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Biomedical subjects

M Stewart

Publications and source records attributed to M Stewart.

At least 91 records · Page 5Linked to original sources
PubMed2000

Crystallization and initial X-ray diffraction characterization of complexes of FxFG nucleoporin repeats with nuclear transport factors.

NTF2 and importin-beta are transport factors that mediate nuclear protein import and which interact with nuclear pore proteins (nucleoporins) during translocation from the cytoplasm to the nucleus through nuclear pore complexes. We employed a native gel electrophoresis method to assess the interaction of nucleoporin constructs that contain FxFG sequence repeats with NTF2 and truncation mutants of importin-beta to determine suitable fragments for crystallization. Based on these data, we obtained crystals of complexes between yeast NTF2 and a construct containing five FxFG nucleoporin repeats from the yeast nucleoporin Nsp1p and between a construct containing residues 1-442 of human importin-beta and the same nucleoporin construct. The yeast NTF2-nucleoporin crystals have trigonal symmetry and diffract past 2.8 A resolution using synchrotron radiation, whereas the importin-beta-nucleoporin complex crystals have P2(1)2(1)2 orthorhombic symmetry and diffract past 3.2 A resolution.

Amino Acid Sequence↗
PubMed2000

Pyranoisoflavones from Rinorea welwitschii.

Reversed-phase HPLC analysis of a dichloromethane extract of the stem-barks of Rinorea welwitschii has afforded two pyranoisoflavones, alpinumisoflavone (1) and di-O-methylalpinumisoflavone (2).

Chromatography, High Pressure Liquid↗
PubMed2000

Breast cancer patients' experiences of patient-doctor communication: a working relationship.

The traumas of diagnosis and treatment for breast cancer are well researched and generally addressed in care. While women with breast cancer continue to identify the need for better communication with physicians, studies to date have not investigated how the process of communication between physicians and women with breast cancer actually unfolds. This phenomenological study therefore explored how women with breast cancer experience patient-physician communication to gain a greater understanding of effective approaches. Interviews of a purposeful sample of 11 women within 6 months of initial diagnosis or recurrence of breast cancer were audiotaped, transcribed verbatim and analyzed using inductive interpretation. Themes and patterns of positive and negative experiences emerged. All experiences began with the woman's feeling of vulnerability. In positive experiences, information sharing and relationship building were inextricably linked components of a working relationship which was at the same time affective, behavioural and instrumental. This experience, in turn, influenced the woman's experience of control and mastery of the illness experience, and their experience of learning to live with breast cancer. Findings illuminate the importance of comprehensively patient-centred, working relationships. Several specific techniques to enhance effective communication are identified.

Adult↗
PubMed2000

The influence of older patient-physician communication on health and health-related outcomes.

Effective patient-physician communication significantly influences health outcomes of older patients. For example, concordance between patient and physician expectations and patient participation in the decision-making process affects older patients. Communication is also linked to patient recall, adherence, and satisfaction. Furthermore, communication impacts emotional and physical outcomes of older patients, although evidence of improved physical outcomes remains under-investigated in this population. Dimensions of communication, such as continuity of relationship, seem to be important in decreasing hospitalization of older patients. This article explores the link between communication and health care outcomes in the older population.

Aged↗
PubMed2000

Case management approaches for in-home care.

Restructuring healthcare delivery systems within limited budgets presents multiple management challenges. As hospitals have downsized, the demand for in-home services has increased. The involvement of multiple provider agencies and professionals has heightened duplication and fragmentation of services and has complicated the need to develop client-focused, evidence-based approaches. In response to these challenges, community-based case management has burgeoned.

Aged↗
PubMed2000

Mycophenolate mofetil, with cyclosporine and prednisone, reduces early rejection while allowing the use of less antilymphocytic agent induction and cyclosporine in renal recipients with delayed graft function.

