The relationship between vascular endothelial growth factor and spermatogenesis disturbance in an experimentally-induced unilateral cryptorchidism murine model

Molecular Biology Reports - This study is to explore the relationship between vascular endothelial growth factor (VEGF) and pathological changes in cryptorchidism by using murine model of...     

Excitation of Broadband Surface Plasmons with Dye Molecules

Rhodamine B and Rhodamine 6G molecules were doped in polymethyl methacrylate solution. Then a silver film on the glass substrate was spin coated with the mixed solution to get a multilayer film. Under the irradiation of a 532-nm green laser, broadband surface plasmons (SPs) on the silver film were generated due to the coupling between the broadband fluorescence and the SP modes allowed in the multilayer film. From the back focal plane image of a leakage radiation microscopy, propagation constants of SP waves at different wavelengths were derived. Numerical calculations were also carried out and were consistent with the experimental results.     

Evaluating osteochondral defect repair potential of autologous rabbit bone marrow cells on type II collagen scaffold

The feasibility of using genipin cross-linked type II collagen scaffold with rabbit bone marrow mesenchymal stem cells (RBMSCs) to repair cartilage defect was herein studied. Induction of RBMSCs into chondrocytic phenotype on type II collagen scaffold in vitro was conducted using TGF-β 3 containing medium. After 3-weeks of induction, chondrocytic behavior, including marker genes expression and specific extracellular matrix (ECM) secretion, was observed. In the in vivo evaluation experiment, the scaffolds containing RBMSCs without prior induction were autologous implanted into the articular cartilage defects made by subchondral drilling. The repairing ability was evaluated. After 2 months, chondrocyte-like cells with lacuna structure and corresponding ECM were found in the repaired sites without apparent inflammation. After 24 weeks, we could easily find cartilage structure the same with normal cartilage in the repair site. In conclusion, it was shown that the scaffolds in combination of in vivo conditions can induce RBMSCs into chondrocytes in repaired area and would be a possible method for articular cartilage repair in clinic and cartilage tissue engineering.     

Association of single-nucleotide polymorphisms in RHOB and TXNDC3 with knee osteoarthritis susceptibility: two case-control studies in East Asian populations and a meta-analysis

Introduction

Conflicting findings on the association of single nucleotide polymorphisms (SNPs) in RHOB and TXNDC3 with susceptibility to knee osteoarthritis (OA) have been reported in European Caucasians. To examine the associations of these SNPs with OA in East Asian populations and to evaluate their global significance, we conducted two case-control studies in 955 Chinese and 750 Japanese patients.

Methods

We genotyped the previously implicated SNPs rs585017 (in RHOB) and rs4720262 (in TXNDC3) in patients with primary symptomatic knee OA with radiographic confirmation and in matched control individuals, and analyzed their associations. We further conducted a meta-analysis of the study findings together with those of previously reported European studies using the DerSimonian-Laird procedure.

Results

A significant association of RHOB with knee OA was observed in male Chinese patients (P = 0.02). No significant associations were found for RHOB in any other comparisons in the East Asian populations. The association of TXNDC3 was replicated in Chinese female (P = 0.04) and Japanese (P = 0.03) patients, although none of these associations persisted after Bonferroni correction. Significant association (P = 0.02 for the allelic frequency) with nonsignificant heterogeneity was found in the East Asian replication study. No significant association was found in any comparison in the meta-analysis for all studies.

Conclusion

Our study replicates the association, previously reported in European Caucasians, of TXNDC3 with knee OA susceptibility in an East Asian population.     

Macroinvertebrate community traits and nitrate removal in stream sediments

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Kinetics of lipase-catalyzed hydrolysis of olive oil in AOT/isooctane reversed micelles

The kinetics of lipase-catalyzed hydrolysis of olive oil in AOT/isooctane reversed micellar media was studied. It was shown that the deactivation of lipase had a great influence on the reaction kinetics. Based on whether the enzyme deactivation and influences of both product and substrate on enzyme stability were included or not, four different kinetic models were established. The simulating results demonstrated that the kinetic model, which including product inhibition, enzyme deactivation and the improvements of lipase stability by both product and substrate, fit the experimental data best with an overall relative error of 4.68%.     

Solvent isotope effects on alpha-glucosidase

The solvent kinetic isotope effects (SKIE) on the yeast alpha-glucosidase-catalyzed hydrolysis of p-nitrophenyl and methyl-d-glucopyranoside were measured at 25 degrees C. With p-nitrophenyl-D-glucopyranoside (pNPG), the dependence of k(cat)/K(m) on pH (pD) revealed an unusually large (for glycohydrolases) solvent isotope effect on the pL-independent second-order rate constant, (DOD)(k(cat)/K(m)), of 1.9 (+/-0.3). The two pK(a)s characterizing the pH profile were increased in D(2)O. The shift in pK(a2) of 0.6 units is typical of acids of comparable acidity (pK(a)=6.5), but the increase in pK(a1) (=5.7) of 0.1 unit in going from H(2)O to D(2)O is unusually small. The initial velocities show substrate inhibition (K(is)/K(m) approximately 200) with a small solvent isotope effect on the inhibition constant [(DOD)K(is)=1.1 (+/-0.2)]. The solvent equilibrium isotope effects on the K(is) for the competitive inhibitors D-glucose and alpha-methyl D-glucoside are somewhat higher [(DOD)K(i)=1.5 (+/-0.1)]. Methyl glucoside is much less reactive than pNPG, with k(cat) 230 times lower and k(cat)/K(m) 5 x 10(4) times lower. The solvent isotope effect on k(cat) for this substrate [=1.11 (+/-0. 02)] is lower than that for pNPG [=1.67 (+/-0.07)], consistent with more extensive proton transfer in the transition state for the deglucosylation step than for the glucosylation step.     

Solvent isotope effects on α-glucosidase

The solvent kinetic isotope effects (SKIE) on the yeast α-glucosidase-catalyzed hydrolysis of p-nitrophenyl and methyl-d-glucopyranoside were measured at 25 °C. With p-nitrophenyl-d-glucopyranoside (pNPG), the dependence of k_cat/K_m on pH (pD) revealed an unusually large (for glycohydrolases) solvent isotope effect on the pL-independent second-order rate constant, ^DOD(k_cat/K_m), of 1.9 (±0.3). The two pK_as characterizing the pH profile were increased in D₂O. The shift in pK_a2 of 0.6 units is typical of acids of comparable acidity (pK_a=6.5), but the increase in pK_a1 (=5.7) of 0.1 unit in going from H₂O to D₂O is unusually small. The initial velocities show substrate inhibition (K_is/K_m～200) with a small solvent isotope effect on the inhibition constant [^DODK_is=1.1 (±0.2)]. The solvent equilibrium isotope effects on the K_is for the competitive inhibitors d-glucose and α-methyl d-glucoside are somewhat higher [^DODK_i=1.5 (±0.1)]. Methyl glucoside is much less reactive than pNPG, with k_cat 230 times lower and k_cat/K_m 5×10⁴ times lower. The solvent isotope effect on k_cat for this substrate [=1.11 (±0. 02)] is lower than that for pNPG [=1.67 (±0.07)], consistent with more extensive proton transfer in the transition state for the deglucosylation step than for the glucosylation step.