609 research outputs found

    Dermatophagoides pteronyssinus and Tyrophagus putrescentiae Allergy in Allergic Rhinitis Caused by Cross-reactivity Not Dual-Sensitization

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    Tyrophagus putrescentiae and Dermatophagoides pteronyssinus are causative factors for the development of airway hypersensitivity. The main objective in this study was to identify the cross-reactive allergens between T putrescentiae and D. pteronyssinus and investigate their sensitization in patients with allergic rhinitis. The prevalence of sensitization to mites was determined by skin prick tests and histamine release assays. Both immunoblot and ELISA inhibition assays were performed by using the recombinant allergens of T putrescentiae and D. pteronyssinus. The cross-reactive allergens were identified by using IgE-binding inhibition analysis. The correlations of specific IgE between T putrescentiae and D. pteronyssinus to group 2 and group 3 mite allergens were compared. A total of 117 allergic rhinitis patients, aged between 16 and 40 years old were recruited to be included in this study. The results showed that 70% (82/117) of allergic rhinitis subjects had skin test positive reactions to D. pteronyssinus or T putrescentiae. Among these mite-sensitive subjects, there were 81 subjects (81/82) sensitive to D. pteronyssinus and 34 subjects (34/82) sensitive to T putrescentiae. Among the T putrescentiae hypersensitive subjects, 97% (33/34) were also sensitized to D. pteronyssinus. In the IgE-binding inhibition analysis, 59% (13/22) subjects had IgE-binding activity of T putrescentiae that was completely absorbed by D. pteronyssinus, especially components with MW at 16 kDa. In ELISA inhibition testing, 69% of IgE-binding was inhibited by rTyr p 2, and 45% inhibited by rTyr p 3. The titers of IgE antibodies to rTyr p 2 and rDer p 2 were well correlated, but not rTyr p 3 and rDer p 3. In conclusion, most T putrescentiae sensitized subjects were also sensitized to D. pteronyssinus in young adult allergic rhinitis patients. The complete absorption of IgE binding activity by D. pteronvssinus indicates that T putrescentiae hypersensitivity might be due to the cross-reactivity, not dual-sensitization of D. pteronyssinus and T putrescentiae. The IgE-binding titers of group 2 allergens were well correlated and the binding activity of Tyr p 2 could be absorbed by Der p 2, suggesting that group 2 allergens are the major cross-reactive allergen of D. pteronyssinus and T putrescentiae

    Andrographolide Inhibits PI3K/AKT-Dependent NOX2 and iNOS Expression Protecting Mice against Hypoxia/Ischemia-Induced Oxidative Brain Injury

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    This study aimed to explore the mechanisms by which andrographolide protects against hypoxia-induced oxidative/nitrosative brain injury provoked by cerebral ischemic/reperfusion (CI/R) injury in mice. Hypoxia in vitro was modeled using oxygen-glucose deprivation (OGD) followed by reoxygenation of BV-2 microglial cells. Our results showed that treatment of mice that have undergone CI/R injury with andrographolide (10-100 mu g/kg, i.v.) at 1 h after hypoxia ameliorated CI/R-induced oxidative/nitrosative stress, brain infarction, and neurological deficits in the mice, and enhanced their survival rate. CI/R induced a remarkable production in the mouse brains of reactive oxygen species (ROS) and a significant increase in protein nitrosylation; this primarily resulted from enhanced expression of NADPH oxidase 2 (NOX2), inducible nitric oxide synthase (iNOS), and the infiltration of CD11b cells due to activation of nuclear factor-kappa B (NF-kappa B) and hypoxia-inducible factor 1-alpha (HIF-1 alpha). All these changes were significantly diminished by andrographolide. In BV-2 cells, OGD induced ROS and nitric oxide production by upregulating NOX2 and iNOS via the phosphatidylinositol-3-kinase (PI3K)/AKT-dependent NF-kappa B and HIF-1 alpha pathways, and these changes were suppressed by andrographolide and LY294002. Our results indicate that andrographolide reduces NOX2 and iNOS expression possibly by impairing PI3K/AKT-dependent NF-kappa B and HIF-1 alpha activation. This compromises microglial activation, which then, in turn, mediates andrographolide's protective effect in the CI/R mice

    Mutations in the Salmonella enterica serovar Choleraesuis cAMP-receptor protein gene lead to functional defects in the SPI-1 Type III secretion system

