嵊泗县居民海水淡化水知信行调查

目的调查嵊泗县居民对海水淡化水的态度、相关知识的知晓程度和用水行为,了解海水淡化水用于市政供水可能存在的问题。方法采用整群分层抽样方法,对嵊泗县常住居民进行问卷调查。结果发放调查问卷690份,收回675份,应答率97.8%。淡化水知晓率为48.47%。34.5%的居民选择放心使用淡化水,跟随大多数人意见的比例为30.4%,有34.7%的居民选择坚决不使用淡化水。完全不以自来水作为饮用水的占47.2%。对淡化水相关信息的获取渠道主要是与他人的交流(44.6%),其次是网络等电子媒体(40.4%)。结论调查人群对海水淡化水的水质安全性存在一定的疑虑,对淡化水的接受程度不高。淡化水的相关知识了解不够全面可能是重要的影响因素。     

上海市社区计划生育综合服务站工作人员紧急避孕知晓程度调查

目的:了解上海市社区计划生育综合服务站工作人员紧急避孕意识和服务水平,探讨社区紧急避孕规范化服务。方法:2010年1月～2010年12月对上海市闵行区和徐汇区25个街道计划生育服务站的275名服务人员进行问卷调查(紧急避孕相关知识及可接受性情况),同时进行紧急避孕专业培训。结果:社区计划生育服务人员均知道有紧急避孕,但在工作中应用比例为38.5%,73.8%调查对象知道紧急避孕的具体方法,能够正确回答紧急避孕使用常见问题的比例有33.87%。社区计划生育服务人员能够区别紧急避孕与常规的避孕方法,而对紧急避孕的局限性、副作用和失败后的处理方法认识还不足。通过紧急避孕专业培训,78.65%服务人员能够正确回答紧急避孕常见问题,同时纠正了原有的一些认识误区,提高了紧急避孕的知晓度和服务意识。结论:社区人口与计划生育服务人员应定期接受紧急避孕知识及技术培训,及时更新知识,提高服务水平。     

骨科抗菌药物使用强度与细菌耐药率的变化趋势研究

目的 研究骨科抗菌药物使用强度与临床常见致病菌耐药率的变化趋势.方法 采用能够准确反映抗菌药物使用强度的DDD/(100人·d)对2006-2009年医院骨科抗菌药物使用情况进行了统计,并分析同期常见致病菌耐药的变化趋势.结果 头孢地嗪的使用强度2006-2009年分别为7.81、7.66、2.92和0.84,呈下降趋势,大肠埃希菌、鲍氏不动杆菌、铜绿假单胞菌和金黄色葡萄球菌对头孢地嗪的耐药率也出现了相应的下降;头孢哌酮/舒巴坦的使用强度分别为3.92、3.55、3.40和0.90,2009年下降幅度较大,2009年大肠埃希菌、鲍氏不动杆菌、铜绿假单胞菌和金黄色葡萄球菌对头孢哌酮/舒巴坦的耐药率也出现了较大幅度的下降:头孢他啶和左氧氟沙星的使用强度变化趋势与大肠埃希菌、鲍氏不动杆菌、铜绿假单胞菌对其耐药率的变化相一致;头孢呋辛和头孢曲松作为主要预防性抗菌药物,其使用强度的变化趋势与主要致病菌对其耐药率的变化无一致性.结论 细菌耐药趋势与部分抗菌药物使用强度的变化有一定关系.     

组织特异性脂蛋白脂酶在2型糖尿病大鼠表达变化的作用

目的比较2型糖尿病大鼠和正常大鼠骨骼肌和脂肪组织脂蛋白脂酶（LPL）基因表达的差异,探讨组织特异性LPL表达异常在胰岛素抵抗（IR）的发生中所起的作用。方法实验大鼠22只分2组：正常对照组10只,2型糖尿病组12只;分别取对照组和实验组各2只大鼠同侧大腿骨骼肌组织及腹部大网膜脂肪,同时取骨骼肌组织送电镜检查;分别从骨骼肌及脂肪组织中抽提RNA,经逆转录分别用Cy3、Cy5荧光标记,获得两组动物来源的cDNA探针;cDNA探针与含糖脂代谢相关基因的芯片杂交,结果由扫描仪扫描并用软件进行统计分析;半定量RT-PCR验证两组织部分基因表达水平。结果在电镜下,2型糖尿病组大鼠骨骼肌细胞内可见脂质沉积;2型糖尿病大鼠骨骼肌组织中LPL基因表达上调,脂肪组织LPL基因表达下调;骨骼肌及脂肪组织脂肪酸b氧化相关酶基因表达上调;用半定量RT-PCR证实了基因芯片的结果。结论2型糖尿病大鼠骨骼肌及脂肪组织特异性LPL表达变化在胰岛素抵抗的发病机制可能起一定作用。     

Construction of a Dengue NanoLuc Reporter Virus for In Vivo Live Imaging in Mice

Since the first isolation in 1943, the dengue virus (DENV) has spread throughout the world, but effective antiviral drugs or vaccines are still not available. To provide a more stable reporter DENV for vaccine development and antiviral drug screening, we constructed a reporter DENV containing the NanoLuc reporter gene, which was inserted into the 5′ untranslated region and capsid junction region, enabling rapid virus rescue by in vitro ligation. In addition, we established a live imaging mouse model and found that the reporter virus maintained the neurovirulence of prototype DENV before engineering. DENV-4 exhibited dramatically increased neurovirulence following a glycosylation site-defective mutation in the envelope protein. Significant mice mortality with neurological onset symptoms was observed after intracranial infection of wild-type (WT) mice, thus providing a visualization tool for DENV virulence assessment. Using this model, DENV was detected in the intestinal tissues of WT mice after infection, suggesting that intestinal lymphoid tissues play an essential role in DENV pathogenesis.     

