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Sample records for physiological snare requirements

  1. SNARE Requirements En Route to Exocytosis

    DEFF Research Database (Denmark)

    Mohrmann, Ralf; Sørensen, Jakob Balslev

    2012-01-01

    and their complexes before and during vesicle exocytosis is still limited. Here, we review recent progress in this expanding field with emphasis on the question of fusion complex stoichiometry, i.e., how many SNARE proteins and complexes are needed for the fusion of a vesicle with the plasma membrane....

  2. Synaptotagmin-1 binds to PIP(2)-containing membrane but not to SNAREs at physiological ionic strength.

    Science.gov (United States)

    Park, Yongsoo; Seo, Jong Bae; Fraind, Alicia; Pérez-Lara, Angel; Yavuz, Halenur; Han, Kyungreem; Jung, Seung-Ryoung; Kattan, Iman; Walla, Peter Jomo; Choi, MooYoung; Cafiso, David S; Koh, Duk-Su; Jahn, Reinhard

    2015-10-01

    The Ca(2+) sensor synaptotagmin-1 is thought to trigger membrane fusion by binding to acidic membrane lipids and SNARE proteins. Previous work has shown that binding is mediated by electrostatic interactions that are sensitive to the ionic environment. However, the influence of divalent or polyvalent ions, at physiological concentrations, on synaptotagmin's binding to membranes or SNAREs has not been explored. Here we show that binding of rat synaptotagmin-1 to membranes containing phosphatidylinositol 4,5-bisphosphate (PIP2) is regulated by charge shielding caused by the presence of divalent cations. Surprisingly, polyvalent ions such as ATP and Mg(2+) completely abrogate synaptotagmin-1 binding to SNAREs regardless of the presence of Ca(2+). Altogether, our data indicate that at physiological ion concentrations Ca(2+)-dependent synaptotagmin-1 binding is confined to PIP2-containing membrane patches in the plasma membrane, suggesting that membrane interaction of synaptotagmin-1 rather than SNARE binding triggers exocytosis of vesicles.

  3. The Polybasic Juxtamembrane Region of Sso1p Is Required for SNARE Function In Vivo†

    OpenAIRE

    Van Komen, Jeffrey S.; Bai, Xiaoyang; Rodkey, Travis L.; Schaub, Johanna; MCNEW, JAMES A.

    2005-01-01

    Exocytosis in Saccharomyces cerevisiae requires the specific interaction between the plasma membrane t-SNARE complex (Sso1/2p;Sec9p)and a vesicular v-SNARE (Snc1/2p). While SNARE proteins drive membrane fusion, many aspects of SNARE assembly and regulation are ill defined. Plasma membrane syntaxin homologs (including Sso1p) contain a highly charged juxtamembrane region between the transmembrane helix and the “SNARE domain” or core complex domain. We examined this region in vitro and in vivo b...

  4. Fast Vesicle Fusion in Living Cells Requires at Least Three SNARE Complexes

    DEFF Research Database (Denmark)

    Mohrmann, Ralf; de Wit, Heidi; Verhage, Matthijs

    2010-01-01

    Exocytosis requires formation of SNARE complexes between vesicle- and target-membranes. Recent assessments in reduced model systems have produced divergent estimates of the number of SNARE complexes needed for fusion. Here, we used a titration approach to answer this question in intact, cultured ...

  5. The Gos28 SNARE protein mediates intra-Golgi transport of rhodopsin and is required for photoreceptor survival.

    Science.gov (United States)

    Rosenbaum, Erica E; Vasiljevic, Eva; Cleland, Spencer C; Flores, Carlos; Colley, Nansi Jo

    2014-11-21

    SNARE proteins play indispensable roles in membrane fusion events in many cellular processes, including synaptic transmission and protein trafficking. Here, we characterize the Golgi SNARE protein, Gos28, and its role in rhodopsin (Rh1) transport through Drosophila photoreceptors. Mutations in gos28 lead to defective Rh1 trafficking and retinal degeneration. We have pinpointed a role for Gos28 in the intra-Golgi transport of Rh1, downstream from α-mannosidase-II in the medial- Golgi. We have confirmed the necessity of key residues in Gos28's SNARE motif and demonstrate that its transmembrane domain is not required for vesicle fusion, consistent with Gos28 functioning as a t-SNARE for Rh1 transport. Finally, we show that human Gos28 rescues both the Rh1 trafficking defects and retinal degeneration in Drosophila gos28 mutants, demonstrating the functional conservation of these proteins. Our results identify Gos28 as an essential SNARE protein in Drosophila photoreceptors and provide mechanistic insights into the role of SNAREs in neurodegenerative disease.

  6. Cysteine residues of SNAP-25 are required for SNARE disassembly and exocytosis, but not for membrane targeting.

    Science.gov (United States)

    Washbourne, P; Cansino, V; Mathews, J R; Graham, M; Burgoyne, R D; Wilson, M C

    2001-08-01

    The release of neurotransmitter at a synapse occurs via the regulated fusion of synaptic vesicles with the plasma membrane. The fusion of the two lipid bilayers is mediated by a protein complex that includes the plasma membrane target soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment protein (SNAP) receptors (t-SNAREs), syntaxin 1A and synaptosome-associated protein of 25 kDa (SNAP-25), and the vesicle SNARE (v-SNARE), vesicle-associated membrane protein (VAMP). Whereas syntaxin 1A and VAMP are tethered to the membrane by a C-terminal transmembrane domain, SNAP-25 has been suggested to be anchored to the membrane via four palmitoylated cysteine residues. We demonstrate that the cysteine residues of SNAP-25 are not required for membrane localization when syntaxin 1A is present. Analysis of the 7 S and 20 S complexes formed by mutants that lack cysteine residues demonstrates that the cysteines are required for efficient SNARE complex dissociation. Furthermore, these mutants are unable to support exocytosis, as demonstrated by a PC12 cell secretion assay. We hypothesize that syntaxin 1A serves to direct newly synthesized SNAP-25 through the Golgi transport pathway to the axons and synapses, and that palmitoylation of cysteine residues is not required for targeting, but to optimize interactions required for SNARE complex dissociation.

  7. Three v-SNAREs and two t-SNAREs, present in a pentameric cis-SNARE complex on isolated vacuoles, are essential for homotypic fusion

    DEFF Research Database (Denmark)

    Ungermann, C; von Mollard, G F; Jensen, Ole Nørregaard

    1999-01-01

    Vacuole SNAREs, including the t-SNAREs Vam3p and Vam7p and the v-SNARE Nyv1p, are found in a multisubunit "cis" complex on isolated organelles. We now identify the v-SNAREs Vti1p and Ykt6p by mass spectrometry as additional components of the immunoisolated vacuolar SNARE complex. Immunodepletion...... cause a synthetic fusion-defective phenotype in our reaction. Our data show that vacuole-vacuole fusion requires a cis-SNARE complex of five SNAREs, the t-SNAREs Vam3p and Vam7p and the v-SNAREs Nyv1p, Vti1p, and Ykt6p....

  8. Three v-SNAREs and two t-SNAREs, present in a pentameric cis-SNARE complex on isolated vacuoles, are essential for homotypic fusion

    DEFF Research Database (Denmark)

    Ungermann, C; von Mollard, G F; Jensen, Ole Nørregaard

    1999-01-01

    in the same cis multi-SNARE complex. After priming, which disassembles the cis-SNARE complex, antibodies to any of the five SNARE proteins still inhibit the fusion assay until the docking stage is completed, suggesting that each SNARE plays a role in docking. Furthermore, vti1 temperature-sensitive alleles...... cause a synthetic fusion-defective phenotype in our reaction. Our data show that vacuole-vacuole fusion requires a cis-SNARE complex of five SNAREs, the t-SNAREs Vam3p and Vam7p and the v-SNAREs Nyv1p, Vti1p, and Ykt6p....

  9. Conversion of functional specificity in Qb-SNARE VTI1 homologues of Arabidopsis.

    Science.gov (United States)

    Niihama, Mitsuru; Uemura, Tomohiro; Saito, Chieko; Nakano, Akihiko; Sato, Masa H; Tasaka, Masao; Morita, Miyo Terao

    2005-03-29

    In higher multicellular eukaryotes, highly specialized membrane structures or membrane trafficking events are required for supporting various physiological functions. SNAREs (soluble NSF attachment protein receptors) play an important role in specific membrane fusions. These protein receptors are assigned to subgroubs (Qa-, Qb-, Qc-, and R-SNARE) according to their specific SNARE structural motif. A specific set of Qa-, Qb-, and Qc-SNAREs, located on the target membrane, interact with R-SNARE on the vesicle to form a tight complex, leading to membrane fusion. The zig-1 mutant of Arabidopsis lacking Qb-SNARE VTI11 shows little shoot gravitropism and abnormal stem morphology. VTI11 and its homolog VTI12 exhibit partially overlapping but distinct intracellular localization and have different biological functions in plants. Little is known about how SNAREs are targeted to specific organelles, even though their functions and specific localization are closely linked. Here, we report that a novel mutation in VTI12 (zip1) was found as a dominant suppressor of zig-1. The zip1 mutation gave VTI12 the ability to function as VTI11 by changing both the specificity of SNARE complex formation and its intracellular localization. One amino acid substitution drastically altered VTI12, allowing it to suppress abnormalities of higher order physiological functions such as gravitropism and morphology. The zip1 mutation may be an indication of the flexibility in plant cell function afforded by gene duplication, particularly among the VTI11 genes and their recently diverged orthologs.

  10. Arabidopsis R-SNARE proteins VAMP721 and VAMP722 are required for cell plate formation.

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    Liang Zhang

    Full Text Available BACKGROUND: Cell plate formation during plant cytokinesis is facilitated by SNARE complex-mediated vesicle fusion at the cell-division plane. However, our knowledge regarding R-SNARE components of membrane fusion machinery for cell plate formation remains quite limited. METHODOLOGY/PRINCIPAL FINDINGS: We report the in vivo function of Arabidopsis VAMP721 and VAMP722, two closely sequence-related R-SNAREs, in cell plate formation. Double homozygous vamp721vamp722 mutant seedlings showed lethal dwarf phenotypes and were characterized by rudimentary roots, cotyledons and hypocotyls. Furthermore, cell wall stubs and incomplete cytokinesis were frequently observed in vamp721vamp722 seedlings. Confocal images revealed that green fluorescent protein-tagged VAMP721 and VAMP722 were preferentially localized to the expanding cell plates in dividing cells. Drug treatments and co-localization analyses demonstrated that punctuate organelles labeled with VAMP721 and VAMP722 represented early endosomes overlapped with VHA-a1-labeled TGN, which were distinct from Golgi stacks and prevacuolar compartments. In addition, protein traffic to the plasma membrane, but not to the vacuole, was severely disrupted in vamp721vamp722 seedlings by subcellular localization of marker proteins. CONCLUSION/SIGNIFICANCE: These observations suggest that VAMP721 and VAMP722 are involved in secretory trafficking to the plasma membrane via TGN/early endosomal compartment, which contributes substantially to cell plate formation during plant cytokinesis.

  11. The trans-Golgi SNARE syntaxin 10 is required for optimal development of Chlamydia trachomatis

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    Andrea L Lucas

    2015-09-01

    Full Text Available Chlamydia trachomatis, an obligate intracellular pathogen, grows inside of a vacuole, termed the inclusion. Within the inclusion, the organisms differentiate from the infectious elementary body (EB into the reticulate body (RB. The RB communicates with the host cell through the inclusion membrane to obtain the nutrients necessary to divide, thus expanding the chlamydial population. At late time points within the developmental cycle, the RBs respond to unknown molecular signals to redifferentiate into infectious EBs to perpetuate the infection cycle. One strategy for Chlamydia to obtain necessary nutrients and metabolites from the host is to intercept host vesicular trafficking pathways. In this study we demonstrate that a trans-Golgi soluble N-ethylmaleimide–sensitive factor attachment protein (SNARE, syntaxin 10, and/or syntaxin10-associated Golgi elements colocalize with the chlamydial inclusion. We hypothesized that Chlamydia utilizes the molecular machinery of syntaxin 10 at the inclusion membrane to intercept specific vesicular trafficking pathways in order to create and maintain an optimal intra-inclusion environment. To test this hypothesis, we used siRNA knockdown of syntaxin 10 to examine the impact of the loss of syntaxin 10 on chlamydial growth and development. Our results demonstrate that loss of syntaxin 10 leads to defects in normal chlamydial maturation including: variable inclusion size with fewer chlamydial organisms per inclusion, fewer infectious progeny, and delayed or halted RB-EB differentiation. These defects in chlamydial development correlate with an overabundance of NBD-lipid retained by inclusions cultured in syntaxin 10 knockdown cells. Overall, loss of syntaxin 10 at the inclusion membrane negatively affects Chlamydia. Understanding host machinery involved in maintaining an optimal inclusion environment to support chlamydial growth and development is critical towards understanding the molecular signals involved in

  12. NSF- and SNARE-mediated membrane fusion is required for nuclear envelope formation and completion of nuclear pore complex assembly in Xenopus laevis egg extracts.

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    Baur, Tina; Ramadan, Kristijan; Schlundt, Andreas; Kartenbeck, Jürgen; Meyer, Hemmo H

    2007-08-15

    Despite the progress in understanding nuclear envelope (NE) reformation after mitosis, it has remained unclear what drives the required membrane fusion and how exactly this is coordinated with nuclear pore complex (NPC) assembly. Here, we show that, like other intracellular fusion reactions, NE fusion in Xenopus laevis egg extracts is mediated by SNARE proteins that require activation by NSF. Antibodies against Xenopus NSF, depletion of NSF or the dominant-negative NSF(E329Q) variant specifically inhibited NE formation. Staging experiments further revealed that NSF was required until sealing of the envelope was completed. Moreover, excess exogenous alpha-SNAP that blocks SNARE function prevented membrane fusion and caused accumulation of non-flattened vesicles on the chromatin surface. Under these conditions, the nucleoporins Nup107 and gp210 were fully recruited, whereas assembly of FxFG-repeat-containing nucleoporins was blocked. Together, we define NSF- and SNARE-mediated membrane fusion events as essential steps during NE formation downstream of Nup107 recruitment, and upstream of membrane flattening and completion of NPC assembly.

  13. The UT-A1 urea transporter interacts with snapin, a SNARE-associated protein.

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    Mistry, Abinash C; Mallick, Rickta; Fröhlich, Otto; Klein, Janet D; Rehm, Armin; Chen, Guangping; Sands, Jeff M

    2007-10-12

    The UT-A1 urea transporter mediates rapid transepithelial urea transport across the inner medullary collecting duct and plays a major role in the urinary concentrating mechanism. To transport urea, UT-A1 must be present in the plasma membrane. The purpose of this study was to screen for UT-A1-interacting proteins and to study the interactions of one of the identified potential binding partners with UT-A1. Using a yeast two-hybrid screen of a human kidney cDNA library with the UT-A1 intracellular loop (residues 409-594) as bait, we identified snapin, a ubiquitously expressed SNARE-associated protein, as a novel UT-A1 binding partner. Deletion analysis indicated that the C-terminal coiled-coil domain (H2) of snapin is required for UT-A1 interaction. Snapin binds to the intracellular loop of UT-A1 but not to the N- or C-terminal fragments. Glutathione S-transferase pulldown experiments and co-immunoprecipitation studies verified that snapin interacts with native UT-A1, SNAP23, and syntaxin-4 (t-SNARE partners), indicating that UT-A1 participates with the SNARE machinery in rat kidney inner medulla. Confocal microscopic analysis of immunofluorescent UT-A1 and snapin showed co-localization in both the cytoplasm and in the plasma membrane. When we co-injected UT-A1 with snapin cRNA in Xenopus oocytes, urea influx was significantly increased. In the absence of snapin, the influx was decreased when UT-A1 was combined with t-SNARE components syntaxin-4 and SNAP23. We conclude that UT-A1 may be linked to the SNARE machinery via snapin and that this interaction may be functionally and physiologically important for urea transport.

  14. Dynamics of SNARE assembly and disassembly during sperm acrosomal exocytosis.

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    Gerardo A De Blas

    2005-10-01

    Full Text Available The dynamics of SNARE assembly and disassembly during membrane recognition and fusion is a central issue in intracellular trafficking and regulated secretion. Exocytosis of sperm's single vesicle--the acrosome--is a synchronized, all-or-nothing process that happens only once in the life of the cell and depends on activation of both the GTP-binding protein Rab3 and of neurotoxin-sensitive SNAREs. These characteristics make acrosomal exocytosis a unique mammalian model for the study of the different phases of the membrane fusion cascade. By using a functional assay and immunofluorescence techniques in combination with neurotoxins and a photosensitive Ca2+ chelator we show that, in unactivated sperm, SNAREs are locked in heterotrimeric cis complexes. Upon Ca2+ entry into the cytoplasm, Rab3 is activated and triggers NSF/alpha-SNAP-dependent disassembly of cis SNARE complexes. Monomeric SNAREs in the plasma membrane and the outer acrosomal membrane are then free to reassemble in loose trans complexes that are resistant to NSF/alpha-SNAP and differentially sensitive to cleavage by two vesicle-associated membrane protein (VAMP-specific neurotoxins. Ca2+ must be released from inside the acrosome to trigger the final steps of membrane fusion that require fully assembled trans SNARE complexes and synaptotagmin. Our results indicate that the unidirectional and sequential disassembly and assembly of SNARE complexes drive acrosomal exocytosis.

  15. Endobronchial Electrocautery Using Snare

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    Masaaki Kawahara

    1996-01-01

    Full Text Available Between May 1987 and March 1994, upper airway and tracheobronchial electrosurgery with snare was performed in 13 patients (10 men and 3 women, ranging in age from 18 to 87 years. Four patients had benign lesions, and nine had malignant tumors. Total eradication has been achieved in the two patients with benign lesions. Electroexcision of the endobronchial portion of the tumor helped to clear the respiratory airways in all cases with malignant tumors. There has been no major side effects such as bleeding due to this method. Electrocautery is an available economical tool, which helps to diagnose and treat obstructing airway mass lesions.

  16. Auxin regulates SNARE-dependent vacuolar morphology restricting cell size.

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    Löfke, Christian; Dünser, Kai; Scheuring, David; Kleine-Vehn, Jürgen

    2015-03-05

    The control of cellular growth is central to multicellular patterning. In plants, the encapsulating cell wall literally binds neighbouring cells to each other and limits cellular sliding/migration. In contrast to its developmental importance, growth regulation is poorly understood in plants. Here, we reveal that the phytohormone auxin impacts on the shape of the biggest plant organelle, the vacuole. TIR1/AFBs-dependent auxin signalling posttranslationally controls the protein abundance of vacuolar SNARE components. Genetic and pharmacological interference with the auxin effect on vacuolar SNAREs interrelates with auxin-resistant vacuolar morphogenesis and cell size regulation. Vacuolar SNARE VTI11 is strictly required for auxin-reliant vacuolar morphogenesis and loss of function renders cells largely insensitive to auxin-dependent growth inhibition. Our data suggests that the adaptation of SNARE-dependent vacuolar morphogenesis allows auxin to limit cellular expansion, contributing to root organ growth rates.

  17. SNARE zippering and synaptic strength.

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    Rene C Prashad

    Full Text Available Synapses vary widely in the probability of neurotransmitter release. We tested the hypothesis that the zippered state of the trans-SNARE (Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptor complex determines initial release probability. We tested this hypothesis at phasic and tonic synapses which differ by 100-1000-fold in neurotransmitter release probability. We injected, presynaptically, three Clostridial neurotoxins which bind and cleave at different sites on VAMP to determine whether these sites were occluded by the zippering of the SNARE complex or open to proteolytic attack. Under low stimulation conditions, the catalytic light-chain fragment of botulinum B (BoNT/B-LC inhibited evoked release at both phasic and tonic synapses and cleaved VAMP; however, neither BoNT/D-LC nor tetanus neurotoxin (TeNT-LC were effective in these conditions. The susceptibility of VAMP to only BoNT/B-LC indicated that SNARE complexes at both phasic and tonic synapses were partially zippered only at the N-terminal end to approximately the zero-layer with the C-terminal end exposed under resting state. Therefore, the existence of the same partially zippered state of the trans-SNARE complex at both phasic and tonic synapses indicates that release probability is not determined solely by the zippered state of the trans-SNARE complex at least to the zero-layer.

  18. SNARE function analyzed in synaptobrevin/VAMP knockout mice.

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    Schoch, S; Deák, F; Königstorfer, A; Mozhayeva, M; Sara, Y; Südhof, T C; Kavalali, E T

    2001-11-01

    SNAREs (soluble NSF-attachment protein receptors) are generally acknowledged as central components of membrane fusion reactions, but their precise function has remained enigmatic. Competing hypotheses suggest roles for SNAREs in mediating the specificity of fusion, catalyzing fusion, or actually executing fusion. We generated knockout mice lacking synaptobrevin/VAMP 2, the vesicular SNARE protein responsible for synaptic vesicle fusion in forebrain synapses, to make use of the exquisite temporal resolution of electrophysiology in measuring fusion. In the absence of synaptobrevin 2, spontaneous synaptic vesicle fusion and fusion induced by hypertonic sucrose were decreased approximately 10-fold, but fast Ca2+-triggered fusion was decreased more than 100-fold. Thus, synaptobrevin 2 may function in catalyzing fusion reactions and stabilizing fusion intermediates but is not absolutely required for synaptic fusion.

  19. Investigation of SNARE-Mediated Membrane Fusion Mechanism Using Atomic Force Microscopy

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    Abdulreda, Midhat H.; Moy, Vincent T.

    2009-01-01

    Membrane fusion is driven by specialized proteins that reduce the free energy penalty for the fusion process. In neurons and secretory cells, soluble N-ethylmaleimide-sensitive factor-attachment protein (SNAP) receptors (SNAREs) mediate vesicle fusion with the plasma membrane during vesicular content release. Although, SNAREs have been widely accepted as the minimal machinery for membrane fusion, the specific mechanism for SNARE-mediated membrane fusion remains an active area of research. Here, we summarize recent findings based on force measurements acquired in a novel experimental system that uses atomic force microscope (AFM) force spectroscopy to investigate the mechanism(s) of membrane fusion and the role of SNAREs in facilitating membrane hemifusion during SNARE-mediated fusion. In this system, protein-free and SNARE-reconstituted lipid bilayers are formed on opposite (trans) substrates and the forces required to induce membrane hemifusion and fusion or to unbind single v-/t-SNARE complexes are measured. The obtained results provide evidence for a mechanism by which the pulling force generated by interacting trans-SNAREs provides critical proximity between the membranes and destabilizes the bilayers at fusion sites by broadening the hemifusion energy barrier and consequently making the membranes more prone to fusion. PMID:20228892

  20. Transpapillary incision of refractory circumscript pancreatic duct stricture using wire-guided snare forceps

    Institute of Scientific and Technical Information of China (English)

    Takao; Itoi; Atsushi; Sofuni; Fumihide; Itokawa; Toshio; Kurihara; Takayoshi; Tsuchiya; Kentaro; Ishii; Shujiro; Tsuji; Nobuhito; Ikeuchi; Fuminori; Moriyasu

    2010-01-01

    Endoscopic therapy of pancreatic duct(PD)strictures using balloon dilation and pancreatic duct stent(PS) placement has been reported to improve the severity of abdominal pain in selected patients with chronic pancreatitis(CP).However,some strictures are refractory and require frequent PS exchange to control symptoms.We describe two cases of successful endoscopic PD incision for difficult PD stricture using a wireguided snare.The snare is partially opened within the strictured pancreatic duct while applying ...

  1. Dsl1p, Tip20p, and the novel Dsl3(Sec39) protein are required for the stability of the Q/t-SNARE complex at the endoplasmic reticulum in yeast

    DEFF Research Database (Denmark)

    Kraynack, Bryan A; Chan, Angela; Rosenthal, Eva Helga

    2005-01-01

    -ER retrograde transport. Size exclusion chromatography and affinity purification approaches confirmed that Dsl3p is associated with subunits of the "Dsl1p complex." The complex also includes the Q/t-SNARE proteins, Use1p, Sec20p, and Ufe1p, integral membrane proteins that constitute the trimeric acceptor for R...

  2. α-SNAP Enhances SNARE Zippering by Stabilizing the SNARE Four-Helix Bundle

    Directory of Open Access Journals (Sweden)

    Lu Ma

    2016-04-01

    Full Text Available Intracellular membrane fusion is mediated by dynamic assembly and disassembly of soluble N-ethylmaleimide-sensitive factor (NSF attachment protein (SNAP receptors (SNAREs. α-SNAP guides NSF to disassemble SNARE complexes after membrane fusion. Recent experiments showed that α-SNAP also dramatically enhances SNARE assembly and membrane fusion. How α-SNAP is involved in these opposing activities is not known. Here, we examine the effect of α-SNAP on the stepwise assembly of the synaptic SNARE complex using optical tweezers. We found that α-SNAP destabilized the linker domain (LD of the SNARE complex but stabilized its C-terminal domain (CTD through a conformational selection mechanism. In contrast, α-SNAP minimally affected assembly of the SNARE N-terminal domain (NTD, indicating that α-SNAP barely bound the partially assembled trans-SNARE complex. Thus, α-SNAP recognizes the folded CTD for SNARE disassembly with NSF and subtly modulates membrane fusion by altering the stabilities of the SNARE CTD and LD.

  3. Combinatorial SNARE complexes with VAMP7 or VAMP8 define different late endocytic fusion events.

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    Pryor, Paul R; Mullock, Barbara M; Bright, Nicholas A; Lindsay, Margaret R; Gray, Sally R; Richardson, Simon C W; Stewart, Abigail; James, David E; Piper, Robert C; Luzio, J Paul

    2004-06-01

    Both heterotypic and homotypic fusion events are required to deliver endocytosed macromolecules to lysosomes and remodel late endocytic organelles. A trans-SNARE complex consisting of Q-SNAREs syntaxin 7, Vti1b and syntaxin 8 and the R-SNARE VAMP8 has been shown by others to be responsible for homotypic fusion of late endosomes. Using antibody inhibition experiments in rat liver cell-free systems, we confirmed this result, but found that the same Q-SNAREs can combine with an alternative R-SNARE, namely VAMP7, for heterotypic fusion between late endosomes and lysosomes. Co-immunoprecipitation demonstrated separate syntaxin 7 complexes with either VAMP7 or VAMP8 in solubilized rat liver membranes. Additionally, overexpression of the N-terminal domain of VAMP7, in cultured fibroblastic cells, inhibited the mixing of a preloaded lysosomal content marker with a marker delivered to late endosomes. These data show that combinatorial interactions of SNAREs determine whether late endosomes undergo homotypic or heterotypic fusion events.

  4. Feasibility of cold snare polypectomy in Japan: A pilot study

    Institute of Scientific and Technical Information of China (English)

    Yoji; Takeuchi; Takeshi; Yamashina; Noriko; Matsuura; Takashi; Ito; Mototsugu; Fujii; Kengo; Nagai; Fumi; Matsui; Tomofumi; Akasaka; Noboru; Hanaoka; Koji; Higashino; Hiroyasu; Iishi; Ryu; Ishihara; Henrik; Thorlacius; Noriya; Uedo

    2015-01-01

    AIM: To investigate the feasibility of cold snare polypectomy(CSP) in Japan.METHODS: The outcomes of 234 non-pedunculated polyps smaller than 10 mm in 61 patients who underwent CSP in a Japanese referral center were retrospectively analyzed. The cold snare polypectomies were performed by nine endoscopists with no prior experience in CSP using an electrosurgical snare without electrocautery.RESULTS: CSPs were completed for 232 of the 234 polyps. Two(0.9%) polyps could not be removed without electrocautery. Immediate postpolypectomy bleeding requiring endoscopic hemostasis occurred in eight lesions(3.4%; 95%CI: 1.1%-5.8%), but all were easily managed. The incidence of immediate bleeding after CSP for small polyps(6-9 mm) was significantly higher than that of diminutive polyps(≤ 5 mm; 15% vs 1%, respectively). Three(5%) patients complained of minor bleeding after the procedure but required no intervention. The incidence of delayed bleeding requiringendoscopic intervention was 0.0%(95%CI: 0.0%-1.7%). In total, 12% of the resected lesions could not be retrieved for pathological examination. Tumor involvement in the lateral margin could not be histologically assessed in 70(40%) lesions.CONCLUSION: CSP is feasible in Japan. However, immediate bleeding, retrieval failure and uncertain assessment of the lateral tumor margin should not be underestimated. Careful endoscopic diagnosis before and evaluation of the tumor residue after CSP are recommended when implementing CSP in Japan.

  5. Interactions within the yeast t-SNARE Sso1p that control SNARE complex assembly.

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    Munson, M; Chen, X; Cocina, A E; Schultz, S M; Hughson, F M

    2000-10-01

    In the eukaryotic secretory and endocytic pathways, transport vesicles shuttle cargo among intracellular organelles and to and from the plasma membrane. Cargo delivery entails fusion of the transport vesicle with its target, a process thought to be mediated by membrane bridging SNARE protein complexes. Temporal and spatial control of intracellular trafficking depends in part on regulating the assembly of these complexes. In vitro, SNARE assembly is inhibited by the closed conformation adopted by the syntaxin family of SNAREs. To visualize this closed conformation directly, the X-ray crystal structure of a yeast syntaxin, Sso1p, has been determined and refined to 2.1 A resolution. Mutants designed to destabilize the closed conformation exhibit accelerated rates of SNARE assembly. Our results provide insight into the mechanism of SNARE assembly and its intramolecular and intermolecular regulation.

  6. The t-SNAREs syntaxin4 and SNAP23 but not v-SNARE VAMP2 are indispensable to tether GLUT4 vesicles at the plasma membrane in adipocyte

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Takayuki [Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine (Japan); Tamori, Yoshikazu, E-mail: tamori@med.kobe-u.ac.jp [Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine (Japan); Kanda, Hajime; Yoshikawa, Mari; Tateya, Sanshiro; Nishino, Naonobu [Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine (Japan); Kasuga, Masato [Research Institute, International Medical Center of Japan (Japan)

    2010-01-15

    SNARE proteins (VAMP2, syntaxin4, and SNAP23) have been thought to play a key role in GLUT4 trafficking by mediating the tethering, docking and subsequent fusion of GLUT4-containing vesicles with the plasma membrane. The precise functions of these proteins have remained elusive, however. We have now shown that depletion of the vesicle SNARE (v-SNARE) VAMP2 by RNA interference in 3T3-L1 adipocytes inhibited the fusion of GLUT4 vesicles with the plasma membrane but did not affect tethering of the vesicles to the membrane. In contrast, depletion of the target SNAREs (t-SNAREs) syntaxin4 or SNAP23 resulted in impairment of GLUT4 vesicle tethering to the plasma membrane. Our results indicate that the t-SNAREs syntaxin4 and SNAP23 are indispensable for the tethering of GLUT4 vesicles to the plasma membrane, whereas the v-SNARE VAMP2 is not required for this step but is essential for the subsequent fusion event.

  7. Characterization of SNAREs Determines the Absence of a Typical Golgi Apparatus in the Ancient Eukaryote Giardia lamblia*S⃞

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    Elias, Eliana V.; Quiroga, Rodrigo; Gottig, Natalia; Nakanishi, Hideki; Nash, Theodore E.; Neiman, Aaron; Lujan, Hugo D.

    2008-01-01

    Giardia is a eukaryotic protozoal parasite with unusual characteristics, such as the absence of a morphologically evident Golgi apparatus. Although both constitutive and regulated pathways for protein secretion are evident in Giardia, little is known about the mechanisms involved in vesicular docking and fusion. In higher eukaryotes, soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) of the vesicle-associated membrane protein and syntaxin families play essential roles in these processes. In this work we identified and characterized genes for 17 SNAREs in Giardia to define the minimal set of subcellular organelles present during growth and encystation, in particular the presence or not of a Golgi apparatus. Expression and localization of all Giardia SNAREs demonstrate their presence in distinct subcellular compartments, which may represent the extent of the endomembrane system in eukaryotes. Remarkably, Giardia SNAREs, homologous to Golgi SNAREs from other organisms, do not allow the detection of a typical Golgi apparatus in either proliferating or differentiating trophozoites. However, some features of the Golgi, such as the packaging and sorting function, seem to be performed by the endoplasmic reticulum and/or the nuclear envelope. Moreover, depletion of individual genes demonstrated that several SNAREs are essential for viability, whereas others are dispensable. Thus, Giardia requires a smaller number of SNAREs compared with other eukaryotes to accomplish all of the vesicle trafficking events that are critical for the growth and differentiation of this important human pathogen. PMID:18930915

  8. Microdomains of SNARE proteins in the plasma membrane

    NARCIS (Netherlands)

    Bogaart, G. van den; Lang, T.; Jahn, R.

    2013-01-01

    Exocytosis is catalyzed by the engagement of SNARE proteins embedded in the plasma membrane with complementary SNAREs in the membrane of trafficking vesicles undergoing exocytosis. In most cells studied so far, SNAREs are not randomly distributed across the plasma membrane but are clustered and

  9. WNK4 inhibits plasma membrane targeting of NCC through regulation of syntaxin13 SNARE formation.

    Science.gov (United States)

    Chung, Woo Young; Park, Hyun Woo; Han, Jung Woo; Lee, Min Goo; Kim, Joo Young

    2013-12-01

    WNK4, a serine/threonine kinase, plays a critical role in the expression of membrane proteins in the cell surface; however, the underlying mechanism of WNK4 is not clear. Here, we demonstrate that WNK4 inhibits the fusion of plasma membrane delivering vesicle with sorting/recycling endosome through disrupting SNARE formation of syntaxin13, an endosomal t-SNARE and VAMP2, the v-SNARE in plasma membrane delivering vesicle. Their interaction and co-localization were enhanced by hyperosmotic stimulation which is known for WNK4 activation. The kinase domain of WNK4 interacts with the transmembrane domain (TM) of syntaxin13 and this interaction was abolished when the TM was replaced with that of syntaxin16. Interestingly, cell fractionation using sucrose gradients revealed that WNK4 inhibited the formation of the syntaxin13/VAMP2 SNARE complex in the endosomal compartment, but not syntaxin16/VAMP2 or syntaxin13/VAMP7. Syntaxin13 was not phosphorylated by WNK4 and WNK4KI also showed the same binding strength and similar inhibitory regulation on SNARE formation of syntaxin13. Physiological relevance of this mechanism was proved with the expression of NCC (Na(+) C1(-) co-transporter) in the cell surface. The inhibiting activity of WNK4 on surface expression of NCC was abolished by syntaxin13 siRNA transfection. These results suggest that WNK4 attenuates PM targeting of NCC proteins through regulation of syntaxin13 SNARE complex formation with VAMP2 in recycling and sorting endosome. © 2013.

  10. The SNARE Sec22b has a non-fusogenic function in plasma membrane expansion.

    Science.gov (United States)

    Petkovic, Maja; Jemaiel, Aymen; Daste, Frédéric; Specht, Christian G; Izeddin, Ignacio; Vorkel, Daniela; Verbavatz, Jean-Marc; Darzacq, Xavier; Triller, Antoine; Pfenninger, Karl H; Tareste, David; Jackson, Catherine L; Galli, Thierry

    2014-05-01

    Development of the nervous system requires extensive axonal and dendritic growth during which neurons massively increase their surface area. Here we report that the endoplasmic reticulum (ER)-resident SNARE Sec22b has a conserved non-fusogenic function in plasma membrane expansion. Sec22b is closely apposed to the plasma membrane SNARE syntaxin1. Sec22b forms a trans-SNARE complex with syntaxin1 that does not include SNAP23/25/29, and does not mediate fusion. Insertion of a long rigid linker between the SNARE and transmembrane domains of Sec22b extends the distance between the ER and plasma membrane, and impairs neurite growth but not the secretion of VSV-G. In yeast, Sec22 interacts with lipid transfer proteins, and inhibition of Sec22 leads to defects in lipid metabolism at contact sites between the ER and plasma membrane. These results suggest that close apposition of the ER and plasma membrane mediated by Sec22 and plasma membrane syntaxins generates a non-fusogenic SNARE bridge contributing to plasma membrane expansion, probably through non-vesicular lipid transfer.

  11. SNARE-Mediated Cholesterol Movement to Mitochondria Supports Steroidogenesis in Rodent Cells.

    Science.gov (United States)

    Lin, Ye; Hou, Xiaoming; Shen, Wen-Jun; Hanssen, Ruth; Khor, Victor K; Cortez, Yuan; Roseman, Ann N; Azhar, Salman; Kraemer, Fredric B

    2016-02-01

    Vesicular transport involving soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins is known to be responsible for many major cellular activities. In steroidogenic tissues, chronic hormone stimulation results in increased expression of proteins involved in the steroidogenic pathway, whereas acute hormone stimulation prompts the rapid transfer of cholesterol to the inner mitochondrial membrane to be utilized as substrate for steroid hormone production. Several different pathways are involved in supplying cholesterol to mitochondria, but mobilization of stored cholesteryl esters appears to initially constitute the preferred source; however, the mechanisms mediating this cholesterol transfer are not fully understood. To study the potential contribution of SNARE proteins in steroidogenesis, we examined the expression levels of various SNARE proteins in response to hormone stimulation in steroidogenic tissues and cells and established an in vitro mitochondria reconstitution assay system to assess the contribution of various SNARE proteins on cholesterol delivery for steroidogenesis. Our results from reconstitution experiments along with knockdown studies in rat primary granulosa cells and in a Leydig cell line show that soluble N-ethylmaleimide sensitive factor attachment protein-α, synaptosomal-associated protein of 25 kDa, syntaxin-5, and syntaxin-17 facilitate the transport of cholesterol to mitochondria. Thus, although StAR is required for efficient cholesterol movement into mitochondria for steroidogenesis, specific SNAREs participate and are necessary to mediate cholesterol movement to mitochondria.

  12. SNARE-Mediated Cholesterol Movement to Mitochondria Supports Steroidogenesis in Rodent Cells

    Science.gov (United States)

    Lin, Ye; Hou, Xiaoming; Shen, Wen-Jun; Hanssen, Ruth; Khor, Victor K.; Cortez, Yuan; Roseman, Ann N.; Azhar, Salman

    2016-01-01

    Vesicular transport involving soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins is known to be responsible for many major cellular activities. In steroidogenic tissues, chronic hormone stimulation results in increased expression of proteins involved in the steroidogenic pathway, whereas acute hormone stimulation prompts the rapid transfer of cholesterol to the inner mitochondrial membrane to be utilized as substrate for steroid hormone production. Several different pathways are involved in supplying cholesterol to mitochondria, but mobilization of stored cholesteryl esters appears to initially constitute the preferred source; however, the mechanisms mediating this cholesterol transfer are not fully understood. To study the potential contribution of SNARE proteins in steroidogenesis, we examined the expression levels of various SNARE proteins in response to hormone stimulation in steroidogenic tissues and cells and established an in vitro mitochondria reconstitution assay system to assess the contribution of various SNARE proteins on cholesterol delivery for steroidogenesis. Our results from reconstitution experiments along with knockdown studies in rat primary granulosa cells and in a Leydig cell line show that soluble N-ethylmaleimide sensitive factor attachment protein-α, synaptosomal-associated protein of 25 kDa, syntaxin-5, and syntaxin-17 facilitate the transport of cholesterol to mitochondria. Thus, although StAR is required for efficient cholesterol movement into mitochondria for steroidogenesis, specific SNAREs participate and are necessary to mediate cholesterol movement to mitochondria. PMID:26771535

  13. Complexin Cross-links Prefusion SNAREs into a Zigzag Array

    Energy Technology Data Exchange (ETDEWEB)

    D Kummel; S Krishnakumar; D Radoff; F Li; C Giraudo; F Pincet; J Rothman; K Reinsch

    2011-12-31

    Complexin prevents SNAREs from releasing neurotransmitters until an action potential arrives at the synapse. To understand the mechanism for this inhibition, we determined the structure of complexin bound to a mimetic of a prefusion SNAREpin lacking the portion of the v-SNARE that zippers last to trigger fusion. The 'central helix' of complexin is anchored to one SNARE complex, while its 'accessory helix' extends away at {approx}45{sup o} and bridges to a second complex, occupying the vacant v-SNARE binding site to inhibit fusion. We expected the accessory helix to compete with the v-SNARE for t-SNARE binding but found instead that the interaction occurs intermolecularly. Thus, complexin organizes the SNAREs into a zigzag topology that, when interposed between the vesicle and plasma membranes, is incompatible with fusion.

  14. Complexin cross-links prefusion SNAREs into a zigzag array

    Energy Technology Data Exchange (ETDEWEB)

    Kümmel, Daniel; Krishnakumar, Shyam S.; Radoff, Daniel T.; Li, Feng; Giraudo, Claudio G.; Pincet, Frederic; Rothman, James E.; Reinisch, Karin M. (Yale-MED)

    2011-09-20

    Complexin prevents SNAREs from releasing neurotransmitters until an action potential arrives at the synapse. To understand the mechanism for this inhibition, we determined the structure of complexin bound to a mimetic of a prefusion SNAREpin lacking the portion of the v-SNARE that zippers last to trigger fusion. The 'central helix' of complexin is anchored to one SNARE complex, while its 'accessory helix' extends away at {approx}45 deg. and bridges to a second complex, occupying the vacant v-SNARE binding site to inhibit fusion. We expected the accessory helix to compete with the v-SNARE for t-SNARE binding but found instead that the interaction occurs intermolecularly. Thus, complexin organizes the SNAREs into a zigzag topology that, when interposed between the vesicle and plasma membranes, is incompatible with fusion.

  15. Esbern Snare og hans borg i Kalundborg

    DEFF Research Database (Denmark)

    Jensen, Lars Meldgaard Sass; Roesdahl, Else

    2014-01-01

    Discussion of the person Esbern Snare and his time and of the complicated building history of the western castle (Vestborgen) in Kalundborg. Some buildings formerly attributed to Esbern were probably erected by his daughter and son in law, the presumed builders of also the town's great five-tower...

  16. Esbern Snare og hans borg i Kalundborg

    DEFF Research Database (Denmark)

    Jensen, Lars Meldgaard Sass; Roesdahl, Else

    2014-01-01

    Discussion of the person Esbern Snare and his time and of the complicated building history of the western castle (Vestborgen) in Kalundborg. Some buildings formerly attributed to Esbern were probably erected by his daughter and son in law, the presumed builders of also the town's great five-tower...

  17. SNARE zippering is hindered by polyphenols in the neuron

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yoosoo [Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Kim, Se-Hyun; Heo, Paul; Kong, Byoungjae; Shin, Jonghyeok; Jung, Young-Hun; Yoon, Keejung; Chung, Woo-Jae [Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Shin, Yeon-Kyun [Biomedical Research Institute, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011 (United States); Kweon, Dae-Hyuk, E-mail: dhkweon@skku.edu [Department of Genetic Engineering and Center for Human Interface Nanotechnology, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-07-18

    Highlights: • Membrane fusion driven by SNARE complex is hindered by several polyphenols. • Distinctive inhibitory effect of each polyphenol on SNARE zippering in neuron was examined. • FRET between fluorescence protein-tagged SNAREs probed well SNARE zippering in PC12 cells. • Delphinidin and cyanidin inhibit N-terminal SNARE nucleation in Ca{sup 2+}-independent manner. • Myricetin inhibits Ca{sup 2+}-dependent transmembrane association of SNARE complex. - Abstract: Fusion of synaptic vesicles with the presynaptic plasma membrane in the neuron is mediated by soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptor (SNARE) proteins. SNARE complex formation is a zippering-like process which initiates at the N-terminus and proceeds to the C-terminal membrane-proximal region. Previously, we showed that this zippering-like process is regulated by several polyphenols, leading to the arrest of membrane fusion and the inhibition of neuroexocytosis. In vitro studies using purified SNARE proteins reconstituted in liposomes revealed that each polyphenol uniquely regulates SNARE zippering. However, the unique regulatory effect of each polyphenol in cells has not yet been examined. In the present study, we observed SNARE zippering in neuronal PC12 cells by measuring the fluorescence resonance energy transfer (FRET) changes of a cyan fluorescence protein (CFP) and a yellow fluorescence protein (YFP) fused to the N-termini or C-termini of SNARE proteins. We show that delphinidin and cyanidin inhibit the initial N-terminal nucleation of SNARE complex formation in a Ca{sup 2+}-independent manner, while myricetin inhibits Ca{sup 2+}-dependent transmembrane domain association of the SNARE complex in the cell. This result explains how polyphenols exhibit botulinum neurotoxin-like activity in vivo.

