Influence of breast cancer risk factors on proliferation and DNA damage in human breast glandular tissues: role of intracellular estrogen levels, oxidative stress and estrogen biotransformation.

Breast cancer etiology is associated with both proliferation and DNA damage induced by estrogens. Breast cancer risk factors (BCRF) such as body mass index (BMI), smoking, and intake of estrogen-active drugs were recently shown to influence intratissue estrogen levels. Thus, the aim of the present study was to investigate the influence of BCRF on estrogen-induced proliferation and DNA damage in 41 well-characterized breast glandular tissues derived from women without breast cancer. Influence of intramammary estrogen levels and BCRF on estrogen receptor (ESR) activation, ESR-related proliferation (indicated by levels of marker transcripts), oxidative stress (indicated by levels of GCLC transcript and oxidative derivatives of cholesterol), and levels of transcripts encoding enzymes involved in estrogen biotransformation was identified by multiple linear regression models. Metabolic fluxes to adducts of estrogens with DNA (E-DNA) were assessed by a metabolic network model (MNM) which was validated by comparison of calculated fluxes with data on methoxylated and glucuronidated estrogens determined by GC- and UHPLC-MS/MS. Intratissue estrogen levels significantly influenced ESR activation and fluxes to E-DNA within the MNM. Likewise, all BCRF directly and/or indirectly influenced ESR activation, proliferation, and key flux constraints influencing E-DNA (i.e., levels of estrogens, CYP1B1, SULT1A1, SULT1A2, and GSTP1). However, no unambiguous total effect of BCRF on proliferation became apparent. Furthermore, BMI was the only BCRF to indeed influence fluxes to E-DNA (via congruent adverse influence on levels of estrogens, CYP1B1 and SULT1A2).

The first synthesis of CdFe12O19 nanostructures and nanocomposites and considering of magnetic, optical, electrochemical and photocatalytic properties.

CdFe12O19 nanostructures and nanocomposites were synthesized via sol-gel auto-combustion method. The CdFe12O19/CdTiO3 nanocomposites were prepared at 850 °C after 1 h calcination, when molar ratio of Cd:Ti is 1:1. Effects of the molar ratio of Cd:Ti, type of precursor and calcination temperature were investigated. Both nanostructures and nanocomposites were ferromagnetic at room temperature, with saturation magnetizations (Ms) 2.561 and 11.269 emu g-1, and coercivities (Hc) 696.517 and 969.068 Oe, respectively. SEM, TEM, FTIR, EDS and XRD showed morphology, composition and particle size of the products. VSM, UV-vis and CV were used to investigate the magnetic, optical and electrochemical properties. The band gap values of the nanocomposites were larger than that in the nanostructures. Also photocatalytic properties of the nanocomposites were investigated. This is the first attempt on the study of photocatalytic performance of the cadmium hexaferrite nanostructures and nanocomposites. The effects of various factors including composition and particle size of the nanocomposites, the Ti:Cd molar ratio and also kind of organic dye on the photocatalytic behavior of the products were evaluated. The photocatalytic activity achieved a maximum when ratio of Ti:Cd was 1:1. Methyl orange, methylene blue and methylene violet decompositions were about 71.35, 55.08 and 62.27% by nanocomposites, respectively.

Investigation of experimental and instrumental parameters on properties of PbFe12O19 nanostructures prepared by sonochemical method.

It is the first time that PbFe12O19 nanostructures were successfully synthesized by sonochemical method. The instrumental and experimental parameters were optimized to achieve the appropriate product. The results showed that Pb+2 to Fe+3 molar ratio and the type of capping agent as experimental parameters and time and power of sonication as instrumental variables can influence on the purity and particle size of products, respectively. According to the results, the synthesis process could improve to sol-gel assisted sonochemical method in presence of PEG as capping agent. In this method, pure product obtained by using the high temperature and pressure in sonication treatment and hydrolysis and condensation processes in sol-gel method, simultaneously. Concurrent presence of sonication treatment and PEG were necessary for preparation of pure hexaferrite nanostructures. Because of metal oxides nanostructures as major product and hexaferrite as minor product were produced in the absence of them. So, sol-gel assisted sonochemical method can be introduced as an effective method for preparation of hexaferrite nanostructures. Furthermore, it was found that the instrumental parameters should be optimized, because of increasing the time and power of sonication is not always favorable for preparation of ultrafine particles and small structures.