通用型脊柱内固定系统椎弓根螺钉翻修作用的生物力学研究

目的测试自行设计的通用型脊柱内固定系统(generalspinesystem,GSS)椎弓根螺钉以及SOCON、TSRH和Diapason螺钉置入椎体的拔出力及旋入力矩,评价GSS螺钉的翻修作用。方法将36个正常成人腰椎椎体标本随机分为三组,每组12个椎体(24侧椎弓根)。各组标本每个椎体的每侧椎弓根均先拧入CCD螺钉(直径6.0mm,长45mm),行螺钉拔出试验,测试并记录螺钉的最大旋入力矩和最大轴向拔出力。然后各组标本每个椎体均随机选择一侧椎弓根经原钉道拧入GSS螺钉(直径6.5mm,长45mm);第一组另一侧拧入SOCON螺钉(直径7.0mm,长45mm),第二组另一侧拧入TSRH螺钉(直径7.0mm,长45mm),第三组另一侧拧入Diapason螺钉(直径6.7mm,长45mm)。分别测试螺钉最大旋入力矩及最大轴向拔出力。结果第一组GSS螺钉最大轴向拔出力为CCD螺钉的114%,SOCON螺钉为CCD螺钉的108%;GSS螺钉最大轴向拔出力大于SOCON螺钉,差异无显著性(P>0.05);GSS螺钉最大旋入力矩小于SOCON螺钉,差异无显著性(P>0.05)。第二组GSS螺钉最大轴向拔出力为CCD螺钉的127%,TSRH螺钉为CCD螺钉的64%;GSS螺钉最大轴向拔出力大于TSRH螺钉,差异有显著性(P<0.01);GSS螺钉最大旋入力矩大于TSRH螺钉,差异有显著性(P<0.01)。第三组GSS螺钉最大轴向拔出力为CCD螺钉的122%,Diapason螺钉为CCD螺钉的8     

膨胀式脊柱内固定系统椎弓根螺钉翻修作用的生物力学研究

目的：评价自行设计的膨胀式脊柱同定系统（expansive spinal fixation system，ESFS）的椎弓根螺钉对椎弓根螺钉固定失败后的翻修作用。方法：将30个深低温冰冻的正常成人腰椎体标本随机分为A、B、C三组．每组10个椎体（20侧椎弓根）。各组标本每个椎体的两侧椎弓根均先拧入直径6．0mm、长45mm的CD-Ⅱ螺钉．行螺钉拔出试验，记录螺钉的最大旋入力矩和最大轴向拔出力。然后将CD-Ⅱ螺钉拔出，各组标本每一椎体随机经一侧椎弓根原钉道拧入直径7．0mm、长45mm的ESFS螺钉；A组另一侧椎弓根拧入直径7．0mm、长45mm的CD-Ⅱ螺钉，B组另一侧拧入直径7．0mm、长45mm的TSRH螺钉．C组另一侧拧入直径7．0mm、长45mm的GSS螺钉。分别测试螺钉最大旋入力矩和最大轴向拔出力。结果：A、B、C三组的ESFS螺钉最大轴向拔出力分别为6mm CD-Ⅱ螺钉的113％、110％和112％，而直径7．0mm、长45mm的CD-Ⅱ螺钉、TSRH螺钉和GSS螺钉的最大轴向拔出力分别只有6mm CD-Ⅱ螺钉的80％、82％和88％，各组ESFS螺钉最大轴向拔出力明显高于其它三种螺钉。差异有显著性（P〈0．01）。各组各螺钉最大旋入力矩之间差异无显著性（P〉0．05）。结论：ESFS螺钉具有很好的椎弓根锚固作用及翻修作用。     

