下颌第二磨牙C形根管

序言自廿世纪后半叶开始,科学技术发展迅速,可以说是日新月异。据报道,医学知识的更新率五年内可能达到50%,这一统计数据不一定精确,但至少说明了两个问题:其一,医学知识更新速度很快;其二,在部分医学领域的知识更新率可能达到甚至超过50%。这说明我们在学校学习的书本知识于参加工作后需要不断更新,才能与时俱进,跟上时代前进的步伐。在生命科学领域,发展最快的应该是生物学。继人类基因组计划完成后,蛋白质组学计划已提上议事日程,目前又有大批科学家正在努力探索与疾病基因相关的知识,还有干细胞研究也在不断取得进展。生物学的发展必然…     

移动医院的创建及其在国际救援中的应用

2004年底苏门答腊岛近海发生9级地震和人类历史上最严重的海啸,中国参加了国际救援活动.中国国际救援队创建了移动医院,在亚齐省班达亚齐市实施救援.移动医院的编制为26名医务人员,下分指挥组、分类检伤组、现场救治组、外科救治组、内科救治组、医技组、留观后送组.展开后占地约200平方米.开展了巡诊、院内救治、卫生防疫、灾后医院重建,及培训灾区当地医务人员等工作.总结出如下经验:应加强战役后方,应将所有信息数字化,培训复合型人才十分重要.移动医院是救援队实施救援的重要手段和有效方式,尤其在重大灾害中抢救危重伤员时可发挥重要作用.     

Two novel gastric cancer-associated genes identified by differential display

AIM To clone novel gastric cancer-associated genes and investigate their roles in gastric cancer occurrence.METHODS A method called differential display was used which allows the identification of differentially expressed genes by using PAGE to display PCR-amplified cDNA fragments between gastric cancer cells and normal gastric mucosa cells. These fragments were cloned into plasmid vector pUC18. Homology analysis was made after sequencing these fragments.RESULTS Two novel genes were identified compared with sequences from GenBank. One was registered with the AD number AF 051783. In situ hybridization showed that these two novel genes expressed specifically in gastric cancer tissues.CONCLUSION The two novel genes obtained by differential display were confirmed to be gastric cancer-associated genes using in situ hybridization.     

对LASIK手术中游离瓣的处理

目的 探讨LASIK手术中出现游离瓣的原因及处理方法。方法 对1500例（2900眼）LASIK手术中出现的9例（9眼）游离瓣进行随访观察。结果 术后1天，9例（9眼）角膜瓣复位良好，边缘整齐，瓣下干净。术后3天取出角膜接触镜，其中7眼视力≥1．0，2眼视力≥0．6。1月视力均达到最佳矫正视力，6月～1年视力稳定。结论LASIK手术中出现游离瓣只要及时正确处理，仍能获得最佳矫正视力。     

接触性热痛诱发电位检测方法的建立

目的 建立接触性热痛诱发电位(CHEP)的检测方法,估测介导此诱发电位的外周神经传导速度.方法 受试者取卧位,应用CHEP刺激器,于两个强度水平(49.5℃和54.5℃)应用可调节脉冲,刺激部位为鱼际肌、手背、前臂的掌侧面.受试者在每次刺激后,按照视觉模拟评分标准对刺激强度分级.以Keypoint仪器记录,记录点为Cz和Pz.测定刺激强度和疼痛分级的关系、诱发电位的主要成分及外周神经传导速度.结果 刺激强度和疼痛分级的关系为:49.5℃和54.5℃刺激鱼际肌皮肤,疼痛分级分别为(3.2±0.3)、(4.4±0.5)级;54.5℃刺激手背和前臂掌侧面皮肤,疼痛分级分别为(6.3±0.8)、(7.2±0.5)级.于记录点记录到3个主要成分:Cz/N550、Cz/P750和Pz/P1000.介导此诱发电位的外周神经传导速度分别为(12.9±7.5)、(1.7±0.4)m/s,分别与Aδ纤维和C纤维的传导速度相对应.结论 CHEP能较为稳定、可靠地引出,介导此诱发电位的外周神经为Aδ纤维和C纤维.     

