Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer

Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of ^{3}He and ^{4}He fluxes are presented. The measurements are based on 100 million ^{4}He nuclei in the rigidity range from 2.1 to 21 GV and 18 million ^{3}He from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the ^{3}He and ^{4}He fluxes exhibit nearly identical variations with time. The relative magnitude of the variations decreases with increasing rigidity. The rigidity dependence of the ^{3}He/^{4}He flux ratio is measured for the first time. Below 4 GV, the ^{3}He/^{4}He flux ratio was found to have a significant long-term time dependence. Above 4 GV, the ^{3}He/^{4}He flux ratio was found to be time independent, and its rigidity dependence is well described by a single power law ∝R^{Δ} with Δ=-0.294±0.004. Unexpectedly, this value is in agreement with the B/O and B/C spectral indices at high energies.

Comparison between tunneling and standard endoscopic submucosal dissection for treatment of large esophageal superficial neoplasm

BACKGROUND AND STUDY AIMS

Endoscopic submucosal dissection (ESD) has been established as a standard endoscopic method for treating esophageal superficial neoplasms, and it can be performed using a conventional or a tunneling method. The aim of the present study was to compare the safety and efficacy of tunneling ESD (t-ESD) and standard ESD (s-ESD) for treating large esophageal superficial neoplasms and to explore the risk factors for postoperative strictures.

PATIENTS AND METHODS

Fifty-five consecutive patients with large esophageal superficial neoplasms were treated by t-ESD or s-ESD. Demographics, lesion characteristics, procedure-related parameters, and follow-up results were retrospectively collected to compare the efficacy and safety of these procedures. Multivariate analyses were conducted to determine the potential risk factors for postoperative strictures.

RESULTS

Of the 55 patients, 13 underwent t-ESD and 42 underwent s-ESD. The dissection speed of t-ESD was significantly faster than that of s-ESD (7.42±1.99 min/cm2 vs. 9.01±2.11 min/cm2, P<0.05). En bloc resection was achieved in 98.2% (54/55) of the cases, while R0 resection was achieved in 92.7% (51/55). Curative resection was achieved in 78.2% (43/55) of the cases. Fourteen patients (25.5%) had postoperative strictures, which resolved with endoscopic dilation and/or stent insertion. Circumferential involvement of >3/4 and lesion length of >3 cm were independent risk factors for strictures.

CONCLUSIONS

T-ESD is a safe and effective method for treating large esophageal superficial neoplasms with a faster dissection speed than s-ESD, but postoperative strictures may be encountered for lesions involving more than three-fourths of the circumference or longer than 3 cm.

The function of microRNA-34a in osteoarthritis

AIM

To discuss the effects and mechanism of microRNA-34a in cell apoptosis induced by osteoarthritis.

METHODS

Collection of the normal and osteoarthritis synovial tissues and measurements of the miRNA-34a and TGIF2 gene expression. In the cell experiment, the cells were divided into Control, Blank and miRNA inhibitor group. The cell proliferation and apoptosis of the different groups were measured by MTT and flow cytometry and the TGIF2 protein expression in the different groups was evaluated by WB assay. The correlation between TGIF2 and miRNA-34a was analyzed by Double luciferase experiment.

RESULTS

Compared with normal synovial tissues, the miRNA-34a gene expression was significantly up-regulated and TGIF2 gene expression was significantly suppressed in osteoarthritis synovial tissues (p < 0.001, respectively). The cell proliferation was significantly depressed and the cell apoptosis rate was significantly increased in miRNA inhibitor group compared with the Control group (p < 0.001, respectively). Using the WB assay it was shown that the TGIF2 protein expression of miRNA inhibitor group was significantly suppressed compared with that of Control group (p < 0.01). By Double luciferase assay, TGIF2 gene was one target gene of miRNA-34a.

CONCLUSION

miRNA-34a could induce osteoarthritis synovial cell apoptosis via regulation of TGIF2 in vitro (Fig. 6, Ref. 29).

