4Y32铝合金空心锭内壁金属瘤分析

通过成分、金相、组织、扫描电镜、能谱分析等措施分析管材内壁金属瘤组成,分析金属瘤产生原因,通过工艺改进解决缺陷。

薄壁喷管的真空铸造

前言薄壁喷管系用于宇航姿控发动机的重要零件,国外同类喷管多采用精密铸件,而国内是用棒材机加工制造。以铸造喷管取代机加工喷管的优点是:其一,可以完全满足设计对喷管特殊型面的要求,在同样推力的条件下,缩短了喷管的长度和减轻了重量。

Clinical signification on the expressions of metallothionein in three types cancer of woman

Objective： To study the expressions and significations of metallothionein （MT） in cervical squamous cell cancer （CSC）, bladder transitional cell cancer （BTC） and breast cancer （BC） of woman. Methods： Immunohistochemical method was used to examine the expresses rate of MT in three types of woman cancer tissue. Results： The expressions rates of MT were 54.35% （29146） in BTC, 67.05% （59188） in BC and 57.14% （40/70） in CSC. The positive rate of MT expression was higher in low differentiation group than well differentiation group in BTC and CSC （P 〈 0.05）. Positive of MT in lobular cancer was significance higher than medullary and duct cancers （P 〈 0.05）. Conclusion： The expression of MT is related to differentiation degree, and it is a guidance for clinical choice of chemotherapy project.

Clinical application of metallic stents in treatment of esophageal carcinoma

AIM: To evaluate the effects of self-expanding metal stents (SEMS) in patients with malignant esophageal obstruction and to analyze their prognosis and complications. METHODS: Seventy-four metallic stents were placed under fluoroscopic guidance in 66 patients with esophageal obstruction secondary to carcinoma, of whom, 6 cases were complicated by fistula. RESULTS: After seventy-two stents were successfully used in 66 cases without any severe complications (technical successful rate was 97%), the dysphagia score improved from 3.3±0.6 to 0.8±0.5 (P<0.01), and life quality improved significantly in all these patients. All fistulae were sealed immediately after coated stents were inserted in the six patients. New stents were placed in two patients: the stent migrated more than 2 cm, in one patients and the stent slipped into stomach in the other. Minor bleeding was found only in 28 patients during the operation. Reobstruction was found in 12 patients, but was successfully cured under endoscopy. The survival rate was 78%, 57% and 11% for 6 mo, 1 year and 2 years respectively. CONCLUSION: Placement of SEMS is a simple, safe, quick and efficient surgical method for treating esophageal carcinoma obstruction. It may be used mainly as a palliative treatment of esophageal obstruction secondary to carcinoma.

Enhancement of radiosensitization by metal-based nanoparticles in cancer radiation therapy

Radiation therapy performs an important function in cancer treatment. However, resistance of tumor cells to radiation therapy still remains a serious concern, so the study of radiosensitizers has emerged as a persistent hotspot in radiation oncology. Along with the rapid advancement of nanotechnology in recent years, the potential value of nanoparticles as novel radiosensitizers has been discovered. This review summarizes the latest experimental findings both in vitro and in vivo and attempts to highlight the underlying mechanisms of response in nanoparticle radiosensitization.

KISS-1 inhibits the proliferation and invasion of gastric carcinoma cells

AIM:To investigate the function of the KISS-1 gene in gastric carcinoma cells and to explore its potential mechanism.METHODS:A KISS-1 eukaryotic expression vector was constructed and transfected into BGC-823 cells.Resistant clones were obtained through G418 selection.reverse transcription-polymerase chain reaction and western blotting were used to detect KISS-1 and matrix metalloproteinase-9(MMP-9)expression in transfected cells.The growth of transfected cells was investigated by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide(MTT)proliferation assays,and the cells'invasive potential was analyzed by basement membrane(Matrigel)invasion assays.The anti-tumor effects of KISS-1 were tested in vivo using allografts in nude mice.RESULTS:The expression level of KISS-1 mRNA andprotein in BGC-823/KISS-1 transfected cells were significantly higher than in BGC-823/pcDNA3.1 transfected cells(P<0.05)or the parental BGC-823 cell line(P< 0.05).The expression level of MMP-9 mRNA and protein in BGC-823/KISS-1 were significantly less than in BGC-823/pcDNA3.1(P<0.05)or BGC-823 cells(P< 0.05).MTT growth assays show the proliferation of BGC-823/KISS-1 cells at 48 h(0.642±0.130)and 72 h(0.530±0.164)were significantly reduced compared to BGC-823/pcDNA3.1(0.750±0.163,0.645±0.140)(P<0.05)and BGC-823 cells(0.782±0.137,0.685± 0.111)(P<0.05).Invasion assays indicate the invasive potential of BGC-823/KISS-1 cells(16.50±14.88)is significantly reduced compared to BGC-823/pcDNA3.1(20.22±14.87)(P<0.05)and BGC-823 cells after 24 h(22.12±16.12)(P<0.05).In vivo studies demonstrate the rate of pcDNA3.1-KISS-1 tumor growth is significantly slower than pcDNA3.1 and control cell tumor growth in nude mice.Furthermore,tumor volume of pcDNA3.1-KISS-1 tumors(939.38±82.08 mm3)was significantly less than pcDNA3.1(1250.46±44.36 mm3) and control tumors(1284.36±55.26 mm3)(P<0.05).Moreover,the tumor mass of pcDNA3.1-KISS-1 tumors(0.494±0.84 g)was significantly less than pcDNA3.1(0.668±0.55 g)and control tumors(0.682±0.38 g)(P <0.05).CONCLUSION:KISS-1 may inhibit the proliferation and invasion of gastric carcinoma cells in vitro and in vivo through the downregulation of MMP-9.

