Taurine reduces ammonia- and N-methyl-D-aspartate-induced accumulation of cyclic GMP and hydroxyl radicals in microdialysates of the rat striatum

Acute ammonia neurotoxicity caused by intraperitoneal administration of ammonium salts is mediated by overactivation of N-methyl-D-aspartate (NMDA) receptors, with ensuing generation of free radicals and extracellular accumulation of cyclic GMP (cGMP) arising from stimulation of nitric oxide (NO) synthesis. In this study, infusion of ammonium chloride or NMDA into the striata of rats via microdialysis probes increased the contents of cyclic GMP and hydroxyl radicals in the microdialysates. Co-infusion of taurine virtually abolished both the ammonia- and NMDA-induced accumulation of cGMP. Taurine also attenuated accumulation of hydroxyl radicals evoked by either treatment. This result is the first evidence of a potential of taurine to attenuate the effects of NMDA receptor overactivation by ammonia in vivo and points to the inhibition of the NMDA receptor-mediated NO synthesis as a possible mechanism of its neuroprotective action. Taurine or its blood-brain barrier penetrating analogues may be applicable in treatment of ammonia-induced neurological deficits.     

Knowledge, Perception of Risk for HIV, and Condom Use: A Comparison of Registered and Freelance Female Sex Workers in Cebu City, Philippines

The HIV infection rate is lower in the Philippines than would be expected based on the numbers of people believed to engage in high-risk behaviors. A national behavioral surveillance system has been implemented to monitor selected behaviors among vulnerable populations. This paper reports on an interview survey of 360 registered and 360 freelance sex workers in Cebu City, the Philippines, from 1997 to 1999. All of the women had engaged in sexual activity in exchange for money during the week preceding the interview. The freelance workers reported more sexual partners than the registered sex workers (p < .00001), assessed themselves as more at risk for HIV (p < .00001), and were less likely to always use condoms during sex (p < .00001). The groups were comparable on a measure of knowledge about HIV transmission. As these women continue to engage in risky behaviors, some form of intervention will be necessary to prevent the escalating HIV/AIDS rates seen in other Southeast Asian countries.     

Induction of Human Umbilical Wharton’s Jelly-Derived Stem Cells Toward Oligodendrocyte Phenotype

In this study, we examined phenotypic features of human Wharton’s jelly mesenchymal stem cells-derived oligodendrocytes. We induced human WJMSCs to form OLs by signaling molecules including basic fibroblastic growth factor, platelet-derived growth factor-AA, and triiodothyronine hormone. Differentiated WJMSCs showed morphologic characteristics of an OL phenotype. Expression of surface markers and genes in oligodendrocyte precursor cells or OLs were analyzed by immunocytochemistry staining and real-time polymerase chain reaction, respectively. These results suggest that WJMSCs could be programmed to OLs and might provide a potential source for cell therapy in neurodegenerative disease.     

Europium oxide nanorod-reduced graphene oxide nanocomposites towards supercapacitors

Fast charge/discharge cycles are necessary for supercapacitors applied in vehicles including, buses, cars and elevators. Nanocomposites of graphene oxide with lanthanide oxides show better supercapacitive performance in comparison to any of them alone. Herein, Eu₂O₃ nanorods (EuNRs) were prepared through the hydrothermal method and anchored onto the surface of reduced graphene oxide (RGO) by utilizing a sonochemical procedure (in an ultrasonic bath) through a self-assembly methodology. The morphologies of EuNRs and EuNR-RGO were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and IR spectroscopy. Then, we used EuNRs and EuNR-RGO as electrode materials to investigate their supercapacitive behavior using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques. In a 3.0 M KCl electrolyte and with a scan rate of 2 mV s⁻¹, EuNR-RGO exhibited a specific capacity of 403 F g⁻¹. Galvanostatic charge–discharge experiments demonstrated a specific capacity of 345.9 F g⁻¹ at a current density of 2 A g⁻¹. The synergy between RGO''s flexibility and EuNR''s high charge mobility caused these noticeable properties.

Fast charge/discharge cycles are necessary for supercapacitors applied in vehicles including, buses, cars and elevators.     

Minimum size and positioning of imaging field for CBCT scans of impacted maxillary canines

Clinical Oral Investigations - In children and adolescents, cone-beam computed tomography (CBCT) is frequently used for localization of unerupted or impacted teeth in the anterior maxilla. CBCT...     

The immunobiology of myeloid-derived suppressor cells in cancer

The tumor microenvironment is a complex and heterogeneous milieu in which multiple interactions occur between tumor and host cells. Immunosuppressive cells which are present in this microenvironment, such as regulatory T (Treg) cells and myeloid-derived suppressor cells (MDSCs), play an important role in tumor progression, via down-regulation of antitumor responses. MDSCs represent a heterogeneous group of cells originated from the myeloid lineage that are in the immature state. These cells markedly accumulate under pathologic conditions, such as cancer, infection, and inflammation, and use various mechanisms to inhibit both adaptive and innate immune responses. These immunosuppressive mechanisms include deprivation of T cells from essential amino acids, induction of oxidative stress, interference with viability and trafficking of T cells, induction of immunosuppressive cells, and finally polarizing immunity toward a tumor-promoting type 2 phenotype. In addition to suppression of antitumor immune responses, MDSCs can also enhance the tumor metastasis and angiogenesis. Previous studies have shown that increased frequency of MDSCs is related to the tumor progression. Moreover, various drugs that directly target these cells or reverse their suppressive activity can improve antitumor immune responses as well as increase the efficacy of immunotherapeutic intervention. In this review, we will first discuss on the immunobiology of MDSCs in an attempt to find the role of these cells in tumor progression and then discuss about therapeutic approaches to target these cells.