BACKGROUND:Mechanotransduction is an issue of concern in the study on the relationship between stress and growth. Mechano-growth factor (MGF) holds stress sensitivity, and exerts similar effect with stress in bone metabolism regulation. OBJECTIVE: To explore the mechanotransduction during bone remodeling, and investigate the relationship between stress and growth at molecular level. METHODS: The governing equations about the relationship between MGF and mechanical stimulation, regulation of MGF on osteoblasts and osteoclasts, regulation of MGF on RANK-RANKL-OPG signaling axis were established, and then the MGF-mediated bone reconstruction model was established to simulate the bone remodeling process under mechanical stimulation. RESULTS AND CONCLUSION:Under the condition of disuse, there was a decrease in osteoblasts/osteoclasts ratio, bone mass and bone volume fraction, and bone resorption was more than bone formation. Under the condition of overload, there was an increase in osteoblasts/osteoclasts ratio, bone mass and bone volume fraction, and bone formation was more than bone resorption. The simulation results were in accordance with Frost mechanostat theory. These findings show that the mechanobiological model of bone remodeling based on MGF can simulate the bone remodeling process under mechanical stimuli, and achieve mechanotransduction.

AIM:To study the relationship between apoptosis, proliferation and expression,mutation of related genes in breast cancer. METHODS: Methods of TUNEL, immunohistochemical S-P and PCR-SSCP were used respectively to study apoptotic index (AI), mitotic index(MI), expression of Bcl-2,p53,c-erbB-2,PCNA,Ki67,TopoⅡ and mutation of p53 in 54 cases of breast cancer. RESULTS: AI and MI were 9.40?3 78 and 5 96?2 36, respectively. There was a significant direct correlation between them( r= 0 46 P

Objective To study whether focal mild hypothermia can prolong the therapeutic time window in ischemic stroke, and inquire into the protection mechanisms of focal mild hypothermia on cerebral ischemia. Methods The focal cerebral ischemia and reperfusion model of rats was achieved by intraluminal middle cerebral artery occlusion (MCAO). The adult rats were randomly divided into sham-operation group, normothermia ischemia and reperfusion group and hypothermia ischemia and reperfusion group. The two ischemic groups were respectively further divided into 5 subgroups (subjected ischemia for 2, 3, 6, 8 and 12 h respectively and then all reperfused for 4 h, n=14 per time point). Brain mild hypothermia was achieved 30 minutes after ischemia and maintained to reperfusion period. The neurological deficit scores were assessed. The infarct volumes were evaluated by TTC staining and measured with a computerized image analysis system. TUNEL method was used to observe the neuron apoptosis. The expressions of NF-?Bp65 and NF-?BP65mRNA were detected by immunohistochemistry and hybridation in situ. Results The infarct volumes of hypothermia group were respectively (57.39?37.62) mm~3, (74.09?61.00) mm~3, (81.26?25.46) mm~3, (87.43?54.81) mm~3 and (111.10?43.67) mm~3, which saw significant reductions of 63%, 55%, 56%, 70% and 63% as compared with the normothermia group. In comparison with the normothermia group, focal mild hypothermia also greatly reduced the neurological deficit scores (P

Objective To study the relationships between cell kinetics, apoptosis and expression, mutation of related genes in breast cancer. Methods Flow cytometry, immunohistochemical SP and PCR SSCP were used respectively to study DNA index(DI), S phase fraction(SPF), proliferation index(PI), apoptosis index(AI), expression of c erbB 2, Bcl 2, p53, PCNA, Ki67, TopoⅡ and mutation of p53 in 54 cases of breast cancer. Results High DI, aneuploidy rate, SPF, PI and AI were coincided with high expression of c erbB 2, p53, PCNA, Ki167 and TopoⅡ. Low DI, SPF, PI and AI were coincided with high expression of Bcl 2. High DI, SPF, PI and AI were coincided with high mutation of p53. High AI was related to a type of p53 mutation——loss of heterozygosity(LOH). Conclusion Abnormal cell kinetics and apoptosis were related with abnormal expression, mutation of related genes in breast cancer. [

