bluuebunny/crossref_metadata_2025 huggingface dataset:
Gut microbiota are linked to increased susceptibility to hepatic steatosis in low-aerobic-capacity rats fed an acute high-fat diet
Authors: Panasevich Matthew R. , Morris E. M. , Chintapalli S. V. , Wankhade U. D. , Shankar K. , Britton S. L. , Koch L. G. , Thyfault J. P. , Rector R. S.
Published: June 2016

Poor aerobic fitness is linked to nonalcoholic fatty liver disease and increased all-cause mortality. We previously found that rats with a low capacity for running (LCR) that were fed an acute high-fat diet (HFD; 45% kcal from fat) for 3 days resulted in positive energy balance and increased hepatic steatosis compared with rats that were highly aerobically fit with a high capacity for running (HCR). Here, we tested the hypothesis that poor physiological outcomes in LCR rats following acute HFD feeding are associated with alterations in cecal microbiota. LCR rats exhibited greater body weight, feeding efficiency, 3 days of body weight change, and liver triglycerides after acute HFD feeding compared with HCR rats. Furthermore, compared with HCR rats, LCR rats exhibited reduced expression of intestinal tight junction proteins. Cecal bacterial 16S rDNA revealed that LCR rats had reduced cecal Proteobacteria compared with HCR rats. Microbiota of HCR rats consisted of greater relative abundance of Desulfovibrionaceae and unassigned genera within this family, suggesting increased reduction of endogenous mucins and proteins. Although feeding rats an acute HFD led to reduced Firmicutes in both strains, short-chain fatty acid-producing Phascolarctobacterium was reduced in LCR rats. In addition, Ruminococcae and Ruminococcus were negatively correlated with energy intake in the LCR/HFD rats. Predicted metagenomic function suggested that LCR rats had a greater capacity to metabolize carbohydrate and energy compared with HCR rats. Overall, these data suggest that the populations and metabolic capacity of the microbiota in low-aerobically fit LCR rats may contribute to their susceptibility to acute HFD-induced hepatic steatosis and poor physiologic outcomes.
High-fat diet-induced obesity alters nitric oxide-mediated neuromuscular transmission and smooth muscle excitability in the mouse distal colon
Authors: Bhattarai Yogesh , Fried David , Gulbransen Brian , Kadrofske Mark , Fernandes Roxanne , Xu Hui , Galligan James
Published: June 2016

We tested the hypothesis that colonic enteric neurotransmission and smooth muscle cell (SMC) function are altered in mice fed a high-fat diet (HFD). We used wild-type (WT) mice and mice lacking the β1-subunit of the BK channel (BKβ1−/−). WT mice fed a HFD had increased myenteric plexus oxidative stress, a 28% decrease in nitrergic neurons, and a 20% decrease in basal nitric oxide (NO) levels. Circular muscle inhibitory junction potentials (IJPs) were reduced in HFD WT mice. The NO synthase inhibitor nitro-l-arginine (NLA) was less effective at inhibiting relaxations in HFD compared with control diet (CD) WT mice (11 vs. 37%, P < 0.05). SMCs from HFD WT mice had depolarized membrane potentials (−47 ± 2 mV) and continuous action potential firing compared with CD WT mice (−53 ± 2 mV, P < 0.05), which showed rhythmic firing. SMCs from HFD or CD fed BKβ1−/−mice fired action potentials continuously. NLA depolarized membrane potential and caused continuous firing only in SMCs from CD WT mice. Sodium nitroprusside (NO donor) hyperpolarized membrane potential and changed continuous to rhythmic action potential firing in SMCs from HFD WT and BKβ1−/−mice. Migrating motor complexes were disrupted in colons from BKβ1−/−mice and HFD WT mice. BK channel α-subunit protein and β1-subunit mRNA expression were similar in CD and HFD WT mice. We conclude that HFD-induced obesity disrupts inhibitory neuromuscular transmission, SMC excitability, and colonic motility by promoting oxidative stress, loss of nitrergic neurons, and SMC BK channel dysfunction.
Early settlers: whichE. colistrains do you not want at birth?
Authors: Secher Thomas , Brehin Camille , Oswald Eric
Published: June 2016

The intestinal microbiota exerts vital biological processes throughout the human lifetime, and imbalances in its composition have been implicated in both health and disease status. Upon birth, the neonatal gut moves from a barely sterile to a massively colonized environment. The development of the intestinal microbiota during the first year of life is characterized by rapid and important changes in microbial composition, diversity, and magnitude. The pioneer bacteria colonizing the postnatal intestinal tract profoundly contribute to the establishment of the host-microbe symbiosis, which is essential for health throughout life. Escherichia coli is one of the first colonizers of the gut after birth. E. coli is a versatile population including harmless commensal, probiotic strains as well as frequently deadly pathogens. The prevalence of the specific phylogenetic B2 group, which encompasses both commensal and extra- or intraintestinal pathogenic E. coli strains, is increasing among E. coli strains colonizing infants quickly after birth. Fifty percent of the B2 group strains carry in their genome the pks gene cluster encoding the synthesis of a nonribosomal peptide-polyketide hybrid genotoxin named colibactin. In this review, we summarize both clinical and experimental evidence associating the recently emerging neonatal B2 E. coli population with several pathology and discuss how the expression of colibactin by both normal inhabitants of intestinal microflora and virulent strains may darken the borderline between commensalism and pathogenicity.
Angiocrine signaling in the hepatic sinusoids in health and disease
Authors: Kostallari Enis , Shah Vijay H.
Published: June 2016

