Cell-free DNA from bile outperformed plasma as a potential alternative to tissue biopsy in biliary tract cancer.

BACKGROUND: Biliary tract cancers (BTCs) are rare and highly heterogenous malignant neoplasms. Because obtaining BTC tissues is challenging, the purpose of this study was to explore the potential roles of bile as a liquid biopsy medium in patients with BTC. PATIENTS AND METHODS: Sixty-nine consecutive patients with suspected BTC were prospectively enrolled in this study. Capture-based targeted sequencing was performed on tumor tissues, whole blood cells, plasma, and bile samples using a large panel consisting of 520 cancer-related genes. RESULTS: Of the 28 patients enrolled in this cohort, tumor tissues were available in eight patients, and plasma and bile were available in 28 patients. Somatic mutations were detected in 100% (8/8), 71.4% (20/28), and 53.6% (15/28) of samples comprising tumor tissue DNA, bile cell-free DNA (cfDNA), and plasma cfDNA, respectively. Bile cfDNA showed a significantly higher maximum allele frequency than plasma cfDNA (P = 0.0032). There were 56.2% of somatic single-nucleotide variant (SNVs)/insertions and deletions (indels) shared between bile and plasma cfDNA. When considering the genetic profiles of tumor tissues as the gold standard, the by-variant sensitivity and positive predictive value for SNVs/indels in bile cfDNA positive for somatic mutations were both 95.5%. The overall concordance for SNVs/indels in bile was significantly higher than that in plasma (99.1% versus 78.3%, P < 0.0001). Moreover, the sensitivity of CA 19-9 combined with bile cfDNA achieved 96.4% in BTC diagnosis. CONCLUSION: We demonstrated that bile cfDNA was superior to plasma cfDNA in the detection of tumor-related genomic alterations. Bile cfDNA as a minimally invasive liquid biopsy medium might be a supplemental approach to confirm BTC diagnosis.

Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region.

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies.

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of π^{0}'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk.

MiR-129-2 weakens proliferation and promotes apoptosis of liver cancer cells by suppressing the Wnt signaling pathway.

OBJECTIVE: To explore the effects of micro ribonucleic acid-129-2 (miR-129-2) on proliferation and migration of liver cancer cells and its possible mechanism. PATIENTS AND METHODS: The expression level of miR-129-2 was measured in liver cancer tissues and adjacent tissues from patients with liver cancer. Its level in liver cancer HepG2 cells and normal liver cells L-02 was also detected via quantitative polymerase chain reaction (qPCR). MiR-192-2 overexpression model was established in the HepG2 cell line. The proliferation and apoptosis levels of cells were determined by methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively. Wound healing assay was performed to detect the migration ability of cells. The expressions level of genes in the Wnt signaling pathway were measured through Western blotting. Xenograft tumor model was conducted in nude mice for exploring the in vivo effects of miR-129-2 on liver cancer growth. RESULTS: The expression level of miR-129-2 was significantly lower in liver cancer tissues than that in adjacent tissues (p<0.01), and it was overtly lower in HepG2 cells than that in L-02 cells (p<0.01). Overexpression of miR-129-2 weakened proliferation and migration abilities of liver cancer cells (p<0.01), and evidently increased apoptosis level (p<0.01). Sex-determining region Y-related HMG-box 4 (Sox4) and matrix metalloproteinase-2 (MMP-2) were downregulated, while phosphorylated glycogen synthase kinase-3ß (p-GSK3ß) was upregulated in liver cancer cells overexpressing miR-129-2. Besides, the weight and volume of tumors in nude mice bearing liver cancer were significantly smaller after overexpression of miR-129-2. CONCLUSIONS: MiR-129-2 weakens proliferation and migration and stimulates apoptosis in liver cancer cells mainly by downregulating Sox4 and inactivating the Wnt signaling pathway.

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source.

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100 TeV. As a result, we observed 24 photonlike events with E>100 TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100 TeV from an astrophysical source.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun.

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

[Drug susceptibility test guided therapy and novel empirical quadruple therapy for Helicobacter pylori infection: a network Meta-analysis].

Objective: To compare the efficacy and the risk of adverse effect of drug susceptibility test guided therapy and novel empirical quadruple therapy for Helicobacter (H.) pylori infection. Methods: Literature retrieval was conducted by using major databases. Related papers published up to June 2015 were considered eligible if they were randomized control trials comparing different pharmacological formulations for H. pylori infection and used in a network Meta-analysis and a single rate Meta-analysis to evaluate the relative and absolute rates of H. pylori eradication and the risk of adverse effect. The Jadad score was used to evaluate the methodological quality. Funnel plot was constructed to evaluate the risk of publication bias. Begg's rank correlation test or Egger's regression intercept test was done for the asymmetry of funnel plot. Results: Twenty randomized control trials for the treatment of 6 753 initial treated patients with H. pylori infection were included. Drug susceptibility test guided therapy was significantly superior to concomitant therapy, hybrid therapy, sequential therapy and bismuth quadruple therapy. The culture-based therapy had the highest likelihood of improving clinical efficacy, with lowest risk of adverse effect. Concomitant therapy had the highest probability of causing adverse effect despite its effectiveness. Hybrid therapy and bismuth quadruple therapy were associated with lower risk of adverse effect and higher effectiveness. Conclusion: Drug susceptibility test guided therapy showed superiority to other 4 interventions for H. pylori eradication mentioned above. Hybrid therapy and bismuth quadruple therapy might be applied in the settings where the culture-based strategy is not available.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun.

