Inhalation of the Rho-kinase inhibitor Y-27632 reverses allergen-induced airway hyperresponsiveness after the early and late asthmatic reaction

BACKGROUND: In guinea pigs, we have previously demonstrated that the contribution of Rho-kinase to airway responsiveness in vivo and ex vivo is enhanced after active sensitization with ovalbumin (OA). Using conscious, unrestrained OA-sensitized guina pigs, we now investigated the role of Rho-kinase in the development of airway hyperresponsiveness (AHR) after the allergen-induced early (EAR) and late asthmatic reaction (LAR) in vivo. METHODS: Histamine and PGF(2α )PC(100)-values (provocation concentrations causing 100% increase in pleural pressure) were assessed before OA-challenge (basal airway responsiveness) and after the OA-induced EAR (5 h after challenge) and LAR (23 h after challenge). Thirty minutes later, saline or the specific Rho-kinase inhibitor Y-27632 (5 mM, nebulizer concentration) were nebulized, after which PC(100)-values were reassessed. RESULTS: In contrast to saline, Y-27632 inhalation significantly decreased the basal responsiveness toward histamine and PGF(2α )before OA-challenge, as indicated by increased PC(100 )-values. Both after the allergen-induced EAR and LAR, AHR to histamine and PGF(2α )was present, which was reversed by Y-27632 inhalation. Moreover, there was an increased effectiveness of Y-27632 to reduce airway responsiveness to histamine and PGF(2α )after the EAR and LAR as compared to pre-challenge conditions. Saline inhalations did not affect histamine or PGF(2α )PC(100)-values at all. Interestingly, under all conditions Y-27632 was significantly more effective in reducing airway responsiveness to PGF(2α )as compared to histamine. Also, there was a clear tendency (P = 0.08) to a more pronounced degree of AHR after the EAR for PGF(2α )than for histamine. CONCLUSION: The results indicate that inhalation of the Rho-kinase inhibitor Y-27632 causes a considerable bronchoprotection to both histamine and PGF(2α). Moreover, the results are indicative of a differential involvement of Rho-kinase in the agonist-induced airway obstruction in vivo. Increased Rho-kinase activity contributes to the allergen-induced AHR to histamine and PGF(2α )after both the EAR and the LAR, which is effectively reversed by inhalation of Y-27632. Therefore, Rho-kinase can be considered as a potential pharmacotherapeutical target in allergic asthma

道徳と幸福 : カント倫理思想の一考察

Asthma is a serious health problem and during the last decade various experimental models of asthma have been developed to study the pathogenesis of this disease. In this study we describe a new mouse model of asthma that uses the spores of Alternaria alternata and Cladosporium herbarum, two allergenic molds recognized as common inducers of rhinitis and asthma in humans. Here we demonstrate that A. alternata and C. herbarum spores are immunogenic when injected into BALB/c mice, and induce the production of specific IgM and IgG1 antibodies and strongly increase IgE serum levels. To induce the allergic response, mice were sensitized by two intraperitoneal (i.p.) injections and then intranasaly (i.n.) challenged with A. alternata and C. herbarum spores. Bronchoalveolar lavages (BALs) from these mice contained numerous macrophages, neutrophils, eosinophils and lymphocytes whereas neutrophils were the predominant BAL inflammatory cells in nonsensitized mice. Histological studies demonstrated an influx of eosinophils in peri-vascular and peri-bronchial areas and the presence of numerous epithelial goblet cells only in sensitized mice. Increased expression of mRNA specific for various chemokines (eotaxin, MIP-1α, MIP-2) and chemokine receptors (CCR-1, CCR-2 and CCR-5) was observed in the lungs of nonsensitized mice challenged with the spores. Expression of CCR-3 mRNA in the lungs and Th2 cytokine (IL-4, IL-5 and IL-13) secretion in the BAL was additionally observed in sensitized and challenged mice. Finally we demonstrate through whole-body plethysmography that mold spore sensitization and challenge induce the development of an airway hyperreactivity in response to nebulized methacholine

Peroxisome Proliferator-Activated Receptor alpha (PPAR alpha) down-regulation in cystic fibrosis lymphocytes

