Processing of DNA Polymerase-Blocking Lesions during Genome Replication Is Spatially and Temporally Segregated from Replication Forks

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Gel mobility shift scanning of the acetate-inducible promoters fromNeurospora crassa reveals a common co-inducible DNA-binding protein

The promoter regions of four acetate-inducible genes ofNeurospora crassa, acu-3, acu-5, acu-8 andacu-9, have been sequenced. Using a scanning gel mobility shift assay particular DNA regions in each promoter have been shown specifically to bind partially purified protein extracted from acetate-induced mycelia. The protein-binding regions so defined have common sequence motifs, elements of which are similar to those required for acetate induction inAspergillus nidulans.     

冠状动脉旁路移植患者围术期的BNP 水平变化及临床意义

目的:研究冠状动脉旁路移植手术后患者B型脑钠钛(BNP)水平变化规律及临床意义。方法:选取我院2014年6月到2015年6月间收治的冠状动脉旁路移植手术患者80名,根据患者心脏左心室射血分数(LVEF)分为A组(45%)和B组(≤45%),观察两组患者在不同时间的BNP水平,对比两患临床相关指标、及心房颤抖和心功能不全发生情况。结果:A组患者在血管活性物质使用量、呼吸机使用时间、监护室停留时间及心房颤抖和心功能不全发生率都明显小于B组,差异有统计学意义(P0.05);术后6h两组患者的BNP水平开始明显上升,在术后24h达到峰值,此后开始下降但仍维持较高水平,组内比较差异均有统计学意义(P0.05)。A组患者在术前及术后各个时间段内BNP水平均明显小于B组,组间比较比较均有统计学意义(P0.05)。结论:冠状动脉旁路移植患者围手术期BNP水平可以反应患者心脏功能状况,BNP水平越高表示患者心脏越差。     

影响心脏骤停患者心肺复苏成功率的因素分析

目的:分析我院心脏骤停患者心肺复苏的成功率,并探讨其影响因素。方法:选取198名行心肺复苏的心脏骤停患者为研究对象,实施心肺复苏,并记录患者一般情况、复苏开始时间和地点、复苏过程和复苏结局等多项指标,统计分析复苏效果。结果:1198名患者,72例取得最终复苏成功,心肺复苏成功率为36.4%;2不同年龄(=15.380,P0.001)、基础性疾病(x~2=11.465,P=0.043)、复苏开始时间(x~2=57.968,P0.001)、地点(x~2=61.384,P0.001)患者心肺复苏成功率差异有统计学意义,年龄16~60岁、非心血管疾病、心脏骤停5分钟内、院内开始心肺复苏者成功率较高;3复苏成功者和失败者复苏持续时间(t=-5.961,P0.001)和气道建立时间(t=-4.045,P=0.004)的差异具有统计学意义,成功者复苏持续时间要短于失败者,而气道建立时间要早于失败者。结论:快速建立人工气道,不盲目延长心肺复苏时间,提高心脏骤停患者心肺复苏的成功率。     

Legume-Rhizobium interactions: host induced alterations in capsular polysaccharides and infectivity of cowpea Rhizobia

Klebsiella aerogenes NCTC418 was cultured anaerobically under glucose-limited conditions in chemostat cultures at various growth rates, ranging from 0.13 h^-1 to 0.82 h^-1. It was found that the specific uptake rate of glucose varied linearly with the growth rate and that under these conditions glucose was fermented solely to acetate and ethanol plus CO₂+H₂ and formate.When steady-state cultures were pulsed with cell saturating concentrations of glucose, the specific glucose aptake rate increased immediately and substantially. However, at steady-state growth rates lower than 0.5 h^-1, this increase was not accompanied by a change in the growth rate, in contrast to cultures growing at higher rates. It was found that relief of the glucose limitation resulted in a shift in fermentation pattern: at the lower growth rates 50% or more of the extra glucose taken up was fermented to D-lactate.Incubation experiments with sonified cells revcaled that K. aerogenes possessed all the enzymes needed to convert dihydroxyacetone phosphate to methylglyoxal and subsequently to D-lactate, and that the rate at which this overall conversion occurred in vitro was in close agreement with the production rate of D-lactate in vivo. Moreover, it was found that the activities of the enzymes of the methylglyoxal bypass were dependent on the imposed growth rate. At higher growth rates, where cells possessed the potential to increase their growth rate immediately, the activity of methylglyoxal synthase was relatively low.it could be shown that, under low growth rate conditions, the uncoupling effect of the methylglyoxal bypass was highly effective and that, as a consequence thereof, a significant increase in the uptake rate of the energy source was accompanied by only a marginal increase in the rate at which ATP was synthesized.     

