the cells with aneugenic agents to determine if induced aneuploidy follows the same pattern and, hence, if there are limitations on the generation of aneuploidy or survival of cells lacking certain chromosomes. Exposing the cells to benomyl (8-100 micrograms/ml for 1 h), caffeine (5 x 10(-5)-2 x 10(-4) M for 2, 24 and 72 h) and colchicine (2 x 10(-4) and 5 x 10(-5) M for 1, 24, 48 and 72 h) resulted in cells primarily aneuploid for the Y2 chromosome. The frequency of cells lacking Y2 was far higher than those having an extra Y2 chromosome. The frequency of cells aneuploid for all other chromosomes combined was much lower than that for Y2. The data imply that the Indian muntjac genome can tolerate loss of the Y2 chromosome only and that aneuploidy for other chromosomes might cause lethality. This might be because the small number of chromosomes in the genome predisposes aneuploid cells to an imbalance of genes carrying out the basic activities required for cell division and cell survival. Because of the small chromosome number, the large size of the chromosomes and the ease of distinguishing every chromosome without banding or any other special treatment, e.g. FISH, this system could be useful and convenient in the study of induction of aneuploidy. This simple and inexpensive system can be utilized as a screening system for preliminary studies dealing with induced aneuploidy.

Aneuploidy↗
PubMed1998

Transcriptional regulation during B cell development.

Information is increasingly available concerning the molecular events that occur during primary and antigen-dependent stages of B cell development. In this review the roles of transcription factors and coactivators are discussed with respect to changes in expression patterns of various genes during B cell development. Transcriptional regulation is also discussed in the context of developmentally regulated immunoglobulin gene V(D)J recombination, somatic hypermutation, and isotype switch recombination.

Animals↗
PubMed1998

Water distribution system and diarrheal disease transmission: a case study in Uzbekistan.

Deteriorating water treatment facilities and distribution systems pose a significant public health threat, particularly in republics of the former Soviet Union. Interventions to decrease the disease burden associated with these water systems range from upgrading distribution networks to installing reverse osmosis technology. To provide insight into this decision process, we conducted a randomized intervention study to provide epidemiologic data for water policy decisions in Nukus, Uzbekistan, where drinking water quality is suboptimal. We interviewed residents of 240 households, 120 with and 120 without access to municipal piped water. Residents of 62 households without piped water were trained to chlorinate their drinking water at home in a narrow-necked water container with a spout. All study subjects (1583 individuals) were monitored biweekly for self-reported diarrheal illness over a period of 9.5 weeks. The home chlorination intervention group had the lowest diarrheal rate (28.8/1,000 subjects/month) despite lack of access to piped water in their homes. Compared with the two groups that did not receive the intervention this rate was one-sixth that of the group with no piped water (179.2/1,000 subjects/month) and one-third that of the households with piped water (75.5/1,000 subjects/month). More than 30% of the households with piped water lacked detectable levels of chlorine residues in their drinking water, despite two-stage chlorination of the source water, and were at increased risk of diarrhea. Forty-two percent of these municipal users reported that water pressure had been intermittent within the previous two days. The dramatic reduction in diarrheal rates in the home-chlorination intervention group indicates that a large proportion of diarrheal diseases in Nukus are water-borne. The home-chlorination group had less diarrhea than the group with piped water, implicating the distribution system as a source of disease transmission. Taken together, these epidemiologic data would support the hypothesis that diarrhea in the piped water group could be attributed to cross-contamination between the municipal water supply and sewer, due to leaky pipes and lack of water pressure. Relatively inexpensive steps, including chlorination, maintaining water pressure, and properly maintaining the distribution system, rather than reverse osmosis technology, should reduce diarrheal rates.

Adult↗
PubMed1998

Where to from here: patients of a day hospital rehabilitation programme perceived needs following stroke.

