局部晚期直肠癌两组术前放疗剂量方案短期疗效分析

目的 评估局部晚期直肠癌新辅助放化疗不同放疗剂量短期疗效差异及耐受性。方法 回顾性分析2010年8月至2015年5月在本院接受新辅助放化疗的局部晚期直肠癌患者。根据放疗剂量分为46和50 Gy两组,同步化疗方案以卡培他滨为基础,<75岁且一般情况较好的患者联合奥沙利铂,所有患者完成新辅助放化疗和直肠癌根治术。结果 共有213例患者纳入研究,其中2010年8月至2013年8月接受46 Gy放疗剂量治疗61例,2013年9月至2015年5月接受50 Gy放疗剂量治疗152例,其中男性145例,女性68例;T₂期22例,T₃期180例,T₄期11例;下、中、上段直肠癌分别为82、115和16例。两组患者年龄、性别、治疗前T分期及N分期差异无统计学意义（P>0.05）,临床特征匹配。50和46 Gy组病理完全缓解（PCR）率分别为24.3%和18.0%（P>0.05）;病理缓解良好（GR）率分别为75.0%和67.2%（P>0.05）;T降期率分别为46.7%和39.3%（P>0.05）。T₃N₂/T₄亚组分析：50和46 Gy组CR率分别为23.3%和6.3%（P>0.05）;GR （病理消退分级3+4）率分别为72.1%和50.0%,差异无统计学意义（P>0.05）。T降期率为46.5%和31.3%,差异无统计学意义（P>0.05）。结论 50 Gy较46 Gy放疗剂量治疗局部晚期直肠癌未能提高肿瘤病理缓解率及T降期率,对T₃N₂/T₄期患者,两组差异也无统计学意义,远期疗效有待进一步随访验证。     

局部进展期直肠癌术前同步放化疗后联合新辅助化疗的前瞻性Ⅱ期随机对照研究

目的 探索术前同步放化疗加新辅助化疗治疗局部进展期直肠癌的疗效及安全性。方法 收集2012年1月-2015年12月贵州省肿瘤医院腹部肿瘤科收治的中低位局部进展期直肠癌患者80例,采用抽签法随机分为：试验组40例,为同步放化疗加化疗组。盆腔放疗D_T：45 Gy/25次 ,5周,直肠肿块同步加量至50 Gy/25次,5周,放疗每周第1~5天同步5-FU持续滴注,随后行4周期FOLFOX4方案化疗,治疗结束后行全直肠系膜切除术（TME手术）,术后4周再行4周期FOLFOX4方案辅助化疗。对照组40例,为同步放化疗组。盆腔同步放化疗方案同试验组,治疗结束后6~8周行TME手术,术后4周行8周期FOLFOX4方案辅助化疗。比较两组患者病理完全缓解率、降期率、R₀切除率、局部复发率、远处转移率、总生存率、不良反应发生率、手术并发症及观察各组治疗完成情况。结果 试验组、对照组病理完全缓解率（pCR率）分别为20.0%、5.0%（χ²=4.114,P<0.05）;降期率分别为77.4%、55.6%（P>0.05）;R₀切除率分别为77.5%和65.0%（P>0.05）。3年局部复发率分别为9.6%及11.5%（P>0.05）,3年总生存率、3年远处转移率分别为72.5%和65.5%（P>0.05）、25.0%和37.5%（P>0.05）。两组完成新辅助同步放化疗、根治性切除术及围手术期全身化疗患者共57例,试验组31例,对照组为26例。接受8周期全身化疗完成率试验组与对照组分别为87.1%及61.5%（χ²=4.985,P<0.05）。试验组患者发生1~4级急性反应低于对照组,但差异无统计学意义（P>0.05）;两组术中出血发生率、伤口延期愈合发生率及吻合口瘘发生率差异均无统计学意义（P>0.05）。结论 术前同步放化疗联合新辅助化疗治疗局部进展期直肠癌较标准术前同步放化疗能提高近期疗效（pCR率）,不良反应发生率更低,但尚需长时间随访观察及扩大病例数进行进一步临床研究。     

