壳聚糖/聚乳酸羟基乙酸组织工程化神经植入犬体内的慢性生物相容性

背景：2个月以内短期生物相容性实验显示,壳聚糖、聚乳酸和聚羟基乙酸对大鼠外周神经均无毒性,可作为组织工程化神经材料。 目的：评价壳聚糖/聚乳酸羟基乙酸组织工程化神经植入Beagle犬体内6个月后的慢性生物相容性。 方法：在壳聚糖神经导管中插入聚乳酸羟基乙酸纤维制备成组织工程化神经,移植桥接Beagle犬坐骨神经50mm缺损,同时以Beagle犬50mm自体神经移植作为对照组。 结果与结论：植入壳聚糖/聚乳酸羟基乙酸组织工程化神经6个月后,Beagle犬精神、食欲、活动等一般情况良好,体质量增加与对照组相当;植入后2,4,6个月血液学和血清生化检测结果与对照组无明显差异;再生神经及其周边组织未出现变性、坏死,心、肝、脾、肺、肾等主要脏器大体解剖和组织切片未见异常。表明壳聚糖/聚乳酸羟基乙酸组织工程化神经植入Beagle犬体内6个月后慢性生物相容性良好。     

局灶性脑缺血预处理上调大鼠梗死区周围巢蛋白的表达

目的观察局灶性脑缺血预处理(IP)对巢蛋白(NESTIN)表达的影响,探讨NESTIN与脑缺血耐受(BIT)的关系及可能的内源性神经保护机制。方法 45只SD雄性大鼠随机分为脑缺血预处理(CIP)组、大脑中动脉阻塞(MCAO)组、假手术(sham)组。采用TTC染色测定脑梗死体积,光镜下观察脑组织病理改变,免疫组织化学染色和图像分析评价各组NESTIN的表达。结果再灌注24及72 h,CIP组脑梗死体积比分别为12.4%±3.2%、9.8%±1.9%,较MCAO组的18.5%±3.7%、15.8%±3.5%明显减小(P<0.05),免疫组化NESTIN阳性细胞数及Western blot测定缺血侧脑组织的NESTIN蛋白表达水平,均高于同时间段的MCAO组(P<0.05)。结论 CIP可有效减小局灶性脑缺血再灌注后的脑梗死体积,并促进梗死区周围脑组织表达敏感的胚性蛋白NESTIN,后者可能与BIT的脑保护机制有关。     

非手术脊柱减压系统DRX9000治疗椎间盘源性腰痛的临床初步报告

目的观察非手术脊柱减压系统DRX9000治疗椎间盘源性腰痛的疗效。方法对50例椎间盘源性腰痛患者进行非手术脊柱减压系统DRX9000治疗,在治疗开始时、治疗1周后、治疗2周后、治疗4周后、整个疗程结束时都对患者进行腰椎活动度、压痛点、双下肢运动感觉、肌力、神经反射的检查并记录,填写《汉化Oswestry功能障碍评分表》,根据分值的变化对疗效进行评估。50例患者均完成了20次治疗。结果 50例患者汉化Oswestry功能障碍评分平均分从治疗前的24.64分,变为治疗1周后13.12分,治疗2周后11.74分,治疗4周后9.70分,治疗结束后9.22分。治疗有效率为86%。将汉化Oswestry功能障碍评分的分值换算为功能障碍指数（CODI）后,发现随着治疗时间的增加,CODI降低的人数逐渐增多。随访50例患者,得到其中36人完整资料,平均随访时间6.2个月,汉化Oswestry功能障碍评分平均分为5.75分。结论非手术脊柱减压系统DRX9000治疗椎间盘源性腰痛,患者恢复良好,效果优。     

Antibody dynamics to SARS-CoV-2 in asymptomatic COVID-19 infections

Background

The missing asymptomatic COVID-19 infections have been overlooked because of the imperfect sensitivity of the nucleic acid testing (NAT). Globally understanding the humoral immunity in asymptomatic carriers will provide scientific knowledge for developing serological tests, improving early identification, and implementing more rational control strategies against the pandemic.

Measure

Utilizing both NAT and commercial kits for serum IgM and IgG antibodies, we extensively screened 11 766 epidemiologically suspected individuals on enrollment and 63 asymptomatic individuals were detected and recruited. Sixty-three healthy individuals and 51 mild patients without any preexisting conditions were set as controls. Serum IgM and IgG profiles were further probed using a SARS-CoV-2 proteome microarray, and neutralizing antibody was detected by a pseudotyped virus neutralization assay system. The dynamics of antibodies were analyzed with exposure time or symptoms onset.

