Following the basic theory of protecting gas-reservoirs from damage with the temporary bridging technology, inert calcium carbonate (CaCO3) particles, whose diameter is consistent with the size of pores or apertures in the reservoir, were selected as the bridging agent, and modified resolvable starch was selected as filtration loss reducing particles to form the non-clay low damage temporary bridging drilling/completion fluids system (NLTDFS). Under the simulated condition of the well bottom during real drilling, NLTDFS was used to conduct dynamic and static damage experiments of cores for 48 hours, respectively, and then the experimented cores were permeated with pure nitrogen from the undamaged end to the damaged one to measure their recovery of permeability. The results showed that the permeability recovery rate of the core reached 90% or so, and the damaged depth was less than 1 cm, which demonstrates that NL TDFS has higher temporary bridging effectiveness and lower damage to the gas-reservoir than other drilling fluids system. NLTDFS has been used to drill many horizontal wells, and four of them have obtained high yield of natural gas. The yield of natural gas of LPl well reached 85 X 104 m3/day after completion with the rump pipe. The formation of the stable well wall and smooth drilling led to an API loss less than 4 mL and an HTHP loss less than 15 mL.

Accidents, Occupational ; Humans ; Hydrogen Sulfide ; poisoning

BACKGROUND: It is a key point to revascularize the tissue-engineered bone during the repairing of large bone defect. Fascia flap is commonly used in clinic to accelerate the blood supply of implant.OBJECTIVE: To observe the feasibility of repairing goat tibia defects with tissue-engineered bone and accelerating revascularization with fascia flaps.DESIGN: Randomized and controlled animal experiment SETTING: Department of Traumatic Orthopaedics, Nanfang Hospital,Southern Medical University.MATERIALS: Totally 36 goats with the body mass of 14.5-15.5 kg of either gender were enrolled.METHODS: This experiment was conducted at the Department of Traumatic Orthopaedics, Nanfang Hospital, formerly the First Military Medical University of Chinese PLA from December 1999 and December 2003.Bone and periosteum defects 20 mm long were made and fixed with plate of left tibia in 36 goats. They were randomly divided into four groups: Group A in which the defects were filled with coral hydroxyapatite (CHAP), Group B I CHAP+ bone marrow stroma cells (BMSc); Group C with fascia flaps;Group D with nothing. Next, the bone regeneration and the revasculariza tion were evaluated. Radionuclide bone imaging was done 2, 4, 8 weeks after operation. After X-ray examination, the index of optical density of Xray films and histology of the implants were analyzed at 4, 8, 12 weeks after operation, and the biomechanical characters were studied 12 weeks postoperatively.MAIN OUTCOME MEASURES: Gross observation and X-ray, radionuclide bone imaging, biomechanical and histological observation RESULTS: Totally 36 goats entered the stage of result analysis. ① Gross observation of the repair sample of bone defects of the animals in each group: there was no osteogenesis postoperatively at each time point in the blank control group . In Group B, at week 8 to 12, there was no obvious osteogenesis and callus formation on the surface of the materials. In Group C,At weeks 8 to 12, bone defects were filled gradually, many bone callus processes were seen on the surface of the materials , centralizing and enwrapping the materials. The osteogenetic process in the Group C were superior to that of theGroup B. ②Examination result with -901/SA PET-CT scanners: It was seen by naked eyes that at weeks 2 to 8 in the Group A,the radioactivity concentration at region of interesting (ROI) of the operation side had obvious increasing trend, and similar trend of changing appeared in the Group B and Group C, but the ROI counts and T/NT value in the Group B were both lower than those in the Group C. The decreasing trend in the Group A was lower than that in the Group B. ③) Radiological results: the osteogenesis volume through measuring absorbance in the order from large to small was Group C, Group B, and Group A[At week 12, they were (4.180±0.192), (3.480±0.453), (2.959±0.682)respectively ].④Biomechanical results: there were significant difference of loading and bending stress in the Group C, Group B and Group A [ The loading was (758.333±88.754), (530.214±65.297), (359.667±60.715)N , respectively; and the bending stress was (13.937±2.199), (10.123±1.243),(6.223±0.945)N/mm2, respectively ].⑤)Histological results: Slices at various time points in the blank control group showed no bone tissue. In the other three 3 groups, with the prolongation of time, the osteagenetic range and quality were in the order of Group C, Group B and Group A.CONCLUSION: The fascia flaps can accelerate the revascularization process in the formation of tissue-engineered bone so that the capability of tissue engineered bone to repair the large bone defects may be enhanced.

