Search

Inlet unstart is detrimental to hypersonic airbreathing flights. By unstart, we mean the separation-induced collapse of a supersonic duct flow. The unstart characteristics of a two-dimensional contraction duct with an expansion corner are numerically investigated to develop a universal prediction method and to determine the unstart mechanism. The unstart boundaries under varying contraction angles, entrance heights, and Reynolds numbers are obtained by translating the cowl plate. A self-similar empirical equation of unstart boundary that unifies multiple variables is proposed through similarity analysis. To estimate the unstart boundaries of large-angle ducts, the alternative area ratio is presented. Three types of unstarts are identified according to the distribution of the unstart boundaries and the evolution mechanism of separation region: the long-cowl, transitional, and short-cowl unstart. The long-cowl unstart stems from the mass flow limit at the throat, while the other two unstarts stem from the separation region growth. The wall pressure criteria for unstart are correlated with the dimensionless cowl length and the characteristic separation scale in the critical state to facilitate unstart detection. Moreover, the self-similar compression intensity is proposed to characterize the maximum pressure increase induced by the unit effective area contraction in the started state. [ABSTRACT FROM AUTHOR]

Activation of oncogenes by mechanisms other than genetic aberrations such as mutations, translocations, or amplifications is largely undefined. Here we report a novel isoform of the anaplastic lymphoma kinase (ALK) that is expressed in ~11% of melanomas and sporadically in other human cancer types, but not in normal tissues. The novel ALK transcript initiates from a de novo alternative transcription initiation (ATI) site in ALK intron 19, and was termed [ALK.sup.ATI]. In [ALK.sup.ATI]-expressing tumours, the ATI site is enriched for H3K4me3 and RNA polymerase II, chromatin marks characteristic of active transcription initiation sites (1). [ALK.sup.ATI] is expressed from both ALK alleles, and no recurrent genetic aberrations are found at the ALK locus, indicating that the transcriptional activation is independent of genetic aberrations at the ALK locus. The [ALK.sup.ATI] transcript encodes three proteins with molecular weights of 61.1, 60.8 and 58.7 kilodaltons, consisting primarily of the intracellular tyrosine kinase domain. [ALK.sup.ATI] stimulates multiple oncogenic signalling pathways, drives growth-factor-independent cell proliferation in vitro, and promotes tumorigenesis in vivo in mouse models. ALK inhibitors can suppress the kinase activity of [ALK.sup.ATI], suggesting that patients with [ALK.sup.ATI]-expressing tumours may benefit from ALK inhibitors. Our findings suggest a novel mechanism of oncogene activation in cancer through de novo alternative transcription initiation., To identify novel mechanisms of oncogene activation, we performed transcriptome analyses (RNA sequencing (RNA-seq)) of metastatic melanoma and thyroid carcinoma. We used an algorithm (2) to investigate the differential expression [...]

Previous studies have identified microRNA-200b (miR-200b) as a powerful regulator of epithelial-mesenchymal transition (EMT) via the control of gene expression. EMT is a critical event that is associated with the initiation of malignant tumor metastasis. A lack of E-cadherin expression and overexpression of vimentin are hallmarks of EMT. It is well‑known that RhoE, which is associated with regulation of the actin cytoskeleton and migration via alterations in cell motility, regulates the expression of E-cadherin, matrix metalloproteinase-9 (MMP-9) and vimentin. However, it remains to be elucidated whether miR‑200b may alter the molecular behavior of RhoE. The present study aimed to determine whether miR‑200b was able to regulate the EMT of cervical cancer, in order to control metastasis. In addition, the correlation between miR‑200b and RhoE, E‑cadherin and vimentin expression was investigated. Notably, miR‑200b was shown to inhibit the function of RhoE and suppress the EMT of cervical cancer. Furthermore, HeLa cells were transfected with miR‑200b mimics or inhibitors, and the protein expression levels of E‑cadherin, MMP‑9, vimentin and RhoE were subsequently detected. A Transwell assay was also conducted, in order to observe the metastatic ability of the HeLa cells. In addition, a luciferase reporter assay was performed using luciferase reporter vectors containing the full length 3'‑untranslated region (UTR) of RhoE; miR‑200b was able to significantly suppress relative luciferase activity by targeting the 3'‑UTR of RhoE. These results suggested that miR‑200b may markedly inhibit metastatic potential by regulating cell EMT and inhibiting RhoE; therefore, miR-200b may be considered an effective target for the treatment of patients with highly metastatic cervical cancer.

