Nos2 Inactivation Promotes the Development of Medulloblastoma in Ptch1+/− Mice by Deregulation of Gap43–Dependent Granule Cell Precursor Migration

Medulloblastoma is the most common malignant brain tumor in children. A subset of medulloblastoma originates from granule cell precursors (GCPs) of the developing cerebellum and demonstrates aberrant hedgehog signaling, typically due to inactivating mutations in the receptor PTCH1, a pathomechanism recapitulated in Ptch1+/− mice. As nitric oxide may regulate GCP proliferation and differentiation, we crossed Ptch1+/− mice with mice lacking inducible nitric oxide synthase (Nos2) to investigate a possible influence on tumorigenesis. We observed a two-fold higher medulloblastoma rate in Ptch1+/− Nos2−/− mice compared to Ptch1+/− Nos2+/+ mice. To identify the molecular mechanisms underlying this finding, we performed gene expression profiling of medulloblastomas from both genotypes, as well as normal cerebellar tissue samples of different developmental stages and genotypes. Downregulation of hedgehog target genes was observed in postnatal cerebellum from Ptch1+/+ Nos2−/− mice but not from Ptch1+/− Nos2−/− mice. The most consistent effect of Nos2 deficiency was downregulation of growth-associated protein 43 (Gap43). Functional studies in neuronal progenitor cells demonstrated nitric oxide dependence of Gap43 expression and impaired migration upon Gap43 knock-down. Both effects were confirmed in situ by immunofluorescence analyses on tissue sections of the developing cerebellum. Finally, the number of proliferating GCPs at the cerebellar periphery was decreased in Ptch1+/+ Nos2−/− mice but increased in Ptch1+/− Nos2−/− mice relative to Ptch1+/− Nos2+/+ mice. Taken together, these results indicate that Nos2 deficiency promotes medulloblastoma development in Ptch1+/− mice through retention of proliferating GCPs in the external granular layer due to reduced Gap43 expression. This study illustrates a new role of nitric oxide signaling in cerebellar development and demonstrates that the localization of pre-neoplastic cells during morphogenesis is crucial for their malignant progression

Intervju: akademik Jakša Barbić

Over the past 20 years evidence has accumulated confirming the immunomodulatory role of the appendix in ulcerative colitis (UC). This led to the idea that appendectomy might alter the clinical course of established UC. The objective of this body of research is to evaluate the short-term and medium-term efficacy of appendectomy to maintain remission in patients with UC, and to establish the acceptability and cost-effectiveness of the intervention compared to standard treatment. These paired phase III multicenter prospective randomised studies will include patients over 18 years of age with an established diagnosis of ulcerative colitis and a disease relapse within 12 months prior to randomisation. Patients need to have been medically treated until complete clinical (Mayo score <3) and endoscopic (Mayo score 0 or 1) remission. Patients will then be randomised 1:1 to a control group (maintenance 5-ASA treatment, no appendectomy) or elective laparoscopic appendectomy plus maintenance treatment. The primary outcome measure is the one year cumulative UC relapse rate - defined both clinically and endoscopically as a total Mayo-score ≥5 with endoscopic subscore of 2 or 3. Secondary outcomes that will be assessed include the number of relapses per patient at 12 months, the time to first relapse, health related quality of life and treatment costs, and number of colectomies in each arm. The ACCURE and ACCURE-UK trials will provide evidence on the role and acceptability of appendectomy in the treatment of ulcerative colitis and the effects of appendectomy on the disease course. NTR2883 ; ISRCTN5652301

Early intervention with inhaled corticosteroids in subjects with rapid decline in lung function and signs of bronchial hyperresponsiveness: results from the DIMCA programme.

