前尿道代后尿道成形术治疗男性复杂性后尿道狭窄

目的探讨长段复杂性后尿道狭窄治疗新方法。方法采用分期前尿道代后尿道成形术治疗3例复杂性后尿道长段狭窄（6．5—10．0cm）患者。第一期行阴茎转位尿道端端吻合术，术后3—6个月行二期阴茎伸直、尿道会阴造口术，6个月后行第三期前尿道成形术（Johanson Ⅱ期尿道成形术）。结果例1术后排尿通畅，膀胱尿道造影检查示尿道通畅，双侧输尿管返流近消失，最大尿流率18．8ml／s，随访2年，最大尿流率18ml／s，无剩余尿。例2术后排尿通畅，最大尿流率19．5ml／s，无剩余尿，尿道扩张可顺利通过22F尿道探子。例3经会阴一耻骨联合径路行第一期阴茎转位尿道端端吻合术、尿道直肠瘘、尿道会阴瘘切除、修补术，术后尿道直肠瘘及尿道会阴瘘治愈，但因耻骨联合切口感染致吻合口狭窄，有待进一步治疗。结论分期前尿道代后尿道加前尿道重建方法是治疗男性长段复杂性尿道狭窄的有效方法。     

过量氟化物导致大鼠腰椎黄韧带退变与骨化

[目的]研究氟化物在黄韧带骨化中可能的作用机理。[方法]36只雄性SD大鼠，实验组饮用含NaF（质量分数为1014）蒸馏水，分别于3个月及6个月时，检测骨密度，血清、骨组织标本中Ca、P^3＋、Mg、Zn、Cu、Fe、F^-含量和血清碱性磷酸酶（ALP）活性；行大鼠腰段标本X线检查后组织病理观察。[结果]3个月实验组10只大鼠中6只出现氟斑牙：6个月实验组均出现氟斑牙，且大鼠中轴骨骨密度显著增加（P〈0．05）。X线检查，6个月实验组中有4只可见黄韧带嵴状骨化影。病理观察，3个月实验组大鼠黄韧带呈退行性改变；6个月实验组部分黄韧带骨化，骨化类型以膜内骨化为主。[结论]过量氟化物可造成SD大鼠腰椎黄韧带的退变、骨化，在黄韧带的骨化中可能起重要作用。     

Mycophenolate Mofetil Use Is Associated with Decreased Risk of Late Acute Rejection in Adult Liver Transplant Recipients

Mycophenolate mofetil (MMF) used in a triple-drug regimen has been shown to decrease acute rejection rates, compared to a double-drug regimen. The impact of MMF on late acute rejection (LAR) episodes has not been well described. To investigate the risk of LAR (rejection > or = 6 months post-transplantation) data from the Scientific Registry of Transplant Recipients (SRTR) were used. We studied adult primary liver transplant recipients transplanted between June 1, 1995, and April 30, 2004, with hepatitis C virus (HCV) (n = 3356), hepatitis B virus (HBV) (n = 550) or a nonviral (n = 5740) primary cause of liver disease who were recorded as receiving continuous 3-(MMF + Tacro + steroids) versus 2-drug (Tacro + steroids) therapy for at least 6 months immediately post transplantation. Kaplan-Meier analysis showed significantly lower LAR rates 4 years post-transplant in 3- versus 2-drug HCV, HBV and nonviral disease patients. Multivariate regression confirmed 3- versus 2-drug therapy to be associated with a decreased risk of LAR. Late graft survival was significantly lower at 4 years post-transplant for patients with LAR 6-12 months post-transplantation versus patients with early rejection (78.0% vs. 87.0%, p < 0.001) and no rejection (88.1%, p < 0.001). Three-drug versus 2-drug therapy for a minimum of 6 months may offer a better treatment strategy to avoid the consequences and expense of LAR episodes.     

Bombesin improves survival from methotrexate-induced enterocolitis.

OBJECTIVE: The authors determined whether bombesin could improve survival from methotrexate (MTX)-induced enterocolitis. SUMMARY BACKGROUND DATA: Bombesin prevents gut mucosal atrophy, which is produced by feeding rats an elemental diet. Administration of MTX produces a lethal enterocolitis in rats fed an elemental diet. METHODS: On treatment day 0, 60 rats were divided randomly into three groups and fed an elemental diet (Vivonex TEN, Sandoz, Minneapolis, MN) as the only source of nutrition. Groups were subdivided further to receive either saline or bombesin (10 micrograms/kg, subcutaneously, three times a day) beginning either on day 0 or day 14. Methotrexate (20 mg/kg, intraperitoneally) was given to all rats 14 days after the start of an elemental diet. RESULTS: Bombesin prevented the mucosal atrophy in the ileum produced by the elemental diet and significantly decreased mortality in rats given MTX (whether given as a pretreatment or at the time of MTX administration). CONCLUSION: Bombesin significantly improved survival in a lethal model of MTX-induced enterocolitis, possibly by maintaining gut mucosal structure. Administration of bombesin to patients receiving chemotherapy may be clinically useful in preventing the severe enterocolitis induced by various chemotherapeutic agents.     

地塞米松对布比卡因诱导小鼠神经元毒性的影响

Objective To investigate the effect of dexamethasone on the toxicity of bupivacaine in murine neurons.Methods Murine neuroblastoma cell line N2a was obtained from ATCC cell bank (USA). The cells were cultured in 10% fetal cow serum/MEM culture medium and divided into 4 groups voup I control (Con); group II bupivacaine ( Bup); group Ⅲ dexamethasone (Dex) and group IV Dex + Bup. The culture medium contained bupivacaine 900 μmol/L in group Bup and dexamethasone 1 μmol/L in group Dex respectively. In group Dex + Bup ( IV ) Bup was added to the culture medium with a final concentration of 900 μmol/L at 12 h after pretreatment with Dex 1 μmol/L. The cells were inoculated in 24 well plates (0.5 ml in each well, 24 wells in each group) and 10 cm culture dishes (7 ml in each dish, 4 dishes in each group). The release rate of LDH was calculated and the morphology of the cells and nucleus condensation (by Hoechst 3334224 fluorescent staining) was detected at 9 h of incubation in 24 well plates. The mitochondrial transmembrane potential (by JC-1 assay) and phosphorylation of Akt and ERKs (by Western blot) were measured at 5 h of incubation in 24 well plates and in culture dishes respectively. ResultsBupivacaine caused severe damage to the N2a cells as evidenced by increase in LDH release and nucleus condensation (apoptosis), dephosphorylation of Akt and ERKs, decrease in mitochondrial transmembrane potential and severe morphological changes. Dexamethasone pretreatment significantly attenuated bupivacaine-induced neurotoxicity. Conclusion Dexamethasone can protect N2a cells from bupivacaine-induced neurotoxicity through stabilization of mitochondrial transmembrane potential and inhibition of dephosphorylation of Akt and ERKs.     

Agilent 2100 Bioanalyzer在基因差异表达研究中的应用

目的观察Agilent 2100 Bioanalyzer 芯片分析系统(以下简称Bioanalyzer)在基因差异表达研究中的应用。方法应用限制性显示技术分别从正常和热休克处理后的酿酒酵母细胞中分离出cDNA片段,然后再用Bioanalyzer和传统的琼脂糖凝胶电泳技术对RD-PCR产物进行检测分析。结果Bioanalyzer能更快速、敏感地分离和显示差异表达的基因片段,并且通过对差异片段进行定量比较,发现了数个表达有明显差异的基因片段。结论Bioanalyzer在基因差异表达研究中具有重要的应用价值。