Synthesis of molybdenum oxide nanoparticles by nanosecond laser ablation

Phothermal therapy (PTT) is one of the most promising techniques to treat cancer. Finding the ideal PTT agent nanomaterial has remained a challenge and has brought the interest of several researchers. In this work, we report the synthesis of molybdenum oxide (MoOx) nanoparticles (NPs), which exhibit absorption in the biological optical window ~840 nm, by using the laser ablation of solids in liquids (LASL) technique with nanosecond (ns) pulses. A Nd:YAG laser was used to synthesize the NPs in deionized (DI) water, free of surfactants or additives, which were optically characterized by absorption spectroscopy and TEM-EDX microscopy. Semi spherical NPs with a suitable average size and shape for potential use as PTT agents were obtained by laser ablation and ablation + fragmentation. The calculated band gap is 3.1 eV, which corresponds to MoO3. Micro-Raman spectroscopy studies determined that these NPs are composed of amorphous molybdenum oxide hydrates (MoO3 · xH2O)

Aspectos ecológicos de la anidación de Caiman crocodilus chiapasius (Bocourt, 1876) en la reserva de la biosfera La Encrucijada, México

Existen pocos estudios sobre el caimán de anteojos, Caiman crocodilus chiapasius, realizados en México. En el presente estudio evaluamos las características clave de la ecología reproductiva del caimán en México. Se realizó una búsqueda de nidos entre abril y septiembre de 2014, y se observó que la construcción de los mismos tiene lugar en junio y las eclosiones, en septiembre y octubre. La fase lunar influye en la anidación. Asimismo, la altura del nido, la distancia al árbol más cercano y la distancia desde el borde superior del nido al primer huevo están relacionadas con el éxito de eclosión y la temperatura de incubación.Ecological aspects of nesting in Caiman crocodilus chiapasius (Bocourt 1876) in La Encrucijada Biosphere Reserve, Mexico Studies on caiman, Caiman crocodilus chiapasius, in Mexico are scarce. The present study was conducted to evaluate the key characteristics regarding the reproductive ecology of caiman in Mexico. We conducted nest searches from April to September 2014. We observed that nests were built in June and that hatching occurred in September and October. The phase of the moon had an effect on nesting events. The height of the nest, the distance to the nearest tree, and the distance from the top of the nest to the first egg were related to hatching success and incubation temperature.Existen pocos estudios sobre el caimán de anteojos, Caiman crocodilus chiapasius, realizados en México. En el presente estudio evaluamos las características clave de la ecología reproductiva del caimán en México. Se realizó una búsqueda de nidos entre abril y septiembre de 2014, y se observó que la construcción de los mismos tiene lugar en junio y las eclosiones, en septiembre y octubre. La fase lunar influye en la anidación. Asimismo, la altura del nido, la distancia al árbol más cercano y la distancia desde el borde superior del nido al primer huevo están relacionadas con el éxito de eclosión y la temperatura de incubación

Ouabain Enhances Cell-Cell Adhesion Mediated by beta1 Subunits of the Na(+),K(+)-ATPase in CHO Fibroblasts

Adhesion is a crucial characteristic of epithelial cells to form barriers to pathogens and toxic substances from the environment. Epithelial cells attach to each other using intercellular junctions on the lateral membrane, including tight and adherent junctions, as well as the Na(+),K(+)-ATPase. Our group has shown that non-adherent chinese hamster ovary (CHO) cells transfected with the canine beta1 subunit become adhesive, and those homotypic interactions amongst beta1 subunits of the Na(+),K(+)-ATPase occur between neighboring epithelial cells. Ouabain, a cardiotonic steroid, binds to the alpha subunit of the Na(+),K(+)-ATPase, inhibits the pump activity and induces the detachment of epithelial cells when used at concentrations above 300 nM. At nanomolar non-inhibiting concentrations, ouabain affects the adhesive properties of epithelial cells by inducing the expression of cell adhesion molecules through the activation of signaling pathways associated with the alpha subunit. In this study, we investigated whether the adhesion between beta1 subunits was also affected by ouabain. We used CHO fibroblasts stably expressing the beta1 subunit of the Na(+),K(+)-ATPase (CHO beta1), and studied the effect of ouabain on cell adhesion. Aggregation assays showed that ouabain increased the adhesion between CHO beta1 cells. Immunofluorescence and biotinylation assays showed that ouabain (50 nM) increases the expression of the beta1 subunit of the Na(+),K(+)-ATPase at the cell membrane. We also examined the effect of ouabain on the activation of signaling pathways in CHO beta1 cells, and their subsequent effect on cell adhesion. We found that cSrc is activated by ouabain and, therefore, that it likely regulates the adhesive properties of CHO beta1 cells. Collectively, our findings suggest that the beta1 subunit adhesion is modulated by the expression levels of the Na(+),K(+)-ATPase at the plasma membrane, which is regulated by ouabain

Green Synthesis of Silver Nanoparticles Using <em>Heterotheca inuloides</em> and Its Antimicrobial Activity in Catgut Suture Threads

