OBJECTIVETo assess the effect of the autologous venous external stents on intimal hyperplasia of the vein grafts in rabbits.

METHODSThirty-six male New Zealand white rabbits, aged 5 months and weighing 2.8 to 3.0 kg, were randomly divided into 3 groups: group A, group B and group C, with 12 rabbits in each group. First, a section about 6 cm long of vein was cut from the right external jugular vein of each rabbit and severed to have 3 equal-length segments. Next, each distal segment prepared for anastomosis. The proximal segment invaginating middle segment in group A and only middle segment in group B were used for the external stent. Later, the left common carotid artery was separated from surrounding tissue, from it a section about 0.5 cm long was cut away. Finally, the vein graft was inverted and end-to-end anastomosed to the two ends of the artery with a 9-0 suture. After bloodstream re-established, the diameter of each vein graft was measured. At 2 and 4 weeks postoperative, the graft veins were cut off and histologically examined by the means of HE staining and Masson staining. The smooth muscle cells (SMC) proliferation was studied by the immunohistochemical detection of proliferating cell nuclear antigen.

RESULTSAfter bloodstream re-established, the diameters of vein graft of group A and group B and group C were (1.6 +/- 0.3) mm, (2.2 +/- 0.4) mm and (2.6 +/- 0.6) mm respectively (P < 0.05). At 4 weeks postoperative, the data of the ratio of intima to media thickness and the index of the proliferating cells of the intima were as follow: group A (1.01 +/- 0.07 and 6.84 +/- 1.98), group B (1.32 +/- 0.08 and 11.01 +/- 2.61), group C (1.55 +/- 0.03 and 14.96 +/- 4.14). Both the data of group A were obviously less than that in group B, and that of group B was less than group C (P < 0.05).

CONCLUSIONThe autologous venous two-layer external stents inhibit intimal hyperplasia of the vein grafts.

Animals ; Hyperplasia ; pathology ; prevention & control ; Male ; Rabbits ; Stents ; Transplantation, Autologous ; Tunica Intima ; pathology ; Veins ; pathology ; transplantation

BACKGROUNDExternal stents have been used to reduce intimal hyperplasia of vein grafts. The aim of the present study was to define the size of an external stent appropriate for a particular graft by comparing vein grafts with different sizes of external stents.

METHODSA series of paired trials was performed to compare femoral vein grafts with different sizes of external stents, where 30 modeled canines were equally divided into three groups: 6-mm external stent vs non-stent control, 4-mm vs 6-mm external stent, and 4-mm vs 8-mm external stent. At day 3 after operation, color Doppler flow imaging (CDFI) was done to observe blood flow in the lumen. Four weeks later, CDFI was re-checked and the veins were harvested, stained and measured.

RESULTSAll grafts were patent without formation of thrombosis. External stents significantly reduced intimal thickness of the vein grafts with a 6-mm external stent compared with the vein grafts without external stents (P < 0.05). The vein grafts with the 4-mm external stent had similar intimal, medial and adventitial thicknesses compared with those with the 6-mm external stent and the 8-mm external stent.

CONCLUSIONSExternal stents can reduce intimal hyperplasia of vein grafts. Stents of different diameters exert the similar effect on prevention of intimal hyperplasia.

Animals ; Aspirin ; therapeutic use ; Dogs ; Femoral Vein ; transplantation ; Hyperplasia ; Stents ; Tunica Intima ; pathology ; Ultrasonography, Doppler, Color

BACKGROUNDThis study was designed to investigate the relationships between changes in the structure and function of carotid arteries and angiotensin converting enzyme (ACE) gene polymorphism in Chinese hypertensive subjects.

METHODSMultiplex polymerase chain reaction amplification was used to evaluate the ACE gene insertion/deletion (I/D) polymorphism. High-resolution B-mode ultrasound examinations were performed to detect parameters of carotid artery remodeling.

RESULTSIntima-media thickness (IMT) was significantly different among the DD, ID and II genotypes of ACE (DD > ID > II, P < 0.05). Carotid internal diameter, distensibility and stiffness were similar among the DD, ID and II genotypes of ACE (P > 0.05) in hypertensive subjects. The frequency of the DD gene and D allele of ACE were higher in patients with thickening carotid than in patients with normal carotid (70.4% vs 24.1%, and 79.5% vs 40.5%, respectively, P < 0.001). In multiple stepwise regression analysis, independent risk factors for increased carotid IMT in hypertensive subjects were ACE genotypes (P < 0.001), age (P < 0.001) and carotid internal diameter (P = 0.032). Moreover, triglycerides and total cholesterol were higher in patients with the DD genotype than in those with the II genotype (P < 0.05).

CONCLUSIONSThe I/D polymorphism of the ACE gene was related to IMT, but not to internal diameter, distensibility and stiffness of the carotid in Chinese hypertensive subjects. ACE gene polymorphism was a main risk factor for increased carotid IMT. These results may imply that there is a link between lipid metabolism and ACE genotype polymorphism in Chinese hypertensive subjects.