Background: PPARs exhibit anti-inflammatory capacities and are potential modulators of the inflammatory response. We hypothesized that their expression and/or function may be altered in cystic fibrosis (CF), a disorder characterized by an excessive host inflammatory response. Methods: PPARα, β and γ mRNA levels were measured in peripheral blood cells of CF patients and healthy subjects via RT-PCR. PPARα protein expression and subcellular localization was determined via western blot and immunofluorescence, respectively. The activity of PPARα was analyzed by gel shift assay. Results: In lymphocytes, the expression of PPARα mRNA, but not of PPARβ, was reduced (-37%; p < 0.002) in CF patients compared with healthy persons and was therefore further analyzed. A similar reduction of PPARα was observed at protein level (-26%; p < 0.05). The transcription factor was mainly expressed in the cytosol of lymphocytes, with low expression in the nucleus. Moreover, DNA binding activity of the transcription factor was 36% less in lymphocytes of patients (p < 0.01). For PPARα and PPARβ mRNA expression in monocytes and neutrophils, no significant differences were observed between CF patients and healthy persons. In all cells, PPARγ mRNA levels were below the detection limit. Conclusion: Lymphocytes are important regulators of the inflammatory response by releasing cytokines and antibodies. The diminished lymphocytic expression and activity of PPARα may therefore contribute to the inflammatory processes that are observed in CF

Chapter 4: Effective Search Strategies for Systematic Reviews of Medical Tests

This article discusses techniques that are appropriate when developing search strategies for systematic reviews of medical tests. This includes general advice for searching for systematic reviews and issues specific to systematic reviews of medical tests. Diagnostic search filters are currently not sufficiently developed for use when searching for systematic reviews. Instead, authors should construct a highly sensitive search strategy that uses both controlled vocabulary and text words. A comprehensive search should include multiple databases and sources of grey literature. A list of subject-specific databases is included in this article

A Randomised Controlled Trial of Two Infusion Rates to Decrease Reactions to Antivenom

Background: Snake envenoming is a major clinical problem in Sri Lanka, with an estimated 40,000 bites annually. Antivenom is only available from India and there is a high rate of systemic hypersensitivity reactions. This study aimed to investigate whether the rate of infusion of antivenom reduced the frequency of severe systemic hypersensitivity reactions. Methods and findings: This was a randomized comparison trial of two infusion rates of antivenom for treatment of non-pregnant adult patients (>14 y) with snake envenoming in Sri Lanka. Snake identification was by patient or hospital examination of dead snakes when available and confirmed by enzyme-immunoassay for Russell’s viper envenoming. Patients were blindly allocated in a 11 randomisation schedule to receive antivenom either as a 20 minute infusion (rapid) or a two hour infusion (slow). The primary outcome was the proportion with severe systemic hypersensitivity reactions (grade 3 by Brown grading system) within 4 hours of commencement of antivenom. Secondary outcomes included the proportion with mild/moderate hypersensitivity reactions and repeat antivenom doses. Of 1004 patients with suspected snakebites, 247 patients received antivenom. 49 patients were excluded or not recruited leaving 104 patients allocated to the rapid antivenom infusion and 94 to the slow antivenom infusion. The median actual duration of antivenom infusion in the rapid group was 20 min (Interquartile range[IQR]:20–25 min) versus 120 min (IQR:75–120 min) in the slow group. There was no difference in severe systemic hypersensitivity reactions between those given rapid and slow infusions (32% vs. 35%; difference 3%; 95%CI:−10% to +17%;p = 0.65). The frequency of mild/moderate reactions was also similar. Similar numbers of patients in each arm received further doses of antivenom (30/104 vs. 23/94). Conclusions: A slower infusion rate would not reduce the rate of severe systemic hypersensitivity reactions from current high rates. More effort should be put into developing better quality antivenoms

CAR-T cell. the long and winding road to solid tumors

Adoptive cell therapy of solid tumors with reprogrammed T cells can be considered the "next generation" of cancer hallmarks. CAR-T cells fail to be as effective as in liquid tumors for the inability to reach and survive in the microenvironment surrounding the neoplastic foci. The intricate net of cross-interactions occurring between tumor components, stromal and immune cells leads to an ineffective anergic status favoring the evasion from the host's defenses. Our goal is hereby to trace the road imposed by solid tumors to CAR-T cells, highlighting pitfalls and strategies to be developed and refined to possibly overcome these hurdles

Age-associated mitochondrial DNA mutations cause metabolic remodelling that contributes to accelerated intestinal tumorigenesis.

Oxidative phosphorylation (OXPHOS) defects caused by somatic mitochondrial DNA (mtDNA) mutations increase with age in human colorectal epithelium and are prevalent in colorectal tumours, but whether they actively contribute to tumorigenesis remains unknown. Here we demonstrate that mtDNA mutations causing OXPHOS defects are enriched during the human adenoma/carcinoma sequence, suggesting they may confer a metabolic advantage. To test this we deleted the tumour suppressor Apc in OXPHOS deficient intestinal stem cells in mice. The resulting tumours were larger than in control mice due to accelerated cell proliferation and reduced apoptosis. We show that both normal crypts and tumours undergo metabolic remodelling in response to OXPHOS deficiency by upregulating the de novo serine synthesis pathway (SSP). Moreover, normal human colonic crypts upregulate the SSP in response to OXPHOS deficiency prior to tumorigenesis. Our data show that age-associated OXPHOS deficiency causes metabolic remodelling that can functionally contribute to accelerated intestinal cancer development

Methods for conducting systematic reviews of risk factors in low- and middle-income countries.

