新型国产二尖瓣夹合器系统的动物实验研究

通过动物实验,对一种新型国产二尖瓣夹合器系统的可行性和安全性进行评价。14只正常三元杂交系猪分为实验组10只和对照组4只,实验组植入新型二尖瓣夹合器系统,对照组行传统二尖瓣修复术。分别于术前、术后不同时间点行超声心动图检查、血液检查,术后140 d对动物安乐死取材,进行心脏及主要脏器大体、病理检查,观察植入后的情况。实验组共8只动物、对照组共4只动物达到实验终点,所有动物术中未出现夹合器脱落、心脏破裂、瓣膜损伤、顽固性心律失常、脏器栓塞、心力衰竭、死亡等严重并发症。超声显示,所有夹合器均固定在二尖瓣处,不同时间点二尖瓣平均跨瓣压差、左心室射血分数等两组间均未见具有统计学意义的差异。血液学检查,未见植入器械对肝肾功能产生明显影响。病理检查提示,夹合器周围瓣叶呈现慢性炎症、黏液样变性、少量出血,未引起二尖瓣及心脏组织损伤,未出现心脏血栓、感染,各脏器也未见血栓栓塞。动物实验结果表明,新型国产二尖瓣夹合器系统生物相容性好,能够有效固定在二尖瓣处而不引起严重的相关并发症。     

经乙二醇诱导的改良型草酸钙肾结石果蝇模型

目的:通过一种改良方法构建果蝇草酸钙肾结石模型。方法:配制标准培养基和造模用培养基，空白对照组果蝇仅予标准培养基，而传统模型组和改良模型组分别从成虫期和幼虫期开始摄入含 0.5%乙二醇( EG)的造模用培养基。于偏光显微镜下观察并评估各组果蝇马氏管内成石情况，分别记录模型组成石率达 100%所花时间，并对成石率 100%时模型组间“ ++”和“ +++”所占比率进行比较；用傅立叶变换拉曼光谱仪鉴定模型组果蝇马氏管内结石成分。绘制各组果蝇生存曲线，并比较生存周期差异。结果:改良模型组和传统模型组分别在果蝇成虫日龄 14 d和 22 d，马氏管内成石率达到 100%。当改良模型组和传统模型组成石率均达到 100%时，两组“ ++”与“+++”所占比率分别为(40.5±4.4)%和(39.0±4.2)%，差异无统计学意义(P＞ 0.05)；拉曼位移的主峰主要集中在 1 462 cm-1、1 463 cm-1和 1 473 cm-1，说明模型组果蝇马氏管内结石成分均为草酸钙。空白对照组、传统模型组和改良模型组的最高寿命分别为 76 d、70 d和 68 d，中位生存时间分别为 35 d、30.5 d和 30 d，与空白对照组相比，模型组生存周期均显著缩短(P均＜ 0.01)，但传统模型组与改良模型组间差异无统计学意义( P＞ 0.05)。结论:改良型造模方法使果蝇在其幼虫期即摄入 0.5% EG，缩短了模型构建周期且具有可重复性，值得进一步研究推广。     

Response of the Axial Skeleton to Bipedal Loading Behaviors in an Experimental Animal Model