  18. The Sec1/Munc18 protein Vps45 regulates cellular levels of its SNARE binding partners Tlg2 and Snc2 in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Scott G Shanks

    Full Text Available Intracellular membrane trafficking pathways must be tightly regulated to ensure proper functioning of all eukaryotic cells. Central to membrane trafficking is the formation of specific SNARE (soluble N-ethylmeleimide-sensitive factor attachment protein receptor complexes between proteins on opposing lipid bilayers. The Sec1/Munc18 (SM family of proteins play an essential role in SNARE-mediated membrane fusion, and like the SNAREs are conserved through evolution from yeast to humans. The SM protein Vps45 is required for the formation of yeast endosomal SNARE complexes and is thus essential for traffic through the endosomal system. Here we report that, in addition to its role in regulating SNARE complex assembly, Vps45 regulates cellular levels of its SNARE binding partners: the syntaxin Tlg2 and the v-SNARE Snc2: Cells lacking Vps45 have reduced cellular levels of Tlg2 and Snc2; and elevation of Vps45 levels results in concomitant increases in the levels of both Tlg2 and Snc2. As well as regulating traffic through the endosomal system, the Snc v-SNAREs are also required for exocytosis. Unlike most vps mutants, cells lacking Vps45 display multiple growth phenotypes. Here we report that these can be reversed by selectively restoring Snc2 levels in vps45 mutant cells. Our data indicate that as well as functioning as part of the machinery that controls SNARE complex assembly, Vps45 also plays a key role in determining the levels of its cognate SNARE proteins; another key factor in regulation of membrane traffic.

  19. Munc18/SNARE proteins' regulation of exocytosis in guinea pig duodenal Brunner's gland acini

    Institute of Scientific and Technical Information of China (English)

    Laura I Cosen-Binker; Gerry P Morris; Stephen Vanner; Herbert Y Gaisano

    2008-01-01

    AIM: To examine the molecular mechanism of exocytosis in the Brunner's gland acinar cell.METHODS: We used a submucosal preparation of guinea pig duodenal Brunner's gland acini to visualize the dilation of the ductal lumen in response to cholinergic stimulus. We correlated this to electron microscopy to determine the extent of exocytosis of the mucin-filled vesicles. We then examined the behavior of SNARE and interacting Munc18 proteins by confocal microscopy.RESULTS: One and 6 μmol/L carbachol evoked a dosedependent dilation of Brunner's gland acini lumen, which correlated to the massive exocytosis of mucin. Munc18c and its cognate SNARE proteins Syntaxin-4 and SNAP-23 were localized to the apical plasma membrane, and upon cholinergic stimulation, Munc18c was displaced into the cytosol leaving Syntaxin-4 and SNAP-23 intact.CONCLUSION: Physiologic cholinergic stimulation induces Munc18c displacement from the Brunner's gland acinar apical plasma membrane, which enables apical membrane Syntaxin-4 and SNAP-23 to form a SNARE complex with mucin-filled vesicle SNARE proteins to affect exocytosis.

  20. The SNARE machinery in mast cell secretion

    Directory of Open Access Journals (Sweden)

    Axel eLorentz

    2012-06-01

    Full Text Available Mast cells are known as inflammatory cells which exert their functions in allergic and anaphylactic reactions by secretion of numerous inflammatory mediators. During an allergic response, the high-affinity IgE receptor, FcεRI, becomes cross-linked by receptor-bound IgE and antigen resulting in immediate release of pre-synthesized mediators – stored in granules – as well as in de novo synthesis of various mediators like cytokines and chemokines. Soluble N-ethylmaleimide-Sensitive Factor (NSF Attachment Protein (SNAP Receptors (SNARE proteins were found to play a central role in regulating membrane fusion events during exocytosis. In addition, several accessory regulators like Munc13, Munc18, Rab GTPases, SCAMPs, complexins or synaptotagmins were found to be involved in membrane fusion. In this review we summarize our current knowledge about the SNARE machinery and its mechanism of action in mast cell secretion.

  1. ER-associated SNAREs and Sey1p mediate nuclear fusion at two distinct steps during yeast mating.

    Science.gov (United States)

    Rogers, Jason V; Arlow, Tim; Inkellis, Elizabeth R; Koo, Timothy S; Rose, Mark D

    2013-12-01

    During yeast mating, two haploid nuclei fuse membranes to form a single diploid nucleus. However, the known proteins required for nuclear fusion are unlikely to function as direct fusogens (i.e., they are unlikely to directly catalyze lipid bilayer fusion) based on their predicted structure and localization. Therefore we screened known fusogens from vesicle trafficking (soluble N-ethylmaleimide-sensitive factor attachment protein receptors [SNAREs]) and homotypic endoplasmic reticulum (ER) fusion (Sey1p) for additional roles in nuclear fusion. Here we demonstrate that the ER-localized SNAREs Sec20p, Ufe1p, Use1p, and Bos1p are required for efficient nuclear fusion. In contrast, Sey1p is required indirectly for nuclear fusion; sey1Δ zygotes accumulate ER at the zone of cell fusion, causing a block in nuclear congression. However, double mutants of Sey1p and Sec20p, Ufe1p, or Use1p, but not Bos1p, display extreme ER morphology defects, worse than either single mutant, suggesting that retrograde SNAREs fuse ER in the absence of Sey1p. Together these data demonstrate that SNAREs mediate nuclear fusion, ER fusion after cell fusion is necessary to complete nuclear congression, and there exists a SNARE-mediated, Sey1p-independent ER fusion pathway.

  2. Snapin mediates insulin secretory granule docking, but not trans-SNARE complex formation

    Energy Technology Data Exchange (ETDEWEB)

    Somanath, Sangeeta [Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT (United Kingdom); Partridge, Christopher J. [Diabetes Research Laboratories, Oxford Centre for Diabetes, Endocrinology and Churchill Hospital, University of Oxford, Oxford, OX3 7LJ (United Kingdom); Marshall, Catriona [Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, E1 2AT (United Kingdom); Rowe, Tony [CSL Limited, 45 Poplar Road, Parkville, Victoria 3052 (Australia); Turner, Mark D., E-mail: mark.turner@ntu.ac.uk [Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS (United Kingdom)

    2016-04-29

    Secretory granule exocytosis is a tightly regulated process requiring granule targeting, tethering, priming, and membrane fusion. At the heart of this process is the SNARE complex, which drives fusion through a coiled-coil zippering effect mediated by the granule v-SNARE protein, VAMP2, and the plasma membrane t-SNAREs, SNAP-25 and syntaxin-1A. Here we demonstrate that in pancreatic β-cells the SNAP-25 accessory protein, snapin, C-terminal H2 domain binds SNAP-25 through its N-terminal Sn-1 domain. Interestingly whilst snapin binds SNAP-25, there is only modest binding of this complex with syntaxin-1A under resting conditions. Instead synataxin-1A appears to be recruited in response to secretory stimulation. These results indicate that snapin plays a role in tethering insulin granules to the plasma membrane through coiled coil interaction of snapin with SNAP-25, with full granule fusion competency only resulting after subsequent syntaxin-1A recruitment triggered by secretory stimulation. - Highlights: • Snapin mediates granule docking. • Snapin binds SNAP-25. • SNARE complex forms downstream.

  3. Localization of plasma membrane t-SNAREs syntaxin 2 and 3 in intracellular compartments

    Directory of Open Access Journals (Sweden)

    Kuismanen Esa

    2005-05-01

    Full Text Available Abstract Background Membrane fusion requires the formation of a complex between a vesicle protein (v-SNARE and the target membrane proteins (t-SNAREs. Syntaxin 2 and 3 are t-SNAREs that, according to previous over-expression studies, are predominantly localized at the plasma membrane. In the present study we investigated localization of the endogenous syntaxin 2 and 3. Results Endogenous syntaxin 2 and 3 were found in NRK cells in intracellular vesicular structures in addition to regions of the plasma membrane. Treatment of these cells with N-ethylmaleimide (NEM, which is known to inactivate membrane fusion, caused syntaxin 3 to accumulate in the trans-Golgi network and syntaxin 2 in perinuclear membrane vesicles. Kinetic analysis in the presence of NEM indicated that this redistribution of syntaxin 2 and 3 takes place via actin containing structures. Conclusion Our data suggest that syntaxin 2 cycles between the plasma membrane and the perinuclear compartment whereas syntaxin 3 cycles between the plasma membrane and the trans-Golgi network. It is possible that this cycling has an important role in the regulation of t-SNARE function.

  4. The Multifaceted Role of SNARE Proteins in Membrane Fusion.

    Science.gov (United States)

    Han, Jing; Pluhackova, Kristyna; Böckmann, Rainer A

    2017-01-01

    Membrane fusion is a key process in all living organisms that contributes to a variety of biological processes including viral infection, cell fertilization, as well as intracellular transport, and neurotransmitter release. In particular, the various membrane-enclosed compartments in eukaryotic cells need to exchange their contents and communicate across membranes. Efficient and controllable fusion of biological membranes is known to be driven by cooperative action of SNARE proteins, which constitute the central components of the eukaryotic fusion machinery responsible for fusion of synaptic vesicles with the plasma membrane. During exocytosis, vesicle-associated v-SNARE (synaptobrevin) and target cell-associated t-SNAREs (syntaxin and SNAP-25) assemble into a core trans-SNARE complex. This complex plays a versatile role at various stages of exocytosis ranging from the priming to fusion pore formation and expansion, finally resulting in the release or exchange of the vesicle content. This review summarizes current knowledge on the intricate molecular mechanisms underlying exocytosis triggered and catalyzed by SNARE proteins. Particular attention is given to the function of the peptidic SNARE membrane anchors and the role of SNARE-lipid interactions in fusion. Moreover, the regulatory mechanisms by synaptic auxiliary proteins in SNARE-driven membrane fusion are briefly outlined.

  5. The cis-acting CTTC-P1BS module is indicative for gene function of LjVTI12, a Qb-SNARE protein gene that is required for arbuscule formation in Lotus japonicus.

    Science.gov (United States)

    Lota, Frédéric; Wegmüller, Sarah; Buer, Benjamin; Sato, Shusei; Bräutigam, Andrea; Hanf, Benjamin; Bucher, Marcel

    2013-04-01

    The majority of land plants live in symbiosis with arbuscular mycorrhizal fungi from the phylum Glomeromycota. This symbiosis improves acquisition of phosphorus (P) by the host plant in exchange for carbohydrates, especially under low-P availability. The symbiosome, constituted by root cortex cells accommodating arbuscular mycorrhizal fungal hyphae, is the site at which bi-directional exchange of nutrients and metabolites takes place. Uptake of orthophosphate (Pi) in the symbiosome is facilitated by mycorrhiza-specific plant Pi transporters. Modifications of the potato Pi transporter 3 (StPT3) promoter were analysed in transgenic mycorrhizal roots, and it was found that the CTTC cis-regulatory element is necessary and sufficient for a transcriptional response to fungal colonization under low-Pi conditions. Phylogenetic footprinting also revealed binary combination of the CTTC element with the Pi starvation response-associated PHR1-binding site (P1BS) in the promoters of several mycorrhiza-specific Pi transporter genes. Scanning of the Lotus japonicus genome for gene promoters containing both cis-regulatory elements revealed a strong over-representation of genes involved in transport processes. One of these, LjVTI12, encoding a member of the SNARE family of proteins involved in membrane transport, exhibited enhanced transcript levels in Lotus roots colonized with the arbuscular mycorrhizal fungus Glomus intraradices. Down-regulation of LjVTI12 by RNA interference resulted in a mycorrhiza-specific phenotype characterized by distorted arbuscule morphology. The results highlight cooperative cis-regulation which integrates mycorrhiza and Pi starvation signaling with vesicle trafficking in symbiosome development.

  6. Physiology

    Science.gov (United States)

    Kay, Ian

    2008-01-01

    Underlying recent developments in health care and new treatments for disease are advances in basic medical sciences. This edition of "Webwatch" focuses on sites dealing with basic medical sciences, with particular attention given to physiology. There is a vast amount of information on the web related to physiology. The sites that are included here…

  7. VAMP subfamilies identified by specific R-SNARE motifs.

    Science.gov (United States)

    Rossi, Valeria; Picco, Raffaella; Vacca, Marcella; D'Esposito, Maurizio; D'Urso, Michele; Galli, Thierry; Filippini, Francesco

    2004-05-01

    In eukaryotes, interactions among the alpha-helical coiled-coil domains (CCDs) of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) play a pivotal role in mediating the fusion among vesicles and target membranes. Surface residues of such CCDs are major candidates to regulate the specificity of membrane fusion, as they may alter local charge at the interaction layers and surface of the fusion complex, possibly modulating its formation and/or the binding of non-SNARE regulatory factors. Based on alternate patterns in surface residues, we have identified two motifs which group vesicular SNAREs in two novel subfamilies: RG-SNAREs and RD-SNAREs. The RG-SNARE CCD is common to all members of the widely conserved family of long VAMPs or longins and to yeast and non-neuronal VAMPs, possibly mediating "basic" fusion mechanisms; instead, only synaptobrevins from Bilateria share an RD-SNARE CCD, which is likely to mediate interactions to specific, yet unknown, regulatory factors and/or be the landmark of rapid fusion reactions like that mediating the release of neurotransmitters.

  8. Endobrevin/VAMP-8 is the primary v-SNARE for the platelet release reaction.

    Science.gov (United States)

    Ren, Qiansheng; Barber, Holly Kalani; Crawford, Garland L; Karim, Zubair A; Zhao, Chunxia; Choi, Wangsun; Wang, Cheng-Chun; Hong, Wanjin; Whiteheart, Sidney W

    2007-01-01

    Platelet secretion is critical to hemostasis. Release of granular cargo is mediated by soluble NSF attachment protein receptors (SNAREs), but despite consensus on t-SNAREs usage, it is unclear which Vesicle Associated Membrane Protein (VAMPs: synaptobrevin/VAMP-2, cellubrevin/VAMP-3, TI-VAMP/VAMP-7, and endobrevin/VAMP-8) is required. We demonstrate that VAMP-8 is required for release from dense core granules, alpha granules, and lysosomes. Platelets from VAMP-8-/- mice have a significant defect in agonist-induced secretion, though signaling, morphology, and cargo levels appear normal. In contrast, VAMP-2+/-, VAMP-3-/-, and VAMP-2+/-/VAMP-3-/- platelets showed no defect. Consistently, tetanus toxin had no effect on secretion from permeabilized mouse VAMP-3-/- platelets or human platelets, despite cleavage of VAMP-2 and/or -3. Tetanus toxin does block the residual release from permeabilized VAMP-8-/- platelets, suggesting a secondary role for VAMP-2 and/or -3. These data imply a ranked redundancy of v-SNARE usage in platelets and suggest that VAMP-8-/- mice will be a useful in vivo model to study platelet exocytosis in hemostasis and vascular inflammation.

  9. Dendritic SNAREs add a new twist to the old neuron theory

    Science.gov (United States)

    Ovsepian, Saak V.; Dolly, J. Oliver

    2011-01-01

    Dendritic exocytosis underpins a broad range of integrative and homeostatic synaptic functions. Emerging data highlight the essential role of SNAREs in trafficking and fusion of secretory organelles with release of peptides and neurotransmitters from dendrites. This Perspective analyzes recent evidence inferring axo-dendritic polarization of vesicular release machinery and pinpoints progress made with existing challenges in this rapidly progressing field of dendritic research. Interpreting the relation of new molecular data to physiological results on secretion from dendrites would greatly advance our understanding of this facet of neuronal mechanisms. PMID:22080607

  10. Identification of SNARE proteins in fish-Tilapia Oreochromis niloticus

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiaohang; LAM Patrick P L; LIN Xuezheng; LIU Chenlin; BIAN Ji; GAISANO Herbert

    2007-01-01

    SNARE proteins are a group of membrane-associated proteins involved in exocytosis, secretion and membrane trafficking events in eukaryotic cells. Research on SNARE protein biology has become a more attractive field in recent years, which is applied to marine biology specifically to the fish Tilapia (Oreochromis niloticus). Plasma membrane fractions of different tissues of Tilapia, including brain, liver-pancreas, intestine, skin and muscle, were extracted, and immuno-decorated with isoform-specific antibodies to the SNARE families and associated proteins. The presence of Syntaxins -1A, 2 and 3, SNAP-23 and SNAP-25, VAMP-2, Munc-18-1 and Munc-13 in the brain was identified, which were differentially distributed in the other organ tissues of the fish Tilapia. The distinct distribution of SNARE and associated proteins will serve as the basis for further investigation into their special secretory function in these tissues of the fish.

  11. News and Views into the SNARE Complexity in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Sang-Jin eKim

    2012-02-01

    Full Text Available Secretory organelles are engaged in a continuous flux of membranes, which is believed to occur mostly via transport vesicles. Being critical in maintaining several cellular functions, transport vesicles are membrane-enclosed sacs that temporarily store and then deliver membrane lipids, protein and polysaccharides. SNAREs have a crucial role in vesicle traffic by driving membrane fusion and conferring fidelity through the formation of specific SNARE complexes. Additionally, specific roles of SNAREs in growth and development implicate that they are versatile components for the life of a plant. Here, we summarize the recent progress on the understanding of the role of SNAREs and highlight some of the questions that are still unsolved.

  12. Concurrent use of pigtail and loop snare catheters for percutaneous retrieval of dislodged central venous port catheter.

    Science.gov (United States)

    Chuang, Ming-Tsung; Wu, Ding-Kwo; Chang, Cheng-Ang; Shih, Ming-Chen Paul; Ou-Yang, Fu; Chuang, Chien-Han; Tsai, Yi-Fan; Hsu, Jui-Sheng

    2011-11-01

    The purpose of this study was to report our experience of percutaneous retrieval of dislodged port catheters with concurrent use of pigtail and loop snare catheters. During a 5-year period at our institute (June 2005 to July 2010), a total of 23 dislodged port catheters were retrieved. The interval between port catheter implantation and dislodged catheter retrieval ranged from 43 days to 1,414 days (mean 586.7 days). The time of delayed retrieval ranged from 1 day to 45 days (mean 4.6 days). All dislodged catheters were retrieved with the concurrent use of pigtail and loop snare catheters via femoral venous route. The prevalence of port catheter dislodgement at our institute was 3.4%. All dislodged port catheters were removed successfully with pigtail and loop snare catheters together. No procedure-related complications were encountered, except for transient arrhythmia in two patients, which required no medication. In conclusion, the concurrent use of pigtail and loop snare catheters is a feasible and easy way for percutaneous retrieval of a dislodged central venous port catheter.

  13. Concurrent use of pigtail and loop snare catheters for percutaneous retrieval of dislodged central venous port catheter

    Directory of Open Access Journals (Sweden)

    Ming-Tsung Chuang

    2011-11-01

    Full Text Available The purpose of this study was to report our experience of percutaneous retrieval of dislodged port catheters with concurrent use of pigtail and loop snare catheters. During a 5-year period at our institute (June 2005 to July 2010, a total of 23 dislodged port catheters were retrieved. The interval between port catheter implantation and dislodged catheter retrieval ranged from 43 days to 1,414 days (mean 586.7 days. The time of delayed retrieval ranged from 1 day to 45 days (mean 4.6 days. All dislodged catheters were retrieved with the concurrent use of pigtail and loop snare catheters via femoral venous route. The prevalence of port catheter dislodgement at our institute was 3.4%. All dislodged port catheters were removed successfully with pigtail and loop snare catheters together. No procedure-related complications were encountered, except for transient arrhythmia in two patients, which required no medication. In conclusion, the concurrent use of pigtail and loop snare catheters is a feasible and easy way for percutaneous retrieval of a dislodged central venous port catheter.

  14. Development of a Single-Sampling Noninvasive Hair Snare

    DEFF Research Database (Denmark)

    Bremner-Harrison, Samantha; Harrison, Stephen W. R.; Cypher, Brian L.

    2006-01-01

    multiple sampling, is cost-effective, easy to construct, and safe for target and nontarget species. Our initial field tests on endangered San Joaquin kit foxes (Vulpes macrotis mutica) and swift foxes (Vulpes velox) suggest that this hair snare may be effective in collecting uncontaminated samples for DNA......Noninvasive hair and fecal DNA sampling provides a means of collecting information on elusive species, while causing little or no disturbance. However, current methods of hair collection do not preclude multiple sampling, thus risking sample contamination. We developed a hair snare that prevents...

  15. Energetics, kinetics, and pathway of SNARE folding and assembly revealed by optical tweezers.

    Science.gov (United States)

    Zhang, Yongli

    2017-07-01

    Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are universal molecular engines that drive membrane fusion. Particularly, synaptic SNAREs mediate fast calcium-triggered fusion of neurotransmitter-containing vesicles with plasma membranes for synaptic transmission, the basis of all thought and action. During membrane fusion, complementary SNAREs located on two apposed membranes (often called t- and v-SNAREs) join together to assemble into a parallel four-helix bundle, releasing the energy to overcome the energy barrier for fusion. A long-standing hypothesis suggests that SNAREs act like a zipper to draw the two membranes into proximity and thereby force them to fuse. However, a quantitative test of this SNARE zippering hypothesis was hindered by difficulties to determine the energetics and kinetics of SNARE assembly and to identify the relevant folding intermediates. Here, we first review different approaches that have been applied to study SNARE assembly and then focus on high-resolution optical tweezers. We summarize the folding energies, kinetics, and pathways of both wild-type and mutant SNARE complexes derived from this new approach. These results show that synaptic SNAREs assemble in four distinct stages with different functions: slow N-terminal domain association initiates SNARE assembly; a middle domain suspends and controls SNARE assembly; and rapid sequential zippering of the C-terminal domain and the linker domain directly drive membrane fusion. In addition, the kinetics and pathway of the stagewise assembly are shared by other SNARE complexes. These measurements prove the SNARE zippering hypothesis and suggest new mechanisms for SNARE assembly regulated by other proteins. © 2017 The Protein Society.

  16. The Longin SNARE VAMP7/TI-VAMP Adopts a Closed Conformation*

    Science.gov (United States)

    Vivona, Sandro; Liu, Corey W.; Strop, Pavel; Rossi, Valeria; Filippini, Francesco; Brunger, Axel T.

    2010-01-01

    SNARE protein complexes are key mediators of exocytosis by juxtaposing opposing membranes, leading to membrane fusion. SNAREs generally consist of one or two core domains that can form a four-helix bundle with other SNARE core domains. Some SNAREs, such as syntaxin target-SNAREs and longin vesicular-SNAREs, have independent, folded N-terminal domains that can interact with their respective SNARE core domains and thereby affect the kinetics of SNARE complex formation. This autoinhibition mechanism is believed to regulate the role of the longin VAMP7/TI-VAMP in neuronal morphogenesis. Here we use nuclear magnetic resonance spectroscopy to study the longin-SNARE core domain interaction for VAMP7. Using complete backbone resonance assignments, chemical shift perturbations analysis, and hydrogen/deuterium exchange experiments, we conclusively show that VAMP7 adopts a preferentially closed conformation in solution. Taken together, the closed conformation of longins is conserved, in contrast to the syntaxin family of SNAREs for which mixtures of open and closed states have been observed. This may indicate different regulatory mechanisms for SNARE complexes containing syntaxins and longins, respectively. PMID:20378544

  17. The longin SNARE VAMP7/TI-VAMP adopts a closed conformation.

    Science.gov (United States)

    Vivona, Sandro; Liu, Corey W; Strop, Pavel; Rossi, Valeria; Filippini, Francesco; Brunger, Axel T

    2010-06-01

    SNARE protein complexes are key mediators of exocytosis by juxtaposing opposing membranes, leading to membrane fusion. SNAREs generally consist of one or two core domains that can form a four-helix bundle with other SNARE core domains. Some SNAREs, such as syntaxin target-SNAREs and longin vesicular-SNAREs, have independent, folded N-terminal domains that can interact with their respective SNARE core domains and thereby affect the kinetics of SNARE complex formation. This autoinhibition mechanism is believed to regulate the role of the longin VAMP7/TI-VAMP in neuronal morphogenesis. Here we use nuclear magnetic resonance spectroscopy to study the longin-SNARE core domain interaction for VAMP7. Using complete backbone resonance assignments, chemical shift perturbations analysis, and hydrogen/deuterium exchange experiments, we conclusively show that VAMP7 adopts a preferentially closed conformation in solution. Taken together, the closed conformation of longins is conserved, in contrast to the syntaxin family of SNAREs for which mixtures of open and closed states have been observed. This may indicate different regulatory mechanisms for SNARE complexes containing syntaxins and longins, respectively.

  18. Adrenomedullin A Novel Peptide Requires Coordination Of Genetic Physiologic And Environmental Factors

    Directory of Open Access Journals (Sweden)

    K. R. Padma

    2015-08-01

    Full Text Available A healthy pregnancy requires strict coordination of genetic physiologic and environmental factors. The relatively common incidence of infertility and pregnancy complications has resulted in increased interest in understanding the mechanisms that underlie normal versus abnormal pregnancy. The peptide hormone adrenomedullin has recently been the focus of some exciting breakthroughs in the pregnancy field. Adrenomedullin ADM is a 52-amino acid peptide with structural homology to calcitonin gene-related peptide CGRP initially isolated from human pheochromocytoma. ADM is synthesized by many mammalian tissues including the adrenal medulla endothelial and vascular smooth muscle cells myocardium and central nervous system. ADM binds to plasma membrane receptors composed of calcitonin receptor-like receptor CRLR a member of serpentine receptor superfamily and receptor activity modifying protein RAMP type 2 or 3. ADM has also some affinity for CGRP receptor composed of CRLR and RAMP1. Supported by mechanistic studies in genetic animal models there continues to be a growing body of evidence demonstrating the importance of adrenomedullin protein levels in a variety of human pregnancy complications. With measurement of foetal resorption sites we can examine the importance of adrenomedullin a peptide hormone in pregnancy which alters due to genetic physiologic and environmental factors. A growing body of evidence illustrates AM as a pivotal component in normal physiology and disease with marked beneficial effects in the host defense mechanism.

  19. Nuclear management in manual small incision cataract surgery by snare technique

    Directory of Open Access Journals (Sweden)

    Bhattacharya Debasish

    2009-01-01

    Full Text Available Manual small incision cataract surgery has evolved into a popular method of cataract surgery in India. However, in supra hard cataract, bringing out the whole nucleus through the sclerocorneal flap valve incision becomes difficult. A bigger incision required in such cataracts loses its value action, as the internal incision and corneal valve slips beyond the limbus into sclera. Struggling with the supra hard cataracts through a regular small incision. Phacofracture in the anterior chamber becomes a useful option in these cases. In the snare technique, a stainless steel wire loop when lassoed around the nucleus in the anterior chamber constricts from the equator, easily dividing the hardest of the nuclei into two halves. The wire loop constricts in a controlled way when the second cannula of snare is pulled. The divided halves can easily be brought out by serrated crocodile forceps. This nuclear management can be safely performed through a smaller sclerocorneal flap valve incision where the corneal valve action is retained within the limbus without sutures, and the endothelium or the incision is not disturbed. However, the technique requires space in the anterior chamber to maneuver the wire loop and anterior chamber depth more than 2.5 mm is recommended. Much evidence to this wonderful technique is not available in literature, as its popularity grew through live surgical workshops and small interactive conferences.

  20. Secretory vesicle priming by CAPS is independent of its SNARE-binding MUN domain.

    Science.gov (United States)

    Nguyen Truong, Cuc Quynh; Nestvogel, Dennis; Ratai, Olga; Schirra, Claudia; Stevens, David R; Brose, Nils; Rhee, JeongSeop; Rettig, Jens

    2014-11-06

    Priming of secretory vesicles is a prerequisite for their Ca(2+)-dependent fusion with the plasma membrane. The key vesicle priming proteins, Munc13s and CAPSs, are thought to mediate vesicle priming by regulating the conformation of the t-SNARE syntaxin, thereby facilitating SNARE complex assembly. Munc13s execute their priming function through their MUN domain. Given that the MUN domain of Ca(2+)-dependent activator protein for secretion (CAPS) also binds syntaxin, it was assumed that CAPSs prime vesicles through the same mechanism as Munc13s. We studied naturally occurring splice variants of CAPS2 in CAPS1/CAPS2-deficient cells and found that CAPS2 primes vesicles independently of its MUN domain. Instead, the pleckstrin homology domain of CAPS2 seemingly is essential for its priming function. Our findings indicate a priming mode for secretory vesicles. This process apparently requires membrane phospholipids, does not involve the binding or direct conformational regulation of syntaxin by MUN domains of CAPSs, and is therefore not redundant with Munc13 action.

  1. Secretory Vesicle Priming by CAPS Is Independent of Its SNARE-Binding MUN Domain

    Directory of Open Access Journals (Sweden)

    Cuc Quynh Nguyen Truong

    2014-11-01

    Full Text Available Priming of secretory vesicles is a prerequisite for their Ca2+-dependent fusion with the plasma membrane. The key vesicle priming proteins, Munc13s and CAPSs, are thought to mediate vesicle priming by regulating the conformation of the t-SNARE syntaxin, thereby facilitating SNARE complex assembly. Munc13s execute their priming function through their MUN domain. Given that the MUN domain of Ca2+-dependent activator protein for secretion (CAPS also binds syntaxin, it was assumed that CAPSs prime vesicles through the same mechanism as Munc13s. We studied naturally occurring splice variants of CAPS2 in CAPS1/CAPS2-deficient cells and found that CAPS2 primes vesicles independently of its MUN domain. Instead, the pleckstrin homology domain of CAPS2 seemingly is essential for its priming function. Our findings indicate a priming mode for secretory vesicles. This process apparently requires membrane phospholipids, does not involve the binding or direct conformational regulation of syntaxin by MUN domains of CAPSs, and is therefore not redundant with Munc13 action.

  2. Probing the structural dynamics of the SNARE recycling machine based on coarse-grained modeling.

    Science.gov (United States)

    Zheng, Wenjun

    2016-08-01

    Membrane fusion in eukaryotes is driven by the formation of a four-helix bundle by three SNARE proteins. To recycle the SNARE proteins, they must be disassembled by the ATPase NSF and four SNAP proteins which together form a 20S supercomplex. Recently, the first high-resolution structures of the NSF (in both ATP and ADP state) and 20S (in four distinct states termed I, II, IIIa, and IIIb) were solved by cryo-electron microscopy (cryo-EM), which have paved the way for structure-driven studies of the SNARE recycling mechanism. To probe the structural dynamics of SNARE disassembly at amino-acid level of details, a systematic coarse-grained modeling based on an elastic network model and related analyses were performed. Our normal mode analysis of NSF, SNARE, and 20S predicted key modes of collective motions that partially account for the observed structural changes, and illuminated how the SNARE complex can be effectively destabilized by untwisting and bending motions of the SNARE complex driven by the amino-terminal domains of NSF in state II. Our flexibility analysis identified regions with high/low flexibility that coincide with key functional sites (such as the NSF-SNAPs-SNARE binding sites). A subset of hotspot residues that control the above collective motions, which will make promising targets for future mutagenesis studies were also identified. Finally, the conformational changes in 20S as induced by the transition of NSF from ATP to ADP state were modeled, and a concerted untwisting motion of SNARE/SNAPs and a sideway flip of two amino-terminal domains were observed. In sum, the findings have offered new structural and dynamic details relevant to the SNARE disassembly mechanism, and will guide future functional studies of the SNARE recycling machinery. Proteins 2016; 84:1055-1066. © 2016 Wiley Periodicals, Inc.

  3. Multiple roles of the vesicular-SNARE TI-VAMP in post-Golgi and endosomal trafficking.

    Science.gov (United States)

    Chaineau, Mathilde; Danglot, Lydia; Galli, Thierry

    2009-12-01

    SNARE (Soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins are the core machinery of membrane fusion. Vesicular SNAREs (v-SNAREs) interact with their target SNAREs (t-SNAREs) to form SNARE complexes which mediate membrane fusion. Here we review the basic properties and functions of the v-SNARE TI-VAMP/VAMP7 (Tetanus neurotoxin insensitive-vesicle associated membrane protein). TI-VAMP interacts with its t-SNARE partners, particularly plasmalemmal syntaxins, to mediate membrane fusion and with several regulatory proteins especially via its amino-terminal regulatory Longin domain. Partners include AP-3, Hrb/(Human immunodeficiency virus Rev binding) protein, and Varp (Vps9 domain and ankyrin repeats containing protein) and regulate TI-VAMP's function and targeting. TI-VAMP is involved both in secretory and endocytic pathways which mediate neurite outgrowth and synaptic transmission, plasma membrane remodeling and lysosomal secretion.

  4. DNA Translocation through Nanopores at Physiological Ionic Strengths Requires Precise Nanoscale Engineering.

    Science.gov (United States)

    Franceschini, Lorenzo; Brouns, Tine; Willems, Kherim; Carlon, Enrico; Maglia, Giovanni

    2016-09-27

    Many important processes in biology involve the translocation of a biopolymer through a nanometer-scale pore. Moreover, the electrophoretic transport of DNA across nanopores is under intense investigation for single-molecule DNA sequencing and analysis. Here, we show that the precise patterning of the ClyA biological nanopore with positive charges is crucial to observe the electrophoretic translocation of DNA at physiological ionic strength. Surprisingly, the strongly electronegative 3.3 nm internal constriction of the nanopore did not require modifications. Further, DNA translocation could only be observed from the wide entry of the nanopore. Our results suggest that the engineered positive charges are important to align the DNA in order to overcome the entropic and electrostatic barriers for DNA translocation through the narrow constriction. Finally, the dependencies of nucleic acid translocations on the Debye length of the solution are consistent with a physical model where the capture of double-stranded DNA is diffusion-limited while the capture of single-stranded DNA is reaction-limited.

  5. Geology and geochronology of the Sub-Antarctic Snares Islands/Tini Heke, New Zealand

    DEFF Research Database (Denmark)

    Scott, JM; Turnbull, IM; Sagar, MW

    2015-01-01

    The first comprehensive geological map, a summary of lithologies and new radiogenic isotope data (U–Pb, Rb–Sr) are presented for crystalline rocks of the Sub-Antarctic Snares Islands/Tini Heke, 150 km south of Stewart Island. The main lithology is Snares Granite (c. 109 Ma from U–Pb dating of zir...

  6. Longins: a new evolutionary conserved VAMP family sharing a novel SNARE domain.

    Science.gov (United States)

    Filippini, F; Rossi, V; Galli, T; Budillon, A; D'Urso, M; D'Esposito, M

    2001-07-01

    This article describes the discovery of a novel SNARE domain that might be involved in the regulation of membrane fusion. This domain is shared by a novel family of VAMPs called long VAMPs or longins. Members of this family are more conserved among eukaryotes than are classical VAMPs, possibly because of their underlying basic SNARE function.

  7. Endosomal SNARE proteins regulate CFTR activity and trafficking in epithelial cells.

    Science.gov (United States)

    Bilan, Frédéric; Nacfer, Magali; Fresquet, Fleur; Norez, Caroline; Melin, Patricia; Martin-Berge, Alice; Costa de Beauregard, Marie-Alyette; Becq, Frédéric; Kitzis, Alain; Thoreau, Vincent

    2008-07-01

    The Cystic Fibrosis Transmembrane conductance Regulator (CFTR) protein is a chloride channel localized at the apical plasma membrane of epithelial cells. We previously described that syntaxin 8, an endosomal SNARE (Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptor) protein, interacts with CFTR and regulates its trafficking to the plasma membrane and hence its channel activity. Syntaxin 8 belongs to the endosomal SNARE complex which also contains syntaxin 7, vti1b and VAMP8. Here, we report that these four endosomal SNARE proteins physically and functionally interact with CFTR. In LLC-PK1 cells transfected with CFTR and in Caco-2 cells endogenously expressing CFTR, we demonstrated that endosomal SNARE protein overexpression inhibits CFTR activity but not swelling- or calcium-activated iodide efflux, indicating a specific effect upon CFTR activity. Moreover, co-immunoprecipitation experiments in LLC-PK1-CFTR cells showed that CFTR and SNARE proteins belong to a same complex and pull-down assays showed that VAMP8 and vti1b preferentially interact with CFTR N-terminus tail. By cell surface biotinylation and immunofluorescence experiments, we evidenced that endosomal SNARE overexpression disturbs CFTR apical targeting. Finally, we found a colocalization of CFTR and endosomal SNARE proteins in Rab11-positive recycling endosomes, suggesting a new role for endosomal SNARE proteins in CFTR trafficking in epithelial cells.

  8. The Application of Programmed Instruction in Fulfilling the Physiology Course Requirements

    Science.gov (United States)

    Stanisavljevic, Jelena; Djuric, Dragan

    2013-01-01

    The aim of this study is to compare the effectiveness of models of programmed instruction and conventional (informative-illustrative) expository teaching in terms of fulfilling the aims of the course "Human anatomy and physiology" which is included in the physiology programme and designed for undergraduate students majoring in biology…

  9. Exercise Physiology: A Brief History and Recommendations Regarding Content Requirements for the Kinesiology Major

    Science.gov (United States)

    Ivy, John L.

    2007-01-01

    The knowledge base that defines exercise physiology is central to the discipline of kinesiology. By the late 19th century, interest in physical training, physical education, and sports began to emerge in the United States. By the beginning of the 20th century, exercise physiology was being included in college physical education degree programs,…

  10. The Application of Programmed Instruction in Fulfilling the Physiology Course Requirements

    Science.gov (United States)

    Stanisavljevic, Jelena; Djuric, Dragan

    2013-01-01

    The aim of this study is to compare the effectiveness of models of programmed instruction and conventional (informative-illustrative) expository teaching in terms of fulfilling the aims of the course "Human anatomy and physiology" which is included in the physiology programme and designed for undergraduate students majoring in biology…

  11. Physicochemical and Nutritional Requirements for Axenic Replication Suggest Physiological Basis for Coxiella burnetii Niche Restriction.

    Science.gov (United States)

    Vallejo Esquerra, Eduardo; Yang, Hong; Sanchez, Savannah E; Omsland, Anders

    2017-01-01

    Bacterial obligate intracellular parasites are clinically significant animal and human pathogens. Central to the biology of these organisms is their level of adaptation to intracellular replication niches associated with physicochemical and nutritional constraints. While most bacterial pathogens can adapt to a wide range of environments, severe niche restriction-an inability to thrive in diverse environments-is a hallmark of bacterial obligate intracellular parasites. Herein the physicochemical and nutritional factors underlying the physiological basis for niche restriction in the zoonotic bacterial obligate intracellular parasite and Q fever agent Coxiella burnetii are characterized. Additionally, these factors are reviewed in the context of C. burnetii evolution and continued (patho) adaptation. C. burnetii replication was strictly dependent on a combination of moderately acidic pH, reduced oxygen tension, and presence of carbon dioxide. Of macronutrients, amino acids alone support replication under physicochemically favorable conditions. In addition to utilizing gluconeogenic substrates for replication, C. burnetii can also utilize glucose to generate biomass. A mutant with a disruption in the gene pckA, encoding phosphoenolpyruvate carboxykinase (PEPCK), the first committed step in gluconeogenesis, could be complemented chemically by the addition of glucose. Disruption of pckA resulted in a moderate glucose-dependent growth defect during infection of cultured host cells. Although, C. burnetii has the theoretical capacity to synthesize essential core metabolites via glycolysis and gluconeogenesis, amino acid auxotrophy essentially restricts C. burnetii replication to a niche providing ample access to amino acids. Overall, the described combination of physiochemical and nutritional growth requirements are strong indicators for why C. burnetii favors an acidified phagolysosome-derived vacuole in respiring tissue for replication.

  12. Architecture of the Synaptotagmin-SNARE Machinery for Neuronal Exocytosis

    Science.gov (United States)

    Zhou, Qiangjun; Lai, Ying; Bacaj, Taulant; Zhao, Minglei; Lyubimov, Artem Y.; Uervirojnangkoorn, Monarin; Zeldin, Oliver B.; Brewster, Aaron S.; Sauter, Nicholas K.; Cohen, Aina E.; Soltis, S. Michael; Alonso-Mori, Roberto; Chollet, Matthieu; Lemke, Henrik T.; Pfuetzner, Richard A.; Choi, Ucheor B.; Weis, William I.; Diao, Jiajie; Südhof, Thomas C.; Brunger, Axel T.

    2015-01-01

    Summary Synaptotagmin-1 and neuronal SNARE proteins play key roles in evoked synchronous neurotransmitter release. However, it is unknown how they cooperate to trigger synaptic vesicle fusion. Here we report atomic-resolution crystal structures of Ca2+- and Mg2+-bound complexes between synaptotagmin-1 and the neuronal SNARE complex, one of which was determined with diffraction data from an X-ray free electron laser, leading to an atomic-resolution structure with accurate rotamer assignments for many sidechains. The structures revealed several interfaces, including a large, specific, Ca2+-independent, and conserved interface. Tests of this interface by mutagenesis suggest that it is essential for Ca2+-triggered neurotransmitter release in neuronal synapses and for Ca2+-triggered vesicle fusion in a reconstituted system. We propose that this interface forms prior to Ca2+-triggering, and moves en bloc as Ca2+ influx promotes the interactions between synaptotagmin-1 and the plasma membrane, and consequently remodels the membrane to promote fusion, possibly in conjunction with other interfaces. PMID:26280336

  13. SNAREing the basis of multicellularity: consequences of protein family expansion during evolution.

    Science.gov (United States)

    Kloepper, Tobias H; Kienle, C Nickias; Fasshauer, Dirk

    2008-09-01

    Vesicle trafficking between intracellular compartments of eukaryotic cells is mediated by conserved protein machineries. In each trafficking step, fusion of the vesicle with the acceptor membrane is driven by a set of distinctive soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins that assemble into tight 4-helix bundle complexes between the fusing membranes. During evolution, about 20 primordial SNARE types were modified independently in different eukaryotic lineages by episodes of duplication and diversification. Here we show that 2 major changes in the SNARE repertoire occurred in the evolution of animals, each reflecting a main overhaul of the endomembrane system. In addition, we found several lineage-specific losses of distinct SNAREs, particularly in nematodes and platyhelminthes. The first major transformation took place during the transition to multicellularity. The primary event that occurred during this transformation was an increase in the numbers of endosomal SNAREs, but the SNARE-related factor lethal giant larvae also emerged. Apparently, enhanced endosomal sorting capabilities were an advantage for early multicellular animals. The second major transformation during the rise of vertebrates resulted in a robust expansion of the secretory set of SNAREs, which may have helped develop a more versatile secretory apparatus.

  14. RGS12 interacts with the SNARE-binding region of the Cav2.2 calcium channel.

    Science.gov (United States)

    Richman, Ryan W; Strock, Jesse; Hains, Melinda D; Cabanilla, Nory Jun; Lau, King-Kei; Siderovski, David P; Diversé-Pierluissi, María

    2005-01-14

    Activation of GABAB receptors in chick dorsal root ganglion (DRG) neurons inhibits the Cav2.2 calcium channel in both a voltage-dependent and voltage-independent manner. The voltage-independent inhibition requires activation of a tyrosine kinase that phosphorylates the alpha1 subunit of the channel and thereby recruits RGS12, a member of the "regulator of G protein signaling" (RGS) proteins. Here we report that RGS12 binds to the SNARE-binding or "synprint" region (amino acids 726-985) in loop II-III of the calcium channel alpha1 subunit. A recombinant protein encompassing the N-terminal PTB domain of RGS12 binds to the synprint region in protein overlay and surface plasmon resonance binding assays; this interaction is dependent on tyrosine phosphorylation and yet is within a sequence that differs from the canonical NPXY motif targeted by other PTB domains. In electrophysiological experiments, microinjection of DRG neurons with synprint-derived peptides containing the tyrosine residue Tyr-804 altered the rate of desensitization of neurotransmitter-mediated inhibition of the Cav2.2 calcium channel, whereas peptides centered about a second tyrosine residue, Tyr-815, were without effect. RGS12 from a DRG neuron lysate was precipitated using synprint peptides containing phosphorylated Tyr-804. The high degree of conservation of Tyr-804 in the SNARE-binding region of Cav2.1 and Cav2.2 calcium channels suggests that this region, in addition to the binding of SNARE proteins, is also important for determining the time course of the modulation of calcium current via tyrosine phosphorylation.