Objective To investigate the clinical value of double contrast-enhanced ultrasonography (DCUS)in diagnosing Lauren classification of advanced gastric carcinoma.Methods Fifty-eight patients with gastric cancer proved by endoscopic biopsy underwent preoperative DCUS examination,and the findings were compared with postoperative pathologic results via hematoxylin-eosin and alcian blue-periodic acid schiff(AB-PAS)staining.Results In 58 patients,34 cases were diagnosed as intestinal type and 24 cases as diffuse type by pathology after operation.In intestinal type,30 cases were enhanced as global homogeneous intensity by using DCUS.another 2 cases as"lamellar"model and the other 2 cases as heterogeneous intensity.However,in diffuse type,22 cases were enhanced heterogeneously with"barrier"signs in 5 cases,"map"signs in 9 cases and"lamellar"signs in 8 cases.the remaining 2 cases of diffuse type enhanced as homogeneous model.The sensitivity and specificity of heterogeneous enhancement in diagnosing diffuse type of advanced gastric cancer was 91.7%and 88.2%respectively,and the Youden's index was 0.8.Conclusions DCUS could be considered as a new valuable method to distinguish the Lauren classification and evaluate the invasiveness,metastasis and prognosis in patients with gastric carcinoma.

Objective To investigate the clinical value of double contrast-enhanced ultrasonography (DCUS)in Borrmann classification of advanced gastric carcinoma preoperatively. Methods A total of 69 patients with advanced gastric carcinoma were examined by ultrasound after taking oral contrast agent and bolus injection of SonoVue preoperatively.A comparison with final pathologic results was made after surgery. Results The accuracy of oral contrast-enhanced ultrasonography and DCUS in Borrmann classification of advanced gastric cancer were 78.3%and 91.3%,respectively.There was a significant difference between two methods(X2=4.087,P＜0.05).In addition,Kappa value of two methods were 0.73 and 0.90,respectively.Conclusions DCUS is a new valuable method for Borrmann classification with its high accuracy preoperatively.

usions DCUS could initial estimate the pathological typing of advanced gastric caner before operation.

Abstract The processs of female Osteoporosis and its prevention by Physical activity were simulated using anisotropic bone remodelling model with mechanostat combining with finite element method. The results show that bone mass declines slowly at the beginning, bone loss accelerates in postmenopause and bone mass declines 25. 84%-28.63% at the age of 60 and 38.50%-40.44% at the age of 80. Bone mass increases 3.05%-10.26% by an increase of 10%-20% in physical activity. The above results are consistent with clinical observations,which proves that declination of mechanical usage is the primary factor leading to osteoporosis, menopause quickens the process of female osteoporosis, physical activity can decelerate it.
Aged ; Biomechanical Phenomena ; Bone Remodeling ; Computer Simulation ; Exercise ; physiology ; Female ; Humans ; Middle Aged ; Models, Biological ; Osteoporosis, Postmenopausal ; prevention & control

AIM: To study the effects of paroxetine on the psychological stress induced by c-fos gene expression in the rat hypothalamus paraventricular nucleus(PVN) and to explore the molecular mechanism of effects of paroxetine on the stress related anxiety disorders. METHODS: The rat psychological stress model was made by restraint stress. The cortisol was analyzed by radioimmnoassay, and expression of c-fos positive cells was detected by S-P immunohistochemical assay in the rat PVN. RESULTS: The level of cortisol and the expression of c-fos positive cells increased more significantly in the other groups than that in the control group, but decreased in the paroxetine group. The paroxetine reduced the level of cortisol and inhibited the expression of c-fos positive cells in the PVN after psychological stress. CONCLUSION: The paroxetine can regulate the nerve centre by alleviating the expression of the c-fos in the hypothalamus paraventricular nucleus(PVN)and the activation of HPA pathway.