121 resultados para Systemic changes and turbulences
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Indirect plant-mediated interactions between herbivores are important drivers of community composition in terrestrial ecosystems. Among the most striking examples are the strong indirect interactions between spatially separated leaf- and root-feeding insects sharing a host plant. Although leaf feeders generally reduce the performance of root herbivores, little is known about the underlying systemic changes in root physiology and the associated behavioral responses of the root feeders. We investigated the consequences of maize (Zea mays) leaf infestation by Spodoptera littoralis caterpillars for the root-feeding larvae of the beetle Diabrotica virgifera virgifera, a major pest of maize. D. virgifera strongly avoided leaf-infested plants by recognizing systemic changes in soluble root components. The avoidance response occurred within 12 h and was induced by real and mimicked herbivory, but not wounding alone. Roots of leaf-infested plants showed altered patterns in soluble free and soluble conjugated phenolic acids. Biochemical inhibition and genetic manipulation of phenolic acid biosynthesis led to a complete disappearance of the avoidance response of D. virgifera. Furthermore, bioactivity-guided fractionation revealed a direct link between the avoidance response of D. virgifera and changes in soluble conjugated phenolic acids in the roots of leaf-attacked plants. Our study provides a physiological mechanism for a behavioral pattern that explains the negative effect of leaf attack on a root-feeding insect. Furthermore, it opens up the possibility to control D. virgifera in the field by genetically mimicking leaf herbivore-induced changes in root phenylpropanoid patterns.
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PURPOSE The aim of this study was to evaluate the antibiotic treatment of postoperative endophthalmitis with combined systemic meropenem and linezolid. METHODS A retrospective analysis of endophthalmitis treated with systemic meropenem and linezolid compared to conventional systemic antibiotics by evaluation of outcome and adverse effects was carried out. RESULTS 26 patients with unilateral postoperative endophthalmitis with a systemic combination regimen of meropenem (2 g TID, mean duration of treatment 5.5 days) and linezolid (600 mg BID, mean duration of treatment 8.9 days) (group 1, mean follow-up time 140 days) were included in this study and compared to 45 postoperative endophthalmitis patients treated with conventional systemic antibiotics (group 2; mean follow-up time 320 days). In group 1, 69.2 % of eyes additionally received intravitreal amikacin and vancomycin (vs. 24.4 % in group 2; p < 0.001), in 92.3 % pars plana vitrectomy was performed (vs. 68.9 % in group 2, p = 0.047). Mean best corrected visual acuity improved from a baseline of 1.76 logMar for group 1 and 1.83 logMar for group 2 to 0.91 logMar (p = 0.0001) and 0.90 logMar (p < 0.0001), respectively, at the end of the follow-up, revealing no significant differences between the two groups at any time point (p > 0.05). Ocular complications were observed in 34.6 % of eyes in group 1 (vs. 37.8 % in group 2; p > 0.05). Adverse drug effects occurred significantly more frequently in group 1 (26.9 % vs. 4.4 % p = 0.02). CONCLUSION In spite of the reported better penetration through the blood-ocular barrier and the broader antibacterial spectrum of meropenem and linezolid, no benefit in outcome was found in the present study. In contrast, adverse effects and costs of the combination regimen were significantly higher.
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Arterial pressure-based cardiac output monitors (APCOs) are increasingly used as alternatives to thermodilution. Validation of these evolving technologies in high-risk surgery is still ongoing. In liver transplantation, FloTrac-Vigileo (Edwards Lifesciences) has limited correlation with thermodilution, whereas LiDCO Plus (LiDCO Ltd.) has not been tested intraoperatively. Our goal was to directly compare the 2 proprietary APCO algorithms as alternatives to pulmonary artery catheter thermodilution in orthotopic liver transplantation (OLT). The cardiac index (CI) was measured simultaneously in 20 OLT patients at prospectively defined surgical landmarks with the LiDCO Plus monitor (CI(L)) and the FloTrac-Vigileo monitor (CI(V)). LiDCO Plus was calibrated according to the manufacturer's instructions. FloTrac-Vigileo did not require calibration. The reference CI was derived from pulmonary artery catheter intermittent thermodilution (CI(TD)). CI(V)-CI(TD) bias ranged from -1.38 (95% confidence interval = -2.02 to -0.75 L/minute/m(2), P = 0.02) to -2.51 L/minute/m(2) (95% confidence interval = -3.36 to -1.65 L/minute/m(2), P < 0.001), and CI(L)-CI(TD) bias ranged from -0.65 (95% confidence interval = -1.29 to -0.01 L/minute/m(2), P = 0.047) to -1.48 L/minute/m(2) (95% confidence interval = -2.37 to -0.60 L/minute/m(2), P < 0.01). For both APCOs, bias to CI(TD) was correlated with the systemic vascular resistance index, with a stronger dependence for FloTrac-Vigileo. The capability of the APCOs for tracking changes in CI(TD) was assessed with a 4-quadrant plot for directional changes and with receiver operating characteristic curves for specificity and sensitivity. The performance of both APCOs was poor in detecting increases and fair in detecting decreases in CI(TD). In conclusion, the calibrated and uncalibrated APCOs perform differently during OLT. Although the calibrated APCO is less influenced by changes in the systemic vascular resistance, neither device can be used interchangeably with thermodilution to monitor cardiac output during liver transplantation.
