bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis of hypocotyl development in epiphytic, lignotuber-forming, and terrestrial Vaccinieae (Ericaceae)
Authors: Evans Rodger C. , Vander Kloet Sam P.
Published: May 2010

A comparative analysis of hypocotyl development was undertaken with seedlings of three Vaccinieae (Ericaceae) species ( Macleania pentaptera Hoerold, Macleania rupestris (Kunth) A.C. Sm., and Vaccinium angustifolium Ait.) to determine the developmental basis for enlarged hypocotyls leading to the development of woody tubers (lignotubers) in M. pentaptera and M. rupestris. Differences in hypocotyl development are apparent after the first true leaves are visible in each species. Vascular tissue in M. rupestris and V. angustifolium is composed primarily of axial columns of secondary xylem. Secondary xylem tissues in M. pentaptera remain mostly parenchymatous and form radial columns of cells through numerous periclinal divisions. Furthermore, the secondary xylem of M. pentaptera comprises random networks of interconnected, small xylem elements in comparison with the secondary xylem of M. rupestris and V. angustifolium. These differences in hypocotyl development persist through the first 200 d of hypocotyl development, and ultimately lead to the development of a large lignotuber in M. pentaptera. Given the large amounts of parenchymatous tissue, a secondary xylem of relatively short secondary xylem elements, and the absence of adventitious buds, we propose that the lignotubers of M. pentaptera are used for short term water storage, rather than regeneration.
Hudsonia ericoides and Hudsonia tomentosa: Anatomy of mycorrhizas of two members in the Cistaceae from Eastern Canada
Authors: Massicotte Hugues B. , Peterson R. Larry , Melville Lewis H. , Tackaberry Linda E.
Published: May 2010

Most species in the family Cistaceae are found in the Mediterranean basin. Several hosts are of special interest, owing to their associations with truffle species, while many are important as pioneer plants in disturbed areas and in soil stabilization. For these reasons, understanding their root systems and their associated fungal symbionts is important. Most studies of the structure of mycorrhizas in this family involve two genera, Cistus and Helianthemum . The present study examines structural features of mycorrhizas in two North American species, Hudsonia ericoides L. and Hudsonia tomentosa Nutt. Root systems of both species are highly branched with most fine roots colonized by mycorrhizal fungi. Based on morphological features, several mycorrhizal fungi were identified; structural details also provided evidence of more than one fungal symbiont for each host species. All mycorrhizas had a multi-layered fungal mantle and Hartig net hyphae confined to radially elongated epidermal cells; no intracellular hyphae were observed. Although the Hartig net was confined to the epidermis, the outer row of cortical cell walls lacked suberin, a known barrier to fungal penetration. Mycorrhizas in H. ericoides and H. tomentosa differed from those of Cistus and Helianthemum species that have a Hartig net that extends into the root cortex, as well as frequently present intracellular hyphae.
ON WAVELET INDUCED ISOMORPHISMS
Authors: SINGH DIVYA
Published: May 2010

While constructing a dyadic wavelet set through an approach which is purely set-theoretic, Ionascu observed that a dyadic one-dimensional wavelet set W gives rise to a specific measurable, bijective, piecewise increasing selfmap [Formula: see text] on [0, 1) and termed it to be a wavelet induced isomorphism. Further, he found that such maps provide wavelet sets which, in turn, characterize wavelet sets. In this paper, we consider two-interval, three-interval and symmetric four-interval wavelet sets and determine their wavelet induced isomorphisms. Also, fixed point sets of [Formula: see text] are determined for these wavelet sets.
A BREGMAN ITERATIVE REGULARIZATION METHOD FOR WAVELET-BASED IMAGE DEBLURRING
Authors: YIN HAIQING , LIU HONGWEI
Published: May 2010

A new Bregman iterative regularization method is introduced for wavelet-based image deblurring. By using a suitable sequence of penalty parameters, we solve the issue of solvability of minimization problems arising in each step of the iterative procedure. Moreover, we give a projection-based algorithm to compute the solution. The convergence of the algorithm is also stated. The procedure is very fast and easy to implement. We also show numerical results of image deblurring using the algorithm.
AN APPROACH OF EXCITING EVENTS DETECTION IN SOCCER SPORTS VIDEOS
Authors: WANG WEI , GAO WEI , LIU YAJUAN , WANG RUNSHENG
Published: May 2010

In this paper, an approach with both the hierarchical tree and the clips temporal structure is proposed for exciting events (such as free kicks near the goal box, corner kicks, etc.) detection in broadcast soccer videos. In this approach, video frames are firstly divided into sections. Then these sections are divided further into clips which have specifically semantic information so that we can use the low-level descriptors to classify the clips and analyze the relationship between them. Low-level descriptors include color, motion descriptors and edge descriptors. To detect the exciting events, the simple classification models are constructed by combining the fixed temporal structures of clips with motion vectors and other low-level descriptors. Experiments on real soccer video programs show the encouraging results.
A MONITORING SYSTEM FOR SUPERMARKET BASED ON TRAJECTORY OF PALM AND ART
Authors: WU YOUFU , ZHOU GANG , WU JING
Published: May 2010

