氯丙嗪对狗胰液分泌的影响

本工作在6只Соловьθв胰瘘狗(其中3只同时带有巴索夫胃瘘)上进行,向十二指肠肠腔内重复注入稀盐酸引起胰液分泌,一共作了78次实验,其主要结果如下:(一)在正常以及颈部迷走封闭与膈上迷走切断的情况下,肠内重复注酸后胰液分泌量一直维持在一个一定高度的水平;脂肪酶与胰蛋白酶活性的变化进程呈现平行关系。(二)在上述三种情况下,静脉注入氯丙嗪(1毫克/公斤)都大幅度地降低胰液分泌量达两小时以上;同时,脂肪酶与胰蛋白酶活性的平行关系发生紊乱。由此说明氯丙嗪对胰腺液体的分泌具有抑制作用,对胰酶活性的平行变化有分离作用,而且不是以迷走神经为其作用的传出途径。(三)文中讨论了氯丙嗪作用的可能机制。     

半胱胺对成年鹅血浆中生长抑素和某些代谢激素的影响

目的:研究半胱胺(CS)对成年鹅生长抑素(SS)和某些代谢激素的影响.方法:14只装有翅静脉瘘管的成年杂交鹅(川白×太湖),经瘘管采取对照期和处理(一次性添喂100 mg/kg bw的半胱胺)后第1、3、5、7 d的血样,用RIA双抗法测定其中激素的含量.结果:实验期第1、3、5和7 d的生长抑素的含量均显著低于对照期(1.89±0.10 μg/L).促甲状腺激素较对照期(2.45±0.31 mIU/L)在第1 d显著下降21.63 %(P<0.05),第3、5 d均降低18.37%(P>0.05),第7 d基本回复正常(P>0.05). 实验期1、3、5和7 d的T4 较对照期(5.41±0.98 μg/L)显著升高(P<0.01);实验期第3 d的T3水平较对照期(1.05±0.06 μg /L)高36.19 %(P<0.01);同样,胰岛素在实验期的第5 d显著高于对照期(P<0.05).结论:CS能够降低成年鹅血液中SS含量,使T4、T3和胰岛素水平升高,提高了机体的代谢水平,同化作用加强,从而有利于生长.     

CO_2浓度升高对不同寄主植物上西花蓟马和花蓟马成虫体内消化酶活性的影响

【目的】为明确大气CO_2浓度升高对入侵昆虫西花蓟马Frankliniella occidentalis及其本地近缘种花蓟马F.intonsa的影响机制。【方法】在CO_2人工气候箱(400和800μL/L)内分别以不同的寄主植物(四季豆、茼蒿、辣椒和黄瓜)饲养西花蓟马和花蓟马3代以后,比较分析两种蓟马成虫体内消化酶(淀粉酶、胰蛋白酶和脂肪酶)活性的差异。【结果】4种寄主植物饲养的西花蓟马和花蓟马成虫体内淀粉酶活性均随着CO_2浓度的升高而降低,其中四季豆、黄瓜、辣椒和茼蒿饲养的西花蓟马成虫体内淀粉酶活性依次降低21.39%,25.33%,44.59%和42.27%;而花蓟马成虫体内淀粉酶活性则分别降低了48.79%,49.47%,38.86%和38.92%。随着CO_2浓度的升高,两种蓟马成虫体内脂肪酶和胰蛋白酶的活性均升高,其中四季豆、黄瓜和辣椒饲养的两种蓟马酶活性均显著升高(P0.05)。高CO_2浓度环境中四季豆饲养的西花蓟马脂肪酶和胰蛋白酶活性分别是对照的2.00和2.49倍,黄瓜饲养的种群其脂肪酶和胰蛋白酶活性分别是对照的2.36和2.27倍,辣椒饲养种群相应的酶活性分别是对照的3.61和3.59倍。而高CO_2浓度环境中四季豆、黄瓜和辣椒饲养的花蓟马脂肪酶活性仅分别是对照的1.76,2.18和2.69倍,胰蛋白酶活性分别为对照的1.72,2.19和2.42倍。【结论】CO_2浓度升高和寄主植物种类是影响两种蓟马成虫体内淀粉酶、胰蛋白酶和脂肪酶活性变化的重要原因,两种蓟马均能通过调节自身的酶活性来适应未来高CO_2浓度的气候环境,其中入侵种西花蓟马对环境的适应性强于本地近缘种花蓟马。     

