内脏脂肪素对SW872脂肪细胞葡萄糖转运的影响

目的 观察不同水平重组人内脏脂肪素(visfatin)对SW872脂肪细胞葡萄糖转运的影响,探讨visfatin在胰岛素抵抗形成中的意义.方法 体外培养SW872前脂肪细胞,当细胞完全汇合后,加入0.6 mmol/L油酸诱导SW872前脂肪细胞分化48 h,光学显微镜下观察SW872前脂肪细胞和成熟脂肪细胞形态的变化.以诱导分化成熟的SW872脂肪细胞为研究对象,利用2-脱氧-[3H]-右旋葡萄糖掺入法测定SW872成熟脂肪细胞的葡萄糖转运能力.结果 油酸诱导分化24 h SW872前脂肪细胞胞体由小变大,形态由梭形变为圆形,胞浆中出现细小脂滴;诱导48 h细胞体积进一步变大,细胞已完全分化,胞浆中脂滴明显增多;诱导分化72 h细胞呈戒环状,胞浆脂滴含量更多.用5、10 nmol/L visfatin作用24 h,对基础状态及胰岛素诱导的SW872成熟脂肪细胞葡萄糖转运无影响;25、50、100、200 nmol/L visfatin作用24 h,使基础状态葡萄糖转运率分别增加2.90%、7.70%、12.01%、12.29%(P<0.05,0.01);胰岛素诱导的SW872脂肪细胞葡萄糖转运率分别增加3.40%、16.37%、30.30%、30.83%(P<0.05,0.01).100 nmol/L visfatin刺激时,SW872脂肪细胞的基础状态和胰岛素诱导的葡萄糖转运率趋近于高峰,与50 nmol/L和对照组0 nmol/L比较均有统计学差异(Pa<0.01);200 nmol/L visfatin刺激时,与100 nmol/L visfatin刺激时的基础状态和胰岛素诱导的葡萄糖转运率比较无统计学差异(Pa>0.05).结论 visfatin可促进SW872脂肪细胞的葡萄糖转运,且以100 nmol/L的质量浓度刺激时,葡萄糖转运率最趋近高峰.     

Visfatin在油酸诱导的SW872脂肪细胞胰岛素抵抗中的作用

目的探讨Visfatin在油酸诱导的SW872成熟脂肪细胞胰岛素抵抗(IR)中的作用。方法体外培养SW872前脂肪细胞,当细胞完全汇合后,加入0.6mmol·L-1油酸诱导分化48h,此时SW872前脂肪细胞被诱导分化为成熟脂肪细胞,以SW872成熟脂肪细胞为研究对象,采用1.0mmol·L-1油酸诱导SW872成熟脂肪细胞产生IR。将其分为正常对照组(成熟SW872脂肪细胞)和IR组(采用1.0mmol·L-1油酸诱导SW872成熟脂肪细胞产生IR)。采用2-脱氧-[3H]-右旋葡萄糖掺入法检测2组SW872成熟脂肪细胞基础状态(基础状态组)、Visfatin和Insulin刺激状态(Visfatin和Insulin刺激组)下的葡萄糖转运能力。结果1.在正常对照组中,Visfatin和Insulin刺激组SW872成熟脂肪细胞葡萄糖转运率显著增加,分别是基础状态组的1.10倍(P<0.01)和1.34倍(P<0.01)。2.在IR组中,SW872成熟脂肪细胞的葡萄糖转运率均显著下降。与正常对照组比较,Visfatin刺激组和基础状态组的葡萄糖转运率分别减少12.30%(P<0.01)和9.73%(P<0.0...     

