916 resultados para shift-share
Resumo:
Objectives: To assess temporal trends in the incidence of surgical procedures for peripheral occlusive arterial disease (POAD) and associated changes in outcome as measured by the rate of major lower limb amputations for POAD. Design: a retrospective descriptive population-based study was conducted of the geographically isolated population of Western Austrialia between 1980 and 1992. Methods: Vascular procedures with an accompanying diagnosis of POAD were identified in a computerised system of name-identified records of all discharges from hospital for the population. These procedures were detected using relevant codes from the International Classification of Disease and Procedures. Records of angioplasty and thrombolysis procedures were augmented by searches of hospital-based registers of invasive radiological procedures. The data for the remaining procedures were validated by a review of a random sample of medical records. Results: over the 13 years of the study, rates of major amputations fell significantly for in non-amputation vascular surgery for individuals under the age of 60. In addition, rather than an overall rise in surgery there was shift away from sympathectomy and thromboendarterectomy to angioplasty and bypass surgery. Furthermore, an increasing proportion of all major amputations had a prior attempt at arterial reconstruction. Conclusion: These observations suggest the decrease in major amputations for POAD may reflect a fall in the incidence of POAD, possibly aided by move effective surgery, rather than increased rates of vascular surgery.
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Mechanisms of leukocyte NADPH oxidase regulation remain actively investigated. We showed previously that vascular and macrophage oxidase complexes are regulated by the associated redox chaperone PDI. Here, we investigated the occurrence and possible underlying mechanisms of PDI-mediated regulation of neutrophil NADPH oxidase. In a semirecombinant cell-free system, PDI inhibitors scrRNase (100 mu g/mL) or bacitracin (1 mM) near totally suppressed superoxide generation. Exogenously incubated, oxidized PDI increased (by similar to 40%), whereas PDIred diminished (by similar to 60%) superoxide generation. No change occurred after incubation with PDI serine-mutated in all four redox cysteines. Moreover, a mimetic CxxC PDI inhibited superoxide production by similar to 70%. Thus, oxidized PDI supports, whereas reduced PDI down-regulates, intrinsic membrane NADPH oxidase complex activity. In whole neutrophils, immunoprecipitation and colocalization experiments demonstrated PDI association with membrane complex subunits and prominent thiol-mediated interaction with p47(phox) in the cytosol fraction. Upon PMA stimulation, PDI was mobilized from azurophilic granules to cytosol but did not further accumulate in membranes, contrarily to p47(phox). PDI-p47(phox) association in cytosol increased concomitantly to opposite redox switches of both proteins; there was marked reductive shift of cytosol PDI and maintainance of predominantly oxidized PDI in the membrane. Pulldown assays further indicated predominant association between PDIred and p47(phox) in cytosol. Incubation of purified PDI (> 80% reduced) and p47(phox) in vitro promoted their arachidonate-dependent association. Such PDI behavior is consistent with a novel cytosolic regulatory loop for oxidase complex (re) cycling. Altogether, PDI seems to exhibit a supportive effect on NADPH oxidase activity by acting as a redox-dependent enzyme complex organizer. J. Leukoc. Biol. 90: 799-810; 2011.
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Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of diseases that share some symptoms such as muscular weakness and inflammation of skeletal muscle. Complete recovery of muscle function with pharmacological treatment does not always occur, suggesting that physical inability is a great concern for these patients. In this context, it has been speculated that physical exercise could result in functional benefits to patients with IIM, leading to an improvement in quality of life. In fact, recent studies of polymyositis (PM) and dermatomyositis (DM) support the notion that exercise training improves or at least stabilizes muscle strength and functional ability without inducing disease flares. Importantly, these benefits were observed not only during the chronic phase, but also in the course of active disease. This positive effect was found to be long term, as demonstrated by a six-month significant improvement in exercise capacity and strength. Together, these findings indicate that a well controlled exercise program can be recommended for patients with DM and PM. The optimal exercise modality training and the underlying mechanism for this encouraging response remain to be determined in future studies. (C) 2008 Elsevier B.V. All rights reserved.