The capillary network irrigating the liver is important not only for nutrient and oxygen delivery, but also for the signals distributed to other hepatic cell types necessary to maintain liver homeostasis. During development, endothelial cells are a key component in liver zonation. In adulthood, they maintain hepatic stellate cells and hepatocytes in quiescence. Their importance in pathobiology is highlighted in liver regeneration and chronic liver diseases, where they coordinate paracrine cell behavior. During regeneration, liver sinusoidal endothelial cells induce hepatocyte proliferation and angiogenesis. During fibrogenesis, they undergo morphological and functional changes, which are reflected by their role in hepatic stellate cell activation, inflammation, and distorted sinusoidal structure. Therapeutic strategies to target angiocrine signaling are in progress but are in the early stages. Here, we offer a short synthesis of recent studies on angiocrine signaling in liver homeostasis, regeneration, and fibrogenesis.
Contribution of programmed cell death receptor (PD)-1 to Kupffer cell dysfunction in murine polymicrobial sepsis
Authors: Wang Fei , Huang Xin , Chung Chun-Shiang , Chen Yaping , Hutchins Noelle A. , Ayala Alfred
Published: June 2016

Recent studies suggest that coinhibitory receptors appear to be important in contributing sepsis-induced immunosuppression. Our laboratory reported that mice deficient in programmed cell death receptor (PD)-1 have increased bacterial clearance and improved survival in experimental sepsis induced by cecal ligation and puncture (CLP). In response to infection, the liver clears the blood of bacteria and produces cytokines. Kupffer cells, the resident macrophages in the liver, are strategically situated to perform the above functions. However, it is not known if PD-1 expression on Kupffer cells is altered by septic stimuli, let alone if PD-1 ligation contributes to the altered microbial handling seen. Here we report that PD-1 is significantly upregulated on Kupffer cells during sepsis. PD-1-deficient septic mouse Kupffer cells displayed markedly enhanced phagocytosis and restoration of the expression of major histocompatibility complex II and CD86, but reduced CD80 expression compared with septic wild-type (WT) mouse Kupffer cells. In response to ex vivo LPS stimulation, the cytokine productive capacity of Kupffer cells derived from PD-1−/− CLP mice exhibited a marked, albeit partial, restoration of the release of IL-6, IL-12, IL-1β, monocyte chemoattractant protein-1, and IL-10 compared with septic WT mouse Kupffer cells. In addition, PD-1 gene deficiency decreased LPS-induced apoptosis of septic Kupffer cells, as indicated by decreased levels of cleaved caspase-3 and reduced terminal deoxynucleotidyl transferase dUTP nick end-labeling-positive cells. Exploring the signal pathways involved, we found that, after ex vivo LPS stimulation, septic PD-1−/− mouse Kupffer cells exhibited an increased Akt phosphorylation and a reduced p38 phosphorylation compared with septic WT mouse Kupffer cells. Together, these results indicate that PD-1 appears to play an important role in regulating the development of Kupffer cell dysfunction seen in sepsis.
Ataxia telangiectasia-mutated kinase deficiency exacerbates left ventricular dysfunction and remodeling late after myocardial infarction
Authors: Daniel Laura L. , Scofield Stephanie L. C. , Thrasher Patsy , Dalal Suman , Daniels Christopher R. , Foster Cerrone R. , Singh Mahipal , Singh Krishna
Published: June 2016

Ataxia telangiectasia-mutated kinase (ATM), a cell cycle checkpoint protein, is activated in response to DNA damage and oxidative stress. We have previously shown that ATM deficiency is associated with increased apoptosis and fibrosis and attenuation of cardiac dysfunction early (1–7 days) following myocardial infarction (MI). Here, we tested the hypothesis that enhanced fibrosis and apoptosis, as observed early post-MI during ATM deficiency, exacerbate cardiac dysfunction and remodeling in ATM-deficient mice late post-MI. MIs were induced in wild-type (WT) and ATM heterozygous knockout (hKO) mice by ligation of the left anterior descending artery. Left ventricular (LV) structural and functional parameters were assessed by echocardiography 14 and 28 days post-MI, whereas biochemical parameters were measured 28 days post-MI. hKO-MI mice exhibited exacerbated LV dysfunction as observed by increased LV end-systolic volume and decreased percent fractional shortening and ejection fraction. Infarct size and thickness were not different between the two genotypes. Myocyte cross-sectional area was greater in hKO-MI group. The hKO-MI group exhibited increased fibrosis in the noninfarct and higher expression of α-smooth muscle actin (myofibroblast marker) in the infarct region. Apoptosis and activation of GSK-3β (proapoptotic kinase) were significantly lower in the infarct region of hKO-MI group. Matrix metalloproteinase 2 (MMP-2) expression was not different between the two genotypes. However, MMP-9 expression was significantly lower in the noninfarct region of hKO-MI group. Thus ATM deficiency exacerbates cardiac remodeling late post-MI with effects on cardiac function, fibrosis, apoptosis, and myocyte hypertrophy.
Sympathetic nervous response to ischemia-reperfusion injury in humans is altered with remote ischemic preconditioning
Authors: Lambert Elisabeth A. , Thomas Colleen J. , Hemmes Robyn , Eikelis Nina , Pathak Atul , Schlaich Markus P. , Lambert Gavin W.
Published: June 2016