Objective: To investigate the feasibility and safety of adult-to-adult living-related donor liver transplantation using a right lobe graft., Methods: The clinical data of 2 cases of living-related donor liver transplantation performed between July, 2010 and November, 2010 were analyzed., Results: Liver transplantation was performed using a right lobe graft including the middle hepatic vein in one case and a right lobe graft without the middle hepatic vein in the other. The ratio of graft volume to standard liver volume was 46.2% and 47.3% in the two cases, with GR/WR of 0.83 and 0.80, and donor residue liver of 42.1% and 39.5%, respectively. The donor operation lasted for 6.5 h and 5 h in the two cases with blood loss of about 200-250 ml without blood transfusion. The donors recovered uneventfully without any surgical complications, whose liver function was normal 7 days after the operation, and were discharged 14 days and 16 days after the surgery, respectively. The recipient operation lasted for 8 h and 7 h with blood loss of about 800-1000 ml. The right hepatic vein, hepatic artery, portal vein and bile duct reconstruction were performed by end-to-end anastomoses in the 2 recipients. Bile duct anastomosis stricture occurred in the first recipient 2 months after transplantation and was treated with percutaneous transhepatic cholangiography and drainage. The second recipient recovered smoothly without any complications. The recipients have so far survived 9 months and 5 months, respectively., Conclusion: Adult-to-adult living-related donor liver transplantation is a safe and effective option for treatment of end-stage liver diseases in the context of cadaveric liver graft shortage.

Objective: To study the clinical effect and feasibility of blood type A donor liver transplantation in blood type O recipients., Methods: The clinical data were analyzed in 6 blood type O patients receiving transplantation of the liver grafts from blood type A donors. The clinical effect and outcomes of the transplantations were evaluated to assess the feasibility of ABO incompatible liver transplantation between type A donors and type O recipients., Results: The operations and the postoperative recovery were smooth in all the 6 recipients. Only one patient died 5 months postoperatively due to liver tumor metastasis, and the other 5 patients survived with the longest survival reaching 14 months. Acute graft rejection occurred in one patient 1 week after the operation on account of abnormally elevated serum bilirubin level, which was successfully managed with immediate methylprednisolone therapy. No such complications as acute graft rejection, bile duct stenosis or bile leakage was found in the other patients., Conclusion: Blood type A donor liver transplantation in type O recipient is feasible in emergency or other special conditions.

Objective: To study the impact of arsenic trioxide (As2O3) on human colorectal carcinoma LS-174T cells and their activity of telomerase., Methods: LS-174T cells and xenograft model of nude mice were treated with As2O3. The inhibitory effect of As2O3 on survival of LS-174T cells was determined by MTT assay. Apoptosis was determined by electron microscopy and fluorescence microscopy. Cell cycle was assessed by flow cytometry. Telomerase activity in LS-174T cells was determined by PCR-ELISA kit., Results: With the increasing concentration of As2O3, the ratio of living cells to dead cells decreased significantly, and the IC50 value was 5.23 micromol/L. Apoptosis curve appeared after 24 h and cells turned to apoptosis in a time-dependent manner. As2O3 inhibited the telomerase activity in cell extraction, obviously in a concentration-dependent and time-dependent manner. Inhibitiory effect of As2O3 on xenograft model of nude mice was observed by tumor volume and weight measurement, showing a significant difference between As2O3 and control groups (P < 0.05)., Conclusion: Both the experiments in vitro and in vivo showed an inhibitory effect of As2O3 on colonrectal cancer S-174T cell growth, probably by induction of apoptosis and inhibition of telomerase activity.

Objective: To explore the effects of survivin antisense RNA on apoptosis and chemosensitivity to docetaxel in gastric cancer line SGC7901 cells, and its relation to mdr-1., Methods: survivin antisense eukaryotic vector anti-pcDNA3-svv was transfected into SGC7901 cells by electorporation and positive clone was screened out. survivin protein and mdr-1 mRNA were determined by Western blot and RT-PCR. Apoptosis-inducing effect was examined by electron microscopy. Sensitivity to docetaxel was examined by MTT. Expression of mdr-1 and survivin mRNA were detected in the SGC7901 cells after drug-resisitance induction., Results: The expression of survivin protein of SGC7901 cells after transfection reduced significantly than that of non-transfected cells. MDR indexes of transfection group and non-transfection group were 0.196 +/- 0.013 and 3.126 +/- 0.019, respectively. The IC50 of transfection group to docetaxel was (16.7 +/- 1.98) microg/L and non-transfection group was (55.7 +/- 1. 89) microg/L, with a statistically significant difference. Expression of survivin mRNA in drug-resistant cells decreased along with the decreasing of mdr-1., Conclusion: Antisense surivivin RNA can induce apoptosis in gastric cancer cells and increase sensitivity to docetaxel. The reversing mechanism of drug resistance is related with decreasing of mdr-1.

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: chi(2) = 4.516, P = 0.034; Krukenberg tumor tissue vs normal ovarian tissue: chi(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: chi(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 (chi(2) = 10.398, P = 0.001), VEGF (chi(2) = 13.149, P = 0.001), MMP-2 (chi(2) = 33.668, P = 0.001) and MMP-9 (chi(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.

