蛇毒神经毒素的研究进展

蛇毒具有广泛的生物活性，国内外对蛇毒神经毒素的镇痛作用的研究越来越多。作者就蛇毒神经毒素的分布及分类﹑结构和理化性质﹑毒理机制及应用作一些简要概述。     

河豚毒素的研究进展

河豚毒素是最先从河鲀中分离提取得到的一种剧毒的生物碱类天然神经毒素,后来在包括水生和陆生的多种动物体中均有发现。河鲀正在成为福建省的一种重要养殖鱼类,药理研究也发现河豚毒素在治疗成瘾、癫痫、局部和全身麻醉及镇痛等方面发挥着重大的作用。河豚毒素的研究具有重要意义,但是河鲀体内河豚毒素的确切来源目前仍没有定论,其生物合成途径也尚待阐明。本文对河豚毒素理化性质、作用及来源等方面进行综述。     

家蚕抗菌肽研究进展

抗菌肽具有理化性质稳定、杀菌谱广、抗肿瘤等特点 ,在生防、医药及农作物抗病育种等领域具有重要的利用价值。从抗菌肽的结构特点与理化性质、生物活性与功能、抗菌肽的分子生物学及应用前景等方面 ,综述了近年来的研究进展。     

腐败梭菌a毒素的研究进展

就腐败梭菌?毒素的理化性质、生物学特性、结构与功能、致病机制、免疫原性和应用等方面国内外的研究进展进行了论述,以期为腐败梭菌病的防治以及病原学和其他相关分子生物学的研究提供借鉴。     

壳聚糖在水产业中的应用

壳聚糖以其独特的理化性质及生物学功能在农业、医药、工业方面有着广阔的前景。对壳聚糖的来源、制备方法、结构、理化性质及其生物学功能等方面做了简要说明,着重介绍其在水产业中的应用状况,并指出其在应用中存在的问题,为壳聚糖今后在水产业中的应用提供有利的科学依据。     

垃圾和污泥堆肥用作无土草皮基质的研究进展

垃圾和污泥经过合理的堆肥化处理之后具有良好的理化性质,可以改善土壤结构、促进草坪植物生长。本研究从垃圾堆肥和污泥堆肥对土壤理化性质、草坪草、环境的影响,在无土草皮开发中的应用,在土地利用方面的相关标准等几个方面进行了综述。     

辣椒素研究及其应用

辣椒素，一种红辣椒的主要辛辣成分，是伤害性感觉神经纤维C和Aδ的特异激活剂，对其心血管效应的研究与应用已有大量报道。本文主要就辣椒素的结构分布、理化性质与生理功能，特别是有关其产品的应用研究前景等方面研究进行了综述。     

β-环糊精在药剂学上的作用

环糊精(CYD)系淀粉经酶解环合后得到的由6个以上葡萄糖分子连结而成的环状低聚化合物,因具有环状中空圆筒状结构而呈现一系列特殊性质,是药物制剂、食品工业、化妆品工业等方面应用较广的新型包合材料,能包合许多有机化合物和稀有气体、卤素等无机化合物,被其包合后的物质稳定性、挥发性、溶解性等各种理化性质发生了显著变化,且环糊精本身基本无毒、无刺激性.     

槲皮素的营养生理功能及其饲用化前景

槲皮素是自然界分布最广的天然黄酮类化合物,具有抗菌消炎、抗氧化、抗肥胖等多种生物学活性,在现代畜禽无抗养殖中表现较高的研究和实践应用价值.本文主要围绕槲皮素的结构、理化性质、营养生理功能及其在养殖生产中的初步应用进行综述,旨在为槲皮素的饲用化研究提供科学依据.     

神经毒素

正神经毒素又称神经毒,是对神经组织有毒性或破坏性的内毒素,可使周围神经有髓鞘、脑和脊髓及其他组织产生脂肪性变。多为天然存在,如蛇毒、蝎毒、蜂毒等动物毒素、植物毒素、海洋毒素、微生物毒素等。神经毒素是从民用有机磷农药杀虫剂发展而来,1935年德国学者成功地研制出速效有机磷农药杀虫剂──塔崩。由于意外事故,研究者中毒而出现一系列胆功能衰竭,这才意识到塔崩对人体有巨大     

蜂毒化学成分的分离方法研究进展

蜂毒是一种成分复杂具有广泛药理活性的昆虫毒素,包括多肽类、酶类和非肽类物质。对近年来蜂毒化学成分及分离方法的最新研究进展进行综述,旨在了解蜂毒的成分研究及其高纯度组分的获取方法,为蜂毒合理利用提供理论依据和实践基础。     

