RV-23

Background: Coronary artery fistula (CAF) is a direct connection of one or more coronary arteries to cardiac chambers or a large vessel; it may be associated with congenital heart disease. Objective: To establish CAF pathway patterns from echocardiographic data and to correlate them with clinical aspects and congenital heart disease. Methods: A total of 7.183 medical records of children under the age of five years with cardiac disease submitted to color Doppler echocardiography and Spearman's Correlation test were used to associate signs and symptoms and cardiopathy to CAF with a significance level of 5%. Results: Twenty six children (0.0036%) presented CAF: from the right coronary artery (RCA) to the right ventricle (RV) 26.92%, from the left coronary artery (LCA) to the RV 23.08%, from the anterior interventricular branch (AIVB) to RV 23.08%, RCA to right atrium (RA) 11.54%, LCA for pulmonary trunk (PT) 7.69% or AIVB for PT 7.69%. In 57.69% of the patients, there was a positively correlated symptomatology to CAF with p=0.445 related to dyspnea or cyanosis (53.84%); in 96.15%, congenital heart disease associated with CAF, mainly interventricular communication (IVC) or interatrial communication (IAC) in 34.62% positively correlated to CAF with p=0.295. CAF pathway was represented in three dimensions by software modeling, texturing and animation Cinema 4D R19. Conclusion: CAF is an uncommon anatomical entity that presents a clinical picture compatible with dyspnea and cyanosis, and this is associated with congenital heart disease, mainly with IVC or IAC. According to echocardiographic analyzes, fistulas in RCA, LCA, or AIVB represent about one-third of the patients, with a priority pathway for right heart chambers.

RV-23 is a melittin-related antibacterial peptide (MRP) with lower cytotoxicity than either melittin or AR-23, another MRP. The aim of this study was to explore the mechanism of RV- 23's antibacterial selectivity and its hemocompatibility. The results showed that all the peptides exhibited lytic activity against Staphylococcus aureus and Escherichia coli, with RV-23 showing the highest potency. Moreover, RV-23 had lower cytotoxicity than melittin or AR-23 at their minimal inhibitory concentration. In addition, CD experiments showed that melittin, RV-23, and AR-23 all had a typical α-helical structure, and RV-23 had the lowest α-helix content. The structural information showed that RV-23 has the lowest hydrophobicity and highest hydrophobic moment. Because hydrophobicity and α-helix content are believed to correlate with hemolysis, the results indicate that the selective lytic activity against bacteria of RV-23 may be due to its low hydrophobicity and α-helicity, which lead to low cytotoxicity without affecting antibacterial activity. Furthermore, RV-23 did not affect the structure and function of blood components such as red blood cells, platelets, albumin, and the blood coagulation system. In conclusion, RV-23 is a cell-selective antibacterial peptide with high hemocompatibility due to its unique structure.

The activities of two antimicrobial peptides belonging to the temporin family (temporin-1DRa from Rana draytonii and temporin-1Va from Rana virgatipes) and two peptides with structural similarity to the bee venom peptide melittin (AR-23 from Rana tagoi and RV-23 from R. draytonii) were evaluated against a range of reference strains and clinical isolates of anaerobic bacteria. These peptides were selected because they show broad-spectrum growth inhibitory activity against reference strains of several medically important aerobic microorganisms and against clinical isolates of methicillin-resistant Staphylococcus aureus. All peptides showed relatively high potency (minimum inhibitory concentration (MIC)