Comparison of microRNAs in adipose and muscle tissue from seven indigenous Chinese breeds and Yorkshire pigs

Elucidation of the pig microRNAome is essential for interpreting functional elements of the genome and understanding the genetic architecture of complex traits. Here, we extracted small RNAs from skeletal muscle and adipose tissue, and we compared their expression levels between one Western breed (Yorkshire) and seven indigenous Chinese breeds. We detected the expression of 172 known porcine microRNAs (miRNAs) and 181 novel miRNAs. Differential expression analysis found 92 and 12 differentially expressed miRNAs in adipose and muscle tissue respectively. We found that different Chinese breeds shared common directional miRNA expression changes compared to Yorkshire pigs. Some miRNAs differentially expressed across multiple Chinese breeds, including ssc-miR-129-5p, ssc-miR-30 and ssc-miR-150, are involved in adipose tissue function. Functional enrichment analysis revealed that the target genes of the differentially expressed miRNAs are associated mainly with signaling pathways rather than metabolic and biosynthetic processes. The miRNA-target gene and miRNA-phenotypic traits networks identified many hub miRNAs that regulate a large number of target genes or phenotypic traits. Specifically, we found that intramuscular fat content is regulated by the greatest number of miRNAs in muscle tissue. This study provides valuable new candidate miRNAs that will aid in the improvement of meat quality and production.

A new diagnostic index for sarcopenia and its association with short-term postoperative complications in patients undergoing surgery for colorectal cancer

AIM

Sarcopenia is a robust prognostic indicator of outcomes after surgery for colorectal cancer (CRC). However, there are no serum markers routinely available for estimating skeletal muscle mass (SMM). The present study aimed to describe a new sarcopenia index (SI), serum creatinine (Scr) × cystatin C-based glomerular filtration rate, and investigate its association with short-term complications after curative resection of CRC.

METHOD

Consecutive patients who underwent curative resection of CRC from December 2011 to January 2017 were retrospectively identified. Skeletal muscle cross-sectional area was analysed on L3 computed tomographic images. Receiver operating characteristic curve analysis showed that the cutoff points of SI for sarcopenia were below 56.1 in men and below 43.7 in women. Patients were classified into low and high SI groups in accordance with these cutoff values. The association between SI and body composition and the impact of preoperative SI on postoperative outcomes were analysed.

RESULTS

Among 417 patients, SI showed a stronger correlation with skeletal muscle area (SMA) (r = 0.537, P < 0.001) than with the Scr/cystatin C ratio (r = 0.469, P < 0.001) and Scr (r = 0.447, P < 0.001). The low SI group had a lower SMA, lower preoperative haemoglobin, a higher prevalence of sarcopenia and experienced more postoperative complications compared with the high SI group (all P < 0.001). Multivariate logistic regression analysis showed that the independent risk factors for overall complications were low preoperative haemoglobin, low SI, sarcopenia and American Society of Anesthesiologists grade ≥ 3.

CONCLUSION

This new SI is a simple and useful surrogate marker for estimating SMM, and is associated with outcomes after CRC surgery.

[An epidemiologic study of pelvic organ prolapse in urban Chinese women: a population-based sample in China]

Objective: This study aimed to assess the prevalence and factors associated with pelvic organ prolapse (POP) in a representative sample of Chinese urban women. Methods: A total of 29613 Chinese urban women were recruited to this cross-sectional study between February 2014 and March 2016. The prevalence of POP, defined as any stage Ⅱ or higher POP resulting in symptoms, was assessed using questionnaires and physical examinations. Multivariable logistic regression was used to assess factors associated with POP. Results: 2 864 of 29 613 women (9.67%) had POP. The prevalence of POP increased with age ranging from 1.23% (82/6 646) of women aged between 20 and 29 years to 26.11% (727/2 784) for those aged 70 years or older (P<0.000 1). Overweight and obese women were more likely to have POP than normal weight women [AOR=1.56, 95%CI 1.42-1.72 vs AOR=1.74, 95%CI 1.48-2.03]. In the multivariate analysis, the independent risk factors were cough (AOR=1.70, 95%CI 1.44-2.02), constipation (AOR=2.05, 95%CI 1.82-2.32), physical disease (AOR=1.27, 95%CI 1.15-1.41), and gynecological diseases (AOR=2.08, 95%CI 1.89-2.29). Nulliparous (AOR=0.12, 95%CI 0.06-0.22) and caesarean section (CS) (AOR=0.55, 95%CI 0.47-0.64) were protective factors for POP. Conclusions: POP affects nearly 10% of women in Chinese urban region. The prevalence of POP increases significantly with age. The independent risk factors for POP are body mass index, cough, constipation, physical disease and gynecological diseases. Nulliparous and CS are protective factors for POP.

