Value of faecal exfoliated cells in colorectal tumour screening using SDC2 methylation test.

BACKGROUND: This study aimed to evaluate the diagnostic value of a non-invasive methylation gene test in clinical colorectal tumour screening. METHOD: The quantitative methylation-specific PCR technique was used to detect faecal methylated syndecan-2 (mSDC2) in patients who received the screening of colorectal cancer (CRC).To evaluate the positive predictive value (PPV) of mSDC2 in patients with colorectal cancer, advanced adenoma (AA), and colorectal tumor (CRN) in risk factor stratification. RESULTS: The PPV of CRC, CRC + AA and CRN in male patients were 28.03%, 43.55% and 56.24%, respectively, which were higher than female patients. The positive detection rate of mSDC2 and the PPV of CRC gradually increased with age; The PPV in patients aged over 80 years was up to 78.05%, which was more significant than in younger patients with CRC. The PPV of CRC, AA and CRN were 37.10%, 11.80% and 63.37%, respectively. mSDC2 has a high detection rate of 85-100% in AA with intramucosal carcinoma alone or in combination with severe atypical hyperplasia or villous adenoma. CONCLUSION: The mSDC2 test has a higher PPV in patients with colorectal cancer and colorectal adenoma (AD), especially in high-risk groups over 50 years of age, and may help in the early diagnosis of colorectal tumours in the future.

Association of Aldehyde Dehydrogenase 2 Gene Polymorphism with Myocardial Infarction.

OBJECTIVE: This study explored the correlation between myocardial infarction (MI) and the Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene in the Qingyuan area. METHODS: The Glu504Lys polymorphism of the ALDH2 gene was analyzed using the polymerase chain reaction and deoxyribonucleic acid microarray analysis for 468 patients diagnosed with MI for the first time and 132 healthy subjects. RESULTS: There was a significant difference in the distribution of the ALDH2 genotype between the MI group and the control group (P = 0.0492), but there was no significant difference in allele frequency between the two groups (P = 0.1363). The clinical data showed that there were statistically significant differences (P < 0.05) in the two groups' gender and age distributions, rates of diabetes and hypertension, levels of alcohol and tobacco use, serological levels of heart markers, blood lipids and glucose. The subgroup analysis of ALDH2 genotypes found that alcohol consumption, high levels of myoglobin, and low levels of high-density lipoprotein cholesterol were significantly associated with a higher incidence of MI (P < 0.05). After adjusting for gender, hypertension, diabetes, and other related influencing factors, logistic regression analysis showed that the ALDH2 genotype GA/AA was an independent risk factor for MI (P < 0.05, OR = 1.479, 95% CI = 1.003-2.179). CONCLUSION: The presence of risk alleles with the genetic effect (ALDH2 genotype GA/AA) is an independent risk factor for MI.

Establishment and Clinical Application of a Method for Detecting T Lymphocyte Subsets by Cellular Immunochip Technology.

OBJECTIVE: To establish and verify the method for detecting the immune phenotype of peripheral blood T lymphocytes by cellular immune chip technology, analyze the immune status, and discuss its clinical diagnostic value of different populations in the Qingyuan area. METHODS: First, a cellular immune chip was used to detect the number of T lymphocyte subsets CD3+, CD4+, CD8+, and CD4/CD8, followed by evaluating the accuracy and precision through a comparison with flow cytometry. After passing the performance verification, a large-scale detection was performed by a cellular immune chip in 8389 cases. Immunochip technology detects the expression of T lymphocyte subsets and analyzes the differences in cellular immune function among people with physical examination, inflammation, and cancer, as well as different cancer types and in genders. RESULTS: The cell immunochip method and flow cytometry method have the same accuracy and precision in detecting specimens, and the former is fast and simple, and is suitable for clinical use; big data analysis is expected to establish a reference range for CD3+, CD4+, and CD8+ T cell counts in Qingyuan. There are statistical differences in CD3+, CD4+, CD8+ T cell counts in physical examination, inflammation and cancer populations; there are also certain differences in CD3+, CD4+, CD8+ T cell counts and CD4/CD8 ratios between different cancer types and different diseases. CONCLUSION: The method of cell immunochip technology to detect T lymphocyte subsets is simple and practical, with accurate results and rapid detection. It can be used for immune function monitoring and treatment prognosis evaluation of people with different diseases, and it is worthy of popularization and application in clinical practice.