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Recently we demonstrated higher galectin-3 in portal venous serum (PVS) compared to hepatic venous serum (HVS) in a small cohort of patients with normal liver function suggesting hepatic removal of galectin-3. Here, galectin-3 was measured by ELISA in PVS, HVS and systemic venous blood (SVS) of 33 patients with alcoholic liver cirrhosis and a larger cohort of 11 patients with normal liver function. Galectin-3 was cleared by the healthy but not the cirrhotic liver, and subsequently HVS and SVS galectin-3 levels were significantly increased in the patients with liver cirrhosis compared to controls. In healthy liver galectin-3 was produced by cholangiocytes and synthesis by hepatocytes was only observed in cirrhotic liver. Hepatic venous pressure gradient did not correlate with galectin-3 levels excluding hepatic shunting as the principal cause of higher SVS galectin-3. Galectin-3 was elevated in all blood compartments of patients with CHILD-PUGH stage C compared to patients with CHILD-PUGH stage A, and was higher in patients with ascites than patients without this complication. Galectin-3 was negatively associated with antithrombin-3 whose synthesis is reduced with worse liver function. Galectin-3 positively correlated with urea and creatinine, and PVS galectin-3 showed a negative association with creatinine clearance as an accepted measure of kidney function. To summarize in the current study systemic, portal and hepatic levels of galectin-3 were found to be negatively associated with liver function in patients with alcoholic liver cirrhosis and this may in part be related to impaired hepatic removal and/or increased synthesis in cirrhotic liver.
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BACKGROUND: Dogs experimentally inoculated with Angiostrongylus vasorum develop severe pulmonary parenchymal lesions and arterial thrombosis at the time of patency. HYPOTHESIS: A. vasorum-induced thrombosis results in arterial hypoxemia, pulmonary hypertension (PH), and altered cardiac morphology and function. ANIMALS: Six healthy Beagles experimentally inoculated with A. vasorum. METHODS: Thoracic radiographs and arterial blood gas analyses were performed 8 and 13 weeks postinoculation (wpi) and 9 weeks posttherapy (wpt). Echocardiography was done before and 2, 5, 8, 13 wpi and 9 wpt. Invasive pulmonary artery pressure (PAP) measurements were obtained 8 wpi. Two untreated dogs were necropsied 13 wpi and 4 treated dogs 9 wpt. RESULTS: All dogs had patent infections at 7 wpi and clinical respiratory signs at 8 wpi. Moderate hypoxemia (median PaO2 of 73 and 74 mmHg) present at 8 and 13 wpi had resolved by 9 wpt. Echocardiographically, no evidence of PH and no abnormalities in cardiac size and function were discernible at any time point. PAP invasively measured at 8 wpi was not different from that of control dogs. Severe radiographic pulmonary parenchymal and suspected thrombotic lesions at 13 wpi were corroborated by necropsy. Most histopathologic changes had resolved at 9 wpt, but focal inflammatory, thrombotic, and fibrotic changes still were present in all dogs. CONCLUSION: In experimentally infected Beagles, pulmonary and vascular changes induced by A. vasorum are reflected by marked radiographic changes and arterial hypoxemia. These did not result in PH and echocardiographic changes in cardiac size and function.