  15. TI-VAMP/VAMP7 and VAMP3/cellubrevin: two v-SNARE proteins involved in specific steps of the autophagy/multivesicular body pathways.

    Science.gov (United States)

    Fader, Claudio Marcelo; Sánchez, Diego Germán; Mestre, María Belén; Colombo, María Isabel

    2009-12-01

    During reticulocyte maturation, some membrane proteins and organelles that are not required in the mature red cell are lost. Several of these proteins are released into the extracellular medium associated with the internal vesicles present in multivesicular bodies (MVBs). Likewise, organelles such as mitochondria and endoplasmic reticulum are wrapped into double membrane vacuoles (i.e., autophagosomes) and degraded via autophagy. Morphological, molecular, and biochemical studies have shown that autophagosomes fuse with MVBs forming the so-called amphisomes, a prelysosomal hybrid organelle. SNAREs are key molecules of the vesicle fusion machinery. TI-VAMP/VAMP7 and VAMP3/cellubrevin are two v-SNARE proteins involved in the endocytic and exocytic pathways. We have previously shown that in the human leukemic K562 cells, Rab11 decorates MVBs and it is necessary for fusion between autophagosomes with MVBs. In the present report, we present evidence indicating that VAMP3 is required for the fusion between MVBs with autophagosomes to generate the amphisome, allowing the maturation of the autophagosome, but it does not seem to be involved in the next step, i. e., fusion with the lysosome. On the other hand, we demonstrate that VAMP7 is necessary for this latter event, allowing the completion of the autophagic pathway. Furthermore, VAMP7 and ATPase NSF, a protein required for SNAREs disassembly, participate in the fusion between MVBs with the plasma membrane to release the internal vesicles (i.e., exosomes) into the extracellular medium.

  16. Giant endobronchial hamartoma resected by fiberoptic bronchoscopy electrosurgical snaring

    Directory of Open Access Journals (Sweden)

    Cavallari Vittorio

    2011-08-01

    Full Text Available Abstract Less than 1% of lung neoplasms are represented by benign tumors. Among these, hamartomas are the most common with an incidence between 0.025% and 0.32%. In relation to the localization, hamartomas are divided into intraparenchymal and endobronchial. Clinical manifestation of an endobronchial hamartoma (EH results from tracheobronchial obstruction or bleeding. Usually, EH localizes in large diameter bronchus. Endoscopic removal is usually recommended. Bronchotomy or parenchimal resection through thoracotomy should be reserved only for cases where the hamatoma cannot be approached through endoscopy, or when irreversible lung functional impairment occurred after prolonged airflow obstruction. Generally, when endoscopic approach is used, this is through rigid bronchoscopy, laser photocoagulation or mechanical resection. Here we present a giant EH occasionally diagnosed and treated by fiberoptic bronchoscopy electrosurgical snaring.

  17. Hydrophobic mismatch sorts SNARE proteins into distinct membrane domains

    Science.gov (United States)

    Milovanovic, Dragomir; Honigmann, Alf; Koike, Seiichi; Göttfert, Fabian; Pähler, Gesa; Junius, Meike; Müllar, Stefan; Diederichsen, Ulf; Janshoff, Andreas; Grubmüller, Helmut; Risselada, Herre J.; Eggeling, Christian; Hell, Stefan W.; van den Bogaart, Geert; Jahn, Reinhard

    2015-01-01

    The clustering of proteins and lipids in distinct microdomains is emerging as an important principle for the spatial patterning of biological membranes. Such domain formation can be the result of hydrophobic and ionic interactions with membrane lipids as well as of specific protein-protein interactions. Here using plasma membrane-resident SNARE proteins as model, we show that hydrophobic mismatch between the length of transmembrane domains (TMDs) and the thickness of the lipid membrane suffices to induce clustering of proteins. Even when the TMDs differ in length by only a single residue, hydrophobic mismatch can segregate structurally closely homologous membrane proteins in distinct membrane domains. Domain formation is further fine-tuned by interactions with polyanionic phosphoinositides and homo and heterotypic protein interactions. Our findings demonstrate that hydrophobic mismatch contributes to the structural organization of membranes.

  18. Organization and dynamics of SNARE proteins in the presynaptic membrane

    Directory of Open Access Journals (Sweden)

    Dragomir eMilovanovic

    2015-03-01

    Full Text Available Our view of the lateral organization of lipids and proteins in the plasma membrane has evolved substantially in the last few decades. It is widely accepted that many, if not all, plasma membrane proteins and lipids are organized in specific domains. These domains vary widely in size, composition, and stability, and they represent platforms governing diverse cell functions. The presynaptic plasma membrane is a well-studied example of a membrane which undergoes rearrangements, especially during exo- and endocytosis. Many proteins and lipids involved in presynaptic function are known, and major efforts have been made to understand their spatial organization and dynamics. Here, we focus on the mechanisms underlying the organization of SNAREs, the key proteins of the fusion machinery, in distinct domains, and we discuss the functional significance of these clusters.

  19. Doc2b promotes GLUT4 exocytosis by activating the SNARE-mediated fusion reaction in a calcium- and membrane bending-dependent manner.

    Science.gov (United States)

    Yu, Haijia; Rathore, Shailendra S; Davis, Eric M; Ouyang, Yan; Shen, Jingshi

    2013-04-01

    The glucose transporter GLUT4 plays a central role in maintaining body glucose homeostasis. On insulin stimulation, GLUT4-containing vesicles fuse with the plasma membrane, relocating GLUT4 from intracellular reservoirs to the cell surface to uptake excess blood glucose. The GLUT4 vesicle fusion reaction requires soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) as the core fusion engine and a group of regulatory proteins. In particular, the soluble C2-domain factor Doc2b plays a key role in GLUT4 vesicle fusion, but its molecular mechanism has been unclear. Here we reconstituted the SNARE-dependent GLUT4 vesicle fusion in a defined proteoliposome fusion system. We observed that Doc2b binds to GLUT4 exocytic SNAREs and potently accelerates the fusion kinetics in the presence of Ca(2+). The stimulatory activity of Doc2b requires intact Ca(2+)-binding sites on both the C2A and C2B domains. Using electron microscopy, we observed that Doc2b strongly bends the membrane bilayer, and this membrane-bending activity is essential to the stimulatory function of Doc2b in fusion. These results demonstrate that Doc2b promotes GLUT4 exocytosis by accelerating the SNARE-dependent fusion reaction by a Ca(2+)- and membrane bending-dependent mechanism. Of importance, certain features of Doc2b function appear to be distinct from how synaptotagmin-1 promotes synaptic neurotransmitter release, suggesting that exocytic Ca(2+) sensors may possess divergent mechanisms in regulating vesicle fusion.

  20. Günther Tulip inferior vena cava filter retrieval using a bidirectional loop-snare technique

    Science.gov (United States)

    Ross, Jordan; Allison, Stephen; Vaidya, Sandeep; Monroe, Eric

    2016-01-01

    Many advanced techniques have been reported in the literature for difficult Günther Tulip filter removal. This report describes a bidirectional loop-snare technique in the setting of a fibrin scar formation around the filter leg anchors. The bidirectional loop-snare technique allows for maximal axial tension and alignment for stripping fibrin scar from the filter legs, a commonly encountered complication of prolonged dwell times. PMID:27338675

  1. Günther Tulip inferior vena cava filter retrieval using a bidirectional loop-snare technique.

    Science.gov (United States)

    Ross, Jordan; Allison, Stephen; Vaidya, Sandeep; Monroe, Eric

    2016-01-01

    Many advanced techniques have been reported in the literature for difficult Günther Tulip filter removal. This report describes a bidirectional loop-snare technique in the setting of a fibrin scar formation around the filter leg anchors. The bidirectional loop-snare technique allows for maximal axial tension and alignment for stripping fibrin scar from the filter legs, a commonly encountered complication of prolonged dwell times.

  2. Secretory vesicle priming by CAPS is independent of the SNARE-bind MUN domain

    OpenAIRE

    Cuc Quynh Nguyen Truong; Dennis Nestvogel; Olga Ratai; Claudia Schirra; David R. Stevens; Nils Brose; JeongSeop Rhee; Jens Rettig

    2014-01-01

    Priming of secretory vesicles is a prerequisite for their Ca2+-dependent fusion with the plasma membrane. The key vesicle priming proteins, Munc13s and CAPSs, are thought to mediate vesicle priming by regulating the conformation of the t-SNARE syntaxin, thereby facilitating SNARE complex assembly. Munc13s execute their priming function through their MUN domain. Given that the MUN domain of Ca2+-dependent activator protein for secretion (CAPS) also binds syntaxin, it was assumed that CAPSs pri...

  3. Secretory vesicles are preferentially targeted to areas of low molecular SNARE density.

    Directory of Open Access Journals (Sweden)

    Lei Yang

    Full Text Available Intercellular communication is commonly mediated by the regulated fusion, or exocytosis, of vesicles with the cell surface. SNARE (soluble N-ethymaleimide sensitive factor attachment protein receptor proteins are the catalytic core of the secretory machinery, driving vesicle and plasma membrane merger. Plasma membrane SNAREs (tSNAREs are proposed to reside in dense clusters containing many molecules, thus providing a concentrated reservoir to promote membrane fusion. However, biophysical experiments suggest that a small number of SNAREs are sufficient to drive a single fusion event. Here we show, using molecular imaging, that the majority of tSNARE molecules are spatially separated from secretory vesicles. Furthermore, the motilities of the individual tSNAREs are constrained in membrane micro-domains, maintaining a non-random molecular distribution and limiting the maximum number of molecules encountered by secretory vesicles. Together our results provide a new model for the molecular mechanism of regulated exocytosis and demonstrate the exquisite organization of the plasma membrane at the level of individual molecular machines.

  4. Physiological and public health basis for assessing micronutrient requirements in children and adolescents. The EURRECA network

    NARCIS (Netherlands)

    Iglesia, I.; Doets, E.L.; Bel-Serrat, S.; Roman, B.; Hermoso, M.; Quintana, X.; Rosario Garcia-Luzardo, Del M.; Santana-Salguero, B.; Garcia-Santos, Y.; Vucic, V.; Frost Andersen, L.; Perez-Rodrigo, C.; Aranceta, J.; Cavelaars, A.J.E.M.; Decsi, T.; Serra-Majem, L.; Gurinovic, M.; Cetin, I.; Koletzko, B.; Moreno, L.A.

    2010-01-01

    This paper provides an overview of the current knowledge relating to the nutritional requirements and corresponding recommended nutrient intake values of children and adolescents for micronutrients and specificities related to these requirements in the course of childhood and adolescence in Europe.

  5. A new role for RINT-1 in SNARE complex assembly at the trans-Golgi network in coordination with the COG complex.

    Science.gov (United States)

    Arasaki, Kohei; Takagi, Daichi; Furuno, Akiko; Sohda, Miwa; Misumi, Yoshio; Wakana, Yuichi; Inoue, Hiroki; Tagaya, Mitsuo

    2013-09-01

    Docking and fusion of transport vesicles/carriers with the target membrane involve a tethering factor-mediated initial contact followed by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-catalyzed membrane fusion. The multisubunit tethering CATCHR family complexes (Dsl1, COG, exocyst, and GARP complexes) share very low sequence homology among subunits despite likely evolving from a common ancestor and participate in fundamentally different membrane trafficking pathways. Yeast Tip20, as a subunit of the Dsl1 complex, has been implicated in retrograde transport from the Golgi apparatus to the endoplasmic reticulum. Our previous study showed that RINT-1, the mammalian counterpart of yeast Tip20, mediates the association of ZW10 (mammalian Dsl1) with endoplasmic reticulum-localized SNARE proteins. In the present study, we show that RINT-1 is also required for endosome-to-trans-Golgi network trafficking. RINT-1 uncomplexed with ZW10 interacts with the COG complex, another member of the CATCHR family complex, and regulates SNARE complex assembly at the trans-Golgi network. This additional role for RINT-1 may in part reflect adaptation to the demand for more diverse transport routes from endosomes to the trans-Golgi network in mammals compared with those in a unicellular organism, yeast. The present findings highlight a new role of RINT-1 in coordination with the COG complex.

  6. Arabidopsis Sec1/Munc18 protein SEC11 is a competitive and dynamic modulator of SNARE binding and SYP121-dependent vesicle traffic.

    Science.gov (United States)

    Karnik, Rucha; Grefen, Christopher; Bayne, Robert; Honsbein, Annegret; Köhler, Tim; Kioumourtzoglou, Dimitrios; Williams, Mary; Bryant, Nia J; Blatt, Michael R

    2013-04-01

    The Arabidopsis thaliana Qa-SNARE SYP121 (=SYR1/PEN1) drives vesicle traffic at the plasma membrane of cells throughout the vegetative plant. It facilitates responses to drought, to the water stress hormone abscisic acid, and to pathogen attack, and it is essential for recovery from so-called programmed stomatal closure. How SYP121-mediated traffic is regulated is largely unknown, although it is thought to depend on formation of a fusion-competent SNARE core complex with the cognate partners VAMP721 and SNAP33. Like SYP121, the Arabidopsis Sec1/Munc18 protein SEC11 (=KEULE) is expressed throughout the vegetative plant. We find that SEC11 binds directly with SYP121 both in vitro and in vivo to affect secretory traffic. Binding occurs through two distinct modes, one requiring only SEC11 and SYP121 and the second dependent on assembly of a complex with VAMP721 and SNAP33. SEC11 competes dynamically for SYP121 binding with SNAP33 and VAMP721, and this competition is predicated by SEC11 association with the N terminus of SYP121. These and additional data are consistent with a model in which SYP121-mediated vesicle fusion is regulated by an unusual "handshaking" mechanism of concerted SEC11 debinding and rebinding. They also implicate one or more factors that alter or disrupt SEC11 association with the SYP121 N terminus as an early step initiating SNARE complex formation.

  7. Comparative analysis of plant genomes allows the definition of the "Phytolongins": a novel non-SNARE longin domain protein family

    OpenAIRE

    Dacks Joel B; Rossi Valeria; Vedovato Marco; Filippini Francesco

    2009-01-01

    Abstract Background Subcellular trafficking is a hallmark of eukaryotic cells. Because of their pivotal role in the process, a great deal of attention has been paid to the SNARE proteins. Most R-SNAREs, or "longins", however, also possess a highly conserved, N-terminal fold. This "longin domain" is known to play multiple roles in regulating SNARE activity and targeting via interaction with other trafficking proteins. However, the diversity and complement of longins in eukaryotes is poorly und...

  8. Comparative analysis of plant genomes allows the definition of the "Phytolongins": a novel non-SNARE longin domain protein family

    OpenAIRE

    Vedovato, Marco; Rossi, Valeria; Joel B Dacks; Filippini, Francesco

    2009-01-01

    Background Subcellular trafficking is a hallmark of eukaryotic cells. Because of their pivotal role in the process, a great deal of attention has been paid to the SNARE proteins. Most R-SNAREs, or "longins", however, also possess a highly conserved, N-terminal fold. This "longin domain" is known to play multiple roles in regulating SNARE activity and targeting via interaction with other trafficking proteins. However, the diversity and complement of longins in eukaryotes is poorly understood. ...

  9. Potential wood protection strategies using physiological requirements of wood degrading fungi

    NARCIS (Netherlands)

    Sailer, M.F.; Etten, B.D. van

    2004-01-01

    Due to the increasing restrictions in the use of wood preserving biocides a number of potential biocide free wood preserving alternatives are currently assessed. Wood degrading fungi require certain conditions in the wood in order to be able to use wood as a food source. This paper discusses the phy

  10. Nutrient requirements and growth physiology of the photoheterotrophic Acidobacterium, Chloracidobacterium thermophilum

    Directory of Open Access Journals (Sweden)

    Donald A Bryant

    2015-03-01

    Full Text Available A novel thermophilic, microaerophilic, anoxygenic and chlorophototrophic member of the phylum Acidobacteria, Chloracidobacterium thermophilum strain BT, was isolated from a cyanobacterial enrichment culture derived from microbial mats associated with Octopus Spring, Yellowstone National Park, Wyoming. C. thermophilum is strictly dependent on light and oxygen and grows optimally as a photoheterotroph at irradiance values between 20 to 50 µmol photons m-2 s-1. C. thermophilum is unable to synthesize branched-chain amino acids, L-lysine, and vitamin B12, which are required for growth. Although the organism lacks genes for autotrophic carbon fixation, bicarbonate is also required. Mixtures of other amino acids and 2-oxoglutarate stiumulate growth. As suggested from genomic sequence data, C. thermophilum requires a reduced sulfur source such as thioglycolate, cysteine, methionine, or thiosulfate. The organism can be grown in a defined medium at 51°C (Topt; range 44 to 58°C in the pH range 5.5 to 9.5 (pHopt = ~7.0. Using the defined growth medium and optimal conditions, it was possible to isolate new C. thermophilum strains directly from samples of hot spring mats Yellowstone National Park, Wyoming. The new isolates differ from the type strain with respect to pigment composition, morphology in liquid culture, and temperature adaptation.

  11. Inhibition of a SNARE-sensitive pathway in astrocytes attenuates damage following stroke.

    Science.gov (United States)

    Hines, Dustin J; Haydon, Philip G

    2013-03-06

    A strong body of research has defined the role of excitotoxic glutamate in animal models of brain ischemia and stroke; however, clinical trials of glutamate receptor antagonists have demonstrated their limited capacity to prevent brain damage following ischemia. We propose that astrocyte-neuron signaling represents an important modulatory target that may be useful in mediating damage following stroke. To assess the impact of astrocyte signaling on damage following stroke, we have used the astrocyte-specific dominant-negative SNARE mouse model (dnSNARE). Recent findings have shown that the astrocytic SNARE signaling pathway can affect neuronal excitability by regulating the surface expression of NMDA receptors. Using focal photothrombosis via the Rose Bengal method, as well as excitotoxic NMDA lesions, we show that dnSNARE animals exhibited a sparing of damaged tissue quantified using Nissl and NeuN staining. At the same time point, animals were also tested in behavioral tasks that probe the functional integrity of stroke- or lesion-damaged motor and somatosensory areas. We found that dnSNARE mice performed significantly better than littermate controls on rung walk and adhesive dot removal tasks following lesion. Together, our results demonstrate the important role of astrocytic signaling under ischemic conditions. Drugs targeting astrocyte signaling have a potential benefit for the outcome of stroke in human patients by limiting the spread of damage.

  12. Capture and release of partially zipped trans-SNARE complexes on intact organelles.

    Science.gov (United States)

    Schwartz, Matthew L; Merz, Alexey J

    2009-05-04

    Soluble N-ethyl-maleimide sensitive fusion protein attachment protein receptors (SNAREs) are hypothesized to trigger membrane fusion by complexing in trans through their membrane-distal N termini and zippering toward their membrane-embedded C termini, which in turn drives the two membranes together. In this study, we use a set of truncated SNAREs to trap kinetically stable, partially zipped trans-SNARE complexes on intact organelles in the absence of hemifusion and content mixing. We show that the C-terminal zippering of SNARE cytoplasmic domains controls the onset of lipid mixing but not the subsequent transition from hemifusion to full fusion. Moreover, we find that a partially zipped nonfusogenic trans-complex is rescued by Sec17, a universal SNARE cochaperone. Rescue occurs independently of the Sec17-binding partner Sec18, and it exhibits steep cooperativity, indicating that Sec17 engages multiple stalled trans-complexes to drive fusion. These experiments delineate distinct functions within the trans-complex, provide a straightforward method to trap and study prefusion complexes on native membranes, and reveal that Sec17 can rescue a stalled, partially zipped trans-complex.

  13. Physiological requirements for growth and competitiveness of Dekkera bruxellensis under oxygen-limited or anaerobic conditions.

    Science.gov (United States)

    Blomqvist, Johanna; Nogué, Violeta Sànchez; Gorwa-Grauslund, Marie; Passoth, Volkmar

    2012-07-01

    The effect of glucose and oxygen limitation on the growth and fermentation performances of Dekkera bruxellensis was investigated in order to understand which factors favour its propagation in ethanol or wine plants. Although D. bruxellensis has been described as a facultative anaerobe, no growth was observed in mineral medium under complete anaerobiosis while growth was retarded under severe oxygen limitation. In a continuous culture with no gas inflow, glucose was not completely consumed, most probably due to oxygen limitation. When an air/nitrogen mixture (O(2)-content ca. 5%) was sparged to the culture, growth became glucose-limited. In co-cultivations with Saccharomyces cerevisiae, ethanol yields/g consumed sugar were not affected by the co-cultures as compared to the pure cultures. However, different population responses were observed in both systems. In oxygen-limited cultivation, glucose was depleted within 24 h after challenging with S. cerevisiae and both yeast populations were maintained at a stable level. In contrast, the S. cerevisiae population constantly decreased to about 1% of its initial cell number in the sparged glucose-limited fermentation, whereas the D. bruxellensis population remained constant. To identify the requirements of D. bruxellensis for anaerobic growth, the yeast was cultivated in several nitrogen sources and with the addition of amino acids. Yeast extract and most of the supplied amino acids supported anaerobic growth, which points towards a higher nutrient demand for D. bruxellensis compared to S. cerevisiae in anaerobic conditions. Copyright © 2012 John Wiley & Sons, Ltd.

  14. A carcinoid tumor of the ampulla of Vater treated by endoscopic snare papillectomy.

    Science.gov (United States)

    Pyun, Dae-Keun; Moon, Gyoo; Han, Jimin; Kim, Myung-Hwan; Lee, Sang Soo; Seo, Dong-Wan; Lee, Sung-Koo

    2004-12-01

    Here, a case of a patient with incidental finding of a carcinoid tumor of the ampulla of Vater, who was treated with endoscopic snare papillectomy, is reported. A 62-year-old male was admitted to our hospital due to a carcinoid tumor of the ampulla of Vater, which was found during follow-up endoscopy after an endoscopic mucosal resection of early gastric cancer. No lymphadenopathy or visceral metastasis was found on an abdominal CT scan, In-111 octerotide scan and EUS. The ampulla was then en bloc removed by endoscopic snare papillectomy. The resected specimen revealed a 0.7 x 0.5 x 0.1 cm sized carcinoid tumor. All margins of resection were negative for tumor. After six months of follow-up, there was no evidence of recurrence and metastasis, either endoscopically or radiologically. To our knowledge, this case is the first report of an ampullary carcinoid tumor treated by endoscopic snare papillectomy in Korea.

  15. Munc18-1 mutations that strongly impair SNARE-complex binding support normal synaptic transmission.

    Science.gov (United States)

    Meijer, Marieke; Burkhardt, Pawel; de Wit, Heidi; Toonen, Ruud F; Fasshauer, Dirk; Verhage, Matthijs

    2012-05-02

    Synaptic transmission depends critically on the Sec1p/Munc18 protein Munc18-1, but it is unclear whether Munc18-1 primarily operates as a integral part of the fusion machinery or has a more upstream role in fusion complex assembly. Here, we show that point mutations in Munc18-1 that interfere with binding to the free Syntaxin1a N-terminus and strongly impair binding to assembled SNARE complexes all support normal docking, priming and fusion of synaptic vesicles, and normal synaptic plasticity in munc18-1 null mutant neurons. These data support a prevailing role of Munc18-1 before/during SNARE-complex assembly, while its continued association to assembled SNARE complexes is dispensable for synaptic transmission.

  16. Exertional myopathy in a grizzly bear (Ursus arctos) captured by leghold snare.

    Science.gov (United States)

    Cattet, Marc; Stenhouse, Gordon; Bollinger, Trent

    2008-10-01

    We diagnosed exertional myopathy (EM) in a grizzly bear (Ursus arctos) that died approximately 10 days after capture by leghold snare in west-central Alberta, Canada, in June 2003. The diagnosis was based on history, post-capture movement data, gross necropsy, histopathology, and serum enzyme levels. We were unable to determine whether EM was the primary cause of death because autolysis precluded accurate evaluation of all tissues. Nevertheless, comparison of serum aspartate aminotransferase and creatine kinase concentrations and survival between the affected bear and other grizzly bears captured by leghold snare in the same research project suggests EM also occurred in other bears, but that it is not generally a cause of mortality. We propose, however, occurrence of nonfatal EM in grizzly bears after capture by leghold snare has potential implications for use of this capture method, including negative effects on wildlife welfare and research data.

  17. Successful removal of endobronchial lipoma by flexible bronchoscopy using electrosurgical snare.

    Science.gov (United States)

    Yun, Seong Cheol; Na, Moon Jun; Choi, Eugene; Kwon, Sun Jung; Lee, Seong Ju; Oh, Sun Hee; Cha, Eun Jung; Son, Ji Woong

    2013-02-01

    A 62-year-old man with a chronic cough presented with atelectasis of the left upper lobe on chest X-ray. Chest computed tomography showed an atelectasis in the left upper lobe with bronchial wall thickening, stenosis, dilatation, and mucoid impaction. We performed bronchoscopy and found a well-circumscribed mass on the left upper lobe bronchus. The mass was removed by flexible bronchoscopy using an electrosurgical snare and diagnosed with lipoma. An endobronchial lipoma is a rare benign tumor that can be treated by a surgical or endoscopic approach. We report the successful removal of endobronchial lipoma via flexible bronchoscopic electrosurgical snare.

  18. Physiological Requirements to Perform the Glittre Activities of Daily Living Test by Subjects With Mild-to-Severe COPD.

    Science.gov (United States)

    Souza, Gérson F; Moreira, Graciane L; Tufanin, Andréa; Gazzotti, Mariana R; Castro, Antonio A; Jardim, José R; Nascimento, Oliver A

    2017-08-01

    The Glittre activities of daily living (ADL) test is supposed to evaluate the functional capacity of COPD patients. The physiological requirements of the test and the time taken to perform it by COPD patients in different disease stages are not well known. The objective of this work was to compare the metabolic, ventilatory, and cardiac requirements and the time taken to carry out the Glittre ADL test by COPD subjects with mild, moderate, and severe disease. Spirometry, Medical Research Council questionnaire, cardiopulmonary exercise test, and 2 Glittre ADL tests were evaluated in 62 COPD subjects. Oxygen uptake (V̇O2 ), carbon dioxide production, pulmonary ventilation, breathing frequency, heart rate, SpO2 , and dyspnea were analyzed before and at the end of the tests. Maximum voluntary ventilation, Glittre peak V̇O2 /cardiopulmonary exercise test (CPET) peak V̇O2 , Glittre V̇E/maximum voluntary ventilation, and Glittre peak heart rate/CPET peak heart rate ratios were calculated to analyze their reserves. Subjects carried out the Glittre ADL test with similar absolute metabolic, ventilatory, and cardiac requirements. Ventilatory reserve decreased progressively from mild to severe COPD subjects (P reserve than the mild and moderate subjects (P = .006 and P = .043, respectively) and significantly lower Glittre peak heart rate/CPET peak heart rate than mild subjects (P = .01). Time taken to carry out the Glittre ADL test was similar among the groups (P = .82 for GOLD 1 vs GOLD 2, P = .19 for GOLD 1 vs GOLD 3, and P = .45 for GOLD 2 vs GOLD 3). As the degree of air-flow obstruction progresses, the COPD subjects present significant lower ventilatory reserve to perform the Glittre ADL test. In addition, metabolic and cardiac reserves may differentiate the severe subjects. These variables may be better measures to differentiate functional performance than Glittre ADL time. Copyright © 2017 by Daedalus Enterprises.

  19. Opposing functions of two sub-domains of the SNARE-complex in neurotransmission

    DEFF Research Database (Denmark)

    Weber, Jens P; Reim, Kerstin; Sørensen, Jakob B

    2010-01-01

    The SNARE-complex consisting of synaptobrevin-2/VAMP-2, SNAP-25 and syntaxin-1 is essential for evoked neurotransmission and also involved in spontaneous release. Here, we used cultured autaptic hippocampal neurons from Snap-25 null mice rescued with mutants challenging the C-terminal, N-terminal...

  20. Clinical evaluation of endoscopic ligation with nylon snares for adenoma of the major duodenal papilla

    Directory of Open Access Journals (Sweden)

    ZHANG Yingchun

    2015-11-01

    Full Text Available ObjectiveTo evaluate the feasibility, safety, and follow-up results of endoscopic ligation with nylon snares for adenoma of the major duodenal papilla. MethodsTwenty-three patients with adenoma of the major papilla who were treated in our hospital from January 2012 to June 2014 were enrolled as subjects. All patients had biliary and pancreatic duct stents placed by endoscopic cholangiopancreatography, followed by complete ligation of tumors with nylon snares. Endoscopic follow-up evaluation of recurrence was performed regularly. ResultsAll patients had biliary and pancreatic duct stents successfully placed and tumors successfully ligated with nylon snares in their first surgery. Endoscopic reexamination at two weeks after surgery showed that tumors were removed in all patients. Postoperative complications, cholangitis and pancreatitis, were found in one (4.3% and two (8.7% patients, respectively, and there were no bleeding, perforation, or death. A follow-up of more than one year in all patients showed that two patients had local recurrence of adenoma. ConclusionEndoscopic ligation with nylon snares is a safe and effective approach for treating adenoma of the major duodenal papilla.

  1. Cooperative endocytosis of the endosomal SNARE protein syntaxin-8 and the potassium channel TASK-1.

    Science.gov (United States)

    Renigunta, Vijay; Fischer, Thomas; Zuzarte, Marylou; Kling, Stefan; Zou, Xinle; Siebert, Kai; Limberg, Maren M; Rinné, Susanne; Decher, Niels; Schlichthörl, Günter; Daut, Jürgen

    2014-06-15

    The endosomal SNARE protein syntaxin-8 interacts with the acid-sensitive potassium channel TASK-1. The functional relevance of this interaction was studied by heterologous expression of these proteins (and mutants thereof) in Xenopus oocytes and in mammalian cell lines. Coexpression of syntaxin-8 caused a fourfold reduction in TASK-1 current, a corresponding reduction in the expression of TASK-1 at the cell surface, and a marked increase in the rate of endocytosis of the channel. TASK-1 and syntaxin-8 colocalized in the early endosomal compartment, as indicated by the endosomal markers 2xFYVE and rab5. The stimulatory effect of the SNARE protein on the endocytosis of the channel was abolished when both an endocytosis signal in TASK-1 and an endocytosis signal in syntaxin-8 were mutated. A syntaxin-8 mutant that cannot assemble with other SNARE proteins had virtually the same effect as wild-type syntaxin-8. Total internal reflection fluorescence microscopy showed formation and endocytosis of vesicles containing fluorescence-tagged clathrin, TASK-1, and/or syntaxin-8. Our results suggest that the unassembled form of syntaxin-8 and the potassium channel TASK-1 are internalized via clathrin-mediated endocytosis in a cooperative manner. This implies that syntaxin-8 regulates the endocytosis of TASK-1. Our study supports the idea that endosomal SNARE proteins can have functions unrelated to membrane fusion.

  2. Snaring to control feral pigs sus scrofa in a remote Hawaiian rain forest

    Science.gov (United States)

    Anderson, Stephen J.; Stone, Charles P.

    1993-01-01

    Feral pig Sus scrofa control in Kipahulu Valley, a remote rain forest in Haleakala National Park, Maui, Hawaiian Islands, has been achieved with snares over a 45-month period. Initial pig densities in fenced management units of 6·2 km2 and 7·8 km2were estimated at 6 animals/km2 and 14·3 animals/km2 for the two units, based on population reconstruction from animals killed and aged. During the 45 months of the study, 1978 snares were set, and 1·6 million snare nights were logged. Snare density reached 96/km2 and 200/km2 for the two management units by the end of the study. A mean effort of 43 worker hours/pig was used to remove 53 pigs from the upper management unit, and a mean of 7 worker hours/pig to remove 175 animals from the more densely populated lower unit. Pig activity monitoring along transects provided a good measure of control effectiveness until densities of about 1 pig/km2 were achieved, after which transects became less useful than scouting for determining pig activity.

  3. Sequence-specific conformational flexibility of SNARE transmembrane helices probed by hydrogen/deuterium exchange.

    Science.gov (United States)

    Stelzer, Walter; Poschner, Bernhard C; Stalz, Holger; Heck, Albert J; Langosch, Dieter

    2008-08-01

    SNARE proteins mediate fusion of intracellular eukaryotic membranes and their alpha-helical transmembrane domains are known to contribute to lipid bilayer mixing. Synthetic transmembrane domain peptides were previously shown to mimic the function of SNARE proteins in that they trigger liposome fusion in a sequence-specific fashion. Here, we performed a detailed investigation of the conformational dynamics of the transmembrane helices of the presynaptic SNAREs synaptobrevin II and syntaxin 1a. To this end, we recorded deuterium/hydrogen-exchange kinetics in isotropic solution as well as in the membrane-embedded state. In solution, the exchange kinetics of each peptide can be described by three different classes of amide deuteriums that exchange with different rate constants. These are likely to originate from exchange at different domains of the helices. Interestingly, the rate constants of each class vary with the TMD sequence. Thus, the exchange rate is position-specific and sequence-specific. Further, the rate constants correlate with the previously determined membrane fusogenicities. In membranes, exchange is retarded and a significant proportion of amide hydrogens are protected from exchange. We conclude that the conformational dynamics of SNARE TMD helices is mechanistically linked to their ability to drive lipid mixing.

  4. AQP2 exocytosis in the renal collecting duct -- involvement of SNARE isoforms and the regulatory role of Munc18b.

    Science.gov (United States)

    Procino, Giuseppe; Barbieri, Claudia; Tamma, Grazia; De Benedictis, Leonarda; Pessin, Jeffrey E; Svelto, Maria; Valenti, Giovanna

    2008-06-15

    Vasopressin regulates the fusion of the water channel aquaporin 2 (AQP2) to the apical membrane of the renal collecting-duct principal cells and several lines of evidence indicate that SNARE proteins mediate this process. In this work MCD4 renal cells were used to investigate the functional role of a set of Q- and R-SNAREs, together with that of Munc18b as a negative regulator of the formation of the SNARE complex. Both VAMP2 and VAMP3 were associated with immunoisolated AQP2 vesicles, whereas syntaxin 3 (Stx3), SNAP23 and Munc18 were associated with the apical plasma membrane. Co-immunoprecipitation experiments indicated that Stx3 forms complexes with VAMP2, VAMP3, SNAP23 and Munc18b. Protein knockdown coupled to apical surface biotinylation demonstrated that reduced levels of the R-SNAREs VAMP2 and VAMP3, and the Q-SNAREs Stx3 and SNAP23 strongly inhibited AQP2 fusion at the apical membrane. In addition, knockdown of Munc18b promoted a sevenfold increase of AQP2 fused at the plasma membrane without forskolin stimulation. Taken together these findings propose VAMP2, VAMP3, Stx3 and SNAP23 as the complementary set of SNAREs responsible for AQP2-vesicle fusion into the apical membrane, and Munc18b as a negative regulator of SNARE-complex formation in renal collecting-duct principal cells.

  5. Decay of oak Wood provoked by fungus Stereum hirsutum (Willd. ex Fr. S. F. Gray. and its' essential physiological requirements

    Directory of Open Access Journals (Sweden)

    Mirić Milenko

    2005-01-01

    Full Text Available White rot fungi usually decompose cell walls of attacked wood destroying tissue elements (i.e. parenchyma cells, wood fibres, tension wood, tracheas etc in different amount, depending to wood-species as well as to its' zones. Different fungi secrete specific enzymes that are responsible for certain damages. As consequence, the wood structure use to be significantly and unfixable decomposed and changed. Microscopical analyses that have been run provided clear and indicative information relating to effects of fungal activity on wood tissue. Physiological requirements of fungi are for shore of the highest importance in understanding of mechanism of decaying process in the wood. The most important factors as like temperature and concentration of H ions, as well as main nutrients as sources of carbon, nitrogen and phosphorus can affect the behaviour of wood decaying fungi. The impacts of these factors on the growth and production on mycelial mass of Stereum hirsutum (Willd. ex Fr. S.F. Gray., have been investigated. This fungus is one of the most frequent appearing on the Sessile- and Pedunculate Oak weakened trees or felled logs, behaving as parasite as well as saprophyte. As a causer of Oak sapwood white rot S. hirsutum causes significant damages of wood at forest- as well as at industrial storages.

  6. Involvement of complexin 2 in docking, locking and unlocking of different SNARE complexes during sperm capacitation and induced acrosomal exocytosis.

    Directory of Open Access Journals (Sweden)

    Pei-Shiue J Tsai

    Full Text Available Acrosomal exocytosis (AE is an intracellular multipoint fusion reaction of the sperm plasma membrane (PM with the outer acrosomal membrane (OAM. This unique exocytotic event enables the penetration of the sperm through the zona pellucida of the oocyte. We previously observed a stable docking of OAM to the PM brought about by the formation of the trans-SNARE complex (syntaxin 1B, SNAP 23 and VAMP 3. By using electron microscopy, immunochemistry and immunofluorescence techniques in combination with functional studies and proteomic approaches, we here demonstrate that calcium ionophore-induced AE results in the formation of unilamellar hybrid membrane vesicles containing a mixture of components originating from the two fused membranes. These mixed vesicles (MV do not contain the earlier reported trimeric SNARE complex but instead possess a novel trimeric SNARE complex that contained syntaxin 3, SNAP 23 and VAMP 2, with an additional SNARE interacting protein, complexin 2. Our data indicate that the earlier reported raft and capacitation-dependent docking phenomenon between the PM and OAM allows a specific rearrangement of molecules between the two docked membranes and is involved in (1 recruiting SNAREs and complexin 2 in the newly formed lipid-ordered microdomains, (2 the assembly of a fusion-driving SNARE complex which executes Ca(2+-dependent AE, (3 the disassembly of the earlier reported docking SNARE complex, (4 the recruitment of secondary zona binding proteins at the zona interacting sperm surface. The possibility to study separate and dynamic interactions between SNARE proteins, complexin and Ca(2+ which are all involved in AE make sperm an ideal model for studying exocytosis.

  7. Comparative analysis of plant genomes allows the definition of the "Phytolongins": a novel non-SNARE longin domain protein family.

    Science.gov (United States)

    Vedovato, Marco; Rossi, Valeria; Dacks, Joel B; Filippini, Francesco

    2009-11-04

    Subcellular trafficking is a hallmark of eukaryotic cells. Because of their pivotal role in the process, a great deal of attention has been paid to the SNARE proteins. Most R-SNAREs, or "longins", however, also possess a highly conserved, N-terminal fold. This "longin domain" is known to play multiple roles in regulating SNARE activity and targeting via interaction with other trafficking proteins. However, the diversity and complement of longins in eukaryotes is poorly understood. Our comparative genome survey identified a novel family of longin-related proteins, dubbed the "Phytolongins" because they are specific to land plants. Phytolongins share with longins the N-terminal longin domain and the C-terminal transmembrane domain; however, in the central region, the SNARE motif is replaced by a novel region. Phylogenetic analysis pinpoints the Phytolongins as a derivative of the plant specific VAMP72 longin sub-family and allows elucidation of Phytolongin evolution. "Longins" have been defined as R-SNAREs composed of both a longin domain and a SNARE motif. However, expressed gene isoforms and splice variants of longins are examples of non-SNARE motif containing longins. The discovery of Phytolongins, a family of non-SNARE longin domain proteins, together with recent evidence on the conservation of the longin-like fold in proteins involved in both vesicle fusion (e.g. the Trs20 tether) and vesicle formation (e.g. sigma and mu adaptin) highlight the importance of the longin-like domain in protein trafficking and suggest that it was one of the primordial building blocks of the eukaryotic membrane-trafficking machinery.

  8. Comparative analysis of plant genomes allows the definition of the "Phytolongins": a novel non-SNARE longin domain protein family

    Directory of Open Access Journals (Sweden)

    Dacks Joel B

    2009-11-01

    Full Text Available Abstract Background Subcellular trafficking is a hallmark of eukaryotic cells. Because of their pivotal role in the process, a great deal of attention has been paid to the SNARE proteins. Most R-SNAREs, or "longins", however, also possess a highly conserved, N-terminal fold. This "longin domain" is known to play multiple roles in regulating SNARE activity and targeting via interaction with other trafficking proteins. However, the diversity and complement of longins in eukaryotes is poorly understood. Results Our comparative genome survey identified a novel family of longin-related proteins, dubbed the "Phytolongins" because they are specific to land plants. Phytolongins share with longins the N-terminal longin domain and the C-terminal transmembrane domain; however, in the central region, the SNARE motif is replaced by a novel region. Phylogenetic analysis pinpoints the Phytolongins as a derivative of the plant specific VAMP72 longin sub-family and allows elucidation of Phytolongin evolution. Conclusion "Longins" have been defined as R-SNAREs composed of both a longin domain and a SNARE motif. However, expressed gene isoforms and splice variants of longins are examples of non-SNARE motif containing longins. The discovery of Phytolongins, a family of non-SNARE longin domain proteins, together with recent evidence on the conservation of the longin-like fold in proteins involved in both vesicle fusion (e.g. the Trs20 tether and vesicle formation (e.g. σ and μ adaptin highlight the importance of the longin-like domain in protein trafficking and suggest that it was one of the primordial building blocks of the eukaryotic membrane-trafficking machinery.

  9. Phylogeny of the SNARE vesicle fusion machinery yields insights into the conservation of the secretory pathway in fungi.

    Science.gov (United States)

    Kienle, Nickias; Kloepper, Tobias H; Fasshauer, Dirk

    2009-01-23

    In eukaryotic cells, directional transport between different compartments of the endomembrane system is mediated by vesicles that bud from a donor organelle and then fuse with an acceptor organelle. A family of integral membrane proteins, termed soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins, constitute the key machineries of these different membrane fusion events. Over the past 30 years, the yeast Saccharomyces cerevisiae has served as a powerful model organism for studying the organization of the secretory and endocytic pathways, and a few years ago, its entire set of SNAREs was compiled. Here, we make use of the increasing amount of genomic data to investigate the history of the SNARE family during fungi evolution. Moreover, since different SNARE family members are thought to demarcate different organelles and vesicles, this approach allowed us to compare the organization of the endomembrane systems of yeast and animal cells. Our data corroborate the notion that fungi generally encompass a relatively simple set of SNARE proteins, mostly comprising the SNAREs of the proto-eukaryotic cell. However, all fungi contain a novel soluble SNARE protein, Vam7, which carries an N-terminal PX-domain that acts as a phosphoinositide binding module. In addition, the points in fungal evolution, at which lineage-specific duplications and diversifications occurred, could be determined. For instance, the endosomal syntaxins Pep12 and Vam3 arose from a gene duplication that occurred within the Saccharomycotina clade. Although the SNARE repertoire of baker's yeast is highly conserved, our analysis reveals that it is more deviated than the ones of basal fungi. This highlights that the trafficking pathways of baker's yeast are not only different to those in animal cells but also are somewhat different to those of many other fungi.

