A nonobstructive condition: Medial arterial calcification / 中南大学学报(医学版)

Vascular calcification, including intimal and medial calcification, is closely associated with a significant increase in cardiovascular diseases. Although increased understandings were achieved, people still know much more about intimal calcification than medial calcification because the latter doesn't obstruct the arterial lumen, commonly considered as a non-significant finding. We clarified the pathologic characteristic of medial calcification, its difference from intimal calcification, principally focused on its clinical relevance, such as diagnosis, nosogenesis, and hemodynamics. We underline the importance of identifying and distinguishing medial calcification, understanding its effect to local/systematic arterial compliance, and relationship to diabetic neuropathy. Recent studies emphasize do not ignore its predictive role in cardiovascular mortality. It is of great clinical significance to summarize the mechanisms of occurrence, lesion characteristics, diagnostic methods, pathogenic mechanisms, hemodynamic changes, and the distinction as well as association of intimal calcification with intimal calcification.

Bioactivity of the peptide P17-bone morphogenetic protein-2/nano-hydroxyapatite-mineralized collagen composite / 中国组织工程研究

BACKGROUND: A mineralized collagen composite, i.e. nano-hydroxyapatite/collagen (nHAC) has biomimetic three-dimensional structure and good bioactive properties. As a bone tissue engineering material, it is widely used in bone defect repair. A newly designed P17-bone morphogenetic protein-2 (P17-BMP2) has good biocompatibility and osteogenic capacity. Therefore, the composite scaffold material was prepared by combining the new P17-BMP-2 and nHAC, which might be used for the enhancement of osteogenic capacity in the treatment of bone defects. OBJECTIVE: To investigate the bioactivity of the P17-BMP-2/nHAC composite. METHODS: Rabbit bone marrow mesenchymal stem cells were seed on the P17-BMP-2/nHAC composite and nHAC. After 3 and 7 days of culture, the relative expression level of alkaline phosphatase was detected by RT-PCR. The subcutaneous implantation of P17-BMP-2/nHAC (experimental group) and nHAC (control group) into Sprague-Dawley rats was performed. Masson staining was performed for histological analysis at 12 and 35 days of implantation. P17-BMP-2/nHAC (experimental group) and nHAC (control group) were implanted into the white rabbit mandibular box-shaped bone defect, respectively. At 5 and 15 weeks, gross observation and X-ray were performed. The study was approved by the Medical Ethics Committee of China Medical University School & Hospital of Stomatology. RESULTS AND CONCLUSION: (1) The relative expression level of alkaline phosphatase in the P17-BMP-2/nHAC group was significantly higher than that in the nHAC group (P < 0.05). (2) The result of subcutaneous implantation showed that the acute inflammatory response initiated by the P17-BMP-2/nHAC or nHAC was not found. More activated fibroblasts growing into the implants could be found on the sections of P17-BMP-2/nHAC compared to that of nHAC at 35 days after implantation. (3) In the bone defect repair test, gross observation showed that both materials held good defect repair ability, the defect area began to reduce at 5 weeks after implantation, and the defect surface became flat at 15 weeks after implantation. X-ray examination showed that compared with the control group, the defect area was more significantly reduced in the experimental group. (4) These results indicate that P17-BMP-2/nHAC composite scaffold has higher bioactivity and a stronger ability to repair bone defect.

Effects of zinc gluconate carbon dots in cell imaging and inducing osteoblastic differentiation in vitro / 吉林大学学报(医学版)

