Association of 22 cytokine gene polymorphisms with rheumatoid arthritis in population of ethnic Macedonians

To examine the possible role of 22 cytokine gene polymorphisms in host susceptibility to or protection against RA in Macedonians. In this study, 301 healthy unrelated individuals and 85 patients with RA were studied. Cytokine genotyping was performed by PCR with sequence-specific priming (PCR–SSP) (Heidelberg kit). Results showed susceptible association for four cytokine alleles, six cytokine genotypes, one haplotype, and four combinations of haplotypes, while protective associations were found for four cytokine alleles, three cytokine genotypes, three haplotypes, and only one combination of haplotypes. These results suggest that IL-4 −1098, IL-4 −590, IL-10 −1082, IL-10 −819, IL-2 −330, IL-6 −174, and TNF-α −238 cytokine gene polymorphisms might be significantly associated and affect host susceptibility and/or resistance to RA in Macedonians.     

Regional activation of chromosomal arm 7q with and without gene amplification in taxane-selected human ovarian cancer cell lines

Taxanes are important drugs in the treatment of ovarian and other cancers, but their efficacy is limited by intrinsic and acquired drug resistance. Expression of the multidrug transporter P-glycoprotein, encoded by the MDR1 (ABCB1) gene, is one of the causes of clinical drug resistance to taxanes. To study the mechanisms of MDR1 activation related to taxanes, we established 11 multidrug-resistant variants from six ovarian cancer cell lines by continuous exposure to either paclitaxel or docetaxel. We profiled gene expression and gene copy number alterations in these cell lines using cDNA microarrays and identified a cluster of genes coactivated with MDR1 in 7q21.11-13. Regional activation was evident in nine resistant variants displaying a coexpression pattern of up to 22 genes over an 8-Mb area, including SRI, MGC4175, CLDN12, CROT, and CDK6. In six of these variants, regional activation was driven by gene copy number alterations, with low-level gains or high-level amplifications spanning the involved region. However, three variants displayed regional increases in gene expression even without concomitant gene copy number changes. These results suggest that regional gene activation may be a fundamental mechanism for acquired drug resistance, with or without changes in gene dosage. In addition to numerical and structural chromosomal changes driven by genome instability in cancer cells, other mechanisms might be involved in MDR1 regional activation, such as chromatin remodeling and DNA or histone modifications of the 7q21 region.     

New RB1 oncogenic mutations and intronic polymorphisms in Serbian retinoblastoma patients: genetic counseling implications

The purpose of this work was to identify germ line RB1 mutations in 16 Serbian retinoblastoma patients for genetic counselling. Mutation analysis was carried out by PCR directed sequencing of the 27 exons. Loss of heterozygosity for two RB1 intragenic markers was also analyzed in 14 tumour samples. Five new RB1 oncogenic mutations (g.2078 del C, g.77047_48 del GC, g.78117_8 del TT, g.160797 del T, and g.64439+2 T>C) and two recurrences (R445X and Q383X) have been found in this study. In addition, four intronic variants were observed germ line in some unilateral patients. Two of these variants (g.44668-15T/G, and g.166204-8T/A) are discussed as potential oncogenic mutation candidates. The results show the relevance of studies aimed to investigate the role of intronic variants in exon splicing regulation. Such studies will help to disclose hidden retinoblastoma susceptibilities, important for accurate genetic counselling.     

A physical analogue of the Schelling model

We present a mathematical link between Schelling's socio-economic model of segregation and the physics of clustering. We replace the economic concept of "utility" by the physics concept of a particle's internal energy. As a result cluster dynamics is driven by the "surface tension" force. The resultant segregated areas can be very large and can behave like spherical "liquid" droplets or as a collection of static clusters in "frozen" form. This model will hopefully provide a useful framework for studying many spatial economic phenomena that involve individuals making location choices as a function of the characteristics and choices of their neighbors.     

Selective small-molecule inhibitor reveals critical mitotic functions of human CDK1

CDK1 is a nonredundant cyclin-dependent kinase (CDK) with an essential role in mitosis, but its multiple functions still are poorly understood at a molecular level. Here we identify a selective small-molecule inhibitor of CDK1 that reversibly arrests human cells at the G(2)/M border of the cell cycle and allows for effective cell synchronization in early mitosis. Inhibition of CDK1 during cell division revealed that its activity is necessary and sufficient for maintaining the mitotic state of the cells, preventing replication origin licensing and premature cytokinesis. Although CDK1 inhibition for up to 24 h is well tolerated, longer exposure to the inhibitor induces apoptosis in tumor cells, suggesting that selective CDK1 inhibitors may have utility in cancer therapy.     

Additive prognostic value of the SYNTAX score over GRACE, TIMI, ZWOLLE, CADILLAC and PAMI risk scores in patients with acute ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention

This study evaluated additive prognostic value of the SYNTAX score over GRACE, TIMI, ZWOLLE, CADILLAC and PAMI risk scores in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI). All six scores were calculated in 209 consecutive STEMI patients undergoing pPCI. Primary end-point was the major adverse cardiovascular event (MACE—composite of cardiovascular mortality, non-fatal myocardial infarction and stroke); secondary end point was cardiovascular mortality. Patients were stratified according to the SYNTAX score tertiles (≤12; between 12 and 19.5; >19.5). The median follow-up was 20 months. Rates of MACE and cardiovascular mortality were highest in the upper tertile of the SYNTAX score (p < 0.001 and p = 0.003, respectively). SYNTAX score was independent multivariable predictor of MACE and cardiovascular mortality when added to GRACE, TIMI, ZWOLLE, and PAMI risk scores. However, the SYNTAX score did not improve the Cox regression models of MACE and cardiovascular mortality when added to the CADILLAC score. The SYNTAX score has predictive value for MACE and cardiovascular mortality in patients with STEMI undergoing primary PCI. Furthermore, SYNTAX score improves prognostic performance of well-established GRACE, TIMI, ZWOLLE and PAMI clinical scores, but not the CADILLAC risk score. Therefore, long-term survival in patients after STEMI depends less on detailed angiographical characterization of coronary lesions, but more on clinical characteristics, myocardial function and basic angiographic findings as provided by the CADILLAC score.