不同浓度氯氮平对小鼠空腹血糖和骨骼肌葡萄糖转运蛋白4基因表达的影响

目的探讨氯氮平对雄性C57BL/6小鼠空腹血糖和骨骼肌葡萄糖转运蛋白4(GLUT4)基因表达的影响。方法将63只雄性C57BL/6小鼠随机分为3组,每组21只,分别灌胃给予蒸馏水、氯氮平4mg/kg及氯氮平20mg/kg,于给药后3h、1周、4周以试纸法测定各组空腹血糖,用逆转录-聚合酶链反应测定GLUT4mRNA表达。结果(1)灌药后3h、1周氯氮平4mg/kg组和氯氮平20mg/kg组空腹血糖和GLUT4mRNA的表达与空白对照组相比,差异无统计学意义(P>0.05);(2)灌药后4周氯氮平4mg/kg组和20mg/kg组的空腹血糖值[(5.6±0.5)mmol/L和(5.8±0.5)mmol/L]高于空白对照组[(4.6±0.6)mmol/L],而GLUT4mRNA的表达(0.50±0.14和0.48±0.12)却低于空白对照组(0.85±0.27),差异均有统计学意义(P<0.01)。结论氯氮平可以慢性升高空腹血糖,降低GLUT4mRNA的表达,可能是抗精神病药长期应用后血糖升高的发生机制之一。     

人钠/二羧基转运蛋白1在肾组织的表达变化及其与肾结石发病的关系

目的研究肾组织钠/二羧基转运蛋白1(hNaDC1)表达变化与肾结石发病的的关系.方法85例肾结石患者分为、尿枸橼酸正常结石组和低枸橼酸尿结石组.并设50例对照为非结石患者.采用RT-PCR及Northem印迹法检测其中部分肾结石患者肾组织的hNaDC1mRNA水平;免疫组化检测hNaDCl蛋白表达的变化;常规生化方法测定血、尿枸橼酸、草酸等生化指标.结果低枸橼酸尿结石组结石复发率(36.1%),显著高于尿枸橼酸正常结石组(16.3%,P＜0.01).hNaDC1mRNA在正常肾组织中有表达,分布于近端肾小管刷状缘;低枸橼酸尿结石患者hNaDC1mRNA/18sRNA比值(0.65±0.21)显著高于对照组(0.36±0.11,P＜0.01);而尿枸橼酸正常结石患者(0.4±0.13)与对照组比较差异无显著意义(P＞0.05);低枸橼酸尿结石组hNaDC1蛋白表达也显著高于对照组及尿枸橼酸正常结石组(P＜0.01),而后两组间差异无显著意义(P＞0.05).低枸橼酸尿结石组尿pH值、尿钠水平显著低于尿枸橼酸正常结石组和对照组;尿钙、尿草酸水平均显著高于对照组,与尿枸橼酸正常结石组无显著差异.结论肾组织hNaDC1表达上调可能是低枸橼酸尿的重要原因,与肾结石的形成和复发存在某种内在联系.     

Galactose uncovers face recognition and mental images in congenital prosopagnosia: The first case report

A woman in her early 40s with congenital prosopagnosia and attention deficit hyperactivity disorder observed for the first time sudden and extensive improvement of her face recognition abilities, mental imagery, and sense of navigation after galactose intake. This effect of galactose on prosopagnosia has never been reported before. Even if this effect is restricted to a subform of congenital prosopagnosia, galactose might improve the condition of other prosopagnosics. Congenital prosopagnosia, the inability to recognize other people by their face, has extensive negative impact on everyday life. It has a high prevalence of about 2.5%. Monosaccharides are known to have a positive impact on cognitive performance. Here, we report the case of a prosopagnosic woman for whom the daily intake of 5 g of galactose resulted in a remarkable improvement of her lifelong face blindness, along with improved sense of orientation and more vivid mental imagery. All these improvements vanished after discontinuing galactose intake. The self-reported effects of galactose were wide-ranging and remarkably strong but could not be reproduced for 16 other prosopagnosics tested. Indications about heterogeneity within prosopagnosia have been reported; this could explain the difficulty to find similar effects in other prosopagnosics. Detailed analyses of the effects of galactose in prosopagnosia might give more insight into the effects of galactose on human cognition in general. Galactose is cheap and easy to obtain, therefore, a systematic test of its positive effects on other cases of congenital prosopagnosia may be warranted.     

