自体干细胞激活疗法治疗2型糖尿病大鼠的疗效及安全性探讨

目的 本实验采用自体干细胞激活疗法治疗糖尿病大鼠过程中对血细胞及生化指标进行了监测,以观察糖尿病干细胞治疗的效果及治疗过程中可能存在的不良反应。方法 46只大鼠随机分为健康对照组10只,拟造模组大鼠36只。予高糖高脂加小剂量链脲佐菌素（30mg/kg）制备糖尿病大鼠模型。造模成功后30只大鼠随机分为糖尿病对照组10只、干细胞治疗组 20只。干细胞治疗组予重组人粒细胞集落刺激因子[3μg/（kg·d）]隔日1次皮下注射,肝细胞生长因子[3mg/（kg·d）]腹腔注射及烟酰胺[100mg/（kg·d）]灌胃;两对照组大鼠予同体积生理盐水隔日1次皮下注射,每日同体积5%葡萄糖加中和量胰岛素腹腔注射及高压灭菌水灌胃。实验过程中,各组大鼠测定血糖、血常规及生化指标。结果 治疗后1周开始干细胞治疗组较糖尿病对照组血糖显著下降（P<0.01）;治疗1~4周时干细胞治疗组较两对照组WBC、PLT明显升高（P<0.05）;治疗前后3组大鼠ALT、GGT无显著变化。治疗前糖尿病对照组较健康对照组大鼠ALP显著升高（P<0.05）,治疗后干细胞治疗组较两对照组大鼠ALP升高更为显著。结论 2型糖尿病大鼠采用自体干细胞激活疗法治疗后,其血糖明显下降,证实糖尿病干细胞治疗有效;WBC、PLT及ALP升高,表明干细胞被成功动员;RBC、LYM计数及ALT及GGT浓度无明显变化;所有改变未见相关不良反应。     

高糖与高尿酸通过醛糖还原酶通路协同作用加重内皮细胞损伤

目的寻找高血糖与高尿酸血症协同加重内皮细胞损伤的共同作用靶点和分子机制,为糖尿病合并高尿酸血症患者心血管疾病的保护提供干预靶点。 方法用人脐静脉内皮细胞系(HUVEC-C)给予高糖(30 mmol/L,HG)、高尿酸(600 μmol/L,UA)和高糖(HG)＋高尿酸(UA)联合培养48 h。利用10 μmol/L阿司他丁阻断醛糖还原酶(AR)的活性。实时定量PCR检测内皮型一氧化氮合成酶(eNOS)和AR mRNA的表达;Western blot检测还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶2 (NOX2)、NOX4、eNOS和AR蛋白的表达;共聚焦显微镜检测细胞内ROS的活性;一氧化氮(NO)试剂盒检测NO活性。 结果与单独HG组和UA组相比,HG＋UA共培养组明显降低eNOS mRNA水平和蛋白表达,减少NO产生,增加内皮细胞胞内ROS活性;HG＋UA共培养明显上调AR mRNA水平和蛋白表达。应用AR抑制剂能够明显增加HG＋UA组内皮细胞eNOS mRNA水平和蛋白表达,增加内皮细胞NO的分泌水平。AR抑制剂能够明显下调HG＋UA组内皮细胞NOX4的蛋白表达,对NOX2无影响;降低细胞内ROS的含量。 结论高血糖和高尿酸协同作用通过激活醛糖还原酶途径下调内皮细胞eNOS的表达,增加ROS活性,减少NO的产生,加重内皮细胞功能障碍;而抑制醛糖还原酶,能够通过抑制NOX4表达,阻断这种协同损伤作用。     

烟酰胺磷酸核糖转移酶在子宫内膜癌中的表达及临床意义

目的:探讨烟酰胺磷酸核糖转移酶（Nampt）蛋白的表达与子宫内膜癌生物学行为之间的关系。方法:选取中国医科大学附属盛京医院2013年5月-2014年5月手术切除的40例子宫内膜癌组织（均为腺癌）及30例正常子宫内膜组织。采用实时定量逆转录聚合酶链反应（RT-PCR）检测其Nampt mRNA的表达、免疫组织化学SP法及蛋白免疫印迹检测Nampt蛋白的表达水平,并分析其表达量与子宫内膜癌临床病理学参数的关系。结果:Nampt mRNA在子宫内膜癌组织和正常子宫内膜组织中的相对表达量分别为3.774±2.399和1.286±0.762,差异有统计学意义（P＜0.05）。Nampt蛋白在子宫内膜癌组织和正常子宫内膜组织中的相对表达量分别为0.426±0.16和0.203±0.129,差异有统计学意义（P＜0.05）。在不同临床分期、不同肌层浸润的子宫内膜癌组织中Nampt蛋白的表达量有统计学差异（P＜0.05）。结论:Nampt蛋白的过度表达在子宫内膜癌的发生、发展过程中可能起到一定的作用。     