中性粒细胞与白蛋白比值预测病理Ⅱ/Ⅲ期直肠癌术后辅助放化疗急性不良反应和生存

目的 探讨辅助放化疗前外周血细胞为基础的炎症标志物与病理Ⅱ/Ⅲ期直肠癌术后辅助放化疗急性不良反应和生存的关系。方法 本研究共纳入109名直肠癌患者。用受试者工作特征（ROC）曲线计算中性粒细胞与淋巴细胞比值（NLR）、血小板与淋巴细胞比值（PLR）、淋巴细胞与单核细胞比值（LMR）和中性粒细胞与白蛋白比值（NAR）对总生存率（OS）的预测能力。结果 NAR与2级以上白细胞减少症的发生有关（OR=4.442,95%CI：1.216~16.221,P<0.05）。NAR ≥ 0.055和NAR<0.055患者的5年总生存率分别为68.2%和83.9%（P>0.05）,5年无瘤生存率分别为59.1%和76.8%（χ²=3.887,P<0.05）。Cox比例风险模型的多变量分析显示,NAR与OS显著相关（HR=3.035,95%CI：1.021~9.019,P<0.05）。结论 辅助放化疗前NAR可作为直肠癌术后辅助放化疗急性不良反应和预后的生物标志物。     

MicroRNA及其靶基因在预测直肠癌放化疗疗效中的作用

目的 MicroRNA及其靶基因参与直肠癌放化疗疗效应答,本研究旨在筛选直肠癌放化疗疗效相关的microRNA及其靶基因,推动直肠癌放化疗疗效的基础研究。方法 基于PubMed数据库挖掘与直肠癌放化疗疗效相关的microRNA,结合microRNA-mRNA调控关系以及基因芯片表达谱数据,寻找与直肠癌放化疗疗效相关的靶基因。通过DAVID、IPA等工具对靶基因进行基因本体论和信号转导通路富集分析。结果 通过文本挖掘,共搜集到38个与直肠癌放化疗相关的microRNA,结合实验验证和计算机预测的microRNA-mRNA调控关系,共得到潜在的靶基因3 545个。其中,131个在基因芯片表达谱（GSE35452）中具有显著的差异表达现象（P<0.05）。基因本体论以及信号转导通路富集结果表明,这些基因与直肠放化疗疗效密切相关。结论 上述microRNA及其调控的差异表达基因参与了直肠癌放化疗疗效相关的多条信号通路,在一定程度上从生物机制的角度解释了直肠癌放化疗疗效的差异。同时,筛选出的microRNA及其靶基因也为预测直肠癌放化疗疗效的研究提供了理论依据。     

