Osteopontin and its receptor alphavbeta(3) integrin are coexpressed in the human endometrium during the menstrual cycle but regulated differentially

Osteopontin is an arginine-glycine-aspartic acid-containing acidic glycoprotein component of the extracellular matrix that is postulated to bind to integrin receptors at the cell surface to mediate cellular adhesion and migration during embryo implantation. The primary aim of this study was to examine the uterine expression of osteopontin throughout the menstrual cycle in normal fertile controls sampled prospectively based on urinary LH surge detection. Expression of osteopontin was documented using Northern blot analysis, in situ hybridization, and immunohistochemistry. Furthermore, the temporal pattern of osteopontin expression was compared with that of its receptor, the alphavbeta3 integrin. Using Ishikawa cells, a well differentiated endometrial adenocarcinoma cell line, the in vitro regulation of osteopontin and its receptor alphavbeta3 integrin was studied. By Northern blot analysis, osteopontin mRNA appears during the early secretory phase, with maximal expression occurring in mid to late secretory-phase endometrium. The in situ hybridization analyses showed that osteopontin mRNA specifically localized in epithelial cells within the endometrium. Immunostaining of osteopontin was detected in the glandular secretions and on the apical portions of surface (luminal) epithelium. The patterns of expression of osteopontin by Northern blotting, in situ hybridization, and immunohistochemistry are remarkably similar to the pattern for the alphavbeta3 integrin. Despite these similarities in distribution, in vitro studies demonstrate that osteopontin and beta3 integrin subunit expression are differentially regulated. The expression of osteopontin was primarily induced in response to progesterone, whereas the beta3 integrin subunit was up-regulated by epidermal growth factor or heparin-binding epidermal growth factor. The differential regulation of these two endometrial proteins suggests the existence of two separate pathways regulating epithelial gene expression in human endometrium during the window of implantation. In adhesion assays using Ishikawa cells, alphavbeta3 but not alphavbeta5 or beta1 integrins appear to be the primary receptors for osteopontin. These findings may better define the factors that favor the development of a receptive endometrium.     

Acute myelofibrosis. A report of four cases and review of the literature

Four new cases of acute myelofibrosis are reported, and 63 cases reported in the literature are reviewed. The typical features of this disease include a rapidly progressive clinical course; nonspecific symptoms such as weight loss, anorexia, fatigue and weakness; the absence of organomegaly; pancytopenia; circulating blast cells; and mild abnormalities in the red blood cell morphology. The bone marrow aspirates are usually "dry." The bone marrow biopsies are essential for the diagnosis and show four consistent features: hypercellularity, reticulin fibrosis, proliferation of blast cells and bizarre, atypical megakaryocytes. In 16 cases, the blast cells in peripheral blood and bone marrow, which are unclassifiable by conventional morphology, could be identified as megakaryoblasts by ultrastructural and immunocytochemical techniques. It is concluded that acute myelofibrosis is a definite clinicopathologic entity, which may be related to acute megakaryoblastic leukemia.     

Inversion domain boundaries in MoSe2 layers

Structural defects, including point defects, dislocation and planar defects, significantly affect the physical and chemical properties of low-dimensional materials, such as layered compounds. In particular, inversion domain boundary is an intrinsic defect surrounded by a 60° grain boundary, which significantly influences electronic transport properties. We study atomic structures of the inversion domain grain boundaries (IDBs) in layered transition metal dichalcogenides (MoSe₂ and MoS₂) obtained by an exfoliation method, based on the aberration-corrected scanning transmission electron microscopy observation and density functional theory (DFT) calculation. The atomic-scale observation shows that the grain boundaries consist of two different types of 4-fold ring point shared and 8-fold ring edge shared chains. The results of DFT calculations indicate that the inversion domain grain boundary behaves as a metallic one-dimensional chain embedded in the semiconducting MoSe₂ matrix with the occurrence of a new state within the band gap.

Structural defects, including point defects, dislocation and planar defects, significantly affect the physical and chemical properties of low-dimensional materials, such as layered compounds.     

Graphene Oxide-Induced Protein Conformational Change in Nasopharyngeal Carcinoma Cells: A Joint Research on Cytotoxicity and Photon Therapy

The objectives of this work aim to investigate the interaction and cytotoxicity between nanometric graphene oxide (GO) and nasopharyngeal carcinoma cells (NPC-BM1), and possible application in photon therapy. GO nanosheets were obtained in the size range of 100–200 nm, with a negative surface charge. This nanometric GO exhibited a limited (<10%) cytotoxicity effect and no significant dimensional change on NPC-BM1 cells in the tested GO concentration range (0.1–10 µg·mL⁻¹). However, the secondary protein structure was modified in the GO-treated NPC-BM1 cells, as determined through synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIRM) mapping. To further study the cellular response of GO-treated NPC-BM1 cancer cells at low GO concentration (0.1 µg·mL⁻¹), photon radiation was applied with increasing doses, ranging from 2 to 8 Gy. The low radiation energy (<5 Gy) did not cause significant cell mortality (5–7%). Increasing the radiation energy to 6–8 Gy accelerated cell apoptosis rate, especially in the GO-treated NPC-BM1 cells (27%). This necrosis may be due to GO-induced conformational changes in protein and DNA/RNA, resulting in cell vulnerability under photon radiation. The findings of the present work demonstrate the potential biological applicability of nanometric GO in different areas, such as targeted drug delivery, cellular imaging, and radiotherapy, etc.     

Charge-induced electromechanical actuation of Mo- and W-dichalcogenide monolayers

Using first-principle density functional calculations, we investigate electromechanical properties of two-dimensional MX₂ (M = Mo, W; X = S, Se, Te) monolayers with the 1H and 1T structures as a function of charge doping for both electron and hole doping. We find that by increasing the atomic number, Z_X, of X atoms (Z_S < Z_Se < Z_Te), the work density per cycle of the MX₂ monolayers are increased and decreased for the 1H and 1T structures, respectively. On the other hand, the work density per cycle of the WX₂ monolayers are higher than that of the MoX₂ monolayers for both the 1H and 1T structures. Therefore, WTe₂ and WS₂ monolayers for the 1H and 1T structures, respectively, have the best electromechanical performances in the MX₂ compounds. In addition, the MX₂ monolayers show a reversible strain up to 3%, which is higher than that of graphene (∼1%). Our results provide an important insight into the electromechanical properties of the MX₂ monolayers, which are useful for artificial muscles applications.

Using first-principle density functional calculations, we investigate electromechanical properties of two-dimensional MX₂ (M = Mo, W; X = S, Se, Te) monolayers with the 1H and 1T structures as a function of charge doping for both electron and hole doping.