In this paper, a monitoring system that can distinguish normal behavior from abnormal ones based on trajectory of palm for supermarket is designed. Our system brings some traditional algorithms and insights together to construct a framework for a new field called Supermarket Monitoring. In this project, only the moving hands are considered. To fulfill the automated monitoring task, the self-adaptive background subtraction technique and the YIQ skin color model are combined to detect the moving hands. In order for accurate localization at the palm, a new method is developed. After successfully detecting the moving hands, a linear prediction model is cited to realize the object tracking. The ART is used to distinguish normal behavior from abnormal ones by analyzing the trajectory characterizations of the moving hands. The experiment results show that this system is robust and effective.
Nitric oxide can acutely modulate its biosynthesis through a negative feedback mechanism on l-arginine transport in cardiac myocytes
Authors: Zhou Jiaguo , Kim David D. , Peluffo R. Daniel
Published: May 2010

Nitric oxide (NO) plays a central role as a cellular signaling molecule in health and disease. In the heart, NO decreases the rate of spontaneous beating and the velocity and extent of shortening and accelerates the velocity of relengthening. Since the cationic amino acid l-arginine (l-Arg) is the substrate for NO production by NO synthases (NOS), we tested whether the transporters that mediate l-Arg import in cardiac muscle cells represent an intervention point in the regulation of NO synthesis. Electrical currents activated by l-Arg with low apparent affinity in whole cell voltage-clamped rat cardiomyocytes were found to be rapidly and reversibly inhibited by NO donors. Radiotracer uptake studies performed on cardiac sarcolemmal vesicles revealed the presence of high-affinity/low-capacity and low-affinity/high-capacity components of cationic amino acid transport that were inhibited by the NO donor S-nitroso- N-acetyl-dl-penicillamine. NO inhibited uptake in a noncompetitive manner with Ki values of 275 and 827 nM for the high- and low-affinity component, respectively. Fluorescence spectroscopy experiments showed that millimolar concentrations of l-Arg initially promoted and then inhibited the release of endogenous NO in cardiomyocytes. Likewise, l-Arg currents measured in cardiac myocytes voltage clamped in the presence of 460 nM free intracellular Ca2+, a condition in which a Ca-CaM complex should activate endogenous NO production, showed fast activation followed by inhibition of l-Arg transport. The NOS inhibitor N-nitro-l-arginine methyl ester, but not blockers of downstream reactions, specifically removed this inhibitory component. These results demonstrate that NO acutely regulates its own biosynthesis by modulating the availability of l-Arg via cationic amino acid transporters.
Transition of kidney tubule cells to a senescent phenotype in early experimental diabetes
Authors: Satriano Joseph , Mansoury Hadi , Deng Aihua , Sharma Kumar , Vallon Volker , Blantz Roland C. , Thomson Scott C.
Published: May 2010

Diabetic nephropathy is the commonest cause of end-stage renal disease. Inordinate kidney growth and glomerular hyperfiltration at the very early stages of diabetes are putative antecedents to this disease. The kidney is the only organ that grows larger with the onset of diabetes mellitus, yet there remains confusion about the mechanism and significance of this growth. Here we show that kidney proximal tubule cells in culture transition to senescence in response to oxidative stress. We further determine the temporal expression of G1 phase cell cycle components in rat kidney cortex at days 4 and 10 of streptozotocin diabetes to evaluate changes in this growth response. In diabetic rats we observe increases in kidney weight-to-body weight ratios correlating with increases in expression of the growth-related proteins in the kidney at day 4 after induction of diabetes. However, at day 10 we find a decrease in this profile in diabetic animals coincident with increased cyclin-dependent kinase inhibitor expressions. We observe no change in caspase-3 expression in the diabetic kidneys at these early time points; however, diabetic animals demonstrate reduced kidney connexin 43 and increased plasminogen activator inhibitor-1 expressions and increased senescence-associated β-galactosidase activity in cortical tubules. In summary, diabetic kidneys exhibit an early temporal induction of growth phase components followed by their suppression concurrent with the induction of cyclin-dependent kinase inhibitors and markers of senescence. These data delineate a phenotypic change in cortical tubules early in the pathogenesis of diabetes that may contribute to further downstream complications of the disease.
Effect of hypernatremia on injury caused by energy deficiency: role of T-type Ca2+ channel
Authors: Pastukh Viktor , Chen Hairu , Wu Songwei , Jong Chian Ju , Alexeyev Mikhail , Schaffer Stephen W.
Published: May 2010

Hypernatremia exerts multiple cellular effects, many of which could influence the outcome of an ischemic event. To further evaluate these effects of hypernatremia, isolated neonatal cardiomyocytes were chronically incubated with medium containing either normal (142 mM) or elevated sodium (167 mM) and then transferred to medium containing deoxyglucose and the electron transport chain inhibitor amobarbital. Chronic hypernatremia diminished the degree of calcium accumulation and reactive oxygen species generation during the period of metabolic inhibition. The improvement in calcium homeostasis was traced in part to the downregulation of the CaV3.1 T-type calcium channel, as deficiency in the CaV3.1 subtype using short hairpin RNA or treatment with an inhibitor of the CaV3.1 variant of the T-type calcium channel (i.e., diphenylhydantoin) attenuated energy deficiency-mediated calcium accumulation and cell death. Although hyperosmotically stressed cells (exposed to 50 mM mannitol) had no effect on T-type calcium channel activity, they were also resistant to death during metabolic inhibition. Both hyperosmotic stress and hypernatremia activated Akt, suggesting that they initiate the phosphatidylinositol 3-kinase/Akt cytoprotective pathway, which protects the cell against calcium overload and oxidative stress. Thus hypernatremia appears to protect the cell against metabolic inhibition by promoting the downregulation of the T-type calcium channel and stimulating cytoprotective protein kinase pathways.
Pregnancy and the endocrine regulation of the baroreceptor reflex
Authors: Brooks Virginia L. , Dampney Roger A. L. , Heesch Cheryl M.
Published: May 2010