We report on a clear solar-cycle variation of the Sun's shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun's shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun's shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun's shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun's shadow observed in the TeV cosmic-ray flux.

Phylogeny of Vibrio cholerae based on recA sequence.

We sequenced a 705-bp fragment of the recA gene from 113 Vibrio cholerae strains and closely related species. One hundred eighty-seven nucleotides were phylogenetically informative, 55 were phylogenetically uninformative, and 463 were invariant. Not unexpectedly, Vibrio parahaemolyticus and Vibrio vulnificus strains formed out-groups; we also identified isolates which resembled V. cholerae biochemically but which did not cluster with V. cholerae. In many instances, V. cholerae serogroup designations did not correlate with phylogeny, as reflected by recA sequence divergence. This observation is consistent with the idea that there is horizontal transfer of O-antigen biosynthesis genes among V. cholerae strains.

[MBP content in serum after closed diffuse cranial injury in rats].

The MBP content change in serum was observed by ELISA in rats with experimental closed diffuse cranial injury. The MBP content was 6.1633 +/- 1.5301 ng/ml (X +/- S) in the normal group, 11.3818 +/- 2.6574 ng/ml in the first group died immediately after injury, 10.8319 +/- 2.3135 ng/ml in the second group of 15 min after injury. This increased level of MBP was lasting in the following 3 days and returned to normal at the 4th and 5th day after injury. The difference of the MBP levels between the groups after injury and that in the normal group is significant (P < 0.01).

[Genetic polymorphism of inter-alpha-trypsin inhibitor in six Chinese populations].

OBJECTIVE: To understand the distribution of allele frequencies of inter-alpha-trypsin inhibitor(ITI) in Chinese populations. METHODS: The polymorphism of this protein in six Chinese populations was investigated using isoelectric focusing followed by immunoblotting technique. RESULTS: Three common alleles, ITI*1, ITI*2, and ITI*3 were observed in four populations, namely Han living in Jilin, Mongol in Hailaer, Tibetan in Lasa, and Bai in Dali respectively. In other two populations, Zhuang in Guangxi and Han in Guangdong, only ITI*1 and ITI*2 were observed. For these populations, the frequency of ITI*1 ranges from 0.5500 to 0.7525; that of ITI*2 from 0.2475 to 0.4322; and that of ITI*3 from 0.0034 to 0.0729. CONCLUSION: This study reveals that there is no parallel relationship between variation of allele frequencies and geographic differences.

[Genetic polymorphism of FXIII B subunit in seven Chinese populations].

OBJECTIVE: To understand the distribution of allele frequencies of blood factor XIIIB subunit(FXIIIB) in Chinese populations and evaluate the genetic polymorphism of FXIIIB for the purposes of population genetics and forensic haemogenetics. METHODS: The genetic polymorphism of FXIIIB subunit in seven Chinese populations was investigated. Isoelectrofocusing technique on polyoacrylamid gels followed by immunoblotting was used to determine the phenotype of individuals in each population sample. RESULTS: There were three common alleles in all the seven Chinese populations. The frequency of FXIIIB*3 was the highest, that of FXIIIB*2 was the lowest, and the one of FXXIIIB*1 was at the middle. All of them reached to the polymorphism's level. A rare variant allele was also found in some Chinese populations. Comparison of the constituents of FXIIIB phenotypes in the seven populations showed that there was no significant difference (P>0.05). The distribution of the allele frequencies in these populations reflected most likely the mode of the distribution in all Chinese populations. The phylogenetic tree and genetic distance, based on the allele frequencies of FXIIIB differentiated the populations in the world into the main ethnic groups as what other authors reported. CONCLUSION: FXIIIB is a useful genetic marker for population genetics and forensic haemogenetics.

Dissociation of basal turnover and cytokine-induced transcript stabilization of the human cyclooxygenase-2 mRNA by mutagenesis of the 3'-untranslated region.

The immediate early gene cyclooxygenase-2 (Cox-2), which encodes the inducible prostaglandin synthase enzyme, is regulated at the level of post-transcriptional mRNA turnover. In this study, the functional role of the 3'-untranslated region (3'-UTR) of the human Cox-2 gene was characterized. Deletion of the distal region of the 3'-UTR strongly inhibited basal mRNA turnover, suggesting that this region contains mRNA instability determinants. However, deletion of the proximal highly-conserved region (CR1: 6082-6198) resulted in increased basal turnover, indicating that it determines mRNA stability. All of the 3'-UTR constructs conferred IL-1-induced stabilization but not dexamethasone-induced down-regulation. Thus, distinct regions of the 3'-UTR of the Cox-2 transcript are involved in the regulation of basal and cytokine-induced mRNA metabolism.

