乌梢蛇胃上皮的组织学研究

用光镜和电镜观察了乌梢蛇胃上皮的组织结构,结果表明,1胃表面上皮均为单层柱状上皮,上皮细胞上部充满电子密度较高的椭圆形或杆状黏液颗粒,PAS反应呈强阳性;2胃体及幽门区上皮分别内陷形成单管状的胃底腺和幽门腺,无贲门腺;③胃底腺腺管分颈部和颈下部,颈部上皮细胞充满电子密度较低的近圆形的黏液颗粒,PAS反应呈强阳性,颈下部上皮细胞均分泌酶原颗粒,PAS反应呈阴性;④幽门腺细胞中亦充满电子密度较低、近圆形的黏液颗粒,PAS反应呈强阳性;⑤胃腺上皮细胞之间和腺细胞基部有不同类型的内分泌细胞分布.本文认为,乌梢蛇胃的消化能力较弱,其胃的进化在爬行动物中处于较低等的地位.     

初生扬子鳄胃粘膜表面及胃腺的形态

观察了２例初生扬子鳄（Ａｌｌｉｇａｔｏｒｓｉｎｅｎｓｉｓ）胃粘膜表面及胃腺的形态。扫描电镜观察：胃贲门具１１—１３个贲门瓣,贲门区及幽门区粘膜上皮凹陷稀而浅,胃体部上皮凹陷密而深,排列很规则,胃小凹明显。组织切片观察：贲门腺及幽门腺均为短的单管腺,腺上皮由单一类型的腺细胞组成,胃底腺为分校管状腺,晚上皮由多种腺细胞组成。对扬子鳄胃粘膜表面及胃腺的形态特点作了讨论。     

虎斑颈槽蛇消化道5-羟色胺免疫活性内分泌细胞的分布与形态学观察

用免疫组织化学ABC(avidin-biotin-peroxidase complex)法,对虎斑颈槽蛇Rhabdophis tigrinus 5-HT免疫反应阳性内分泌细胞的分布及形态学进行了观察.结果 表明,5-HT阳性细胞从食管到直肠的消化道各段均有分布.细胞密度分布呈"N"型,胃体最高,胃幽门部和胃贲门部次之,空肠最少.5-HT阳性细胞的形态多样,其中贲门和胃以圆形或椭圆形为主,肠道(除直肠)则以锥形为主;广泛分布于上皮基部、上皮细胞之间、腺泡上皮及腺泡之间,有时可见于固有膜内.     

北京鸭产卵期输卵管管状腺细胞超微结构研究

用电子显徽镜对北京鸭输卵管管状腺细胞进行观察。鸭输卵管由五部分组成:漏斗、蛋白分泌部、峡部、壳腺和阴道。蛋白分泌部的管状腺细胞有四种类型。A型细胞有电子密度深色颗粒;B型细胞充满了无定型低电子密度物质;C型细胞具有非常明显的粗面内质网和高尔基复合体;D型细胞是由致密的颗粒和低电子密度的颗粒所组成,腔内充满分泌颗粒。我们在这篇文章中分析了蛋白分泌周期的四个不同阶段。     

N-乙酰氨基葡萄糖残基在发育鼠胃底腺颈粘液细胞中的表达

目的 通过大鼠在不同发育阶段中胃底腺细胞表达α-N-乙酰氨基葡萄糖（GluNAc)残基的情况,来研究大鼠胃底腺颈粘液细胞的发生。方法 利用单克隆抗体HIK1083能特异性识别α-GluNA残基的特点,进行免疫组化研究。结果 HIK1083阳性细胞从第19.5天胚胎鼠的胃底腺中开始辨认出来,一直存在至成鼠,这些细胞最初出现在胃底腺的底部,然后向上方移动,最后位于腺体的颈部。结论 胚胎晚期开始表达α-GluNAc残基的细胞可能是原始的颈粘液细胞,随着鼠胃底腺的发育。这些细胞逐渐向上方移动,最终成为颈粘液细胞。     

中华大蟾蜍多种组织内5-羟色胺免疫染色细胞的分布

用过氧化物酶-抗过氧化物酶(PAP)法,对中华大蟾蜍消化道(冬眠期与非冬眠期),脑及其他组织的5-HT分布进行了研究。5-HT免疫染色细胞位于脑干中缝核区和间脑的第Ⅲ脑室腹侧的室管膜细胞区。阳性神经元呈圆形或卵圆形,细胞常有突起与其他阳性细胞突起相连,上述部位中还有一些阳性神经纤维。消化道的免疫染色细胞密度在胃幽门、胃体和胃贲门处最高,食道和十二指肠次之,大肠和小肠最低。非冬眠期蟾蜍消化道内免疫染色细胞密度明显高于冬眠期的(P<0.05)。阳性细胞位于粘膜上皮或腺上皮细胞间,细胞有一个或一个以上呈阳性反应的突起,有的突起伸入肠腔面或腺腔面,有的穿过基膜到达固有层,表明这些细胞兼有内、外分泌的功能。在甲状旁腺的主细胞间,肺呼吸性细支气管上皮和肺泡管上皮细胞间都有5-HT免疫染色细胞,细胞呈立方形、圆形、卵圆形或不规则形,常有几个细胞成簇分布。     