聚甲基丙烯酸甲酯强化对骨质疏松椎弓根螺钉固定的生物力学作用

目的探讨聚甲基丙烯酸甲酯 (polymethylmethacrylate,PMMA)骨水泥强化椎弓根螺钉的方法和评价 PMMA强化骨质疏松椎弓根螺钉后的生物力学性质。方法 6具新鲜老年女性胸腰段骨质疏松脊柱标本 (T10～ L5),使用双能 X线骨密度吸收仪测试每个椎体的骨密度,随机取 16个椎体 (32侧椎弓根 ),一侧椎弓根拧入 CCD螺钉,测量最大旋入力偶矩后拔出螺钉作为正常对照组,用 PMMA骨水泥强化椎弓根螺钉作为修复固定组,行螺钉拔出试验;另一侧经导孔直接强化椎弓根螺钉后拔出作为强化固定组,记录三组螺钉的最大轴向拔出力。结果椎体平均骨密度为 (0.445± 0.019)g/cm2;螺钉最大旋入力偶矩为（ 0.525± 0.104） Nm;正常对照组螺钉最大轴向拔出力为 (271.5± 57.3)N;修复固定组为 (765.9± 130.7)N;强化固定组为 (845.7± 105.0)N。 PMMA骨水泥强化或修复骨质疏松椎弓根螺钉后最大抗压力明显高于强化前,差异有非常显著性意义 (P< 0.01)。结论 PMMA骨水泥强化骨质疏松椎弓根螺钉能显著增加螺钉在椎体内的稳固性。     

在同一钉道二次置入颈椎椎体螺钉对螺钉拔出力的影响

目的 :评价在同一钉道二次置入颈椎椎体螺钉对螺钉拔出力的影响。方法 :取5具成人新鲜尸体颈椎标本(C3~C7),游离出25个完整颈椎椎骨。在椎体两侧分别置入直径4.0mm的颈椎椎体螺钉,测量螺钉置入时的最大扭矩,并将两侧的最大扭矩进行比较。随机选取任意一侧的椎体螺钉(即试验组,另一侧即对照组),将其旋出,然后再将螺钉旋入原钉道,再次测量螺钉旋入时的最大扭矩,并与同侧螺钉首次置入时的最大扭矩进行比较。在生物力学试验机上行最大轴向拔出力试验,比较同一椎体两侧螺钉固定的最大轴向拔出力,分析初次旋入扭矩、二次旋入扭矩及最大轴向拔出力之间的关系。结果:试验组最大轴向拔出力为372.86±171.44N,对照组为343.91±169.90N,两者比较差异无统计学意义(P0.05)。试验组螺钉初次置入的最大扭矩为2.47±1.04kgf·cm,对照组为2.35±1.00kgf·cm,两者比较差异无统计学意义(P0.05)。试验组螺钉二次置入的最大扭矩为1.36±0.77kgf·cm,与试验组螺钉初次置入的最大扭矩比较差异有统计学意义(P0.05)。对照组螺钉置入的最大扭矩与最大轴向拔出力显著相关(r=0.784,P=0.00),试验组螺钉初次置入的最大扭矩与二次置钉的最大轴向拔出力显著相关(r=0.800,P=0.00),试验组螺钉二次置入的最大扭矩与最大轴向拔出力显著相关(r=0.732,P=0.00)。结论 :在同一钉道二次置入颈椎椎体螺钉时的最大扭矩显著减小,但螺钉的最大拔出力并无明显减小,因此,当需要二次置钉时,在原钉道未被破坏的情况下,理论上可以选择将原螺钉旋入原钉道。     

L_5、S_1前路经椎弓根螺钉固定的生物力学研究

目的探讨L5、S1前路经椎弓根螺钉固定生物力学特性。方法 7具完整新鲜尸体腰骶段(L5、S1)脊柱标本,双能X线骨密度测量后排除严重骨质疏松者,分解成两个独立完整椎体(L5、S1)。每个椎体植入前路椎弓根螺钉(ATPS)、后路椎弓根螺钉(PTPS)和椎体螺钉(TVS),对置入的3种螺钉进行旋入扭矩和抗拔出力试验,比较3种螺钉固定方式的最大扭矩和轴向拔出力。结果 L5、S1的平均最大扭矩:ATPS为(1.25±0.01)N·m,PTPS为(1.35±0.01)N·m,TVS为(0.40±0.01)N·m;ATPS和PTPS之间差异无统计学意义(P0.05),ATPS、PTPS与TVS间差异有统计学意义(P0.05)。L5、S1的平均最大拔出力:ATPS为(1 630±65)N,PTPS为(1 730±60)N,TVS为(680±50)N;ATPS和PTPS之间差异无统计学意义(P0.05),ATPS、PTPS与TVS之间差异有统计学意义(P0.05)。螺钉旋入最大扭矩与螺钉拔出力呈正相关性。结论 L5、S1ATPS和L5、S1PTPS两种固定的平均最大扭矩和平均最大拔出强度差异并不明显,但均大于TVS固定。L5、S1ATPS固定有较好的生物力学优势。     

