生物胆汁液晶态的研究

本文报导了用偏光显微镜、电子显微镜研究人体胆汁中的液晶态.结果表明:胆汁中存在有双射折的微粒,它们的图象指出是具有片层结构的液晶态.胆汁中还存在有类脂球滴液晶.     

生物胆汁液晶的观察

从1946年至1960年,世界上许多学者相继发现了生物体中的液晶,至今有更多的学者仍在从事这种探索性的研究。Olsewski等曾在1973年指出胆汁中可能存在各种不同的相,有些构型有清楚的液晶性质。G.H.Brown在1979年说明了胆汁中液晶的作用。     

鸡胚发育中肝脏类脂滴液晶态及体外结晶态的相变特性研究

观察到鸡胚发育中肝脏液晶类脂滴在降低温度时,可向结晶态转变,类脂滴液晶——结晶——各向同性态三相之间可互相转变。肝脏组织中液晶类脂滴在0℃左右转变为结晶;结晶在39—43℃时转变成各向同性类脂滴(正交偏光下无双折射);后者在热的铜样品台上,随样品台缓慢自然降温至35—36℃时又转变成结晶态;各向同性类脂滴在较快速度降温时,则转变成液晶态类脂滴。     

中西医结合治疗胆汁返流性胃炎的观察

目的：探讨中西医结合在胆汁反流性胃炎治疗中的应用及疗效。方法：将64例胆汁反流性胃炎患者随机平均分为对照组和观察组,对照组采用多潘立酮和铝碳酸镁进行治疗,观察组在对照组的基础上加用中药大柴胡汤,疗程为6周。观察治疗后患者主要症状改善情况和胃镜下表现情况,并行疗效比较。结果：观察组患者上腹痛、恶心、胃内胆汁、胃黏膜充血、胃黏膜糜烂等症状的改善率高于对照组（P〈0．05）;观察组治愈14例、显效9例、有效6例、无效3例,疗效优于对照组,差异有显著性（Z=2．864,P〈0．01）。结论：中西医结合是治疗胆汁反流性胃炎的有效治疗方案,建议临床推广应用。     

中蜂（Apis cerana）蛹期脂肪体营养细胞蛋白质颗粒…

本文以差分析法;小角Ｘ－射线散射及偏光显微镜等方法证明,中蜂蛹期脂肪体内营养细胞蛋白质颗粒呈液晶态,表现出结构有序的特征。正交偏光下,“蛋白质颗粒”显示出外区具强双折射的马尔它十字消光现象;以ＤＴＡ等方法测得,液晶态“蛋白质颗粒”在２６℃时可向各向同态转变,且具可逆性,由于“蛋白质颗粒”的大量存在,以ＳＡＸＳ直接测定脂肪体,证实中蜂蛹期体内营养细胞液晶态“蛋白质颗粒”的Ｂｒａｇｇ间距为４４Ａ,属于     

胆汁酸盐和低pH值对乳酸菌活性的影响

本文比较了几种乳酸菌对胆汁酸盐的耐受性和ｐＨ值的残活能力。研究结果表明,在０．２％的ＭＲＳ或ＢＭ培养基上,婴儿双歧杆菌的生长速率受到的抑制最小,依次为嗜酸乳杆菌、保加利亚乳杆菌和嗜热链球菌。胆汁酸盐对其生长的完全抑制浓度分别为１．５％、１．２％、０．５％和０．３％。在ｐＨ３时,嗜热链球菌活菌数量降低较为明显,在ｐＨ２时,在３７℃１ｈ过程中,婴儿双歧杆菌活菌数量基本不变;嗜酸乳杆菌在３７℃２０ｍｉｎ后,活菌数量迅速降低;保加利亚乳杆菌数量在３７℃２０ｍｉｎ时几乎为零。     

DNA液晶膜的结构与压电性研究

本文报导了在正交偏振片下观察DNA液晶膜的偏光显微图像,以及用小角激光光散射技术测定该膜的光散射,结果表明;液晶膜内聚核苷酸分子聚集形成棒状分子簇,其最大极化率方向倾斜于棒轴.在这种极化状态下,可测量到DNA膜对单轴机械应力的电压响应,压缩时,具有正的电信号,伸长时,具有负的电信号.     

中蜂（Apis cerana）蛹期脂肪体营养细胞蛋白质颗粒液晶性质的证明

本文以差热分析法（ＤＴＡ）,小角Ｘ－射线散射（ＳＡＸＳ）及偏光显微镜等方法证明、中峰（Ａｐｉｓｃｅｒａｎａ）蛹期脂肪体内营养细胞蛋白质颗粒（ｐｒｏｔｅｉｎｇｒａｎｕｌｅ）呈液晶态,表现出结构有序的特征。正交偏光下,“蛋白质颗”显示出外区具强双折射的马尔它十字消光现象;以ＤＴＡ等方法测得,液晶态“蛋白质颗粒”在２６℃时可向各向同性态转变,且具可逆性,由于“蛋白质颗粒”的大量存在、以ＳＡＸＳ直接测定脂肪体,证实中蜂蛹期体内营养细胞液晶态“蛋白质颗粒”的Ｂｒａｇｇ间距为４４Ａ,属于液晶片层相。     

利用偏光影像技术定量观察大鼠胸主动脉中纤维结构

目的：本实验选取大鼠胸主动脉为研究对象,探讨定量偏光影像技术对双折光性物质的成像特点与适用研究领域。方法：采用Abrio液晶偏光影像系统在未经染色条件下对青年和衰老大鼠胸主动脉纤维结构进行观察,然后对主动脉切片进行苦味酸天狼猩红染色,对比Abrio和传统偏振光技术成像的差别。结果：较传统偏振光显微镜不同,Abfio可以对纤维双折射的方位角和光程差进行定量分析。在未经染色的条件下,Abrio可对大鼠胸主动脉中具有双折光性的纤维结构清晰成像,而传统偏光显微镜在未经染色条件下不能给出有意义的信息。经苦味酸天狼猩红染色后,对比传统偏振光技术,Abrio使成像不受纤维排列方向和人为因素的影响,较为完整地反映主动脉中纤维的结构及分布情况。结论：Abrio液晶偏光影像技术能够实现对样本双折光的强弱及方向的定性和定量分析,在未经染色的条件下给出微观结构信息,适合于心血管疾病的检测与评估,可拓展应用面宽,将在未来生物医药领域中体现更大的价值。     

离体胆汁稳定外源性气核的作用

用显微放大及摄录像方法观察了高空减压条件下溶液中气泡的生成。研究了３０只豚鼠离体胆汁在体外稳定外源性气核的作用,发现离体胆汁具有与胆盐相同的稳定气核作用;胆汁溶液中的气核能悬浮稳定２天,胆汁的此种离体活性可保持８天。结果提示胆汁中的某些成分与目前减压气泡形成机制研究工作中正在寻找的稳定体内气核物质有重要关系。此工作对阐明减压病病因有重要意义。     

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.