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The regulation of putrescine transport in difluoromethylornithine-treated B16 melanoma cells by extracellular Ca2+ has been investigated. It was found that physiological concentrations of Ca2+ were essential for optimum uptake of putrescine and spermidine. Mg2+, albeit at higher concentrations, also could potentiate polyamine transport. The maximum rate of putrescine uptake increased from 1698 +/-: 67 pmol/min/mg DNA in the absence of Ca2+ to 3100 +/- 98 pmol/min/mg DNA in the presence of 0.5 mM Ca2+. There was no change in K-m. While Ca2+ enhanced transport of both putrescine and spermidine it did not affect the uptake of deoxyglucose, thymidine or leucine. Putrescine did not alter Ca2+ fluxes suggesting that the two cations do not share a common transport system. The effects of Ca2+ on putrescine uptake appeared to be mediated extracellularly firstly because Ca2+ did not potentiate putrescine uptake in the presence of A23187 and secondly, because the effects of Ca2+ were completely inhibited by the lanthanide Tb3+, which binds to calcium-dependent proteins and does not readily cross biological membranes. Ca2+ did not affect putrescine transport in the absence of extracellular Na+. Moreover, the rate of putrescine uptake in the absence of Ca2+ was similar to that in the absence of extracellular Na+. The results from this study indicate that polyamine transport is stimulated by extracellular Ca2+ and suggest that Ca2+ is required for activity of the Na+-dependent transporter only. This transporter appears to possess a regulatory binding site for divalent cations. (C) 1997 Elsevier Science Ltd.
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A postal survey was conducted of all hospitals in Australia known to have a department of anaesthesia and an intensive care or high dependency unit. Each hospital was asked to report the anaesthetic and postoperative analgesic techniques used for the last ten cases of four common major surgical procedures-aorto-femoral bypass, repair of an abdominal aortic aneurysm, hemicolectomy and anterior resection of the rectum. Half of 76 hospitals sent a survey form completed and returned it. Responding hospitals were larger on average, than non-responding ones, but otherwise typical of them in terms of university affiliation and metropolitan versus rural location. For each of the procedures studied the proportion of cases in which epidural block was used intra- or postoperatively varied from 0% to 100%. Depending on the procedure, between 65% and 85% of hospitals used epidural block sometimes, with between 10% and 90% of patients in these hospitals being managed with this technique. There is wide variation in the use of epidural block, intra- and postoperatively, in Australia, variation that is unlikely to be explained by systematic differences between institutions in the patients seen or their suitability for one or other technique. This pattern of practice mirrors the lack of agreement about the proper place for epidural techniques evident in the recent literature. There is a widespread belief among clinicians that this is a question of great importance. Accordingly, we believe that anaesthetists and surgeons share an ethical responsibility to enter suitable patients in an appropriately designed randomized controlled trial in order to resolve this question.
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Background: Galectin-3 is a lectin that presents pivotal roles in tumor biology and there are no studies evaluating their expression in dysplasias and carcinomas developed from tongue carcinogenesis models. Aims: To investigate the role of galectin-3 in the development of tongue carcinomas using a mouse model of oral carcinogenesis. Methods: Galectin-3-deficient (gal3(-/-)) and wild-type (gal3(+/+)) mice were challenged with 4-nitroquinoline-1-oxide in drinking water for 16 weeks and killed at different times. Tongues were removed and the number of dysplasias and carcinomas was counted. An immunohistochemical study for galectin-3 was performed only in the tongue from gal3(+/+) mice. Results: In both groups, a reduction of dysplasias and an increase of carcinomas from week 16 to week 32 (p > 0.05) were observed. A predominance of high cytoplasmic and nuclear galectin-3 expression was observed in carcinomas (64.7%) and dysplasias (55.5%), respectively (p > 0.05). The perilesional areas always presented a statistical cytoplasmic and nuclear galectin-3 overexpression. Conclusions: Absence of galectin-3 did not directly affect the process of carcinogenesis and a cytoplasm shift of galectin-3 seems to be associated with development of tongue carcinomas. (C) 2010 Elsevier Inc. All rights reserved.