A Study of Early Pregnancy Factor Activity in Preimplantation

PROBLEM and METHOD: Early pregnancy factor (EPF), an Immunosuppressive substance, which appears in pregnant women's sera 48 h after fertilization, is a kind of pregnancy-specific protein. To determine whether the EPF activity could be a super early indicator of pregnancy, we used rosette inhibition assay to detect EPF activity in the sera, collected from 70 women 2–7 days after ovulation intending to conceive monitored by ultrasonography. Simultaneously we selected 40 non-pregnant sera and 12 early-pregnant sera as negative control and positive control, respectively. RESULTS: The results of this study demonstrated that EPF activity is detected in 35 women's sera out of 70 women within 2–7 days after ovulation, and 28 women out of the 35 were pregnant, which was known by follow-up, and 7 were not pregnant, possibly due to either false positive results or embryo loss because of preimplantation failure, thus causing no pregnancy. The other 35 out of 70 had no EPF activity and 34 of them were not pregnant, which was known by follow-up, but one case became pregnant, which was false negative result. Our study showed that diagnosis of the super early pregnancy could be made by detecting EPF activity in maternal serum within the time of preimplantation. The accuracy of pregnancy diagnosis by this method is 88.6%, with a false negative rate of 3.4% and a false positive rate of 17.1%. The β-HCG level was measured from the above 70 women's sera in order to contrast EPF activity. All of the sera collected 2–6 days following ovulation indicated that there were lower β-HCG values in very early pregnancy (≥a5 mIU/ml). On the seventh day after ovulation, EPF activity was detected in 11 out of 15 sera with only 2 of them with a b-HCG level that reached or slightly surpassed that of the early pregnancy diagnosis (5 mIU/ml and 5.4 mIU/ml, respectively). This demonstrated that β-HCG is not the earliest signal of pregnancy; otherwise the EPF activity is one that appears 2–6 days earlier than β-HCG appears. We measured the progesterone level of the 48 sera from the 70 collected above within 2–7 days postovulation and found most of them reached the level of progesterone in the luteal phase (7.5–98.3 nmol/L). This indicated that ovulation had taken place in these women, which was in accordance with observations by ultrasonography. CONCLUSIONS: Our study showed that diagnosis (of 88.6%) of super early pregnancy could be made with an accuracy of 88.6% by detecting EPF activity in maternal serum within 2-days after ovulation. This offers a basis for pregnancy diagnosis for the women who attempt to terminate their pregnancy safely or who conceive unexpectedly, and it contributes to family-planning.     

树突状细胞在胆囊癌组织内浸润的研究

目的通过对胆囊癌组织中树突状细胞浸润情况的研究,阐述树突状细胞与肿瘤免疫之间的关系。方法采用免疫组化SP法。结果树突状细胞在胆囊癌组织的浸润程度与年龄、性别和病理组织学类型无关,与病理分化程度呈负相关关系(P<005)。结论树突状细胞在胆囊癌组织的浸润程度与病理分化程度、Nevin分期、肝浸润及淋巴结转移存在密切的关系。树突状细胞的定量检测可作为估计胆囊癌预后的标志。     

2450MHz介质复介电常数的测量

目的测量2450MHz频率下蒸馏水和不同浓度NaCl溶液的复介电常数,用以判定系统的可靠性和稳定性.方法根据微扰法得到复介电常数的测量公式,然后通过实验对已知参数的蒸馏水和NaCl溶液进行测量,并计算其复介电常数和电导率,验证计算结果的可靠性和稳定性.结果对计算结果进行统计分析和误差分析,其均值、标准差和变异系数表明,最终结果可与M.I.T标准较好地吻合.结论这种系统可较好地测量2450MHz频率下高损耗介质的复介电常数,测量系统的主要误差是由介质体积的误差引起的,因此精确测量介质体积是测量生物组织等高损耗介质复介电常数的关键.     

人类白细胞抗原-G突变体cDNA克隆及在K562细胞上的表达

目的：克隆人类白细胞抗原-G(Human leukocyte antligen-G，HLA-G)突变体cDNA，并使其在HLA-I类阴性的K562细胞上获得稳定表达，为研究配-受体之间的识别机制奠定基础。方法：用RT-PCR方法从人子宫蜕膜组织扩增出HLA-GcDNA，得到全长HLA-GPCR产物后，用桥式PCR方法进行定点点突变，将突变的目的基因亚克隆于逆转录，将突变的目的基因亚克隆于逆转录mG-pLNCX表达载体，采用感染的方法将重组质粒转入K562细胞，最后经G418筛选及有限稀释，利用单克隆抗体W6/32进行FACS及mRNA检测，观察HLA-G突变体在靶细胞表面的表达。结果：HLA-G突变体分子在经mG-pLNCX转染的靶细胞表面获得稳定高表达。结论：成功构建了mG-pLNCX表达载体，并使HLA-G突变体分子在HLA-I类阴性的靶细胞K562细胞上获得稳定表达。     

