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Biomedical subjects

A Long

Publications and source records attributed to A Long.

At least 91 records · Page 5Linked to original sources
PubMed1997

Nursing: a spiritual perspective.

This article explores and examines the fundamental need for nurses to include the promotion of the spiritual dimension of the health of human beings as well as the physical, mental and social facets if they truly wish to engage in holistic care. The author attempts to define the phenomenon of spirituality, aware of the dilemma that many individuals face when thinking and reflecting on this very personal and intangible issue. To be spiritual is to become fully human, the article argues, and the reverse is also true. Spirituality in health is inextricable in each person's search for the discovery of the truth about self and the meaning and purpose of life. Healthy communities are the product of healthy individuals who sow spiritual seeds such as unconditional positive regard, acceptance, respect and dignity for the benefit and advancement of individuals and humankind as a whole. The global nature of the phenomenon of spirituality is also shown by using examples of people who demonstrate compassion and communion with other human beings, in other countries in times of suffering, war and disaster. Compassion and empathy is expressed and experienced for victims of earthquakes that happen miles from home and far removed from personal or religious beliefs. Yet at such times we are all connected in the tapestry of life by our own human spirituality and earthiness. Abstract themes like compassion and justice are treated in the text within the context of spirituality. The author argues that being just and fair means that all patients have the right to achieve spiritual healing regardless of their belief systems, culture or creed. The works of some spiritual philosophers are used to reflect on this integral aspect of human caregiving. Historical symbols of spirituality are examined. The need for nurses to explore and reflect on the paradoxical concepts involved in their own spirituality is highlighted. Nurses are the essential providers of care and, therefore, the paper argues, guardians of that essential humanity that ensures that patients never become less than full human beings, whatever their condition, faith, culture or belief, or whoever they may be. The author contends that this responsibility is uniquely essential to being a nurse.

Attitude of Health Personnel↗
PubMed1996

A role for CD9 molecules in T cell activation.

Costimulation mediated by the CD28 molecule plays an important role in optimal activation of T cells. However, CD28-deficient mice can mount effective T cell-dependent immune responses, suggesting the existence of other costimulatory systems. In a search for other costimulatory molecules on T cells, we have developed a monoclonal antibody (mAb) that can costimulate T cells in the absence of antigen-presenting cells (APC). The molecule recognized by this mAb, 9D3, was found to be expressed on almost all mature T cells and to be a protein of approximately 24 kD molecular mass. By expression cloning, this molecule was identified as CD9, 9D3 (anti-CD9) synergized with suboptimal doses of anti-CD3 mAb in inducing proliferation by virgin T cells. Costimulation was induced by independent ligation of CD3 and CD9, suggesting that colocalization of these two molecules is not required for T cell activation. The costimulation by anti-CD9 was as potent as that by anti-CD28. Moreover, anti-CD9 costimulated in a CD28-independent way because anti-CD9 equally costimulated T cells from the CD28-deficient as well as wild-type mice. Thus, these results indicate that CD9 serves as a molecule on T cells that can deliver a potent CD28-independent costimulatory signal.

Animals↗
PubMed1996

Structural basis for the excision repair of alkylation-damaged DNA.

Base-excision DNA repair proteins that target alkylation damage act on a variety of seemingly dissimilar adducts, yet fail to recognize other closely related lesions. The 1.8 A crystal structure of the monofunctional DNA glycosylase AlkA (E. coli 3-methyladenine-DNA glycosylase II) reveals a large hydrophobic cleft unusually rich in aromatic residues. An Asp residue projecting into this cleft is essential for catalysis, and it governs binding specificity for mechanism-based inhibitors. We propose that AlkA recognizes electron-deficient methylated bases through pi-donor/acceptor interactions involving the electron-rich aromatic cleft. Remarkably, AlkA is similar in fold and active site location to the bifunctional glycosylase/lyase endonuclease III, suggesting the two may employ fundamentally related mechanisms for base excision.

Alkylation↗
PubMed1996

pim-1 proto-oncogene expression in anti-CD3-mediated T cell activation is associated with protein kinase C activation and is independent of Raf-1.