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    Salmonella enterica serovar Choleraesuis (Salmonella Choleraesuis) causes a lethal systemic infection (salmonellosis) in swine. Live attenuated Salmonella Choleraesuis vaccines are effective in preventing the disease, and isolates of Salmonella Choleraesuis with mutations in the cAMP-receptor protein (CRP) gene (Salmonella Choleraesuis Delta crp) are the most widely used, although the basis of the attenuation remains unclear. The objective of this study was to determine if the attenuated phenotype of Salmonella Choleraesuis Delta crp was due to alterations in susceptibility to gastrointestinal factors such as pH and bile salts, ability to colonize or invade the intestine, or cytotoxicity for macrophages. Compared with the parental strain, the survival rate of Salmonella Choleraesuis Delta crp at low pH or in the presence of bile salts was higher, while the ability of the mutant to invade intestinal epithelia was significantly decreased. In examining the role of CRP on the secretory function of the Salmonella pathogenicity island 1 (SPI-1) encoded type III secretion system (T3SS), it was shown that Salmonella Choleraesuis Delta crp was unable to secrete the SPI-1 T3SS effector proteins, SopB and SipB, which play a role in Salmonella intestinal invasiveness and macrophage cytotoxicity, respectively. In addition, caspase-1 dependent cytotoxicity for macrophages was significantly reduced in Salmonella Choleraesuis Delta crp. Collectively, this study demonstrates that the CRP affects the secretory function of SPI-1 T3SS and the resulting ability to invade the host intestinal epithelium, which is a critical element in the pathogenesis of Salmonella Choleraesuis

    Kernel Spectral Clustering and applications

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    In this chapter we review the main literature related to kernel spectral clustering (KSC), an approach to clustering cast within a kernel-based optimization setting. KSC represents a least-squares support vector machine based formulation of spectral clustering described by a weighted kernel PCA objective. Just as in the classifier case, the binary clustering model is expressed by a hyperplane in a high dimensional space induced by a kernel. In addition, the multi-way clustering can be obtained by combining a set of binary decision functions via an Error Correcting Output Codes (ECOC) encoding scheme. Because of its model-based nature, the KSC method encompasses three main steps: training, validation, testing. In the validation stage model selection is performed to obtain tuning parameters, like the number of clusters present in the data. This is a major advantage compared to classical spectral clustering where the determination of the clustering parameters is unclear and relies on heuristics. Once a KSC model is trained on a small subset of the entire data, it is able to generalize well to unseen test points. Beyond the basic formulation, sparse KSC algorithms based on the Incomplete Cholesky Decomposition (ICD) and L0L_0, L1,L0+L1L_1, L_0 + L_1, Group Lasso regularization are reviewed. In that respect, we show how it is possible to handle large scale data. Also, two possible ways to perform hierarchical clustering and a soft clustering method are presented. Finally, real-world applications such as image segmentation, power load time-series clustering, document clustering and big data learning are considered.Comment: chapter contribution to the book "Unsupervised Learning Algorithms

    Scoping review : intergenerational resource transfer and possible enabling factors

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    We explore the intergenerational pattern of resource transfer and possible associated factors. A scoping review was conducted of quantitative, peer-reviewed, English-language studies related to intergenerational transfer or interaction. We searched AgeLine, PsycINFO, Social Work Abstracts, and Sociological Abstracts for articles published between Jane 2008 and December 2018. Seventy-five studies from 25 countries met the inclusion criteria. The scoping review categorised resource transfers into three types: financial, instrumental, and emotional support. Using an intergenerational solidarity framework, factors associated with intergenerational transfer were placed in four categories: (1) demographic factors (e.g., age, gender, marital status, education, and ethno-cultural background); (2) needs and opportunities factors, including health, financial resources, and employment status; (3) family structures, namely, family composition, family relationship, and earlier family events; and (4) cultural-contextual structures, including state policies and social norms. Those factors were connected to the direction of resource transfer between generations. Downward transfers from senior to junior generations occur more frequently than upward transfers in many developed countries. Women dominate instrumental transfers, perhaps influenced by traditional gender roles. Overall, the pattern of resource transfer between generations is shown, and the impact of social norms and social policy on intergenerational transfers is highlighted. Policymakers should recognise the complicated interplay of each factor with different cultural contexts. The findings could inform policies that strengthen intergenerational solidarity and support.</jats:p