Gap-filling and bypass at the replication fork are both active mechanisms for tolerance of low-dose ultraviolet-induced DNA damage in the human genome

Ultraviolet (UV)-induced DNA damage are removed by nucleotide excision repair (NER) or can be tolerated by specialized translesion synthesis (TLS) polymerases, such as Polη. TLS may act at stalled replication forks or through an S-phase independent gap-filling mechanism. After UVC irradiation, Polη-deficient (XP-V) human cells were arrested in early S-phase and exhibited both single-strand DNA (ssDNA) and prolonged replication fork stalling, as detected by DNA fiber assay. In contrast, NER deficiency in XP-C cells caused no apparent defect in S-phase progression despite the accumulation of ssDNA and a G2-phase arrest. These data indicate that while Polη is essential for DNA synthesis at ongoing damaged replication forks, NER deficiency might unmask the involvement of tolerance pathway through a gap-filling mechanism. ATR knock down by siRNA or caffeine addition provoked increased cell death in both XP-V and XP-C cells exposed to low-dose of UVC, underscoring the involvement of ATR/Chk1 pathway in both DNA damage tolerance mechanisms. We generated a unique human cell line deficient in XPC and Polη proteins, which exhibited both S- and G2-phase arrest after UVC irradiation, consistent with both single deficiencies. In these XP-C/Polη^KD cells, UVC-induced replicative intermediates may collapse into double-strand breaks, leading to cell death. In conclusion, both TLS at stalled replication forks and gap-filling are active mechanisms for the tolerance of UVC-induced DNA damage in human cells and the preference for one or another pathway depends on the cellular genotype.     

腹腔镜袖状胃切除术和胃旁路术治疗肥胖合并2型糖尿病近期疗效的对比研究

摘要 目的：对比腹腔镜袖状胃切除术（LSG）和胃旁路术（LRYGB）治疗肥胖合并2型糖尿病（T2DM）的近期疗效。方法：回顾性分析我院于2016年2月至 2019年1月期间收治的63例肥胖合并T2DM患者的临床资料，根据患者手术方式，将患者分为LRYGB组34例、LSG组29例。对比两组术中、术后临床指标，对比两组术前、术后6个月的体质量指数（BMI）、腰臀比（WHR）、糖脂代谢指标，记录两组治疗期间并发症发生情况。结果：两组术后胃肠功能恢复时间、下床活动时间、术中出血量组间对比无统计学差异（P>0.05），LSG组手术时间、住院时间短于LRYGB组（P<0.05）。两组术后6个月BMI、WHR均较术前下降（P<0.05）。两组术后6个月总胆固醇（TC）、糖化血红蛋白（HbAlc）、甘油三酯（TG）、低密度脂蛋白（LDL-C）、空腹血糖（FBG）、餐后2 h 血糖 （2hPG）均较术前下降（P<0.05），高密度脂蛋白（HDL-C）较术前升高（P<0.05）。两组并发症发生率对比无统计学差异（P>0.05）。结论：LSG、LRYGB治疗肥胖合并T2DM患者，均可有效控制患者体重，调节血糖血脂，两者近期疗效相当，但是LSG的手术操作相对更简单，可视患者具体病情选择合适的术式。     

床旁超声联合颅内血流监测预测心肺复苏患者颅内压升高的效果研究

摘要 目的：探讨床旁超声联合颅内血流监测预测心肺复苏患者颅内压升高的效果。方法：选择2020年1月至2022年12月在本院重症医学科行心肺复苏治疗的60例患者作为研究对象，于心肺复苏术后采用脑室测压导管测定颅内压，根据颅内压结果将患者分为颅内高压组和正常组。采用酶联免疫吸附法检测两组患者血清脑源性神经营养因子（BDNF）、中枢神经特异性蛋白（S100β）和神经元特异性烯醇化酶（NSE）水平。比较两组患者视神经鞘宽度（ONSD）、大脑中动脉搏动指数（MCA-PI）。采用Pearson分析颅内压、ONSD与MCA-PI之间的相关性。绘制受试者工作特征（ROC）曲线分析患者ONSD、MCA-PI对的心肺复苏术后颅内压升高的预测价值。结果：（1）60例心肺复苏患者中19例出现颅内压升高；（2）颅内高压组患者血清BDNF、S100β和NSE水平均显著高于正常组（P<0.05）；（3）颅内高压组患者ONSD和MCA-PI均显著高于正常组（P<0.05）；（4）心肺复苏患者ICP与ONSD、MCA-PI均呈显著正相关关系（r=0.872、0.848，P<0.05）。（5）ONSD和MCA-PI预测心肺复苏患者发生颅内压升高的AUC分别为0.875（95%CI：0.739~1.000）、0.841（95%CI：0.735~0.948）。ONSD预测心肺复苏患者颅内压升高的最佳截断值为≥5.69 mm，对应敏感度、特异度、约登指数、阳性预测值和阴性预测值分别为78.95%、100.00%、78.95%、100.00%和91.11%；MCA-PI预测心肺复苏患者颅内压升高的最佳截断值为≥0.945，对应敏感度、特异度、约登指数、阳性预测值和阴性预测值分别为78.95%、80.49%、59.44%、65.22%和89.19%。结论：床旁超声和颅内血流监测均无创安全，ONSD和MCA-PI都可以有效预测心内复苏患者颅内压升高，ONSD预测效能更佳。     

