4-N，N-二甲胺基偶氮苯-4′-异硫氰酸酯(DABITC)用于多肽微量氨基酸顺序的测定

前文曾介绍一种高灵敏度DABITC方法,今已成功地应用于微量多肽激素的氨基酸顺序测定,所取样品为猪胰岛素-B链、促黄体生成素释放激素及未知顺序的蝮蛇毒舒缓激肽增强因子等。样品量仅为8—30毫微克分子(nmol)。一、实验部分 1.材料和试剂猪胰岛素-B链,促黄体生成素释放激素(LRH)分别由本所胰岛素组和东风厂提供,蝮蛇毒舒缓激肽增强因子,由本实验室自制。DABITC试剂本所东风厂产品,化学试剂和溶剂的纯度,均为分析纯,并经重新处理聚酰胺薄膜为黄岩实验化工厂出品。 2.实验操作多肽激素(8—30nmol)置于1×5厘米刻度离心管,使溶于100微升50％v/v吡啶溶液,用50微升DABITC溶液(0.6毫克DABITC溶于260微升吡啶溶液)充氮气1分钟。在52℃水浴保温     

蝮蛇咬伤中毒的机制与治疗新进展

蝮蛇(Agkistrodon halys pallas)又名土蛇、大公蛇、地皮蛇,因其色泽似土而得名[1]。在我国除西藏、青海、云南省外均有发现,为我国剧毒蛇中分布最广的一种,蝮蛇咬伤多见于夏秋季节。蝮蛇毒素为混合毒素,被咬伤后可引起心、肝、肺、肾等脏器功能衰竭,如不及时抢救,预后差。故正确、及时、有效的救治蝮蛇咬伤是急救医学的重要课题。1发病机制蝮蛇属管牙类毒蛇,其毒是以血循毒为主的混合毒,即血循毒和神经毒。蝮蛇咬伤1次的注毒量为45～150mg(干重),而致死量为25mg(干重)[2]。1·1神经毒素蝮蛇毒的神经毒素含量较低,约占毒素干重的1%～2%。其…     

蝮蛇咬伤伤肢肿胀疼痛的护理现状

正相关资料显示,在我国有毒蛇50多种,每年被毒蛇咬伤病例在50万人次以上,死亡率为5%~10%,致残率为25%~30%~([1])。而蝮蛇在我国是分布最广的一种蛇类,蝮蛇伤是夏秋季常见的危急症,其具有发病急、病程短、病势变化快等特点~([2]),一旦被蝮蛇咬伤,蛇毒素经伤口吸收迅速,常引起伤肢肿胀明显,疼痛剧烈,即使应用抗蝮蛇毒血清及其他解毒药物后,伤肢肿胀疼痛仍不易缓解~([3]),是蝮蛇咬伤患者的主     

野外工作中虫伤的处理方法

进行野外考察或采集标本时,常会受到虫伤,下面就简单地谈谈几种常见虫伤的处理。１毛虫毒伤先用放大镜检视,拔出毒毛,或用橡皮胶、透明胶纸粘去毒毛,再用漂白粉溶液洗,用马齿苋捣烂外敷。皮疹广泛或痛痒剧烈者口服抗组织胺药物,或内服野菊花、蒲公英和乌蔹萄等。２蜂毒伤蜂毒主要含蚁酸、神经毒素和组织胺等,和蛇毒相似。被蜂类螫伤,先要拔出蜂刺,蜜蜂螫伤用５％～１０％碳酸氢钠溶液、肥皂水或３％氨水溶液洗涤、螫伤黄蜂用醋酸、食醋洗涤。伤口周围可外涂南通蛇药,或敷中草药,适合的中草药有蒲公英、紫花地丁、景天三七、青苔…     

王锦蛇血清对尖吻蝮蛇毒的抑制作用

目的 探讨王锦蛇血清对尖吻蝮蛇毒的抑制作用。方法 王锦蛇血清与不同剂量的尖吻蝮蛇毒分别混合后,注射到小鼠背皮下,测定王锦蛇血清对尖吻蝮蛇毒的抗出血活力;腹腔注射此混合物后,测定王锦蛇血清对尖吻蝮蛇毒的抗毒效价;先后注射尖吻蝮蛇毒和王锦蛇血清,测定王锦蛇血清对尖吻蝮蛇毒引起的死亡、组织损伤和炎症的抑制、保护和治疗作用。结果 1ml王锦蛇血清可完全抑制10mg（干重）的尖吻蝮蛇毒的出血活力;1ml王锦蛇血清可中和11mg（干重）尖吻蝮蛇毒的致死活力;王锦蛇血清对由尖吻蝮蛇毒引起的致死、组织损伤和炎症有显著的抑制、保护和治疗作用。结论 王锦蛇血清是尖吻蝮蛇毒的强抑制剂,可能成为未来新的蛇伤治疗药物的原料。     

满山香水煎液对流行性感冒病毒的抑制效果观察

一、满山香水煎液75％浓度,在鸡胚内对流感病毒亚．洲甲型赣防71-5株、京科68一1株(60EID50感染量)均有较明显的抑制作用。 二、“毒一药”或“药一毒”,虽感染和注药先后不同(相隔60分钟),其抑制效果无显著差异。 三、鸡胚尿襄腔感染病毒,60分钟后,经卵黄襄注药,对流感病毒赣防71-5株,京科68-1株也均有抑制作用。 四、阴性尿液经鸡胚尿囊腔盲传两代后,除个别血凝转阳外,大部分仍为阴性,药液在鸡胚内的抑毒作用比较显著。     