Asian Continental Ancestry Group ; genetics ; Carotid Arteries ; pathology ; China ; Humans ; Hypertension ; pathology ; Middle Aged ; Peptidyl-Dipeptidase A ; genetics ; Polymorphism, Genetic ; Tunica Intima ; pathology ; Tunica Media ; pathology

PURPOSE: Prader-Willi syndrome (PWS) is a genetic disorder characterized by childhood-onset obesity and endocrine dysfunction that leads to cardiovascular disability. The objective of the study is to assess the relationship between carotid intima-media thickness (IMT) and atherosclerotic risk factors. MATERIALS AND METHODS: Twenty-seven PWS children and 24 normal controls were enrolled. Correlations of IMT with atherosclerotic risk factors were assessed. RESULTS: IMTs in the PWS group did not differ from those in the controls (p = 0.172), although total ghrelin levels were higher in the PWS children (p = 0.003). The multivariate analysis revealed positive correlations between total ghrelin levels (rho = 0.489, p = 0.046) and IMT in the PWS group and between body mass index-standard deviation score (BMI-SDS) (rho = 0.697, p = 0.005) and IMT in the controls. CONCLUSION: Considering the positive correlation of IMT with total ghrelin levels and the high level of ghrelin in PWS children, a further study is warranted to evaluate the role of elevated ghrelin on atherosclerosis for PWS.
Adolescent ; Carotid Arteries/*pathology ; Child ; Female ; Ghrelin/*blood ; Humans ; Male ; Prader-Willi Syndrome/*blood/*pathology ; Tunica Intima/*pathology ; Tunica Media/*pathology

Increased intima-media thickness (IMT) and pulse wave velocity (PWV) are noninvasive markers of early arterial wall alteration and are more widely used in adult clinical research. We investigated whether IMT and PWV are useful predictors of cardiovascular risk in hypertensive adolescents. Fifteen hypertensive adolescents (13-18 yr old, systolic BP > or = 140 mmHg, diastolic BP > or = 90 mmHg) and seventeen normotensive subjects were included. Height, weight, obesity index, body mass index (BMI), and fat distribution were obtained from each group. Serum lipid, insulin, vitamine B12, folate, renin, aldosterone, angiotensin-converting enzyme (ACE), and homocysteine levels were compared. The carotid IMT and PWV were measured. Arterial wall compliance and distensibility were calculated with the equation. High systolic blood pressure significantly correlated with height, weight, BMI, obesity index, arm circumference, fat mass, and fat distribution. Hypertensive adolescents had significantly greater cIMT (carotid intima-media thickness) and lower elastic properties such as cross-sectional compliance and distensibility of the carotid artery. The carotid IMT significantly correlated with brachial-ankle PWV. In conclusion, the measurement of carotid IMT and brachial-ankle PWV might be useful to predict the development of atherosclerosis in hypertensive adolescents.
Adolescent ; Arteries/*pathology/physiopathology ; Body Mass Index ; Elasticity ; Female ; Humans ; Hypertension/*pathology/physiopathology ; Male ; Tunica Intima/*pathology/physiopathology ; Tunica Media/*pathology/physiopathology

Adult ; Biopsy ; methods ; Cardiac Catheterization ; Female ; Humans ; Pulmonary Artery ; pathology ; Sarcoma ; diagnosis ; pathology ; Tunica Intima ; pathology ; Vascular Neoplasms ; diagnosis ; pathology

The aim of the present study was to investigate the effect of removal of the adventitia on vascular remodeling and vasoconstriction of the carotid artery in New Zealand rabbit. Adventitia of carotid artery was removed mechanically. The histology, morphology and reactivity of the carotid artery was observed by immunohistochemistry and measurement of carotid ring tension immediately, 1 week and 2 weeks after removal of the adventitia. No damage of intima and media was observed after removing the adventitia. Removal of the adventitia caused a remarkable proliferation of the vascular media and formed the neointima. Compared with the control ring, norepinephrine (NE)-induced vasocontraction in adventitia-denuded carotid artery was significantly reduced immediately and 1 week after the operation (P<0.05). Adventitia removal promoted the neointima formation and decreased vasoconstriction of the carotid artery, indicating that the adventitia is involved in the regulation of vascular remodeling and vasoconstriction.
Animals ; Carotid Arteries ; pathology ; physiology ; surgery ; Connective Tissue ; physiology ; surgery ; Muscle, Smooth, Vascular ; pathology ; Rabbits ; Tunica Intima ; pathology ; Vasoconstriction ; physiology

