bluuebunny/crossref_metadata_2025 huggingface dataset:
The Possible Role That Buffalo Played in the Recent Outbreaks of Foot‐and‐Mouth Disease in South Africa
Authors: VOSLOO WILNA , BOSHOFF KARIN , DWARKA RAHANA , BASTOS ARMANDA
Published: July 2009

Abstract: African buffalo (Syncerus caffer) act as maintenance hosts for foot‐and‐mouth disease (FMD) in southern Africa. A single buffalo can become infected with all three of the endemic serotypes of FMD virus (SAT‐1, SAT‐2, and SAT‐3) and pose a threat of infection to other susceptible cloven‐hoofed animals. The floods of 2000 in southern Africa damaged the Kruger National Park (KNP) game fence extensively, and there were several accounts of buffalo that had escaped from the park. The VP1 gene, which codes for the major antigenic determinant of the FMD virus, was used to determine phylogenetic relationships between virus isolates obtained from the outbreaks and those previously obtained from buffalo in the KNP. These results demonstrate that buffalo were most probably the source of the outbreaks, indicating that disease control using fencing as well as vaccination is extremely important to ensure that FMD does not become established in domestic livestock.
Implications of Agricultural and Wildlife Policy on Management and Eradication of Bovine Tuberculosis and Brucellosis in Free‐Ranging Wood Bison of Northern Canada
Authors: NISHI J. S. , STEPHEN C. , ELKIN B. T.
Published: July 2009

Abstract: Although disease is often an important factor in the population dynamics of wild ungulates, it is largely the threat—both real and perceived—that sylvatic disease reservoirs pose to the health status of commercial livestock or game farm industry that has led governments to establish policy and legislation for disease management, trade, and movement. With respect to bovine tuberculosis and brucellosis in wildlife, policies are largely borrowed from the existing regulatory framework for domestic livestock. In this paper, we review how general policy goals for managing these reportable diseases in domestic livestock have also affected conservation and management of bison in Canada. We argue that there is a need to better integrate conservation biology with agricultural livestock policy to develop management options and better address the unique conservation challenges that diseased free‐ranging bison populations present.
Emergency Response Planning for Anthrax Outbreaks in Bison Herds of Northern Canada
Authors: NISHI J. S. , DRAGON D. C. , ELKIN B. T. , MITCHELL J. , ELLSWORTH T. R. , HUGH‐JONES M. E.
Published: July 2009

Abstract: Anthrax outbreaks in northern Canada have implications for ongoing recovery efforts for the threatened wood bison and may pose a health risk to humans, other wildlife, and domestic livestock. RWED and WBNP maintain Anthrax Emergency Response Plans (AERPs) for their respective jurisdictions. An AERP is a pre‐planned logistical framework for responding effectively and rapidly to an outbreak so as to minimize spread of the disease, reduce environmental load of spores available for future outbreaks, and minimize risk to public health. In this paper, we describe the main components of an AERP and outline areas for future research.
Increasing Risks of Introduction of Heartwater onto the American Mainland Associated with Animal Movements
Authors: BURRIDGE MICHAEL J. , SIMMONS LEIGH‐ANNE , PETER TREVOR F. , MAHAN SUMAN M.
Published: July 2009

Abstract: Opportunities to introduce heartwater onto the American mainland through animal movements include importation from Africa of tick‐infested reptiles and of subclinically infected wild ungulates and importation of livestock from islands in the Caribbean infested with Amblyomma variegatum ticks. Measures to control importation of heartwater vectors on reptiles include importation bans of infested species, treatment of imported reptiles, and eradication of established infestations on the American mainland. Measures to control importation of infected wildlife must focus on improved methods, such as the PCR assay, of screening animals to prevent the entry of carriers of Cowdria ruminantium. Measures to control importation of infected animals from the Caribbean must be based on knowledge of the islands that are infected with C. ruminantium so that the risk of dissemination of heartwater can be established.
Effect of the Association of Cattle and Rusa Deer (Cervus timorensis russa) on Populations of Cattle Ticks (Boophilus microplus)
Authors: BARRÉ N. , BIANCHI M. , DE GARINE‐WICHATITSKY M.
Published: July 2009

Abstract: The wild population of rusa deer (Cervus timorensis russa) in New Caledonia (South Pacific) is nearly as large as the cattle population. The cattle tick is widespread and occurs all year round. Opinions are divided on the role of deer in the biological cycle of the tick: i) Do they maintain a sustainable tick population that is secondarily available for cattle? ii) Do they decrease the infestation of the environment by collecting larvae on the pasture, but preventing their development to the engorged female stage? or iii) Do they contribute to both situations? An experiment was conducted in three groups of pastures, each seeded with 450 000 larvae/ha and allowed to be grazed only by cattle, only by deer, and by a mixed herd of deer and cattle (deer representing 30% of the biomass), at approximately the same stocking rate (470‐510 kg/ha). After 15 months of exposure, the tick burden per weight unit of host was 42 ticks/kg for the steers‐only herd and 0.01/kg for the deer‐only herd. The steers in the “mixed group” harbored 7 times fewer ticks (6.2/kg) than the cattle‐only group, and the deer in the “mixed group,” 130 times more (1.3/kg) than the deer‐only group. Five emergency acaricide treatments had to be applied in the cattle‐only group, but none in the other groups. The long‐term sustainability of a viable tick population on deer as well as the potential benefit resulting from the association of deer and susceptible cattle in the tick control of cattle are highlighted.
Tick Reference Collection of the Late Dr. P.C. Morel
Authors: DUCORNEZ S. , DE GARINE‐WICHATITSKY M. , BARRÉ N. , UILENBERG G. , CAMICAS J. L.
Published: July 2009

