A review of cell traction forces (CTFs) measurement based on Biological MiCro Electromechanical Systems (BioMEMS) microposts matrix is presented.CTFs are exerted by cells and ansmitted to the underly-ing substrate through focal adhesions and close contacts.which is essential for cells movement.Cells probe the mechanicaI compliance of the exlracellular mabix (ECM) in part by locally deforming it with nanonewton-scale traction forces.Precision measurement of CTFs is significant for many researches such as call biology and tissue engineering and so on.Enabled by the advancement in BioMEMS technology,surface treated high aspeect ratio Polydimethyisiloxane(PDMS)micropos matrix devices,which serve as BioMEMS sensom for de-tecting cellular nanoforces and studying in vitro cell mechanics,have been developed.Closely spaced vartical microposts matrixes were designed to encourage cells to attach and spread across multiple microposts,and to bend the microposts like vertical cantilevers as the cells locomote on the surface.Using this dense and dis-crete matrix of microposts rather than a convanfional continuous substrate,CTFs can be directly measured and quantified by processing the microscopy images of the deformations of microposts.The resolution of the force was in tens of nN/μm scale.At first,the conventional CTFs measurement methods were concisely summa-rized.Then BioMEMS microposts matrix method was described in detail,including principle and fabfication process,Surface treatment and cell expedment results.Furthermore,high aspect ratio structure collapse prob-lem was investigated.

Objective To discuss the surgical treatment of spinal injury, and provide insights on key points and related issues for operations. Methods Two hundred and five cases of spinal fracture were treated through posterior surgical treatment. Under C-arm X-ray monitoring, surgeries had been operated on pedicle screws insertion, vertebral canal decompression, over-extending reduction position, and placed the connecting rod, knocked in the bone graft and finally transplanted the paraspinal bone. Results After operations , the height and morphology of vertebral bodies and spinal physiological curvature were basically recovered analyzed by X ray examination. The follow-up results (in the average of 14 to 36 months) indicated that there were 4 cases of delayed infection, 7 cases of loosen screw, 6 cases of broken screw (14 screws)and 1 case of broken stick, with no secondary nerve injury or other syndromes. Conclusion The vertebral pedicle screw internal fixation manipulated easily, which could sufficiently enlarge vertebral canal in order to decompression. In addition, during the operation, together with over-extending reduction position is beneficial to regain the height of fractured vertebral bodies.

A review of cell traction forces (CTFs) measurement based on Biological MiCro Electromechanical Systems (BioMEMS) microposts matrix is presented.CTFs are exerted by cells and ansmitted to the underly-ing substrate through focal adhesions and close contacts.which is essential for cells movement.Cells probe the mechanicaI compliance of the exlracellular mabix (ECM) in part by locally deforming it with nanonewton-scale traction forces.Precision measurement of CTFs is significant for many researches such as call biology and tissue engineering and so on.Enabled by the advancement in BioMEMS technology,surface treated high aspeect ratio Polydimethyisiloxane(PDMS)micropos matrix devices,which serve as BioMEMS sensom for de-tecting cellular nanoforces and studying in vitro cell mechanics,have been developed.Closely spaced vartical microposts matrixes were designed to encourage cells to attach and spread across multiple microposts,and to bend the microposts like vertical cantilevers as the cells locomote on the surface.Using this dense and dis-crete matrix of microposts rather than a convanfional continuous substrate,CTFs can be directly measured and quantified by processing the microscopy images of the deformations of microposts.The resolution of the force was in tens of nN/μm scale.At first,the conventional CTFs measurement methods were concisely summa-rized.Then BioMEMS microposts matrix method was described in detail,including principle and fabfication process,Surface treatment and cell expedment results.Furthermore,high aspect ratio structure collapse prob-lem was investigated.

Adult ; Aged ; Aged, 80 and over ; Bone Cements ; Bone Neoplasms ; diagnostic imaging ; surgery ; Diaphyses ; diagnostic imaging ; pathology ; surgery ; Female ; Humans ; Limb Salvage ; methods ; Male ; Middle Aged ; Radiography ; Treatment Outcome

3 cm)and small lesions(diameter≤3 cm)were 80.6%(79/98)and 67.2% (45/67),respectively(P