We examined whether alterations in vascular endothelial function and early structural changes in atherosclerosis are associated with microvascular complications in patients with type 1 diabetes mellitus (DM). Flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (IMT) measurement were performed in 70 young adults (aged 19 to 35 yr), 48 with type 1 DM, and 22 normal controls. Patients with diabetes had a lower peak FMD response (7.8+/-3.9 vs. 11.1 +/-1.9%, p<0.001) and increased IMT (0.51+/-0.10 vs. 0.42+/-0.07 mm, p<0.001) compared with controls. Twenty (41.7%) of the patients had microvascular complications including neuropathy, nephropathy, or retinopathy. In these complicated diabetic patients, we found a lower FMD response (6.1+/-2.5 vs. 9.9+/-3.5%, p=0.001) compared with diabetics without microvascular complications. The presence of microvascular complications was also associated with older age and longer duration of the disease. However, no differences were observed in IMT, body size, blood pressure, HbA1c, C-reactive protein, low-density lipoprotein or high-density lipoprotein cholesterol levels between complicated and non-complicated patients. Endothelial dysfunction and early structural atherosclerotic changes are common manifestations in type 1 DM, and endothelial dysfunction is thought to be an early event in the atherosclerotic process and important in the pathogenesis of microvascular complications.
Adult ; Diabetes Mellitus, Type 1/*complications ; Diabetic Angiopathies/*etiology ; Endothelium, Vascular/*physiology ; Female ; Humans ; Male ; *Microcirculation ; Tunica Intima/pathology ; Tunica Media/pathology ; Vasodilation

OBJECTIVETo understand whether hyperhomocysteinemia and early arterial atherosclerosis exist in simply obese children.

METHODSTotally 68 simply obese children (age 6-14 years, mean 10.8 +/- 2.3 years) were enrolled in this study, 50 were male and 18 were female. Body mass index (BMI) of the obese children was equal to or more than 22. The height of the children was (145 +/- 22) cm. Meanwhile, 26 normal children (age 6 - 14 years, mean 10.9 +/- 2.0 years) were selected as control group, 17 of these children were male and 9 were female. Their height was (148.5 +/- 5.8) cm. There were no significant differences in height and age between the obese and the control children. The carotid intimal-medial thickness (IMT), brachial artery flow-mediated vasodilation were examined by Doppler Flow/Dimension System and the liver was examined by B-mode ultrasound imager. Plasma homocysteine was determined by the automated chemiluminescent enzyme immunoassays. Serum lipid concentration was determined by biochemical analytic method. Blood pressure of the right upper limbs was measured. A detailed medical and family history was systematically recorded.

RESULTSBMI was (27.8 +/- 4.5) in the obese children and (16.2 +/- 2.5) in the controls. There was significant difference between two groups (P < 0.01). The obese children had significantly increased values than the controls for the carotid intimal-medial thickness (P < 0.01). Right carotid IMT, right inner-carotid IMT, left carotid IMT and left inner-carotid IMT were respectively (0.54 +/- 0.13) mm, (0.69 +/- 0.14) mm, (0.52 +/- 0.12) mm and (0.67 +/- 0.14) mm in obese children and were respectively (0.45 +/- 0.04) mm, (0.46 +/- 0.04) mm, (0.45 +/- 0.05) mm and (0.46 +/- 0.03) mm in control groups. Conversely, the flow-mediated brachial artery dilation of the obese children was significantly lower than that of the controls [(11.0 +/- 4.3)% vs. (17.5 +/- 4.9)%, P < 0.01]. The obese children had higher level of plasma homocysteine than the controls [(7.9 +/- 2.7) micromol/L vs. (5.6 +/- 2.1) micromol/L, P < 0.01]. Total cholesterol (TC) in the obese children dramatically increased, so did triglyceride concentration (TG), LDL-cholesterol (LDL-ch) and apolipoprotein-B (apo-B). Of the obese children, had fatty liver or the tendency to fatty liver. Six cases of the 68 obese children (8%) had hypertension. Of the 68 obese children, 57 (84%) had the history of consuming excessive food or taking less exercise. Forty-four percent of the obese children (30/68) came from the obese families in which at least one of the parents or grandparents was obese. Twenty-nine percent (20/68) and 22% (15/68) of the obese children respectively came from the families in which at least one of the parents or grandparents suffered from hypertension or coronary heart disease.

CONCLUSIONEarly arterial atherosclerotic changes existed in simply obese children. Hyperhomocysteinemia may be an important factor of the obesity-induced early arterial atherosclerosis during childhood.

Adolescent ; Atherosclerosis ; blood ; etiology ; Carotid Artery Diseases ; etiology ; Child ; Female ; Homocysteine ; blood ; Humans ; Hyperhomocysteinemia ; complications ; Lipids ; blood ; Male ; Obesity ; blood ; complications ; Tunica Intima ; pathology ; Tunica Media ; pathology

Humans ; Hyperplasia ; etiology ; Male ; Middle Aged ; Prosthesis Failure ; Stents ; Tomography, Optical Coherence ; adverse effects ; Tunica Intima ; pathology