Elapid snake envenomation in dogs in New South Wales: a review

Elapid snake envenomation in dogs is a commonly occurring yet poorly described clinical entity. Twelve species of dangerously venomous elapid snakes are found in New South Wales that are capable of causing disease in dogs. Geographical distribution of these species varies, as does their venom composition and systemic envenomation syndromes produced in target species. Elapid venom may be divided into the components of prothrombin activating enzymes, lipases and peptidic neurotoxins. Each species of elapid snake may possess venom components that fit any or all of these classifications. The action of these venom components may result in neurotoxic (pre-synaptic and post-synaptic), haemotoxic (red-cell destruction and coagulation disturbance), cardiovascular, myotoxic and secondary nephrotoxic effects. Marked variability may occur in venom composition between and within snake species, resulting in varying toxicity between species and also potentially unreliable clinical syndromes following envenomation. The existence of certain components consistently within the venom of each snake species allows the broad definition of basic pathological processes and clinicopathological changes resulting from snake species-specific envenomation and these are discussed. Diagnosis of snake envenomation is unreliable if based on clinical signs alone and the use of these signs in conjunction with history, physical examination and laboratory investigation, including snake venom detection kits, is recommended. Treatment of systemic envenomation should be undertaken with initial effective first aid and subsequent administration of snake species-specific antivenom.     

Prospective determination of the specificity of a commercial snake venom detection kit in urine samples from dogs and cats

Objective To determine the specificity of a snake venom detection kit in urine samples from dogs and cats presenting to a referral centre for diseases unrelated to snake envenomation. Design Urine was collected from 50 dog and 25 cats presented for investigation and treatment of diseases unrelated to snake envenomation. Urine was collected as a voided sample, by cystocentesis or by catheterisation, and routine urinanalysis was performed. Snake venom testing was performed within 2 h of collection using a commercially available snake venom detection kit, which was observed continuously during the 10-min colour reaction phase for evidence of a visible colour indicating a positive test. Results No false-positive reactions occurred in any sample analysed. Conclusion The snake venom detection kit appears to have 100% specificity for using urine as a test sample.     

An investigation, in vitro, of the actions of three Western Australian snakes on the blood coagulation of the dog, cat, horse and wallaby

Venoms of the tiger snake and brown snake were procoagulant, in vitro, when tested with cat, dog, horse and wallaby plasma. In the absence of calcium and phospholipid the coagulant activity of tiger snake venom was minimal. In contrast, brown snake venom alone had marked procoagulant activity. This activity, however, was enhanced by the presence of calcium and phospholipid. Death adder venom exerted an anticoagulant effect. Apparent species' differences in susceptibility to the coagulant venoms were noted. However, the probable explanation of these differences was attributed to variation in the control values of the special studies rather than to a difference in the postulated actions of the venoms on prothrombin. A possible role for clotting studies in suspected snake bite in veterinary practice is suggested.     

Clinicopathologic abnormalities associated with snake envenomation in domestic animals

Envenomation of domestic animals by snakes occurs frequently in certain geographic areas. However, reports describing clinical signs, clinicopathologic abnormalities, therapeutic approaches, and outcomes are sparse. This review summarizes various snake families, venom types associated with harmful snakes, and the significant hematologic, hemostatic, and biochemical abnormalities associated with envenomation. Hematologic abnormalities include RBC membrane abnormalities, hemolysis, hemoconcentration, leukogram changes, and platelet abnormalities, specifically thrombocytopenia. Coagulopathies associated with snake envenomation are well described in human medicine, and many studies have demonstrated properties of venoms that lead to both procoagulation and anticoagulation. As expected, similar abnormalities have been described in domestic animals. Biochemical abnormalities are associated with the effects of venom on tissues such as liver, skeletal and cardiac muscle, vascular endothelium, and kidney as well as effects on protein components and cholesterol. This comprehensive review of clinicopathologic abnormalities associated with envenomation and their relationships to characterized venom constituents should be useful both in the diagnosis and management of envenomation and should serve as a foundation for future research in this field.     

粘杆菌素研究及其应用

本文阐述了粘杆菌素的理化性质、药理作用、体内代谢、毒性及对免疫器官的影响等方面及其应用前景。     

Myotoxicity and nephrotoxicity of common tiger snake (Notechis scutatus) venom in the dog

SUMMARY The myotoxicity and neurotoxicity of common tiger snake (Notechis scutatus) venom are major factors in the pathogenesis of envenomation in the dog. Histological examination of the tissues of experimentally envenomed dogs has demonstrated the importance of muscle damage in affecting the clinical syndrome of tiger snake envenomation. Within one hour of injection of the venom into dogs, there was selective involvement of some muscles. Cardiac and smooth muscles were not significantly affected. The severity of myofibre damage was influenced by the amount of venom injected. Immobilisation under general anaesthesia resulted in significant protection against the myotoxic effects of high doses of venom. Lesions in the kidneys of experimentally envenomed dogs were acute tubular necrosis and the variable presence of a small amount of proteinaceous material in tubules. These lesions, which were similar to those in cases of natural snake bite, were indicative of a direct nephrotoxic effect, which could be complicated by the effects of myoglobinuria. These findings emphasise the need for supportive treatment aimed at maintenance of renal function in the treatment of dogs suffering from tiger snake envenomation.     