Silver nanoparticles were synthesized through a green method, using Heterotheca inuloides as a bioreducing agent. Moreover, catgut suture threads were decorated with those biogenic silver nanoparticles, and their antibacterial activity versus highly resistant pathogenic microorganisms was evaluated. The principles of green chemistry and nanotechnology allow us to obtain advanced materials, such as suture threads, which can reduce or avoid the prevalence of infectious processes in the medical field. Mexican medicinal plants, such as H. inuloides, represent an adequate alternative for biosynthesis; this plant species is known for its medicinal benefits and its antibacterial activity, and for that reason, it is being used in folk medicine

Serum human chorionic gonadotropin is associated with angiogenesis in germ cell testicular tumors

<p>Abstract</p> <p>Background</p> <p>Germ cell testicular tumors have survival rate that diminishes with high tumor marker levels, such as human chorionic gonadotropin (hCG). hCG may regulate vascular neoformation through vascular endothelial growth factor (VEGF). Our purpose was to determine the relationship between hCG serum levels, angiogenesis, and VEGF expression in germ cell testicular tumors.</p> <p>Methods</p> <p>We conducted a retrospective study of 101 patients. Serum levels of hCG, alpha-fetoprotein (AFP), and lactate dehydrogenase were measured prior to surgery. Vascular density (VD) and VEGF tissue expression were determined by immunohistochemistry and underwent double-blind analysis.</p> <p>Results</p> <p>Histologically, 46% were seminomas and 54%, non-seminomas. Median follow-up was 43 ± 27 months. Relapse was present in 7.5% and mortality in 11.5%. Factors associated with high VD included non-seminoma type (<it>p </it>= 0.016), AFP ≥ 14.7 ng/mL (<it>p </it>= 0.0001), and hCG ≥ 25 mIU/mL (<it>p </it>= 0.0001). In multivariate analysis, the only significant VD-associated factor was hCG level (<it>p </it>= 0.04). When hCG levels were stratified, concentrations ≥ 25 mIU/mL were related with increased neovascularization (<it>p </it>< 0.0001). VEGF expression was not associated with VD or hCG serum levels.</p> <p>Conclusion</p> <p>This is the first study that relates increased serum hCG levels with vascularization in testicular germ cell tumors. Hence, its expression might play a role in tumor angiogenesis, independent of VEGF expression, and may explain its association with poor prognosis. hCG might represent a molecular target for therapy.</p

Use of an orthovoltage X-ray treatment unit as a radiation research system in a small-animal cancer model

<p>Abstract</p> <p>Background</p> <p>We explore the use of a clinical orthovoltage X-ray treatment unit as a small-animal radiation therapy system in a tumoral model of cervical cancer.</p> <p>Methods</p> <p>Nude mice were subcutaneously inoculated with 5 × 10⁶HeLa cells in both lower limbs. When tumor volume approximated 200 mm³treatment was initiated. Animals received four 2 mg/kg intraperitoneal cycles (1/week) of cisplatin and/or 6.25 mg/kg of gemcitabine, concomitant with radiotherapy. Tumors were exposed to 2.5 Gy/day nominal surface doses (20 days) of 150 kV X-rays. Lead collimators with circular apertures (0.5 to 1.5 cm diameter) were manufactured and mounted on the applicator cone to restrict the X-ray beam onto tumors. X-ray penetration and conformality were evaluated by measuring dose at the surface and behind the tumor lobe by using HS GafChromic film. Relative changes in tumor volume (RTV) and a clonogenic assay were used to evaluate the therapeutic response of the tumor, and relative weight loss was used to assess toxicity of the treatments.</p> <p>Results</p> <p>No measurable dose was delivered outside of the collimator apertures. The analysis suggests that dose inhomogeneities in the tumor reach up to ± 11.5% around the mean tumor dose value, which was estimated as 2.2 Gy/day. Evaluation of the RTV showed a significant reduction of the tumor volume as consequence of the chemoradiotherapy treatment; results also show that toxicity was well tolerated by the animals.</p> <p>Conclusion</p> <p>Results and procedures described in the present work have shown the usefulness and convenience of the orthovoltage X-ray system for animal model radiotherapy protocols.</p

Etiology of Diarrhea in Older Children, Adolescents and Adults: A Systematic Review

Diarrhea is an important cause of illness and death around the world and among people of all ages, but unfortunately we often do not know what specific bacterium or virus causes the illness. We conducted a review of the scientific literature with the goal of finding published studies that identified bacteria and viruses among patients with diarrhea in the community and in hospital settings. We initially found nearly 26,000 papers on this topic but narrowed the list to 22 studies that met all of our specific criteria for inclusion in our review. Among patients hospitalized for diarrhea, E coli and Vibrio cholerae were found in more than 49% of people living in middle income and poor countries. Among patients who sought care from their doctor on an outpatient basis, Salmonella spp., Shigella spp., and E. histolytica were most often found. In our review we focused on the differences in the distribution of pathogens between patients in inpatient vs. outpatient settings because these estimates may best approximate what we would expect to see if the distribution were applied to global estimates of diarrhea deaths vs. uncomplicated illnesses