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Purpose We investigated the efficacy of fluorouracil (FU), leucovorin, irinotecan, and bevacizumab (FOLFIRI + B) in a phase II trial in patients previously untreated for metastatic colorectal cancer (mCRC), and changes during treatment in plasma cytokines and angiogenic factors (CAFs) as potential markers of treatment response and therapeutic resistance. Patients and Methods We conducted a phase II, two-institution trial of FOLFIRI + B. Each 14-day cycle consisted of bevacizumab (5 mg/kg), irinotecan (180 mg/m(2)), bolus FU (400 mg/m(2)), and leucovorin (400 mg/m(2)) followed by a 46-hour infusion of FU (2,400 mg/m(2)). Levels of 37 CAFs were assessed using multiplex-bead assays and enzyme-linked immunosorbent assay at baseline, during treatment, and at the time of progressive disease (PD). Results Forty-three patients were enrolled. Median progression-free survival (PFS), the primary end point of the study, was 12.8 months. Median overall survival was 31.3 months, with a response rate of 65%. Elevated interleukin-8 at baseline was associated with a shorter PFS (11 v 15.1 months, P = .03). Before the radiographic development of PD, several CAFs associated with angiogenesis and myeloid recruitment increased compared to baseline, including basic fibroblast growth factor (P = .046), hepatocyte growth factor (P = .046), placental growth factor (P < .001), stromal-derived factor-1 (P = .04), and macrophage chemoattractant protein-3 (P < .001). Conclusion Efficacy and tolerability of FOLFIRI + B appeared favorable to historical controls in this single arm study. Before radiographic progression, there was a shift in balance of CAFs, with a rise in alternate pro-angiogenic cytokines and myeloid recruitment factors in subsets of patients that may represent mechanisms of resistance.
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The Egr proteins, Egr-1, Egr-2, Egr-3 and Egr-4, are closely related members of a subclass of immediate early gene-encoded, inducible transcription factors. They share a highly homologous DNA-binding domain which recognises an identical DNA response element. In addition, they have several less-well conserved structural features in common. As immediate early proteins, the Egr transcription factors are rapidly induced by diverse extracellular stimuli within the nervous system in a discretely controlled manner. The basal expression of the Egr proteins in the developing and adult rat brain and the induction of Egr proteins by neurotransmitter analogue stimulation, physiological mimetic and brain injury paradigms is reviewed. We review evidence indicating that Egr proteins are subject to tight differential control through diverse mechanisms at several levels of regulation. These include transcriptional, translational and posttranslational (including glycosylation, phosphorylation and redox) mechanisms and protein-protein interaction. Ultimately the differentially co-ordinated Egr response may lead to discrete effects on target gene expression. Some of the known target genes of Egr proteins and functions of the Egr proteins in different cell types are also highlighted. Future directions for research into the control and function of the different Egr proteins are also explored. (C) 1997 Elsevier Science Ltd.
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The use of cell numbers rather than mass to quantify the size of the biotic phase in animal cell cultures causes several problems. First, the cell size varies with growth conditions, thus yields expressed in terms of cell numbers cannot be used in the normal mass balance sense. Second, experience from microbial systems shows that cell number dynamics lag behind biomass dynamics. This work demonstrates that this lag phenomenon also occurs in animal cell culture. Both the lag phenomenon and the variation in cell size are explained using a simple model of the cell cycle. The basis for the model is that onset of DNA synthesis requires accumulation of G1 cyclins to a prescribed level. This requirement is translated into a requirement for a cell to reach a critical size before commencement of DNA synthesis. A slower gl-owing cell will spend more time in G1 before reaching the critical mass. In contrast, the period between onset of DNA synthesis and mitosis, tau(B), is fixed. The two parameters in the model, the critical size and tau(B), were determined from eight steady-state measurements of mean cell size in a continuous hybridoma culture. Using these parameters, it was possible to predict with reasonable accuracy the transient behavior in a separate shift-up culture, i.e., a culture where cells were transferred from a lean environment to a rich environment. The implications for analyzing experimental data for animal cell culture are discussed. (C) 1997 John Wiley & Sons, Inc.
