谷氨酸诱导体外培养的鸡胚脊髓神经细胞释放NO

用鸡胚脊髓神经细胞的原代培养,测定细胞中亚硝酸盐的含量,研究了谷氨酸(Glu)对原代培养神经细胞中NO的影响。结果表明,谷氨酸作用于原代培养的鸡胚脊髓神经细胞,在诱导神经细胞释放乳酸脱氢酶(LDH)的同时,还可诱导细胞释放一氧化氮(NO)。如先用NO合成酶抑制剂L-NOARG作用细胞,再加入Glu,则发现L-NOARG能降低Glu导致的培养液中LDH活性升高。提示NO可能参与介导Glu的神经毒性作用。     

胆囊癌组织中NDPK／nm23的表达及意义

作者用免疫组化ＡＢＣ法对４１例胆囊癌标本核苷二磷酸激酶（ＮＤＰＫ，下同）／ｎｍ２３表达进行了测定，结果发现：ｎｍ２３在恶性肿瘤中的表达率明显高于良性病变（Ｐ＜０．０５）。ＮＤＰＫ／ｎｍ２３表达与胆囊癌组织的分化、局部浸润及淋巴转移密切相关（Ｐ＜０．０１）。ＮＤＰＫ／ｎｍ２３阳性患者生存中位数１２．２５个月，阴性患者６．５个月，两者存在显著差异（Ｐ＜０．０１），提示ｎｍ２３检测对预后有重要价值。     

补肾中药对肾虚骨质疏松症大鼠红细胞膜PKC、 Ca2+-Mg2+- ATP酶活性影响的实验研究

本实验研究切除卵巢造成肾虚骨质疏松症大鼠模型。通过观测红细胞膜蛋白激酶Ｃ（ＰＫＣ）和Ｃａ２＋－Ｍｇ２＿－ＡＴＰ酶的活性，探讨肾虎骨质疏松症病理机制中肌醇脂质系统的变化，并结合全身和脊柱骨密度（ＢＭＤ）指标观察了补肾中药（密骨灵）的疗效，与正常对照组、模型空白组和阳性药（骨疏康颗粒剂）对照组进行对照，探讨补肾法的防治机理。结果表明；模型空白组大鼠红细胞膜ＰＫＣ和Ｃａ２＋－Ｍｇ２＋－ＡＴＰ酶、Ｍｇ２＋－ＡＴＰ酶的活性明显低于正常组（ｐ均＜０．０５）；密骨灵组与骨疏康组大鼠全身、脊柱ＢＭＤ和红细胞膜ＰＫＣ、Ｃａ２＋－Ｍｇ２＋－ＡＴＰ酶的活性均明显高于模型空白组（ｐ均＜０．０５），并且与正常组大鼠无明显差别（ｐ均＞０．０５）；密骨灵组大鼠红细胞膜Ｍｇ２＋－ＡＴＰ酶活性高于模型空白组和骨疏康组（ｐ＜０．０５），并且与正常组无显著性差异（ｐ＞０．０５）；密骨灵组大鼠红细胞膜ＰＫＣ活性高于骨疏康组（Ｐ＜０．０５）。结论：肾虎骨质疏松症具有红细胞膜ＰＫＣ和Ｃａ２＋－Ｍｇ２＋－ＡＴＰ酶、Ｍｇ２＋－ＡＴＰ酶活性的改变；密骨灵可以恢复肾虎骨质疏松症大鼠全身骨量，达到防治目的；补肾中药可以恢复红细胞膜ＰＫＣ活性和钙镁泵的活性，是补     

