糖基化终产物对U937巨噬细胞高密度脂蛋白受体蛋白表达的影响

目的　研究诱导分化及糖基化终产物 (AGEs)对人单核 /巨噬细胞 (U937细胞 )高密度脂蛋白受体 (SR BI)蛋白表达的影响 ,探讨AGEs和巨噬细胞SR BI在动脉粥样硬化中的作用。方法　U937细胞经PMA诱导分化 ,并将不同浓度或同一浓度AGEs与诱导分化 48h后的U937细胞共同孵育 ,用免疫细胞化学法和Western印迹法检测SR BI蛋白的表达。结果　诱导分化后U937细胞SR BI表达在 2 4、48h逐渐升高 ,72h下降 ;1 0 0、2 0 0和 40 0 μg/mlAGEs刺激后细胞表面SR BI蛋白表达量分别是BSA组的 1 44、2 38和 2 77倍 (P <0 0 5) ;40 0 μg/ml的AGEs作用 6、1 2、2 4、48h后 ,U937巨噬细胞SR BI蛋白表达量分别为 0h的 1 38、2 49、3 76和 4 2 5倍 (P <0 0 5)。结论　AGEs可增加U937巨噬细胞SR BI蛋白表达且呈浓度和时间依赖性。     

糖基化终产物对大鼠主动脉平滑肌细胞单核细胞趋化蛋白1基因表达的影响

为探讨糖基化终产物对大鼠主动脉平滑肌细胞表达单核细胞趋化蛋白 1基因的影响 ,体外分离培养大鼠主动脉平滑肌细胞 ,然后用不同浓度葡萄糖 (0、5、2 0、5 0和 80mmol L)制备的糖基化终产物 BSA(2 0 0mg L)干预 2 4h和用葡萄糖浓度为 5 0mmol L孵育的糖基化终产物 BSA干预 0、12、2 4和 36h ,逆转录聚合酶链反应检测细胞中单核细胞趋化蛋白 1mRNA表达水平。结果发现 ,葡萄糖浓度 2 0mmol L、5 0mmol L和 80mmol L孵育的糖基化终产物都增加单核细胞趋化蛋白 1mRNA的表达 ,其中 5 0mmol L组作用最明显 (P <0 .0 0 5 ) ,干预 12h、2 4h、36h后单核细胞趋化蛋白 1mRNA表达均较未干预组明显增加 (P <0 .0 0 1)。结果提示 ,糖基化终产物促进大鼠主动脉平滑肌细胞单核细胞趋化蛋白 1基因的表达     

载脂蛋白A1对胆固醇逆转运及三磷酸腺苷结合盒转运体A1表达的影响

目的 观察载脂蛋白A1(apoAl)对人急性单核细胞白血病细胞株(THP-1)源性泡沫细胞内胆固醇、胆固醇酯含量和三磷酸腺苷结合盒转运蛋白A1(ABCAl)表达的影响和机制.方法 以50 ng/ml的佛波酯诱导人THP-1,使其分化为巨噬细胞,再经50μg/ml氧化型低密度脂蛋白充分诱导使其转变为负脂的泡沫细胞;然后用不同浓度apoAl(5μg/ml、10μg/ml、15μg/ml、20 μg/ml)孵育泡沫细胞24 h,以apoAl(10μg/ml)孵育泡沫细胞6 h、12 h、24 h.采用油红O染色观察细胞内脂滴的变化,用氧化酶法检测细胞内总胆固醇、游离胆固醇和胆固醇酯的含量;用反转录聚合酶链反应检测不同浓度apoAl干预泡沫细胞后ABCA1 mRNA的表达;用免疫荧光法检测经不同浓度和不同时间apoAl和ABCAl多克隆抗体干预泡沫细胞后ABCA1蛋白的表达.结果 (1)THP-1经佛波酯(50 ng/ml)和氧化型低密度脂蛋白(50μg/ml)分别干预48 h后可成功诱导为富含脂质的泡沫细胞;(2)apoA1可促进THP-1巨噬细胞源性泡沫细胞内胆固醇逆向转运,减少细胞内胆固醇含量,呈浓度依赖性和时间依赖性;(3)随着apoA1干预浓度增加,THP-1巨噬细胞源性泡沫细胞内ABCA1 mRNA的表达变化不显著,但蛋白表达增加,0 μg/ml与5 μg/ml、10μg/ml、15μg/ml、20μg/ml apoAl干预浓度下油红O染色阳性细胞率分别为(55±4)%与(43±9)%、(33±4)%、(28±1)%、(26±2)%,差异有统计学意义(均P<0.05);(4)ABCAl抗体干预可增加THP-1巨噬细胞源性泡沫细胞ABCA1蛋白的表达.结论 apoA1-ABCA1通路参与泡沫细胞胆固醇逆向转运,apoA1起关键作用,apoA1增加ABCA1蛋白的表达可能与降低ABCA1蛋白的降解有关.     