Many derived aspects of modern human axial skeletal morphology reflect our reliance on obligate bipedal locomotion. Insight into the adaptive significance of features, particularly in the spine, has been gained through experimental studies that induce bipedal standing or walking in quadrupedal mammals. Using an experimental animal model (Rattus norvegicus), the present study builds on earlier work by incorporating additional metrics of the cranium, employing quantitative methods established in the paleoanthropological literature, and exploring how variation in mechanical loading regimes impacts axial anatomy. Rats were assigned to one of five experimental groups, including “fully loaded bipedal walking,” “partially loaded bipedal walking,” “standing bipedally,” “quadrupedal walking,” and “no exercise control,” and engaged in the behavior over 12-weeks. From μCT data obtained at the beginning and end of the experiment, we measured foramen magnum position and orientation, lumbar vertebral body wedging, cranial surface area of the lumbar and first sacral vertebral bodies, and sacral mediolateral width. Results demonstrate that bipedal rodents generally have more anteriorly positioned foramina magna, more dorsally wedged lumbar vertebrae, greater articular surface areas of lumbar and first sacral vertebral bodies, and sacra that exhibit greater mediolateral widths, compared to quadrupedal rodents. We further document variation among bipedal loading behavior groups (e.g., bipedal standing vs. walking). Our experimental animal model reveals how loading behaviors and adaptations may be specifically linked, and implicates a potential role for developmental plasticity in the evolutionary acquisition of bipedal adaptations in the hominin lineage. Anat Rec, 2018. © 2018 American Association for Anatomy.     

杜仲醇提取物可促进根尖周炎模型大鼠骨组织的愈合

文题释义：杜仲：杜仲是中国传统的中药药材，其具有增加机体免疫性、强身健骨的疗效，研究表明杜仲可以促进成骨细胞的增殖并且可以促进骨组织的愈合。近年来对于杜仲的研究主要集中于其有效成分的提取及分析。 杜仲醇：是杜仲的主要有效成分之一，可以增强关节炎大鼠骨组织的强度，并且具有降血压以及促进伤口愈合的能力。 背景：目前关于杜仲的研究主要集中于其治疗骨关节炎能增强骨组织的愈合能力，但是关于杜仲对根尖周炎骨破坏的修复作用尚未见报道。 目的：探讨杜仲醇提取物对根尖周炎大鼠组织蛋白酶K的影响。 方法：选取24只SD大鼠随机分为根尖周炎组20只及对照组4只，根尖周炎组于右侧下颌第一磨牙开髓后建立根尖周炎模型，对照组不做任何处理。饲养4周后，取根尖周炎组及对照组各4只拍摄MICRO-CT，计算根尖周炎骨破坏量，确认大鼠根尖周炎动物模型构建成功。饲养第5周，将剩余16只根尖周炎大鼠随机分为杜仲醇提取物组及生理盐水组，每组8只，每天灌胃杜仲醇提取物5 mL/kg或等量生理盐水。灌胃4周后，每组取4只大鼠拍摄MICRO-CT，分析杜仲醇提取物对根尖周骨组织的修复能力，另外取4只大鼠采用免疫组化染色观察右下颌第一磨牙牙槽骨组织蛋白酶K的表达。 结果与结论：①MICRO-CT结果显示，对照组骨吸收体积为(0.223±0.009) mm³，根尖周炎组骨吸收体积为(0.945±0.037) mm³，两组骨吸收量比较差异有显著性意义(P=0.00)，说明大鼠根尖周炎模型构建成功；②灌胃4周后，MICRO-CT结果显示杜仲醇提取物组骨吸收体积较灌胃前减小，差异有显著性意义(P < 0.05)；③灌胃4周后，免疫组化结果显示杜仲醇提取物根尖周炎骨破坏标志因子组织蛋白酶K的表达较灌胃前降低，差异有显著性意义(P < 0.05)；④结果表明，杜仲醇提取物可以抑制骨破坏标志因子组织蛋白酶K的表达，并且可以促进大鼠根尖周炎骨组织的愈合。 ORCID: 0000-0001-5450-7016(吴大雷) 中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程     

Immunomodulatory role of chitosan‐based nanoparticles and oligosaccharides in cyclophosphamide‐treated mice

