CpG island evolution in the mammalian DHRS4 gene cluster and its role in the regulation of gene transcription.

The dehydrogenase/reductase (SDR family) member 4 (DHRS4) gene is copied during mammalian evolution; therefore, while only one DHRS4 gene is expressed in the mouse genome, the gene cluster consists of two (DHRS4 and DHRS4L1) and three (DHRS4, DHRS4L2, and DHRS4L1) copies in chimpanzees and humans, respectively. In this study, we explored the possible regulatory mechanism of the DHRS4 gene cluster in mammalian evolution by analyzing the promoter sequence, methylation of CpG islands, and RNA expression of the DHRS4 gene cluster in mice, chimpanzees, and humans by bioinformatics prediction, bisulfite sequencing PCR, and real-time reverse transcriptase-PCR. The results indicated that the DHRS4 gene was actively expressed in the three model species. The RNA level of DHRS4L1 was much lower than those of DHRS4 and DHRS4L2, and expressed lower homologous sequence identity to DHRS4 and DHRS4L2. DHRS4L2, the latest evolutionary copy of the DHRS4 gene in mammals, received a high promoter prediction score, and was the only copy of the DHRS4 gene cluster presenting hypermethylated CpG islands in the promoter region. An analysis of the relationship between the promoter characteristics and RNA expression of the DHRS4 gene cluster indicated that the development of CpG islands, in addition to the promoter sequence, during mammalian evolution could modulate the dose compensatory regulation of the copy number-varied DHRS4 gene cluster.

Investigating the recheck rules for urine analysis in children.

The aim of this study was to establish recheck rules of urinalysis in children by investigating the concordance rate of the results obtained using the LabUMat urine dry chemistry analyzer (referred to as dry chemistry) and the UriSed tangible composition analyzer with that of the microscopic examination. First, 1040 urine samples from children (mean age 6.5 years) were analyzed using LabUMat and UriSed analyzers, and subsequently subjected to microscopic examination. The missed detection rate was evaluated and recheck rules were established to avoid missed diagnoses of abnormal renal function. Finally, clinical validations of the recheck rules were performed on 200 additional specimens. Among the samples used to investigate the recheck rules, the samples with positive microscopic examination results accounted for 58.65% of the total, while the samples with negative results accounted for 41.35%. Of the positive samples, a major portion (>50%) were RBC positive. The samples that were WBC positive and CAST positive accounted for 23.08 and 7.69%, respectively. The concordance rate was 87.5% and the missed detection rate was 2.9%. For the validation of the recheck rules in 200 urine samples, the concordance rate was 87.5% and the missed detection rate was 2.4%. When the detection of occult blood, WBC, and protein by dry chemistry, and the detection of RBC, WBC, and CAST by the UriSed analyzer are inconsistent, or the differences between them greater than 2 levels, recheck by microscopic examination is suggested.

Weak cation magnetic separation technology and MALDI-TOF-MS in screening serum protein markers in primary type I osteoporosis.

We investigated weak cation magnetic separation technology and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in screening serum protein markers of primary type I osteoporosis. We selected 16 postmenopausal women with osteoporosis and nine postmenopausal women as controls to find a new method for screening biomarkers and establishing a diagnostic model for primary type I osteoporosis. Serum samples were obtained from controls and patients. Serum protein was extracted with the WCX protein chip system; protein fingerprints were examined using MALDI-TOF-MS. The preprocessed and model construction data were handled by the ProteinChip system. The diagnostic models were established using a genetic arithmetic model combined with a support vector machine (SVM). The SVM model with the highest Youden index was selected. Combinations with the highest accuracy in distinguishing different groups of data were selected as potential biomarkers. From the two groups of serum proteins, 123 cumulative MS protein peaks were selected. Significant intensity differences in the protein peaks of 16 postmenopausal women with osteoporosis were screened. The difference in Youden index between the four groups of protein peaks showed that the highest peaks had mass-to-charge ratios of 8909.047, 8690.658, 13745.48, and 15114.52. A diagnosis model was established with these four markers as the candidates, and the model specificity and sensitivity were found to be 100%. Two groups of specimens in the SVM results on the scatterplot were distinguishable. We established a diagnosis model, and provided a new serological method for screening and diagnosis of osteoporosis with high sensitivity and specificity.

