Antibacterial and anti-inflammatory effects of genistein in Staphylococcus aureus induced osteomyelitis in rats

Methicillin-resistant Staphylococcus aureus (MRSA) is a highly infectious Gram-positive pathogen known to cause severe diseases such as endocarditis, food poisoning, pneumonia, osteomyelitis, and septicemia. MRSA is a major public health issue. Among these, osteomyelitis is inflammation of the bone caused by the invasion of the bacterial pathogen in the bones. Its prominent symptoms include fever, pain, and redness of bones. In the case of children, it affects the long bones of arms and legs, whereas in the case of adults it affects the hip, feet, and spine. Bacterial osteomyelitis can trigger pathological remodeling of bones and hence causes substantial morbidity and mortality. The present study aims to evaluate the isoflavone genistein's (5,7-dihydroxy-3-(4-hydroxyphenyl)−4H-1-benzopyran-4-one,4′,5,7 trihydroxyisoflavone) antimicrobial and anti-inflammatory effects against osteomyelitis induced by MRSA in male Wistar rats. Classification of the animals was into the following: sham (Group I), osteomyelitis (Group II, control), genistein (25 mg/kg body weight, Group III), and genistein (50 mg/kg body weight, Group IV). The rats did not receive any treatment for 4 weeks after bacterial inoculation. Genistein was then administered twice daily for 2 weeks. Bacterial growth, mean body weight bone infection status, and side effects of genistein treatment were assessed. Furthermore, lipid peroxidation, superoxide dismutase, glutathione (GSH) peroxidase, catalase, reduced GSH, tumor necrosis factor-α (TNF-α), and interleukin (IL)-6 were also determined. Two days after treatment, it was found that genistein significantly suppressed bacterial growth and reduced serum pro-inflammatory cytokines TNF-α and IL-6. Therefore, the study suggests that genistein could be a promising lead against MRSA-induced osteomyelitis.     

粤港澳大湾区生态系统健康时空变化及其对城镇化的响应

区域生态系统健康评价是获取区域生态系统状况的重要手段，对生态保护和恢复具有现实的指导意义。研究从人类与生态系统耦合角度出发，基于生态系统完整性以及人类对生态系统服务的需求，在“活力-组织力-弹性”框架基础上引入生态系统服务供需指标构建评价框架。以粤港澳大湾区为例，分析2005—2018年生态系统健康时空变化特征及其对城镇化的响应。研究结果表明：(1)2005—2018年间，大湾区生态系统健康呈现中部低四周高的空间格局，以好，较好和一般水平为主；从时间变化上来看，大湾区四周山区生态系统健康状况有所改善，而中部地区健康状况则逐渐恶化。(2)大湾区生态系统活力在改善区域生态系统健康中发挥了重要的作用；此外，生态系统服务供需对传统生态系统健康评价结果进行适当修正，生态系统服务供需赤字加剧了中部地区生态系统健康状况的恶化。(3)大湾区生态系统健康与人口城镇化、土地城镇化间均存在显著的空间负相关性，其中，土地城镇化对生态系统健康的负面影响越来越显著，特别是大湾区中部地区。研究以期为生态系统健康评价提供新思路，同时为大湾区生态系统保护与管理提供参考。     

Flavonoid-producing tomato plants have a direct negative effect on the zoophytophagous biological control agent Orius sauteri

Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is often used for biological control of small arthropod pests in greenhouse vegetable production systems in Asia. In addition to feeding on arthropod prey, O. sauteri consumes small quantities of plant material. Previous studies demonstrated that tomato plant chemistry confers antixenosis resistance to phloem-feeding whiteflies, but the potential nontarget effects of phytochemicals on the beneficial predator O. sauteri are unknown. Comparison of O. sauteri confined to near-isogenic lines (NILs) of tomatoes producing high levels of flavonoids (NIL-purple hypocotyl; resistant to whiteflies) and low levels of flavonoids (NIL-green hypocotyl; susceptible to whiteflies) revealed that O. sauteri had reduced oviposition, nymphal survival, and development on resistant plants, even if they were also provided with prey that did not feed on the host plant. Moreover, O. sauteri showed a significant ovipositional preference in choice assays, laying significantly more eggs on susceptible than on resistant plants. Molecular gut content analysis using the specific chloroplast trnL gene from tomato confirmed that adult and immature O. sauteri feed on both resistant and susceptible genotypes, and feeding behavior assays revealed that resistance did not affect plant feeding or prey acceptance by O. sauteri adults. These results demonstrate a direct negative effect of phytochemicals on a nontarget beneficial species and indicate that resistance mediated by phytochemicals can affect organisms that do not solely feed on phloem sap. The results also indicate that the mode of action and the potential ecological effects of phytochemical-mediated resistance are broader than previously recognized.     