[Investigation of C1R gene frequencies in three Han populations in China].

To reveal the C1R polymorphism in Chinese, three Han populations in Guangzhou (101 samples), Jilin (105 samples) and Chengdu (111 samples) were investigated with a technique using PAGIF followed by immunoblotting. The results showed in Chengdu the C1R * 1 = 0.5676, C1R * 2 = 0.3424 and C1R * 5 = 0.0856, in Guangzhou C1R * 1 = 0.5248, C1R * 2 = 0.2663 and C1R * 5 = 0.1089, and in Jilin C1R * 1 = 0.5381, C1R * 2 = 0.2619 and C1R * 5 = 0.1714. Three rare genes C1R * 6, C1R * 7 and C1R * 8 were found in the investigation. These indicate that the frequency of C1R * 2 is elevated from north to south which may imply a geographic cline in this locus. The cumulated heterogeneity of C1R in Han population is 61.5% which means that this polymorphic system is useful in anthropolgy as well as in forensic science.

[Genetic polymorphism of antithrombin III in five Chinese populations].

The genetic polymorphisms of antithrombin III (AT III) in 5 Chinese populations were studied by isoelectric focusing on polyacrylamide gels followed by immunoblotting. The products of two alleles at the antithrombin III locus together with 1 AT III anodic variant and 3 cathode variants were observed. The results revealed that the predominant allele of AT III blood group system in Chinese populations was AT III *1, with frequencies between 0.9773-0.9850. Frequencies of AT III *2 ranged from 0.0091 to 0.0169. These results indicate that the polymorphic information content of AT III blood group system in Chinese populations is limited.

[Simultaneous phenotyping of proteins with various pHs by complex IEF and its application in forensic haemogenetics].

We have developed a new technique of complex isoelectric focusing (IEF) by which various proteins with different pHs can be detected out in polyacrylamide gels containing ampholytes with different pH ranges at the same time. The success of phenotyping 12 human proteins by this technique proved it was reliable and efficient. The cumulative Epp and the cumulative Dp reached 0.9 and 0.9999 respectively. It provides a new approach to analysis of genetic markers in the field of forensic haemogenetics.

[Population genetics of short tandem repeat locus HUMTH01].

The distributions of genotypes and allele frequencies for the short tandem repeat locus HUMTH01 in Chinese and German populations were studied by amplified fragment length polymorphism analysis. The PCR amplification products with different primers were compared by coelectrophoresis and the population data from different laboratories were evaluated. Based on the allele frequencies of HUMTH01, the genetic distances among 25 populations were computed and a phylogenetic tree was constructed accordingly. Some new implications for population genetics were obtained from this phylogenetic tree.

A study of polymorphism of antithrombin III at the level of both protein and DNA in a Chinese population.

The protein and DNA polymorphisms of human antithrombin III (ATIII) were studied by isoelectric focusing (IEF) and PCR techniques in a Chinese population sample (n = 51). Products of two alleles within the coding region of the ATIII locus were observed by IEF. The allele frequencies were: ATIII*1 = 0.9608, ATIII*2 = 0.0392. The PCR analysis of the fragment length polymorphism (FLP) for the ATIII 5' locus disclosed two alleles. Their frequencies were: ATIII5'*1 = 0.4118, ATIII 5'*2 = 0.5882. An association analysis between these two ATIII polymorphisms revealed the incompatibility between the ATIII 5'FLP and the ATIII IEF variants, indicating that the ATIII 5' FLP is not responsible for ATIII variants.

[The sandwich enzyme-linked immunoabsorbent assay of serum transferrin receptor by using monoclonal and polyclonal antibodies].

The human placenta transferrin receptor was purified in the form of transferrin-transferrin receptor complex (Tf-TfR), and a monospecific polyclonal antibody against TfR was developed by a Tf-coupled Sepharose 4B affinity chromatography to remove the anti-Tf components in the antiserum. A sandwich enzyme-linked immunoabsorbent assay (ELISA) was established for measuring serum transferrin receptor (sTfR) by using monoclonal antibody OKT9 and monospecific polyclonal antibody. This method is simple, specific and sensitive and has a good accuracy. The measurement of sTfR showed that the level of normal children was 4.54 +/- 1.08 mg/L. There were increased levels of sTfR in patients with severe iron deficiency anemia and those with hemolytic anemia (13.92 +/- 4.45 mg/L and 9.94 +/- 3.22 mg/L, respectively). In patients with aplastic anemia, the level was decreased (2.06 +/- 0.82 mg/L). These results indicate that the sTfR measurement has a differential significance for diagnoses of various anemia.

[Genetic polymorphism of properdin factor B in the Han population in Chengdu, China].

The genetic polymorphism of properdin factor B(Bf) was first investigated in the Han population in Chengdu by isoelectrofocusing and immunofixation. The results revealed BfSS (129 cases), BfFS (48 cases) and BfFF (9 cases). No Bf variants were noted in this study. The allele frequencies were: Bf * S 0.8226, Bf * F 0.1774.