可灌注骨水泥椎弓根螺钉的生物力学研究

目的 探讨可灌注骨水泥椎弓根螺钉(novel perfusional pedicle screw,NPPS)在骨质疏松椎体内的生物力学稳定性.方法 选取平均年龄73岁的完整湿润脊柱标本(T11～L5)6具,共42个椎体,平均骨密度为(0.696±0.14)g/cm2.所有椎体均任取一侧椎弓根置入可灌注螺钉后,使用配套的骨水泥推杆和灌注筒向椎体内灌注骨水泥2ml,对侧椎弓根置入常规螺钉,作为对照组.随机选取3个椎体,剖开椎体观察骨水泥分布情况.余39个椎体随机分成3组,每组13个,分别行最大轴向拔出力、最大旋出力矩、周期抗屈试验.另取10个可灌注螺钉和10个对照组螺钉行三点弯曲实验.结果 所有椎体均没有观察到骨水泥渗漏.可灌注螺钉的最大轴向拔出力为(760±178)N,对照组为(355±87)N;可灌注螺钉的最大旋出力矩为(1.347±0.377)N·m,对照组为(0.488±0.205)N·m.4枚(4/13,占30.8%)可灌注螺钉发生松动,其平均载荷为(150±46)N;未松动的螺钉中,松动位移半均(0.661±0.289)mm,对照组中所有的螺钉在最大负荷介于50～200 N时开始松动(位移>2.000 mm),平均载荷(104±35)N.可灌注螺钉的平均极限弯曲载荷为(3082±144)N,对照组螺钉为(3357±263)N.结论 可灌注椎弓根螺钉,结合骨水泥推杆和灌注筒能有效控制骨水泥渗漏,明显增强椎弓根螺钉在骨质疏松椎体内的稳定性.     

强化膨胀式椎弓根螺钉翻修作用的生物力学评价

目的测试骨水泥强化膨胀式椎弓根螺钉(augmentation expansive pedicle screwfixa-tion with polymethyl methacrylate,AEPS),未强化的膨胀式椎弓根螺钉(expansive pedicle screw,EPS),CDH椎弓根螺钉翻修后的最大轴向拔出力,评价AEPS螺钉的翻修效应。方法24个新鲜小牛腰椎随机分成三组,AEPS组、EPS组、CDH组,每组8个椎体,三组椎体的椎弓根处均预先植入直径6.5mm CDH螺钉,拔出螺钉造成螺钉松动脱出的脊柱模型,然后分别植入AEPS、EPS、CDH螺钉,再次拔出螺钉,记录翻修后最大轴向拔出力。结果AEPS、EPS、CDH螺钉翻修后的最大拔出力分别为(2723.3±565.4)、(2216.3±475.6)和(1321.4±346.7)N,AEPS和EPS螺钉最大拔出力均显著高于CDH螺钉(P<0.05),AEPS轴向拔出力高于EPS螺钉,但差异无统计学意义(P>0.05)。结论AEPS与EPS螺钉具有相当的翻修作用。     

骨密度对椎弓根螺钉系统固定的影响之生物力学研究

目的：探讨骨密度（ＢＭＤ）对椎弓根螺钉系统固定的影响。方法：采用６具新鲜腰段脊柱标本，应用ＤＥＸＡ测试每个椎体的ＢＭＤ，并游离成单个完整椎体标本，按ＢＭＤ０．９ｇ／ｃｍ２为正常值的最低限。将标本分为正常组和骨质疏松组。按标准操作安置Ｄｉｃｋ钉，应用生物力学方法，测试螺钉最大轴向拔出力和矢状面摆动１°～５°时的弯矩、旋入螺钉时的最大扭力矩及螺钉拔出过程中的应变、位移和能量吸收率。结果：正常组平均ＢＭＤ为１．０２±０．１２ｇ／ｃｍ２，骨质疏松组为０．７１±０．１６ｇ／ｃｍ２，前者最大轴向拔出力和弯矩分别为１０６２．８±７２．２Ｎ、２．６Ｎ·ｍ，后者为２３２±９２．４Ｎ、０．４９Ｎ·ｍ。ＢＭＤ与最大拔出力有正相关关系（ｒ＝０．９０７）。旋入螺钉时的最大扭力矩与轴向拔出力密切相关（ｒ＝０．８９４）。螺钉在椎体内摆动５°时正常组承受的最大弯矩为２．６Ｎ·ｍ，骨质疏松组为０．４９Ｎ·ｍ。结论：ＢＭＤ对椎弓根螺钉的稳定性具有重要影响，是预测螺钉牢固程度的重要指标，术前应常规测试脊柱的ＢＭＤ，尤其对于老年人更为重要，最大扭力矩是术中预测螺钉稳定性的一个较好的力学指标。     