Objective: To synthesize the zinc gluconate carbon dots (Zn-CDs) by one-step hydrothermal method, and to investigate their effects on the cell imaging and inducing osteoblastic differentiation of preosteoblasts in the mice. Methods: The Zn-CDs were synthesized by one-step hydrothermal method, and the characteristics were observed and detected by transmission electron microscope (TEM), Fourier transform-infrared spectrum (FT-IR) and fluorescence spectrometer. The MC3T3-E1 cells were divided into blank control group and experimental groups; different concentrations (0.01, 0.10, 1.00, 10.00, 100.00, 1 000 mg middot; L-1) of Zn-CDs were added into the cells in experimental groups, and nothing was added into the cells in blank control group. MTT assay was used to determin the relative growth rate (RGR) of MC3T3-E1 cells in various groups; the imaging characteristics of MC3T3-E1 cells were observed under confocal microscope; the relative expression levels of Runt-relateed transcription factor-2 (Runx2), alkaline phosphatase (ALP) and osteocalcin (OC) mRNA in the MC3T3-E1 cells in various groups were detected by qRT-PCR; the number of calcified nodules was detected by alizarin red staining. Results: The TEM results showed that the particle size of Zn-CDs was about 5. 25 nm. The fluorescence spectrometer results showed that the Zn-CDs had the fluorescence properties of 360 nm ultraviolet excited light and 450 nm blue emission light, and the Zn-CDs showed the characteristics of excitation wavelength dependence. The FT-IR results showed that the surface of Zn-CDs was mainly composed of carboxyl groups and hydroxyl groups. Compared with blank control group, the RGR of MC3T3-E1 cells in 1 000. 00 mg middot; L-1 Zn-CDs group was decreased significantly at 24 h after co-culture (P<0. 01). The results of fluorescence imaging showed that the blue, green and red fluorescence in the MC3T3-E1 cells, the outline was clear, and the fluorescence intensity of the cytoplasm was stronger than that of the nucleus after co-cultured with Zn-CDs. The qRT-PCR results showed that the relative expression levels of Runx2, ALP and OC mRNA were significantly increased with the increasing of Zn-CDs concentration. The alizarin red staining results showed that the number of calcium deposits in the MC3T3-E1 cells in different concentrations of Zn-CDs groups were more than that in blank control group after induced for 21 d. Conclusion: Zn-CDs can effectively perform the fluorescence imaging in the MC3T3-E1 cells, and Zn-CDs have a certain ability to promote the osteoblastic differentiation of the MC3T3-E1 cells.

Down-regulation of osteocytic TGF-β/Smad4inhibits the osteoblastic and osteoclastic differentiation in mouse BMSCs / 基础医学与临床

Objective To determine the effect of ostecytic TGF-β/Smad4 signaling on osteoblastic and osteoclastic differentiation in bone marrow stromal cells (BMSCs).Methods Mice with osteocytic TGF-β/Smad4 conditional knock down (Smad4ot CKD) were generated as previously by crossing DMP1-8kb-Cre mice with Smad4lox(ex8)/lox(ex8) mice.The osteocytes were isolated from tibial and femoral diaphysis and co-cultured with wild-type BMSCs.ALP staining, Alizarin red staining and TRAP staining were performed to show osteoblastic and osteoclastic differentiation.Then, their marker genes were detected by qPCR and proteins measured by Western blot.ResultsThe expression of Runx2 and Osterix were reduced in smad4 CKDot co-cultured with BMSCs compared with controls(P<0.01).Similarly, the specific markers of osteoblastic differentiation were decreased (P<0.01).Additionally, the expression of RANKL was not significantly changed in with BMSCs.However, OPG was highly expressed incontrol group compared with smad4 CKD in co-cultured group (P<0.05).Thus, the radio of RANKL/OPG was significantly reduced (P<0.05).Furthermore, the expression of RANK was inhibited.Conclusions The terminally-differentiated osteocytes are the cells regulating bone metabolism, while down-regulation of osteocytic-TGF-β/Smad4 inhibits BMSC osteoblastic and osteoclastic differentiation.

Hypoxia inhibits the expression of semaphorin 3A in breast cancer cells and regulates the differentiation of preosteoblast cells / 肿瘤

Objective: To compare the effect of MCF-7 conditioned medium under normoxia or hypoxia condition on the differentiation of osteoblastic precursor MC3T3-E1 cells after exposing breast cancer MCF-7 cells to hypoxia, and to investigate the role of semaphorin 3A (Sema3A) on osteogenic differentiation regulated by hypoxia in breast cancer with bone metastasis. Methods: The conditioned medium was collected from breast cancer MCF-7 cells cultured under the normoxia or hypoxia condition for 48 h, and used to incubate osteoblastic precursor MC3T3-E1 cells. The content and activity of alkaline phosphatase (ALP) in MC3T3-E1 cells were evaluated by BCIP/NBT ALP color development kit and ALP activity assay kit, respectively. The mineralization of MC3T3-E1 cells was detected by alizarin red S (ARS) staining. The expressions of Sema3A mRNA and protein in MCF-7 cells under normoxia or hypoxia condition for 0, 12, 24 and 48 h were detected by real-time fluorescent quantitative PCR and Western blotting, respectively. The recombinant human Sema3A (rhSema3A) was added into MC3T3-E1 cells incubated with MCF-7 hypoxia conditioned medium, then the mRNA expression levels of osteogenic differentiation-related proteins ALP, Runt-related transcription factor 2 (RUNX2), osteocalcin (OCN) and Osterix (Osx) in MC3T3-E1 cells were measured by real-time fluorescent quantitative PCR. Results: Compared with normoxia cultured MCF-7 conditioned medium (NorCM) group, the activity of ALP in MC3T3-E1 cells was significantly decreased in hypoxia cultured MCF-7 conditioned medium (HyCM) group (P<0.05), and the area of mineralization nodes stained with ARS was also markedly reduced in HyCM group (P<0.05). The mRNA and protein expressions of Sema3A in MCF-7 cells after hypoxia culture for 24 and 48 h were significantly lower than those after normoxia culture for the same time (all P<0.05). After rhSema3A was used to treat MC3T3-E1 cells which were incubated with HyCM, the mRNA expression levels of ALP, RUNX2, OCN and Osx were significantly increased as compared with the rhSema3A untreated group (all P<0.05). Conclusion: Hypoxia down-regulates the expression of Sema3A in MCF-7 cells in vitro, and inhibits the differentiation of osteoblast, which indicates that Sema3A is probably an important factor for the inhibition of osteoblastic differentiation by breast cancer conditioned medium under hypoxic environment.