EXPRESSION OF MATRIX METALLOPROTEINASE-7 INVOLVING IN GROWTH, INVASION, METASTASIS AND ANGIOGENESIS OF GASTRIC CANCER

Objective. To investigate the role of matrix metalloproteinase-7 (MMP-7) expression in caricinogenesisand progression of gastric cancer.Methods. We studied MMP-7 expression and microvessel density (MVD) in adjacent mucosa and pri-mary foci of 113 cases of gastric cancer by streptavidin-biotin-immunoperoxidase method using anti-MMP-7 and anti-CD34 antibodies. MMP-7 expression and mean MVD were compared with clinicopatholog-ical features of gastric cancer, with the relationship between MMP-7 expression and MVD concerned in gastric cancer.Results. MMP-7 showed positive expression in adjacent mucosa of gastric cancer (29.20%, 33/113),less than that in gastric cancer (69.03%, 78/113). MMP-7 expression in primary foci of gastric cancerwas positively correlated with tumor size, invasive depth, metastasis and TNM staging (P＜0.05), but notwith differentiation or growth pattern of gastric cancer (P＞0.05). Positive correlation of mean MVD withtumor size, invasive depth, metastasis and TNM staging was found (P＜0.05), despite no relationshipbetween mean MVD and differentiation of gastric cancer (P＞0.05). Mean MVD was dependent on MMP-7expression in gastric cancer (P＜0.05).Conclusion. Up-regulated expression of MMP-7 played an important role in carcinogenesis and pro-gression by participating in growth, invasion, metastasis and angiogenesis of gastric cancer. MMP-7 ex-pression could be regarded as an effective and objective marker to reflect the biological behaviors of gas-tric cancer.

Ornithine decarboxylase, mitogen-activated protein kinase and matrix metalloproteinase-2 expressions in human colon tumors

AIM: To investigate the expressions of omithine decarboxylase (ODC), MMP-2, and Erk, and their relationship in human colon tumors.METHODS: ODC activity, MMP-2 expression, and mitogenactivated protein (MAP) kinase activity (Erk phosphorylation) were determined in 58 surgically removed human colon tumors and their adjacent normal tissues, using [1-14C]-ornithine as a substrate, ELISA assay, and Western blotting, respectively.RESULTS: ODC activity, MMP-2 expression, and Erk phosphorylation were significantly elevated in colon tumors, compared to those in adjacent normal tissues. A significant correlation was observed between ODC activities and MMP-2 levels.CONCLUSION: This is the first report showing a significant correlation between ODC activities and MMP-2 levels in human colon tumors. As MMP-2 is involved in cancer invasion and metastasis, and colon cancer overexpresses ODC, suppression of ODC expression may be a rational approach to treat colon cancer which overexpresses ODC.

EFFECTS OF GENISTEIN ON INVASION AND MATRIX METALLOPROTEINASE ACTIVITIES OF HT1080 HUMAN FIBROSARCOMA CELLS

Effects of genistein on invasion and matrix metalloproteinase activities were investigated in HT1080 human sarcoma cells.Invasion of HT1080 cells through reconstituted basement membrane was inhibited when the cells were treated with 100 μ mol/L and 200 μ mol/L genistein.At the same concentrations,genistein not only suppressed latent forms of matrix metalloprotinese 2 and 9(MMP 2 and MMP 9) to convert into active forms,but also increase dramatically the tissue inhibitor of metalloproteinase(TIMP 1) mRNA contents and reverse the imbalance of MMPs and TIMPs.However,expressions of MMP 2 and MMP 9 were not significantly affected.Suppression of MMP activation and increase of TIMP 1 expression will decrease matrix degradation by MMPs,and consequently inhibit invasions of the cells.These results emphasized the existence of the imbalance between MMPs and TIMPs in tumor invasion and metastasis formation.The value of genistein as a drug for antiinvasion and anti metastasis chemotherapy was suggested.