Abstract: Host preference of ticks is an important, but still controversial, subject. Recent developments in molecular biology provide new opportunities to test some hypotheses about host preference in a given environment if appropriate specimens are available. Since the unique collection gathered by Dr. P.C. Morel could help achieve this goal, we present an overview of the samples available in his collection.
Immunolocalization of Vesicular Stomatitis Virus in Black Flies (Simulium vittatum)
Authors: HOWERTH ELIZABETH W. , MEAD DANIEL G. , STALLKNECHT DAVID E.
Published: July 2009

Abstract: Vesicular stomatitis, a disease of cattle, horses, and swine, is caused by either vesicular stomatitis virus, New Jersey serotype (VSV‐NJ), or vesicular stomatitis virus, Indiana serotype, which are related viruses in the genus Vesiculovirus, family Rhabdoviridae. Although recognized for at least 160 years, the epidemiology and pathogenesis of this disease remains undefined. Black flies have been suggested as a vector for VSV‐NJ. In this study we infected three‐ to four‐week‐old female black flies with VSV‐NJ via feeding of virus‐spiked ox blood or intrathoracic inoculation, and demonstrated the location of virus by immunohistochemistry. These preliminary findings suggest that VSV‐NJ initially infects the gut in the natural situation but that subsequent spread to the salivary gland may be blocked in older flies, decreasing their ability to transmit the virus. The pattern of staining was different in intrathoracic inoculated flies. In these flies, salivary gland involvement was more likely, and extensive staining of eye, brain, and hemolymph suggested a more generalized infection that apparently circumvented the gut. We conclude that intrathoracic inoculation may be an inappropriate method of infection for determining vector competence and that the age of the vector should be considered when conducting competency studies.
The Medical Management of Cushing's Syndrome
Authors: MORRIS DAMIAN , GROSSMAN ASHLEY
Published: July 2009

Abstract:Cushing's syndrome results from prolonged exposure to excessive circulating glucocorticosteroids, and is associated with significant morbidity and mortality. While the treatment of choice in most patients is surgical, the metabolic consequences of the syndrome, including increased tissue fragility, poor wound healing, hypertension, and diabetes mellitus, increase the risks of such surgery. The hypercortisolemia and its sequelae can be efficiently reversed using medical therapy, either as a temporary measure prior to definitive treatment, or longer term in more difficult cases. Drug treatment has been targeted at the hypothalamic/pituitary level, the adrenal glands, and also at the glucocorticoid receptor level. In this review we discuss the pharmacotherapeutic agents that have been used in Cushing's syndrome, and their efficacy, the monitoring of treatment, and potential therapies that may prove useful in the future in this complex endocrinological disorder.
Association of Hypertension and Hypokalemia with Cushing's Syndrome Caused by Ectopic ACTH Secretion
Authors: TORPY DAVID J. , MULLEN NANCY , ILIAS IOANNIS , NIEMAN LYNNETTE K.
Published: July 2009

Abstract: Cushing's syndrome is associated with hypertension in approximately 80% of cases. Hypertension contributes to the marked increased mortality risk of past or current Cushing's syndrome, largely because of increased cardiovascular risk. Observation of the pathophysiological effect of chronically elevated ACTH and cortisol values in patients with ectopic ACTH secretion complements the available data from acute studies of the effects of ACTH and glucocorticoid infusions in normal volunteers. In a retrospective case review, we identified 58 patients with Cushing's syndrome caused by ectopic ACTH secretion, who were treated at the National Institutes of Health between 1983‐1997. The diagnosis of an ectopic ACTH cause was confirmed by inferior petrosal sinus sampling and/or pathologic examination of tumor. The commonest causes were bronchial carcinoid (40%) and thymic carcinoid (10%), but 18 of 58 (31%) patients had an unknown source of ectopic ACTH. Hypertension (systolic blood pressure >140 mmHg and/or diastolic blood pressure >90 mmHg in adults) was noted in 45 of 58 (78%) ectopic Cushing's patients, a prevalence similar to that noted in other endogenous Cushing's syndrome etiologies. Hypertension was severe, deemed to require 3 or more drugs by the treating physicians, in 26 of 58 (45%) patients. Hypokalemia was much more prevalent than in patients with other causes of Cushing's syndrome, affecting 33 of 58 (57%) patients. The range of plasma ACTH (17‐1557 pg/mL, normal <60) and 24‐hour urine cortisol (UC) excretion (192‐1600 mcg/24 hr, normal <90) allowed analysis of the influence of these hormones on blood pressure and plasma potassium. There was a significant relationship between 24‐hour UC excretion and the presence of hypokalemia (P= 0.003). Eight of nine patients with a UC >6000 mcg/24 hr had hypokalemia. There was no relation between ACTH level and hypokalemia. In addition, we did not find blood pressure severity to be related to UC excretion or ACTH levels. Urine and plasma cortisol and cortisol metabolite measurements suggest that cortisol may act as a mineralocorticoid when in excess, perhaps by saturating the 11β‐hydroxysteroid‐dehydrogenase (11β‐HSD2 enzyme) that inactivates cortisol at the renal tubule. The current data suggest that high cortisol levels may be the principal cause of hypokalemic alkalosis in Cushing's syndrome, rather than inhibition of the 11βHSD2 enzyme by ACTH or the effects of adrenal steroid biosynthetic intermediaries with mineralococorticoid activity.
Hypertension in Congenital Adrenal Hyperplasia and Apparent Mineralocorticoid Excess
Authors: NEW MARIA I.
Published: July 2009

