降钙素原和超敏C-反应蛋白在病毒和细菌感染早期鉴别中的临床应用

为探讨降钙素原(PCT)和超敏C-反应蛋白(hs-CRP)在病毒感染和细菌感染患者鉴别诊断中的价值,对我院276例患者,包括病毒感染组(64例)、细菌感染组(164例)和非感染组(48例)进行降钙素原和超敏C-反应蛋白水平的检测,并对三组间的差异进行分析。结果显示,细菌感染组和病毒感染组PCT、hs-CRP水平显著性高于非感染组(p<0.05);细菌感染组PCT、hs-CRP水平显著性高于病毒感染组(p<0.05)。工作特征曲线及Logistic回归分析结果显示,PCT在鉴别诊断细菌感染和病毒感染的效果高于hs-CRP。研究结果表明,降钙素原、超敏C-反应蛋白可对病毒感染和细菌感染进行早期的鉴别诊断,而降钙素原的效果较好。     

Viral peptide immunogens: current challenges and opportunities.

Synthetic peptide vaccines have potential to control viral infections. Successful experimental models using this approach include the protection of mice against the lethal Sendai virus infection by MHC class I binding CTL peptide epitope. The main benefit of vaccination with peptide epitopes is the ability to minimize the amount and complexity of a well-defined antigen. An appropriate peptide immunogen would also decrease the chance of stimulating a response against self-antigens, thereby providing a safer vaccine by avoiding autoimmunity. In general, the peptide vaccine strategy needs to dissect the specificity of antigen processing, the presence of B-and T-cell epitopes and the MHC restriction of the T-cell responses. This article briefly reviews the implications in the design of peptide vaccines and discusses the various approaches that are applied to improve their immunogenicity.     

母源性抗体抗病毒性疾病研究进展

母源性抗体能够保护新生儿和婴幼儿早期抵御多种病毒的感染,但它也严重抑制婴幼儿疫苗接种后主动免疫应答的建立．母源性抗体降至失去有效保护作用但又足以抑制婴幼儿对疫苗的免疫应答这样一段时期是婴幼儿病毒性疾病的易感期．目前有多种解释试图阐明母源性抗体抑制作用的机理．综述了近年来母源性抗体及其在抗病毒性疾病中的相关研究结果,主要从母源性抗体的传递途径、母源性抗体保护新生儿和婴幼儿早期抗病毒感染、母源性抗体对婴幼儿疫苗接种后主动免疫应答的影响以及母源性抗体抑制婴幼儿主动免疫应答机理假说等方面进行阐述．     

沙漠化过程中四个共有种的生长和抗氧化系统酶类变化

探讨了自然条件下沙质草原沙漠化过程中4个共有植物种群的形态、生长和抗氧化系统酶类变化规律．结果表明,沙漠化过程中共有种种群株高、密度、密度百分比总体上呈降低趋势,其中扁蓿豆中度沙漠化阶段前生长渐趋旺盛,中度沙漠化阶段后生长受到限制,未达到显著水平(P>0．05)．羊草受损最重,中度沙漠化阶段株高下降至原生植被阶段的57．19％,密度和密度百分比仅为原生植被阶段的2．50％和6．22％．糙隐子草和冷蒿在潜在沙漠化、轻度沙漠化或中度沙漠化阶段株高的增加与种群所处的阶段性优势地位及其抗逆性增强有关．共有种群SOD、POD活性普遍在潜在沙漠化、中度沙漠化阶段增加,轻度沙漠化、重度沙漠化阶段降低．羊草过氧化氢酶(CAT)活性较高,对沙漠化的响应不显著(P>0．05);扁蓿豆CAT活性在潜在沙漠化、重度沙漠化阶段明显升高(P≤0．01)．在重度沙漠化阶段,共有种3种酶活性普遍下降,只有扁蓿豆CAT活性上升．共有种群丙二醛含量从原生植被到中度沙漠化阶段均呈“先升后降再升”的变化,不同阶段之间差异显著(P≤0．05)．综合分析表明,4个共有种中,羊草对沙漠化较敏感,扁蓿豆则生命力最强。     

热休克蛋白HSP70和gp96在抗病毒感染中的作用

热休克蛋白(HSP)是一组在进化上高度保守、具有重要生理功能的蛋白质家族,是生物在应激条件下产生的一种非特异性防御产物,在调节免疫应答和抗病毒反应中起重要作用。现简要介绍HSP70、gp96(HSP96,GRP94)这两种HSP与病毒感染的关系及在抗病毒感染中的作用。     

