Prognostic significance of preoperative and postoperative CK19 and CEA m RNA levels in peripheral blood of patients with gastric cardia cancer

AIM To evaluate the clinical and prognostic significance of preoperative and postoperative cytokeratin 19(CK19) and carcinoembryonic antigen(CEA) m RNA levels in peripheral blood of patients with gastric cardia cancer(GCC).METHODS We detected the preoperative and postoperative mR NA levels of CK19 and CEA in peripheral blood of 129 GCC patients by using reverse transcription-polymerase chain reaction and evaluated their clinical and prognostic significance by univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard analysis. A new prognostic model which stratified patients into three different risk groups was established based on the independent prognostic factors.RESULTS Elevated preoperative and postoperative CK19 and CEA mR NA levels in peripheral blood of GCC patients were associated with lymph node metastasis. Univariate analysis showed that tumor size, histological grade, depth of tumor invasion, lymph node metastasis, preoperative CK19 m RNA, and preoperative and postoperative CEA m RNA levels were correlated with the prognosis of GCC patients. The multivariate analysis showed that lymph node status(P = 0.018), preoperative CK19(P = 0.035) and CEA(P = 0.011) m RNA levels were independent prognostic factors for overall survival(OS). The 5-year OS rates for the low-, intermediate-, and high-risk groups were 48.3%, 22.6%, and 4.6%, respectively(P < 0.001).CONCLUSION Elevated preoperative CK19 and CEA mR NA levels may be regarded as promising biomarkers for predicting lymph node metastasis and poor prognosis in patients with GCC. This new prognostic model may help us identify the subpopulations of GCC patients with the highest risk.

Neoadjuvant chemoradiotherapy for resectable esophageal cancer:an in-depth study of randomized controlled trials and literature review

Surgery following neoadjuvant chemoradiotherapy(NCRT) is a common multidisciplinary treatment for resectable esophageal cancer(EC). After analyzing 12 randomized controlled trials(RCTs), we discuss the key issues of surgery in the management of resectable EC. Along with chemoradiotherapy, NCRT is recommended for patients with squamous cell carcinoma(SCC) and adenocarcinoma(AC), and most chemotherapy regimens are based on cisplatin, fluorouracil(FU), or both(CF). However, taxane-based schedules or additional studies, together with newer chemotherapies, are warranted. In nine clinical trials, post-operative complications were similar without significant differences between two treatment groups. In-hospital mortality was significantly different in only 1 out of 10 trials. Half of the randomized trials that compare NCRT with surgery in EC demonstrate an increase in overall survival or disease-free survival. NCRT offers a great opportunity for margin negative resection, decreased disease stage, and improved loco-regional control. However, NCRT does not affect the quality of life when combined with esophagectomy. Future trials should focus on the identification of optimum regimens and selection of patients who are most likely to benefit from specific treatment options.

Elevated serum levels of human relaxin-2 in patients with esophageal squamous cell carcinoma

AIM: To assess the prognostic value of serum human relaxin 2 (H2 RLN) level in patients with esophageal squamous cell carcinoma (ESCC). METHODS: From October 1998 to September 2009, 146 patients with histopathologically confirmed ESCC were enrolled in this study. One hundred patients underwent en bloc esophagectomy, and 46 patients with unresectable tumors underwent palliative surgery. Five of the 146 patients died of surgical complications. Serum levels of H2 RLN were measured by enzyme linked immunosorbent assay. The relationship between serum H2 RLN level and each of the clinicopathological parameters was analyzed using the χ2 test. Patients were classified into two groups according to their H2 RLN level (< 0.462 ng/mL vs ≥ 0.462 ng/mL). When any analysis cell had fewer than five cases, the Fisher's exact test was used. The statistical difference between groups A and B in each clinicopathological category was determined by the Student's t test (two-tailed) or analysis of variance. Survival curves were plotted using the Kaplan-Meier method. The statistical difference in survival between the different groups was compared using the log-rank test. Survival correlation with the prognostic factors was further investigated by multivariate analysis using the Cox proportional hazards model with backward stepwise likelihood ratio. RESULTS: ESCC patients tended to have significantly higher serum H2 RLN concentrations (0.48 ± 0.17 ng/ mL, n=141) compared with the healthy control group (0.342 ± 0.12 ng/mL, n=112). There was a significant difference between patients with lymph node involvement (0.74 ± 0.15 ng/mL, n=90), distant metastasis (0.90 ± 0.19 ng/mL, n=32) and those without lymph node involvement (0.45 ± 0.12 ng/mL, n=51), and distant metastasis (0.43 ± 0.14 ng/mL, n=109), respectively (P < 0.01). Patients with high H2 RLN levels (≥ 0.462 ng/mL) had a poorer prognosis than patients with low serum H2 RLN levels (< 0.462 ng/mL; P=0.0056). The H2 RLN level was also correlated with survival and tumor-node-metastasis staging, but not with age, tumor size, gender, lymphovascular invasion or the histological grade of tumors. Cox regression analysis showed that H2 RLN was an independent variable. CONCLUSION: Serum concentrations of H2 RLN are frequently elevated in ESCC patients and are correlated with disease metastasis and survival. Serum concentrations of H2 RLN may be an important prognostic marker in ESCC patients.