阿托伐他汀对C反应蛋白诱导的CD14+单核细胞Toll样受体4表达影响的实验研究

目的 观察阿托伐他汀对C反应蛋白(CRP)诱导的外周血CD14+单核细胞Toll样受体4(TLR4)表达,以及TLR4信号传导下游炎症因子肿瘤坏死因子α(TNFα)、白细胞介素-6(IL-6)和基质金属蛋白酶-9(MMP-9)的影响,探讨阿托伐他汀的抗炎机制.方法 不同浓度(0、5、25、50、100 μg/ml)和不同作用时间(0、6、12、24、48 h)的C反应蛋白(CRP)刺激正常人外周血CD14+单核细胞.给予CRP 50 μg/ml预先干预CD14+单核细胞2 h后,再用不同浓度的阿托伐他汀(1.0、2.5、5.0、7.5、10.0 μmol/L)进行干预.应用流式细胞仪检测细胞表面TLR4蛋白的表达,并应用定量PCR方法检测TLR4 mRNA和髓样分化蛋白2(myeloid differentiation protein,MD2)mRNA的表达,ELISA法检测刺激前后细胞上清液TNFα、IL-6和MMP-9的蛋白水平.结果 (1)CRP 0 μg/ml组TLR4蛋白表达量为19.59%,CRP 5 μg/ml组的TLR4蛋白表达为29.33%,差异有统计学意义(P<0.01),并随着CRP浓度的增加,TLR4蛋白表达量逐渐增加.以CRP 0 h组为空白对照,CRP 6 h组的TLR4蛋白表达量为25.75%,差异有统计学意义(P<0.01),并随着时间的增加,TLR4表达量逐渐增加.(2)以CRP 50 μg/ml组为对照组,CRP 50 μg/ml和阿托伐他汀1.0 μmol/L组、2.5 μmol/L组、5.0 μmol/L组、7.5 μmol/L组、10.0 μmol/L组,TLR4蛋白表达分别为(68.17±1.71)%、(52.43±1.38)%、(27.72±4.55)%、(17.46±3.20)%、(9.99±2.81)%.(3)以CRP 50 μg/ml组为标准,CRP 50 μg/ml〖JP〗和阿托伐他汀1.0 μmol/L组、2.5 μmol/L组、5.0 μmol/L组、7.5 μmol/L组、10.0 μmol/L组,TLR4 mRNA分别为对照组的82.72%、67.34%、48.16%、30.88%、13.85%.MD2 mRNA分别为对照组的81.78%、71.04%、47.85%、27.06%、18.30%.随着阿托伐他汀浓度增加,TLR4和MD2的mRNA含量减少.(4)当单核细胞未受CRP和阿托伐他汀刺激时,分泌TNFα、IL-6和MMP-9的基础值分别为(16.3±5.8)pg/ml、(31.1±9.5)pg/ml 和(155.0±47.2)ng/ml.CRP 50 μg/ml组,单核细胞分泌TNFα、IL-6和MMP-9分别为(106.9±7.5)pg/ml、(566.9±10.0)pg/ml和(416.9±37.1)ng/ml,与空白对照组比较,差异均有统计学意义,P均<0.01.而CRP和阿托伐他汀2.5 μmol/L组,单核细胞分泌TNFα、IL-6和MMP-9分别为(81.1±5.4)pg/ml、(433.9±18.1)pg/ml和(310.5±16.3)ng/ml,与CRP 50 μg/ml组比较差异均有统计学意义,P均<0.01.结论 CRP可剂量依赖性和时间依赖性地增加CD14+单核细胞TLR4和MD2的表达,阿托伐他汀通过抑制CRP诱导单核细胞TLR4信号转导途径,降低炎症因子TNFα、IL-6和MMP-9的分泌,是其抗炎作用的机制之一.

