The effect of exercise on regional adipose tissue and splanchnic lipid metabolism in overweight Type 2 diabetic subjects

Aims/hypothesis To test the hypothesis that adipose tissue lipolysis is enhanced in patients with Type 2 diabetes mellitus, we examined the effect of exercise on regional adipose tissue lipolysis and fatty acid mobilisation and measured the acute effects of exercise on the co-ordination of adipose tissue and splanchnic lipid metabolism.Methods Abdominal, subcutaneous adipose tissue and splanchnic lipid metabolism were studied by conducting measurements of arterio-venous concentrations and regional blood flow in six overweight Type 2 diabetic subjects before, during and after exercise.Results Exercise induced an increase in adipose tissue lipolysis and fatty acid release. However, the increase in adipose tissue blood flow was small, limiting fatty acid mobilisation from this tissue. Some of the fatty acids were released in excess in the post-exercise phase. The splanchnic fatty acid uptake was unchanged during the experiment but splanchnic ketogenesis increased in the post-exercise phase. The arterial glucose concentration decreased during exercise and continued to decrease afterwards, indicating an imbalance between splanchnic glucose production and whole-body glucose utilisation.Conclusions/interpretation Regional subcutaneous, abdominal adipose tissue lipolysis is no higher in patients with Type 2 diabetes than in young, healthy subjects. Exercise stimulates adipose tissue lipolysis, but due to an insufficient increase in blood flow, a high fraction of the fatty acids liberated by lipolysis cannot be released to the blood. Splanchnic glucose release is smaller than whole-body glucose utilisation during exercise and post-exercise recovery.Abbreviations ICG indocyanine green - 3-OHB 3-hydroxybutyrate - TAG triacylglycerol - VO_2,max peak oxygen consumption     

2型糖尿病患者脂联素和体脂含量及分布与胰岛素敏感性的相关研究

目的　分析脂联素 (ADIPO)与机体脂肪含量、分布及组织胰岛素敏感性 (IS)的关系。　方法　符合 1999年WHO糖尿病诊断标准的 2型糖尿病 (T2DM )患者 4 0例 ,男 16例 ,女 2 4例 ,平均年龄 (5 5± 7)岁 ,体质指数 (BMI) (2 5 0± 2 5 )kg/m2 ,病程 (3± 4 )年。测定常规临床检查项目和血糖、血浆胰岛素水平。按HOMA模型计算胰岛素抵抗 (IR)指数。其中 2 0例患者应用正常血糖高胰岛素钳夹试验测定组织葡萄糖代谢率 (M)。同时测定ADIPO、肿瘤坏死因子α(TNFα)和游离脂肪酸(FFA)水平。应用双能X线测定机体的全身脂肪含量、全身瘦肉组织含量 ,并计算全身脂肪含量百分比。其中 17例患者同时应用核磁共振测定脂肪分布 ,以电子计算机计算腹内脂肪面积 (VFA)、腹部皮下脂肪面积 (SFA) ,并计算VFA/SFA比值。　结果　 (1)肥胖或体脂含量增加的T2DM患者其血浆ADIPO显著降低 ;(2 )腰围或腹内脂肪增加的T2DM患者其血浆ADIPO显著降低 ;(3)T2DM患者ADIPO水平与M值显著正相关 ,与TNFα、FFA呈显著负相关。　结论　T2DM患者体脂含量和分布影响血浆ADIPO水平 ,ADIPO与IS呈显著正相关。     

Ectopic nodal structures in a patient with atrial tachycardia originating from the mitral valve annulus.

We report a case, which we believe to be rare, of adenosine-sensitive atrial tachycardia (AT) originating from the mitral valve annulus. The patient, a 73-year-old woman, died of unrelated cause 4 years after radiofrequency (RF) ablation therapy. Histologically, fibrous replacement of atrial musculature by mature collagenous tissue produced by the RF current was observed at the left inferior atrioventricular junction. In serial sections that included the coronary sinus, two distinct nodal structures containing small, pale myocytes within the fibrous tissue matrix were identified around the region of the ablation lesion. Our case appears to be a unique representation of tissue that was associated with the occurrence and maintenance of AT.     

