Nanocrystalline magnetite Fe3O4 samples with a grain size of about 40 nm have been synthesized by an optimized sol-gel method. The single phase of spinel magnetite was confirmed by both X-ray diffraction and transmission electron microscopy. It has been found that the magnetoresistance of the samples at low field (LFMR) is relatively large, and with the decrease of temperature its value at a field of 0.5 T changes dramatically from -2.5% at 300 K to -17.0% at 55 K. With the further decrease of temperature a sharp drop occurs for the magnitude of the magnetoresistance (MR), regarded as a spin (cluster) glass transition in the surface region of the grains that can be confirmed by the zero-field-cooled and field-cooled magnetization and ac susceptibility measurement. The mechanism of the magnetic and transport properties was discussed.

ABSTRACT.We assessed the role of single nucleotide polymorphisms (SNPs) in ERCC1 and ERCC2 genes in the clinical outcomes for osteosarcoma patients receiving cisplatin-based treatment. A perspective study was conducted on 260 patients with osteosarcoma during 2010 and 2011. A polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay was used to assess the ERCC1 rs11615 and rs3212986, and the ERCC2 rs1799793 and rs13181 gene polymorphisms. After adjustment for clinical variables, we found that the CC genotype of ERCC1 rs11615 was significantly associated with better response to chemotherapy (OR = 2.87, 95%CI = 1.24-6.97). Our study found that those carrying the CC genotype of ERCC1 rs11615 had a longer overall survival compared with the TT genotype, and the OR (95%CI) was 0.35 (0.12-0.92). In conclusion, our results suggest 11236 Q. Zhang et al. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 11235-11241 (2015) that the ERCC1 rs11615 polymorphism might influence the response to cisplatin-based chemotherapy and affect the clinical outcome for osteosarcoma patients.

Purpose Intravitreal bevacizumab, a humanized monoclonal antibody to VEGF‐A, was originally developed as an anti‐tumour treatment, and is used to treat macular edema in radiation retinopathy. As this drug may potentially be used to treat primary uveal melanoma (UM) and/or its metastases, we analyzed the effect of bevacizumab on UM growth. Methods Mice inoculated with B16F10 melanoma cells into the anterior chamber of the eye were monitored for tumour growth and vascularisation after bevacizumab treatment. UM cell proliferation and the expression of VEGF‐A, GLUT‐1, and HIF‐1α were analyzed in vitro. Results Bevacizumab treatment resulted in an acceleration of intraocular tumour growth in mice, but did not induce UM cell proliferation in vitro. Incubation with bevacizumab induced VEGF‐A and GLUT‐1 mRNA expression via the HIF‐1α pathway in UM cell lines and primary cell cultures. Surprisingly, VEGF‐A expression in mice did not result in more vessels, but we did perceive more anterior chamber hemorrhages in vivo. Conclusion Anti‐VEGF treatment with bevacizumab induces intraocular tumour growth in mice. Although bevacizumab did not induce the number of vessels in treated mice, we did observe more anterior chamber hemorrhages. One of the mechanism involved, is the induction of VEGF‐A expression in hypoxic UM cell lines and cultures through the HIF‐1α pathway, resulting in a ‘pseudohypoxic’ condition. This phenomenon has been described in other tumours and maybe the consequence of tumour adaptive or evasive resistance. The use of bevacizumab for treatment of macular edema (due to radiation retinopathy) after irradiation of UM should therefore be carefully considered.

Purpose One of the prognostically bad parameters in uveal melanoma is the presence of an inflammatory phenotype, characterized by an increased expression of HLA antigens and an immunologic infiltrate. We wondered whether the presence of specific chemokines and cytokines in the aqueous humor (AqH) from uveal melanoma‐containing eyes is associated with this inflammatory phenotype, with the presence of macrophages, and/or with survival. Methods Directly following enucleation, AqH was obtained from 37 eyes containing uveal melanoma. Samples were stored at ‐80 °C till use. Using a multiplex bead array, 15 different cytokines were measured. Determination of intratumoral macrophages was performed by immunohistochemistry and immunofluorescence. The presence of specific cytokines was compared to histopathological, genetic and clinical tumor characteristics, as well as patient survival. Results Several cytokines showed a significantly higher expression in the AqH from uveal melanoma‐containing eyes compared to the AqH from eyes undergoing cataract surgery. Only MCP‐3 was associated with the presence of macrophages and the tumor promoting M2‐type macrophage in uveal melanoma patients. Hardly any correlations were found between cytokine levels and known prognostic factors for uveal melanoma. Also, cytokine levels were not of predictive value for survival. Conclusion Although increased levels of inflammation‐related cytokines are present in the AqH of uveal melanoma‐containing eyes, hardly any associations with the presence of macrophages and their subtypes, with clinical and histopathological parameters, and prognosis were found.