Industrial application of antimicrobial peptides based on their biological activity and structure-activity relationship.

Last several years, a rapid increase in drug resistance to traditional antibiotics has driven the emergence and development of antimicrobial peptides (AMPs). AMPs have also gained considerable attention from scientists due to their high potency in combatting infectious pathogens. A subset of analogues and their derivatives with specific targets have been successfully designed based on natural peptide patterns. In this review, scientific knowledge on the mechanisms of action related to biological activity and structure-activity relationship (SAR) of AMPs are summarized, and the biological applications in several important fields are critically discussed. SAR shows that the positive charge, secondary structure, special amino acid residues, hydrophobicity, and helicity of AMPs are closely related to their biological activities. The combination of nanotechnology, bioinformatics, and genetic engineering can accelerate to achieve the application of AMPs as effective, safe, economical, and nonresistant antimicrobial agents in medicine, the food and feed industries, and agriculture in coming years. Given the intense interest in AMPs, further investigations are needed in the future to evaluate the specific structure and function that make their use favorable in several industries. This review may provide a comprehensive reference for future studies on chemical modifications, mechanistic exploration, and applications of AMPs.

Recent two-year advances in anti-dengue small-molecule inhibitors.

Dengue is an acute tropical infectious disease transmitted by mosquitoes, which has posed a major challenge to global public health. Unfortunately, there is a lack of clinically proven dengue-specific drugs for its prevention and treatment. As the pathogenesis of dengue has not been fully elucidated, the development of specific drugs is seriously hindered. This article briefly describes the pathogenesis of dengue fever, the molecular characteristics, and epidemiology of dengue virus, and focuses on the potential small-molecule inhibitors of dengue virus, including on-target and multi-targeted inhibitors, which have been reported in the past two years.

[Relationship between clinical features and prognosis of highly pathogenic avian influenza A/H5N1 infection in humans in mainland China].

OBJECTIVE: To investigate the relationship between clinical features of patients with A/H5N1 infection and their prognosis in mainland China. METHODS: This study included 28 human cases with A/H5N1 infection in mainland China from October 2005 to May 2008. Data were collected and reviewed from hospital medical records and publishied papers. A database was built by EPIDATA 3.02 and statistical analyses were performed with SPSS 13.0. RESULTS: The median age of the 28 cases was 29 years (range 6-62), and 15 were females. Ten patients survived, and 18 died. The typically clinical manifestations of human influenza A/H5N1 infection included fever and lower respiratory infection. The numbers of peripheral white blood cells, lymphocytes and platelets in the survival and non-survival groups were (4.01 +/- 1.86) x 10(9)/L vs (5.1 +/- 2.9) x 10(9)/L, (1.09 +/- 0.49) x 10(9)/L vs (0.98 +/- 0.44) x 10(9)/L, and (116 +/- 39) x 10(9)/L vs (101 +/- 40) x 10(9)/L, respectively; the differences were not statistically significant between the 2 groups (P>0.05). There was also no statistically significant difference in the increased serum enzymes, such as aspartate aminotransferase [(173 +/- 246) U/L vs (272 +/- 263) U/L], lactate dehydrogenase [(1016 +/- 568) U/L vs (1512 +/- 1052) U/L], creatine kinase [(1099 +/- 1590) U/L vs (2534 +/- 4281) U/L] and MB isoenzyme of creatine kinase [(28 +/- 30) U/L vs (125 +/- 197) U/L] (P>0.05) between the survival and the non-survival groups. However, there was a statistically significant difference in the number of patients with an initial LDH level more than 8 fold of the normal value between the survival and the non-survival groups (none vs 6, P<0.05). All of the 28 cases developed bilateral multiple infiltrates and consolidation in chest radiographs. Acute respiratory distress syndrome occurred in 22 cases, 17 of them died. All the 9 patients with acute kidney injury died. Ten patients received antiviral treatment with oseltamivir, and 6 of them survived. There was a statistical difference in the time of initiating oseltamivir treatment between the survival and the non-survival cases [(6.5 +/- 3.0) d vs (11.8 +/- 3.3) d, Z = 3.70, P<0.05]. Broad spectrum antibiotics and corticosteroids were administered in all of the 28 cases. There was no statistical difference between the survival and the non-survival groups regarding to the corticosteroid treatment (P>0.05). CONCLUSIONS: Initial LDH level reaching more than 8 fold of the normal value suggests a poor prognosis for human H5N1 infection. Patients complicated with either ARDS or acute kidney injury had a higher risk of death. Early administration of effective antiviral agents might improve the prognosis and decrease case fatality.