  10. Phylogeny of the SNARE vesicle fusion machinery yields insights into the conservation of the secretory pathway in fungi

    Directory of Open Access Journals (Sweden)

    Fasshauer Dirk

    2009-01-01

    Full Text Available Abstract Background In eukaryotic cells, directional transport between different compartments of the endomembrane system is mediated by vesicles that bud from a donor organelle and then fuse with an acceptor organelle. A family of integral membrane proteins, termed soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE proteins, constitute the key machineries of these different membrane fusion events. Over the past 30 years, the yeast Saccharomyces cerevisiae has served as a powerful model organism for studying the organization of the secretory and endocytic pathways, and a few years ago, its entire set of SNAREs was compiled. Results Here, we make use of the increasing amount of genomic data to investigate the history of the SNARE family during fungi evolution. Moreover, since different SNARE family members are thought to demarcate different organelles and vesicles, this approach allowed us to compare the organization of the endomembrane systems of yeast and animal cells. Our data corroborate the notion that fungi generally encompass a relatively simple set of SNARE proteins, mostly comprising the SNAREs of the proto-eukaryotic cell. However, all fungi contain a novel soluble SNARE protein, Vam7, which carries an N-terminal PX-domain that acts as a phosphoinositide binding module. In addition, the points in fungal evolution, at which lineage-specific duplications and diversifications occurred, could be determined. For instance, the endosomal syntaxins Pep12 and Vam3 arose from a gene duplication that occurred within the Saccharomycotina clade. Conclusion Although the SNARE repertoire of baker's yeast is highly conserved, our analysis reveals that it is more deviated than the ones of basal fungi. This highlights that the trafficking pathways of baker's yeast are not only different to those in animal cells but also are somewhat different to those of many other fungi.

  11. Steel-Jawed Leghold Traps and Killing Neck Snares: Similar Injuries Command Change to Agreement on International Humane Trapping Standards.

    Science.gov (United States)

    Proulx, Gilbert; Rodtka, Dwight

    2017-01-01

    According to the Agreement on International Humane Trapping Standards (AIHTS), which was signed by the European Community, Canada, and Russia in 1997, killing devices used for the capture of canids and other fur-bearing nonhuman animals should render an animal irreversibly unconscious within 300 s. However, killing neck snares are not included in the agreement. In this commentary, a parallel is drawn between injuries caused by steel-jawed leghold traps, which have been banned by the AIHTS signatory countries, and killing neck snares to demonstrate that these snares should also be included in international humane trapping standards (i.e., AIHTS). Previous scientific investigations have shown that neither manual nor power-killing neck snares can consistently render canids unconscious rapidly. Animals caught in killing neck snares suffer injuries that are similar to or worse than those reported for leg-captured canids. The authors strongly recommend that AIHTS be modified to include killing neck snares and that such devices be subject to the criteria applied to other trapping devices. Alternative restraining trapping devices, which are effective and more humane, are available for capturing wild canids.

  12. A novel Netrin-1–sensitive mechanism promotes local SNARE-mediated exocytosis during axon branching

    Science.gov (United States)

    Winkle, Cortney C.; McClain, Leslie M.; Valtschanoff, Juli G.; Park, Charles S.; Maglione, Christopher

    2014-01-01

    Developmental axon branching dramatically increases synaptic capacity and neuronal surface area. Netrin-1 promotes branching and synaptogenesis, but the mechanism by which Netrin-1 stimulates plasma membrane expansion is unknown. We demonstrate that SNARE-mediated exocytosis is a prerequisite for axon branching and identify the E3 ubiquitin ligase TRIM9 as a critical catalytic link between Netrin-1 and exocytic SNARE machinery in murine cortical neurons. TRIM9 ligase activity promotes SNARE-mediated vesicle fusion and axon branching in a Netrin-dependent manner. We identified a direct interaction between TRIM9 and the Netrin-1 receptor DCC as well as a Netrin-1–sensitive interaction between TRIM9 and the SNARE component SNAP25. The interaction with SNAP25 negatively regulates SNARE-mediated exocytosis and axon branching in the absence of Netrin-1. Deletion of TRIM9 elevated exocytosis in vitro and increased axon branching in vitro and in vivo. Our data provide a novel model for the spatial regulation of axon branching by Netrin-1, in which localized plasma membrane expansion occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion. PMID:24778312

  13. [Preparation, characterization and application of rice Qb-SNARE protein OsNPSN11 polyclonal antibody].

    Science.gov (United States)

    Bao, Yong-Mei; Liu, Yong-Hui; Xu, Dong-Qing; Huang, Ji; Wang, Zhou-Fei; Wang, Jian-Fei; Zhang, Hong-Sheng

    2010-09-01

    Membrane fusion in vesicle trafficking in the cells of eukaryotic organisms is mediated by soluble-N-ethyl- maleimide-sensitive fusion protein attachment protein receptor (SNARE) proteins. OsNPSN11 is a member of Qb-SNARE gene family isolate from rice. The cDNA of OsNPSN11 was subcloned into pET-30a and fusion to the 6 × His tag. Induced by 0.5 mmol/L IPTG for four hours, the recombinant protein was highly expressed in Escherichia coli, which was purified by Ni2+ -NTA His-bind resin affinity chromatography column to be used as an antigen to raise the antibody in New Zealand rabbits. Western blotting analysis showed that the antibody can specifically recognize the expressed antigen and the OsNPSN11 in plasma membrane protein from various rice tissues. This indicated that the antibody can be used for expres-sion analysis in transgenic rice.

  14. Rescue endoscopic bleeding control for nonvariceal upper gastrointestinal hemorrhage using clipping and detachable snaring.

    Science.gov (United States)

    Lee, J H; Kim, B K; Seol, D C; Byun, S J; Park, K H; Sung, I K; Park, H S; Shim, C S

    2013-06-01

    Nonvariceal upper gastrointestinal (UGI) bleeding recurs after appropriate endoscopic therapy in 10 % - 15 % of cases. The mortality rate can be as high as 25 % when bleeding recurs, but there is no consensus about the best modality for endoscopic re-treatment. The aim of this study was to evaluate clipping and detachable snaring (CDS) for rescue endoscopic control of nonvariceal UGI hemorrhage. We report a case series of seven patients from a Korean tertiary center who underwent endoscopic hemostasis using the combined method of detachable snares with hemoclips. The success rate of endoscopic hemostasis with CDS was 86 %: six of the seven patients who had experienced primary endoscopic treatment failure or recurrent bleeding after endoscopic hemostasis were treated successfully. In conclusion, rescue endoscopic bleeding control by means of CDS is an option for controlling nonvariceal UGI bleeding when no other method of endoscopic treatment for recurrent bleeding and primary hemostatic failure is possible.

  15. Cloning and characterization of three genes encoding Qb-SNARE proteins in rice.

    Science.gov (United States)

    Bao, Yong-Mei; Wang, Jian-Fei; Huang, Ji; Zhang, Hong-Sheng

    2008-03-01

    Qb-SNARE proteins belong to the superfamily of SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) and function as important components of the vesicle trafficking machinery in eukaryotic cells. Here, we report three novel plant SNARE (NPSN) genes isolated from rice and named OsNPSN11, OsNPSN12 and OsNPSN13. They have about 70% nucleotide identity over their entire coding regions and similar genomic organization with ten exons and nine introns in each gene. Multiple alignment of deduced amino acid sequences indicate that the OsNPSNs proteins are homologous to AtNPSNs from Arabidopsis, containing a Qb-SNARE domain and a membrane-spanning domain in the C-terminal region. Semi-quantitative RT-PCR assays showed that the OsNPSNs were ubiquitously and differentially expressed in roots, culms, leaves, immature spikes and flowering spikes. The expression of OsNPSNs was significantly activated in rice seedlings treated with H(2)O(2), but down-regulated under NaCl and PEG6000 stresses. Transient expression method in onion epidermal cells revealed that OsNPSNs were located in the plasma membrane. Transformed yeast cells with OsNPSNs had better growth rates than empty-vector transformants when cultured on either solid or liquid selective media containing various concentrations of H(2)O(2), but more sensitive to NaCl and mannitol stresses. The 35S:OsNPSN11 transgenic tobacco also showed more tolerance to H(2)O(2) and sensitivity to NaCl and mannitol than non-transgenic tobacco. These results indicate that OsNPSNs may be involved in different aspects of the signal transduction in plant and yeast responses to abiotic stresses.

  16. Visualization of SNARE-Mediated Hemifusion between Giant Unilamellar Vesicles Arrested by Myricetin

    Science.gov (United States)

    Heo, Paul; Park, Joon-Bum; Shin, Yeon-Kyun; Kweon, Dae-Hyuk

    2017-01-01

    Neurotransmitters are released within a millisecond after Ca2+ arrives at an active zone. However, the vesicle fusion pathway underlying this synchronous release is yet to be understood. At the center of controversy is whether hemifusion, in which outer leaflets are merged while inner leaflets are still separated, is an on-pathway or off-pathway product of Ca2+-triggered exocytosis. Using the single vesicle fusion assay, we recently demonstrated that hemifusion is an on-pathway intermediate that immediately proceeds to full fusion upon Ca2+ triggering. It has been shown that the flavonoid myricetin arrests soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor (SNARE)-mediated vesicle fusion at hemifusion, but that the hemifused vesicles spontaneously convert to full fusion when the myricetin clamp is removed by the enzyme laccase. In the present study, we visualized SNARE-mediated hemifusion between two SNARE-reconstituted giant unilamellar vesicles (GUVs) arrested by myricetin. The large size of the GUVs enabled us to directly image the hemifusion between them. When two merging GUVs were labeled with different fluorescent dyes, GUV pairs showed asymmetric fluorescence intensities depending on the position on the GUV pair consistent with what is expected for hemifusion. The flow of lipids from one vesicle to the other was revealed with fluorescence recovery after photobleaching (FRAP), indicating that the two membranes had hemifused. These results support the hypothesis that hemifusion may be the molecular status that primes Ca2+-triggered millisecond exocytosis. This study represents the first imaging of SNARE-driven hemifusion between GUVs. PMID:28408867

  17. Endoscopic snare excision of adenoma of the papilla of Vater without prophylactic pancreatic-duct stent.

    Science.gov (United States)

    Attaallah, Wafi; Gunal, Omer; Mokhtare, Sina; Ozmen, Tolga; Cingi, Asim

    2014-11-28

    The endoscopic excision of adenomas of the papilla of Vater has gained increased popularity in the recent years. Temporary pancreatic drainage has been advised to accompany snare papillectomy in order to prevent ductal obstruction and serious pancreatitis. We evaluated treatment outcome of patients who had undergone endoscopic papillectomy without pancreatic drainage. Three consecutive adult patients with adenomas of the papilla of Vater presented with jaundice and pain were treated by endoscopic snare excision between October 2013 and February 2014 in a single center. ERCP procedures revealed papillary tumors and endoscopic biopsy specimens revealed tubular adenoma the papilla of Vater. Adenomas were treated by snare papillectomy method and a biliary stent was inserted as a prophylactic procedure immediately after excision of the adenoma in each case. In addition to physical examination, laboratory tests were repeated in the follow-up period after papillectomy in order to document if there is any complication particularly pancreatitis. None of the patients experienced an immediate complication, including pancreatitis after papillectomy. Also neither patient experienced abnormal fluctuations of laboratory tests during the follow-up. Histopathologic evaluation of the resection specimens revealed a tubular adenoma with low grade dysplasia in the first two patients and a tubular adenoma with high-grade dysplasia in the third one. Endoscopy and pathologic evaluation revealed no recurrent/residual disease during the follow-up period of these patients. Endoscopic snare resection of adenoma of the major papilla of the duodenum is a safe and minimal invasive alternative to surgical therapy. Biliary stent is sufficient to prevent biliary ductal patency and pancreatic stenting might not be necessary to prevent pancreatitis.

  18. Assessing the efficacy of hair snares as a method for noninvasive sampling of Neotropical felids

    Directory of Open Access Journals (Sweden)

    Tatiana P. Portella

    2013-02-01

    Full Text Available Hair snares have been used in North and Central America for a long time in assessment and monitoring studies of several mammalian species. This method can provide a cheap, suitable, and efficient way to monitor mammals because it combines characteristics that are not present in most alternative techniques. However, despite their usefulness, hair snares are rarely used in other parts of the world. The aim of our study was to evaluate the effectiveness of hair snares and three scent lures (cinnamon, catnip, and vanilla in the detection of felids in one of the largest remnants of the Brazilian Atlantic Forest. We performed tests with six captive felid species - Panthera onca (Linnaeus, 1758, Leopardus pardalis (Linnaeus, 1758, L. tigrinus (Schreber, 1775, L. wiedii (Schinz, 1821, Puma concolor (Linnaeus, 1771, and P. yagouaroundi (É. Geoffroy Saint-Hilaire, 1803 - to examine their responses to the attractants, and to correlate those with lure efficiency in the field. The field tests were conducted at the Parque Estadual Pico do Marumbi, state of Paraná, Brazil. Hair traps were placed on seven transects. There were equal numbers of traps with each scent lure, for a total of 1,551 trap-days. In captivity, vanilla provided the greatest response, yet no felids were detected in the field with any of the tested lures, although other species were recorded. Based on the sampling of non-target species, and the comparison with similar studies elsewhere, this study points to a possible caveat of this method when rare species or small populations are concerned. Meanwhile, we believe that improved hair snares could provide important results with several species in the location tested and others.

  19. Subcellular compartmentalization in protoplasts from Artemisia annua cell cultures: engineering attempts using a modified SNARE protein.

    Science.gov (United States)

    Di Sansebastiano, Gian Pietro; Rizzello, Francesca; Durante, Miriana; Caretto, Sofia; Nisi, Rossella; De Paolis, Angelo; Faraco, Marianna; Montefusco, Anna; Piro, Gabriella; Mita, Giovanni

    2015-05-20

    Plants are ideal bioreactors for the production of macromolecules but transport mechanisms are not fully understood and cannot be easily manipulated. Several attempts to overproduce recombinant proteins or secondary metabolites failed. Because of an independent regulation of the storage compartment, the product may be rapidly degraded or cause self-intoxication. The case of the anti-malarial compound artemisinin produced by Artemisia annua plants is emblematic. The accumulation of artemisinin naturally occurs in the apoplast of glandular trichomes probably involving autophagy and unconventional secretion thus its production by undifferentiated tissues such as cell suspension cultures can be challenging. Here we characterize the subcellular compartmentalization of several known fluorescent markers in protoplasts derived from Artemisia suspension cultures and explore the possibility to modify compartmentalization using a modified SNARE protein as molecular tool to be used in future biotechnological applications. We focused on the observation of the vacuolar organization in vivo and the truncated form of AtSYP51, 51H3, was used to induce a compartment generated by the contribution of membrane from endocytosis and from endoplasmic reticulum to vacuole trafficking. The artificial compartment crossing exocytosis and endocytosis may trap artemisinin stabilizing it until extraction; indeed, it is able to increase total enzymatic activity of a vacuolar marker (RGUSChi), probably increasing its stability. Exploring the 51H3-induced compartment we gained new insights on the function of the SNARE SYP51, recently shown to be an interfering-SNARE, and new hints to engineer eukaryote endomembranes for future biotechnological applications.

  20. Physiologic responses of grizzly bears to different methods of capture.

    Science.gov (United States)

    Cattet, Marc R; Christison, Katina; Caulkett, Nigel A; Stenhouse, Gordon B

    2003-07-01

    The physiologic effects of two methods of capture, chemical immobilization of free-ranging (FR) bears by remote injection from a helicopter and physical restraint (PR) by leg-hold snare prior to chemical immobilization, were compared in 46 grizzly bears (Ursus arctos) handled during 90 captures between 1999 and 2001. Induction dosages and times were greater for FR bears than PR bears, a finding consistent with depletion of, or decreased sensitivity to, catecholamines. Free-ranging bears also had higher rectal temperatures 15 min following immobilization and temperatures throughout handling that correlated positively with induction time. Physically restrained bears had higher white blood cell counts, with more neutrophils and fewer lymphocytes and eosinophils, than did FR bears. This white blood cell profile was consistent with a stress leukogram, possibly affected by elevated levels of serum cortisol. Serum concentrations of alanine aminotransferase, aspartate aminotransferase, and creatine kinase were higher in PR bears that suggested muscle injury. Serum concentrations of sodium and chloride also were higher in PR bears and attributed to reduced body water volume through water deprivation and increased insensible water loss. Overall, different methods of capture resulted in different patterns of physiologic disturbance. Reducing pursuit and drug induction times should help to minimize increase in body temperature and alteration of acid-base balance in bears immobilized by remote injection. Minimizing restraint time and ensuring snare-anchoring cables are short should help to minimize loss of body water and prevent serious muscle injury in bears captured by leg-hold snare.

  1. Insulin and hypertonicity recruit GLUT4 to the plasma membrane of muscle cells by using N-ethylmaleimide-sensitive factor-dependent SNARE mechanisms but different v-SNAREs: role of TI-VAMP.

    Science.gov (United States)

    Randhawa, Varinder K; Thong, Farah S L; Lim, Dawn Y; Li, Dailin; Garg, Rami R; Rudge, Rachel; Galli, Thierry; Rudich, Assaf; Klip, Amira

    2004-12-01

    Insulin and hypertonicity each increase the content of GLUT4 glucose transporters at the surface of muscle cells. Insulin enhances GLUT4 exocytosis without diminishing its endocytosis. The insulin but not the hypertonicity response is reduced by tetanus neurotoxin, which cleaves vesicle-associated membrane protein (VAMP)2 and VAMP3, and is rescued upon introducing tetanus neurotoxin-resistant VAMP2. Here, we show that hypertonicity enhances GLUT4 recycling, compounding its previously shown ability to reduce GLUT4 endocytosis. To examine whether the canonical soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) mechanism is required for the plasma membrane fusion of the tetanus neurotoxin-insensitive GLUT4 vesicles, L6 myoblasts stably expressing myc-tagged GLUT4 (GLUT4myc) were transiently transfected with dominant negative N-ethylmaleimide-sensitive factor (NSF) (DN-NSF) or small-interfering RNA to tetanus neurotoxin-insensitive VAMP (TI-VAMP siRNA). Both strategies markedly reduced the basal level of surface GLUT4myc and the surface gain of GLUT4myc in response to hypertonicity. The insulin effect was abolished by DN-NSF, but only partly reduced by TI-VAMP siRNA. We propose that insulin and hypertonicity recruit GLUT4myc from partly overlapping, but distinct sources defined by VAMP2 and TI-VAMP, respectively.

  2. Importance of the N-Terminal Domain of the Qb-SNARE Vti1p for Different Membrane Transport Steps in the Yeast Endosomal System

    Science.gov (United States)

    Gossing, Michael; Chidambaram, Subbulakshmi; Fischer von Mollard, Gabriele

    2013-01-01

    SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) on transport vesicles and target membranes are crucial for vesicle targeting and fusion. They form SNARE complexes, which contain four α-helical SNARE motifs contributed by three or four different SNAREs. Most SNAREs function only in a single transport step. The yeast SNARE Vti1p participates in four distinct SNARE complexes in transport from the trans Golgi network to late endosomes, in transport to the vacuole, in retrograde transport from endosomes to the trans Golgi network and in retrograde transport within the Golgi. So far, all vti1 mutants investigated had mutations within the SNARE motif. Little is known about the function of the N-terminal domain of Vti1p, which forms a three helix bundle called Habc domain. Here we generated a temperature-sensitive mutant of this domain to study the effects on different transport steps. The secondary structure of wild type and vti1-3 Habc domain was analyzed by circular dichroism spectroscopy. The amino acid exchanges identified in the temperature-sensitive vti1-3 mutant caused unfolding of the Habc domain. Transport pathways were investigated by immunoprecipitation of newly synthesized proteins after pulse-chase labeling and by fluorescence microscopy of a GFP-tagged protein cycling between plasma membrane, early endosomes and Golgi. In vti1-3 cells transport to the late endosome and assembly of the late endosomal SNARE complex was blocked at 37°C. Retrograde transport to the trans Golgi network was affected while fusion with the vacuole was possible but slower. Steady state levels of SNARE complexes mediating these steps were less affected than that of the late endosomal SNARE complex. As different transport steps were affected our data demonstrate the importance of a folded Vti1p Habc domain for transport. PMID:23776654

  3. Importance of the N-terminal domain of the Qb-SNARE Vti1p for different membrane transport steps in the yeast endosomal system.

    Science.gov (United States)

    Gossing, Michael; Chidambaram, Subbulakshmi; Fischer von Mollard, Gabriele

    2013-01-01

    SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) on transport vesicles and target membranes are crucial for vesicle targeting and fusion. They form SNARE complexes, which contain four α-helical SNARE motifs contributed by three or four different SNAREs. Most SNAREs function only in a single transport step. The yeast SNARE Vti1p participates in four distinct SNARE complexes in transport from the trans Golgi network to late endosomes, in transport to the vacuole, in retrograde transport from endosomes to the trans Golgi network and in retrograde transport within the Golgi. So far, all vti1 mutants investigated had mutations within the SNARE motif. Little is known about the function of the N-terminal domain of Vti1p, which forms a three helix bundle called H(abc) domain. Here we generated a temperature-sensitive mutant of this domain to study the effects on different transport steps. The secondary structure of wild type and vti1-3 H(abc) domain was analyzed by circular dichroism spectroscopy. The amino acid exchanges identified in the temperature-sensitive vti1-3 mutant caused unfolding of the H(abc) domain. Transport pathways were investigated by immunoprecipitation of newly synthesized proteins after pulse-chase labeling and by fluorescence microscopy of a GFP-tagged protein cycling between plasma membrane, early endosomes and Golgi. In vti1-3 cells transport to the late endosome and assembly of the late endosomal SNARE complex was blocked at 37°C. Retrograde transport to the trans Golgi network was affected while fusion with the vacuole was possible but slower. Steady state levels of SNARE complexes mediating these steps were less affected than that of the late endosomal SNARE complex. As different transport steps were affected our data demonstrate the importance of a folded Vti1p H(abc) domain for transport.

  4. Importance of the N-terminal domain of the Qb-SNARE Vti1p for different membrane transport steps in the yeast endosomal system.

    Directory of Open Access Journals (Sweden)

    Michael Gossing

    Full Text Available SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptor on transport vesicles and target membranes are crucial for vesicle targeting and fusion. They form SNARE complexes, which contain four α-helical SNARE motifs contributed by three or four different SNAREs. Most SNAREs function only in a single transport step. The yeast SNARE Vti1p participates in four distinct SNARE complexes in transport from the trans Golgi network to late endosomes, in transport to the vacuole, in retrograde transport from endosomes to the trans Golgi network and in retrograde transport within the Golgi. So far, all vti1 mutants investigated had mutations within the SNARE motif. Little is known about the function of the N-terminal domain of Vti1p, which forms a three helix bundle called H(abc domain. Here we generated a temperature-sensitive mutant of this domain to study the effects on different transport steps. The secondary structure of wild type and vti1-3 H(abc domain was analyzed by circular dichroism spectroscopy. The amino acid exchanges identified in the temperature-sensitive vti1-3 mutant caused unfolding of the H(abc domain. Transport pathways were investigated by immunoprecipitation of newly synthesized proteins after pulse-chase labeling and by fluorescence microscopy of a GFP-tagged protein cycling between plasma membrane, early endosomes and Golgi. In vti1-3 cells transport to the late endosome and assembly of the late endosomal SNARE complex was blocked at 37°C. Retrograde transport to the trans Golgi network was affected while fusion with the vacuole was possible but slower. Steady state levels of SNARE complexes mediating these steps were less affected than that of the late endosomal SNARE complex. As different transport steps were affected our data demonstrate the importance of a folded Vti1p H(abc domain for transport.

  5. The SNARE protein SNAP23 and the SNARE-interacting protein Munc18c in human skeletal muscle are implicated in insulin resistance/type 2 diabetes

    DEFF Research Database (Denmark)

    Boström, Pontus; Andersson, Linda; Vind, Birgitte

    2010-01-01

    for regulation of SNAP23 were also investigated in the skeletal muscle cell line L6. RESULTS: We showed increased SNAP23 levels in skeletal muscle from patients with type 2 diabetes compared with that from lean control subjects. Moreover, SNAP23 was redistributed from the plasma membrane to the microsomal....../cytosolic compartment in the patients with the type 2 diabetes. Expression of the SNARE-interacting protein Munc18c was higher in skeletal muscle from patients with type 2 diabetes. Studies in L6 cells showed that Munc18c promoted the expression of SNAP23. CONCLUSIONS: We have translated our previous in vitro results...... into humans by showing that there is a change in the distribution of SNAP23 to the interior of the cell in skeletal muscle from patients with type 2 diabetes. We also showed that Munc18c is a potential regulator of SNAP23....

  6. The R-SNARE endobrevin/VAMP-8 mediates homotypic fusion of early endosomes and late endosomes.

    Science.gov (United States)

    Antonin, W; Holroyd, C; Tikkanen, R; Höning, S; Jahn, R

    2000-10-01

    Endobrevin/VAMP-8 is an R-SNARE localized to endosomes, but it is unknown in which intracellular fusion step it operates. Using subcellular fractionation and quantitative immunogold electron microscopy, we found that endobrevin/VAMP-8 is present on all membranes known to communicate with early endosomes, including the plasma membrane, clathrin-coated pits, late endosomes, and membranes of the trans-Golgi network. Affinity-purified antibodies that block the ability of endobrevin/VAMP-8 to form SNARE core complexes potently inhibit homotypic fusion of both early and late endosomes in vitro. Fab fragments were as active as intact immunoglobulin Gs. Recombinant endobrevin/VAMP-8 inhibited both fusion reactions with similar potency. We conclude that endobrevin/VAMP-8 operates as an R-SNARE in the homotypic fusion of early and late endosomes.

  7. A Carcinoid Tumor of the Ampulla of Vater Treated by Endoscopic Snare Papillectomy

    OpenAIRE

    Pyun, Dae-Keun; Moon, Gyoo; Han, Jimin; Kim, Myung-Hwan; Lee, Sang Soo; Seo, Dong-Wan; Lee, Sung-Koo

    2004-01-01

    Here, a case of a patient with incidental finding of a carcinoid tumor of the ampulla of Vater, who was treated with endoscopic snare papillectomy, is reported. A 62-year-old male was admitted to our hospital due to a carcinoid tumor of the ampulla of Vater, which was found during follow-up endoscopy after an endoscopic mucosal resection of early gastric cancer. No lymphadenopathy or visceral metastasis was found on an abdominal CT scan, In-111 octerotide scan and EUS. The ampulla was then en...

  8. SNARE protein FgVam7 controls growth, asexual and sexual development, and plant infection in Fusarium graminearum.

    Science.gov (United States)

    Zhang, Haifeng; Li, Bing; Fang, Qin; Li, Ying; Zheng, Xiaobo; Zhang, Zhengguang

    2016-01-01

    Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins play critical and conserved roles in membrane fusion and vesicle transport of eukaryotic cells. Previous studies have shown that various homologues of SNARE proteins are also important in the infection of host plants by pathogenic fungi. Here, we report the characterization of a SNARE homologue, FgVam7, from Fusarium graminearum that causes head blight in wheat and barley worldwide. Phylogenetic analysis and domain comparison reveal that FgVam7 is homologous to Vam7 proteins of Saccharomyces cerevisiae (ScVam7), Magnaporthe oryzae (MoVam7) and several additional fungi by containing a PhoX homology (PX) domain and a SNARE domain. We show that FgVam7 plays a regulatory role in cellular differentiation and virulence in F. graminearum. Deletion of FgVAM7 significantly reduces vegetative growth, conidiation and conidial germination, sexual reproduction and virulence. The ΔFgvam7 mutant also exhibits a defect in vacuolar maintenance and delayed endocytosis. Moreover, the ΔFgvam7 mutant is insensitive to salt and osmotic stresses, and hypersensitive to cell wall stressors. Further characterization of FgVam7 domains indicate that the PX and SNARE domains are conserved in controlling Vam7 protein localization and function, respectively. Finally, FgVam7 has been shown to positively regulate the expression of several deoxynivalenol (DON) biosynthesis genes TRI5, TRI6 and TRI101, and DON production. Our studies provide evidence for SNARE proteins as an additional means of regulatory mechanisms that govern growth, differentiation and virulence of pathogenic fungi.

  9. Differential localization of SNARE complex proteins SNAP-25, syntaxin, and VAMP during development of the mammalian retina.

    Science.gov (United States)

    Greenlee, M H; Roosevelt, C B; Sakaguchi, D S

    2001-02-12

    SNARE complex proteins have critical functions during regulated vesicular release of neurotransmitter. In addition, they play critical roles during neurite outgrowth and synaptogenesis. Although it is clear that the function of any one SNARE complex protein during release of neurotransmitter is dependent on its association with other members of the complex, it is less certain whether their function during development and differentiation is dependent on interaction with one another. Previously, we have observed transient high levels of SNARE complex protein SNAP-25 in developing cholinergic amacrine cells (West Greenlee et al. [1998] J Comp Neurol 394:374-385). In addition, we detected, high levels of SNAP-25 in developing and mature photoreceptors. To better understand the functional significance of these high levels of SNAP-25 expression, we used immunocytochemistry to examine the developmental expression of the three members of the SNARE complex, SNAP-25, Syntaxin, and vesicle associated membrane protein (VAMP/also Synaptobrevin). Our results demonstrate that the high levels of SNAP-25 in cholinergic amacrine cells and photoreceptors are not accompanied by the same relatively high levels of other SNARE complex proteins. These results suggest that high levels of SNAP-25 in specific cell types may function independently of association with Syntaxin and VAMP. In this analysis, we characterized the changing patterns of immunoreactivity for the three SNARE complex proteins during the development and differentiation of the mammalian retina. We have compared the pattern of expression of the core SNARE complex proteins in the Brazilian opossum, Monodelphis domestica, and in the rat and found common patterns of expression between these diverse mammalian species. We observed temporal differences in the onset of immunoreactivity between these three proteins, and differences in their localization within synaptic layers in the developing and mature mammalian retina. This

  10. The c-ring stoichiometry of ATP synthase is adapted to cell physiological requirements of alkaliphilic Bacillus pseudofirmus OF4

    Science.gov (United States)

    Preiss, Laura; Klyszejko, Adriana L.; Hicks, David B.; Liu, Jun; Fackelmayer, Oliver J.; Yildiz, Özkan; Krulwich, Terry A.; Meier, Thomas

    2013-01-01

    The c-rings of ATP synthases consist of individual c-subunits, all of which harbor a conserved motif of repetitive glycine residues (GxGxGxG) important for tight transmembrane α-helix packing. The c-ring stoichiometry determines the number of ions transferred during enzyme operation and has a direct impact on the ion-to-ATP ratio, a cornerstone parameter of cell bioenergetics. In the extreme alkaliphile Bacillus pseudofirmus OF4, the glycine motif is replaced by AxAxAxA. We performed a structural study on two mutants with alanine-to-glycine changes using atomic force microscopy and X-ray crystallography, and found that mutants form smaller c12 rings compared with the WT c13. The molar growth yields of B. pseudofirmus OF4 cells on malate further revealed that the c12 mutants have a considerably reduced capacity to grow on limiting malate at high pH. Our results demonstrate that the mutant ATP synthases with either c12 or c13 can support ATP synthesis, and also underscore the critical importance of an alanine motif with c13 ring stoichiometry for optimal growth at pH >10. The data indicate a direct connection between the precisely adapted ATP synthase c-ring stoichiometry and its ion-to-ATP ratio on cell physiology, and also demonstrate the bioenergetic challenges and evolutionary adaptation strategies of extremophiles. PMID:23613590

  11. Science and Measurement Requirements for a Plant Physiology and Functional Types Mission: Measuring the Composition, Function and Health of Global Land and Coastal Ocean Ecosystems

    Science.gov (United States)

    Green, Robert O.; Rogez, Francois; Green, Rob; Ungar, Steve; Knox, Robert; Asner, Greg; Muller-Karger, Frank; Bissett, Paul; Chekalyuk, Alex; Dierssen, Heidi; Gamon, John; Hook, Simon; Meister, Gerhard; Middleton, Betsy; Ollinger, Scott; Roberts, Dar; Siegel, Dave; Townsend, Phil; Saatchi, Sassan; Unstin, Susan; Turner, Woody; Wickland, Diane; Bontempi, Paula; Emanuel, Bill

    2007-01-01

    This slide presentation reviews the proposed Plant Physiology and Functional Types (PPFT) Mission. The National Academy of Sciences Decadal Survey, placed a critical priority on a Mission to observe distribution and changes in ecosystem functions. The PPFT satellite mission provides the essential measurements needed to assess drivers of change in biodiversity and ecosystem services that affect human welfare. The presentation reviews the science questions that the mission will be designed to answer, the science rationale, the science measurements, the mission concept, the planned instrumentation, the calibration method, and key signal to noise ratios and uniformity requirements.

  12. Selective regulation of maize plasma membrane aquaporin trafficking and activity by the SNARE SYP121.

    Science.gov (United States)

    Besserer, Arnaud; Burnotte, Emeline; Bienert, Gerd Patrick; Chevalier, Adrien S; Errachid, Abdelmounaim; Grefen, Christopher; Blatt, Michael R; Chaumont, François

    2012-08-01

    Plasma membrane intrinsic proteins (PIPs) are aquaporins facilitating the diffusion of water through the cell membrane. We previously showed that the traffic of the maize (Zea mays) PIP2;5 to the plasma membrane is dependent on the endoplasmic reticulum diacidic export motif. Here, we report that the post-Golgi traffic and water channel activity of PIP2;5 are regulated by the SNARE (for soluble N-ethylmaleimide-sensitive factor protein attachment protein receptor) SYP121, a plasma membrane resident syntaxin involved in vesicle traffic, signaling, and regulation of K(+) channels. We demonstrate that the expression of the dominant-negative SYP121-Sp2 fragment in maize mesophyll protoplasts or epidermal cells leads to a decrease in the delivery of PIP2;5 to the plasma membrane. Protoplast and oocyte swelling assays showed that PIP2;5 water channel activity is negatively affected by SYP121-Sp2. A combination of in vitro (copurification assays) and in vivo (bimolecular fluorescence complementation, Förster resonance energy transfer, and yeast split-ubiquitin) approaches allowed us to demonstrate that SYP121 and PIP2;5 physically interact. Together with previous data demonstrating the role of SYP121 in regulating K(+) channel trafficking and activity, these results suggest that SYP121 SNARE contributes to the regulation of the cell osmotic homeostasis.

  13. Selective Regulation of Maize Plasma Membrane Aquaporin Trafficking and Activity by the SNARE SYP121[W

    Science.gov (United States)

    Besserer, Arnaud; Burnotte, Emeline; Bienert, Gerd Patrick; Chevalier, Adrien S.; Errachid, Abdelmounaim; Grefen, Christopher; Blatt, Michael R.; Chaumont, François

    2012-01-01

    Plasma membrane intrinsic proteins (PIPs) are aquaporins facilitating the diffusion of water through the cell membrane. We previously showed that the traffic of the maize (Zea mays) PIP2;5 to the plasma membrane is dependent on the endoplasmic reticulum diacidic export motif. Here, we report that the post-Golgi traffic and water channel activity of PIP2;5 are regulated by the SNARE (for soluble N-ethylmaleimide-sensitive factor protein attachment protein receptor) SYP121, a plasma membrane resident syntaxin involved in vesicle traffic, signaling, and regulation of K+ channels. We demonstrate that the expression of the dominant-negative SYP121-Sp2 fragment in maize mesophyll protoplasts or epidermal cells leads to a decrease in the delivery of PIP2;5 to the plasma membrane. Protoplast and oocyte swelling assays showed that PIP2;5 water channel activity is negatively affected by SYP121-Sp2. A combination of in vitro (copurification assays) and in vivo (bimolecular fluorescence complementation, Förster resonance energy transfer, and yeast split-ubiquitin) approaches allowed us to demonstrate that SYP121 and PIP2;5 physically interact. Together with previous data demonstrating the role of SYP121 in regulating K+ channel trafficking and activity, these results suggest that SYP121 SNARE contributes to the regulation of the cell osmotic homeostasis. PMID:22942383

  14. A Homemade Snare: An Alternative Method for Mechanical Removal of Dirofilaria immitis in Dogs

    Directory of Open Access Journals (Sweden)

    Ana Margarida Alho

    2016-01-01

    Full Text Available Canine dirofilariosis is a life-threatening parasitic disease that is increasingly reported worldwide. Once diagnosed the main treatment goals are to improve the animal’s clinical condition and to eliminate all life stages of the parasite with minimal posttreatment side effects. This can be achieved through mechanical, surgical, or chemotherapeutical approaches. Currently, manual extraction is the preferred method to remove adult heartworms due to its diminished invasiveness, reduced damage to the vascular endothelium, and shortened anaesthesia duration. However, it remains an expensive technique that can be highly traumatic. To address this issue, a nontraumatic homemade catheter-guided snare was developed for heartworm removal by adapting and folding a 0.014-inch coronary wire (BMW, Abbott Vascular. Transvenous heartworm extraction was performed on a dog severely infected with adult heartworms by inserting the modified snare into a 6-F Judkins right coronary guiding catheter BMW (Cordis and advancing it into the right ventricle under fluoroscopic guidance. Fifteen adult specimens of Dirofilaria immitis were successfully extracted from the pulmonary artery and right ventricle without complications. To assure the death of both larvae and adults, postoperative treatment was successfully managed using ivermectin, doxycycline, and melarsomine, with no recurrence after surgery.

  15. Mechanical thrombectomy with snare in patients with acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Alejandro; Mayol, Antonio [Hospital Universitario Virgen del Rocio, Interventional Neuroradiology, Department of Radiology, Seville (Spain); Martinez, Eva; Gonzalez-Marcos, Jose R.; Gil-Peralta, Alberto [Hospital Universitario Virgen del Rocio, Department of Neurology, Seville (Spain)

    2007-04-15

    We evaluated the efficacy and safety of thrombus extraction using a microsnare in patients with acute ischemic stroke (AIS). This was a prospective, observational, cohort study in which consecutive patients with AIS (<6 hours of ischemia for anterior circulation and <24 hours for posterior circulation) who had been previously excluded from intravenous tissue plasminogen activator (tPA) thrombolysis were included and followed-up for 3 months. Mechanical embolectomy with a microsnare of 2-4 mm was undertaken as the first treatment. Low-dose intraarterial thrombolysis or angioplasty was used if needed. TIMI grade and modified Rankin stroke scale (mRSS) score were used to evaluate vessel recanalization and clinical efficacy, respectively. Nine patients (mean age 55 years, range 17-69 years) were included. Their basal mean NIHSS score was 16 (range 12-24). In seven out of the nine patients (77.8%) the clot was removed, giving a TIMI grade of 3 in four patients and TIMI grade 2 in three patients. Occlusion sites were: middle cerebral artery (four), basilar artery (two) and anterior cerebral artery plus middle cerebral artery (one). The mean time for recanalization from the start of the procedure was 50 min (range 50-75 min). At 3 months, the mRSS score was 0 in two patients and 3-4 in three patients (two patients died). According to our results, the microsnare is a safe procedure for mechanical thrombectomy with a good recanalization rate. Further studies are required to determine the role of the microsnare in the treatment of AIS. (orig.)

  16. A simultaneous navigation and radiation evasion algorithm (SNARE)

    Energy Technology Data Exchange (ETDEWEB)

    Khasawneh, Mohammed A., E-mail: mkha@ieee.org [Department of Electrical Engineering, Jordan University of Science and Technology, Irbid 221 10 (Jordan); Jaradat, Mohammad A., E-mail: majaradat@just.edu.jo [Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid 221 10 (Jordan); Al-Shboul, Zeina Aman M., E-mail: xeinaaman@gmail.com [Department of Electrical Engineering, Jordan University of Science and Technology, Irbid 221 10 (Jordan)

    2013-12-15

    ruggedness against rough radiation terrains, navigational performance was assessed for a U-shaped radiation field: a case typical of testing for robotics applications and a multi-island radiation environment. Under these two test environments, the algorithm was shown to perform in accordance with set optimization criteria. Simulations reveal that localization of the mobile device is achieved in compliance with design requirements leading to navigational paths that compare favorably to Dijkstra navigation in terms of the (radiation × time) product and the time needed to reach an exit. Results of these simulations also show that while there were cases of failure encountered under navigation involving the “Radiation Evasion” criterion, algorithm performed favorably well when operated to optimize the “Nearest Exit” criterion with no cases of failure reported in any of the simulations.

  17. Fluoroscopy-guided snare retrieval of the celt ACD(®) metallic vascular closure device following failed deployment.

    Science.gov (United States)

    Cahill, Thomas J; Choji, Kiyoshi; Kardos, Attila

    2014-03-01

    We report a case of endovascular snare retrieval of a new stainless steel vascular closure device (Celt ACD(®) , Kimal, Middlesex, UK) from the common femoral artery, following device failure after diagnostic coronary angiography. The stainless steel composition of the device aided successful fluoroscopic localization and removal.

  18. AQP2 exocytosis in the renal collecting duct -- involvement of SNARE isoforms and the regulatory role of Munc18b.

    NARCIS (Netherlands)

    Procino, G.; Barbieri, C.; Tamma, G.; Benedictis, L De; Pessin, J.E.; Svelto, M.; Valenti, G.

    2008-01-01

    Vasopressin regulates the fusion of the water channel aquaporin 2 (AQP2) to the apical membrane of the renal collecting-duct principal cells and several lines of evidence indicate that SNARE proteins mediate this process. In this work MCD4 renal cells were used to investigate the functional role of

  19. The Structure of the Synaptic Vesicle-Plasma Membrane Interface Constrains SNARE Models of Rapid, Synchronous Exocytosis at Nerve Terminals

    Science.gov (United States)

    Gundersen, Cameron B.

    2017-01-01

    Contemporary models of neurotransmitter release invoke direct or indirect interactions between the Ca2+ sensor, synaptotagmin and the incompletely zippered soluble, N-ethyl-maleimide-sensitive factor attachment protein receptor (SNARE) complex. However, recent electron microscopic (EM) investigations have raised pragmatic issues concerning the mechanism by which SNAREs trigger membrane fusion at nerve terminals. The first issue is related to the finding that the area of contact between a “fully primed” synaptic vesicle and the plasma membrane can exceed 600 nm2. Approximately four-thousands lipid molecules can inhabit this contact zone. Thus, renewed efforts will be needed to explain how the zippering of as few as two SNARE complexes mobilizes these lipids to achieve membrane fusion. The second issue emerges from the finding that “docking filaments” are sandwiched within the area of vesicle-plasma membrane contact. It is challenging to reconcile the location of these filaments with SNARE models of exocytosis. Instead, this commentary outlines how these data are more compatible with a model in which a cluster of synaptotagmins catalyzes exocytotic membrane fusion. PMID:28280457

  20. AQP2 exocytosis in the renal collecting duct – involvement of SNARE isoforms and the regulatory role of Munc18b

    Science.gov (United States)

    Procino, Giuseppe; Barbieri, Claudia; Tamma, Grazia; De Benedictis, Leonarda; Pessin, Jeffrey E.; Svelto, Maria; Valenti, Giovanna

    2015-01-01

    Summary Vasopressin regulates the fusion of the water channel aquaporin 2 (AQP2) to the apical membrane of the renal collecting-duct principal cells and several lines of evidence indicate that SNARE proteins mediate this process. In this work MCD4 renal cells were used to investigate the functional role of a set of Q- and R-SNAREs, together with that of Munc18b as a negative regulator of the formation of the SNARE complex. Both VAMP2 and VAMP3 were associated with immunoisolated AQP2 vesicles, whereas syntaxin 3 (Stx3), SNAP23 and Munc18 were associated with the apical plasma membrane. Co-immunoprecipitation experiments indicated that Stx3 forms complexes with VAMP2, VAMP3, SNAP23 and Munc18b. Protein knockdown coupled to apical surface biotinylation demonstrated that reduced levels of the R-SNAREs VAMP2 and VAMP3, and the Q-SNAREs Stx3 and SNAP23 strongly inhibited AQP2 fusion at the apical membrane. In addition, knockdown of Munc18b promoted a sevenfold increase of AQP2 fused at the plasma membrane without forskolin stimulation. Taken together these findings propose VAMP2, VAMP3, Stx3 and SNAP23 as the complementary set of SNAREs responsible for AQP2-vesicle fusion into the apical membrane, and Munc18b as a negative regulator of SNARE-complex formation in renal collecting-duct principal cells. PMID:18505797

  1. Expression and subcellular localization of the Qa-SNARE syntaxin17 in human eosinophils

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Lívia A.S.; Dias, Felipe F.; Malta, Kássia K.; Amaral, Kátia B. [Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG (Brazil); Shamri, Revital; Weller, Peter F. [Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (United States); Melo, Rossana C.N., E-mail: rossana.melo@ufjf.edu.br [Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG (Brazil); Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (United States)

    2015-10-01

    Background: SNARE members mediate membrane fusion during intracellular trafficking underlying innate and adaptive immune responses by different cells. However, little is known about the expression and function of these proteins in human eosinophils, cells involved in allergic, inflammatory and immunoregulatory responses. Here, we investigate the expression and distribution of the Qa-SNARE syntaxin17 (STX17) within human eosinophils isolated from the peripheral blood. Methods: Flow cytometry and a pre-embedding immunonanogold electron microscopy (EM) technique that combines optimal epitope preservation and secondary Fab-fragments of antibodies linked to 1.4 nm gold particles for optimal access to microdomains, were used to investigate STX17. Results: STX17 was detected within unstimulated eosinophils. Immunogold EM revealed STX17 on secretory granules and on granule-derived vesiculotubular transport carriers (Eosinophil Sombrero Vesicles-EoSVs). Quantitative EM analyses showed that 77.7% of the granules were positive for STX17 with a mean±SEM of 3.9±0.2 gold particles/granule. Labeling was present on both granule outer membranes and matrices while EoSVs showed clear membrane-associated labeling. STX17 was also present in secretory granules in eosinophils stimulated with the cytokine tumor necrosis factor alpha (TNF-α) or the CC-chemokine ligand 11 CCL11 (eotaxin-1), stimuli that induce eosinophil degranulation. The number of secretory granules labeled for STX17 was significantly higher in CCL11 compared with the unstimulated group. The level of cell labeling did not change when unstimulated cells were compared with TNF-α-stimulated eosinophils. Conclusions: The present study clearly shows by immunanonogold EM that STX17 is localized in eosinophil secretory granules and transport vesicles and might be involved in the transport of granule-derived cargos. - Highlights: • First demonstration of the Qa-SNARE syntaxin-17 (STX17) in human eosinophils. • High

  2. Nasal Physiology

    Science.gov (United States)

    ... Caregivers Contact ARS HOME ANATOMY Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy Skull Base Anatomy Virtual Anatomy Disclosure ... Patient Education About this Website Font Size + - Home > ANATOMY > Nasal Physiology Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy ...