A chimeric tyrosine/tryptophan hydroxylase

The neurotransmitter biosynthetic enzymes, tyrosine hydroxylase (TH), and tryptophan hydroxylase (TPH) are each composed of an amino-terminal regulatory domain and a carboxylterminal catalytic domain. A chimeric hydroxylase was generated by coupling the regulatory domain of TH (TH-R) to the catalytic domain of TPH (TPH-C) and expressing the recombinant enzyme in bacteria. The chimeric junction was created at proline 165 in TH and proline 106 in TPH because this residue is within a conserved five amino-acid span (ValProTrpPhePro) that defines the beginning of the highly homologous catalytic domains of TH and TPH. Radioenzymatic activity assays demonstrated that the TH-R/TPH-C chimera hydroxylates tryptophan, but not tyrosine. Therefore, the regulatory domain does not confer substrate specificity. Although the TH-R/TPH-C enzyme did serve as a substrate for protein kinase (PKA), activation was not observed following phosphorylation. Phosphorylation studies in combination with kinetic data provided evidence that TH-R does not exert a dominant influence on TPH-C. Stability assays revealed that, whereas TH exhibited a t_1/2 of 84 min at 37°C, TPH was much less stable (t _1/2=28.3 min). The stability profile of TH-R/TPH-C, however, was superimposable on that of TH. Removal of the regulatory domain (a deletion of 165 amino acids from the N-terminus) of TH rendered the catalytic domain highly unstable, as demonstrated by at _1/2 of 14 min. The authors conclude that the regulatory domain of TH functions as a stabilizer of enzyme activity. As a corollary, the well-characterized instability of TPH may be attributed to the inability of its regulatory domain to stabilize the catalytic domain.     

Lines of Murine Oligodendroglial Precursor Cells Immortalized by an Activated neu Tyrosine Kinase Show Distinct Degrees of Interaction with Axons In Vitro and In Vivo

Replication-defective retroviruses expressing the t- neu oncogene, or a hybrid protein with the neu tyrosine kinase linked to the external region of the human epidermal growth factor receptor ( egfr-neu ), were used to establish lines of murine oligodendroglial precursor cells. Differentiation of the t- neu lines into myelin-associated glycoprotein (MAG)-positive oligodendrocytes was induced by dibutyryl cAMP, and the egfr-neu line showed limited differentiation in vitro upon withdrawal of epidermal growth factor. Cerebellar granule cell neurons expressed mitogens for the cell lines. Upon transplantation into demyelinated lesions, t- neu line cells engaged with the demyelinated axons whereas the egfr-neu line cells differentiated further and ensheathed the axons. These cell lines thus interact with neurons in vitro and in vivo and can be used as tools to define the molecules involved in different stages of neuron-glia interaction.     

人酪氨酸羟化酶基因真核表达载体的构建及在哺乳动物细胞中的表达

用限制性内切酶EcoRI从pKS(-)HTH_1切下全长为1.9 kb的人酪氨酸羟化酶基因,在T_4DNA连接酶的作用下连接在真核表达载体pCDNA_3的EcoR Ⅰ位点,构建成重组质粒pcD-NA_3HTH_1,该质粒转染COS-7细胞,免疫荧光组织化学染色证实酪氨酸羟化酶在其中的表达。     

Treatment of diabetic autonomic neuropathy with an aldose reductase inhibitor

To evaluate the effects of the aldose reductase inhibitor Ponalrestat (Statil) on diabetic autonomic neuropathy, a double-blind placebo controlled trial was carried out on a group of 34 diabetic patients with documented cardiac autonomic neuropathy. After a 4-week, placebo run-in period, patients were randomised for treatment with 600 mg Statil or placebo for another 24 weeks. Moreover, the reliability of the autonomic nerve function tests was investigated by comparing the results at onset and at week 4. Fifteen patients treated with Statil and 12 with placebo completed the study. Neither symptom scores nor cardiovascular reflexes, pupil reflexes and skin vasomotor reflexes improved after Statil therapy, which led us to conclude that Statil is not effective in the treatment of diabetic autonomic neuropathy. Reliability coefficients for cardiovascular reflexes and pupil reflex showed high values, ranging from 60% to 80%. Therefore these methods are recommended in future therapy trials.     