Association and prognostic significance of alpha-L-fucosidase-1 and matrix metalloproteinase 9 expression in esophageal squamous cell carcinoma

BACKGROUND Alpha-L-fucosidase-1(FUCA1)has been demonstrated to play opposing regulatory roles in adenocarcinoma and non-adenocarcinoma.Moreover,recent studies reported that FUCA1 could decrease the invasion capability by downregulating matrix metalloproteinase 9(MMP-9)expression.However,the potential role and prognostic significance of FUCA1 in esophageal squamous cell carcinoma(ESCC)have not yet been explored.AIM To evaluate the status,association,and prognostic value of FUCA1 and MMP-9 expression in ESCC.METHODS Patients who underwent esophagectomy for ESCC between January 1,2014,and December 31,2014 at Sun Yat-Sen University Cancer Center were enrolled.The expression status of FUCA1 and MMP-9 in cancerous tissues was detected using immunohistochemistry.In addition,the expression profiles of the FUCA1 and MMP-9 genes in non-metastatic ESCC were extracted from The Cancer Genome Atlas(TCGA)database.RESULTS High expression of FUCA1 and MMP-9 was found in 90 patients(75.6%)and 62 patients(52.1%),respectively.In the high FUCA1 expression group,the constituent ratios of patients with stage III disease(61.1%vs 37.9%,P=0.029),lymphatic invasion(62.2%vs 31.0%,P=0.003),and high MMP-9 expression(60.0%vs 27.6%,P=0.002)were significantly higher than those in the low FUCA1 expression group.In Kaplan-Meier univariate analysis,advanced tumor-nodemetastasis stage(III,P=0.001),positive regional lymph node metastasis(N+,P=0.002),high FUCA1 expression(P=0.001),and high MMP-9 expression(P=0.002)were potential predictors of shorter overall survival(OS),which was similar to the results analyzed based on the TCGA database.Further Cox multivariate regression analyses still demonstrated that FUCA1 and MMP-9 expression levels were independent prognostic factors of OS[hazard ratio(HR):0.484,95%confidence interval(CI):0.239-0.979;P=0.044;and HR:0.591,95%CI:0.359-0.973,P=0.039,respectively].CONCLUSION FUCA1 cooperation with MMP-9 may have a major role in affecting the ESCC invasion and metastatic capability,and serve as a valuable prognostic biomarker in ESCC.

Structural,mechanical and electronic properties of precipitates in Mg−Zn alloys

To accelerate the development and design of magnesium(Mg)alloys,the structural and mechanical properties of important precipitates in Mg−Zn alloys were studied by experiments and density functional theory.The nano-indentation tests revealed that the hardness of the precipitates initially increased and then decreased with increasing Zn content,and was significantly higher than that of pure Mg and Zn.The calculation results revealed that the precipitates stability initially increased and then decreased with increasing Zn concentration.The bulk moduli of the precipitates increased,whereas their shear and Young’s moduli initially increased and then decreased with increasing Zn content.The decreasing order of ductility for these compounds is MgZn_(2)>Mg21Zn_(2)5>Mg2Zn11>Mg4Zn7.The surface profiles of the compounds revealed that they are obvious anisotropy.Both the degree of covalency and bond length of covalent bonds initially increased and then decreased with increasing Zn content.

Designation and development of biomedical Ti alloys with finer biomechanical compatibility in long-term surgical implants

Developing the new titanium alloys with excellent biomechanical compatibility has been an important research direction of surgical implants materials. Present paper summarizes the international researches and developments of biomedical titanium alloys. Aiming at increasing the biomechanical compatibility, it also introduces the exploration and improvement of alloy designing, mechanical processing, microstructure and phase transformation, and finally outlines the directions for scientific research on the biomedical titanium alloys in the future.

Microstructural adjustments and mechanical properties of a cold-rolled biomedical near β-Ti alloy sheet

In this study, microstructural adjustments and mechanical properties of a cold-rolled near β-type alloy Ti-25Nb-3Zr-3Mo-2Sn （wt%） sheet were investigated. Microstructures and phase transformation products strongly depended on aging temperatures. Solution treatments within single β-phase field removed the stress-induced at martensites and produced a few new lath-shaped ones, but metastable β phase still dominated. This is exactly the reason why current alloy exhibits the lowest modulus （54 GPa） and best elongation to fracture （39 %）, but the worst yield strength of only 340 MPa, at solutiontreated state. A fairly large number of ellipsoidal ω phase nanoparticles precipitated throughout parent β phase during aging at 380℃. These ω nanoparticles possess remarkable strengthening effect, but deteriorate ductility seriously. A novel post-aging process was proposed to remove brittle ω phase. By contrast, aging at 450 ℃ resulted in sufficient precipitation of fine needle-like α phase. This brought about the best combination of high yield strength （770 MPa） and moderate elastic modulus （75 GPa） and good elongation （15 %） for biomedical implants.

Thermal stability of bimodal grain structure in a cobalt-based superalloy subjected to high-temperature exposure

The present work investigates the thermal stability and mechanical properties of a Co-20 Cr-15 W-10 Ni(wt%) alloy with a bimodal grain(BG) structure.The BG structure consisting of fine grains(FGs) and coarse grains(CGs) is thermally stable under high-temperature exposure treatments of 760℃ for 100 h and 870℃ for 100-1000 h.The size of both FGs and CGs remains no significant changes after thermal exposure treatments.The microstructural stability is associated with the slow kinetics of grain growth and the pinning of carbides.The thermal stability enables to maintain the BG structures,leading to the same mechanical properties as the sample without thermal exposure treatment.In particular,the BG alloy samples after thermal exposure treatment exhibit superior mechanical properties of both high strength and high ductility compared to the unimodal grain(UG) structured ones.The BG structure of the alloy samples after thermal exposure is capable of avoiding severe loss of ductility and retaining high strength.More specifically,the ductility of the BG alloy samples after thermal exposure treatments of 870℃ for 500-1000 h is ten times higher(44.6% vs.3.5% and 52.6% vs.5.0%) than that of the UG ones.The finding in the present work may give new insights into high-temperature applications of the Co-20 Cr-15 W-10 Ni alloy and other metallic materials with a BG structure.