Male papillomavirus infection and genotyping in the Qingyuan area.

BACKGROUND: This study aims to screen the male human papillomavirus (HPV) infection status and genotyping in Qingcheng District, Qingyuan City, Guangdong Province, China to provide a reference basis for formulating prevention strategies for HPV infection. METHODS: The present study collected urethral epithelium or scraped penile epidermis from high-risk male patients in Qingyuan People's Hospital during the last five years, extracted DNA fragments using the boiling method, and detected 23 types of HPV genotypes by PCR-reverse blot hybridization. RESULTS: The positive detection rate was 54.31% of 1044 males with high risk of HPV (567/1044). Among these males, the positive detection rate of HPV was the highest in patients initially diagnosed with warts, and the rate was 66.47%. Five main HPV types are identified as follows: HPV6 18.87% (197/1044), HPV11 10.25% (107/1044), HPV52 8.81% (92/1044), HPV16 6.90% (72/1044), and HPV51 5.08% (53/1044). Among these HPV-infected patients, single infection mainly by low-risk HPV6 and HPV11 accounted for 56.61% (321/567); high- and low-risk combined HPV co-infections accounted for 29.10% (165/567). The HPV infected patients was mainly between 21 and 40 years old, and the HPV infection rate was higher with increased age. CONCLUSIONS: The HPV infection rate in the Qingyuan area is higher than in other areas and the main infection is single infection. Furthermore, HPV52, HPV16, and HPV51 are the main high-risk infection types, while HPV6 and HPV11 are the main low-risk infection types.

An analysis of the correlation between the human apolipoprotein E gene polymorphism and lipoprotein-associated phospholipase A2.

BACKGROUND: Atherosclerosis is one of the most common cardiovascular and cerebrovascular diseases. This study aimed to explore the correlation between gene polymorphism of human apolipoprotein E (ApoE) and lipoprotein-associated phospholipase A2 (Lp-PLA2). METHODS: A total of 220 patients with atherosclerotic cardiovascular disease who were treated in our hospital from June 2016 to March 2017 were enrolled in this study and assigned as the atherosclerotic cardiovascular disease group and 193 patients who were treated contemporaneously in our hospital but had no atherosclerotic cardiovascular disease were enrolled and assigned as the control group. Gene polymorphism of ApoE was detected by PCR-fluorescent probe technique and the level of Lp-PLA2 was detected by ELISA. RESULTS: There were a total of 5 genotypes of ApoE in these two groups, which were E2/3, E3/3, E3/4, E2/4, and E4/4. E2/2 was not found in any of the patients. E3/3 made up the majority in both groups. There was no significant difference between the proportion of genotypes and frequencies of alleles in the two groups (P>0.05). There was no difference between LP-PLA2 among the different genotypes in these two groups (P>0.05). CONCLUSIONS: We cannot conclude that ApoE gene polymorphism is related to atherosclerotic cardiovascular and cerebrovascular diseases. And it cannot be concluded that ApoE gene polymorphism is related to Lp-PLA2 level.

LncRNA SNHG12 inhibits miR-199a to upregulate SIRT1 to attenuate cerebral ischemia/reperfusion injury through activating AMPK signaling pathway.

Cerebral ischemia caused severe disability, and associated with a series of neurological events. Long non-coding RNA SNHG12 was found to be upregulated in mouse brain microvascular endothelial cells by cerebral ischemia. Moreover, it was reported that SNHG12 could directly interact with miR-199a and sirtuin 1 (SIRT1) as a direct target of miR-199a in other diseases. However, the function and mechanism of SNHG12 in cerebral ischemia and reperfusion (I/R) injury of neuronal cells remains unclear. The present study was thus designed to explore the potential effect of SNHG12 and to investigate the underlying mechanism in I/R neuronal cells. we found that SNHG12 was upregulated in primary neuronal cells and N2a cells and peaked at 12 h and 24 h after OGD/R treatment, respectively. Meanwhile, MTT assay showed that knockdown SNHG12 inhibited cell proliferation under OGD/R condition. And flow cytometry analyses revealed more apoptosis rate was caused by SNHG12 knockdown. Mechanistically, SNHG12 interacted with miR-199a and decreased the expression of miR-199a. Overexpression miR-199a largely inhibited the cell proliferation and induced the cell apoptosis. Meanwhile, SNHG12 was proven to target miR-199a and then activated SIRT1 expression, which finally led to activation of AMPK signaling pathway. In summary, we demonstrate SNHG12 targets miR-199a to upregulate SIRT1 expression, which attenuates cerebral ischemia/reperfusion injury through AMPK pathway activation. Our findings provide molecular mechanism by which SNHG12 attenuates cerebral I/R injury and facilitate development of therapeautical strategies for treating ischemia-induced stroke.