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It has been argued that past changes in the sources of Nd could hamper the use of the Nd isotopic composition (ϵNd) as a proxy for past changes in the overturning of deep water masses. Here we reconsider uncertainties associated with ϵNd in seawater due to potential regional to global scale changes in the sources of Nd by applying a modeling approach. For illustrative purposes we describe rather extreme changes in the magnitude of source fluxes, their isotopic composition or both. We find that the largest effects on ϵNd result from changes in the boundary source. Considerable changes also result from variations in the magnitude or ϵNd of dust and rivers but are largely constrained to depths shallower than 1 km, except if they occur in or upstream of regions where deep water masses are formed. From these results we conclude that changes in Nd sources have the potential to affect ϵNd. However, substantial changes are required to generate large-scale changes inϵNd in deep water that are similar in magnitude to those that have been reconstructed from sediment cores or result from changes in meridional overturning circulation in model experiments. Hence, it appears that a shift in ϵNdcomparable to glacial-interglacial variations is difficult to obtain by changes in Nd sources alone, but that more subtle variations can be caused by such changes and must be interpreted with caution.
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Macrophage activating syndrome (MAS) is a rare hematological disorder associated with uncontrolled systemic T-cell activation. Persistent fever, fatigue and hepatosplenomegaly are frequent clinical manifestations, whereas hyperferritinemia, elevated serum lactate dehydrogenase levels and cytopenia are key criteria for the diagnosis of MAS. The nature of liver pathology in MAS has been partially elucidated but destructive biliary lesions have been rarely described. This report illustrates four cases of MAS developing marked cholestasis, leading to one case of biliary cirrhosis necessitating liver transplantation. Histologically, liver involvement was characterized in all cases by acute lobular hepatitis, marked hepatocyte apoptosis and small bile duct injury similar to the vanishing bile duct syndrome. Immuno-histological studies showed that the inflammatory changes and bile duct lesions were dominated by the presence of activated macrophages and T-cells, in particular CD8+ lymphocytes, and in part NK-cells. These findings suggest that in MAS, various T-cell triggers such as infection, autoimmune disease and malignancy might result in the release of cytokines, which in turn activate macrophages to trigger a systemic acute phase response and local tissue damage. This communication suggests that a macrophage, T- and NK-cell network is operational in the pathogenesis of the cholangiocyte, hepatocyte and sinus endothelial cell damage in MAS.
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Sustainable natural resource use requires that multiple actors reassess their situation in a systemic perspective. This can be conceptualised as a social learning process between actors from rural communities and the experts from outside organisations. A specifically designed workshop oriented towards a systemic view of natural resource use and the enhancement of mutual learning between local and external actors, provided the background for evaluating the potentials and constraints of intensified social learning processes. Case studies in rural communities in India, Bolivia, Peru and Mali showed that changes in the narratives of the participants of the workshop followed a similar temporal sequence relatively independently from their specific contexts. Social learning processes were found to be more likely to be successful if they 1) opened new space for communicative action, allowing for an intersubjective re-definition of the present situation, 2) contributed to rebalance the relationships between social capital and social, emotional and cognitive competencies within and between local and external actors.
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PURPOSE: To report a novel association of uveitic glaucoma with Rosai-Dorfman disease. METHODS: Case report. RESULTS: A 67-year-old Caucasian woman presented with a chronic bilateral granulomatous uveitis which did not respond to conventional topical steroid therapy. She also had raised intraocular pressures, glaucomatous optic disc changes and diffuse nodular fibrous skin lesions. Subsequent skin biopsy immuno-cytochemistry showed S-100 staining, consistent with Rosai-Dorfman disease. The uveitis and glaucoma were highly resistant to standard medical treatments, but completely resolved together with the systemic features of the disease after six months. CONCLUSIONS: Rosai-Dorfman disease has not previously been reported to cause uveitic glaucoma and should be considered in non-responsive cases presenting with a rash. The disease is entirely self-limiting and early diagnosis may therefore avoid unnecessary trabeculectomy and/or systemic immune suppression.