BACKGROUND: The main aspect of the study in the bone histological engineering is how to maintain and improve theosteogenesis of the osteoblasts in vivo and in vitro. The gene transference may provide a new effective method to deal with theproblem.OBJECTIVE: To discuss the effect of the reverse transcription virus mediated human bone morphogenetic protein7(hBMP-7) gene transfection on the proliferation and osteogenetic differentiation of the bone marrow mesenehymal stemcells (BMSCs) of the rabbits.DESIGN:Cells taken as the study object, grouping control, repeat observation andmeasurement.SETTING: Traumatological and othopaedic lab of a medical university hospital.PARTICIPANTS: The study wascompleted in the Traumatological and Othopaedic Lab in the Affiliated Nanfang Hospital of the Southern Medical University from July 2001 to July 2003. Four New Zealand rabbits,whose weights varied from 1.0 to 1.5 kg, were provided without sexlimit by the Animal Experiment Center of the First Military Medical University of Chinese PLA.METHODS:The reverse transcription virus carriersof the hBMP-7 were constructed,and then the BMSCs were transfected by the virus containing target genes. The expression of the hBMP-7 protein was detected with the immunohistochemical method. The cell proliferation, cycle and ALP synthesis were respectively detected with the MTT method,flow cytometer and NPP method.MAIN OUTCOME MEASURES: Primary results: ① the detection results of the cell proliferation. ② the detection results of the ALP.Secondary results: ① the expression of the hBMP-7 protein in the transfected BMSCs. ② the detection results of the cell cycle.RESULTS: After the BMP-7 gene transfection, there was hBMP-7 positive expression in the BMSCs of the rabbits,using the immunohistochemical detection. There was no significant change in the BMSCs proliferation of the rabbits after the hBMP-7 gene transfection ( P ＞ 0.05). Compared with the ALP synthesis of the transfected BMSCs(294. 592 ± 86. 567) nkat/L, there was significant difference in the ALP synthesis of the empty carrier transfected BMSCs(155. 231 ±86.567) nkat/L and the un-transfected BMSCs (160. 866 ±91. 585)nkat/L( F =5. 660, P ＜ 0. 05).CONCLUSION: After the BMP-7 gene transfection, the BMSCs can synthesize and express the extragenous BMP-7. The hBMP gene transfection can promote the differentiation of the BMSCs cultured in vitro into the osteoblasts and can be used as the seed cells in the construction of the histological en gineering bone tissues and in further application.

The voltage-gated potassium channels Kvl.5 is widely expressed in the plasma membranes of numerous tumor cells and it can contribute to a variety of cellular functions such as proliferation,ap optosis,and cell cycle.Several types of antineoplastic drugs can change the expression of Kv1.5 and then affect the biological processes.Kv1.5 is identified as a novel target for therapy in human cancer.The researches of Kv1.5 will contribute to gain a further understanding of the molecular mechanism of tumor and provide therapeutic opportunity for the prevention and treatment of cancer.

Objectives:To investigate the clinical significance of the expression level of cytokeratin5/6/18 positive cells in peripheral blood cells from patients with breast carcinoma.Methods:The expression rates of ck5/6/18 positive cells in peripheral blood cells from 56 patients with breast carcinoma were measured and analyzed by flow cytometry.Results:The expression rates of ck5/6/18 positive cells in peripheral blood cells from 56 patients with breast carcinoma was 46.4% and there was significant differences compared with healthy volunteers and the patients with breast benign diseases.The positive rates increased significantly with the pathological staging and show no significant relationship with the ER and PR.Conclusion:The expression of ck5/6/18 positive cells in peripheral blood cells correlates significantly with the pathological staging of breast carcinoma and it could be an effective signal to clinical monitor and prognosis.

