913 resultados para resident
Resumo:
This study examined the impact of the Nursing Home Reform Act of 1987 on resident-and-facility-level risk factors for physical restraint use in nursing homes. Data on the 1990 and 1993 cohorts were obtained from 268 facilities in 10 states, and data on a 1996 cohort were obtained from the Medical Expenditure Panel Survey, which sampled more than 800 nursing homes nationwide. Multivariate logistic regression models were generated for each cohort to identify the impact of resident- and facility-level risk factors for restraint use. The results indicate that the use of physical restraints continues to decline. Thirty-six percent of the 1990 cohort, 26 percent of the 1993 cohort, and 17 percent of the 1996 cohort were physically restrained. Although there was a reduced rate of restraint use from 1990 to 1996, similar resident-level factors but different facility-level factors were associated with restraint use at different points in time.
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Intestinal bacteria outnumber our own human cells in conditions of both health and disease. It has long been recognized that secretory antibody, particularly IgA, is produced in response to these microbes and hypothesized that this must play an important role in defining the relationship between a host and its intestinal microbes. However, the exact role of IgA and the mechanisms by which IgA can act are only beginning to be understood. In this review we attempt to unravel the complex interaction between so-called "natural," "primitive" (T-cell-independent), and "classical" IgA responses, the nature of the intestinal microbiota/intestinal pathogens and the highly flexible dynamic homeostasis of the mucosal immune system. Such an analysis reveals that low-affinity IgA is sufficient to protect the host from excess mucosal immune activation induced by harmless commensal microbes. However, affinity-maturation of "classical" IgA is essential to provide protection from more invasive commensal species such as segmented filamentous bacteria and from true pathogens such as Salmonellatyphimurium. Thus a correlation is revealed between "sophistication" of the IgA response and aggressiveness of the challenge. A second emerging theme is that more-invasive species take advantage of host inflammatory mechanisms to more successfully compete with the resident microbiota. In many cases, the function of IgA may be to limit such inflammatory responses, either directly by coagulating or inhibiting virulence of bacteria before they can interact with the host or by modulating immune signaling induced by host recognition. Therefore IgA appears to provide an added layer of robustness in the intestinal ecosystem, promoting "commensal-like" behavior of its residents.
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The large numbers of microorganisms that inhabit mammalian body surfaces have a highly coevolved relationship with the immune system. Although many of these microbes carry out functions that are critical for host physiology, they nevertheless pose the threat of breach with ensuing pathologies. The mammalian immune system plays an essential role in maintaining homeostasis with resident microbial communities, thus ensuring that the mutualistic nature of the host-microbial relationship is maintained. At the same time, resident bacteria profoundly shape mammalian immunity. Here, we review advances in our understanding of the interactions between resident microbes and the immune system and the implications of these findings for human health.
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Piroplasmosis has been identified as a possible cause of mortality in reintroduced Przewalski's horses (Equus ferus przewalskii) in the Dsungarian Gobi (Mongolia). A cross-sectional and a longitudinal study were conducted in a representative sample (n = 141) of the resident domestic horse population and in 23 Przewalski's horses to assess the prevalence of Theileria equi and Babesia caballi. Piroplasms were detected in blood by light microscopy in 6.7% (95% confidence interval [CI]: 3.6-12.2%) of the domestic horse samples. Antibody prevalence was 88.6% (95% CI: 82.4-92.9%) for T. equi and 75.2% (95% CI: 67.4-81.6%) for B. caballi. Antibody prevalence did not change over time, but antibody prevalence for both piroplasms were significantly lower in animals less than 1 yr of age. For both piroplasms, the prevalence of presumably maternal antibodies (falling titers) in foals was 100%. Only one of 16 foals seroconverted against T. equi during the study period, despite that piroplasms were found in two other individuals. The incidence density (ID) of T. equi in foals was therefore 0.0012 seroconversions per horse day (95% CI: 0.00029-0.0057). In contrast, yearlings had an ID of 0.0080 (95% CI: 0.0049-0.010) for T. equi and 0.0064 (95% CI: 0.0036-0.0093) for B. caballi, and in seven individuals piroplasms were detected. The seroprevalence of both piroplasms rose from 20% in spring to 100% in autumn. Comparison of domestic and Przewalski's horses resulted in a standardized prevalence ratio (SPR) of 0.98 (95% CI: 0.80-1.24, not significant) for B. caballi; in contrast, the prevalence of T. equi in Przewalski's horses was significantly lower than expected (SPR = 0.51, 95% CI: 0.50-0.64).
