bluuebunny/crossref_metadata_2025 huggingface dataset:
Supramolecular complex formation of resorcin[4]arene-modified zinc phthalocyanine and fullerene
Authors: Momose Hitomi , Suzuki Hiroyuki , Kimura Mutsumi
Published: November 2014

A resorcin[4]arene-strapped zinc phthalocyanine 1, in which two benzene rings of the upper rim of resorcin[4]arene were fused to the adjacent phthalocyanine ligand, was synthesized from two phthalonitriles. Introducing resorcin[4]arene on one side of zinc phthalocyanine strongly affects the spectroscopic property of the phthalocyanine. The Q-band of 1 in CH 2 Cl 2 is split into 694 and 740 nm due to the self-protonation of 1 on the meso-nitrogen of phthalocyanine ligand. Bowl-shaped resorcin[4]arene can capture C 60 through the non-covalent interactions, and the complexation between 1 and C 60 results in an efficient photo-induced electron transfer.
Solving polynomial equations with elliptic modular functions
Authors: Schultz Dan
Published: November 2014

Klein's method of solving algebraic equations is discussed and generalized to provide conditions for the unnecessity of the so-called accessory irrationality. We use the modular curve of level N to produce a "hyper-radical" of level N and discuss the accessory irrationalities involved in solving polynomial equations by means of the algebraic hypergeometric functions that define this hyper-radical. The quintic normal forms of Brioschi and Hermite elegantly fit into this framework, and we find explicit conditions for the unnecessary of accessory irrationalities for these normal forms.
Graphene-Based Resonant Sensors for Detection of Ultra-Fine Nanoparticles: Molecular Dynamics and Nonlocal Elasticity Investigations
Authors: Jalali S. Kamal , Naei M. Hassan , Pugno Nicola Maria
Published: November 2014

Application of single layered graphene sheets (SLGSs) as resonant sensors in detection of ultra-fine nanoparticles (NPs) is investigated via molecular dynamics (MD) and nonlocal elasticity approaches. To take into consideration the effect of geometric nonlinearity, nonlocality and atomic interactions between SLGSs and NPs, a nonlinear nonlocal plate model carrying an attached mass-spring system is introduced and a combination of pseudo-spectral (PS) and integral quadrature (IQ) methods is proposed to numerically determine the frequency shifts caused by the attached metal NPs. In MD simulations, interactions between carbon–carbon, metal–metal and metal–carbon atoms are described by adaptive intermolecular reactive empirical bond order (AIREBO) potential, embedded atom method (EAM), and Lennard–Jones (L–J) potential, respectively. Nonlocal small-scale parameter is calibrated by matching frequency shifts obtained by nonlocal and MD simulation approaches with same vibration amplitude. The influence of nonlinearity, nonlocality and distribution of attached NPs on frequency shifts and sensitivity of the SLGS sensors are discussed in detail.
Rapid analysis of spatial distribution of PVPP and hardness of Yinhuang dispersible tablets by NIR-CI
Authors: Wang Yifei , Wu Zhisheng , Wang Zhaoyi , Xu Manfei , Shi Xinyuan , Qiao Yanjiang
Published: November 2014

The present study aimed at investigating the relationship between tablet hardness and homogeneity of different Yinhuang dispersible tablets by near-infrared chemical imaging (NIR-CI) technology. The regularity of best hardness was founded between tablet hardness and the spatial distribution uniformity of Yinhuang dispersible tablets. The ingredients homogeneity of Yinhuang dispersible tablets could be spatially determined using basic analysis of correlation between analysis (BACRA) method and binary image. Then different hardnesses of Yinhuang dispersible tablets were measured. Finally, the regularity between tablet hardness and the spatial distribution uniformity of Yinhuang dispersible tablets was illuminated by quantifying the agglomerate of polyvinyl poly pyrrolidone (PVPP). The result demonstrated that the distribution of PVPP was unstable when the hardness was too large or too small, while the agglomerate of PVPP was smaller and more stable when the best tablet hardness was 75[Formula: see text]N. This paper provided a novel methodology for selecting the best hardness in the tabletting process of Chinese Medicine Tablet.
Strontium-substituted Ba(Ce,Zr)O3-δ oxides for proton conducting membranes
Authors: Zając Wojciech , Hanc Emil
Published: November 2014

This paper is focused on Ba 1-x Sr x( Ce 0.75 Zr 0.25)0.9 Nd 0.1 O 2.95 proton-conducting oxides, for which the effect of substitution of barium by strontium in a full range of compositions is studied. Crystal lattice symmetry, proton conductivity and stability in CO 2 atmosphere are discussed. Substitution of barium by strontium reduces toxicity and does not deteriorate chemical stability, however, crystal lattice of the strontium-substituted perovskites is more distorted, causing reduction of proton conductivity more than one order of magnitude. Balance between opposite tendencies can be found at low Sr content, e.g., 25 at.%.
THE EFFECT OF UPPER-HEATING SYSTEM IN SOLAR WATER STORAGE TANK
Authors: SON HYO SEOK , KWON JAE-WOOK , LEE SEONG HOON , KIM CHUL , HONG HIKI
Published: November 2014

Thermal stratification in the water storage tank of solar heating system is essential to increase the collection efficiency. We previously investigated the stratification performance of side-heating system, where the hot water returning from the collector heats up the side wall of storage tank. Subsequently, we studied an evolved heating system for further improvement, where we added an upper-heating to the side-heating. Here we thoroughly examine the stratification performance of the evolved heating system using TRNSYS-based simulation. As the essential result, contrary to expectation, evolved system does not show substantial improvement of collection efficiency compared to side-heating. However, we confirm that evolved system excels in the useful energy.
NUMERICAL ANALYSIS OF CHEST FREEZER'S CONDENSING UNIT
Authors: DOIPHODE PUSHPAK , TENDOLKAR MANDAR , BALAN PATRIC ANANDA , SAMANTA INDRANEEL
Published: November 2014