Objective:To study the biological effects of new monomer 3 from Radix Curcumae on proliferation of human gastric cancer cells SGC-7901.Methods:Uing fluorescence microscope to observe the impact on SGC-7901 cells with different concentrations of the new monomer 3 at different times,using MTT assay to observe the growth inhibition rate of SGC-7901 cells,using flow cytometry to observe the apoptosis rate and cell cycle distribution of SGC-7901 cell.Results:Pronounced apoptosis had been found by fluorescence microscopy,apoptosis had a certain amount of time-dependent and concentration-dependent;Early apoptotic cells near normal morphology,normal nuclear morphology;late apoptotic cells'size shrink or round in shape,nuclear pyknosis or fragmentation.MTT method showed that the new monomer 3 had significantly inhibition on SGC-7901 cells,the half inhibition rate(IC50) was 30.14?g/mL.Flow cytometry(FCM) showed that:the new monomer 3 can increase the SGC-7901 cells in the S phase and G0/G1 and reduce it in G2/M.The change had time and concentration dependence;The apoptotic rates of dosing unit(24h,48h) compared with the control group had significant differences.The maximum apoptosis rate was 60.07%.Conclusion:The new monomer 3 inhibited human gastric cancer SGC-7901 cells significantly and had the impact on cell cycle distribution of the SGC-7901 cells and induction of apoptosis.

Objective To establish three dimensional finite element model libraries of telescopic dentures and removable partial dentures by means of model libraries, and compare the characteristics of stress distribution among three prostheses. Methods Normal model libraries were imported and edited, and models of bilateral free-ended cases were established. Based on the model libraries of fixed partial dentures and removable partial dentures, the finite element models of telescopic dentures and removable partial dentures with medial or distal occlusal rest were established using softwares such as DELL Precision Graphics Workstation, UG 5.0, HyperMesh 7.0 and Abaqus 6.5, then finite element stress analysis was performed. Results The stress distribution on abutment root, parodontium, alveolar mucosa and alveolar bone was uniform. The maximum value of stress on the abutment root (6.205 Mpa) was much less than those of two removable partial dentures (18.41 Mpa and 34.49 Mpa). Conclusion For bilateral free-ended cases, the telescopic denture design is uniform in stress distribution with less stress on abutment root, which is healthy to the abutment root and surrounding tissues.

Objective To redevelop the finite element model libraries and to analyse the stress distribution of telescopic crown dentures. Methods The finite element model libraries were redeveloped based on the model libraries of normal dentition, fixed partial denture and removable partial denture. With the help of softwares such as DELL Precision Graphics Workstation, UG 5.0, HyperMesh 7.0 and Abaqus 6.5, the telescopic denture models on the bilateral free-ended case were imported and edited, then the finite element stress analysis was performed. Results The models were easily established. The maximum value of stress and its distribution on abutment root, periodontal membrane, alveolar mucosa, alveolar bone and dental prostheses were observed and studied by the finite element stress analysis. Conclusion The way to establish models of telescopic crown dentures by model libraries is feasible and reliable.

Objective To investigate the expression and clinical significance of p27 protein in stage Ⅱ colon cancer.Methods The expression of p27 protein in 57 samples of stage Ⅱ colon cancer tissue from BeijingCancer Hospital was detected by immunohistochemistry and tissue microarray technique.Survival was analyzed by the Kaplan-Meier method,and the correlation between the expression of p27 protein and the prognosis of patients was analyzed by Pearson chi-square test.Multivariate analysis was done by using Cox proportional hazard regression model.Results The rate of high expression of p27 protein in stage Ⅱ colon cancer was 60%(34/57).The differentiation.location and distal metastasis of the tumor were correlated with the expression of p27 protein(X2=5.97,5.93,5.05,P＜0.05);while age,tumor size,growth patterns of tumor were not correlated with the expression of p27 protein(X2=0.64,0.49,0.33,P＞0.05).The 5-year survival rate of the patients with high expression of p27 protein was 94%(32/34),which was significantly higher than the 78%(18/23)of the patients with low expression of p27 protein(X2=3.86,P＜0.05).Multivariate analysis showed that low expression of p27 protein and tumor penetrating serous membrane are the independent adverse prognostic factors for stage Ⅱ coloR cancer.Conclusions Low expression of p27 protein is one of the independent adverse prognostic factors for stage Ⅱ colon cancer,and the expression of p27 protein should be consulted when screening out the patients who are in the high risk group of stage Ⅱ colon cancer.