常见支原体感染误诊与对策

临床支原体感染易发生误诊,不但加重患者精神和经济负担,而且延误患者病情,甚至留下后遗症。为此,我们综述了常见支原体感染误诊的特点和原因,深挖其中思维和思想根源,探讨减少或避免该类误诊现象的策略,旨在为临床医护人员和检验技术人员提供参考建议。     

血清胱抑素C对帕金森病的临床诊断价值

目的:探讨血清胱抑素C(CysC)对帕金森病(PD)的临床诊断意义,为帕金森病的早期诊断和预防治疗提供可参考的血清学指标。方法:采用日立7170全自动生化分析仪检测53例帕金森病患者的血清CysC,以33例健康人作为对照,采用SPSS13.0软件对数据进行统计分析。结果:PD组CysC平均水平为(1.18±0.37)mg/mL,健康对照组为(0.79±0.15)mg/mL,组间均数有显著性差异(t=6.663,P=0.000<0.05)。诊断PD的ROC曲线下的面积为0.860,面积下95%可信区间为(0.782±0.938)。在ROC曲线上确定诊断界点,当界点为0.938时,灵敏度为0.755,特异度为0.888;当界点为1.030时,灵敏度为0.528,特异度为0.970。当CysC水平>0.938 mg/mL时,PD组阳性率为75.47%;当CysC水平>1.03 mg/mL时,PD组阳性率为52.83%。结论:血清CysC对PD的诊断有一定的意义,CysC水平越高,确诊为PD的可能性越大;CysC水平>0.938 mg/mL时,能很好地区别于健康对照组。     

猪链球菌2型强毒株S.suis 05ZY和弱毒株S.suis 1940的比较转录谱分析

目的:比较猪链球菌2型强毒株S.suis 05ZY和弱毒株S.suis 1940毒力相关基因转录水平的差异,为进一步研究强毒株S.suis 05ZY毒力增强的原因提供实验基础。方法:分别提取S.suis 05ZY和S.suis 1940的RNA,反转录成cDNA并纯化,用Cy5或Cy3标记,与猪链球菌全基因组DNA芯片进行杂交,扫描芯片进行数据分析,比较二者在转录水平上的差异基因。结果:编码溶血素、精氨酸氨基肽酶的基因分别上调4.4和6.0倍,参与荚膜多糖合成的相关基因cps2H、cps2I、cps2J和一些可能的毒力相关基因ofs、dpr、SSU05₀196、SSU05₀272、SSU05₁408-1409均发生转录水平的上调。结论:溶血素、荚膜多糖、精氨酸氨基肽酶及一些可能的毒力因子在转录水平的上调很可能与S.suis 05ZY的毒力增强有关。     

Biomechanical analysis of foot with different foot arch heights: a finite element analysis

Clinically, different foot arch heights are associated with different tissue injuries to the foot. To investigate the possible factors contributing to the difference in foot arch heights, previous studies have mostly measured foot pressure in either low-arched or high-arched feet. However, little information exists on stress variation inside the foot with different arch heights. Therefore, this study aimed to implement the finite element (FE) method to analyse the influence of different foot arches. This study established a 3D foot FE model using software ANSYS 11.0. After validating the FE model, this study created low-arched, high-arched and normal-arched foot FE models. The FE analysis found that both the stress and strain on the plantar fascia and metatarsal were higher in the high-arched foot, whereas the stress and strain on the calcaneous, navicular and cuboid were higher in low-arched foot. Additionally, forefoot pressure was increased with an increase in arch height.     

QTL Analysis of Popping Fold and the Consistency of QTLs Under Two Environments in Popcorn

Popping fold (PF) is the most important quality trait in popcorn. In this study, a total of 259 F_2:3 families, derived from the cross between a dent corn inbred Dan232 and a popcorn inbred N04, were evaluated for their popping folds in replicated experiments under two environments. Of 613 simple sequence repeat (SSR) primer pairs screened, 183 pairs were selected to construct a genetic linkage map with the genetic distance of 1 762.2 cM (centimorgan) and on average 9.63 cM every marker. Quantative trait loci (QTL) were identified, and their genetic effects were estimated using CIM (composite interval mapping) method. The interactions among QTLs detected were calculated using MIM (multiple interval mapping) method. In all, 22 QTLs were detected, and only 5 of them were common under two environments. Contribution to phenotypic variation of a single QTL varied from 3.07% to 12.84%, and total contributions of all QTLs under two environments were 66.46% and 51.90%, respectively. Three QTLs (qPF-6-1, qPF-8-1 and qPF-1-3) with more than 10% contributions were observed. The additive effects were larger than dominant effects for most QTLs. The amount of QTLs showing additive, partially dominant, dominant and over-dominant effects were 4, 5, 0, 2 in spring sowing and 2, 5, 2, 2 in summer sowing, respectively. There were only 2.60% pairs of QTLs or maker intervals expressing AA, DA or DD interactions.     