Contains fulltext : 51862.pdf (publisher's version ) (Open Access)BACKGROUND: Asthma is generally accepted as an inflammatory disease that needs steroid treatment. However, when to start with inhaled steroids remains unclear. A study was undertaken to determine when inhaled corticosteroids should be introduced as the first treatment step. OBJECTIVE: To investigate the effectiveness of early introduction of inhaled steroids on decline in lung function in steroid-naive subjects with a rapid decline in lung function in general practice. SUBJECTS: Patients with signs/symptoms suspect of asthma (i.e., persistent and/or recurrent respiratory symptoms) and a decline in forced expiratory volume in 1 s (FEV(1)) during 1-year monitoring of 0.080 l or more and reversible obstruction (> or =10% predicted) or bronchial hyperresponsiveness (PC(20)< or =8 mg/ml) were studied. They had been identified in a population screening aiming to detect subjects at risk for chronic obstructive pulmonary disease (COPD) or asthma. DESIGN: A placebo-controlled, randomized, double-blind study. METHODS: 75 subjects out of a random population of 1155 were found eligible, and 45 were willingly to participate. Subjects were randomly treated with placebo or fluticasone propionate 250 microg b.i.d., and FEV(1) and PC(20) were monitored over a 2-year period. OUTCOME VARIABLES: The primary outcome measure was decline in FEV(1); the secondary outcome measure was bronchial hyperresponsiveness (PC(20)). RESULTS: 22 subjects were randomly allocated to the active group with inhaled corticosteroids and 23 to placebo. Change of FEV(1) in the active treated group was +43 ml in post-bronchodilator FEV(1) (p =0.341) and +62 ml/year (p =0.237) in pre-bronchodilator FEV(1) after 1 year, and -22 ml (p =0.304) for post-bronchodilator FEV(1) and -9.4 ml (p =0.691) for pre-bronchodilator FEV(1) after 2 years, compared to placebo. The effect on PC(20) was almost one dose-step (p =0.627) after 1 year and one dose-step (p =0.989) after 2 years. CONCLUSION: In this study, the early introduction of inhaled corticosteroids in newly diagnosed asthmatic subjects with rapid decline in lung function did not prove to be either clinically relevant or statistically significant in reversing the decline in FEV(1). For PC(20), no significant changes were detected

Short- and long-term efficacy of fluticasone propionate in subjects with early signs and symptoms of chronic obstructive pulmonary disease. Results of the DIMCA study.

Item does not contain fulltextBACKGROUND: Early treatment with inhaled corticosteroids may prevent progression of irreversible obstruction in COPD, especially in patients with bronchial hyperresponsiveness. We investigated the clinical effects of early introduction of inhaled steroids in subjects showing early signs and symptoms of COPD without a prior clinical diagnosis. METHODS: Study subjects were detected in a general population screening and monitoring program. Those with a moderately accelerated annual FEV1 decline and persistent respiratory symptoms were invited to participate in a 2-year randomized controlled trial comparing fluticasone propionate DPI 250 microg b.i.d. with placebo. Pre- and post-bronchodilator (BD) FEV1, PC20 histamine, functional status (COOP/WONCA charts) and occurrence of exacerbations were periodically assessed. Subjects recorded respiratory symptoms. Post-BD FEV1 decline served as the main outcome. Multivariable repeated measurements analysis techniques were applied. RESULTS: 48 subjects were randomized (24 fluticasone, 24 placebo). After 3 months, the post-BD FEV1 had increased with 125 ml (SE = 68, P = 0.075) and the pre-BD FEV1 with 174 ml (SE 90, P = 0.059) in the fluticasone relative to the placebo group. The subsequent post-BD and pre-BD FEV1 decline were not beneficially modified by fluticasone treatment. There were no statistically significant differences in respiratory symptoms, functional status, or exacerbations favoring fluticasone. Subgroup analysis indicated that the presence of bronchial hyperresponsiveness modified the initial FEV1 response on fluticasone, but not the subsequent annual FEV1 decline. CONCLUSION: Early initiation of inhaled steroid treatment does not seem to affect the progressive deterioration of lung function or other respiratory health outcomes in subjects with early signs and symptoms of COPD. In subjects at risk for, or in an early stage of COPD, long-term inhaled steroid treatment should not be based on a single spirometric evaluation after 3 months

Quality of life of patients with irritable bowel syndrome is low compared to others with chronic diseases

BACKGROUND: Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal dysmotility disorder. This study aimed to estimate the burden of illness of a Dutch population of community dwelling patients suffering from IBS. METHODS: Patients identified at community pharmacies, using mebeverine as a proxy for IBS, were administered a questionnaire regarding (1) the Rome II criteria for IBS, (2) predominant type of stool during complaints, (3) severity of symptoms (abdominal pain and discomfort), (4) generic and disease-specific quality of life, (5) current health status (utilities), and (6) loss of productivity. RESULTS: Three hundred and seventy-five users of mebeverine were identified of which 169 patients met the Rome II criteria for IBS, and were included in the study. More than half (58%) of the IBS patients reported severe abdominal pain and complaints. Generic and disease-specific quality of life outcomes showed impairment on all dimensions. Current health status in IBS patients, calculated on the basis of the EQ-5D VAS, was perceived on 62% of full health (95% CI, 60-66%). A calculation of health status in these patients based on the SF-6D algorithm showed a comparable score of 0.67 (1 is full health; 95% CI, 0.65-0.68). The loss in productivity of IBS patients was 1.8 days (95% CI, 1.1-2.5) per month. CONCLUSIONS: This study confirmed that the burden of illness of IBS in the Netherlands is substantial. IBS patients treated with mebeverine experienced low quality of life and suffered from severe pain. Based on these results, more attention for the diagnosis and treatment of IBS seems to be justified

Treatment patterns and health care costs of mebeverine-treated IBS patients: a case-control study