Opg/Rankl mRNA dynamic expression in the bone tissue of ovariectomized rats with osteoporosis.

We established animal models of osteoporosis in ovariectomized rats to detect osteoprogerin (Opg)/receptor activator of nuclear factor-κB ligand (Rankl) mRNA expression levels in the tibias and serum estradiol concentrations at different time points. Sixty Sprague-Dawley female rats were randomly selected and divided into an ovariectomized (OVX) group and sham-operated (SHAM) group. In the SHAM group, only a small amount of abdominal fat and tissues was removed from the rats. Ten rats in each group were sacrificed at 0, 6, and 12 months after establishing the animal models (12 weeks). Opg mRNA expression and serum estradiol concentration in the OVX group were significantly lower than those in the SHAM group (P < 0.05). In contrast, Rankl mRNA expression in the OVX group was significantly higher than that in the SHAM group (P < 0.05). In the OVX group, Opg mRNA expression and serum estradiol concentrations decreased significantly from 0 to 12 months (P < 0.05), whereas Rankl mRNA expression increased significantly (P < 0.05). Opg mRNA expression and serum estradiol concentrations in the OVX group continually decreased, whereas Rankl mRNA expression continually increased. The Opg/Rankl ratio showed a decrease. The OPG/RANKL ratio may be a key factor affecting the osteoblast-mediated reaction.

Effects of autologous SCF- and G-CSF-mobilized bone marrow stem cells on hypoxia-inducible factor-1 in rats with ischemia-reperfusion renal injury.

To explore the mechanism whereby stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) jointly mobilize bone marrow stem cells (BMSCs) and promote kidney repair, male Sprague-Dawley rats were randomly assigned into 4 groups. In the treatment control group, rats were administered SCF (200 µg·kg(-1)·day(-1)) and G-CSF (50 µg·kg-1·day-1) for 5 days. In the treatment group, RIRI models were established, and 6 h later, SCF (200 µg·kg(-1)·day(-1)) and G-CSF (50 µg·kg(-1)·day(-1)) were administered for 5 days. In the model and treatment groups, tubular epithelial cell degeneration and necrosis were noticed, but the extent of repair in the treatment group was significantly better than in the model group. Five days after the operation, renal tissue CD34+ cells significantly increased in the model and treatment groups compared with the control and treatment control groups. HIF-1α, VEGF, and EPO expression in treatment groups increased significantly compared with the other groups. HIF- 1α, VEGF, EPO expression in the treatment control group increased significantly compared with the control group. Joint use of SCF and G-CSF increased the number of BMSCs in damaged kidney tissue and reduced the degree of renal tissue damage. BMSCs promote increased HIF-1α expression in renal tissue. Increased kidney tissue HIF- 1α and its target gene products VEGF and EPO expression possibly induce SCF and G-CSF to promote acute tubular necrosis repair.

Kill curve analysis and response of first generation Capsicum annuum L. B12 cultivar to ethyl methane sulfonate.

Pepper seeds (Capsicum annuum L.) var. B12 were mutagenized by four presoaking treatments in ten concentrations of ethyl methane sulfonate (EMS) to determine the sensitivity of the first generation (M1) to mutagens. The spectrum of mutations and induced variability for various quantitative traits, including germination, percent plant height, injury occurrence, survival ratio, first three fruits weight, and number of seeds per first fruit, were observed in the M1 generation. Our results indicated that all of the test parameters decreased with increasing EMS concentration, except for seedling injury. There were significant differences in germination ratio, LD50, plant height, percent injury, and survival ratio among the tested presoaking treatment. The LD50 was 1% EMS in seeds that were not presoaked (T1) and seeds presoaked for 12 h before treating with EMS (T3). In contrast, the LD50 was 0.5% EMS in seeds presoaked for 6 h (T2) and seeds presoaked in water for 6 h then incubated at 28°C for 12 h before EMS treatment (T4). Five dwarf plants were observed in mutagenized seeds without presoaking as compared to control seeds (at the maturity stage of the control plant).