Antilymphocytic agent induction (ALAI), with antithymocyte globulin or monoclonal antibody, is generally used in renal transplantation (TX) to spare renal allografts with poor initial function from the toxic effects of cyclosporine (CsA) and/or to augment immunosuppression (IS) in the patient at a high risk for early rejection. ALAI, unfortunately, increases the cost of TX and the risk to the patient, having been associated with many adverse side effects. An IS protocol, which results in a low incidence of early rejection while using less CsA and ALAI, is a worthwhile goal. We compare our experience with mycophenolate mofetil (MMF), CsA, and prednisone (MMFCP; n = 62) to our azathioprine (AZA), CsA, and prednisone (AZACP; n = 50) triple-drug IS, with and without ALAI. The patient characteristics for age, race, first TX, cadaveric donor, pediatric recipient, and dialysis in the first post-op week (DGF) were not different for the MMFCP versus AZACP groups. There were more females in the MMFCP group (51.6% versus 30.0%, p = 0.022). We report that rejection-free survival at 6 months (RF6) was better in the MMFCP versus AZACP group (83.9% versus 60.0%, p = 0.005). Less ALAI and CsA were used in the MMFCP patients. At 1 year, actuarial graft survival was 91.9% in the MMFCP group and 81.9% in the AZACP group (p = 0.116). Actuarial 1-year patient survivals were not different in the two patient groups. In the sub-population of patients with DGF, the RF6 in the MMFCP (n = 13) group was 92.3% versus 57.1% in the AZACP (n = 14) group (p = 0.041). The reduction in early rejection episodes in the patients on MMFCP with DGF was accomplished while using half as much ALAI and lower CsA doses and levels. The African-American recipient sub-population on MMFCP also demonstrated an improvement in RF6 while using less ALAI and CsA (78.6% versus 48.0%, p = 0.022). We conclude that the use of MMF-based triple-drug IS results in fewer rejection episodes while allowing for lower CsA levels and less ALAI, even in patients with delayed graft function.

Actuarial Analysis↗
PubMed2000

The molecular mechanism of transport of macromolecules through nuclear pore complexes.

Trafficking of macromolecules between nuclear and cytoplasmic compartments takes place through the nuclear pore complexes (NPCs) of the nuclear envelope. Nuclear trafficking involves a complex series of interactions between cargo, soluble transport factors (carriers) and nuclear pore proteins (nucleoporins) that are orchestrated by the Ras-family GTPase Ran. The primary role of Ran is probably to establish directionality and to sort molecules to be transported by controlling the interaction between carriers and cargoes, so that they bind in one compartment but dissociate in the other. Translocation of carriers and cargo-carrier complexes through NPCs requires interactions between the carriers and nucleoporins that contain distinctive tandem sequence repeats based on cores rich in glycine and phenylalanine residues that are separated by hydrophilic linkers. Much recent work has focused on these interactions and, in particular, their specificity, regulation and function. Evidence is accumulating that carriers move through the NPC by distinct but overlapping routes using specific subsets of nucleoporins.

Animals↗
PubMed2000

Myocardial infarction: survivors' and spouses' stress, coping, and support.

Despite evidence that spouses play an important role in the recovery of MI survivors, there have been few studies of pertinent psychosocial factors from the perspectives of both survivors and spouses. Accordingly, the aim of this study was to describe stress, coping strategies and social support experienced by survivors and spouses. This study was limited to first-time MI to focus on a time of uncertainty and transition. Twenty-eight persons (14 couples) participated. Both survivors and their spouses reported similar post-MI stresses: emotional impact, lifestyle changes, encounters with health professionals, and their partners' reactions. Spouses and survivors used diverse strategies to cope with the stresses of MI. Seeking informational support was prevalent. Both spouses and survivors engaged in 'protective buffering' of their partners. Couples described deficient support, conflict and miscarried helping efforts within their relationships. Spouses and survivors referred to inadequate informational support from health professionals.

Adaptation, Psychological↗
PubMed2000

Risk of HIV transmission from patients to surgeons in the era of post-exposure prophylaxis.

