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Rheological Therapy
Published in Gordon D. O. Lowe, Clinical Blood Rheology, 2019
Ancrod and batroxobin are thrombin-like enzymes which are purified from pit viper venom, and are commercially available in Europe for their anticoagulant and rheological therapeutic effects. These have recently been reviewed in detail,6 hence only a brief review is given in the present chapter.
Stimulation of Endogenous Fibrinolysis
Published in Cornelis Kluft, Tissue-Type Plasminogen Activator (t-PA): Physiological and Clinical Aspects, 1988
Gordon D. O. Lowe, Michael Small
Ancrod and batroxobin are thrombin-like enzymes purified from pit viper venoms. Their pharmacology,114 effects on hemostasis and hemorheology,115 and clinical effects115 have recently been reviewed. Unlike thrombin, they do not release fibrinopeptide B, activate factor XIII, or activate platelets; a relatively soluble type of fibrin is formed which is rapidly removed from the circulation, resulting in decreased fibrinogen levels and increased levels of fibrin(ogen) degradation products.114,115 The reduction in plasma fibrinogen lowers plasma and blood viscosity and reduces platelet aggregation.115 Ancrod is an effective alternative to heparin for treatment of venous thrombosis,115 and two double-blind, placebo-controlled trials showed that ancrod reduced the incidence or extent of venographic deep vein thrombosis after hip surgery.116,117 The clinical efficacy of ancrod and batroxobin in arterial disease awaits confirmation in controlled trials.115
Biology and Distribution of Venomous Snakes of Medical Importance and The Composition of Snake Venoms
Published in Jürg Meier, Julian White, Handbook of: Clinical Toxicology of Animal Venoms and Poisons, 2017
Many Viperidae venoms contain serine proteinases which convert fibrinogen into fibrin by splitting off fibrinopeptides. As this phenomenon corresponds to the best known action of thrombin, these snake venom components are generally termed “thrombin-like snake venom enzymes”. Such serine proteinases have been isolated and characterized from one Colubridae and several Viperidae snake venoms (Table 8). Parts of the primary structure of some of them, the complete cDNA sequence coding for batroxobin from Bothrops atrox moojeni venom and the complete amino acid sequence of flavoxobin from Trimeresurus flavoviridis venom have been determined107,149. Due to their primary structure and to the organization of their genes, these enzymes may be allocated to serine proteinases of the trypsin-kallikrein family. Some of these enzymes, like crotalase, also split kininogens and synthetic kallikrein substrates and they are also inhibited by selective kallikrein inhibitors109. The numerous characteristics of fibrinogen-coagulating snake venom enzymes reflect a broad and flexible development of these proteins. There are enzymes, like gabonase from the venom of the Gaboon viper (Bitis gabonica), which like thrombin catalyze the release of fibrinopeptides A and B from fibrinogen. A selective splitting off of fibrinopeptide A is catalyzed e.g. by batroxobin from Bothrops atrox moojeni venom, whereas a preferential fibrinopeptide B release is catalyzed e.g. by an enzyme from Agkistrodon contortrix venom. All the thoroughly investigated proteinases of this group act with a pronounced species specificity on fibrinogen of different mammals, and the serum proteinase inhibitors (serpines and α2-macroglobulin) of various species react with a species-dependent preference with these enzymes, the majority of which is not inhibited by natural thrombin inhibitors. Numerous Viperidae and some Elapidae venoms contain proteinases with fibrin(ogen)olytic activity151. According to the fibrinogen chain, which is preferentially or exclusively attacked, a-fibrinogenases and b-fibrinogenases, respectively, are distinguished (Table 9). It has been shown that several haemorrhagic proteinases also exert fibrin(ogen)olytic activity58. This is just mentioned to point out how difficult it is to categorize venom components according to their pharmacological action since often they are multifunctional proteins.
