体质量指数对结直肠癌切除术中淋巴结检测数目的影响

目的:探讨体质量指数(body mass index,BMI)对结直肠癌切除术淋巴结检测数目的影响。方法:回顾性分析自2014年12月至2017年1月福建省立医院收治的328例结直肠癌患者的临床病理资料,全部患者均行结直肠癌切除术,以术后病理的淋巴结检测数目为依据分为两组(<12枚组与≥12枚组),将各组的临床病理因素进行统计学分析。结果:单因素分析显示,患者的BMI(χ^2=7.697,P=0.006)、肿瘤部位(χ^2=7.900,P=0.048),肿瘤TNM分期(χ^2=34.795,P<0.010)等因素在两组间的淋巴结检测数目方面差异具有统计学意义;Logistic回归分析提示,根据世界卫生组织(WHO)标准(正常值范围:18.5~24.9 kg/m^2)对BMI进行分组,BMI≥25 kg/m^2组与BMI<25 kg/m^2组相比,淋巴结检测数目<12枚的风险显著增加(OR=2.557,95%CI:1.231~5.309;P=0.012)。肿瘤位于直肠、乙状结肠的患者与其他部位患者相比,淋巴结检测数目<12枚的风险显著增加(OR=1.731,95%CI:1.066~2.810;P=0.027)。结论:高BMI指数可影响结直肠癌手术中是否获取足够的淋巴结检测数目,进而影响其术后病理分期。

Genomic analysis of Nypa fruticans elucidates its intertidal adaptations and early palm evolution

Nypa fruticans(Wurmb),a mangrove palm species with origins dating back to the Late Cretaceous period,is a unique species for investigating long-term adaptation strategies to intertidal environments and the early evolution of palms.Here,we present a chromosome-level genome sequence and assembly for N.fruticans.We integrated the genomes of N.fruticans and other palm family members for a comparative genomic analysis,which confirmed that the common ancestor of all palms experienced a whole-genome duplication event around 89 million years ago,shaping the distinctive characteristics observed in this clade.We also inferred a low mutation rate for the N.fruticans genome,which underwent strong purifying selection and evolved slowly,thus contributing to its stability over a long evolutionary period.Moreover,ancient duplicates were preferentially retained,with critical genes having experienced positive selection,enhancing waterlogging tolerance in N.fruticans.Furthermore,we discovered that the pseudogenization of Early Methionine-labelled 1(EM1)and EM6 in N.fruticans underly its crypto-vivipary characteristics,reflecting its intertidal adaptation.Our study provides valuable genomic insights into the evolutionary history,genome stability,and adaptive evolution of the mangrove palm.Our results also shed light on the long-term adaptation of this species and contribute to our understanding of the evolutionary dynamics in the palm family.

Applications of protein engineering in the microbial synthesis of plant triterpenoids

Triterpenoids are a class of natural products widely used in fields related to medicine and health due to their biological activities such as hepatoprotection,anti-inflammation,anti-viral,and anti-tumor.With the advancement in biotechnology,microorganisms have been used as cell factories to produce diverse natural products.Despite the significant progress that has been made in the construction of microbial cell factories for the heterogeneous biosynthesis of triterpenoids,the industrial production of triterpenoids employing microorganisms has been stymied due to the shortage of efficient enzymes as well as the low expression and low catalytic activity of heterologous proteins in microbes.Protein engineering has been demonstrated as an effective way for improving the specificity,catalytic activity,and stability of the enzyme,which can be employed to overcome these challenges.This review summarizes the current progress in the studies of Oxidosqualene cyclases(OSCs),cytochrome P450s(P450s),and UDP-glycosyltransferases(UGTs),the key enzymes in the triterpenoids synthetic pathway.The main obstacles restricting the efficient catalysis of these key enzymes are analyzed,the applications of protein engineering for the three key enzymes in the microbial synthesis of triterpenoids are systematically reviewed,and the challenges and prospects of protein engineering are also discussed.