Abstract: Most often, low‐renin hypertension in the child or adolescent has a clearly definable hormonal cause; thus while each of its numerous forms is moderately rare, a specific hormonal basis is to be expected. An endocrine evaluation is indicated after exclusion of cardiologic pathology or renovascular or portal abnormality in a hypertensive child. The evaluation should include analysis of catecholamine and of thyroid hormone plasma levels, and plasma renin activity (PRA) level. Hormonal hypertension with high or normal renin conditions is rare. Elevated blood pressure with high or normal renin levels may be in fact within normal range in the context of growth at upper percentile limits, possibly in conjunction with simple obesity. Diagnosis may be made at any age in most forms of low‐renin hypertension.
The Diagnosis and Management of Endocrine Tumors Causing Hypertension in Children
Authors: NEWMAN KURT D. , PONSKY TODD
Published: July 2009

Abstract: In contrast to that in adults, hypertension in children is frequently amenable to surgical therapy. With advancing techniques in imaging, surgery, and anesthesia, the outcomes of surgery are excellent for children with endocrine tumors causing hypertension.
Molecular Biology of the Chromaffin Cell
Authors: TRIFARÓ JOSÉ‐MARÍA
Published: July 2009

Abstract:A large number of molecular biology studies have been performed on chromaffin cells, and many genes involved in catecholamine synthesis, storage, and release have been cloned and their function determined. Catecholamine synthesis takes place in different cellular compartments, and enzymes involved in this process are subject to a fine regulation, as demonstrated by recent studies on their gene promoters. Genes coding for such intravesicular proteins as chromogranin A, B, and secretogranin II (chromogranin C) are also regulated in response to a variety of stimuli. Chromogranin gene promoters and transcription factors involved in their regulation have been elucidated. This review serves as an introduction to the studies described in the chapters to follow.
Ions, Channels, and Receptors
Authors: POWIS DAVID A. , MARLEY PHILIP D.
Published: July 2009

Abstract:In this section eight presenters focus on three distinct aspects of chromaffin cell biology: first, the properties of neuronal nicotinic receptors; second, the shaping of the Ca2+signals that underlie chromaffin cell function; and third, the properties and expression of cell surface transporter proteins. Together these studies provide considerable new insight into the complexity of the signaling mechanisms that regulate the functional activity of the cell.
Regulation of Voltage‐Dependent Sodium Channel Expression in Adrenal Chromaffin Cells
Authors: KOBAYASHI HIDEYUKI , SHIRAISHI SEIJI , YANAGITA TOSHIHIKO , YOKOO HIROKI , YAMAMOTO RYUICHI , MINAMI SHIN‐ICHI , SAITOH TOMOKAZU , WADA AKIHIKO
Published: July 2009

Abstract:The density and electrical activity of cell surface voltage‐dependent Na+channels are key determinants regulating the neuronal plasticity including development, differentiation, and regeneration. Abnormalities of Na+channels are associated with various neurological diseases. In this paper, we review the regulatory mechanisms of cell surface Na+channel expression mediated by Ca2+signaling pathways in cultured bovine adrenal chromaffin cells. Sustained, but not transient, elevation of intracellular Ca2+concentration reduced the number of cell surface Na+channels. The reduction of Na+channels was suppressed by an inhibitor of calpain, a Ca2+‐dependent protease, and by an inhibitor of protein kinase C (PKC). The activation of conventional PKC‐α and novel PKC‐ε reduced cell surface Na+channels by the acceleration of internalization of the channels and by the increased degradation of Na+channel α‐subunit mRNA, respectively. On the contrary, the activation of PKC‐ε increased Na+channel β1‐subunit mRNA level. The inhibition of calcineurin, a Ca2+/calmodulin‐dependent protein phosphatase 2B, by immunosuppressants upregulated cell surface Na+channels by both stimulating externalization and inhibiting internalization of the channels without changing Na+channel α‐ and β1‐subunit mRNA levels. Thus, the signal transduction pathways mediated by intracellular Ca2+modulate cell surface Na+channel expression via multiple Ca2+‐dependent events, and the changes in the intracellular vesicular trafficking are the important mechanisms in the regulation of Na+channel expression.
Evidence for Constitutive Expression of Bovine Adrenal a3β4* Nicotinic Acetylcholine Receptors
Authors: FREE R. BENJAMIN , McKAY SUSAN B. , BOYD R. THOMAS , McKAY DENNIS B.
Published: July 2009

Abstract:Many pathological conditions involve alterations in expression of nicotinic acetylcholine receptors (nAChRs). The following studies were designed to investigate cellular mechanisms involved with expression and turnover of α3β4* nAChRs. These studies support constitutive turnover of adrenal α3β4* nAChRs and the use of cultured adrenal chromaffin cells to study nAChR regulation.
How Does Histamine Evoke Catecholamine Secretion from Bovine Chromaffin Cells?
Authors: MARLEY PHILIP D. , WALLACE DAMIAN , DONALD AMANDA , McKENZIE SACHA
Published: July 2009

Abstract: Histamine‐evoked catecholamine secretion from bovine chromaffin cells was studied. Secretion was not prevented by inhibitors of IP3 receptors, protein kinase C, or phospholipase C; depleting Ca2+ stores; or omitting extracellular Na+ or Cl−. Patch clamp studies showed histamine inhibited an M current, causing depolarization and firing of action potentials.
Exocytosis: The Chromaffin Cell As a Model System
Authors: BADER MARIE‐FRANCE , HOLZ RONALD W. , KUMAKURA KONOSUKE , VITALE NICOLAS
Published: July 2009

