ABSTRACT
Objective To investigate the elasticity and hemodynamics of femoral artery in patients with type 2 diabetes mellitus (T2DM).Methods Subjects recruited in this study were divided into three groups,healthy control ( n =30),T2DM patients with femoral arterial intima-media thickness(IMT) ＜1.0mm ( n =32) and IMT≥1.0 mm( n =22).The IMT and diameter were measured by two-dimensional ultrasound.The blood velocity in early and late systolic stages and early diastolic reverse blood velocity,resistance index and pulsatile index were measured by pulse Doppler.The stiffness parameter,pressurestrain elasticity modulus,arterial compliance,argumentation index and one-point pulse wave velocity were measured by echo-tracking technique.Results The early diastolic reverse blood velocity,resistance index,pulsatile index,stiffness parameter,pressure-strain elasticity modulus and one-point pulse wave velocity were significantly elevated in T2DM patients compared with healthy control (P ＜ 0.05),the arterial compliance was significantly lower in T2DM subjects.Stiffness parameter,pressure-strain elasticity modulus and one-point pulse wave velocity were more pronounced in the patients with IMT≥1.0 mm than those with IMT ＜ 1.0 mm ( P ＜0.05).Conclusions There is atherosclerosis in femoral arteries in patients with T2DM.A decrease in arterial elasticity occurs prior to the morphological changes in vascular atherosclerosis,the arterial elasticity abnormality causes insufficient blood supply to peripheral tissues.
ABSTRACT
BACKGROUND:Single photon emission computed tomography (SPECT)measurement is capable of detecting very early cerebral circulatory disorders accurately and assessing the time-window and the possibility of reversible brain function after reperfusion at various post-ischemia time points.OBJECTIVE: To establish the swine model of ischemic stroke, to assess the time-window of reversible ischemia and to evaluate the significance of SPECT cerebral ischemia-perfusion imaging on predicting very early time window.DESIGN: Randomized, controlled and experimental study.SETTING: Neurological department of a municipal hospital.MATERIALS: From January to August 2002, it was completed at the Laboratory Animal Research Center of Qingdao Municipal Hospital. Twelve 4 months old domestic swine (Sus scrofa), males and females and weighing 8-10 kg, were selected and fed with conventional method.INTERVENTIONS: Twelve swine pigs were divided into block group and reperfusion group, 6 in each group. In all the pigs, common carotid artery in one lateral was blocked by a clamp. Animals in block group sacrificed at 2, 4, 5, 6, 8 and 10 hour respectively. In perfusion group, clamps were removed at 2, 4, 5, 6, 8 and 10 hour respectively, and then the animals were killed 24 hours later. Before sacrifice, all the animals underwent SPECT examination, regional cerebral blood flow (rCBF) measurement and CT scan. After sacrifice, 1 mm3 brain tissues were taken from each lobe and were stained by HE staining. Then light microscope and electron microscope were used to study the histological changes.MAIN OUTCOME MEASURES: SPECT and brain CT scan were used to investigate the cytological changes in brain tissues after various length of ischemiaRESULTS: Twelve swine pigs entered the statistical analysis procedure.By using light microscope and electron microscope, it was found that at 5 hour after operation, neurons in operational side were a little swelled, with swelled mitochondria, a mitochondria crests loss and a progressive plasma loss in a few neurons. While in those with clamps removed within 4 hours after turn off, brain tissue structures were mainly restored.CONCLUSION: SPECT is capable of detecting ischemic brain injury immediately. It is proved by histological evidence that a more-than-5-hour ischemia will cause irreversible changes in neurons.