Objective To investigate the inhibitory effect and mechanism of soybean-derived Bowman-Birk inhibi-tor (BBI)on LPS-induced expression of inflammatory cytokines in intestinal epithelial cells.Methods Cytotoxicity effect of LPS and BBI on intestinal epithelial cells was analyzed by MTT assay.Intestinal epithelial cells were pre-treated with BBI,followed by LPS stimulation,expression of inflammatory cytokines(TNF-α,IL-1β,IL-8,and MCP-1)was detected by quantitative real-time polymerase chain reaction;the activation of NF-κB was measured by pNF-κB-luc system and Western Blot.Results The maximum concentration of LPS (10000 ng/mL)and BBI (1000 μg/mL)had no cytotoxicity effect on intestinal epithelial cells.LPS could potently up-regulate the expression of inflammatory cytokines(TNF-α,IL-1β,IL-8,and MCP-1 ),the up-regulation was positively correlated to the concentration of LPS;LPS-induced expression of inflammatory cytokines in intestinal epithelial cells could achieve the highest level,then decreased over time.The up-regulation of LPS on inflammatory cytokines in intestinal epi-thelial cells had dose-time effect;when intestinal epithelial cells were pretreated by BBI for 6 hours,the inhibitory effect of BBI on LPS-induced expression of inflammatory cytokines in intestinal epithelial cells was most obvious, and had dose-time effect.Conclusion BBI can potently inhibit LPS-induced expression of inflammatory cytokines through inhibiting NF-κB in intestinal epithelial cells.

The reaction conditions of baicalin hydrolyzed into baicalein by a kind of thermophilic and sugar-tolerant beta-glucosidase were studied in this paper. The beta-glucosidase could catalyze baicalin into baicalein well in the acetic acid-sodium acetate buffer. The optimal enzyme activity was at 85 degrees C and pH 5.5. The enzyme was stable at the temperature less than 85 degrees C and pH range of 5-7.5. The maximum reaction rate V. and michaelis constant K. were 0.41 mmol x L(-1) x min(-1) and 3.31 mmol x L(-1) respectively. Different metal ions had different effects on the activity of enzyme. Na+ existing in acetic acid-sodium acetate buffer had an activation effect on enzyme. The enzyme activity was enhanced by the concentrations of glucose below 0.6 mol x L(-1), and was gradually inhibited when monosaccharide concentration was over 0.6 mol x L(-1). When the monosaccharide concentration reached 1.2 mol x L(-1), the inhibition rate of enzyme activity was about 50%, which showed good glucose tolerance. The good reaction conditions through the experiment have been determined as follows, the substrate: enzyme dose was 1 g: 0.2 mL, acetic acid-sodium acetate buffer pH 5.5, reaction temperature 85 degrees C, reaction time 10 h, and the enzymatic hydrolyzation ratio could reach 97%.
Biocatalysis ; Enzyme Stability ; Flavanones ; chemistry ; Flavonoids ; chemistry ; Glucose ; chemistry ; Hot Temperature ; Hydrolysis ; Kinetics ; beta-Glucosidase ; chemistry

OBJECTIVETo investigate the effect of chitosan on the capsule inside the expanded flap.

METHODSThe expanders were implanted in animals with the treatment of chitosan(experimental group, n = 15) or without (control group, n = 15). After taking out the expanders, the flap contraction rate was calculated. The samples were observed through HE, Masson dyeing and CD34 immunohistochemical study. The thickness of capsule inside the expanded flap was measured under microscope. The samples were also studied under electron microscope.

RESULTSThe thickness of capsule was 516.000 +/- 128.491 microm in the experimental group, and 833.000 +/- 227.379 microm in the control group (P < 0.05). The number of microvessels was 8.200 +/- 2.150 per visual in experimental group, and 7.900 +/- 1.729 per visual in control group (P > 0.05). Under the electron microscope, the rough endoplasmic reticulum (RER) in the capsule in experimental group decreased and enlarged with degranulation. The mitochondria emerged or disappeared. The number of ribosome was reduced. In the control group, the RER enlarged without degranulation, the mitochondria was intact. The number of ribosome was not reduced.

CONCLUSIONSThe chitosan can effectively reduce the contraction of expanded flap through collagen secretion of fibroblast, delaying the differentiation from fibroblast to fiber cell, inhibiting thansform from fibroblast to myofibroblast. It has no effect on the microvascular generation and expansion, so the flap blood supply will not be affected with thicker capsule.