Chest freezers are high energy consuming refrigeration systems generally used for food storage. In a chest freezer, components such as condenser coil and fan, compressor, expansion device, etc. are placed at one corner of freezer and are covered by grills. All these components together are referred as condensing unit. Position of grills with respect to these components plays an important role in air flow distribution over condenser coil. Present work deals with the study of air flow distribution in condensing unit using Computational Fluid Dynamics (CFD) tool. Performance of the condenser is analyzed using CoilDesigner®. It is found that some air enters from side grill and bypasses the condenser coil without producing any condensing effect, resulting in degradation of performance. Effect of complete blockage of some portion of side grill on air flow distribution over condenser coil and performance of condenser is presented. Quantity of air flowing over condenser coil measured as Cubic Feet per Minute (CFM) and condenser capacity are found to be increased by approximately 10% and 2%, respectively.
Exendin-4 promotes endothelial barrier enhancement via PKA- and Epac1-dependent Rac1 activation
Authors: Li Ai Q. , Zhao Liang , Zhou Teng F. , Zhang Meng Q. , Qin Xiao M.
Published: November 2014

Among emerging antidiabetic agents, glucagon-like peptide-1 (GLP-1)-based therapies carry special cardiovascular implications, exerting both direct and indirect effects. The control of vascular permeability is of pivotal importance in vascular pathologies. The objective of the present study was to determine the effect of GLP-1 on endothelial barrier function and assess the underlying mechanism(s). Here we show for the first time that the stable GLP-1 analog exendin-4 attenuated the leakage of subcutaneous blood vessels in mice indexed by dye extravasation caused by injections of thrombin. Moreover, in cultured endothelial cells, exendin-4 significantly prevented the thrombin-induced FITC-dextran permeability of endothelial monolayers via GLP-1 receptor. Immunofluorescence microscopy reveals that exendin-4 abrogates detrimental effects of thrombin on VE-cadherin and the F-actin cytoskeleton, with decreased stress fiber and gap formation. Importantly, exendin-4 reduced thrombin-induced tyrosine phosphorylation of VE-cadherin at Y731 and Y658. Moreover, small GTPase Rac1 was significantly activated as a result of exendin-4 treatment. The efficacy of exendin-4 to counteract the barrier-compromising effect of thrombin was blunted when Rac1 was inactivated by Rac1 inhibitor NSC-23766. Inhibition of PKA activity or small-interfering RNA for exchange protein directly activated by cAMP 1 (Epac1) decreased exendin-4-induced Rac1 activation and barrier enhancement, indicating the participation of both PKA and Epac1 in the barrier-stabilizing effect of exendin-4 elicited on thrombin-impaired barrier function. Thus, our findings have uncovered an unpredicted role for exendin-4 in the coordination of vascular permeability and clarified the molecular underpinnings that contribute to barrier restoration initiated by exendin-4.
Loss of NHE8 expression impairs ocular surface function in mice
Authors: Xu Hua , Zhao Yang , Li Jing , Wang Mingwu , Lian Fangru , Gao Minghong , Ghishan Fayez K.
Published: November 2014

Sodium/hydrogen exchanger (NHE) 8 is expressed at the apical membrane of the epithelial cells and plays important roles in neutral sodium absorption in the gastrointestinal tract and the kidney. It also has an important role in epithelial mucosal protection in the gastric gland and the intestine. Although NHE8 has broad tissue distribution, the precise location and the physiological role of NHE8 in the eye remain unknown. In the present study, we successfully detected the expression of NHE8 in the ocular surface by PCR and Western blot in human and mouse eyes. Immunohistochemistry staining located NHE8 protein at the plasma membrane of the epithelial cells in the conjunctiva, the cornea, and the lacrimal gland both in human and mouse. We also detected the expression of downregulated-in-adenoma (DRA, a Cl−/HCO3−transporter) in the ocular surface epithelial cells. Using NHE8−/− mouse model, we found that loss of NHE8 function resulted in reduced tear production and increased corneal staining. These NHE8−/− mice also showed increased expression of TNF-α and matrix metalloproteinase 9 (MMP9) genes. The expression of epithelial keratinization marker genes, small proline-rich protein 2h (Sprr2h) and transglutaminase 1 (Tgm1), were also increased in NHE8−/− eyes. Furthermore, DRA expression in NHE8−/− mice was reduced in the conjunctiva, the cornea, and the lacrimal glands in association with a reduction in conjunctival mucosal pH. Altered ocular surface function and reduced epithelial DRA expression in NHE8−/− mice suggest that the role of NHE8 in ocular surface tissue involve in tear production and ocular epithelial protection. This study reveals a potential novel mechanism of dry eye condition involving abnormal NHE8 function.
The calcium stored in the sarcoplasmic reticulum acts as a safety mechanism in rainbow trout heart
Authors: Cros Caroline , Sallé Laurent , Warren Daniel E. , Shiels Holly A. , Brette Fabien
Published: November 2014

