Context New-onset fibrillation (AF) has been reported in 6–20% of patients with severe sepsis. Whereas chronic AF is a known risk factor for stroke and death, the clinical significance of new-onset AF in the setting of severe sepsis is uncertain. Objective To determine the in-hospital stroke and in-hospital mortality risks associated with new-onset AF in patients with severe sepsis. Design Retrospective population-based cohort of California State Inpatient Database administrative claims data from 1/1/2007 through 12/31/2007. Setting Non-Federal acute care hospitals. Patients Data was available from 3,144,787 hospitalized adults. Severe sepsis [N=49,082 (1.56%)] was defined by validated ICD-9-CM code 995.92. New-onset AF was defined as AF that occurred during the hospital stay, after excluding AF cases present at admission. Main Outcome Measures A priori outcome measures were in-hospital ischemic stroke (ICD-9-CM codes of 433, 434, or 436) and mortality. Results Patients with severe sepsis were 69±16 years old and 48% were women. New-onset atrial fibrillation occurred in 5.9% of patients with severe sepsis versus 0.6% of patients without severe sepsis [multivariable-adjusted odds ratio (OR), 6.82; 95% confidence interval (CI), 6.54–7.11; P<0.001]. Severe sepsis was present in 14% of all new-onset AF in hospitalized adults. Compared with severe sepsis patients without new-onset AF, patients with new-onset AF during severe sepsis had greater risks of in-hospital stroke (75/2896 (2.6%) vs. 306/46186 (0.6%) strokes, adjusted OR 2.70; 95% CI, 2.05–3.57; P <0.0001) and in-hospital mortality (1629 (56%) vs. 18027 (39%) deaths, adjusted relative risk, 1.07; 95% CI, 1.04–1.11; P <0.0001). Findings were robust across two definitions of severe sepsis, multiple methods of addressing confounding, and multiple sensitivity analyses. Conclusion Among patients with severe sepsis, patients with new-onset AF were at increased risk for in-hospital stroke and death compared with patients with no AF and patients with pre-existing AF.

The mechanisms by which multiple myeloma (MM) cells migrate and home to the bone marrow are not well understood. In this study, we sought to determine the effect of the chemokine SDF-1 (CXCL12) and its receptor CXCR4 on the migration and homing of MM cells. We demonstrated that CXCR4 is differentially expressed at high levels in the peripheral blood and is down-regulated in the bone marrow in response to high levels of SDF-1. SDF-1 induced motility, internalization, and cytoskeletal rearrangement in MM cells evidenced by confocal microscopy. The specific CXCR4 inhibitor AMD3100 and the anti-CXCR4 antibody MAB171 inhibited the migration of MM cells in vitro. CXCR4 knockdown experiments demonstrated that SDF-1-dependent migration was regulated by the PI3K and ERK/ MAPK pathways but not by p38 MAPK. In addition, we demonstrated that AMD3100 inhibited the homing of MM cells to the bone marrow niches using in vivo flow cytometry, in vivo confocal microscopy, and whole body bioluminescence imaging. This study, therefore, demonstrates that SDF-1/CXCR4 is a critical regulator of MM homing and that it provides the framework for inhibitors of this pathway to be IntroductionMultiple myeloma (MM) is the second most prevalent hematologic malignancy; it remains incurable, and the median survival time is 3 to 5 years. 1,2 It is characterized by the presence of multiple lytic lesions and widespread involvement of the bone marrow at diagnosis, implying a continuous (re)circulation of MM cells in the peripheral blood and (re)entrance into the bone marrow. 1 Studies have demonstrated the presence of circulating malignant plasma cells in more than 70% of patients diagnosed with MM. 3,4 Migration of cells through the blood to the bone marrow niches requires active navigation, a process termed homing.Chemokines are small chemoattractant cytokines that bind to specific G-protein-coupled 7-span transmembrane receptors present on the plasma membranes of target cells. [5][6][7] Chemokines play a central role in lymphocyte trafficking and homing. [8][9][10][11] One of the most extensively studied chemokines in migration is SDF-1 and its receptor, CXCR4. 12,13 SDF-1 is primarily produced by stromal cells. CXCR4 is expressed on the surfaces of normal cells such as hematopoietic stem cells and T and B lymphocytes and on malignant cells such as breast cancer cells and lymphoid malignancies. 6,11,[14][15][16] To date, the role of CXCR4 in homing of MM cells to the bone marrow has not been fully elucidated. Inhibitors of CXCR4, such as AMD3100 (AnorMED, Toronto, ON, Canada), have been shown to induce the mobilization of stem cells. 17,18 AMD3100 (AnorMED) is a bicyclam molecule that reversibly blocks the binding of CXCR4 with SDF-1. 19 Because SDF-1/CXCR4-dependent signaling differs between cell types and between malignant and normal counterparts, 20 it is critical to investigate the unique role of CXCR4/SDF-1 in MM. In this study, we sought to determine the effect of CXCR4 and its specific inhibitor, AMD3100, on the migration and in vivo ...