Neuroprotective effects of lentivirus-mediated cystathionine-beta-synthase overexpression against 6-OHDA-induced parkinson's disease rats.

Parkinson's disease (PD) is age-related neurodegenerative disorder by a progressive loss of dopaminergic(DA) neurons in the substantia nigra (SN) and striatum, which is at least partly associated with α-synuclein protein accumulation in these neurons. Hydrogen sulfide (H2S) plays an important role in the nervous system. Studies have shown that H2S has a protective effect on PD. However, as a kind of gas molecules, H2S is lively, volatile, and not conducive to scientific research and clinical application. Cystathionine-beta-synthase(CBS) is the main enzymes of synthesis of H2S in the brain. In order to examine the neuroprotective effects of CBS on PD, we detected the effects of CBS overexpression on 6-Hydroxydopamine (6-OHDA)-lesioned PD rats using lentivirus-mediated gene transfection techniques. In the injured SN of 6-OHDA-induced PD rats, the CBS expression and the endogenous H2S level markedly decreased, while administration of lentivirus-mediated CBS overexpression increased the CBS expression and the endogenous H2S production.CBS overexpression dramatically reversed apomorphine-induced rotation of the 6-OHDA model rats, decreased the number of TUNEL-positive neurons and the loss of the nigral DA neurons，specifically inhibited 6-OHDA-induced oxidase stress injury, and down-regulated the expression of α-synuclein(α-SYN) in the injured SN. NaHS (an H2S donor) had similar effects to CBS overexpression, while Amino-oxyacetate(AOAA, a CBS inhibitor) had opposite effects on PD rats. In summary, we demonstrated that CBS overexpression was able to provide neuroprotective on PD rats and improving the expression of CBS may be a potential therapeutic method for PD.

Width-Tuned Magnetic Order Oscillation on Zigzag Edges of Honeycomb Nanoribbons.

Quantum confinement and interference often generate exotic properties in nanostructures. One recent highlight is the experimental indication of a magnetic phase transition in zigzag-edged graphene nanoribbons at the critical ribbon width of about 7 nm [ Magda , G. Z. et al. Nature 2014 , 514 , 608 ]. Here we show theoretically that with further increase in the ribbon width, the magnetic correlation of the two edges can exhibit an intriguing oscillatory behavior between antiferromagnetic and ferromagnetic, driven by acquiring the positive coherence between the two edges to lower the free energy. The oscillation effect is readily tunable in applied magnetic fields. These novel properties suggest new experimental manifestation of the edge magnetic orders in graphene nanoribbons and enhance the hopes of graphene-like spintronic nanodevices functioning at room temperature.

Interfacial Coupling-Induced Ferromagnetic Insulator Phase in Manganite Film.

Interfaces with subtle differences in atomic and electronic structures in perovskite ABO3 heterostructures often yield intriguingly different properties, yet their exact roles remain elusive. Here, we report an integrated study of unusual transport, magnetic, and structural properties of Pr0.67Sr0.33MnO3 film on SrTiO3 substrate. The variations in the out-of-plane lattice constant and BO6 octahedral rotation across the Pr0.67Sr0.33MnO3/SrTiO3 interface strongly depend on the thickness of the Pr0.67Sr0.33MnO3 film. In the 12 nm film, a new interface-sensitive ferromagnetic polaronic insulator (FI') phase is formed during the cubic-to-tetragonal phase transition of SrTiO3, apparently due to the enhanced electron-phonon interaction and atomic disorder in the film. The transport properties of the FI' phase in the 30 nm film are masked because of the reduced interfacial coupling and smaller interface-to-volume ratio. This work demonstrates how thickness-dependent interfacial coupling leads to the formation of a theoretically predicted ferromagnetic-polaronic insulator, as illustrated in a new phase diagram, that is otherwise ferromagnetic metal (FM) in bulk form.

Intra-unit-cell nematic charge order in the titanium-oxypnictide family of superconductors.

