The obesity-associated peptide leptin induces hypertrophy in neonatal rat ventricular myocytes

One of the major manifestations of obesity is increased production of the adipocyte-derived 16-kDa peptide leptin, which is also elevated in heart disease, including congestive heart failure. However, whether leptin can directly alter the cardiac phenotype is not known. We therefore studied the effect of leptin as a potential hypertrophic factor in cultured myocytes from 1- to 4-day-old neonatal rat heart ventricles. Using RT-PCR, we demonstrate that these cells express the short-form (OB-Ra) leptin receptor. Twenty-four hours of exposure to leptin (0.31 to 31.3 nmol/L) produces a significantly increased cell surface area that peaked at 0.63 nmol/L. Subsequent experiments were done with 3.1 nmol/L leptin, which significantly increased cell area by 42%, protein synthesis by 32%, and alpha-skeletal actin and myosin light chain-2 expression by 250% and 300%, respectively. These events occurred in the absence of any increased cell death. Hypertrophy was preceded by rapid activation of the mitogen-activated protein kinase system including p38 and p44/42 as early as 5 minutes after leptin addition, whereas hypertrophy was inhibited by the p38 inhibitor SB203580 but not by the p44/42 inhibitor PD98059. Our results demonstrate a direct hypertrophic effect of leptin and may offer a biological link between hypertrophy and hyperleptinemic conditions such as obesity.     

Blockade of the MEK/ERK signalling cascade by AS703026, a novel selective MEK1/2 inhibitor,induces pleiotropic anti‐myeloma activity in vitro and in vivo

This study investigated the cytotoxicity and mechanism of action of AS703026, a novel, selective, orally bioavailable MEK1/2 inhibitor, in human multiple myeloma (MM). AS703026 inhibited growth and survival of MM cells and cytokine‐induced osteoclast differentiation more potently (9‐ to 10‐fold) than AZD6244. Inhibition of proliferation induced by AS703026 was mediated by G₀‐G₁ cell cycle arrest and was accompanied by reduction of MAF oncogene expression. AS703026 further induced apoptosis via caspase 3 and Poly ADP ribose polymerase (PARP) cleavage in MM cells, both in the presence or absence of bone marrow stromal cells (BMSCs). Importantly, AS703026 sensitized MM cells to a broad spectrum of conventional (dexamethasone, melphalan), novel or emerging (lenalidomide, perifosine, bortezomib, rapamycin) anti‐MM therapies. Significant tumour growth reduction in AS703026‐ vs. vehicle‐treated mice bearing H929 MM xenograft tumours correlated with downregulated pERK1/2, induced PARP cleavage, and decreased microvessels in vivo. Moreover, AS703026 (<200 nmol/l) was cytotoxic against the majority of tumour cells tested from patients with relapsed and refractory MM (84%), regardless of mutational status of RAS and BRAF genes. Importantly, BMSC‐induced viability of MM patient cells was similarly blocked within the same dose range. Our results therefore support clinical evaluation of AS703026, alone or in combination with other anti‐MM agents, to improve patient outcome.     

Expression of polycomb protein EZH2 in multi-stage tissues of gastric carcinogenesis

OBJECTIVE: To study the role and significance of the polycomb group (PcG) protein EZH2 (enhancer of zeste homolog 2) in the multi-step process of intestinal-type gastric carcinogenesis. METHODS: Gastric specimens were obtained from 142 patients with gastric disease, including 34 with chronic non-atrophic gastritis (NCAG), 33 chronic atrophic gastritis (CAG) with intestinal metaplasia (IM), 40 CAG with dysplasia (DYS) and 35 with intestinal-type gastric carcinomas (GC), and 32 Helicobacter pylori-negative controls. The EZH2 protein was stained by the immunohistochemical method and was expressed as the intensity and percentage of the total number of epithelial cells. The chronic gastritis and the grading of dysplasia were classified according to Chinese National Consensus on chronic gastritis and the Padova international classification. RESULTS: The EZH2 protein levels in the specimens of normal gastric tissue, NCAG, CAG with IM, DYS and intestinal-type GC were gradually increased (P < 0.05), but statistical significance was not found between the groups of DYS and GC. CONCLUSION: PcG protein EZH2 plays an important role in the multi-step process of intestinal-type gastric carcinogenesis.     