Abstract: Neurons and neuroendocrine cells release transmitters and hormones by exocytosis of secrctory vesicles or granules. Among the cell models that have provided insight into the molecular machinery underlying the successive steps of exocytosis, adrenal chromaffin cells have taken a prominent place. Thus, most of the molecular players that orchestrate the formation, targeting, docking, and fusion of secrctory granules have been identified in chromaffin cells. By offering the opportunity to combine the use of recent biophysical techniques allowing single‐vesicle resolution and specific biochemical modifications in the protein machinery involved in exocytosis, chromaffn cells remain a powerful model to address new and still open questions in the field of secretion.
Molecular Analysis of SNAP‐25 Function in Exocytosis
Authors: GRAHAM MARGARET E. , WASHBOURNE PHILIP , WILSON MICHAEL C. , BURGOYNE ROBERT D.
Published: July 2009

Abstract: It is generally accepted that the SNARE proteins form the core of the machinery for intracellular membrane fusion and that formation of a SNARE complex is crucially important. Our aim is to dissect the molecular roles of the SNARE proteins and their regulators in physiological membrane fusion during exocytosis. We have developed approaches that allow us to manipulate protein expression in model secretory cells, PC12 and adrenal chromaffin cells, and to combine this with assay of exocytosis at high‐time resolution using carbon‐fiber amperometry. This technique allows us to assess the extent of exocytosis and to follow the kinetics of single secretory granule release events with millisecond time resolution. We established that manipulation of proteins involved in the exocytotic machinery can lead to detectable and interpretable changes in exocytosis kinetics that have revealed novel roles in late stages of exocytosis. Using this approach we have begun to analyze the function of SNAP‐25B using a mutant resistant to the Clostridial neurotoxin BoNT/E. This SNAP‐25 mutant can reconstitute exocytosis in BoNT/E‐treated cells. With this construct it is possible to analyze the consequences of any introduced mutation in the absence of functional endogenous protein. We review here its use in the analysis of palmitoylated cysteines of SNAP‐25 and the conserved residues of the 0 layer of the SNARE complex. The data suggest an important role of the cysteines, but not the 0 layer glutamines, in triggered exocytosis.
Molecular Motors Involved in Chromaffin Cell Secretion
Authors: ROSÉ SERGIO D. , LEJEN TATIANA , CASALETTI LUCIANA , LARSON ROY E. , PENE TEODORA DUMITRESCU , TRIFARÓ JOSÉ‐MARÍA
Published: July 2009

Abstract: Neurosecretory cells, including chromaffin cells, possess a mesh of filamentous actin underneath the plasma membrane. It has been proposed that filamentous actin network separates the secretory vesicles into two compartments: the reserve pool and the release‐ready vesicle pool. Disassembly of chromaffin cell cortical filamentous actin in response to stimulation allows the movement of vesicles from the reserve pool into the release‐ready vesicle pool. Electron microscopy of cytoskeletons revealed the presence of polygonal areas almost devoid of actin filaments in stimulated cells. The percentage of stimulated cells showing disrupted cytoskeleton correlates well with the increase in secretion in these cells. Fine filaments also remain in these areas of disassembly, and these reacted with actin antibodies, as demonstrated by immunogold staining. In addition, the movement of vesicles between pools requires Ca2+ and ATP, a condition for activation of a molecular motor. Confocal microscopy images demonstrated colocalization of myosin Va with dopamine‐β‐hydroxylase. Cell depolarization induced the dissociation of myosin Va from chromaffin vesicles. 2,3‐Butadione‐2‐monoxime (BDM), an inhibitor of myosin ATPase, inhibited secretion, suggesting a blockage for chromaffin vesicle transport between the reserve pool and the release‐ready vesicle pool. On the other hand, myosin II subcellular distribution was not affected by cell depolarization. Confocal microscopy images show myosin II to be localized in the cell cortex and in some perinuclear structures. Chromaffin vesicles were not stained by myosin II antibody.
Neuroendocrine Secretory Protein 55
Authors: FISCHER‐COLBRIE REINER , EDER SUSANNE , LOVISETTI‐SCAMIHORN PAOLA , BECKER ALEXANDRA , LASLOP ANDREA
Published: July 2009

Abstract: The chromogranins constitute a class of acidic proteins comprising the structurally related chromogranins A and B and secretogranin II. These proteins are widely distributed in endocrine and nervous tissues; they are localized to the large dense core vesicles and released from them after stimulation of cells. In all the tissues examined chromogranins are proteolytically processed into small peptides, some of which have defined physiological activities. Chromogranin A plays a key role in large dense core vesicle biogenesis and can induce the formation of the regulated pathway. We have recently cloned neuroendocrine secretory protein 55 (NESP55), a protein that shares several features with the class of chromogranins. NESP55 is a soluble, acidic, heat‐stable secretory protein that is expressed exclusively in endocrine and nervous tissues, although less widely than chromogranins. NESP55 is genomically imprinted and transcribed only from the maternal allele. It is proteolytically processed in some tissues into the small octapeptide GAIPIRRH located at the C terminus of NESP55. In the brain NESP55 is found in cell bodies and axons but not in terminals. At the subcellular level NESP55 is localized to a large vesicle, which is anterogradely transported by the fast axonal flow in neurons. From this vesicle NESP55 is constitutively released. However, in some tissues like the adrenal, medulla, and bovine splenic nerve, NESP55 is also found in the large dense transmitter storage organelles. Thus, NESP55 represents a novel peptidergic marker for a large constitutively secreting vesicle pool found in the central and peripheral nervous system.
Regulation of Endothelial Cell Shape and Barrier Function by Chromogranin A
Authors: FERRERO E. , MAGNI E. , CURNIS F. , VILLA A. , FERRERO M. E. , CORTI A.
Published: July 2009