重组人白细胞介素-6对脂肪细胞蛋白质酪氨酸磷酸酶1B、白细胞介素-6及抵抗素基因表达的影响

目的观察重组人白细胞介素-6(rhIL-6)对SW872脂肪细胞蛋白质酪氨酸磷酸酶1B(PTP1B)、抵抗素及IL-6基因表达的影响,探讨rhIL-6对脂肪细胞分泌功能的调节作用。方法体外培养,油酸诱导SW872前脂肪细胞分化为成熟的脂肪细胞,在培养液中加入不同水平rhIL-6(0、1、5、10、20、50μg/L)作用24 h,加入20μg/L rhIL-6后分别作用不同时间(0、4、8、12、24 h)。收集细胞提取总RNA,采用半定量反转录酶聚合酶链反应方法检测SW872脂肪细胞PTP1B、抵抗素、IL-6 mRNA水平。结果rhIL-6 1μg/L作用24 h,对SW872脂肪细胞IL-6 mRNA的表达无影响;随着rhIL-6水平的增加,SW872脂肪细胞IL-6 mRNA的表达水平逐渐增加,但以20μg/L rhIL-6的作用最强(F=233.9 P<0.01);20μg/L rhIL-6作用4 h即可促进SW872脂肪细胞IL-6 mRNA的表达,随着作用时间的延长,其促进作用更加明显(F=247.8 P<0.01)。1μg/L rhIL-6作用24 h,对SW872脂肪细胞PTP1B mRNA的表达无影响;5μg/L rhIL-6即可促进SW872脂肪细胞PTP1B mRNA表达,50μg/L rhIL-6作用24 h,对PTP1B mRNA的表达促进作用更明显(F=515.58 P<0.01);20μg/L rhIL-6作用4 h对脂肪细胞PTP1B mRNA的表达无影响,作用8 h即可促进PTP1BmRNA的表达,随着作用时间的延长其作用更加明显(F=498.62 P<0.01)。不同水平、不同作用时间下,rhIL-6对SW872脂肪细胞抵抗素mRNA的表达无明显影响(F=9.6,10.5 Pa>0.05)。结论rhIL-6以剂量和时间相关的方式促进SW872脂肪细胞PTP1B及IL-6 mRNA表达,对抵抗素mRNA的表达无影响。     

重组人白细胞介素6对SW872脂肪细胞增殖和凋亡的影响

目的　探讨白细胞介素 6(IL 6)对SW872脂肪细胞增殖及凋亡的影响。方法　体外培养SW872脂肪细胞 ,0 .6mmol/L油酸诱导SW872前脂肪细胞分化 ,化学比色法检测细胞内三酰甘油的总量 ;油红O染色观察细胞内脂肪的聚积 ;MTT法检测不同浓度IL 6对SW872前脂肪细胞增殖活力的影响 ;流式细胞仪分析IL 6对SW872成熟脂肪细胞凋亡的影响。结果　 0 .6mmol/L油酸刺激 72h ,几乎 10 0 %SW872前脂肪细胞分化为成熟的脂肪细胞 ,细胞内三酰甘油的含量明显增加 ,油红O染色胞浆内可见丰富的脂滴 ;5 μg/LIL 6对SW872前脂肪细胞的增殖没有影响 ,10～ 5 0 μg/LIL 6明显抑制SW872前脂肪细胞的增殖 ;IL 6对SW872成熟脂肪细胞的凋亡无影响。结论　IL 6能明显抑制SW872前脂肪细胞的增殖 ,其抑制效应呈剂量依赖性 ,表明IL 6可能与肥胖有关 ,高剂量IL 6可降低肥胖的程度。     

NYGGF4基因过表达对脂肪细胞胰岛素敏感性及分泌功能的影响

目的：观察肥胖相关新基因NYGGF4过表达对脂肪细胞的胰岛素敏感性及分泌功能的影响。方法：体外培养稳定转染NYGGF4基因（NYGGF4-pcDNA3.1）的3T3-L1前体脂肪细胞,以转染空载体（pcDNA 3.1）的3T3-L1细胞为对照,胰岛素加地塞米松加1-甲基-3-异丁基黄嘌呤(MDI)方案诱导细胞分化成熟,液闪仪测定3H标记的葡萄糖摄取率,Western blot检测葡萄糖转运体4（GLUT4）的表达及转位;采用ELISA双抗体夹心法检测培养上清中TNF-α、IL-6、脂联素、抵抗素4种细胞因子的水平。结果：NYGGF4过表达显著降低胰岛素刺激的葡萄糖摄取率（P<0.05）。NYGGF4过表达对总的GLUT4的表达量没有影响,但明显降低胰岛素刺激的GLUT4由细胞浆向细胞膜的转位（P<0.05）。过表达NYGGF4的脂肪细胞其培养上清中TNF-α、IL-6、脂联素及抵抗素的分泌水平与对照组相比差异无显著性（P>0.05）。结论：NYGGF4基因过表达通过下调胰岛素刺激的GLUT4的转位而减少脂肪细胞的葡萄糖摄取率,提示脂肪细胞对胰岛素的敏感性降低,而对脂肪细胞的分泌功能无明显影响。［中国当代儿科杂志,2009,11（10）：846-849］     

