Prevalence of A2143G mutation of H. pylori-23S rRNA in Chinese subjects with and without clarithromycin use history

<p>Abstract</p> <p>Background</p> <p>A2143G mutation of <it>23S rRNA </it>gene of <it>H. pylori </it>results in clarithromycin (CLR) resistance. To investigate the prevalence of the CLR resistance-related A2143G mutation of the <it>H. pylori</it>-specific <it>23S rRNA </it>gene in Chinese subjects with and without CLR use history, 307 subjects received the treatment with amoxicillin and omeprazole (OA) and 310 subjects received a placebo in 1995, and 153 subjects received a triple therapy with OA and CLR (OAC) in 2000. DNA was extracted from fasting gastric juice at the end of the intervention trial in 2003. <it>H. pylori </it>infection was determined by <it>H. pylori</it>-specific <it>23S rRNA </it>PCR, ELISA, and¹³C-urea breath test assays. Mutations of the <it>23S rRNA </it>gene were detected by RFLP assays.</p> <p>Results</p> <p>The presence of <it>23S rRNA </it>due to <it>H. pylori </it>infection in the OA group remained lower than that in the placebo group 7.3 yrs after OA-therapy [51.1% (157/307) vs. 83.9% (260/310), p = 0.0000]. In the OAC group, the <it>23S rRNA </it>detection rate was 26.8% (41/153) three yrs after OAC-treatment. The A2143G mutation rate among the <it>23S rRNA</it>-positive subjects in the OAC group [31.7% (13/41)] was significantly higher than that in the OA group [10.2% (16/157)] and the placebo group [13.8% (36/260)]. The frequency of the AAGGG → CTTCA (2222–2226) and AACC → GAAG (2081–2084) sequence alterations in the OAC group was also significantly higher than those in the OA group and the placebo group.</p> <p>Conclusion</p> <p>Primary prevalence of the A2143G mutation was 10~14% among Chinese population without history of CLR therapy. Administration of CLR to eliminate <it>H. pylori </it>infection increased the prevalence of the A2143G mutation in Chinese subjects (32%) significantly.</p

MicroRNA-145 Regulates Chondrogenic Differentiation of Mesenchymal Stem Cells by Targeting Sox9

Chondrogenic differentiation of mesenchymal stem cells (MSCs) is accurately regulated by essential transcription factors and signaling cascades. However, the precise mechanisms involved in this process still remain to be defined. MicroRNAs (miRNAs) regulate various biological processes by binding target mRNA to attenuate protein synthesis. To investigate the mechanisms for miRNAs-mediated regulation of chondrogenic differentiation, we identified that miR-145 was decreased during transforming growth factor beta 3 (TGF-β3)-induced chondrogenic differentiation of murine MSCs. Subsequently, dual-luciferase reporter gene assay data demonstrated that miR-145 targets a putative binding site in the 3′-UTR of SRY-related high mobility group-Box gene 9 (Sox9) gene, the key transcription factor for chondrogenesis. In addition, over-expression of miR-145 decreased expression of Sox9 only at protein levels and miR-145 inhibition significantly elevated Sox9 protein levels. Furthermore, over-expression of miR-145 decreased mRNA levels for three chondrogenic marker genes, type II collagen (Col2a1), aggrecan (Agc1), cartilage oligomeric matrix protein (COMP), type IX collagen (Col9a2) and type XI collagen (Col11a1) in C3H10T1/2 cells induced by TGF-β3, whereas anti-miR-145 inhibitor increased the expression of these chondrogenic marker genes. Thus, our studies demonstrated that miR-145 is a key negative regulator of chondrogenic differentiation by directly targeting Sox9 at early stage of chondrogenic differentiation

Electromagnetic Field Representations in Uniaxial Bianisotropic-Semiconductor Material by Cylindrical Vector Wave Functions

Uniaxial bianisotropic-semiconductor material is a generalization of the well-studied semiconductor material and uniaxial medium. It could be realized by arranging chiral objects in a host semiconductor medium, with a preferred direction. This class of material probably opens up the opportunity to realize artificial intelligence in living organisms. In the present study, based on the concept of characteristic waves and the method of angular spectral expansion, electromagnetic field representations in this class of materials are developed. The analysis indicates that solutions of source-free Maxwell equations for uniaxial bianisotropic-semiconductor material can be represented in sum-integral forms of cylindrical vector wave functions. Addition theorem of vector wave functions for uniaxial bianisotropic-semiconductor material can be straightforwardly derived from that of vector wave functions for isotropic medium. An application of the proposed theory in scattering is presented to show how to use these formulations in a practical way

Green Dyadics in Composite Chiral-Ferrite Medium by Cylindrical Vector Wave Functions

Composite chiral-ferrite medium, which is a generalization of the well-studied chiral medium, has potential application in chirality management. In the present investigation, based on the concept of spectrl eigenwaves, eigenfunction expansion of the Green dyadics in an unbounded composite chiral-ferrite medium is developed in the forms of the cylindrical vector wave functions. The formulations are considerably simplified by analytically evaluating the integrals with respect to the spectral longitudinal and radial wevenumbers, respectively. The analysis indicates that the solutions of the source-incorporated Maxwell's equations for a homogeneous composite chiral-ferrite medium, which can be represented in sum-integral forms of the cylindrical vector wave functions, are composed of two (or four) eigenwaves travelling with different wavenumbers. Each of these eigenwaves is a superposition of two transverse waves and a longitudinal wave. The Green dyadics of planarly and cylindrically multilayered structures consisting of composite chiral-ferrite media can be straightforwardly obtained by applying the method of scattering superposition and appropriate boundary conditions, respectively. The present formulations, which can be theoretically verified by comparing their special forms with the already existed results, provide fundamental basis to analyze the physical phenomena of the composite chiral-ferrite media

The effect of secure attachment state and infant facial expressions on childless adults’ parental motivation

This study examined the association between infant facial expressions and parental motivation as well as the interaction between attachment state and expressions. Two-hundred eighteen childless adults (Mage=19.22, 118 males, 100 females) were recruited. Participants completed the Chinese version of the State Adult Attachment Measure and the E-prime test, which comprised three components a) liking, the specific hedonic experience in reaction to laughing, neutral, and crying infant faces; b) representational responding, actively seeking infant faces with specific expressions; and c) evoked responding, actively retaining images of three different infant facial expressions. While the first component refers to the liking of infants, the second and third components entail the wanting of an infant. Random intercepts multilevel models with emotion nested within participants revealed a significant interaction between secure attachment state and emotion on both liking and representational response. A hierarchical regression analysis was conducted to examine the unique contributions of secure attachment state. Findings demonstrated that, after controlling for sex, anxious, and avoidant, secure attachment state positively predicted parental motivations (liking and wanting) in the neutral and crying conditions, but not the laughing condition. These findings demonstrate the significant role of secure attachment state in parental motivation, specifically when infants display uncertain and negative emotions

Spectral impedance boundary condition (SIBC) method for a spherical perfect electric conductor (PEC) with an uniform biisotropic coating

An analysis for electromagnetic response of a PEC of spherical shape having an uniform concentrical coating of biisotropic medium is rigorously formulated by constructing spherical vector wavefunctions. For the prescribed radius and thickness of the coating, an anisotropic impedance boundary condition at the outer surface of the coating is developed in the spectral domain, which is useful for solving the scattering problem of the biisotropically coated spherical PEC structure