Abstract: We have found that chromogranin A (CgA), a protein released in circulation by neuroendocrine cells and neurons, prevents the vascular leakage induced by tumor necrosis factor (TNF) in a mouse model. Studies of the mechanism of action showed that CgA and its NH2‐terminal fragments inhibit TNF‐induced vascular permeability by preventing endothelial cytoskeleton rearrangements. We propose that neuronal/endocrine secretion of CgA could contribute to the regulation of endothelial barrier function and the protection of vessels against plasma leakage in inflammatory diseases.
Structural and Biological Characterization of Chromofungin, the Antifungal Chromogranin A (47‐66)‐Derived Peptide
Authors: LUGARDON K. , CHASSEROT‐GOLAZ S. , KIEFFER A. E. , MAGET‐DANA R. , NULLANS G. , KIEFFER B. , AUNIS D. , METZ‐BOUTIGUE M. H.
Published: July 2009

Abstract: The antifungal peptide named chromofungin is the most active vasostatin‐I‐derived peptide, corresponding to the sequence 47‐66 of chromogranin A. 1H‐NMR analysis revealed that it adopts a helical structure. The mechanism implicated in the interaction of chromofungin with fungi and yeast cells was studied by penetration of monolayers and confocal laser microscopy. Chromofungin is able to interact with the cell wall, to cross the plasma membrane, to accumulate in the microorganism, and to inhibit calcineurin activity.
Chromaffin Cells as Models of Endocrine Cells and Neurons
Authors: TISCHLER ARTHUR S.
Published: July 2009

Abstract: Chromaffin cells have many functional similarities to amine‐ and peptide‐producing endocrine cells throughout the body and to both peripheral and central neurons. The hypothesis of a shared, neural origin for chromaffin cells and most other endocrine cells is not tenable. However, chromaffin cells and their neoplastic counterparts, known as pheochromocytomas, are valuable models for studies of endocrine and neural properties. In this session, PC12 rat pheochromocytoma cells are used in two novel applications: to identify profiles of gene expression that may mediate cell death in neurodegenerative disorders and to study mechanisms for transduction of hypoxic signals. Recently described pheochromocytoma cell lines from neurofibromatosis knockout mice are shown to be novel models for signaling by the receptor tyrosine kinase ret, and purified enterochromaffin‐like (ECL) cells are shown to offer new opportunities to study the shared and distinctive aspects of neuroendocrine function using a normal cell type.
Studies of the Dysglycemic Peptide, Pancreastatin, Using a Human Forearm Model
Authors: CADMAN PETER E. , RAO FANGWEN , MAHATA SUSHIL K. , O'CONNOR DANIEL T.
Published: July 2009

Abstract: The physiologic effects of the chromogranin A peptide fragment, pancreastatin, were studied in six healthy Caucasian men, ages 25‐46 years. Synthetic pancreastatin (human chromogranin A273‐301‐amide) was infused into the brachial artery of each subject to achieve a local concentration of ∼200 nM over 15 minutes. Forearm blood flow was measured by strain‐gauge plethysmography while (A‐V)glucose was monitored by arterial and venous sampling. Pancreastatin infusion significantly reduced forearm glucose uptake (mean reduction ± 1 SEM, 54 ± 15%; P= 0.028) but did not alter forearm blood flow—indicating a metabolic, rather than hemodynamic, effect. Simultaneous infusion of pancreastatin with insulin (0.1 mU/kg/min) did not diminish insulin‐induced forearm glucose uptake, suggesting pancreastatin is not simply a negative insulin modulator. The results of this study suggest that pancreastatin may contribute to the dysglycemia associated with type 2 diabetes and essential hypertension, two common human disease states in which plasma pancreastatin levels are elevated.
Computing the Chromaffin Cell
Authors: EIDEN LEE E. , HIRSCH MICHAEL D.
Published: July 2009

Abstract: Exocytosis, stimulus‐secretion coupling, real‐time measurements of neurosecretion, and stimulus‐secretion‐synthesis coupling (stimulus‐transcription coupling) were all initially proposed and verified in the chromaffin cell. Detailed analysis of the molecules and pathways responsible for secretion and transsynaptic regulation of gene expression patterns in neuroendoccrine cells have been very fruitfully explored in chromaffin cells and the related PC12 pheochromocytoma cell line, using modern molecular biologcal, cellular imaging, and expression profiling techniques. The time is clearly at hand for a concerted bioinformatics approach to acquiring and synthesizing electrophysiological, biochemical, and proteomic/genomic data on the chromaffin cell. Accelerating this process will fully realize the unique attributes of the chromaffin cell as a homogeneous, accessible, fully functional model of the posttmitotic neuroendocrine cell.
Computational Analysis of Isoform‐Specific Signal Regulation by CEACAM1—A Cell Adhesion Molecule Expressed in PC12 Cells
Authors: ÖBRINK BJÖRN , SAWA HIROKI , SCHEFFRAHN INKA , SINGER BERNHARD B. , SIGMUNDSSON KRISTMUNDUR , SUNDBERG ULLA , HEYMANN ROBERT , BEAUCHEMIN NICOLE , WENG GEHZI , RAM PRAHLAD , IYENGAR RAVI
Published: July 2009

Abstract: CEACAM1 is a signal‐regulating, homophilic cell adhesion receptor system expressed in epithelia, vessel endothelia, and leukocytes. Here, we demonstrate that CEACAM1 is expressed also in PC12 cells, both as the common transmembrane isoforms, CEACAM1‐L and CEACAM1‐S, and as a novel, secreted, differentially spliced isoform. CEACAM1 can have both positive and negative effects on cell signaling. In an attempt to explain this dual behavior, we have initiated computational analysis of the signal‐regulating effects of CEACAM1. This suggests that CEACAM1 can exert its signal‐regulating activities by discriminating between binding of Src kinases and SHP phosphatases, respectively. Major factors that regulate this discrimination are the expression levels and expression ratios of transmembrane CEACAM1‐L and CEACAM1‐S, the concentration of secreted CEACAM1, and homophilic binding of CEACAM1 presented by neighboring cells.
New Technologies in Exocytosis and Ion Movement
Authors: POLLARD HARVEY B. , APPS DAVID K.
Published: July 2009