Objective: To study endoglin (CD105) gene expression in breast cancer and its clinicopathologic significance., Methods: In 40 patients with breast cancers, CD105 mRNA was detected at center and periphery of tumor and at nearby normal tissue by RT-PCR., Results: The difference in CD105 mRNA expressions between cancer and normal breast tissue was significant (t = 12.08, P < 0.05), and the expression was significantly higher at the tumor periphery than at the tumor center (t = 7.52, P < 0.05). CD105 over-expression was related to lymph node metastases (t = 2.71, P < 0.05), but not to age, tumor size, pathologic grade or pathologic type (P > 0.05)., Conclusion: CD105 over-expression may play a crucial role in the progression of breast cancer and lymph node metastasis.

Background & Objective: Cellular FLICE inhibitory protein (cFLIP) plays an important role in cell apoptosis, researches of antisense oligonucleotides (ASODN) of cFLIP gene may provide a new method or protocol for treatment of human gastric cancer. This study was to explore effect of cFLIP ASODN on apoptosis of human gastric cancer cell line BGC823., Methods: Human cervical cancer cell line HeLa was used as control, cFLIP ASODN was introduced into BGC823 cells and HeLa cells, reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot were used to detect cFLIP(L/S) (cellular FLIP(Short) and cellular FLIP(long)) mRNA and protein. The 5'FAM-conjugated ASODN was created complementary to a sequence that included the start site of FLIP open reading frame. After introducing, MTT was used to detect cell inhibition rate,TUNEL and flow cytometry (FCM) were used to detect cell apoptosis, and Western blot was used to detect protein level of cFLIP., Results: The encoding mRNA and protein of cFLIP(L) and cFLIP(S) can be detected in both HeLa and BGC823 cells. MTT revealed that cFLIP ASODN significantly inhibited proliferation of BGC823 cells (P< 0.05) in a concentration-dependent manner. TUNEL staining detected positive FLIP expression, specific apoptotic peak can be detected before G1 peak by FCM, and Western blot revealed that protein level of cFLIP(L) and cFLIP(S) decreased significantly (P< 0.05)., Conclusion: The cFLIP(L/S) mRNA and encoded proteins expressed in both HeLa and BGC823 cells. ASODN may down-regulate cFLIP(L/S) protein level, and initiate apoptosis of BGC823 cells.

Background: Peptide nucleic acid (PNA) has many characteristics useful in molecular biology. This paper described an effective way to raise the cell ingestion rate of PNA so as to kill gastric cancer cells., Methods: Heteroduplexes of PNAs and oligonucleotides, wrapped by Lipofectamine 2000, were used to infect SGC7901 cells. The inhibitive effect of heteroduplexes was evaluated by analyzing cell clone forming and cell growth rate. Telomerase activity of SGC7901 cells was detected by polymerase chain reaction enzyme-linked immunosorbent assay (PCR-ELISA) and silver staining assay., Results: PNAs showed a dose-dependent inhibition of cell proliferation. The percentage of proliferation inhibition was 99.4% after 7 days; the rate of cloning inhibition was 98.2% after 8 days; whereas for oligonucleotide groups, at the same concentration, the percentages were 50.1% and 67.5% respectively. Antisense PNA-DNA-Lipofectamine 2000 group (AP-D-L group) exhibited significantly different percentages from the control groups (P < 0.05). The test result indicated that telomerase activity of the AP-D-L group was inhibited (P < 0.05). At the same time, the impact on cell morphology was observed., Conclusions: The results showed that PNAs are potent antisense reagents. The telomerase-associated therapies are very promising for the treatment of malignant tumours.

Aim: To study the expression of cyclooxygenase-2 (COX-2) gene in gastric cancer and the relationship between COX-2 expression and clinicopathologic features of gastric cancer., Methods: With reference to the expression of beta-actin gene, COX-2 mRNA level was examined in cancerous tissues and adjacent noncancerous mucosa from 33 patients by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). Quantitation of relative band Adj volume counts was performed using molecular Analyst for windows software. The COX-2 index was determined from the band Adj volume counts ratio of COX-2 to constitutively expressed actin., Results: The COX-2 index in gastric carcinoma was significantly higher than that in normal mucosa (0.5966+/-0.2659 vs 0.2979+/-0.171, u=5.4309, P<0.01). Significantly higher expression of COX-2 mRNA was also observed in patients with lymph node involvement than that in those without (0.6775+/-0.2486 vs 0.4105+/-0.2182, t=2.9341, P<0.01). Furthermore, the staging in the UICC TNM classification significantly correlated with COX-2 overexpression (F=3.656, P<0.05), the COX-2 index in stage III and IV was significantly higher than those in stage I and II (q=3.2728 and q=3.4906, P<0.05). The COX-2 index showed no correlation with patient's age, sex, blood group, tumor location, gross typing, depth of invasion, differentiation, and the greatest tumor dimension (P>0.05)., Conclusion: Expression of COX-2 mRNA in gastric carcinoma was significantly higher, which may enhance lymphatic metastasis in patients with gastric carcinoma. The staging in the UICC TNM classification was significantly correlated with COX-2 over-expression. COX-2 may contribute to progression of tumor in human gastric adenocarcinoma.