Association of XRCC5 polymorphisms with COPD and COPD-related phenotypes in the Han Chinese population: a case-control cohort study.

Genome-wide association studies (GWAS) and integrative genomic approaches have demonstrated significant associations between chronic obstructive pulmonary disease (COPD) and polymorphisms of the X-ray repair cross-complementing protein 5 gene (XRCC5) in non-Asian populations. We investigated whether XRCC5 polymorphisms might be associated with COPD susceptibility and COPD-related phenotypes in the Chinese Han population. Nine single nucleotide polymorphisms (SNPs) (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, rs7573191, and rs207906) in the XRCC5 gene were genotyped in a case-control study including 680 COPD patients and 687 controls. To estimate the strength of association, odds ratios (ORs) were calculated and the effects of potentially confounding variables were tested by logistic regression analysis. The association between haplotypes and COPD outcome was also assessed. Our data identified that the SNP rs207936 was associated with COPD with an adjusted P value of 0.038, which was also found when analyzing only data of current smokers (P=0.046). No significant associations were found between any of the SNPs and pulmonary function. Eight SNPs (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, and rs7573191) showed strong linkage disequilibrium (R2≥0.9). Two major haplotypes were observed and showed a significant difference between case and control groups (P=0.0054 and 0.0081, respectively). The present study showed that the XRCC5 locus might be a contributor to COPD susceptibility in the Chinese Han population.

Anisotropic Confinement, Electronic Coupling and Strain Induced Effects Detected by Valence-Band Anisotropy in Self-Assembled Quantum Dots.

A method to determine the effects of the geometry and lateral ordering on the electronic properties of an array of one-dimensional self-assembled quantum dots is discussed. A model that takes into account the valence-band anisotropic effective masses and strain effects must be used to describe the behavior of the photoluminescence emission, proposed as a clean tool for the characterization of dot anisotropy and/or inter-dot coupling. Under special growth conditions, such as substrate temperature and Arsenic background, 1D chains of In0.4Ga0.6 As quantum dots were grown by molecular beam epitaxy. Grazing-incidence X-ray diffraction measurements directly evidence the strong strain anisotropy due to the formation of quantum dot chains, probed by polarization-resolved low-temperature photoluminescence. The results are in fair good agreement with the proposed model.

Differential desensitization of A1 adenosine receptor-mediated inhibition of cardiac myocyte contractility and adenylate cyclase activity. Relation to the regulation of receptor affinity and density.

Effects of chronic exposure of cultured atrial myocytes to R-N6-(2-phenylisopropyl)-adenosine (R-PIA) on the A1 adenosine receptor-mediated inhibition of adenylate cyclase activity and myocyte contractility were examined. Chronic exposure of atrial myocytes cultured from 14-day-old chick embryos to R-PIA desensitized the myocyte to the inhibitory effects of R-PIA on contractility and adenylate cyclase activity in a time- and dose-dependent manner. Desensitization of the negative inotropic response was only partial, whereas the adenosine receptor-mediated inhibition of adenylate cyclase activity was almost completely absent after 24 hours of R-PIA (1 microM) exposure. Furthermore, the contractile response to R-PIA desensitized more slowly than the desensitization of A1 adenosine receptor-mediated inhibition of adenylate cyclase (t1/2 = 11.4 +/- 0.7 hours versus 7.5 +/- 1 hours, mean +/- SEM, n = 12 and 6, respectively). Thus, the two A1 adenosine receptor-linked functional responses desensitized differently in response to chronic exposure of the myocyte to R-PIA. Binding of the antagonist radioligand [3H]-8-cyclopentyl-1,3-dipropylxanthine [( 3H]CPX) in membranes from myocytes preexposed to R-PIA demonstrated a time-dependent decrease in receptor density without any change in the affinity for the antagonist radioligand. Computer analyses of agonist competition with [3H]CPX binding in membranes from control and R-PIA-treated myocytes revealed a conversion of the high-affinity A1 adenosine receptor to a low-affinity form such that after 24 hours of 1 microM R-PIA exposure, all of the receptors were in a low-affinity form.(ABSTRACT TRUNCATED AT 250 WORDS)