The loss of ability to perform routine activities can result in difficulties for the stroke patient to resume their normal lifestyle. A desire to assist stroke patients after discharge prompted this pilot study into the needs of these patients during and after a program of rehabilitation at a day hospital. A longitudinal approach was used for this pilot study. The aim of the study was to identify patients' needs pertaining to the resumption of their lifestyle, and social and emotional well-being, that emerged during the rehabilitation programme at the day hospital, on its completion and within six months of discharge from the day hospital. The study consisted of three semi-structured interviews with ten stroke patients over a period of nine to twelve months. The semi-structured interview employed open-ended questions to collect information from the participants. The interview process sought to elicit the needs of the participants during their time at the day hospital and then after discharge. It was evident from the interviews that the needs of the participants were primarily the opportunity to practice activities which could improve physical capabilities as the physical limitations placed on the participants by the stroke affected their motivation, morale and general sense of self. The day hospital was instrumental in providing participants with opportunities to learn to 'use' what was functioning, and therefore help the participants improve their physical capabilities. This assisted them to regain their independence. During the interviews participants also spoke about social and emotional needs. While they received some support from interactions with the staff and other patients at the day hospital, participants stated that mostly social and emotional support came from their families. After discharge from the day hospital participants were unable to identify specific needs which they believed the day hospital could provide.

Activities of Daily Living↗
PubMed1997

Adult intensive care in an environment of resource restriction: how should the unit director respond?

Adult intensive care touches the lives of very few while consuming a disproportionately high level of resources. To survive in the future environment of resource restriction and accountability, the unit director must rapidly acquire a wide range of professional management skills. The intensive care unit director must be able to demonstrate to colleagues, health managers and the community that the large amount of resources provided to intensive care, and the remarkable freedom given to intensivists to use those resources, are justified in terms of compassionate evidenced-based care, efficiency, efficacy and appropriateness. While many outcomes may be subjected to audit, intensive care units must publish minimal performance data indexed to severity of illness and including their mortality, hospital mortality and length of stay and an overall indicator of patient acuity to identify patients at low risk who need not be admitted to an expensive intensive care bed.

Adult↗
PubMed1997

Fungal transformations of antihistamines: metabolism of cyproheptadine hydrochloride by Cunninghamella elegans.

1. Metabolites formed during incubation of the antihistamine cyproheptadine hydrochloride with the zygomycete fungus Cunninghamella elegans in liquid culture were determined. The metabolites were isolated by hple and identified by mass spectrometric and proton nmr spectroscopic analysis. Two C elegans strains, ATCC 9245 and ATCC 36112, were screened and both produced essentially identical metabolites. 2. Within 72 h cyproheptadine was extensively biotransformed to at least eight oxidative phase-I metabolites primarily via aromatic hydroxylation metabolic pathways. Cyproheptadine was biotransformed predominantly to 2-hydroxycyproheptadine. Other metabolites identified were 1- and 3-hydroxycyproheptadine, cyproheptadine 10,11-epoxide, N-desmethylcyproheptadine, N-desmethyl-2-hydroxycyproheptadine, cyproheptadine N-oxide, and 2-hydroxycyproheptadine N-oxide. Although a minor fungal metabolite, cyproheptadine 10,11-epoxide represents the first stable epoxide isolated from the microbial biotransformation of drugs. 3. The enzymatic mechanism for the formation of the major fungal metabolite, 2-hydroxycyproheptadine, was investigated. The oxygen atom was derived from molecular oxygen as determined from 18O-labelling experiments. The formation of 2-hydroxycyproheptadine was inhibited 35, 70 and 97% by cytochrome P450 inhibitors metyrapone, proadifen and 1-aminobenzotriazole respectively. Cytochrome P450 was detected in the microsomal fractions of C. elegans. In addition, 2-hydroxylase activity was found in cell-free extracts of C. elegans. This activity was inhibited by proadifen and CO, and was inducible by naphthalene. These results are consistent with the fungal epoxidation and hydroxylation reactions being catalysed by cytochrome P450 monooxygenases. 4. The effects of types of media on the biotransformation of cyproheptadine were investigated. It appears that the glucose level significantly affects the biotransformation rates of cyproheptadine; however it did not change the relative ratios between metabolites produced.