Knockdown of tissue transglutaminase in SaOS-2 cell line inhibits its osteoblastic differentiation and mineralization / 中国实验动物学报

Objective To investigate whether TG2 plays an important role in the osteoblast differentiation and mineralization.Methods TG2 mRNA of SaOS-2 cells was knocked down using a lentivirus stably expressing short-hairpin ( sh) RNA targeting TG2.Then the cells were cultured in osteo-inductive medium for 14 d to measure mineralization and for 7 d to measure the levels of osteoblastic differentiation markers including ALP activity and mRNA of collagen I, osteocalcin ( OCN) and BMP-2.The wild-type SaOS-2 cells and scrambled shRNA-transducted SaOS-2 cells served as the controls. Results The controls displayed an increasing trend of the level of ALP activity and mRNA of collagen I, osteocalcin and BMP-2,and notable mineralization at 14 d.When TG2 was knocked down, ALP activity, mRNA of collagen I, osteocalcin and BMP-2 at 7d,and mineralization at 14 d were all significantly lower in comparison with the corresponding values in the controls.Conclusion TG2 is involved in the differentiation and mineralization of osteoblasts in vitro.

Role of TAZ in genistein induced osteoblastogenic differentiation of mouse bone marrow-derived mesenchymal stem cells / 中华内分泌代谢杂志

Objective To investigate the role of transcriptional-coactivator with PDZ-binding motif( TAZ) in genistein-induced osteoblastogenic differentiation of mouse bone marrow-derived mesenchymal stem cells ( BMSCs) .Methods Mouse BMSCs were cultured in phenol red-freeα-MEM containing osteogenic supplements for inducing osteogenic differentiation.BMSCs were transfected with siRNA-TAZ and treated with genistein.The temporal sequence of osteoblastic differentiation in BMSCs cultures was assayed by measuring alkaline phosphatase activity (ALP) and calcium deposition.The mRNA expression of bone sialoprotein ( BSP) and osteocalcin ( OC) were detected by reverse transcription-polymerase chain reaction(RT-PCR).The binding interaction between TAZ and cbfa1 was identified by co-immunoprecipitation.Results TAZ expression was detected during the induction of osteogenic differentiation, the ALP activity and calcium deposition were significantly decreased in BMSCs which were transfected with siRNA-TAZ.Genistein(0.01-1 μmol/L) exhibited a dose-dependent effect on TAZ expression in mouse BMSCs cultures.Treatment with genistein ( 1 μmol/L ) resulted in increased ALP avtivity and calcium deposition of BMSC cultures as function of time.Genistein(1μmol/L) also promoted the nuclear localization of TAZ and augmented the interaction between TAZ and cbfa1, and by which upregulated cbfa1-mediated gene expression such as BSP and OC.However, the ALP avtivity and calcium deposition, as well as the expression of BSP and OC were not promoted by genistein in BMSCs transfected with siRNA-TAZ.Conclusion These data suggest that the TAZ plays an important role in genistein-induced osteoblastic differentiation of mouse BMSCs cultures.

