Objective To improve the flexibil ity and hemostatic properties of chitosan (CS)/carboxymethyl chitosan (CMCS) hemostatic membrane by using glycerol and etamsylate to modify CS/CMCS hemostatic membrane. To investigate themechanical properties and hemostatic capabil ity of modified CS/CMCS hemostatic membrane. Methods The 2% CS solution, 2% CMCS solution, 10%, 15%, 20%, 25%, 30% glycerol with or without 0.5% etamsylate were used to prepare CS/CMCS hemostatic membrane with or without etamsylate by solution casting according to ratio of 16 ∶ 4 ∶ 5. The tensile properties were evaluated by tensile test according to GB 13022-1991. Twenty venous incisions and five arterial incisions hemorrhage of 1 cm × 1 cm in rabbit ears were treated by CS/CMCS hemostatic membrane modified by 15% (group A) and 25% (group B) of glycerol, and a combination of them and 0.5% etamsylate (groups C and D). The bleeding time and blood loss were recorded. Results The pH of yellow CS/ CMCS hemostatic membrane with thickness of 30-50 μm was 3-4. The incorporation glycerol into CS/CMCS hemostatic membrane resulted in decreasing in tensile strength (7.6%-60.2%) and modulus (97%-99%). However, elongation at break and water content increased 5.7-11.6 times and 13%-125% markedly. CS/CMCS hemostatic membrane adhered to wound rapidly, absorbed water from blood and became curly. The bleeding time and blood loss of venous incisions were (70 ± 3) seconds and (117.2 ± 10.8) mg, (120 ± 10) seconds and (121.2 ± 8.3) mg, (52 ± 4) seconds and (98.8 ± 5.5) mg, and (63 ± 3) seconds and (90.3 ± 7.1) mg in groups A, B, C, and D, respectively; showing significant differences (P lt; 0.05) between groups A, B and groups C, D. The bleeding time and blood loss of arterial incision were (123 ± 10) seconds and (453.3 ± 30.0) mg in group C. Conclusion CS/CMCS hemostatic membrane modified by glycerol and etamsylate can improve the flexibil ity, and shorten the bleeding time.
ObjectiveTo systematically review the efficacy and safety of dexamethasone in the treatment of viral myocarditis.MethodsThe Cochrane Library, PubMed, EMbase, Biosis Preview, Web of Science, CBM, WanFang Data, VIP, and CNKI databases were electronically searched to collect randomized controlled trials (RCTs) on dexamethasone for patients with viral myocarditis from inception to April 30th, 2021. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.4 software.ResultsA total of 7 RCTs involving 749 patients were included. The results of meta-analysis showed that the dexamethasone treatment group exhibited an increased efficacy rate (RR=1.26, 95%CI 1.18 to 1.34, P<0.000 01), decreased levels of C-reactive protein (CRP) (MD=−11.49, 95%CI −19.25 to −3.72, P=0.004), cardiac troponin I (cTnI) (MD=−26.14, 95%CI −40.82 to −11.47, P=0.0005), and creatine kinase MB (CK-MB) (MD=−20.06, 95%CI −28.35 to −11.77, P<0.000 01), and a decreased adverse event rate (RR=0.40, 95%CI 0.24 to 0.65, P=0.000 3).ConclusionsCurrent evidence shows that dexamethasone can significantly improve the efficacy rate, reduce the levels of CRP, cTnI, and CK-MB, and reduce the incidence of adverse events in patients with viral myocarditis. Due to the limited quantity and quality of included studies, more high-quality studies are required to verify above conclusions.