Reprogramming cells for transplantation

The field of tissue engineering, involving the reprogramming of stem cells or rejuvenation of specific differentiated cells, is emerging as a promising strategy to repair the damaged myocardium. The eventual goal is to be able to take a patient's own cells, expand them ex vivo, genetically engineer them to enhance specific properties, and then reintroduce them into the patient's heart to create a replacement tissue. Our review paper describes data that supports the potential of this strategy. This clinically relevant, combined strategy of genetic and tissue engineering could be of importance in treating elderly patients with massive myocardial damage, patients whose normal myogenic or angiogenic cells have been depleted or are inadequate in their growth potential, to prevent LV deterioration and heart failure.     

Responses to Norepinephrine of Normal and "Ischemic" Canine Purkinje Fibers are Consistent with Activation of Different α1-Receptor Subtypes

α₁-Receptor Subtype Stimulation of Purkinje Fibers. Introduction: Previously we found that WB4101 (WB) 10^-7 M competitively blocks three α₁-adrenergic receptor-effector responses: the increase in normal automaticity occurring in Purkinje fibers (PF) at high membrane potentials: the increase in abnormal automaticity occurring in PF at depolarized membrane potentials; and the prolongation of PF action potential duration. These observations are consistent with two different hypotheses: (1) WB blocks a single α₁-receptor subtype, which subserves different effector pathways; and (2) WB blocks different receptor subtypes, eacb of which subserves an independent patbway. The aim of this study was to test both hypotheses. Methods and Results: We used standard microelectrode techniques to study the concentration-dependent actions of three α₁-adrenoreceptor blockers (WB (α_1A?α_1D], 5-methylurapidil [5-MU] [α_1A, ?α_1D], and UK52,046 [nonselective]) on norepinephrine (NK) effects in normal PF and in PF depolarized with a simulated ischemic solution ([K⁺]_o= 10 mM; pO₂ < 20 mmHg; pH 6.8; maximum diastolic potential -60 ± 1 mV). In normally polarized PF, concentration-dependent actions of all blockers on both the positive cbronotropic response and the prolongation of action potential duration completely coincide. In contrast, the response to NE of abnormal automaticity in “ischemic” PF differs from normals: there is a bigh sensitivity to WB and 5-MU and no response to UK52,046. Conclusions: (1) A single receptor subtype appears responsible for botb the α₁-induced prolongation of repolarization and the positive chronotropic effect in normal PF. (2) Two different receptor subtypes may be responsible for the α₁-induced effects on automaticity in normal and ischemic fibers. It is likely that the latter one is α_1A, and that consideration of antiarrhythmic therapy with α₁-adrenergic blockers should focus on this subtype as a potential target.     

Nailfold computed videomicroscopy in morpho-functional assessment of diabetic microangiopathy

Summary Although careful measurement of the size of capillary loops is mandatory in the evaluation of diabetic microangiopathy, no current technique allows rapid and careful morphometric analysis of capillaroscopic findings. In an attempt to solve this problem, assembling readily available instruments, the authors have set up an original apparatus for computed videomicroscopy. The apparatus ensures detailed morphological assessment of single loops at high magnification. Each single frame stored on videocassettes can be digitalized for morphometric analysis, saved on floppy disk or printed by means of a graphic printer.     

氯吡格雷联合溶栓治疗急性心肌梗死的疗效评价

目的探讨和研究氯吡格雷联合溶栓治疗急性心肌梗死的临床疗效。方法选取2012年1月—2013年5月之间该院收治的50例急性心肌梗死患者作为研究对象,根据入院编号进行随机分组,分为观察组和对照组,各25例,对照组单纯采用重组人组织型纤溶酶原激酶衍生物进行溶栓治疗,观察组患者则在溶栓治疗基础上加用氯吡格雷联合治疗,对比两组患者的疗效及心肌酶谱变化。结果观察组患者总有效率92.0%,显著高于对照组患者的76.0%,差异有统计学意义(P<0.05);治疗前两组患者的肌酸激酶、肌酸激酶同工酶对比差异无统计学意义,治疗后观察组显著低于对照组,差异有统计学意义(P<0.05)。结论氯吡格雷联合溶栓治疗急性心肌梗死的疗效确切,相较于单纯溶栓治疗更具优势,能够有效降低心肌酶水平,提高疗效,值得在临床上推广和应用。