SOX13抗体对酮症倾向糖尿病患者胰岛功能的影响

目的 探讨SOX13抗体(sry related HMG box 13-antibody,SOX13-Ab)对酮症倾向糖尿病(KPD)患者胰岛功能的影响,进一步确定SOX13-Ab在KPD患者中的自身免疫反应特征.方法 2005年1月至2009年11月对南京鼓楼医院内分泌科就诊的245例KPD患者[男138例,女107例,年龄33(1～80)岁]均检测SOX13-Ab、谷氨酸脱羧酶抗体(GAD-Ab)和蛋白酪氨酸磷酸酶抗体(IA-2A),以SOX13-Ab单一阳性患者为病例组,以GAD-Ab、IA-2A单一阳性及抗体均阴性组患者为对照组,比较4组患者的胰岛功能.各组平均C肽水平采用中位数(四分位数间距)表示,经自然对数转化后进一步采用方差分析比较组间差异.结果 (1)女性患者中SOX13-Ab单一阳性、GAD-Ab单一阳性组空腹C肽(FCP)和餐后2 h C肽(PCP)水平分别为166.0(300.0)和166.5(159.3)、285.0(527.0)和231.0(502.5)pmol/L,均显著低于抗体阴性组[FCP为287.5(302.7)pmol/L、PCP为528.0(774.0)pmol/L;均P＜0.05];(2)发病年龄≤40岁或病程≤5年的KPD患者中,其FCP水平SOX13-Ab组[166.0(56.0)vs 228.0(250.0)pmol/L]、GAD-Ab单一阳性组[191.0(137.5)vs 324.0(340.0)pmol/L]均显著低于抗体阴性组[167.1(223.1)vs 324.0(340.0)pmol/L];而在病程＞5年的KPD患者中,GAD-Ab单一阳性组FCP水平为130.0(458.8)pmol/L、SOX13-Ab单一阳性组为189.5(357.7)pmol/L,两组比较差异有统计学意义(P＜0.05);(3)协方差分析显示SOX13-Ab单一阳性与抗体阴性组之间FCP、PCP比较差异无统计学意义(P＞0.05);而GAD-Ab/SOX13-Ab双阳性组FCP与抗体阴性组比较差异有统计学意义(P＜0.05);(4)GAD-Ab、IA-2A单一阳性组内FCP与病程均呈显著负相关(r值分别为-0.500、-0.821,P值分别为0.007、0.023),而SOX13-Ab单一阳性组内FCP与病程之间无显著负相关性(r=-0.104,P=0.606).结论 SOX13-Ab对KPD患者胰岛功能的影响弱于GAD-Ab.     

Molecular differentiation of Angiostrongylus taxa (Nematoda: Angiostrongylidae) by cytochrome c oxidase subunit I (COI) gene sequences

Nematodes of the genus Angiostrongylus are parasites of rodents and carnivores. They reside in the pulmonary or mesenteric arteries of their hosts. Two species are pathogenic in humans - Angiostrongylus cantonensis causes eosinophilic meningitis or meningoencephalitis, and Angiostrongylus costaricensis produces abdominal angiostrongyliasis. In addition Angiostrongylus malaysiensis may have the potential of being pathogenic in humans. The mitochondrial gene cytochrome c oxidase subunit I (COI) of these Angiostrongylus species and three geographical isolates (China, Hawaii and Thailand) of A. cantonensis were studied by polymerase chain reaction amplification and DNA sequencing. COI sequences of A. cantonensis, A. costaricensis and Angiostrongylus vasorum in the GenBank were included for comparison. Phylogenetic analysis by maximum-likelihood (ML), maximum-parsimony (MP), neighbour-joining (NJ) and Bayesian inference (BI) produced similar tree topology except variation in the bootstrap support values. There were two major clades - (1) A. cantonensis and A. malaysiensis, and (2) A. costaricensis and A. vasorum. The three geographical isolates of A. cantonensis formed a clade with low to high bootstrap values, and consisted of two subclades: (a) China and Hawaii isolates, and (b) monophyletic Thailand isolate. The individuals of each isolate formed a distinct cluster. In the second major clade, the Europe isolates of A. vasorum were distinctly different from the Brazil isolates. For A. costaricensis, the Costa Rica isolate was distinct from the Brazil isolate with an uncorrected (p) distance of 11.39%, indicating the possible occurrence of cryptic species. The present results indicate that COI sequences might be a useful marker for differentiating geographical isolates of A. cantonensis and in uncovering cryptic species. Efforts are being made to carry out an extensive collaborative study to cover a wide range of Angiostrongylus species and geographical isolates.     

