Vav1 inhibits RANKL-induced osteoclast differentiation and bone resorption

Vav1 is a Rho/Rac guanine nucleotide exchange factor primarily expressed in hematopoietic cells. In this study, we investigated the potential role of Vav1 in osteoclast (OC) differentiation by comparing the ability of bone marrow mononuclear cells (BMMCs) obtained from Vav1-deficient (Vav1−/−) and wild-type (WT) mice to differentiate into mature OCs upon stimulation with macrophage colony stimulating factor and receptor activator of nuclear kappa B ligand in vitro. Our results suggested that Vav1 deficiency promoted the differentiation of BMMCs into OCs, as indicated by the increased expression of tartrate-resistant acid phosphatase, cathepsin K, and calcitonin receptor. Therefore, Vav1 may play a negative role in OC differentiation. This hypothesis was supported by the observation of more OCs in the femurs of Vav1−/− mice than in WT mice. Furthermore, the bone status of Vav1−/− mice was analyzed in situ and the femurs of Vav1−/− mice appeared abnormal, with poor bone density and fewer number of trabeculae. In addition, Vav1-deficient OCs showed stronger adhesion to vitronectin, an αvβ3 integrin ligand important in bone resorption. Thus, Vav1 may inhibit OC differentiation and protect against bone resorption

Angiopoietin-1 is an apoptosis survival factor for endothelial cells

AbstractWe examined the effect of angiopoietin-1 (Ang1) on apoptosis in human umbilical vein endothelial cells (HUVECs). Ang1 (5–1000 ng/ml) dose-dependently inhibited apoptosis under a serum-deprived state. A significant apoptotic inhibition occurred with as low as 50 ng/ml. Two hundred ng/ml of Ang1 inhibited to approximately 50% of the control apoptotic rates for 96 h. Furthermore, an augmented antiapoptotic effect of Ang1 by the addition of 20 ng/ml vascular endothelial growth factor was observed. This Ang1-induced strong antiapoptotic effect in endothelial cells is a novel and intriguing finding and could be an additional description of Ang1-induced direct biological function

Catalyst design, measurement guidelines, and device integration for H2O2 electrosynthesis from oxygen reduction

The electrosynthesis of H2O2 via a two-electron pathway oxygen reduction reaction (2e??? ORR) has emerged as a promising way of carbon-free and on-site production of H2O2. Active and selective electrocatalysts for the 2e??? ORR are essential for achieving high O2-to-H2O2 conversion efficiency. In this review, we present the recent progress in the development of 2e??? ORR electrocatalysts including Pt-group-metal (PGM) and non-PGM atomically dispersed catalysts and metal-free heteroatom-doped carbons. The impact of the active sites and interface structures on the electrocatalytic process is summarized. Benchmarking of the electrocatalytic activities in terms of O2-to-H2O2 mass activity and site-normalized activity is presented to understand the current status of advancement and to provide an insight into possible future research directions. In addition, some guidelines and pitfalls in typical laboratory measurements for assessing 2e??? ORR performance are proposed. Finally, recent advances in high-current-density H2O2 electrosynthesis reactors and devices that exploit electrosynthesized H2O2 are introduced

Spin reorientation in FeCrAs revealed by single-crystal neutron diffraction

The magnetic structure of the "nonmetallic metal" FeCrAs, a compound with the characters of both metals and insulators, was examined as a function of temperature using single-crystal neutron diffraction. The magnetic propagation vector was found to be $\mathit{k}$ = (1/3, 1/3, 0), and the magnetic reflections disppeared above $\mathit{T_{N}}$ = 116(1) K. In the ground state, the Cr sublattice shows an in-plane spiral antiferromagnetic order. The moment sizes of the Cr ions were found to be small, due to strong magnetic frustration in the distorted Kagome lattice or the itinerant nature of the Cr magnetism, and vary between 0.8 and 1.4 $\mu_{B}$ on different sites as expected for a spin-density-wave (SDW) type order. The upper limit of the moment on the Fe sublattice is estimated to be less than 0.1 $\mu_{B}$. With increasing temperature up to 95 K, the Cr moments cant out of the $\mathit{ab}$ plane gradually, with the in-plane components being suppressed and the out-of-plane components increasing in contrast. This spin-reorientation of Cr moments can explain the dip in the $\mathit{c}$-direction magnetic susceptibility and the kink in the magnetic order parameter at $\mathit{T_{O}}$ ~ 100 K, a second magnetic transition which was unexplained before. We have also discussed the similarity between FeCrAs and the model itinerant magnet Cr, which exhibits spin-flip transitions and SDW-type antiferromagnetism.Comment: 8 pages, 7 figures, Accepted by Phys. Rev.