oxygen species (ROS) induce matrix metalloproteinase (MMP) activity that mediates hypertrophy and cardiac remodeling. Adiponectin (APN), an adipokine, modulates cardiac hypertrophy, but it is unknown if APN inhibits ROS-induced cardiomyocyte remodeling. We tested the hypothesis that APN ameliorates ROS-induced cardiomyocyte remodeling and investigated the mechanisms involved. Cultured adult rat ventricular myocytes (ARVM) were pretreated with recombinant APN (30 g/ml, 18 h) followed by exposure to physiologic concentrations of H2O2 (1-200 M). ARVM hypertrophy was measured by [ 3 H]leucine incorporation and atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) gene expression by RT-PCR. MMP activity was assessed by in-gel zymography. ROS was induced with angiotensin (ANG)-II (3.2 mg·kg Ϫ1 ·day Ϫ1 for 14 days) in wild-type (WT) and APN-deficient (APN-KO) mice. Myocardial MMPs, tissue inhibitors of MMPs (TIMPs), p-AMPK, and p-ERK protein expression were determined. APN significantly decreased H2O2-induced cardiomyocyte hypertrophy by decreasing total protein, protein synthesis, ANF, and BNP expression. H2O2-induced MMP-9 and MMP-2 activities were also significantly diminished by APN. APN significantly increased p-AMPK in both nonstimulated and H2O2-treated ARVM. H 2O2-induced p-ERK activity and NF-B activity were both abrogated by APN pretreatment. ANG II significantly decreased myocardial p-AMPK and increased p-ERK expression in vivo in APN-KO vs. WT mice. ANG II infusion enhanced cardiac fibrosis and MMP-2-to-TIMP-2 and MMP-9-to-TIMP-1 ratios in APN-KO vs. WT mice. Thus APN inhibits ROS-induced cardiomyocyte remodeling by activating AMPK and inhibiting ERK signaling and NF-B activity. Its effects on ROS and ultimately on MMP expression define the protective role of APN against ROSinduced cardiac remodeling. reactive oxygen species; adenosine 5=-monophosphate-activated protein kinase; matrix metalloproteinase; cardiomyocyte hypertrophy

Context-New-onset fibrillation (AF) has been reported in 6-20% of patients with severe sepsis. Whereas chronic AF is a known risk factor for stroke and death, the clinical significance of newonset AF in the setting of severe sepsis is uncertain.Objective-To determine the in-hospital stroke and in-hospital mortality risks associated with new-onset AF in patients with severe sepsis. Conclusion-Among patients with severe sepsis, patients with new-onset AF were at increased risk for in-hospital stroke and death compared with patients with no AF and patients with preexisting AF. Design-Retrospective

To better understand the molecular changes that occur in Waldenstrom macroglobulinemia (WM), we employed antibody-based protein microarrays to compare patterns of protein expression between untreated WM and normal bone marrow controls. Protein expression was defined as a >2-fold or 1.3-fold change in at least 67% of the tumor samples. Proteins up-regulated by >2-fold included Ras family proteins, such as Rab-4 and p62DOK, and Rho family proteins, such as CDC42GAP and ROKA. Other proteins up-regulated by >1.3-fold included cyclin-dependent kinases, apoptosis regulators, and histone deacetylases (HDAC). We then compared the samples of patients with symptomatic and asymptomatic WM and showed similar protein expression signatures, indicating that the dysregulation of signaling pathways occurs early in the disease course. Three proteins were different by >2-fold in symptomatic versus asymptomatic, including the heat shock protein HSP90. Elevated protein expression was confirmed by immunohistochemistry and immunoblotting. Functional significance was validated by the induction of apoptosis and inhibition of proliferation using specific HDAC and HSP90 inhibitors. This study, therefore, identifies, for the first time, multiple novel proteins that are dysregulated in WM, which both enhance our understanding of disease pathogenesis and represent targets of novel therapeutics.