The purpose of this review is to delineate the general features of endocrine regulation of the baroreceptor reflex, as well as specific contributions during pregnancy. In contrast to the programmed changes in baroreflex function that occur in situations initiated by central command (e.g., exercise or stress), the complex endocrine milieu often associated with physiological and pathophysiological states can influence the central baroreflex neuronal circuitry via multiple sites and mechanisms, thereby producing varied changes in baroreflex function. During pregnancy, baroreflex gain is markedly attenuated, and at least two hormonal mechanisms contribute, each at different brain sites: increased levels of the neurosteroid 3α-hydroxy-dihydroprogesterone (3α-OH-DHP), acting in the rostral ventrolateral medulla (RVLM), and reduced actions of insulin in the forebrain. 3α-OH-DHP appears to potentiate baroreflex-independent GABAergic inhibition of premotor neurons in the RVLM, which decreases the range of sympathetic nerve activity that can be elicited by changes in arterial pressure. In contrast, reductions in the levels or actions of insulin in the brain blunt baroreflex efferent responses to increments or decrements in arterial pressure. Although plasma levels of angiotensin II are increased in pregnancy, this is not responsible for the reduction in baroreflex gain, although it may contribute to the increased level of sympathetic nerve activity in this condition. How these different hormonal effects are integrated within the brain, as well as possible interactions with additional potential neuromodulators that influence baroreflex function during pregnancy and other physiological and pathophysiological states, remains to be clearly delineated.
Metabolic profiling of muscle contraction in lean compared with obese rodents
Authors: Thyfault John P. , Cree Melanie G. , Tapscott Edward B. , Bell Jill A. , Koves Timothy R. , Ilkayeva Olga , Wolfe Robert R. , Dohm G. Lynis , Muoio Deborah M.
Published: May 2010

Interest in the pathophysiological relevance of intramuscular triacylglycerol (IMTG) accumulation has grown from numerous studies reporting that abnormally high glycerolipid levels in tissues of obese and diabetic subjects correlate negatively with glucose tolerance. Here, we used a hindlimb perfusion model to examine the impact of obesity and elevated IMTG levels on contraction-induced changes in skeletal muscle fuel metabolism. Comprehensive lipid profiling was performed on gastrocnemius muscles harvested from lean and obese Zucker rats immediately and 25 min after 15 min of one-legged electrically stimulated contraction compared with the contralateral control (rested) limbs. Predictably, IMTG content was grossly elevated in control muscles from obese rats compared with their lean counterparts. In muscles of obese (but not lean) rats, contraction resulted in marked hydrolysis of IMTG, which was then restored to near resting levels during 25 min of recovery. Despite dramatic phenotypical differences in contraction-induced IMTG turnover, muscle levels of diacylglycerol (DAG) and long-chain acyl-CoAs (LCACoA) were surprisingly similar between groups. Tissue profiles of acylcarnitine metabolites suggested that the surfeit of IMTG in obese rats fueled higher rates of fat oxidation relative to the lean group. Muscles of the obese rats had reduced lactate levels immediately following contraction and higher glycogen resynthesis during recovery, consistent with a lipid-associated glucose-sparing effect. Together, these findings suggest that contraction-induced mobilization of local lipid reserves in obese muscles promotes β-oxidation, while discouraging glucose utilization. Further studies are necessary to determine whether persistent oxidation of IMTG-derived fatty acids contributes to systemic glucose intolerance in other physiological settings.
Estrogen improves TIMP-MMP balance and collagen distribution in volume-overloaded hearts of ovariectomized females
Authors: Voloshenyuk Tetyana G. , Gardner Jason D.
Published: May 2010

Our previous studies demonstrate that 17β-estradiol limits chronic volume overload-induced hypertrophy and improves heart function in ovariectomized rats. One possible cardioprotective mechanism involves the interaction between estrogen, estrogen receptors, and proteins of the extracellular matrix (ECM). The impact of estrogen deficiency and replacement on left ventricular (LV) hypertrophy and ECM protein expression was studied using five female rat groups: intact sham-operated, ovariectomized sham-operated, intact with volume overload, ovariectomized with volume overload, and ovariectomized with volume overload treated with estrogen. After 8 wk, LV protein extracts were evaluated by Western blot analysis for matrix metalloproteinase-2 (MMP-2) and MMP-9, MT1-MMP, tissue inhibitors of MMPs (TIMP)-1, TIMP-2, TIMP-3 and TIMP-4, collagens type I and III, and estrogen receptor α and β expression. MMP proteolytic activity was assessed by zymography. All volume-overloaded groups exhibited LV hypertrophy, which was associated with a loss of interstitial collagen and perivascular fibrosis. After 8 wk of volume overload, 70% of ovariectomized rats developed heart failure, in contrast to only one intact rat. A downregulation of MMP-2, estrogen receptor-α (ERα), and ERβ, and upregulation of MMP-9 and MT1-MMP were found in the volume-overloaded hearts of ovariectomized rats. Estrogen treatment improved TIMP-2/MMP-2 and TIMP-1/MMP-9 protein balance, restored ERα expression, and prevented MMP-9 activation, perivascular collagen accumulation and development of heart failure. However, estrogen did not fully restore ERβ expression and did not prevent the increase of MMP-9 expression or loss of interstitial collagen. These results support that estrogen limits undesirable ECM remodeling and LV dilation, in part, through modulation of ECM protein expression in volume-overloaded hearts of ovariectomized rats.
Prolactin restores branchial mitochondrion-rich cells expressing Na+/Cl−cotransporter in hypophysectomized Mozambique tilapia
Authors: Breves Jason P. , Watanabe Soichi , Kaneko Toyoji , Hirano Tetsuya , Grau E. Gordon
Published: May 2010