Sympathetic neural activation may be detrimentally involved in tissue injury caused by ischemia-reperfusion (IR). We examined the effects of experimental IR in the forearm on sympathetic nerve response, finger reactive hyperemia, and oxidative stress, and the protection afforded by applying remote ischemic preconditioning (RIPC). Ischemia was induced in the forearm for 20 min in healthy volunteers. RIPC was induced by applying two cycles, 5 min each, of ischemia and reperfusion to the upper leg immediately before IR. We examined muscle sympathetic nerve activity (MSNA) in the contralateral leg using microneurography, finger reactive hyperemia [ischemic reactive hyperemia index (RHI)], erythrocyte production of reduced gluthathione (GSH), and plasma nitric oxide (NO) concentration. In controls (no RIPC; n = 15), IR increased MSNA in the early and late phase of ischemia (70% at 5 min; 101% at 15 min). In subjects who underwent RIPC ( n = 15), the increase in MSNA was delayed to the late phase of ischemia and increased only by 40%. GSH increased during ischemia in the control group ( P = 0.05), but not in those who underwent RIPC. Nitrate and nitrite concentration, taken as an index of NO availability, decreased during the reperfusion period in control individuals ( P < 0.05), while no change was observed in those who underwent RIPC. Experimental IR did not affect RHI in the control condition, but a significant vasodilatory response occurred in the RIPC group ( P < 0.05). RIPC attenuated ischemia-induced sympathetic activation, prevented the production of an erythrocyte marker of oxidative stress and the reduction of NO availability, and ameliorated RHI.
Dysfunction of mitochondria and deformed gap junctions in the heart of IL-18-deficient mice
Authors: Li Wen , Jin Denan , Hata Masaki , Takai Shinji , Yamanishi Kyosuke , Shen Weili , El-Darawish Yosif , Yamanishi Hiromichi , Okamura Haruki
Published: June 2016

Interleukin-18 (IL-18) was discovered as an interferon-γ-inducing factor and has been regarded as a proinflammatory cytokine. However, IL-18 is ubiquitously expressed both in immune/inflammatory cells and in nonimmune cells, and its biological roles have not been sufficiently elucidated. Here, we demonstrate that IL-18-deficient [IL-18 knockout (KO)] mice have heart abnormalities that may be related to impaired autophagy. In endurance running tests, IL-18KO mice ran significantly shorter distances compared with wild-type (WT) mice. Echocardiographs indicated disability in the systolic and diastolic functions of the IL-18KO mouse heart. Immunostaining of connexin 43 showed heterogeneous localization of gap junctions in the lateral membranes of the IL-18KO cardiac myocytes. Western blotting analysis revealed decreased phosphorylated connexin 43 in the IL-18KO heart. Electron microscopy revealed unusual localization of intercalated disks, swollen or damaged mitochondria, and broad, indistinct Z-lines in the IL-18KO heart. In accordance with the morphological observation, mitochondrial respiratory function, including that of complexes I and IV, was impaired, and production of reactive oxygen species was augmented in IL-18KO hearts. Notably, levels of LC3-II were markedly lower in the IL-18KO hearts than in WT hearts. In the culture of cardiac myocytes of IL-18KO neonates, exogenous IL-18 upregulated LC3-II and increased the number of intact mitochondria with high mitochondrial membrane potential. These results indicated that IL-18 has roles apart from those as a proinflammatory cytokine in cardiac myocytes and suggested that IL-18 contributes to the homeostatic maintenance of mitochondrial function and gap-junction turnover in cardiac myocytes, possibly by upregulating autophagy.
TLR9 expression is required for the development of cigarette smoke-induced emphysema in mice
Authors: Foronjy Robert F. , Salathe Matthias A. , Dabo Abdoulaye J. , Baumlin Nathalie , Cummins Neville , Eden Edward , Geraghty Patrick
Published: June 2016

The expression of Toll-like receptor (TLR)-9, a pathogen recognition receptor that recognizes unmethylated CpG sequences in microbial DNA molecules, is linked to the pathogenesis of several lung diseases. TLR9 expression and signaling was investigated in animal and cell models of chronic obstructive pulmonary disease (COPD). We observed enhanced TLR9 expression in mouse lungs following exposure to cigarette smoke. Tlr9−/− mice were resistant to cigarette smoke-induced loss of lung function as determined by mean linear intercept, total lung capacity, lung compliance, and tissue elastance analysis. Tlr9 expression also regulated smoke-mediated immune cell recruitment to the lung; apoptosis; expression of granulocyte-colony stimulating factor (G-CSF), the CXCL5 protein, and matrix metalloproteinase-2 (MMP-2); and protein tyrosine phosphatase 1B (PTP1B) activity in the lung. PTP1B, a phosphatase with anti-inflammatory abilities, was identified as binding to TLR9. In vivo delivery of a TLR9 agonist enhanced TLR9 binding to PTP1B, which inactivated PTP1B. Ptp1b−/− mice had elevated lung concentrations of G-CSF, CXCL5, and MMP-2, and tissue expression of type-1 interferon following TLR9 agonist administration, compared with wild-type mice. TLR9 responses were further determined in fully differentiated normal human bronchial epithelial (NHBE) cells isolated from nonsmoker, smoker, and COPD donors, and then cultured at air liquid interface. NHBE cells from smokers and patients with COPD expressed more TLR9 and secreted greater levels of G-CSF, IL-6, CXCL5, IL-1β, and MMP-2 upon TLR9 ligand stimulation compared with cells from nonsmoker donors. Although TLR9 combats infection, our results indicate that TLR9 induction can affect lung function by inactivating PTP1B and upregulating expression of proinflammatory cytokines.
Lung epithelial MyD88 drives early pulmonary clearance of Pseudomonas aeruginosa by a flagellin dependent mechanism
Authors: Anas Adam A. , van Lieshout Miriam H. P. , Claushuis Theodora A. M. , de Vos Alex F. , Florquin Sandrine , de Boer Onno J. , Hou Baidong , van't Veer Cornelis , van der Poll Tom
Published: June 2016