Cardiomyocyte contraction depends on rapid changes in intracellular Ca2+. In mammals, Ca2+influx as L-type Ca2+current ( ICa) triggers the release of Ca2+from sarcoplasmic reticulum (SR) and Ca2+-induced Ca2+release (CICR) is critical for excitation-contraction coupling. In fish, the relative contribution of external and internal Ca2+is unclear. Here, we characterized the role of ICato trigger SR Ca2+release in rainbow trout ventricular myocytes using ICaregulation by Ca2+as an index of CICR. ICawas recorded with a slow (EGTA) or fast (BAPTA) Ca2+chelator in control and isoproterenol conditions. In the absence of β-adrenergic stimulation, the rate of ICainactivation was not significantly different in EGTA and BAPTA (27.1 ± 1.8 vs. 30.3 ± 2.4 ms), whereas with isoproterenol (1 μM), inactivation was significantly faster with EGTA (11.6 ± 1.7 vs. 27.3 ± 1.6 ms). When barium was the charge carrier, inactivation was significantly slower in both conditions (61.9 ± 6.1 vs. 68.0 ± 8.7 ms, control, isoproterenol). Quantification revealed that without isoproterenol, only 39% of ICainactivation was due to Ca2+, while with isoproterenol, inactivation was Ca2+-dependent (∼65%) and highly reliant on SR Ca2+(∼46%). Thus, SR Ca2+is not released in basal conditions, and ICais the main trigger of contraction, whereas during a stress response, SR Ca2+is an important source of cytosolic Ca2+. This was not attributed to differences in SR Ca2+load because caffeine-induced transients were not different in both conditions. Therefore, Ca2+stored in SR of trout cardiomyocytes may act as a safety mechanism, allowing greater contraction when higher contractility is required, such as stress or exercise.
HMGB1 exacerbates renal tubulointerstitial fibrosis through facilitating M1 macrophage phenotype at the early stage of obstructive injury
Authors: Tian Shaojiang , Zhang Lansing , Tang Junming , Guo Xia , Dong Kun , Chen Shi-You
Published: November 2014

Previous studies have indicated that macrophage phenotype diversity is involved in the progression of renal fibrosis. However, the factors facilitating M1 or M2 phenotypes and the function of these polarized macrophages in kidney injury and fibrosis remain largely unknown. In the present study, we found that macrophages accumulated in the kidney interstitium exhibited mainly as the M1 phenotype at the early stage of unilateral ureter obstruction (UUO). High-mobility group box 1 (HMGB1) protein expressed and released from tubular epithelial cells and interstitial macrophages was essential for the M1 macrophage transition. HMGB1 significantly induced the expression of the M1 marker inducible nitric oxide synthase while decreasing the M2 marker IL-10 in macrophages. Moreover, a glycyrrhizic acid derivative, a blocker of HMGB1 release, reduced UUO-mediated kidney injury and ameliorated UUO-induced renal fibrosis. Interestingly and importantly, UUO caused a low pH value in the urine accumulated in the obstructed ureter, and the acidified urine induced HMGB1 release from tubular epithelial cells and macrophages in vitro. Our data demonstrate that HMGB1 is an essential contributor in facilitating M1 polarization at the early stage of UUO. Inhibition of HMGB1 release may alter macrophage phenotype and contribute to the protection of kidney tissue from injury and fibrosis.
The discovery of hypertension: evolving views on the role of the kidneys, and current hot topics
Authors: Johnson Richard J. , Lanaspa Miguel A. , Gabriela Sánchez-Lozada L. , Rodriguez-Iturbe Bernardo
Published: November 2014

Primary hypertension is increasingly common and is associated with significant morbidity. Here, we review the history of its discovery and rise during the last century with an emphasis on studies trying to identify its cause. Early studies identified a defect in sodium excretion by the kidney as being central to the pathogenesis. Recent studies have focused on a variety of genetic, congenital (fetal programming), and acquired mechanisms for causing the defect in natriuresis. Certain risk factors are apparent, including genetic polymorphisms that regulate sodium excretion, a congenital reduction in nephron number, obesity and hyperleptinemia, an elevated sympathetic nervous system, diet (salt and fructose), and metabolic (hyperuricemia) mechanisms. The kidney shows evidence for renal arteriolar vasoconstriction, an intrarenal inflammatory response, local oxidative stress, and intrarenal activation of the renin-angiotensin system. Recent studies suggest that intrarenal T cells have an important role in causing hypertension to be persistent, likely due to the induction of a local autoimmune response to neoantigens such as heat shock protein 70 and protein aggregates formed by isoketals resulting from lipid peroxidation. Salt retention due to impairment in pressure-diuresis leads to the release of cardiotonic steroids and central nervous system effects that cause systemic vasoconstriction and a rise in blood pressure. Some recent studies suggest that salt may increase blood pressure not simply by effects on extracellular volume but rather as a consequence of hyperosmolarity. These new insights could lead to new approaches for the prevention and treatment of this important disease.
Pharmacological inhibition of soluble epoxide hydrolase prevents renal interstitial fibrogenesis in obstructive nephropathy
Authors: Kim Jinu , Yoon Sang Pil , Toews Myron L. , Imig John D. , Hwang Sung Hee , Hammock Bruce D. , Padanilam Babu J.
Published: November 2014