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BACKGROUND: In general cantons regulate and control the Swiss health service system; patient flows within and between cantons are thereby partially disregarded. This paper develops an alternative spatial model, based upon the construction of orthopedic hospital service areas (HSAOs), and introduces indices for the analysis of patient streams in order to identify areas, irrespective of canton, with diverse characteristics, importance, needs, or demands. METHODS: HSAOs were constructed using orthopedic discharge data. Patient streams between the HSAOs were analysed by calculating three indices: the localization index (% local residents discharged locally), the netindex (the ratio of discharges of nonlocal incoming residents to outgoing local residents), and the market share index (% of local resident discharges of all discharges in local hospitals). RESULTS: The 85 orthopedic HSAOs show a median localization index of 60.8%, a market share index of 75.1%, and 30% of HSAOs have a positive netindex. Insurance class of bed, admission type, and patient age are partially but significantly associated with those indicators. A trend to more centrally provided health services can be observed not only in large urban HSAOs such as Geneva, Bern, Basel, and Zurich, but also in HSAOs in mountain sport areas such as Sion, Davos, or St.Moritz. Furthermore, elderly and emergency patients are more frequently treated locally than younger people or those having elective procedures. CONCLUSION: The division of Switzerland into HSAOs provides an alternative spatial model for analysing and describing patient streams for health service utilization. Because this small area model allows more in-depth analysis of patient streams both within and between cantons, it may improve support and planning of resource allocation of in-patient care in the Swiss healthcare system.
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Folliculo-stellate cells are a nonendocrine, sustentacular-like complementary population of the anterior pituitary. They currently are considered as functionally and phenotypically heterogeneous, with one subpopulation of folliculo-stellate cells possibly representing resident adenohypophyseal macrophages. We took advantage of a limited T-cell mediated inflammatory reaction selectively involving tumor tissue in three cases of pituitary adenoma (2 prolactin cell adenomas, and 1 null cell adenoma) to test the hypothesis whether some folliculo-stellate cells within inflammatory foci would also assume monocytic/dendritic properties. Immunohistochemical double labeling for S-100 protein and the class II major histocompatibility antigen HLA-DR indeed showed several arborized cells to coexpress both epitopes. These were distributed both amidst adenomatous acini and along intratumoral vessels, and were morphologically undistinguishable from conventional folliculo-stellate cells. On the other hand, markers of follicular dendritic cells (CD21) and Langerhans' cells (CD1a) tested negative. Furthermore, no S-100/HLA-DR coexpressing folliculo-stellate cells were seen in either peritumoral parenchyma of the cases in point nor in control pituitary adenomas lacking inflammatory reaction. These findings suggest that a subset of folliculo-stellate cells may be induced by an appropriate local inflammatory microenvironment to assume a dendritic cell-like immunophenotype recognizable by their coexpression of S-100 protein and HLA-DR. By analogy with HLA-DR expressing cells in well-established extrapituitary inflammatory constellations, we speculate that folliculo-stellate cells with such immunophenotype may actually perform professional antigen presentation. A distinctly uncommon finding in pituitary adenomas, lymphocytic infiltrates may therefore be read as a manifestation of tumoral immunosurveillance.
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In experimental bacterial meningitis, matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) contribute to brain damage. MMP-9 increases in cerebrospinal fluid (CSF) during bacterial meningitis and is associated with the brain damage that is a consequence of the disease. This study assesses the origin of MMP-9 in bacterial meningitis and how ROS modulate its activity. Rat brain-slice cultures and rat polymorphonuclear cells (PMNs) that had been challenged with capsule-deficient heat-inactivated Streptococcus pneumoniae R6 (hiR6) released MMP-9. Coincubation with either catalase, with the myeloperoxidase inhibitor azide, or with the hypochlorous acid scavenger methionine almost completely prevented activation, but not the release, of MMP-9, in supernatants of human PMNs stimulated with hiR6. Thus, in bacterial meningitis, both brain-resident cells and invading PMNs may act as sources of MMP-9, and stimulated PMNs may activate MMP-9 via an ROS-dependent pathway. MMP-9 activation by ROS may represent a target for therapeutic intervention in bacterial meningitis.
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PURPOSE: Understanding the learning styles of individuals may assist in the tailoring of an educational program to optimize learning. General surgery faculty and residents have been characterized previously as having a tendency toward particular learning styles. We seek to understand better the learning styles of general surgery residents and differences that may exist within the population. METHODS: The Kolb Learning Style Inventory was administered yearly to general surgery residents at the University of Cincinnati from 1994 to 2006. This tool allows characterization of learning styles into 4 groups: converging, accommodating, assimilating, and diverging. The converging learning style involves education by actively solving problems. The accommodating learning style uses emotion and interpersonal relationships. The assimilating learning style learns by abstract logic. The diverging learning style learns best by observation. Chi-square analysis and analysis of variance were performed to determine significance. RESULTS: Surveys from 1994 to 2006 (91 residents, 325 responses) were analyzed. The prevalent learning style was converging (185, 57%), followed by assimilating (58, 18%), accommodating (44, 14%), and diverging (38, 12%). At the PGY 1 and 2 levels, male and female residents differed in learning style, with the accommodating learning style being relatively more frequent in women and assimilating learning style more frequent in men (Table 1, p < or = 0.001, chi-square test). Interestingly, learning style did not seem to change with advancing PGY level within the program, which suggests that individual learning styles may be constant throughout residency training. If a resident's learning style changed, it tended to be to converging. In addition, no relation exists between learning style and participation in dedicated basic science training or performance on the ABSIT/SBSE. CONCLUSIONS: Our data suggests that learning style differs between male and female general surgery residents but not with PGY level or ABSIT/SBSE performance. A greater understanding of individual learning styles may allow more refinement and tailoring of surgical programs.