BACKGROUND: Rates of youth violence are disproportionately high in many low- and middle-income countries [LMICs] but existing reviews of risk factors focus almost exclusively on high-income countries. Different search strategies, including non-English language searches, might be required to identify relevant evidence in LMICs. This paper discusses methodological issues in systematic reviews aiming to include evidence from LMICs, using the example of a recent review of risk factors for child conduct problems and youth violence in LMICs. METHODS: We searched the main international databases, such as PsycINFO, Medline and EMBASE in English, as well as 12 regional databases in Arabic, Chinese, English, French, Spanish, Portuguese and Russian. In addition, we used internet search engines and Google Scholar, and contacted over 200 researchers and organizations to identify potentially eligible studies in LMICs. RESULTS: The majority of relevant studies were identified in the mainstream databases, but additional studies were also found through regional databases, such as CNKI, Wangfang, LILACS and SciELO. Overall, 85% of eligible studies were in English, and 15% were reported in Chinese, Spanish, Portuguese, Russian or French. Among eligible studies in languages other than English, two-thirds were identified only by regional databases and one-third was also indexed in the main international databases. CONCLUSIONS: There are many studies on child conduct problems and youth violence in LMICs which have not been included in prior reviews. Most research on these subjects in LMICs has been produced in the last two-three decades and mostly in middle-income countries, such as China, Brazil, Turkey, South Africa and Russia. Based on our findings, it appears that many studies of child conduct problems and youth violence in LMICs are reported in English, Chinese, Spanish and Portuguese, but few such studies are published in French, Arabic or Russian. If non-English language searches and screening had not been conducted in the current review, 15% of eligible studies would have been missed. Although there are benefits to non-English language searches and the inclusion of non-English studies in meta-analyses, systematic reviewers also need to consider the resources required to incorporate multi-lingual research.We are grateful to the Wellcome Trust [089963/Z/09/Z] and Bernard van Leer Foundation for financial support for the research

Does Proximity to Retailers Influence Alcohol and Tobacco Use Among Latino Adolescents?

Despite decades of research surrounding determinants of alcohol and tobacco (A&T) use among adolescents, built environment influences have only recently been explored. This study used ordinal regression on 205 Latino adolescents to explore the influence of the built environment (proximity to A&T retailers) on A&T use, while controlling for recognized social predictors. The sample was 45% foreign-born. A&T use was associated with distance from respondents’ home to the nearest A&T retailer (−), acculturation (+), parents’ consistent use of contingency management (−), peer use of A&T (+), skipping school (+), attending school in immediate proximity to the US/Mexico border (+), and the interaction between the distance to the nearest retailer and parents’ consistent use of contingency management (+). The association between decreasing distance to the nearest A&T retailer and increased A&T use in Latino adolescents reveals an additional risk behavior determinant in the US–Mexico border region

Treating asthma with omega-3 fatty acids: where is the evidence? A systematic review

BACKGROUND: Considerable interest exists in the potential therapeutic value of dietary supplementation with the omega-3 fatty acids. Given the interplay between pro-inflammatory omega-6 fatty acids, and the less pro-inflammatory omega-3 fatty acids, it has been thought that the latter could play a key role in treating or preventing asthma. The purpose was to systematically review the scientific-medical literature in order to identify, appraise, and synthesize the evidence for possible treatment effects of omega-3 fatty acids in asthma. METHODS: Medline, Premedline, Embase, Cochrane Central Register of Controlled Trials, CAB Health, and, Dissertation Abstracts were searched to April 2003. We included randomized controlled trials (RCT's) of subjects of any age that used any foods or extracts containing omega-3 fatty acids as treatment or prevention for asthma. Data included all asthma related outcomes, potential covariates, characteristics of the study, design, population, intervention/exposure, comparators, and co interventions. RESULTS: Ten RCT's were found pertinent to the present report. CONCLUSION: Given the largely inconsistent picture within and across respiratory outcomes, it is impossible to determine whether or not omega-3 fatty acids are an efficacious adjuvant or monotherapy for children or adults. Based on this systematic review we recommend a large randomized controlled study of the effects of high-dose encapsulated omega-3 fatty acids on ventilatory and inflammatory measures of asthma controlling diet and other asthma risk factors. This review was limited because Meta-analysis was considered inappropriate due to missing data; poorly or heterogeneously defined populations, interventions, intervention-comparator combinations, and outcomes. In addition, small sample sizes made it impossible to meaningfully assess the impact on clinical outcomes of co-variables. Last, few significant effects were found