北京鸭视网膜节细胞的大小、密度和分布

采用Nissl染色法、视神经溃变法和神经元逆行追踪标记辣根过氧化物酶(HRP)法,研究了北京鸭视网膜节细胞(RGCs)的大小和密度及其分布的变化。北京鸭RGCs形态多样,有圆形、椭圆形和多角形等,RGCs总数为1.3×106个(P0),RGCs平均密度为5370个/mm2(P0),在视网膜中央有一个偏向鼻侧的高密度区即中央高密度区(8860个/mm2),由中央区至周边部,细胞密度逐渐降低,颞侧周边部最低(3440个/mm2)。不同区域RGCs大小差异显著,中央区以小细胞为主(62.2±23.3μm2,P0),而周边部RGCs逐渐增大,颞侧周边部最大(P0:133.7±75.7μm2;P8:152.9±55.9μm2)。由此可见,伴随RGCs大小由中央区至周边部的递增而细胞密度呈现递减的变化,这种变化趋势在颞侧周边部最明显。与此同时,随日龄增长,RGCs总数和密度均递减而细胞大小递增。dACs是位于视网膜节细胞层的小神经元,细胞大小为23.7±4.0μm2     

()、纵纹腹小()和红隼视器的比较形态学研究

为了探讨猛禽视器结构与生活习性的关系,用光镜和扫描电镜观察、测量并统计了、纵纹腹小和红隼视网膜各层的厚度,三个核层的胞核层数和视细胞密度.视网膜外核层、内核层和节细胞层胞核的平均层数在依次为2.6、7.6和0.4层;在小为3.0、11.4和1.9层;红隼为1.6、14.6和1.7层.视网膜中央区视锥细胞密度(±SD)在为190 117±27 304个/mm2,小为202 122±49 542个/mm2,红隼为234 039±44 916个/mm2.视网膜周围区视杆细胞的密度在为190 422±26 595个/mm2,小为165 800±26 408个/mm2,红隼为178 015±40 165个/mm2.红隼视网膜周围区还有视锥细胞分布,其密度为22 082±9 864个/mm2.结果表明,视器的结构为夜行性特征,而小有趋于晨昏活动的特点,红隼为典型的昼行性视觉特征.3种猛禽栖息于同一生态环境内,视器的结构差异显示出其时间活动格局上的差异.     

蜡皮蜥消化系统组织学初步研究

应用石蜡常规切片,HE染色,对蜡皮蜥的消化系统组织结构进行了观察。结果表明:消化道管壁除口咽腔外,其余由粘膜层、粘膜下层、肌层和浆膜层组成;不同部位的消化道管壁厚度各不相同,其中胃壁最厚,幽门胃壁厚达658.0μm,其次为大肠和食道,分别为393.3μm和215.9μm,小肠壁最薄,约为126.8μm;皱襞的发达程度也随消化道的部位不同而有所差异,十二指肠皱襞数量最多,约为27~42个,平均高度为733.2μm,其次分别为回肠、口咽腔和食道,大肠皱襞数量最少约为3~11个,平均高度为484.2μm;食道上皮为复层鳞状上皮细胞,口咽腔、胃、小肠和大肠上皮均为单层柱状上皮;食道和大肠上皮的杯状细胞较多,密度分别为927个/mm2、899个/mm2;肝脏中色素细胞发达并含大量深色颗粒,胰脏泡心细胞较少且胰岛不发达,肝脏小叶和胰脏小叶界限不清晰。这充分说明了蜡皮蜥消化系统的组织结构特征与其食性和生态习性相适应,与鸟类和哺乳动物相比,具有一定的不完善性和低等性。     

稀有鮈鲫眼的形态发生研究

详细观察和描述了稀有鮈鲫眼发育的形态变化,并分别对视网膜发育早期神经层、色素上皮层的厚度及眼发育后期视网膜的总厚度进行了测量。结果表明:稀有鲫眼的发生始于神经胚时期形成的眼原基,与两栖、哺乳类动物不同,其眼原基是由间脑向左右伸出的对称外突实体;在尾芽期眼原基向腹侧弯曲、侧向伸长,随后开始内陷,在尾泡期形成视杯。眼原基外层与外胚层紧贴的部分将发育为视杯的内层、神经视网膜,而眼原基其余部分将分化为视杯的外层、视网膜色素层。在尾泡期之后,视网膜色素层停止有丝分裂开始形成色素颗粒,此时视网膜神经层开始分化。视网膜这两层结构在发育早期分化的有序进行可能与早期胚胎头部内空间以及附近的间充质细胞有关。从神经胚期到尾泡期,视网膜色素层厚度由42.3±0.8μm减小到4.8±0.4μm,视网膜神经层厚度从37.1±0.2μm增加到43.7±0.6μm,而从尾鳍期到孵出期视网膜总厚度从42.7±1.2μm逐渐增加到98.3±2.1μm。与所有脊椎动物一样,稀有鲫眼的视网膜分化也是按照由内向外的顺序进行,晶状体、角膜及其他结构在孵出时已基本发育完全。     