The HIV prevalence, among patients either undergoing, or with the potential to undergo, surgery were estimated using data from unlinked anonymous HIV surveys of patients in Glasgow hospitals during 1992-1997 in order to quantify the risk of surgeons acquiring HIV occupationally in the era of post-exposure prophylaxis (PEP) availability. A range of prevalence rates was applied to data on other factors influencing risk; these comprised, i) the probability of a percutaneous injury from a sharp instrument used on an HIV infected patient resulting in HIV transmission, ii) the number of injuries sustained and iii) whether or not PEP was administered. On the basis of, for example, a surgeon sustaining three percutaneous injuries over 12 months and not taking PEP after each, the annual risks ranged from 1 in 2,000,000 for urological/renal surgeons to 1 in 200,000 for those performing general surgery/ENT/gynaecological procedures. The administration of PEP after each injury would reduce these rates to 1 in 10,000,000 and 1 in 1,000,000 respectively. The risk of surgeons acquiring HIV occupationally in a city which has an HIV prevalence typical of most urban areas in the UK, is 'minimal' or 'negligible'. In the context of such low risk and our limited knowledge of the adverse effects of PEP, the risk assessment to decide whether or not to give PEP should be well informed and consistent. Current guidelines to help physicians and affected healthcare workers in their decision making need to be improved.

Adolescent↗
PubMed2000

Pharmaceuticals--cost or investment? An employer's perspective.

Employers are becoming increasingly concerned about rising pharmaceutical costs. Are improved health and cost outcomes achieved as a result of increasing pharmaceutical costs? One should approach this issue with a holistic view that considers the overall impact that disease conditions have on health and productivity. To illustrate, we first identified the "top ten" most expensive physical and mental health concerns facing American businesses, using data from over 60 firms from the 1996 MarketScan Private Pay Fee-For-Service Research Database. For some of these top ten conditions, the literature already addresses the drug cost versus investment issue, with mixed results. For conditions in which uncertainty prevails and for other high-cost conditions, empirical analyses should address the drug cost versus investment issue to minimize the risk of a penny-wise and pound-foolish payment/coverage policy. A similar strategy should be applied to individual corporate diagnostic assessments.

Cost Control↗
PubMed2000

Crystallization and preliminary X-ray diffraction analysis of the Saccharomyces cerevisiae ran-binding protein Mog1p.

Mog1p binds the Ras-family GTPase Ran/Gsp1p, which has a central role in nucleocytoplasmic transport and cell-cycle progression. Overexpression of MOG1 is able to suppress temperature-sensitive gsp1 mutants in yeast; Deltamog1 null mutants display temperature-sensitive defects in nuclear trafficking. Orthorhombic crystals of bacterially expressed Mog1p that diffract to beyond 2 A resolution using synchrotron radiation have been obtained. The crystals have P2(1)2(1)2(1) symmetry, with unit-cell parameters a = 39.67, b = 51.96, c = 112.23 A, a Matthews coefficient of 2.44 A(3) Da(-1), an estimated solvent content of 49.5% and one chain in the asymmetric unit.

Crystallization↗
PubMed2000

Nonparametric and parametric estimation for a linear germination-growth model.

Seeds are planted on the interval [0, L] at various locations. Each seed has a location x and a potential germination time t epsilon [0, infinity), and it is assumed that the collection of such (x, t) pairs forms a Poisson process in [0, L] x [0, infinity) with intensity measure dxd lambda(t). From each seed that germinates, an inhibiting region grows bidirectionally at rate 2v. These regions inhibit germination of any seed in the region with a later potential germination time. Thus, seeds only germinate in the uninhibited part of [0, L]. We want to estimate lambda on the basis of one or more realizations of the process, the data being the locations and germination times of the germinated seeds. We derive the maximum likelihood estimator of v and a nonparametric estimator of lambda and describe methods of obtaining parametric estimates from it, illustrating these with reference to gamma densities. Simulation results are described and the methods applied to some neurobiological data. An Appendix outlines the S-PLUS code used.

Animals↗
PubMed2000

Early onset of Friedreich's ataxia in a compound heterozygote.

Friedreich's ataxia (FA) is an autosomal recessive condition caused by a GAA trinucleotide repeat expansion in the X25 gene on chromosome 9. We describe an unusual form of "pseudodominant" inheritance to illustrate how a diagnosis of FA in a parent does not preclude the diagnosis in the child.

Age of Onset↗
PubMed2000

Unlinked anonymous HIV study of hospital patients and general practice attenders in Glasgow, 1991-1997.

