Preoperative prediction of mediastinal lymph node metastasis in non-small cell lung cancer based on 18F-FDG PET/CT radiomics.

AIM: To establish and verify a 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT)-based radiomics nomogram to predict mediastinal lymph node metastasis (LNM) in non-small cell lung cancer (NSCLC) patients preoperatively. MATERIALS AND METHODS: This retrospective study enrolled 155 NSCLC patients (primary cohort, n=93; validation cohort, n=62). For each patient, 2,704 radiomic features were extracted from the primary lung cancer regions. Four procedures including the Mann-Whitney U-test, Spearman's correlation analysis, minimum redundancy-maximum relevance (mRMR), and least absolute shrinkage and selection operator (LASSO) binary logistic regression were utilised for determining essential features and establishing a radiomics signature. After that, a nomogram was established. The nomogram's potential was assessed based on its discrimination, calibration, and clinical usefulness. The radiomics signature and nomogram predictive performances were evaluated with respect to the area under the receiver operating characteristic curve (AUC), specificity, accuracy, and sensitivity. RESULTS: The radiomics signature composed of eight selected features had good discriminatory performance of LNM versus non-LNM groups an AUC of 0.851 and 0.826 in primary and validation cohorts, respectively. The nomogram also indicated good discrimination with an AUC of 0.869 and 0.847 in the primary and validation cohorts, respectively. Furthermore, good calibration was demonstrated utilising the nomogram. CONCLUSIONS: An 18F-FDG PET/CT-based radiomics nomogram that integrates the radiomics signature and age was promoted to predict mediastinal LNM within NSCLC patients, which could potentially facilitate individualised therapy for mediastinal LNM before treatment. The nomogram was beneficial in clinical practice, as illustrated by decision curve analysis.

[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 ß1, 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 (integrinß1, 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 integrinß1, cyclinD1 and uPAR.

High corrosion resistance and weak corrosion anisotropy of an as-rolled Mg-3Al-1Zn (in wt.%) alloy with strong crystallographic texture.

Combining with electrochemical corrosion measurements, immersion and hydrogen evolution testing performed in 0.9 wt.% NaCl solution at 37 °C, the corrosion resistance of an as-rolled Mg-3%Al-1%Zn alloy before and after a 3% compressive strain along the rolling direction was investigated. Results revealed that the corrosion behavior of differently oriented surfaces of the as-rolled samples with a strong basal texture was obviously different. Among them, the corrosion rate of sample surface with the orientation parallel to the normal direction (ND) of the plate was the fastest, the corrosion rate of sample surface with the orientation parallel to the rolling direction (RD) of the plate took the second place and the corrosion rate of sample surface with the orientation parallel to the transverse direction (TD) was the slowest. After being pre-strained, the activation of a high density of {10-12} twins could remarkably reduce the corrosion rate of surrounding α-Mg matrix and simultaneously weaken the corrosion anisotropy between differently oriented samples. The main reason was that similar to grain boundaries, twin boundaries acted as physical barriers to the corrosion attack. Moreover, the activated twins increased the protectiveness of surface films and then suppressed the micro corrosion couples occurred in twinned grains.

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 ß-Li phases of both two alloys during ageing process. Since a certain amount of Mg atoms in ß-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 ß-Li phases exhibited a slight age-softening response. Compared with the Mg-6%Li alloy, the age-softening response of ß-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/ß-Li interfaces. For the Mg-6%Li-6%Zn-1.2%Y alloy, cracks occurred at both α-Mg/ß-Li interfaces and slip bands in α-Mg and ß-Li phases.

Effect of solution treatment on stress corrosion cracking behavior of an as-forged Mg-Zn-Y-Zr alloy.

Effect of solid solution treatment (T4) on stress corrosion cracking (SCC) behavior of an as-forged Mg-6.7%Zn-1.3%Y-0.6%Zr (in wt.%) alloy has been investigated using slow strain rate tensile (SSRT) testing in 3.5 wt.% NaCl solution. The results demonstrated that the SCC susceptibility index (ISCC) of as-forged samples was 0.95 and its elongation-to-failure (εf) was only 1.1%. After T4 treatment, the SCC resistance was remarkably improved. The ISCC and εf values of T4 samples were 0.86 and 3.4%, respectively. Fractography and surface observation indicated that the stress corrosion cracking mode for as-forged samples was dominated by transgranular and partially intergranular morphology, whereas the cracking mode for T4 samples was transgranular. In both cases, the main cracking mechanism was associated with hydrogen embrittlement (HE). Through alleviating the corrosion attack of Mg matrix, the influence of HE on the SCC resistance of T4 samples can be greatly suppressed.

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.

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.

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.

[Highperformance liquid chromatographic assay for lomefloxacin in plasma and its pharmacokinetics in healthy volunteers].

A sensitive and simplified high performance liquid chromatographic procedure has been developed for quantification of lomefloxacin in human plasma. The recovery of lomefloxacin was 95 to 102%. The relative standard deviation was 2.1 to 7.8%. The calibration curve was linear in the range from 0.125 micrograms/ml to 5.012 micrograms/ml with r = 0.9998. The detection limit of the method is 25 ng/ml. The plasma drug concentration-time course after medication conformed to a 1-compartment open model with a first order absorption. Mean t1/2 value was 5.5 h.

[Determination of ofloxacin in human plasma and studies of its pharmacokinetics using HPLC method].

Ofloxacin is a new broad-spectrum oral bactericidal antimicrobial agent. Its primary effect is the inhibition of bacterial DNA gyrase. This paper describes the development of a simple method for its determination using HPLC with UV detection. We used a Waters liquid chromatograph equipped with a Model 490 E multi-wavelength detector, a Model 510 pump and a U6K injector. The separation was performed on a Spherisorb C18 column (200 mm x 4.6 mm ID, 5 microns) with a mobile phase of methanol-0.01 mol/L phosphate buffer-0.5 mol/L tetrabutylammonium bromide (35:65:4, pH 2.50). The flow-rate was 1.0 ml/min and detection was at 294 nm. A specimen (0.2 ml) was spiked with the internal standard (norfloxacin) and deproteinized by adding 1.0 ml methanol. The precipitated mixture was shaken and then centrifuged at 3000 x g for 10 min, the supernatant was evaporated at 75 degrees C under a nitrogen stream. The residue was taken up with 0.4 ml of the mobile phase and 50 microliters aliquots were injected into the system. The minimal detectable concentration in plasma is 20 ng/ml. There is a linear relationship between the peak area ratio over the range of 0.5-4.0 micrograms/ml with r = 0.9999. The method has been applied to assay ofloxacin concentration in human plasma. The pharmacokinetic characteristics were studied.

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.

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.