Hypophysectomy and hormone replacement therapy were conducted to investigate the regulation of branchial mitochondrion-rich cell (MRC) recruitment and hormone receptor expression in euryhaline tilapia ( Oreochromis mossambicus). Gene expression and immunolocalization of Na+/Cl−cotransporter (NCC) and Na+/K+/2Cl−cotransporter (NKCC) were used as markers for freshwater (FW)- and seawater (SW)-type MRCs, respectively. In FW fish, hypophysectomy resulted in a significant drop in plasma osmolality, an effect associated with a marked reduction of NCC gene expression and the disappearance of MRCs with apical-NCC immunoreactivity. In contrast, hypophysectomy in SW fish did not impact plasma osmolality, NKCC, or Na+, K+-ATPaseα1gene expression, or the recruitment of MRCs with basolateral-NKCC. Hypophysectomized fish in SW exhibited reduced mRNA levels of prolactin (PRL) receptor 1 and growth hormone (GH) receptor in the gill; GH receptor expression was also reduced following hypophysectomy in FW. PRL replacement therapy restored NCC gene expression and the appearance of MRCs with apical NCC in both FW and SW; there was no interaction of PRL with cortisol. In FW, cortisol modestly stimulated NKCC mRNA levels, while no effect of GH was evident. In SW, no clear effects of hormone replacement on gene expression of NKCC, Na+, K+-ATPaseα1, or hormone receptors were detected. Taken together, the essential nature of PRL to survival of Mozambique tilapia in FW is derived, at least in part, from its ability to stimulate the recruitment of MRCs that express NCC, while recruitment of SW-type MRCs does not require pituitary mediation in this euryhaline tilapia.
Effect of metabolic and respiratory acidosis on intracellular calcium in osteoblasts
Authors: Frick Kevin K. , Bushinsky David A.
Published: May 2010

In vivo, metabolic acidosis {decreased pH from decreased bicarbonate concentration ([HCO3−])} increases urine calcium (Ca) without increased intestinal Ca absorption, resulting in a loss of bone Ca. Conversely, respiratory acidosis [decreased pH from increased partial pressure of carbon dioxide (Pco2)] does not appreciably alter Ca homeostasis. In cultured bone, chronic metabolic acidosis (Met) significantly increases cell-mediated net Ca efflux while isohydric respiratory acidosis (Resp) does not. The proton receptor, OGR1, appears critical for cell-mediated, metabolic acid-induced bone resorption. Perfusion of primary bone cells or OGR1-transfected Chinese hamster ovary (CHO) cells with Met induces transient peaks of intracellular Ca (Cai). To determine whether Resp increases Cai, as does Met, we imaged Caiin primary cultures of bone cells. pH for Met = 7.07 ([HCO3−] = 11.8 mM) and for Resp = 7.13 (Pco2= 88.4 mmHg) were similar and lower than neutral (7.41). Both Met and Resp induced a marked, transient increase in Caiin individual bone cells; however, Met stimulated Caito a greater extent than Resp. We used OGR1-transfected CHO cells to determine whether OGR1 was responsible for the greater increase in Caiin Met than Resp. Both Met and Resp induced a marked, transient increase in Caiin OGR1-transfected CHO cells; however, in these cells Met was not different than Resp. Thus, the greater induction of Caiby Met in primary bone cells is not a function of OGR1 alone, but must involve H+receptors other than OGR1, or pathways sensitive to Pco2, HCO3−, or total CO2that modify the effect of H+in primary bone cells.
Parenteral iron formulations differentially affect MCP-1, HO-1, and NGAL gene expression and renal responses to injury
Authors: Johnson Ali CM , Becker Kirsten , Zager Richard A.
Published: May 2010