Selective reduction of natural killer T cells in the bone marrow of aplastic anaemia

T cell-mediated suppression of haematopoiesis is believed to play an important role in the pathophysiology of aplastic anaemia (AA) and in the pancytopenia of some myelodysplastic syndromes (MDS). Natural-killer T (NKT) cells belong to a unique lymphocyte subset that expresses an invariant T-cell receptor (TCR), consisting of Valpha24JalphaQ, and common NK cell surface markers. NKT cells have been hypothesized to play a role in immune regulation, and many human autoimmune conditions are associated with NKT cell deficiency. Here we investigate the role of NKT cells in AA and MDS patients. Flow cytometry demonstrated that NKT cells, unlike other T-lymphocyte subpopulations, were disproportionally decreased in AA and MDS marrow. When we compared variability within the CDR3 region of Valpha24 in CD4-CD8- T cells derived from AA and healthy individuals, the CDR3 size of Valpha24 cells showed a polyclonal distribution in AA patients, while in control subjects a typical oligoclonal or monoclonal pattern was found. Southern blot and sequence analysis of Valpha24 polymerase chain reaction products revealed that the NKT cell-specific JalphaQ region was predominant in control subjects, whereas it was not, or only very weakly, detected in AA and MDS patients. These results show that NKT cells are profoundly decreased in AA and MDS, and their deficiency may, as in other human autoimmune diseases, play a role in the local immune dysregulation in AA and MDS.     

氧化低密度脂蛋白诱导Zucker肥胖大鼠肾小球系膜细胞AP-1活性的变化

目的 :研究氧化低密度脂蛋白 (oxidizedlow densitylipoprotein ,Ox LDL)对体外培养的Zucker大鼠肾小球系膜细胞 (glomerularmesangialcell,GMC)中核转录因子激活蛋白 1(activatorprotein 1,AP 1)活化的影响 ,以及观察Ox LDL诱导的AP 1活性的变化与Zucker大鼠鼠龄以及基因型的相关性。　 方法 :①采用Zucker肥胖大鼠 (3月龄和 10月龄 )及Zucker瘦型大鼠 (3月龄和 10月龄 )的 4种GMC株 (O3m,O10m,L3m,L10m)进行传代培养。②利用凝胶迁移率实验 (EMSA)和超迁移率实验检测不同浓度及不同时相Ox LDL对Zucker大鼠GMCAP 1活性的影响 ,以及AP 1二聚体中c jun和c fos成分的变化。　 结果 :①经Ox LDL诱导后 ,4个组GMC内AP 1活性均较对照组明显增强 (F =177 84 ,P <0 0 1) ;②随着Ox LDL刺激浓度增加和时间的延长 ,GMC内AP 1活性相应增强 ,5 0mg/L的Ox LDL刺激 8h时 ,AP 1活性强度达最高峰 ;③Ox LDL主要激活AP 1二聚体成分中的c jun ;④O10m组AP 1的活性显著高于O3m组 (P <0 0 1) ,L10m组AP 1的活性显著高于L3m组 (P <0 0 1) ,O10m组显著高于L10m组 (P <0 0 1) ,O3m组显著高于L3m组 (P <0 0 1)。　 结论 :Ox LDL可诱导Zucker大鼠GMC内AP 1活化 ,其活化方式呈时间和剂量依赖 ;活化强度与大鼠的基因型及鼠龄     

甘肃省边远贫困地区肺结核病人DOT管理现状调查分析

目的调查边远贫困地区肺结核病人DOT管理现状,了解边远贫困地区肺结核病人DOT管理中存在的问题和影响因素。方法随机抽取2个人口在40万以上的国家级贫困县查阅2005年2006年的季报表、年报、病案等归档材料进行汇总、分析,并抽取这2个县距县城10km以上的12个乡,对2005年登记管理化疗结束的涂阳肺结核病人采用现场问卷方式调查和追访,了解病人DOT管理情况及影响因素,分析评价边远贫困地区肺结核病人DOT管理质量。结果有效的109例涂阳病人中直接面视服药率为19.3%,75.2%的病人为自服药;治愈率为41.3%,完成疗程率为38.5%, 18.4%的病人因各种原因为不规则治疗;县、乡、村3级防痨人员由于人力、时间、经济等因素不能做到直接面视规律服药;影响病人服药依从性、疗程期间查痰多为主观因素,并与病人年龄、结核病知识知晓情况、督导管理质量和频次、药物不良反应相关。结论边远贫困地区肺结核病人的DOT管理质量情况不尽人意。探索适合远贫困地区实际情况,切实可行的病人DOT管理方法,是我省边远贫困地区实施DOT策略亟待解决的问题,同时提高病人对结核病防治知晓率是提高病人规律服药的重要措施之一。