Pseudomonas aeruginosa is a flagellated pathogen frequently causing pneumonia in hospitalized patients and sufferers of chronic lung disease. Here we investigated the role of the common Toll-like receptor (TLR) adaptor myeloid differentiation factor (MyD)88 in myeloid vs. lung epithelial cells in clearance of P. aeruginosa from the airways. Mice deficient for MyD88 in lung epithelial cells (Sftpccre -MyD88-lox mice) or myeloid cells (LysMcre- MyD88-lox mice) and bone marrow chimeric mice deficient for TLR5 (the receptor recognizing Pseudomonas flagellin) in either parenchymal or hematopoietic cells were infected with P. aeruginosa via the airways. Sftpccre -MyD88-lox mice demonstrated a reduced influx of neutrophils into the bronchoalveolar space and an impaired early antibacterial defense after infection with P. aeruginosa, whereas the response of LysMcre- MyD88-lox mice did not differ from control mice. The immune-enhancing role of epithelial MyD88 was dependent on recognition of pathogen-derived flagellin by epithelial TLR5, as demonstrated by an unaltered clearance of mutant P. aeruginosa lacking flagellin from the lungs of Sftpccre -MyD88-lox mice and an impaired bacterial clearance in bone marrow chimeric mice lacking TLR5 in parenchymal cells. These data indicate that early clearance of P. aeruginosa from the airways is dependent on flagellin-TLR5-MyD88-dependent signaling in respiratory epithelial cells.
Aging-related changes in respiratory system mechanics and morphometry in mice
Authors: Elliott Jonathan E. , Mantilla Carlos B. , Pabelick Christina M. , Roden Anja C. , Sieck Gary C.
Published: June 2016

Previous work investigating respiratory system mechanics in mice has reported an aging-related increase in compliance and mean linear intercept ( Lm). However, these changes were assessed using only a young (2-mo-old) and old (20- and 26-mo-old) group yet were interpreted to reflect a linear evolution across the life span. Therefore, to investigate respiratory system mechanics and lung morphometry across a more complete spectrum of ages, we utilized 2 (100% survival, n = 6)-, 6 (100% survival, n = 12)-, 18 (90% survival, n = 12)-, 24 (75% survival, n = 12)-, and 30 (25% survival, n = 12)-mo-old C57BL/6 mice. We found a nonlinear aging-related decrease in respiratory system resistance and increase in dynamic compliance and hysteresis between 2- and 24-mo-old mice. However, in 30-mo-old mice, respiratory system resistance increased, and dynamic compliance and hysteresis decreased relative to 24-mo-old mice. Respiratory system impedance spectra were measured between 1–20.5 Hz at positive end-expiratory pressures (PEEP) of 1, 3, 5, and 7 cmH2O. Respiratory system resistance and reactance at each level of PEEP were increased and decreased, respectively, only in 2-mo-old animals. No differences in the respiratory system impedance spectra were observed in 6-, 18-, 24-, and 30-mo-old mice. Additionally, lungs were fixed following tracheal instillation of 4% paraformaldehyde at 25 cmH2O and processed for Lm and airway collagen deposition. There was an aging-related increase in Lm consistent with emphysematous-like changes and no evidence of increased airway collagen deposition. Accordingly, we demonstrate nonlinear aging-related changes in lung mechanics and morphometry in C57BL/6 mice.
(Z)-3,5,4′-Trimethoxystilbene Limits Hepatitis C and Cancer Pathophysiology by Blocking Microtubule Dynamics and Cell-Cycle Progression
Authors: Nguyen Charles B. , Kotturi Hari , Waris Gulam , Mohammed Altaf , Chandrakesan Parthasarathy , May Randal , Sureban Sripathi , Weygant Nathaniel , Qu Dongfeng , Rao Chinthalapally V. , Dhanasekaran Danny N. , Bronze Michael S. , Houchen Courtney W. , Ali Naushad
Published: June 2016

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths worldwide. Chronic hepatitis C virus (HCV) infection causes induction of several tumors/cancer stem cell (CSC) markers and is known to be a major risk factor for development of HCC. Therefore, drugs that simultaneously target viral replication and CSC properties are needed for a risk-free treatment of advanced stage liver diseases, including HCC. Here, we demonstrated that (Z)-3,5,4′-trimethoxystilbene (Z-TMS) exhibits potent antitumor and anti-HCV activities without exhibiting cytotoxicity to human hepatocytes in vitro or in mice livers. Diethylnitrosamine (DEN)/carbon tetrachloride (CCl4) extensively induced expression of DCLK1 (a CSC marker) in the livers of C57BL/6 mice following hepatic injury. Z-TMS exhibited hepatoprotective effects against DEN/CCl4-induced injury by reducing DCLK1 expression and improving histologic outcomes. The drug caused bundling of DCLK1 with microtubules and blocked cell-cycle progression at G2–M phase in hepatoma cells via downregulation of CDK1, induction of p21cip1/waf1 expression, and inhibition of Akt (Ser473) phosphorylation. Z-TMS also inhibited proliferation of erlotinib-resistant lung adenocarcinoma cells (H1975) bearing the T790M EGFR mutation, most likely by promoting autophagy and nuclear fragmentation. In conclusion, Z-TMS appears to be a unique therapeutic agent targeting HCV and concurrently eliminating cells with neoplastic potential during chronic liver diseases, including HCC. It may also be a valuable drug for targeting drug-resistant carcinomas and cancers of the lungs, pancreas, colon, and intestine, in which DCLK1 is involved in tumorigenesis. Cancer Res; 76(16); 4887–96. ©2016 AACR.
Survival of Patients with Gastrointestinal Cancers Can Be Predicted by a Surrogate microRNA Signature for Cancer Stem–like Cells Marked by DCLK1 Kinase
Authors: Weygant Nathaniel , Ge Yang , Qu Dongfeng , Kaddis John S. , Berry William L. , May Randal , Chandrakesan Parthasarathy , Bannerman-Menson Edwin , Vega Kenneth J. , Tomasek James J. , Bronze Michael S. , An Guangyu , Houchen Courtney W.
Published: June 2016