Effect of titanium surface microgrooves and thermal oxidation on in vitro osteoblast responses / 대한치과보철학회지

PURPOSE: We aimed to investigate the effect of combined various microgrooves and thermal oxidation on the titanium (Ti) and to evaluate various in vitro responses of human periodontal ligament cells (PLCs). MATERIALS AND METHODS: Grade II titanium disks were fabricated. Microgrooves were applied on titanium discs to have 0/0 microm, 15/3.5 microm, 30/10 microm, and 60/10 microm of respective width/depth by photolithography. Thermal oxidation was performed on the microgrooves of Ti substrata for 3 h at 700degrees C in air. The experiments were divided into 3 groups: control group (ST), thermal oxidation group (ST/TO), and combined microgrooves and thermal oxidation group (Gr15-TO, Gr30-TO, Gr60-TO). Surface characterization was performed by field-emission scanning microscopy. Cell adhesion, osteoblastic differentiation, and mineralization were analyzed using the bromodeoxyurdine (BrdU), Alkaline phosphatase (ALP) activity, and extracellular calcium deposition assays, respectively. Statistical analysis was performed using the oneway analysis of variance and Pearson's bivariate correlation analysis (SPSS Version 17.0). RESULTS: In general, the combined microgrooves and thermal oxidation group (Gr15-TO, Gr30-TO, Gr60-TO) showed significantly higher levels compared with the control (ST) or thermal oxidation (ST-TO) groups in the BrdU expression, ALP activity, and extracellular calcium deposition. Gr60-TO group induced highest levels of cell adhesion and osteoblastic differentiation. CONCLUSION: Within the limitation of this study, we conclude that the Ti surface treatment using combined microgrooves and thermal oxidation is highly effective in inducing the cell adhesion andosteoblastic differentiation. The propose surface is also expected to be effective in inducing rapid and strong osseointegration of Ti oral implants.

Isoliquiritigenin Inhibits Metastatic Breast Cancer Cell-induced Receptor Activator of Nuclear Factor Kappa-B Ligand/Osteoprotegerin Ratio in Human Osteoblastic Cells

Bone destruction induced by the metastasis of breast cancer cells is a frequent complication that is caused by the interaction between cancer cells and bone cells. Receptor activator of nuclear factor kappa-B ligand (RANKL) and the endogenous soluble RANKL inhibitor, osteoprotegerin (OPG), directly play critical roles in the differentiation, activity, and survival of osteoclasts. In patients with bone metastases, osteoclastic bone resorption promotes the majority of skeletal-related events and propagates bone metastases. Therefore, blocking osteoclast activity and differentiation via RANKL inhibition can be a promising therapeutic approach for cancer-associated bone diseases. We investigated the potential of isoliquiritigenin (ISL), which has anti-proliferative, anti-angiogenic, and anti-invasive effects, as a preventive and therapeutic agent for breast cancer cell-induced bone destruction. ISL at non-toxicity concentrations significantly inhibited the RANKL/OPG ratio by reducing the production of RANKL and restoring OPG production to control levels in hFOB1.19 cells stimulated with conditioned medium (CM) of MDA-MB-231 cells. In addition, ISL reduced the expression of cyclooxygenase-2 in hFOB1.19 cells stimulated by CM of MDA-MB-231 cells. Therefore, ISL may have inhibitory potential on breast cancer-induced bone destruction.

Pattern of Bone Metastasis in Breast Cancer Patients at a Radiotherapy Facility in Lagos.

Aim: To determine the pattern of bone metastasis in breast cancer patients. Study Design: Retrospective case series Place and Duration of Study: Data were collected at Eko Hospital radiotherapy facility, Lagos, Nigeria, between years 2006 and 2011. Methodology: A total of 67 patients with a histologically confirmed diagnosis of breast cancer from 2006 to 2011 treated at a radiotherapy facility were analysed to describe the pattern of bone metastasis. Radiological imaging included chest X-ray, X-rays of the bone, bone scan, and Computed Tomography scan (CT scan). Result: Of the 67 eligible breast cancer patients, one is male and 66 are female. The average age of the patients was 46 years old, ranging from 28 to 77 year old. Among the 67 patients who received radiotherapy, 58 (87%) have bone metastases. The most common sites of bone metastases are spine (61%), pelvis (22%), and long bones (22%). Among the 32 patients without metastasis at presentation, the median duration from diagnosis to onset of symptoms of bone metastasis was 16.5 months, ranging from 5 to 38 months. Thirty-one patients had osteoblastic lesions, 24 patients had osteolytic lesions, and 2 patients had mixed osteolytic and osteoblastic lesions. Conclusion: Bone metastasis remains common and incurable. Early recognition and better description of bone relapse patterns of metastatic breast disease will allow rapid administration of effective palliative treatment.

