血毒清联合杂合肾脏替代治疗对重症脓毒症的疗效、血流动力学和预后干预作用的研究

目的探讨血毒清联合杂合肾脏替代治疗（HRRT）重症脓毒症的效果及对血流动力学、预后的影响。 方法选取2017年3月至2019年8月十堰市太和医院重症脓毒症患者135例,在常规治疗基础上,按简单随机化法分为血毒清组、HHRT组和血毒清联合HRRT组（联合组）,每组45例,治疗5 d。治疗前和治疗5 d后序贯器官衰竭评分（SOFA）、急性生理学与慢性健康状况评分系统Ⅱ评分（APACHEⅡ）、炎症因子指标[白细胞介素-10（IL-10）、IL-6、降钙素原（PCT）、C反应蛋白（CRP）]水平、血流动力学指标[全身血管阻力指数（SVRI）、血管外肺水指数（EVLWI）、胸腔内血容积指数（ITBVI）、心指数（CI）]及重症监护室（ICU）住院时间比较采用配对t检验,多组间差异采用方差分析,组间两两比较采用LSD-t检验,3组28 d病死率采用c²检验。 结果治疗5 d后,与联合组比较,HHRT组和血毒清组SOFA评分[（4.29±1.17）分比（6.15±1.39）分、（7.03±1.52）分]、APACHEⅡ评分[（11.68±2.12）分比（14.26±3.04）分、（15.17±2.85）分]、血清IL-10 [（36.61±6.50）μg/L比（42.75±7.42） μg/ L、（45.06±8.37） μg / L]、IL-6 [（130.26±41.04） pg/ mL比（169.84±46.75） pg/ mL、（178.36±50.91） pg/ mL]、PCT [（0.87±0.29） ng/mL比（1.96±0.47） ng/mL、（2.24±0.53）ng/mL]、CRP [（34.93±9.71） mg/ L比（51.67±10.32）mg/L、（56.79±11.82）mg/L] 、EVLWI [（4.12±1.38）mL/kg比（5.38±1.69） mL/ kg、（6.04±1.85）mL/kg]降低,而SVRI [（2079.54±124.75） dyn·s·cm^{- 5}·m²比（1865.37±109.38） dyn·s·cm^-5·m²、（1796.28±131.75）dyn·s·cm^-5·m²]、ITBVI [（1189.40±92.36） mL/ m²比（986.97±75.32）mL/m²、（902.37±68.64） mL/ m²]、CI [（4.26±0.65） L·min^-1·m^-2比（3.83±0.58）L·min^-1·m^-2、（3.67±0.53）L·min^-1·m^-2]均升高,差异均有统计学意义（P < 0.05）。与联合组比较,HHRT组和血毒清组ICU住院时间[（14.82±4.40）d比（17.20±3.47）d、（18.46±4.25）d]缩短（P < 0.05）。 结论血毒清联合HRRT治疗重症脓毒症,对减少炎性因子水平,调节血流动力学具有一定作用,能够缩短ICU住院时间。     

实时荧光定量PCR检测金山醋酸乳杆菌的方法与应用

[目的] 建立基于实时荧光定量PCR （RT-qPCR）的金山醋酸乳杆菌特异性检测方法,并将其应用于食醋和白酒发酵过程样品的快速检测。[方法] 筛选金山醋酸乳杆菌基因组中特异性强的基因序列作为模板设计特异性引物,通过标准菌株、醋醅样品进行PCR验证引物的特异性和准确性,建立RT-qPCR方法分析金山醋酸乳杆菌在不同地区酒醅、醋醅和食醋样品中的含量。[结果] 以金山醋酸乳杆菌的苯丙氨酰-tRNA合成酶α亚基（编码pheS基因）为参考序列,设计了一对GC含量55%、T_m值59℃、可扩增199 bp片段的引物。建立的RT-qPCR方法特异性强、灵敏度高且重复性好,检测浓度范围为2.24-10.24 lg （copies/μL）,成功应用于4个地区的酒醅、醋醅和食醋样品检测。对镇江香醋醋酸发酵过程的研究表明,醋醅中的金山醋酸乳杆菌数量先迅速增加,随后稳定在10⁸ copies/g干醅。[结论] 本研究建立的RT-qPCR方法可对食醋和白酒发酵过程中金山醋酸乳杆菌进行特异性鉴定和快速定量。     