甲型流感病毒合并肺部感染与非病毒性肺部感染的表现及治疗分析

目的:通过与非病毒性肺部感染对比,分析甲型流感病毒合并肺部感染患者的常见临床实验检查及治疗效果,为经验性治疗甲型流感病毒提供一定依据。方法:选择2017年11月至2018年4月期间在我科接受治疗的已确诊存在甲型流病毒合并肺部感染(A组)及非病毒性肺感染(B组)各25例,对于确诊的甲型流感患者给予奥司他韦抗病毒治疗一周外,两组均正常给予常规抗感染治疗,对比两组患者的炎症指标白细胞计数、中性粒细胞比例、C-反应蛋白及治疗天数、住院天数、症状消失时间、不良反应发生率。结果:两组患者的CT检查表现无统计学差异(P0.05),A组患者的白细胞计数水平明显低于B组,差异有统计学意义(P0.05),而两组患者的中性粒细胞比例及C反应蛋白水平差异无统计学意义(P0.05)。两组患者的治疗天数及住院天数差异均无统计学意义(P0.05)。两组患者在体温恢复正常时间、咳嗽消失时间、肺部湿罗音消失时间、气促消失时间等比较差异无统计学意义(P0.05)。A组不良反应发生率为16.00%(4/25),B组不良反应发生率为12.00%(3/25),组间差异无统计学意义(P0.05)。结论:甲型病毒性肺部感染常表现为血常规未见异常,常伴发不同程度炎症反应,除常规抗感染治疗外,口服抗病毒药物奥司他韦可促进疾病转归。     

Epidemiology and Pathogenesis of Staphylococcus Bloodstream Infections in Humans: a Review

Staphylococci are among the most frequent human microbiota components associated with the high level of bloodstream infection (BSI) episodes. In predisposed patients, there is a high risk of transformation of BSI episodes to sepsis. Both bacterial and host factors are crucial for the outcomes of BSI and sepsis. The highest rates of BSI episodes were reported in Africa, where these infections were up to twice as high as the European rates. However, there remains a great need to analyze African data for comprehensive quantification of staphylococcal BSI prevalence. The lowest rates of BSI exist in Australia. Asian, European, and North American data showed similar frequency values. Worldwide analysis indicated that both Staphylococcus aureus and coagulase-negative staphylococci (CoNS) are the most frequent BSI agents. In the second group, the most prevalent species was Staphylococcus epidermidis, although CoNS were not identified at the species level in many studies. The lack of a significant worldwide decrease in BSI episodes indicates a great need to implement standardized diagnostic methods and research etiological factors using advanced genetic methods.     

Structurally unrelated algal oligosaccharides differentially stimulate growth and defense against tobacco mosaic virus in tobacco plants

Tobacco plants were treated with structurally unrelated oligosaccharides obtained from Chilean marine macroalgae. These oligosaccharides were prepared by chemical depolymerization of native polysaccharides extracted from brown and red algae and correspond to pure polymers of around 20 units of guluronic acid (Poly-Gu), mannuronic acid (Poly-Ma) and sulphated galactan (Poly-Ga). These oligosaccharides were solubilized in water, at a final concentration of 500 μg mL⁻¹, and sprayed on tobacco leaves, once a week for a month. Their effects on the stimulation of growth and defense against tobacco mosaic virus (TMV) were determined 7 and 15 days after the final spraying, respectively. The activities of several defense and antioxidant enzymes and the levels of water-soluble antioxidant compounds were determined. Plants treated with Poly-Ga and Poly-Ma showed an increase in height of 23% and 49%, respectively, whereas Poly-Gu did not stimulate growth. Plants treated with Poly-Gu, Poly-Ma and Poly-Ga showed an increase in defense against TMV corresponding to decreases in the number of necrotic lesions of 9%, 22% and 74%, respectively. The stimulation of plant growth correlates with activation of the antioxidant enzyme ascorbate peroxidase (AP) and with a decrease in ascorbate level. On the other hand, the stimulation of defense against TMV is correlated with the activation of the defense enzyme phenylalanine ammonia-lyase (PAL). These results indicate that algal oligosaccharides differentially stimulate growth and defense against TMV in tobacco plants and that these processes involve the activation of the enzymes AP and PAL, respectively.     

Iron withholding: A defense against viral infections

A variety of laboratory and clinical investigations during the past 15 years have observed that one of the dangers of excessive iron is its ability to favor animal viral infections. The metal is essential for host cell synthesis of virions and can also impair defense cell function and increase oxidative stress. In both animal models and humans, viral infections cause upregulation of the iron withholding defense system. Factors that suppress the system enhance viral progression; factors that strengthen the system augment host defense. Procedures designed to reinforce the system are being developed and tested; some of these may become useful adjuncts in prevention and management of viral diseases.     