Animals ; Chitosan ; administration & dosage ; pharmacology ; Female ; Graft Survival ; Male ; Rabbits ; Skin Transplantation ; methods ; Surgical Flaps ; Tissue Expansion

To investigate the changes of platelet activated state and platelet activated function by trace whole blood flow cytometry (FCM), and to explore the mechanism of hemorrhage and infiltration in adults with acute leukemia, the expression percentage and changes of these expressions of CD62p and PAC-1 on platelet surface were determined by FCM of trace whole blood after platelet activated by ADP in patients with new diagnosed AL (group I), complete remission (CR, group II) and continuously complete remission (CCR, group III). Healthy adults were used as control group. The result showed that the expression of CD62p in group I and II was higher than that in control group, before and after platelet activated by ADP (P < 0.01). The expression of PAC-1 in group I was higher than that in control group (P < 0.01), the expression of PAC-1 in group II was lower than that in control group (P > 0.01), There was no significant difference in expression of CD62p and PAC-1 between group III and control group (P > 0.01), and no significant difference was found between AL group with megakaryocyte malignant pathological changes and AL group without megakaryocyte malignant pathological changes before platelet activated by ADP (P > 0.01). After platelet activated by ADP, the expression of PAC-1 in the former was lower than that in the latter (P < 0.01). It is concluded that (1) high level activated platelet in peripheral blood of AL patients show that interaction between activated platelet and leukemia cells can be one of reason resulting in widespread hemorrhage and infiltration AL patiens; (2) the decrease of number and activted function of platelet at the first stage of AL patients may be caused by malignant hyperplasia of leukemia cells and damage of megakaryopoiesis in bone marrow.
Acute Disease ; Adenosine Diphosphate ; pharmacology ; Adolescent ; Adult ; Aged ; Blood Platelets ; cytology ; metabolism ; Cell Membrane ; drug effects ; metabolism ; Female ; Flow Cytometry ; Humans ; Leukemia ; blood ; pathology ; Male ; Middle Aged ; P-Selectin ; biosynthesis ; Platelet Activation ; drug effects ; physiology ; Platelet Glycoprotein GPIIb-IIIa Complex ; biosynthesis

BACKGROUNDOsteosarcoma is a common primary malignant tumor of bone with a poor prognosis due to its propensity for metastasis. The prognosis of patients is highly dependent on the presence or absence of lung metastasis and on the effectiveness of treatment against it. It has been reported that low level expression of Fas protein in human osteosarcoma cell is closely associated with lung metastasis. A large number of studies have shown that arsenic trioxide (ATO) can inhibit proliferation and induce apoptosis of many cancer cell lines; however, its effects on human osteosarcoma cells (Saos-2 cell line) remains unknown. The aim of this study was to investigate the effects of ATO on Saos-2 cells and to characterize its mechanism of Fas-expressing.

METHODSA group of Saos-2 cells was treated with or without 0.5, 1, 2, 4 and 8 micromol/L ATO for three successive days, and the cytotoxicity of ATO was determined by an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological changes in cells were studied by acridine orange/ethidium bromide (AO/EB) double staining. Flow cytometry (FCM) was used to assay cell DNA distribution. Another group of cells was pretreated with 10 nmol/L matrix metalloproteinase 7 (MMP-7) for 3 hours. They were then incubated with or without 2 micromol/L ATO for 24, 48 and 72 hours. Cytotoxicity, Fas protein and mRNA levels were systematically studied using MTT, Western blotting and real-time PCR, respectively. Cell proliferation, cell cycle progression and apoptosis were examined in this study.

RESULTSProliferation of Saos-2 cells was inhibited by ATO in both a dose- and time-dependent manner. The IC(50) values at 24, 48 and 72 hours were 9.30, 5.54 and 3.49 micromol/L, respectively. The survival rate of Saos-2 cells in the MMP-7 and ATO co-treated group was significantly higher than the ATO group, but it was lower than the control group. ATO induced G(1) phase arrest of the cell cycle and very efficiently stimulated apoptosis in Saos-2 cells, as evidenced by flow cytometric detection of sub-G(1) DNA content and AO/EB staining. Western blotting results indicated that Fas (FasL) protein expression in osteosarcoma cultures markedly increases in a time dependent manner after exposure to ATO. Compared with control, treatment with ATO 2 micromol/L and 4 micromol/L for 48 hours, resulted in increase of Fas gene expression to 28.31% and 56.74%, respectively. Our results indicated that ATO induced-apoptosis of Saos-2 cells may be mediated through the Fas pathway.

CONCLUSIONSATO suppressed cell proliferation of Saos-2 cell in a dose- and time-dependent manner and increased Fas protein expression. However, Fas-mediated apoptosis was incompletely interrupted by MMP-7, which suggested that other molecular mechanisms may mediate this process.

Antineoplastic Agents ; therapeutic use ; Apoptosis ; drug effects ; Arsenicals ; therapeutic use ; Blotting, Western ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Flow Cytometry ; Humans ; Osteosarcoma ; drug therapy ; metabolism ; Oxides ; therapeutic use ; Reverse Transcriptase Polymerase Chain Reaction ; fas Receptor ; genetics ; metabolism