椎弓根螺钉不同翻修方法的生物力学研究

目的：研究增加螺钉直径和长度、钉孔内植骨以及聚四氟乙烯膨胀螺栓强化这四种椎弓根螺钉翻修方法所各自产生的最大轴向拔出力和最大置入扭矩变化，以确定椎弓根螺钉的最佳翻修方法。方法：将6具成人T10～L5椎体标本，分为：(1)增加椎弓根螺钉直径组，(2)延长椎弓根螺钉长度组，(3)增加直径 延长长度组，(4)植骨组，(5)聚四氟乙烯膨胀螺栓组，(6)退出后再置组。将最初置入的直径5．0mm、长40mm螺钉时所测得的最大扭矩和最大轴向拔出力作为对照组数据；记录翻修螺钉最大扭矩和最大轴向拔出力与相应对照组数据之间的变化量，各组之间结果行统计学分析。结果：在增加螺钉直径和(或)长度的方法中，当螺钉直径增加2mm且长度增加10mm时，扭矩和最大轴向拔出力的增加最明显，分别为37．06％和18．22％；螺钉直径增加2mm，扭矩增加20．15％，最大轴向拔出力增加19．99％；螺钉直径增加1mm、长度增加5mm，扭矩增加19．23％，最大轴向拔出力增加10．07％；螺钉长度单纯增加5mm与10m，扭矩分别下降32．80％和14．02％，最大轴向拔出力分别下降27.36％和增加43．25％；钉孔内植骨后再置入螺钉，扭矩和轴向拔出力分别下降了14．99％和29．34％；聚四氟乙烯膨胀螺栓强化后再置入螺钉，扭矩显著增加，而轴向拔出力下降了37．40％；螺钉退出后再置，扭矩下降了34．22％。结论：螺钉直径增加2mm对椎弓根螺钉翻修最有效，其次为螺钉直径增加1mm、长度增加5mm。钉孔内植骨的方法不可取。聚四氟乙烯膨胀螺栓强化的翻修方法需进一步研究。     

椎弓根外侧壁破坏对脊柱椎弓根钉内固定生物力学强度的影响

目的探讨椎弓根螺钉内固定术中椎弓根外侧壁穿破后,向内侧重新定向后打入矫正螺钉(redirectionally correctly placed pedicle screw,RS)对脊柱内固定的生物力学影响。方法 6只市售家猪,体重95~105 kg,雌雄不限。取其新鲜腰椎标本30个(L1~5椎体各6个)。每个椎体标本一侧椎弓根打入最佳位置的椎弓根螺钉(optimu m placed pedicle screw,OS);对侧在椎弓根和椎体连接处破坏椎弓根外侧壁,然后拧入RS螺钉。分别测量每个椎弓根钉最大拧入扭矩、锁紧扭矩、螺钉松动力和轴向拔出力。结果 OS螺钉和RS螺钉的最大拧入扭矩分别为(111.4±8.2)N·cm和(78.9±6.4)N·cm,差异有统计学意义(Z=3.038,P=0.002);OS螺钉和RS螺钉的锁紧扭矩分别为(86.3±7.7)N·cm和(59.7±5.3)N·cm,差异有统计学意义(Z=2.802,P=0.005)。OS螺钉和RS螺钉的螺钉松动力分别为(76.3±6.2)N和(53.0±5.8)N,差异有统计学意义(Z=2.861,P=0.004);OS螺钉和RS螺钉的轴向拔出力分别为(343.0±12.6)N和(287.0±10.5)N,差异有统计学意义(Z=2.964,P=0.003)。结论与OS相比,椎弓根外侧壁破坏后RS在最大拧入扭矩、锁紧扭矩、螺钉松动力和轴向拔出力方面均显著降低,强化螺钉可能是较好的补救方法。     