A Signaling Pathway Linking Nitric Oxide Production to Heterotrimeric G Protein and Hydrogen Peroxide Regulates Extracellular Calmodulin Induction of Stomatal Closure in Arabidopsis

Extracellular calmodulin (ExtCaM) regulates stomatal movement by eliciting a cascade of intracellular signaling events including heterotrimeric G protein, hydrogen peroxide (H₂O₂), and Ca²⁺. However, the ExtCaM-mediated guard cell signaling pathway remains poorly understood. In this report, we show that Arabidopsis (Arabidopsis thaliana) NITRIC OXIDE ASSOCIATED1 (AtNOA1)-dependent nitric oxide (NO) accumulation plays a crucial role in ExtCaM-induced stomatal closure. ExtCaM triggered a significant increase in NO levels associated with stomatal closure in the wild type, but both effects were abolished in the Atnoa1 mutant. Furthermore, we found that ExtCaM-mediated NO generation is regulated by GPA1, the Gα-subunit of heterotrimeric G protein. The ExtCaM-dependent NO accumulation was nullified in gpa1 knockout mutants but enhanced by overexpression of a constitutively active form of GPA1 (cGα). In addition, cGα Atnoa1 and gpa1-2 Atnoa1 double mutants exhibited a similar response as did Atnoa1. The defect in gpa1 was rescued by overexpression of AtNOA1. Finally, we demonstrated that G protein activation of NO production depends on H₂O₂. Reduced H₂O₂ levels in guard cells blocked the stomatal response of cGα lines, whereas exogenously applied H₂O₂ rescued the defect in ExtCaM-mediated stomatal closure in gpa1 mutants. Moreover, the atrbohD/F mutant, which lacks the NADPH oxidase activity in guard cells, had impaired NO generation in response to ExtCaM, and H₂O₂-induced stomatal closure and NO accumulation were greatly impaired in Atnoa1. These findings have established a signaling pathway leading to ExtCaM-induced stomatal closure, which involves GPA1-dependent activation of H₂O₂ production and subsequent AtNOA1-dependent NO accumulation.Plant guard cells control opening and closure of the stomata in response to phytohormones (e.g. abscisic acid [ABA]) and various environmental signals such as light and temperature, thereby regulating gas exchange for photosynthesis and water status via transpiration (Schroeder et al., 2001). Cytosolic calcium ([Ca²⁺]_i) has been shown to be a key second messenger that changes in response to multiple stimuli in guard cells (McAinsh et al., 1995; Grabov and Blatt, 1998; Wood et al., 2000). A large proportion of Ca²⁺ is localized in extracellular space. It has been shown that external Ca²⁺ concentration ([Ca²⁺]_o) promotes stomatal closure and induces oscillation in [Ca²⁺]_i in guard cells (MacRobbie, 1992; McAinsh et al., 1995; Allen et al., 2001). However, how the guard cells perceive [Ca²⁺]_o concentration and convert [Ca²⁺]_o changes into [Ca²⁺]_i changes was not understood until a calcium-sensing receptor (CAS) in the plasma membrane of guard cells in Arabidopsis (Arabidopsis thaliana) was identified (Han et al., 2003). The external Ca²⁺ (Ca²⁺_o)-induced [Ca²⁺]_i increase is abolished in CAS antisense lines (Han et al., 2003). Both [Ca²⁺]_o and [Ca²⁺]_i show diurnal oscillation that is determined by stomatal conductance, whereas the amplitude of [Ca²⁺]_i oscillation is reduced in CAS antisense lines (Tang et al., 2007). The reduced amplitude of [Ca²⁺]_i diurnal oscillation in response to Ca²⁺_o treatment suggests the potential existence of other [Ca²⁺]_o sensor(s) that may transmit [Ca²⁺]_o information into the [Ca²⁺]_i response in coordination with CAS. Extracellular calmodulin (ExtCaM) could be such an additional [Ca²⁺]_o sensor.Calmodulin is a well-known Ca²⁺ sensor that is activated upon binding of Ca²⁺. It has been shown that calmodulin exists not only intracellularly but also extracellularly in many plant species (Biro et al., 1984; Sun et al., 1994, 1995; Cui et al., 2005). ExtCaM has been implicated in several important biological functions, such as the promotion of cell proliferation, pollen germination, and tube growth (Sun et al., 1994, 1995; Ma and Sun, 1997; Ma et al., 1999; Cui et al., 2005; Shang et al., 2005). ExtCaM is found in the cell wall of guard cells in Vicia faba and in the epidermis of Arabidopsis by immunogold labeling/electron microscopy and western-blot analyses, respectively, and the endogenous CaM in the extracellular space has been shown to regulate stomatal movements (Chen et al., 2003; Xiao et al., 2004). Under natural conditions, once the activity of ExtCaM has been inhibited by its membrane-impermeable antagonist W7-agrose or CaM