AKT1 and AKT2 Promote Malignant Transformation in Human Brain Glioma LN229 Cells

OBJECTIVE To confirm the role played by AKT1 and AKT2 in the β- catenin/Tcf-4 signaling pathway in promoting malignant transfor- mation of glioma cells. METHODS LN229 cells were divided into five groups： a control group, acetone （ACE）group, acetylsalicylic acid （ASA; aspirin） group, ASA＋AKT1 plasmid group and ASA＋AKT2 plasmid group. Western blot and PCR were used to detect the expression of AKT1 and AKT2 after dealing with ASA and transferring AKTI/2 genes into LN229 cells. Cell proliferation was determined by flow cytometry, cell invasion was evaluated by transwell assay and cell apoptosis was detected with annexin V staining. The molecules regulating proliferation and invasion were examined by western blot analysis. RESULTS Aspirin down-regulates AKT1 and AKT2 expression by modulating β-cateninfrcf-4 activity. AKT1 and AKT2 can enhance cell proliferation and invasion by up-regulating the expression of cyclin-D and matrix metalloprotein-9 （MMP-9） in LN229 glioma cells. CONCLUSION AKT1 and AKT2 play an important role in the β- catenin/Tcf-4 signaling pathway promoting malignant transformation; AKT1 is more effective than AKT2. AKT1 and AKT2 may be potential targets for brain glioma therapy and an effective way to prevent metastasis of gliomas.

Wedge BUE of SiC reinforced aluminium composites

Several orthogonal cutting experiments were carried out on SiC reinforced aluminium composites. In the cutting process, photos of the chip bottom specimen SEM were gotten with the aid of ‘quick stop tool device’. According to the photos, the build up edge (BUE) can be produced in circumferential cutting experiments. In comparison with carbon steel BUE, aluminium composites BUE is like a wedge in shape, and its development mechanism is mechanical enchasing other than "cold welding". In addition to the above mentioned conclusions, the minishing BUE height H b is also analyzed.

Expression and correlation of CD44v6, vascular endothelial growth factor, matrix metalloproteinase-2, and matrix metalloproteinase-9 in Krukenberg tumor

AIM： To explore the expression and correlation of CD44v6, vascular endothelial growth factor （VEGF）, matrix metalloproteinase （MMP）-2 and matrix metalloproteinase （MMP）-9 in Krukenberg and primary epithelial ovarian carcinoma. METHODS： The expressions of CD44v6, VEGF, MMP-2 and MMP-9 were detected by immunohistochemical method in 20 cases of normal ovarian tissues, 38 cases of Krukenberg tumor and 45 cases of primary epithelial ovarian carcinoma. RESULTS： The expression of CD44v6 （primary epithelial ovarian carcinoma tissue vs normal ovarian tissue： χ^2= 4.516, P= 0.034; Krukenberg tumor tissue vsnormal ovarian tissue： χ^2 = 19.537, P = 0.001） and VEGF （primary epithelial ovarian carcinoma tissue vs normal ovarian tissue： P = 0.026; Krukenberg tumor tissue vs normal ovarian tissue： χ^2 = 22.895, P = 0.001） was significantly higher in primary epithelial ovarian carcinoma tissue and Krukenberg tumor tissue than in normal ovarian tissue. The positive expression rate of MMP-2 and MMP-9 was 0% in the normal ovarian tissue. The positive expression rate of CD44v6 （ χ^2= 10.398, P= 0.001）, VEGF （ χ^2= 13.149, P = 0.001）, MMP-2 （ χ^2 = 33.668, P = 0.001） and MMP-9 （ χ^2= 38.839, P = 0.001） was remarkably higher in Krukenberg tumor than in primary epithelial ovarian carcinoma. The correlation of CD44v6, VEGF, MMP-2, and MMP-9 was observed in primary epithelial ovarian carcinoma and Krukenberg tumor. CONCLUSION： CD44v6, VEGF, MMP-2, and MMP-9 are involved in ovarian carcinoma, gastric cancer and Krukenberg tumor. Detection of CD44v6, VEGF, MMP-2 and MMP-9 may contribute to the diagnosis of ovarian carcinoma, gastric cancer, and Krukenberg tumor.