Doublecortin-like kinase 1 (DCLK1) is a gastrointestinal (GI) tuft cell kinase that has been investigated as a biomarker of cancer stem–like cells in colon and pancreatic cancers. However, its utility as a biomarker may be limited in principle by signal instability and dilution in heterogeneous tumors, where the proliferation of diverse tumor cell lineages obscures the direct measurement of DCLK1 activity. To address this issue, we explored the definition of a miRNA signature as a surrogate biomarker for DCLK1 in cancer stem–like cells. Utilizing RNA/miRNA-sequencing datasets from the Cancer Genome Atlas, we identified a surrogate 15-miRNA expression signature for DCLK1 activity across several GI cancers, including colon, pancreatic, and stomach cancers. Notably, Cox regression and Kaplan–Meier analysis demonstrated that this signature could predict the survival of patients with these cancers. Moreover, we identified patient subgroups that predicted the clinical utility of this DCLK1 surrogate biomarker. Our findings greatly strengthen the clinical significance for DCLK1 expression across GI cancers. Further, they provide an initial guidepost toward the development of improved prognostic biomarkers or companion biomarkers for DCLK1-targeted therapies to eradicate cancer stem–like cells in these malignancies. Cancer Res; 76(14); 4090–9. ©2016 AACR.
Lenalidomide Induces Interleukin-21 Production by T Cells and Enhances IL21-Mediated Cytotoxicity in Chronic Lymphocytic Leukemia B Cells
Authors: Browning Rebekah L. , Byrd William H. , Gupta Nikhil , Jones Jeffrey , Mo Xiaokui , Hertlein Erin , Yu Lianbo , Muthusamy Natarajan , Byrd John C.
Published: June 2016

The immunomodulatory drug lenalidomide has demonstrated efficacy in patients with chronic lymphocytic leukemia (CLL), despite a lack of direct cytotoxic effects in vitro. The mechanism of lenalidomide efficacy in vivo is thought to occur via a combination of enhanced immune activity and an alteration of tumor cell–microenvironment interactions. We demonstrate in whole blood from patients with CLL that lenalidomide significantly depletes malignant B cells. Lenalidomide also induced production of interleukin-21 (IL21) and its mRNA in T cells from patients with CLL. In addition, lenalidomide enhanced upregulation of functional IL21 receptor (IL21R) on the cell surface and increased receptor mRNA in vitro. The in vitro combination of IL21 and lenalidomide enhanced IL21-mediated cytotoxicity toward CLL cells through a variety of mechanisms. We show association of cell death with upregulation of Bid by IL21, enhanced upregulation of Bid by the combination therapy, and diminished Lck and downstream BCR signaling activation of Syk and PLCG2. Collectively, we demonstrated an immune cell–tumor cell interaction through lenalidomide-mediated induction of IL21 and IL21R, with enhanced IL21-mediated cytotoxicity, which provides justification for this combination in clinical trials for patients with CLL. Cancer Immunol Res; 4(8); 698–707. ©2016 AACR.
Atrioventricular Node Slow‐Pathway Ablation Reduces Atrial Fibrillation Inducibility: A Neuronal Mechanism
Authors: Yin Xiaomeng , Xi Yutao , Zhang Shulong , Xia Yunlong , Gao Lianjun , Liu Jinqiu , Cheng Nancy , Chen Qi , Cheng Jie , Yang Yanzong
Published: June 2016

Background

Radiofrequency ablation (
RFA
) for atrioventricular nodal reentrant tachycardia appears to reduce atrial tachycardia, which might relate to parasympathetic denervation at cardiac ganglionated plexuses.

Methods and Results

Compared to 7 control canines without
RFA
, in 14 canines,
RFA
at the bottom of Koch's triangle attenuated vagal stimulation–induced effective refractory periods prolongation in atrioventricular nodal and discontinuous atrioventricular conduction curves but had no effect on the sinoatrial node.
RFA
attenuated vagal stimulation–induced atrial effective refractory periods shortening and vulnerability window of atrial fibrillation widening in the inferior right atrium and proximal coronary sinus but not in the high right atrium and distal coronary sinus. Moreover,
RFA
anatomically impaired the epicardial ganglionated plexuses at the inferior vena cava‒inferior left atrial junction. This method was also investigated in 42 patients who had undergone ablation of atrioventricular nodal reentrant tachycardia, or 12 with an accessory pathway (
AP
) at the posterior septum (
AP
‐
PS
), and 34 patients who had an
AP
at the free wall as control. In patients with atrioventricular nodal reentrant tachycardia and
AP
‐
PS
,
RFA
at the bottom of Koch's triangle prolonged atrial effective refractory periods and reduced vulnerability windows of atrial fibrillation widening at the inferior right atrium, distal coronary sinus and proximal coronary sinus but not the high right atrium. In patients with
AP
‐free wall,
RFA
had no significant atrial effects.

Conclusions

RFA
at the bottom of Koch's triangle attenuated local autonomic innervation in the atrioventricular node and atria, decreased vagal stimulation–induced discontinuous atrioventricular nodal conduction, and reduced atrial fibrillation inducibility due to impaired ganglionated plexuses. In patients with atrioventricular nodal reentrant tachycardia or
AP
‐
PS
,
RFA
prolonged atrial effective refractory periods, and narrowed vulnerability windows of atrial fibrillation.
Dysfunction of the Voltage‐Gated K
+
Channel β2 Subunit in a Familial Case of Brugada Syndrome
Authors: Portero Vincent , Le Scouarnec Solena , Es‐Salah‐Lamoureux Zeineb , Burel Sophie , Gourraud Jean‐Baptiste , Bonnaud Stéphanie , Lindenbaum Pierre , Simonet Floriane , Violleau Jade , Baron Estelle , Moreau Eléonore , Scott Carol , Chatel Stéphanie , Loussouarn Gildas , O'Hara Thomas , Mabo Philippe , Dina Christian , Le Marec Hervé , Schott Jean‐Jacques , Probst Vincent , Baró Isabelle , Marionneau Céline , Charpentier Flavien , Redon Richard
Published: June 2016

Background

The Brugada syndrome is an inherited cardiac arrhythmia associated with high risk of sudden death. Although 20% of patients with Brugada syndrome carry mutations in

SCN
5A

, the molecular mechanisms underlying this condition are still largely unknown.