Understanding the role played by broken-symmetry states such as charge, spin and orbital orders in the mechanism of emergent properties, such as high-temperature superconductivity, is a major current topic in materials research. That the order may be within one unit cell, such as nematic, was only recently considered theoretically, but its observation in the iron-pnictide and doped cuprate superconductors places it at the forefront of current research. Here, we show that the recently discovered BaTi2Sb2O superconductor and its parent compound BaTi2As2O form a symmetry-breaking nematic ground state that can be naturally explained as an intra-unit-cell nematic charge order with d-wave symmetry, pointing to the ubiquity of the phenomenon. These findings, together with the key structural features in these materials being intermediate between the cuprate and iron-pnictide high-temperature superconducting materials, render the titanium oxypnictides an important new material system to understand the nature of nematic order and its relationship to superconductivity.

Strong coupling of the iron-quadrupole and anion-dipole polarizations in Ba(Fe(1-x)Co(x))2As2.

We use a quantitative convergent beam electron diffraction based method to image the valence electron density distribution in Ba(Fe1-xCox)2As2. We show a remarkable increase in both the charge quadrupole of the Fe cations and the charge dipole of the arsenic anions upon Co doping from x=0 (Tc=0 K) to x=0.1 (Tc=22.5 K). Our data suggest that an unexpected electronic correlation effect, namely strong coupling of Fe orbital fluctuation and anion electronic polarization, is present in iron-based superconductors.

Evidence for short-range-ordered charge stripes far above the charge-ordering transition in La1.67Sr0.33NiO4.

The temperature evolution of structural effects associated with charge order (CO) and spin order in La1.67Sr0.33NiO4 has been investigated using neutron powder diffraction. We report an anomalous shrinking of the c/a lattice parameter ratio that correlates with T(CO). The sign of this change can be explained by the change in interlayer Coulomb energy between the static-stripe-ordered state and the fluctuating-stripe-ordered state or the charge-disordered state. In addition, we identify a contribution to the mean-square displacements of Ni and in-plane O atoms whose width correlates quite well with the size of the pseudogap extracted from the reported optical conductivity, with a non-Debye-like component that persists below and well above T(CO). We infer that dynamic charge-stripe correlations survive to T∼2T(CO).

Ferromagnetic exchange anisotropy from antiferromagnetic superexchange in the mixed 3d-5d transition-metal compound Sr3CuIrO6.

We report a combined experimental and theoretical study of the unusual ferromagnetism in the one-dimensional copper-iridium oxide Sr(3)CuIrO(6). Utilizing Ir L(3) edge resonant inelastic x-ray scattering, we reveal a large gap magnetic excitation spectrum. We find that it is caused by an unusual exchange anisotropy generating mechanism, namely, strong ferromagnetic anisotropy arising from antiferromagnetic superexchange, driven by the alternating strong and weak spin-orbit coupling on the 5d Ir and 3d Cu magnetic ions, respectively. From symmetry consideration, this novel mechanism is generally present in systems with edge-sharing Cu(2+)O(4) plaquettes and Ir(4+)O(6) octahedra. Our results point to unusual magnetic behavior to be expected in mixed 3d-5d transition-metal compounds via exchange pathways that are absent in pure 3d or 5d compounds.

Hepatitis B virus induces expression of cholesterol metabolism-related genes via TLR2 in HepG2 cells.

AIM: To investigate whether hepatitis B virus (HBV) exacerbates hepatic cholesterol accumulation, and explore the underlying mechanisms. METHODS: HepG2 cells were infected with adenovirus (Ad) containing 1.3-fold overlength HBV genome. Real-time polymerase chain reaction and Western blotting were used to measure mRNA and protein expression of target genes. Cholesterol accumulation was measured by fluorescence microscopy. Cell toxicity due to Ad-HBV treatment was determined by the mitochondrial tetrazolium assay. The protein levels of toll-like receptors (TLRs) were determined by Western blotting. RESULTS: Ad-HBV increased hepatic cholesterol accumulation and enhanced the mRNA and protein levels of low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methylglutharyl-coenzyme A reductase (HMGCoAr) mRNA and protein expression in HepG2 cells. In addition, these inductive effects were partly offset by suppressing TLR2 expression levels by small interfering RNA in HepG2 cells. CONCLUSION: Ad-HBV increases LDLR and HMGCoAr expression, resulting in exacerbated cholesterol accumulation in HepG2 cells, which was mediated via the TLR2 pathway.