Abstract: Evolving new technologies for the study of exocytosis have been successfully exploited for the analysis of secretory events in the well‐characterized chromaffin cell system. These technologies include amperometry, fluorescence resonance energy transfer (FRET), confocal and total internal reflection fluorescence (TIRF), and organelle‐targeted aequorins.
New Approaches for Analysis of Amperometrical Recordings
Authors: GÓMEZ J. FRANCISCO , BRIOSO MIGUEL A. , MACHADO J. DAVID , SÁNCHEZ JOSÉ L. , BORGES RICARDO
Published: July 2009

Abstract:Amperometry is a powerful tool for studying the exocytotic process. Catecholamines released from a single secretory vesicle are oxidized by a carbon fiber microelectrode placed on a chromaffin cell membrane. This phenomenon can be recorded online as an amperometric signal. Each event of exocytosis is called a secretory spike. Several kinetic parameters can be extracted from spikes to get important information about catecholamine storage and to follow the time course of exocytosis. The large amount of data requires the use of computer programs. We describe software, written for Igor Pro (Wavemetrics, Lake Oswego, OR, USA), that allows the offline analysis of amperometric signals. It includes (1) the automatic analysis of a large collection of experiments without user intervention; (2) the visual check of located spikes; (3) data pooling from several experiments to create galleries with hundreds of thousands of spikes. In addition, we have designed a new filtering method for amperometric data. It provides an excellent tool to enhance the signal/noise ratio with minimal artifacts. This filter allows one to obtain more reliable spike parameters.
Quantitative Flow Visualization
Authors: GHARIB MORY , PEREIRA FRANCISCO , DABIRI DANA , MODARRESS DARIUS
Published: July 2009

Abstract: Quantitative flow visualization has many roots and has taken several approaches. The advent of digital image processing has made it practical to extract useful information from every kind of flow image. In a direct approach, the image intensity or color (wavelength or frequency) can be used as an indication of concentration, density and temperature field, or gradients of these scalar fields in the flow.1 For whole‐field velocity measurement, the method of choice for experimental fluid mechanicians has been digital particle image velocimetry (DPIV). This paper presents a novel approach to extend the DPIV technique from a planar method to a full three‐dimensional volume mapping technique.
A New Definition of Contours in Images Applications in Heat and Mass Transfer
Authors: RACHEK ADIL , PADET JACQUES , STOIAN MONICA , PADET COLETTE
Published: July 2009

Abstract: A new definition for the contours of objects used in experimental visualization is proposed and used for edge detection and image smoothing in infrared thermography. This work is a contribution to image analysis, in the search for outlines of the features and their structures, aimed at identifying the trends they represent. A good example is the discovery of structures in the flow of liquids.
Color Interpolation Algorithms in Visualizing Results of Numerical Simulations
Authors: MOGILENSKIKH DMITRY V. , PAVLOV IGOR V.
Published: July 2009

Abstract: The paper addresses the application of graphical replenishment (GR) color interpolation algorithms for visualizing numerical simulation of physical processes in order to enhance the information density of the graphic interpretation of these processes. The GR algorithms presented here may be successfully applied to two‐ and three‐dimensional grids, and grids of various structures.
Effects of a Splitter Plate in the Near Wake of a Divergent Trailing Edge
Authors: NEAU L. , PRUVOST J. , RODRIGUEZ O. , LOC TA PHUOC
Published: July 2009

Abstract: This paper discusses experimental research aimed at defining a base drag reduction device based on splitter plates. The unsteady three‐dimensional nature of the flow is studied by Schlieren photography, particle image velocimetry, and measurement of the total unsteady lift and drag loads.
Assessment of Physiologic and Pathologic Radiative Heat Dissipation Using Dynamic Infrared Imaging
Authors: ANBAR MICHAEL
Published: July 2009

Abstract:This paper reviews the mechanism and assessment of regulated radiative heat dissipation, involving the circulatory system and the skin. It describes the quantitative assessment of skin temperature modulation. The main regulating process, which can be quantitatively monitored by fast and sensitive dynamic infrared imaging, involves autonomic nervous control of cutaneous and subcutaneous perfusion. This control is significantly affected by a variety of local or systemic pathologic conditions, including cancer and certain neuropathies. A potential clinical application that objectively assesses local attenuation of temperature modulation in the presence of breast cancer is described in some detail. Systemic aberrations in skin temperature modulation can be clinically useful also in neurology. It can be used also in psychology and psychiatry to evaluate transient effects of mental stress on the autonomic nervous system.
Molecular Motion and Cardiac Muscle Motor Dynamics
Authors: LANDESBERG AMIR , LANDESBERG YOLANDA , SIDEMAN SAMUEL , TER KEURS HENK E.D.J.
Published: July 2009

