Citrus phenylpropanoids and defence against pathogens. Part II: Gene expression and metabolite accumulation in the response of fruits to Penicillium digitatum infection

The effect of infection of Citrus sinensis (var. Navelina) fruits with Penicillium digitatum was studied at gene expression and metabolite levels. In this study, expression of genes involved in the phenylpropanoid pathway was studied in the flavedo (outer coloured part of the peel) and albedo (inner white part) in response to pathogen infection. Results of the time-course experiment showed that maximal expression of 10 out of 17 phenylpropanoid genes analysed occurred at 48 h post-inoculation, when decay symptoms started to appear, and mRNA levels either kept constant or decreased after 72 h post-inoculation. To further investigate the putative involvement of the phenylpropanoid pathway in the defence of citrus fruit, changes in the metabolic profile of both tissues infected with P. digitatum was studied by means of HPLC-PDA-FD. Metabolite accumulation levels along the time course suggest that flavanones, flavones, polymethoxylated flavones and scoparone are induced in citrus fruit in response to P. digitatum infection, although with different trends depending on the tissue.     

医院空调净化的新趋向--日本"医院空调规范"2004修订版给予的新意

主要介绍日本“医院空调设备的设计管理指南”,2004年的新版本的修订背景、修订特征,医院感染的防止措施,以及室内环境与洁净度分区的修订内容等。建议以科学态度结合国内情况,学习国外新经验。     

Detection of soybean rust using a multispectral image sensor

Soybean rust, caused by Phakopsora pachyrhizi, is one of the most destructive diseases for soybean production. It often causes significant yield loss and may rapidly spread from field to field through airborne urediniospores. In order to implement timely fungicide treatments for the most effective control of the disease, it is essential to detect the infection and severity of soybean rust. This research explored feasible methods for detecting soybean rust and quantifying severity. In this study, images of soybean leaves with different rust severity were collected using both a portable spectroradiometer and a multispectral CDD camera. Different forms of vegetation indices were used to investigate the possibility of detecting rust infection. Results indicated that both leaf development stage and rust infection severity changed the surface reflectance within a wide band of spectrum. In general, old leaves with most severe rust infection resulted in lowest reflectance. A difference vegetation index (DVI) showed a positive correlation with reflectance differences. However, it lacks solid evidence to identify such reflectance change was solely caused by rust. As an alternative, three parameters, i.e. ratio of infected area (RIA), lesion color index (LCI) and rust severity index (RSI), were extracted from the multispectral images and used to detect leaf infection and severity of infection. The preliminary results obtained from this laboratory-scale research demonstrated that this multispectral imaging method could quantitatively detect soybean rust. Further tests of field scale are needed to verify the effectiveness and reliability of this sensing method to detect and quantify soybean rust infection in real time field scouting.     

德莫林应用于白血病肛周感染患者的疗效观察

目的探讨德莫林（皮肤创面无机活性诱导敷料）治疗肛周感染的效果。方法将60例肛周感染患者随机分为2组观察组30例理疗加德莫林;对照组30例局部换药、理疗,比较两组疗效。结果观察组疗效明显优于对照组,两组比较差异有统计学意义（P〈0．01）。结论德莫林治疗肛周感染,有效提高了肛周感染的治愈率,减少患者痛苦。     

计算机病毒知识简介

本文从计算机病毒的科学定义谈起,介绍了计算机病毒的种类,特征、破坏能力传染方式和计算机病毒的预防等方面的知识。     

原因不明发热148例病因分析

The pathogenic causes and ths clinic characteristics for fever of unknown origin were discussed.     

Possibilities and impossibilities of magnetic nanoparticle use in the control of infectious biofilms

Targeting of chemotherapeutics towards a tumor site by magnetic nanocarriers is considered promising in tumor-control. Magnetic nanoparticles are also considered for use in infection-control as a new means to prevent antimicrobial resistance from becoming the number one cause of death by the year 2050. To this end, magnetic nanoparticles can either be loaded with an antimicrobial for use as a delivery vehicle or modified to acquire intrinsic antimicrobial properties. Magnetic nanoparticles can also be used for the local generation of heat to kill infectious microorganisms. Although appealing for tumor-and infectioncontrol, injection in the blood circulation may yield reticuloendothelial uptake and physical obstruction in organs that yield reduced targeting efficiency. This can be prevented with suitable surface modification. However, precise techniques to direct magnetic nanoparticles towards a target site are lacking. The problem of precise targeting is aggravated in infection-control due to the micrometer-size of infectious biofilms, as opposed to targeting of nanoparticles towards centimeter-sized tumors. This review aims to identify possibilities and impossibilities of magnetic targeting of nanoparticles for infection-control. We first review targeting techniques and the spatial resolution they can achieve as well as surface-chemical modifications of magnetic nanoparticles to enhance their targeting efficiency and antimicrobial efficacy.It is concluded that targeting problems encountered in tumor-control using magnetic nanoparticles, are neglected in most studies on their potential application in infection-control. Currently biofilm targeting by smart, self-adaptive and pH-responsive, antimicrobial nanocarriers for instance, seems easier to achieve than magnetic targeting. This leads to the conclusion that magnetic targeting of nanoparticles for the control of micrometer-sized infectious biofilms may be less promising than initially expected.However, using propulsion rather than precise targeting of magnetic nanoparticles in a magnetic field to traverse through infectious-biofilms can create artificial channels for enhanced antibiotic transport.This is identified as a more feasible, innovative application of magnetic nanoparticles in infection-control than precise targeting and distribution of magnetic nanoparticles over the depth of a biofilm.     

Home hemodialysis associated infection—The “Achilles' Heel” of intensive hemodialysis

Home hemodialysis (HHD) is emerging as an important alternate renal replacement therapy. Although there are multiple clinical advantages with HHD, concerns surrounding increased risks of infection in this group of patients remain a major barrier to its implementation. In contrast to conventional hemodialysis, infection related complication represents the major morbidity in this mode of renal replacement therapy. Vascular access related infection is an important cause of infection in this population. Use of central vein catheters and buttonhole cannulation in HHD are important modifiable risk factors for HHD associated infection. Several preventive measures are suggested in the literature, which will require further prospective validation.     

不同预处理方法建立幽门螺杆菌感染动物模型的比较

目的 确定感染率高且稳定的幽门螺杆菌感染动物模型预处理方案。方法 取蒙古沙鼠200只,随机分为3个实验组及1个对照组。实验组沙鼠在断食、水12h后分别应用pH2盐酸、消炎痛+胃复安和50％乙醇3种不同方案进行预处理,对照组用生理盐水处理。此后继续断食、水12h,再灌喂Hp菌液（109cfu/ml）0.5ml/只。共3次,每次间隔12h。最后1次灌喂后2h给食、水。后每隔4周解剖一批动物,每组10只,进行分离培养、ELISA、PCR、快速尿素酶检测和病理切片检查。结果3组实验动物感染率不同,其中50％乙醇组沙鼠感染率相对较高,达到80％,其病理组织学变化与人体相应病变也极为相似。结论50％乙醇组沙鼠预处理方案感染效果最好,可作为Hp感染动物模型的预处理方法。     

颌面颈坏死性进筋膜炎的临床诊治

目的总结坏死性筋膜炎的临床诊治经验。方法回顾分析11例坏死性筋膜炎的临床特点,诊断,病理和治疗要点。结果 9例治愈,1例死亡,1例自动出院。结论应增强对该病的认识。早期诊断,早期积极彻底清创,应用敏感抗菌药物,支持治疗及并发症的防治是治疗的关键。