Treating chronic kidney disease (CKD) has been challenging because of its pathogenic complexity. Epoxyeicosatrienoic acids (EETs) are cytochrome P-450-dependent derivatives of arachidonic acid with antihypertensive, anti-inflammatory, and profibrinolytic functions. We recently reported that genetic ablation of soluble epoxide hydrolase (sEH), an enzyme that converts EETs to less active dihydroxyeicosatrienoic acids, prevents renal tubulointerstitial fibrosis and inflammation in experimental mouse models of CKD. Here, we tested the hypothesis that pharmacological inhibition of sEH after unilateral ureteral obstruction (UUO) would attenuate tubulointerstitial fibrosis and inflammation in mouse kidneys and may provide a novel approach to manage the progression of CKD. Inhibition of sEH enhanced levels of EET regioisomers and abolished tubulointerstitial fibrosis, as demonstrated by reduced collagen deposition and myofibroblast formation after UUO. The inflammatory response was also attenuated, as demonstrated by decreased influx of neutrophils and macrophages and decreased expression of inflammatory cytokines keratinocyte chemoattractant, macrophage inflammatory protein-2, monocyte chemotactic protein-1, TNF-α, and ICAM-1 in kidneys after UUO. UUO upregulated transforming growth factor-β1/Smad3 signaling and induced NF-κB activation, oxidative stress, tubular injury, and apoptosis; in contrast, it downregulated antifibrotic factors, including peroxisome proliferator-activated receptor (PPAR) isoforms, especially PPAR-γ. sEH inhibition mitigated the aforementioned malevolent effects in UUO kidneys. These data demonstrate that pharmacological inhibition of sEH promotes anti-inflammatory and fibroprotective effects in UUO kidneys by preventing tubular injury, downregulation of NF-κB, transforming growth factor-β1/Smad3, and inflammatory signaling pathways, and activation of PPAR isoforms. Our data suggest the potential use of sEH inhibitors in treating fibrogenesis in the UUO model of CKD.
Glycosuria-mediated urinary uric acid excretion in patients with uncomplicated type 1 diabetes mellitus
Authors: Lytvyn Yuliya , Škrtić Marko , Yang Gary K. , Yip Paul M. , Perkins Bruce A. , Cherney David Z. I.
Published: November 2014

Plasma uric acid (PUA) is associated with metabolic, cardiovascular, and renal abnormalities in patients with type 2 diabetes but is less well understood in type 1 diabetes (T1D). Our aim was to compare PUA levels and fractional uric acid excretion (FEUA) in patients with T1D vs. healthy controls (HC) during euglycemia and hyperglycemia. PUA, FEUA, blood pressure (BP), glomerular filtration rate (GFR-inulin), and effective renal plasma flow (ERPF-paraaminohippurate) were evaluated in patients with T1D ( n = 66) during clamped euglycemia (glucose 4–6 mmol/l) and hyperglycemia (9–11 mmol/l), and in HC ( n = 41) during euglycemia. To separate the effects of hyperglycemia vs. increased glycosuria, parameters were evaluated during clamped euglycemia in a subset of T1D patients before and after sodium glucose cotransporter 2 (SGLT2) inhibition for 8 wk. PUA was lower in T1D vs. HC (228 ± 62 vs. 305 ± 75 μmol/l, P < 0.0001). In T1D, hyperglycemia further decreased PUA (228 ± 62 to 199 ± 65 μmol/l, P < 0.0001), which was accompanied by an increase in FEUA(7.3 ± 3.8 to 11.6 ± 6.7, P < 0.0001). In T1D, PUA levels correlated positively with SBP ( P = 0.029) and negatively with ERPF ( P = 0.031) and GFR ( P = 0.028). After induction of glycosuria with SGLT2 inhibition while maintaining clamped euglycemia, PUA decreased ( P < 0.0001) and FEUAincreased ( P < 0.0001). PUA is lower in T1D vs. HC and positively correlates with SBP and negatively with GFR and ERPF in T1D. Glycosuria rather than hyperglycemia increases uricosuria in T1D. Future studies examining the effect of uric acid-lowering therapies should account for the impact of ambient glycemia, which causes an important uricosuric effect.
Parabiotic model for differentiating local and systemic effects of continuous and intermittent hypoxia
Authors: Torres Marta , Rojas Mauricio , Campillo Noelia , Cardenes Nayra , Montserrat Josep M. , Navajas Daniel , Farré Ramon
Published: November 2014

Hypoxia can be damaging either because cells are directly sensitive to low oxygen pressure in their local microenvironment and/or because they are exposed to circulating factors systemically secreted in response to hypoxia. The conventional hypoxia model, breathing hypoxic air, does not allow one to distinguish between these local and systemic effects. Here we propose and validate a model for differentially applying local and systemic hypoxic challenges in an animal. We used parabiosis, two mice sharing circulation by surgical union through the skin, and tested the hypothesis that when one of the parabionts breathes room air and the other one is subjected to hypoxic air, both mice share systemic circulation but remain normoxic and hypoxic, respectively. We tested two common hypoxic paradigms in 10 parabiotic pairs: continuous hypoxia (10% O2) mimicking chronic lung diseases, and intermittent hypoxia (40 s, 21% O2; 20 s, 5% O2) simulating sleep apnea. Arterial oxygen saturation and oxygen partial pressure at muscle tissue were measured in both parabionts. Effective cross-circulation was assessed by intraperitoneally injecting a dye in one of the parabionts and measuring blood dye concentration in both animals after 2 h. The results confirmed the hypothesis that tissues of the parabiont under room air were perfused with normally oxygenated blood and, at the same time, were exposed to all of the systemic mediators secreted by the other parabiont actually subjected to hypoxia. In conclusion, combination of parabiosis and hypoxic/normoxic air breathing is a novel approach to investigate the effects of local and systemic hypoxia in respiratory diseases.
Whole-hand water flow stimulation increases motor cortical excitability: a study of transcranial magnetic stimulation and movement-related cortical potentials
Authors: Sato Daisuke , Yamashiro Koya , Onishi Hideaki , Yasuhiro Baba , Shimoyama Yoshimitsu , Maruyama Atsuo
Published: November 2014

