[Study of correlation between different scales that measure smoking dependence]. / Estudio de correlación entre diferentes escalas que miden la dependencia al tabaquismo.

OBJECTIVE: To analyze the correlation between the degrees of smoking dependence, measured with the Fagerström Test Nicotine Dependence (FTND), Glover-Nilsson Smoking Behavioral Dependence (GN-SBQ) and a measure of self-perceived-dependence (SPD). DESIGN: Cross-sectional descriptive observational study. SITE: Urban primary health-care center. PARTICIPANTS: Men and women between 18 and 65 years old, daily smokers, selected by non-random consecutive sampling. INTERVENTIONS: Self-administration of various questionnaires though an electronic device. MAIN MEASUREMENTS: Age, sex and nicotine dependence assessed by: FTND, GN-SBQ and SPD. Statistical analysis, with SPSS 15.0: descriptive statistics, Pearson correlation analysis and conformity analysis. RESULTS: Two hundred fourteen smokers were included, 54.7% were women. Median age 52 years (range: 27-65). Depending on the test used, different results of the high/very high degree of dependence were found: FTND 17.3%, GN-SBQ 15.4% and SPD 69.6%. A moderate magnitude (r≈0.5) correlation between the 3 test was found. When assessing concordance, comparing the FTND with SPD, 70.6% of smokers didn't coincide in the severity of dependence, reporting a milder degree of dependence with the FTND than with SPD. Comparing GN-SBQ versus FTND, showed conformity in 44.4% of patients while in 40.7%, the FTND underestimated the severity of dependence. Likewise, when comparing SPD with the GN-SBQ, in the 64% GN-SBQ underestimates, while in 34.1% smokers conformity was demonstrated. CONCLUSIONS: The number of patients who consider their SPD to be high/very high was four times higher compared to the GN-SBQ or the FNTD; the latter, being the most demanding, categorizing patients with very high dependence. Requiring a FTND score greater than 7 to prescribe drugs for smoking cessation may exclude subsidiary patients from receiving treatment.

The IKK inhibitor BMS-345541 affects multiple mitotic cell cycle transitions.

The IkappaB kinase (IKK) complex controls processes such as inflammation, immune responses, cell survival and the proliferation of both normal and tumor cells. By activating NFkappaB, the IKK complex contributes to G1/S transition and first evidence has been presented that IKKalpha also regulates entry into mitosis. At what stage IKK is required and whether IKK also contributes to progression through mitosis and cytokinesis, however, has not yet been determined. In this study, we use BMS-345541, a potent allosteric small molecule inhibitor of IKK, to inhibit IKK specifically during G2 and during mitosis. We show that BMS-345541 affects several mitotic cell cycle transitions, including mitotic entry, prometaphase to anaphase progression and cytokinesis. Adding BMS-345541 to the cells released from arrest in S-phase blocked the activation of Aurora A, B and C, Cdk1 activation and histone H3 phosphorylation. Additionally, treatment of the mitotic cells with BMS-345541 resulted in precocious cyclin B1 and securin degradation, defective chromosome separation and improper cytokinesis. BMS-345541 was also found to override the spindle checkpoint in nocodazole-arrested cells. In vitro kinase assays using BMS-345541 indicate that these effects are not primarily due to a direct inhibitory effect of BMS-345541 on mitotic kinases such as Cdk1, Aurora A or B, Plk1 or NEK2. This study points towards a new potential role of IKK in cell cycle progression. Since deregulation of the cell cycle is one of the hallmarks of tumor formation and progression, the newly discovered level of BMS-345541 function could be useful for cell cycle control studies and may provide valuable clues for the design of future therapeutics.

Genomic targets of the human c-Myc protein.

The transcription factor Myc is induced by mitogenic signals and regulates downstream cellular responses. If overexpressed, Myc promotes malignant transformation. Myc modulates expression of diverse genes in experimental systems, but few are proven direct targets. Here, we present a large-scale screen for genomic Myc-binding sites in live human cells. We used bioinformatics to select consensus DNA elements (CACGTG or E-boxes) situated in the 5' regulatory region of genes and measured Myc binding to those sequences in vivo by quantitative chromatin immunoprecipitation. Strikingly, most promoter-associated E-boxes showed selective recovery with Myc, unlike non-E-box promoters or E-boxes in bulk genomic DNA. Promoter E-boxes were distributed in two groups bound by Myc at distinct frequencies. The high-affinity group included an estimated 11% of all cellular loci, was highly conserved among different cells, and was bound independently of Myc expression levels. Overexpressed Myc associated at increased frequency with low-affinity targets and, at extreme levels, also with other sequences, suggesting that some binding was not sequence-specific. The strongest DNA-sequence parameter defining high-affinity targets was the location of E-boxes within CpG islands, correlating with an open, preacetylated state of chromatin. Myc further enhanced histone acetylation, with or without accompanying induction of mRNA expression. Our findings point to a high regulatory and biological diversity among Myc-target genes.

Hijacking of host cell IKK signalosomes by the transforming parasite Theileria.

Parasites have evolved a plethora of mechanisms to ensure their propagation and evade antagonistic host responses. The intracellular protozoan parasite Theileria is the only eukaryote known to induce uncontrolled host cell proliferation. Survival of Theileria-transformed leukocytes depends strictly on constitutive nuclear factor kappa B (NF-kappaB) activity. We found that this was mediated by recruitment of the multisubunit IkappaB kinase (IKK) into large, activated foci on the parasite surface. IKK signalosome assembly was specific for the transforming schizont stage of the parasite and was down-regulated upon differentiation into the nontransforming merozoite stage. Our findings provide insights into IKK activation and how pathogens subvert host-cell signaling pathways.