Methods and Results

We combined whole‐exome sequencing and linkage analysis to identify the genetic variant likely causing Brugada syndrome in a pedigree for which

SCN
5A

mutations had been excluded. This approach identified 6 genetic variants cosegregating with the Brugada electrocardiographic pattern within the pedigree. In silico gene prioritization pointed to 1 variant residing in

KCNAB
2

, which encodes the voltage‐gated K
+
channel β2‐subunit (Kvβ2‐R12Q). Kvβ2 is widely expressed in the human heart and has been shown to interact with the fast transient outward K
+
channel subunit Kv4.3, increasing its current density. By targeted sequencing of the

KCNAB
2

gene in 167 unrelated patients with Brugada syndrome, we found 2 additional rare missense variants (L13F and V114I). We then investigated the physiological effects of the 3

KCNAB
2

variants by using cellular electrophysiology and biochemistry. Patch‐clamp experiments performed in
COS
‐7 cells expressing both Kv4.3 and Kvβ2 revealed a significant increase in the current density in presence of the R12Q and L13F Kvβ2 mutants. Although biotinylation assays showed no differences in the expression of Kv4.3, the total and submembrane expression of Kvβ2‐R12Q were significantly increased in comparison with wild‐type Kvβ2.

Conclusions

Altogether, our results indicate that Kvβ2 dysfunction can contribute to the Brugada electrocardiographic pattern.
Relationship Between Low‐Density Lipoprotein Cholesterol, Free Proprotein Convertase Subtilisin/Kexin Type 9, and Alirocumab Levels After Different Lipid‐Lowering Strategies
Authors: Rey Jacques , Poitiers Franck , Paehler Tobias , Brunet Aurélie , DiCioccio A. Thomas , Cannon Christopher P. , Surks Howard K. , Pinquier Jean‐Louis , Hanotin Corinne , Sasiela William J.
Published: June 2016

Background

Alirocumab undergoes target‐mediated clearance via binding of proprotein convertase subtilisin/kexin type 9 (
PCSK
9). Statins increase
PCSK
9 levels; the effects of nonstatin lipid‐lowering therapies are unclear. Every‐4‐weeks dosing of alirocumab may be appropriate for some patients in absence of background statin but is not yet approved.

Methods and Results

Low‐density lipoprotein cholesterol (
LDL
‐C),
PCSK
9, and alirocumab levels were assessed in subjects (
LDL
‐C >130 mg/dL, n=24/group) after a 4‐week run‐in taking oral ezetimibe, fenofibrate, or ezetimibe placebo, when alirocumab 150 mg every 4 weeks (days 1, 29, and 57) was added. Maximal mean
LDL
‐C reductions from day −1 baseline (prealirocumab) occurred on day 71 in all groups: alirocumab plus placebo, 47.4%; alirocumab plus ezetimibe, 56.6%; and alirocumab plus fenofibrate, 54.3%.
LDL
‐C reductions were sustained through day 85 with alirocumab plus placebo (47.0%); the duration of effect was slightly diminished at day 85 versus day 71 with ezetimibe (49.6%) or fenofibrate combinations (43.2%). Free
PCSK
9 concentrations were lowest at day 71 in all groups, then increased over time; by day 85, free
PCSK
9 concentrations were higher, and alirocumab levels lower, with alirocumab plus fenofibrate, and to a lesser extent alirocumab plus ezetimibe, versus alirocumab plus placebo.

Conclusions

Alirocumab 150 mg every 4 weeks produced maximal
LDL
‐C reductions of 47% in combination with placebo and 54% to 57% in combination with ezetimibe or fenofibrate. The oral lipid‐lowering therapies appear to increase
PCSK
9 levels, leading to increased alirocumab clearance. Although the duration of effect was modestly diminished with alirocumab plus ezetimibe/fenofibrate versus placebo, the effect was less than observed in trials with background statins, and it would not preclude the use of alirocumab every 4 weeks in patients taking these nonstatin lipid‐lowering therapies concomitantly.

Clinical Trial Registration

URL
:
http://www.Clinicaltrials.gov
. Unique identifier:
NCT
01723735.
Variation in Practice Regarding Pretreatment With Dual Antiplatelet Therapy for Patients With Non–ST Elevation Myocardial Infarction
Authors: Shafiq Ali , Valle Javier , Jang Jae‐Sik , Qintar Mohammed , Gosch Kensey , Cohen David J. , Singh Mandeep , Bach Richard , Spertus John A.
Published: June 2016

Background

Despite guideline recommendations, a significant number of patients with non–
ST
elevation myocardial infarction (
NSTEMI
) do not receive dual antiplatelet therapy (
DAPT
) before angiography “pretreatment.” While there may be valid clinical reasons to not pretreat, such as concern for bleeding or multivessel disease warranting coronary artery bypass graft surgery, the degree of variability and factors associated with
DAPT
pretreatment are unknown.