Egy tanúságtevő hitvalló, szolgáló, tudományos és papi pálya lezárult

Passed a Wittness of the Faith, Scientist, a Servant of The Lord, True Priest: Nicefor Petrashevich (1915–2013), canon of the Preshov Greek Catholic Eparchy. Abstract Decease of the witness of the Faith, a servant of the Lord and a famous researcher of the religious folklore: Nicefor Joseph Petrashevich (1915–2013) distinguished member of the Capitol of Preshov Greek Catholic Eparchy. Born in Čukalovce, East-Slovakia (then Csukalóc, Upper-Hungary) in 1915 as the sixth of the eleven children in the family of a Greek Catholic bishop, he was inspired by his father and elder brother who served the Lord. He studied in the high school (gymnasium) of the Cistercian Order in Eger (Northern Hungary) which provided its pupils with knowledge and deep faith. He became a choir-minister of the Uzghorod Bishopric Basilica where he turned to the examination of folklore traditions reflected in the liturgical chants. Apparently, it was his calling and his findings on the Byzantine chants contributed significantly to the understanding of religious folklore. He was known as a gift ed composer and singer, too. The Greek Catholic Church was banned in the Soviet Union which obtained Subcarpathia after the World War II, and this church was oppressed in Slovakia as well, so he faced a dilemma: to convert to the Ortodox (Pravoslav) Christianity and live free, or to remain faithful to the Catholic Church and be persecuted. Moreover, he was a coelebs, a priest who did not have a wife (despite the fact that Greek Catholic priests are allowed to have families). Consequently, he could have been elected as bishop, as the higher ranks in the Byzantine Churches are open for monks. The communist authorities offered Father Nicefor the episcopate of the Slovak Ortodox Church, if he converted to the Ortodoxy. He refused it: “my head does not accept the mithra (bishops’ crone) by leaving my Catholic faith” –he said. As a result, he was imprisoned for more than two years in Slovakia. Later he came to Hungary where could not serve as a parochial priest, but worked as cantor or helping pope in various places and in centres of pilgrimage where performed the liturgy in Church Slavonic which he sang excellently. Continuing his researches in the folk sings in the liturgy and the local traditions of the liturgical chants, he gained a small grant of the Soros Foundation in 1986 and delivered lectures for two semesters at the Department of the Folklore at the Eötvös University in Budapest in 1988–89. His papers have been partially published, but most of them are still preserved as manuscripts in the Institute of Musicology at the Hungarian Academy of Sciences, or even in unknown places worldwide, as he sent his works to his brothers-in-faith to the United States. In his eighties, instead of enjoying the golden days of ageing, he moved to Slovakia in order to serve as a pastor who spoke both Slovakian and Hungarian as mother tongues. He was buried in Szikszó, Hungary where the Greek Catholic Bishop of Preshov and approximately forty popes from Ukraine, Hungary and Slovakia commemorated him on 20 July 2013. Church historians and folklorists honored his memory as a researcher with a conference on 4 October 2013 in Szikszó. Proceedings are to be published next year. A memorial website about him is open for bloggers

Antiretroviral Genotypic Resistance Mutations in HIV-1 Infected Korean Patients with Virologic Failure

Resistance assays are useful in guiding decisions for patients experiencing virologic failure (VF) during highly-active antiretroviral therapy (HAART). We investigated antiretroviral resistance mutations in 41 Korean human immunodeficiency virus type 1 (HIV-1) infected patients with VF and observed immunologic/virologic response 6 months after HAART regimen change. Mean HAART duration prior to resistance assay was 45.3±27.5 months and commonly prescribed HAART regimens were zidovudine/lamivudine/nelfinavir (22.0%) and zidovudine/lamivudine/efavirenz (19.5%). Forty patients (97.6%) revealed intermediate to high-level resistance to equal or more than 2 antiretroviral drugs among prescribed HAART regimen. M184V/I mutation was observed in 36 patients (87.7%) followed by T215Y/F (41.5%) and M46I/L (34%). Six months after resistance assay and HAART regimen change, median CD4+ T cell count increased from 168 cells/µL (interquartile range [IQR], 62-253) to 276 cells/µL (IQR, 153-381) and log viral load decreased from 4.65 copies/mL (IQR, 4.18-5.00) to 1.91 copies/mL (IQR, 1.10-3.60) (P<0.001 for both values). The number of patients who accomplished viral load <400 copies/mL was 26 (63.4%) at 6 months follow-up. In conclusion, many Korean HIV-1 infected patients with VF are harboring strains with multiple resistance mutations and immunologic/virologic parameters are improved significantly after genotypic resistance assay and HAART regimen change