Screen of Bacillus thuringiensis toxins for transgenic rice to control Sesamia inferens and Chilo suppressalis

Transgenic rice to control stem borer damage is under development in China. To assess the potential of Bacillus thuringiensis (Bt) transgenes in stem borer control, the toxicity of five Bt protoxins (Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba and Cry1Ca) against two rice stem borers, Sesamia inferens (pink stem borer) and Chilo suppressalis (striped stem borer), was evaluated in the laboratory by feeding neonate larvae on artificial diets containing Bt protoxins. The results indicated that Cry1Ca exhibited the highest level of toxicity to both stem borers, with an LC₅₀ of 0.24 and 0.30 μg/g for C. suppressalis and S. inferens, respectively. However, S. inferens was 4-fold lower in susceptibility to Cry1Aa, and 6- and 47-fold less susceptible to Cry1Ab and Cry1Ba, respectively, compared to C. suppressalis. To evaluate interactions among Bt protoxins in stem borer larvae, toxicity assays were performed with mixtures of Cry1Aa/Cry1Ab, Cry1Aa/Cry1Ca, Cry1Ac/Cry1Ca, Cry1Ac/Cry1Ba, Cry1Ab/Cry1Ac, Cry1Ab/Cry1Ba, and Cry1Ab/Cry1Ca at 1:1 (w/w) ratios. All protoxin mixtures demonstrated significant synergistic toxicity activity against C. suppressalis, with values of 1.6- to 11-fold higher toxicity than the theoretical additive effect. Surprisingly, all but one of the Bt protoxin mixtures were antagonistic in toxicity to S. inferens. In mortality-time response experiments, S. inferens demonstrated increased tolerance to Cry1Ab and Cry1Ac compared to C. suppressalis when treated with low or high protoxin concentrations. The data indicate the utility of Cry1Ca protoxin and a Cry1Ac/Cry1Ca mixture to control both stem borer populations.     

Antifungal susceptibility of epigallocatechin 3-O-gallate (EGCg) on clinical isolates of pathogenic yeasts

This is the first report to investigate the antifungal susceptibility of 21 clinical isolates of seven Candida species to epigallocatechin 3-O-gallate (EGCg) and to compare with six antifungal agents, amphotericin B (AMPH), fluconazole (FLCZ), flucytosin (5FC), itraconazole (ITCZ), micafungin (MCFG), and miconazole (MCZ), using a method following the National Committee for Clinical Laboratory Standards (NCCLS) M27-A guidelines. Among the tested species, Candida glabrata exhibited the highest susceptibility to EGCg (MIC50, 0.5-1 microg/ml and MIC90, 1-2 microg/ml) compared favorably with FLCZ, although they were slightly less susceptible than to AMPH, 5FC, MCFG, ITCZ, and MCZ. Candida guilliemondii and Candida parapsilosis (MIC50, 1-4 microg/ml and MIC90, 2-16 microg/ml) were also susceptible to EGCg, although they appear to be slightly less susceptible to EGCg than C. glabrata and the other antifungal agents tested. Moreover, the susceptibility of Candida krusei strains (MIC50, 2 microg/ml and MIC90, 4-8 microg/ml) to EGCg was approximately 2- to 8-fold higher than those of 5FC and FLCZ. Our data indicate that EGCg can inhibit clinically pathogenic Candida species, although the concentrations of EGCg for antifungal susceptibility were slightly higher than those of tested antifungal agents on the whole. Based on these results, we suggest that EGCg may be effectively used as a possible agent or adjuvant for antifungal therapy in Candidiasis.     

GSTT1 、GSTM1 基因多态性与重度慢性牙周炎 易感性关系的研究

目的：研究GSTTI＋／0和GSTM1＋／0基因型及其联合基因型与重度慢性牙周（chronic pefiodontitis,cp）易感性的关系。方法：用聚合酶链反应检测50例重度慢性牙周炎患者和51例正常对照者的GSIT1＋／0、GSTM1＋／0的基因型。结果：GSTM1（0／0）和GSTT1（0／0）基因型及GSTMI（0／0）与GSTT1（0／0）联合基因型对重度慢性牙周炎相对危险度（OR）分别为9．56（95％CI．3．88—23．59）,8．68（95％CI,3．50—21．51）,36．83（95％CI,10．42—130．13）。结论：在内蒙古汉族人群中,基因型GSTT1（0／0）和GSTM1（0／0）增加了个体对重度慢性牙周炎易感性,且上述两种基因型间存在协同作用。     