Methods and Results

From the multicenter
TRIUMPH
registry, 1632
NSTEMI
patients were not taking
DAPT
on admission and were included in the study cohort. Among the study patients, only 22% patients received
DAPT
pretreatment. A multivariable logistic regression model showed that race other than white or black (odds ratio [
OR]
0.41, 95%
CI
0.21–0.83), hemoglobin level (
OR
1.18, 95%
CI
1.08–1.29), patients’ bleeding risk (assessed with
NCDR
Cath
PCI
Bleeding Risk Score) (
OR
0.85, 95%
CI
0.74–0.99), and severe left ventricular dysfunction (
OR
0.3, 95%
CI
0.13–0.65) were the main predictors of pretreatment with
DAPT
, whereas likelihood of needing coronary artery bypass graft surgery (
GRACE
prediction model) was not (
OR
1.09, 95%
CI
0.88–1.35). Median ORs were calculated to assess variability of receiving
DAPT
pretreatment across sites after adjustment for patient characteristics. Receiving
DAPT
pretreatment varied substantially across sites (range 0–100%, mean
OR
3.94,
P
<0.0001).

Conclusions

While deviating from guideline‐recommended
DAPT
pretreatment in patients with
NSTEMI
was associated with patient factors (eg, bleeding risk), marked variation was present across sites after accounting for patient‐level characteristics. This suggests that site‐level interventions are needed to improve concordance with current guidelines.
Utility of the Highly Articulated Flex Robotic System for Head and Neck Procedures
Authors: Newsome Hillary , Mandapathil Magis , Koh Yoon Woo , Duvvuri Umamaheswar
Published: June 2016

Objective:

Robotic head and neck surgery potentially reduces the morbidity associated with traditional open procedures. This study’s goal was to employ a novel highly articulated robotic system (Flex Robotic System) for head and neck procedures, including a postauricular facelift approach thyroidectomy, submandibular gland (SMG) removal, and cervical lymphadenectomy.

Study Design:

It was hypothesized that the Medrobotics Flex Robotic System could be used for transcervical head and neck surgical procedures.

Methods:

Three fresh upper body human cadavers were used. The Flex Robotic System was used to complete a thyroidectomy, neck dissection, and SMG removal on each cadaver.

Results:

A postauricular incision and flap was manually raised. The robotic system was positioned on the right side of the cadaver’s head. The system’s manually controlled flexible instruments and highly shapeable, robot-assisted scope were used to perform a thyroid lobectomy. Neck dissection and SMG removal were also performed.

Conclusions:

Although a promising technology, the current robotic system (Intuitive Surgical Inc, Sunnyvale, California, USA) has limitations due to its rigid and large configuration, which decreases exposure and access. The new system’s shapeable, computer-assisted scope seeks to reduce some of these difficulties and may be better adapted for transcervical approaches to the neck operations.
Esophageal Swallowing Timing Measures in Healthy Adults During Videofluoroscopy
Authors: Miles Anna , Clark Stacie , Jardine Marie , Allen Jacqui
Published: June 2016

Objectives:

Establishing the range of normal esophageal bolus transit times (ETT) is valuable when distinguishing pathology from normal variance, especially in elderly patients, and has not been documented for paste or pill. The aim of this study was to measure esophageal transit of liquid, paste, and pill during upright videofluoroscopy.

Methods:

One hundred eighteen healthy adults (mean age 54; range 20-98 years; SD = 21.40) with no complaints of dysphagia completed a videofluoroscopy with esophageal visualization including 20 ml liquid barium, 5 ml paste, and pill.

Results:

Mean ETTs were: 20 ml fluid, 10.7 seconds (SD = 13.6, median = 5.76, IQR = 4.33, range, 2.0-60.0); pill, 25.3 seconds (SD = 24.0, median = 12.70, IQR = 49.81, range, 1.0-60.0); paste, 28.6 seconds (SD = 23.31, median = 17.47, IQR = 53, range, 4.0-60.0). Age was significantly associated with increasing 20 ml fluid ETT ( P < .001) but not pill ( P = .58) or paste ETT ( P = .12). Fluid ETT over 10 seconds occurred in 10% of participants between 20 and 59 years, in comparison to 35% over 60 years ( P < .001).

Conclusions:

These normative values provide a standardized protocol and guidance in interpretation when completing esophageal visualization as part of videofluoroscopy. While measuring fluid ETT may support referral for further specialist investigations, slower paste and pill ETT may be normal findings. Age-related slowing in fluid ETT was seen in healthy adults. Further investigation of ETT is needed in both normal and dysphagic subjects.
Linear and Nonlinear Calibration Methods for Predicting Mechanical Properties of Polypropylene Pellets Using Raman Spectroscopy
Authors: Banquet-Terán Julio , Johnson-Restrepo Boris , Hernández-Morelo Alveiro , Ropero Jorge , Fontalvo-Gomez Miriam , Romañach Rodolfo J
Published: June 2016

A nondestructive and faster methodology to quantify mechanical properties of polypropylene (PP) pellets, obtained from an industrial plant, was developed with Raman spectroscopy. Raman spectra data were obtained from several types of samples such as homopolymer PP, random ethylene–propylene copolymer, and impact ethylene–propylene copolymer. Multivariate calibration models were developed by relating the changes in the Raman spectra to mechanical properties determined by ASTM tests (Young’s traction modulus, tensile strength at yield, elongation at yield on traction, and flexural modulus at 1% secant). Several strategies were evaluated to build robust models including the use of preprocessing methods (baseline correction, vector normalization, de-trending, and standard normal variate), selecting the best subset of wavelengths to model property response and discarding irrelevant variables by applying genetic algorithm (GA). Linear multivariable models were investigated such as partial least square regression (PLS) and PLS with genetic algorithm (GA-PLS) while nonlinear models were implemented with artificial neural network (ANN) preceded by GA (GA-ANN). The best multivariate calibration models were obtained when a combination of genetic algorithms and artificial neural network were used on Raman spectral data with relative standard errors (%RSE) from 0.17 to 0.41 for training and 0.42 to 0.88% validation data sets.
Comparative Variable Temperature Studies of Polyamide II with a Benchtop Fourier Transform and a Miniature Handheld Near-Infrared Spectrometer Using 2D-COS and PCMW-2D Analysis
Authors: Unger Miriam , Pfeifer Frank , Siesler Heinz W.
Published: June 2016