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Tubulo-interstitial fibrosis is a constant feature of chronic renal failure and it is suspected to contribute importantly to the deterioration of renal function. In the fibrotic kidney there exists, besides normal fibroblasts, a large population of myofibroblasts, which are supposedly responsible for the increased production of intercellular matrix. It has been proposed that myofibroblasts in chronic renal failure originate from the transformation of tubular cells via epithelial-mesenchymal transition (EMT) or from infiltration by bone marrow-derived precursors. Little attention has been paid to the possibility of a transformation of resident fibroblasts into myofibroblasts in renal fibrosis. Therefore we examined the fate of resident fibroblasts in the initial phase of renal fibrosis in the classical model of unilateral ureter obstruction (UUO) in the rat. Rats were perfusion-fixed on days 1, 2, 3 and 4 after ligature of the right ureter. Starting from 1 day of UUO an increasing expression of alpha-smooth muscle actin (alphaSMA) in resident fibroblasts was revealed by immunofluorescence and confirmed by the observation of bundles of microfilaments and webs of intermediate filaments in the electron microscope. Inversely, there was a decreased expression of 5'-nucleotidase (5'NT), a marker of renal cortical fibroblasts. The RER became more voluminous, suggesting an increased synthesis of matrix. Intercellular junctions, a characteristic feature of myofibroblasts, became more frequent. The mitotic activity in fibroblasts was strongly increased. Renal tubules underwent severe regressive changes but the cells retained their epithelial characteristics and there was no sign of EMT. In conclusion, after ureter ligature, resident peritubular fibroblasts proliferated and they showed progressive alterations, suggesting a transformation in myofibroblasts. Thus the resident fibroblasts likely play a central role in fibrosis in that model.
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The vitamin A metabolite retinoic acid (RA) plays a fundamental role in cellular functions by activating nuclear receptors. Retinaldehyde dehydrogenase-II (RALDH2) creates localized RA gradients needed for proper embryonic development, but very little is known regarding its regulated expression in adults. Using a human ex vivo model of allergic inflammation by coincubating IgE receptor-activated mast cells (MCs) with blood basophils, we observed prominent induction of a protein that was identified as RALDH2 by mass spectroscopy. RALDH2 was selectively induced in basophils by MC-derived interleukin-3 (IL-3) involving PI3-kinase and NF-kappaB pathways. Importantly, neither constitutive nor inducible RALDH2 expression was detectable in any other human myeloid or lymphoid leukocyte, including dendritic cells. RA generated by RALDH2 in basophils modulates IL-3-induced gene expression in an autocrine manner, providing positive (CD25) as well as negative (granzyme B) regulation. It also acts in a paracrine fashion on T-helper cells promoting the expression of CD38 and alpha4/beta7 integrins. Furthermore, RA derived from IL-3-activated basophils provides a novel mechanism of Th2 polarization. Thus, RA must be viewed as a tightly controlled basophil-derived mediator with a high potential for regulating diverse functions of immune and resident cells in allergic diseases and other Th2-type immune responses.
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A supply of so-called "copper pitch" ore was received by the Montana Bureau of Mines and Geology in response to a request by them from a resident of Kalispell, who had previously sent a specimen to the Bureau for a mineralogical analysis. Since this material was little known and had apparently received but little study under a reflecting microscope, it was thought that such a study might throw some light on the mineralogical and chemical composition of the material.