Previous studies examining the influence of afferent stimulation on corticospinal excitability have demonstrated that the intensity of afferent stimulation and the nature of the afferents targeted (cutaneous/proprioceptive) determine the effects. In this study, we assessed the effects of whole-hand water immersion (WI) and water flow stimulation (WF) on corticospinal excitability and intracortical circuits by measuring motor evoked potential (MEP) recruitment curves and conditioned MEP amplitudes. We further investigated whether whole-hand WF modulated movement-related cortical activity. Ten healthy subjects participated in three experiments, comprising the immersion of participants' right hands with (whole-hand WF) or without (whole-hand WI) water flow, and no immersion (control). We evaluated MEP recruitment curves produced by a single transcranial magnetic stimulation (TMS) pulse at increasing stimulus intensities, short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF) using the paired TMS technique before and after 15 min of intervention. Movement-related cortical potentials (MRCPs) were evaluated to examine primary motor cortex, supplementary motor area, and somatosensory cortex excitability upon movement before and after whole-hand WF. After whole-hand WF, the slope of the MEP recruitment curve significantly increased, whereas SICI decreased and ICF increased in the contralateral motor cortex. The amplitude of the Bereitschaftspotential, negative slope, and motor potential of MRCPs significantly increased after whole-hand WF. We demonstrated that whole-hand WF increased corticospinal excitability, decreased SICI, and increased ICF, although whole-hand WI did not change corticospinal excitability and intracortical circuits. Whole-hand WF modulated movement-related cortical activity, increasing motor cortex activation for the planning and execution of voluntary movements.
Ghosts in the machine: memory interference from the previous trial
Authors: Papadimitriou Charalampos , Ferdoash Afreen , Snyder Lawrence H.
Published: November 2014

Previous memoranda can interfere with the memorization or storage of new information, a concept known as proactive interference. Studies of proactive interference typically use categorical memoranda and match-to-sample tasks with categorical measures such as the proportion of correct to incorrect responses. In this study we instead train five macaques in a spatial memory task with continuous memoranda and responses, allowing us to more finely probe working memory circuits. We first ask whether the memoranda from the previous trial result in proactive interference in an oculomotor delayed response task. We then characterize the spatial and temporal profile of this interference and ask whether this profile can be predicted by an attractor network model of working memory. We find that memory in the current trial shows a bias toward the location of the memorandum of the previous trial. The magnitude of this bias increases with the duration of the memory period within which it is measured. Our simulations using standard attractor network models of working memory show that these models easily replicate the spatial profile of the bias. However, unlike the behavioral findings, these attractor models show an increase in bias with the duration of the previous rather than the current memory period. To model a bias that increases with current trial duration we posit two separate memory stores, a rapidly decaying visual store that resists proactive interference effects and a sustained memory store that is susceptible to proactive interference.
Characteristics of GABAergic and cholinergic neurons in perinuclear zone of mouse supraoptic nucleus
Authors: Wang Lie , Ennis Matthew , Szabó Gábor , Armstrong William E.
Published: November 2014

The perinuclear zone (PNZ) of the supraoptic nucleus (SON) contains some GABAergic and cholinergic neurons thought to innervate the SON proper. In mice expressing enhanced green fluorescent protein (eGFP) in association with glutamate decarboxylase (GAD)65 we found an abundance of GAD65-eGFP neurons in the PNZ, whereas in mice expressing GAD67-eGFP, there were few labeled PNZ neurons. In mice expressing choline acetyltransferase (ChAT)-eGFP, large, brightly fluorescent and small, dimly fluorescent ChAT-eGFP neurons were present in the PNZ. The small ChAT-eGFP and GAD65-eGFP neurons exhibited a low-threshold depolarizing potential consistent with a low-threshold spike, with little transient outward rectification. Large ChAT-eGFP neurons exhibited strong transient outward rectification and a large hyperpolarizing spike afterpotential, very similar to that of magnocellular vasopressin and oxytocin neurons. Thus the large soma and transient outward rectification of large ChAT-eGFP neurons suggest that these neurons would be difficult to distinguish from magnocellular SON neurons in dissociated preparations by these criteria. Large, but not small, ChAT-eGFP neurons were immunostained with ChAT antibody (AB144p). Reconstructed neurons revealed a few processes encroaching near and passing through the SON from all types but no clear evidence of a terminal axon arbor. Large ChAT-eGFP neurons were usually oriented vertically and had four or five dendrites with multiple branches and an axon with many collaterals and local arborizations. Small ChAT-eGFP neurons had a more restricted dendritic tree compared with parvocellular GAD65 neurons, the latter of which had long thin processes oriented mediolaterally. Thus many of the characteristics found previously in unidentified, small PNZ neurons are also found in identified GABAergic neurons and in a population of smaller ChAT-eGFP neurons.
Anodal transcranial direct current stimulation applied over the supplementary motor area delays spontaneous antiphase-to-in-phase transitions
Authors: Carter Michael J. , Maslovat Dana , Carlsen Anthony N.
Published: November 2014