根除幽门螺杆菌疗效与细胞色素氧化酶P450 2C19基因多态性的关系

目的 比较雷贝拉唑与奥美拉唑三联疗法根除幽门螺杆菌（Hp）的疗效与细胞色素氧化酶P4502 C19（CYP 2C19）基因多态性的关系。方法 采用随机、对照研究方法，将169例因消化不良症状接受常规胃镜检查确诊为慢性胃炎且Hp阳性的连续患者分人两组：雷贝拉唑三联疗法组（RAC组85例）和奥美拉唑三联疗法组（OAC组84例）。Hp诊断依靠组织病理学检查并参考快速尿素酶试验、血清Hp抗体检测结果。RAC组、OAC组均给予三联治疗：RAC组：雷贝拉唑10mg，OAC组：奥美拉唑20mg，两组均联用羟氨苄青霉素1000mg和克拉霉素500mg，全部药物每日2次，疗程7d。采用聚合酶链式反应结合限制性内切酶技术（PCR-RFLP），进行CYP 2C19基因型分析，治疗结束后第28天用^14C尿素呼气实验检测Hp根除疗效。结果 160例完成治疗方案，RAC组及OAC组的Hp根除率按PP分析及ITT分析均无统计学差异（P〉0．05）。根据CYP 2C19基因型分析，160例中，弱代谢型（PM）、中间代谢型（IM）及强代谢型（EM）的Hp根除率分别为95．5%（21／22）、85．9％（73／85）和67．9％（36／53）。PM型及IM型的Hp根除率均显著高于EM型（P〈0．05），而PM型与IM型间差异无统计学意义（P〉0．05）。RAC组中，各基因型的Hp根除率差异无统计学意义（P〉0．05）。OAC组中。IM型与EM型间（P〈0．01）及EM型与PM型间（P〈0．05）差异均有统计学意义。结论 雷贝拉唑与奥美拉唑两种三联疗法均能有效根除Hp。总疗效差异无统计学意义。雷贝拉唑三联疗法疗效较稳定，个体间差异小。PM型及IM型的Hp根除率均较EM型为高。     

增殖细胞核抗原及nm23在胃癌中的表达及意义

目的 :探讨增殖细胞核抗原 (PCNA)及nm2 3基因在胃癌中的表达及其与生物学行为的关系。方法 :应用免疫组化SP法研究 85例胃癌手术标本中PCNA及nm2 3基因的表达。结果 :在 85例胃癌中PCNA、nm2 3的总阳性表达率分别为 5 2 9% (4 4 / 85例 )和 4 4 .7% (38/ 85例 ) ,PCNA及nm2 3在胃癌中的表达与其淋巴结转移、浸润深度、分化程度有关 (P <0 0 5 ,P <0 0 1 ) ;PCNA与分化程度无关 ,P >0 0 5。结论 :PCNA及nm2 3参与了胃癌的发生、发展、浸润及转移     

Comparison of histopathological characteristics of allograft biopsy between responder and non-responder to antiproteinuric effect of angiotensin-converting enzyme inhibitor (ACEI)

Abstract:  Angiotensin-converting enzyme inhibitor (ACEI) has become recognized as agents that have renoprotective effects in the treatment of progressive renal diseases including post-transplant kidneys. Previously we demonstrated the safety and effectiveness of ACEI treatment on the hypertensive proteinuric post-transplant patients ( N  = 10) who had been followed up for 12 months. However, not all patients show good response in urinary protein reduction. We aimed to analyse the histopathological factor(s) affecting the responsiveness of proteinuria to ACEI treatment. Fourteen post-transplant patients with proteinuria who were treated with ACEI and underwent allograft biopsy were analysed. Eight patients showed 50% or more reduction in proteinuria (responder). The other 6 patients showed less (< 50%) reduction in proteinuria (non-responder). There was no difference in clinical characteristics (BP, renal function, donor age, recipient body mass index), dietary sodium or protein intake, and diuretic use between the two groups. As a histopathological characteristic, glomerular size in responder group was significantly larger than that in non-responder group. This suggests that the large glomerular size at least partly contributes to the responsiveness in urinary protein reduction to ACEI treatment in kidney allograft recipients with proteinuria.