治疗前血液炎性标志物对食管鳞癌患者放化疗疗效及预后的影响

目的 探讨治疗前血液炎性标志物,对食管鳞状细胞癌（ESCC）接受放（化）疗患者治疗效果及生存预后的影响。方法 回顾性分析2013年1月至2014年12月在扬州大学附属泰兴人民医院行根治性放疗（RT）或放化疗（CRT）的107例ESCC患者,根据治疗前中性粒细胞与淋巴细胞比值（NLR）、血小板与淋巴细胞比值（PLR）和C反应蛋白与白蛋白比值（CRP/Alb）的中位值将患者分为NLR<3.06组（54例）和NLR ≥ 3.06组（53例）,PLR<145.26组（54例）与PLR ≥ 145.26组（53例）,CRP/Alb<0.13组（52例）和CRP/Alb ≥ 0.13组（55例）,治疗效果采用logistic回归分析;生存预后采用Kaplan-Meier法计算无疾病进展生存率并用Log-rank法检验,Cox模型多因素分析。结果 放化疗、NLR<3.06组、PLR<145.26组和CRP/Alb<0.13组患者的治疗效果分别优于单纯放疗、NLR ≥ 3.06、PLR ≥ 145.26和CRP/Alb ≥ 0.13患者,差异均有统计学意义（HR=2.118、4.138、2.297、3.784,P<0.05）;进一步分析显示放化疗（HR=1.342,95% CI 1.023~2.467,P<0.05）与CRP/Alb<0.13（HR=7.004,95% CI 2.088~23.496,P<0.05）是疗效好的独立危险因素。另外,单因素Cox回归分析显示,TNM分期、治疗方式、NLR、PLR和CRP/Alb均与食管鳞癌患者的无疾病进展生存时间（PFS）密切相关（P<0.05）;在多因素COX回归模型中显示：TNM分期（HR=1.326,95% CI 1.070~1.838,P<0.05）、治疗方式（HR=0.400,95% CI 0.230~0.694,P<0.05）与CRP/Alb（HR=3.518;95% CI 1.975~6.266;P<0.05）是无进展生存（PFS）的独立预后因素。而根据TNM分期及治疗方式的亚组分析得出无论在食管鳞癌的早期患者（Ⅰ+Ⅱ期）,还是晚期患者（Ⅲ期）,是接受单纯放疗,还是同步放化疗,CRP/Alb<0.13的无疾病进展生存时间均优于CRP/Alb ≥ 0.13。最后,受试者工作特征（ROC）曲线也证实CRP/Alb在预测食管鳞癌接受放化疗患者的近期疗效和无疾病进展生存时间方面优于NLR和PLR。结论 血液炎性指标CRP/Alb在预测胸段食管鳞状细胞癌接受放（化）疗患者近期疗效及生存预后方面具有重要价值。     

早期结外鼻型NK/T细胞淋巴瘤放化疗疗效与不良反应分析

目的 探讨早期结外鼻型NK/T细胞淋巴瘤放化疗综合治疗的疗效及不良反应。方法 回顾性分析本院收治的174例经病理证实的结外鼻型NK/T细胞淋巴瘤患者资料。生存分析及组间比较采用Kaplan-Meier法和Log-rank检验。结果 全组Ⅰ期患者102例,Ⅱ期患者72例。2例患者接受单纯放疗,172例患者接受放化疗综合治疗。全组总有效率为94.2%（164/174）,其中完全缓解（CR）患者153例（87.9%）。5年总生存率（OS）为87.3%,5年无进展生存率（PFS）为83.1%,5年局部区域控制率为91.9%。放化疗期间最常见不良反应为骨髓抑制和口腔黏膜炎,≥ 3级骨髓抑制占62.1%,≥ 3级口腔黏膜炎占10.9%。多因素分析结果显示,高龄、B症状及Ann Arbor分期Ⅱ期是OS的独立预后不良因素,而高龄和Ann Arbor分期Ⅱ期是PFS的独立预后不良因素。放疗剂量≥ 50 Gy较低剂量组可显著提高总PFS,两组5年PFS分别为83.5%和76.5%（HR 0.374,95%CI 0.169~0.826,P=0.015）。结论 早期NK/T细胞淋巴瘤经过放化疗综合治疗可达到较好疗效,不良反应可以耐受。     

局部中晚期直肠癌术前同期加量调强放疗前瞻性临床研究的初步结果

目的 评估对Ⅱ~Ⅲ期可手术切除的直肠癌患者行术前同期加量调强放疗(SIB-IMRT)并同步口服卡培他滨化疗的可行性、安全性及近期疗效。 方法 2012年8月至2013年5月间共13例Ⅱ~Ⅲ期可手术切除的直肠癌患者接受术前调强放疗,给予肿瘤原发病灶及转移淋巴结56.25 Gy/25次 (2.25 Gy/次),高危复发区域和区域淋巴引流区50 Gy/25次 (2.0 Gy/次),同时口服卡培他滨同步化疗(825 mg/m²,2次/d, 5 d/周×5周)。放化疗结束后4~8周患者接受全直肠系膜切除术(TME)。研究主要终点为病理完全缓解率(ypCR率)、TNM降期率、急性期不良反应及术后并发症发生率,次要终点为保肛手术率。 结果 所有患者顺利完成术前同步放化疗并接受TME, TNM降期率为10/13,其中T降期率为9/13,N降期率为4/6, ypCR率为 3/13。放化疗期间不良反应全部为1~2级,包括2级骨髓抑制5例,1级骨髓抑制4例,1级腹泻2例。1例患者术后出现膀胱瘘。保肛手术率为10/13。 结论 局部中晚期直肠癌患者行SIB-IMRT并口服卡培他滨的术前同步放化疗方案的初步结果表明其疗效好、安全可行、不良反应发生率低。     