  3. The SNARE VAMP7 Regulates Exocytic Trafficking of Interleukin-12 in Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Giulia Chiaruttini

    2016-03-01

    Full Text Available Interleukin-12 (IL-12, produced by dendritic cells in response to activation, is central to pathogen eradication and tumor rejection. The trafficking pathways controlling spatial distribution and intracellular transport of IL-12 vesicles to the cell surface are still unknown. Here, we show that intracellular IL-12 localizes in late endocytic vesicles marked by the SNARE VAMP7. Dendritic cells (DCs from VAMP7-deficient mice are partially impaired in the multidirectional release of IL-12. Upon encounter with antigen-specific T cells, IL-12-containing vesicles rapidly redistribute at the immune synapse and release IL-12 in a process entirely dependent on VAMP7 expression. Consistently, acquisition of effector functions is reduced in T cells stimulated by VAMP7-null DCs. These results provide insights into IL-12 intracellular trafficking pathways and show that VAMP7-mediated release of IL-12 at the immune synapse is a mechanism to transmit innate signals to T cells.

  4. Binding of SEC11 indicates its role in SNARE recycling after vesicle fusion and identifies two pathways for vesicular traffic to the plasma membrane.

    Science.gov (United States)

    Karnik, Rucha; Zhang, Ben; Waghmare, Sakharam; Aderhold, Christin; Grefen, Christopher; Blatt, Michael R

    2015-03-01

    SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins drive vesicle fusion in all eukaryotes and contribute to homeostasis, pathogen defense, cell expansion, and growth in plants. Two homologous SNAREs, SYP121 (=SYR1/PEN1) and SYP122, dominate secretory traffic to the Arabidopsis thaliana plasma membrane. Although these proteins overlap functionally, differences between SYP121 and SYP122 have surfaced, suggesting that they mark two discrete pathways for vesicular traffic. The SNAREs share primary cognate partners, which has made separating their respective control mechanisms difficult. Here, we show that the regulatory protein SEC11 (=KEULE) binds selectively with SYP121 to affect secretory traffic mediated by this SNARE. SEC11 rescued traffic block by dominant-negative (inhibitory) fragments of both SNAREs, but only in plants expressing the native SYP121. Traffic and its rescue were sensitive to mutations affecting SEC11 interaction with the N terminus of SYP121. Furthermore, the domain of SEC11 that bound the SYP121 N terminus was itself able to block secretory traffic in the wild type and syp122 but not in syp121 mutant Arabidopsis. Thus, SEC11 binds and selectively regulates secretory traffic mediated by SYP121 and is important for recycling of the SNARE and its cognate partners.

  5. Application of a snare technique in retrograde chronic total occlusion percutaneous coronary intervention - a step by step practical approach and an observational study.

    Science.gov (United States)

    Fang, Hsiu-Yu; Lee, Wei-Chieh; Fang, Chih-Yuan; Wu, Chiung-Jen

    2016-10-01

    Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has recently become popular among interventional cardiologists. CTO originating from the ostium has been one of the most difficult CTO lesions to treat with PCI for a number of reasons. Our aim was to illustrate a specific technique during retrograde CTO PCI referred to as the "snare technique."We retrospectively examined the use of "snare technique" among 371 consecutive retrograde CTO PCIs performed at our institution between 2006 and 2015."Snare technique" was used in 10 patients among the 371 retrograde CTO PCIs. The baseline clinical and angiographic characteristics of patients with or without "snare technique" were similar. The "snare technique" group had significantly fewer side branches at occlusion (30.0% vs 71.2%, P = 0.01) and a higher incidence of externalization (90% vs 25.5%, P technique" group (285.0 ± 68.5 vs 379.2 ± 144.0, P = 0.04). The incidence of major complications, retrograde success, or final success did not differ between the groups.The "snare technique" is safe and feasible in retrograde CTO PCI, especially in cases of difficult coronary engagement in cases such as ostial occlusion, challenging coronary anatomy, or retrograde guidewire cannot get in antegrade guiding catheter.

  6. Heterogeneous expression of SNARE proteins SNAP-23, SNAP-25, Syntaxin1 and VAMP in human parathyroid tissue.

    Science.gov (United States)

    Lu, Ming; Forsberg, Lars; Höög, Anders; Juhlin, Christofer C; Vukojević, Vladana; Larsson, Catharina; Conigrave, Arthur D; Delbridge, Leigh W; Gill, Anthony; Bark, Christina; Farnebo, Lars-Ove; Bränström, Robert

    2008-06-11

    In regulated exocytosis synaptosomal-associated protein of 25kDa (SNAP-25) is one of the key-players in the formation of SNARE (soluble N-ethylmaleimide-sensitive fusion attachment protein receptor) complex and membrane fusion. SNARE proteins are essentially expressed in neurons, neuroendocrine and endocrine cells. Whether parathyroid cells express these proteins is not known. In this study, we have examined the expression of the SNARE protein SNAP-25 and its cellular homologue SNAP-23, as well as syntaxin1 and VAMP (vesicle-associated membrane protein) in samples of normal parathyroid tissue, chief cell adenoma, and parathyroid carcinoma, using immunohistochemistry and Western blot analysis. SNAP-23 and VAMP were evenly expressed in all studied parathyroid tissues using immunohistochemistry and/or Western blot analysis. SNAP-25 (and Syntaxin1) was not expressed in normal parathyroid tissue, but in approximately 20% of chief cell adenomas, and in approximately 45% of parathyroid carcinoma samples. It is likely that the SNARE proteins SNAP-23 and VAMP play a role in the stimulus-secretion coupling and exocytosis of parathyroid hormone as these proteins were expressed in all of the parathyroid samples we studied. In particular, preferential expression of SNAP-23 rather than SNAP-25 provides an explanation of the high level of PTH secretion that occurs under conditions of low cytoplasmic free Ca(2+) concentration (around 0.1micromol/l). SNAP-25 (and Syntaxin1) appears to be a tumour-specific protein(s) in parathyroid tissues since its expression was restricted to pathological tissues.

  7. Equatorin is not essential for acrosome biogenesis but is required for the acrosome reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Jianxiu [State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Chen, Min [State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Ji, Shaoyang; Wang, Xiaona; Wang, Yanbo [State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Huang, Xingxu [MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center of Nanjing University, Nanjing Biomedical Research Institute, National Resource Center for Mutant Mice, Nanjing 210061 (China); Yang, Lin; Wang, Yaqing [State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101 (China); Cui, Xiuhong; Lv, Limin [State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Liu, Yixun, E-mail: liuyx@ioz.ac.cn [State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Gao, Fei, E-mail: gaof@ioz.ac.cn [State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

    2014-02-21

    Highlights: • Eqtn knockout mice were used for these experiments. • In vivo and in vitro fertilization analyses were performed. • Eqtn-deficient sperm were evaluated by transmission electron microscopy (TEM) and an A23187-induced acrosome reaction (AR) assay. • Co-immunoprecipitation (Co-IP) was performed to assess the interaction between Eqtn and the SNARE complex. - Abstract: The acrosome is a specialized organelle that covers the anterior part of the sperm nucleus and plays an essential role in mammalian fertilization. However, the regulatory mechanisms controlling acrosome biogenesis and acrosome exocytosis during fertilization are largely unknown. Equatorin (Eqtn) is a membrane protein that is specifically localized to the acrosomal membrane. In the present study, the physiological functions of Eqtn were investigated using a gene knockout mouse model. We found that Eqtn{sup −/−} males were subfertile. Only approximately 50% of plugged females were pregnant after mating with Eqtn{sup −/−} males, whereas more than 90% of plugged females were pregnant after mating with control males. Sperm and acrosomes from Eqtn{sup −/−} mice presented normal motility and morphology. However, the fertilization and induced acrosome exocytosis rates of Eqtn-deficient sperm were dramatically reduced. Further studies revealed that the Eqtn protein might interact with Syntaxin1a and SNAP25, but loss of Eqtn did not affect the protein levels of these genes. Therefore, our study demonstrates that Eqtn is not essential for acrosome biogenesis but is required for the acrosome reaction. Eqtn is involved in the fusion of the outer acrosomal membrane and the sperm plasma membrane during the acrosome reaction, most likely via an interaction with the SNARE complex.

  8. A SNARE-like superfamily protein SbSLSP from the halophyte Salicornia brachiata confers salt and drought tolerance by maintaining membrane stability, K+/Na+ ratio, and antioxidant machinery

    Directory of Open Access Journals (Sweden)

    Dinkar eSingh

    2016-06-01

    Full Text Available About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP, (Salicornia brachiata SNARE-like superfamily protein showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterised proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localisation studies indicated that the SbSLSP protein is mainly localised in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na+ ion and reactive oxygen species (ROS. Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signalling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

  9. A SNARE-Like Superfamily Protein SbSLSP from the Halophyte Salicornia brachiata Confers Salt and Drought Tolerance by Maintaining Membrane Stability, K(+)/Na(+) Ratio, and Antioxidant Machinery.

    Science.gov (United States)

    Singh, Dinkar; Yadav, Narendra Singh; Tiwari, Vivekanand; Agarwal, Pradeep K; Jha, Bhavanath

    2016-01-01

    About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na(+) ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

  10. A SNARE-Like Superfamily Protein SbSLSP from the Halophyte Salicornia brachiata Confers Salt and Drought Tolerance by Maintaining Membrane Stability, K+/Na+ Ratio, and Antioxidant Machinery

    Science.gov (United States)

    Singh, Dinkar; Yadav, Narendra Singh; Tiwari, Vivekanand; Agarwal, Pradeep K.; Jha, Bhavanath

    2016-01-01

    About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na+ ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil. PMID:27313584

  11. Application of a snare technique in retrograde chronic total occlusion percutaneous coronary intervention – a step by step practical approach and an observational study

    Science.gov (United States)

    Fang, Hsiu-Yu; Lee, Wei-Chieh; Fang, Chih-Yuan; Wu, Chiung-Jen

    2016-01-01

    Abstract Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has recently become popular among interventional cardiologists. CTO originating from the ostium has been one of the most difficult CTO lesions to treat with PCI for a number of reasons. Our aim was to illustrate a specific technique during retrograde CTO PCI referred to as the “snare technique.” We retrospectively examined the use of “snare technique” among 371 consecutive retrograde CTO PCIs performed at our institution between 2006 and 2015. “Snare technique” was used in 10 patients among the 371 retrograde CTO PCIs. The baseline clinical and angiographic characteristics of patients with or without “snare technique” were similar. The “snare technique” group had significantly fewer side branches at occlusion (30.0% vs 71.2%, P = 0.01) and a higher incidence of externalization (90% vs 25.5%, P CTO PCI, especially in cases of difficult coronary engagement in cases such as ostial occlusion, challenging coronary anatomy, or retrograde guidewire cannot get in antegrade guiding catheter. PMID:27741138

  12. Plin2 inhibits cellular glucose uptake through interactions with SNAP23, a SNARE complex protein.

    Directory of Open Access Journals (Sweden)

    Subramanian Senthivinayagam

    Full Text Available Although a link between excess lipid storage and aberrant glucose metabolism has been recognized for many years, little is known what role lipid storage droplets and associated proteins such as Plin2 play in managing cellular glucose levels. To address this issue, the influence of Plin2 on glucose uptake was examined using 2-NBD-Glucose and [(3H]-2-deoxyglucose to show that insulin-mediated glucose uptake was decreased 1.7- and 1.8-fold, respectively in L cell fibroblasts overexpressing Plin2. Conversely, suppression of Plin2 levels by RNAi-mediated knockdown increased 2-NBD-Glucose uptake several fold in transfected L cells and differentiated 3T3-L1 cells. The effect of Plin2 expression on proteins involved in glucose uptake and transport was also examined. Expression of the SNARE protein SNAP23 was increased 1.6-fold while levels of syntaxin-5 were decreased 1.7-fold in Plin2 overexpression cells with no significant changes observed in lipid droplet associated proteins Plin1 or FSP27 or with the insulin receptor, GLUT1, or VAMP4. FRET experiments revealed a close proximity of Plin2 to SNAP23 on lipid droplets to within an intramolecular distance of 51 Å. The extent of targeting of SNAP23 to lipid droplets was determined by co-localization and co-immunoprecipitation experiments to show increased partitioning of SNAP23 to lipid droplets when Plin2 was overexpressed. Taken together, these results suggest that Plin2 inhibits glucose uptake by interacting with, and regulating cellular targeting of SNAP23 to lipid droplets. In summary, the current study for the first time provides direct evidence for the role of Plin2 in mediating cellular glucose uptake.

  13. Incomplete resection rate of cold snare polypectomy: a prospective single-arm observational study.

    Science.gov (United States)

    Matsuura, Noriko; Takeuchi, Yoji; Yamashina, Takeshi; Ito, Takashi; Aoi, Kenji; Nagai, Kengo; Kanesaka, Takashi; Matsui, Fumi; Fujii, Mototsugu; Akasaka, Tomofumi; Hanaoka, Noboru; Higashino, Koji; Tomita, Yasuhiko; Ito, Yuri; Ishihara, Ryu; Iishi, Hiroyasu; Uedo, Noriya

    2017-03-01

    Background and study aims Cold snare polypectomy (CSP) is considered to be safe for the removal of subcentimeter colorectal polyps. This study aimed to determine the rate of incomplete CSP resection for subcentimeter neoplastic polyps at our center. Patients and methods Patients with small or diminutive adenomas (diameter 1 - 9 mm) were recruited to undergo CSP until no polyp was visible. After CSP, a 1 - 3 mm margin around the resection site was removed using endoscopic mucosal resection. The polyps and resection site marginal specimens were microscopically evaluated. Incomplete resection was defined as the presence of neoplastic tissue in the marginal specimen. We also calculated the frequency at which the polyp lateral margins could be assessed for completeness of resection. Results A total of 307 subcentimeter neoplastic polyps were removed from 120 patients. The incomplete resection rate was 3.9 % (95 % confidence interval [CI] 1.7 % - 6.1 %); incomplete resection was not associated with polyp size, location, morphology, or operator experience. The polyp lateral margins could not be assessed adequately for 206 polyps (67.1 %). Interobserver agreement between incomplete resection and lateral polyp margins that were inadequate for assessment was poor (κ = 0.029, 95 %CI 0 - 0.04). Female sex was an independent risk factor for incomplete resection (odds ratio 4.41, 95 %CI 1.26 - 15.48; P  = 0.02). Conclusions At our center, CSP resection was associated with a moderate rate of incomplete resection, which was not associated with polyp characteristics. However, adequate evaluation of resection may not be routinely possible using the lateral margin from subcentimeter polyps that were removed using CSP.Trial registered at University Hospital Medical Information Network (UMIN 000010879).

  14. Transurethral exchange of double-J ureteral stent using goose- neck snare

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Chang Ho; Kim, Yun Hwan; Cho, Sung Bum; Kim, Chul Joong; Kim, Hyoung Rae; Kim, Hong Weon; Suh, Won Hyuck [College of Medicine, Korea University, Seoul (Korea, Republic of); Cho, Sung Bum [Eulji Hospital, Eulji College of Medicine, Taejon (Korea, Republic of)

    2000-09-01

    To evaluate the usefulness of transurethral exchange of double-J ureteral stent as an effective alternative to the cystoscopic approach. There were 20 exchange cases involving seven patients (six women and one man) who initially underwent anterograde manipulation of a double-J ureteral stent. Indications for stent placement were ureteral stricture caused by malignancy in six patients (cervical carcinoma (n=3D5), stomach carcinoma (n=3D1)), and renal tuberculosis in one. An 8-F Nelaton catheter was inserted in the bladder via the urethra and contrast material was injected until the bladder was fully distended. The distal end of a double-J ureteral stent was extracted to the urethral orifice using a goose-neck snare and a 0.035{sup s}tiff guide wire was then advanced to the renal pelvis through the stent. After that, the stent was removed and a 4-F Cobra catheter was advanced to the renal pelvis along the guide wire. Contrast material was injected through the catheter, and the renal pelvis, calyx and ureter were opacified. The 0.035 stiff guide wire was again inserted via the catheter, and a new double-J ureteral stent was inserted, and the catheter removed. Finally, the new double-J stent was properly located within the renal pelvis and the bladder. Double-J ureteral stents were successfully exchanged in 19 of 20 exchange cases. After the procedure, all patients reported tolerable, minimal lower abdominal pain. Transurethral exchange of double-J ureteral stent is a useful alternative to cystoscopy. (author)

  15. A SNARE-Like Protein and Biotin Are Implicated in Soybean Cyst Nematode Virulence.

    Directory of Open Access Journals (Sweden)

    Sadia Bekal

    Full Text Available Phytoparasitic nematodes that are able to infect and reproduce on plants that are considered resistant are referred to as virulent. The mechanism(s that virulent nematodes employ to evade or suppress host plant defenses are not well understood. Here we report the use of a genetic strategy (allelic imbalance analysis to associate single nucleotide polymorphisms (SNPs with nematode virulence genes in Heterodera glycines, the soybean cyst nematode (SCN. To accomplish this analysis, a custom SCN SNP array was developed and used to genotype SCN F3-derived populations grown on resistant and susceptible soybean plants. Three SNPs reproducibly showed allele imbalances between nematodes grown on resistant and susceptible plants. Two candidate SCN virulence genes that were tightly linked to the SNPs were identified. One SCN gene encoded biotin synthase (HgBioB, and the other encoded a bacterial-like protein containing a putative SNARE domain (HgSLP-1. The two genes mapped to two different linkage groups. HgBioB contained sequence polymorphisms between avirulent and virulent nematodes. However, the gene encoding HgSLP-1 had reduced copy number in virulent nematode populations and appears to produce multiple forms of the protein via intron retention and alternative splicing. We show that HgSLP-1 is an esophageal-gland protein that is secreted by the nematode during plant parasitism. Furthermore, in bacterial co-expression experiments, HgSLP-1 co-purified with the SCN resistance protein Rhg1 α-SNAP, suggesting that these two proteins physically interact. Collectively our data suggest that multiple SCN genes are involved in SCN virulence, and that HgSLP-1 may function as an avirulence protein and when absent it helps SCN evade host defenses.

  16. TaSYP71, a Qc-SNARE, Contributes to Wheat Resistance against Puccinia striiformis f. sp. tritici

    Directory of Open Access Journals (Sweden)

    Minjie eLiu

    2016-04-01

    Full Text Available N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs are involved in plant resistance; however, the role of SYP71 in the regulation of plant–pathogen interactions is not well known. In this study, we characterized a plant-specific SNARE in wheat, TaSYP71, which contains a Qc-SNARE domain. Three homologues are localized on chromosome 1AL, 1BL and 1DL. Using Agrobacterium-mediated transient expression, TaSYP71 was localized to the plasma membrane in Nicotiana benthamiana. Quantitative real-time PCR assays revealed that TaSYP71 homologues was induced by NaCl, H2O2 stress and infection by virulent and avirulent Puccinia striiformis f. sp. tritici (Pst isolates. Heterologous expression of TaSYP71 in Schizosaccharomyces pombe elevated tolerance to H2O2. Meanwhile, H2O2 scavenging gene (TaCAT was downregulated in TaSYP71 silenced plants treated by H2O2 compared to that in control, which indicated that TaSYP71 enhanced tolerance to H2O2 stress possibly by influencing the expression of TaCAT to remove the excessive H2O2 accumulation. When TaSYP71 homologues were all silenced in wheat by the virus-induced gene silencing system, wheat plants were more susceptible to Pst, with larger infection area and more haustoria number, but the necrotic area of wheat mesophyll cells were larger, one possible explanation that minor contribution of resistance to Pst was insufficient to hinder pathogen extension when TaSYP71were silenced, and the necrotic area was enlarged accompanied with the pathogen growth. Of course, later cell death could not be excluded. In addition, the expression of pathogenesis-related genes were down-regulated in TaSYP71 silenced wheat plants. These results together suggest that TaSYP71 play a positive role in wheat defence against Pst.

  17. Proteomics of photoreceptor outer segments identifies a subset of SNARE and Rab proteins implicated in membrane vesicle trafficking and fusion.

    Science.gov (United States)

    Kwok, Michael C M; Holopainen, Juha M; Molday, Laurie L; Foster, Leonard J; Molday, Robert S

    2008-06-01

    The outer segment is a specialized compartment of vertebrate rod and cone photoreceptor cells where phototransduction takes place. In rod cells it consists of an organized stack of disks enclosed by a separate plasma membrane. Although most proteins involved in phototransduction have been identified and characterized, little is known about the proteins that are responsible for outer segment structure and renewal. In this study we used a tandem mass spectrometry-based proteomics approach to identify proteins in rod outer segment preparations as an initial step in defining their roles in photoreceptor structure, function, renewal, and degeneration. Five hundred and sixteen proteins were identified including 41 proteins that function in rod and cone phototransduction and the visual cycle and most proteins previously shown to be involved in outer segment structure and metabolic pathways. In addition, numerous proteins were detected that have not been previously reported to be present in outer segments including a subset of Rab and SNARE proteins implicated in vesicle trafficking and membrane fusion. Western blotting and immunofluorescence microscopy confirmed the presence of Rab 11b, Rab 18, Rab 1b, and Rab GDP dissociation inhibitor in outer segments. The SNARE proteins, VAMP2/3, syntaxin 3, N-ethylmaleimide-sensitive factor, and Munc 18 detected in outer segment preparations by mass spectrometry and Western blotting were also observed in outer segments by immunofluorescence microscopy. Syntaxin 3 and N-ethylmaleimide- sensitive factor had a restricted localization at the base of the outer segments, whereas VAMP2/3 and Munc 18 were distributed throughout the outer segments. These results suggest that Rab and SNARE proteins play a role in vesicle trafficking and membrane fusion as part of the outer segment renewal process. The data set generated in this study is a valuable resource for further analysis of photoreceptor outer segment structure and function.

  18. Three new techniques for creation of a steerable sheath, a 4F snare, and bidirectional sheath inversion using existing endovascular materials.

    Science.gov (United States)

    Mallios, Alexandros; Yankovic, Willy; Boura, Benoit; Combes, Myriam

    2012-09-01

    We present three novel techniques for creation of (1) a steerable sheath, (2) a 4F snare device, and (3) dual anterograde and retrograde double-wire percutaneous transluminal angioplasty access technique using a single femoral puncture. These techniques were conceived and bench-tested in our institution, allowing the utilization of inexpensive equipment for complicated endovascular procedures. They offer (1) controlled navigation, no-touch vessel cannulation and cannulation of angulated vessels, contralateral limb of stent grafts, fenestrations, and branches; (2) a low-profile (4F external diameter) modifiable snare with the ability to expand to the size of an entire aneurysm and the ability to undo the snare in case of blockage with other endovascular material; and (3) in situ sheath inversion for concomitant anterograde and retrograde percutaneous angioplasty with a single femoral puncture.

  19. Physiological Networks: towards systems physiology

    Science.gov (United States)

    Bartsch, Ronny P.; Bashan, Amir; Kantelhardt, Jan W.; Havlin, Shlomo; Ivanov, Plamen Ch.

    2012-02-01

    The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate new dimensions to the field of systems physiology.

  20. Convolutional Neural Networks with Batch Normalization for Classifying Hi-hat, Snare, and Bass Percussion Sound Samples

    DEFF Research Database (Denmark)

    Gajhede, Nicolai; Beck, Oliver; Purwins, Hendrik

    2016-01-01

    After having revolutionized image and speech processing, convolu- tional neural networks (CNN) are now starting to become more and more successful in music information retrieval as well. We compare four CNN types for classifying a dataset of more than 3000 acoustic and synthesized samples...... of the most prominent drum set instru- ments (bass, snare, hi-hat). We use the Mel scale log magnitudes (MLS) as a representation for the input of the CNN. We compare the classification results of 1) a CNN (3 conv/max-pool layers and 2 fully connected layers) without drop-out and batch normalization vs. three...

  1. Functional Interaction of the SNARE Protein NtSyp121 in Ca2+ Channel Gating,Ca2+ Transients and ABA Signalling of Stomatal Guard Cells

    Institute of Scientific and Technical Information of China (English)

    Sergei Sokolovski; Adrian Hills; Robert A.Gay; Michael R.Blatt

    2008-01-01

    There is now growing evidence that membrane vesicle trafficking proteins,especially of the superfamily of SNAREs,are critical for cellular signalling in plants.Work from this laboratory first demonstrated that a soluble,inhibitory (dominant-negative) fragment of the SNARE NtSyp121 blocked K+ and Cl- channel responses to the stress-related hormone abscisic acid (ABA),but left open a question about functional impacts on signal intermediates,especially on Ca2+-mediated signalling events.Here,we report one mode of action for the SNARE mediated directly through alterations in Caz+ channel gating and its consequent effects on cytosolic-free [Ca2+] ([Ca2+]i) elevation.We find that expressing the same inhibitory fragment of NtSyp121 blocks ABA-evoked stomatal closure,but only partially suppresses stomatal closure in the presence of the NO donor,SNAP,which promotes [Ca2+]i elevation independently of the plasma membrane Ca2+ channels.Consistent with these observations,Ca2+ channel gating at the plasma membrane is altered by the SNARE fragment in a manner effective in reducing the potential for triggering a rise in [Ca2+]i,and we show directly that its expression in vivo leads to a pronounced suppression of evoked [Ca2+]i transients.These observations offer primary evidence for the functional coupling of the SNARE with Ca2+ channels at the plant cell plasma membrane and,because [Ca2+]i plays a key role in the control of K+ and Cl- channel currents in guard cells,they underscore an important mechanism for SNARE integration with ion channel regulation during stomatal closure.

  2. The Qb-SNARE Memb11 interacts specifically with Arf1 in the Golgi apparatus of Arabidopsis thaliana.

    Science.gov (United States)

    Marais, Claireline; Wattelet-Boyer, Valérie; Bouyssou, Guillaume; Hocquellet, Agnès; Dupuy, Jean-William; Batailler, Brigitte; Brocard, Lysiane; Boutté, Yohann; Maneta-Peyret, Lilly; Moreau, Patrick

    2015-11-01

    The SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins are critical for the function of the secretory pathway. The SNARE Memb11 is involved in membrane trafficking at the ER-Golgi interface. The aim of the work was to decipher molecular mechanisms acting in Memb11-mediated ER-Golgi traffic. In mammalian cells, the orthologue of Memb11 (membrin) is potentially involved in the recruitment of the GTPase Arf1 at the Golgi membrane. However molecular mechanisms associated to Memb11 remain unknown in plants. Memb11 was detected mainly at the cis-Golgi and co-immunoprecipitated with Arf1, suggesting that Arf1 may interact with Memb11. This interaction of Memb11 with Arf1 at the Golgi was confirmed by in vivo BiFC (Bimolecular Fluorescence Complementation) experiments. This interaction was found to be specific to Memb11 as compared to either Memb12 or Sec22. Using a structural bioinformatic approach, several sequences in the N-ter part of Memb11 were hypothesized to be critical for this interaction and were tested by BiFC on corresponding mutants. Finally, by using both in vitro and in vivo approaches, we determined that only the GDP-bound form of Arf1 interacts with Memb11. Together, our results indicate that Memb11 interacts with the GDP-bound form of Arf1 in the Golgi apparatus.

  3. Inhibition of Calpains Protects Mn-Induced Neurotransmitter release disorders in Synaptosomes from Mice: Involvement of SNARE Complex and Synaptic Vesicle Fusion.

    Science.gov (United States)

    Wang, Can; Xu, Bin; Ma, Zhuo; Liu, Chang; Deng, Yu; Liu, Wei; Xu, Zhao-Fa

    2017-06-16

    Overexposure to manganese (Mn) could disrupt neurotransmitter release via influencing the formation of SNARE complex, but the underlying mechanisms are still unclear. A previous study demonstrated that SNAP-25 is one of substrate of calpains. The current study investigated whether calpains were involved in Mn-induced disorder of SNARE complex. After mice were treated with Mn for 24 days, Mn deposition increased significantly in basal nuclei in Mn-treated and calpeptin pre-treated groups. Behaviorally, less time spent in the center of the area and decreased average velocity significantly in an open field test after 24 days of Mn exposure. With the increase in MnCl2 dosage, intracellular Ca(2+) increased significantly, but pretreatment with calpeptin caused a dose-dependent decrease in calpains activity. There were fragments of N-terminal of SNAP-25 protein appearance in Mn-treated groups, but it is decreased with pretreatment of calpeptin. FM1-43-labeled synaptic vesicles also provided evidence that the treatment with Mn resulted in increasing first and then decreasing, which was consistent with Glu release and the 80 kDa protein levels of SNARE complexes. In summary, Mn induced the disorder of neurotransmitter release through influencing the formation of SNARE complex via cleaving SNAP-25 by overactivation of calpains in vivo.

  4. Mathematical physiology

    CERN Document Server

    Sneyd, James

    2009-01-01

    There has been a long history of interaction between mathematics and physiology. This book looks in detail at a wide selection of mathematical models in physiology, showing how physiological problems can be formulated and studied mathematically, and how such models give rise to interesting and challenging mathematical questions. With its coverage of many recent models it gives an overview of the field, while many older models are also discussed, to put the modern work in context. In this second edition the coverage of basic principles has been expanded to include such topics as stochastic differential equations, Markov models and Gibbs free energy, and the selection of models has also been expanded to include some of the basic models of fluid transport, respiration/perfusion, blood diseases, molecular motors, smooth muscle, neuroendrocine cells, the baroreceptor loop, turboglomerular oscillations, blood clotting and the retina. Owing to this extensive coverage, the second edition is published in two volumes. ...

  5. Reproductive physiology

    Science.gov (United States)

    Gee, G.F.; Russman, S.E.; Ellis, David H.; Gee, George F.; Mirande, Claire M.

    1996-01-01

    Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

  6. Exercise physiology

    DEFF Research Database (Denmark)

    Kiens, Bente; Richter, Erik; Wojtaszewski, Jørgen

    2014-01-01

    The passing of Professor Bengt Saltin on September 12, 2014 truly marks the end of an era. As editor of the Journal of Applied Physiology and one of Bengt’s many collaborators and colleagues, I wanted the Journal to celebrate his many seminal contributions by means of an Editorial. Professor Bent...

  7. Paracrine intercellular communication by a Ca2+- and SNARE-independent release of GABA and glutamate prior to synapse formation.

    Science.gov (United States)

    Demarque, Michael; Represa, Alfonso; Becq, Hélène; Khalilov, Ilgam; Ben-Ari, Yehezkel; Aniksztejn, Laurent

    2002-12-19

    GABA and glutamate receptors are expressed in immature "silent" CA1 pyramidal neurons prior to synapse formation, but their function is unknown. We now report the presence of tonic, spontaneous, and evoked currents in embryonic and neonatal CA1 neurons mediated primarily by the activation of GABA(A) receptors. These currents are mediated by a nonconventional release of transmitters, as they persist in the presence of calcium channel blockers or botulinium toxin and are observed in Munc18-1-deficient mice in which vesicular release is abolished. This paracrine communication is modulated by glutamate but not GABA transporters, which do not operate during this period of life. Thus, a Ca(2+)- and SNARE-independent release of transmitters underlies a paracrine mode of communication before synapse formation.

  8. Laryngeal snaring by ingested fishing net in a common bottlenose dolphin (Tursiops truncatus) off the Israeli shoreline.

    Science.gov (United States)

    Levy, Alon M; Brenner, Ori; Scheinin, Aviad; Morick, Dan; Ratner, Eliana; Goffman, Oz; Kerem, Dan

    2009-07-01

    We report an unusual snaring of the larynx in an adult, female common bottlenose dolphin (Tursiops truncatus). The dolphin was observed swimming and diving in Haifa Port, Israel, but was found dead the next day, 60 km south, on the coast. Postmortem examination revealed stranded-cordage, nylon filaments wrapped around the larynx, cutting through the soft tissue, and extending down into the forestomach, where a large mass of netting was found. The cachectic state of the dolphin and the subacute to chronic, hyper-plastic response of soft tissue surrounding the filaments lodged around the larynx, suggest a prolonged period of starvation, which led to the final weakness and wasting of the dolphin.

  9. Occupational physiology

    CERN Document Server

    Toomingas, Allan; Tornqvist, Ewa Wigaeus

    2011-01-01

    In a clear and accessible presentation, Occupational Physiology focuses on important issues in the modern working world. Exploring major public health problems-such as musculoskeletal disorders and stress-this book explains connections between work, well-being, and health based on up-to-date research in the field. It provides useful methods for risk assessment and guidelines on arranging a good working life from the perspective of the working individual, the company, and society as a whole.The book focuses on common, stressful situations in different professions. Reviewing bodily demands and r

  10. Chromatographic purification of an insoluble histidine tag recombinant Ykt6p SNARE from Arabidopsis thaliana over-expressed in E. coli.

    Science.gov (United States)

    Vincent, Patrick; Dieryck, Wilfrid; Maneta-Peyret, Lilly; Moreau, Patrick; Cassagne, Claude; Santarelli, Xavier

    2004-08-25

    In order to undertake in plant cell the study of the endoplasmic reticulum (ER)-Golgi apparatus (GA) protein and/or lipid vesicular transport pathway, expressed sequence tag (EST) coding for a homologue to the yeast soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) Ykt6p has been cloned in Arabidopsis thaliana by reverse transcription polymerase chain reaction (RT-PCR). The corresponding protein was over-expressed as a recombinant histidine-tag (his-tag) protein in E. coli. Starting from one litter of culture, an ultrasonic homogenization was performed for cell disruption and after centrifugation the Arabidopsis Ykt6p SNARE present in inclusion bodies in the pellet was solubilized. After centrifugation, the clarified feedstock obtained was injected onto an immobilized metal affinity chromatography (IMAC) in presence of 6 M guanidine and on-column refolding was performed. Folded and subsequently purified (94% purity) recombinant protein was obtained with 82% of recovery.

  11. Advances in X-ray free electron laser (XFEL) diffraction data processing applied to the crystal structure of the synaptotagmin-1 / SNARE complex.

    Science.gov (United States)

    Lyubimov, Artem Y; Uervirojnangkoorn, Monarin; Zeldin, Oliver B; Zhou, Qiangjun; Zhao, Minglei; Brewster, Aaron S; Michels-Clark, Tara; Holton, James M; Sauter, Nicholas K; Weis, William I; Brunger, Axel T

    2016-10-12

    X-ray free electron lasers (XFELs) reduce the effects of radiation damage on macromolecular diffraction data and thereby extend the limiting resolution. Previously, we adapted classical post-refinement techniques to XFEL diffraction data to produce accurate diffraction data sets from a limited number of diffraction images (Uervirojnangkoorn et al., 2015), and went on to use these techniques to obtain a complete data set from crystals of the synaptotagmin-1 / SNARE complex and to determine the structure at 3.5 Å resolution (Zhou et al., 2015). Here, we describe new advances in our methods and present a reprocessed XFEL data set of the synaptotagmin-1 / SNARE complex. The reprocessing produced small improvements in electron density maps and the refined atomic model. The maps also contained more information than those of a lower resolution (4.1 Å) synchrotron data set. Processing a set of simulated XFEL diffraction images revealed that our methods yield accurate data and atomic models.

  12. Lysophosphatidylinositol-acyltransferase-1 (LPIAT1 is required to maintain physiological levels of PtdIns and PtdInsP(2 in the mouse.

    Directory of Open Access Journals (Sweden)

    Karen E Anderson

    Full Text Available We disrupted the gene encoding lysophosphatidylinositol-acyltransferase-1 (LPIAT1 in the mouse with the aim of understanding its role in determining cellular phosphoinositide content. LPIAT1(-/- mice were born at lower than Mendelian ratios and exhibited a severe developmental brain defect. We compared the phospholipid content of livers and brains from LPIAT1(-/- and LPIAT1(+/+ littermates by LC-ESI/MS. In accord with previous studies, the most abundant molecular species of each phosphoinositide class (PtdIns, PtdInsP, PtdInsP2 and PtdInsP3 possessed a C38∶4 complement of fatty-acyl esters (C18∶0 and C20∶4 are usually assigned to the sn-1 and sn-2 positions, respectively. LPIAT1(-/- liver and brain contained relatively less of the C38∶4 species of PtdIns, PtdInsP and PtdInsP2 (dropping from 95-97% to 75-85% of the total species measured for each lipid class and relatively more of the less abundant species (PtdInsP3 less abundant species were below our quantification levels. The increases in the less abundant PtdIns and PtdInsP2 species did not compensate for the loss in C38∶4 species, resulting in a 26-44% reduction in total PtdIns and PtdInsP2 levels in both brain and liver. LPIAT1(-/- brain and liver also contained increased levels of C18∶0 lyso-PtdIns (300% and 525% respectively indicating a defect in the reacylation of this molecule. LPIAT1(-/- brain additionally contained significantly reduced C38∶4 PC and PE levels (by 47% and 55% respectively, possibly contributing to the phenotype in this organ. The levels of all other molecular species of PC, PE, PS and PA measured in the brain and liver were very similar between LPIAT1(-/- and LPIAT1(+/+ samples. These results suggest LPIAT1 activity plays a non-redundant role in maintaining physiological levels of PtdIns within an active deacylation/reacylation cycle in mouse tissues. They also suggest that this pathway must act in concert with other, as yet unidentified, mechanisms to

  13. Physiological Acoustics

    Science.gov (United States)

    Young, Eric D.

    The analysis of physiological sound in the peripheral auditory system solves three important problems. First, sound energy impinging on the head must be captured and presented to the transduction apparatus in the ear as a suitable mechanical signal; second, this mechanical signal needs to be transduced into a neural representation that can be used by the brain; third, the resulting neural representation needs to be analyzed by central neurons to extract information useful to the animal. This chapter provides an overview of some aspects of the first two of these processes. The description is entirely focused on the mammalian auditory system, primarily on human hearing and on the hearing of a few commonly used laboratory animals (mainly rodents and carnivores). Useful summaries of non-mammalian hearing are available [1]. Because of the large size of the literature, review papers are referenced wherever possible.

  14. Discovery of the selective androgen receptor modulator MK-0773 using a rational development strategy based on differential transcriptional requirements for androgenic anabolism versus reproductive physiology.

    Science.gov (United States)

    Schmidt, Azriel; Kimmel, Donald B; Bai, Chang; Scafonas, Angela; Rutledge, Sujane; Vogel, Robert L; McElwee-Witmer, Sheila; Chen, Fang; Nantermet, Pascale V; Kasparcova, Viera; Leu, Chih-Tai; Zhang, Hai-Zhuan; Duggan, Mark E; Gentile, Michael A; Hodor, Paul; Pennypacker, Brenda; Masarachia, Patricia; Opas, Evan E; Adamski, Sharon A; Cusick, Tara E; Wang, Jiabing; Mitchell, Helen J; Kim, Yuntae; Prueksaritanont, Thomayant; Perkins, James J; Meissner, Robert S; Hartman, George D; Freedman, Leonard P; Harada, Shun-ichi; Ray, William J

    2010-05-28

    Selective androgen receptor modulators (SARMs) are androgen receptor (AR) ligands that induce anabolism while having reduced effects in reproductive tissues. In various experimental contexts SARMs fully activate, partially activate, or even antagonize the AR, but how these complex activities translate into tissue selectivity is not known. Here, we probed receptor function using >1000 synthetic AR ligands. These compounds produced a spectrum of activities in each assay ranging from 0 to 100% of maximal response. By testing different classes of compounds in ovariectomized rats, we established that ligands that transactivated a model promoter 40-80% of an agonist, recruited the coactivator GRIP-1 <15%, and stabilized the N-/C-terminal interdomain interaction <7% induced bone formation with reduced effects in the uterus and in sebaceous glands. Using these criteria, multiple SARMs were synthesized including MK-0773, a 4-aza-steroid that exhibited tissue selectivity in humans. Thus, AR activated to moderate levels due to reduced cofactor recruitment, and N-/C-terminal interactions produce a fully anabolic response, whereas more complete receptor activation is required for reproductive effects. This bimodal activation provides a molecular basis for the development of SARMs.

  15. Discovery of the Selective Androgen Receptor Modulator MK-0773 Using a Rational Development Strategy Based on Differential Transcriptional Requirements for Androgenic Anabolism Versus Reproductive Physiology*

    Science.gov (United States)

    Schmidt, Azriel; Kimmel, Donald B.; Bai, Chang; Scafonas, Angela; Rutledge, SuJane; Vogel, Robert L.; McElwee-Witmer, Sheila; Chen, Fang; Nantermet, Pascale V.; Kasparcova, Viera; Leu, Chih-tai; Zhang, Hai-Zhuan; Duggan, Mark E.; Gentile, Michael A.; Hodor, Paul; Pennypacker, Brenda; Masarachia, Patricia; Opas, Evan E.; Adamski, Sharon A.; Cusick, Tara E.; Wang, Jiabing; Mitchell, Helen J.; Kim, Yuntae; Prueksaritanont, Thomayant; Perkins, James J.; Meissner, Robert S.; Hartman, George D.; Freedman, Leonard P.; Harada, Shun-ichi; Ray, William J.

    2010-01-01

    Selective androgen receptor modulators (SARMs) are androgen receptor (AR) ligands that induce anabolism while having reduced effects in reproductive tissues. In various experimental contexts SARMs fully activate, partially activate, or even antagonize the AR, but how these complex activities translate into tissue selectivity is not known. Here, we probed receptor function using >1000 synthetic AR ligands. These compounds produced a spectrum of activities in each assay ranging from 0 to 100% of maximal response. By testing different classes of compounds in ovariectomized rats, we established that ligands that transactivated a model promoter 40–80% of an agonist, recruited the coactivator GRIP-1 <15%, and stabilized the N-/C-terminal interdomain interaction <7% induced bone formation with reduced effects in the uterus and in sebaceous glands. Using these criteria, multiple SARMs were synthesized including MK-0773, a 4-aza-steroid that exhibited tissue selectivity in humans. Thus, AR activated to moderate levels due to reduced cofactor recruitment, and N-/C-terminal interactions produce a fully anabolic response, whereas more complete receptor activation is required for reproductive effects. This bimodal activation provides a molecular basis for the development of SARMs. PMID:20356837

  16. Space Physiology within an Exercise Physiology Curriculum

    Science.gov (United States)

    Carter, Jason R.; West, John B.