Human CST complex protects stalled replication forks by directly blocking MRE11 degradation of nascent‐strand DNA

Degradation and collapse of stalled replication forks are main sources of genomic instability, yet the molecular mechanisms for protecting forks from degradation/collapse are not well understood. Here, we report that human CST (CTC1‐STN1‐TEN1) proteins, which form a single‐stranded DNA‐binding complex, localize at stalled forks and protect stalled forks from degradation by the MRE11 nuclease. CST deficiency increases MRE11 binding to stalled forks, leading to nascent‐strand degradation at reversed forks and ssDNA accumulation. In addition, purified CST complex binds to 5’ DNA overhangs and directly blocks MRE11 degradation in vitro, and the DNA‐binding ability of CST is required for blocking MRE11‐mediated nascent‐strand degradation. Our results suggest that CST inhibits MRE11 binding to reversed forks, thus antagonizing excessive nascent‐strand degradation. Finally, we uncover that CST complex inactivation exacerbates genome instability in BRCA2 deficient cells. Collectively, our findings identify the CST complex as an important fork protector that preserves genome integrity under replication perturbation.     

Proteomic profiling of clinical and environmental strains of Pseudomonas aeruginosa

Molecular Biology Reports - Pseudomonas aeruginosa is a ubiquitous bacterium, which is able to change its physiological characteristics in response to different habitats. Environmental strains are...     

城市化对鸟类筑巢的影响研究综述

繁殖期筑巢是鸟类生活史的重要阶段, 是鸟类繁殖成功的关键保障。全球范围的城市化加速推进, 使城市中筑巢繁殖的鸟类面临挑战的同时又为其提供了特殊机遇。本文通过搜索现有文献, 利用Biblioshiny程序提取并整合关键词, 得到城市鸟类生态研究的热点领域, 分析了城市气候、食物资源、巢址资源、捕食压力、污染和人为干扰对鸟类筑巢的影响, 并对今后城市化对鸟类筑巢影响研究中亟需解决的问题进行了展望。城市化对鸟类筑巢期、巢址选择及巢材选择产生显著影响, 与栖息在村镇生境的鸟类相比, 在城市中繁殖的鸟类在筑巢时间、空间和巢材使用上出现变化。在城市中筑巢的鸟类到底是通过调整行为策略作出积极适应, 还是被动接受城市环境中的诸多负面干扰, 需要针对研究对象和特定的城市栖息生境进行及时评估, 而非泛泛之谈。要在研究结论基础上, 深入思考并提出城市化建设过程中有利于鸟类种群和群落保护的具体措施, 高效发挥公民科学作用以解决城市中的鸟类保护实践问题。     

Antifeedant activity of numb and salty taste compounds against the larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