山西耕作土壤样品磁性空间分异及其环境意义

本文分析了山西高原土壤耕作层（0-20cm）25个样品的磁性,用GIS空间分析方法,得出土壤磁化率平面分布等值线图和空间三维模型.磁化率空间分布机理如下：首先,强烈的人为影响使土壤中磁性矿物人为来源占有重要地位.第二,土壤磁性矿物以亚铁磁性的磁铁矿和磁赤铁矿为主导.第三,土壤磁化率极值差及其与母质之间的差异均受广泛而较均一的黄土母质的影响.第四,晋西北和晋中等区域出现土壤磁化率高值区域.第五,人为作用强烈影响掩盖了气温、降水等气候因子对土壤磁化率的作用.     

棋盘稀释法在解脲脲原体药敏试验中的应用

解脲脲原体是引起泌尿生殖道感染的重要病原体。目前使用的药敏试验方法即药敏卡法没有考虑样本中脲原体的实际含量而存在局限性。本研究将棋盘稀释法应用于解脲脲原体的药敏试验,可获得脲原体的准确耐药情况,有助于临床治疗中抗生素的正确选择;同时,有利于控制耐药菌株的产生和在人群中的扩散。     

血流感染真菌的分布及耐药性分析

目的了解真菌性血液感染常见病原真茵的菌群分布及耐药性状况,为临床真菌感染性疾病提供病原学诊断和合理使用抗真菌药物的依据。方法回顾性分析浙江大学医学院附属第一医院5年（2008-2012年）间导致真菌性血液感染的217株真菌的菌群分布及药物敏感性状况。结果217株真菌标本中以假丝酵母菌属为主,占88. 5%;其中又以白假丝酵母菌比例最高,占35.4%。菌种分布与患者的性别和年龄存在相关性。60-79岁年龄组感染白假丝酵母菌多见,占49% ,这一比例明显高于其他真菌。男性更容易感染白假丝酵母菌（40.1% vs 24.6%,P〈0.05）,女性感染近平滑假丝酵母菌更常见（24.6% vs 11.8%,P〈0.05）.假丝酵母菌和新生隐球菌对两性霉素B、伏立康唑、氟康唑、伊曲康唑、5-氟胞嘧啶的敏感性均较高。光滑假丝酵母菌对伊曲康唑敏感率较低,仅为60.0%。结论真菌血流感染在临床呈上升趋势,抗真菌药物均体现较高抗菌活性,对真菌感染进行地区层面流行病学调查和耐药监测很重要。     

广州地区生殖系统念珠菌感染的菌型及其体外药敏分析

【摘 要】 目的 了解性传播疾病病人中生殖系统念珠菌感染的菌型及其对临床常用抗真菌药物的敏感性。 方法 采用法国梅里埃公司的ATB ID32C酵母菌鉴定反应板鉴定菌种并使用Rosco纸片扩散法进行体外药敏检测,比较不同菌型念珠菌的药敏情况。 结果 临床131例生殖系统念珠菌感染者中,白色念珠菌116例（88.55%）、近平滑念珠菌7例（5.34%）、光滑念珠菌5例（3.82%）、季也蒙念珠菌2例（1.53%）、克柔念珠菌1例（0.76%）。药敏分析结果：念珠菌属对制霉菌素（96.18%）、酮康唑（90.84%）、氟康唑（70.23%）敏感,而对咪康唑（31.30%）、嗌康唑（31.30%）、伊曲康唑（47.33%）和特比奈酚（7.63%）的中度敏感性和耐药性比较高。 结论 生殖系统念珠菌感染以白色念珠菌为主,感染的念珠菌除了对多烯类药物敏感率高外,对唑类抗真菌药有不同程度的交叉耐药,不同菌型其药敏谱存在差异。     

Tissue responses exhibited by Biomphalaria alexandrina snails from different Egyptian localities following Schistosoma mansoni exposure

