268份人类免疫缺陷病毒抗体待确定样本的检测结果分析

为了提高实验室人类免疫缺陷病毒(human immunodeficiency virus,HIV)抗体检测能力及对免疫蛋白印迹(Western blot,WB)实验结果的判断能力,对送检至北京市东城区艾滋病确证实验室的268份HIV抗体待确定样本进行确证实验及结果分析。按照试剂说明书和实验室标准作业程序(Standard Operation Procedure,SOP)操作对送检的全部样本进行WB确证实验;了解HIV筛查实验结果与确证实验结果的相关性,并分析不同送检机构、送检人群样本的检测结果差异以及不同试剂、不同检测方法的结果差异。结果显示在筛查出抗体待确定的268份样本中,确证阳性170份,阳性率63.43%;确证阴性51份,阴性率19.03%;不确定结果47份,占筛查有反应的17.54%。确证阳性病例来自监管场所、自愿咨询检测门诊(Voluntary Counseling and Test,VCT)和医疗机构,不同送检单位及不同人群的阳性样本率有显著统计学意义(P<0.01)。WB确证阳性样本带型以全条带和次全条带为主,且所有确证阳性标本均来自双试剂阳性样本。不同检测方法阳性样本率的差异有显著统计学意义(P<0.01),其中化学发光法的样本阳性率占46.27%,酶联免疫吸附实验(ELISA)占88.29%,胶体硒法占43.48%。本研究结果提示,对潜在HIV感染者,应扩大检测面,加强医疗机构检测,并提供一种以上方法的多次检测,以减少漏检的风险。     

超声引导下腔内射频消融联合点式剥脱治疗下肢静脉曲张的临床效果观察

目的:探讨超声引导下腔内射频消融(radiofrequency endovenous obliteration,RFO)联合点式剥脱治疗下肢静脉曲张的临床疗效及安全性。方法:选取2017年10月至2018年10月哈尔滨医科大学附属第一医院收治的下肢静脉曲张患者共320例(320条肢体),将其随机分为观察组200例和对照组120例。观察组200例(200条肢体)采用超声引导下腔内射频消融联合点式剥脱进行治疗,对照组120例(120条肢体)采用传统大隐静脉高位结扎剥脱、曲张静脉点式剥脱治疗。比较两组患者平均住院时间、术后并发症的发生情况及术后1年下肢静脉的彩超随访情况。结果:观察组患者平均住院时间较对照组显著缩短,术后皮肤瘀斑、皮下血肿、隐神经损伤、切口感染的发生率显著低于对照组(P0.05),两组患者术后1年复查,其复发率及大隐静脉主干闭塞情况比较差异没有统计学意义(P0.05)。结论:与传统大隐静脉高位结扎剥脱、曲张静脉点式剥脱治疗相比,超声引导下腔内射频消融联合点式剥脱治疗下肢静脉曲张的疗效及安全性均更高,有利于患者术后康复。     

RPN2与肝癌患者预后及对肝癌细胞生长的作用

目的:探讨核糖蛋白2(ribophorin II,RPN2)在肝细胞肝癌(HCC)组织中的表达和对HCC患者生存的影响,同时分析RPN2对肝癌HepG2细胞生长和克隆形成的作用。方法:应用免疫组化方法和HCC公共芯片数据,从蛋白和m RNA水平检测HCC组织中RPN2的表达,同时分析RPN2与HCC患者临床参数的关系及预后相关性;进一步利用MTS法和克隆形成实验在肝癌HepG2细胞中检测RPN2对细胞生长的作用。结果:98例肝癌组织中,RPN2阳性表达率88.78%,对应癌旁肝组织中,RPN2阳性表达率74.49%;癌组织中RPN2染色评分为5.80±3.15,癌旁肝组织RPN2染色评分为2.13±1.59,肝癌组织中RPN2表达显著上调(P0.001)。3个肝癌公共芯片数据(共522例肝癌)中RPN2的m RNA表达水平同样显著升高(均P0.001)。98例肝癌患者RPN2表达水平与肿瘤直径(P=0.004)、门脉侵袭(P=0.012)和TNM分期(P=0.009)相关;RPN2高表达的患者总体生存期(OS)和无复发生存期(RFS)较RPN2低表达的患者短(OS:P=0.027;RFS:P=0.036)。肝癌HepG2细胞转染RPN2小干扰RNA后,细胞生长能力显著受抑制。结论:RPN2在肝癌中表达显著升高,RPN2的表达与肝癌的恶性进展有关,RPN2显著促进肝癌细胞生长。     