A polymorphic MYC response element in KBTBD11 influences colorectal cancer risk, especially in interaction with an MYC-regulated SNP rs6983267

Background

MYC is a well-established cancer driver gene regulating the expression of numerous genes, indicating that polymorphisms in MYC response elements could affect tumorigenesis through altering MYC regulation. We performed integrative multistage study to evaluate the effects of variants in MYC response elements and colorectal cancer (CRC) risk.

Patients and methods

We systematically integrated ChIP-Seq, DNase-Seq and transcription factor motif data to screen variants with potential ability to affect the MYC binding affinity. Then, we conducted a two-stage case-control study, totally consisting of 4830 CRC cases and 4759 controls in Chinese population to identify risk polymorphisms and interactions. The effects of risk variants were confirmed by functional assays in CRC LoVo, SW480 and HCT15 cells.

Results

We identified a novel polymorphism rs11777210 in KBTBD11 significantly associated with CRC susceptibility (P = 2.43 × 10-12). Notably, we observed a significant interaction between rs11777210 and MYC nearby rs6983267 (P-multi = 0.003, P-add = 0.005), subjects carrying rs6983267 GG and rs11777210 CC genotypes showing higher susceptibility to CRC (2.83-fold) than those carrying rs6983267 TT and rs11777210 TT genotypes. We further demonstrated that rs6983267 T > G increased MYC expression, and MYC bound to and negatively regulated KBTBD11 expression when the rs11777210 C risk allele was present. KBTBD11 was downregulated in tumor tissues, and KBTBD11 knockdown promoted cell proliferation and inhibited cell apoptosis.

Conclusion

The rs11777210 is a potential predictive biomarker of CRC susceptibility, and KBTBD11 functions as a putative tumor suppressor in tumorigenesis. Our study highlighted the high CRC risk of people carrying rs6983267 G and rs11777210 C alleles, and provided possible biological mechanism of the interaction.

Towards Understanding the Origin of Cosmic-Ray Electrons

Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1×10^{6} electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux exhibits a significant excess starting from 42.1_{-5.2}^{+5.4}  GeV compared to the lower energy trends, but the nature of this excess is different from the positron flux excess above 25.2±1.8  GeV. Contrary to the positron flux, which has an exponential energy cutoff of 810_{-180}^{+310}  GeV, at the 5σ level the electron flux does not have an energy cutoff below 1.9 TeV. In the entire energy range the electron flux is well described by the sum of two power law components. The different behavior of the cosmic-ray electrons and positrons measured by the Alpha Magnetic Spectrometer is clear evidence that most high energy electrons originate from different sources than high energy positrons.

Quantitative factors of unenhanced CT for predicting fragmenting efficacy of extracorporeal shock wave lithotripsy on pancreatic duct stones

AIM

To find potential predictors at unenhanced computed tomography (CT) to evaluate the stone clearance rate (SCR) of pancreatic duct stones (PDS) by extracorporeal shock wave lithotripsy (ESWL).

MATERIALS AND METHODS

A total of 106 consecutive patients with multiple stones of maximal transverse length (MTL) 0.3-3.6 cm in pancreatic head region were enrolled. Unenhanced CT was performed both before and after ESWL therapy. All patients underwent ESWL therapy using an electromagnetic lithotripter, and were divided into three groups with threshold values of >90%, 50-90% and <50% of SCR. Factors including sex, age, MTL, mean stone density (MSD), standard deviation of stone density (SDSD), variation coefficient of stone density (VCSD), attenuation density (AD), pancreatic duct diameter (PDD), skin-to-stone distance (SSD), and number of ESWL sessions were analysed, and their impact on SCR was evaluated by univariate and multivariate analyses. The diagnostic threshold of the independent predicting index was further calculated, and its relationship with SCR and ESWL was analysed by drawing a trend line.