重组人生长激素对SW872脂肪细胞脂联素及其受体基因表达和蛋白分泌的影响

目的 观察重组人生长激素（rhGH）对脂肪细胞脂联素及其受体mRNA表达及蛋白分泌的影响，探讨GH诱导胰岛素抵抗的机制。方法体外培养、油酸诱导SW872前脂肪细胞分化为成熟脂肪细胞，加入rhGH干预；RT-PCR方法检测脂联素、脂联素受体1和2（AdipoR1，2）mRNA水平，ELISA方法检测细胞培养上清中脂联素蛋白含量。结果rhGH100～1000μg／L作用24h不同程度的降低SW872脂肪细胞脂联素及AdipoR1 mRNA的表达及脂联素的分泌，且rhGH浓度越高抑制作用越强；500μg／L rhGH作用4h，对脂联素及AdipoR1基因表达及脂联素的分泌无影响；随作用时间的延长，rhGH抑制脂联素及AdipoR1 mRNA的表达和脂联素的分泌；rhGH对AdipoR2基因表达无影响。结论rhGH以剂量和时间相关的方式抑制SW872脂肪细胞脂联素及AdipoR1 mRNA的表达和脂联素蛋白的分泌。     

U937巨噬细胞对SW872脂肪细胞增殖及凋亡的影响

目的 探讨U937巨噬细胞与SW872脂肪细胞混合培养状态下对脂肪细胞增殖及凋亡的影响,及巨噬细胞在脂肪细胞胰岛素抵抗形成中的意义.方法 以SW872前脂肪细胞,0.6、1.2 mmol/L油酸诱导分化成熟SW872脂肪细胞为研究对象,分别与U937巨噬细胞混合培养,采用酶联免疫吸附法测定各组混合培养前后TNF-α、单核细胞趋化因子-1(MCP-1)分泌水平的变化,应用四甲基偶氮唑盐比色法检测对前脂肪细胞增殖的影响,采用流式细胞术检测各组脂肪细胞在不同炎性反应状态下对细胞凋亡的影响.采用配对t检验对数据进行分析处理.结果 随着油酸诱导水平的增加及SW872前脂肪细胞分化成熟,TNF-α、MCP-1分泌水平均明显升高,脂肪细胞凋亡率亦逐渐增加(Pa<0.05);在与U937巨噬细胞混合培养后,TNF-α、MCP-1分泌水平进一步升高,但炎性反应状态改变对各脂肪细胞组混合培养前后的凋亡率无明显影响(Pa>0.05);U937巨噬细胞的混合培养对SW872前脂肪细胞的增殖率有明显抑制作用(P<0.05).结论 油酸诱导SW872前脂肪细胞成熟分化,在高脂负荷下,炎性反应因子分泌水平急剧升高,同时脂肪细胞凋亡率增加.炎性反应负荷改变对脂肪细胞凋亡率无明显影响.巨噬细胞的趋化加重了其炎性反应状态,并抑制了前脂肪细胞的增殖.     

Resistin结合多肽对胰岛β细胞株RINm5F分泌功能的影响

目的 先前研究已显示resistin结合多肽(RBP)能拮抗resistin对脂肪细胞脂质代谢和内分泌功能的调节作用.本研究试图阐明RBP对胰岛β细胞株RINm5F分泌功能的影响.方法 以不同水平RBP(10-10,10-11,1012mol/L)与RINm5F共培养30min、60min、2h后取上清,ELISA法测其胰岛素,RT-PCR法检测细胞中葡萄糖转运子2(GLUT2)mRNA表达水平,Western blotting法检测细胞中GLUT2的蛋白水平,并采用FURA-3/AM钙荧光染色法检测胰岛素分泌的重要启动因素:细胞内钙水平.结果 RBP在10-12mol/L时干预2h,不影响胰岛β细胞株RINm5F的细胞活性.但能显著刺激胰岛素分泌,RBP为10-12mol/L时干预2h,细胞内钙明显增多.在Resistin刺激下,GLUT2 mRNA水平和蛋白水平均显著上调.结论 RBP能促进RINm5F细胞株胰岛素的分泌,其可能机制是RBP上调了GLUT2的表达,进而增加了细胞内钙的水平,最终导致胰岛素分泌增加.     