The main objective of this communication is to compare the performance of a miniaturized handheld near-infrared (NIR) spectrometer with a benchtop Fourier transform near-infrared (FT-NIR) spectrometer. Generally, NIR spectroscopy is an extremely powerful analytical tool to study hydrogen-bonding changes of amide functionalities in solid and liquid materials and therefore variable temperature NIR measurements of polyamide II (PAII) have been selected as a case study. The information content of the measurement data has been further enhanced by exploiting the potential of two-dimensional correlation spectroscopy (2D-COS) and the perturbation correlation moving window two-dimensional (PCMW2D) evaluation technique. The data provide valuable insights not only into the changes of the hydrogen-bonding structure and the recrystallization of the hydrocarbon segments of the investigated PAII but also in their sequential order. Furthermore, it has been demonstrated that the 2D-COS and PCMW2D results derived from the spectra measured with the miniaturized NIR instrument are equivalent to the information extracted from the data obtained with the high-performance FT-NIR instrument.
Can Professional Development Improve School Leadership? Results From a Randomized Control Trial Assessing the Impact of McREL’s Balanced Leadership Program on Principals in Rural Michigan Schools
Authors: Miller Robert James , Goddard Roger D. , Kim Minjung , Jacob Robin , Goddard Yvonne , Schroeder Patricia
Published: June 2016

Purpose: This multiyear experimental study was designed to examine (1) the causal impact of McREL International’s Balanced Leadership® Professional Development (BLPD) program on school principals’ learning, beliefs, and behaviors and (2) whether there were differences in the types of outcomes the professional development influenced. Outcomes included principals’ reported sense of efficacy, perceptions of school climate, and leadership behaviors. Research Methods: Approximately 100 school principals in rural Michigan were randomly assigned to either a treatment group that was offered 2 years of BLPD training or a control group that conducted business as usual. We employed principal survey data from the first and third years of the School Leadership Improvement Study. The treatment effect on each outcome was assessed through regression analysis, which controlled for baseline scores and school demographics. Findings: Results from the School Leadership Improvement Study show that BLPD participants reported substantively significant growth on the majority of the outcomes targeted by the program. Interestingly, treatment principals were more likely to report growth on broad, school-level outcomes than in areas that involved them working directly with teachers. Implications: This evaluation demonstrates that the McREL Balanced Leadership program caused gains in the majority of knowledge, belief, and behavior outcomes with the largest impacts on principals’ sense of efficacy for instructional improvement, reported ability to bring about change, and strength of norms for teachers’ instructional practice. The authors explore possibilities for why broad, school-level outcomes were more likely to be affected than areas that involve principals more directly in teachers’ work.
Men’s physical activity and dietary behaviours on Kangaroo Island, South Australia
Authors: Drummond Murray , Elliott Sam , Drummond Claire , Lewis Felicity
Published: June 2016

Background:

Men’s health has been subjected to diverse approaches to research over the past two decades. Much of the literature has focused on specific medical and health issues. Other contributions have focused more broadly on masculinities and its relationship to health. It is arguable that there has not been a lot of attention paid to Australian rural men’s health and even less on their understanding of health as it relates to physical activity and dietary behavior.

Objectives:

To gain a better understanding of these issues this paper provides rich, descriptive qualitative data from men living on Kangaroo Island, which is 13.5 kilometres off the South Australian mainland and is regarded as a rural and remote area.

Methods:

Qualitative data is used to develop greater understanding of the men’s attitudes and behaviours as they relate to physical activity and dietary behaviours. The semistructured interviews and focus groups were conducted with 40 men aged between 23–64.

Conclusions:

The results indicated that the locality in which the men lived provided them with an excellent opportunity to be physically active and eat fresh, locally produced, foods. However, it was identified that many of the men did not have a comprehensive understanding of health and seemingly displayed low levels of health knowledge. As a result for many of these men, their physical health was left to chance. There was little evidence of any planned health promotion to assist them with making improvements to their nutrition and physical activity levels as they aged. Recommendations and population-based strategies are provided to assist men living in remote rural settings to enhance not only their health ultimately their health knowledge. This will positively impact community health.
The systems psychodynamics of gendered hiring: Personal anxieties and defensive organizational practices within the New Zealand film industry
Authors: Handy Jocelyn , Rowlands Lorraine
Published: June 2016

This article uses systems psychodynamic concepts to explore the creation and reproduction of gendered inequality within the New Zealand film industry. The article focuses on the ways in which senior film production workers’ anxieties about hiring, or working with, women influence the process of assembling project teams. It suggests that the process of choosing team members creates considerable anxiety for both senior film production workers with responsibility for hiring and lower-status team members who need to rely on them to create high-functioning teams. The industry ideal of the autonomous creative worker is implicitly gendered, conforming more closely to traditional concepts of the unencumbered male worker than traditional ideals of femininity and motherhood. The antithesis between these representations creates anxiety, raising unconscious fears that women as a category are less trustworthy workers. Consequently, discriminatory hiring practices that diminish these anxieties become collectively accepted as rational responses to organizational problems and embedded within the social system as collectively endorsed defences against anxiety. Given that project-based employment is temporary, this pattern of discrimination against women is regularly repeated and contributes to entrenched gender inequality within the film industry. Qualitative data from interviews with 12 male and 13 female film production workers is presented to illustrate this analysis.