Despite their prooxidant effects, ferric iron compounds are routinely administered to patients with renal disease to correct Fe deficiency. This study assessed relative degrees to which three clinically employed Fe formulations [Fe sucrose (FeS); Fe gluconate (FeG); ferumoxytol (FMX)] impact renal redox- sensitive signaling, cytotoxicity, and responses to superimposed stress [endotoxin; glycerol-induced acute renal failure (ARF)]. Cultured human proximal tubule (HK-2) cells, isolated proximal tubule segments (PTS), or mice were exposed to variable, but equal, amounts of FeS, FeG, or FMX. Oxidant-stimulated signaling was assessed by heme oxygenase-1 (HO-1) or monocyte chemoattractant protein (MCP)-1 mRNA induction. Cell injury was gauged by MTT assay (HK-2 cells), %LDH release (PTS), or renal cortical neutrophil gelatinase-associated lipoprotein (NGAL) protein/mRNA levels. Endotoxin sensitivity and ARF severity were assessed by TNF-α and blood urea nitrogen concentrations, respectively. FeS and FeG induced lethal cell injury (in HK-2 cells, PTS), increased HO-1 and MCP-1 mRNAs (HK-2 cells; in vivo), and markedly raised plasma (∼10 times), and renal cortical (∼3 times) NGAL protein levels. Both renal and extrarenal (e.g., hepatic) NGAL production likely contributed to these results, based on assessments of tissue and HK-2 cell NGAL mRNA. FeS pretreatment exacerbated endotoxemia. However, it conferred marked protection against the glycerol model of ARF (halving azotemia). FMX appeared to be “bioneutral,” as it exerted none of the above noted FeS/FeG effects. We conclude that 1) parenteral iron formulations that stimulate redox signaling can evoke cyto/nephrotoxicity; 2) secondary adaptive responses to this injury (e.g., HO-1/NGAL induction) can initiate a renal tubular cytoresistant state; this suggests a potential new clinical application for intravenous Fe therapy; and 3) FMX is bioneutral regarding these responses. The clinical implication(s) of the latter, vis a vis the treatment of Fe deficiency in renal disease patients, remains to be defined.
Superoxide dismutase mimetic drug tempol aggravates anti-GBM antibody-induced glomerulonephritis in mice
Authors: Lu Hua , Zhen Junhui , Wu Tianfu , Peng Ai , Ye Ting , Wang Tao , Yu Xueqing , Vaziri Nosratola D. , Mohan Chandra , Zhou Xin J.
Published: May 2010

Oxidative stress plays an important role in the pathogenesis of anti-glomerular basement membrane antibody-induced glomerulonephritis (anti-GBM-GN). Superoxide dismutase (SOD) is the first line of defense against oxidative stress by converting superoxide to hydrogen peroxide (H2O2). We investigated the effect of the SOD mimetic drug tempol on anti-GBM-GN in mice. 129/svJ mice were challenged with rabbit anti-mouse-GBM sera to induce GN and subsequently divided into tempol (200 mg·kg−1·day−1, orally) and vehicle-treated groups. Routine histology, SOD and catalase activities, malondialdehyde (MDA), H2O2, and immunohistochemical staining for neutrophils, lymphocytes, macrophages, p65-NF-κB, and osteopontin were performed. Mice with anti-GBM-GN had significantly reduced renal SOD and catalase activities and increased H2O2and MDA levels. Unexpectedly, tempol administration exacerbated anti-GBM-GN as evidenced by intensification of proteinuria, the presence of severe crescentic GN with leukocyte influx, and accelerated mortality in the treated group. Tempol treatment raised SOD activity and H2O2level in urine, upregulated p65-NF-κB and osteopontin in the kidney, but had no effect on renal catalase activity. Thus tempol aggravates anti-GBM-GN by increasing production of H2O2which is a potent NF-κB activator and as such can intensify inflammation and renal injury. This supposition is supported by increases seen in p65-NF-κB, osteopontin, and leukocyte influx in the kidneys of the tempol-treated group.
Nedd4–2 interacts with occludin to inhibit tight junction formation and enhance paracellular conductance in collecting duct epithelia
Authors: Raikwar Nandita S. , Vandewalle Alain , Thomas Christie P.
Published: May 2010

Nedd4–2, a E3 ubiquitin ligase, regulates epithelial sodium channel-mediated transcellular Na+transport in the collecting duct. We investigated the effect of Nedd4–2 on the junctional complex and paracellular conductance in mpkCCDc14cells, a collecting duct cell line. We demonstrate that Nedd4–2 coimmunoprecipitated with and reduced the expression of transfected occludin in HEK293 cells. This interaction was mediated via a conserved PY motif in the COOH terminus of occludin and mutation of this PY motif increased the half-life of transfected occludin in HEK293 cells from 6.4 to 11.4 h. We demonstrate that Nedd4–2 ubiquitinates occludin, which was not seen when a catalytically inactive form of Nedd4–2 was used. Overexpression of Nedd4–2 in mpkCCDc14cells reduced occludin at the tight junction and transiently increased paracellular conductance in a Ca2+switch assay consistent with a delay in the formation of tight junctions. Conversely, siRNA-mediated knockdown of Nedd4–2 increased occludin levels and reduced paracellular conductance. In summary, we demonstrate that Nedd4–2 plays a role in tight junction assembly and the regulation of paracellular conductance in the collecting duct.
Modeling the dynamics of airway constriction: effects of agonist transport and binding
Authors: Amin Samir D. , Majumdar Arnab , Frey Urs , Suki Béla
Published: May 2010

Recent advances have revealed that during exogenous airway challenge, airway diameters cannot be adequately predicted by their initial diameters. Furthermore, airway diameters can also vary greatly in time on scales shorter than a breath. To better understand these phenomena, we developed a multiscale model that allowed us to simulate aerosol challenge in the airways during ventilation. The model incorporates agonist-receptor binding kinetics to govern the temporal response of airway smooth muscle contraction on individual airway segments, which, together with airway wall mechanics, determines local airway caliber. Global agonist transport and deposition are coupled with pressure-driven flow, linking local airway constrictions with global flow dynamics. During the course of challenge, airway constriction alters the flow pattern, redistributing the agonist to less constricted regions. This results in a negative feedback that may be a protective property of the normal lung. As a consequence, repetitive challenge can cause spatial constriction patterns to evolve in time, resulting in a loss of predictability of airway diameters. Additionally, the model offers new insights into several phenomena including the intra- and interbreath dynamics of airway constriction throughout the tree structure.
Deficits in Action Selection Based on Numerical Information After Inactivation of the Posterior Parietal Cortex in Monkeys
Authors: Sawamura Hiromasa , Shima Keisetsu , Tanji Jun
Published: May 2010