2015年乳腺癌辅助化疗进展

【摘要】〓乳腺癌是危害我国女性健康的头号杀手,尽管近年来辅助化疗的研究进展突飞猛进,但临床中仍有不少问题未能明确,如辅助化疗的合适人群、化疗的开始时间、蒽环及紫杉类的地位和用法、强化维持治疗的作用、疗效及预后的生物标志物等。本文结合乳腺癌辅助化疗在临床上的常见问题和2015年各大乳腺癌会议阐述乳腺癌辅助化疗的最新进展。     

西宁地区烧伤病人动脉血气分析观察

对高海拔地区的27例烧伤病人动脉血气变化进行了分析和观察。结果证明:无论是存活病人还是死亡病人伤后均存在有低氧血症问题。并且在死亡病人和烧伤合并吸入性损伤病人其低氧血症的发生早于单纯烧伤病人。提示:吸入性损伤病人应立即行气管切开术以保障氧气供给,单纯烧伤病人可常规吸氧以维持正常血 PaO_2,ARDS 均发生在合并吸入性损伤的病人,高频喷射通气技术对纠正低氧血症有一定效果。     

Controversies in Fistula in Ano

Managing a complex fistula in ano can be a daunting task for most surgeons; largely due to the two major dreaded complications—recurrence & fecal incontinence. It is important to understand the anatomy of the anal sphincters & the aetiopathological process of the disease to provide better patient care. There are quite a few controversies associated with fistula in ano & its management, which compound the difficulty in treating fistula in ano. This article attempts to clear some of those major controversies.     

β-半乳糖苷酶在体内外成骨细胞中的表达

目的 研究β—半乳糖苷酶(β—gal)在成骨细胞中的表达状况，为阐明MorquioB综合征的发病机制提供依据。方法 裸鼠各器官和骨组织标本行X-gal染色检测。抽取羊和人骨髓行骨髓基质细胞(BMSCs)培养，分为4组：I：Adv-hBMP-2转染组；Ⅱ：Adv—β—gal转染组；Ⅲ：未转染组；Ⅳ：地塞米松诱导组。分别行X-gal染色和RT-PCR检测β—gal的表达。结果 裸鼠骺板两侧、骨膜内面及松质骨的成骨细胞和破骨细胞可见多量β—gal的表达。未转染BMSCs组有少量β—gal的表达，其他3组细胞的β—gal表达增高。结论成骨细胞和破骨细胞可表达多量β—gal，该两种细胞的β—gal缺乏可能是MorquioB综合征骨骼异常的直接原因。     

Alterations in T-Cell Subset Frequency in Peripheral Blood in Obesity

Background: Obesity affects the regulation of immune and inflammatory responses. This study characterizes differences in peripheral blood lymphocyte phenotype in obese humans. Methods: Frequencies of lymphocyte subsets among peripheral blood mononuclear cells were compared between 10 obese (BMI ≥35) and 10 lean subjects, as determined by antibodies directed against cluster differentiation (CD) markers. Results: Obese patients demonstrated an increased frequency of CD3+CD4+ T-cells (mean difference 12%, P=0.004), a decreased frequency of CD3+CD8+ T-cells (mean difference 9.4%, P=0.016) and an increased frequency of CD3+CD8+CD95+ T-cells (mean difference 13.3%, P=0.032). No other differences among T-cell or monocyte subsets were noted. Conclusions: Obesity is associated with alterations in frequencies of peripheral CD4+ and CD8+ T-cells and aberrations in the expression of CD95 among CD8+ T-cells. These data suggest both CD4+ and CD8+ T-cell compartments, as well as the regulation of CD95 expression on CD8+ T-cells, as targets for further study into obesity's effects on the immune system.     