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In this study, hypotheses were tested that the quality of leader-member exchanges (LMX) depends on congruity of values between leader and member. Data on negotiating latitude and personal values were gathered from 160 members of 30 work groups in Australian organizations. Factor analysis revealed 5 value dimensions: Freedom, Achievement, Mateship, Obedience, and Coping. Analyses of variance supported the hypothesis that LMX quality is higher when leaders and members share achievement and obedience values. Subsequent exploratory analysis, however, indicated that a more complex model based on compatibility of leader authority and member affiliation values may provide a more complete representation.
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Context: It has been reported that childhood psychotic symptoms are common in the general population and may signal neurodevelopmental processes that lead to schizophrenia. However, it is not clear whether these symptoms are associated with the same extensive risk factors established for adult schizophrenia. Objective: To examine the construct validity of children`s self-reported psychotic symptoms by testing whether these symptoms share the risk factors and clinical features of adult schizophrenia. Design: Prospective, longitudinal cohort study of a nationally representative birth cohort in Great Britain. Participants: A total of 2232 twelve-year-old children followed up since age 5 years ( retention, 96%). Main Outcome Measure: Children`s self-reported hallucinations and delusions. Results: Children`s psychotic symptoms are familial and heritable and are associated with social risk factors (eg, urbanicity); cognitive impairments at age 5; home-rearing risk factors ( eg, maternal expressed emotion); behavioral, emotional, and educational problems at age 5; and comorbid conditions, including self-harm. Conclusions: The results provide a comprehensive picture of the construct validity of children`s self-reported psychotic symptoms. For researchers, the findings indicate that children who have psychotic symptoms can be recruited for neuroscience research to determine the pathogenesis of schizophrenia. For clinicians, the findings indicate that psychotic symptoms in childhood are often a marker of an impaired developmental process and should be actively assessed.
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Human immunodeficiency virus type 1 (HIV-1) and human T-cell lymphotropic virus types 1 and 2 (HTLV-1 and -2) are retroviruses that share similar routes of transmission and some individuals may have a dual infection. These co-infected subjects may be at increased risk for tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM)-like. To study the prevalence of tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM) among coinfected HIV-1/HTLV-1 subjects. Since July 1997, our group has been following a cohort to study the interaction of HTLV with HIV and/or hepatitis C virus (HCV), as well as HTLV-1-only infected asymptomatic carriers or those already presenting with TSP/HAM. During these 9 years, 296 HTLV-1-infected individuals were identified from a total of 538 patients who were referred to our clinic at the Institute of Infectious Diseases ""Emilio Ribas,"" in Sao Paulo, Brazil. All subjects were evaluated by two neurologists, blinded to the HTLV status. TSP/HAM diagnosis was based on Kagoshima diagnostic criteria. Results: A total of 38 HIV-1/HTLV-1 co-infected subjects were identified in this cohort: Twenty-six had already been diagnosed with AIDS and 12 remained asymptomatic. Six of 38 co-infected subjects (18%) were diagnosed as having TSP/HAM and also AIDS, and for 5 of them TSP/HAM was their first illness. One additional incident case was diagnosed after 2 years of follow-up. No modifications on HIV-1 viral load was seen. In contrast, the co-infected with TSP/HAM-like group showed higher HTLV-1 proviral load (505 +/- 380 vs. 97 +/- 149 copies/10(4) PBMC, P= 0.012) than asymptomatic co-infected subjects, respectively. The incidence of myelopathy among HIV-1/HTLV-1 co-infected subjects is probably higher than among patients infected only with HTLV-1, and related to a higher HTLV-1 proviral load. Thus, HTLV-1/2 screening should be done for all HIV-1-infected patients in areas where HTLV-1 infection is endemic.
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The present study aims at the use of Raman spectroscopy in the quantification of unsaturated fats in fat-containing foods, compared to the information available in the Nutritional Table, to obtain a non-destructive optical quantification of unsaturation. Raman spectra of edible oil, margarine, mayonnaise, hydrogenated fat, and butter were obtained with a near-infrared Raman spectrometer (830nm). By analyzing selected bands in the regions of 1750, 1660, 1440, 1300, and 1260cm-1, the amount of total and unsaturated fat of samples of oil, margarine, and mayonnaise were correlated with the information displayed in the Nutritional Table. The amount of unsaturated trans fat in selected samples was correlated to the Raman shift of 1660cm-1. Dispersive Raman spectroscopy was shown to be effective in quantifying the unsaturated fats in oil, margarine, and mayonnaise, and trans fat in hydrogenated oils and butter.