Elevated plasma level of matrix metalloproteinases-9 and its significance in patients with abdominal aortic aneurysms

Objective: To investigate the changes of the plasma level of MMP-9 (Matrix Metalloproteinase-9, MMP-9) in the patients with abdominal aortic aneurysms (AAAs) before and after the treatment, and evaluate the significance of MMP-9 in the pathogenesis of AAAs. Methods: Blood samples of 35 patients with AAAs and 10 patients with the arterial occlusive diseases (AODs) , which enrolled into the Vascular Surgery Center of Colonge University Hospital from February to August of 2002, were collected before and one month after surgical repair or less-invasive endovascular exclusion. The plasma concentrations of MMP-9 of all the collected samples were measured by means of enzyme-linked immunosorbent assay(ELISA), and compared between the two groups patients at different time point. Results: The mean plasma concentration of MMP-9 of AAAs was significantly higher than that of AODs prior to treatment [(90.3±9.1) ng/ml vs (23.6±7.3) ng/ml, P<0.05], and no apparent difference was showed in the patients with AODs [(23.6±7.3) ng/ml vs (25.3±5.8) ng/ml, P>0.05)] before and after the surgical bypass operation. However, in the patients with AAAs the plasma concentration of MMP-9 was apparently decreased one month after the surgical repair or endovascular exclusion compared with before [(28.6±8.4) ng/ml vs (90.3±9.1) ng/ml, P<0.05)]. No meaningful difference of the mean plasma MMP-9 concentration was seen between two groups after the both being successfully treated [(28.6±8.4) ng/ml vs (25.3±5.8) ng/ml, P>0.05]. Conclusion: Apparent elevation of plasma concentration of MMP-9 in the AAAs and its dramatic decrease after being treated implicated that MMP-9 might play an important role in the formation and development of AAAs. Meanwhile, to investigate the changes of MMP-9 level of AAAs could provide an practical way to facilitate the earlier diagnosis and long term surveillance for AAAs. More importantly, pharmacologic prevention and treatment of AAAs, in which the MMP-9 serves as effective target, might be possible in the future.

Effects of carbon dioxide pneumoperitoneum on metastasis of ovarian carcinoma cell line SKOV_3

The long suspicion of the potential harm of carbon dioxide （CO2） pneumoperitoneum exists in laparoscopic cancer surgery. For better understanding of this problem, we targeted this study at the effects of CO2 pneumoperitoneum on the invasive ability of ovarian carcinoma cell line and the possible mechanism within it. To study the effects of CO2 pneumoperitoneum on carcinoma cell, SKOV3 cells were divided into 2 groups, respectively exposed to pneumoperitoneal CO2-insuffiation and normal conditions. To study the possible mechanism, SKOV3 cells were divided into 3 groups, one was exposed to CO2 pneumoperitoneum, one to N2 and the other to normal conditions served as control. The in vitro adhesive and invasive ability of the cells was analyzed through 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay and Boyden filters metastasis model; the expressions of vascular endothelial growth factor C （VEGF-C） and matrix metalloproteinase 9 （MMP9） were determined by reverse transcription polymerase chain reaction（RT-PCR）, and Western blot. We found that the adhesive ratio of SKOV3 cells exposed to CO2 was significantly higher than that of the control group; cells exposed to CO2 invaded the matrigel with a greater number （P〈0.01）; the expression of VEGF-C exposed to both CO2 and N2 was significantly increased compared with control group （P〈0.05）; the MMP9 expression level of CO2 group was higher than that of N2 group, P〈0.05. We concluded that carbon dioxide pneumoperitoneum may improve the adhesive and invasive ability of ovarian carcinoma cell line in vitro and CO2 can also be an independent factor to stimulate the expression of MMP9.