肺康复训练联合规律性有氧运动疗法对稳定期COPD患者心肺运动功能、生活质量和Th17/Treg细胞亚群失衡的影响

摘要 目的：观察肺康复训练联合规律性有氧运动疗法对稳定期慢性阻塞性肺疾病（COPD）患者心肺运动功能、生活质量和Th17/Treg细胞亚群失衡的影响。方法：选取2019年6月-2021年6月期间于我院接受治疗的80例稳定期COPD患者,根据随机数字表法分为观察组（40例,肺康复训练联合规律性有氧运动疗法）、对照组（40例,接受肺康复训练）,比较两组患者心肺运动功能、运动耐量、生活质量和Th17/Treg细胞亚群失衡相关指标。结果：两组干预3个月后最大分钟通气量（VEmax）、峰值摄氧量（PeakVO₂）升高,且观察组高于对照组（P<0.05）。两组干预3个月后无氧阈时二氧化碳通气当量（VE/CO₂ at AT）下降,且观察组低于对照组（P<0.05）。两组干预3个月后圣?乔治呼吸问卷（SGRQ）评分降低,且观察组低于对照组（P<0.05）。两组干预3个月后6 min步行试验（6MWT）距离、运动时间延长,且观察组长于对照组（P<0.05）。两组干预3个月后Treg含量升高,且观察组高于对照组（P<0.05）;两组干预3个月后Th17/Treg比值、Th17含量下降,且观察组低于对照组（P<0.05）。结论：肺康复训练联合规律性有氧运动疗法用于稳定期COPD患者,可改善其心肺运动功能,提高运动耐量,提高生活质量,同时还可调节Th17/Treg细胞亚群失衡。     

右美托咪定联合丙泊酚对体外循环下心脏瓣膜置换术患者心肌损伤、肾功能和细胞免疫功能的影响

摘要 目的：观察右美托咪定联合丙泊酚对体外循环（CPB）下心脏瓣膜置换术患者心肌损伤、肾功能和细胞免疫功能的影响。方法：回顾性分析2020年1月~2020年12月期间新疆医科大学第一附属医院收治的120例CPB下心脏瓣膜置换术患者的临床资料,根据麻醉方案的不同将患者分为对照组和研究组,各为60例,对照组患者接受丙泊酚麻醉,研究组患者接受右美托咪定联合丙泊酚麻醉。观察两组患者围术期指标、血流动力学、心肌损伤、肾功能和细胞免疫功能变化情况,记录两组围术期不良反应发生情况。结果：研究组患者的心脏复跳时间、术后苏醒时间、术后拔管时间、ICU滞留时间、术后住院时间均短于对照组患者（P<0.05）。术前（T0）~术毕（T3）时间点,两组患者的平均动脉压（MAP）、心率（HR）先下降后升高,肌酸激酶同工酶（CK-MB）和肌钙蛋白I（cTnI）水平则持续升高（P<0.05）,但CPB开始后30 min（T1）~ T3时间点,研究组患者的MAP、HR高于对照组患者,CK-MB、cTnI水平则低于对照组患者（P<0.05）。两组患者T0、术中、术后24 h 的尿素氮（BUN）、血清胱抑素C（CysC）水平呈升高趋势（P<0.05）。术中、术后24 h两组患者的CD4⁺、CD4⁺/CD8⁺均较T0下降,但研究组高于对照组（P<0.05）;术中、术后24 h两组患者的CD8⁺较T0升高,但研究组低于对照组（P<0.05）。两组不良反应发生率对比无统计学差异（P>0.05）。结论：右美托咪定联合丙泊酚应用于CPB下心脏瓣膜置换术患者,可减轻心肌损伤和细胞免疫功能抑制,维持血流动力学稳定,且不增加肾功能损伤和不良反应发生率。