RESULTS

The only significant predictor of SCR by ESWL was MSD (p<0.05). More courses of ESWL therapy are required in PDS patients with an MSD higher than the cut-off value of 375.4 HU (mean, 2.6 versus 1.8), but with a relatively lower SCR (mean, 43.96 versus 88.68%) .

CONCLUSION

MSD on pre-treatment unenhanced CT is an independent predictor for SCR of PDS patients treated with ESWL. Using a cut-off value of 375.4 HU, patients with low MSD are good candidates for ESWL therapy.

Towards Understanding the Origin of Cosmic-Ray Positrons

Precision measurements of cosmic ray positrons are presented up to 1 TeV based on 1.9 million positrons collected by the Alpha Magnetic Spectrometer on the International Space Station. The positron flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25.2±1.8  GeV compared to the lower-energy, power-law trend, (b) a sharp dropoff above 284_{-64}^{+91}  GeV, (c) in the entire energy range the positron flux is well described by the sum of a term associated with the positrons produced in the collision of cosmic rays, which dominates at low energies, and a new source term of positrons, which dominates at high energies, and (d) a finite energy cutoff of the source term of E_{s}=810_{-180}^{+310}  GeV is established with a significance of more than 4σ. These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter annihilation or from other astrophysical sources.

The prognostic value of combination of CD90 and OCT4 for hepatocellular carcinoma after curative resection

CD90 has been identified as a candidate marker of cancer stem cells (CSCs) for HCC, whereas it also has been considered as a marker for tumor-associated fibroblasts (CAFs). OCT4, as a key transcription factor required to maintain pluripotency of human embryonic stem cell and cancer cells, has been characterized to be involved in malignant transformation and tumorigenesis of various cancers. This study aimed to examine expression patterns of CD90 in HCC and investigate whether combination of both CD90 and OCT4 could provide a more powerful predictor for prognosis of HCC than either one alone.CD90 and OCT4 were examined by immunohistochemistry. The relationship between CD90/OCT4 expression and clinicopathologic characteristics was analyzed. The correlation between CD90/OCT4 expression and overall survival and disease-free survival was determined with Kaplan-Meier analysis.CD90 was found mainly expressed in tumor-associated CAFs and OCT4 was mainly expressed in tumor cells. The expression of CD90 and OCT4 in HCC was significantly higher than in adjacent non-tumor and normal liver tissues. CD90 expression was correlated with pathological grade, satellite lesion, PVTT and recurrence. OCT4 expression was correlated with pathological grade, tumor size and recurrence. Data demonstrated no correlation between CD90 and OCT4. High expression of CD90 or OCT4 predicts a poor prognosis. Furthermore, combination of both CD90 and OCT4 provides a more sensitive predictor for prognosis of HCC than either marker alone.CD90 and OCT4 are both independent and reliable biomarker for predicting prognosis of HCC patients after hepatic resection. Our results indicated the accuracy of prediction can be enhanced by their combination.

Immunization with subunits of a novel pilus produced by virulent Clostridium perfringens strains confers partial protection against necrotic enteritis in chickens

Necrotic enteritis (NE) is an economically important disease of broiler chickens that is caused primarily by Clostridium perfringens strains that produce the NetB toxin. It is controlled in North America principally through the application of in-feed antimicrobials, but alternative control methods, such as vaccination, are urgently needed. We previously identified a cluster of C. perfringens genes prevalent in disease-causing strains, denominated VR-10B, that is predicted to encode a pilus. The current study evaluated the ability of three predicted pilin structural subunits (CnaA, FimA, FimB) to protect against NE in two immunization studies. In the first study, young broiler chickens were immunized twice intramuscularly (i.m.) with CnaA or FimA, which resulted in only a weak serum antibody response, and no reduction in the severity of intestinal lesions following experimental challenge with C. perfringens strain CP1. In the second study, chickens were injected subcutaneously (s.c.) with CnaA, FimB, or a combination of all three proteins, on days 7, 14 and 19, which resulted in a marked antibody response specific to each antigen. Chickens immunized with either CnaA or FimB had significantly reduced NE lesion severity, whereas immunization with all three proteins in combination did not provide protection. Western blot experiments using serum from immunized birds were also performed, providing the first experimental evidence to suggest that this locus may in fact encode a functional pilus structure.