We have studied pim-1 proto-oncogene expression in human T cell responses to Ag receptor-generated signals. The pim-1 gene encodes a serine/threonine protein kinase that is expressed primarily in cells of hematopoietic lineage and is implicated in the intracellular signaling processes accompanying lymphocyte activation. We show here that pim-1 mRNA expression is rapidly induced after receptor cross-linking with anti-CD3 Abs. We examined the linkage of pim-1 expression to known signaling pathways generated through the T cell Ag receptor. pim-1 mRNA was not substantially induced after elevation of intracellular free Ca2+. In contrast, PMA, which directly activates PKC, induced rapid pim-1 expression. Further, anti-CD3- or PMA-induced pim-1 expression was markedly reduced by various PKC inhibitors and by deficiency of the PKC epsilon isoform in a mutant T cell line. Thus, T cell Ag receptor-linked pim-1 expression appears to be coupled to the PKC component of transmembrane signaling. Because the activation of protein kinase C has been shown to activate Raf-1 kinase activity, the involvement of Raf-1 in pim-1 expression was also investigated using a human T cell line stably transfected with an inducible Raf expression vector. Although the overexpression of activated Raf was shown to cause a substantial increase in IL-2 expression, no discernible effects on pim-1 were apparent. In addition, we examined transcriptional and post-transcriptional mechanisms involved in PKC-mediated pim-1 expression and observed that both transcriptional and post-transcriptional mechanisms are coordinately involved in the up-regulation of the pim-1 proto-oncogene.

Calcium↗
PubMed1996

Predictive utility of the CSQ in low back pain: individual vs. composite measures.

Researchers have typically used factor-analytic composite measures of coping, instead of individual scales, to predict rehabilitation outcome. There are, however, both advantages and disadvantages to using individual or composite scores. This study extended the findings of Jensen et al. (1992), by prospectively comparing the individual and composite scores of the Coping Strategies Questionnaire (CSQ) in the prediction of 4 types of adjustment to low back pain. Two-hundred patients completed the CSQ, the Oswestry Index, the SCL-90R, and 4 lifting tasks at admission and discharge from a multidisciplinary pain clinic. Return to work was determined at 9-month follow-up. The CSQ scales were factor-analyzed to devise composite indices, and the 3 resultant factors were compared to the individual scales in the prediction of pain and other outcomes. The results indicated that the relative predictive utility of the composite or individual scales depended on which outcome measure was used to define adjustment.

Adaptation, Psychological↗
PubMed1996

Patient awareness of the adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs).

We set out to determine the extent to which two groups of patients reported having been informed about the adverse effects of NSAIDs. These consisted of 50 patients who had suffered an acute gastrointestinal bleed while taking a NSAID, and 100 age, sex and drug matched controls who had not. Eight (16%) of the index patients, and 41 (41%) of the control patients remembered having been informed of potential adverse effects, an odds ratio of 3.65 (95% CI 1.55-8.58, P < 0.002). Two (4%) of the index patients recalled having been advised what to do should adverse symptoms develop, whereas 21 (21%) of the control patients did so, an odds ratio of 6.38 (95% CI 1.4-28.4, P < 0.01). Eighteen (36%) of patients who bled had experienced gastrointestinal pain prior to the bleed, but of these only two (11%) admitted reduced compliance with NSAID therapy. In contrast, 10 (67%) of the 15 control patients who had suffered epigastric discomfort admitted reduced compliance, an odds ratio of 16.0 (95% CI 2.6-98.8, P < 0.001). Our results suggest that patients who report not having been informed of adverse effects of NSAIDs are less likely to reduce intake in response to epigastric pain than patients who report having received such information. If the patients who bled had reduced their intake of NSAIDs to the same extent as apparently better informed control patients in response to epigastric pain, it is possible that some episodes of acute gastrointestinal bleeding would have been avoided.

Adult↗
PubMed1996

Effect of ageing upon warfarin dose requirements: a longitudinal study.

This longitudinal study was designed to establish the rate of age-related change in warfarin dose requirements. Warfarin dosage was recorded retrospectively in 104 patients who had been stabilized on warfarin for a median period of 10 years (range 6-24 years) for prophylaxis of thromboembolic disease. There was a significant negative correlation between dosage and age at the start of therapy (p = 0.002, r = -0.30). Warfarin requirements fell over time, dosage difference being significantly correlated with age difference (p = 0.01, r = 0.25). Use of regression equation derived from these data suggests a 21% fall in warfarin requirements in this population over a 15-year period. The relationship between change in warfarin dose requirements and ageing established in this longitudinal study is in good agreement with that established by cross-sectional studies, suggesting that no major birth cohort effect is influencing requirements in our warfarin-treated population.

