Review of high-resolution peripheral quantitative computed tomography for the assessment of bone microstructure and strength / 生物医学工程学杂志

Trabecular microstructure is an important factor in determining bone strength and physiological function. Normal X-ray and computed tomography (CT) cannot accurately reflect the microstructure of trabecular bone. High-resolution peripheral quantitative computed tomography (HR-pQCT) is a new imaging technique in recent years. It can qualitatively and quantitatively measure the three-dimensional microstructure and volume bone mineral density of trabecular bone . It has high precision and relative low dose of radiation. This new imaging tool is helpful for us to understand the trabecular microstructure more deeply. The finite element analysis of HR-pQCT data can be used to predict the bone strength accurately. We can assess the risk of osteoporosis and fracture with three-dimensional reconstructed images and trabecular microstructure parameters. In this review, we summarize the technical flow, data parameters and clinical application of HR-pQCT in order to provide some reference for the popularization and extensive application of HR-pQCT.

Evaluation of adequate surgery for papillary thyroid microcarcinoma / 国际外科学杂志

Objective To explore the best operation method in the patients with papillary thyroid microcarcinoma.Methods A total of 139 patients with papillary thjroid microcarcinoma were treated at our institute between Jan.2000 and Jan.2010.The data on the clinicopathological characteristics of patients and treatment were collected.Results The mean tumor size was (0.45 ± 0.24) cm.Of the 139 patients,30.2％ had multifocal tumors,19.4％ had bilateral tumors,42.4％ neck lymph node metastases.The number of eases of lymph node metastasis in level Ⅵ,Ⅱa,Ⅲ and Ⅳ was 58(41.7％),3(2.2％),10(7.9％),5(3.6％),respectively.Only one had lymph node metastasis in Level Ⅲ Microscopic extrathyroid extension was associated with neck lymph node metastases in papillary thyroid microcareinoma patients (x2 =38.39,P ＜0.001).No one developed permanent hypoparathyroidism.The median follow-up time was 103 (range,30-154) months,and local recurrence in the thyoid was diagnosed in 2 patients who underwent hemi-or subtotal thyroidectomy.Follow-up of 10 years was done in 16 cases,and the survival rate of 139 patients for 10-year was 100％.Conclusions It suggested that patients with papillary thyroid microcarcinoma has uniform clinicopathologic characteristics and the pattern of lymph node metastasis from those with papillary thyroid carcinoma.Total thyroidectomy plus level Ⅵ dissection is the optimal surgical treatment of papillary thyroid microcarcinoma.

Pathological status of internal mammary node in patients with breast cancer: 229 cases / 中华内分泌外科杂志

Objective To determine the clinical implications of internal mammary node biopsy for neoplasm stage,treatment,and prognosis in patients with breast cancer.Methods Internal mammary node biopsy via intercostal space was performed in 229 cases of breast cancer.Anatomical location of internal mammary nodes was recorded.Results Internal mammary node biopsy was successfully finished in 220 patients.There were 56 cases (24.45％ ) with internal mammary nodes metastasis,126 cases (55.02％ ) with axillary nodes metastasis,43 cases (34.13％ ) with regional metastases in both the axillary and internal mammary lymph nodes and 13 cases ( 12.62％ ) with internal mammary node metastasis only.Internal mammary node metastasis rate in patients with the number of positive axillary nodes ≥4 was 49.32％ (36/73).pN stage migration was seen in 56 patients with positive internal mammary nodes.There was no statistic relation between internal mammary nodes metastases and tumor location ( x2 =0.661,P =0.719).70.7％ patients with medial/central tumors and 50.7％ patients with the number of positive axillary nodes ≥4 were free from internal mammary node radiotherapy on account of internal mammary node biopsy.There was no complication such as pneumothorax or haemorrhagia.Conclusions Internal mammary node biopsy from intercostal space is a reliable surgical technique and can improve pN stage in some breast cancer patients.With internal mammary node biopsy,patients with a negative internal mammary node can be prevented from radiation to internal mammary nodal areas.

Reevaluation on the mechanical properties of dentine microstructure / 医用生物力学

Objective:It is demostrated that the porous protein-mineral mechanics model could provide more accurate prediction for biomaterial properties of dentine compared with the other established models.This paper would use the model to reevaluate the mechanical properties and its interacting mechanism of human dentine.Method:By using a porous proteinmineral mechanics model,the effect from the interactions between tubules,pedtubular and intertubular matrix on dentine microstructure was discussed.Results:The dentinal micromechanical properties were dependent on the tubular direction,and the absolute values of the stresses derived from the hydraulic and gas tubular pressures increased parabolically with theincreasing diameter of the tubules.It was also found that the effective elastic constants of the dentine microstructure would vary with the aging and the distribution of mineral and collagen within peritubular and intertubular matrix of detine.Conclusions:The theoretical analyses provided in this paper demonstrated that the microstructural characteristics of tubules,peritubular and intertubular dentinal matdx could have different influences on the micromechanical properties of human dentine,which showed the validity of porous protein-mineral mechanics model,and the limitation of some models that neglected the interacting mechanism.