Abstract：

Objective To investigate the effects of atorvastatin on C-reactive protein (CRP)induced Toll-Like receptor 4(TLR4)expression on CD14+ monocyte, and the production of proinflammatory cytokines tumor necrosis factor α (TNFα), interleukin-6 (IL-6), matrix metalloproteinases-9 (MMP-9), and to study the anti-inflammatory mechanisms of statins. Methods The monocytes were isolated from blood of healthy volunteers by the Ficoll density gradient and stimulated by CRP with different doses (5, 25, 50, 100 μg/ml)and different exposure time (6, 12, 24, 48 h). Cells were also incubated with atorvastatin of different doses (1.0, 2.5, 5.0, 7.5, 10.0 μmol/L)in the presence of CRP 50 μg/ml. The protein expression of TLR4 was measured by flow cytometry, mRNA expression of TLR4 and of myeloid differentiation protein (MD2)was detected by quantitative PCR. TNFα, IL-6, MMP-9 concentrations in supernatants of cultured medium were measured by ELISA.Results (1)Compared with the un-stimulated control group, enhanced TLR4 protein expression was already detected at a concentration of 5 μg/ml of CRP and increased in a dose-dependent manner (32.22±2.80)%, (49.94±5.58)%, (74.82±3.24)% and (90.82±2.88)% at 5, 25, 50 and 100 μg/ml CRP. (2)TLR4 protein expression on 50 μg/ml CRP stimulated cells also increased in a time-dependent manner (29.80±2.70)%, (47.44±4.41)%, (81.71±2.92)% and (50.57±3.34)% after 6 h, 12 h, 24 h, 48 h.(3)When monocytes were incubated with CRP 50 μg/ml and atorvastatin (1.0, 2.5, 5.0, 7.5, 10.0 μmol/L), protein expression [(68.17±1.71)%, (52.43±1.38)%, (27.72±4.55)%, (17.46±3.20)%, (9.99±2.81)%］and mRNA expression (82.72%, 67.34%, 48.16%, 30.88%, 13.85%)of TLR4 as well as mRNA expression of MD2 (81.78%, 71.04%, 47.85%, 27.06%, 18.30%)were reduced in a dose-dependent manner. (4)Level of TNFα, IL-6 and MMP-9 in supernatants was significantly reduced by atorvastatin (2.5 μmol/L)compared with control group(P<0.01). When monocyte incubated with CRP 50 μg/ml and atorvastatin 10.0 μmol/L, the level of TNFα, IL-6, MMP-9 decreased to (25.8±2.5)pg/ml, (128.2±14.7)pg/ml, (65.2±12.3)ng/ml, respectively.Conclusion CRP increased the protein expression of TLR4 on CD14+ monocyte in a dose-dependent and time-dependent manner. Atorvastatin can inhibit the signal transduction of TLR4 and reduce proinflammatory cytokines release induced by CRP on CD14+ monocyte, and this might be one of the anti-inflammatory mechanisms of atorvastatin.     