原发性结直肠癌氟尿嘧啶代谢相关酶类的表达与临床意义

目的:研究氟尿嘧啶代谢相关酶在原发性结直肠癌的表达及临床意义.方法:收集北京大学临床肿瘤学院2003年8月至2004年2月收治的经病理确诊的61例原发性结直肠癌患者的标本,应用RT-PCR方法检测原发性结直肠癌组织和非肿瘤组织中胸苷酸合成酶(thymidylate synthase,TS)、二氢胸腺嘧啶脱氢酶(dihydropyrimidinedehydrogenase,DPD)、乳清酸磷酸核糖基转移酶(orotate phosphoribosyl transferase,OPRT)的基因表达.结果:每种酶在肿瘤组织和非肿瘤组织中的基因表达水平存在正相关.肿瘤组织与非肿瘤组织相比,TS和DPD表达近似.结直肠癌肿瘤组织中OPRT表达水平是非肿瘤组织中OPRT表达水平的4.38倍(P=0.000),OPRT的表达量在黏液腺癌中是最低的,在低分化腺癌中是最高的.肿瘤组织/非肿瘤组织OPRT表达量的比值(TOPRT/NoPRT)与淋巴结转移(r=0.36;P=0.005)、脉管转移(r=0.26;p=0.041)和组织学分化(r=-0.33;P=0.009)具有相关性.结论:采用RT-PCR法检测三种酶在结直肠癌中的表达切实可行,有良好的临床应用前景.提示OPRT可能是潜在的结直肠癌预后指标.     

Antinociceptive and anti-inflammatory activities of nicotinamide and its isomers in different experimental models

Although there is evidence for the anti-inflammatory activity of nicotinamide, there is no evaluation of its effects in models of nociceptive and inflammatory pain. In addition, there is no information about the potential anti-inflammatory and antinociceptive activities of the nicotinamide isomers, picolinamide and isonicotinamide. Per os (p.o.) administration of nicotinamide (1000 mg/kg, −1 h) inhibited the first and second phases of the nociceptive response induced by formalin in mice. In the model of nociceptive pain, exposure of mice to a hot-plate (50 °C), nicotinamide (1000 mg/kg, −1 h) also presented antinociceptive activity. Nicotinamide (500 mg/kg, −1 and 3 h) also inhibited the mechanical allodynia induced by carrageenan in rats, a model of inflammatory pain. In addition to inhibiting the nociceptive response, nicotinamide (500 or 1000 mg/kg, −1 and 3 h) inhibited the paw edema induced by carrageenan in mice and rats. P.o. administration of picolinamide (125 mg/kg, −1 h) and isonicotinamide (500 or 1000 mg/kg, −1 h) inhibited the second phase of the nociceptive response induced by formalin in mice. The paw edema induced by carrageenan in mice was also inhibited by isonicotinamide (500 or 1000 mg/kg, −1 h) and picolinamide (125 mg/kg, −1 h and 3 h). The results represent the first demonstration of the activity of nicotinamide and its isomers in models of nociceptive and inflammatory pain and provide support to their anti-inflammatory activity. The demonstration of new activities for nicotinamide is important as it may contribute to expand its use in the treatment of other pathological conditions.     

