Aspirin plus tirofiban inhibit the thrombosis induced by Russell's viper venom

Quantum Biochemical Investigation of Lys49-PLA2 from Bothrops moojeni

Envenomation via snakebites occurs largely in areas where it is harder to access the hospital. Its mortality rate and sequelae acquired by the survivors symbolize a big challenge for antivenom therapy. In particular, the homologous phospholipase A₂ (Lys49-PLA₂) proteins can induce myonecrosis and are not effectively neutralized by current treatments. Thus, by taking advantage of crystallographic structures of Bothrops moojeni Lys49-PLA₂ complexed with VRD (varespladib) and AIN (aspirin), a quantum biochemistry study based on the molecular fractionation with conjugate cap scheme within the density functional theory formalism is performed to unveil these complexes' detailed interaction energies. The calculations revealed that important interactions between ligands and the Lys49-PLA₂ pocket could occur up to a pocket radius of r = 6.5 (5.0 Å) for VRD (AIN), with the total interaction energy of the VRD ligand being higher than that of the AIN ligand, which is well-correlated with the experimental binding affinity. Furthermore, we have identified the role played by the amino acids LYS0069, LYS0049, LEU0005, ILE0009, CYS0029, GLY0030, HIS0048, PRO0018, ALA0019, CYS0045, TYR0052, TYR0022, PRO0125*, and PHE0126* (LYS0069, LYS0049, GLY0032, LEU0002, and LEU0005) in the VRD↔Lys49-PLA₂ (AIN↔Lys49-PLA₂) complex. Our simulations are a valuable tool to support the big challenge for neutralizing the damages in victims of snakebites.

Effects of Tirofiban and Nicorandil on Effective Reperfusion and the Levels of IL-4 and sICAM-1 After PCI for Chronic Coronary Total Occlusion

Aim: The effects of tirofiban combined with nicorandil on effective reperfusion, and the levels of interleukin-4 (IL-4)and soluble intercellular adhesion molecule-1 (sICAM-1) after percutaneous coronary intervention (PCI) for chronic coronary total occlusion (CTO) were investigated.Method: From January 1, 2017, to June 31, 2019, a total of 40 patients with CTO receiving PCI in Shandong QianfoshanHospital were randomly divided into a control group (treated with single tirofiban) and a cocktail group (treated with nicorandil combined with tirofiban). Effective reperfusion was compared between groups. In addition, differences in coronary serum IL-4 and sICAM-1 levels before and 10 min after the operation were compared between groups, and the incidence rates of adverse reactions were observed. Finally, patient follow-up occurred at 1 month and 6 months, and the total incidence rates of adverse cardiac events in both groups were assessed.Results: The levels of IL-4 and sICAM-1 in the cocktail group significantly decreased after the operation (P < 0.05).In addition, after the operation, significantly greater decreases in the IL-4 and sICAM-1 levels were observed in thecocktail group than the control group (P < 0.05). The Seattle Angina Scale (SAQ) score of the cocktail group, comparedwith the control group, showed a significant improvement after vessel opening in the patients with CTO. At the 1-month follow-up, the SAQ score of the cocktail group, compared with the control group, indicated further improvements in terms of angina attack frequency. No significant differences were observed in the incidence rates of adverse reactions between groups (P > 0.05).Conclusion: The treatment of patients with CTO undergoing PCI with nicorandil and tirofiban alleviated the inflammatoryresponse, improved the SAQ scores, and decreased the occurrence of angina pectoris in patients. Moreover, this treatment is safe and reliable, and has important clinical significance.

Search for efficient inhibitors of myotoxic activity induced by ophidian phospholipase A2-like proteins using functional, structural and bioinformatics approaches

Ophidian accidents are considered an important neglected tropical disease by the World Health Organization. Particularly in Latin America, Bothrops snakes are responsible for the majority of the snakebite envenomings that are not efficiently treated by conventional serum therapy. Thus, the search for simple and efficient inhibitors to complement this therapy is a promising research area, and a combination of functional and structural assays have been used to test candidate ligands against specific ophidian venom compounds. Herein, we tested a commercial drug (acetylsalicylic acid, ASA) and a plant compound with antiophidian properties (rosmarinic acid, RA) using myographic, crystallographic and bioinformatics experiments with a phospholipase A2-like toxin, MjTX-II. MjTX-II/RA and MjTX-II/ASA crystal structures were solved at high resolution and revealed the presence of ligands bound to different regions of the toxin. However, in vitro myographic assays showed that only RA is able to prevent the myotoxic effects of MjTX-II. In agreement with functional results, molecular dynamics simulations showed that the RA molecule remains tightly bound to the toxin throughout the calculations, whereas ASA molecules tend to dissociate. This approach aids the design of effective inhibitors of PLA2-like toxins and, eventually, may complement serum therapy.

Clinical and laboratory features distinguishing between Deinagkistrodon acutus and Daboia siamensis envenomation

Background

There are 6 species of venomous snakes in Taiwan. Two of them, Deinagkistrodon acutus (D. acutus) and Daboia siamensis (D. siamensis), can cause significant coagulopathy. However, a significant proportion of patients with snakebites cannot identify the correct snake species after envenomation, which hampers the application of antivenom. Hence, the differential diagnosis between the two snakebites by clinical presentations is important. This study aims to compare their clinical and laboratory features for the purpose of differential diagnosis between the two snakebites.

