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To study the physical and chemical characteristics of single-particle aerosols in the background area of east China, a single-particle time-of-flight mass spectrometer (SPAMS) was used to observe the atmospheric particles in Mt. Huangshan from September 5, 2012 to October 28, 2012 and explore the influence of different air masses on the types and proportions of particles in combination with the HYSPLIT backward trajectory model. The results showed that the particles in Mt. Huangshan area can be divided into nine categories:Aged-EC, K, ECOC, OC, NaK, EC, ECHM, HM, and Minerals. Aged-EC accounted for the highest proportion, followed by K, and the aging degree of carbon particles was critical. The carbon particles classified as Aged-EC, ECOC, and OC were concentrated in the accumulation mode (0.2-1.4 μm), whereas HM, NaK, and Minerals were concentrated in the coarse particle mode (>1.4 μm). Apart from K, ECHM, and ECOC, higher wind speed was unfavorable to the accumulation of particles. The higher RH was, the higher the proportion of carbon particles was, while the proportions of K, OC, Minerals, and NaK were smaller. Cluster analysis results showed that the Mt. Huangshan area was mainly affected by northwest air mass, marine air mass, and local air mass. Industrial emissions and coal-burning activities in the surrounding areas were the primary contribution sources of Aged-EC.

Objective: To investigate the regulation of JAK2 tyrosine kinase inhibitor ruxolitinib on extracellular matrix metalloproteinase (MMP in JAK2V617F positive myeloproliferative neoplasms (MPN) cells. Methods: ①Forty cases of newly diagnosed JAK2V617F positive MPN patients and 15 healthy volunteers as control in Baoding No.1 Hospital between January 2012 and December 2015 were enrolled in this study. JAK2V617F/JAK2 ratio was detected by real-time-PCR; the expression levels of phosphorylation protein tyrosine kinase 2 (p-JAK2) , MMP-2 and MMP-9 in pathological tissues of bone marrow were detected by immunohistochemistry. The bone marrow cells of JAK2V617F positive MPN patients were treated with ruxolitinib, then the migration ability and MMP-2, MMP-9 gene and protein expression levels were detected. ②The human erythroleukemia cell line HEL cells were treated with different concentrations of ruxolitinib (0, 50, 100, 250, 500, 1 000 nmol/L) . The cell viability was detected by CCK-8 test; cell migration ability was tested by transwell chambers. The mRNA expression levels of JAK2, MMP-2 and MMP-9 were detected by real-time-PCR. The protein expression levels of p-JAK2, MMP-2 and MMP-9 were detected by Western blot. Results: ①The expression levels of p-JAK2, MMP-2 and MMP-9 in the newly diagnosed group were significantly higher than control group respectively [ (78.56±24.55) % vs (41.59±17.29) %, P <0.05; (48.25±18.74) % vs (22.79±13.89) %, P <0.05; (53.29±19.28) % vs (15.56±14.96) %, P <0.05]. Spearman correlation analysis showed the positive correlation of MMP-2 and MMP-9 protein expression levels with JAK2V617F mutation ( r =0.526, P =0.001; r =0.543, P =0.001) . ② The proliferation of HEL cells was inhibited by different concentrations of ruxolitinib in time and dose dependent manner. ③Cell migration test showed the number of cells leaked to the low chamber in MPN patients bone marrow cells and HEL cells treated with 5 nmol/L of ruxolitinib group were significantly lower than that without ruxolitinib treatment after 24 h [ (154.7±27.5) vs (320.3±67.3) , t =13.47, P <0.05; (70.7±10.5) vs (135.3±16.7) , t =13.89, P <0.05]. The mRNA and protein expression levels of JAK2, MMP-2 and MMP-9 decreased with the increased concentration of ruxolitinib. Conclusion: Ruxolitinib inhibits MPN cell migration and expression of MMP-2 and MMP-9 via JAK2 signal pathway.