波叶大黄多糖对胰腺五种酶的抑制作用

 本文报道波叶大黄多糖(Rheum hotaoense polysaccharide,RHP)对胰腺五种酶的抑制作用。结果表明。(1)RHP对胰蛋白酶、胰脂肪酶、胰淀粉酶、胰弹性蛋白酶和胰激肽释放酶均有很明显的抑制作用。IC_(50)分别为250μg/mL、21μg/mL、18μg/mL,189μg/mL和300μg/mL。(2)动力学研究表明,RHP对胰蛋白酶和胰脂肪酶的抑制均是非竞争性的,Km值分别为1.2×10~(-4)μmol/mL和1.2mg/mL,Ki值分别为355.0μg/mL和63.85μg/mL。(3)牛血清白蛋白(BSA)对RHP抑制胰蛋白晦和胰脂肪酶具有拮抗作用。当BSA浓度达72.0mg/mL时,对胰蛋白酶活性的恢复率为71.54％。当BSA浓度达20.0mg/mL时,对胰脂肪酶活性的恢复率为63.64％。上述结果表明,RHP对胰腺五种酶的抑制作用,可能是大黄治疗急性胰腺炎作用的生化机制之一,预示RHP在临床上将有重要应用前景。     

半胱胺对成年鹅糖和蛋白质代谢的影响

经瘘管收集 14只装有翅静脉瘘管的成年杂交鹅 (川白×太湖 )的血样作为对照 ,随后一次性添喂10 0mg/kg·bw的半胱胺 (处理 )。分别用放射免疫和分光光度等方法测定一些与糖和蛋白质代谢有关的激素和生化指标。处理后第 1、 3、 5、 7天分别收集血样。其中 ,4个检测日的血浆尿酸含量降低 ,谷丙转氨酶升高 ;第 5天和第 7天的血糖降低 ;第 5天胰岛素高于对照 ,而胰高血糖素低于对照 ,二者比值最大。这些结果暗示半胱胺促进了鹅机体的同化作用     

胰酶中镉的去除研究

综合对酶活性的影响,研究胰酶中镉的去除条件.在pH为6.0,HCA-1加入量为0.8%,树脂加入量为40 mL(胰脏投料200 g),胰脏活化时用HCA-1络合去除胰酶中的镉,其最高去除率可达54.9%,此时胰蛋白酶、胰脂肪酶、胰淀粉酶的活力几乎没有什么影响.该工艺可以很好地嵌入现有胰酶生产工艺中,几乎不增加生产步骤,具有非常好的工业应用前景.     

电离辐射降低大鼠胰淀粉酶和胰蛋白酶活性机制的一些初步分析

1.丙线照射后胰淀粉酶、胰蛋白酶活性明显降低,胰酶活性降低程度和胰腺重量有关。在一定照射剂量范围内,胰酶活性和腺重量随着照射剂量的增加而下降。2.同样剂量的丙线照射后,胰腺组织匀浆上清液中的胰酶活性无变化。3.丙线照射后胰腺腺泡由M受体激动剂氨甲酰胆碱引起的淀粉酶分泌量明显减少。4.电镜观察表明,丙线照射后大鼠胰腺腺泡内合成及分泌酶原的内质网、线粒体等超微结构紊乱,这可能是电离辐射后胰酶活性降低的主要原因。     