    2013-01-01

    Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

  17. Potassium physiology.

    Science.gov (United States)

    Thier, S O

    1986-04-25

    Potassium is the most abundant exchangeable cation in the body. It exists predominantly in the intracellular fluid at concentrations of 140 to 150 meq/liter and in the extracellular fluid at concentrations of 3.5 to 5 meq/liter. The maintenance of the serum potassium concentration is a complex bodily function and results from the balance between intake, excretion, and distribution between intracellular and extracellular space. Ingested potassium is virtually completely absorbed from and minimally excreted through the intestine under nonpathologic circumstances. Renal excretion of potassium, which is the major chronic protective mechanism against abnormalities in potassium balance, depends on filtration, reabsorption, and a highly regulated distal nephron secretory process. Factors regulating potassium secretion include prior potassium intake, intracellular potassium, delivery of sodium chloride and poorly reabsorbable anions to the distal nephron, the urine flow rate, hormones such as aldosterone and beta-catecholamines, and the integrity of the renal tubular cell. The maintenance of distribution between the inside and outside of cells depends on the integrity of the cell membrane and its pumps, osmolality, pH, and the hormones insulin, aldosterone, beta 2-catecholamines, alpha-catecholamines, and prostaglandins. Both distribution across cell membranes and/or renal excretion of potassium may be altered by pharmacologic agents such as diuretics, alpha- and beta-catechol antagonists and agonists, depolarizing agents, and digitalis. Problems with hypokalemia and hyperkalemia can be analyzed on the basis of potassium physiology and pharmacology; proper treatment depends on an accurate analysis.

  18. ERG2 and ERG24 Are Required for Normal Vacuolar Physiology as Well as Candida albicans Pathogenicity in a Murine Model of Disseminated but Not Vaginal Candidiasis.

    Science.gov (United States)

    Luna-Tapia, Arturo; Peters, Brian M; Eberle, Karen E; Kerns, Morgan E; Foster, Timothy P; Marrero, Luis; Noverr, Mairi C; Fidel, Paul L; Palmer, Glen E

    2015-10-01

    Several important classes of antifungal agents, including the azoles, act by blocking ergosterol biosynthesis. It was recently reported that the azoles cause massive disruption of the fungal vacuole in the prevalent human pathogen Candida albicans. This is significant because normal vacuolar function is required to support C. albicans pathogenicity. This study examined the impact of the morpholine antifungals, which inhibit later steps of ergosterol biosynthesis, on C. albicans vacuolar integrity. It was found that overexpression of either the ERG2 or ERG24 gene, encoding C-8 sterol isomerase or C-14 sterol reductase, respectively, suppressed C. albicans sensitivity to the morpholines. In addition, both erg2Δ/Δ and erg24Δ/Δ mutants were hypersensitive to the morpholines. These data are consistent with the antifungal activity of the morpholines depending upon the simultaneous inhibition of both Erg2p and Erg24p. The vacuoles within both erg2Δ/Δ and erg24Δ/Δ C. albicans strains exhibited an aberrant morphology and accumulated large quantities of the weak base quinacrine, indicating enhanced vacuolar acidification compared with that of control strains. Both erg mutants exhibited significant defects in polarized hyphal growth and were avirulent in a mouse model of disseminated candidiasis. Surprisingly, in a mouse model of vaginal candidiasis, both mutants colonized mice at high levels and induced a pathogenic response similar to that with the controls. Thus, while targeting Erg2p or Erg24p alone could provide a potentially efficacious therapy for disseminated candidiasis, it may not be an effective strategy to treat vaginal infections. The potential value of drugs targeting these enzymes as adjunctive therapies is discussed.

  19. A Critical Analysis of the Role of SNARE Protein SEC22B in Antigen Cross-Presentation

    Directory of Open Access Journals (Sweden)

    S. Julia Wu

    2017-06-01

    Full Text Available Cross-presentation initiates immune responses against tumors and viral infections by presenting extracellular antigen on MHC I to activate CD8+ T cell-mediated cytotoxicity. In vitro studies in dendritic cells (DCs established SNARE protein SEC22B as a specific regulator of cross-presentation. However, the in vivo contribution of SEC22B to cross-presentation has not been tested. To address this, we generated DC-specific Sec22b knockout (CD11c-Cre Sec22bfl/fl mice. Contrary to the paradigm, SEC22B-deficient DCs efficiently cross-present both in vivo and in vitro. Although in vitro small hairpin RNA (shRNA-mediated Sec22b silencing in bone-marrow-derived dendritic cells (BMDCs reduced cross-presentation, treatment of SEC22B-deficient BMDCs with the same shRNA produced a similar defect, suggesting the Sec22b shRNA modulates cross-presentation through off-target effects. RNA sequencing of Sec22b shRNA-treated SEC22B-deficient BMDCs demonstrated several changes in the transcriptome. Our data demonstrate that contrary to the accepted model, SEC22B is not necessary for cross-presentation, cautioning against extrapolating phenotypes from knockdown studies alone.

  20. Caesium accumulation in yeast and plants is selectively repressed by loss of the SNARE Sec22p/SEC22.

    Science.gov (United States)

    Dräxl, Stephan; Müller, Johannes; Li, Wei B; Michalke, Bernhard; Scherb, Hagen; Hense, Burkhard A; Tschiersch, Jochen; Kanter, Ulrike; Schäffner, Anton R

    2013-01-01

    The non-essential cation caesium (Cs(+)) is assimilated by all organisms. Thus, anthropogenically released radiocaesium is of concern to agriculture. Cs(+) accumulates owing to its chemical similarity to the potassium ion (K(+)). The apparent lack of a Cs(+)-specific uptake mechanism has obstructed attempts to manipulate Cs(+) accumulation without causing pleiotropic effects. Here we show that the SNARE protein Sec22p/SEC22 specifically impacts Cs(+) accumulation in yeast and in plants. Loss of Saccharomyces cerevisiae Sec22p does not affect K(+) homeostasis, yet halves Cs(+) concentration compared with the wild type. Mathematical modelling of the uptake time course predicts a compromised vacuolar Cs(+) deposition in sec22Δ. Biochemical fractionation confirms this and indicates a new feature of Sec22p in enhancing non-selective cation deposition. A developmentally controlled loss-of-function mutant of the orthologous Arabidopsis thaliana SEC22 phenocopies the reduced Cs(+) uptake without affecting plant growth. This finding provides a new strategy to reduce radiocaesium entry into the food chain.

  1. Membrane translocation of t-SNARE protein syntaxin-4 abrogates ground-state pluripotency in mouse embryonic stem cells

    Science.gov (United States)

    Hagiwara-Chatani, Natsumi; Shirai, Kota; Kido, Takumi; Horigome, Tomoatsu; Yasue, Akihiro; Adachi, Naoki; Hirai, Yohei

    2017-01-01

    Embryonic stem (ES) and induced pluripotent stem (iPS) cells are attractive tools for regenerative medicine therapies. However, aberrant cell populations that display flattened morphology and lose ground-state pluripotency often appear spontaneously, unless glycogen synthase kinase 3β (GSK3β) and mitogen-activated protein kinase kinase (MEK1/2) are inactivated. Here, we show that membrane translocation of the t-SNARE protein syntaxin-4 possibly is involved in this phenomenon. We found that mouse ES cells cultured without GSK3β/MEK1/2 inhibitors (2i) spontaneously extrude syntaxin-4 at the cell surface and that artificial expression of cell surface syntaxin-4 induces appreciable morphological changes and mesodermal differentiation through dephosphorylation of Akt. Transcriptome analyses revealed several candidate elements responsible for this, specifically, an E-to P-cadherin switch and a marked downregulation of Zscan4 proteins, which are DNA-binding proteins essential for ES cell pluripotency. Embryonic carcinoma cell lines F9 and P19CL6, which maintain undifferentiated states independently of Zscan4 proteins, exhibited similar cellular behaviors upon stimulation with cell surface syntaxin-4. The functional ablation of E-cadherin and overexpression of P-cadherin reproduced syntaxin-4-induced cell morphology, demonstrating that the E- to P-cadherin switch executes morphological signals from cell surface syntaxin-4. Thus, spontaneous membrane translocation of syntaxin-4 emerged as a critical element for maintenance of the stem-cell niche. PMID:28057922

  2. Multiple Roles of VARP in Endosomal Trafficking: Rabs, Retromer Components and R-SNARE VAMP7 Meet on VARP.

    Science.gov (United States)

    Fukuda, Mitsunori

    2016-07-01

    VARP (VPS9-ankyrin-repeat protein, also known as ANKRD27) was originally identified as an N-terminal VPS9 (vacuolar protein sorting 9)-domain-containing protein that possesses guanine nucleotide exchange factor (GEF) activity toward small GTPase Rab21 and contains two ankyrin repeat (ANKR) domains in its central region. A number of VARP-interacting molecules have been identified during the past five years, and considerable attention is now being directed to the multiple roles of VARP in endosomal trafficking. More specifically, VARP is now known to interact with three different types of key membrane trafficking regulators, i.e. small GTPase Rabs (Rab32, Rab38 and Rab40C), the retromer complex (a sorting nexin dimer, VPS26, VPS29 and VPS35) and R-SNARE VAMP7. By binding to several of these molecules, VARP regulates endosomal trafficking, which underlies a variety of cellular events, including melanogenic enzyme trafficking to melanosomes, dendrite outgrowth of melanocytes, neurite outgrowth and retromer-mediated endosome-to-plasma membrane sorting of transmembrane proteins.

  3. SNAREs Interact with Retinal Degeneration Slow and Rod Outer Segment Membrane Protein-1 during Conventional and Unconventional Outer Segment Targeting.

    Science.gov (United States)

    Zulliger, Rahel; Conley, Shannon M; Mwoyosvi, Maggie L; Stuck, Michael W; Azadi, Seifollah; Naash, Muna I

    2015-01-01

    Mutations in the photoreceptor protein peripherin-2 (also known as RDS) cause severe retinal degeneration. RDS and its homolog ROM-1 (rod outer segment protein 1) are synthesized in the inner segment and then trafficked into the outer segment where they function in tetramers and covalently linked larger complexes. Our goal is to identify binding partners of RDS and ROM-1 that may be involved in their biosynthetic pathway or in their function in the photoreceptor outer segment (OS). Here we utilize several methods including mass spectrometry after affinity purification, in vitro co-expression followed by pull-down, in vivo pull-down from mouse retinas, and proximity ligation assay to identify and confirm the SNARE proteins Syntaxin 3B and SNAP-25 as novel binding partners of RDS and ROM-1. We show that both covalently linked and non-covalently linked RDS complexes interact with Syntaxin 3B. RDS in the mouse is trafficked from the inner segment to the outer segment by both conventional (i.e., Golgi dependent) and unconventional secretory pathways, and RDS from both pathways interacts with Syntaxin3B. Syntaxin 3B and SNAP-25 are enriched in the inner segment (compared to the outer segment) suggesting that the interaction with RDS/ROM-1 occurs in the inner segment. Syntaxin 3B and SNAP-25 are involved in mediating fusion of vesicles carrying other outer segment proteins during outer segment targeting, so could be involved in the trafficking of RDS/ROM-1.

  4. Physiological attributes of triathletes.

    Science.gov (United States)

    Suriano, R; Bishop, D

    2010-05-01

    Triathlons of all distances can be considered endurance events and consist of the individual disciplines of swimming, cycling and running which are generally completed in this sequential order. While it is expected that elite triathletes would possess high values for submaximal and maximal measures of aerobic fitness, little is known about how these values compare with those of single-sport endurance athletes. Earlier reviews, conducted in the 1980s, concluded that triathletes possessed lower V(O2(max)) values than other endurance athletes. An update of comparisons is of interest to determine if the physiological capacities of elite triathletes now reflect those of single-sport athletes or whether these physiological capacities are compromised by the requirement to cross-train for three different disciplines. It was found that although differences in the physiological attributes during swimming, cycling and running are evident among triathletes, those who compete at an international level possess V(O2(max)) values that are indicative of success in endurance-based individual sports. Furthermore, various physiological parameters at submaximal workloads have been used to describe the capacities of these athletes. Only a few studies have reported the lactate threshold among triathletes with the majority of studies reporting the ventilatory threshold. Although observed differences among triathletes for both these submaximal measures are complicated by the various methods used to determine them, the reported values for triathletes are similar to those for trained cyclists and runners. Thus, from the limited data available, it appears that triathletes are able to obtain similar physiological values as single-sport athletes despite dividing their training time among three disciplines.

  5. A Functional Core of IncA Is Required for Chlamydia trachomatis Inclusion Fusion.

    Science.gov (United States)

    Weber, Mary M; Noriea, Nicholas F; Bauler, Laura D; Lam, Jennifer L; Sager, Janet; Wesolowski, Jordan; Paumet, Fabienne; Hackstadt, Ted

    2016-04-01

    Chlamydia trachomatis is an obligate intracellular pathogen that is the etiological agent of a variety of human diseases, including blinding trachoma and sexually transmitted infections. Chlamydiae replicate within a membrane-bound compartment, termed an inclusion, which they extensively modify by the insertion of type III secreted proteins called Inc proteins. IncA is an inclusion membrane protein that encodes two coiled-coil domains that are homologous to eukaryotic SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) motifs. Recent biochemical evidence suggests that a functional core, composed of SNARE-like domain 1 (SLD-1) and part of SNARE-like domain 2 (SLD-2), is required for the characteristic homotypic fusion of C. trachomatis inclusions in multiply infected cells. To verify the importance of IncA in homotypic fusion in Chlamydia, we generated an incA::bla mutant. Insertional inactivation of incA resulted in the formation of nonfusogenic inclusions, a phenotype that was completely rescued by complementation with full-length IncA. Rescue of homotypic inclusion fusion was dependent on the presence of the functional core consisting of SLD-1 and part of SLD-2. Collectively, these results confirm in vitro membrane fusion assays identifying functional domains of IncA and expand the genetic tools available for identification of chlamydia with a method for complementation of site-specific mutants. Chlamydia trachomatis replicates within a parasitophorous vacuole termed an inclusion. The chlamydial inclusions are nonfusogenic with vesicles in the endocytic pathway but, in multiply infected cells, fuse with each other to form a single large inclusion. This homotypic fusion is dependent upon the presence of a chlamydial inclusion membrane-localized protein, IncA. Specificity of membrane fusion in eukaryotic cells is regulated by SNARE (soluble N-ethylmaleimide sensitive factor attachment receptor) proteins on the cytosolic face of vesicles and target

  6. [Human physiology: kidney].

    Science.gov (United States)

    Natochin, Iu V

    2010-01-01

    The content of human physiology as an independent part of current physiology is discussed. Substantiated is the point that subjects of human physiology are not only special sections of physiology where functions are inherent only in human (physiology of intellectual activity, speech, labor, sport), but also in peculiarities of functions, specificity of regulation of each of physiological systems. By the example of physiology of kidney and water-salt balance there are shown borders of norm, peculiarities of regulation in human, new chapters of renal physiology which have appeared in connection with achievements of molecular physiology.

  7. Segregation of the Qb-SNAREs GS27 and GS28 into Golgi vesicles regulates intra-Golgi transport.

    Science.gov (United States)

    Fusella, Aurora; Micaroni, Massimo; Di Giandomenico, Daniele; Mironov, Alexandre A; Beznoussenko, Galina V

    2013-05-01

    The Golgi apparatus is the main glycosylation and sorting station along the secretory pathway. Its structure includes the Golgi vesicles, which are depleted of anterograde cargo, and also of at least some Golgi-resident proteins. The role of Golgi vesicles remains unclear. Here, we show that Golgi vesicles are enriched in the Qb-SNAREs GS27 (membrin) and GS28 (GOS-28), and depleted of nucleotide sugar transporters. A block of intra-Golgi transport leads to accumulation of Golgi vesicles and partitioning of GS27 and GS28 into these vesicles. Conversely, active intra-Golgi transport induces fusion of these vesicles with the Golgi cisternae, delivering GS27 and GS28 to these cisternae. In an in vitro assay based on a donor compartment that lacks UDP-galactose translocase (a sugar transporter), the segregation of Golgi vesicles from isolated Golgi membranes inhibits intra-Golgi transport; re-addition of isolated Golgi vesicles devoid of UDP-galactose translocase obtained from normal cells restores intra-Golgi transport. We conclude that this activity is due to the presence of GS27 and GS28 in the Golgi vesicles, rather than the sugar transporter. Furthermore, there is an inverse correlation between the number of Golgi vesicles and the number of inter-cisternal connections under different experimental conditions. Finally, a rapid block of the formation of vesicles via COPI through degradation of ϵCOP accelerates the cis-to-trans delivery of VSVG. These data suggest that Golgi vesicles, presumably with COPI, serve to inhibit intra-Golgi transport by the extraction of GS27 and GS28 from the Golgi cisternae, which blocks the formation of inter-cisternal connections.

  8. Exploration into physiology teaching reform in local higher learning institutions under outstanding doctors training requirements%基于卓越医师培养要求的地方院校生理学教学改革探索

    Institute of Scientific and Technical Information of China (English)

    尹蔚兰; 张新华; 唐志晗; 曾国; 陈熙; 田英; 姜志胜

    2016-01-01

    Implementing "Five-year Outstanding Doctors Training Plan"poses new requirements for basic medical courses teaching.As for physiology course,we put more emphasis on basic theory, knowledge and skills,cultivation of critical thinking and innovation ability.By citing the example of our university's practice in reform of outstanding doctors class,this article explores physiology teaching reform regarding the following aspects:integrating biology courses,optimizing experiment teaching contents, reasonably connecting with the clinic,integrating humanities education,introducing PBL and case-based teaching,and perfecting experiment assessment and evaluation system.%实施“五年制卓越医师教育培养计划”项目对医学基础课程教学提出了新的要求。对生理学课程而言则更加强调基础知识、基本理论和基本技能,更加强调批判性思维能力和创新能力培养。结合南华大学“卓越医师班”的改革实践,文章从生理学课程的体系整合、实验教学内容优化、合理联系临床、融入人文教育、引入PBL和案例教学、完善考核评价体系等方面介绍了其生理学教学改革。

  9. Physiological effects in aromatherapy

    OpenAIRE

    2004-01-01

    The effects of aromas on humans are divided into physiological and psychological effects. The physiological effect acts directly on the physical organism, the psychological effect acts via the sense of smell or olfactory system, which in turn may cause a physiological effect. This paper reviews on the physiological effects which are used for the evaluation of the effects of aromas. Physiological parameters, i.e. heart rate blood pressure, electrodermal activity, electroencephalogram, slow pot...

  10. Physiological adaptation in desert birds

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Williams, Joseph B.

    2005-01-01

    We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement

  11. Vasogenic shock physiology

    Directory of Open Access Journals (Sweden)

    Sotiria Gkisioti

    2011-01-01

    Full Text Available Sotiria Gkisioti, Spyros D MentzelopoulosDepartment of Intensive Care Medicine, University of Athens Medical School, Evaggelismos General Hospital, Athens, GreeceAbstract: Shock means inadequate tissue perfusion by oxygen-carrying blood. In vasogenic shock, this circulatory failure results from vasodilation and/or vasoplegia. There is vascular hyporeactivity with reduced vascular smooth muscle contraction in response to α1 adrenergic agonists. Considering vasogenic shock, one can understand its utmost importance, not only because of its association with sepsis but also because it can be the common final pathway for long-lasting, severe shock of any cause, even postresuscitation states. The effective management of any patient in shock requires the understanding of its underlying physiology and pathophysiology. Recent studies have provided new insights into vascular physiology by revealing the interaction of rather complicated and multifactorial mechanisms, which have not been fully elucidated yet. Some of these mechanisms, such as the induction of nitric oxide synthases, the activation of adenosine triphosphate-sensitive potassium channels, and vasopressin deficiency, have gained general acceptance and are considered to play an important role in the pathogenesis of vasodilatory shock. The purpose of this review is to provide an update on the pathogenesis of vasogenic shock.Keywords: nitric oxide synthases, KATP channels, vasopressin, H2S, vasoplegic syndrome

  12. VAMP4 is required to maintain the ribbon structure of the Golgi apparatus.

    Science.gov (United States)

    Shitara, Akiko; Shibui, Toru; Okayama, Miki; Arakawa, Toshiya; Mizoguchi, Itaru; Sakakura, Yasunori; Shakakura, Yasunori; Takuma, Taishin

    2013-08-01

    The Golgi apparatus forms a twisted ribbon-like network in the juxtanuclear region of vertebrate cells. Vesicle-associated membrane protein 4 (VAMP4), a v-SNARE protein expressed exclusively in the vertebrate trans-Golgi network (TGN), plays a role in retrograde trafficking from the early endosome to the TGN, although its precise function within the Golgi apparatus remains unclear. To determine whether VAMP4 plays a functional role in maintaining the structure of the Golgi apparatus, we depleted VAMP4 gene expression using RNA interference technology. Depletion of VAMP4 from HeLa cells led to fragmentation of the Golgi ribbon. These fragments were not uniformly distributed throughout the cytoplasm, but remained in the juxtanuclear area. Electron microscopy and immunohistochemistry showed that in the absence of VAMP4, the length of the Golgi stack was shortened, but Golgi stacking was normal. Anterograde trafficking was not impaired in VAMP4-depleted cells, which contained intact microtubule arrays. Depletion of the cognate SNARE partners of VAMP4, syntaxin 6, syntaxin 16, and Vti1a also disrupted the Golgi ribbon structure. Our findings suggested that the maintenance of Golgi ribbon structure requires normal retrograde trafficking from the early endosome to the TGN, which is likely to be mediated by the formation of VAMP4-containing SNARE complexes.

  13. Single Cell Physiology

    Science.gov (United States)

    Neveu, Pierre; Sinha, Deepak Kumar; Kettunen, Petronella; Vriz, Sophie; Jullien, Ludovic; Bensimon, David

    The possibility to control at specific times and specific places the activity of biomolecules (enzymes, transcription factors, RNA, hormones, etc.) is opening up new opportunities in the study of physiological processes at the single cell level in a live organism. Most existing gene expression systems allow for tissue specific induction upon feeding the organism with exogenous inducers (e.g., tetracycline). Local genetic control has earlier been achieved by micro-injection of the relevant inducer/repressor molecule, but this is an invasive and possibly traumatic technique. In this chapter, we present the requirements for a noninvasive optical control of the activity of biomolecules and review the recent advances in this new field of research.

  14. Applied physiology of water polo.

    Science.gov (United States)

    Smith, H K

    1998-11-01

    Water polo has been played for over a century. While the rules of the game have evolved considerably over this time, the sport has consistently remained, physiologically, a highly demanding activity. Much attention has been paid to the technical and strategic elements of the game; however, despite the potential for improvements in athletic performance and the maintenance of athletes' health, there are few published studies (particularly in English) on the physical and physiological demands and adaptations to water polo training and competition. Game analyses have demonstrated that water polo is an 'intermittent' sport comprised of intense bursts of activity of movements required for playing water polo also place considerable demands on the neuromuscular system. Observations of the frequency and duration of the different activities, and of the physiological responses to participating in a water polo match, are initial sources of information for designing training programmes specific to the game and to the different playing positions. The physical and physiological attributes of elite water polo players offer some insight into the minimum requirements for participation and the adaptations that result from training and competition. Further systematic documentation and experimentation are required to facilitate the design and specification of individual training programmes and to better understand the long term effects of water polo on athletes' health.

  15. Absalon and Esbern Snare

    DEFF Research Database (Denmark)

    Nørby, Søren; Wismann, Tom

    2017-01-01

    of Africa, as well as in Operation RECSYR where the world community removed Syria's chemical weapons from the civil war-stricken country. This e-book tells the fascinating story of the ships' design, building, their equipment, life on board and the first years of operations. The e-book contains over 150...

  16. Design Projects in Human Anatomy & Physiology

    Science.gov (United States)

    Polizzotto, Kristin; Ortiz, Mary T.

    2008-01-01

    Very often, some type of writing assignment is required in college entry-level Human Anatomy and Physiology courses. This assignment can be anything from an essay to a research paper on the literature, focusing on a faculty-approved topic of interest to the student. As educators who teach Human Anatomy and Physiology at an urban community college,…

  17. Design Projects in Human Anatomy & Physiology

    Science.gov (United States)

    Polizzotto, Kristin; Ortiz, Mary T.

    2008-01-01

    Very often, some type of writing assignment is required in college entry-level Human Anatomy and Physiology courses. This assignment can be anything from an essay to a research paper on the literature, focusing on a faculty-approved topic of interest to the student. As educators who teach Human Anatomy and Physiology at an urban community college,…

  18. Physiological Information Database (PID)

    Science.gov (United States)

    EPA has developed a physiological information database (created using Microsoft ACCESS) intended to be used in PBPK modeling. The database contains physiological parameter values for humans from early childhood through senescence as well as similar data for laboratory animal spec...

  19. Chewing Over Physiology Integration

    Science.gov (United States)

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

    2005-01-01

    An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

  20. Chewing Over Physiology Integration

    Science.gov (United States)

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

    2005-01-01

    An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

  1. Towards ambulatory mental stress measurement from physiological parameters

    NARCIS (Netherlands)

    Wijsman, J.L.P; Vullers, Ruud; Polito, Salvatore; Agell, Carlos; Penders, Julien; Hermens, Hermanus J.

    Ambulatory mental stress monitoring requires longterm physiological measurements. This paper presents a data collection protocol for ambulatory recording of physiological parameters for stress measurement purposes. We present a wearable sensor system for ambulatory recording of ECG, EMG, respiration

  2. Towards ambulatory mental stress measurement from physiological parameters

    NARCIS (Netherlands)

    Wijsman, Jacqueline; Vullers, Ruud; Polito, Salvatore; Agell, Carlos; Penders, Julien; Hermens, Hermie

    2013-01-01

    Ambulatory mental stress monitoring requires longterm physiological measurements. This paper presents a data collection protocol for ambulatory recording of physiological parameters for stress measurement purposes. We present a wearable sensor system for ambulatory recording of ECG, EMG, respiration

  3. Loss-of-function mutations of retromer large subunit genes suppress the phenotype of an Arabidopsis zig mutant that lacks Qb-SNARE VTI11.

    Science.gov (United States)

    Hashiguchi, Yasuko; Niihama, Mitsuru; Takahashi, Tetsuya; Saito, Chieko; Nakano, Akihiko; Tasaka, Masao; Morita, Miyo Terao

    2010-01-01

    Arabidopsis thaliana zigzag (zig) is a loss-of-function mutant of Qb-SNARE VTI11, which is involved in membrane trafficking between the trans-Golgi network and the vacuole. zig-1 exhibits abnormalities in shoot gravitropism and morphology. Here, we report that loss-of-function mutants of the retromer large subunit partially suppress the zig-1 phenotype. Moreover, we demonstrate that three paralogous VPS35 genes of Arabidopsis have partially overlapping but distinct genetic functions with respect to zig-1 suppression. Tissue-specific complementation experiments using an endodermis-specific SCR promoter show that expression of VPS35B or VPS35C cannot complement the function of VPS35A. The data suggest the existence of functionally specialized paralogous VPS35 genes that nevertheless share common functions.

  4. Loss-of-Function Mutations of Retromer Large Subunit Genes Suppress the Phenotype of an Arabidopsis zig Mutant That Lacks Qb-SNARE VTI11[C][W

    Science.gov (United States)

    Hashiguchi, Yasuko; Niihama, Mitsuru; Takahashi, Tetsuya; Saito, Chieko; Nakano, Akihiko; Tasaka, Masao; Morita, Miyo Terao

    2010-01-01

    Arabidopsis thaliana zigzag (zig) is a loss-of-function mutant of Qb-SNARE VTI11, which is involved in membrane trafficking between the trans-Golgi network and the vacuole. zig-1 exhibits abnormalities in shoot gravitropism and morphology. Here, we report that loss-of-function mutants of the retromer large subunit partially suppress the zig-1 phenotype. Moreover, we demonstrate that three paralogous VPS35 genes of Arabidopsis have partially overlapping but distinct genetic functions with respect to zig-1 suppression. Tissue-specific complementation experiments using an endodermis-specific SCR promoter show that expression of VPS35B or VPS35C cannot complement the function of VPS35A. The data suggest the existence of functionally specialized paralogous VPS35 genes that nevertheless share common functions. PMID:20086190

  5. Combined Use of Clips and Nylon Snare (“Tulip-Bundle” as a Rescue Endoscopic Bleeding Control in a Mallory-Weiss Syndrome

    Directory of Open Access Journals (Sweden)

    Hrvoje Ivekovic

    2014-01-01

    Full Text Available Mallory-Weiss syndrome (MWS accounts for 6–14% of all cases of upper gastrointestinal bleeding. Prognosis of patients with MWS is generally good, with a benign course and rare recurrence of bleeding. However, no strict recommendations exist in regard to the mode of action after a failure of primary endoscopic hemostasis. We report a case of an 83-year-old male with MWS and rebleeding after the initial endoscopic treatment with epinephrine and clips. The final endoscopic control of bleeding was achieved by a combined application of clips and a nylon snare in a “tulip-bundle” fashion. The patient had an uneventful postprocedural clinical course and was discharged from the hospital five days later. To the best of our knowledge, this is the first case report showing the “tulip-bundle” technique as a rescue endoscopic bleeding control in the esophagus.

  6. Combined use of clips and nylon snare ("tulip-bundle") as a rescue endoscopic bleeding control in a mallory-weiss syndrome.

    Science.gov (United States)

    Ivekovic, Hrvoje; Radulovic, Bojana; Jankovic, Suzana; Markos, Pave; Rustemovic, Nadan

    2014-01-01

    Mallory-Weiss syndrome (MWS) accounts for 6-14% of all cases of upper gastrointestinal bleeding. Prognosis of patients with MWS is generally good, with a benign course and rare recurrence of bleeding. However, no strict recommendations exist in regard to the mode of action after a failure of primary endoscopic hemostasis. We report a case of an 83-year-old male with MWS and rebleeding after the initial endoscopic treatment with epinephrine and clips. The final endoscopic control of bleeding was achieved by a combined application of clips and a nylon snare in a "tulip-bundle" fashion. The patient had an uneventful postprocedural clinical course and was discharged from the hospital five days later. To the best of our knowledge, this is the first case report showing the "tulip-bundle" technique as a rescue endoscopic bleeding control in the esophagus.

  7. Single Vesicle Assaying of SNARE-Synaptotagmin-Driven Fusion Reveals Fast and Slow Modes of Both Docking and Fusion and Intrasample Heterogeneity

    DEFF Research Database (Denmark)

    M. Christensen, Sune; W. Mortensen, Michael; Stamou, Dimitrios

    2011-01-01

    the docking or the fusion of vesicles. Here we report a fluorescence microscopy-based assay to monitor SNARE-mediated docking and fusion of individual vesicle pairs. In situ measurement of the concentration of diffusing particles allowed us to quantify docking rates by a maximum-likelihood approach....... This analysis showed that C2AB and Ca(2+) accelerate vesicle-vesicle docking with more than two orders of magnitude. Comparison of the measured docking rates with ensemble lipid mixing kinetics, however, suggests that in most cases bilayer fusion remains therate-limiting step. Our single vesicle results show...... that only 60% of the vesicles dock and only 6% of docked vesicles fuse. Lipid mixing on single vesicles was fast (t(mix)docking and fusion pathways cannot be rationalized...

  8. Physiological effects in aromatherapy

    Directory of Open Access Journals (Sweden)

    Tapanee Hongratanaworakit

    2004-01-01

    Full Text Available The effects of aromas on humans are divided into physiological and psychological effects. The physiological effect acts directly on the physical organism, the psychological effect acts via the sense of smell or olfactory system, which in turn may cause a physiological effect. This paper reviews on the physiological effects which are used for the evaluation of the effects of aromas. Physiological parameters, i.e. heart rate blood pressure, electrodermal activity, electroencephalogram, slow potential brain waves (contingent negativevariation, and eye blink rate or pupil functions, are used as indices for the measurement of the aroma effects

  9. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

  10. Alternative splicing of the human gene SYBL1 modulates protein domain architecture of longin VAMP7/TI-VAMP, showing both non-SNARE and synaptobrevin-like isoforms

    Directory of Open Access Journals (Sweden)

    De Franceschi Nicola

    2011-05-01

    Full Text Available Abstract Background The control of intracellular vesicle trafficking is an ideal target to weigh the role of alternative splicing in shaping genomes to make cells. Alternative splicing has been reported for several Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptors of the vesicle (v-SNAREs or of the target membrane (t-SNARES, which are crucial to intracellular membrane fusion and protein and lipid traffic in Eukaryotes. However, splicing has not yet been investigated in Longins, i.e. the most widespread v-SNAREs. Longins are essential in Eukaryotes and prototyped by VAMP7, Sec22b and Ykt6, sharing a conserved N-terminal Longin domain which regulates membrane fusion and subcellular targeting. Human VAMP7/TI-VAMP, encoded by gene SYBL1, is involved in multiple cell pathways, including control of neurite outgrowth. Results Alternative splicing of SYBL1 by exon skipping events results in the production of a number of VAMP7 isoforms. In-frame or frameshift coding sequence modifications modulate domain architecture of VAMP7 isoforms, which can lack whole domains or domain fragments and show variant or extra domains. Intriguingly, two main types of VAMP7 isoforms either share the inhibitory Longin domain and lack the fusion-promoting SNARE motif, or vice versa. Expression analysis in different tissues and cell lines, quantitative real time RT-PCR and confocal microscopy analysis of fluorescent protein-tagged isoforms demonstrate that VAMP7 variants have different tissue specificities and subcellular localizations. Moreover, design and use of isoform-specific antibodies provided preliminary evidence for the existence of splice variants at the protein level. Conclusions Previous evidence on VAMP7 suggests inhibitory functions for the Longin domain and fusion/growth promoting activity for the Δ-longin molecule. Thus, non-SNARE isoforms with Longin domain and non-longin SNARE isoforms might have somehow opposite regulatory functions

  11. Physiology of Volition

    Science.gov (United States)

    Hallett, Mark

    The idea of free will is a conscious awareness of the brain concerning the nature of the movement that it produces. There is no evidence for it to be a driving force in movement generation. This review considers the physiology of movement generation and how the concepts of willing and agency might arise. Both the anatomical substrates and the timing of events are considered. Movement initiation and volition are not necessarily linked, and one line of evidence comes from consideration of patients with disorders of volition. Movement is generated subconsciously, and the conscious sense of willing the movement comes later, but the exact time of this event is difficult to assess because of the potentially illusory nature of introspection. The evidence suggests that movement is initiated in frontal lobe, particularly the mesial areas, and the sense of volition arises as the result of a corollary discharge from premotor and motor areas likely involving the parietal lobe. Agency probably involves a similar region in the parietal lobe and requires both the sense of volition and movement feedback.

  12. Applied physiology of cycling.

    Science.gov (United States)

    Faria, I E

    1984-01-01

    Historically, the bicycle has evolved through the stages of a machine for efficient human transportation, a toy for children, a finely-tuned racing machine, and a tool for physical fitness development, maintenance and testing. Recently, major strides have been made in the aerodynamic design of the bicycle. These innovations have resulted in new land speed records for human powered machines. Performance in cycling is affected by a variety of factors, including aerobic and anaerobic capacity, muscular strength and endurance, and body composition. Bicycle races range from a 200m sprint to approximately 5000km. This vast range of competitive racing requires special attention to the principle of specificity of training. The physiological demands of cycling have been examined through the use of bicycle ergometers, rollers, cycling trainers, treadmill cycling, high speed photography, computer graphics, strain gauges, electromyography, wind tunnels, muscle biopsy, and body composition analysis. These techniques have been useful in providing definitive data for the development of a work/performance profile of the cyclist. Research evidence strongly suggests that when measuring the cyclist's aerobic or anaerobic capacity, a cycling protocol employing a high pedalling rpm should be used. The research bicycle should be modified to resemble a racing bicycle and the cyclist should wear cycling shoes. Prolonged cycling requires special nutritional considerations. Ingestion of carbohydrates, in solid form and carefully timed, influences performance. Caffeine appears to enhance lipid metabolism. Injuries, particularly knee problems which are prevalent among cyclists, may be avoided through the use of proper gearing and orthotics. Air pollution has been shown to impair physical performance. When pollution levels are high, training should be altered or curtailed. Effective training programmes simulate competitive conditions. Short and long interval training, blended with long

  13. Advances in physiological computing

    CERN Document Server

    Fairclough, Stephen H

    2014-01-01

    This edited collection will provide an overview of the field of physiological computing, i.e. the use of physiological signals as input for computer control. It will cover a breadth of current research, from brain-computer interfaces to telemedicine.

  14. Phun Week: Understanding Physiology

    Science.gov (United States)

    Limson, Mel; Matyas, Marsha Lakes

    2009-01-01

    Topics such as sports, exercise, health, and nutrition can make the science of physiology relevant and engaging for students. In addition, many lessons on these topics, such as those on the cardiovascular, respiratory, and digestive systems, align with national and state life science education standards. Physiology Understanding Week (PhUn…

  15. Physiology of sport.

    Science.gov (United States)

    Maughan, Ron

    2007-07-01

    The elite athlete represents the extreme of the human gene pool, where genetic endowment is developed by an intensive training programme. Sport encompasses many different activities, calling for different physical and mental attributes. Understanding the physiology of exercise provides insights into normal physiological function.

  16. Physiological changes in pregnancy

    OpenAIRE

    SOMA-PILLAY, Priya; Catherine, Nelson-Piercy; Tolppanen, Heli; Mebazaa, Alexandre

    2016-01-01

    Abstract Physiological changes occur in pregnancy to nurture the developing foetus and prepare the mother for labour and delivery. Some of these changes influence normal biochemical values while others may mimic symptoms of medical disease. It is important to differentiate between normal physiological changes and disease pathology. This review highlights the important changes that take place during normal pregnancy.

  17. PHYSIOLOGY OF ACID BASE BALANCE

    Directory of Open Access Journals (Sweden)

    Awati

    2014-12-01

    Full Text Available Acid-base, electrolyte, and metabolic disturbances are common in the intensive care unit. Almost all critically ill patients often suffer from compound acid-base and electrolyte disorders. Successful evaluation and management of such patients requires recognition of common patterns (e.g., metabolic acidosis and the ability to dissect one disorder from another. The intensivists needs to identify and correct these condition with the easiest available tools as they are the associated with multiorgan failure. Understanding the elements of normal physiology in these areas is very important so as to diagnose the pathological condition and take adequate measures as early as possible. Arterial blood gas analysis is one such tool for early detection of acid base disorder. Physiology of acid base is complex and here is the attempt to simplify it in our day to day application for the benefit of critically ill patients.

  18. Vesicle-associated membrane protein 3 (VAMP-3) and VAMP-8 are present in human platelets and are required for granule secretion.

    Science.gov (United States)

    Polgár, János; Chung, Sul-Hee; Reed, Guy L

    2002-08-01

    Secretion of platelet granules is necessary for normal hemostasis. Platelet secretion requires soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor (SNARE) complex formation between different members of the syntaxin, SNAP-25, and vesicle-associated membrane protein (VAMP) gene families. Using microcapillary reverse-phase high-performance liquid chromatography-nano-electrospray tandem mass spectrometry, we identified VAMP-3 and VAMP-8 as VAMP isoforms coimmunoprecipitated from platelets with syntaxin 4. Immunoblotting experiments confirmed the presence of VAMP-3 and VAMP-8 but not VAMP-1 or VAMP-2 in platelets. To examine the effect of VAMP proteins on platelet secretion, soluble recombinant (r) VAMP-2, rVAMP-3, and rVAMP-8 were incubated with streptolysin O-permeabilized platelets. Secretion of alpha granules (monitored by flow cytometric measurement of P-selectin) was blocked, and dense-granule secretion (assessed by release of carbon 14-serotonin) was almost completely inhibited by rVAMP-3, whereas rVAMP-8 inhibited secretion of dense granules but not alpha granules. In contrast, rVAMP-2, which formed SNARE complexes in vitro, had no effect on platelet exocytosis. We conclude that VAMP-3 and VAMP-8 form SNARE complexes with platelet syntaxin 4 and are required for platelet granule secretion.

  19. Syntaxin 7 and VAMP-7 are soluble N-ethylmaleimide-sensitive factor attachment protein receptors required for late endosome-lysosome and homotypic lysosome fusion in alveolar macrophages.

    Science.gov (United States)

    Ward, D M; Pevsner, J; Scullion, M A; Vaughn, M; Kaplan, J

    2000-07-01

    Endocytosis in alveolar macrophages can be reversibly inhibited, permitting the isolation of endocytic vesicles at defined stages of maturation. Using an in vitro fusion assay, we determined that each isolated endosome population was capable of homotypic fusion. All vesicle populations were also capable of heterotypic fusion in a temporally specific manner; early endosomes, isolated 4 min after internalization, could fuse with endosomes isolated 8 min after internalization but not with 12-min endosomes or lysosomes. Lysosomes fuse with 12-min endosomes but not with earlier endosomes. Using homogenous populations of endosomes, we have identified Syntaxin 7 as a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) required for late endosome-lysosome and homotypic lysosome fusion in vitro. A bacterially expressed human Syntaxin 7 lacking the transmembrane domain inhibited homotypic late endosome and lysosome fusion as well as heterotypic late endosome-lysosome fusion. Affinity-purified antibodies directed against Syntaxin 7 also inhibited lysosome fusion in vitro but had no affect on homotypic early endosome fusion. Previous work suggested that human VAMP-7 (vesicle-associated membrane protein-7) was a SNARE required for late endosome-lysosome fusion. A bacterially expressed human VAMP-7 lacking the transmembrane domain inhibited both late endosome-lysosome fusion and homotypic lysosome fusion in vitro. These studies indicate that: 1) fusion along the endocytic pathway is a highly regulated process, and 2) two SNARE molecules, Syntaxin 7 and human VAMP-7, are involved in fusion of vesicles in the late endocytic pathway in alveolar macrophages.

  20. Fetal cardiovascular physiology.

    Science.gov (United States)

    Rychik, J

    2004-01-01

    The cardiovascular system of the fetus is physiologically different than the adult, mature system. Unique characteristics of the myocardium and specific channels of blood flow differentitate the physiology of the fetus from the newborn. Conditions of increased preload and afterload in the fetus, such as sacrococcygeal teratoma and twin-twin transfusion syndrome, result in unique and complex pathophysiological states. Echocardiography has improved our understanding of human fetal cadiovasvular physiology in the normal and diseased states, and has expanded our capability to more effectively treat these disease processes.

  1. Reproduction, physiology and biochemistry

    Science.gov (United States)

    This chapter summarizes fundamental knowledge and recent discoveries about the reproduction, physiology and biochemistry of plant-parasitic nematodes. Various types of reproduction are reviewed, including sexual reproduction and mitotic and meiotic parthenogenesis. Although much is known about the p...

  2. Music Preferences, Friendship, and Externalizing Behavior in Early Adolescence: A SIENA Examination of the Music Marker Theory Using the SNARE Study.

    Science.gov (United States)

    Franken, Aart; Keijsers, Loes; Dijkstra, Jan Kornelis; Ter Bogt, Tom

    2017-01-18

    Music Marker Theory posits that music is relevant for the structuring of peer groups and that rock, urban, or dance music preferences relate to externalizing behavior. The present study tested these hypotheses, by investigating the role of music preference similarity in friendship selection and the development of externalizing behavior, while taking the effects of friends' externalizing behavior into account. Data were used from the first three waves of the SNARE (Social Network Analysis of Risk behavior in Early adolescence) study (N = 1144; 50% boys; M age = 12.7; SD = 0.47), including students who entered the first-year of secondary school. Two hypotheses were tested. First, adolescents were expected to select friends based both on a similarity in externalizing behavior and music genre preference. Second, a preference for rock, urban, or dance, music types was expected to predict the development of externalizing behavior, even when taking friends' influence on externalizing behavior into account. Stochastic Actor-Based Modeling indicated that adolescents select their friends based on both externalizing behavior and highbrow music preference. Moreover, both friends' externalizing behavior and a preference for dance music predicted the development of externalizing behavior. Intervention programs might focus on adolescents with dance music preferences.