Short-term dietary supplementation with fructose accelerates gastric emptying of a fructose but not a glucose solution

ObjectiveShort-term dietary glucose supplementation has been shown to accelerate the gastric emptying rate of both glucose and fructose solutions. The aim of this study was to examine gastric emptying rate responses to monosaccharide ingestion following short-term dietary fructose supplementation.MethodsThe gastric emptying rate of a fructose solution containing 36 g of fructose and an equicaloric glucose solution containing 39.6 g glucose monohydrate were measured in 10 healthy non-smoking men with and without prior fructose supplementation (water control) using a randomized crossover design. Gastric emptying rate was assessed for a period of 1 h using the [¹³C]breath test with sample collections at baseline and 10-min intervals following drink ingestion. Additionally, appetite ratings of hunger, fullness, and prospective food consumption were recorded at baseline and every 10 min using visual analog scales.ResultsIncreased dietary fructose ingestion resulted in significantly accelerated half-emptying time of a fructose solution (mean = 48, SD = 6 versus 58, SD = 14 min control; P = 0.037), whereas the emptying of a glucose solution remained unchanged (mean = 85, SD = 31 versus 78, SD = 27 min control; P = 0.273). Time of maximal emptying rate of fructose was also significantly accelerated following increased dietary fructose intake (mean = 33, SD = 6 versus 38, SD = 9 min control; P = 0.042), while it remained unchanged for glucose (mean = 45, SD = 14 versus 44, SD = 14 min control; P = 0.757). No effects of supplementation were observed for appetite measures.ConclusionThree d of supplementation with 120 g/d of fructose resulted in an acceleration of gastric emptying rate of a fructose solution but not a glucose solution.     

低氧诱导因子1α对子宫颈癌细胞生物学行为的影响

目的探讨低氧诱导因子1α（HIF-1α）对宫颈癌细胞的生物学行为的影响以及其中可能存在的分子机制。方法通过CoCl2化学诱导宫颈癌HeLa细胞缺氧;构建靶向HIF-1α的反义真核表达载体、经脂质体介导转染HeLa细胞的方法沉默HIF-1α的表达。将实验细胞分为常氧未转染对照（NN）组、常氧空质粒转染对照（NI）组、常氧转染pcDNA3．0／HIF-1α质粒（NT）组、缺氧未转染对照（HN）组、缺氧空质粒转染对照（HI）组、缺氧转染pcDNA3．0／HIF-1α质粒（HT）组。用四甲基偶氮唑蓝法、Transwell侵袭小室方法观察各组细胞的增殖、侵袭能力的改变,用流式细胞仪检测各组细胞的凋亡率,用RT-PCR技术检测各组细胞目的基因HIF-1α及其靶基因血管内皮生长因子（VEGF）、葡萄糖转运体1（GLUT1）、多药耐药基因1（MDR1）的表达变化。结果NT组细胞在培养12、24、48、72h时的活细胞数分别为0．053±O．003、0．074±0．004、0．148±0．015、0．192±0．038,而HT组分别为0．069±0．003、0．155±0．022、0．224±0．022、0．308±0．069;NT和HT组的细胞增殖受到抑制,NT组与NN及NI组、HT组与HN及HI组间的活细胞数分别比较,差异均有统计学意义（P〈0．01）。各组细胞的凋亡率分别是,NN组（29．27±0．18）％、NI组（31．13±0．08）％、NT组（51．11±0．14）％、HN组（11．46±0．28）％、HI组（15．77±0．49）％、HT组（40．05±0．97）％;HT组与HN及HI组、NT组与NN及NI组间分别比较,差异均有统计学意义（P〈0．01）。各组细胞的侵袭能力由高到低依次为HI、HN、NI、NN、HT、NT组,分别为（40±9）％、（37±12）％、（28±5）％、（26±7）％、（19±7）％、（10±5）％;NT组与NN及NI组、HT组与HN及HI组间分别比较,差异均有统计学意义（P〈0．05）。NT组细胞HIF-1α、VEGF、GLUT1、MDR1 mRNA的相对表达量分别为0．05±0．12、0．09±0．11、0．08±0．15、0．05±0．15,而HT组分别为0．04±0．16、0．16±0．16、0．12±0．20、0．20±0．21;NT组与NN及NI组、HT组与HN及HI组间分别比较,HIF-1α、VEGF、GLUT1、MDR1 mRNA的相对表达量均有降低,差异均有统计学意义（P〈0．01）。结论HIF-1α可能主要通过其下游的靶基因对宫颈癌细胞的恶性生物学行为产生影响,包括抗凋亡、促增殖、增加血液供应和能量供应、耐药等,且体外抑制HIF-1α的表达对宫颈癌细胞有抑制作用。     

