4种黏结剂对牙本质黏结强度的比较研究

目的:比较两种第六代黏结剂-XenoⅢ、AdaperPrompt与两种第五代黏结剂-Singlebond、Singlebond2两两之间黏结强度的差异,为临床选择黏结剂提供参考依据。方法:暴露新鲜拔除的牛牙根牙本质,按照上述4种黏结剂各自的操作要求进行黏结,测试标本的微拉伸强度(μTBS)和剪切强度。结果:XenoⅢ、AdaperPrompt、Singlebond和Singlebond2的微拉伸强度(MPa)依次为:20.87±4.88,24.81±5.24,30.41±3.48,31.61±6.95;剪切强度依次为:14.85±4.26,17.23±2.57,19.18±5.65,20.92±3.73。结论:第五代黏结剂较第六代黏结剂具有更高的黏结强度,推荐使用。     

Antisense Smad2 inhibits high glucose-stimulated production of extracellular matrix in cultured rat glomerular mesangial cells

Transforminggrowthfactor-β1(TGF-β1)is amultifunctionalpolypeptidethatregulatesanum-berofcellularprocesses,includingcellprolifera-tion,differentiation,apoptosis,migration,matrix synthesis,andtheimmuneresponse[1,2].Inchron-icrenaldiseases,TGF-β1isakeymediatorofex-tracellularmatrix(ECM)accumulation[3].Oneof thetargetrenalcellsforTGF-β1isglomerular mesangialcellsthatarecapableofproducingcom-ponentsofECM,suchascollagens,lamininand fibronectin[4,5].Recentstudiesindicatedthatinhi-bitionofT…     

Effects of the AMPA receptor antagonist NBQX on the development and expression of behavioral sensitization to cocaine and amphetamine

 We examined the effect of 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX), an antagonist of the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) subtype of glutamate receptor, on the development and expression of behavioral sensitization to amphetamine and cocaine in rats. A single injection of NBQX (12.5 mg/kg) administered 30 min prior to cocaine during the induction phase (days 1–5) prevented the development of cocaine sensitization, assessed by responsiveness to cocaine challenge on day 8. This NBQX regimen did not affect development of amphetamine sensitization. Two pretreatment injections of NBQX, one 20 min before and one 70 min after amphetamine on each day of the induction phase (days 1–6), did not affect sensitization of stereotypy but prevented sensitization of post-stereotypy ambulatory hyperactivity (both assessed by responsiveness to amphetamine challenge on day 8). The effect of NBQX on ambulatory sensitization was dose-dependent (attenuation with 12.5 mg/kg, complete prevention with 25 mg/kg). In contrast to its effects on development, NBQX (25 mg/kg) did not prevent expression of sensitization to cocaine or amphetamine. NBQX itself exerted no significant effects on locomotor activity in either drug-naive rats or rats that had received either NBQX or amphetamine repeatedly. These findings support a requirement for AMPA receptor stimulation in the development of locomotor sensitization to cocaine and amphetamine, but suggest a different mechanism for sensitization of amphetamine stereotypy. Received: 14 January 1997 / Final version: 24 June 1997     

双头加压螺纹钉贴股骨距内固定治疗股骨颈骨折

在Ｘ光电视下采用双头加压螺纹钉贴股骨距内固定治疗新鲜股骨颈骨折４２例，随访平均２．５年，其中１６例随访３年以上，骨折愈合率９５．２％，骨折不愈合并股骨头缺血性坏死率４．７６％。认为加压螺纹钉贴股骨距内固定可使钉的受力由较大剪应力变为较大轴向力承受，减少骨折处的剪应力，并加压于骨折端能促进骨折愈合。具有操作简单、进钉准确、创伤小、固定牢靠、并发症少等优点。     

外伤性急性颈椎间盘突出症(附19例报告)

本文旨在阐明MRI对急性颈椎间盘突出的诊断价值。19例均有明显的外伤史,X线片无骨折脱位者12例。其中C_(5～6),髓核突出7例,C_(5～6)、C_(1～5),突出5例。有小关节绞锁半脱位者7例,MRI均示损伤间隙有髓核突出。19例均为不全瘫。全部病例经前路椎间盘切除、植骨融合。平均随访15个月,植骨块平均于12周愈合。除1例骨块退出4～5mm外,余位置良好。脊髓功能均有明显恢复。结论:外伤是急性颈椎间盘突出的主要原因,而颈椎间盘突出又是SCIWORA综合征的主要原因。对小关节绞锁半脱位者应考虑同时有椎间盘突出的可能。手术治疗一般效果良好。     

从自由基生物学角度评价鸡肉质量的实验研究

本文把外观健康和非健康的活鸡各20只分成两组,宰后测其肝、腿肌中超氧化物歧化酶(SOD)含量和脂质过氧化产物丙二醛(MDA)水平,发现两组中上述指标值差异显著(P<0.050 ;同时对两组实验鸡胴体在宰后4小时做了感官鉴别,也判断出其品质存在差异。提示体内SOD活性和MDA水平可以反映鸡肉质量,比感官鉴别更具敏感性,同时也可以反映宰前鸡的健康状况。     

氟烷吸入麻醉引起c—fos基因在中枢神经系统的表达与分布

研究氟烷吸入麻醉在中枢神经系统作用部位。应用ｃ－ｆｏｓ基因免疫组织化学方法。ＳＤ大鼠在吸入氟烷浓度为０．７５％．１。５％和２％麻醉１ｈ后，Ｆｏｓ阳性神经元主要分布于端脑；梨状皮层，杏仁核簇，伏核，外侧隔核，终纹麻核、海马ＣＡＩ区，海马回嗅觉小岛；     

剌玫果对烹饪油烟引起小鼠骨髓PCE微核率增高的影响

本文研究了剌玫果对烹饪油烟引起的小鼠骨髓嗜多染红细胞微核率的影响。结果表明，烹饪油烟各实验组的小鼠骨髓嗜多染红细胞微核率明显高于阴性对照组（Ｐ〈０．０１），且呈现剂量－反应关系，剌玫果明显降低烹饪油烟诱发的微核率。     

巨噬细胞杀伤白色念珠菌作用的探讨

本研究经杀菌试验和免疫后保护力试验探讨小鼠巨噬细胞在抗白色念珠菌感染中的作用,结果表明白色念珠菌酵母形体对巨噬细胞杀伤作用的抵抗力及对小鼠的毒力均较菌丝形体强。小鼠体内不同部位巨噬细胞杀伤白色念珠菌的作用不同,脾脏巨噬细胞作用大于腹腔残存巨噬细胞。经白色念珠菌活菌静脉免疫后脾巨噬细胞杀白色念珠菌作用增强,但其对再感染的抵抗力不增强。     

耐热锻炼对人体热暴露时血浆丙二醛和中分子物质含量的影响

本文报告热习服对血浆丙二醛和中分子物质含量的影响。15名健康男子,平均年龄21.8±0.7岁,于平均气温27.3±1.2℃负重行军90min,2周内共锻炼11次(天)。标准热暴露试验对比表明获得了热习服,肛温和心率增值大大降低(P<0.01和P<0.05)。锻炼期前、后标准试验时血浆丙二醛含量降幅分别为29.4%(P<0.01)和30.1%(P<0.01),而中分子物质含量增幅分别为6.3%(P<0.05)和9.2%(P<0.01)。热前、后血浆丙二醛含量较锻炼期前仅分别降低5.5和6.5%(P>0.05),而中分子物质含量分别降低18.3和16.1%(P<0.01),可见,热习服后血浆丙二醛和中分子物质含量没有同步降低。