antibody, stomatal opening under light is enhanced and stomatal closure in darkness is inhibited in V. faba and Arabidopsis (Chen et al., 2003; Xiao et al., 2004). [Ca²⁺]_i and cytosolic hydrogen peroxide (H₂O₂) changes, two events involved in ExtCaM-regulated stomatal movement (Chen et al., 2004), are likely regulated by light/darkness (Chen and Gallie, 2004; Tang et al., 2007), suggesting that ExtCaM plays an important physiological role in the regulation of stomatal diurnal rhythm. Calmodulin-binding proteins have been found in the protoplast of suspension-cultured Arabidopsis cells, supporting the idea that ExtCaM functions as a peptide-signaling molecule (Cui et al., 2005). Furthermore, ExtCaM triggers [Ca²⁺]_i elevation in guard cells of V. faba and Arabidopsis and in lily (Lilium daviddi) pollen (Chen et al., 2004; Xiao et al., 2004; Shang et al., 2005). These observations support the notion that ExtCaM could be a potential [Ca²⁺]_o sensor for external calcium, and this external calcium sensing could subsequently regulate the [Ca²⁺]_i level through a signaling cascade.It is interesting that ExtCaM and ABA induce some parallel changes in second messengers in guard cell signaling. Our previous studies show that ExtCaM induces [Ca²⁺]_i increase and H₂O₂ generation through the Gα-subunit (GPA1) of a heterotrimeric G protein, and increased H₂O₂ further elevates [Ca²⁺]_i (Chen et al., 2004). G protein, Ca²⁺, and H₂O₂ are well-known second messengers in ABA-induced guard cell signaling (McAinsh et al., 1995; Grabov and Blatt, 1998; Pei et al., 2000; Wang et al., 2001; Zhang et al., 2001; Liu et al., 2007). However, the signaling cascade triggered by ExtCaM in guard cells is poorly understood. New ABA signaling components in guard cells could provide a clue in the study of the molecular mechanism of ExtCaM guard cell signaling.Recently, nitric oxide (NO) has been shown to serve as an important signal molecule involved in many aspects of developmental processes, including floral transition, root growth, root gravitropism, adventitious root formation, xylogenesis, seed germination, and orientation of pollen tube growth (Beligni and Lamattina, 2000; Pagnussat et al., 2002; He et al., 2004; Prado et al., 2004; Gabaldón et al., 2005; Stohr and Stremlau, 2006). Increasing evidence points to a role for NO as an essential component in ABA signaling in guard cells (Garcia-Mata and Lamattina, 2001, 2002; Neill et al., 2002). It has been shown that nitrate reductase (NR) reduces nitrite to NO, and the nia1, nia2 NR-deficient mutant in Arabidopsis showed reduced ABA induction of stomatal closure (Desikan et al., 2002; Bright et al., 2006). Although animal nitric oxide synthase (NOS) activity has been detected in plants and inhibitors of mammalian NOS impair NO production in plants (Barroso et al., 1999; Corpas et al., 2001), the gene(s) encoding NOS in plants is still not clear. AtNOS1 in Arabidopsis was initially reported to encode a protein containing NOS activity (Guo et al., 2003). However, recent studies have raised critical questions regarding the nature of AtNOS1 and suggested that AtNOS1 appears not to encode a NOS (Crawford et al., 2006; Zemojtel et al., 2006). However, the originally described Atnos1 mutant is deficient in NO accumulation (Crawford et al., 2006). Consequently, AtNOS1 was renamed AtNOA1 (for NITRIC OXIDE ASSOCIATED1; Crawford et al., 2006). Therefore, the Atnoa1 mutant provides a useful tool for dissecting the function of NO in plants. At present, the molecules that regulate NO generation in ABA-mediated guard cell signaling are not clear. Evidence suggests that H₂O₂, a second messenger important for the regulation of many developmental processes and stomatal movement (Pei et al., 2000; Zhang et al., 2001; Coelho et al., 2002; Demidchik et al., 2003; Kwak et al., 2003), regulates NO generation in guard cells (Lum et al., 2002; He et al., 2005; Bright et al., 2006).Given the parallel signaling events induced by ABA and ExtCaM, we investigated whether NO is involved in the regulation of ExtCaM-induced stomatal closure in Arabidopsis and whether it is linked to G protein and H₂O₂, two key regulators of both ExtCaM and ABA regulation of stomatal movements. Using Arabidopsis mutants (e.g. GPA1 null mutants, the NO-producing mutant Atnoa1, and the guard cell H₂O₂ synthetic enzymatic mutant atrbohD/F) combined with pharmacological analysis, we present compelling evidence to establish a linear functional relationship between Gα, H₂O₂, and NO in ExtCaM guard cell signaling.     