    Stress corrosion cracking in Al-Zn-Mg-Cu aluminum alloys in saline environments

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    Copyright 2013 ASM International. This paper was published in Metallurgical and Materials Transactions A, 44A(3), 1230 - 1253, and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.Stress corrosion cracking of Al-Zn-Mg-Cu (AA7xxx) aluminum alloys exposed to saline environments at temperatures ranging from 293 K to 353 K (20 °C to 80 °C) has been reviewed with particular attention to the influences of alloy composition and temper, and bulk and local environmental conditions. Stress corrosion crack (SCC) growth rates at room temperature for peak- and over-aged tempers in saline environments are minimized for Al-Zn-Mg-Cu alloys containing less than ~8 wt pct Zn when Zn/Mg ratios are ranging from 2 to 3, excess magnesium levels are less than 1 wt pct, and copper content is either less than ~0.2 wt pct or ranging from 1.3 to 2 wt pct. A minimum chloride ion concentration of ~0.01 M is required for crack growth rates to exceed those in distilled water, which insures that the local solution pH in crack-tip regions can be maintained at less than 4. Crack growth rates in saline solution without other additions gradually increase with bulk chloride ion concentrations up to around 0.6 M NaCl, whereas in solutions with sufficiently low dichromate (or chromate), inhibitor additions are insensitive to the bulk chloride concentration and are typically at least double those observed without the additions. DCB specimens, fatigue pre-cracked in air before immersion in a saline environment, show an initial period with no detectible crack growth, followed by crack growth at the distilled water rate, and then transition to a higher crack growth rate typical of region 2 crack growth in the saline environment. Time spent in each stage depends on the type of pre-crack (“pop-in” vs fatigue), applied stress intensity factor, alloy chemistry, bulk environment, and, if applied, the external polarization. Apparent activation energies (E a) for SCC growth in Al-Zn-Mg-Cu alloys exposed to 0.6 M NaCl over the temperatures ranging from 293 K to 353 K (20 °C to 80 °C) for under-, peak-, and over-aged low-copper-containing alloys (~0.8 wt pct), they are typically ranging from 20 to 40 kJ/mol for under- and peak-aged alloys, and based on limited data, around 85 kJ/mol for over-aged tempers. This means that crack propagation in saline environments is most likely to occur by a hydrogen-related process for low-copper-containing Al-Zn-Mg-Cu alloys in under-, peak- and over-aged tempers, and for high-copper alloys in under- and peak-aged tempers. For over-aged high-copper-containing alloys, cracking is most probably under anodic dissolution control. Future stress corrosion studies should focus on understanding the factors that control crack initiation, and insuring that the next generation of higher performance Al-Zn-Mg-Cu alloys has similar longer crack initiation times and crack propagation rates to those of the incumbent alloys in an over-aged condition where crack rates are less than 1 mm/month at a high stress intensity factor

    Effect of left ventricular hypertrophy on long-term survival of patients with coronary artery disease following percutaneous coronary intervention

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    The impact of left ventricular hypertrophy (LVH) on survival among patients with established coronary artery disease (CAD) is not well understood. We sought to evaluate the effect of LVH on the survival of patients with CAD following percutaneous coronary intervention (PCI). Three hospitals in New York City contributed prospectively defined data on 4284 consecutive patients undergoing PCI. Allcause mortality at a mean follow-up of three years was the primary endpoint. LVH was present in 383 patients (8.9%). LVH patients had a greater prevalence of hypertension (88% vs. 68%, p<0.001), vascular disease (21% vs. 6.6%, p=0.001), and prior heart failure (10% vs. 5.5%, p<0.001). LVH patients presented less often with one-vessel disease (38% vs. 50%, p=0.040) and more often with two- (34% vs. 29%, p=0.014) or three-vessel (22% vs. 18%, p=0.044) disease. Ejection fractions and angiographic success were similar in both groups. In-hospital mortality did not differ between groups. At three-year follow-up, the survival rate for patients with LVH was 86% vs. 91% in patients without LVH (log-rank p=0.001). However, after adjustment for differences in baseline characteristics using Cox proportional hazards analysis, LVH was found not to be an independent predictor of mortality (hazard ratio, 0.93; 95% confidence interval, 0.68–1.28; p=0.67). We conclude that LVH at the time of PCI is not independently associated with an increase in the hazard of death at three years

    VHL substrate transcription factor ZHX2 as an oncogenic driver in clear cell renal cell carcinoma

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    Inactivation of the von Hippel-Lindau (VHL) E3 ubiquitin ligase protein is a hallmark of clear cell renal cell carcinoma (ccRCC). Identifying how pathways affected by VHL loss contribute to ccRCC remains challenging. We used a genome-wide in vitro expression strategy to identify proteins that bind VHL when hydroxylated. Zinc fingers and homeoboxes 2 (ZHX2) was found as a VHL target, and its hydroxylation allowed VHL to regulate its protein stability. Tumor cells from ccRCC patients with VHL loss-of-function mutations usually had increased abundance and nuclear localization of ZHX2. Functionally, depletion of ZHX2 inhibited VHL-deficient ccRCC cell growth in vitro and in vivo. Mechanistically, integrated chromatin immunoprecipitation sequencing and microarray analysis showed that ZHX2 promoted nuclear factor κB activation. These studies reveal ZHX2 as a potential therapeutic target for ccRCC
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