加味八珍汤联合PFNA术治疗老年股骨转子间骨折患者的临床效果及对血液流变学指标的影响

目的:研究加味八珍汤联合股骨近端防旋髓内钉(Proximal Femoral Nail Antirotation,PFNA)对老年股骨转子间骨折患者的临床效果及对术后隐性失血和血液流变学的影响。方法:选择2014年3月至2017年3月我院收治的68例接受PFNA治疗的转子间骨折者,将其随机平均分为观察组(34例,术后口服加味八珍汤颗粒7天)、对照组(34例)。对比两组总失血量、隐性失血量、隐性失血比例、血液流变学指标(血浆粘度及全血黏度低、中、高切)、不良反应等。结果:⑴两组各剔除2例,94.12%(64/68)的受试者完成研究。⑵两组总失血量相当,差异无统计学意义(P0.05);与对照组相比,观察组隐性失血量及隐性失血发生率均显著降低(P0.05)。⑶治疗前,两组血浆粘度及低、中、高切全血黏度比较差异无统计学意义(P0.05);治疗后,两组血浆粘度及低、中、高切全血黏度均显著低于本组治疗前(P0.05),且观察组以上指标均明显低于对照组(P0.05)。⑷观察组发生肌间静脉血栓1例,无药物过敏及毒副反应;对照组发生1例深静脉血栓、4例肌间静脉血栓。观察组不良反应率为3.125%,显著低于对照组(15.625%,P0.05)。结论:加味八珍汤既可显著减少老年股骨转子间骨折患者PFNA术后隐性失血,又能改善血流动力学、减少并发症。     

Molecular phylogeny and species delimitation of Stachyuraceae: Advocating a herbarium specimen‐based phylogenomic approach in resolving species boundaries

Species concept and delimitation are fundamental to taxonomic and evolutionary studies. Both inadequate informative sites in the molecular data and limited taxon sampling have often led to poor phylogenetic resolution and incorrect species delineation. Recently, the whole chloroplast genome sequences from extensive herbarium specimen samples have been shown to be effective to amend the problem. Stachyuraceae are a small family consisting of only one genus Stachyurus of six to 16 species. However, species delimitation in Stachyurus has been highly controversial because of few and generally unstable morphological characters used for classification. In this study, we sampled 69 individuals of seven species (each with at least three individuals) covering the entire taxonomic diversity, geographic range, and morphological variation of Stachyurus from herbarium specimens for genome‐wide plastid gene sequencing to address species delineation in the genus. We obtained high‐quality DNAs from specimens using a recently developed DNA reconstruction technique. We first assembled four whole chloroplast genome sequences. Based on the chloroplast genome and one nuclear ribosomal DNA sequence of Stachyurus, we designed primers for multiplex polymerase chain reaction and high throughput sequencing of 44 plastid loci for species of Stachyurus. Data of these chloroplast DNA and nuclear ribosomal DNA internal transcribed spacer sequences were used for phylogenetic analyses. The phylogenetic results showed that the Japanese species Stachyurus praecox Siebold & Zucc. was sister to the rest in mainland China, which indicated a typical Sino‐Japanese distribution pattern. Based on diagnostic morphological characters, distinct distributional range, and monophyly of each clade, we redefined seven species for Stachyurus following an integrative species concept, and revised the taxonomy of the family based on previous reports and specimens, in particular the type specimens. Furthermore, our divergence time estimation results suggested that Stachyuraceae split from its sister group Crossosomataceae from the New World at ca. 54.29 Mya, but extant species of Stachyuraceae started their diversification only recently at ca. 6.85 Mya. Diversification time of Stachyurus in mainland China was estimated to be ca. 4.45 Mya. This research has provided an example of using the herbarium specimen‐based phylogenomic approach in resolving species boundaries in a taxonomically difficult genus.     