  3. Effects of chronic fluoride exposure on object recognition memory and mRNA expression of SNARE complex in hippocampus of male mice.

    Science.gov (United States)

    Han, Haijun; Du, Wenjuan; Zhou, Bingrui; Zhang, Wen; Xu, Guoli; Niu, Ruiyan; Sun, Zilong

    2014-04-01

    This study aimed to investigate the effects of long-term fluoride exposure on object recognition memory and mRNA expression of soluble N-ethylmaleimidesensitive fusion protein attachment protein receptors (SNARE) complex (synaptosome-associated protein of 25 kDa (SNAP-25), vesicle-associated membrane protein 2 (VAMP-2), and syntaxin 1A) in the hippocampus of male mice. Sixty sexually matured male Kunming mice were randomly divided into four groups: control group (given distilled water), low F group (25 mg/L NaF, corresponding to 11 mg/L F(-)), medium F group (50 mg/L NaF, corresponding to 22 mg/L F(-)), and high F group (100 mg/L NaF, corresponding to 45 mg/L F(-)). After 180 days, the spontaneous locomotor behavior and object recognition memory were detected by open field test and novel object recognition (NOR) test. Results showed that compared with the control group, frequency in each zone, total distance, and line crosses were significantly increased in low F and medium F groups, suggesting fluoride enhanced excitement of mice, while there were no marked changes in high F group. Twenty-four hours after training, a deficit of long-term memory (LTM) occurred only in high F group (P recognition memory, and upregulate VAMP-2 mRNA expression, which are involved in the adverse effects of fluoride on the object recognition memory of nervous system.

  4. Physiological mechanisms of prosociality.

    Science.gov (United States)

    Miller, Jonas G

    2017-08-12

    Psychophysiological perspectives can provide unique insights into the nature and motivations of children's prosociality and inform our understanding of individual differences. Here, I review current research on prosociality involving some of the most common physiological measures in developmental psychology, including cortisol, various sympathetic nervous system measures, and high-frequency heart rate variability. The literature has been quite mixed, in part because the link between physiology and prosociality is context-dependent and person-dependent. However, recent advances are refining our understanding of the basic physiological mechanisms of prosociality. Resting physiology that contributes to a balance of regulation and vigilance prepares children to effectively cope with future social challenges, like noticing and attending to the needs of others. Experiencing some arousal is an important aspect of empathy-related responding, but physiological patterns of both heightened and hypoarousal can undermine prosociality. Physiological flexibility in response to others' needs may support emotional and behavioral flexibility important for prosociality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Physiology of in vitro culture

    Directory of Open Access Journals (Sweden)

    Maria Jesús Cañal

    2001-01-01

    Full Text Available The culture procedures described up to the eighties, did not made any mention to the environmental control of in vitro plant development. However, growth rate, development and many of the physiologic-morphologic features of the in vitro grown plants are influenced by the culture vessel. The increasing knowledge about the environmental control of culture vessels under sterile conditions, is helping to change micorpropagation procedures. The in vitro environment with lower rate ventilation, brings about low flow rates of matter and energy, with minimum variations of temperature, high relative humidity and large daily changes of the concentration of CO2 inside the culture vessel. The type of culture vessel (size, shape, fabric and closing system can influence the evolution of the atmosphere along the time of culture. Although submitted to different stresses factors plant can be grown in vitro, but plants can be faulty in their anatomy, morphology and physiology. As a consequence, these plants shown a phenotype unable to survive to ex vitro conditions. Different strategies can be used to control the atmosphere along the different phases of micropropagation, in heterotrophic, mixotrophic or autotrophic cultures. The election of the best strategy will be based on different factors as species, number of transplantes required, or quality-price relationship. enviromental control, tissue culture, micropropagation Keywords: in vitro enviromental, characteristic physiology,

  6. Physiological and pathological cardiac hypertrophy.

    Science.gov (United States)

    Shimizu, Ippei; Minamino, Tohru

    2016-08-01

    The heart must continuously pump blood to supply the body with oxygen and nutrients. To maintain the high energy consumption required by this role, the heart is equipped with multiple complex biological systems that allow adaptation to changes of systemic demand. The processes of growth (hypertrophy), angiogenesis, and metabolic plasticity are critically involved in maintenance of cardiac homeostasis. Cardiac hypertrophy is classified as physiological when it is associated with normal cardiac function or as pathological when associated with cardiac dysfunction. Physiological hypertrophy of the heart occurs in response to normal growth of children or during pregnancy, as well as in athletes. In contrast, pathological hypertrophy is induced by factors such as prolonged and abnormal hemodynamic stress, due to hypertension, myocardial infarction etc. Pathological hypertrophy is associated with fibrosis, capillary rarefaction, increased production of pro-inflammatory cytokines, and cellular dysfunction (impairment of signaling, suppression of autophagy, and abnormal cardiomyocyte/non-cardiomyocyte interactions), as well as undesirable epigenetic changes, with these complex responses leading to maladaptive cardiac remodeling and heart failure. This review describes the key molecules and cellular responses involved in physiological/pathological cardiac hypertrophy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Neuropeptide physiology in helminths.

    Science.gov (United States)

    Mousley, Angela; Novozhilova, Ekaterina; Kimber, Michael J; Day, Tim A

    2010-01-01

    Parasitic worms come from two distinct, distant phyla, Nematoda (roundworms) and Platyhelminthes (flatworms). The nervous systems of worms from both phyla are replete with neuropeptides and there is ample physiological evidence that these neuropeptides control vital aspects of worm biology. In each phyla, the physiological evidence for critical roles for helminth neuropeptides is derived from both parasitic and free-living members. In the nematodes, the intestinal parasite Ascaris suum and the free-living Caenorhabditis elegans have yielded most of the data; in the platyhelminths, the most physiological data has come from the blood fluke Schistosoma mansoni. FMRFamide-like peptides (FLPs) have many varied effects (excitation, relaxation, or a combination) on somatic musculature, reproductive musculature, the pharynx and motor neurons in nematodes. Insulin-like peptides (INSs) play an essential role in nematode dauer formation and other developmental processes. There is also some evidence for a role in somatic muscle control for the somewhat heterogeneous grouping ofpeptides known as neuropeptide-like proteins (NLPs). In platyhelminths, as in nematodes, FLPs have a central role in somatic muscle function. Reports of FLP physiological action in platyhelminths are limited to a potent excitation of the somatic musculature. Platyhelminths are also abundantly endowed with neuropeptide Fs (NPFs), which appear absent from nematodes. There is not yet any data linking platyhelminth NPF to any particular physiological outcome, but this neuropeptide does potently and specifically inhibit cAMP accumulation in schistosomes. In nematodes and platyhelminths, there is an abundance of physiological evidence demonstrating that neuropeptides play critical roles in the biology of both free-living and parasitic helminths. While it is certainly true that there remains a great deal to learn about the biology of neuropeptides in both phyla, physiological evidence presently available points

  8. Status of physiology education in US Doctor of Pharmacy programs.

    Science.gov (United States)

    Islam, Mohammed A; Khan, Seher A; Talukder, Rahmat M

    2016-12-01

    The purpose of the present study was to assess the current status of physiology education in US Doctor of Pharmacy (PharmD) programs. A survey instrument was developed and distributed through SurveyMonkey to American Association of Colleges of Pharmacy (AACP) Biological Sciences section members of 132 PharmD programs. Survey items focused on soliciting qualitative and quantitative information on the delivery of physiology curricular contents and faculty perceptions of physiology education. A total of 114 programs responded to the survey, resulting in a response rate of 86%. Out of 114 schools/colleges, 61 programs (54%) offered standalone physiology courses, and 53 programs (46%) offered physiology integrated with other courses. When integrated, the average contact hours for physiology contents were significantly reduced compared with standalone courses (30 vs. 84 h, P physiology contents. Eighty percent of the responding faculty (n = 204) agree/strongly agree that physiology is underemphasized in PharmD curriculum. Moreover, 67% of the respondents agree/strongly agree that physiology should be taught as a standalone foundational course. A wide variation in the depth and breadth of physiology course offerings in US PharmD programs remains. The reduction of physiology contents is evident when physiology is taught as a component of integrated courses. Given current trends that favor integrated curricula, these data suggest that additional collaboration among basic and clinical science faculty is required to ensure that physiology contents are balanced and not underemphasized in a PharmD curriculum.

  9. Cassava biology and physiology.

    Science.gov (United States)

    El-Sharkawy, Mabrouk A

    2004-11-01

    Cassava or manioc (Manihot esculenta Crantz), a perennial shrub of the New World, currently is the sixth world food crop for more than 500 million people in tropical and sub-tropical Africa, Asia and Latin America. It is cultivated mainly by resource-limited small farmers for its starchy roots, which are used as human food either fresh when low in cyanogens or in many processed forms and products, mostly starch, flour, and for animal feed. Because of its inherent tolerance to stressful environments, where other food crops would fail, it is often considered a food-security source against famine, requiring minimal care. Under optimal environmental conditions, it compares favorably in production of energy with most other major staple food crops due to its high yield potential. Recent research at the Centro Internacional de Agricultura Tropical (CIAT) in Colombia has demonstrated the ability of cassava to assimilate carbon at very high rates under high levels of humidity, temperature and solar radiation,which correlates with productivity across all environments whether dry or humid. When grown on very poor soils under prolonged drought for more than 6 months, the crop reduce both its leaf canopy and transpiration water loss, but its attached leaves remain photosynthetically active, though at greatly reduced rates. The main physiological mechanism underlying such a remarkable tolerance to drought was rapid stomatal closure under both atmospheric and edaphic water stress, protecting the leaf against dehydration while the plant depletes available soil water slowly during long dry periods. This drought tolerance mechanism leads to high crop water use efficiency values. Although the cassava fine root system is sparse, compared to other crops, it can penetrate below 2 m soil,thus enabling the crop to exploit deep water if available. Leaves of cassava and wild Manihot possess elevated activities of the C4 enzyme PEP carboxylase but lack the leaf Kranz anatomy typical of C4

  10. Human physiology in space

    Science.gov (United States)

    Vernikos, J.

    1996-01-01

    The universality of gravity (1 g) in our daily lives makes it difficult to appreciate its importance in morphology and physiology. Bone and muscle support systems were created, cellular pumps developed, neurons organised and receptors and transducers of gravitational force to biologically relevant signals evolved under 1g gravity. Spaceflight provides the only microgravity environment where systematic experimentation can expand our basic understanding of gravitational physiology and perhaps provide new insights into normal physiology and disease processes. These include the surprising extent of our body's dependence on perceptual information, and understanding the effect and importance of forces generated within the body's weightbearing structures such as muscle and bones. Beyond this exciting prospect is the importance of this work towards opening the solar system for human exploration. Although both appear promising, we are only just beginning to taste what lies ahead.

  11. Circadian physiology of metabolism.

    Science.gov (United States)

    Panda, Satchidananda

    2016-11-25

    A majority of mammalian genes exhibit daily fluctuations in expression levels, making circadian expression rhythms the largest known regulatory network in normal physiology. Cell-autonomous circadian clocks interact with daily light-dark and feeding-fasting cycles to generate approximately 24-hour oscillations in the function of thousands of genes. Circadian expression of secreted molecules and signaling components transmits timing information between cells and tissues. Such intra- and intercellular daily rhythms optimize physiology both by managing energy use and by temporally segregating incompatible processes. Experimental animal models and epidemiological data indicate that chronic circadian rhythm disruption increases the risk of metabolic diseases. Conversely, time-restricted feeding, which imposes daily cycles of feeding and fasting without caloric reduction, sustains robust diurnal rhythms and can alleviate metabolic diseases. These findings highlight an integrative role of circadian rhythms in physiology and offer a new perspective for treating chronic diseases in which metabolic disruption is a hallmark.

  12. Plant Physiology and Development

    DEFF Research Database (Denmark)

    Taiz, Lincoln; Zeiger, Eduardo; Møller, Ian Max

    Physiology and Development. As before, Unit III begins with updated chapters on Cell Walls and Signals and Signal Transduction. The latter chapter has been expanded to include a discussion of major signaling molecules, such as calcium ions and plant hormones. A new, unified chapter entitled Signals from......Throughout its twenty-two year history, the authors of Plant Physiology have continually updated the book to incorporate the latest advances in plant biology and implement pedagogical improvements requested by adopters. This has made Plant Physiology the most authoritative, comprehensive......, and widely used upper-division plant biology textbook. In the Sixth Edition, the Growth and Development section (Unit III) has been reorganized and expanded to present the complete life cycle of seed plants from germination to senescence. In recognition of this enhancement, the text has been renamed Plant...

  13. From Clinical Application of Cardiopulmonary Exercise Testing to View the Requirement for Holistic Integrative Physiology and Medicine%从心肺运动的应用价值看医学整体整合的需求

    Institute of Scientific and Technical Information of China (English)

    谭晓越; 孙兴国

    2013-01-01

    The cardiopulmonary exercise testing is one important clinical functional test method.While patients do the loaded exercise, from rest to peak exercise to recovery, we continuously record the functions of respiratory, circulatory, metabolic and neurohumoral etc.systems.Based on these results, we can non-invasively evaluate the whole functional capacity and healthy condition, diagnose the diseases, grade the diseases' severity, evaluate the effective effect of the drug or treatment, and prognoses the death survival outcome.From the view of clinical using of cardiopulmonary exercise testing, we need a theoretical system of physiology and medicine for the all systems in human body in whole.%心肺运动试验是一个重要的人体整体功能学检测方法.让患者运动,连续动态记录以呼吸、循环、代谢和神经体液等多系统的功能活动,由此实现人体整体生理功能状态评价、疾病诊断、病情评估、治疗效果评估和预后转归预测.从心肺运动试验的临床应用出发,需要建立生理学医学的整体整合理论用以指导该技术的正确运用和解读.

  14. Talk about Hygiene Requirements in Sports Teaching from Anatomy and Physiology Characteristics of Children and Adolescents.%从儿童少年解剖生理特点谈体育教学中的卫生要求

    Institute of Scientific and Technical Information of China (English)

    张楚明

    2011-01-01

    儿童少年体内各组织器官和系统尚未发育成熟,大脑皮质兴奋性占有优势,软骨多、肌纤维细长,关节灵活,牢固性差,心率较快,血压偏低、肺活量小,因此要在体育教学过程据其解剖生理特点科学合理的进行锻炼。儿童少年正处于身体迅速生长发育时期,体内新陈代谢旺盛,各组织、器官和系统的结构和功能、智力和心里发育都尚未成熟,并受到先天的遗传和后天的营养、环境、体育活动。%Children and Teenagers' body tissues and organs and systems are not mature, take advantage of the cerebral cortex ex- citability, cartilage and more slender muscle, joint flexibility, strong, poor, rapid heart rate, low blood pressure, lung capacity is small, and therefore in physical education. Therefore, in physical education, we should do exercise according to its anatomy and physiology characteristics scientific and rationally.

  15. Conceptual Learning: Enhancing Student Understanding of Physiology

    Science.gov (United States)

    Waltz, Micah J.

    Students are leaving undergraduate science programs without the knowledge and skills they are expected to have. This is apparent in professional programs, such as medical and veterinary school, where students do not possess the critical thinking skills necessary to be successful. Physiology is a required discipline for these professional programs and often before, as a pre-requisite. Physiology classrooms are an excellent place to teach critical thinking skills because the content consists of integrated processes. Therefore, in one study, it was investigated whether focusing on physiological concepts improved student understanding of physiology in both a non-physiological science course, Invertebrate Zoology, and in an undergraduate physiology course. An educational intervention was used in Invertebrate Zoology, where students were exposed to human physiology concepts that were similar to comparative physiology concepts they had learned during the semester. A pre-/post-test was used to assess learning gains. In a second study, the use of multimedia file usage was correlated to student exam scores in a physiology course. This was done to see if providing additional study materials that focused on specific concepts improved student understanding, as assessed using exam scores. Overall these studies indicate that encouraging assimilation of new concepts that expand upon material from lecture may help students gain a more complete understanding of a concept. The integration of these concepts into pre-existing conceptual frameworks may serve to teach students valuable critical thinking skills such as evaluation of new ideas within their current understanding and synthesizing the new content with the existing information. Focusing on this type of conceptual learning may enable students to apply content knowledge and think through problems. Additionally, focusing on concepts may enable students to improve their understanding of material without being overwhelmed by

  16. Lewy Body Variant of Alzheimer's Disease: Selective Neocortical Loss of t-SNARE Proteins and Loss of MAP2 and α-Synuclein in Medial Temporal Lobe

    Directory of Open Access Journals (Sweden)

    Elizabeta B. Mukaetova-Ladinska

    2009-01-01

    Full Text Available Lewy bodies (LBs appear in the brains of nondemented individuals and also occur in a range of neurodegenerative disorders, such as dementia with Lewy bodies (DLB and Parkinson's disease. A number of people with a definite diagnosis of Alzheimer's disease (AD also exhibit these intraneuronal inclusions in allo- and/or neocortical areas. The latter, referred to as Lewy body variant of AD (LBV, bears a clinical resemblance to AD in terms of age at onset, duration of illness, cognitive impairment, and illness severity. Since the presence of LBs is accompanied by neuronal cytoskeleton changes, it is possible that the latter may influence neuronal connectivity via alterations to the synaptic network. To address this, we examined the expression of synaptic proteins (synaptophysin, syntaxin, SNAP-25, and α-synuclein and two cytoskeletal proteins (tau and MAP2 in the brain tissue of subjects enrolled in a population-based autopsy study (n = 47. They were divided into groups with no memory problems (control group, n = 15, LBV (n = 5, AD devoid of LBs (n = 17, cerebrovascular dementia (n = 3, and mixed dementia (n = 7. The LBV and AD groups had a similar degree of cognitive impairment and neuropathological staging in terms of Braak staging and CERAD score. In comparison with the control group and the dementia groups without LBs, the LBV group had significantly lower levels of syntaxin and SNAP-25 (23% in the neocortex, and depletion of MAP2 (64%, SNAP-25 (34%, and α-synuclein (44% proteins in the medial temporal lobes. These findings suggest that the t-SNARE complex deficit present in LBV may be associated with the presence of LB-related pathology and may explain the more profound cholinergic loss seen in these patients.

  17. The Face of Physiology

    Directory of Open Access Journals (Sweden)

    Paul White

    2008-10-01

    Full Text Available This article explores the relationship between the physiology of the emotions and the display of character in Victorian Britain. Charles Bell and others had begun to link certain physiological functions, such as respiration, with the expression of feelings such as fear, regarding the heart and other internal organs as instruments by which the emotions were made visible. But a purely functional account of the emotions, which emerged through the development of reflex physiology during the second half of the century, would dramatically alter the nature of feelings and the means of observing them. At the same time, instinctual or acquired sympathy, which had long underpinned the accurate reading of expressions, became a problem to be surmounted by new 'objectively'. Graphic recording instruments measuring a variety of physiological functions and used with increasing frequency in clinical diagnostics became of fundamental importance for tracing the movement of feelings during the period prior to the development of cinematography. They remained, in the form of devices such as the polygraph, a crucial and controversial means of measuring affective states, beneath the potentially deceptive surface of the body.

  18. Starting Physiology: Bioelectrogenesis

    Science.gov (United States)

    Baptista, Vander

    2015-01-01

    From a Cartesian perspective of rational analysis, the electric potential difference across the cell membrane is one of the fundamental concepts for the study of physiology. Unfortunately, undergraduate students often struggle to understand the genesis of this energy gradient, which makes the teaching activity a hard task for the instructor. The…

  19. Physiology of Sleep.

    Science.gov (United States)

    Carley, David W; Farabi, Sarah S

    2016-02-01

    IN BRIEF Far from a simple absence of wakefulness, sleep is an active, regulated, and metabolically distinct state, essential for health and well-being. In this article, the authors review the fundamental anatomy and physiology of sleep and its regulation, with an eye toward interactions between sleep and metabolism.

  20. Integrative Physiology of Fasting.

    Science.gov (United States)

    Secor, Stephen M; Carey, Hannah V

    2016-03-15

    Extended bouts of fasting are ingrained in the ecology of many organisms, characterizing aspects of reproduction, development, hibernation, estivation, migration, and infrequent feeding habits. The challenge of long fasting episodes is the need to maintain physiological homeostasis while relying solely on endogenous resources. To meet that challenge, animals utilize an integrated repertoire of behavioral, physiological, and biochemical responses that reduce metabolic rates, maintain tissue structure and function, and thus enhance survival. We have synthesized in this review the integrative physiological, morphological, and biochemical responses, and their stages, that characterize natural fasting bouts. Underlying the capacity to survive extended fasts are behaviors and mechanisms that reduce metabolic expenditure and shift the dependency to lipid utilization. Hormonal regulation and immune capacity are altered by fasting; hormones that trigger digestion, elevate metabolism, and support immune performance become depressed, whereas hormones that enhance the utilization of endogenous substrates are elevated. The negative energy budget that accompanies fasting leads to the loss of body mass as fat stores are depleted and tissues undergo atrophy (i.e., loss of mass). Absolute rates of body mass loss scale allometrically among vertebrates. Tissues and organs vary in the degree of atrophy and downregulation of function, depending on the degree to which they are used during the fast. Fasting affects the population dynamics and activities of the gut microbiota, an interplay that impacts the host's fasting biology. Fasting-induced gene expression programs underlie the broad spectrum of integrated physiological mechanisms responsible for an animal's ability to survive long episodes of natural fasting.

  1. Colonoscopia com polipectomia: análise crítica de fatores de risco e complicações Colonic snare polipectomy: critical analysis of risk factors and complications

    Directory of Open Access Journals (Sweden)

    Edson Jurado da Silva

    2009-12-01

    Full Text Available Objetivo: Analisar complicações de polipectomia com alça ditérmica em cólon. Pacientes e Métodos: Estudo retrospectivo de polipectomias em colonoscopias realizadas em dois hospitais de 2001 a 2007. Teste t de Student foi usado para média, desvio padrão e qui-quadrado para números absolutos. P0,05. Síndrome pós-polipectomia em 6 (0,35%. Ressecção fatiada somente em maiores que 2 cm, 89/116 (77% sésseis e 11/87 (13% pediculados pPurpose: The aim of this study was to evaluate adverse events from snare polypectomy. Methods: We retrospectively analysed the rate of complications of 1687 snare polypectomies carried out in 8447 colonoscopies between 2001 and 2007 at two Medical Institutions. Student t test was used for statistical analysis of mean and chi-square to compare absolute numbers. A significant p-value was defined as 0,05.Post-polypectomy syndrome occurred in 6 patients (0,35%. In polyps larger than 2 cm, piecemeal resection was performed more often in sessile than in pedunculated ones 89/116 ( 77% versus 11/87 (13% p<0,01. Invasive carcinoma was present in 40 adenoma larger than 2 cm (19,7%. Conclusion: Snare polypectomy is safe procedure, being bleeding the most common complication, related with polyp size mainly its base, treated most of the time endoscopically. Perforation being the next, treated too without surgery.

  2. Avian reproductive physiology

    Science.gov (United States)

    Gee, G.F.; Gibbons, Edward F.; Durrant, Barbara S.; Demarest, Jack

    1995-01-01

    Knowledge of the many physiological factors associated with egg production , fertility, incubation, and brooding in nondomestic birds is limited. Science knows even less about reproduction in most of the 238 endangered or threatened birds. This discussion uses studies of nondomestic and, when necessary, domestic birds to describe physiological control of reproduction. Studies of the few nondomestic avian species show large variation in physiological control of reproduction. Aviculturists, in order to successfully propagate an endangered bird, must understand the bird's reproductive peculiarities. First, investigators can do studies with carefully chosen surrogate species, but eventually they need to confirm the results in the target endangered bird. Studies of reproduction in nondomestic birds increased in the last decade. Still, scientists need to do more comparative studies to understand the mechanisms that control reproduction in birds. New technologies are making it possible to study reproductive physiology of nondomestic species in less limiting ways. These technologies include telemetry to collect information without inducing stress on captives (Howey et al., 1987; Klugman, 1987), new tests for most of the humoral factors associated with reproduction, and the skill to collect small samples and manipulate birds without disrupting the physiological mechanisms (Bercovitz et al., 1985). Managers are using knowledge from these studies to improve propagation in zoological parks, private and public propagation facilities, and research institutions. Researchers need to study the control of ovulation, egg formation, and oviposition in the species of nondomestic birds that lay very few eggs in a season, hold eggs in the oviduct for longer intervals, or differ in other ways from the more thoroughly studied domestic birds. Other techniques that would enhance propagation for nondomestlc birds include tissue culture of cloned embryonic cells, cryopreservation of embryos

  3. Herpetological diversity along Andean elevational gradients: links with physiological ecology and evolutionary physiology.

    Science.gov (United States)

    Navas, Carlos A

    2002-11-01

    A well-defined macroecological pattern is the decline in biodiversity with altitude. However, this decline is taxa-specific. For example, amphibians are more diverse than squamates at extreme elevations in the tropical Andes, but this pattern is reversed at extreme elevations in the southern latitudes. Several ecophysiological and evolutionary factors may be related to this difference. At high-elevations in southern latitudes temperature differs dramatically among seasons and dry soils dominate, characteristics that appear to favor lizard physiological ecology. Tropical high altitudes, in contrast, are humid and offer abundant and diverse water resources. These characteristics allow for a richer anuran community but might complicate lizard egg development through temperature and oxygen constrains. Differences in strategies of thermal adaptation might also modulate diversity patterns. The thermal physiology of anurans is extremely labile so that behavioral and physiological performance is maintained despite an altitudinal decrease in field body temperature. Lizards, in contrast, exhibit a conservative thermal physiology and rely on behavioral thermoregulation to face cold and variable temperatures. Both, lizard behavioral strategies and anuran physiological adjustments seem equally efficient in allowing ecological success and diversification for both groups in the tropics up to approximately 3000 m. At higher elevations physiological thermal adaptation is required, and lizards are ecologically constrained, perhaps at various ontogenetic stages. Patterns of biodiversity along environmental clines can be better understood through a physiological approach, and can help to refine and propose hypotheses in evolutionary physiology.

  4. Tuna comparative physiology.

    Science.gov (United States)

    Graham, Jeffrey B; Dickson, Kathryn A

    2004-11-01

    Thunniform swimming, the capacity to conserve metabolic heat in red muscle and other body regions (regional endothermy), an elevated metabolic rate and other physiological rate functions, and a frequency-modulated cardiac output distinguish tunas from most other fishes. These specializations support continuous, relatively fast swimming by tunas and minimize thermal barriers to habitat exploitation, permitting niche expansion into high latitudes and to ocean depths heretofore regarded as beyond their range.

  5. Neonatal cardiovascular physiology.

    Science.gov (United States)

    Hines, Michael H

    2013-11-01

    The pediatric surgeon deals with a large number and variety of congenital defects in neonates that frequently involve early surgical intervention and care. Because the neonatal cardiac physiology is unique, starting with the transition from fetal circulation and including differences in calcium metabolism and myocardial microscopic structure and function, it serves the pediatric surgeon well to have a sound understanding of these principles and how they directly and indirectly affect their plans and treatments. In addition, many patients will have associated congenital heart disease that can also dramatically influence not only the surgical and anesthetic care but also the timing and planning of procedures. Finally, the pediatric surgeon is often called upon to treat conditions and complications associated with complex congenital heart disease such as feeding difficulties, bowel perforations, and malrotation in heterotaxy syndromes. In this article, we will review several unique aspects of neonatal cardiac physiology along with the basic physiology of the major groups of congenital heart disease to better prepare the training and practicing pediatric surgeon for care of these complex and often fragile patients.

  6. Animal reproduction and physiology: from basis to application

    Institute of Scientific and Technical Information of China (English)

    GUI JianFang

    2010-01-01

    @@ Animal reproduction and physiology is one of the traditional subjects in biology, and also one of the most rapidly developing fields because it is related to human food requirements.Along with advances in the life sciences and biotechnology, animal reproduction and physiology has achieved new theoretical developments and potential applications.

  7. Physiological assessment of long pepper seeds

    Directory of Open Access Journals (Sweden)

    Francisco Pacheco Júnior

    2015-12-01

    Full Text Available The environmental and economic potential of long pepper (Piper hispidinervum requires the development of methodology to evaluate seed potential physiological. The work aimed to evaluate the physiological potential of long pepper seeds (Piper hispidinervum C. DC. through different tests and accelerated aging. Seeds were harvested in four different commercial planting and evaluated to water content (%, germination (G%, germination speed index (GSI, seedling emergence (SE%, emergence rate index (ERI and accelerated aging (AA 41 and 45 °C during 24, 48, 72 and 96 hours. The experimental design was completely randomized with a simple scheme for G, GSI, SE and ERI, and 4 x 4 factorial (lots and times at each temperature for AA. Physiological potential of long pepper seeds can be evaluated by germination test, germination speed index, seedling emergence, seedlings emergence speed index and accelerated aging at 41 °C during 24 hours.

  8. A Brief History of Bacterial Growth Physiology

    Directory of Open Access Journals (Sweden)

    Moselio eSchaechter

    2015-04-01

    Full Text Available Arguably, microbial physiology started when Leeuwenhoek became fascinated by observing a Vorticella beating its cilia, my point being that almost any observation of microbes has a physiological component. With the advent of modern microbiology in the mid 19th century, the field became recognizably distinctive with such discoveries as anaerobiosis, fermentation as a biological phenomenon, and the nutritional requirements of microbes. Soon came the discoveries of Winogradsky and his followers of the chemical changes in the environment that result from microbial activities. Later, during the first half of the 20th century, microbial physiology became the basis for much of the elucidation of central metabolism.Bacterial physiology then became a handmaiden of molecular biology and was greatly influenced by the discovery of cellular regulatory mechanisms. Microbial growth, which had come of age with the early work of Hershey, Monod, and others, was later pursued by studies on a whole cell level by what became known as the Copenhagen School. During this time, the exploration of physiological activities became coupled to modern inquiries into the structure of the bacterial cell.Recent years have seen the development of a further phase in microbial physiology, one seeking a deeper quantitative understanding of phenomena on a whole cell level. This pursuit is exemplified by the emergence of systems biology, which is made possible by the development of technologies that permit the gathering of information in huge amounts. As has been true through history, the research into microbial physiology continues to be guided by the development of new methods of analysis. Some of these developments may well afford the possibility of making stunning breakthroughs.

  9. A brief history of bacterial growth physiology.

    Science.gov (United States)

    Schaechter, Moselio

    2015-01-01

    Arguably, microbial physiology started when Leeuwenhoek became fascinated by observing a Vorticella beating its cilia, my point being that almost any observation of microbes has a physiological component. With the advent of modern microbiology in the mid-19th century, the field became recognizably distinctive with such discoveries as anaerobiosis, fermentation as a biological phenomenon, and the nutritional requirements of microbes. Soon came the discoveries of Winogradsky and his followers of the chemical changes in the environment that result from microbial activities. Later, during the first half of the 20th century, microbial physiology became the basis for much of the elucidation of central metabolism. Bacterial physiology then became a handmaiden of molecular biology and was greatly influenced by the discovery of cellular regulatory mechanisms. Microbial growth, which had come of age with the early work of Hershey, Monod, and others, was later pursued by studies on a whole cell level by what became known as the "Copenhagen School." During this time, the exploration of physiological activities became coupled to modern inquiries into the structure of the bacterial cell. Recent years have seen the development of a further phase in microbial physiology, one seeking a deeper quantitative understanding of phenomena on a whole cell level. This pursuit is exemplified by the emergence of systems biology, which is made possible by the development of technologies that permit the gathering of information in huge amounts. As has been true through history, the research into microbial physiology continues to be guided by the development of new methods of analysis. Some of these developments may well afford the possibility of making stunning breakthroughs.

  10. Physiology of bile secretion

    Institute of Scientific and Technical Information of China (English)

    Alejandro Esteller

    2008-01-01

    The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment,in different situations,results in the syndrome of cholestasis.The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed.Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane.This review summarizes recent data on the molecular determinants of this primary bile formation.The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bileduct epithelial cells (cholangiocytes) as bile passes through bile ducts.The mechanisms of fluid and solute transport in cholangiocytes will also be discussed.In contrast to hepatocytes where secretion is constant and poorly controlled,cholangiocyte secretion is regulated by hormones and nerves.A short section dedicated to these regulatory mechanisms of bile secretion has been included.The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.

  11. Network Physiology: Mapping Interactions Between Networks of Physiologic Networks

    Science.gov (United States)

    Ivanov, Plamen Ch.; Bartsch, Ronny P.

    The human organism is an integrated network of interconnected and interacting organ systems, each representing a separate regulatory network. The behavior of one physiological system (network) may affect the dynamics of all other systems in the network of physiologic networks. Due to these interactions, failure of one system can trigger a cascade of failures throughout the entire network. We introduce a systematic method to identify a network of interactions between diverse physiologic organ systems, to quantify the hierarchical structure and dynamics of this network, and to track its evolution under different physiologic states. We find a robust relation between network structure and physiologic states: every state is characterized by specific network topology, node connectivity and links strength. Further, we find that transitions from one physiologic state to another trigger a markedly fast reorganization in the network of physiologic interactions on time scales of just a few minutes, indicating high network flexibility in response to perturbations. This reorganization in network topology occurs simultaneously and globally in the entire network as well as at the level of individual physiological systems, while preserving a hierarchical order in the strength of network links. Our findings highlight the need of an integrated network approach to understand physiologic function, since the framework we develop provides new information which can not be obtained by studying individual systems. The proposed system-wide integrative approach may facilitate the development of a new field, Network Physiology.

  12. [Physiology of the neuropeptides].

    Science.gov (United States)

    García-López, M J; Martínez-Martos, J M; Mayas, M D; Carrera, M P; Ramírez- Expósito, M J

    In the present review, the characteristics of mammalian neuropeptides have been studied. Neuropeptides are widely distributed not only in the nervous system but also in the periphery. They are synthesised by neurons as large precursor molecules (pre propeptides) which have to be cleaved and modified in order to form the mature neuropeptides. Neuropeptides may exert actions as neurotransmitters, neuromodulators and/or neurohormones. In the neurons, they coexist with classic transmitters and often with other peptides. After their releasing, they bind to especific receptors to exert their action in the target cell. Most of these receptors belongs to a family of G protein coupled receptors. Finally, peptidases are the enzymes involved in the degradation of neuropeptides. Conclusions. In the last years, the number of known neuropeptides and the understanding of their functions have been increased. With these data, present investigations are looking for the treatment of different pathologies associated with alterations in the physiology of neuropeptides.

  13. Physiology for engineers applying engineering methods to physiological systems

    CERN Document Server

    Chappell, Michael

    2016-01-01

    This book provides an introduction to qualitative and quantitative aspects of human physiology. It looks at biological and physiological processes and phenomena, including a selection of mathematical models, showing how physiological problems can be mathematically formulated and studied. It also illustrates how a wide range of engineering and physics topics, including electronics, fluid dynamics, solid mechanics and control theory can be used to describe and understand physiological processes and systems. Throughout the text there are introductions to measuring and quantifying physiological processes using both signal and imaging technologies. Physiology for Engineers describes the basic structure and models of cellular systems, the structure and function of the cardiovascular system, the electrical and mechanical activity of the heart and provides an overview of the structure and function of the respiratory and nervous systems. It also includes an introduction to the basic concepts and applications of reacti...

  14. Network Physiology reveals relations between network topology and physiological function

    CERN Document Server

    Bashan, Amir; Kantelhardt, Jan W; Havlin, Shlomo; Ivanov, Plamen Ch; 10.1038/ncomms1705

    2012-01-01

    The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate the development of a new field, Network Physiology.

  15. Physiological phenotyping of plants for crop improvement.

    Science.gov (United States)

    Ghanem, Michel Edmond; Marrou, Hélène; Sinclair, Thomas R

    2015-03-01

    Future progress in crop breeding requires a new emphasis in plant physiological phenotyping for specific, well-defined traits. Success in physiological phenotyping to identify parents for use in breeding efforts for improved cultivars has been achieved by employing a multi-tier screening approach with different levels of sophistication and trait resolution. Subsequently, cultivar development required an integrated mix of classical breeding approaches and one or more tiers of phenotyping to identify genotypes expressing the desired trait. The role of high throughput systems can be useful; here, we emphasize that this approach is likely to offer useful results at an initial tier of phenotyping and will need to be complemented with more directed tiers of phenotyping. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Network physiology reveals relations between network topology and physiological function

    OpenAIRE

    Bashan, Amir; Bartsch, Ronny P.; Kantelhardt, Jan W.; Havlin, Shlomo; Ivanov, Plamen Ch.

    2012-01-01

    The human organism is an integrated network where complex physiological systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here we develop a framework to probe interactions among diverse systems, and we identify a physiological network. We find that each physiological state is...

  17. Ethics Issues Snare School Leaders

    Science.gov (United States)

    Borja, Rhea R.

    2005-01-01

    This article reports on ethics issues involving school leaders. Some superintendents have landed in murky ethical waters for their ties to for-profit companies, highlighting the temptations administrators face as industry and education increasingly intersect. Some questionable judgments by superintendents--from accepting company-paid trips to…

  18. Cardiovascular physiology and sleep.

    Science.gov (United States)

    Murali, Narayana S; Svatikova, Anna; Somers, Virend K

    2003-05-01

    Sleep is a natural periodic suspension of consciousness during which processes of rest and restoration occur. The cognitive, reparative and regenerative accompaniments of sleep appear to be essential for maintenance of health and homeostasis. This brief overview will examine the cardiovascular responses to normal and disordered sleep, and their physiologic and pathologic implications. In the past, sleep was believed to be a passive state. The tableau of sleep as it unfolds is anything but a passive process. The brain's activity is as complex as wakefulness, never "resting" during sleep. Following the demise of the 'passive theory of sleep' (the reticular activating system is fatigued during the waking day and hence becomes inactive), there arose the 'active theory of sleep' (sleep is due to an active general inhibition of the brain) (1). Hess demonstrated the active nature of sleep in cats, inducing "physiological sleep" with electrical stimulation of the diencephalon (2). Classical experiments of transection of the cat brainstem (3) at midpontine level inhibited sleep completely, implying that centers below this level were involved in the induction of sleep (1, 4). For the first time, measurement of sleep depth without awakening the sleeper using the electroencephalogram (EEG) was demonstrated in animals by Caton and in humans, by Berger (1). This was soon followed by discovery of the rapid eye movement sleep periods (REM) by Aserinski and Kleitman (5), demonstration of periodical sleep cycles and their association with REM sleep (6, 7). Multiple studies and steady discoveries (4) made polysomnography, with its ability to perform simultaneous whole night recordings of EEG, electromyogram (EMG), and electrooculogram (EOC), a major diagnostic tool in study of sleep disorders. This facility has been of further critical importance in allowing evaluation of the interaction between sleep and changes in hemodynamics and autonomic cardiovascular control. Consequently the

  19. Physiology of vitreous surgery.

    Science.gov (United States)

    Stefánsson, Einar

    2009-02-01

    Vitreous surgery has various physiological and clinical consequences, both beneficial and harmful. Vitrectomy reduces the risk of retinal neovascularization, while increasing the risk of iris neovascularization, reduces macular edema and stimulates cataract formation. These clinical consequences may be understood with the help of classical laws of physics and physiology. The laws of Fick, Stokes-Einstein and Hagen-Poiseuille state that molecular transport by diffusion or convection is inversely related to the viscosity of the medium. When the vitreous gel is replaced with less viscous saline, the transport of all molecules, including oxygen and cytokines, is facilitated. Oxygen transport to ischemic retinal areas is improved, as is clearance of VEGF and other cytokines from these areas, thus reducing edema and neovascularization. At the same time, oxygen is transported faster down a concentration gradient from the anterior to the posterior segment, while VEGF moves in the opposite direction, making the anterior segment less oxygenated and with more VEGF, stimulating iris neovascularization. Silicone oil is the exception that proves the rule: it is more viscous than vitreous humour, re-establishes the transport barrier to oxygen and VEGF, and reduces the risk for iris neovascularization in the vitrectomized-lentectomized eye. Modern vitreous surgery involves a variety of treatment options in addition to vitrectomy itself, such as photocoagulation, anti-VEGF drugs, intravitreal steroids and release of vitreoretinal traction. A full understanding of these treatment modalities allows sensible combination of treatment options. Retinal photocoagulation has repeatedly been shown to improve retinal oxygenation, as does vitrectomy. Oxygen naturally reduces VEGF production and improves retinal hemodynamics. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and the permeability effect of VEGF reduced with corticosteroids

  20. Procedures of Exercise Physiology Laboratories

    Science.gov (United States)

    Bishop, Phillip A.; Fortney, Suzanne; Greenisen, Michael; Siconolfi, Steven F.; Bamman, Marcas M.; Moore, Alan D., Jr.; Squires, William

    1998-01-01

    This manual describes the laboratory methods used to collect flight crew physiological performance data at the Johnson Space Center. The Exercise Countermeasures Project Laboratory is a standard physiology laboratory; only the application to the study of human physiological adaptations to spaceflight is unique. In the absence of any other recently published laboratory manual, this manual should be a useful document staffs and students of other laboratories.

  1. Conservation physiology of marine fishes

    DEFF Research Database (Denmark)

    Jørgensen, Christian; Peck, Myron A.; Antognarelli, Fabio

    2012-01-01

    At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology...... to different extents, ranging from no explicit consideration to detailed physiological mechanisms, and across scales from a single fish to global fishery resources. Biologists from different sub-disciplines are collaborating to rise to the challenge of projecting future changes in distribution and productivity...

  2. Principles and standards for reporting animal experiments in The Journal of Physiology and Experimental Physiology.

    Science.gov (United States)

    Grundy, David

    2015-07-01

    The Journal of Physiology and Experimental Physiology have always used UK legislation as the basis of their policy on ethical standards in experiments on non-human animals. However, for international journals with authors, editors and referees from outside the UK the policy can lack transparency and is sometimes cumbersome, requiring the intervention of a Senior Ethics Reviewer or advice from external experts familiar with UK legislation. The journals have therefore decided to set out detailed guidelines for how authors should report experimental procedures that involve animals. As well as helping authors, this new clarity will facilitate the review process and decision making where there are questions regarding animal ethics.

  3. Starting physiology: bioelectrogenesis.

    Science.gov (United States)

    Baptista, Vander

    2015-12-01

    From a Cartesian perspective of rational analysis, the electric potential difference across the cell membrane is one of the fundamental concepts for the study of physiology. Unfortunately, undergraduate students often struggle to understand the genesis of this energy gradient, which makes the teaching activity a hard task for the instructor. The topic of bioelectrogenesis encompasses multidisciplinary concepts, involves several mechanisms, and is a dynamic process, i.e., it never turns off during the lifetime of the cell. Therefore, to improve the transmission and acquisition of knowledge in this field, I present an alternative didactic model. The design of the model assumes that it is possible to build, in a series of sequential steps, an assembly of proteins within the membrane of an isolated cell in a simulated electrophysiology experiment. Initially, no proteins are inserted in the membrane and the cell is at a baseline energy state; the extracellular and intracellular fluids are at thermodynamic equilibrium. Students are guided through a sequence of four steps that add key membrane transport proteins to the model cell. The model is simple at the start and becomes progressively more complex, finally producing transmembrane chemical and electrical gradients. I believe that this didactic approach helps instructors with a more efficient tool for the teaching of the mechanisms of resting membrane potential while helping students avoid common difficulties that may be encountered when learning this topic.

