Synthesis,biological studies and molecular dynamics of new anticancer RGD-based peptide conjugates for targeted drug delivery

New cyclic RGD peptide-anticancer agent conjugates, with different chemical functionalities attached to the parent peptide were synthesized in order to evaluate their biological activities and to provide a comparative study of their drug release profiles. The Integrin binding c(RGDfK) penta-peptide was used for the synthesis of Camptothecin (CPT) carbamate and Chlorambucil (CLB) amide conjugates. Substitution of the amino acid Lys with Ser resulted in a modified c(RGDfS) with a new attachment site, which enabled the synthesis of an ester CLB conjugate. Functional versatility of the conjugates was reflected in the variability of their drug release profiles, while the conserved RGD sequence of a selective binding to the α_v integrin family, likely preserved their recognition by the Integrin and consequently their favorable toxicity towards targeted cancer cells. This hypothesis was supported by a computational analysis suggesting that all conjugates occupy conformational spaces similar to that of the Integrin bound bio-active parent peptide.     

Induced resistance during the interaction pathogen x plant and the use of resistance inducers

Plants react to aggressions through different defence responses. Mechanical barriers consist in the increase of production and deposition of substances capable of containing pathogen invasion. Chemical barriers consist in the increase of concentration or activity of defence proteins and synthesis of phenolic compounds and phytoalexins. Elicitor substances have been widely used in plant disease control showing impressive results and a low impact to the environment and man. This review contains information about plant defence mechanisms and shows the use of inducers of resistance in the control of pathogens and prospects of advance towards sustainable agriculture.     

A combined transcriptional,biochemical and histopathological study unravels the complexity of Alternaria resistance and susceptibility in Brassica coenospecies

Alternaria blight is one of the most devastating diseases of rapeseed-mustard caused by a necrotrophic fungus Alternaria brassicae. Lack of satisfactory resistance resource in Brassica is still a main obstruction for developing resistance against Alternaria. In this study, we have selected Brassica juncea, Sinapis alba and Camelina sativa to understand and unravel the mechanism of disease resistance against Alternaria. Histopathological studies showed early onset of necrosis in B. juncea (1 dpi) and delayed in S. alba (2 dpi) and C. sativa (3 dpi) respectively. Early and enhanced production of hydrogen peroxide (H₂O₂) was observed in C. sativa and S. alba (6 hpi) when compared to B. juncea (12 hpi). An increase in catalase activity was observed in both C. sativa (36 % at 6 hpi) and S. alba (15 % at 12 hpi), whereas it significantly decreased in B. juncea at 6 hpi (23 %), 12 hpi (30 %) and 24 hpi (8 %). Gene expression analysis showed induction of PR-3 and PR-12 genes only in C. sativa and S. alba when compared to B. juncea suggesting their vital role for Alternaria resistance. In contrast, SA marker genes were significantly expressed in B. juncea only which provides evidence of hormonal cross talk in B. juncea during Alternaria infection thereby increasing its susceptibility.     

肺癌合并肺部感染患者病原菌分布、耐药性分析及血清炎性因子检测的临床意义

摘要 目的：探讨肺癌合并肺部感染患者病原菌分布、耐药性分析及血清炎性因子检测的临床意义。方法：选取我院于2018年6月~2020年3月期间收治的肺癌合并肺部感染患者90例为感染组，选取同期我院收治的肺癌未合并肺部感染患者100例为肺癌组，选取同期于我院进行体检的健康志愿者60例为对照组，对肺癌合并肺部感染患者的感染病原菌类型进行总结分析，分析常见病原菌药敏试验结果，统计病原菌耐药率。对比三组受试者的炎性因子水平。结果：90例肺癌合并肺部感染患者的送检痰液标本共检出100株病原菌，100株病原菌中以革兰阴性菌为主，其次为革兰阳性菌、真菌，分别占比63.00%、22.00%、15.00%。肺炎克雷伯菌、鲍氏不动杆菌、铜绿假单胞菌对亚胺培南的耐药率较低，对氨苄西林、甲氨苄啶的耐药率均较高。凝固酶阴性葡萄球菌、金黄色葡萄球菌对万古霉素的耐药率较高，对左氧氟沙星的耐药率较低。白色念珠菌、热带念珠菌对两性霉素B、氟康唑、酮康唑、伊曲康唑的耐药率均较低。感染组、肺癌组的血清白介素-6（IL-6）、降钙素原（PCT）、肿瘤坏死因子-α（TNF-α）水平均高于对照组，且感染组以上指标水平高于肺癌组（P<0.05）。结论：肺癌合并肺部感染患者体内病原菌种类繁多，对常见抗菌药物的耐药性存在差异，且患者体内存在较强的炎性反应，临床应根据药敏结果合理应用抗菌药物 。     

Advances in improvement of quality and resistance in a multipurpose crop: sea buckthorn

Sea buckthorn is a berry crop with multiple uses. The berries are highly appreciated for their unique taste but are also very rich in bioactive compounds with powerful nutritional and medicinal values. In addition, the plants grow well under adverse conditions, and are often used to fight soil erosion. Utilization of sea buckthorn has therefore increased around the world but serious problems have, nevertheless, been encountered due to drought, salinity, diseases and insect pests. This review covers important aspects of sea buckthorn research, such as heritable and environmentally induced variation in biochemical compounds, causes and effects of the devastating dried-shrink disease, susceptibility to insect pests, methods for conventional breeding, and the utilization of DNA markers for taxonomical and population genetic analyses, and for investigating the inheritance of quality and resistance traits. We also present possibilities to implement innovative biotechnological breeding methods, especially metabolite profiling and MAS/GRC-based markers, for fast and efficient development of elite genotypes with specific nutritional- and health-related bioactive compounds and strong resistance to biotic and abiotic stress.     

耐药细菌蛋白质的分泌——新抗攻击的靶点

几十年来,由于抗生素的大量使用,导致了细菌对很多药物的抗药性.为了克服细菌的抗药性问题,需要用新的思路去发掘新的抗生素,包括发掘细菌细胞中存在的抗生素作用的新靶点.蛋白质的分泌过程对于细菌是生死攸关的,它可能成为新药物的适合靶点.