葡萄糖转运体3在脑缺血/再灌注后半影区表达的变化及意义

目的:研究大鼠局灶性脑缺血不同缺血时间和不同再灌注时间的脑梗塞体积比、皮质半影区葡萄糖转运体3(GLUT3)转录水平和蛋白水平的表达。方法:用线栓法复制大鼠局灶性脑缺血模型,用Kontron IBAS2.5全自动图像分析系统检测脑梗塞体积比;剥取缺血半影区皮质组织,采用反转录-聚合酶链反应(RT-PCR)测定GLUT3 mRNA水平的变化;用免疫组织化学方法半定量测定GLUT3蛋白水平的变化。结果:脑缺血1 h后再灌注组的脑梗塞体积明显小于缺血3 h再灌注组梗塞体积。GLUT3自3 h即开始升高,24 h到达高峰,1周时仍高于假手术对照组;缺血3 h再灌注组在3 h有一下降点,然后升高,24 h到高峰,1周时接近正常水平。GLUT3蛋白水平的表达与mRNA相符合。结论:GLUT3在缺血半影区的表达上调,可能是机体对缺血／再灌注的保护性反应。     

2型糖尿病大鼠心肌葡萄糖转运体4的变化及其对葡萄糖和脂肪酸代谢的影响

目的探讨2型糖尿病大鼠心肌葡萄糖转运体4(GLUT4)的表达与葡萄糖及其脂肪酸氧化代谢的关系,同时观察罗格列酮使用后上述指标的变化。方法24只SD雄性大鼠随机分为实验治疗组(6只)、实验对照组(6只)、正常治疗组(6只)和正常对照组(6只)。采用高脂喂养(40%脂肪、42%碳水化合物和18%蛋白质)4周及小剂量链脲佐菌素(35mg/kg)一次性腹腔注射建立2型糖尿病大鼠模型。实验治疗组和正常治疗组给予罗格列酮3mg·kg-1·d-1灌胃2周;各组大鼠进行30min等容离体心脏Langendorff灌注,灌注液含100μU胰岛素、5mmol/L葡萄糖、0.4mmol/L3H软脂酸,测定样本葡萄糖含量及3H2O计数,评估心肌葡萄糖和脂肪酸氧化率;Western印迹法检测心肌细胞膜GLUT4表达水平。结果与正常对照组比较,实验对照组大鼠心肌葡萄糖总氧化量明显较少[(55±6)μmol/g干重vs(69±6)μmol/g干重,P<0.01],葡萄糖氧化比例较少(18%vs25%),脂肪酸氧化率较高(82%vs75%);同时心肌细胞膜上GLUT4的表达量减少53%。与实验对照组比较,给予RSG的实验治疗组,心肌葡萄糖的氧化量较高为(64±6)μmol/g干重(P<0.05),葡萄糖和脂肪酸的氧化比例分别为24%和76%,GLUT4表达量也明显较大(92%vs47%,P<0.01)。结论心肌细胞膜上GLUT4表达减少可能是2型糖尿病心肌葡萄糖和脂肪酸氧化代谢改变的重要原因,罗格列酮通过增加GLUT4的表达,可以提高心肌葡萄糖氧化、降低脂肪酸氧化,这将有助于减轻糖尿病心肌细胞损伤,增强抗缺血的能力。     