Chitosan, the deacetylated form of chitin, a natural polysaccharide, is known for its various biomedical applications. The present study aimed at exploring the immunomodulatory properties of chitosan (CSNP) and gallic acid‐grafted chitosan (cGANP) nanoparticles in mice model of cyclophosphamide (CPA)‐induced immunosuppression. In addition, chitooligosaccharides, the hydrolysed form of chitin and chitosan, were also evaluated for its potential against immunosuppression in mice. CPA (80 mg/kg/ip) induced significant immunosuppression, which was reversed with cGANP treatment as indicated by a significant increase in the thymus and spleen indices compared to the CPA‐treated group. The CSNP and chitooligosaccharides (chitin and chitosan) failed to reverse CPA‐induced changes. ELISA revealed an elevation in the levels of IL‐6 and a reduction in IFN‐γ levels with CPA treatment. All the test compounds reduced the IL‐6 levels, whereas only the nanoparticle formulations (CSNP and cGANP) exhibited a significant augmentation in the IFN‐γ levels. Both the cytokines, IL‐6 and IFN‐γ, are secreted separately by two different types of T helper cells (Th cells), which mediate cellular and humoral immune responses in a coordinated manner. Th‐1 cells release IFN‐γ, facilitating cell‐mediated immunity, whereas IL‐6 is released by Th‐2 cells, expediting humoral immune response. The nanoparticles (CSNP and cGANP) seemed to be better immune enhancers than the chitooligosaccharides owing to their ability to reverse the cytokine changes induced by CPA. Overall, it was evident that the nanoparticles, most likely, boosted the cell‐mediated immunity through the induction of the Th‐1 branch of the immune response.     

Drug discovery strategies for acute radiation syndrome

Introduction: There are at the minimum two major, quite different approaches to advance drug discovery. The first being the target-based drug discovery (TBDD) approach that is commonly referred to as the molecular approach. The second approach is the phenotype-based drug discovery (PBDD), also known as physiology-based drug discovery or empirical approach.

Area covered: The authors discuss, herein, the need for developing radiation countermeasure agents for various sub-syndromes of acute radiation syndromes (ARS) following TBDD and PBDD approaches. With time and continuous advances in radiation countermeasure drug development research, the expectation is to have multiple radiation countermeasure agents for each sub-syndrome made available to radiation exposed victims.

Expert opinion: The majority of the countermeasures currently being developed for ARS employ the PBDD approach, while the TBDD approach is clearly under-utilized. In the future, an improved drug development strategy might be a ‘hybrid’ strategy that is more reliant on TBDD for the initial drug discovery via large-scale screening of potential candidate agents, while utilizing PBDD for secondary screening of those candidates, followed by tertiary analytics phase in order to pinpoint efficacious candidates that target the specific sub-syndromes of ARS.     

虚实结合的翻转课堂在解剖实验教学中的应用

目的评价虚实相结合的翻转课堂在系统解剖学实验教学中的应用。方法选取齐齐哈尔医学院2018级临床专业和医学影像学专业学生共107名,在系统解剖学实验课中,对某些章节采用部分翻转课堂的教学模式,对照章节则采用传统的教学方法。教学结束后进行考核,比较前后章节的课堂测验成绩,另外采用调查问卷,分析学生对两种教学方法的满意度。结果临床医学和医学影像学专业的学生第二次课堂测试的成绩均高于第一次课堂测试的成绩(P <0.01),同时学生对翻转课堂教学模式的满意度高于传统教学法。结论在系统解剖学实验教学中实行翻转课堂教学模式,同时讲解实物标本并应用数字人解剖学系统进行知识内化,不仅能提高学生的学习成绩,也能调动学生学习系统解剖学的热情,增加教学效果满意度,并为其他解剖学专业课的教学模式改革提供参考和借鉴。     

肾虚证动物模型研究进展

肾虚证动物模型一直是中医证候研究的重点,提供与人类疾病类似的肾虚证动物模型,有助于深入研究肾虚证本质及其治疗。近年来建立了不少肾虚证动物模型,然而不同的肾虚证模型特点也不尽相同。对临床常见肾虚证型,从肾阳虚、肾阴虚、肾精不足、肾气虚方面进行概述,并对其存在的不足进行思考,以期为肾虚证动物模型的构建及其证候生物学机制研究提供新思路。