Coordinated bimanual oscillatory movements often involve one of two intrinsically stable phasing relationships characterized as in-phase (symmetrical) or antiphase (asymmetrical). The in-phase mode is typically more stable than antiphase, and if movement frequency is increasing during antiphase movements, a spontaneous transition to the in-phase pattern occurs. There is converging neurophysiological evidence that the supplementary motor area (SMA) plays a critical role in the successful performance of these patterns, especially during antiphase movements. We investigated whether modulating the excitability of the SMA via offline transcranial direct current stimulation (tDCS) would delay the onset of anti-to-in-phase transitions. Participants completed two sessions (separated by ∼48 h), each consisting of a pre- and post-tDCS block in which they performed metronome-paced trials of rhythmic in- and antiphase bimanual supination-pronation movements as target oscillation frequency was systematically increased. Anodal or cathodal tDCS was applied over the SMA between the pre- and post-tDCS blocks in each session. Following anodal tDCS, participants performed the antiphase pattern with increased accuracy and stability and were able to maintain the coordination pattern at a higher oscillation frequency. Antiphase performance was unchanged following cathodal tDCS, and neither tDCS polarity affected the in-phase mode. Our findings suggest increased SMA excitability induced by anodal tDCS can improve antiphase performance and adds to the accumulating evidence of the pivotal role of the SMA in interlimb coordination.
Enriching the diet with menhaden oil improves peripheral neuropathy in streptozotocin-induced type 1 diabetic rats
Authors: Coppey Lawrence J. , Davidson Eric P. , Obrosov Alexander , Yorek Mark A.
Published: November 2014

The purpose of this study was to determine the effect of supplementing the diet of type 1 diabetic rats with menhaden oil on diabetic neuropathy. Menhaden oil is a natural source for n-3 fatty acids, which have been shown to have beneficial effects in cardiovascular disease and other morbidities. Streptozotocin-induced diabetic rats were used to examine the influence of supplementing their diet with 25% menhaden oil on diabetic neuropathy. Both prevention and intervention protocols were used. Endpoints included motor and sensory nerve conduction velocity, thermal and mechanical sensitivity, and innervation and sensitivity of the cornea and hindpaw. Diabetic neuropathy as evaluated by the stated endpoints was found to be progressive. Menhaden oil did not improve elevated HbA1C levels or serum lipid levels. Diabetic rats at 16-wk duration were thermal hypoalgesic and had reduced motor and sensory nerve conduction velocities, and innervation and sensitivity of the cornea and skin were impaired. These endpoints were significantly improved with menhaden oil treatment following the prevention or intervention protocol. We found that supplementing the diet of type 1 diabetic rats with menhaden oil improved a variety of endpoints associated with diabetic neuropathy. These results suggest that enriching the diet with n-3 fatty acids may be a good treatment strategy for diabetic neuropathy.
Isn't functional neuroimaging all about Ca2+ signaling in astrocytes?
Authors: DiNuzzo Mauro
Published: November 2014

Extensive research over the past decades about the multifaceted roles of brain astrocytes led to the suggestion that the signals observed with functional neuroimaging might primarily reflect astrocytic rather than neuronal activity. The basis for this paradigm-shifting concept was the evidence for an involvement of astrocytes in the control of local cerebral blood flow through intracellular Ca2+ signaling. In this Neuro Forum, I discuss new important experimental findings obtained by Jego et al. (Jego P, Pacheco-Torres J, Araque A, Canals S. J Cereb Blood Flow Metab 34: 1599–1603, 2014) as well as other closely related studies published recently, prompting a dismissal of substantial astrocytic contribution in functional neuroimaging.
Modulation of gamma oscillations in the pedunculopontine nucleus by neuronal calcium sensor protein-1: relevance to schizophrenia and bipolar disorder
Authors: D'Onofrio Stasia , Kezunovic Nebojsa , Hyde James R. , Luster Brennon , Messias Erick , Urbano Francisco J. , Garcia-Rill Edgar
Published: November 2014

Reduced levels of gamma-band activity are present in schizophrenia and bipolar disorder patients. In the same disorders, increased neuronal calcium sensor protein-1 (NCS-1) expression was reported in a series of postmortem studies. These disorders are also characterized by sleep dysregulation, suggesting a role for the reticular activating system (RAS). The discovery of gamma-band activity in the pedunculopontine nucleus (PPN), the cholinergic arm of the RAS, revealed that such activity was mediated by high-threshold calcium channels that are regulated by NCS-1. We hypothesized that NCS-1 normally regulates gamma-band oscillations through these calcium channels and that excessive levels of NCS-1, such as would be expected with overexpression, decrease gamma-band activity. We found that PPN neurons in rat brain slices manifested gamma-band oscillations that were increased by low levels of NCS-1 but suppressed by high levels of NCS-1. Our results suggest that NCS-1 overexpression may be responsible for the decrease in gamma-band activity present in at least some schizophrenia and bipolar disorder patients.
Serine Deprivation Enhances Antineoplastic Activity of Biguanides
Authors: Gravel Simon-Pierre , Hulea Laura , Toban Nader , Birman Elena , Blouin Marie-José , Zakikhani Mahvash , Zhao Yunhua , Topisirovic Ivan , St-Pierre Julie , Pollak Michael
Published: November 2014