糖基化终末产物对破骨细胞骨吸收功能的影响

目的　观察糖基化终末产物 (AGEs)对破骨细胞骨吸收功能的影响。方法　用人血清白蛋白和葡萄糖恒温孵育制备人AGEs,采用甲苯胺蓝染色和图像分析评价AGE对破骨细胞形成骨吸收陷窝的影响。结果　低浓度AGEs(50～ 2 0 0 μg/ml)对骨吸收陷窝的面积和数目无明显影响 ;只有高浓度AGEs(50 0～ 1 0 0 0 μg/ml)才能促进骨吸收陷窝面积的扩大和数目增加 (P <0 .0 5)。结论　AGE可能促进破骨细胞的骨吸收功能     

胆固醇过负荷对脂肪细胞分泌内脂素的影响及其机制

3T3-L1细胞促分化成熟后,分别以酯酰辅酶A胆固醇酯酰转移酶(ACAT)抑制剂(2μg/ml)和不同浓度(0、25、50、75和100 μg/ml)的氧化型低密度脂蛋白(ox-LDL)干预48 h,ACAT抑制剂(2μg/ml)和ox-LDL( 50 μg/ml)干预0、6、18、36和48 h,ACAT抑制剂(2μg/ml)、ox-LDL( 50 μg/ml)和不同浓度(0、100、200和400 μmol/L)的牛磺酸熊去氧胆酸(TUDCA)干预48 h.用ELISA法检测细胞上清内脂素的水平,Western印迹法检测脂肪细胞总蛋白GRP78和CHOP表达.ACAT抑制剂和不同浓度的ox-LDL干预脂肪细胞48 h后,随着ox-LDL浓度的增加,脂肪细胞内胆固醇浓度、GRP78和CHOP蛋白表达及内脂素水平显著升高,实验组与空白对照组比较,差异均具有统计学意义(均P＜0.05);ACAT抑制剂和ox-LDL干预后,随干预时间的延长,脂肪细胞GRP78、CHOP蛋白表达及内脂素水平均显著升高,实验组与空白对照组比较,差异均有统计学意义(均P＜0.05);ACAT抑制剂、ox-LDL和不同浓度TUDCA干预48 h后,脂肪细胞GRP78及CHOP蛋白表达水平及内脂素水平逐渐降低,实验组(200和400 μmol/L)与空白对照组比较,差异均有统计学意义(均P＜0.05).脂肪细胞胆固醇负荷增加可促进脂肪细胞分泌内脂素,其机制可能与脂肪细胞的内质网应激增强有关.     

晚期糖基化终产物对结肠癌干细胞增殖及凋亡的影响研究

目的探讨晚期糖基化终产物(AGEs)对结肠癌干细胞AGEs受体(RAGE)表达及增殖和凋亡的影响。方法以人SW480结肠癌干细胞为研究对象,不同浓度AGEs及50μmol/L PD98059、40mmol/L二甲双胍(MET)干预结肠癌干细胞后,分别应用RT-PCR和Western blot检测24h细胞RAGE mRNA和RAGE、细胞外信号调节蛋白激酶(ERK)、磷酸化ERK(p-ERK)蛋白表达;CCK-8检测24h细胞增殖;流式细胞术检测细胞凋亡。结果应用不同浓度(100、200、300μg/ml)AGEs干预后,与Con组(未加AGEs)比较,200μg/ml AGEs组RAGE mRNA和蛋白表达均增加,(p-ERK1/2)/(ERK1/2)也升高(P0.05)。PD98059干预后,RAGE蛋白表达及(p-ERK1/2)/(ERK1/2)均降低。与不同浓度(100、200、300、500μg/ml)BSA组比较,相应浓度(100、200、300、500μg/ml)AGEs组细胞吸光度(OD)升高(P0.05),细胞活力分别增加11.6%、16.3%、13.8%、13.9%。200μg/ml AGEs组PD98059干预,细胞OD值下降(P0.05)。24h后,200μg/ml AGEs组细胞凋亡率与Con组比较,差异无统计学意义(P0.05),MET组细胞凋亡率升高(P0.05);与MET组比较,MET+AGEs组凋亡率降低(P0.05);与MET+AGEs组比较,MET+AGEs+PD组凋亡率升高(P0.05)。结论 AGEs可促进结肠癌干细胞增殖,抑制其凋亡,作用机制可能是通过作用于RAGE,上调其表达量,激活ERK1/2通路来实现。     