Gene expression profile of continuous mechanical stress-induced osteoblastic differentiation of rat bone marrow stromal cells / 医用生物力学

Objective To evaluate differences in genes expression of rat bone marrow stromal cells (rBMSCs) under continuous mechanical strain by gene microarray technology．Methods rBMSCs were isolated and cultured in vitro. Continuous stresses with amplitude of 10% and frequency of 1 Hz were applied on rBMSCs for 6 hours by Flexercell mechanical loading system to investigate rBMSC gene expression profiles, and quantitative PCR was used to verify gene expression changes related to osteoblastic differentiation. Results Compared with the control group, 1 244 differentially expressed genes were found in mechanical loading group, among which 793 genes were up-regulated, while 451 genes were down-regulated．GO (gene ontology) analysis suggested that differentially expressed genes were mainly involved in multicellular organismal development, cell differentiation, chemotaxis, cell adhesion and so on. Four signaling pathways as Notch, Wnt, FGF and IGF might participate in the regulation of stress-induced osteoblastic differentiation. PCR validation results were consistent with the gene chip results. Conclusions Mechanical stress could induce osteoblastic differentiation of the BMSCs, while several differentially expressed genes screened by gene microarray may attribute to this process.

Clinical application of percutaneous vertebroplasty in treating osteoblastic spinal metastases / 介入放射学杂志

Objective To discuss the feasibility and short-term clinical effectiveness of DSA-guided percutaneous vertebroplasty (PVP) for the treatment of painful osteoblastic metastatic spinal lesions. Methods During the period from Jan. 2010 to Dec. 2011 at authors’ hospital PVP was carried out in 23 patients with osteoblastic spinal metastases (34 lesions in total). Coexisting osteoblastic pathological fracture was found in twelve patients. The WHO standards, visual analogue scale (VAS) and karnofsky-KPS score were used to evaluate the therapeutic results. Results Technical success was achieved in all patients. All patients were followed up for at least 3 months. Of 20 patients who had complete clinical data, complete remission (CR) was obtained in 6, partial remission (PR) in 10, mild remission (MR) in 3 and no remission (NR) in one. The clinical effectiveness (CR+PR) was 80%. The mean VAS scores dropped from preoperative (7.0 ± 1.6) to (2.2 ± 1.9) at 24 hours after the treatment, and to (2.4 ± 2.1) and (2.5 ± 2.1) at one and three months after the treatment respectively. The mean KPS scores rose from preoperative (76.5 ± 10.4) to (86.5 ± 11.8), (88.0 ± 12.0) and (89.0 ± 10.8) at 24 hours and one, three months after the treatment respectively. Small amount leakage of PMMA was observed in 4 cases (17.4%) with no obvious clinical symptoms. Conclusion DSA-guided PVP is a feasible and effective treatment for painful osteoblastic spinal metastases. This therapy can immediately relieve pain and reinforce spine, besides, it can remarkably improve the living quality and decrease the incidence of paraplegia.

Overexpression of hsa-miR-125b during osteoblastic differentiation does not influence levels of Runx2, osteopontin, and ALPL gene expression

Multipotent mesenchymal stromal cells (MSCs) were first isolated from bone marrow and then from various adult tissues including placenta, cord blood, deciduous teeth, and amniotic fluid. MSCs are defined or characterized by their ability to adhere to plastic, to express specific surface antigens, and to differentiate into osteogenic, chondrogenic, adipogenic, and myogenic lineages. Although the molecular mechanisms that control MSC proliferation and differentiation are not well understood, the involvement of microRNAs has been reported. In the present study, we investigated the role of miR-125b during osteoblastic differentiation in humans. We found that miR-125b increased during osteoblastic differentiation, as well as Runx2 and ALPL genes. To study whether the gain or loss of miR-125b function influenced osteoblastic differentiation, we transfected MSCs with pre-miR-125b or anti-miR-125b and cultured the transfected cells in an osteoblastic differentiation medium. After transfection, no change was observed in osteoblastic differentiation, and Runx2, OPN, and ALPL gene expression were not changed. These results suggest that the gain or loss of miR-125b function does not influence levels of Runx2, OPN, and ALPL during osteoblastic differentiation.

