ObjectiveTo investigate the plasma endothelin(ET),angiotensin (Ang) Ⅱ levels on middle cerebral artery resistance in hypertension patients.MethodsThe plasma ET and Ang Ⅱ levels were determined in hypertension grade 1 (grade 1 group,40 cases),grade 2 (grade 2 group,40 cases ),grade 3(grade 3 group,40 cases) and healthy adults (control group,50 cases).The systolic velocity and pulsatility index of middle cerebral artery were determined by transcranial Doppler,and 24 h ambulatory blood pressure was monitored.ResultsThe pulsatility index in grade 2 group and grade 3 group was higher than that in control group and grade 1 group (1.23 ±0.22,1.31 ±0.21 vs.0.76 ±0.18,0.78 +0.13)(P＜0.05).The systolic velocity in grade 2 group was higher than that in control group,grade 1 group and grade 3 group [(87.8 ± 11.7) cm/s vs.(60.8 ± 10.6),(63.8 ± 11.8),(49.9 ± 10.8) cm/s](P ＜ 0.05),and in grade 3 group was lower than that in control group,grade 1 group and grade 2 group(P ＜ 0.05 ).The plasma ET,Ang Ⅱ in grade 1,2,3 group was higher than that in control group[(46.83 ± 8.83 ),(55.63 ± 10.28 ),(67.19 ± 10.73)ng/L vs.( 38.94 ± 7.83 ) ng/L and ( 50.23 ± 9.23 ),(64.34 ± 12.23 ),( 79.83 ± 13.43 ) ng/L vs.(41.63 ± 8.76 )ng/L] (P ＜0.05).A increasing trend in the plasma ET and Ang Ⅱ was present with increasing the hypertension grade(P ＜ 0.05 ).The night average systolic pressure,night average diastolic pressure and plasma ET,Ang Ⅱ levels in dipper hypertension patients (60 cases) were lower than those in non-dipper hypertension patients(60 cases) [(121.83 ± 11.83) mm Hg(1 mm Hg =0.133 kPa) vs.(138.84 ± 13.29)mm Hg,(77.23 ± 8.54) mm Hg vs.(86.93 ± 10.34) mm Hg,(48.83 ± 10.14) ng/L vs.(59.83 ± 11.29)ng/L,(55.84 ± 10.83 ) ng/L vs.(72.83 ± 20.29) ng/L,P ＜ 0.05].ConclusionMonitoring plasma ET,Ang Ⅱ levels and ambulatory blood pressure in hypertension patients is helpful in using medicine to improve endothelial function and to promote its dynamic type into a dipper blood pressure in the treatment of patients,thereby to reduce the incidence of hypertension adverse events.

BACKGROUND: The biomechanical features of arch-dental shape memory connector designed for fractures in pelvis or the parts adjacent to joints are analyzed through biomechanical calculation and experimental measurements.OBJECTIVE: To explore the relationship between the changes in shape of arch-dental shape memory connector and the load on it.DESIGN: Both biomechanical calculation and the experimental measurement were conducted for mutual supplementation and confirmation.SETTING: The Orthopedic Department of Changhai Hospital Affiliated to the Second Military Medical University of Chinese PLA and the Life Science and Bioengineering College of Tongji University.MATERIALS:The trial was conducted from at Shanghai Changhai Hospital and Life Science Laboratory of Tongji University from April 2002 to April 2004. The subjects were arch-dental shape memory connectors.METHODS: We calculated the stress in and around the fracture face produced by arch-dental shape memory connector according to Moire principle and we also measured the changes in the shape of arch-dental shape memory connector. The relationship between load and the changes in the shape of arch-dental shape memory connector was explored.MAIN OUTCOME MEASURES: To explore whether the results of biomechanical calculation and those of the experimental measurement are consistent.RESULTS: Biomechanical calculation found that the relationship between the load (P) and the displacement(δ) in arch-dental shape memory connector was P = 13.69δ. The experimental measurement found that the load on the connector and the displacement were in a linear relationship.CONCLUSION: The relationship between the load and the displacement in arch-dental shape memory connector was linear within its elastic range and the biomechanical calculation results were consistent with the results of the experimental measurement.

Objective:To study the biomechanical basis of swan like memory compressive connector (SMC) for treating fractures and nonunions, and the facilitating effects of dynamic memorial stress of SMC for bone healing. Methods:By computer emulation and three dimensional (3D) finite element analysis, the biomechanical behavior of humeral type connector for fixing humerus was emulated and analyzed. The finite element model of humeral type connector was divided into 3 487 units. The number of nodes was 5 397. The element was a unit with 20 nodes, 4 faces. The finite element model of humerus was divided into 5 783 units, the number of nodes was 9 863. And the finite element was a 3D unit with 10 nodes, 4 faces.Results:When the connector fixated humerus, it came in for tension stress in its inner surface, and compressing stress in its outer surface. The maximum first structural major stress of metamorphosed compressive part was 224.5 MPa and -34 MPa, far less than its utmost stress and fatigue limit. The initiative memorial bone holding force for maintaining axial stability was 125.05 N, and the longitudinal initiative memorial compression force was 196 N. The stress distribution in fixed humerus was even, the stress in most nodes was positive stress. Conclusion:The SMC has good anti fatigue and reuse characters. The dynamic memorial compressive stress field is good for the stability of fixation and enhancement of bone healing.