Resumo:
Many eukaryotic proteins are posttranslationally modified by the esterification of cysteine thiols to long-chain fatty acids. This modification, protein palmitoylation, is catalyzed by a large family of palmitoyl acyltransferases that share an Asp-His-His-Cys Cys-rich domain but differ in their subcellular localizations and substrate specificities. In Trypanosoma brucei, the flagellated protozoan parasite that causes African sleeping sickness, protein palmitoylation has been observed for a few proteins, but the extent and consequences of this modification are largely unknown. We undertook the present study to investigate T. brucei protein palmitoylation at both the enzyme and substrate levels. Treatment of parasites with an inhibitor of total protein palmitoylation caused potent growth inhibition, yet there was no effect on growth by the separate, selective inhibition of each of the 12 individual T. brucei palmitoyl acyltransferases. This suggested either that T. brucei evolved functional redundancy for the palmitoylation of essential palmitoyl proteins or that palmitoylation of some proteins is catalyzed by a noncanonical transferase. To identify the palmitoylated proteins in T. brucei, we performed acyl biotin exchange chemistry on parasite lysates, followed by streptavidin chromatography, two-dimensional liquid chromatography-tandem mass spectrometry protein identification, and QSpec statistical analysis. A total of 124 palmitoylated proteins were identified, with an estimated false discovery rate of 1.0%. This palmitoyl proteome includes all of the known palmitoyl proteins in procyclic-stage T. brucei as well as several proteins whose homologues are palmitoylated in other organisms. Their sequences demonstrate the variety of substrate motifs that support palmitoylation, and their identities illustrate the range of cellular processes affected by palmitoylation in these important pathogens.
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Study Objectives: Metabolic syndrome (MetSyn) increases overall cardiovascular risk. MetSyn is also strongly associated with obstructive sleep apnea (OSA), and these 2 conditions share similar comorbidities. Whether OSA increases cardiovascular risk in patients with the MetSyn has not been investigated. We examined how the presence of USA in patients with MetSyn affected hemodynamic and autonomic variables associated with poor cardiovascular outcome. Design: Prospective clinical study. Participants: We studied 36 patients with MetSyn (ATP-III) divided into 2 groups matched for age and sex: (1) MetSyn+OSA (n = 18) and (2) MetSyn-OSA (n = 18). Measurements: USA was defined by an apnea-hypopnea index (AHI) > 15 events/hour by polysomnography. We recorded muscle sympathetic nerve activity (MSNA - microneurography), heart rate (HR), and blood pressure (BP - Finapres). Baroreflex sensitivity (BRS) was analyzed by spontaneous BP and HR fluctuations. Results: MSNA (34 +/- 2 vs 28 +/- 1 bursts/min, P = 0.02) and mean BP (111 +/- 3 vs. 99 +/- 2 mm Hg, P = 0.003) were higher in patients with MetSyn+OSA versus patients with MetSyn-USA. Patients with MetSyn+OSA had lower spontaneous BRS for increases (7.6 +/- 0.6 vs 12.2 +/- 1.2 msec/mm Hg, P = 0.003) and decreases (7.2 +/- 0.6 vs 11.9 +/- 1.6 msec/mm Hg, P = 0.01) in BP. MSNA was correlated with AHI (r = 0.48; P = 0.009) and minimum nocturnal oxygen saturation (r = -0.38, P = 0.04). Conclusion: Patients with MetSyn and comorbid USA have higher BP, higher sympathetic drive, and diminished BRS, compared with patients with MetSyn without USA. These adverse cardiovascular and autonomic consequences of USA may be associated with poorer outcomes in these patients. Moreover, increased BP and sympathetic drive in patients with MetSyn+OSA may be linked, in part, to impairment of baroreflex gain.