GADD45β基因在脂肪细胞分化过程中的表达及肿瘤坏死因子-α对其的调节作用

目的观察3T3-L1脂肪细胞诱导分化过程中生长抑制和DNA损伤诱导家族45β(GADD45β)基因mRNA表达水平的变化,探讨TNF-α对成熟脂肪细胞中GADD45β基因表达水平的调节作用。方法体外培养3T3-L1脂肪细胞,在诱导3T3-L1脂肪细胞分化成熟的基础上,应用重组TNF-α干预分化成熟的脂肪细胞,采用逆转录-聚合酶链反应(RT-PCR)技术检测诱导分化不同时段及TNF-α干预后不同时间脂肪细胞中GADD45β基因表达水平。结果随脂肪细胞逐渐分化成熟,GADD45β基因mRNA表达水平渐降低。GADD45β基因表达水平除在细胞分化d1~7、d8~10各时段内差异无显著意义(P>0.05)外,余各时段之间表达水平差异均具有显著意义(P<0.05)。不同质量浓度重组TNF-α(0.1~10.0μg/L)均能显著促进成熟脂肪细胞中GADD45β基因mRNA的表达。TNF-α质量浓度为0.1μg/L时,GADD45β基因表达水平6 h内上升51.39%,24 h内上升100.15%;TNF-α质量浓度为1.0μg/L时,GADD45β基因表达水平6 h内上升44.15%,24 h内上升100.63%;TNF-α质量浓度达10.0μg/L,GADD45β基因表达水平6 h内即上升104.26%,24 h内上升122.17%。结论GADD45β基因可能参与脂肪细胞分化及脂质形成过程;TNF-α对成熟脂肪细胞中GADD45β基因表达具有促进作用,其促进效应总体趋势呈现时间依赖性特征。     

葡萄糖转运子1缺乏综合征的临床特点与基因突变分析

目的 探讨葡萄糖转运子1缺乏综合征(GLUT1-DS)的临床与SLC2A1基因突变特点.方法 对6例GLUT1-DS患儿的临床表现、脑脊液、脑电图、头颅影像学、治疗与转归等临床资料进行总结;应用聚合酶链式反应与测序、多重连接探针扩增技术对SLC2A1基因进行突变分析.结果 本组6例,3例患儿为经典型GLUT1-DS,以早发惊厥为主要临床表现,3例患儿为非经典型GLUT1-DS,表现为发作性精神行为异常、意识障碍、共济失调等.5例患儿伴智力运动发育落后.6例患儿血糖均正常,脑脊液糖在1.10 ～2.45 mmoL/L之间,均降低,平均值1.68 mmol/L,脑脊液糖与血糖比值为0.16 ～0.51:1,均降低,平均值0.34.4例患儿脑电图正常,2例有局灶性或弥漫性(癎)样放电,其中一例同时有大量弥漫性慢波.3例头颅MRI正常,3例呈非特异性改变,其中1例呈轻度脑萎缩,1例双侧脑室饱满,1例左侧额、枕叶白质发育迟缓.6例患儿均存在SLC2A1基因突变,例1于第2外显子存在大片段缺失,例2至例6分别为c.741 G＞A(E247K)、599delA、761delA、c.1148 C＞A(P383H)、c.1198 C＞T(R400C).2例患儿行生酮饮食治疗,3例予增加饮食次数,疗效显著,1例放弃治疗.结论 GLUT1-DS临床症状多样,以癫(癎)及多种发作性的临床症状为主要表现,饥饿与疲劳可诱发临床症状的出现或加重,此特点为本病重要的临床诊断线索,而脑脊液糖与血糖比值的降低是本病最为重要的临床诊断依据.GLUT1-DS是可治性的神经系统疾病,早诊断、早治疗可显著改善患儿的预后.     

