Effects of SITS on urate transport by isolated,perfused snake renal tubules

Effects of an inhibitor of membrane anion-exchange transport processes, 4-acetamido-4-isothiocyano-2,2-disulfonic stilbene (SITS), on urate transport by isolated, perfused snake (Thamnophis spp.) proximal renal tubules were studied. SITS (10^–4 mol/l) in the luminal perfusate had absolutely no effect on net urate secretion (J _urate ^net ) or on net fluid absorption (J _v). This observation is compatible with other data that give no support to the concept of a mediated transport step for urate from the cells to the lumen. SITS (10^–4 mol/l) in the bathing medium reversibly inhibitedJ _urate ^net without affectingJ _v. At the time of maximum inhibition ofJ _urate ^net , the concentration of urate in the cell water was increased and the apparent permeability of the luminal membrane to urate was decreased, but the urate efflux across the peritubular membrane and the apparent permeability of the peritubular membrane to urate were unchanged. There was no evidence of significant intracellular binding or trapping of urate. Although an increase in the initial rate of urate transport into the cells across the peritubular membrane could not be demonstrated conclusively in nonperfused tubules, the results still suggest that SITS in the bathing medium may inhibitJ _urate ^net by inhibiting urate movement from the cells to the lumen while actually enhancing transport from the bathing medium into the cells.     

Confirmed Cases of Ophidiomycosis in Museum Specimens from as Early as 1945, United States

Ophidiomycosis represents a conservation threat to wild snake populations. The disease was reported in North America early in the 21st century, but the history of ophidiomycosis has not been investigated. We examined museum specimens and confirmed cases of ophidiomycosis >50 years before the disease’s reported emergence.     

基于对称边缘方向直方图自动提取主要道路

提出一种从航空影像中自动提取主要道路的方法。以对称边缘方向直方图作为主要道路特征矢量,先采用一种顾及数据空间分布特性的模糊C均值聚类算法分割提取主要道路种子段,然后利用Snakes算法跟踪提取完整主要道路网络。实验结果表明,所提方法能有效地从航空影像中自动提取主要道路网。     

被毒蛇咬伤患者血浆D-二聚体和常规凝血指标的变化及意义

目的探讨被不同毒性毒蛇咬伤后患者血浆D-二聚体(D-D)和常规凝血指标的变化及临床意义。方法58例被毒蛇咬伤患者(其中血循毒35例,非血循毒23例),在被毒蛇咬伤后就诊未治疗前,采集血标本检测D-D和血浆凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、血浆纤维蛋白原(FIB)含量及血小板计数(PLT)等,并与30例正常对照比较分析。结果血循毒组及非血循毒组D-D、PT、APTT明显高于对照组,其中血循毒组明显高于非血循毒组;PLT明显低于对照组,其中血循毒组明显低于非血循毒组;FIB血循毒组明显低于对照组,而非血循毒组明显高于对照组。血循毒组D-D含量与PT、APTT、FIB和PLT的异常变化具有一定的相关性;非血循毒患者血浆D-D含量变化与上述凝血指标的变化均无相关性。结论被血循毒毒蛇咬伤后易导致弥散性血管内凝血(DIC),检测患者D-D及常规凝血指标,可了解患者的凝血状况,防止DIC的进一步发生具有很好的临床意义。     

Medullary efferent and afferent neurons of the facial nerve of the pit viper Gloydius brevicaudus

For the purposes of comparative anatomy, we used tracer techniques and immunohistochemistry to study the facial nerve in the pit viper Gloydius brevicaudus and obtained much new data applicable to the function of this nerve in snakes and, in particular, pit vipers. We were able to identify the superior salivatory nucleus in these snakes. Preganglionic fibers from this nucleus pass along the palatine nerve and an anterior communicating branch to reach the pterygopalatine ganglion attached to the deep branch of the trigeminal maxillary nerve. The palatine nerve also contains general somatic afferents and a very few special visceral afferents from some taste buds on the palate. In the mandibular direction, preganglionic fibers from the superior salivatory nucleus join special visceral efferents from the motor nucleus in the hyomandibular nerve, from which they pass into the chorda tympani to course together for a short distance. The special visceral efferents branch off outside the cranium, and the preganglionic fibers continue on to join the trigeminal mandibular nerve to project to small ganglia within the mandible. The chorda tympani also contains general somatic afferents from the mandibular region but no special visceral afferents. This is the first time that the superior salivatory nucleus and its adjuncts have been identified in a snake. The chorda tympani of these snakes is also distinguished from the mammalian condition by lacking any special visceral afferents and by branching outside the cranium.     