Testosterone induces cardiomyocyte hypertrophy in rats and upregulates the expression of ERK1/2 / 基础医学与临床

Objective To explore the role of ERK1/2 protein in development of myocardial hypertrophy.Methods Myocardial cells were isolated from ventricles of 1～3-day-old neonate rats and purifed by a culture method.Neonate rat cardiomyocyte hypertrophic responses were assayed by measuring protein content,protein synthesis rate and cell surface area.Expression of protein ERK1/2 were detected by Western blot.Results Cell protein content,~3H-leucine(~3 H-Leu)incorporation and cell surface area increased by treating of cardiomyocytes with T(10~(-10)～10~(-6) mol/L)for 24 h.The maxium effect was observed at the concentration of 10~(-8) mol/L.The increase of cell protein content induced by T was inhibited by pretreating with flutamide(10~(-5) mol/L)for 2 h,while there was no effect on cardiomyocytes pretreating with flutamide alone.The increase of ~3H-Leu incorporation induced by T was blocked by PD98059(50 μmol/L).Expression of ERK1/2 was upregulated significantly by treating with testoster one for 24 h at the level of 10~(-8) mol/L.The increased expression of ERK1/2 induced by T was reversed by pretreating with flutamide(10~(-5) mol/L)for 2 h.Conclusion T with physio-concentration may induce cardiomyocyte hypertrophy and this effect was possibly mediated through the activation of ERK1/2 signalling.During this procession,T upregulated the protein expression of ERK1/2 mediated by androgen receptor.

Numerical computation on the scaffolds models with regular square holes using nonlinear fluid-solid-coupling approaches / 医用生物力学

Objective The influencing parameters of solid and fluid computing fields for the scaffolds models with regular square holes were discussed by nonlinear fluid-solid-coupling approaches.The numerical computational resuits of which the models were regarded as both rigid body and non-linear elasticity were compared as well.Method One direct fluid-solid-coupling approach and two indirect fluid-solid-coupling approaches were adopted,and the calculating reliability of three kinds of fluid-solid coupling methods was verified.Rasults The solid-fluidcoupling computational results are obtained in light of 12 kinds of scaffolds models which are constructed by 3 groups of square side length(50,100 and 150 μm)and 4 groups of porosity(61%,65%,77%and 84%).The field parameters of those solid models including stress,strain and displacement and those fluid models including static pressure,velocity,wall shear stress and strain rate are achieved and compared.Conclusion There appear some difference between the results of porous scaffold models as a rigid body and as non-linear elasticity.The different porosity with the same pore radius or the different pore radius with the same porosity would affect the field parameters of solid models and fluid models in varying degrees.

Role of NO Pathway in Membrane Estrogen Receptor Mediated Proliferation and Apoptosis of Endothelial Progenitor Cells / 中山大学学报(医学科学版)

[Objective] The aim of the present study was to investigate the role of membrane estrogen receptor (mER) mediated pathway in the proliferation and apoptosis of endothelial progenitor cells (EPCs). [Methods] Bone marrow (BM)-derived EPCs were cultured. The cells were divided into different groups, plus or not plus estrogen receptor blocker (ICI 182,780), PI3K inhibitors (LY294002), and NOS inhibitor (L-NAME) to show the effect of E_2-BSA on EPCs. The proliferation of EPCs was determined by MTT and nitric oxide (NO) release was measured by chromatometry. Apoptotic cell death was determined using the Hochest 33258 staining. The expression of phosphorylated eNOS (p-eNOS) were detected by Western blot. [Results] E_2-BSA could increase EPCs proliferation, and this effect was inhibited by estrogen receptor blocker ICI 182,780, thus indicated that mER-initiated membrane signaling pathways were involved in the action of estrogen on EPCs. E_2-BSA increased nitric oxide production and inhibited apoptosis induced by serum withdrawal, and this effect also inhibited by PI3K inhibitor (LY294002), NOS inhibitor (L-NAME)and estrogen receptor blocker(ICI 182,780), thus indicated that PI3K/Akt/NO pathway was involved the effect of estrogen on EPCs apoptosis. Moreover, E_2-BSA treatment increased phosphorylation of eNOS (p-eNOS). PI3K inhibitors (LY294002) also blocked these effects. [Conclusions] The results of present study suggested that mER mediated EPCs proliferation and apoptosis were related to the PI3K/Akt/eNOS pathway.

The effects of 17?-estradiol on cardiomyocyte hypertrophy induced by endothelin / 中国病理生理杂志

AIM: To investigate the effect of 17?-estradiol(E2) on myocardial hypertrophy induced by endothelin-1(ET-1) and the related mechanism.METHODS: Myocardial cells from neonate rats were cultured in vitro and myocardial hypertrophy model was established with ET-1.The effects of 17?-estradiol on myocardial hypertrophy were observed.The role of ERK1/2 in the effects of 17?-estradiol was also detected.RESULTS: Compared with control group,ET-1 increased cell protein content,cell surface area and -Leucine(-Leu) incorporation.Pretreatment with E2 for 24 h could inhibit the increase in cell protein content,cell surface area and -Leu incorporation induced by ET-1.ET-1 significantly stimulated ERK1/2 activity,which was prevented by pretreatment with E2.Tamoxifen,estradiol receptor antagonist,partially inhibited the effect of E2.The ability of ET-1 to stimulate -Leu incorporation was significantly blocked by PD98059,which could enhance the inhibitory effect of E2 on the increase of -Leu incorporation in cardiomyocytes induced by ET-1.CONCLUSION: E2 can inhibit cardiomyocyte hypertrophy induced by ET-1.This effect is mediated by estrogen receptor.ERK1/2 signal pathway is closely correlated with the inhibitory effect of E2 on cardiomyocyte hypertrophy induced by ET-1.