[Clinical analysis of laparoscopic remedial surgery for endoscopic lesions in early colorectal cancer]

Objective: To investigate the safety and feasibility of laparoscopic remedial surgery in patients who didn't reach the cure criterion of early colorectal cancer after endoscopic resection. Methods: The clinical and follow-up data of 12 patients who didn't reach the cure criterion of early colorectal cancer and then underwent endoscopic resection was collected. The clinicalpathological features and remedial indications were analyzed to evaluate the effects of laparoscopic remedial surgery. Results: The average number of lymph nodes in the lymph node dissection was 15 during remedial surgery, and 3 of them had lymph node metastasis. Among the 3 patients with residual cancer, two cases were poorly differentiated, 1 case was moderately differentiated, 1 case was positive for basal margin, and 1 case had vascular invasion. No lymph node metastasis occurred in the 9 patients who had no residual cancer. Among these, 8 cases were moderately differentiated, 1 case was poorly differentiated and 2 cases had positive basal margin. The average follow-up duration was 40 months and all 12 patients were in a state of survival at the last follow-up. During the follow-up of the 3 patients with residual cancer, 1 patient received adjuvant chemotherapy with unknown prognosis; 1 patient received postoperative adjuvant radiochemotherapy, and lung metastasis occurred; 1 patient did not receive any treatment after surgery and survived for 33 months. Conclusions: Laparoscopic remedial surgery is a safe and feasible remedy for patients who didn't reach the cure criterion of early colorectal cancer after endoscopic resection. However, the choice of remedial strategy for colorectal carcinoma needs further investigation for patients with no vascular invasion, high degree of differentiation, and negative basal margin.

[Effects of MTA1 on biological behaviors of gastric cancer cells]

Objective: To study the effects of metastasis associated 1 (MTA1) on biological characteristics such as migration, invasion and proliferation of gastric cancer (GC) cells. Methods: pSilencer3.1-MTA1-siRNA vector was used to establish human gastric cancer BGC-823 cell lines with constitutive MTA1-knockdown. Boyden, wound healing, clony forming assay and 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay were performed to identify the effects of MTA1-deficiency on the biological behaviors of BGC-823 cells in vitro. Simultaneously, MTA1 overexpressed BGC-823 cell line was established by pcDNA3-MTA1 plasmid transfection for reverse verification. In addition, the role of MTA1 in the tumorigenicity of gastric cancer BGC823 cells in vivo was examined by subcutaneous injection of BGC-823 cells expressing different MTA1 levels into nude mice. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot were used to detect the expression levels of integrin β1, cyclin D1 and uPAR in pSilencer3.1-MTA1-siRNA, pcDNA3-MTA1 transfected cells and control cells. Results: MTA1 knocked down or upregulated BGC-823 cell lines were successfully generated by transfecting pSilencer3.1-MTA1-siRNA or pcDNA3-MTA1 vector with lipofectamine 2000, respectively. The Boyden and wound healing experiments showed metastasis and invasion ability in MTA1 knocked down cells (25±2, 12±1) were significantly decreased when compared with those of control (78±2, 50±2) and MTA1-overexpressed groups (218±2, 269±3; P<0.05). The results of MTT assay and colony forming assay were significantly decreased when compared with those of showed that MTA1 overexpressed cells grew more rapidly and formed more colonies in vitro and induced worse malignant tumors in vivo, while MTA1 knocked down cells presented the reversed phenotype[control group (1 482.41±511.90) mm(3,) (1.39±0.29)g; MTA1 overexpressed group [(3 158.73±1 823.22) mm(3,) (2.23±0.51)g; MTA1-downregulated group (711.32±284.30)mm(3,) (0.87±0.21) g ; P<0.05)]. In addition, RT-PCR result showed that the expression level of MTA1 was positively correlated with the known metastasis-related genes (integrinβ1, cyclinD1, uPAR). Conclusions: MTA1 promotes the invasion, migration and proliferation of human gastric cancer BGC-823 cells. On the contrary, down-regulation of MTA1 significantly inhibits tumorigenicity of BGC-823 cells and induces favorable phenotypes. MTA1 may promote the malignant phenotype of BGC-23 cells via regulating the expressions of integrinβ1, cyclinD1 and uPAR.