The Role of Viral Infection in Inducing Variability in Virus-Free Progeny in Tomato

The effect of virus-host interactions on subsequent generations is poorly understood. The evaluation of the effects of viral infection on inheritance of quantitative traits in the progeny of infected plants and elucidation of a possible relationship between chiasma frequency in the infected plants and variability of traits in the progeny were investigated. The current study involved genotypes of four intraspecific hybrids of tomato (Solanum lycopersicum L.), their parental forms and two additional cultivars. Used as infection were the tobacco mosaic virus (TMV) and potato virus X (PVX). The consequences of the effect of viral infection were evaluated based on chromosome pairing in diakinesis and/or by examining quantitative and qualitative traits in the progeny of the infected tomato plants. Tomato plants infected with TMV + PVX were found to differ in chiasma frequency per pollen mother cell or per bivalent. Deviations have been observed for genotypes of both F1 hybrids and cultivars. At the same time, differences in mean values of the traits under study have only been found for progeny populations (F2-F4) derived from virus-infected F1 hybrids, but not in the case of progeny of the infected cultivars. The rate of recombinants combining traits of both parents increased significantly (2.22-8.24 times) in progeny populations of hybrids infected with TMV + PVX. The above suggests that the observed effects could be the result of modification of recombination frequencies that can be manifested in heterozygous hybrids and make small contributions to variability in cases of 'homozygous' tomato genotypes (I.e. Cultivars).     

Genomic Analysis of the Viral Population in Genital Secretions Early after Infection of Simian Immunodeficiency Viruses in Macaque Monkeys

To clarify the change in the viral population during passage from the vaginal cavity to blood circulation and vice versa, we examined the viral clones detected in cells in vaginal washes (VWCs) early after inoculation and after systemic infection with polyclonal SIV. In two intravaginally inoculated monkeys, the viral clones found in VWCs at 18 days p.i. were shown to be some of those contained in the inoculum, whereas the viral population in the peripheral blood mononuclear cells (PBMCs) was a monotype. This gradual decrease of viral clones suggested the possible existence of two barriers, one at the genital tract and the other between the genital tract and the blood. Later, at one month p.i., the viral clones in VWCs became rather restricted, whereas those in PBMCs diverged from a single clone to several clones. This suggested that different mechanisms affect the viral populations in PBMCs and VWCs. In order to examine how the viral population was affected by passage from the blood to the vaginal cavity, a monkey was intravenously inoculated and the viral clones in VWCs were analyzed at 14 days p.i., at a time of the heterogeneous population in PBMCs. The viral population in VWCs was found to be a single clone and this clone was a minor type in PBMCs, suggesting that the major clone in PBMCs was not always secreted to the vaginal cavity.     

牲畜粪便对草地生态系统影响的研究进展

粪便归还是放牧影响草地生态系统的主要途径之一。本文对粪便分解过程和粪便对草地生态系统的土壤理化性质、微生物活性、植物群落结构和生物量、牲畜取食格局影响等方面的研究进展进行了综述,最后提出了草地生态系统牲畜粪便研究的未来趋势。     

PANoptosis in Viral Infection: The Missing Puzzle Piece in the Cell Death Field

In the past decade, emerging viral outbreaks like SARS-CoV-2, Zika and Ebola have presented major challenges to the global health system. Viruses are unique pathogens in that they fully rely on the host cell to complete their lifecycle and potentiate disease. Therefore, programmed cell death (PCD), a key component of the host innate immune response, is an effective strategy for the host cell to curb viral spread. The most well-established PCD pathways, pyroptosis, apoptosis and necroptosis, can be activated in response to viruses. Recently, extensive crosstalk between PCD pathways has been identified, and there is evidence that molecules from all three PCD pathways can be activated during virus infection. These findings have led to the emergence of the concept of PANoptosis, defined as an inflammatory PCD pathway regulated by the PANoptosome complex with key features of pyroptosis, apoptosis, and/or necroptosis that cannot be accounted for by any of these three PCD pathways alone. While PCD is important to eliminate infected cells, many viruses are equipped to hijack host PCD pathways to benefit their own propagation and subvert host defense, and PCD can also lead to the production of inflammatory cytokines and inflammation. Therefore, PANoptosis induced by viral infection contributes to either host defense or viral pathogenesis in context-specific ways. In this review, we will discuss the multi-faceted roles of PCD pathways in controlling viral infections.     

