The role of Iron on breast cancer stem-like cells.

Iron is a fundamental nutrient that enables the functions of vital enzymes involved in cell replication, metabolism and growth. Cancer cells contain higher systemic iron levels relative to normal cells. In breast cancer cells, human epidermal growth factor receptor 2 (HER2) is overexpressed more than 30% of normal and its poorly prognosis results in elevated the proportion of cancer stem cells (CSCs) which are the main drivers in cancer recurrence. Finding a relation between increases of iron levels, HER2 expression and CSC population may provide new tools for breast cancer therapy. In this study, therefore, iron dependency in HER2 overexpression and CSC survival is examined in breast cancer cell line, MCF7. It has shown that cells overexpressing HER2 require iron more than their vector counterparts and HER2-increased CSCs are vulnerable to iron chelation. Additionally, this sensitivity of CSCs to iron reduction is obviously indicated in various breast cancer cell lines; HCC1954, MDA-MB-435 and Hs578T. Finally, the concept is also shown in neoplastically transformed breast cancer cell line, HMLER. Altogether, this study demonstrates that iron depletion causes toxicity for CSCs.

Salicylic acid derivatives form stable complexes with scandium(III) ion in aqueous solution.

The stability constants of 5-nitrosalicylic acid (5-NSA) and 5-sulfosalicylic acid (5-SSA) complexes of Sc(III) were determined by potentiomeric pH titration. ML and ML2 type first and second complexes were observed in the solutions of 5-NSA and 5-SSA with Sc(III) at 25 degrees C in I=0.1 M ionic medium. The stability constants of Sc(III)-5NSA and Sc(III)-5SSA systems were also investigated by spectrophotometry to determine the stoichiometries of the complexes formed in the reactions. Our results showed that Sc(III)-5SSA complexes are more stable than the Sc(III)-5NSA complexes in aqueous solutions.

Determination and parameterization of some air pollutants as a function of meteorological parameters in Kayseri, Turkey.

In this paper, the statistical relations between meteorological parameters and some pollutant ground level concentrations are presented. The daily average sulfur dioxide and smoke values were measured at five stations in Kayseri over 20 months. The model adopted for analysis differed from the power-law form selected by former investigators. Wind speed, degree-day temperature, the percentage of relative humidity, the previous day's pollution concentrations, and the amount of global solar radiation were the variables of multiple regression equations that were derived to calculate pollutant concentrations. The amount of cloud cover, however, had no important effect on the pollutant concentrations. The average variances of these regression equations were found as 84 and 75% for sulfur dioxide and smoke concentrations, respectively. The calculated pollutant concentrations utilizing forecast meteorological parameters reflected that the occurrence of high pollutant concentrations can be predicted.

Microsomal metabolism of N-benzyl-N-ethylaniline and N-benzyl-N-ethyl-p-toluidine.

The in vitro hepatic microsomal metabolism of two tertiary anilines, N-benzyl-N-ethylaniline (NBNEA) and N-benzyl-N-ethyl-p-toluidine (NBNEPT), was examined in order to determine whether these compounds produce amide derivatives (benzoyl or acetyl) in addition to N-dealkylation and N-oxidation products as metabolites. The preparation of these tertiary anilines and their corresponding potential metabolites was undertaken. The amines and metabolites were separated using TLC and HPLC. Incubations were performed using hamster microsomal preparations fortified with NADPH. The substrates and their potential metabolites were extracted into dichloromethane and examined by TLC and HPLC. The metabolic process of particular interest was the formation of amides from NBNEA and NBNEPT. The results from these experiments indicated that neither tertiary aniline (NBNEA and NBNEPT) produced amide (acetyl or benzoyl) or N-oxide metabolites. These substrates were dealkylated to the corresponding secondary amines via debenzylation and de-ethylation. Uncharacterised metabolites observed with substrates are proposed to be phenolic (for NBNEA) and hydroxymethyl (for NBNEPT). These findings support the concept that: nitrones are essential intermediates for the formation of amides from secondary aromatic amines (chemical rearrangement to amide via an oxaziridine intermediate); carbinolamines produced by NBNEA and NBNEPT are not stable enough to allow further oxidation to amides and therefore these intermediates are broken down to dealkylated products. The results are discussed in relation to the mechanism of metabolic amide formation from amines.

Atmospheric pollutants in Uludag National Park.

Gas phase pollutants and major ions were measured in the Sarýalan region of Uludag Mountain, which is experiencing severe deforestation. Short- and long-term trends in the concentration of the gas pollutants were computed from the samples obtained in order to identify the source of these pollutants. The higher concentration of O3 during summer months was consistent with the higher photochemical production from precursor gases (NOx) with increased solar flux. The diurnal pattern of O3, NO, NO2 and TSP describes a photochemical smog scenario. A lower pH in aerosols associated with high levels of SO4(2-) and NO3- is an indication of acid deposition. Wind sector analysis revealed that the major contributing source regions are north and south of the sampling site, that is, the city of Bursa, local industries, and the Orhaneli power plant.

Air pollution profile of Bursa.

Rapid urbanization and industrial development are the most important causes of air pollution in Bursa. Smoke and sulfur dioxide concentrations were measured at five stations over a period of 20 months between 1986 and 1987; the concentrations of the total suspended particles were determined in the samples collected at two stations in June and October 1986. Some of the trace elements (Fe, Pb, Cd, Zn) were measured in October 1988 by atomic absorption spectroscopy of 28 samples from two stations. The first-order regression equations were calculated in order to find the relationship between the concentrations of smoke, sulfur dioxide, and meteorological conditions. The trends in the concentrations of measured air pollutants were compared by the long- and short-term limit values, as specified in the regulation.