龟足白垩腺的组织学和超微结构

应用光学显微镜和透射电子显微镜对龟足(Capitulum mitella)白垩腺的组织学和超微结构进行观察。龟足的白垩腺由腺细胞和管道系统组成,外周覆有一层结缔组织膜。腺细胞为单细胞,其发育与个体发育不同步。年幼腺细胞较小,形态为圆形或椭圆形,细胞核也为圆形或椭圆形。随着腺细胞的发育,细胞及细胞核逐渐变大,形状不规则具多态性。成熟腺细胞的细胞质电子密度高,充满大量粗面内质网和游离核糖体;线粒体很丰富,但未见高尔基体。细胞质中含有丰富的颗粒状物质以及大小不一的囊泡,小囊泡的聚集和融合形成了大囊泡即胞内管。管道系统根据位置和功能分为4个层次:胞内管、收集管、次级管和初级管。收集管、次级管和初级管的管壁均由单层上皮细胞组成,初级管较收集管和次级管大且内腔衬有几丁质层。收集管的管壁上皮细胞与腺细胞之间形成隔状连接,各级管壁上皮细胞之间也形成隔状连接,这种结构保证了管道的紧密性。总之,龟足白垩腺的形态结构类似于茗荷(Lepas anatifera)和Dosima fascicularis。     

扬子鳄小胃黏膜的组织化学和细胞学

扬子鳄（Alligator sinensis）的小胃是在胃幽门部与十二指肠的交接处由胃幽门括约肌和十二指肠括约肌突入管腔形成的一个小腔,其生理功能一直不清楚。本文采用组织化学、电子显微镜和免疫组织化学技术对扬子鳄小胃黏膜的组织化学成分、细胞超微结构及细胞类型进行了较全面的研究。小胃黏膜上皮PAS反应呈强阳性,AB染色呈弱阳性,主要分泌中性糖蛋白和少量的含硫酸性糖蛋白。电子显微镜下,扬子鳄小胃黏膜上皮主要由表面黏液细胞组成,偶见内分泌细胞。小胃腺部则70％-90％为内分泌细胞,其余为少量的腺黏液细胞和泌酸胃酶细胞。应用7种胃肠激素的抗血清在小胃黏膜中检测出了5-羟色胺（5-HT）、胃泌素（Gas）、胰高血糖素（Glu）、生长抑素（SS）、P-物质（SP）和血管活性肠肽（VIP）细胞,以Glu细胞密度最高,VIP细胞密度最低。未检测到胰多肽（PP）细胞。本研究结果表明,从组织化学成分和细胞类型看,扬子鳄的小胃与胃同源;从细胞超微结构和内分泌细胞所占百分比例看,扬子鳄的小胃已出现了明显的特化,泌酸胃酶细胞中未见泌酸小管,可能没有泌酸功能。内分泌细胞含量丰富,可能在调节胃肠道功能中发挥重要作用[动物学报54（6）：1044—1050,2008]。     

环颈雉消化系统组织形态学观察

１９８９年４月至１９９０年４月作者对６只健康成年环颈雉消化系统组织采用常规方法制成显微和超薄切片。研究表明：环颈雉消化管的粘膜层，肌层和管状消化腺发达。食管为角化的覆层扁平上皮，角化层厚０．７２－０．８０μｍ，粘液腺丰富，腺细胞内充满粘原颗粒。腺胃内有发达的复管状腺和单管腺二种腺体；单管腺由颈粘液细胞、长柱状细胞和内充泌细胞组成。肌胃内有肌胃腺，无粘膜肌层。十二指肠绒毛长而密集且分支明显；无中央乳     

Ghrelin、KGF、TGF-β(β2、β3)在大鵟胃肠道中的表达

应用免疫组织化学方法和体视学半定量方法,检测了ghrelin、KGF、TGF-β(TGF-β_2,TGF-β_3)在大鵟(Buteo hemilasius)胃肠道中的表达,利用IPP专业图像分析软件对其表达强度进行了定量分析.结果表明,ghrelin免疫反应阳性物质分布在十二指肠、空肠、回肠、盲肠和直肠的黏膜层,主要分布于黏膜上皮、肠腺上皮和固有层.从十二指肠到盲肠阳性细胞的分布密度逐渐减小,直肠阳性细胞的分布密度高于盲肠.胃肠道呈KGF免疫反应阳性,胃内阳性物质分布于腺胃浅腺和深腺、肌胃黏膜、肌胃单管腺的上皮细胞;肠内阳性物质分布于固有层的血管、淋巴和平滑肌纤维.胃黏膜、腺胃深腺、肌胃单管腺、肠道黏膜、肠腺呈TGF-β_2及TGF-β_3免疫反应阳性,阳性物质分布于黏膜、肠腺上皮细胞胞质中.图像分析显示,KGF的阳性表达水平呈波浪形变化,在空肠和直肠处达到峰值;TGF-β2的阳性表达水平呈波浪形变化,分别在肌胃和空肠处有峰值;TGF-β_3从腺胃到空肠阳性表达水平逐渐增强,之后阳性表达水平又逐渐下降,到盲肠阳性表达水平回升.ghrelin、KGF、TGF-β_2和TGF-β_3的阳性表达强弱可能与胃肠道的消化能力有关,它们的协同表达调控鸟类胃肠道的生长和发育.     

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.