The Crucial Role of Chloroplast-Related Proteins in Viral Genome Replication and Host Defense against Positive-Sense Single-Stranded RNA Viruses

Plant viruses are responsible for worldwide production losses of numerous economically important crops. The most common plant RNA viruses are positive-sense single-stranded RNA viruses [(+)ss RNA viruses]. These viruses have small genomes that encode a limited number of proteins. The viruses depend on their host’s machinery for the replication of their RNA genome, assembly, movement, and attraction to the vectors for dispersal. Recently researchers have reported that chloroplast proteins are crucial for replicating (+)ss plant RNA viruses. Some chloroplast proteins, including translation initiation factor [eIF(iso)4E] and 75 DEAD-box RNA helicase RH8, help viruses fulfill their infection cycle in plants. In contrast, other chloroplast proteins such as PAP2.1, PSaC, and ATPsyn-α play active roles in plant defense against viruses. This is also consistent with the idea that reactive oxygen species, salicylic acid, jasmonic acid, and abscisic acid are produced in chloroplast. However, knowledge of molecular mechanisms and functions underlying these chloroplast host factors during the virus infection is still scarce and remains largely unknown. Our review briefly summarizes the latest knowledge regarding the possible role of chloroplast in plant virus replication, emphasizing chloroplast-related proteins. We have highlighted current advances regarding chloroplast-related proteins’ role in replicating plant (+)ss RNA viruses.     

病毒感染引起的炎症反应：宿主对抗病毒的“双刃剑”

先天性免疫系统作为宿主抵抗外来病原入侵的第一道防线,也是最迅速的防御系统。宿主先天性免疫系统中的模式识别受体识别入侵信号并激活炎症信号通路,诱导产生大量促炎性细胞因子,引起炎症反应。病毒感染是激活炎症反应的条件之一,诱导机体产生强烈的免疫应答,强大的炎症反应调控网络在宿主抗病毒过程中发挥关键作用,以维持机体的平衡。本文综述了病毒感染引起的炎症反应,重点介绍了宿主对炎症反应的调控网络,以及DNA和RNA病毒对炎症反应的调节机制,为病毒感染引起的免疫性疾病的治疗提供参考。     

Spread of Pathogens Causing Respiratory Viral Diseases Before and During CoVID-19 Pandemic in Kazakhstan

Analyze clinical samples collected and determine the etiology of viral pathogens and the dynamics of their spread. Acute respiratory viral infections remain one of the key health problems worldwide. They constitute etiologically independent diseases, with similar clinical infection manifestations and a single mechanism for the transmission of pathogens. 4712 nasopharyngeal swabs were collected from people before and during the COVID-19 pandemic with acute respiratory infections that tested negative for COVID-19 and were examined in this study. The collected samples were screened by a real-time polymerase chain reaction on a Rotor-Gene Q6 plex instrument. Statistical processing of the results, tabular, and graphical data were analyzed in the MS Excel. The largest number of the nasopharyngeal swabs were collected from children under 17 years of age (60.75%). In 702 samples (9.85%) pathogens of respiratory infections of non-influenza etiology were detected, including adenovirus, bocavirus, coronavirus, metapneumovirus, paramyxovirus types I–IV, respiratory syncytial virus, and rhinovirus. At the same time, both before and during the COVID-19 pandemic, different influenza virus variants co-circulation (A/H1N1, A/H3N2, and type B) were discovered, with a predominance of viruses with the antigenic formula A/H1N1. The results of the study indicate the need for continuous monitoring of the viral pathogens spread, which will expand the existing knowledge of the viral etiology of respiratory diseases and highlight the importance of viruses in the respiratory infections occurrence.     

植物内生细菌对植物健康的作用

植物内生菌是一个多样性十分丰富的微生物类群,存在于没有外在感染症状的健康植物组织内,并与宿主植物协同进化.随着研究领域的不断拓宽和研究方法的不断更新,植物内生菌与植物健康的关系以及应用逐渐成为研究热点.本文主要综述了内生细菌的多样性、进入植物组织内的机制以及内生细菌的主要功能及应用,提出了现阶段内生菌研究存在的问题,并展望了内生菌研究的前景.     

Modelling Environmental Responses of Plant Associations: A Review of Some Critical Concepts in Vegetation Study

The definition of vegetation types at different hierarchical levels, both to study the vegetation processes and for practical cartographic representation, is still considered a critical issue in many circles of plant ecologists. The problems are mainly related to the misleading idea that classification of the vegetation system, as developed by European phytosociologists during the last century within the discipline called syntaxonomy, would imply the assumption of the organismic concept of the plant community. After a short discussion on the role of Braun-Blanquet approach in plant ecology and in landscape ecology, the methods to detect multispecies responses along environmental gradients are briefly reviewed. In the main part of this article, we intend to stress that concepts considered critical, such as plant association and its ecological niche, are just operational tools that have nothing to do with the individualistic or organismic interpretation of plant communities in vegetation studies. Important to our views on vegetation, we believe that plant associations as well as the higher syntaxa can be regarded as fuzzy sets in an operational context for describing vegetation along ecological gradients in synthetic ways and can further the understanding of vegetation variation.