晚期糖基化终产物对心肌细胞p57、p27、p21及hhLIM蛋白表达的影响

目的　探讨晚期糖基化终产物 (advancedglycationendproducts ,AGEs)对体外培养乳鼠心肌细胞p5 7、p2 7、p2 1及hhLIM蛋白表达的影响。方法　采用酶消化法体外培养乳鼠心肌细胞 ,实验前换用含 1%胎牛血清的DMEM培养液饥饿培养 2 4h。应用Western蛋白印迹法检测不同浓度AGEs(5 0mg L、10 0mg L)对心肌细胞刺激 12、2 4、4 8h后细胞中p5 7、p2 7、p2 1及hhLIM蛋白表达情况。结果　不同浓度的AGEs刺激心肌细胞 12h均可使p2 7蛋白表达增加 ,以 5 0mg L浓度作用更为明显 ,刺激 2 4、4 8h无影响。AGEs对p5 7蛋白的表达呈动态变化 :刺激 12h时表达下降 ,2 4、4 8h呈增加趋势。p2 1蛋白在心肌细胞表达较弱 ,AGEs对其表达无显著影响。AGEs增加hhLIM蛋白的表达 ,以 5 0mg L浓度作用 12h最为显著。结论　AGEs通过增加心肌细胞细胞周期素依赖性激酶抑制因子p5 7和p2 7蛋白及hhLIM蛋白的表达 ,参与心室重塑的发生和发展。     

糖基化终产物对大鼠主动脉平滑肌细胞巨噬细胞炎性蛋白-1α表达的影响

目的　探讨糖基化终产物 (AGEs)对大鼠主动脉平滑肌细胞巨噬细胞炎性蛋白 1α(MIP 1α)mRNA及蛋白表达的影响。　方法　将培养的大鼠主动脉平滑肌细胞用不同浓度 (10 0、2 0 0、4 0 0mg/L)的AGEs孵育 2 4h及同一浓度 (4 0 0mg/L)AGEs孵育 0、12、2 4、36h ,采用RT PCR方法及流式细胞仪检测MIP 1αmRNA及蛋白的表达水平。　结果　对照组平滑肌细胞内MIP 1α呈弱表达 ,10 0、2 0 0、4 0 0mg/LAGEs培养平滑肌细胞 2 4h显著增高MIP 1αmRNA的表达 ,其电泳条带相对积分吸光度值分别为对照组的 1 36、1 75、2 4 5倍 (P <0 0 5 ) ;10 0、2 0 0、4 0 0mg/LAGEs孵育2 4h后 ,各组平滑肌细胞MIP 1α蛋白的平均荧光强度分别为 197± 3、2 6 0± 6及 375± 6 ,分别为对照组(15 8± 4 )的 1 2 4、1 6 3、2 37倍 (P <0 0 5 )。 4 0 0mg/LAGEs培养 12、2 4、36h后 ,各组平滑肌细胞MIP 1αmRNA的表达也明显增高 ,其电泳条带相对积分吸光度值分别为 0h组的 1 5 2、2 38、2 5 3倍(P <0 0 5 ) ;4 0 0mg/LAGEs孵育 12、2 4、36h后 ,各组平滑肌细胞MIP 1α蛋白的平均荧光强度分别为 2 4 4± 5、375± 6及 4 2 5± 3,分别为 0h组 (170± 5 )的 1 4 3、2 2 1、2 4 9倍 (P <0 0 5 )。　结论　糖基化终产物以时间及剂量     