Biotransformation↗
PubMed1997

Estimating health risks from natural hazards using risk assessment and epidemiology.

Risk assessment is the process of estimating the likelihood that an adverse effect may result from exposure to a specific health hazard. The process traditionally involves hazard identification, dose-response assessment, exposure assessment, and risk characterization to answer "How many excess cases of disease A will occur in a population of size B due to exposure to agent C at dose level D?" For natural hazards, however, we modify the risk assessment paradigm to answer "How many excess cases of outcome Y will occur in a population of size B due to natural hazard event E of severity D?" Using a modified version involving hazard identification, risk factor characterization, exposure characterization, and risk characterization, we demonstrate that epidemiologic modeling and measures of risk can quantify the risks from natural hazard events. We further extend the paradigm to address mitigation, the equivalent of risk management, to answer "What is the risk for outcome Y in the presence of prevention intervention X relative to the risk for Y in the absence of X?" We use the preventable fraction to estimate the efficacy of mitigation, or reduction in adverse health outcomes as a result of a prevention strategy under ideal circumstances, and further estimate the effectiveness of mitigation, or reduction in adverse health outcomes under typical community-based settings. By relating socioeconomic costs of mitigation to measures of risk, we we illustrate that prevention effectiveness is useful for developing cost-effective risk management options.

Disaster Planning↗
PubMed1997

The absence of the transcription activator TFE3 impairs activation of B cells in vivo.

TFE3 is a ubiquitously expressed member of the TFE3/mi family of basic helix loop helix zipper transcription factors. TFE3 binds to muE3 sites located in the immunoglobulin heavy-chain (IgH) intronic enhancer, heavy-chain variable region promoters, the Ig kappa intronic enhancer, and regulatory sites in other genes. To understand the role of TFE3 in Ig expression and lymphoid development, we used embryonic stem (ES) cell-mediated gene targeting and RAG2-/- blastocyst complementation to generate mice which lack TFE3 in their B and T lymphocytes. TFE3- ES cells fully reconstitute the B- and T-cell compartments, giving rise to normal patterns of IgM+ B220+ B cells and CD4+ and CD8+ T cells. However, TFE3- B cells show several defects consistent with poor B-cell activation. Serum IgM levels are reduced twofold and IgG and IgA isotypes are reduced three- to sixfold in the TFE3- chimeras even though in vitro, the TFE3- splenocytes secrete normal levels of all isotypes in response to lipopolysaccharide activation. Peripheral TFE3- B cells also show reduced surface expression of CD23 and CD24 (heat-stable antigen).

Alleles↗
PubMed1997

In-hand manipulation in young children: translation movements.

OBJECTIVE: The purpose of this study was to look at the development of in-hand translation skills in young children; that is, the child's ability to move a small object from the fingers into the palm and from the palm to the fingers. Three questions were asked: (a) Do boys' and girls' performance differ significantly? (b) Does the performance of the children improve with age? and (c) Can periods of rapid improvement with age be seen on the tasks presented? METHOD: In-hand manipulation translation was measured with a pegboard task for 154 right-handed children between 3-0 years and 6-11 years of age and 13 adults. Participants were videotaped as they picked up two to five pegs, one at a time; stored them in the hand; and moved the pegs out of storage to place them in the pegboard. The number of pegs handled in each trial as well as the methods used to move the peg to and from the palm were recorded. RESULTS: Boys and girls did not show significant differences in their performance, but when slight differences did occur, they favored the girls. Age was found to be a significant factor in both the number of pegs handled and the method used in handling them. The older children tended to place more pegs successfully and were more likely to use the methods most commonly used by the adults. A major finding was the marked difference in how the children solved the problem of moving the peg in and out of the palm compared with the adults. The adults used gravity to assist the movement of the peg; the children tended to use methods that allowed them to maintain contact with the peg throughout the movement. CONCLUSION: In-hand manipulation translation skills appear to have a long developmental course. Children are closer to adults in their ability to perform the task than in the methods that they use. This study shows the importance of observing how children perform tasks, not just whether they complete the tasks. Differences in the methods used help to determine efficiency. Observation of these skills in children may expand a therapist's understanding of children's fine motor abilities.

