RESUMO
The ability of amphipathic peptides to arrange themselves in aqueous solutions, known as self-assembly, has been found to reduce the effectiveness of these peptides in interacting with cell membranes. Therefore, minimizing their tendency to self-assemble could be a potential strategy for enhancing the pharmacological properties of antimicrobial peptides (AMPs). To explore this idea, this study prepared a series of natural peptides mastoparan C (MPC) with increased net charge and hydrophilicity via alanine-to-lysine substitution and investigated the impact on the biological activity. The preliminary data suggested the influence of both the overall positive charge and the position of a lysine residue on the self-assembly of MPC and its derivatives. Besides, the analogue MPC-A5K,A8K displayed higher anticancer activity and comparable antimicrobial activity with significantly lower hemolysis than MPC. Hence, reducing self-assembly by expanding the cationic area could be a promising approach for developing potent and selective AMPs.
RESUMO
Background: Rotavirus type A is the most common cause of acute gastrointestinal inflammatory in children under 5 years old, especially in age groups 6 and 36 months. Some rotavirus strains are common; seen recently in Vietnam are G1, G2, G3, G4 and G9, P4, P6 and P8. Objective: Surveillance of epidemiological characteristics of rotavirus induced diarrhea in the National Pediatric Hospital from September, 2007 to March, 2008. Subject and methods: Collection of 322 stool specimens of pediatric patients with acute diarrhea (including 213 specimens from male, 109 specimens from female), who were treated in the National Pediatric Hospital. All of these specimens were determined for causes of rotavirus with the enzyme immunoassay (EIA). Results and Conclusion: Among these 322 stool specimens, there were 195 rotavirus positive specimens, accounted for 60.56%. The rate of monthly distribution of rotavirus diarrhea from September, 2007 to March, 2008 were 76%, 56%, 62%, 61%, 64%, 56% and 44%, respectively. Number of rotavirus positive cases in male and female was 56 (26.29%) and 79 (72.48%), respectively. The rate of rotavirus positive children compared to total number of specimens with the age 0-3 months, 3-6 months, 6-12 months, 12-24 months, 24-36 months and over 36 months was 7.69%, 15.9%, 41.54%, 32.82%, 1.54% and 0.51%, respectively. The results of type identification indicated that phenotypes of 37 among 40 specimens were identified (92.5%) in which there were 5 specimens of G1P8 (12.5%), 20 specimens of G3P8 (50%), 1 specimen of G9P8 (2.5%), 2 specimens of G1Pmixed (5%), 9 specimens of G3Pmixed (22.5%), 1 specimen of G unidentified-type P8 (2.5%) and 2 specimens of G3 P unidentified-type (5%).
Assuntos
Rotavirus , Diarreia , EpidemiologiaRESUMO
Background: Acute gastroenterophathy usually caused by the Rota virus for children under 5 years old. Objectives: To present various types of data on epidemiology of ROTA virus diarrhea in Ho Chi Minh city from 12/2006-11/2007. Material and method: The data were collected from 500 stool specimens of diarrhea diagnosed chilren hosptalised at Thuy Dien Pediatric hospital 1, Ho Chi Minh city from December/2006 to November /2007. Results:There were 322 rotavirus-positive specimens, representing 64.4%. The proportions of monthly distribution of cases with diarrhea due to rotavirus were 90.1%, 54.39%, 85.37%, 74.51%, 72.92%, 41.67%, 26.67%, 58.33%, 79.31%, 52.63%, 69.05% and 57.78%, respectively. The numbers of rotavirus-positive cases in male and female were 216 (65.26%) and 106 (62.72%), respectively. The proportions of Rota virus positive children compared to total number of diarrheal cases with age 0-3, 3-6, 6-12, 12-24, 24-36 and over 36 months were 2.80%, 7.76%, 40.06%, 40.68%, 5.28% and 3.42%, respectively.\r\n', u'The results of typing identification indicated that the phenotypes of 98 among 100 specimens were identified (98%) in which there were sixty-one specimens of G1P8 (61%), one specimen of G2P8 (1%), fourteen specimens of G3P8 (14%), four of specimens of G4P8 (4%), eighteen specimens of GmixedP8 (18%). There were only two specimens of GnontypeableP8 (2%). Conclusion: Further studies should be carried out to clear this issue.\r\n', u'
