BACKGROUND:As a bone reconstruction material, nano-hydroxyapatite has good biocompatibility and osteoconduction, but the clinical use of nano-hydroxyapatite alone stil has many deficiencies. OBJECTIVE:To explore the in vivo osteogenic capability of nano-hydroxyapatite/ polyamide composites. METHODS: Twenty-four New Zealand white rabbits were subjected to humeral head replacement using nano-hydroxyapatite/polyamide composite material. X-ray observation and histological observation were done at 3, 6, 12, 24 weeks after replacement. RESULTS AND CONCLUSION: (1) X-ray observation: No thinned cortical bone and ectopic ossification occurred on the upper end of the composite material at different time, and the nano-hydroxyapatite/polyamide material had no signs of fragmentation. The cortical bone around the composite material was fuzzy, and the bone mineral density was increased with time. (2) Histological observation: At 3 weeks after replacement, a large number of cels could be visible, including mesenchymal stem cels and mononuclear macrophages. At 6 weeks after replacement, a large amount of fibrous tissues, fibroblasts and mononuclear macrophages stil existed in the boundary membrane, but chondrocytes and osteoblasts distributed less. At 12 weeks after replacement, a wide range of original trabecular bone began to form and were mostly flat that arranged regularly. At 24 weeks after replacement, the boundary membrane was ful of bone cels, but the cels on the surface of trabecular bone were relatively regular and primitive cels in the bone tissue began to transform into the lamelar bone. These findings indicate that the nano-hydroxyapatite/polyamide material has good osteogenic capability.

Objective To assess left ventricular systolic and diastolic function in patients with hypertrophic cardiomyopathy(HCM) with the aid of pulsed Doppler tissue imaging (DTI) to measure the four sides of mitral annular. Methods Thirty subjects with HCM and Twenty five age and sex matched controls were performed 2D and Doppler echocardiography . Two groups were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. The velocities of systolic wave(Sa)、early diastolic filling wave (Ea)、late filling wave (Aa) and isovolumetric relaxation time were measured by DTI. Results Compared with normal control group, HCM group shows: (1) conventional data: LV wall thickness and mass indices were significantly greater. There were no significant difference in mitral flow Velocity. (2) DTI: There were more lower velocities of systolic and early diastolic filling wave. But isovolumetric relaxation time、mitra flow velocity / mitral annual early diastolic velocity ratio(E/Ea) increased. The velocities of systolic and early diastolic of septal site were the lowest among the 4 sides of the mitral annular and were the most closely with the average velocities of systolic and early diastolic of mitral annual. In addition, DTI may detect the pseudonormalization of mitral inflow. Conclusions DTI is more sensitive than conventional echocardiogram data and may be clinically used in exactly detecting left ventricular systolic and diastolic dysfunction in patients with HCM

Animals ; Cardiomyopathy, Hypertrophic ; drug therapy ; physiopathology ; Disease Models, Animal ; Enalapril ; pharmacology ; therapeutic use ; Rabbits ; Ventricular Remodeling

Adult ; Aneurysm, Dissecting ; complications ; Aortic Valve Insufficiency ; complications ; Female ; Humans ; Pregnancy ; Pregnancy Complications, Cardiovascular

Objective To characterize the systolic torsion in dilated cardiomyopathy (DCM) by velocity vector imaging(VVI).Methods Eighty-seven subjects were studied using VVI:27 patients with DCM and 60 healthy control subjects.Left ventricular short-axis acoustic images were acquired at base and apex levels.The rotation angle and rotation velocity of endocardium and epicardium were measured.Results LVEF of DCM group was significantly lower than that of control group ( P＜0.01).The basal and apical rotation angle, rotation velocity were significantly lower in DCM group.The endocardial and epicardial rotation angle, rotation velocity were also significantly lower in DCM group than those in control group (P＜0.01).Conclusions VVI is a rapid and noninvasive tool to quantitatively assess cardiac torsional deformation in DCM patients,which providing another useful modality for evaluating cardiac function.

Objective To investigate strain and strain rate of right ventricular(RV)based on twodimensional image by velocity vector imaging in normal subjects.Methods Thirty-two healthy adults were rolled in this study.Echocardiographic images in 4 chamber view were analyzed by conventional manual tracing for volumes and ejection fractions,which were also measured by velocity vector imaging.Myocardial velocity,strain rate,and strain were determined at the basal,mid,and apical segments of the RV free wall and ventricular septum by velocity vector imaging.Results RV ejection fractions obtained with manual tracing correlated strongly with the same indexes obtained by velocity vector imaging method in all subjects(r=0.91,P＜0.01).The strain and strain rate value of middle segment and basal segment in RV free wall were higher than those of apical segment.There were same trend in ventricular septal.The strain and strain rate of middle segment and basal segment in RV free wall were higher than those of homologous segments in ventricular septal,but the indexes of apical segment in free wail and septal had no difference.The strain and strain rate in RV were not correlated with age.Conclusions Velocity vector imaging could accurately and quantitatively assess the strain and strain rate of RV.