Adult↗
PubMed1996

An extended literature review of health professionals' perceptions of illicit drugs and their clients who use them.

The literature relating to health professionals and illicit drugs and clients who use them shows many common themes. It is evident that the majority of health professionals hold negative, stereotypical perceptions of illicit drug-users. Consequently, these negative attitudes become prejudicial, hence blocking the professional from carrying out effective and humane nursing care to this client group. Evidence also shows that health professionals' perceptions on the legalization of currently illicit drugs is linked to their own use of these drugs rather than any social or health reasons. Professionals' views on the different illicit substances are also coloured by their use, not by the actual evidence relating to the effects of that drug, in particular, cannabis. The literature shows that health professionals project heavily on to the client all their own negative perceptions of illicit drug use, in the care setting. This has produced very unsatisfactory and unsafe care, resulting in both client and carer being dissatisfied with the whole aspect of care. In addition, specialist teams are being swamped by health professionals who are referring almost every illicit drug-user to these services. The future may be brighter with the generalist and specialist working closely together for the benefit of all, especially the client and, ultimately, the community.

Attitude of Health Personnel↗
PubMed1996

An exploration of nurses' attitudes to the nursing care of the suicidal patient in an acute psychiatric ward.

Suicidal patients admitted to hospital following a suicidal attempt or expressing suicidal ideation present a real challenge to health professionals with regard to their therapeutic care. This study was undertaken to explore the attitudes of psychiatric nurses caring for such patients. Results reveal that psychiatric nurses do hold positive views on caring for potentially suicidal patients, contradicting previous studies where more negative feeling were expressed by nurses, especially those with initial contact. Findings also show that some nurses experience an element of distress, and the length of experience within such a working environment does not affect the nurses' level of satisfaction gained on caring for the suicidal patient. This study also identifies an expression of need for further education and practice in interpersonal skills and therapeutic modalities to enhance and develop a more effective delivery of care for this group of patients.

Adolescent↗
PubMed1996

Expression of CD44 and its variants on gastric epithelial cells of patients with Helicobacter pylori colonisation.

BACKGROUND: Studies have suggested that expression of the adhesion molecule CD44 may be of prognostic importance in gastric cancer. In addition, there is strong evidence that Helicobacter pylori has a role in gastric cancer. AIMS: To determine the expression of CD44 and its variants (v6, v9) and HLA class II molecules on human gastric epithelial cell and intraepithelial lymphocytes in patients with and without H pylori infection. PATIENTS: Eighteen patients (seven men and 11 women) attending for endoscopic evaluation because of upper gastrointestinal symptoms were included. An additional 10 patients (five men and five women) were analysed for CD44 variant expression). METHODS: Biopsy specimens were taken from the gastric antrum during endoscopy. Gastric epithelial cells and intraepithelial lymphocytes were examined by two colour flow cytometry and compared in patients with and without H pylori infection. RESULTS: Expression of CD44 and its variants (CD44 v9) was increased in epithelial cells but not in intraepithelial lymphocytes. Both epithelial cells and intraepithelial lymphocytes expressed higher levels of HLA class II molecules (DR and DP), possibly as a result of local cytokine production. Furthermore, results showed upregulation of CD44 on a gastric epithelial cell line (AGS) by cytokines and peripheral blood mononuclear cell supernatant. CONCLUSIONS: These data suggest that H pylori, either directly or through a local inflammatory response, is responsible for increased expression of CD44 and its variant CD44 v9. These data are of potential importance in relation to increased expression of CD44 and CD44 v9 on gastric carcinoma.

Adult↗
PubMed1996

HIV risk behavior, street outreach, and condom use in eight high-risk populations.

In this paper we examine risk behavior, exposure to street outreach, and condom use in samples of injecting drug users (IDUs) and high-risk youth. We used systematic sampling methods to produce representative samples of injecting drug users IDUs (five sites) and high-risk youth (three sites). The populations surveyed engaged in high levels of sexual risk behavior: 20% to 46% reported two or more sex partners in the last month. The majority (62% to 97%) knew someone infected with HIV. Condom use rates approached national health promotion goals for nonsteady partners but not for steady or main partners. Having a condom at time of interview was the most consistent predictor of condom use at last intercourse. Many of the respondents have been in contact with street outreach programs and many acknowledged some personal risk for HIV infection. However, most of the injecting drug users and high-risk youth interviewed (and their sex partners) were still at risk through unprotected sex.

