Objective To compare the difference of the left ventricular structure and diastolic func-tion in normotensive offspring with or without a family history of hypertension. Methods One hundred nor-motensive offspring were assessed. Fifty had a family history of hypertension (experimental group) and 50 had no family hi.history of hypertension (control group). By eehocardiography and Doppler tissue imaging, the following parameters of left ventricular structure and diastolic function were examined: interventricular septal thickness (IVST), left ventrieular posterior wall thickness (LVPWT), left ventricular internal dimension (LVIDed), left ventrieular mass index(LVMI) and E/A. Results Compared with control group, experimen-tal group had higher IVST, LVPWT and LVMI, lower peak velocity of the early diastolic wave (e) of mitral annulus, and lower e/a (P<0.05). No differences in LVIDed, left atrial diameter (LA),aortic dimension(AOD), E,A and E/A were found between the two groups. Conclusion The results indicate that genetic factor of parental hypertension influence left ventrieular structure and diastolic function in normotensive offspring, which may precede the elevation of blood pressure.

OBJECTIVETo construct a three-dimensional finite element model of the upper airway and adjacent structure of an obstructive sleep apnea hypopnea syndrome (OSAHS) patient for biomechanical analysis. And to study the influence of glossopharyngeum of an OSAHS patient with three-dimensional finite element model during titrated mandible advancement.

METHODSDICOM format image information of an OSAHS patient's upper airway was obtained by thin-section CT scanning and digital image processing were utilized to construct a three-dimensional finite element model by Mimics 10.0, Imageware 10.0 and Ansys software. The changes and the law of glossopharyngeum were observed by biomechanics and morphology after loading with titrated mandible advancement.

RESULTSA three-dimensional finite element model of the adjacent upper airway structure of OSAHS was established successfully. After loading, the transverse diameter of epiglottis tip of glossopharyngeum increased significantly, although the sagittal diameter decreased correspondingly. The principal stress was mainly distributed in anterior wall of the upper airway. The location of principal stress concentration did not change significantly with the increasing of distance. The stress of glossopharyngeum increased during titrated mandible advancement.

CONCLUSIONA more precise three-dimensional finite model of upper airway and adjacent structure of an OSAHS patient is established and improved efficiency by Mimics, Imageware and Ansys software. The glossopharyngeum of finite element model of OSAHS is analyzed by titrated mandible advancement and can effectively show the relationship between mandible advancement and the glossopharyngeum.

Finite Element Analysis ; Humans ; Mandible ; Sleep Apnea, Obstructive ; Tomography, X-Ray Computed

OBJECTIVETo visualize epicardial and intramyocardial coronary blood flow by using a noninvasive echocardiography system.

METHODSIn five juvenile swines, coronary flow imaging was used to visualize the different segments of epicardial coronary and intramyocardial arteries. Pulsed-Doppler spectrums were recorded and analyzed. The left anterior descending artery (LAD) and intramyocardial coronary blood flow signals were recorded at baseline and during dipyridamole administration.

RESULTSEpicardial and intramyocardial coronary arteries could be visualized by coronary flow imaging. The systolic component of coronary flow in the right coronary artery (RCA) was greater than in the LAD. The intramyocardial blood flow was characterized by persistent retrograde blood flow velocity during systole. Vasodilation with dipyridamole produced exaggerated differences in the phasic pattern of coronary blood flow in epicardial and intramyocardial vessels.

CONCLUSIONColor Doppler coronary flow imaging provides a noninvasive method to study the coronary blood flow.

Animals ; Coronary Circulation ; Coronary Vessels ; diagnostic imaging ; Dipyridamole ; Echocardiography ; methods ; Male ; Swine

BACKGROUND:Due to the lack of mechanical stimulation generated by functional loading,alveolar bone atrophy and bone loss in the missing area prevents the effective embedding of dental implants.Therefore,it is necessary to implant bone meal during implantation to compensate for the lack of alveolar bone height on the stability of the implant. OBJECTIVE:To derive the optimal time point for second-stage restorations from a biomechanical perspective by means of finite element analysis,thereby providing a biomechanical basis for selecting the correct time point for second-stage restoration to shorten the clinical course of dental implantation. METHODS:Three-dimensional finite element models of the maxilla were developed for normal,16-deficient with conventional implant surgery(model B)and 16-deficient with internal maxillary sinus lift(model A).Model A was filled with hydroxyapatite bone powder between the mucosa and the maxillary sinus floor,and Model B and the normal maxillary bone model did not require bone grafting.The healing time of bone grafting was set at 3-9 months postoperatively,and a force of 200 N was applied to the adjacent teeth at 3-5 months postoperatively,and directly to the implant at 6-9 months,simulating the load applied to the implant in the second stage of restoration.Biomechanical analysis of the three models was performed with the aid of the implants and the surrounding hard and soft tissues. RESULTS AND CONCLUSION:The stress on Model A and Model B was around 103 MPa and 95 MPa respectively when the force was directly loaded onto the implant.Bone grafting increased the stress values on the implant,while not doing bone grafting reduced the stress on the implant and the whole system.As the strength of the bone powder increased,the stress values on the alveolar bone decreased.When the healing time was up to 6-9 months postoperatively,the stress values were ranked as follows:normal model