Objective To analyze the emergency medical services of the 2006 Olympic Came opening ceremony,and meanwhile to provide information and data for medical treatment at future international activities.Method About 120 000 people,consisting of athletes,actors,audience and staff,joined the opening ceremony.The emergency medical services were completed according to gathering regions,flowing directions,routes,and peaks,and the results were statistically analyzed.Results Twenty-two medical stations and 61 emergency medical supervising units provided pre-hospital services,and there turned out to be 573 patients during the opening ceremony.All of the patients were provided with emergent medical services on the spot,and some critically ill patients were sent to the local hospital after first aid.There was no death,serious.injuries,or chaos during the Opening Ceremony.Conchusions The foundation of emergency service is to set up a sound emergency response system.To successfully fulfill the minion.it is well-advised to enforce the pre-hospital human resources and emergency equipments,make serial trainings.collocate the medical station and supervising stands according to the the number of patients and its peak.

Objective To evaluate the value of MSCT perfusion imaging in assessment of single renal function of hydronephrotic kidney.Methods 64-slice spiral CT perfusion was performed in 36 obstructive nephrohydrosis patients whose split renal glomerular filtration rate(GFR) was measured by SPECT renal dynamic imaging. ①The perfusion parameters of the renal cortex and renal medulla of the hydronephrotic kidney were compared with the normal kidney studied by contrast group. ②The 72 kidneys were divided into normal renal function, mild and severe renal impairment groups according to renal function. Differences between the groups respect to all the mean perfusion parameters of the renal cortex and renal medulla were assesses by ANOVA. ③Using Pearsons correlation test, the correlations between all the mean perfusion parameters of the renal cortex and renal medulla and renal GFR were examined.Results ① The time-density curves of bilateral normal renal cortex and medulla were not symmetric. The mean BF, BV, PS, PBV of renal cortex were (203. 2±44.9)ml·100 ml~(-1)·min~(-1), (27.6±3.9)ml/100 ml, (30.7±6.5)ml·100 ml~(-1)· min~(-1), (46.5±10. 9)ml/100 ml; and the mean BF, BV, PS, PBV of renal medulla were (99.9±24.1)ml·100 ml~(-1)·min~(-1) ,(18. 3±4.3)ml/100 ml, (51.8±12.1)ml · 100 ml~(-1)· min~(-1) , (21.3±3.0)ml/100 ml. The mean perfusion parameters of the cortex and medulla of obstructed kidney were lower compared to that of normal kidney. ②There were significant differences of all the perfusion parameters of the renal cortex and me-dulla between 3 groups (P<0. 05). ③The perfusion parameters of the renal cortex and medulla had positive linear correlation with GFR. The best correlation was the blood flow of the cortex of kidney. The correlation coefficient r=0.852.Conclusions64-slice spiral CT perfusion imaging can quantita-tively evaluate the haemodynamic condition and functional lesion of the kidney, classify the impaired kidney function. The perfusion parameters of the renal cortex and medulla had positive linear correlation with GFR.

Objective To investigate the feasibility and accuracy of velocity vector imaging(VVI)to assess strain and strain rate of right ventrieule(RV)during varying myocardial functional states.Methods VVI of the longitudinal RV were recorded in 7 closed-chest anesthetized mongrel dogs from the apical 4-chamber view during 3 different inotropic states.Peak dp/dt from the RV contraction during the right cardiac catheterization,which was used as the gold standard of RV contractility,was obtained simultaneously in each inotropic state.Peak systolic velocities(V), peak systolic strain rates(SR),peak systolic strains(S)at the basal, middle and apical segments of RV free wall and septal from the longitudinal axis were quantitatively measured by using VVI software system respectively.Results The peak systolic strain and strain rate of the longitudinal RV free wall and septal were increased with the infusion of dobutamine and decreased with the infusion of metoprolol.A significant correlation was found between peak RV dp/dt and RV mean strain and mean strain rate(r=0.79, 0.75;P <0.01).Among all RV segments, the peak systolic S,SR of RV basal free wall had the most significant correlation to peak dp/dt (r=0.83,0.78;P<0.01).Conclusions Strain rate imaging drived from VVI could quantitatively and sensitively detect the longitudinal RV contractile function.Peak systolic S and SR determined at the longitudinal RV basal free wall were the strong noninvasive indices of RV contractility.

valuating the unilateral renal function of hydronephresis.