2种国产蝮蛇毒降纤酶的降纤作用比较

目的　比较尖吻蝮蛇毒降纤酶及白眉蝮蛇毒降纤酶降凝血因子 的作用。　方法　选用 1个厂家生产的以尖吻蝮蛇毒为原料的降纤酶及 2个厂家生产的以白眉蝮蛇毒为原料的降纤酶分别治疗 1 7例、 4 0例、 31例急性脑梗死。用降纤酶 1 0 u加入 0 .9%生理盐水 2 5 0 ml中 ,静脉滴注 ,1 h滴完 ,每天 1次 ,共 3天 ,每次用药前用凝固法测定凝血因子 。　结果　 2种白眉蝮蛇毒降纤酶降纤作用不明显 ,尖吻蝮蛇毒降纤作用明显且迅速。用药前 Fg为 4 .0 4± 1 .2 g/L,用药 1次后 Fg降至 2 .1 1± 0 .6 g/L,P <0 .0 1。　结论　尖吻蝮蛇毒降纤酶降纤作用明显优于白眉蝮蛇毒降纤酶。     

中西医结合治疗蝮蛇咬伤96例

蝮蛇又名地扁蛇 ,是我国分布最广 ,数量最多的一种毒蛇 ,其危害大 ,是农村常见急症之一 ,作者自 1 969年至今 ,共收治 9 6例蝮蛇咬伤病人 ,其中男 65例 ,女 31例 ;临床分型 :轻型 49例 ,中型 30例 ,重型 1 6例 ,危重型 1例。局部治疗后给予口服蝮蛇解毒汤并配合西药治疗。早期使用抗蝮蛇蛇毒血清 60 0 0～1 2 0 0 0 U加入 5%葡萄糖注射液 (50 0 ml)中静滴 ,肌肉注射破伤风抗毒素 1 50 0 U,应用地塞米松 1 0～30 mg减轻毒性反应 ,并对症治疗。结果痊愈 95例 ,占 98.95% ,死亡 1例 ,占 1 .0 5% ,住院治疗时间最短 3天 ,最长 1 5天 ,平均治愈…     

墨旱莲对4种蝮蛇毒引起的炎症和出血的影响

目的探讨墨旱莲提取液对短尾蝮蛇毒、蛇岛蝮蛇毒、白眉蝮蛇毒及尖吻蝮蛇毒所致的炎症和出血的影响。方法应用短尾蝮蛇毒、蛇岛蝮蛇毒、白眉蝮蛇毒及尖吻蝮蛇毒所致大鼠足跖肿胀的致炎模型,观察墨旱莲提取液对蛇毒所致大鼠足跖肿胀的影响。墨旱莲提取液分别与不同蛇毒混合,给小鼠腹部皮下注射,观察其对蛇毒引起的小鼠皮下出血的影响。结果墨旱莲提取液15g／kg连续2次灌胃给药,对短尾蝮蛇毒、蛇岛蝮蛇毒、白眉蝮蛇毒或尖吻蝮蛇毒所致大鼠足跖肿胀的急性炎症造模和短尾蝮蛇毒棉球肉芽肿的慢性炎症造模(20g／kg)均有明显的抑制作用,对这些蛇毒引起的小鼠皮下出血也能明显抑制。结论墨旱莲提取液对短尾蝮蛇毒、蛇岛蝮蛇毒、白眉蝮蛇毒及尖吻蝮蛇毒引起的炎症和出血均有明显的抑制作用。     

蝮蛇毒的神经毒成分的研究 Ⅲ.蝮蛇毒阻遏神经肌肉传递的作用部位

据报道凡含有神经毒的蛇毒都具有与终板区乙酰胆碱受体结合,从而阻断神经肌肉传递的突触后阻遏作用,其中只有银环蛇毒和澳大利亚虎蛇毒等兼有突触前阻遏作用。本工作对蝮蛇(Agkistrodon halys Pallas)毒阻遏神经肌肉传递的作用点进行了分析。当小鸡颈二腹肌标本在蝮蛇毒作用下出现传递完全阻遏之后,其肌肉对乙酰胆碱还保持着约50%的敏感性,同时由离子电泳注射法测知,蝮蛇毒能降低大白鼠膈肌终板区的乙酰胆碱敏感性。蝮蛇毒对神经肌肉传递除具有突触后作用外,尚应具有突触前作用。在较低浓度(40～100微克/毫升)蝮蛇毒作用下,小终板电位频率和终板电位的量子含量都有一短暂的增加,然后逐渐下降,但在高浓度下(200微克/毫升),两者在逐渐下降之前均无暂时增加现象。增加溶液中的镁离子浓度或降低钙离子浓度均能使蝮蛇毒引起的神经肌肉完全阻遏的出现时间延长。这些又进一步证实了蝮蛇毒中除含有作用于突触后的成分外,尚含有作用于突触前的成分。从蝮蛇毒中分离神经毒成分的方法已初步建立,根据本工作的启示,再进一步分离突触前毒素的工作已初获成功,有关资料将另行发表。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.

     

Novel compounds with potent CDK9 inhibitory activity for the treatment of myeloma

Cyclin-dependent kinases (CDKs) and Polo-like kinases (PLKs) play key role in the regulation of the cell cycle. The aim of our study was originally the further development of our recently discovered polo-like kinase 1 (PLK1) inhibitors. A series of new 2,4-disubstituted pyrimidine derivatives were synthesized around the original hit, but their PLK1 inhibitory activity was very poor. However the novel compounds showed nanomolar CDK9 inhibitory activity and very good antiproliferative effect on multiple myeloma cell lines (RPMI-8226).