Metformin, a biguanide widely used in the treatment of type II diabetes, clearly exhibits antineoplastic activity in experimental models and has been reported to reduce cancer incidence in diabetics. There are ongoing clinical trials to evaluate its antitumor properties, which may relate to its fundamental activity as an inhibitor of oxidative phosphorylation. Here, we show that serine withdrawal increases the antineoplastic effects of phenformin (a potent biguanide structurally related to metformin). Serine synthesis was not inhibited by biguanides. Instead, metabolic studies indicated a requirement for serine to allow cells to compensate for biguanide-induced decrease in oxidative phosphorylation by upregulating glycolysis. Furthermore, serine deprivation modified the impact of metformin on the relative abundance of metabolites within the citric acid cycle. In mice, a serine-deficient diet reduced serine levels in tumors and significantly enhanced the tumor growth–inhibitory actions of biguanide treatment. Our results define a dietary manipulation that can enhance the efficacy of biguanides as antineoplastic agents that target cancer cell energy metabolism. Cancer Res; 74(24); 7521–33. ©2014 AACR.
Antitumor Activity of the MEK Inhibitor TAK-733 against Melanoma Cell Lines and Patient-Derived Tumor Explants
Authors: Micel Lindsey N. , Tentler John J. , Tan Aik-Choon , Selby Heather M. , Brunkow Kelsey L. , Robertson Kelli M. , Davis S. Lindsey , Klauck Peter J. , Pitts Todd M. , Gangolli Esha , Fabrey Robyn , O'Connell Shawn M. , Vincent Patrick W. , Eckhardt S. Gail
Published: November 2014

The goal of this study was to investigate the activity of the selective MEK1/2 inhibitor TAK-733 in both melanoma cell lines and patient-derived melanoma xenograft models. In vitro cell proliferation assays using the sulforhodamine B assay were conducted to determine TAK-733 potency and melanoma responsiveness. In vivo murine modeling with eleven patient-derived melanoma explants evaluated daily dosing of TAK-733 at 25 or 10 mg/kg. Immunoblotting was performed to evaluate on-target activity and downstream inhibition by TAK-733 in both in vitro and in vivo studies. TAK-733 demonstrated broad activity in most melanoma cell lines with relative resistance observed at IC50 > 0.1 μmol/L in vitro. TAK-733 also exhibited activity in 10 out of 11 patient-derived explants with tumor growth inhibition ranging from 0% to 100% (P < 0.001–0.03). Interestingly, BRAFV600E and NRAS mutational status did not correlate with responsiveness to TAK-733. Pharmacodynamically, pERK was suppressed in sensitive cell lines and tumor explants, confirming TAK-733–mediated inhibition of MEK1/2, although the demonstration of similar effects in the relatively resistant cell lines and tumor explants suggests that escape pathways are contributing to melanoma survival and proliferation. These data demonstrate that TAK-733 exhibits robust tumor growth inhibition and regression against human melanoma cell lines and patient-derived xenograft models, suggesting that further clinical development in melanoma is of scientific interest. Particularly interesting is the activity in BRAF wild-type models, where current approved therapy such as vemurafenib has been reported not to be active. Mol Cancer Ther; 14(2); 317–25. ©2014 AACR.
Modeling Targeted Inhibition of MEK and PI3 Kinase in Human Pancreatic Cancer
Authors: Junttila Melissa R. , Devasthali Vidusha , Cheng Jason H. , Castillo Joseph , Metcalfe Ciara , Clermont Anne C. , Otter Douglas Den , Chan Emily , Bou-Reslan Hani , Cao Tim , Forrest William , Nannini Michelle A. , French Dorothy , Carano Richard , Merchant Mark , Hoeflich Klaus P. , Singh Mallika
Published: November 2014

Activating mutations in the KRAS oncogene occur in approximately 90% of pancreatic cancers, resulting in aberrant activation of the MAPK and the PI3K pathways, driving malignant progression. Significant efforts to develop targeted inhibitors of nodes within these pathways are underway and several are currently in clinical trials for patients with KRAS-mutant tumors, including patients with pancreatic cancer. To model MEK and PI3K inhibition in late-stage pancreatic cancer, we conducted preclinical trials with a mutant Kras-driven genetically engineered mouse model that faithfully recapitulates human pancreatic ductal adenocarcinoma development. Treatment of advanced disease with either a MEK (GDC-0973) or PI3K inhibitor (GDC-0941) alone showed modest tumor growth inhibition and did not significantly enhance overall survival. However, combination of the two agents resulted in a significant survival advantage as compared with control tumor-bearing mice. To model the clinical scenario, we also evaluated the combination of these targeted agents with gemcitabine, the current standard-of-care chemotherapy for pancreatic cancer. The addition of MEK or PI3K inhibition to gemcitabine, or the triple combination regimen, incrementally enhanced overall survival as compared with gemcitabine alone. These results are reminiscent of the survival advantage conferred in this model and in patients by the combination of gemcitabine and erlotinib, an approved therapeutic regimen for advanced nonresectable pancreatic cancer. Taken together, these data indicate that inhibition of MEK and PI3K alone or in combination with chemotherapy do not confer a dramatic improvement as compared with currently available therapies for patients with pancreatic cancer. Mol Cancer Ther; 14(1); 40–47. ©2014 AACR.
Inhibition of FOXO1/3 Promotes Vascular Calcification
Authors: Deng Liang , Huang Lu , Sun Yong , Heath Jack M. , Wu Hui , Chen Yabing
Published: November 2014

Objective—

Vascular calcification is a characteristic feature of atherosclerosis, diabetes mellitus, and end-stage renal disease. We have demonstrated that activation of protein kinase B (AKT) upregulates runt-related transcription factor 2 (Runx2), a key osteogenic transcription factor that is crucial for calcification of vascular smooth muscle cells (VSMC). Using mice with SMC-specific deletion of phosphatase and tensin homolog (PTEN), a major negative regulator of AKT, the present studies uncovered a novel molecular mechanism underlying PTEN/AKT/FOXO (forkhead box O)-mediated Runx2 upregulation and VSMC calcification.