Results

A combination test of NAT and serological testing for IgM antibody discovered 55.5% of the total of 63 asymptomatic infections, which significantly raises the detection sensitivity when compared with the NAT alone (19%). Serum proteome microarray analysis demonstrated that asymptomatics mainly produced IgM and IgG antibodies against S1 and N proteins out of 20 proteins of SARS-CoV-2. Different from strong and persistent N-specific antibodies, S1-specific IgM responses, which evolved in asymptomatic individuals as early as the seventh day after exposure, peaked on days from 17 days to 25 days, and then disappeared in two months, might be used as an early diagnostic biomarker. 11.8% (6/51) mild patients and 38.1% (24/63) asymptomatic individuals did not produce neutralizing antibody. In particular, neutralizing antibody in asymptomatics gradually vanished in two months.

Conclusion

Our findings might have important implications for the definition of asymptomatic COVID-19 infections, diagnosis, serological survey, public health, and immunization strategies.

     

Aβ(1-40)及192-IgG-saporin联合作用对大鼠学习记忆以及海马区锥体细胞和胆碱能纤维的影响

目的探讨Aβ(1-40)及192-IgG-saporin联合应用对大鼠学习记忆及海马区锥体细胞及胆碱能纤维的影响。方法采用Aβ(1-40)和192-IgG-saporin侧脑室内注射方法建造老年性痴呆(AD)动物模型。2周后,Y迷宫检测大鼠学习记忆能力并观察海马区形态学变化。结果Y迷宫结果显示联合组,Aβ(1-40)组及192-IgG-saporin组学习记忆能力与正常组均有下降(P<0.05)。刚果红染色阳性结果证明Aβ(1-40)以及联合组海马区内有类老年斑样物质沉积.尼氏染色表明,与正常组和192-IgG-saporin组相比Aβ(1-40)以及联合组,海马区锥体细胞数量均出现减少(P<0.05)。免疫组织化学显示,与正常组以及Aβ(1-40)比较,192-IgG-saporin以及联合组胆碱能纤维数量均出现明显减少(P<0.01)。结论 Aβ(1-40)及192-IgG-saporin联合应用制造的AD模型能够更全面的模拟AD病理特征,是较理想的模型。     

续断对大鼠骨质疏松性骨折愈合影响的生物力学实验研究

目的:观察续断对大鼠去卵巢骨质疏松性骨折模型骨折愈合中生物力学性能的影响。材料与方法:选取30只4月龄大鼠,分为假手术骨折对照组、去卵巢骨折对照组、去卵巢骨折中药处理组。后两组去卵巢3月造成绝经后骨质疏松模型,之后三组均造成桡骨远端骨折,灌药1月后检测桡骨骨痂生物力学强度。结果:中药处理组最大剪切力17.76±1.25N,剪切应力1.12±0.13N/mm2,生物力学性能与基础骨折对照组相接近,明显优于去卵巢骨折对照组(P<0.01)。结论:续断能改善骨质疏松性骨折愈合骨痂的生物力学性能,具有一定的促进骨折愈合的作用。     

Combination Therapy with Thymosin Alpha1 and Dexamethasone Helps Mice Survive Sepsis

Immune dysfunction is a major cause of mortality in septic patients. Current evidence indicates an important role for dendritic cells (DCs) in the pathophysiology of immune dysfunction, and these cells are potential targets of immunomodulation therapies. In the present study, our aim was to enhance the resistance of endotoxemic mice to bacterial translocation and secondary infection and to improve the outcome of these infections using a combination therapy consisting of thymosin alpha1 and dexamethasone in a timely manner according to the changes of DCs’ number. The effect of treatment with dexamethasone (DXM) and thymosin alpha1 (Tα1) on DCs was investigated by examining their number, MHCII and CD86 expression and their capacity to induce T cell activation. Endotoxemic mice were randomly divided into five treatment groups. The survival rates, the levels of TNF-α and IL-10, the occurrence of bacterial translocation, and the ability to clear secondary infections were determined. Additionally, the behavior of DCs over time was also evaluated. Tα1 induced significant increases in DC numbers in vivo, whereas DXM reduced cell numbers both in vitro and in vivo. However, neither drug induced significant changes in the capacity of DCs to induce T cell activation or their expression of MHCII or CD86. Among the five treatment groups, the mice treated with a combination of DXM and Tα1 had the highest survival rate; this increased survival was associated with a decrease in bacterial translocation to extra-intestinal organs and an enhanced ability to eradicate secondary infections by reversing the change in DC numbers during endotoxemia. Immunomodulatory therapy that combines Tα1 and DXM in a timely manner and was based on changes in DCs enhanced the resistance of endotoxemic mice to bacterial translocation and secondary infections, improving the outcome of the infection.     