Adolescent↗
PubMed1996

Molecular cloning and characterization of murine interleukin-11.

Human interleukin-11 (IL-11) has been shown to have pleiotropic action on hematopoietic, hepatic, stromal, epithelial, neural, and osteoclast cells. In the present work, the murine IL-11 cDNA has been isolated from a fetal thymic cell line, and its structure and function compared with human IL-11. The murine protein was demonstrated to have identical actions on the proliferation of a murine plasmacytoma cell line, murine primitive bone marrow progenitor cells, and megakaryocyte precursors. The murine IL-11 protein was synthesized as a soluble thioredoxin-IL-11 fusion in Escherichia coli and the expression of murine IL-11 was examined by pulse-chase radiolabeling in COS cells. The chromosomal location of the murine IL-11 gene was assigned to the proximal arm of chromosome 7.

Amino Acid Sequence↗
PubMed1995

Cellular proliferation and activation of NF kappa B are induced by autocrine production of tumor necrosis factor alpha in the human T lymphoma line HuT 78.

Tumor necrosis factor (TNF) is a pleiotropic cytokine which has both cytotoxic and proliferative effects. HuT 78, a T-cell line derived from a Sezary lymphoma, is resistant to the cytotoxic effects of TNF, suggesting that TNF may be a growth factor for this cell line. The aim of this study was to determine whether autocrine TNF production could function as a growth factor for HuT 78. Resting HuT 78 and K-4 cells, a protein kinase C-beta-deficient clone of HuT 78, both produced significant amounts of TNF compared with Jurkat cells. Thymidine incorporation by HuT 78 and K-4 cells was inhibited by 90.5 and 73.2%, respectively, with addition of a neutralizing monoclonal antibody to TNF alpha, suggesting that TNF is an autocrine growth factor for these cells. HuT 78 and K-4 cells also expressed high levels of constitutively active NF kappa B, unlike Jurkat cells, which expressed high levels only upon activation with TNF or phorbol 12-myristate 13-acetate. p50 was the major component in the NF kappa B complexes in HuT 78 and K-4 cells. Anti-TNF alpha antibody dramatically decreased levels of NF kappa B in both HuT 78 and K-4 cells. As the TNF gene has an NF kappa B binding motif, an autocrine loop involving TNF induction of NF kappa B is therefore likely in these cells. These findings in a neoplastic T-cell line suggest that therapy directed against TNF could be effective in a subset of T-cell lymphomas.

Antibodies, Monoclonal↗
PubMed1995

[Endovascular treatment of sclerotic arteriopathies of the lower limbs].

Percutaneous transluminal angioplasty is performed to treat arterial stenoses or occlusions. Currently, balloon angioplasty is still considered as the gold standard even if new interventional devices and techniques have been proposed to improve immediate and long-term results: stents, intraarterial thrombolysis, percutaneous aspiration embolectomy, atherectomy, laser and ultrasound angioplasty. Evaluations of these methods in the treatment of peripheral arterial diseases are ongoing. An interventional procedure is indicated only after a thorough analysis of the medical and anatomo-angiographic data. A stenosis or a short occlusion of the iliac or the femoro-popliteal arteries are typical indications for percutaneous angioplasty in case of claudication; more complex lesions become gradually accessible to percutaneous methods in patients with chronic critical and even acute arterial ischaemia of the lower limbs. During the follow-up, the development of a restenosis is detected by careful clinical examination and ultrasound duplex scanning.

Acute Disease↗
PubMed1995

Regulation of non-classical protein kinase C isoenzymes in a human T cell line.