Approach and Results—

SMC-specific PTEN deletion mice were generated by crossing PTEN floxed mice with SM22α-Cre transgenic mice. The PTEN deletion resulted in sustained activation of AKT that upregulated Runx2 and promoted VSMC calcification in vitro and arterial calcification ex vivo. Runx2 knockdown did not affect proliferation but blocked calcification of the PTEN-deficient VSMC, suggesting that PTEN deletion promotes Runx2-depedent VSMC calcification that is independent of proliferation. At the molecular level, PTEN deficiency increased the amount of Runx2 post-transcriptionally by inhibiting Runx2 ubiquitination. AKT activation increased phosphorylation of FOXO1/3 that led to nuclear exclusion of FOXO1/3. FOXO1/3 knockdown in VSMC phenocopied the PTEN deficiency, demonstrating a novel function of FOXO1/3, as a downstream signaling of PTEN/AKT, in regulating Runx2 ubiquitination and VSMC calcification. Using heterozygous SMC-specific PTEN-deficient mice and atherogenic ApoE
−/−
mice, we further demonstrated AKT activation, FOXO phosphorylation, and Runx2 ubiquitination in vascular calcification in vivo.

Conclusions—

Our studies have determined a new causative effect of SMC-specific PTEN deficiency on vascular calcification and demonstrated that FOXO1/3 plays a crucial role in PTEN/AKT-modulated Runx2 ubiquitination and VSMC calcification.
Interaction Between Digoxin and Dronedarone in the PALLAS Trial
Authors: Hohnloser Stefan H. , Halperin Jonathan L. , Camm A. John , Gao Peggy , Radzik David , Connolly Stuart J.
Published: November 2014

Background—

Elevated serum digoxin concentration can cause toxicity, including death. Dronedarone increases digoxin concentration by P-glycoprotein interaction. In Permanent Atrial Fibrillation Outcome Study Using Dronedarone On Top Of Standard Therapy Trial (PALLAS), dronedarone was associated with both increased cardiovascular death and heart failure in patients with permanent atrial fibrillation. The present analysis examines whether the dronedarone–digoxin interaction might explain these adverse outcomes.

Methods and Results—

Subgroup analysis was performed to compare outcomes of patients on digoxin at baseline or not. In PALLAS, 1619 patients were randomized to dronedarone and 1617 to placebo, of whom 544 (33.6%) and 526 (32.5%) were receiving digoxin, respectively. Median (Q1,Q3) digoxin serum concentration on day 7 was 1.1 (0.7,1.5) ng/mL on dronedarone and 0.7 (0.5,1.1) ng/mL on placebo (
P
<0.001). Among patients on digoxin, there were 15 (8.6%/year) cardiovascular deaths on dronedarone and 2 (1.2%/year) on placebo (adjusted hazard ratio, 7.31; 95% confidence interval, 1.66–32.20;
P
=0.009). Among patients not on digoxin, there were 6 cardiovascular deaths on dronedarone (1.7%/year) and 8 on placebo (2.2%/year; adjusted hazard ratio, 0.67; 95% confidence interval, 0.23–1.95;
P
=0.46; interaction
P
value 0.01). In patients on digoxin, there were 11 arrhythmic deaths on dronedarone and none on placebo; and in patients not on digoxin, there were 2 arrhythmic deaths on dronedarone and 4 on placebo (
P
value for interaction 0.002). There was no interaction between baseline digoxin use and the adverse effect of dronedarone on heart failure events.

Conclusions—

In PALLAS, there was a strong effect of concurrent digoxin use on the adverse effect of dronedarone on cardiovascular death, but not on occurrence of heart failure.

Clinical Trial Registration—

http://www.clinicaltrials.gov. Unique identifier: NCT01151137.
Tenascin‐C Aggravates Autoimmune Myocarditis via Dendritic Cell Activation and Th17 Cell Differentiation
Authors: Machino‐Ohtsuka Tomoko , Tajiri Kazuko , Kimura Taizo , Sakai Satoshi , Sato Akira , Yoshida Toshimichi , Hiroe Michiaki , Yasutomi Yasuhiro , Aonuma Kazutaka , Imanaka‐Yoshida Kyoko
Published: November 2014

Background

Tenascin‐C (
TN
‐C), an extracellular matrix glycoprotein, appears at several important steps of cardiac development in the embryo, but is sparse in the normal adult heart.
TN
‐C re‐expresses under pathological conditions including myocarditis, and is closely associated with tissue injury and inflammation in both experimental and clinical settings. However, the pathophysiological role of
TN
‐C in the development of myocarditis is not clear. We examined how
TN
‐C affects the initiation of experimental autoimmune myocarditis, immunologically.

Methods and Results

A model of experimental autoimmune myocarditis was established in
BALB
/c mice by immunization with murine α‐myosin heavy chains. We found that
TN
‐C knockout mice were protected from severe myocarditis compared to wild‐type mice.
TN
‐C induced synthesis of proinflammatory cytokines, including interleukin (
IL
)‐6, in dendritic cells via activation of a Toll‐like receptor 4, which led to T‐helper (Th)17 cell differentiation and exacerbated the myocardial inflammation. In the transfer experiment, dendritic cells loaded with cardiac myosin peptide acquired the functional capacity to induce myocarditis when stimulated with
TN
‐C; however,
TN
‐C‐stimulated dendritic cells generated from Toll‐like receptor 4 knockout mice did not induce myocarditis in recipients.

Conclusions

Our results demonstrated that
TN
‐C aggravates autoimmune myocarditis by driving the dendritic cell activation and Th17 differentiation via Toll‐like receptor 4. The blockade of Toll‐like receptor 4‐mediated signaling to inhibit the proinflammatory effects of
TN
‐C could be a promising therapeutic strategy against autoimmune myocarditis.