Effects of different prostate cancer cells on the proliferation and differentiation of osteoblastic progenitor cells / 肿瘤

Objective: To investigate the effects of conditioned medium (CM) of prostate cancer LNCaP and PC-3 cells on the proliferation and differentiation of pre-osteoblastic cell MC3T3-E1. Methods: MC3T3-E1 cells were incubated with 20% LNCaP CM, 20% PC-3 CM or a-MEM without CM (as a control), respectively. The proliferation of MC3T3-E1 cells was detected by cell counting kit-8 (CCK-8) method. The alkaline phosphatase (ALP) assay kit was used to evaluate the ALP activity in MC3T3-E1 cells. The alizarin red staining was used to detect the mineralization of MC3T3-E1 cells. The mRNA expression levels of collagen type ? alpha 1 (Col1a1), osteocalcin (OCN) and runt-related transcription factor 2 (RUNX2) mRNAs were measured by real-time fluorescence quantitative-PCR. Results: As compared with the control and LNCaP CM groups, PC-3 CM promoted the proliferation of MC3T3-E1 cells notably (P < 0.05). The ALP activity in MC3T3-E1 cells in the LNCaP CM group was higher than that in the control group (P < 0.05), and the area of mineralizaion nodes was wider (P < 0.05), but the result was opposite in the PC-3 CM group. The expression levels of Col1a1, OCN and RUNX2 mRNAs in MC3T3-E1 cells in LNCaP CM group were higher than those in the control group (P < 0.05), but PC-3 CM inhibited the expression levels of these mRNAs (P < 0.05). Conclusion: The PC-3 CM can stimulate the proliferation of osteoblastic progenitor cells and inhibit their differentiation. On the contrary, LNCaP CM can promote the differentiation of osteoblastic progenitor cells. These models can be used in vitro for further research on prostate cancer bone metastasis, as they can affect proliferation and differentiation of osteoblastic progenitor cells differently. Copyright © 2013 by TUMOR.

Emerging applications of an experimental single photon emission computed tomography: an analysis of 16 areas of interest in the pig's model / Aplicaciones emergentes experimentales de la tomografía computarizada por emisión de fotones individuales: un análisis de 16 áreas de interés en el modelo de cerdo

This paper aims to affirm various new applications of single photon emission computed tomography (SPECT) technique by utilizing the pig's models. Evaluation and subsequent analysis of SPECT results was conducted on the jaws of eight experimental pigs with a total of 16 areas of interest. The various reasons for which each experiment was conducted were evaluated and these reasons include: i) validation of a new bone grafting technique for closure of oro-antral communications, ii) comparison of autogeneous bone graft with other bone grafts, iii) sequential confirmation of osteoblastic activity of the sandwich bone regeneration technique with another technique, iv) validation of the use of a new membrane for guided tissue regeneration (GTR), v) validation of the fact that osseointegration is better with beaded implants than with threaded implants, and vi) validation of the fact that GTR is essential for immediate implant practice. The outcome of this evaluation is critically analysed against the background of the substantial clinical evidence where applicable, so as to appreciate the position of SPECT. Following the evaluation of 16 areas of interest in eight experimental pigs, it was shown that experimental SPECT was valuable in the validation of the above reasons. It appears to be a modality that can continuously be utilized to validate and compare situations which would display osteoblastic activities. It is concluded that the bone scintigraphy imaging technique accurately reflects osteoblastic activities and can now be used to validate osseointegration of any implant or bone-grafting system. This can be done in conjunction with histological and histomorphometic analysis and such results obtained from SPECT should be correlated with the histological and histomorphometric analysis if available.

El presente trabajo tiene por objeto dar a conocer varias nuevas aplicaciones de la técnica de la tomografía computarizada por emisión de fotones individuales (inglés SPECT), utilizando modelos de cerdo. Se llevó a cabo una evaluación y el posterior análisis de los resultados de la SPECT en relación con las mandíbulas de ocho cerdos experimentales con un total de 16 áreas de interés. Se evaluaron las varias razones por las que se llevó a cabo cada experimento. Las razones incluyen: i) validación de una nueva técnica de injerto óseo para el cierre de las comunicaciones oroantrales; ii) comparación del injerto óseo autógeno con otros injertos óseos; iii) confirmación secuencial de la actividad osteoblástica de la técnica de regeneración ósea por "sándwich" o membrana inter-posicional con otra técnica; iv) validación del uso de una nueva membrana para la regeneración tisular guiada (RTG); v) validación del hecho que la osteointegración es mejor con implantes porosos que con implantes roscados; y vi) valoración del hecho de que la RTG es esencial para la práctica del implante inmediato. El resultado de esta evaluación se analiza críticamente contra el trasfondo de la evidencia clínica sustancial donde es aplicable, para apreciar la posición de SPECT. Tras la evaluación de 16 áreas de interés en ocho cerdos experimentales, se vio que la SPECT experimental era valiosa para la validación de las razones anteriores. Parece ser una modalidad que puede utilizarse para validar y comparar situaciones que desplegarían actividades osteoblásticas. Se concluye que la gammagrafía ósea refleja las actividades osteoblásticas con precisión, y puede ahora usarse para validar la osteointegración de cualquier implante o sistema de injerto óseo. Esto puede hacerse junto con análisis histológicos y análisis histomorfométicos. Los resultados obtenidos de la tomografía SPECT deben ponerse en correlación con el análisis histológico e histomorfométrico, si estuviese disponible.