A previous study identified neuronal activity in area 5 of the monkey posterior parietal cortex that reflects the numerosity of a series of self-performed actions. It is not known, however, whether area 5 is crucially involved in the selection of an action based on numerical information or, instead, merely reflects numerosity-related signals that originate in other brain regions. We transiently and focally inactivated area 5 to test its functional contributions to numerosity-based action selection. Two monkeys were trained to either push or turn a handle in response to a visual trigger signal. The selection of the action was solely based on numerical information from a series of actions performed by the monkey: select A five times, select B five times, and then return to A in a cyclical fashion. When muscimol was applied to a portion of area 5 in which the activity in the numerosity-selective cells was recorded, the error rate in the selection task increased significantly. This transient neural inactivation also caused omission errors that were not observed before the muscimol injection. A control task showed that the errors were not caused by motor deficits or impaired ability to select between two possible actions. Our results indicate that area 5 is crucial for selecting actions on the basis of numerical information about a series of actions performed by the tested individual.
Matching the Oculomotor Drive During Head-Restrained and Head-Unrestrained Gaze Shifts in Monkey
Authors: Bechara Bernard P. , Gandhi Neeraj J.
Published: May 2010

High-frequency burst neurons in the pons provide the eye velocity command (equivalently, the primary oculomotor drive) to the abducens nucleus for generation of the horizontal component of both head-restrained (HR) and head-unrestrained (HU) gaze shifts. We sought to characterize how gaze and its eye-in-head component differ when an “identical” oculomotor drive is used to produce HR and HU movements. To address this objective, the activities of pontine burst neurons were recorded during horizontal HR and HU gaze shifts. The burst profile recorded on each HU trial was compared with the burst waveform of every HR trial obtained for the same neuron. The oculomotor drive was assumed to be comparable for the pair yielding the lowest root-mean-squared error. For matched pairs of HR and HU trials, the peak eye-in-head velocity was substantially smaller in the HU condition, and the reduction was usually greater than the peak head velocity of the HU trial. A time-varying attenuation index, defined as the difference in HR and HU eye velocity waveforms divided by head velocity [α = ( Ḣhr − Ėhu)/ Ḣ] was computed. The index was variable at the onset of the gaze shift, but it settled at values several times greater than 1. The index then decreased gradually during the movement and stabilized at 1 around the end of gaze shift. These results imply that substantial attenuation in eye velocity occurs, at least partially, downstream of the burst neurons. We speculate on the potential roles of burst-tonic neurons in the neural integrator and various cell types in the vestibular nuclei in mediating the attenuation in eye velocity in the presence of head movements.
Theta Modulation in the Medial and the Lateral Entorhinal Cortices
Authors: Deshmukh Sachin S. , Yoganarasimha D. , Voicu Horatiu , Knierim James J.
Published: May 2010

Hippocampal neurons show a strong modulation by theta frequency oscillations. This modulation is thought to be important not only for temporal encoding and decoding of information in the hippocampal system, but also for temporal ordering of neuronal activities on timescales at which physiological mechanisms of synaptic plasticity operate. The medial entorhinal cortex (MEC), one of the two major cortical inputs to the hippocampus, is known to show theta modulation. Here, we show that the local field potentials (LFPs) in the other major cortical input to the hippocampus, the lateral entorhinal cortex (LEC), show weaker theta oscillations than those shown in the MEC. Neurons in LEC also show weaker theta modulation than that of neurons in MEC. These findings suggest that LEC inputs are integrated into hippocampal representations in a qualitatively different manner than the MEC inputs. Furthermore, MEC grid cells increase the scale of their periodic spatial firing patterns along the dorsoventral axis, corresponding to the increasing size of place fields along the septotemporal axis of the hippocampus. We show here a corresponding gradient in the tendency of MEC neural firing to skip alternate theta cycles. We propose a simple model based on interference of delta oscillations with theta oscillations to explain this behavior.
New Types of Continuities
Authors: Çanak İbrahim , Dik Mehmet
Published: May 2010

A new concept of quasi slowly oscillating continuity is introduced. Furthermore, it is shown that this kind of continuity implies ordinary continuity, but the converse is not always true.
Endosonography-Guided Pancreatic Duct Drainage for Chronic Pancreatitis: A Case Report and Review
Authors: Ito Kei , Fujita Naotaka , Noda Yutaka , Kobayashi Go , Obana Takashi , Horaguchi Jun , Koshita Shinsuke , Kanno Yoshihide
Published: May 2010

A 50-year-old man was admitted to our department, complaining of epigastric pain and high fever. CT revealed a pseudocyst at the pancreatic head with upstream dilatation of the pancreatic duct (PD) and fluid collection surrounding the pancreas. Endosonography-guided PD drainage (ESPD) was performed because of unsuccessful ERCP. With a curved linear array echoendoscope, a 7.2 F catheter was placed in the PD. Laboratory data showed improvement in a few days and revealed disappearance of the fluid collection. Ten days after ESPD, a 7 F stent was placed in the PD via the puncture tract across the papilla of Vater followed by transpapillary replacement with a 10 F stent. CT showed a reduction in diameter of the PD and disappearance of the pseudocyst. ESPD is a feasible and useful procedure in selected patients with chronic pancreatitis showing stenosis of the main PD when transpapillary approach is impossible.
Synthesis and Characterization of New Photoluminescent Oxadiazole/Carbazole-Containing Polymers
Authors: Concilio Simona , Bugatti Valeria , Iannelli Pio , Piotto Stefano Piotto
Published: May 2010