葡萄糖转运蛋白在非小细胞肺癌中的表达及其临床意义

目的：探讨葡萄糖转运蛋白（Glucose transporter，Glut）的两种异构体Glutl、Glut3及缺氧诱导因子-1（Hypoxia induciblefactor-1，HIF-1）的亚基HIF—1α，在非小细胞肺癌中的表达及临床意义。方法：选取34例手术切除非小细胞肺癌（包括癌组织和癌旁组织）和17例肺良性病变标本，用免疫组织化学法测定Glutl、Glut3及HIF-1α在肺组织中的表达；用RT—PCR半定量检测Glutl、Glut3及HIF-1α的mRNA表达；用Western Blot检测Glutl、Glut3及HIF-1α蛋白的表达，并测两者相关性。结果：Glutl、Glut3及HIF-1α在肺癌组织中mRNA相对含量为0．689&#177;0．245、0．506&#177;0．246、0．693&#177;0．248，对应癌旁组织为0．338&#177;0．157、0．482&#177;0．238、0．351&#177;0．184，Glutl和HIF-1α在肺癌组织中显著升高（P〈0．001），而Glut3差别无显著性（P〉0．05）。Glutl、Glut3、HIF—1α在癌组织中蛋白相对含量为0．582&#177;0．247、0．551&#177;0．251、0．525&#177;0．246，癌旁组织为0．288&#177;0．151、0．436&#177;0．224、0．261&#177;0．135，在肺良性病变中为0．291&#177;0．142、0．402&#177;0．206、0．271&#177;0．176，Glutl和HIF-1α在癌组织中的表达均明显高于癌旁组织（P〈0．001）和肺良性病变组织（P〈0．001）；而Glut3差别无显著性（P〉0．05）。Glutl和HIF-1α在低分化组明显高于中高分化组（P〈0．05），Ⅲ期明显高于Ⅰ和Ⅱ期（P〈0．05），且HIF-1α的表达与Glutl明显相关（r=0．854，P〈0．01）。结论：在非小细胞肺癌中，Glutl和HIF-1a存在高表达，其表达与细胞分化程度、TNM分期密切相关，且Glutl和HIF-1α具有相关性。     

Protracted diarrhoea: Secondary monosaccharide malabsorption and zinc deficiency with cutaneous manifestations during total parenteral nutrition

Protracted diarrhoea in early infancy gives rise to many diagnostic and therapeutic problems. Jejunal biopsy often reveals villous atrophy of varying degrees. Severe reduction of small intestinal absorptive area causes secondary monosaccharide malabsorption, as well as secondary disaccharide deficiency, consequences which are relevant in any attempts at oral feeding. Morphologic, metabolic, endocrinological and microbiological studies have to be undertaken in order to establish a definitive diagnosis in protracted diarrhoea, but these studies often fail to reveal the aetiology of the disease. Immunologic abnormalities like phagocyte dysfunction, thymic atrophy and hypoplasia of B-cell regions in lymph nodes might be secondary events, but some types of immunodeficiency are of primary importance in the development of protracted diarrhoea. Total parenteral nutrition in many cases has to be instituted, with all its implications and hazards: septicaemia is the most dangerous of these. Zinc deficiency and acrodermatitis enteropathica may occur during total parenteral nutrition, and zinc deficiency secondarily contributes to the symptoms of diarrhoea. Parenteral administration of zinc is able to overcome these effects.     

Sugar transport in the perifused left atrium: effects of contraction frequency, digitalis and ionic alterations.

The activity of the sugar transport system in the rat left atrium was studied by measuring the distribution of 3-methylglucose. Sugar transport increased progressively with the rate of muscle contraction, from rest to 240 beat/min. This effect persisted for up to 15 min after contraction had ceased. Hyperosmolarity increased sugar transport in parallel with cell shrinkage, expansion of extracellular space and increase in intracellular Na⁺ and ionic strength; opposite changes were induced by hypo-osmolarity. Anoxia, uncouplers of oxidative phosphorylation, K⁺-free medium, as well as 10^?5 g/ml ouabain or 1.0 mm diphenylhydantoin (DPH) stimulated sugar transport and inhibited the Na⁺ pump. In contrast, 10^?9 g/ml ouabain or 0.5 mm DPH decreased sugar transport and intracellular Na⁺ and increased intracellular K⁺. In all these respects sugar transport in atria resembled that in skeletal muscle. The data are consistent with the proposed role of Ca²⁺ as regulator of sugar transport but exclude cytoplasmic Ca²⁺ from this function. The effect of 10^?9 g/ml ouabain appears not to be related to the inotropic effect of the drug.