BACKGROUND: Various therapies can be used to treat humeral fracture,but serious complications like bone disunion, etc. Are often left over. New biomechanical analytical methods are tried to be applied to provide new approaches for the functional prognosis in humeral fracture and bone disunion.OBJECTIVE: To construct humeral three-dimension model to explore its correlated biomechanical significance.DESIGN: To construct humeral three-dimension finite element model. SETTING: Department of orthopedics of a military medical university-affiliated hospital and institute for biological science and bioengineering of a university.PARTICIPANTS: The study was conducted in Shanghai Changhai Hospital and the Laboratory of Biological Science of Shanghai Tongji University. One piece of typical adult wet humerus sample was selected.INTERVENTIONS: Cross section image of each humeral layer was obtained from the selected wet humerus sample by CT scanning, and humeral three-dimensional model was constructed by large finite element analytic software ANSYS5.6.MAIN OUTCOME MEASURES: ① Biomechanical features of the constructed humeral three-dimension mode; ② Differences from clinical reality and key similarities.RESULTS: The constructed humeral three-dimensional model vividly reflected the true humeral anatomic morphology and biomechanical behavior. Its precision was judged by the comparison with CT image.CONCLUSION: The construction of humeral three-dimension finite element model provides a precise model for the researches of normal humeral mechanical behavior and the basic mechanics of internal fixation after fracture.

BACKGROUND: The biomechanical features of Swan-like memory compression connector designed for fractures in hemerus or the parts adjacent to joints are analyzed through biomechanical calculation and experimental measurements.OBJECTIVE: To analyze the relative memory biomechanieal significance through biomechanical measurement of Swan-like memory compression connectorDESIGN: Both biomechanieal calculation and the experimental measurement were conducted for mutual supplementation and confirmation SETTING: The Orthopaedic Department of Changhai Hospital Affiliated to Second Military Medical University of Chinese PLA and the Life Science and Tissue Engineering Institute of Tongji University MATERIALS: This experiment was conducted at the laboratory of Orthopaedic Department of Changhai Hospital Affiliated to Second Military Medical University of Chinese PLA and the Life Science and Tissue Engineering Institute of Tongji University between January 2001 and May 2003.Totally 20 hemerus from adult males who died of craniocerebral injury were chosen.METHODS: Humid hemerus from the adult corpse was chosen to prepare fracture. Encircling the prescale followed by fixation of Swan-like memory compression connector, then we measured the stress produced by compression part and encircle part at fixing the fracture.MAIN OUTCOME MEASURES: ①The stress of holding part; ② the stress of the compression part RESULTS: The stress range of holding part contacting with humerus was 2.42-22.68 N, and the stress in the fracture face, which was produced by compression part, was about 13.6 Mpa.CONCLUSION: The stress of holding part of Swan-like memory compression connector is useful in fixing the fracture parts of humerus, and the stress of compression part is suitable for the healing of fracture.

BACKGROUND: During the therapy of the fracture of humerus, the main problem is the loading direction and power of the stress.OBJECTIVE: To analyze the choice of the different loading manners using Swain Memory Compression Bone Reduction Apparatus so as to provide the clinical evidence for the set position of the internal fixation apparatus, the loading direction and power during the therapy of the fracture of humerus.DESIGN: To construct the three-dimensional finite element model of the fracture of humerus with different loading manners.SETTING: Department of Orthopaedics of Changhai Hospital of Second Military Medical University of Chinese PLA; College of Life Sciences and Bioengineering of Tongji University,MATERIALS: The study was conducted during the period from January 2001 to May 2003 in the Orthopedic Laboratory of Changhai Hospital of Second Military Medical University of Chinese PLA and the laboratory of Life Science and Bioengineering Academy of Tongji University. The samples of the humerus taken from the wet adult cadavers, and the Swain Memory Compression Bone Reduction Apparatuses of the corresponding size were prepared.METHODS: The CT scanning was done on the samples of the wet humerus to obtain the cross section image of each layer of the humerus.The images were analyzed by a large-scale finite element analysis software ANSYSS.6 to construct the three-dimensional model of the humerus, Swain Memory Bone Reduction Apparatus and the fixed humerus using Swain Memory Bone Reduction Apparatus.MAIN OUTCOME MEASURES: To get the reference values for the clinical therapy through the comparison of the power endurance with different loading manners.RESULTS: The three-dimensional model of the fixed humerus using Swain Memory Bone Reduction Apparatus reflects the real anatomical configuration and the biomechanics behavior; meanwhile the status of the power endurance of humerus with different loading manners is also obtained.CONCLUSION: The three-dimensional model of the fixed humerus using Swain Memory Bone Reduction Apparatus may provide an accurate model for the basic study of the biomechanics behavior of the normal and fixed humerus after the fracture.