新广谱大肠杆菌噬菌体IME11的分离及鉴定

目的 分离广谱大肠杆菌噬菌体并对其进行种属的鉴定。方法 以不同种临床致病性大肠杆菌为指示菌,从未经处理的污水样品中分离噬菌体;采用蛋白酶K/SDS的方法提取噬菌体基因组,制备重组载体,将阳性重组质粒进行测序;将测序结果进行BLAST,推测该噬菌体种属分类位置。结果 分别以大肠杆菌E1 ～ E17共17种细菌作为指示菌,成功分离出一种广谱噬菌体,可裂解31株临床分离致病性大肠杆菌中的13株,并将其命名为IME11;由噬菌体基因组限制性酶切片段分析表明其遗传物质为dsDNA;将噬菌体IME11基因组的2个随机片段测序结果进行BLAST,推测其属于N4-like噬菌体属。结论 分离出了一种广谱噬菌体,在分类学上属于N4-like噬菌体属。     

草木犀流浸液片对脓毒症大鼠肺组织VEGF及肺血管通透性的影响

探讨草木犀流浸液片对盲肠结扎穿孔术(CLP)脓毒症大鼠肺VEGF及肺血管通透性的影响。将80只雄性SD大鼠随机分为四组:①正常对照组20只;②假手术组20只;③对照组20只;④治疗组20只。假手术组只开腹,不行CLP;对照组和治疗组建立CLP脓毒症模型。术前2h治疗组给予草木犀流浸液片20mg/kg,每8h一次,24h处死各组大鼠大鼠,观察肺组织VEGF mRNA、NF-κB mRNA、NF-κB p65及血清VEGF-a、TNF-α、IL-6、IL-1β、IL-8、IFN-γ、IL-10、IL-12的变化;同时测定肺组织通透性(EB)、湿/干重比(W/D)及肺组织病理变化。研究发现:与正常对照组比较,VEGFmRNA、NF-κB p65mRNA、NF-κB p65、VEGF、TNF-α、IL-6、IL-1β、IL-8、IFN-γ、IL-10、IL-12在假手术者无明显变化,差异无统计学意义P>0.05;对照组、治疗组显著升高,差异有非常显著意义P<0.01;与对照组比较,治疗组VEGF mRNA、NF-κB p65mRNA、NF-κB p65、VEGF、TNF-α、IL-6、IL-1β、IL-8显著降低,IFN-γ、IL-10、IL-12显著升高,差异有统计学意义P<0.05。VEGF mRNA与NF-κB mRNA、VEGF与NF-κB p65分别具有正相关性(r=0.852,P<0.05;r=0.794,P<0.05)。病检也发现,治疗组肺病病理损伤较对照组明显减轻。结果提示:草木犀流浸液片能够抑制CLP脓毒症大鼠肺组织NF-κB mRNA、VEGF mRNA的表达,降低血清VEGF、TNF-α、IL-6、IL-1β、IL-8水平,促进IFN-γ、IL-10、IL-12的产生,显著降低脓毒症大鼠肺组织微血管通透性,对脓毒症大鼠肺组织具有保护作用。     

护理专业学生职业成熟度的调查

目的比较某校中专,大专,本科不同学历的护理专业学生职业成熟度差异,为针对性的对学生进行就业指导和职业生涯规划提供依据。方法运用职业成熟度量表测试某校中专,大专,本科护理专业学生职业成熟度。结果①中专,大专护生职业成熟度均高于本科护生。中专护生与大专护生职业成熟度无显著性差异（p〉0.05）;②绝大多数因子间的发展不平衡,中专护生在主动性、灵活性、职业自我知识、专业知识因子方面高于本科护生;大专护生在主动性、自信心、职业自我知识、专业知识因子方面高于本科护生。结论不同学历的护生对将来从事的职业的看法和职业成熟度不近相同,每个护生都应量体裁衣,保持平和心态,给自己一个合理而正确的定位。