Adult↗
PubMed1997

Exploring the everyday world of the patient in isolation.

PURPOSE/OBJECTIVES: To explore the phenomenon of isolation from the perspective of patients cared for in reverse isolation for bone marrow transplant (BMT). DESIGN: Interpretive, phenomenologic. SETTING: Hematology and bone marrow transplant unit of a large teaching hospital in Brisbane, Australia. SAMPLE: Seven patients undergoing BMT. METHODS: Phenomenologic interviews and thematic analysis of transcribed data. MAIN RESEARCH VARIABLE: Patient's day-to-day experiences of reverse isolation. FINDINGS: Although appreciative of the physical care and attention given to them, participants did not convey a sense that healthcare professionals understood the experience of the BMT recipient's isolation or illness from their perspective. Major themes elicited from analysis of the transcripts included (a) striving to take charge, which refers to participants' attempts to maintain control in a seemingly out-of-control situation. (b) intellectualizing the need for isolation, and (c) being in touch: contact with family and staff. CONCLUSIONS: Elements of caring for the patient appeared to dominate the comments associated with staff contact. Other forms of care (e.g., caring about) emphasize the importance of nurses understanding and connecting with peoples' meanings and experiences of their illness and treatment. IMPLICATIONS FOR NURSING PRACTICE: Although all participants were aware that they could ask for information about their diagnosis and treatment at any time, most had not been offered the opportunity to describe their feelings or experiences before. Unless nurses take more initiative to gain insight and a greater appreciation of the patient's understanding of his or her situation, they will continue to focus on unidimensional aspects of care and neglect the multidimensional or holistic nature of nursing care.

Adaptation, Psychological↗
PubMed1996

Cardiovascular syndromes X, endothelial dysfunction and insulin resistance.

Cardiac Syndrome X (microvascular angina) and the more recently described metabolic Syndrome X (an epidemiological association between insulin resistance and atheroma, dyslipidaemia, and hypertension) may have more in common than the chance of their common sobriquet, in view of evidence that microvascular angina too is characterised by insulin resistance and endothelial dysfunction. The implications are discussed.

Endothelium, Vascular↗
PubMed1996

Theatre in AIDS education--a controlled study.

Theatre is now widely used in HIV and AIDS education for young people. However, research concerning its effectiveness has largely been conducted without using comparison or control groups and there is little evidence that other types of intervention are more or less effective. The present study was designed to measure the effects of a theatre production on HIV knowledge, attitudes and risk behaviour of young people compared with that of a standard health education seminar which used group work techniques. Both interventions were designed for young people between the ages of 12 and 18 and held in 10 youth projects in socially deprived areas of Glasgow. Five youth projects were randomly assigned to each intervention. All participants were asked to complete a self-administered HIV knowledge, attitude and behavioural questionnaire immediately before and after the event and 2 months later. Research focus groups were also used. A total of 35 young people attending the standard seminars completed three self-administered questionnaires, and 18 participated in all three focus groups. Forty-two young people attending the theatre performances completed three self-administered questionnaires and 16 participated in all three focus groups. There was little impact on the knowledge and attitudes of either audience, although there was some evidence of attitudinal change among those exposed to the health education discussion session. More of the theatre group reported a behavioural change 2 months after attending the play but only in relation to buying and carrying condoms. It is uncertain whether this led to safer sex practices. This study does not support the view that theatre in AIDS education has a significant impact on HIV knowledge, attitudes and risk behaviour.

Acquired Immunodeficiency Syndrome↗