We report on the synthesis and the characterization of a new class of segmented polyethers POC containing the oxadiazole and carbazole units. The polymers exhibit a high thermal stability, high glass transition temperatures, and good solubility in common organic solvents, despite the extended aromatic portion in the main polymer chain. The synthetic procedures are simple, and no acid side-products are obtained. According to previous reports on oxadiazole/carbazole-containing materials, POCs show high photoluminescence activity in the blue region of the visible spectra. The good solubility in chlorinate solvents allows the preparation of films with homogeneous thickness by spin coating. Glass transition temperature in the range 115– ensures good stability of film morphology at room temperature. The only exception is POC(6), which shows a poor solubility and higher (), due to its shorter aliphatic chain portion. For these features, polymers POC are potential candidate materials for fabricating blue light-emitting devices.
Solution of Extraordinary Differential Equations with Physical Reasoning by Obtaining Modal Reaction Series
Authors: Das Shantanu
Published: May 2010

Mathematical modeling of many engineering and physics problem leads to extraordinary differential equations like Nonlinear, Delayed, and Fractional Order. An effective method is required to analyze the mathematical model which provides solutions conforming to physical reality. A Fractional Differential Equation (FDE), where the leading differential operator is Riemann‐Liouvelli (RL) type requires fractional order initial states which are sometimes hard to physically relate. Therefore, we must be able to solve these extraordinary systems, in space, time, frequency, area, volume, with physical reality conserved. Extra Ordinary Differential equation Systems and its solution, with Physical Principle, of action‐reaction and equivalent mathematical decomposition method, are obtained as an aid for Physicists and Engineers to tackle the process dynamics with ease. This reactions‐chain generates internal modes from zeroth mode reaction to first mode second mode and to infinite modes; instantaneously in parallel time or space‐scales; and the sum of all these modes gives entire system reaction. This modal reaction as explained by physics theory exactly matches the principle of Adomian Decomposition Method (ADM). Fractional Differential Equation (FDE) with Riemann‐Liouvelli formulation linear and non‐linear is solved as per ADM. In this formulation of FDE by RL method it is found that there is no need to worry about the fractional initial states; instead one can use integer order initial states (the conventional ones) to arrive at solution of FDE. This new finding too is highlighted in this paper‐along with several other problems to give physical insight to the solution of extraordinary differential equation systems. This way one gets insight to Physics of General Differential Equation Systems‐and its solution‐by Physical Principle and equivalent mathematical decomposition method. This facilitates ease in modeling.
Sympathetic Modulation of the Host Defense Response to Infectious Challenge during Recovery from Hemorrhage
Authors: Whitaker Annie M. , Sulzer Jesse , Walker Edith , Mathis Keisa , Molina Patricia E.
Published: May 2010

Background: Trauma/hemorrhage (TxHem) is associated with an immediate pro-inflammatory response that, if exaggerated or prolonged, is thought to contribute to the subsequent immunosuppression that characterizes the period after injury. Previously we have demonstrated that chemical sympathectomy (SNSx) accentuates this immediate pro-inflammatory response to TxHem. These findings suggest that the noradrenergic system plays a critical role in limiting the magnitude of the inflammatory response during TxHem and preserving the integrity of the host defense response to a subsequent infectious challenge during the period after TxHem. Objective: To examine the contribution of tissue norepinephrine to the host defense response to an infectious challenge during recovery from TxHem. Methods: Male Sprague-Dawley rats underwent SNSx (6-hydroxydopamine, i.p. daily for 3 days) prior to vascular catheter implantation. Conscious, unrestrained rats were subjected to traumatic injury (muscle crush) prior to a fixed-pressure hemorrhage (40 mm Hg for 60 min) and fluid resuscitation followed 24 h later by cecal ligation and puncture (CLP). Results: SNSx impaired the hemodynamic and thermoregulatory response to hemorrhage as indicated by decreased basal blood pressure, impaired blood pressure recovery during fluid resuscitation, and greater hypothermia after CLP. Furthermore, SNSx accentuated the TNF-α, IL-1, IL-6, and IL-10 response to TxHem + infection in plasma 6 h after CLP and in peritoneal lavage fluid 24 h after CLP. Conclusion: These results indicate that the integrity of the noradrenergic system is necessary for adequate hemodynamic, thermoregulatory, and inflammatory responses to infection during the period following TxHem.
Forced Swimming Test Decreases Chemotactic Responsiveness and Expression of CD11a in Rat Monocytes
Authors: Briceño Francisco , Arcaya José Luis , Carrizo Edgardo , Rincón Jaimar , Mosquera Jesús
Published: May 2010