肾上腺髓质素在糖尿病视网膜细胞高表达的研究

探讨肾上腺髓质素(Adrenomedullin,AM)在糖尿病视网膜病变(Diabeticretinopathy,DR)发病中的作用。Sprague-Dawley雄性大鼠尾静脉注射链脲佐菌素造模,以血糖测定和尿糖水平测定进行筛选,正常对照组尾静脉注射等量枸橼酸钠缓冲液。成模后继续饲养4周,取出眼球视网膜组织,连续冰冻切片,用免疫组织化学SABC法染色观察各组大鼠视网膜RPE细胞AM的表达情况。糖尿病大鼠成模前,两组动物的体重、血糖和尿糖检测结果间无显著性差异(P>0.05)。成模后4周,糖尿病组与正常组大鼠体重、血糖和尿糖数值差异有显著性意义(P<0.01)。AM在正常组大鼠视网膜节细胞层及内核层均有表达,正常组大鼠视网膜AM的光密度值为76.3±5.3,单位面积AM阳性细胞数为(4.5±1.1)×103/mm2。糖尿病大鼠视网膜内RPE细胞肾上腺髓质素表达显著增强,糖尿病大鼠视网膜RPE细胞AM的光密度值为105.7±11.9,单位面积AM阳性细胞数为(17.9±2.3)×103/mm2。两组相比,差异具有显著性(P<0.01)。AM在糖尿病大鼠视网膜RPE细胞表达量增加很可能是DR发生、发展的重要因素。     

江南油杉营养器官的解剖结构及其生态适应性

采用石蜡切片和光学显微技术对江南油杉(Keteleeria fortunei(Murr.)Carr.var.cyclolepis(Flous)Silba)根、茎、叶的解剖结构进行观测,研究其形态结构对环境的适应性。结果显示:江南油杉叶片为异面叶,上表皮厚11.5μm,外侧覆盖厚4.5μm的角质层,下表皮厚8.6μm,外侧覆盖厚2.4μm的角质层,有气孔器分布,栅栏组织由1~2层细胞组成,海绵组织由2~3层细胞组成,主脉为单脉,厚474.1μm。茎的初生结构中表皮细胞1~2层,外皮层细胞4~6层,内皮层细胞6~8层,其内分布有树脂道;次生结构中木栓层细胞2~3层,栓内层细胞1~2层,皮层内有树脂道和分泌腔分布,维管束紧密排列连成环状。根的初生结构中外皮层细胞3层,内皮层细胞1~2层,具凯氏带,初生木质部为四原型;次生结构中木栓层细胞3~4层,栓内层细胞2~3层。江南油杉营养器官的解剖结构表现出较大的可塑性,使之既能较好地适应阳生环境又对阴生环境具备一定的适应性,还可耐受一定的干旱和寒冷。     

中国八种麻蜥(蜥蜴科,麻蜥属)形态学研究

对8种麻蜥外部形态进行主成分分析,可分为4个种组:1)丽斑麻蜥Eremias argus与山地麻蜥Eremiasbrenchleyi;2)快步麻蜥Eremias velox与虫纹麻蜥Eremias vermiculata;3)密点麻蜥Eremias multiocellata、荒漠麻蜥Eremias przewalskii与敏麻蜥Eremias arguta;4)网纹麻蜥Eremias grammica.研究表明丽斑麻蜥前额鳞数不稳定;密点麻蜥莎车亚种Eremias multiocelfata yarkandensis可能为独立物种;荒漠麻蜥物种有效性值得怀疑.     