AIM: To determine whether HIV is spreading from injecting drug users and homosexual/bisexual males into lower risk heterosexual populations in Glasgow, Scotland, and to pilot a method of monitoring HIV prevalence which involves testing routine biochemistry specimens. METHODS: An unlinked anonymous HIV testing study of hospital patients and general practice attenders was conducted during January 1992 to December 1997. Testing was performed on routine biochemistry specimens from patients aged 16-49 years attending two hospitals with catchment areas covering the north and the east of the city. RESULTS: 78,260 specimens were tested in the study period and no patient objected to their samples being tested anonymously. HIV prevalence rates among male and female subjects were 0.63% and 0.01%, respectively; the large difference in prevalence resulted, in part, from the inclusion of HIV infected haemophiliac patients who attended one of the hospitals. Prevalence among male general practice patients ranged between 0.1% and 0.2%, while that for male patients attending surgical or surgically related specialties was 0.1%. CONCLUSIONS: The prevalence data indicate that HIV has not seeded from the high risk groups into the wider heterosexual population, and that the risk of a surgeon acquiring HIV occupationally is extremely low in a city which has an HIV prevalence similar to or greater than that seen in most other parts of the United Kingdom. Large numbers of residual specimens from busy biochemistry laboratories can be processed for unlinked anonymous testing without interfering with the laboratories' routine functions. This survey approach might be best suited to monitoring HIV trends in developing countries with relatively high prevalence rates and where transmission is principally heterosexual.

Adolescent↗
PubMed2000

Immunological tolerance to inhaled antigen.

Regulatory mechanisms exist in the immune system to limit the induction of pathogenic responses to antigens encountered within the respiratory tract. The development of allergic disease is thought to arise as a result of the breakdown in these regulatory processes. In this review we examine the nature of immune responses generated to inhaled protein antigens and the mechanisms used to establish tolerance to inhaled antigens.

Antigens↗
PubMed2000

Abdominal aortic aneurysm rupture following endoluminal graft deployment: report of a predictable event.

PURPOSE: To describe the predictability of an abdominal aortic aneurysm (AAA) rupture secondary to a type II endoleak following stent-graft exclusion. METHODS AND RESULTS: An 81-year-old man with an enlarging AAA underwent endovascular repair using an AneuRx aortic stent-graft, but a type II endoleak fed by an accessory renal artery was detected at postprocedural computed tomography (CT). Surveillance CT scans at 6 and 16 months showed an increase in the aneurysm diameter and endoleak volume, but the patient refused advised treatment to close the leak. He suffered a fatal aneurysm rupture 24 months after endografting. Retrospective analysis of CT data documented progressive aneurysm enlargement that correctly predicted the rupture. CONCLUSIONS: Type II endoleaks can lead to aneurysm rupture. Three-dimensional (3D) spiral CT angiography offers an opportunity to track endoleak volume and the effect of exposure to systemic pressure on the aneurysm sac.

Aged↗
PubMed2000

Use of complementary/alternative medicine by breast cancer survivors in Ontario: prevalence and perceptions.

PURPOSE: To determine the prevalence of use of complementary/alternative medicine (CAM) by breast cancer survivors in Ontario, Canada, and to compare the characteristics of CAM users and CAM nonusers. PATIENTS AND METHODS: A questionnaire was mailed to a random sample of Ontario women diagnosed with breast cancer in 1994 or 1995. RESULTS: The response rate was 76.3%. Overall, 66.7% of the respondents reported using CAM, most often in an attempt to boost the immune system. CAM practitioners (most commonly chiropractors, herbalists, acupuncturists, traditional Chinese medicine practitioners, and/or naturopathic practitioners) were visited by 39.4% of the respondents. In addition, 62.0% reported use of CAM products (most frequently vitamins/minerals, herbal medicines, green tea, special foods, and essiac). Almost one half of the respondents informed their physicians of their use of CAM. Multiple logistic regression analysis determined that support group attendance was the only factor significantly associated with CAM use. CONCLUSION: CAM use is common among Canadian breast cancer survivors, many of whom are discussing CAM therapy options with their physicians. Knowledge of CAM therapies is necessary for physicians and other health care practitioners to help patients make informed choices. CAM use may play a role in the positive benefits associated with support group attendance.

Attitude↗