Helicoverpa armigera, an important polyphagous insect pest in agriculture, attacks more than 200 plant species of more than 30 families. Our previous study showed that the choice feeding percentages of H. armigera larvae to tobacco leaf discs treated with sweet, bitter, and hot taste substances were higher than the control leaf discs, while numb and salty substances could significantly inhibit their feeding. To quantitatively determine the synergistic effect of numb and salty substances, in this paper, the antifeeding activities of numb and salty substances and their mixtures blended in different doses or volume ratios were assayed on H. armigera larvae. The first bioassay was designed to elucidate the relative feeding preference of the larvae to the leaves from several common host species, each paired with tobacco leaf discs, and the result indicated that the most preferred host leaf by the larvae was tobacco leaf, followed by cotton and peanut leaves, suggesting that tobacco leaf was the most suitable matrix for the antifeeding bioassay, and the larval consumption of maize, pepper, or tomato leaves were significantly lower than that of tobacco leaf. The second bioassay was to test the choice feeding response of H. armigera larvae to tobacco leaf discs treated with Zanthoxylum bungeanum extracts obtained with different solvents, and the result showed that the antifeeding activity of the alcohol extracts was the strongest (93.38%), and the leaf consumption in the treatment and the control showed extremely significant difference (t = 4.23, t_0.01 = 3.25, P = 0.0022), followed by the dichloromethane extracts (47.64%), while the other three solvents (water, acetone, and n-hexane) could not extract the active antifeeding components from Z. bungeanum. The larval consumption of tobacco leaf discs treated with the alcohol extracts of Z. bungeanum and NaCl solution were significantly less than their corresponding controls. The mean larval consumption of the treated leaf discs decreased with ever-increasing dosage, and the consumption of tobacco leaf discs coated with different doses of alcohol extracts of Z. bungeanum or NaCl solution showed extremely significant difference (F_{alcohol extract of Z. bungeanum} = 3.88, F_0.01 = 3.58, P = 0.0064; F_{NaCl solution} = 54.29, F_0.01 = 3.58, P = 0.0000), with maximum antifeeding effects at a dosage of 30 μL per 1.5 cm ID leaf disc. We further tested the larval consumption of tobacco leaf discs treated with alcohol extracts of Z. bungeanum in saturated NaCl solution mixed in different volume ratios, and the result showed that the choice antifeeding percentages of the treatments with 15 μL or more Z. bungeanum alcohol extracts were higher than 90%, among which the mixture with 25:15 volume ratio of Z. bungeanum alcohol extracts and saturated NaCl solution exhibited the strongest antifeeding activity, and the mean consumed leaf area of tobacco leaf discs coated with this blend was only 0.10 mm². In the further test on feeding dose-response of the 25:15 mixture, the mean leaf consumption decreased linearly with ever-increasing dosage, with a regression equation y = ?3.9356x + 120.78(R² = 0.9998), and the 30 μL dose could completely inhibit H. armigera feeding.     

Malaria Hotspots Drive Hypoendemic Transmission in the Chittagong Hill Districts of Bangladesh

Background

Malaria is endemic in 13 of 64 districts of Bangladesh, representing a population at risk of about 27 million people. The highest rates of malaria in Bangladesh occur in the Chittagong Hill Districts, and Plasmodium falciparum (predominately chloroquine resistant) is the most prevalent species.

Methods

The objective of this research was to describe the epidemiology of symptomatic P. falciparum malaria in an area of Bangladesh following the introduction of a national malaria control program. We carried out surveillance for symptomatic malaria due to P. falciparum in two demographically defined unions of the Chittagong Hill Districts in Bangladesh, bordering western Myanmar, between October 2009 and May 2012. The association between sociodemographics and temporal and climate factors with symptomatic P. falciparum infection over two years of surveillance data was assessed. Risk factors for infection were determined using a multivariate regression model.

Results

472 cases of symptomatic P. falciparum malaria cases were identified among 23,372 residents during the study period. Greater than 85% of cases occurred during the rainy season from May to October, and cases were highly clustered geographically within these two unions with more than 80% of infections occurring in areas that contain approximately one-third of the total population. Risk factors statistically associated with infection in a multivariate logistic regression model were living in the areas of high incidence, young age, and having an occupation including jhum cultivation and/or daily labor. Use of long lasting insecticide-treated bed nets was high (89.3%), but its use was not associated with decreased incidence of infection.

Conclusion

Here we show that P. falciparum malaria continues to be hypoendemic in the Chittagong Hill Districts of Bangladesh, is highly seasonal, and is much more common in certain geographically limited hot spots and among certain occupations.