老年营养风险指数与接受根治性放化疗的老年食管癌患者的预后关系研究

目的 研究老年营养风险指数（GNRI）与接受根治性放疗或放化疗的老年食管癌患者预后间的关系。方法 回顾性分析河北医科大学第四医院2007年1月至2013年12月197例接受根治性放疗或放化疗且年龄≥75岁的食管鳞癌患者的临床资料,计算患者放疗前后老年营养风险指数（GNRI）、体质量指数（BMI）并进行分组。Kaplan-Meier法对生存时间行单因素预后分析,Cox回归模型行多因素预后分析。结果 放疗前GNRI评分正常组139例,异常组58例,两组5年生存率及无进展生存率分别为11.08%、9.82%和8.73%、6.18%（P>0.05）。放疗后GNRI评分正常组68例,异常组129例,5年生存率及无进展生存率分别为17.04%、7.42%和16.17%、3.65%（χ²=12.316、14.617,P<0.05）。单因素分析显示,T分期、N分期、TNM分期、大体肿瘤体积（GTV）、放疗前中性粒细胞与淋巴细胞比值（NLR）及放疗后BMI、放疗后血红蛋白水平、放疗后GNRI与总生存时间（OS）相关（χ²=6.569~22.434,P<0.05）;T分期、GTV、放疗前NLR及放疗后的BMI、放疗后血红蛋白水平、放疗后GNRI与无进展生存时间（PFS）相关（χ²=4.579~18.990,P<0.05）。多因素分析显示,T分期、N分期、放疗前NLR、放疗后血红蛋白水平、放疗后GNRI为患者OS的独立影响因素（P<0.05）。放疗前NLR、放疗后血红蛋白水平、放疗后GNRI为患者PFS的独立影响因素（P<0.05）。多因素分析显示,T分期、放疗后的血红蛋白水平、GNRI均为影响患者近期疗效的独立相关因素（χ²=4.716、13.083、4.519,P<0.05）。结论 营养指标GNRI可作为老年食管鳞癌患者的有效预后指标。临床工作中对GNRI评分风险较高的老年患者可积极行营养干预以改善患者预后。     