小梁切除术中应用丝裂霉素C 对角膜内皮细胞的影响

目的:观察小梁切除术中应用丝裂霉素C(MMC)对角膜内皮细胞的影响。方法:收集2010年9月2011年5月在我院行小梁切除术的青光眼患者60例(78眼),随机分为术中应用丝裂霉素C的36例(46眼)患者为A组,术中不用丝裂霉素C的24例(32眼)为B组,分别观察术前、术后1个月和术后3个月两组眼压(IOP)、角膜内皮细胞的密度(CD)、平均细胞面积(AVG)及细胞面积变异系数(CV),分析其数量的改变及两组间的差异。结果:A组术前眼压为(35.4±13.7)mmHg,B组术前眼压为(32.5±13.5)mmHg差异无统计学意义(P>0.05),A组术后1个月及术后3个月眼压分别为(15.7±3.7)mmHg、(17.0±3.2)mmHg,均低于B组的(19.4±3.7)mmHg、(20.2±2.1)mmHg,差异有统计学意义(P<0.05)。A组术前、术后1个月及术后3个月角膜内皮细胞密度分别为(2475±484)个/mm2、(2199±373)个/mm2、(2164±332)个/mm2;平均细胞面积分别为(431.4±67.6)μm2、(480.6±66.8)μm2、(463.8±46.2)μm2;细胞面积变异系数分别为(31.1±7.4)%、(34.4±6.3)%、(31.2±7.5)%;术后1个月及术后3个月各参数与术前比较,差异均有统计学意义(P<0.05)。B组术前、术后1个月及术后3个月角膜内皮细胞密度分别为(2342±94)个/mm2、(2185±215)个/mm2、(2074±218)个/mm2;平均细胞面积分别为(453.9±94.8)μm2、(516.3±100.8)μm2、(499.81±106.4)μm2;细胞面积变异系数分别为(30.2±3.0)%、(32.7±2.9)%、(31.4±4.3)%;除术后3个月角膜内皮细胞与术前比较有意义(P<0.05)外,余参数术后1个月及术后3个月与术前比较差异均无统计学意义(P>0.05)。术后1个月A组的角膜内皮细胞丢失率为10.4%高于B组的6.1%,差异有统计学意义(P<0.05);术后3个月A组的角膜内皮细胞丢失率为11.1%高于B组的10.0%,差异无统计学意义(P>0.05)。结论:小梁切除术中用丝裂霉素C的降压效果比不用丝裂霉素C的效果好,但短期内前者角膜内皮细胞的丢失率高于后者。     

中国大鲵视网膜的光镜和扫描电镜研究

用光镜和扫描电镜观察了大鲵视网膜各类细胞的形态及分布, 对视细胞和节细胞进行计数。视网腊中三个核层及两个网状层分布均匀,无中央凹。每张视网膜的视细胞总数约130000,节细胞约8000,视杆与视锥之比为8.5：1。扫描电镜下,视杆外节表面的小叶间沟清晰;视杆视锥外节均有从内节伸出的20-30条萼状突起;核周体表面亦有20-30条细胞质突起。文中还报道了幼体视细胞的形态及密度。讨论了上述结构的机能。     

恒河猴和树鼩角膜内皮细胞的比较分析

目的对比分析恒河猴和树鼩角膜内皮细胞的特点和差异。方法利用非接触式自动角膜内皮细胞仪SP3000P分别对6只恒河猴(12眼)和20只树鼩(40眼)进行角膜内皮细胞测量,并获得角膜的8个相关参数:中央角膜厚度(CCT)、最小细胞面积(Smin)、最大细胞面积(Smax)、平均细胞面积(Savg)、细胞面积标准差(SSD)、细胞面积变异系数(CV)、细胞密度(CD)和六边形细胞百分比(HG),并结合文献与人眼的相关参数进行对比分析。结果 SP3000P角膜内皮细胞仪能在较短时间内完成恒河猴和树鼩角膜内皮的图像采集和参数的检查,耗时差异无显著性。恒河猴和树鼩CCT分别为(449.2±12.8)μm和(262.4±24.6)μm;Smin分别为(120.4±26.3)S/μm2和(153.2±42.9)S/μm2;Smax分别为(705.0±130.8)S/μm2和(468.7±109.3)S/μm2;Savg分别为(351.1±26.1)和(295.4±18.9)S/μm2;SSD分别为(113.1±27.4)和(75.9±27.3)S/μm2;CV分别为(31.9±6.0)和(25.3±8.3);CD分别为(2874.2±203.8)p/cell·mm-2和(3399.3±224.7)p/cell·mm-2;HG%分别为(58.6±9.1)和(94.0±9.7)。二者的上述参数差异均有显著性(P0.05)。树鼩角膜厚度比恒河猴小,内皮细胞面积、变异系数也较恒河猴小,但是角膜内皮细胞密度和六边形细胞比例显著高于恒河猴。恒河猴角膜厚度、角膜内皮细胞变异系数和六边形细胞比例与人眼高度相似,但内皮细胞密度低于人眼;树鼩角膜厚度为恒河猴的60%、人眼的50%,但角膜内皮细胞密度和平均细胞面积更接近于10~20岁人眼。结论恒河猴和树鼩角膜内皮细胞的形态和各项参数均有显著差异,各自与人眼角膜内皮细胞既有相似之处,也有不同点,恒河猴和树鼩均是研究人类角膜内皮疾病可以选择的合适实验动物。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.