乙酰紫草素注射液对小鼠Lewis肺癌生长抑制的研究

目的:探讨乙酰紫草素注射液对小鼠Lewis肺癌的生长抑制作用。方法:建立C57BL/6小鼠lewis肺癌模型进行体内抗瘤实验并计算抑瘤率。结果:乙酰紫草素注射液高中低剂量组的抑瘤率分别为55.49%,45.25%和28.09%。结论:乙酰紫草素注射液能明显抑制小鼠Lewis肺癌的生长。     

Dromedary camel nanobodies broadly neutralize SARS-CoV-2 variants

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike is a trimer of S1/S2 heterodimers with three receptor-binding domains (RBDs) at the S1 subunit for human angiotensin-converting enzyme 2 (hACE2). Due to their small size, nanobodies can recognize protein cavities that are not accessible to conventional antibodies. To isolate high-affinity nanobodies, large libraries with great diversity are highly desirable. Dromedary camels (Camelus dromedarius) are natural reservoirs of coronaviruses like Middle East respiratory syndrome CoV (MERS-CoV) that are transmitted to humans. Here, we built large dromedary camel V_HH phage libraries to isolate nanobodies that broadly neutralize SARS-CoV-2 variants. We isolated two V_HH nanobodies, NCI-CoV-7A3 (7A3) and NCI-CoV-8A2 (8A2), which have a high affinity for the RBD via targeting nonoverlapping epitopes and show broad neutralization activity against SARS-CoV-2 and its emerging variants of concern. Cryoelectron microscopy (cryo-EM) complex structures revealed that 8A2 binds the RBD in its up mode with a long CDR3 loop directly involved in the ACE2 binding residues and that 7A3 targets a deeply buried region that uniquely extends from the S1 subunit to the apex of the S2 subunit regardless of the conformational state of the RBD. At a dose of ≥5 mg/kg, 7A3 efficiently protected transgenic mice expressing hACE2 from the lethal challenge of variants B.1.351 or B.1.617.2, suggesting its therapeutic use against COVID-19 variants. The dromedary camel V_HH phage libraries could be helpful as a unique platform ready for quickly isolating potent nanobodies against future emerging viruses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of COVID-19 (1, 2) that enters human cells by binding its envelope anchored type I fusion protein (spike) to angiotensin-converting enzyme 2 (ACE2) (3, 4). The SARS-CoV-2 spike is a trimer of S1/S2 heterodimers with three ACE2 receptor-binding domains (RBDs) attached to the distal end of the spike via a hinge region that allows conformational flexibility (4). In the all-down conformation, the RBDs are packed with their long axes contained in a plane perpendicular to the axis of symmetry of the trimer. Transition to the roughly perpendicular up conformation exposes the receptor-binding motif (RBM), located at the distal end of the RBD, which is sterically occluded in the down state. Numerous neutralizing antibodies targeting the spike, particularly its RBD, have been developed to treat COVID-19 using common strategies such as single B cell cloning, animal immunization, and phage display (5–9). Most vaccines, including those that are messenger RNA based, are designed to induce immunity against the spike or RBD (10–12). However, emerging SARS-CoV-2 variants such as D614G, B.1.1.7 (Alpha, United Kingdom), B.1.351 (Beta, South Africa), and P.1 (Gamma, Brazil) have exhibited increased resistance to neutralization by monoclonal antibodies or postvaccination sera elicited by the COVID-19 vaccines (13, 14). Monoclonal antibodies with Emergency Use Authorization for COVID-19 treatment partially (Casirivimab) or completely (Bamlanivimab) failed to inhibit the B.1.351 and P.1 variants. Similarly, these variants were less effectively inhibited by convalescent plasma and sera from individuals vaccinated with a COVID-19 vaccine (BNT162b2) (13). The B.1.617.2 (Delta, India) variant became the prevailing strain in many countries (15). Highly effective and broadly neutralizing antibody therapy is urgently demanded for COVID-19 patients.Due to their small size and unique conformations, camelid V_HH single-domain antibodies (also known as nanobodies) can recognize protein cavities that are not accessible to conventional antibodies (16). To isolate high-affinity nanobodies without a need for further affinity maturation, it is highly desirable to construct large nanobody libraries with great diversity. Dromedary camels have been found as potential natural reservoirs of Middle East respiratory syndrome CoV (MERS-CoV) (17). We speculated that dromedary camels would be an ideal source of neutralizing nanobodies against coronaviruses. In the present study, we built large camel V_HH single-domain antibody phage libraries with a diversity of over 10¹¹ from six dromedary camels (Camelus dromedarius), three males and three females, with ages ranging from 3 mo to 20 y. We used both the SARS-CoV-2 RBD and the stabilized spike ectodomain trimer protein as baits to conduct phage panning for nanobody screening. Among all the binders, we found NCI-CoV-7A3 (7A3), NCI-CoV-1B5 (1B5), NCI-CoV-8A2 (8A2), and NCI-CoV-2F7 (2F7) to be potent ACE2 blockers. In addition, these dromedary camel nanobodies displayed potent neutralization activity against the B.1.351 and B.1.1.7 variants and the original strain (Wuhan-Hu-1). The cryoelectron microscopy (cryo-EM) structure of the spike trimer protein complex with these V_HH nanobodies revealed two distinct nonoverlapping epitopes for neutralizing SARS-CoV-2. In particular, 7A3 recognizes a unique and deeply buried region that extends to the apex of the S2 subunit of the spike. Combined treatment with 7A3 and 8A2 shows more potent protection against various variants in culture and mice infected with the B.1.351 variant. Interestingly, 7A3 alone retains its neutralization activity against the lethal challenge of the B.1.617.2 variant in mice.