术后辅助放疗对N2期非小细胞肺癌患者预后的影响

目的 探讨术后辅助放疗对N₂期行肺癌根治术的非小细胞肺癌（NSCLC）患者预后的影响。方法 将美国SEER数据库2004-2016年间收录的接受肺癌根治术联合化疗或术后辅助放化疗的N₂期1 208例非小细胞肺癌患者资料纳入研究,其中接受肺癌根治术联合化疗的有627例（手术+化疗组）,接受肺癌根治术联合放化疗的有581例（手术+放化疗组）。分析并比较术后辅助放疗对N₂期行肺癌根治术的非小细胞肺癌患者预后的影响,同时采用1：1倾向性匹配方法分析两组患者预后情况。结果 纳入研究的两组N₂期非小细胞肺癌患者中,手术+放化疗组患者中位生存期为51月,3年、5年肿瘤特异性生存分别为58.3%、44.9%;手术+化疗组患者中位生存期为50月,3年、5年肿瘤特异性生存分别为59.9%、46.5%;两组患者的肿瘤特异性生存差异无统计学意义（P>0.05）;亚组分析发现,T₁期患者中手术+放化疗组的特异性生存明显差于手术+化疗组（χ²=5.085,P<0.05）;多因素Cox回归分析提示,年龄、性别、G分期、T分期及淋巴结转移数目是影响N₂期非小细胞肺癌患者肿瘤特异性生存的重要因素（Wald=15.236、7.039、4.841、10.155、11.192,P<0.05）。倾向性评分匹配两组N₂期非小细胞肺癌患者后分析发现,手术+放化疗组与手术+化疗组的肿瘤特异性生存差异无统计学意义（P>0.05）;而T₁期NSCLC患者中手术+放化疗组的特异性生存明显差于手术+化疗组（χ²=5.364,P<0.05）,而T_3~4期的亚组手术+放化疗组的肿瘤特异性生存明显优于手术+化疗组（χ²=4.486,P<0.05）;针对病理亚组倾向性匹配后发现,非腺癌亚组中手术+放化疗组的肿瘤特异性生存亦明显优于手术+化疗组（χ²=6.279,P<0.05）。多因素Cox回归分析也提示,术后放疗的加入是影响N₂期肺非腺癌患者肿瘤特异性生存的重要因素（Wald=7.300,P<0.05）;但肺腺癌亚组患者倾向性匹配后手术+放化疗组与手术+化疗组肿瘤特异性生存之间差异无统计学意义（P>0.05）。结论 术后辅助放疗能够改善T_3~4期或者非腺癌N₂期非小细胞肺癌患者的预后。而对T₁期术后辅助放疗选择仍需谨慎。     

局部晚期直肠癌新辅助治疗同期加量调强与三维适形放疗随机对照研究

目的 评估局部晚期直肠癌新辅助治疗同期加量调强放疗对比三维适形放疗疗效及安全性。方法 前瞻性研究自2010年5月至2015年5月,临床分期为T₃/T₄或淋巴结阳性且肿瘤下缘距肛门10 cm以内初治直肠腺癌患者共130例。采用随机数字表法分为调强放疗组和三维适形放疗组,调强放疗组66例,三维适形放疗组64例。调强放疗方案为盆腔放疗剂量45 Gy,1.8 Gy/次,共5周,同步原发病灶及转移淋巴结外放1 cm加量放疗剂量至55 Gy。三维适形放疗为盆腔放疗45 Gy,1.8 Gy/次,共5周,两组于放疗第1~14天及第22~35天接受卡培他滨1 650 mg·m^-2·d^-1口服化疗。手术于放化疗结束后6~8周进行。结果 两组患者性别、年龄、肿瘤位置、病理分化程度以及临床分期基线指标差异均无统计学意义(P>0.05)。2例患者出现放疗终止情况,分别为调强放疗组1例3级腹泻与三维适形放疗组1例3级乏力。两组血液及非血液不良反应差异均无统计学意义,无4级及以上不良反应出现。手术类型及术后并发症两组差异均无统计学意义。术后4级病理降期(病理完全缓解)率调强放疗组为22.7%,三维适形放疗组为15.6%,两组比较差异无统计学意义(P>0.05),3级与4级病理降期率两组比例分别为42.4%和25.0%,两组比较差异有统计学意义(χ²=4.406, P=0.036)。结论 局部晚期直肠癌新辅助同期加量调强放疗为可行治疗方案,与三维适形放疗相比可进一步提高病理降期。临床试验注册 中国临床试验注册中心,ChiCTR-INR-16008004。     

DNA excision repair and double-strand break repair gene polymorphisms and the level of chromosome aberration in children with long-term exposure to radon

Purpose: To study polymorphic variants of repair genes in people affected by long-term exposure to radon. The chromosome aberration frequency in peripheral blood lymphocytes was used as the biological marker of genotoxicity.

Materials and methods: Genotyping of 12 single nucleotide polymorphisms in DNA repair genes (APE, XRCC1, OGG1, ADPRT, XpC, XpD, XpG, Lig4 and NBS1) was performed in children with long-term resident exposure to radon. Quantification of the aberrations was performed using light microscopy.

