热量限制对成年弱视小鼠初级视皮质突触可塑性的调控作用

目的：探讨热量限制（CR）对成年单眼形觉剥夺（MD）弱视小鼠视皮质突触可塑性的调控作用及可能的分子机制。方法：实验研究。将54只新生健康昆明小鼠按随机数字表法分为正常组、MD+自由进食（AL）组、MD+CR组,每组18 只。小鼠21 日龄时构建MD模型,35 日龄时去除剥夺因素,63 日龄时通过行为学检测视敏度及电生理检测视功能;免疫组织化学及Western Blot法检测视皮质组织中可塑性相关蛋白突触后致密蛋白95（PSD95）、突触素（SYP）、生长相关蛋白43（GAP-43）等的表达;RT-PCR检测胰岛素样生长因子1（IGF-1）的表达。采用重复测量双因素方差分析比较各组数据差异。结果：最终正常组、MD+AL组、MD+CR组分别有14、18、18 只小鼠完成研究。从第1 周开始,MD+CR组小鼠体质量百分比的增加明显低于MD+AL组（P<0.05）。MD+AL组小鼠视敏度明显低于正常组和MD+CR组小鼠的视敏度（P<0.05）。MD+AL组小鼠PSD95、GAP-43、SYP的表达均明显低于正常组和MD+CR组小鼠（P<0.05）。MD+AL组小鼠视皮质中IGF-1 mRNA水平较正常组和MD+CR组显著降低（P<0.05）。结论：CR能改善成年MD弱视小鼠视觉功能,增加视皮质中可塑性相关蛋白的表达,重新激活视皮质可塑性,其机制可能与其调节IGF-1的表达有关。     

High-Resolution Melting Assay (HRMA) is a Simple and Sensitive Stool-Based DNA Test for the Detection of Mutations in Colorectal Neoplasms

BackgroundStool-based DNA testing for colorectal cancer is becoming a favored alternative to existing DNA screening tests. However, current methods of analysis often become more complicated and costly with increased sensitivity. The high-resolution melting assay (HRMA) is a simple and rapid mutation scanning method with low cost and superb accuracy. In this study, we verified the accuracy of HRMA for screening KRAS/TP53 mutations in stool-isolated DNA from patients with colorectal cancer.Materials and MethodsComparing to direct DNA sequencing, the accuracy of HRMA was verified by detecting KRAS/TP53 mutations in 2 independent stages. In study stage I, both tissue and stool samples from colorectal neoplasm patients were analyzed. In study stage II, stool samples from patients with colorectal neoplasms, and normal controls in clinical screening settings were examined.ResultsIn study stage I, the HRMA identified 14 of 17 target mutations (82.4%) in stools from cancer patients, and 4 of 5 (80.0%) target mutations in stools from advanced adenoma patients. The mutation detection rate in fecal samples (45.0%; 18/40) and referred tissue samples (55.0%; 22/40) was highly consistent (κ = 0.79). The HRMA detected 1% mutant DNA in a background of wild type DNA. In study stage II, the HRMA assay detected 58.8% (20/34) mutations in tumor samples, 41.5% (17/41) in advanced adenomas samples, and 3.33% (2/60) in age-matched normal control samples. The results from HRMA and DNA sequencing revealed 100% sensitivity and specificity in both tissue and stool samples.ConclusionHRMA is a simple, reliable, and sensitive method for detecting DNA mutations in the stool samples from patients with colorectal neoplasms.     

Genome-wide DNA methylation profiling identifies ALDH1A3 promoter methylation as a prognostic predictor in G-CIMP− primary glioblastoma

To date, the aberrations in the DNA methylation patterns that are associated with different prognoses of G-CIMP− primary GBMs remain to be elucidated. Here, DNA methylation profiling of primary GBM tissues from 13 long-term survivors (LTS; overall survival ?18 months) and 20 short-term survivors (STS; overall survival ?9 months) was performed. Then G-CIMP+ samples were excluded. The differentially expressed CpG loci were identified between residual 18 STS and 9 LTS G-CIMP− samples. Methylation levels of 11 CpG loci (10 genes) were statistically significantly lower, and 43 CpG loci (40 genes) were statistically significantly higher in the tumor tissues of LTS than those of STS G-CIMP− samples (P < 0.01). Of the 43 CpG loci that were hypermethylated in LTS G-CIMP− samples, 3 CpG loci localized in the promoter of ALDH1A3. Furthermore, using an independent validation cohort containing 37 primary GBM samples without IDH1 mutation and MGMT promoter methylation, the hypermethylation status of ALDH1A3 promoter predicted a better prognosis with an accompanied low expression of ALDH1A3 protein. Taken together, our results defined prognosis-related methylation signatures systematically for the first time in G-CIMP− primary GBMs. ALDH1A3 promoter methylation conferred a favorable prognosis in G-CIMP− primary GBMs.     