Brain cancer stem cells are a subset of tumor cells present in several types of brain tumor that evade treatment regimens and are responsible for tumor recurrence. Recent reports on several tumors have suggested that Hoechst 33342 dye exclusion is a powerful technique for isolating cancer stem cell-like side population (SP) cells. In the present study, we attempted to isolate the SP cells from medulloblastoma, a malignant brain tumor in children. The tumor samples obtained were subjected to fluorescence-activated cell sorting analysis for SP cell isolation. Further, the SP cells were characterized by a sphere-formation assay and analyzed for expression of stem cell genes by reverse transcription-polymerase chain reaction (RT-PCR). Using flow cytometry, we isolated 2.9% of cancer stem-like SP cells from malignant medulloblastoma, which was reduced to 0.4% in the presence of verapamil, an inhibitor of ABC transporter. These SP cells undergo rapid proliferation and have a high tendency to form tumor spheres when compared with non-SP cells. Further, RT-PCR analysis revealed that the isolated SP cells have increased expression of neural stem cell markers such as nestin, Notch1, and the ABC transporter protein ABCG2. Therefore, our findings suggest that SP cells of medulloblastoma share the characteristics of cancer stem cells. The increased expression of stem cell markers and ABCG2 protein may function collectively and be responsible for drug and apoptosis resistance, as well as tumor recurrence and invasion.

Aim: To discuss the features, feasibility, and safety of a combined bilateral approach in the endovascular treatment of intracranial anterior communicating artery (ACoA) aneurysm., Material and Methods: We performed a retrospective analysis of the clinical data of patients with ACoA aneurysm treated with a combined bilateral approach., Results: We successfully embolized aneurysms in nine patients with intracranial ACoA aneurysm using a combined bilateral approach. All treated patients had an open ACoA connecting with the bilateral anterior cerebral arteries., Conclusion: Because the ACoA connects the intracranial arteries in both hemispheres, patients with ACoA aneurysm can be endovascularly treated with a combined bilateral approach. Notably, surgeon experience and dexterity play important roles in the success of this procedure.

Conventional endovascular treatment may have limitations for vertebral dissecting aneurysm involving the origin of the posterior inferior cerebellar artery (PICA). We report our experiences of treating vertebral dissecting aneurysm with PICA origin involvement by placing a stent from the distal vertebral artery (VA) to the PICA to save the patency of the PICA. Stenting from the distal VA to the PICA was attempted to treat ruptured VA dissecting aneurysm involving the PICA origin with sufficient contralateral VA in eight patients. The procedure was successfully performed in seven patients with one failure because of PICA origin stenosis, which was treated with two overlapping stents. In the seven patients, PICAs had good patency on postoperative angiography and transient lateral brainstem ischemia represents a procedure-related complication. Follow-up angiographies were performed in seven patients and showed recanalization of the distal VA in three patients without evidence of aneurysmal filling. There was no evidence of aneurysm rupture during the follow-up period, and eight patients had favorable outcomes (mRS, 0 - 1). Placing a stent from the distal VA to the PICA with VA occlusion may present an alternative to conventional endovascular treatment for vertebral dissecting aneurysm with PICA origin involvement with sufficient contralateral VA.

Aim: To investigate the effect of tyrosine kinase inhibitor imatinib mesylate on the PTEN signaling pathway and the cell invasion in K562 cells., Methods: K562 cells were treated with different concentrations of imatinib mesylate. After different time periods, the mRNA levels of BCR/ABL, PTEN and FAK were detected by real-time fluorescent quantitative PCR (FQ-PCR) to analyze their relationships. The protein level of FAK was detected by immunocytochemistry. The cell invasive ability was examined by Transwell (Boyden chamber) assay., Results: In the initial 36 h, the expression level of PTEN mRNA was up-regulated and the FAK mRNA was down-regulated with the reduction of BCR/ABL fusion gene expression and the cell invasive ability of K562 cells was inhibited by 2 μg/mL imatinib mesylate. 48 h later, the PTEN mRNA expression level decreased and the FAK mRNA expression level was elevated with the restore of BCR/ABL fusion gene. BCR/ABL mRNA level presented a positive correlation with PTEN mRNA expression level, and a negative correlation with FAK mRNA., Conclusion: Tyrosine kinase inhibitor imatinib mesylate can regulate PTEN/FAK pathway and inhibit the leukemia K562 cell invasive ability via restraining BCR/ABL fusion gene.