Results: The total frequency of aberrations was increased in carriers of the G/G genotype for the XpD gene (rs13181) polymorphism in recessive model confirmed by the results of ROC-analysis (‘satisfactory predictor’, AUC?=?0.609). Single chromosome fragments frequency was increased in carriers of the G/G genotype in comparison with the T/T genotype. In respect to the total frequency of aberrations, the G/G genotype for the XpG gene (rs17655) polymorphism was also identified as a ‘satisfactory predictor’ (AUC?=?0.605). Carriers of the T/C genotype for the ADPRT gene (rs1136410) polymorphism were characterized by an increased level of single fragments relative to the T/T genotype.

Conclusion: The relationships with several types of cytogenetic damage suggest these three SNP (rs13181, rs17655 and rs1136410) may be considered radiosensitivity markers.     

Cytogenetic monitoring of hospital staff exposed to ionizing radiation: optimize protocol considering DNA repair genes variability

Purpose: Chronic occupational exposure to ionizing radiation (IR) induces a wide spectrum of DNA damages. The aim of this study was to assess the frequencies of micronucleus (MN), sister chromatid exchanges (SCE) and to evaluate their association with XRCC1 399 Arg/Gln and XRCC3 241 Thr/Met polymorphisms in Hospital staff occupationally exposed to IR.

Materials and methods: A questionnaire followed by a cytogenetic analysis was concluded for each subject in our study. The exposed subjects were classified into two groups based on duration of employment (Group I?<?15 years; Group II ≥15years). The genotypes of all individuals (subjects and controls) were determined by the polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP).

Results: DNA damage frequencies were significantly greater in IR workers compared with controls (p?<?.05). However, no association arised between XRCC1 399 Arg/Gln and XRCC3 241 Thr/Met polymorphisms, on one hand, and the severity of DNA damages in the studied cohort of Tunisian population, on the other hand.

Conclusion: Our data provide evidence for an obvious genotoxic effect associated with IR exposure and reinforce the high sensitivity of cytogenetic assays for biomonitoring of occupationally exposed populations. These results indicate that workers exposed to IR should have periodic monitoring, along their exposure. The variants, rs25487 and rs861539, of XRCC1 and XRCC3 genes have obvious functional effects. Paradoxically, these variants are not associated with the severity of damages, according to used assays, in the studied cohort of Tunisian population, unlike other studies.     

中国北方汉族男性铁调素基因rs7251432多态性与HiHiLo训练前后血象指标变化的关联性研究

目的:探讨铁调素(HEPC)基因rs7251432多态性与HiHiLo训练前后血象指标变化的关联性。方法:65名中国北方汉族男性健康受试者在模拟海拔约为2500m～2800m高度(氧浓度14.8%～14.3%)进行30天HiHiLo训练(低氧暴露10h/d,低氧训练3次/周)。分别测定训练前,训练第4、7、16、23和30天的RBC、Hct和Hb。采用RCP-RFLP方法解析基因多态性,探讨HEPC基因rs7251432多态性与30天HiHiLo训练前后血象指标变化率的关联性。结果:3种基因型的分布频率分别为AA(0.11)、AG(0.29)和GG(0.60),符合Hardy-Weinberg遗传平衡定律,具有群体代表性。基因多态性与各项指标初始值不关联,且所有指标未见基因型与HiHiLo效果的交互作用。在HiHiLo过程中,RBC、Hct和Hb均出现不同程度变化趋势,AA基因型受试者RBC、Hct和Hb提高幅度明显高于AG和GG基因型(P<0.05)。结论:rs7251432多态性与HiHiLo训练前后血象指标的变化关联,AA基因型可以作为预测血象指标HiHiLo低氧训练效果的分子遗传学标记。     