Abstract: This paper reports on the kinetics of molecular motion in cardiac (and skeletal) muscles, studied by image analysis of the motility assay of an isolated actin filament sliding over isolated myosin heads that perform as linear motors. Image analysis allows us to study the dynamics of the crossbridges (Xbs) formed by the interactions between the actin molecule and the myosin heads, and to explore the rate kinetics of the interactions between the two. A most significant result pertains to the identification and characterization of two kinds of kinetics involved in Xb dynamics. The analysis of the acquired images suggests that Xb dynamics is determined by two distinctive kinetic mechanisms: fast physical kinetics that relates to the actin‐myosin Xb attachment and detachment cycle and a process that is orders of magnitude slower in biochemical kinetics that relates to the reactions of nucleotide binding and dissociation.
Ice/Water Slurry Blocking Phenomenon at a Tube Orifice
Authors: HIROCHI TAKERO , YAMADA SHUICHI , SHINTATE TUYOSHI , SHIRAKASHI MASATAKA
Published: July 2009

Abstract: The phenomenon of ice‐particle/water mixture blocking flow through a pipeline is a problem that needs to be solved before mixture flow can be applied for practical use in cold energy transportation in a district cooling system. In this work, the blocking mechanism of ice‐particle slurry at a tube orifice is investigated and a criterion for blocking is presented. The cohesive nature of ice particles is shown to cause compressed plug type blocking and the compressive yield stress of a particle cluster is presented as a measure for the cohesion strength of ice particles.
Convective Heat Transfer and Infrared Thermography
Authors: CARLOMAGNO GIOVANNI M. , ASTARITA TOMMASO , CARDONE GENNARO
Published: July 2009

Abstract: Infrared (IR) thermography, because of its two‐dimensional and non‐intrusive nature, can be exploited in industrial applications as well as in research. This paper deals with measurement of convective heat transfer coefficients (h) in three complex fluid flow configurations that concern the main aspects of both internal and external cooling of turbine engine components: (1) flow in ribbed, or smooth, channels connected by a 180° sharp turn, (2) a jet in cross‐flow, and (3) a jet impinging on a wall. The aim of this study was to acquire detailed measurements of h distribution in complex flow configurations related to both internal and external cooling of turbine components. The heated thin foil technique, which involves the detection of surface temperature by means of an IR scanning radiometer, was exploited to measure h. Particle image velocimetry was also used in one of the configurations to precisely determine the velocity field.
Particle Image Velocimetry and Thermometry for Two‐Phase Flow Problems
Authors: KOWALEWSKI TOMASZ A.
Published: July 2009

Abstract: Image processing in fluid mechanics has become an important quantitative tool for flow analysis. The feasibility of simultaneous measurements of instantaneous velocity and temperature fields, as well as for tracking interfaces, creates a functional tool to describe thermally driven flows accompanied by phase change. The information thus gathered is essential for the verification and validation of computation models. The paper reviews the image processing methods developed by the author and his coworkers to analyze typical problems of two‐phase flow. Simultaneous measurement of temperature and velocity fields, obtained by using liquid crystal tracers, are applied to elucidate solidification and growing vapor bubble problems.
Velocity Measurements by Particle Image Velocimetry Using a Direct Intercorrelation Algorithm
Authors: RICHARD JEROME , SUSSET ARNAUD , VANTELON JEAN‐PIERRE
Published: July 2009

Abstract: The aim of this study was to obtain better characterization of the interaction between a water mist and a diffusion flame of small‐scale size. A PIV algorithm was used to determine the flow pattern with and without a water mist and its relation to the velocity of water droplets.
Transonic Injection in Interaction with Transverse Compressible Flow
Authors: DIZENE R. , CHARBONNIER J.M. , DORIGNAC E. , LABLANC R.
Published: July 2009

Abstract: An extensive study devoted to modelling blade cooling was undertaken at CEAT a few years ago in collaboration with SNECMA. For the turbomachinery applications, an experimental configuration of a turbulent boundary layer with heat transfer was studied for compressible and incompressible flows. The research presented here is a part of that study and this paper reports on the experimental results of an investigation concerned with a row of transonic jets interacting with a transverse flow. In many applications, the cooling layer does not emerge onto the surface from a tangential slot but comes from a slot normal to or inclined to what is otherwise a flush surface. In this case the freestream interacts with the coolant flow. The secondary (jet) flow is introduced at an angle of 45° to the mainstream flow direction. Visualization studies using the surface flow patterns and surface temperature flow patterns are reported and discussed.
Visualization Studies of an Acoustically Excited Liquid Sheet
Authors: SIVADAS VAYALAKKARA , HEITOR MANUEL V.
Published: July 2009

Abstract: The interaction between atomizing air and a liquid sheet initiates interfacial instabilities that develop into large amplitude waves, which ultimately promote liquid disintegration. However, to reduce atomizing airflow, the dynamic influence of the surrounding gas is not sufficient to affect the inner core of the liquid. In other words, the characteristic length scales of perturbation promoting break‐up are small in comparison with the initial liquid momentum. Therefore, to enhance the disintegration process, the intact liquid‐core near the nozzle outlet must be influenced by artificial or external excitations. To accomplish this, the present investigation employed a plane laminar liquid‐sheet that was perturbed by acoustic excitations at an optimum frequency through the impinging air‐streams.
Quantification of Myocardial Microcirculatory Function with X‐ray CT
Authors: MÖHLENKAMP STEFAN , LERMAN LILACH O. , BAJZER ŽELJKO , LUND PATRICIA E. , RITMAN ERIK L.
Published: July 2009