葛花、枳椇子及其配伍对小鼠急性酒精性胃黏膜损伤的保护作用及机制

目的 探讨葛花、枳椇子及其配伍对急性酒精性胃黏膜损伤的改善作用,为进一步开展葛花、枳椇子及其配伍防治酒精致多脏器损伤奠定基础。方法 采用多次灌胃给予56%红星二锅头白酒（15 mL·kg^-1）建立小鼠急性酒精性胃黏膜损伤模型,将120只ICR雄性小鼠随机分为空白组、模型组、奥美拉唑组（0.026 g·kg^-1）、葛花-枳椇子（配伍）高、中、低剂量组（29.2、14.6、7.3 g·kg^-1）、葛花组（19.5 g·kg^-1）、枳椇子组（19.5 g·kg^-1）共8个组,每组15只,动物适应性喂养1周后,按10 mL·kg^-1预给相应药物3 d,从第4天开始,给药1 h后按15 mL·kg^-1灌胃二锅头白酒,空白组给予相同体积去离子水,记录小鼠醉酒和醒酒时间,连续给药给酒3 d,末次给药1 h后摘眼球处死;气相色谱仪测定各组小鼠血清中乙醇体积分数,紫外-可见分光光度计检测各组小鼠胃黏膜中乙醇脱氢酶（ADH）活性;苏木素-伊红（HE）染色观察胃黏膜病理变化;酶联免疫吸附测定法（ELISA）检测各组小鼠血清中炎症因子含量;实时荧光定量聚合酶链式反应（Real-time PCR）检测核转录因子-κB（NF-κB）p65和NF-κB抑制蛋白α（IκBα）mRNA表达。结果 与正常组比较,模型组血清中白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）含量升高（P<0.05）,胃黏膜组织NF-κB p65 mRNA表达升高（P<0.01）,IκBα mRNA表达降低（P<0.01）;与模型组比较,奥美拉唑组、配伍高、中剂量组、葛花组醉酒时间延长（P<0.05）,配伍高、中剂量组醒酒时间缩短（P<0.05）,配伍高剂量组血清中乙醇体积分数降低（P<0.05）,奥美拉唑组、配伍高、中剂量组胃黏膜中ADH活性升高（P<0.05）,配伍各剂量组、葛花组肉眼损伤评分降低（P<0.05）,奥美拉唑组、配伍各剂量组、葛花组病理损伤评分降低（P<0.01）,各给药组血清中IL-6表达降低（P<0.05）,奥美拉唑组、配伍各剂量组、枳椇子组血清中IL-1β表达降低（P<0.05）,配伍高、中剂量组血清中TNF-α表达降低（P<0.05）,各给药组胃黏膜组织NF-κB p65 mRNA表达降低（P<0.05）,奥美拉唑组、配伍各剂量组胃黏膜组织IκBα mRNA表达增加（P<0.05）;与高剂量组比较,配伍低剂量组与枳椇子组醉酒时间缩短（P<0.01）,葛花、枳椇子组醒酒时间延长（P<0.01）,配伍中、低剂量组、葛花组、枳椇子组血清中乙醇体积分数升高（P<0.05）,配伍中、低剂量组、枳椇子组肉眼损伤积分增加（P<0.05）,配伍中、低剂量组、葛花组、枳椇子组病理损伤积分增加（P<0.01）,配伍低剂量组、葛花组、枳椇子组血清中IL-1β含量升高（P<0.01）,葛花组与枳椇子组胃黏膜组织IκBα mRNA表达量降低（P<0.05）;与配伍中剂量组比较,枳椇子组醉酒时间缩短（P<0.05）,葛花组醒酒时间延长（P<0.05）,葛花组、枳椇子组病理损伤积分增加（P<0.01）,配伍低剂量组、葛花组、枳椇子组血清中IL-1β含量升高（P<0.05）;与配伍低剂量组比较,枳椇子组病理损伤积分增加（P<0.05）。结论 葛花、枳椇子及其配伍能起到对小鼠急性酒精性胃黏膜损伤的防治作用,可能与抑制胃黏膜NF-κB信号通路的表达有关,且配伍高剂量组药效最佳。