Efficacy of intratympanic corticosteroid, intravenous batroxobin and combined treatment for sudden sensorineural hearing loss with type-2 diabetes
Published in Acta Oto-Laryngologica, 2019
Hongguang Jia, Zhan Yu, Xiping Li, Jianhong Wang, Xiaohui Ge, Zhi-ting Chen, Xiaobing Huang, Yongxiang Wei
It is known that viral infection and circulatory disorders are the most common etiological mechanisms in SSNHL [2], which may induce inflammation and microangiopathy in cochlea. On the other hand, the elevated levels of inflammatory factors and fibrinogen in diabetic patients can contribute to microangiopathy and increase the risk of SSNHL [12,13]. When injected intratympanically, corticosteroids enter the inner ear through the round window membrane [14], the annular ligament of the oval window downregulates the level of local proinflammatory cytokines, mediate antioxidant action, inhibit of autoimmune process, and increase cochlear blood flow [6,15]. Compared with systemic application, IC may achieve higher concentrations of agent in the inner ear and reduce the incidence of side effects. Batroxobin is a proteolytie enzyme isolated from snake venom, which can promote the effects of plasma fibrinogen degradation, thrombolysis, decrease the blood viscosity, and improve microcirculation in cochlea [9]. The results of our study suggested that the combination of IC and IB achieved the superior therapeutic effect in suppressing the progression of SSNHL and promoting hearing recovery.
Polybia occidentalis and Polybia fastidiosa venom: a cytogenotoxic approach of effects on human and vegetal cells
Published in Drug and Chemical Toxicology, 2021
Marcel José Palmieri, Amanda Ribeiro Barroso, Larissa Fonseca Andrade-Vieira, Marta Chagas Monteiro, Andreimar Martins Soares, Pedro Henrique Souza Cesar, Mariana Aparecida Braga, Marcus Vinicius Cardoso Trento, Silvana Marcussi, Lisete Chamma Davide
Some components of the venom can be benefic when isolated and administered in the proper doses, as there are many medicines fabricated from isolated fractions of venoms, such as antihypertensive (e.g., Captopril and Ranatensin), anticoagulants (e.g., Ancrod, Batroxobin, and Echistatin) (Koh and Kini 2012), drugs against diabetes mellitus, and analgesics (Koh and Kini 2012, Prashanth et al. 2017).
Efficacy of combination therapy in adolescent and adult patients with total-deafness sudden sensorineural hearing loss
Published in Acta Oto-Laryngologica, 2019
Hongcun Sun, Jiandao Hu, Zhenyu Mao, ZhaoXin Ma
The study collected the data of patients with total-deafness SSNHL admitted to our department from May 2008 to May 2018. All patients must meet the following criteria: (1) unilateral SSNHL; (2) no history of otitis media, Meniere's disease, autoimmune diseases or long-term exposure to noise;(3) no contraindications of drugs here; (4) first treatment in our department. Once recruited, they would receive the test of MRI or CT. Occupied lesions in cerebellopontine angle area were excluded. Patients were stratified into two groups in accordance with their age: adolescent group (aged between 12 and 18 years) and adult group (aged between 18 and 65 years). Finally, there were 25 patients in the adolescent group and 106 patients in the adult group. The diagnostic criterion for total-deafness SSNHL was over 80 dB hearing loss (mean hearing threshold at 500, 1000, 2000, 4000 Hz) within 3 days of symptom onset. During the hospitalization, all received the following drug treatment. Gastrodin was administered intravenously at the dose of 0.6 g/day. Medical therapy also included 80 mg per day methylprednisolone injection for the first 3 days, followed by tapering to 40 mg/day for another 3 days. Besides, batroxobin, administered intravenously once every other day, was used for defibrinogenation therapy. The initial dose was 10BU. Next, a dose of 5BU was administered 4 times in total. Serum fibrinogen was measured 24 h after each administration of batroxobin. Once the fibrinogen level was <100 mg/dl, the administration of batroxobin would be skipped to the next day for safety. The combination therapy continued for 10 days. All patients should be given the tests of pure tone audiometry and acoustic immittance for 1 week after the end of initial treatment. This study was based on the data and approved by the hospital ethics committee. Their information was reviewed: gender, age, interval between onset and treatment initiation, mean pure tone audiometry threshold and severity of tinnitus before and after the treatment.