Dynamic properties of human round window membrane in auditory frequencies running head: Dynamic properties of round window membrane

Round window is one of the two openings into cochlea from the middle ear. Mechanical properties of round window membrane (RWM) affect cochlear fluid motion and play an important role in the transmission of sound into cochlea. However, no measurement of mechanical properties of RWM has been reported because of the complication of its location and small size. This paper reports the first investigation on dynamic properties of human RWM using acoustic stimulation and laser Doppler vibrometry measurement. The experiments on RWM specimens were subsequently simulated in finite element (FE) model and an inverse-problem solving method was used to determine the complex modulus in frequency-domain and the relaxation modulus in time-domain. The results show that the average storage modulus of human RWM changes from 2.32 to 3.83 MPa and the average loss modulus from 0.085 to 0.925 MPa over frequencies of 200–8000 Hz. The effects of specimen geometry and experimental condition on complex modulus measurements were discussed through FE modeling analysis. Dynamic properties of RWM reported in this paper provide important data for the study of middle ear and cochlear mechanics.     

血清C反应蛋白及补体C3水平与急性阑尾炎患儿预后相关性

目的：探讨血清中C反应蛋白（CRP）和补体C3水平在急性阑尾炎患儿预后中的关系。方法：筛选我院收治确诊为急性阑尾炎的32例患儿以及28例健康儿童血液样本，检测血清CRP和C3水平。对相关的各检测结果分别进行Pearson直线相关性分析和Logistic回归分析。结果：急性阑尾炎患儿血清CRP升高（P＜0.01），C3含量降低（P＜0.01）；随严重程度升高，CRP增加，C3降低。Pearson分析表明，CRP与C3表达呈负相关（P＜0.05）；Logistic分析表明，CRP和C3均与急性阑尾炎诊断具有显著相关性（P＜0.01）；ROC曲线分析，结果显示CRP和C3在诊断急性阑尾炎中均具有显著的价值（P<0.01）。结论：CRP与C3能够诊断儿童急性阑尾炎，评估发病严重程度，指导临床采取合理治疗措施，改善患儿预后。     

A simple Bayesian decision‐theoretic design for dose‐finding trials

A flexible and simple Bayesian decision‐theoretic design for dose‐finding trials is proposed in this paper. In order to reduce the computational burden, we adopt a working model with conjugate priors, which is flexible to fit all monotonic dose‐toxicity curves and produces analytic posterior distributions. We also discuss how to use a proper utility function to reflect the interest of the trial. Patients are allocated based on not only the utility function but also the chosen dose selection rule. The most popular dose selection rule is the one‐step‐look‐ahead (OSLA), which selects the best‐so‐far dose. A more complicated rule, such as the two‐step‐look‐ahead, is theoretically more efficient than the OSLA only when the required distributional assumptions are met, which is, however, often not the case in practice. We carried out extensive simulation studies to evaluate these two dose selection rules and found that OSLA was often more efficient than two‐step‐look‐ahead under the proposed Bayesian structure. Moreover, our simulation results show that the proposed Bayesian method's performance is superior to several popular Bayesian methods and that the negative impact of prior misspecification can be managed in the design stage. Copyright © 2012 John Wiley & Sons, Ltd.     

RAGE: a new frontier in chronic airways disease

Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous inflammatory disorders of the respiratory tract characterized by airflow obstruction. It is now clear that the environmental factors that drive airway pathology in asthma and COPD, including allergens, viruses, ozone and cigarette smoke, activate innate immune receptors known as pattern-recognition receptors, either directly or indirectly by causing the release of endogenous ligands. Thus, there is now intense research activity focused around understanding the mechanisms by which pattern-recognition receptors sustain the airway inflammatory response, and how these mechanisms might be targeted therapeutically. One pattern-recognition receptor that has recently come to attention in chronic airways disease is the receptor for advanced glycation end products (RAGE). RAGE is a member of the immunoglobulin superfamily of cell surface receptors that recognizes pathogen- and host-derived endogenous ligands to initiate the immune response to tissue injury, infection and inflammation. Although the role of RAGE in lung physiology and pathophysiology is not well understood, recent genome-wide association studies have linked RAGE gene polymorphisms with airflow obstruction. In addition, accumulating data from animal and clinical investigations reveal increased expression of RAGE and its ligands, together with reduced expression of soluble RAGE, an endogenous inhibitor of RAGE signalling, in chronic airways disease. In this review, we discuss recent studies of the ligand–RAGE axis in asthma and COPD, highlight important areas for future research and discuss how this axis might potentially be harnessed for therapeutic benefit in these conditions.