XRCC1单核苷酸多态性与鼻咽癌放疗近期 疗效的相关性分析

目的 探讨XRCC1单核苷酸多态性与鼻咽癌放疗敏感性的关联性。 方法 放疗前采鼻咽癌患者静脉血,用多聚链酶反应-高温连接酶反应(PCR-LDR)进行XRCC1Arg399Gln基因的分型,观察各型放疗中及放疗后3个月的疗效。结果 放疗中期Gln/Gln基因型的肿瘤退缩率为0.855±0.026,显著高于Arg/Gln基因型的0.386±0.183和Arg/Arg基因型的0.377±0.169,差异有统计学意义( F =11.16, P =0.0003);XRCC1 Codon399Gln/Gln型放疗后3个月CR达100%,Arg/Gln型为76.2%,Arg/Arg型为66.7%,三者差异无统计学意义。结论 XRCC1Codon399基因型可以预测鼻咽癌放疗中期的局部疗效。     

Association analysis of the ACTN3 R577X polymorphism with passive muscle stiffness and muscle strain injury

Passive muscle stiffness is considered to be a major factor affecting joint flexibility and is thought to relate to the occurrence of muscle strain injury. In skinned muscle fiber experiments, the R577X polymorphism of the α‐actinin‐3 gene (ACTN 3 ) has been associated with passive muscle stiffness. Our primary purpose was to clarify whether the ACTN 3 R577X polymorphism influences passive stiffness of human muscle in vivo. We also examined whether the ACTN 3 R577X polymorphism is associated with the occurrence of hamstring strain injury. Seventy‐six healthy young male subjects were genotyped for the ACTN 3 R577X (rs1815739) polymorphism. Shear modulus (an index of stiffness) of each hamstring muscle (biceps femoris, semitendinosus, and semimembranosus) was assessed using ultrasound shear wave elastography, and history of hamstring strain injury was collected via a questionnaire. The muscle shear moduli of the semitendinosus and semimembranosus were significantly higher in R‐allele (RR  + RX genotype) carriers than in XX genotype carriers, whereas the shear modulus of the biceps femoris did not differ among the ACTN 3 R577X genotypes. Frequency of past hamstring strain injury also did not differ between the 3 genotypes nor between the R‐allele and XX genotype carriers. This study indicates that RR and RX genotypes of the ACTN 3 R577X polymorphism (corresponding to the presence of α‐actinin‐3 in type II muscle fibers) are associated with increased passive muscle stiffness of the human hamstring in vivo. However, this altered mechanical property might not affect the risk of hamstring muscle strain injury.     

Caffeine and 3‐km cycling performance: Effects of mouth rinsing,genotype, and time of day

We assessed the efficacy of caffeine mouth rinsing on 3‐km cycling performance and determined whether caffeine mouth rinsing affects performance gains influenced by the CYP1A2 polymorphism. Thirty‐eight recreational cyclists completed four simulated 3‐km time trials (TT). Subjects ingested either 6 mg/kg BW of caffeine or placebo 1 h prior to each TT. Additionally, 25 mL of 1.14% caffeine or placebo solution were mouth rinsed before each TT. The treatments were Placebo, caffeine Ingestion, caffeine Rinse and Ingestion+Rinse. Subjects were genotyped and classified as AA homozygotes or AC heterozygotes for the rs762551 polymorphism of the CYP1A2 gene involved in caffeine metabolism. Magnitude‐based inferences were used to evaluate treatment differences in mean power output based on a predetermined meaningful treatment effect of 1.0%. AC heterozygotes (4.1%) and AA homozygotes (3.4%) benefited from Ingestion+Rinse, but only AC performed better with Ingestion (6.0%). Additionally, Rinse and Ingestion+Rinse elicited better performance relative to Placebo among subjects that performed prior to 10:00 h (Early) compared with after 10:00 h (Late). The present study provides additional evidence of genotype and time of day factors that affect the ergogenic value of caffeine intake that may allow for more personalized caffeine intake strategies to maximize performance.     