Patients with Crohn's disease have an increased risk of developing intestinal tumours. However, the carcinogenic mechanisms remain poorly understood. To address this question, this report describes an unusual case of Crohn's disease complicated by synchronous small intestinal and colonic adenocarcinomas. Genetic events in both the tumours and their adjacent mucosae were evaluated and the tumorigenesis of these cancers is discussed.

Background & Aims: The potential role of p16 inactivation by CDKN2A/p16 promoter hypermethylation and/or loss of heterozygosity (LOH) of the CDKN2A gene was investigated in neoplastic progression of Barrett's esophagus., Methods: CDKN2A promoter hypermethylation was studied by methylation sensitive single-strand conformation analysis and sequencing using bisulfite modified DNA in Barrett's esophageal adenocarcinomas, premalignant lesions, and normal squamous esophageal epithelium. All of the lesions of interest were sampled by microdissection from paraffin-embedded fixed tissue sections., Results: No methylation of the CDKN2A promoter was found in normal esophageal squamous cell epithelia, whereas methylation was detected in 18 of 22 (82%) adenocarcinomas and 10 of 33 (30%) premalignant lesions, including 4 of 12 (33%) samples with intestinal metaplasia only. LOH at the CDKN2A gene locus was found in 68% of adenocarcinomas and in 55% of premalignant lesions. Of 28 samples without p16 immunoreactivity, 25 (89%) showed CDKN2A promoter hypermethylation with or without LOH of CDKN2A. Only 2 (8%) samples expressing p16 protein were found to be methylated; these showed a mixture of completely methylated and unmethylated CDKN2A promoters. In 7 of 19 (37%) informative samples without LOH of CDKN2A, the CDKN2A promoter was found to be methylated at both alleles. Loss of p16 protein expression was strongly associated with CDKN2A promoter hypermethylation (P < 0.00001), but not with LOH (P = 0.33)., Conclusions: Our results indicate that methylation of the CDKN2A promoter is the predominant mechanism for p16 inactivation. This hypermethylation is a very common event in esophageal adenocarcinoma and occurs as early as metaplasia.

The majority of the adenocarcinomas arising in Barrett esophagus manifest clinically at an advanced stage and have a poor prognosis. As a result of this poor prognosis, much attention has been directed toward the exploration of markers for neoplastic progression in Barrett esophagus. The objective of the present study was to determine the expression of beta-catenin by immunohistochemical analysis in 70 adenocarcinomas developed in Barrett esophagus and to examine its relationship to various prognostic factors currently in use. Abnormal beta-catenin expression, consisting of the loss of membranous staining and the appearance of the nuclear staining, was found in 43 cases (61%). Of patients with the 43 tumors showing abnormal beta-catenin expression, 25 (58%) survived more than 1 year. In contrast, only 7 (26%) of 27 patients with tumors showing normal beta-catenin expression survived longer than 1 year. Most of the superficial (Tis-T1) tumors (83% [10/12]) exhibited abnormal beta-catenin expression compared with only 53% (31/58) in the T2-T3 group. These results suggest a possible correlation among beta-catenin expression, tumor stage, and length of survival as prognostic factors in patients with adenocarcinoma in Barrett esophagus.