Snake bite: coral snakes

North American coral snakes are distinctively colored beginning with a black snout and an alternating pattern of black, yellow, and red. They have fixed front fangs and a poorly developed system for venom delivery, requiring a chewing action to inject the venom. The severity of a coral snake bite is related to the volume of venom injected and the size of the victim. The length of the snake correlates positively with the snakes venom yield. Coral snake venom is primarily neurotoxic with little local tissue reaction or pain at the bite site. The net effect of the neurotoxins is a curare like syndrome. In canine victims there have been reports of marked hemolysis with severe anemia and hemoglobinuria. The onset of clinical signs may be delayed for as much as 10 to 18 hours. The victim begins to have alterations in mental status and develops generalized weakness and muscle fasciculations. Progression to paralysis of the limbs and respiratory muscles then follows. The best flied response to coral snake envenomation is rapid transport to a veterinary medical facility capable of 24 hour critical care and assisted ventilation. First aid treatment advocated in Australia for Elapid bites is the immediate use of a compression bandage. The victim should be hospitalized for a minimum of 48 hours for continuous monitoring. The only definitive treatment for coral snake envenomation is the administration of antivenin (M. fulvius). Once clinical signs of coral snake envenomation become manifest they progress with alarming rapidity and are difficult to reverse. If antivenin is not available or if its administration is delayed, supportive care includes respiratory support. Assisted mechanical ventilation can be used but may have to be employed for up to 48 to 72 hours.     

基于群落结构及土壤理化性质对围封7年青藏高原东南缘高山草地的综合评价

过度放牧作为青藏高原长期存在的人为干扰方式,严重地破坏了高山草地生态系统的结构及其功能。简便有效的围栏封育方式广泛应用于退化草地的修复过程中,但其修复效果存在两面性,因此系统科学地评估草地围封后的质量状况至关重要。本研究针对围封7年的青藏高原东南缘退化高山草地,基于围栏与放牧处理之间的草地群落生物量、物种多样性及土壤理化性质的差异对比,对草地质量进行了综合评估。结果表明:1)通过围栏修复7年后,围栏内大部分土壤理化指标有所改善,但仅有硝态氮含量差异达到显著水平;2)围栏内地上生物量和凋落物量均显著高于放牧区,分别增加了35.73%和65.75%,而围栏内外的物种多样性无显著性变化;3)采用主成分分析法对土壤质量进行评估,发现围栏内土壤质量有所改善,其综合得分(0.1)高于放牧区(-0.02),同时利用草地各项指标的变化与其权重值之间的关系对草地进行综合质量评估,发现围封7年后草地综合质量得到一定程度的恢复(相对得分为0.209),更多归因于土壤理化性质的改善。研究表明,围栏7年后退化高山草地质量有所提高。针对其修复作用的时效性,需实际应用中定期评估草地的修复状况,以达到围栏的最优实施效果。     

The diagnosis and management of snakebite in dogs--a southern African perspective

Cases of snakebite envenomation are frequently presented to veterinary practitioners in southern Africa. Despite this, no published guidelines exist on how this medical emergency should be managed. Southern African snake venoms can be classified into 3 main types based on the main mechanism of venom action and clinical presentation. A polyvalent antivenom is manufactured in South Africa and contains antibodies against the most important southern African snake venoms. The cytotoxic venoms are represented mainly by the puff-adder (Bitis arietans), Mozambique spitting cobra (Naja mossabica), black-necked spitting cobra (Naja nigricollis) (in the Western Cape and Namibia) and the stiletto snake (Atractaspis bibronii). These venoms may cause dramatic local swelling, high morbidity and low mortality and infrequently require the use of antivenom for survival (the only cytotoxic venoms used to prepare the antivenom are the puff-adder and Mozambique spitting cobra). The neurotoxic venoms (represented chiefly by the non-spitting cobras and mambas) cause high mortality due to rapid onset of paresis and require antivenom and mechanical ventilatory support which is life-saving. The boomslang (Dispholidus typus) and the vine snake (coagulopathic venom) rarely bite humans but dogs may be bitten more frequently. These venoms cause a consumption coagulopathy and successful treatment of boomslang bites requires the use of snake species-specific monovalent antivenom. There is no antivenom available for treating vine snake (Thelotornis capensis), berg adder (Bitis atropos), night adder (Causus spp.), stiletto snake and other lesser adder bites. There are some important differences between the way snakebites are managed in humans and dogs.