The rs12594956 polymorphism in the NRF-2 gene is associated with top-level Spanish athlete's performance status

ObjectivesTo determine the association between the nuclear respiratory factor 2 (NRF-2) polymorphisms and elite athletic performance.DesignWe compared the genotype and allele frequencies of the NRF-2 A/C (rs12594956), NRF-2 A/G (rs7181866), and NRF-2 C/T (rs8031031) polymorphisms between world-class endurance athletes (n = 89), elite power-oriented athletes (n = 38), and non-athletic controls (n = 110) of the same Caucasian (Spanish) origin.MethodsGenomic DNA was extracted from peripheral EDTA-treated, anti-coagulated blood using a standard protocol. Genotyping was performed using polymerase chain reaction (PCR).ResultsThe frequency of the AA genotype of the NRF-2 A/C (rs12594956) polymorphism was significantly higher in endurance athletes compared with power athletes (P < 0.01) and controls (P < 0.01) (48% vs. 13% and 21%, respectively). The likelihood of having the AA (rs12594956) genotype was higher in elite endurance athletes compared with controls [odds ratio (OR): 3.536, 95% confidence interval (CI): 1.903–6.571] and elite power athletes (OR: 6.170, 95%CI: 2.206–17.253).ConclusionsOur results suggest that the NRF-2 A/C polymorphism might belong to a growing group of polymorphisms associated with endurance performance at the elite level. However, it is important to replicate these findings in other groups of elite athletes using larger sample sizes.     

Influence of the MCT1-T1470A polymorphism (rs1049434) on blood lactate accumulation during different circuit weight trainings in men and women

ObjectivesTo analyze the effect of the MCT1 T1470A polymorphism (rs1049434) on venous blood lactate levels in men and women, during three different circuit weight training protocols.DesignCross-sectional laboratory study.Methods14 women and 15 men, all caucasian and moderately active, performed three circuit training sessions (Weight Machine Protocol, Free Weight Protocol and Combined Protocol) at 70% of the 15 repetition maximum and 70% of the heart rate reserve, in non-consecutive days. The sessions included three sets of a circuit of eight exercises. Venous lactate measurements were obtained after each set and during the recoveries between sets (i.e. in min 3, 5, 7 and 9). One-way analysis of covariance and one-way analysis of covariance with repeated measures were used to determine differences among genotypes (AA, TA and TT) in lactate levels.ResultsIn men, the AA group had higher lactate values than the TT group in all the measures (p ≤ 0.03) except for the average lactate during the Weight Machine Protocol, in which a borderline significant difference was found (p = 0.07). We did not observe differences across genotypes in females.ConclusionsOur data suggest an influence of the MCT1 polymorphism on lactate transport across sarcolemma in males. Future studies on lactate transport and metabolism should take into account the gender-specific results.     

新辅助放化疗治疗低位进展期直肠癌的临床研究

目的探讨术前辅助放化疗对低位进展期直肠癌治疗效果。方法 47例低位进展期直肠癌患者（cTNMⅡ期和Ⅲ期）,进行术前联合放化疗。放疗每周5d,每次1.8～2Gy,总剂量45～60Gy。同时持续口服卡培他滨1250mg/m2化疗,休息4～8周进行手术。结果新辅助放化疗的急性毒副反应较小,一般为Ⅰ～Ⅱ度反应,全部患者均完成了治疗,其中施行了保肛手术44例（93.6%）,Miles手术3例。肿瘤分期降低明显,术后局部复发率明显下降,仅为4.3%。结论新辅助放化疗能使低位进展期直肠癌肿瘤降期,提高根治性切除率和保肛成功率,降低局部复发率,是低位进展期直肠癌综合治疗的一种有效方法。     

治疗前Naples预后评分对胸段食管鳞癌患者放化疗疗效及预后的影响

目的:探讨治疗前Naples预后评分(NPS)对胸段食管鳞癌接受放化疗患者治疗效果及生存预后的影响。方法:回顾性分析2014年1月至2017年12月在扬州大学附属泰兴人民医院行根治性放疗或放化疗的123例胸段食管鳞癌患者,根据治疗前NPS评分分为0分组(18例)、1或2分组(60例)、3或4分组(45例)。治疗效果采用...