Contribution of oxidative stress to pulmonary arterial hypertension

Recent data implicate oxidative stress as a mediator of pulmonary hypertension (PH) and of the associated pathological changes to the pulmonary vasculature and right ventricle (RV). Increases in reactive oxygen species (ROS), altered redox state, and elevated oxidant stress have been demonstrated in the lungs and RV of several animal models of PH, including chronic hypoxia, monocrotaline toxicity, caveolin-1 knock-out mouse, and the transgenic Ren2 rat which overexpresses the mouse renin gene. Generation of ROS in these models is derived mostly from the activities of the nicotinamide adenine dinucleotide phosphate oxidases, xanthine oxidase, and uncoupled endothelial nitric oxide synthase. As disease progresses circulating monocytes and bone marrow-derived monocytic progenitor cells are attracted to and accumulate in the pulmonary vasculature. Once established, these inflammatory cells generate ROS and secrete mitogenic and fibrogenic cytokines that induce cell proliferation and fibrosis in the vascular wall resulting in progressive vascular remodeling. Deficiencies in antioxidant enzymes also contribute to pulmonary hypertensive states. Current therapies were developed to improve endothelial function, reduce pulmonary artery pressure, and slow the progression of vascular remodeling in the pulmonary vasculature by targeting deficiencies in either NO (PDE-type 5 inhibition) or PGI(2) (prostacyclin analogs), or excessive synthesis of ET-1 (ET receptor blockers) with the intent to improve patient clinical status and survival. New therapies may slow disease progression to some extent, but long term management has not been achieved and mortality is still high. Although little is known concerning the effects of current pulmonary arterial hypertension treatments on RV structure and function, interest in this area is increasing. Development of therapeutic strategies that simultaneously target pathology in the pulmonary vasculature and RV may be beneficial in reducing mortality associated with RV failure.     

Gender- and age-dependent changes in nucleoside levels in the cerebral cortex and white matter of the human brain

Nucleosides are neuromodulators that participate in various neuronal functions in the brain. In previous studies, we described regional differences in the concentrations of nucleosides and their derivatives in the human brain. To better understand the functions of nucleosides in the central nervous system, we investigated gender- and age-dependent changes in the levels of nucleosides and their metabolites. The concentrations of uridine, inosine, guanosine and adenosine as well as uracil, hypoxanthine and xanthine were measured in the frontal cortex and white matter of post-mortem brain tissue samples of middle-aged and old men as well as women. The average in vivo concentrations calculated from the 40 samples investigated (regardless of anatomical locations, gender or age; mean ± S.E.M.) were as follows (pmol/mg wet tissue weight): 9.7 ± 0.8 adenosine, 85.8 ± 3.9 inosine, 14.3 ± 0.9 guanosine, 37.3 ± 1.8 uridine, 8.9 ± 0.6 uracil, 63.3 ± 2.1 hypoxanthine and 38.7 ± 1.5 xanthine. We conclude that concentration differences between uridine, inosine, guanosine and adenosine in the frontal cortex and cerebral white matter suggest that nucleoside metabolism is altered with aging and regulated differently between men and women.     

Of mice,rats and men: Revisiting the quinolinic acid hypothesis of Huntington's disease

The neurodegenerative disease Huntington's disease (HD) is caused by an expanded polyglutamine (polyQ) tract in the protein huntingtin (htt). Although the gene encoding htt was identified and cloned more than 15 years ago, and in spite of impressive efforts to unravel the mechanism(s) by which mutant htt induces nerve cell death, these studies have so far not led to a good understanding of pathophysiology or an effective therapy. Set against a historical background, we review data supporting the idea that metabolites of the kynurenine pathway (KP) of tryptophan degradation provide a critical link between mutant htt and the pathophysiology of HD. New studies in HD brain and genetic model organisms suggest that the disease may in fact be causally related to early abnormalities in KP metabolism, favoring the formation of two neurotoxic metabolites, 3-hydroxykynurenine and quinolinic acid, over the related neuroprotective agent kynurenic acid. These findings not only link the excitotoxic hypothesis of HD pathology to an impairment of the KP but also define new drug targets and therefore have direct therapeutic implications. Thus, pharmacological normalization of the imbalance in brain KP metabolism may provide clinical benefits, which could be especially effective in early stages of the disease.     

Potential role of NADPH oxidase in pathogenesis of pancreatitis

Studies have demonstrated that reactive oxygen species(ROS) are closely related to inflammatory disorders. Nicotinamide adenine dinucleotide phosphate oxidase(NOX), originally found in phagocytes, is the main source of ROS in nonphagocytic cells. Besides directly producing the detrimental highly reactive ROS to act on biomolecules(lipids, proteins, and nucleic acids), NOX can also activate multiple signal transduction pathways, which regulate cell growth, proliferation, differentiation and apoptosis by producing ROS. Recently, research on pancreatic NOX is no longer limited to inflammatory cells, but extends to the aspect of pancreatic acinar cells and pancreatic stellate cells, which are considered to be potentially associated with pancreatitis. In this review, we summarize the literature on NOX protein structure, activation, function and its role in the pathogenesis of pancreatitis.