Objectives: Previous reports have shown that the depressive status in humans and experimental animals is associated with decreased immune response. Since monocyte chemotaxis and expression of CD11a are pivotal mechanisms in immune response, impairment of these events could explain the diminished immune response in depression. Methods: To test this, rats were submitted to the forced swimming test (FST) for 3 and 15 days. Animals were sacrificed at days 4 (3 days’ FST), 16 (15 days’ FST) and 30 (15 days’ FST and 15 days of recovery time). At these times, a blood sample was obtained for serum and leukocyte isolation. Mononuclear leukocytes were obtained by Histopaque gradient. Chemotaxis responsiveness was determined in Boyden chambers using zymosan-activated rat serum. Cellular CD11a expression and serum CD11a were determined by immunofluorescence and ELISA, respectively. Results: Decreased chemotaxis was observed in FST animals at days 4 and 16 with total recovery at day 30. Diminished expression of cellular CD11a was observed at day 16 and remained decreased at day 30. There were no significant differences in serum CD11a content. Conclusion: Decreased chemotactic response and expression of CD11a found in this experimental model of depression could be important mechanisms to induce impairment immune response in experimental and clinical depression.
Acute and Chronic Stress and the Inflammatory Response in Hyperprolactinemic Rats
Authors: Ochoa-Amaya J.E. , Malucelli B.E. , Cruz-Casallas P.E. , Nasello A.G. , Felicio L.F. , Carvalho-Freitas M.I.R.
Published: May 2010

Background/Aim: Prolactin (PRL), a hormone produced by the pituitary gland, has multiple physiological functions, including immunoregulation. PRL can also be secreted in response to stressful stimuli. During stress, PRL has been suggested to oppose the immunosuppressive effects of inflammatory mediators. Therefore, the aim of the present study was to analyze the effects of short- and long-term hyperprolactinemia on the inflammatory response in rats subjected to acute or chronic cold stress. Methods: Inflammatory edema was induced by carrageenan in male rats, and hyperprolactinemia was induced by injections of the dopamine receptor antagonist domperidone. The volume of inflammatory edema was measured by plethysmography after carrageenan injection. Additionally, the effects of hyperprolactinemia on body weight and serum corticosterone levels were evaluated. Results and Conclusion: Five days of domperidone-induced hyperprolactinemia increased the volume of inflammatory edema. No differences in serum corticosterone levels were observed between groups. No significant differences were found among 30 days domperidone-induced hyperprolactinemic animals subjected to acute stress and the inflammatory response observed in chronic hyperprolactinemic animals subjected to chronic stress. The results suggest that short-term hyperprolactinemia has pro-inflammatory effects. Because such an effect was not observed in long-term hyperprolactinemic animals, PRL-induced tolerance seems likely. We suggest that short-term hyperprolactinemia may act as a protective factor in rats subjected to acute stress. These data suggest that hyperprolactinemia and stress interact differentially according to the time period.
Genetic Alterations at 13q14 May Correlate with Differences in the Biological Behavior of Prostate Cancer between Japanese and Caucasian Men
Authors: Misumi Taku , Yamamoto Yoshiaki , Murakami Tomoyuki , Kawai Yoshihisa , Ito Hideaki , Eguchi Satoshi , Yano Seiji , Nagao Kazuhiro , Hara Takahiko , Sakano Shigeru , Naito Katsusuke , Sasaki Kohsuke , Fuellhase Claudius , Arenas Luis , Fichtner Jan , Matsuyama Hideyasu
Published: May 2010

The incidence of prostate cancer and the resultant mortality rates in Japanese men are lower compared with the rates for Caucasians; however, the Gleason score at diagnosis is higher in Japanese men compared with Caucasians. Loss of 13q is one of the most common chromosomal alterations in prostate cancer. To elucidate the difference in the rate of loss of 13q between Japanese and Caucasian men, we examined the allelic imbalance (AI) on chromosome 13q in 32 Japanese and 39 German prostate cancer patients with a fluorescent polymerase chain reaction technique using 12 microsatellite markers. Benign and malignant histology was identified by a single pathologist and laser capture microdissection was used to gather cancer cells. Although there were no statistical differences in patient background characteristics, the frequency of AI at 13q14 (D13S1253) and at 13q21 (D13S166) was significantly higher in Japanese patients compared with German patients (p = 0.0128 and p = 0.0078, respectively). The frequency of AI at 13q14 was significantly higher in tumors with high Gleason scores (GS) compared with tumors with low GS (p = 0.0478). The present observations suggest that the frequency of genetic alterations at 13q14 may underlie differences in the biological behavior of prostate cancer between Japanese and Caucasian populations.
Impact of Benign Prostatic Hyperplasia Surgery on Erectile Function
Authors: Martínez-Jabaloyas José M. , Villamón-Fort Rafael , Gil-Salom Manuel , Chuan-Nuez Pascual
Published: May 2010

Aim: We evaluate the prevalence of erectile dysfunction (ED) prior to surgery for benign prostatic hyperplasia (BPH) and changes produced after surgical intervention. Patients and Methods: This prospective study included 128 patients treated surgically for BPH. The prevalence of ED was determined before and after surgery according to the International Index of Erectile Function (IIEF). The influence of different clinical variables on erectile function (EF) improvement or deterioration after surgery was determined using uni- and multivariate analyses. Results: Mean IIEF score before surgery was 20.5 ± 7.6. Overall, ED was absent in 32% of patients, mild in 42%, moderate in 13.3%, and severe in 12.5%. Mean IIEF score following surgery was 21.5 ± 7.4 (p = n.s.). After surgery EF improved in 26.6% (34/128) of patients and worsened in 18.8% (24/128) (p < 0.05). Analysing the subset of patients with presurgical ED, 39% reported improvement and 21.1% reported worsening of EF postoperatively. None of the variables analyzed showed a significant relationship with improvement or worsening of EF. Only age was related to worsening EF in the subgroup of non-ED patients. Conclusions: There is a high prevalence of ED amongst candidates for BPH surgery. Although the risk of worsening EF exists postsurgically, an important percentage of ED patients will improve.