脓毒血症早晚期肝细胞核被膜NTPase活性及poly(A)+mRNA核浆转运的变化

目的和方法 :在盲肠结扎穿孔脓毒血症大鼠模型上 ,研究早晚期脓毒血症肝细胞核被膜核苷三磷酸酶 (NT Pase)活性及 poly(A) mRNA核浆转运的变化。结果 :脓毒血症早期NTPase活性增加而晚期活性降低 ,即早期Vmax与对照组比增加 6 2 % (ATP ,P <0 .0 5 )和 18% (GTP ,P <0 .0 5 ) ;晚期Vmax下降 2 6 % (ATP ,P <0 .0 5 )和5 6 % (GTP ,P <0 .0 5 )。脓毒血症仅晚期NTPase底物亲和力降低 ,即晚期Km与对照组比分别升高 2 6 % (ATP ,P<0 .0 5 )和 37% (GTP ,P <0 .0 5 )。脓毒血症早期 poly(A) mRNA核浆转运速率增加而晚期降低 ,即早期组 10min转运速率较对照组增加 2 7% (ATP ,P <0 .0 5 )和 30 % (GTP ,P <0 .0 5 ) ;晚期组降低 2 1% (P <0 .0 1)和 35 % (P <0 .0 1)。结论 :脓毒血症肝细胞核膜NTPase活性呈早期升高、晚期下降的双相变化与肝细胞核被膜 poly(A) mR NA核浆转运速率的早、晚期变化相平行 ,同时与脓毒血症血糖浓度的早、晚期变化相关。本实验在一定程度上解释了脓毒血症早晚期代谢双相变化发生的分子机理     

蛋白酶抑制剂对绿豆象幼虫中肠蛋白酶活性的影响

为明确蛋白酶抑制剂对绿豆象幼虫中肠蛋白酶活性的影响,采用室内人工接虫和生化测定的方法,研究了在离体条件和饲喂条件下4种蛋白酶抑制剂对绿豆象幼虫中肠蛋白酶的抑制作用,并测定了绿豆象幼虫取食不同含量的绿豆胰蛋白酶抑制剂(MBTI)的人工绿豆后,其中肠内总蛋白酶、类胰蛋白酶和类胰凝乳蛋白酶活性的变化.结果表明:在离体条件下,供试4种蛋白酶抑制剂对绿豆象幼虫总蛋白酶、类胰蛋白酶和类胰凝乳蛋白酶活性均有明显的抑制作用,且浓度越大,抑制效果越显著,其中以20μg·mL^-1的MBTI对3种酶活性的抑制效果最强,3种酶活性分别比对照降低了62.5%、41.2%和38.7%,而卵粘蛋白抑制剂(OI)抑制效果最弱.绿豆象幼虫取食含不同抑制剂的人工绿豆后,中肠内3种酶活性也均受到一定的抑制作用,取食后随龄期的延长,3种酶活性有所升高但仍显著低于对照,且以MBTI的抑制作用最强.当绿豆象幼虫取食不同含量MBTI的人工绿豆后,随MBTI含量的增加,对总蛋白酶活性和类胰蛋白酶活性的抑制作用均逐渐增强,但对类胰凝乳蛋白酶活性的抑制作用并不显著,只有当MBTI含量达20%时,对类胰凝乳蛋白酶活性才表现出明显的抑制作用.     

吗啡和纳洛酮对酸化十二指肠引起狗胰液分泌的影响

本工作用制备 Thomas 胰瘘和胃痿的5条狗进行慢性实验。实验时用0.1N 盐酸灌入十二指肠以刺激胰液分泌,并分別注射吗啡或/和纳洛酮,观察它们对胰液分泌和对胰液中碳酸氢盐和蛋白质浓度的影响。另外我们还观察了吗啡和纳洛酮对6条狗离体胰主导管紧张性的影响。结果表明:(1)吗啡抑制了胰液分泌量,对胰液中碳酸氢盐和蛋白质浓度无影响,由于分泌量减少故两者的排出量显著减少(P<0.05),(2)纳洛酮本身对胰液分泌量和碳酸氢盐及蛋白质浓度均无影响;(3)纳洛酮可以加强吗啡抑制胰液分泌的作用(P<0.01);(4)吗啡能增加狗的离体胰主导管肌条的紧张性,纳洛酮不能阻断或翻转吗啡的这一效应,相反能加强其效应。本工作表明,吗啡抑制酸化十二指肠所引起的胰碳酸氢盐和蛋白质排出量,其机制可能是吗啡刺激胰导管收缩,而纳洛酮则加强吗啡的这种抑制效应。     

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.