Testing the validity of the strong spin-orbit-coupling limit for octahedrally coordinated iridate compounds in a model system Sr3CuIrO6.

The electronic structure of Sr3CuIrO6, a model system for the 5d Ir ion in an octahedral environment, is studied through a combination of resonant inelastic x-ray scattering and theoretical calculations. Resonant inelastic x-ray scattering spectra at the Ir L3 edge reveal an Ir t(2g) manifold that is split into three levels, in contrast to the expectations of the strong spin-orbit-coupling limit. Effective Hamiltonian and ab inito quantum chemistry calculations find a strikingly large noncubic crystal field splitting comparable to the spin-orbit coupling, which results in a strong mixing of the j(eff)=1/2 and j(eff)=3/2 states and modifies the isotropic wave functions on which many theoretical models are based.

One-Fe versus two-Fe Brillouin zone of Fe-based superconductors: creation of the electron pockets by translational symmetry breaking.

We investigate the physical effects of translational symmetry breaking in Fe-based high-temperature superconductors due to alternating anion positions. In the representative parent compounds, including the newly discovered Fe-vacancy-ordered K(0.8)Fe(1.6)Se(2), an unusual change of orbital character is found across the one-Fe Brillouin zone upon unfolding the first-principles band structure and Fermi surfaces, suggesting that covering a larger one-Fe Brillouin zone is necessary in experiments. Most significantly, the electron pockets (critical to the magnetism and superconductivity) are found only created with broken symmetry, advocating strongly its full inclusion in future studies, particularly on the debated nodal structures of the superconducting order parameter.

Unified picture for magnetic correlations in iron-based superconductors.

The varying metallic antiferromagnetic correlations observed in iron-based superconductors are unified in a model consisting of both itinerant electrons and localized spins. The decisive factor is found to be the sensitive competition between the superexchange antiferromagnetism and the orbital-degenerate double-exchange ferromagnetism. Our results reveal the crucial role of Hund's rule coupling for the strongly correlated nature of the system and suggest that the iron-based superconductors are closer kin to manganites than cuprates in terms of their diverse magnetism and incoherent normal-state electron transport. This unified picture would be instrumental for exploring other exotic properties and the mechanism of superconductivity in this new class of superconductors.

Ferro-orbital order and strong magnetic anisotropy in the parent compounds of iron-pnictide superconductors.

The puzzling nature of magnetic and lattice phase transitions of iron pnictides is investigated via a first-principles Wannier function analysis of representative parent compound LaOFeAs. A rare ferro-orbital ordering is found to give rise to the recently observed highly anisotropic magnetic coupling, and drive both phase transitions--without resorting to widely employed frustration or nesting picture. The revealed necessity of the additional orbital physics leads to a correlated electronic structure fundamentally distinct from that of the cuprates. In particular, the strong coupling to the magnons advocates active roles of light orbitons in spin dynamics and electron pairing in iron pnictides.

Orbital ordering in LaMnO3 : electron-electron versus electron-lattice interactions.

The relative importance of electron-lattice (e-l) and electron-electron (e-e) interactions in ordering orbitals in LaMnO3 is systematically examined within the local-density approximation + Hubbard U approximation of density functional theory. A realistic effective Hamiltonian is derived from novel Wannier state analysis of the electronic structure. Surprisingly, e-l interaction (approximately or = 0.9 eV) alone is found insufficient to stabilize the orbital ordered state. On the other hand, e-e interaction (approximately or = 1.7 eV) not only induces orbital ordering, but also greatly facilitates the Jahn-Teller distortion via enhanced localization. Further experimental means to quantify the competition between these two mechanisms are proposed.

Coexistence of gapless excitations and commensurate charge-density wave in the 2H transition metal dichalcogenides.

An unexpected feature common to 2H transition metal dichalcogenides ( 2H TMDs) is revealed with a first-principles Wannier function analysis of the electronic structure of the prototype 2H TaSe2: The low-energy Ta "5d(z2)" bands governing the physics of a charge-density wave (CDW) is dominated by hopping between next-nearest neighbors. With this motivation we develop a minimal effective model for the CDW formation, in which the unusual form of the hopping leads to an approximate decoupling of the three sublattices. In the CDW phase one sublattice remains undistorted, leaving the bands associated with it ungapped everywhere in the Fermi surface, resolving the long-standing puzzle of the coexistence of gapless excitations and commensurate CDW in the 2H TMDs.