Repetitiveness of the oral glucose tolerance test in children and adolescents

BACKGROUNDData regarding the most suitable diagnostic method for the diagnosis of glucose impairment in asymptomatic children and adolescents are inconclusive. Furthermore, limited data are available on the reproducibility of the oral glucose tolerance test (OGTT) in children and adolescents who are obese (OB).AIMTo investigate the usefulness of the OGTT as a screening method for glucose dysregulation in children and adolescents.METHODSEighty-one children and adolescents, 41 females, either overweight (OW), OB or normal weight (NW) but with a strong positive family history of type 2 diabetes mellitus (T2DM), were enrolled in the present observational study from the Outpatient Clinic of Paediatric Endocrinology of the University Hospital of Patras in Greece. One or two 3-h OGTTs were performed and glucose, insulin and C-peptide concentrations were measured at several time points (t = 0 min, t = 15 min, t = 30 min, t = 60 min, t = 90 min, t = 120 min, t = 180 min).RESULTSGood repetitiveness was observed in the OGTT response with regard to T2DM, while low repetitiveness was noted in the OGTT response with regard to impaired glucose tolerance (IGT) and no repetitiveness with regard to impaired fasting glucose (IFG). In addition, no concordance was observed between IFG and IGT. During the 1^st and 2^nd OGTTs, no significant difference was found in the glucose concentrations between NW, OW and OB patients, whereas insulin and C-peptide concentrations were higher in OW and OB compared to NW patients at several time points during the OGTTs. Also, OW and OB patients showed a worsening insulin and C-peptide response during the 2^nd OGTT as compared to the 1^st OGTT.CONCLUSIONIn mild or moderate disorders of glucose metabolism, such as IFG and IGT, a diagnosis may not be reached using only one OGTT, and a second test or additional investigations may be needed. When glucose metabolism is profoundly impaired, as in T2DM, one OGTT is probably more reliable and adequate for establishing the diagnosis. Excessive weight and/or a positive family history of T2DM possibly affect the insulin and C-peptide response in the OGTT from a young age.     

抵抗素及其结合多肽对大鼠骨骼肌细胞糖摄取功能的影响

目的探讨抵抗素及其结合多肽(RBP)对大鼠骨骼肌细胞糖摄取功能的影响。方法体外培养的大鼠骨骼肌细胞(L6)随机分为对照组,抵抗素(10 nmol/L)组,RBP(1 nmol/L)组、抵抗素(10 nmol/L) RBP(1 nmol/L)组,培养0.5 h后,液闪计数法(LSC)观察L6细胞糖摄取功能的变化,RT-PCR、Western blot法检测葡萄糖转运载体(GLUT)4基因的表达及转位变化。结果与对照组相比,抵抗素组糖摄取功能下降,RBP组及抵抗素 RBP组糖摄取功能无明显变化(P<0.05);与抵抗素组相比,抵抗素 RBP组糖摄取功能明显上调(P<0.05)。4组L6细胞的GLUT4基因的蛋白表达及转位均无明显变化(P>0.05)。结论抵抗素能抑制骨骼肌细胞的糖摄取;但对正常骨骼肌细胞糖摄取功能无明显影响;RBP但能有效拮抗抵抗素抑制骨骼肌细胞糖摄取的作用。     

Glucose and the newborn baby: Sweet justice?

Abstract: Neonatal hypoglycaemia remains a controversial issue. Uncertainty surrounds what constitutes the optimal safe blood glucose for newborn babies. There are good reasons and evidence for maintaining blood glucose greater than 2.5mmol/L in newborn babies. Since 1986 neonatal paediatricians have changed in their definition of neonatal hypoglycaemia. Ideally, screening of blood glucose in neonatal intensive care units should be done with an on-site glucose analyzer.     