Abstract: A mathematical model of the intramyocardial coronary microcirculation is used to explore the validity of a fast CT imaging method for characterizing the myocardial microcirculatory functional status. The fast CT method depends on the demonstrated CT‐based estimation of myocardial perfusion (F) and the intramyocardial blood volume (Bv). The observed curvilinear myocardial blood volume‐to‐flow relationship, empirically fitted to Bv=a·F+b·F0.5, is a signature of the underlying early pathophysiologic processes thought to be involved in systemic disease processes, such as atherosclerosis, hypertension, and diabetes mellitus. The sensitivity and specificity of the CT‐based estimate of this characteristic relationship is explored by altering the characteristics of the vascular diameter‐to‐flow relationship and the variation in the fraction of capillaries perfused at different coronary flows. The simulation results also indicate that if the vascular diameters change so that the vascular resistance corresponds to the change in flow, then the empirically observed myocardial Bv‐to‐F relationship holds well.
Biosimulation and Visualization
Authors: OSHIMA MARIE , KOBAYASHI TOSHIO , TAKAGI KIYOSHI
Published: July 2009

Abstract: Hemodynamics plays an important role in cardiovascular disorders, and the authors are applying numerical and experimental studies of cerebrovascular blood flow to the creation and rupture of cerebral aneurysms. In particular, this study aims to investigate the effects of cerebrovascular geometry on hemodynamics, such as flow pattern, wall shear stress distribution, and pressure. This report consists mainly of two parts: numerical study of blood flow in the artery extracted from computer tomography data, and numerical and experimental studies of a curved pipe model. The simulation was conducted by using a finite element method; the experiment was conducted by particle imaging velocimetry. Numerical and experimental results are compared and both show similar secondary flow behavior.
The Role of PPAR‐γ/RXR‐α Heterodimers in the Regulation of Human Trophoblast Invasion
Authors: FOURNIER THIERRY , PAVAN LAETITIA , TARRADE ANNE , SCHOONJANS KRISTINA , AUWERX JOHAN , ROCHETTE‐EGLY CECILE , EVAIN‐BRION DANIELE
Published: July 2009

Abstract: PPAR‐γ/RXR heterodimers play a key regulatory role in murine placental development. We report here that PPAR‐γ and RXR‐α are highly expressed in cultured primary extravillous cytotrophoblasts (EVCT) isolated from human first‐trimester placenta. Using this cell culture model, we showed that PPAR‐γ agonists inhibit EVCT invasion, whereas PPAR‐γ or pan‐RXR antagonists promoted EVCT invasion by themselves and abolished PPAR‐γ agonist‐mediated effect. Together these data underscore an important function of PPAR/RXR heterodimers in the modulation of trophoblast invasion.
Ultraviolet‐B Irradiation and Matrix Metalloproteinases
Authors: BRENNEISEN PETER , SIES HELMUT , SCHARFFETTER‐KOCHANEK KARIN
Published: July 2009

Abstract: Effects of sunlight have fascinated researchers for decades because nearly every living thing on earth is likely to be exposed to sunlight and the ultraviolet (UV) fraction of it. In addition to detrimental long‐term effects such as immunosuppression and skin cancer, premature aging of the skin (photoaging) is a well‐documented consequence of exposure to UVA and UVB. Photoaged skin is biochemically characterized by an overgrowth of abnormal elastic fibers in the dermis and by a dramatic decrease of distinct collagen types. Ultraviolet irradiation induces delayed UV‐responsive genes, among them matrix metalloproteinases, which degrade macromolecules of the extracellular matrix, a hallmark in carcinogenesis and aging. We are interested in UVB‐triggered initial events and in subsequent signaling resulting in enhanced expression of two major members of the matrix metalloproteinase family, the interstitial collagenase (MMP‐1) and stromelysin‐1 (MMP‐3), in human dermal fibroblasts. Especially, these skin cells play a central role in connective tissue breakdown in photoaging and as stromal cells in tumor invasion and metastasis by means of their capability to produce matrix metalloproteinases. In this review, we will focus on UVB‐triggered induction of matrix metalloproteinases, the so far identified components of the UVB‐modulated signal transduction pathway(s), and the UVB irradiation‐associated generation of reactive oxygen species (ROS). Finally, a potentially novel aspect in UVB irradiation‐mediated expression of interstitial collagenase and stromelysin‐1—namely, the involvement of reactive nitrogen species (RNS)—is discussed.
Expression of the Chemokine Receptor CXCR4 and Its Ligand Stromal Cell‐Derived Factor 1 in Human Brain Tumors and Their Involvement in Glial Proliferation in Vitro
Authors: BARBERO SIMONE , BAJETTO ADRIANA , BONAVIA RUDY , PORCILE CAROLA , PICCIOLI PATRIZIA , PIRANI PAOLO , RAVETTI JEAN LOUIS , ZONA GIANLUIGI , SPAZIANTE RENATO , FLORIO TULLIO , SCHETTINI GENNARO
Published: July 2009

Abstract: Chemokines are a family of proteins that chemoattract and activate cells by interacting with specific receptors on the surface of their targets. They are grouped into four classes based on the position of key cysteine residues: C, CC, CXC, and CX3C. Stromal cell‐derived factor 1 (SDF1), the ligand of the CXCR4 receptor, is a CXC chemokine involved in chemotaxis and brain development that also acts as coreceptor for HIV‐1 infection. It has been proposed that CXCR4 is overexpressed and required for proliferation in human brain tumor cells. We previously demonstrated that CXCR4 and SDF1 are expressed in culture of cortical type I rat astrocytes, cortical neurons, and cerebellar granule cells. In this study, we analyzed the expression of CXCR4 and SDF1 in four human brain tumor tissues, showing that CXCR4 is expressed in all tumors analyzed, whereas SDF1 is expressed only in two tumor tissues. We also investigated the possible functions of CXCR4 expressed in rat type I cortical astrocytes, demonstrating that SDF1α stimulates the proliferation of these cells in vitro. Moreover, we studied by western blot the intracellular pathway involved in cell proliferation, demonstrating that SDF1α induces the ERK1/2 phosphorylation that is reduced by the PD98059 compound, an MEK inhibitor.