Pathophyslology of Bone Metastsis And Its Implications - A Review.

In tumors with a propensity to spread to bone a significant proportion of patients who present with cancer that appears to be localized will eventually develop incurable metastatic disease. Bone metastases are common in many advanced cancers and are an avoidable yet, annoying source of skeletal morbidity. The bone mineral matrix contains numerous growth factors that are released during normal bone remodeling, providing a fertile microenvironment for tumor cell colonization and proliferation. Tumor cells then release a variety of growth factors that promote bone resorption and increase the risk of skeletal complications. Metastasis of tumor cells to bone requires a complex cascade of events involving detachment from the primary tumor site, invasion of the vasculature, migration and adherence to distant capillaries of the bone, extravasation, and proliferation. Metastatic bone lesions are classified as osteolytic or osteoblastic, based on their radiographic appearance. Bone is the third most common site of metastatic disease .Carcinomas are much more likely to metastasize to bone than sarcomas. Routine use of whole body PET/CT in restaging HNSCC can therefore, facilitate early detection of occult bone metastases and this detection often influences therapeutic decision making.

Effect of perfusion flow rate on proliferation and osteoblastic differentiation of human mesenchymal stem cells / 医用生物力学

Objective To investigate the effect of different perfusion flow rates on proliferation and osteoblastic differentiation of human mesenchymal stem cells (hMSCs) in large scale β-TCP (tricalcium phosphate) scaffold at perfusion bioreactor. Methods hMSCs isolated from iliac bone marrow aspiration were loaded into large scale β-TCP scaffold and cultured in perfusion bioreactor at the perfusion flow rate of 3, 6 or 9 mL/min for 15 days. The culture media were collected for D-glucose consumption assay every 3 days. After perfusion culture for 15 days, the cell-scaffold composites were harvested for assessment of cell viability by MTT colorimetric method, SEM observation and osteogenic gene expression by real-time PCR. Results The proliferation of hMSCs assayed by daily glucose consumption showed that at early stage of culture, cells proliferated faster at flow rate of 9 mL/min than at 3 or 6 mL/min (P<0.001); while at late stage of culture, cells proliferated faster at flow rate of 6 mL/min (P<0.05). The cell viability indicated that the cell-scaffold composites at flow rate of 6 mL/min exhibited the most viable cells (P<0.001). SEM indicated that all the macropores of the scaffold at different flow rates were filled with cellular layers. All cellular layers at flow rate of 3 mL/min were incompact, but that at 9 mL/min were compact; at flow rate of 6 mL/min, the cellular layers were either compact or incompact. Real-time PCR revealed that after perfusion culture for 15 days, the mRNA expression of osteobalstic genes including ALP and OP, were enhanced significantly at flow rate of 6 and 9 mL/min as compared to that at 3 mL/min (P<0.01); however, the 9 mL/min group presented the higher OC expression than 3 and 6 mL/min group (P<0.001). Conclusions At early stage of perfusion culture, the proliferation of hMSCs was promoted at flow rate of 9 mL/min, while at late stage, there was more viable cells in scaffolds at flow rate of 6 mL/min. The osteoblastic differentiation of hMSCs was facilitated with the increase of perfusion flow rate, which was attributed to the increased flow shear stress.