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BACKGROUND: Surfactant protein D (SP-D) deficient mice develop emphysema-like pathology associated with focal accumulations of foamy alveolar macrophages, an excess of surfactant phospholipids in the alveolar space and both hypertrophy and hyperplasia of alveolar type II cells. These findings are associated with a chronic inflammatory state. Treatment of SP-D deficient mice with a truncated recombinant fragment of human SP-D (rfhSP-D) has been shown to decrease the lipidosis and alveolar macrophage accumulation as well as production of proinflammatory chemokines. The aim of this study was to investigate if rfhSP-D treatment reduces the structural abnormalities in parenchymal architecture and type II cells characteristic of SP-D deficiency. METHODS: SP-D knock-out mice, aged 3 weeks, 6 weeks and 9 weeks were treated with rfhSP-D for 9, 6 and 3 weeks, respectively. All mice were sacrificed at age 12 weeks and compared to both PBS treated SP-D deficient and wild-type groups. Lung structure was quantified by design-based stereology at the light and electron microscopic level. Emphasis was put on quantification of emphysema, type II cell changes and intracellular surfactant. Data were analysed with two sided non-parametric Mann-Whitney U-test. MAIN RESULTS: After 3 weeks of treatment, alveolar number was higher and mean alveolar size was smaller compared to saline-treated SP-D knock-out controls. There was no significant difference concerning these indices of pulmonary emphysema within rfhSP-D treated groups. Type II cell number and size were smaller as a consequence of treatment. The total volume of lamellar bodies per type II cell and per lung was smaller after 6 weeks of treatment. CONCLUSION: Treatment of SP-D deficient mice with rfhSP-D leads to a reduction in the degree of emphysema and a correction of type II cell hyperplasia and hypertrophy. This supports the concept that rfhSP-D might become a therapeutic option in diseases that are characterized by decreased SP-D levels in the lung.
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BACKGROUND: Body fat changes are common in patients with HIV. For patients on protease inhibitor (PI)-based highly active antiretroviral therapy (HAART), these changes have been associated with increasing exposure to therapy in general and to stavudine in particular. Our objective is to show whether such associations are more or less likely for patients on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based HAART. METHODS: We included all antiretroviral-naive patients in the Swiss HIV Cohort Study starting HAART after April 2000 who had had body weight, CD4 cell count and plasma HIV RNA measured between 6 months before and 3 months after starting HAART, and at least one assessment of body fat changes after starting HAART. At visits scheduled every 6 months, fat loss or fat gain is reported by agreement between patient and physician. We estimate the association between reported body fat changes and both time on therapy and time on stavudine, using conditional logistical regression. RESULTS: Body fat changes were reported for 85 (9%) out of 925 patients at their first assessment; a further 165 had only one assessment. Of the remaining 675 patients, body fat changes were reported for 156 patients at a rate of 13.2 changes per 100 patient-years. Body fat changes are more likely with increasing age [odds ratio (OR) 1.18 (1.00-1.38) per 10 years], with increasing BMI [OR 1.06 (1.01-1.11)] and in those with a lower baseline CD4 cell count [OR 0.91 (0.83-1.01) per 100 cells/microl]. There is only weak evidence that body fat changes are more likely with increasing time on HAART [OR 1.16 (0.93-1.46)]. After adjusting for time on HAART, fat loss is more likely with increasing stavudine use [OR 1.70 (1.34-2.15)]. There is no evidence of an association between reported fat changes and time on NNRTI therapy relative to PI therapy in those patients who used either one therapy or the other [OR 0.98 (0.56-1.63)]. CONCLUSION: Fat loss is more likely to be reported with increasing exposure to stavudine. We find no evidence of major differences between PI and NNRTI therapy in the risk of reported body fat changes.
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Metabolic abnormalities during bacterial meningitis include hypoglycorrhachia and cerebrospinal fluid (CSF) lactate accumulation. The mechanisms by which these alterations occur within the central nervous system (CNS) are still incompletely delineated. To determine the evolution of these changes and establish the locus of abnormal metabolism during meningitis, glucose and lactate concentrations in brain interstitial fluid, CSF, and serum were measured simultaneously and sequentially during experimental pneumococcal meningitis in rabbits. Interstitial fluid samples were obtained from the frontal cortex and hippocampus by using in situ brain microdialysis, and serum and CSF were directly sampled. There was an increase of CSF lactate concentration, accompanied by increased local production of lactate in the brain, and a decrease of CSF-to-serum glucose ratio that was paralleled by a decrease in cortical glucose concentration. Brain microdialysate lactate concentration was not affected by either systemic lactic acidosis or artificially elevated CSF lactate concentration. These data support the hypothesis that the brain is a locus for anaerobic glycolysis during meningitis, resulting in increased lactate production and perhaps contributing to decreased tissue glucose concentration.