Functional analysis of ScSwil and CaSwil in invasive and pseudohyphal growth of Saccharomyces cerevisiae

Here we reported that, in Saccharomyces cerevisiae, deleting Swil （ScSwil）, a core component in Swi/Snf complex, caused defects of invasive growth, pseudohyphal growth, FLOll expression, and proper cell separation. Re-introduction of SWII into the swil mutants could suppress all defects observed. We also showed that overproducing Swil could suppress the defect offlo8 cells in pseudohyphal growth in diploids, but not invasive growth in haploids. Overexpression of SWII could not bypass the requirement of Ste12 or Tecl in invasive growth or pseudohyphal growth. We concluded that the Swi/Snf complex was required for FLO11 expression and proper cell separation, and both the FL08 and STE12 genes should be present for the complex to function for the invasive growth but only the STE12 gene was required for the pseudohyphal growth. Ectopic expression of Candida albicans SWI1 （CaSWII） could partially complement the defects examined of haploid Scswil mutants, but failed to complement the defects examined of diploid Scswil/ Scswil mutants. Overexpressing CaSwil mitigated invasive and pseudohyphal growth defects resulting from deletions in the MAP kinase and cAMP pathways. The integrity of S. cerevisiae Swi/Snf complex is required for invasive and filamentous growth promoted by overexpressing CaSwil.     

广西北部湾茅尾海浮游真菌群落结构及其影响因子

浮游真菌在海洋食物网和生物地球化学循环中发挥着关键作用。【目的】为解析广西北部湾茅尾海不同季节浮游真菌群落结构及其关键环境影响因子，于2017年7月(夏季)、9月(秋季)、12月(冬季)和2018年3月(春季)期间在该海域设置7个站点，采集表层海水样品。【方法】利用内部转录间隔区(internal transcribed spacer, ITS)基因高通量测序技术，分析茅尾海浮游真菌群落结构与多样性。【结果】茅尾海海域浮游真菌隶属6个门、26个纲、71个目、167个科、282个属和374个种。主要浮游真菌类群为子囊菌门(Ascomycota, 82.14%)和担子菌门(Basidiomycota, 10.74%)，共占浮游真菌总丰度的92.88%。茅尾海浮游真菌群落Shannon指数和Simpson指数在春季最高，Chao1指数和丰富度(richness)指数在冬季最高。主坐标分析(principal coordinates analysis, PCoA)和相似性分析(analysis of similarities, ANOSIM)结果显示，不同季节浮游真菌群落的β多样性具有极显著差异(R=0.591 2, P<0.001)。通过随机森林模型分析(random forest modeling analysis, RF)，发现黄曲霉(Aspergillus flavus)、二色胶孔菌(Gloeoporus dichrous)、杂色曲霉(Aspergillus subversicolor)和微扁沃利雅炭皮菌(Whalleya microplaca)、翹鱗香菇(Lentinus squarrosulus)等20种海洋浮游真菌对环境变化敏感，可用于评估茅尾海富营养化状况。Spearman相关性分析表明，浮游真菌α多样性与海水pH、盐度和溶解氧(dissolved oxygen, DO)呈显著正相关关系(P<0.05)，与温度、叶绿素-a (chlorophyll a, Chl-a)以及总有机碳(total organic carbon, TOC)呈显著负相关关系(P<0.05)。方差分解分析(variance partitioning analysis, VPA)发现营养因子是浮游真菌群落结构的主要驱动因子。【结论】本研究可为揭示北部湾海洋浮游真菌多样性提供理论参考，并为茅尾海生态环境监测与资源利用提供科学依据。     

生物产品的经济效益优化

为了优化经济效益，许多文献一般以现值作为目标函数，其贴现率的主观性很大．本文以内部收益率作为目标函数，从根本上排除了主观性，与实际目标较为相符．     

Paradoxical HBsAg and anti-HBs coexistence among Chronic HBV Infections: Causes and Consequences

Hepatitis B surface antigen (HBsAg) and Hepatitis B surface antibody (anti-HBs) were reported simultaneously among Hepatitis B virus (HBV) infections. HBsAg is a specific indicator of acute or chronic HBV infections, while anti-HBs is a protective antibody reflecting the recovery and immunity of hosts. HBsAg and anti-HBs coexist during seroconversion and then form immune complex, which is rare detected in clinical cases. However, with the promotion of vaccination and the application of various antiviral drugs, along with the rapid development of medical technology, the coexistence of HBsAg and anti-HBs has become more prevalent. Mutations in the viral genomes, immune status and genetic factors of hosts may contribute to the coexistence. Novel HBsAg assays, with higher sensitivity and ability to detect mutations or immune complexes, can also yield HBsAg/anti-HBs coexistence. The discovery of coexistence has shattered the idea of traditional serological patterns and raised questions about the effectiveness of vaccines. Worth noting is that HBsAg/anti-HBs double positivity is strongly associated with progressive liver diseases, especially hepatocellular carcinoma. In conclusion, viral mutations, host factors, and methodology impacts can all lead to the coexistence of HBsAg and anti-HBs. This coexistence is not an indicator of improvement, as an increased risk of adverse clinical outcomes still exists.