Oral glucose tolerance test in children and adolescents: positives and pitfalls

Objectives:   To describe the glycaemic status (assessed by an oral glucose tolerance test (OGTT)) and associated comorbidities in a cohort of Australian children and adolescents at risk of insulin resistance and impaired glucose homeostasis (IGH).
Methods:   Twenty-one children and adolescents (three male, 18 female) (18 Caucasian, one Indigenous, two Asian) (20 obese, one lipodystrophy) referred to the Paediatric Endocrinology and Diabetes Clinic underwent a 2-h OGTT with plasma glucose and insulin measured at baseline, + 60 and + 120 min. If abnormal, the OGTT was repeated.
Results:   The mean (SD) age was 14.2 (1.6) years, BMI 38.8 (7.0) kg/m² and BMI-SDS 3.6 (0.6). Fourteen patients had fasting insulin levels >21 mU/L. Type 2 diabetes mellitus was diagnosed in one patient, impaired glucose tolerance (IGT) in four patients and impaired fasting glycaemia (IFG) in one patient. Despite no weight loss, only one patient had a persistently abnormal OGTT on repeat testing. Three patients with IGH were medicated with risperidone at the time of the initial OGTT. One patient who had persistent IGT had continued risperidone. The other two patients had initial OGTT results of IGT and diabetes mellitus type 2. They both ceased risperidone between tests and repeat OGTT showed normal glycaemic status.
Conclusions:   Use of fasting glucose alone may miss cases of IGH. Diagnosis of IGT should not be made on one test alone. Interpretation of glucose and insulin responses in young people is limited by lack of normative data. Larger studies are needed to generate Australian screening recommendations. Further assessment of the potential adverse effects of atypical antipsychotic medication on glucose homeostasis in this at-risk group is important.     

Survey of the definition and screening of neonatal hypoglycaemia in Australia

Objective : To determine the approach to identifying neonatal hypoglycaemia and the definition of neonatal hypoglycaemia used by neonatal paediatricians in Australian Level 3 neonatal intensive care units (NICU).
Methodology : A questionnaire was sent to the 101 neonatal paediatricians in the 22 Level 3 NICU in Australia asking their method of screening for, and definition of, neonatal hypoglycaemia.
Results : Responses were received from 70 neonatal paediatricians, including all 22 directors. A bedside glucose meter is used in 19 of 22 NICU to screen for hypoglycaemia, whilst one NICU uses a glucose analyzer and another NICU uses a visual colour comparison method. One NICU does not screen, but has blood glucose measured in a satellite laboratory. If the screening method suggests hypoglycaemia, 62 of 63 neonatal paediatricians proceed to blood glucose determination in a laboratory, mostly using plasma samples. Based on the laboratory measurement, the definition of neonatal hypoglycaemia ranged from <1.1 to 3.0 mmol/L.
Conclusions : The majority of neonatal paediatricians in Australian NICU screen for neonatal hypoglycaemia using a bedside glucose meter. There is a wide range in the definition of neonatal hypoglycaemia from <1.1 to 3.0mmol/L.     

Determining the best method for first-line assessment of neonatal blood glucose levels

OBJECTIVE: To evaluate and compare the accuracy and performance of two electrochemical glucose meters. To determine the user acceptability of these glucose meters and the ABL 620 Blood Gas Analyser (Radiometer, Copenhagen, Denmark) with an electrochemical glucose oxidase electrode for use in a Level 2 special care baby unit. METHODOLOGY: A total of 108 blood samples were collected from 47 babies at risk for hypoglycaemia. The blood glucose level was measured with two glucose meters, the Advantage Glucose Meter (Roche Diagnostics, Castle Hill, Australia) and the Precision-G Blood Glucose Testing System (Medisense, Melbourne, Australia), and the true blood glucose (TBG) measured with the ABL 620 blood gas analyser. Results from the glucose meters were compared with the TBG (as a percentage of the TBG). RESULTS: The mean (SD) percentage difference between the Advantage Glucose Meter and TBG was 4.5% (12. 5), and Precision-G Glucose Meter and TBG was 15.4% (12.4). The sample haematocrit did not significantly influence the glucose meter/TBG differences. There was an overall preference by the nursing staff for the Advantage Glucose Meter. CONCLUSIONS: The Advantage Glucose Meter was significantly more accurate than the Precision-G with similar precision. It was the preferred method of screening for neonatal hypoglycaemia.