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Objectives To prospectively evaluate histopathologic, blood cellular, serological and clinical changes in response to abatacept treatment in patients with primary Sjögren's syndrome (pSS). Methods Blood, saliva and minor salivary gland biopsies were obtained before and after the last of 8 doses of abatacept in 11 pSS patients. The histologic data evaluated the number of lymphocytic foci and of B- and T-cell subtypes (CD20(+) , CD3(+) , CD4(+) , CD8(+) ). The numbers of FoxP3(+) regulatory T-cells were measured and the FoxP3 /CD 3 ratio was calculated. Histologic data were compared with results from peripheral blood and with changes in saliva secretion. Results The numbers of lymphocytic foci decreased significantly (p=0.041). Numbers of local FoxP3(+) T-cells decreased significantly in percentage of total lymphocytic infiltrates (p=0.037). In the peripheral blood B-cells increased (p=0.038). This was due to an expansion of the naïve B cell pool (p=0.034). When adjusting for disease duration, an increase was also noted for total lymphocytes (p=0.044) and for CD 4 cells (p=0.009). Gamma globulins decreased significantly (p=0.005), but IgG reduction did not reach significance. Adjusted for disease duration, saliva production increased significantly (p=0.029). Conclusions CTLA4-Ig treatment significantly reduces glandular inflammation in pSS, induces several celluar changes and increases saliva production. Remarkably, this increase in saliva production is significantly influenced by disease duration.
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Equine recurrent airway obstruction (RAO) is an inflammatory, obstructive airway disease induced by exposure of susceptible horses to inhaled organic dust particles. The immunological process underlying RAO is still unclear. Previous studies have shown that RAO is linked to the Interleukin-4 receptor (IL-4R) gene in one Warmblood family (F1), but not in another (F2). It has also been shown that in F1, but not in F2, RAO is associated with resistance against parasites, suggesting that this association may have an immuno-genetic basis. Therefore, we hypothesized that the T helper (h)1/Th2/regulatory (Treg) cytokine profiles of RAO-associated antigen- and parasite-antigen-stimulated peripheral blood mononuclear cells (PBMC) differ between RAO-affected and healthy horses depending on their genetic background. In our study, PBMC from 17 RAO-affected and 14 healthy control horses of F1 and F2 were stimulated for 24h with antigens relevant to RAO [hay dust extract (HDE), Aspergillus fumigatus extract (AFE) and lipopolysaccharids (LPS)]; cyathostomin extract (CE) and recombinant cyathostomin antigen (RCA) or with concanavalin A (ConA). Total mRNA levels of IL-4, IL-4R, IL-13, interferon (INF)-γ and IL-10 were examined by qRT-PCR. Stimulation with either HDE or RCA resulted in significant differences in IL-4R mRNA levels between RAO-affected and control horses in F1, but not in F2. For IL-10 mRNA expression, a significant difference between RAO-affected and control horses in F1 but not in F2 was observed only following stimulation with HDE. In contrast to HDE, stimulation with CE resulted in a significant difference of IL-10 mRNA expression level between RAO-affected horses of F2 and healthy horses of F1. No significant differences were detected upon stimulation with any of the other challenge agents. These findings indicate that the immunological response, specifically IL-4R expression, in response to hay dust and cyathostomin antigens, differs between RAO-affected and healthy horses depending on their genetic background. This study shows that analysis of PBMC reveals systemic changes associated with RAO and helps to elucidate immunological pathways involved in this disease.
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Purpose Skill variety in terms of opportunities for utilizing different skills is an important element of job design; it is associated with well-being and health, but most pertinent research is cross-sectional. Positive associations with well-being, and with intellectual flexibility, have been shown longitudinally, but these studies focus on levels of skill variety at time 1 and do not use changes in skill variety as a predictor. We expect changes in skill variety to be associated with well-being in terms of higher job satisfaction and fewer psychosomatic complaints. Design/Methodology Skill variety, job satisfaction, and psychosomatic complaints were assessed in 2005, 2006, 2007, and 2010 (N = 317 young employees). Data were analyzed using latent growth modeling. Results Skill variety decreased over the first three years after labor market entry. Initial levels of skill variety predicted higher job satisfaction in 2010. Steeper decreases in skill variety from 2005 to 2007 predicted lower levels of job satisfaction and more psychosomatic complaints three years later. Limitations This longitudinal study used only self-report. Research/Practical Implications Our results extend the often found association between challenging work content and job satisfaction in terms of a) showing it for young employees, b) longitudinally, c) not only for initial level but also for changes, and d) for psychosomatic complaints; they underscore the importance of maintaining a high level of challenging work content beyond the initial phase by enriching work as routine increases. Originality/Value Compared to the few existing longitudinal studies, we focus on changes and their relations with well-being.