Can We Assess Pulsus Paradoxus through Polysomnography in a Patient with Chronic Obstructive Pulmonary Disease and Sleep-Disordered Breathing?

ABSTRACT: Pulsus paradoxus (PP) is a decrease in systolic blood pressure greater than 10 mm Hg during inspiration that occurs in various medical conditions. Using polysomnography pulse oximetry signal, photoplethysmography variations of the amplitude of the pulse pressure within the respiratory cycle were observed. There is a proportional relationship between the changes of inspiratory waveform values and the generated PP. A 59-year-old male underwent polysomnography that showed sleep hypoxemia, obstructive sleep-disordered breathing (apnea hypopnea index [AHI] = 5.1and respiratory disturbance index [RDI] = 87.9), with variations of pulse pressure induced primarily by inspiration. The highest variations in the pulse wave were observed in NREM sleep during obstructive respiratory events and in biocalibration during nasal breathing. The lowest variations occurred after the correction of inspiratory obstructive events and during biocalibration when asked to hold his breath.

Temporal gene expression profile of human precursor B leukemia cells induced by adhesion receptor: identification of pathways regulating B-cell survival.

The physical interactions between B cells and stromal cells from the lymphoid tissue microenvironment are critical to the survival of normal and malignant B cells. They are principally mediated by integrins expressed on B cells and counterreceptors on stromal cells. Specifically, alpha4beta1 integrin engagement rescues B cells from physiological or drug-induced apoptosis. Therefore, in order to understand the mechanisms by which integrins prevent apoptosis in leukemia B cells, we compared the temporal gene expression profiles induced by beta1-integrin ligation with fibronectin (Fn) or adhesion by poly-L-Lysine in serum-starved precursor B leukemia cells. Among the 38 selected differentially expressed genes, 6 genes involved in adhesion (VAV2, EPB41L1, CORO1A), proliferation (FRAP1, CCT4), and intercellular communication (GJB3) were validated by real-time quantitative polymerase chain reaction (RT-Q-PCR). Gene expression modulation could also be validated at the protein level for 5 other genes. We show that integrin stimulation up-regulated FBI-1 expression but inhibited CD79a, Requiem, c-Fos, and caspase 7 induction when the cells underwent apoptosis. We further demonstrate that Fn stimulation also inhibits caspase 3 activation but increases XIAP and survivin expression. Moreover, integrin stimulation also prevents caspase activation induced by doxorubicin. Therefore, we identified genes modulated by adhesion of human precursor B leukemia cells that regulate proliferation and apoptosis, highlighting new pathways that might provide insights into future therapy aiming at targeting apoptosis of leukemia cells.