Natural ageing responses of duplex structured Mg-Li based alloys

Natural ageing responses of duplex structured Mg-6%Li and Mg-6%Li-6%Zn-1.2%Y alloys have been investigated. Microstructural analyses revealed that the precipitation and coarsening process of α-Mg particles could occur in β-Li phases of both two alloys during ageing process. Since a certain amount of Mg atoms in β-Li phases were consumed for the precipitation of abundant tiny MgLiZn particles, the size of α-Mg precipitates in Mg-6%Li-6%Zn-1.2%Y alloy was relatively smaller than that in Mg-6%Li alloy. Micro hardness measurements demonstrated that with the ageing time increasing, the α-Mg phases in Mg-6%Li alloy could have a constant hardness value of 41 HV, but the contained β-Li phases exhibited a slight age-softening response. Compared with the Mg-6%Li alloy, the age-softening response of β-Li phases in Mg-6%Li-6%Zn-1.2%Y alloy was much more profound. Meanwhile, a normal age-hardening response of α-Mg phases was maintained. Tensile results indicated that obvious ageing-softening phenomenon in terms of macro tensile strength occurred in both two alloys. Failure analysis demonstrated that for the Mg-6%Li alloy, cracks were preferentially initiated at α-Mg/β-Li interfaces. For the Mg-6%Li-6%Zn-1.2%Y alloy, cracks occurred at both α-Mg/β-Li interfaces and slip bands in α-Mg and β-Li phases.

Effect of solution treatment on the fatigue behavior of an as-forged Mg-Zn-Y-Zr alloy

Through investigating and comparing the fatigue behavior of an as-forged Mg-6.7Zn-1.3Y-0.6Zr (wt.%) alloy before and after solid solution treatment (T4) in laboratory air, the effect of T4 treatment on fatigue crack initiation was disclosed. S-N curves illustrated that the fatigue strength of as-forged samples was 110 MPa, whereas the fatigue strength of T4 samples was only 80 MPa. Observations to fracture surfaces demonstrated that for as-forged samples, fatigue crack initiation sites were covered with a layer of oxide film. However, due to the coarse grain structure and the dissolution of MgZn₂ precipitates, the activation and accumulation of {10–12} twins in T4 samples were much easier, resulting in the preferential fatigue crack initiation at cracked twin boundaries (TBs). Surface characterization demonstrated that TB cracking was mainly ascribed to the incompatible plastic deformation in the twinned area and nearby α-Mg matrix.

[Study on the estrogen derivative marked by CdTe quantum dots]

Water-soluble CdTe quantum dots (QDs) stabilized by thioglycolic acid (TGA) with high quantum yield were synthesized. And the small biomolecule 17beta-amino-estradiol was marked successfully by CdTe QDs. The analysis of UV-Vis spectroscopy, fluorescence spectroscopy, infrared spectroscopy and inverted microscope photographs showed that the surface carboxyl of CdTe quantum dots conjugated with the amino of 17beta-amino-estradiol through the activation of N-hydroxysuccinimide. 17beta-amino-estradiol marked by CdTe QDs successfully provided an experimental basis for new drug screening model.

An antibody microarray assay for screening serum biomarkers for liver cancer

AIM: To develop an antibody microarray assay for screening serum biomarkers for liver cancer.

METHODS: Antibody microarrays targeting 14 potential liver cancer biomarkers were prepared on aldehyde-coated glass slides. The prepared antibody microarrays were incubated with NHS-biotin-labeled serum samples and visualized with streptavidin-Cy3 fluorescent dye. The serum expression levels of 14 biomarkers were then compared between 44 liver cancer patients and 46 healthy individuals.