同型半胱氨酸促THP-1巨噬细胞表达单核细胞趋化蛋白和他汀药的拮抗作用

目的 :探讨同型半胱氨酸 (Hcy)促进人单核细胞系 (THP 1)分化而来的巨噬细胞 (THP 1巨噬细胞 )表达单核细胞趋化蛋白 1(MCP 1)及辛伐他汀的调节作用。方法 :调细胞密度到 1.0× 10 6个 /ml,培养液中加入佛波脂 (PMA) ,终浓度为 2 0ng/ml,培养 4 8h ,弃去悬浮细胞 ,贴壁细胞呈巨噬细胞样分化。他汀组和Hcy组分别加入含有辛伐他汀 (10 μmol/L ,5 0 μmol/L)或不含辛伐他汀完全培养基培养 2 4h ,再加入含DL Hcy(0 .1mmol/L)完全培养基 ,对照组只用完全培养基 ,37℃培养 2～ 2 4h ,收集上清 5 0 0g离心 10min ,- 2 0℃保存。用ELISA法检测上清中MCP 1蛋白的量 ,每孔重复 3次。结果 :与对照组比较 ,加入 0 .1mmol/LHcy可使THP 1巨噬细胞MCP 1蛋白表达升高 ,4h后显著升高 (P <0 .0 5 ) ,6h达高峰 (P <0 .0 1) ,12h后逐渐下降 (P <0 .0 5 ) ,分别为对照组的 2 .9倍、5 .8倍和 2 .6倍 ,2 4h与对照组比较差异无显著性意义。 10 μmol/L、5 0 μmol/L辛伐他汀分别使与Hcy共孵育 6h峰值时的MCP 1蛋白量下降至他汀组的5 7.11%、2 3.6 4 %。结论 :病理浓度(0 .1mmol/L)的Hcy可时间依赖性促进THP 1巨噬细胞表达MCP 1蛋白 ,该作用可被辛伐他汀下调。     

胰岛素瘤的解剖分布特点分析

目的胰岛素瘤是最常见的胰腺神经内分泌肿瘤，因其临床表现多样，导致诊断困难。影像学诊断尤其是超声内镜(EUS)在胰岛素瘤的诊断中起着重要作用，拥有较高的敏感性和特异性。本研究拟通过明确胰岛素瘤的解剖分布特点，以期有助于提高影像学的诊断准确率和降低漏诊率，尤其是在教育和培训实践中对于EUS的学习者更具有指导价值。 方法回顾性分析解放军总医院第一医学中心病案资料数据库1993年1月至2019年11月经外科手术、病理确诊为胰岛素瘤的患者的临床资料，检索方法采取搜索术后病理诊断为"胰岛素瘤"的病例，通过查阅病例的方法，提取出胰岛素瘤的大小和解剖分布等数据，进一步分析其特点。 结果共检索到确诊为胰岛素瘤的患者116例，其中，男45例、女71例，年龄13～76岁，平均年龄(44.4±14.85)岁。胰岛素瘤单发110例(94.8%)、多发6例(5.2%)。位置分布：头颈部46例(39.7%)，单发45例、多发1例；体尾部68例(58.6%)，单发65例、多发3例；全胰腺多发2例(1.7%)。病变大小特点：最大径0.4～3.4 cm，平均大小(1.53±0.58)cm。≤1 cm 29例、>1 cm而≤1.5 cm41例、>1.5 cm而≤2.0 cm28例，≤3 cm 15例，>3 cm 3例。年龄与肿瘤的大小相关，≤44岁患者肿瘤平均大小为(1.36±0.51)cm、>44岁患者肿瘤平均大小为(1.70±0.60)cm，P<0.05。头颈部的肿瘤大于体尾部的肿瘤，头颈部肿瘤平均大小(1.66±0.63)cm，体尾部(1.42±0.52)cm，P<0.05。 结论胰岛素瘤在胰腺体尾部较头颈部更好发；绝大多数单发，但可以全胰腺多发；多数小于1.5 cm，肿瘤的大小与患者年龄和肿瘤的解剖分布相关。     