We have examined the expression and responses to activation, of novel/atypical protein kinase C (PKC) isoforms epsilon, zeta, and delta in the T cell lymphoma cell line K-4. The effects of 1-h phorbol 12-myristate 13-acetate (PMA) and OKT3 activation of K-4 cells on PKC isoform distribution were examined. In addition, the effects of PMA-mediated down-regulation on the expression of PKC epsilon and zeta were determined using high concentrations of PMA over 24- and 48-h time periods in these cells. PKC zeta expression was not altered by incubation of K-4 cells with up to 200 ng/ml PMA over a 24- or 48-h period. PKC epsilon was down-regulated in a concentration-dependent manner by PMA after both 24- and 48-h of activation. Expression of PKC epsilon was not completely depressed, however, even at the highest concentration of the phorbol ester after 48-h incubation with PMA. The presence of PKC epsilon, zeta, and delta was confirmed by immunohistochemistry with distinct patterns of expression observed. PMA-induced PKC activation for a 1-h period resulted in a translocation of PKC delta from resting cytoplasmic/nuclear staining to a cytoplasmic aggregate. Following 1-h activation through the T cell receptor-associated complex CD3, PKC delta translocated from a peri-nuclear/cytoplasmic compartment to a putative cytoskeletal location in K-4 cells. This translocation was time dependent and redistributed to a cytoplasmic aggregate prior to the cytoskeleton. Similarly, following 1-h activation through the T cell receptor, PKC zeta redistributed directly to what is possibly a cytoskeletal cell compartment. The cytoplasmic distribution of PKC zeta was unaltered following activation with PMA over a 1-h time period. There was no apparent redistribution of PKC epsilon cytoplasmic staining pattern following a 1-h direct or indirect activation. These results underline the differences in individual PKC isoform distribution, and responses to different stimuli, thereby providing additional evidence for the use of discrete PKC isoform signaling pathways in T cells. Furthermore, this data underlines the differences in PMA-mediated PKC activation and activation through the T cell receptor.

Biological Transport↗
PubMed1995

Origin of sex for error repair. I. Sex, diploidy, and haploidy.

Genetic damage is a fundamental problem for living systems. Recombination can repair a damaged gene, so long as there is an undamaged copy of the gene available in the cell. This requires that the cell be diploid for the damaged locus. During sex, outcrossing generates the diploid state by temporarily fusing two haploid cells (as in the case of meiosis) or by bringing DNA into the cell from outside (as in the case of bacterial transformation). But why should cells alternate between the haploid and diploid states in the first place? Why not just remain diploid, if damage repair is the only problem for a cell? The goal of our work is to understand if the problem of genetic damage would select for diploidy or for the alternation between diploid and haploid states--that is, sex--early in the history of life. Using mathematical models we study competition between asexual haploids (termed "haploids"), sexuals (termed "sexuals"), and asexual diploids (termed "diploids"). Haploid cells are efficient replicators, while diploid cells are resistant to damage. A sexual may combine the advantages of both: spending much of its life cycle in the haploid state, then temporarily fusing to become diploid, followed by splitting to the haploid state. During the diploid state DNA damage can be repaired, since there are two copies of the gene in the cell and one copy is presumed to be undamaged. We describe the competition in terms of mathematical models, employing five rate parameters which represent the life processes of cells most probably active at the time that sexuality arose: birth and death; genomic damage (for the haploids alone); and, for the sexual cell, fusion and splitting. Parameter space bifurcation diagrams for the equilibria are drawn in the three-dimensional space of damage, splitting, and fusion, and solutions of the equations (i.e., the outcomes of the competition) are described in terms of them. It turns out that those three parameters suffice to give an essentially complete description of the qualitative behavior possible, since one parameter can be scaled out of the equations we ultimately consider, and the other permits generic analysis, for the range of parameter values of interest, at a fixed value of that parameter. Each type of cell has a region of the parameter space that it occupies exclusively (given its initial presence in the competition). The haploid can win only in environments characterized by low damage (relative to mortality), while the diploid can win only in environments characterized by high damage (relative to mortality).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1995

Origin of sex for error repair. II. Rarity and extreme environments.

In a previous paper we studied the simultaneous, and at times conflicting, needs of coping with DNA damage, efficient cell replication, and the avoidance of cell mortality. These selective factors operated on sexual and asexual haploid and diploid populations that were reproductively isolated from one another. We concluded, in part, that a sexual type of cell could not expand from extreme rarity in populations dominated by asexual haploid and diploid cells. In the present paper we show that it is relatively easy for a rare sexual mutant to expand in a population dominated by asexual haploid cells if some matings occur between sexual and asexual cell types. We also study the persistence of sex in high mortality, high damage environments, in which neither the asexual diploid nor haploid can survive. The diploid cannot survive because its lower birth rate cannot overcome mortality and the haploid cannot survive because its birth rate cannot overcome gene damage. Sex can persist in these punishing environments by tuning the parameters of the sexual cycle, and the fusion and splitting rates, into a specified region, thereby reaping both benefits of damage repair and efficient replication.

Animals↗