BACKGROUND: The most frequently encountered problem that an orthopedic doctor encounters in treating humerus fracture is how to choose the exact direction and amount of load applied on humerus.OBJECTIVE: To explore the clinical significance of establishing a three-dimensional model and finite element analysis in treating humerus fracture and to provide theoretical basis for applying appropriate axial stress.DESIGN: The three dimensional model of humerus was reconstructed, on which compression from different directions was applied.SETTING: Orthopedic department of an affiliated hospital and life science laboratory of a university.MATERIALS: A humerus specimen received CT scanning and the trial was conducted in Shanghai Changhai Hospital and Life Science Laboratory of Tongji University from April 2002 to April 2004.METHODS: The three dimensional model of humerus was established and relevant calculation was completed with ANSYS 5.6 software. The humerus model was divided into 2 729 nodes and 49 041 units based on a three-dimensional ten-node tetrahedron as one unit. The distribution and intensity of axial compression on the fracture gap section were calculated and analyzed in the following conditions, i. e. when the humerus was fixed in X, Y and Z directions and the fracture gap section was 30°, 45°, 90° to Z axis.MAIN OUTCOME MEASURES: The axial pressure on the fracture gap section in different conditions to provide evidence for clinical treatment.RESULTS: The stress applied on the fracture gap was relatively concentrated and was 2 -3 times stronger than that in other areas, and it was generally symmetrically distributed within 10 mm around the fracture gap.CONCLUSION: The required load on humerus fracture should be calculated before a suitable implant is applied to accommodate the movement of humerus without compromising healing of the fracture.

Objective To observe the influence of pioglitazone on the expression of adiponectin in the liver of high fat diet-induced obese rats.Methods Forty male SD rats were randomly divided into control group which received regular diet ( n =10),high fat diet group ( n =15 ) and high fat diet goup administened pioglitazone ( n =15 ) on high fat diet.After twelve weeks,fasting blood glucose,fasting serum insulin,triglyceride,total cholesterol,and the histomorphologieal changes in liver were observed;insulin sensitivity test was performed;the fatty experimental group are treated with Pioglitazone(30mg · kg-1 · d-1,oral gavage),treatment was administered daily for 2 weeks.The control group and fatty control group all received an equal volume of vehicle (saline).The protein expression of adiponectin in the liver of rats was determined by immunohistochemistry.Results The insulin sensitive index was significantly decreased in the high-fat-diet rats compared with the control group[(0.021 ±0.010),(0.015 ±0.007),P ＜0.05] ;The protein level of adiponectin in the liver of fatty,control group was significantly decreased compared with the control group[(2929.73 ± 157.45 ),(3814.21 ±211.42),P ＜0.05],adiponectin in the liver of fatty experimental group was significantly increased compared with the fatty control group[(2929.73 ± 157.45),(3657.68 ±217.31 ),P ＜0.05].Conclusion Pioglitazone could improve the expression of adiponectin,and improve the resistance of insulin.

OBJECTIVETo determine whether the level of serum cardiac troponin T (cTnT) was increased in patients with congestive heart failure (CHF).

METHODSThis study consisted of 265 patients with CHF and 75 healthy people. Serum cTnT was measured by electrochemiluminescence immunoassay using an Elecsys 1010 automatic analyzer.

RESULTScTnT concentration was 0.181 +/- 0.536 ng/mL in CHF patients and 0.003 +/- 0.001 ng/mL in controls (P < 0.001). Patients were categorized according to the levels of heart function and left ventricular ejection fraction (LVEF). In the first group consisting of 105 patients with LVEF 35%, cTnT was 0.07 +/- 0.0 5 ng/mL (P < 0.01). In patients with NYHA class I, II, III and IV, cTnT values were 0.062 +/- 0.022 ng/mL, 0.113 +/- 0.121 mg/mL, 0.191 +/- 0.231 mg/ml and 0.384 +/- 0.211 mg/mL, respectively (class I vs class II P > 0.05, class II vs class III P < 0.01, class III vs class IV P < 0.01). A negative correlation was observed between serum cTnT concentration and LVEF in 265 patients with CHF (r = -0.493, P < 0.001).

CONCLUSIONSThis study shows that the level of serum cTnT is increased in patients with CHF and that the increased level indicates the severity of CHF.

Adult ; Aged ; Female ; Heart Failure ; blood ; physiopathology ; Humans ; Male ; Middle Aged ; Stroke Volume ; Troponin T ; blood ; Ventricular Function, Left