The aim of the present study was to characterize expression and mutation of p53 during the neoplastic progression from Barrett's esophagus to adenocarcinoma and to test the reliability of immunohistochemistry for p53 overexpression as an indicator of p53 mutation in this context. The association of both gene mutation and protein accumulation with clinicopathological findings and survival was also studied. A total of 77 samples from 30 esophagectomy specimens with Barrett's esophagus and adenocarcinoma of patients in longitudinal clinical follow-up were analyzed. Different lesions (intestinal metaplasia, dysplasia, and adenocarcinoma) as well as normal squamous-cell esophageal epithelia were sampled from formalin-fixed, paraffin-embedded tissues by microdissection. Mutations in p53 Exons 5 to 9 were detected by polymerase chain reaction-single-strand conformation polymorphisms (PCR-SSCP) and confirmed by direct DNA sequencing. Nuclear accumulation of p53 protein was analyzed immunohistochemically from tissue sections adjacent to those used for microdissection. p53 gene mutations were found in 17 and p53 protein accumulation were found in 20 tumor samples. Of the 17 adenocarcinomas with a p53 mutation, 16 stained positive for p53 protein. p53 mutations were detected significantly more frequently in high-grade dysplastic than in low-grade dysplastic lesions (77% versus 29%, P < 0.01). In contrast, nuclear accumulation of p53 was detected in 85% of high-grade and 71% of low-grade dysplastic lesions. In eight cases with p53 mutation, the mutation identified in the tumors was also detected in premalignant lesions, mainly in high-grade dysplasia. In four cases of p53-mutated tumors, clones with different p53 mutations were detected in premalignant lesions. Neither p53 mutations nor p53 protein accumulations were found in metaplastic lesions. In summary, we found that p53 mutations occurred mainly during the transition from low-grade to high-grade dysplasia in the neoplastic progression of Barrett's esophagus but not in the nondysplastic Barrett's mucosa. Mutational analysis of p53 by PCR-SSCP and p53 accumulation by immunohistochemistry were mostly concordant in adenocarcinoma and high-grade dysplastic lesions but frequently discordant in low-grade dysplastic lesions. No correlation between p53 gene mutation or p53 accumulation and clinicopathological findings was observed in this study.

Methylation-sensitive single-strand conformation analysis (MS-SSCA) is a new method of screening for DNA methylation changes. The combination of bisulfite modification and PCR results in the conversion of unmethylated cytosines to thymines, whereas methylated cytosines remain unchanged. This sequence conversion can lead to methylation-dependent alterations of single-strand conformation, which can be detected by SSCA. An analysis of mixtures of methylated and unmethylated DNA at known ratios revealed that the relative intensities of the corresponding bands following MS-SSCA were maintained. MS-SSCA was applied for methylation analysis of human p16 promoter region using genomic DNA obtained from either frozen, fixed, or microdissected fixed tissue sections. MS-SSCA is a rapid, specific, and semiquantitative approach that allows the detection of methylation of the p16 gene promoter. In reconstruction experiments, the method permits the detection of 10% or less of cells harboring a methylated p16 promoter. We have been successful in analyzing by MS-SSCA almost all (96%) tumor samples microdissected from archival paraffin-embedded fixed tissue sections and obtaining reproducible results. In addition, when microdissection was performed, the clonality of this genetic alteration could be identified.

Our aim was to characterize expression and mutation of beta-catenin in the progression of Barrett esophagus to adenocarcinoma. Immunohistochemical analysis of beta-catenin was performed on paraffin-embedded tissue from 30 cases with adenocarcinomas and premalignant lesions. To determine whether there is a correlation between beta-catenin nuclear accumulation and exon 3 mutation of this gene, mutational analysis by polymerase chain reaction-single-strand conformation polymorphism was performed on DNA extracted from the same 30 adenocarcinomas. As a result, the prevalence of reduced expression of beta-catenin on the membrane, with or without nuclear staining, increased significantly from low-grade (LG) to high-grade (HG) dysplasia. Focal nuclear staining for beta-catenin was present in 19 cases of adenocarcinoma, and nuclear staining was associated significantly with progression from metaplasia to LG dysplasia. In addition, in glands with clear histologic transition from metaplasia to LG dysplasia, nuclear accumulation of beta-catenin was found only in the LG dysplastic areas. No mutation in exon 3 of the beta-catenin gene was detected in adenocarcinomas. These results demonstrate that disturbance of the APC/beta-catenin pathway, as indicated by nuclear accumulation of beta-catenin, is a common and early event during neoplastic progression in Barrett esophagus.