Pathogenesis of carcinoma of the papilla of Vater

Most adenomas and carcinomas of the small intestine and extrahepatic bile ducts arise in the region of the papilla of Vater. In familial adenomatous polyposis (FAP) it is the main location for carcinomas after proctocolectomy. In many cases symptoms due to stenosis lead to diagnosis at an early tumor stage. In about 80%, curative intended resection is possible. Operability is the most relevant prognostic factor. Most ampullary carcinomas resp. carcinomas of the papilla of Vater develop from adenomatous or flat dysplastic precursor lesions. They can be sited in the ampulloduodenal part of the papilla of Vater, which is lined by intestinal mucosa. They also can develop in deeper parts of the ampulla, which are lined by pancreaticobiliary duct mucosa. Intestinal-type adenocarcinoma and pancreaticobiliary-type adenocarcinoma represent the main histological types of ampullary carcinoma. Furthermore, there exist unusual types and undifferentiated carcinomas. Many carcinomas of intestinal type express the immunohistochemical marker profile of intestinal mucosa (keratin 7?, keratin 20+, MUC2+). Carcinomas of pancreaticobiliary type usually show the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20?, MUC2?). Even poorly differentiated carcinomas, as well as unusual histological types, may conserve the marker profile of the mucosa they developed from. These findings underline the concept of histogenetically different carcinomas of the papilla of Vater which develop either from intestinal- or from pancreaticobiliary-type mucosa of the papilla of Vater. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear at different frequencies. In future studies, molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. Consequently, the histologic classification should reflect the histogenesis of ampullary tumors from the two different types of papillary mucosa.     

Demonstration of the mechanism of action of biguanides

Summary Palmitic acid oxidation in rat diaphragm homogenate is depressed by biguanide concentrations that are still incapable of inhibiting oxidative phosphorylation. Glucose oxidation is not directly effected by the same biguanide concentrations: however, the inhibitory effect of palmitic acid on glucose oxidation is partly removed by biguanides. Inhibition of fatty acid oxidation, which accounts for most of the metabolic effects caused by these drugs, can be regarded as the fundamental mechanism of action of biguanides. There is some evidence suggesting that these drugs might interact with carnitine, thus preventing long-chain fatty acids from being transported across the mitochondrial membrane to the site of oxidation. Traduzione a cura degli AA.     

Lack of correlation of degree of villous atrophy with severity of clinical presentation of coeliac disease

BACKGROUND AND AIM: Both the clinical presentation and the degree of mucosal damage in coeliac disease vary greatly. In view of conflicting information as to whether the mode of presentation correlates with the degree of villous atrophy, we reviewed a large cohort of patients with coeliac disease. PATIENTS AND METHODS: We correlated mode of presentation (classical, diarrhoea predominant or atypical/silent) with histology of duodenal biopsies and examined their trends over time. RESULTS: The cohort consisted of 499 adults, mean age 44.1 years, 68% females. The majority had silent coeliac disease (56%) and total villous atrophy (65%). There was no correlation of mode of presentation with the degree of villous atrophy (p=0.25). Sixty-eight percent of females and 58% of males had a severe villous atrophy (p=0.052). There was a significant trend over time for a greater proportion of patients presenting as atypical/silent coeliac disease and having partial villous atrophy, though the majority still had total villous atrophy. CONCLUSIONS: Among our patients the degree of villous atrophy in duodenal biopsies did not correlate with the mode of presentation, indicating that factors other than the degree of villous atrophy must account for diarrhoea in coeliac disease.     

血吸虫童虫生长发育及其机制的研究进展

血吸虫童虫是宿主免疫系统攻击的重要靶标,包括皮肤型、肺型和肝门型童虫。宿主分子对童虫生长发育具有重要作用。童虫生长发育机制包括免疫调节、信号转导、性别发育及凋亡等。肌动蛋白、组织蛋白酶、烯醇化酶和葡萄糖基转移酶等分子为血吸虫童虫生长发育的重要分子。本文对血吸虫童虫生长发育及其机制的研究进展做一综述。     

氯硝柳胺悬浮剂的毒性评价

目的评价氯硝柳胺悬浮剂的毒性，为现场大规模应用灭螺提供依据。方法按照中华人民共和国国家标准GB 15670-1995《农药登记毒理学试验方法》和鱼类毒性试验方法进行。结果经口、经皮肤的LDso雌、雄性大鼠均>5 000 mg/kg，经呼吸道的LCso雌、雄性大鼠均>5 000mg/m3，该药经口、经皮肤、经呼吸道毒性均属微毒类药物；兔眼用药后，观察期内无不良反应，对眼无刺激性；皮肤用药后对皮肤无刺激性。与氯硝柳胺原药、氯硝柳胺乙醇胺盐原药和氯硝柳胺乙醇胺盐可湿性粉剂相比，氯硝柳胺悬浮剂对鱼急性毒性最低。结论氯硝柳胺悬浮剂属微毒类药物，对鱼的毒性低于其乙醇胺盐可湿性粉剂，适合于现场应用。     