BITES AND ENVENOMATIONS BY COLUBRID SNAKES IN MEXICO AND CENTRAL AMERICA

Information on bites by snakes of the family Colubridae in Mexico and Central America is reviewed. Little is known of the biochemistry and pharmacology of the Duvernoy gland secretion (venom) of colubrids from this region, although some reports describe proteolytic, phosphodiesterase, phospholipase A₂ and hemorrhagic activities. A search of published reports and an effort to obtain reliable unpublished information on colubrid snake bites in the region documented cases inflicted by species of the genera Conophis, Coniophanes, Crisantophis, Erythrolamprus, Pliocercus, Oxybelis and Dryadophis (=Mastigodryas). The following general pattern emerges from the analysis of these cases: 1) Bites occurred mainly in hands and fingers on people that frequently manipulate colubrids, i.e. herpetologists, herpetoculturists and people that take care of these snakes at museums, exhibits or zoos; and 2) In most cases, only mild local effects were described, i.e. pain, swelling and, in few cases, ecchymosis. In only one case by Erythrolamprus bizonus there was ecchymosis beyond the bitten region, whereas persistent bleeding at the bite site was reported in a Conophis lineatus case. No systemic alterations were described in any of the cases. Management of colubrid bites in Mexico and Central America includes cleaning and disinfection of the bitten area, together with administration of tetanus toxoid. In the case of local infection, antibiotics are administered. There is no experimental or clinical evidence supporting the use of Crotalinae antivenoms in these bites. Despite the lack of systemic alterations in the cases described, caution should be exercised when manipulating these snakes, and bitten people should be closely observed for the potential development of bleeding and coagulopathies, since these effects have been described in bites by colubrid snakes from other regions of the world.     

Exotic venomous snakebite drill

Background. There were 900 exotic venomous snakebites reported from 2000 to 2009. The Association of Zoos and Aquariums’ recommends institutions housing venomous reptiles have protocols for appropriate and timely transport of envenomed individuals to hospitals. The study objective was to evaluate functional aspects and potential problems of our emergency operation procedure designed for handling the response to an exotic venomous snakebite during implementation via a simulated drill. The emergency operation procedure consists of two protocols, the protocol for zoo personnel and exotic snakebite protocol for hospital personnel. Methods. Before the exercise the poison center (PC), zoo, Emergency Medical Services (EMS), receiving hospital emergency department (ED), and pharmacy were contacted. The emergency operation procedure was reviewed to determine areas of deficiency. A checklist of all required actions for each participating institution was created for use during the exercise. The exercise was divided into four phases: zoo, EMS, PC, and ED. Each phase was evaluated by an independent observer. Results. Review of the emergency operation procedure revealed sufficient and easy to follow information for zoo personnel. However, the exotic snakebite protocol for hospital personnel lacked details regarding signs and symptoms expected from each exotic venomous species in the zoo; and indications, dosing, and instructions on reconstitution for each of the antivenom carried by the zoo. Zoo, EMS, ED, and PC personnel completed 95%, 90%, 83%, and 25% of the required tasks, respectively. The PC encountered problems communicating the exotic snakebite protocol for hospital personnel to the ED due to phone and fax equipment failures. Creative solutions to the PC system issues were not identified in a timely manner. Despite the shortcomings, the time from simulated envenomation to antivenom (AV) administration was under an hour. Conclusions. This drill identified several issues leading to revision of our exotic snakebite protocol for hospital personnel. We also identified suboptimal PC response in the application of the emergency operation procedure. We encourage every poison center in cooperation with local zoos to perform a similar exercise.     

海马龙蛇丸质量标准研究

目的：探讨海马龙蛇丸的质量检测及标准。方法：对该处方中的僵蚕、土鳖虫、穿山甲、甘草、鸡血藤、木瓜进行了显微鉴别,对麻黄、三七进行了薄层鉴别以及士的宁的限量检查。结果：薄层色谱斑点清晰,重复性好,阴性对照无干扰。结论：本品处方组成合理,制备简单,质量控制方法简单易行。