RESULTS: The accuracy and reproducibility of data from the developed antibody microarray assay were satisfactory. The serum expression levels of HSP70, CK19, GPC3, PTMA, AFU, GP73, HBxAg and CA125 differed significantly between liver cancer patients and healthy individuals (all P < 0.01).

CONCLUSION: An effective antibody microarray assay for screening serum biomarkers for liver cancer has been successfully developed.

The clinical value of serum CEA, CA19-9, and CA242 in the diagnosis and prognosis of pancreatic cancer

AIM

Serum tumour markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and CA242 were investigated to evaluate the values of single and combined test in the diagnosis and prognosis of pancreatic cancer.

METHODS

Pre-operative serum CEA, CA19-9 and CA242 were measured in 105 pancreatic cancers, 70 non-pancreatic malignancies and 30 benign pancreatic diseases.

RESULTS

The sensitivity of CA19-9 alone was the highest in pancreatic cancer patients (80%), but the specificity was significantly lower than that of CEA and CA242 (P<0.01). The combination of CEA and CA242 could increase the specificity to 92%. In serum CA242 positive patients, the survival time was remarkably shorter than that of patients with negative result (P<0.01). The survival time in patients with more than two markers positive expression of CEA, CA19-9 and CA242 was obviously shorter than that of only one or no marker positive expression (P<0.05).

CONCLUSION

The diagnostic rate of CA19-9 in pancreatic cancer is better than that of CEA and CA242. Combined detection of CEA and CA242 can improve the diagnostic specificity obviously. High levels of serum markers are associated with advanced stage of the disease. Patients with two or three markers positive expression of CEA, CA19-9, and CA242 simultaneously had a shorter survival time.

Identification and quantitative determination of uric acid in human urine and plasma by capillary electrophoresis with amperometric detection

Application of capillary zone electrophoresis with electrochemical detection to the identification and quantitative determination of uric acid in human urine as well as plasma is described. This work was carried out in a 30 cm x 25 microm I.D. fused-silica capillary with tricine buffer and a carbon fiber bundle was employed as a working electrode, the working voltage in amperometric detection was set at +0.80 V (vs. SCE). The sample constituent is identified by stopped flow-linear sweep voltammetry. Under optimal conditions, a lower detection limit of 0.48 fmol was obtained for uric acid.

Simultaneous determination of purine bases, ribonucleosides and ribonucleotides by capillary electrophoresis-electrochemistry with a copper electrode

Simultaneous determination of purine bases, ribonucleosides and ribonucleotides was achieved by coupling capillary electrophoresis (CE) with wall-jet amperometric detection. A 200 microm diameter copper disk electrode was applied at working potential, +0.65 V vs. saturated calomel electrode. The current response of high sensitivity and stability was obtained in strong basic solutions which were suitable for satisfactory CE separations. The calibration curve was linear over 2-3 orders of magnitude and the limits of detection for adenine, guanine, xanthine, uric acid, adenosine, guanosine, adenosine-5'- monophosphate and guanosine-5'-monophosphate were below 9 fmol (SIN=3). The use of this method for the separation and detection of compounds present in human plasma samples was reported.

High-performance liquid chromatographic assay for amiloride in plasma and urine

A sensitive and simplified high-performance liquid chromatographic procedure has been developed for quantification of amiloride in rabbit plasma, as well as human plasma and urine. Following protein precipitation with perchloric acid, the supernatant was directly injected into a C18 Nucleosil column. The mobile phase consisted of methanol-water (45:55) containing 0.1 M perchloric acid, and the compound was quantitated using a fluorescence detector at excitation and emission wavelengths of 286 and 418 nm, respectively. The average recovery was 97.6%. The calibration curve was linear over the range 2.0-20.0 ng/ml. The limit of detection was 0.5 ng/ml.