124例耐多药结核分枝杆菌基因突变特征分析

目的对临床分离的耐多药结核分枝杆菌相关基因的突变特征进行分析。方法对124例耐多药结核分枝杆菌以及50株敏感株的耐药相关基因(包括异烟肼inh A、kat G、oxyR-ahp C间隔区以及利福平rpo B)进行序列测定,分析其基因突变情况。结果异烟肼耐药inh A基因突变率为14.5%;kat G基因突变率为70.2%(87/124),主要位于315位;oxyR-ahp C间隔区突变率为15.3%;inh A、kat G两种基因同时突变率75.0%,三种基因同时突变率为89.5%。利福平rpo B基因突变的检出率高达95.2%,突变主要发生在531、526、516位点。结论我省耐多药菌异烟肼耐药相关基因最常见突变为kat G 315、inh A C-T(-15)、axyR-ahp C间隔区(-10)C-T,利福平为rpo B531、526、516。结合MDR-TB耐药相关基因的特征分析,可以建立一种快速、准确、特异的适合于我省的检测结核菌耐多药性的新方法。     

Assessment of quality of life of parents of children with juvenile chronic arthritis

The aim of the study was to assess the quality of life (QOL) and the psychological status of parents of children with juvenile chronic arthritis (JCA). The QOL, anxiety and depression of the parents of 28 children with JCA were evaluated and compared to those of the parents of 28 healthy children. Mothers of JCA children and mothers of healthy children reported similar QOL. The reported anxiety and depression levels were similar for mothers and fathers in both groups. The parents of children with pauciarticular-type JCA reported lower QOL and higher levels of anxiety and depression than the parents of children with other types, namely polyarticular and systemic JCA. These findings may be explained by the fact that the pauciarticular patients had shorter disease duration and were less frequently seen in the outpatient clinic. The QOL of mothers of children with JCA was found to be slightly impaired in the group of children with pauciarticular JCA. Future larger studies are needed to confirm these results, as the number of subjects in the three groups was rather low. Received: 26 September 2001 / Accepted: 8 February 2002     

Numerical Simulation of the Effect of Rate of Change of Glucose on Measurement Error of Continuous Glucose Monitors

Background

A 5-day in-patient study designed to assess the accuracy of the FreeStyle Navigator® Continuous Glucose Monitoring System revealed that the level of accuracy of the continuous sensor measurements was dependent on the rate of glucose change. When the absolute rate of change was less than 1 mg•dl⁻¹•min⁻¹ (75% of the time), the median absolute relative difference (ARD) was 8.5%, with 85% of all points falling within the A zone of the Clarke error grid. When the absolute rate of change was greater than 2 mg•dl⁻¹•min⁻¹ (8% of the time), the median ARD was 17.5%, with 59% of all points falling within the Clarke A zone.

Method

Numerical simulations were performed to investigate effects of the rate of change of glucose on sensor measurement error. This approach enabled physiologically relevant distributions of glucose values to be reordered to explore the effect of different glucose rate-of-change distributions on apparent sensor accuracy.

Results

The physiological lag between blood and interstitial fluid glucose levels is sufficient to account for the observed difference in sensor accuracy between periods of stable glucose and periods of rapidly changing glucose.

Conclusions

The role of physiological lag on the apparent decrease in sensor accuracy at high glucose rates of change has implications for clinical study design, regulatory review of continuous glucose sensors, and development of performance standards for this new technology. This work demonstrates the difficulty in comparing accuracy measures between different clinical studies and highlights the need for studies to include both relevant glucose distributions and relevant glucose rate-of-change distributions.     

Study of constancy of hydrogen-consuming flora of human colon

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H₂-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.Supported in part by the Department of Veterans Affairs and NIDDKD RO1 DK 13309-25.