BackgroundThe diagnosis of benign renal oncocytomas (RO) and chromophobe renal cell carcinomas (RCC) based on their morphology remains uncertain in several cases.MethodsWe have applied Affymetrix GeneChip Mapping 250 K NspI high-density oligoarrays to identify small genomic alterations, which may occur beyond the specific losses of entire chromosomes, and also Affymetrix GeneChip HG-U133 Plus2.0 oligoarrays for gene expression profiling.ResultsBy analysing of DNA extracted from 30 chRCCs and 42 ROs, we have confirmed the high specificity of monosomies of chromosomes 1, 2, 6, 10, 13, 17 and 21 in 70–93% of the chRCCs, while ROs displayed loss of chromosome 1 and 14 in 24% and 5% of the cases, respectively. We demonstrated that chromosomal gene expression biases might correlate with chromosomal abnormalities found in chromophobe RCCs and ROs. The vast majority genes downregulated in chromophobe RCC were mapped to chromosomes 2, 6, 10, 13 and 17. However, most of the genes overexpressed in chromophobe RCCs were located to chromosomes without any copy number changes indicating a transcriptional regulation as a main event.ConclusionThe SNP-array analysis failed to detect recurrent small deletions, which may mark loci of genes involved in the tumor development. However, we have identified loss of chromosome 2, 10, 13, 17 and 21 as discriminating alteration between chromophobe RCCs and ROs. Therefore, detection of these chromosomal changes can be used for the accurate diagnosis in routine histology.

Multi-component alloys containing 5 and 6 platinum group metals have been prepared by thermal decomposition of single-source precursors. It is the first successful example of high-entropy alloy preparation not requiring direct melting at high temperature or mechanical alloying, and can be further extended to other multicomponent metallic systems. Our single-source precursor strategy for the preparation of multicomponent alloys can be considered as a new approach in the design and optimization of refractory high-entropy alloys for a broad range of applications. Thermal decomposition occurs at low temperatures (below 800°C in H2 flow). The resulting hexagonal Ir0.19Os0.22Re0.21Rh0.20Ru0.19 alloy is the first example of a single-phase hexagonal high-entropy alloy. Heat treatment does not result in any phase changes up to 1500 K, which is a record temperature stability for a single-phase high-entropy alloy. Room temperature hydrostatic compression up to 45 GPa also highlights the system's stability as a single phase, with a bulk modulus smaller then individual platinum group metals (except Rh). The prepared alloys show pronounced electrocatalytic activity in methanol oxidation, which opens a route for the use of highentropy alloys as materials for sustainable energy conversion.

Due to overlapping morphology, malignant chromophobe renal cell carcinomas (RCC) and benign renal oncocytomas (RO) may pose a diagnostic problem. In the present study, we have applied different algorithms to evaluate the data sets obtained by hybridisation of pooled and also individual samples of renal cell tumours (RCT) onto two different gene expression platforms. The two approaches revealed high similarities in the gene expression profiles of chromophobe RCCs and ROs but also some differences. After identifying the differentially expressed genes by statistic analyses, the candidate genes were further selected by a real time and normal RT-PCR and their products were analysed by immunohistochemistry. We have identified CD82 and S100A1 as valuable markers for chromophobe RCC as well as AQP6 for ROs. However, these genes are expressed at the protein level in other types of RCTs as well albeit at a low frequency and low intensity. As none of the selected genes marks exclusively one type of RCTs, for the differential diagnosis of chromophobe RCCs and ROs, a set of markers such as CD82, S100A1 and AQP6 as well as some others would be an option in routine histological laboratories.