Factors associated with noninvasive coronary flow reserve in severe aortic stenosis.

BACKGROUND: Coronary flow reserve (CFR) is progressively impaired with aortic stenosis (AS) severity. However, there is a broad range of CFR in patients with severe AS, and the factors responsible for this variability are weakly characterized. The aim of this study was to assess the correlates of noninvasive CFR in patients with severe AS (≤1 cm(2) or ≤0.6 cm(2)/m(2)) and preserved left ventricular (LV) ejection fractions (LVEFs) (>50%). METHODS: Sixty-six consecutive patients (mean age, 74 ± 11 years; 31 women; mean LVEF, 69 ± 10%) with isolated severe AS (mean, 0.75 ± 0.2 cm(2) and 0.42 ± 0.1 cm(2)/m(2)), without coronary artery disease, underwent prospectively Doppler transthoracic echocardiography including CFR measurement in the distal part of the left anterior descending coronary artery (LAD) with intravenous adenosine infusion (140 µg/kg/min over 2 min). CFR was defined as hyperemic peak LAD flow velocity divided by baseline flow velocity. Twenty controls matched for age and gender served as a comparative group. Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) was also assessed. RESULTS: Compared with controls, patients with AS had higher baseline LAD flow velocities (36 ± 11 vs 27 ± 6 cm/sec, P < 0.01), lower hyperemic LAD flow velocities (80 ± 20 vs 89 ± 18 cm/sec, P = .09), and consequently lower CFR (2.3 ± 0.7 vs 3.3 ± 0.7, P < .01). In patients with AS, there were significant inverse correlations between CFR and age, E/e', indexed LV mass, NT-proBNP, pulmonary artery systolic pressure (PASP), baseline LV rate-pressure product, heart rate, and indexed left atrial volume and a significant positive correlation between CFR and LVEF (all P values < .05). Furthermore, compared with patients with asymptomatic AS (n = 22), those with symptomatic AS had more severely impaired CFR (2.15 ± 0.6 vs 2.7 ± 0.65), and higher NT-proBNP values (all P values < .05). In multivariate analysis, NT-proBNP, PASP, and LV rate-pressure product were the main independent correlates of CFR (all P values ≤ .01), and PASP was independently predicted by E/e' and indexed left atrial volume (all P values < .01). CONCLUSIONS: In patients with severe AS and preserved LVEFs, there is a relatively broad range of CFR values. CFR is more severely impaired in patients with symptomatic AS and is mainly linked with NT-proBNP, a surrogate of increased LV wall stress, workload as measured by LV rate-pressure product, and PASP.

Synthesis and biological evaluation of 7-azaindole derivatives, synthetic cytokinin analogues.

Cytokinins, N6-substituted adenine derivatives, are plant hormones playing important roles in various processes in plant development. Furthermore, cytokinins and their derivatives are able to control mammalian cell apoptosis and differentiation. The aim of our study was the synthesis of 7-azaindole derivatives as cytokinin analogues with the Hartwig-Buchwald coupling reaction in order to evaluate their biological properties on human myeloblastic leukaemia cells (HL-60 cell line). All these compounds presented a cytotoxic activity on HL-60 cells especially the 4-phenylaminopyrrolo[2,3-b]pyridine and the 4-phenethylaminopyrrolo[2,3-b]pyridine.

CXCL12 polymorphism and malignant cell dissemination/tissue infiltration in acute myeloid leukemia.

Stromal cell-derived factor 1 (SDF-1), a chemokine abundantly produced by the bone marrow microenvironment, and its receptor CXCR4 have crucial roles in malignant cell trafficking. In acute myeloid leukemia (AML), blasts invade the bloodstream and may localize in extramedullar sites, with variations from one patient to another. We hypothesized that a polymorphism in the SDF-1 coding gene (CXCL12 G801A) could influence blast dissemination and tissue infiltration in AML. CXCL12 G801A polymorphism was determined in 86 adult patients and 100 healthy volunteers. The allelic status and CXCR4 expression on bone marrow blasts were analyzed in relation to peripheral blood blast (PBB) counts and frequency of extramedullar tumor sites. 801A carrier status (801G/A, 801A/A) was found to be associated with a higher PBB count compared with 801G/G homozygous patients (P=0.031) and higher frequency of extramedullar tumor sites (odds ratio 2.92, 95% confidence interval 1.18-7.21, P=0.018). Moreover, the PBB count was correlated with CXCR4 expression (correlation coefficient 0.546, P=0.001) when considering 801A carriers. In conclusion, a polymorphism in the SDF-1 gene is shown for the first time to be associated with the clinical presentation of a malignant hematological disease and more generally with the risk of distant tissue infiltration by tumor cells.