绵马贯众多糖超声提取工艺优化及抗氧化活性分析

绵马贯众是中国传统常用中药,本研究以温度、时间、超声功率、液料比为影响因子,多糖得率为评价指标,通过响应面法优化超声辅助提取绵马贯众多糖的工艺条件,同时测定其基本理化性质及抗氧化活性。研究结果表明,绵马贯众多糖的最佳提取工艺条件为:温度64℃、时间60 min、超声功率210 W、液料比27 mL/g。此时多糖得率为9.57%,与预测值接近。理化性质分析表明绵马贯众多糖为含少量蛋白的酸性多糖。体外抗氧化研究表明绵马贯众多糖具有很强的DPPH自由基清除活性,IC50值为0.29 mg/mL;较好的羟基自由基清除活性,其IC50值为1.10 mg/mL;对DNA的氧化损伤有显著的保护作用。绵马贯众多糖可以作为一种潜在的抗氧化剂应用于食品和化妆品等领域。     

Microbial assemblages associated with the rhizosphere and endosphere of an herbage,Leymus chinensis

Root-associated microbiomes play significant roles in plant productivity, health and ecological services. However, our current understanding of the microbial assemblages in the rhizosphere and endosphere of herbage is still limited. To gain insights into these microbial assemblages, Illumina MiSeq high-throughput sequencing was performed to investigate the characteristics of microbial communities of an herbage, Leymus chinensis. Hierarchical clustering analysis and principal coordinate analysis (PCoA) results showed that microbial communities of the rhizosphere and endosphere samples were clearly distinguished. Rhizosphere soil communities showed a greater sensitivity than root endosphere communities using linear discriminant analysis (LDA) effect size (LEfSe). Rhizosphere and endosphere communities performed their respective functions in the soil as a cohesive collective, and Rhizobiales were observed to function as generalists. Redundancy analysis (RDA) and variance partitioning analysis (VPA) results revealed that the contribution of the interaction between soil physicochemical parameters and soil enzymes was greater than their individual contributions. In summary, this study is the first to elucidate the microbial diversity and community structure of L. chinensis and compare the diversity and composition between rhizospheric and endosphere microbiomes.     

Aging shifts mitochondrial dynamics toward fission to promote germline stem cell loss

Changes in mitochondrial dynamics (fusion and fission) are known to occur during stem cell differentiation; however, the role of this phenomenon in tissue aging remains unclear. Here, we report that mitochondrial dynamics are shifted toward fission during aging of Drosophila ovarian germline stem cells (GSCs), and this shift contributes to aging‐related GSC loss. We found that as GSCs age, mitochondrial fragmentation and expression of the mitochondrial fission regulator, Dynamin‐related protein (Drp1), are both increased, while mitochondrial membrane potential is reduced. Moreover, preventing mitochondrial fusion in GSCs results in highly fragmented depolarized mitochondria, decreased BMP stemness signaling, impaired fatty acid metabolism, and GSC loss. Conversely, forcing mitochondrial elongation promotes GSC attachment to the niche. Importantly, maintenance of aging GSCs can be enhanced by suppressing Drp1 expression to prevent mitochondrial fission or treating with rapamycin, which is known to promote autophagy via TOR inhibition. Overall, our results show that mitochondrial dynamics are altered during physiological aging, affecting stem cell homeostasis via coordinated changes in stemness signaling, niche contact, and cellular metabolism. Such effects may also be highly relevant to other stem cell types and aging‐induced tissue degeneration.     

Traits mediate drought effects on wood carbon fluxes

CO₂ fluxes from wood decomposition represent an important source of carbon from forest ecosystems to the atmosphere, which are determined by both wood traits and climate influencing the metabolic rates of decomposers. Previous studies have quantified the effects of moisture and temperature on wood decomposition, but these effects were not separated from the potential influence of wood traits. Indeed, it is not well understood how traits and climate interact to influence wood CO₂ fluxes. Here, we examined the responses of CO₂ fluxes from dead wood with different traits (angiosperm and gymnosperm) to 0%, 35%, and 70% rainfall reduction across seasonal temperature gradients. Our results showed that drought significantly decreased wood CO₂ fluxes, but its effects varied with both taxonomical group and drought intensity. Drought‐induced reduction in wood CO₂ fluxes was larger in angiosperms than gymnosperms for the 35% rainfall reduction treatment, but there was no significant difference between these groups for the 70% reduction treatment. This is because wood nitrogen density and carbon quality were significantly higher in angiosperms than gymnosperms, yielding a higher moisture sensitivity of wood decomposition. These findings were demonstrated by a significant positive interaction effect between wood nitrogen and moisture on CO₂ fluxes in a structural equation model. Additionally, we ascertained that a constant temperature sensitivity of CO₂ fluxes was independent of wood traits and consistent with previous estimates for extracellular enzyme kinetics. Our results highlight the key role of wood traits in regulating drought responses of wood carbon fluxes. Given that both climate and forest management might extensively modify taxonomic compositions in the future, it is critical for carbon cycle models to account for such interactions between wood traits and climate in driving dynamics of wood decomposition.