Smoking-Attributable mortality in Spain in 2016

IntroductionSmoking-attributable mortality (SAM) is a valuable indicator that can be used to characterize the course and health burden of the smoking epidemic. The aim of this paper was to estimate SAM in Spain in 2016 in the population aged 35 and over, using the best available evidence.MethodsA smoking prevalence-dependent analysis based on the estimation of population-attributable fractions was performed. Smoking prevalence (never, former, and current smokers) was calculated from a combination of the Spanish Health Survey (2016) and the European Health Survey (2014); the relative risk of death among current and former smokers was taken from the follow-up of various cohorts; and mortality rates were obtained from National Center for Statistics data. SAM estimates are presented globally, and by sex, age groups, and major disease categories: cancer, cardiometabolic diseases and respiratory diseases.ResultsIn 2016, 56,124 deaths were attributed to tobacco consumption, 84% in men (47,000), and 50% in the population aged over 74 (27,795). Overall, 50% of SAM was due to cancer (28,281), 65% of which was lung cancer. One in 4 attributable deaths (13,849) occurred before the age of 65.ConclusionsOne in 7 deaths in Spain in 2016 were attributable to smoking. This estimation of SAM clearly highlights the great impact of smoking on mortality in Spain, mainly due to lung cancer and chronic obstructive pulmonary disease.     

Fluid-phase transcytosis in the primate epididymis in vitro and in vivo

Ligated tubules from the corpus epididymidis of men and monkeys were incubated in medium containing horseradish peroxidase (HRP) as a marker for fluid-phase endocytosis. HRP was localized by light and electron microscopy after 0, 15, 30 and 60 min of incubation. Movement between the cells was prevented by tight junctions, but bypass of this barrier was apparently achieved by an intracellular vesicular mechanism leading to a time-dependent appearance of HRP in the lumen. Uptake of HRP into basal cells and capture by the lysosomal apparatus of principal cells were also observed. HRP-filled vesicles also appeared in the basal, mid and apical cytoplasm of epithelial cells in the caput 1 h after injection of the tracer into the epididymal circulation of the monkey, suggesting that this pathway also operates in vivo.     

Surgical management of ductal carcinoma in situ in Australia in 1995

Background: In the present paper we describe the presentation and management of ductal carcinoma in situ (DCIS) of the breast in women in Australia in 1995. This representative, national data set provides a historical comparator for studies examining DCIS management that follow. Methods: Surgeons identified by population‐based cancer registries as having treated a new diagnosis of DCIS between 1 April and 30 September 1995 completed a questionnaire on the presentation and management of each case. Results: Two hundred and five surgeons supplied treatment details on 418 DCIS tumours in 415 women . Half of all tumours were detected at BreastScreen clinics and a further 25% were detected at other mammography centres. Twenty‐six percent of tumours were palpable at presentation, 33% were multifocal and 55% were high grade (including comedocarcinoma). Breast conserving therapy (BCT) rather than mastectomy was utilized in 260 (62%) of cases. Tumours that were of low grade, small in size and not multifocal were more likely to be treated by BCT. Surgeons seeing six or more DCIS cases in the 6‐month period were more likely to utilize BCT. Of the conservatively treated cases, 22% were referred for a radiation oncology consultation. The most common reasons for treating DCIS with mastectomy were that the tumour was too extensive or multifocal (63%), it extended to margins of the specimen (42%), or patient concerns about recurrence (34%). Conclusions: In 1995 the majority of DCIS was treated with breast conserving surgery alone. Surgeons treating more DCIS cases were more likely to perform conservative surgery than surgeons treating only one DCIS case in the study period.     

MicroRNAs in hepatic pathophysiology in diabetes

MicroRNAs(miRNAs or miRs) are small approximately 22 nucleotide RNA species that are believed to regulate diverse metabolic and physiological processes.In the recent past,several reports have surfaced that demonstrate the role of miRNAs in various biological processes and numerous disease states.For a disease as complex as diabetes,the emergence of miRNAs as key regulators leading to the disease phenotype has added a novel dimension to the area of diabetes research.On the other hand,the liver,a metabolic hub,contributes in a major way towards maintaining normal glucose levels in the body as it can both stimulate and inhibit hepatic glucose output.This equilibrium is frequently disturbed in diabetes and hence,the liver assumes special significance considering the correlation between altered hepatic physiology and diabetes.While the understanding of the mechanisms behind this altered hepatic behavior is not yet completely understood,recent reports on the status and role of miRNAs in the diabetic liver have further added to the complexities of the knowledge of hepatic pathophysiology in diabetes.Here,we bring together the various miRNAs that play a role in the altered hepatic behavior during diabetes.