Real-time monitoring of tumor vascular disruption induced by radiofrequency assisted gadofullerene

The anti-vascular therapy has been extensively studied for high performance tumor therapy by suppressing the tumor angiogenesis or cutting off the existing tumor vasculature. We have previously reported a novel anti-tumor treatment technique using radiofrequency （RF）-assisted ga- dofullerene nanocrystals （GFNCs） to selectively disrupt the tumor vasculature. In this work, we further revealed the changes on morphology and functionality of the tumor vas-culature during the high-performance RF-assisted GFNCs treatment in vivo. Here, a dearly evident mechanism of this technique in tumor vascular disruption was elucidated. Based on the H22 tumor bearing mice with dorsal skin flap chamber （DSFC） mode] and the dynamic contrast enhanced magnetic resonance imaging （DCE-MRI） technique, it was revealed that the GFNCs would selectively inset in the gaps of tumor vas-culature due to the innately incomplete structures and unique microenvironment of tumor vasculature,＇ and they damaged the surrounding endothelia cells excited by the RF to induce a phase transition accompanying with size expansion. Soon afterwards, the blood flow of the tumor blood vessels was permanently shut off, causing the entire tumor vascular net- work to collapse within 24 h after the treatment. The RF-as- sistant GFNCs technique was proved to aim at the tumor vasculatnre precisely, and was harmless to the normal vascu- lature. The current studies provide a rational explanation on the high efficiency anticancer activity of the RF-assisted GFNCs treatment, suggesting a novel technique with potent clinical application.

Antineoplastic activities of Gd@C_(82)(OH)_(22) nanoparticles: tumor microenvironment regulation

Malignant tumors are complex organs consisting of tumor cells and their microenvironment. Increasing evidence has shown that the tumor microenvironment is critical to the initiation and progression of tumors. Rational design of tumor therapies via targeting the tumor microenvironment to inhibit tumor growth is thus becoming a consensus strategy. Gd@C 82 (OH) 22 nanoparticles, as novel endohedral hydroxylated metallofullerenes, have been demonstrated to be a potent antitumor nanomedicine via targeting multiple factors in the tumor microenvironment. Gd@C 82 (OH) 22 nanoparticles possess excellent biocompatibility and remarkable antineoplastic activity, as a result not of direct tumor cytotoxicity but of their diverse biological effects, including antioxidation, immune activation, angiogenesis inhibition, imprisoning cancer cells, and reversal of drug-resistance. In this article, we summarize the unique nanoscale physiochemical properties and the antineoplastic activities of Gd@C 82 (OH) 22 nanoparticles, and focus on the mechanisms underlying their regulation of the tumor microenvironment.

Biodegradable magnesium implants:a potential scaffold for bone tumor patients

Relapse and metastasis of tumor may occur for osteosarcoma(OS)patients after clinical resection.Conventional metallic scaffolds provide sufficient mechanical support to the defected bone but fail to eradicate recurring tumors.Here we report that biodegradable magnesium(Mg)wirebased implant can inhibit OS growth.In brief,the Mg wires release Mg ions to activate the transport of zinc finger protein Snail1 from cytoplasm to cell nucleus,which induces apoptosis and inhibits proliferation of OS cells through a parallel antitumor signaling pathway of miRNA-181d-5p/TIMP3 and miRNA-181c-5p/NLK downstream.Simultaneously,the hydrogen gas evolution from Mg wires eliminates intracellular excessive reactive oxygen species,by which the growth of bone tumor cells is suppressed.The subcutaneous tumor-bearing experiment of OS cells in nude mice further confirms that Mg wires can effectively inhibit the growth of tumors and prolong the survival of tumor-bearing mice.In addition,Mg wires have no toxicity to normal cells and tissues.These results suggest that Mg implant is a potential anti-tumor scaffold for OS patients.

Gadofullerene nanoparticles extend survival rate and down-regulate thrombin expression in orthotopic pancreatic cancer

Pancreatic cancer is a devastating malignant disease with 5-year survival rate less than 8%.The impenetrable desmoplastic stroma of pancreatic tissue and serious side-effects of existing drugs hinder the effective treatment for pancreatic carcinoma.Thus,it is imperative to exploit much more safe and efficient methods to prolong the survival of pancreatic cancer patients.In this study,we explored a superior anti-pancreatic cancer strategy based on gadofullerene nanoparticles(GFNPs)using an orthotopic human pancreatic carcinoma(PANC-1)tumor model.It was demonstrated that GFNPs could efficiently suppress orthotopic pancreatic cancer in a dose manner,and significantly extend the survival rate of tumor-bearing mice.Of note,the proteomic profiling of tumor tissues revealed that GFNPs ameliorated the coagulation cascade dysfunction and downregulated the thrombin expression in pancreatic tumor tissues.The regulation of abnormal thrombin by GFNPs was validated in vitro and in vivo.More importantly,GFNPs suppressed orthotopic pancreatic cancer with negligible adverse effects,superior to the widely recognized clinical antipancreatic cancer drug,gemcitabine.Together,this study provides a promising therapeutic for intractable pancreatic cancer as well as a potential to alleviate the cancer-associated thromboembolic diseases.