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Intestinal intraepithelial lymphocytes (IEL) are specialized subsets of T cells with distinct functional capacities. While some IEL subsets are circulating, others such as CD8alphaalpha TCRalphabeta IEL are believed to represent non-circulating resident T cell subsets [Sim, G.K., Intraepithelial lymphocytes and the immune system. Adv. Immunol., 1995. 58: 297-343.]. Current methods to obtain enriched preparations of intraepithelial lymphocytes are mostly based on Percoll density gradient or magnetic bead-based technologies [Lundqvist, C., et al., Isolation of functionally active intraepithelial lymphocytes and enterocytes from human small and large intestine. J. Immunol. Methods, 1992. 152(2): 253-263.]. However, these techniques are hampered by a generally low yield of isolated cells, and potential artifacts due to the interference of the isolation procedure with subsequent functional assays, in particular, when antibodies against cell surface markers are required. Here we describe a new method for obtaining relatively pure populations of intestinal IEL (55-75%) at a high yield (>85%) by elutriation centrifugation. This technique is equally suited for the isolation and enrichment of intraepithelial lymphocytes of both mouse and human origin. Time requirements for fractionating cell suspensions by elutriation centrifugation are comparable to Percoll-, or MACS-based isolation procedures. Hence, the substantially higher yield and the consistent robust enrichment for intraepithelial lymphocytes, together with the gentle treatment of the cells during elutriation that does not interfere with subsequent functional assays, are important aspects that are in favor of using this elegant technology to obtain unmanipulated, unbiased populations of intestinal intraepithelial lymphocytes, and, if desired, also of pure epithelial cells.
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In the intestinal tract, only a single layer of epithelial cells separates innate and adaptive immune effector cells from a vast amount of antigens. Here, the immune system faces a considerable challenge in tolerating commensal flora and dietary antigens while preventing the dissemination of potential pathogens. Failure to tightly control immune reactions may result in detrimental inflammation. In this respect, 'conventional' regulatory CD4(+) T cells, including naturally occurring and adaptive CD4(+) CD25(+) Foxp3(+) T cells, Th3 and Tr1 cells, have recently been the focus of considerable attention. However, regulatory mechanisms in the intestinal mucosa are highly complex, including adaptations of nonhaematopoietic cells and innate immune cells as well as the presence of unconventional T cells with regulatory properties such as resident TCRgammadelta or TCRalphabeta CD8(+) intraepithelial lymphocytes. This review aims to summarize the currently available knowledge on conventional and unconventional regulatory T cell subsets (Tregs), with special emphasis on clinical data and the potential role or malfunctioning of Tregs in four major human gastrointestinal diseases, i.e. inflammatory bowel diseases, coeliac disease, food allergy and colorectal cancer. We conclude that the clinical data confirms some but not all of the findings derived from experimental animal models.
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PURPOSE: The aim of this study was to evaluate ECG-gated whole chest CTA as a routine triage tool for patients with acute chest pain. MATERIAL AND METHODS: Whole chest CTA with retrospective ECG-gating was performed in 30 patients with acute atypical chest pain. The ten main segments of the coronary arteries, the pulmonary arteries, the aorta, and the myocardium (function, morphology) were independently analyzed by a resident and two senior radiologists. The inter-observer agreement between resident and senior radiologists was calculated. A final diagnosis was determined by consensus. RESULTS: Thirty patients were included. The coronary artery segments, myocardium and pulmonary arteries were considered analyzable in 84%, 90% and 97% of cases respectively. A final diagnosis for the cause of pain was retained in 19 patients: significant coronary artery stenosis (5), pulmonary embolus (5), aortic dissection (1), hypokinetic cardiomyopathy (2), lung parenchymal abnormalities (5), and hiatus hernia (1). Inter-observer agreement ranged from 0.76 to 1 between senior radiologists and from 0.76 to 1 between resident and senior radiologists. The average time of image interpretation ranged from 14 to 15 minutes. CONCLUSION: ECG-gated whole chest CT angiography appears as a promising tool for the evaluation of acute chest pain. Combined evaluation of appearance and function of the myocardium can reveal additional interesting information.
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Phagocytosis of fine particles (1 mum) by macrophages is a ligand-receptor-mediated, actin-based process, whereas the entering of smaller particles (= 0.2 mum) in macrophages occurs also by other mechanisms. Virosomes with a diameter of 0.12-0.18 mum are widely used as carrier systems for drugs, vectors, and plasmids in cancer therapy or for vaccines. We investigated their interactions with airway cells, in particular penetration into monocyte-derived macrophages. The microscopic analysis of phagocytic cells incubated with virosomes and polystyrene particles showed that virosomes and particles penetrated cells even in the presence of cytochalasin D, a drug inhibiting actin-based phagocytosis. The charge of the virosomes and particles did not influence their penetration. Also, different inhibitors of endocytotic pathways did not prevent the particles and virosomes from penetrating into the cells. Additionally, to study the ability of virosomes to overcome the epithelial airway barrier, a triple cell co-culture model composed of epithelial cells, monocyte-derived macrophages and dendritic cells of the respiratory tract was used. We found virosomes and polystyrene particles in both populations of antigen-presenting cells, monocyte-derived macrophages, and dendritic cells, in the latter even if they were not directly exposed. In conclusion, virosomes are readily taken up by monocyte-derived macrophages, both by conventional phagocytosis and by actin-independent mechanisms. Further, they can penetrate the airway barrier and reach resident dendritic cells. Therefore, virosomes are promising vaccine candidates.