Effects of 137 Cs γ-rays on proliferation, differentiation and mineralization of osteoblastic cells in vitro / 中华放射医学与防护杂志

Objective To evaluate the effect of gamma irradiation on the proliferation,differentiation,and mineralization of murine osteoblastic cells,and to investigate the related molecular mechanism.Methods Osteoblastic cells were irradiated by different doses (0,0.5,1.0,2.0,5.0 Gy)of 137Cs γ-rays.Cell morphology was observed with a microscopy,cell viability was analyzed by MTT assay,and ALP activity was analyzed by the methods of enzyme histochemistry and PNPP.Meanwhile,gene expressions of ALP,osteocalcin (OC),collagen Ⅰ,osteoprotegerin (OPG) and receptor activator of nuclear factor-kB ligand (RANKL) were measured by semi-quantified RT-PCR.Results Cell viability decreased with the radiation doses over 1.0 Gy ( t =6.197 - 18.677,P ＜ 0.05 ).After radiation with a dose over 2.0 Gy,the cell number and the junctions of cell protrusions decreased,the cells had low refractivity and the activity and mineralization ability of ALP were also inhibited ( t =2.790 -2l.374,P ＜0.05).In addition,the expressions of ALP and OC mRNA were down-regulated significantly (t =3.563 -16.508,P ＜ 0.05) when the radiation dose was higher than 0.5 Gy,and the expressions of OPG,OPG/RANKL mRNA were down-regulated ( t =12.942,4.954,P ＜ 0.05 ) at 5 Gy.But the expressions of collagen Ⅰ and RANKL mRNA were not affected by irradiation.Conclusions The osteoblastic cells were significantly influenced by γ-irradiation,including morphological changes,inhibition of cell proliferation,differentiation and mineralization ability. Meanwhile,mRNA expressions of ALP and OC were downregulated.OPG/RANKL may be a main pathway of osteoblastic cell damage under high dose radiation.

Influence of peroxisome proliferator activated receptor γ2 endogenous ligands on mRNA expression of bone metabolism related genes in osteoblastic cells / 中华内分泌代谢杂志

Objective To observe the effect of oxidized low-density lipoproteins (Ox-LDL),15-Deoxy-△ 12,14-prostaglandin J2 ( 15d-PGJ2 ),leukotrienes B4 ( LTB4 ) on mRNA expressions of peroxisome proliferator activated receptor γ2 ( PPARγ2 ),receptor activator of NF-κB ligand (RANKL),alkaline phosphatase ( ALP),and osteoprotegerin(OPG) in osteoblastic cells of rats; and to investigate the influence of these PPARγ2 endogenous ligands on bone metabolism.Methods Rat osteoblastic cells were cultured in vitro for 24 h in medium with different PPARγ2 endogenous ligands at various concentrations ( the final concentrations of Ox-LDL were 0,12.5,25,50μg/ml; the final concentrations of 15 d-PGJ2 were 0,10,20,30 μmol/L; the final concentrations of LTB4 were 0,0.1,1.0,10 μ mol/L).RT-PCR was performed to determine the mRNA expressions of PPARγ2,RANKL,ALP,and OPG in osteoblastic cells.Results RT-PCR analysis showed that Ox-LDL,15d-PGJ2,and LTB4 all down-regulated the mRNA expressions of RANKL,ALP,and OPG,while up-regulated the mRNA expressions of PPARγ2 in osteoblastic cells in a dose-dependent manner.Significant differences were found in interclass comparisons( P＜0.05 or P＜ 0.01 ).Conclusions These findings suggest that Ox-LDL,15d-PGJ2,and LTB4 suppress the expressions of osteogenic genes through activating the transcription activity of PPARγ2,and this may be a plausible mechanism of senile osteoporosis.

Effects from mechanical stimulation and osteogenic chemical inductor on osteoblastic differentiation of rat bone mesenchymal stem cells / 医用生物力学

Objective To investigate the effect from mechanical stimulation and osteogenic chemical inductor on osteoblastic differentiation markers and formation of calcified nodules in rat bone mesenchymal stem cells (rBMSCs). Method The rBMSC were cultured in medium contained with or without osteogenic chemical inductor. The cyclic biaxial mechanical strain (2%), at a frequency of 1 Hz, was applied to the rBMSCs for periods of 2 hours each time, at intervals of 2 hours, 3 times every day, lasting 3 days and 6 days, respectively. The mRNA expression of alkaline phosphatase (ALP), collagen type I (COL I) and osteocalcin (OCN) were analyzed with real time fluorescent quantitation reverse transcription polymerase chain reaction(qRT-PCR) and formation of calcified nodules were detected with alizarin red staining method. Results The mRNA expression of ALP, COL I and OCN were significantly increased in induced group compared with that in the corresponding uninduced group and calcified nodule was observed in the osteogenic chemical inductor group after 6 days with mechanical stimulation. Conclusions Osteogenic chemical inductor and mechanical stimulation can promote the osteoblastic differentiation of rBMSCs.