Snails’ susceptibilities to infection with Schistosoma mansoni were determined through observation of infection rates, total cercarial production and tissue responses of the first generation (F1) of Biomphalaria alexandrina snails, originally collected from different Egyptian governorates (Giza, Fayoum, Kafr El-Sheikh, Ismailia and Damietta) and responses were compared between groups. The emergence of cercariae for a 3-month period and the calculation of survival and infection rates, in control (Schistosome Biological Supply Center; SBSC) and infected snails were evaluated. SBSC and Giza snails showed greater susceptibilities to infection and lower mortality rates. In addition, at 6 and 72 h post-exposure to miracidia all the snail groups showed no difference in the anatomical locations of sporocysts. The larvae were found in the head-foot, the mantle collar and the tentacles of the snails. Sporocysts showed normal development with low tissue reactions in SBSC and Giza snail groups infected with S. mansoni miracidia (SBSC). However, in Fayoum, Kafr El-Sheikh, Ismailia and Damietta snail groups, variable tissue responses were observed in which numerous hemocytes made direct contact with S. mansoni larvae forming capsules. The results suggested that, different responses of B. alexandrina snail’s hemocytes towards S. mansoni are related to the degree of susceptibility of these snails. So this is important in planning the strategy of schistosomiasis control.     

The identification of candidate genes and SNP markers for classical bovine spongiform encephalopathy susceptibility

Classical bovine spongiform encephalopathy is a transmissible prion disease that is fatal to cattle and is a human health risk due to its association with a strain of Creutzfeldt-Jakob disease (vCJD). Mutations to the coding region of the prion gene (PRNP) have been associated with susceptibility to transmissible spongiform encephalopathies in mammals including bovines and humans. Additional loci such as the retinoic acid receptor beta (RARB) and stathmin like 2 (STMN2) have also been associated with disease risk. The objective of this study was to refine previously identified regions associated with BSE susceptibility and to identify positional candidate genes and genetic variation that may be involved with the progression of classical BSE. The samples included 739 samples of either BSE infected animals (522 animals) or non-infected controls (207 animals). These were tested using a custom SNP array designed to narrow previously identified regions of importance in bovine genome. Thirty one single nucleotide polymorphisms were identified at p < 0.05 and a minor allele frequency greater than 5%. The chromosomal regions identified and the positional and functional candidate genes and regulatory elements identified within these regions warrant further research.     

Artifact quantification of venous stents in the MRI environment: Differences between braided and laser-cut designs

PurposeTo quantify B₀- and B₁-induced imaging artifacts of braided venous stents and to compare the artifacts to a set of laser-cut stents used in venous interventions.MethodsThree prototypes of braided venous stents with different geometries were tested in vitro. B₀ field distortion maps were measured via the frequency shift $\mathrm{\Delta }f$ using multi-echo imaging. B₁ distortions were quantified using the double angle method. The relative amplitudes $B_1^{\mathit{rel}}$ were calculated to compare the intraluminal alteration of B₁. Measurements were repeated with the stents in three different orientations: parallel, diagonal and orthogonal to B₀.ResultsAt 1.5 T, the braided stents induced a maximum frequency shift of $\left|\mathrm{\Delta }f\left(\mathit{x}\right)\right|<100\mathrm{H}\mathrm{z}$. Signal voids were limited to a distance of 2 mm to the stent walls at an echo time of 3 ms. No substantial difference in the B₀ field distortions was seen between laser-cut and braided venous stents. $B_1^{\mathit{rel}}$ maps showed strongly varying distortion patterns in the braided stents with the mean intraluminal $B_1^{\mathit{rel}}$ ranging from $\left(63\pm 18\right)\%$ in prototype 1 to $\left(98\pm 38\right)\%$ in prototype 2. Compared to laser-cut stents the braided stents showed a 5 to 9 times higher coefficient of variation of the intraluminal $B_1^{\mathit{rel}}$.ConclusionBraided venous stent prototypes allow for MR imaging of the intraluminal area without substantial signal voids due to B₀-induced artifacts. Whereas B₁ is attenuated homogeneously in laser-cut stents, the B₁ distortion in braided stents is more inhomogeneous and shows areas with enhanced amplitude. This could potentially be used in braided stent designs for intraluminal signal amplification.