高温冲击对山楂叶螨的影响

为探索高温冲击对山楂叶螨的影响,在室内采用叶碟饲养的方法,将山楂叶螨不同螨态暴露于33-42℃高温下1-6h,然后在温度(25±1)℃、相对湿度(60±7)%、光周期16h∶8h(L∶D)下测定其寿命、产卵量和孵化率。结果表明,高温冲击对山楂叶螨的影响主要表现在对其产卵量和孵化率的影响,而对成螨的寿命无明显影响;影响的程度取决于高温的强度、持续时间以及处理的螨态。卵经历33-42℃的高温处理1-6h,其孵化率无明显变化,但在随后的发育过程中,幼若螨的发育历期在39℃和42℃6h处理中显著延长,发育至成螨后其产卵量分别增加34.50%和37.41%;幼螨经历39℃和42℃的高温处理6h后发育至成螨时产卵量比对照高出27.02%和35.83%;静止期第二若螨经历39℃和42℃的高温处理,其发育成的雌雄螨的交配和受精能力无明显影响;初羽化雌成螨经历39℃和42℃的高温处理6h后,产卵量不受影响,但卵的孵化率降低了7.01%-11.36%。     

猪链球菌2型强毒株05ZYH33转录调控因子Rgg基因敲除突变体与野生株的基因表达差异分析

目的:为了解猪链球菌2型强毒株05Z33转录调控因子Rgg的调控作用,用基因芯片方法分析野生株与rgg基因敲除突变体之间的差异表达基因。方法:用猪链球菌2型全基因组序列点样制备芯片,将芯片运用于rgg敲除株与野生株的基因表达差异研究,采用定量real-time PCR(qRT-PCR)验证表达谱结果。结果:在突变体中共发现45个基因表达量变化在2倍以上,其中19个基因表达上调,26个基因表达下调。这些基因在细菌毒力、免疫抗原、DNA合成和修复、基础代谢和ABC转运系统等方面起着重要作用。结论:转录调控因子Rgg是一个全局调控因子,但rgg敲除后并不影响猪链球菌的毒力。     

猪链球菌2型05Z33强毒株转录调控因子Rgg基因敲除突变体的构建及毒力分析

目的:构建猪链球菌2型强毒株05ZYH33转录调控因子Rgg的基因敲除突变体,观察其生物学性状,并在动物感染实验中比较敲除株与野生株的毒力差异,为进一步研究猪链球菌转录调控因子在致病中的作用提供实验基础。方法:分别以猪链球菌2型05ZYH33基因组和pSET1质粒为模板,扩增基因SSU05_1997两侧各约500 bp的片段为上下游同源臂,氯霉素(Cm)抗性基因为中间片段,采用重叠PCR方法连接3个片段;连接产物先克隆到T载体上,再经过酶切克隆到温度敏感自杀载体pSET4S上;将构建的基因敲除载体pSET4S-1997电转化入05ZYH33感受态细胞,通过改变培养温度筛选出基因敲除突变体05Z33△rgg;对敲除株和野生株的生物学性状及小鼠和猪的致病性进行了初步比较。结果:PCR分析和测序结果均显示基因SSU05_1997完全被Cm抗性基因所替代,基因敲除突变体构建成功;05ZYH33△rgg对小鼠和猪的致病性与野生株相比无明显差异。结论:转录调控因子Rgg可能和猪链球菌2型的毒力无关。