BACKGROUND: Irritable bowel syndrome (IBS) is a functional disorder affecting the quality of life of patients. In the Netherlands, mebeverine is currently the only medical treatment registered for IBS, although its efficacy is considered disputable. OBJECTIVE: To assess treatment patterns and associated health care cost in mebeverine users relative to matched controls. METHODS: A matched case-control study was performed using pharmacy data. Cases were mebeverine users as proxy for IBS patients. Controls were non-mebeverine users and matched to cases by age, gender and pharmacy. Prevalence and incidence of mebeverine use, concomitant drug use and hospitalizations were assessed in 3431 cases and 3431 controls. Concomitant drug use and hospitalizations was also assessed in a subgroup of 1222 users of mebeverine and laxatives (proxy for constipation-IBS) and their controls. RESULTS: Twelve per 1000 residents were ever-dispensed mebeverine in 1998. One-third of these mebeverine users used laxatives concomitantly. Concomitant drug use and hospitalizations were increased in mebeverine users. The odds ratio for hospitalizations for gastrointestinal reasons was increased predominantly in mebeverine users with concomitant laxative use (OR:8.7; 95%CI [4.3-17.3]). Excess yearly costs for all concomitant medications were 94 Euros [95%CI 79 Euros-109 Euros] and for hospital admissions 120 Euros [74 Euros-166 Euros] per mebeverine user. In mebeverine users with concomitant laxative use these costs were 136 Euros and 251 Euros respectively. CONCLUSIONS: In treated IBS patients, concomitant drug use and hospitalizations are increased relative to matched controls. Medical resource use and associated health care costs are particularly increased in mebeverine users using laxatives. The total mean excess cost per patient per year is 482 Euro

Lisfranc injuries:fix or fuse? : a systematic review and meta-analysis of current literature presenting outcome after surgical treatment for Lisfranc injuries

Aims: This systematic review and meta-analysis was conducted to compare open reduction and internal fixation (ORIF) with primary arthrodesis (PA) in the treatment of Lisfranc injuries, regarding patient-reported outcome measures (PROMs), and risk of secondary surgery. The aim was to conclusively determine the best available treatment based on the most complete and recent evidence available. Methods: A systematic search was conducted in PubMed, Cochrane Controlled Register of Trials (CENTRAL), EMBASE, CINAHL, PEDro, and SPORTDiscus. Additionally, ongoing trial registers and reference lists of included articles were screened. Risk of bias (RoB) and level of evidence were assessed using the Cochrane risk of bias tools and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool. The random and fixed-effect models were used for the statistical analysis. Results: A total of 20 studies were selected for this review, of which 12 were comparative studies fit for meta-analysis, including three randomized controlled trials (RCTs). This resulted in a total analyzed population of 392 patients treated with ORIF and 249 patients treated with PA. The mean differences between the two groups in American Orthopedic Foot and Ankle Society (AOFAS), VAS, and SF-36 scores were -7.41 (95% confidence interval (CI) -13.31 to -1.51), 0.77 (95% CI -0.85 to 2.39), and -1.20 (95% CI -3.86 to 1.46), respectively. Conclusion: This is the first study to find a statistically significant difference in PROMs, as measured by the AOFAS score, in favour of PA for the treatment of Lisfranc injuries. However, this difference may not be clinically relevant, and therefore drawing a definitive conclusion requires confirmation by a large prospective high-quality RCT. Such a study should also assess cost-effectiveness, as cost considerations might be decisive in decision-making. Level of Evidence:

BRAF gene duplication constitutes a mechanism of MAPK pathway activation in low-grade astrocytomas

The molecular pathogenesis of pediatric astrocytomas is still poorly understood. To further understand the genetic abnormalities associated with these tumors, we performed a genome-wide analysis of DNA copy number aberrations in pediatric low-grade astrocytomas by using array-based comparative genomic hybridization. Duplication of the BRAF protooncogene was the most frequent genomic aberration, and tumors with BRAF duplication showed significantly increased mRNA levels of BRAF and a downstream target, CCND1, as compared with tumors without duplication. Furthermore, denaturing HPLC showed that activating BRAF mutations were detected in some of the tumors without BRAF duplication. Similarly, a marked proportion of low-grade astrocytomas from adult patients also had BRAF duplication. Both the stable silencing of BRAF through shRNA lentiviral transduction and pharmacological inhibition of MEK1/2, the immediate downstream phosphorylation target of BRAF, blocked the proliferation and arrested the growth of cultured tumor cells derived from low-grade gliomas. Our findings implicate aberrant activation of the MAPK pathway due to gene duplication or mutation of BRAF as a molecular mechanism of pathogenesis in low-grade astrocytomas and suggest inhibition of the MAPK pathway as a potential treatment