Methods

We retrospectively reviewed the medical records of patients who arrived at the emergency department due to D. acutus or D. siamensis envenomation, between 2003 and 2016, in one medical center in eastern Taiwan. Since these snakebites are rare, we also included 3 cases reported from another hospital in central Taiwan.

Results

In total, 15 patients bitten by D. acutus and 12 patients by D. siamensis were analyzed. Hemorrhagic bulla formation and the need for surgical intervention only presented for D. acutus envenomation cases (Both 53.3% vs. 0.0%, P = 0.003). As to laboratory features, lower platelet counts (20.0 ×  10³/μL [interquartile range, 14–66 × 10³/μL] vs. 149.0 × 10³/μL [102.3–274.3 × 10³/μL], P = 0.001), lower D-dimer level (1423.4 μg/L [713.4–4212.3 μg/L] vs. 12,500.0 μg/L [2351.4–200,000 μg/L], P = 0.008), higher proportion of patients with moderate-to-severe thrombocytopenia (platelet count < 100 × 10³/μL) (80% vs. 16.7%, odds ratio (OR) = 20.0, 95% CI, 2.77–144.31; P = 0.002), and lower proportion of patients with extremely high D-dimer (> 5000 ng/mL) (16.7% vs. 66.7%, adjusted OR = 0.1 (95% CI, 0.01–0.69; P = 0.036) were found among cases of D. acutus envenomation compared to D. siamensis envenomation. The combination of hemorrhagic bulla, thrombocytopenia, and a lack of extremely high D-dimer had good discriminatory power (area under the curve (AUC) = 0.965; 95% CI, 0.904–1.00) for distinguishing D. acutus from D. siamensis envenomation.

Conclusions

The presentation of moderate to severe thrombocytopenia (platelet count < 100 × 10³/μL) and hemorrhagic bulla formation may indicate D. acutus envenomation. However, the envenomed patient with extremely high D-dimer levels may indicate a D. siamensis envenomation. These findings may help diagnose and select the right antivenom in patients with unknown snakebites who present significant coagulopathy.

Effects of tirofiban on stent thrombosis, Hs-CRP, IL-6 and sICAM-1 after PCI of acute myocardial infarction

Effects of tirofiban on stent thrombosis, high-sensitivity C-reactive protein (Hs-CRP), interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) after percutaneous coronary intervention (PCI) of acute myocardial infarction (AMI) were investigated. A total of 94 AMI patients receiving PCI in Shouguang City People's Hospital from January 2016 to September 2016 were selected and randomly divided into control (n=47) and observation group (n=47). The control group was treated with aspirin + clopidogrel before and after operation, while the observation group was treated with tirofiban based on the treatment of control group. The postoperative stent thrombosis was compared between the two groups, and the serum Hs-CRP, IL-6 and sICAM-1 levels before operation and at 24 and 48 h after operation were also compared between two groups. Moreover, the incidence rates of adverse reactions in the groups were observed. Finally, patients were followed-up for 1 year to observe the total incidence rate of adverse cardiac events and life quality of patients in both groups. The thrombolysis in myocardial infarction flow grading in observation after treatment was significantly superior to that in control group (P<0.05). The levels of Hs-CRP, IL-6 and sICAM-1 in both groups at 24 and 48 h after operation were significantly decreased compared with those before operation, and they were decreased more obviously in observation group (P<0.05); there were no significant differences in the incidence rates of adverse reactions between the groups (P>0.05). Besides, the 1-year follow-up showed that the total incidence rate of adverse cardiac events in observation was significantly lower than that in control group, and the life quality scores were obviously higher than those in control group (P<0.05). The treatment of AMI patients undergoing PCI with tirofiban can effectively prevent stent thrombosis, and alleviate the inflammatory response of patients, it is safe and reliable with important clinical significance.

Disseminated intravascular coagulation caused by moojenactivase, a procoagulant snake venom metalloprotease

Snake venom toxins that activate coagulation factors are key players in the process of venom-induced coagulopathy, and account for severe clinical manifestations. The present study applies a variety of biochemical, hematological, and histopathological approaches to broadly investigate the intravascular and systemic effects of moojenactivase (MooA), the first described PIIId subclass metalloprotease isolated from Bothrops sp. venom that activates coagulation factors. MooA induced consumption coagulopathy with high toxic potency, characterized by prolongation of prothrombin and activated partial thromboplastin time, consumption of fibrinogen and the plasma coagulation factors X and II, and thrombocytopenia. MooA promoted leukocytosis and expression of the proinflammatory cytokines interleukin-6 and tumor necrosis factor-α, accompanied by tissue factor-dependent procoagulant activity in peripheral blood mononuclear cells. This metalloprotease also caused intravascular hemolysis, elevated plasma levels of creatine kinase-MB, aspartate transaminase, and urea/creatinine, and induced morphopathological alterations in erythrocytes, heart, kidney, and lungs associated with thrombosis and hemorrhage. Diagnosis of MooA-induced disseminated intravascular coagulation represents an important approach to better understand the pathophysiology of Bothrops envenomation and develop novel therapeutic strategies targeting hemostatic disturbances.