  4. Hypertension: physiology and pathophysiology.

    Science.gov (United States)

    Hall, John E; Granger, Joey P; do Carmo, Jussara M; da Silva, Alexandre A; Dubinion, John; George, Eric; Hamza, Shereen; Speed, Joshua; Hall, Michael E

    2012-10-01

    Despite major advances in understanding the pathophysiology of hypertension and availability of effective and safe antihypertensive drugs, suboptimal blood pressure (BP) control is still the most important risk factor for cardiovascular mortality and is globally responsible for more than 7 million deaths annually. Short-term and long-term BP regulation involve the integrated actions of multiple cardiovascular, renal, neural, endocrine, and local tissue control systems. Clinical and experimental observations strongly support a central role for the kidneys in the long-term regulation of BP, and abnormal renal-pressure natriuresis is present in all forms of chronic hypertension. Impaired renal-pressure natriuresis and chronic hypertension can be caused by intrarenal or extrarenal factors that reduce glomerular filtration rate or increase renal tubular reabsorption of salt and water; these factors include excessive activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, increased formation of reactive oxygen species, endothelin, and inflammatory cytokines, or decreased synthesis of nitric oxide and various natriuretic factors. In human primary (essential) hypertension, the precise causes of impaired renal function are not completely understood, although excessive weight gain and dietary factors appear to play a major role since hypertension is rare in nonobese hunter-gathers living in nonindustrialized societies. Recent advances in genetics offer opportunities to discover gene-environment interactions that may also contribute to hypertension, although success thus far has been limited mainly to identification of rare monogenic forms of hypertension. © 2012 American Physiological Society

  5. Physiology in Modelica

    Directory of Open Access Journals (Sweden)

    Marek Mateják

    2014-05-01

    Full Text Available Modelica is an object-oriented language, in which models can be created and graphically represented by connecting instances of classes from libraries. These connections are not only assignments of values; they can also represent acausal equality. Even more, they can model Kirchhoff’s laws of circuits. In Modelica it is possible to develop library classes which are an analogy of electrical circuit components. The result of our work in this field is Physiolibrary (www.physiolibrary.org – a free, open-source Modelica library for human physiology. By graphical joining instances of Physiolibrary classes, user can create models of cardiovascular circulation, thermoregulation, metabolic processes, nutrient distribution, gas transport, electrolyte regulation, water distribution, hormonal regulation and pharmacological regulation. After simple setting of the parameters, the models are ready to simulate. After simulation, the user can examine variables as their values change over time. Representing the model as a diagram has also great educational advantages, because students are able to better understand physical principles when they see them modeled graphically.

  6. Smolt physiology and endocrinology

    Science.gov (United States)

    McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

    2013-01-01

    Hormones play a critical role in maintaining body fluid balance in euryhaline fishes during changes in environmental salinity. The neuroendocrine axis senses osmotic and ionic changes, then signals and coordinates tissue-specific responses to regulate water and ion fluxes. Rapid-acting hormones, e.g. angiotensins, cope with immediate challenges by controlling drinking rate and the activity of ion transporters in the gill, gut, and kidney. Slow-acting hormones, e.g. prolactin and growth hormone/insulin-like growth factor-1, reorganize the body for long-term acclimation by altering the abundance of ion transporters and through cell proliferation and differentiation of ionocytes and other osmoregulatory cells. Euryhaline species exist in all groups of fish, including cyclostomes, and cartilaginous and teleost fishes. The diverse strategies for responding to changes in salinity have led to differential regulation and tissue-specific effects of hormones. Combining traditional physiological approaches with genomic, transcriptomic, and proteomic analyses will elucidate the patterns and diversity of the endocrine control of euryhalinity.

  7. Polyamines in plant physiology

    Science.gov (United States)

    Galston, A. W.; Sawhney, R. K.

    1990-01-01

    The diamine putrescine, the triamine spermidine, and the tetramine spermine are ubiquitous in plant cells, while other polyamines are of more limited occurrence. Their chemistry and pathways of biosynthesis and metabolism are well characterized. They occur in the free form as cations, but are often conjugated to small molecules like phenolic acids and also to various macromolecules. Their titer varies from approximately micromolar to more than millimolar, and depends greatly on environmental conditions, especially stress. In cereals, the activity of one of the major polyamine biosynthetic enzymes, arginine decarboxylase, is rapidly and dramatically increased by almost every studied external stress, leading to 50-fold or greater increases in putrescine titer within a few hours. The physiological significance of this increase is not yet clear, although most recent work suggests an adaptive, protective role. Polyamines produced through the action of ornithine decarboxylase, by contrast, seem essential for DNA replication and cell division. The application of exogenous polyamines produces effects on patterns of senescence and morphogenesis, suggesting but not proving a regulatory role for polyamines in these processes. The evidence for such a regulatory role is growing.

  8. DOSHIC PHYSIOLOGY OF SKIN

    Directory of Open Access Journals (Sweden)

    Shivprasad Chiplunkar

    2013-06-01

    Full Text Available The balance of dosha  represents the healthy state and imbalance will cause various diseases. In normalcy doshas will be performing their own functions and individual doshas will be having their own specific sites. By telling the various sthana of each dosha, different function that is taken up by individual dosha in different sites has been highlighted.By mentioning ‘sparshanendriyam’ as one of the sthana of vata dosha the sensory functions of skin to vata dosha has been emphasised. By mentioning ‘sparshanam’ as one of the sthana of pittadosha, the function of colouring/pigmentation of skin, which is majorly carried out  by melanocytes by secreting melanin pigment has been highlighted. Meda is one among the sthanas of kapha dosha; this can be considered as the adipose tissue of skin/below skin. Since sweda is mala of meda it can be also considered as the secretions from the eccrine glands.With respect to skin, sensory functions, both tactile and thermal is carried out by vata dosha more specifically vyana vata, pigmentation to the skin carried out by meloncytes by secreting melanin, it is nothing but function of pitta dosha more specifically brajaka pitta with the help of udana vata and finally production of sweat in sweat glands is the function of kapha. So there is the need for further study and research regarding the sthanas of all three doshas in different structures/organs in the body and its physiology.

  9. Dehydration: physiology, assessment, and performance effects.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W

    2014-01-01

    This article provides a comprehensive review of dehydration assessment and presents a unique evaluation of the dehydration and performance literature. The importance of osmolality and volume are emphasized when discussing the physiology, assessment, and performance effects of dehydration. The underappreciated physiologic distinction between a loss of hypo-osmotic body water (intracellular dehydration) and an iso-osmotic loss of body water (extracellular dehydration) is presented and argued as the single most essential aspect of dehydration assessment. The importance of diagnostic and biological variation analyses to dehydration assessment methods is reviewed and their use in gauging the true potential of any dehydration assessment method highlighted. The necessity for establishing proper baselines is discussed, as is the magnitude of dehydration required to elicit reliable and detectable osmotic or volume-mediated compensatory physiologic responses. The discussion of physiologic responses further helps inform and explain our analysis of the literature suggesting a ≥ 2% dehydration threshold for impaired endurance exercise performance mediated by volume loss. In contrast, no clear threshold or plausible mechanism(s) support the marginal, but potentially important, impairment in strength, and power observed with dehydration. Similarly, the potential for dehydration to impair cognition appears small and related primarily to distraction or discomfort. The impact of dehydration on any particular sport skill or task is therefore likely dependent upon the makeup of the task itself (e.g., endurance, strength, cognitive, and motor skill).

  10. Virtual physiological human: training challenges.

    Science.gov (United States)

    Lawford, Patricia V; Narracott, Andrew V; McCormack, Keith; Bisbal, Jesus; Martin, Carlos; Bijnens, Bart; Brook, Bindi; Zachariou, Margarita; Freixa, Jordi Villà I; Kohl, Peter; Fletcher, Katherine; Diaz-Zuccarini, Vanessa

    2010-06-28

    The virtual physiological human (VPH) initiative encompasses a wide range of activities, including structural and functional imaging, data mining, knowledge discovery tool and database development, biomedical modelling, simulation and visualization. The VPH community is developing from a multitude of relatively focused, but disparate, research endeavours into an integrated effort to bring together, develop and translate emerging technologies for application, from academia to industry and medicine. This process initially builds on the evolution of multi-disciplinary interactions and abilities, but addressing the challenges associated with the implementation of the VPH will require, in the very near future, a translation of quantitative changes into a new quality of highly trained multi-disciplinary personnel. Current strategies for undergraduate and on-the-job training may soon prove insufficient for this. The European Commission seventh framework VPH network of excellence is exploring this emerging need, and is developing a framework of novel training initiatives to address the predicted shortfall in suitably skilled VPH-aware professionals. This paper reports first steps in the implementation of a coherent VPH training portfolio.

  11. Syntaxin 7 and VAMP-7 are Soluble N-Ethylmaleimide–sensitive Factor Attachment Protein Receptors Required for Late Endosome–Lysosome and Homotypic Lysosome Fusion in Alveolar Macrophages

    Science.gov (United States)

    Ward, Diane McVey; Pevsner, Jonathan; Scullion, Matthew A.; Vaughn, Michael; Kaplan, Jerry

    2000-01-01

    Endocytosis in alveolar macrophages can be reversibly inhibited, permitting the isolation of endocytic vesicles at defined stages of maturation. Using an in vitro fusion assay, we determined that each isolated endosome population was capable of homotypic fusion. All vesicle populations were also capable of heterotypic fusion in a temporally specific manner; early endosomes, isolated 4 min after internalization, could fuse with endosomes isolated 8 min after internalization but not with 12-min endosomes or lysosomes. Lysosomes fuse with 12-min endosomes but not with earlier endosomes. Using homogenous populations of endosomes, we have identified Syntaxin 7 as a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) required for late endosome–lysosome and homotypic lysosome fusion in vitro. A bacterially expressed human Syntaxin 7 lacking the transmembrane domain inhibited homotypic late endosome and lysosome fusion as well as heterotypic late endosome–lysosome fusion. Affinity-purified antibodies directed against Syntaxin 7 also inhibited lysosome fusion in vitro but had no affect on homotypic early endosome fusion. Previous work suggested that human VAMP-7 (vesicle-associated membrane protein-7) was a SNARE required for late endosome–lysosome fusion. A bacterially expressed human VAMP-7 lacking the transmembrane domain inhibited both late endosome–lysosome fusion and homotypic lysosome fusion in vitro. These studies indicate that: 1) fusion along the endocytic pathway is a highly regulated process, and 2) two SNARE molecules, Syntaxin 7 and human VAMP-7, are involved in fusion of vesicles in the late endocytic pathway in alveolar macrophages. PMID:10888671

  12. Causality in physiological signals.

    Science.gov (United States)

    Müller, Andreas; Kraemer, Jan F; Penzel, Thomas; Bonnemeier, Hendrik; Kurths, Jürgen; Wessel, Niels

    2016-05-01

    Health is one of the most important non-material assets and thus also has an enormous influence on material values, since treating and preventing diseases is expensive. The number one cause of death worldwide today originates in cardiovascular diseases. For these reasons the aim of understanding the functions and the interactions of the cardiovascular system is and has been a major research topic throughout various disciplines for more than a hundred years. The purpose of most of today's research is to get as much information as possible with the lowest possible effort and the least discomfort for the subject or patient, e.g. via non-invasive measurements. A family of tools whose importance has been growing during the last years is known under the headline of coupling measures. The rationale for this kind of analysis is to identify the structure of interactions in a system of multiple components. Important information lies for example in the coupling direction, the coupling strength, and occurring time lags. In this work, we will, after a brief general introduction covering the development of cardiovascular time series analysis, introduce, explain and review some of the most important coupling measures and classify them according to their origin and capabilities in the light of physiological analyses. We will begin with classical correlation measures, go via Granger-causality-based tools, entropy-based techniques (e.g. momentary information transfer), nonlinear prediction measures (e.g. mutual prediction) to symbolic dynamics (e.g. symbolic coupling traces). All these methods have contributed important insights into physiological interactions like cardiorespiratory coupling, neuro-cardio-coupling and many more. Furthermore, we will cover tools to detect and analyze synchronization and coordination (e.g. synchrogram and coordigram). As a last point we will address time dependent couplings as identified using a recent approach employing ensembles of time series. The

  13. Physiology of Visceral Pain.

    Science.gov (United States)

    Gebhart, G F; Bielefeldt, Klaus

    2016-09-15

    Pain involving thoracic, abdominal, or pelvic organs is a common cause for physician consultations, including one-third of chronic pain patients who report that visceral organs contribute to their suffering. Chronic visceral pain conditions are typically difficult to manage effectively, largely because visceral sensory mechanisms and factors that contribute to the pathogenesis of visceral pain are poorly understood. Mechanistic understanding is particularly problematic in "functional" visceral diseases where there is no apparent pathology and pain typically is the principal complaint. We review here the anatomical organization of the visceral sensory innervation that distinguishes the viscera from innervation of all other tissues in the body. The viscera are innervated by two nerves that share overlapping functions, but also possess notably distinct functions. Additionally, the visceral innervation is sparse relative to the sensory innervation of other tissues. Accordingly, visceral sensations tend to be diffuse in character, are typically referred to nonvisceral somatic structures and thus are difficult to localize. Early arguments about whether the viscera were innervated ("sensate") and later, whether innervated by nociceptors, were resolved by advances reviewed here in the anatomical and functional attributes of receptive endings in viscera that contribute to visceral pain (i.e., visceral nociceptors). Importantly, the contribution of plasticity (i.e., sensitization) of peripheral and central visceral nociceptive mechanisms is considered in the context of persistent, chronic visceral pain conditions. The review concludes with an overview of the functional anatomy of visceral pain processing. © 2016 American Physiological Society. Compr Physiol 6:1609-1633, 2016. Copyright © 2016 John Wiley & Sons, Inc.

  14. Assessing prebaccalaureate human physiology courses.

    Science.gov (United States)

    McCleary, V L

    1998-12-01

    Two surveys were conducted between 1994 and 1996. The purpose of the initial survey was to obtain demographic information about prebaccaulareate human physiology courses. Of the 117 responding physiology departments, 50% offered human physiology at the prebaccalaureate level to 14,185 students during the 1994-1995 academic year. The mean was 245 students per year (+/- 30 SE). Class size was limited by 44% of the respondents. Prebaccaluareate human physiology was offered as a separate course from anatomy by 93% of the departments. Sixty-one percent scheduled the course once a year. The purpose of the second survey was to determine how physiology departments evaluated prebaccalaureate physiology courses and faculty. All responding departments utilized student feedback; 38% of the departments included physiology chair review, 38% peer review, and 9% allied health faculty review. Twenty-eight percent of allied health programs evaluated the course. Results indicated that, whereas a significant number of undergraduate students are enrolled in prebaccaluareate physiology courses annually, those courses appear to lack formal, consistent formative evaluation.

  15. Context-aware sensing of physiological signals.

    Science.gov (United States)

    Wu, Winston H; Batalin, Maxim A; Au, Lawrence K; Bui, Alex A T; Kaiser, William J

    2007-01-01

    Recent advancement in microsensor technology permits miniaturization of conventional physiological sensors. Combined with low-power, energy-aware embedded systems and low power wireless interfaces, these sensors now enable patient monitoring in home and workplace environments in addition to the clinic. Low energy operation is critical for meeting typical long operating lifetime requirements. Some of these physiological sensors, such as electrocardiographs (ECG), introduce large energy demand because of the need for high sampling rate and resolution, and also introduce limitations due to reduced user wearability. In this paper, we show how context-aware sensing can provide the required monitoring capability while eliminating the need for energy-intensive continuous ECG signal acquisition. We have implemented a wearable system based on standard widely-used handheld computing hardware components. This system relies on a new software architecture and an embedded inference engine developed for these standard platforms. The performance of the system is evaluated using experimental data sets acquired for subjects wearing this system during an exercise sequence. This same approach can be used in context-aware monitoring of diverse physiological signals in a patient's daily life.

  16. Physical and physiological profiles of taekwondo athletes.

    Science.gov (United States)

    Bridge, Craig A; Ferreira da Silva Santos, Jonatas; Chaabène, Helmi; Pieter, Willy; Franchini, Emerson

    2014-06-01

    Taekwondo has evolved into a modern-day Olympic combat sport. The physical and physiological demands of modern-day taekwondo competition require athletes to be competent in several aspects of fitness. This review critically explores the physical and physiological characteristics of taekwondo athletes and presents implications for training and research. International taekwondo athletes possess low levels of body fat and a somatotype that characterises a blend of moderate musculoskeletal tissue and relative body linearity. While there is some variation in the maximum oxygen uptake of taekwondo athletes, moderate to high levels of cardio-respiratory fitness are necessary to support the metabolic demands of fighting and to facilitate recovery between consecutive matches. Taekwondo athletes demonstrate high peak anaerobic power characteristics of the lower limbs and this attribute appears to be conducive to achieving success in international competition. The ability to generate and sustain power output using both concentric and 'stretch-shortening cycle' muscle actions of the lower limbs may be important to support the technical and tactical actions in combat. Taekwondo competitors also display moderate to high maximum dynamic strength characteristics of the lower and upper extremities, and moderate endurance properties of the trunk and hip flexor musculature. The dynamic nature of the technical and tactical actions in the sport demand high flexibility of the lower limbs. More extensive research is required into the physical and physiological characteristics of taekwondo athletes to extend existing knowledge and to permit specialised conditioning for different populations within the sport.

  17. Applied physiology of swimming.

    Science.gov (United States)

    Lavoie, J M; Montpetit, R R

    1986-01-01

    Scientific research in swimming over the past 10 to 15 years has been oriented toward multiple aspects that relate to applied and basic physiology, metabolism, biochemistry, and endocrinology. This review considers recent findings on: 1) specific physical characteristics of swimmers; 2) the energetics of swimming; 3) the evaluation of aerobic fitness in swimming; and 4) some metabolic and hormonal aspects related to swimmers. Firstly, the age of finalists in Olympic swimming is not much different from that of the participants from other sports. They are taller and heavier than a reference population of the same age. The height bias in swimming may be the reason for lack of success from some Asian and African countries. Experimental data point toward greater leanness, particularly in female swimmers, than was seen 10 years ago. Overall, female swimmers present a range of 14 to 19% body fat whereas males are much lower (5 to 10%). Secondly, the relationship between O2 uptake and crawl swimming velocity (at training and competitive speeds) is thought to be linear. The energy cost varies between strokes with a dichotomy between the 2 symmetrical and the 2 asymmetrical strokes. Energy expenditure in swimming is represented by the sum of the cost of translational motion (drag) and maintenance of horizontal motion (gravity). The cost of the latter decreases as speed increases. Examination of the question of size-associated effects on the cost of swimming using Huxley's allometric equation (Y = axb) shows an almost direct relationship with passive drag. Expressing energy cost in litres of O2/m/kg is proposed as a better index of technical swimming ability than the traditional expression of VO2/distance in L/km. Thirdly, maximal direct conventional techniques used to evaluate maximal oxygen consumption (VO2 max) in swimming include free swimming, tethered swimming, and flume swimming. Despite the individual peculiarities of each method, with similar experimental conditions

  18. Hearables: Multimodal physiological in-ear sensing

    CERN Document Server

    Goverdovsky, Valentin; Nakamura, Takashi; Looney, David; Sharp, David J; Papavassiliou, Christos; Morrell, Mary J; Mandic, Danilo P

    2016-01-01

    Future health systems require the means to assess and track the neural and physiological function of a user over long periods of time and in the community. Human body responses are manifested through multiple modalities, such as the mechanical, electrical and chemical; yet current physiological monitors (actigraphy, heart rate) largely lack in both the desired cross-modal and non-stigmatizing aspects. We address these challenges through an inconspicuous and comfortable earpiece, equipped with miniature multimodal sensors, which benefits from the relatively stable position of the ear canal with respect to vital organs to robustly measure the brain, cardiac and respiratory functions. Comprehensive experiments validate each modality within the proposed earpiece, while its potential in health monitoring is illustrated through case studies. We further demonstrate how combining data from multiple sensors within such an integrated wearable device improves both the accuracy of measurements and the ability to deal wit...

  19. Model parameters for simulation of physiological lipids

    Science.gov (United States)

    McGlinchey, Nicholas

    2016-01-01

    Coarse grain simulation of proteins in their physiological membrane environment can offer insight across timescales, but requires a comprehensive force field. Parameters are explored for multicomponent bilayers composed of unsaturated lipids DOPC and DOPE, mixed‐chain saturation POPC and POPE, and anionic lipids found in bacteria: POPG and cardiolipin. A nonbond representation obtained from multiscale force matching is adapted for these lipids and combined with an improved bonding description of cholesterol. Equilibrating the area per lipid yields robust bilayer simulations and properties for common lipid mixtures with the exception of pure DOPE, which has a known tendency to form nonlamellar phase. The models maintain consistency with an existing lipid–protein interaction model, making the force field of general utility for studying membrane proteins in physiologically representative bilayers. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26864972

  20. Physiological Demands of Flat Horse Racing Jockeys.

    Science.gov (United States)

    Cullen, SarahJane; OʼLoughlin, Gillian; McGoldrick, Adrian; Smyth, Barry; May, Gregory; Warrington, Giles D

    2015-11-01

    The physiological demands of jockeys during competition remain largely unknown, thereby creating challenges when attempting to prescribe sport-specific nutrition and training guidelines. The purpose of this study was to evaluate the physiological demands and energy requirements of jockeys during flat racing. Oxygen uptake (V[Combining Dot Above]O2) and heart rate (HR) were assessed in 18 male trainee jockeys during a race simulation trial on a mechanical horse racing simulator for the typical time duration to cover a common flat race distance of 1,400 m. In addition, 8 male apprentice jockeys participated in a competitive race, over distances ranging from 1,200 to 1,600 m, during which HR and respiratory rate (RR) were assessed. All participants performed a maximal incremental cycle ergometer test. During the simulated race, peak V[Combining Dot Above]O2 was 42.74 ± 5.6 ml·kg·min (75 ± 11% of V[Combining Dot Above]O2peak) and below the mean ventilatory threshold (81 ± 5% of V[Combining Dot Above]O2peak) reported in the maximal incremental cycle test. Peak HR was 161 ± 16 b·min (86 ± 7% of HRpeak). Energy expenditure was estimated as 92.5 ± 18.8 kJ with an associated value of 9.4 metabolic equivalents. During the competitive race trial, peak HR reached 189 ± 5 b·min (103 ± 4% of HRpeak) and peak RR was 50 ± 7 breaths per minute. Results suggest that horse racing is a physically demanding sport, requiring jockeys to perform close to their physiological limit to be successful. These findings may provide a useful insight when developing sport-specific nutrition and training strategies to optimally equip and prepare jockeys physically for the physiological demands of horse racing.

  1. The Effects of Aquatic Exercise on Physiological and Biomechanical Responses

    OpenAIRE

    Denning, Matthew M.

    2010-01-01

    Due to recent advances in aquatic research, technology, and facilities, many modes of aquatic therapy now exist. These aquatic modes assist individuals (e.g., osteoarthritis patients) in the performance of activities that may be too difficult to complete on land. However, the biomechanical requirements of each aquatic therapy mode may elicit different physiological and functional responses. Therefore, the purpose of this thesis was to: (a) provide a review of the physiological and biomechani...

  2. Understanding the physiology of schizophrenia.

    Science.gov (United States)

    Kirkpatrick, Brian

    2013-03-01

    The physiology of schizophrenia includes complex genetic and environmental interactions. Current treatment largely focuses on positive symptoms, but many patients with schizophrenia present with additional symptoms and conditions that hinder their social and occupational functioning. The study of the physiology of this disorder has expanded beyond dopamine dysfunction to include the glutamate, serotonin, and nicotinic/acetylcholine systems, as well as physiologic abnormalities such as diabetes and inflammation. Clinicians who understand these additional problem areas can incorporate them into their assessment and treatment plans for patients with schizophrenia. © Copyright 2013 Physicians Postgraduate Press, Inc.

  3. Physiology and Pathology of Endosome-to-Golgi Retrograde Sorting

    OpenAIRE

    Burd, Christopher G.

    2011-01-01

    Bi-directional traffic between the Golgi apparatus and the endosomal system sustains the functions of the trans Golgi network (TGN) in secretion and organelle biogenesis. Export of cargo from the TGN via the anterograde pathways depletes the organelle of sorting receptors, processing proteases, SNARE molecules, and other factors that are subsequently retrieved from endosomes via the retrograde pathway. Recent studies indicate that retrograde trafficking is vital to early metazoan development,...

  4. Medical electronics and physiological measurement

    Science.gov (United States)

    Cochrane, T.

    1989-07-01

    This article describes some recent developments in physiological measurement since the last `special issue' in 1978. Nine examples are given covering mature applications, new techniques and some `ideas for the future'. The need for good scientists in this interesting and challenging area is stressed. Physiological measurement is challenging because human physiology is complex. The examples described in this article illustrate some areas where cooperation between basic scientists, engineers, clinicians and, not least, patients has led to remarkable advances in our understanding of man and his physiology. Many challenges still lie ahead. There is no doubt that good quality graduates, with fresh minds and fresh enthusiasm, are needed to build on the foundation that has already been laid.

  5. Survey of Departments of Physiology

    Science.gov (United States)

    Ganong, William F.

    1977-01-01

    Presents data of the 1976 survey of departments of physiology. Includes comparison to 1974 and 1975 data for number of academic positions available, department budgets, graduate students and post doctoral fellows, and salaries. (SL)

  6. Physiology of the fetal circulation.

    Science.gov (United States)

    Kiserud, Torvid

    2005-12-01

    Our understanding of fetal circulatory physiology is based on experimental animal data, and this continues to be an important source of new insight into developmental mechanisms. A growing number of human studies have investigated the human physiology, with results that are similar but not identical to those from animal studies. It is time to appreciate these differences and base more of our clinical approach on human physiology. Accordingly, the present review focuses on distributional patterns and adaptational mechanisms that were mainly discovered by human studies. These include cardiac output, pulmonary and placental circulation, fetal brain and liver, venous return to the heart, and the fetal shunts (ductus venosus, foramen ovale and ductus arteriosus). Placental compromise induces a set of adaptational and compensational mechanisms reflecting the plasticity of the developing circulation, with both short- and long-term implications. Some of these aspects have become part of the clinical physiology of today with consequences for surveillance and treatment.

  7. Olfaction: anatomy, physiology and behavior

    OpenAIRE

    Benignus, Vernon A.; Prah, James D.

    1982-01-01

    The anatomy, physiology and function of the olfactory system are reviewed, as are the normal effects of olfactory stimulation. It is speculated that olfaction may have important but unobtrusive effects on human behavior.

  8. Survey of Departments of Physiology

    Science.gov (United States)

    Ganong, William F.

    1977-01-01

    Presents data of the 1976 survey of departments of physiology. Includes comparison to 1974 and 1975 data for number of academic positions available, department budgets, graduate students and post doctoral fellows, and salaries. (SL)

  9. Physiological Control of Germline Development

    OpenAIRE

    Hubbard, E. Jane Albert; Korta, Dorota Z.; Dalfó, Diana

    2013-01-01

    The intersection between developmental programs and environmental conditions that alter physiology is a growing area of research interest. The C. elegans germ line is emerging as a particularly sensitive and powerful model for these studies. The germ line is subject to environmentally regulated diapause points that allow worms to withstand harsh conditions both prior to and after reproduction commences. It also responds to more subtle changes in physiological conditions. Recent studies demons...

  10. Seasonal changes in reindeer physiology

    OpenAIRE

    A. Reeta Pösö

    2005-01-01

    The seasonal changes in the photoperiod, temperature and availability of food need to be converted to hormonal signals in order to induce adaptations in the physiology of the reindeer. The most reliable of the seasonal changes in the environment is the photoperiod, which affects the reindeer physiology through pineal gland and its hormone, melatonin. Usually there are large diurnal changes in the concentration of melatonin, but in the reindeer the daily rhythm disappears during the arctic sum...

  11. Seasonal changes in reindeer physiology

    Directory of Open Access Journals (Sweden)

    A. Reeta Pösö

    2005-04-01

    Full Text Available The seasonal changes in the photoperiod, temperature and availability of food need to be converted to hormonal signals in order to induce adaptations in the physiology of the reindeer. The most reliable of the seasonal changes in the environment is the photoperiod, which affects the reindeer physiology through pineal gland and its hormone, melatonin. Usually there are large diurnal changes in the concentration of melatonin, but in the reindeer the daily rhythm disappears during the arctic summer to return again in the autumn. Seasonal changes in melatonin secretion are involved in the regulation of reproduction, the growth of pelage, thermogenesis, body mass and immune function. Melatonin may exert its effects through gene activation, but the mechanisms are not completely understood. Other hormones that show seasonality are thyroid hormones, insulin and leptin. Thus the observed physiological changes are a result of actions of several hormones. Appetite, energy production and thermogenesis are all vital for survival. During winter, when energy balance is negative, the reindeer uses mainly body fat for energy production. The use of fat stores is economical as the rate of lipolysis is controlled and the use of fatty acids in tissues such as muscle decreases. Only in severe starvation the rate of lipolysis increases enough to give rise to accumulation of ketone bodies. The protein mass is maintained and only in starved individuals muscle protein is used for energy production. The winter feed of the reindeer, the lichens, is poor in nitrogen and the nitrogen balance during winter is strongly negative. Reindeer responds to limited availability of nitrogen by increasing the recycling of urea into rumen. In general the adaptation of reindeer physiology enables the reindeer to survive the winter and although several aspects are known many others require further studies.Abstract in Finnish / Tiivistelmä: Valaistus, lämpötila ja ravinnon saatavuus

  12. Amateur boxing: physical and physiological attributes.

    Science.gov (United States)

    Chaabène, Helmi; Tabben, Montassar; Mkaouer, Bessem; Franchini, Emerson; Negra, Yassine; Hammami, Mehrez; Amara, Samiha; Chaabène, Raja Bouguezzi; Hachana, Younés

    2015-03-01

    Boxing is one of the oldest combat sports. The aim of the current review is to critically analyze the amateur boxer's physical and physiological characteristics and to provide practical recommendations for training as well as new areas of scientific research. High-level male and female boxers show a propensity for low body fat levels. Although studies on boxer somatotypes are limited, the available information shows that elite-level male boxers are characterized by a higher proportion of mesomorphy with a well-developed muscle mass and a low body fat level. To help support the overall metabolic demands of a boxing match and to accelerate the recovery process between rounds, athletes of both sexes require a high level of cardiorespiratory fitness. International boxers show a high peak and mean anaerobic power output. Muscle strength in both the upper and lower limbs is paramount for a fighter's victory and is one of the keys to success in boxing. As boxing punches are brief actions and very dynamic, high-level boxing performance requires well-developed muscle power in both the upper and lower limbs. Albeit limited, the available studies reveal that isometric strength is linked to high-level boxing performance. Future investigations into the physical and physiological attributes of boxers are required to enrich the current data set and to help create a suitable training program.

  13. Physiologically relevant organs on chips.

    Science.gov (United States)

    Yum, Kyungsuk; Hong, Soon Gweon; Healy, Kevin E; Lee, Luke P

    2014-01-01

    Recent advances in integrating microengineering and tissue engineering have generated promising microengineered physiological models for experimental medicine and pharmaceutical research. Here we review the recent development of microengineered physiological systems, or also known as "ogans-on-chips", that reconstitute the physiologically critical features of specific human tissues and organs and their interactions. This technology uses microengineering approaches to construct organ-specific microenvironments, reconstituting tissue structures, tissue-tissue interactions and interfaces, and dynamic mechanical and biochemical stimuli found in specific organs, to direct cells to assemble into functional tissues. We first discuss microengineering approaches to reproduce the key elements of physiologically important, dynamic mechanical microenvironments, biochemical microenvironments, and microarchitectures of specific tissues and organs in microfluidic cell culture systems. This is followed by examples of microengineered individual organ models that incorporate the key elements of physiological microenvironments into single microfluidic cell culture systems to reproduce organ-level functions. Finally, microengineered multiple organ systems that simulate multiple organ interactions to better represent human physiology, including human responses to drugs, is covered in this review. This emerging organs-on-chips technology has the potential to become an alternative to 2D and 3D cell culture and animal models for experimental medicine, human disease modeling, drug development, and toxicology.

  14. Processing of physiological signals in automotive research.

    Science.gov (United States)

    Dambier, Michael; Altmüller, Tobias; Ladstätter, Ulrich

    2006-12-01

    The development of innovative driver assistance systems requires the evaluation of the predisposed hypotheses such as acceptance and driving safety. For this purpose, the conduction of experiments with end-users as subjects is necessary. Analysis and evaluation are based on the recording of numerous sensor values and system variables. Video, gaze and physiological data are recorded for the analysis of gaze distraction and emotional reactions of subjects to system behaviour. In this paper, a modular data streaming and processing architecture is suggested and a concept for this architecture is defined for consistent data evaluation, which integrates off-the-shelf products for data analysis and evaluation.

  15. The Cardiovascular Physiology of Sports and Exercise.

    Science.gov (United States)

    Opondo, Mildred A; Sarma, Satyam; Levine, Benjamin D

    2015-07-01

    Athletes represent the extremes of human performance. Many of their remarkable abilities stem from a cardiovascular system that has adapted to meet the metabolic needs of exercising muscle. A large and compliant heart is a hallmark feature of athletes who engage in highly aerobic events. Despite high fitness levels, athletes may present with symptoms that limit performance. Understanding and dissecting these limitations requires a strong background in sports science and the factors that determine sports capabilities. This article reviews the basic principles of exercise physiology, cardiovascular adaptations unique to the "athlete's heart," and the utility of exercise testing in athletes.

  16. Calcium signaling in physiology and pathophysiology

    Institute of Scientific and Technical Information of China (English)

    He-ping CHENG; Sheng WEI; Li-ping WEI; Alexei VERKHRATSKY

    2006-01-01

    Calcium ions are the most ubiquitous and pluripotent cellular signaling molecules that control a wide variety of cellular processes.The calcium signaling system is represented by a relatively limited number of highly conserved transporters and channels,which execute Ca2+ movements across biological membranes and by many thousands of Ca2+-sensitive effectors.Molecular cascades,responsible for the generation of calcium signals,are tightly controlled by Ca2+ ions themselves and by genetic factors,which tune the expression of different Ca2+-handling molecules according to adaptational requirements.Ca2+ ions determine normal physiological reactions and the development of many pathological processes.

  17. Conservation physiology of animal migration.

    Science.gov (United States)

    Lennox, Robert J; Chapman, Jacqueline M; Souliere, Christopher M; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D; Cooke, Steven J

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  18. Syntaxin 7 is localized to late endosome compartments, associates with Vamp 8, and Is required for late endosome-lysosome fusion.

    Science.gov (United States)

    Mullock, B M; Smith, C W; Ihrke, G; Bright, N A; Lindsay, M; Parkinson, E J; Brooks, D A; Parton, R G; James, D E; Luzio, J P; Piper, R C

    2000-09-01

    Protein traffic from the cell surface or the trans-Golgi network reaches the lysosome via a series of endosomal compartments. One of the last steps in the endocytic pathway is the fusion of late endosomes with lysosomes. This process has been reconstituted in vitro and has been shown to require NSF, alpha and gamma SNAP, and a Rab GTPase based on inhibition by Rab GDI. In Saccharomyces cerevisiae, fusion events to the lysosome-like vacuole are mediated by the syntaxin protein Vam3p, which is localized to the vacuolar membrane. In an effort to identify the molecular machinery that controls fusion events to the lysosome, we searched for mammalian homologues of Vam3p. One such candidate is syntaxin 7. Here we show that syntaxin 7 is concentrated in late endosomes and lysosomes. Coimmunoprecipitation experiments show that syntaxin 7 is associated with the endosomal v-SNARE Vamp 8, which partially colocalizes with syntaxin 7. Importantly, we show that syntaxin 7 is specifically required for the fusion of late endosomes with lysosomes in vitro, resulting in a hybrid organelle. Together, these data identify a SNARE complex that functions in the late endocytic system of animal cells.

  19. Syntaxin 7 Is Localized to Late Endosome Compartments, Associates with Vamp 8, and Is Required for Late Endosome–Lysosome Fusion

    Science.gov (United States)

    Mullock, Barbara M.; Smith, Chez W.; Ihrke, Gudrun; Bright, Nicholas A.; Lindsay, Margaret; Parkinson, Emma J.; Brooks, Doug A.; Parton, Robert G.; James, David E.; Luzio, J. Paul; Piper, Robert C.

    2000-01-01

    Protein traffic from the cell surface or the trans-Golgi network reaches the lysosome via a series of endosomal compartments. One of the last steps in the endocytic pathway is the fusion of late endosomes with lysosomes. This process has been reconstituted in vitro and has been shown to require NSF, α and γ SNAP, and a Rab GTPase based on inhibition by Rab GDI. In Saccharomyces cerevisiae, fusion events to the lysosome-like vacuole are mediated by the syntaxin protein Vam3p, which is localized to the vacuolar membrane. In an effort to identify the molecular machinery that controls fusion events to the lysosome, we searched for mammalian homologues of Vam3p. One such candidate is syntaxin 7. Here we show that syntaxin 7 is concentrated in late endosomes and lysosomes. Coimmunoprecipitation experiments show that syntaxin 7 is associated with the endosomal v-SNARE Vamp 8, which partially colocalizes with syntaxin 7. Importantly, we show that syntaxin 7 is specifically required for the fusion of late endosomes with lysosomes in vitro, resulting in a hybrid organelle. Together, these data identify a SNARE complex that functions in the late endocytic system of animal cells. PMID:10982406

  20. EVA Physiology and Medical Considerations Working in the Suit

    Science.gov (United States)

    Parazynski, Scott

    2012-01-01

    This "EVA Physiology and Medical Considerations Working in the Suit" presentation covers several topics related to the medical implications and physiological effects of suited operations in space from the perspective of a physician with considerable first-hand Extravehicular Activity (EVA) experience. Key themes include EVA physiology working in a pressure suit in the vacuum of space, basic EVA life support and work support, Thermal Protection System (TPS) inspections and repairs, and discussions of the physical challenges of an EVA. Parazynski covers the common injuries and significant risks during EVAs, as well as physical training required to prepare for EVAs. He also shares overall suit physiological and medical knowledge with the next generation of Extravehicular Mobility Unit (EMU) system designers.

  1. Intrinsic optical signal imaging of retinal physiology: a review

    Science.gov (United States)

    Yao, Xincheng; Wang, Benquan

    2015-09-01

    Intrinsic optical signal (IOS) imaging promises to be a noninvasive method for high-resolution examination of retinal physiology, which can advance the study and diagnosis of eye diseases. While specialized optical instruments are desirable for functional IOS imaging of retinal physiology, in depth understanding of multiple IOS sources in the complex retinal neural network is essential for optimizing instrument designs. We provide a brief overview of IOS studies and relationships in rod outer segment suspensions, isolated retinas, and intact eyes. Recent developments of line-scan confocal and functional optical coherence tomography (OCT) instruments have allowed in vivo IOS mapping of photoreceptor physiology. Further improvements of the line-scan confocal and functional OCT systems may provide a feasible solution to pursue functional IOS mapping of human photoreceptors. Some interesting IOSs have already been detected in inner retinal layers, but better development of the IOS instruments and software algorithms is required to achieve optimal physiological assessment of inner retinal neurons.

  2. Homeostatic reinforcement learning for integrating reward collection and physiological stability.

    Science.gov (United States)

    Keramati, Mehdi; Gutkin, Boris

    2014-12-02

    Efficient regulation of internal homeostasis and defending it against perturbations requires adaptive behavioral strategies. However, the computational principles mediating the interaction between homeostatic and associative learning processes remain undefined. Here we use a definition of primary rewards, as outcomes fulfilling physiological needs, to build a normative theory showing how learning motivated behaviors may be modulated by internal states. Within this framework, we mathematically prove that seeking rewards is equivalent to the fundamental objective of physiological stability, defining the notion of physiological rationality of behavior. We further suggest a formal basis for temporal discounting of rewards by showing that discounting motivates animals to follow the shortest path in the space of physiological variables toward the desired setpoint. We also explain how animals learn to act predictively to preclude prospective homeostatic challenges, and several other behavioral patterns. Finally, we suggest a computational role for interaction between hypothalamus and the brain reward system.

  3. Physiological Studies of Lactococcus lactis

    DEFF Research Database (Denmark)

    Hansen, Gunda

    industrial production by employing flow cytometry for viability assessment, cell size comparison, intracellular pH (pHi) determination and cell sorting. The physiological studies of L. lactis were complemented by examining the growth behavior, glucose consumption, lactate production, culturability on solid...... was found to facilitate the differentiation and accurate quantification of L. lactis cells in different physiological states, which agreed with the reproductive viability of reference samples and of exponential cells. The high viability of one particular L. lactis strain demonstrated its robustness during......, cell size comparison and pHi determination reflected the increasing physiological impairment during this accelerated stability test, while a preincubation in buffer led to inconsistent flow cytometric results. The comparison of reproductive and growth-independent viability suggested the presence...

  4. Stimulating Student Interest in Physiology: The Intermedical School Physiology Quiz

    Science.gov (United States)

    Cheng, Hwee-Ming

    2010-01-01

    The Intermedical School Physiology Quiz (IMSPQ) was initiated in 2003 during the author's last sabbatical from the University of Malaya. At this inaugural event, there were just seven competing teams from Malaysian medical schools. The challenge trophy for the IMSPQ is named in honor of Prof. A. Raman, who was the first Malaysian Professor of…

  5. Electronic Textbook in Human Physiology.

    Science.gov (United States)

    Broering, Naomi C.; Lilienfield, Lawrence S.

    1994-01-01

    Describes the development of an electronic textbook in human physiology at the Georgetown University Medical Center Library that was designed to enhance learning and visualization through a prototype knowledge base of core instructional materials stored in digital format on Macintosh computers. The use of computers in the medical curriculum is…

  6. Exercise Effects on Sleep Physiology

    Directory of Open Access Journals (Sweden)

    Sunao eUchida

    2012-04-01

    Full Text Available This mini-review focuses on the effects of exercise on sleep. In its early days, sleep research largely focused on central nervous system (CNS physiology using standardized tabulations of several sleep-specific landmark electroencephalogram (EEG waveforms. Though coarse, this method has enabled the observation and inspection of numerous uninterrupted sleep phenomena. Thus, research on the effects of exercise on sleep began, in the 1960’s, with a focus primarily on sleep EEG (CNS sleep changes. Those early studies found only small effects of exercise on sleep. More recent sleep research has explored not only CNS functioning, but somatic physiology as well. As physical exercise mostly affects somatic functions, endocrine and autonomic nervous system (ANS changes that occur during sleep should be affected by daytime exercise. Since endocrinological, metabolic and autonomic changes can be measured during sleep, it should be possible to assess exercise effects on somatic physiology in addition to CNS sleep quality, building from standard polysomnographic (PSG techniques. Incorporating measures of somatic physiology in the quantitative assessment of sleep could further our understanding of sleep's function as an auto-regulatory, global phenomenon.

  7. Physiological aspects of paired stimulation

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1966-01-01

    Starling's law of the heart states that "the energy of contraction, however measured, is a function of the length of the muscle fibre" (Starling, 1915). This physiological property of myocardial and skeletal muscle enables the heart, within certain limits, to eject during each systole the amount

  8. The Limits of Exercise Physiology

    DEFF Research Database (Denmark)

    Gabriel, Brendan M; Zierath, Juleen R

    2017-01-01

    Many of the established positive health benefits of exercise have been documented by historical discoveries in the field of exercise physiology. These investigations often assess limits: the limits of performance, or the limits of exercise-induced health benefits. Indeed, several key findings have...

  9. Physiological specialization of Stagonospora nodorum

    Science.gov (United States)

    Septoriosis is a harmful disease of wheat, widespread all over the world, including Russia. Stagonospora nodorum (Berk.) Castellani and E.G. Germano is one of the main agents of Septoria wheat diseases. There is no information on physiological specialization of this pathogen. Not many authors stud...

  10. Reproductive Physiology in Cetaceans (Review)

    OpenAIRE

    1996-01-01

    This paper briefly reviews some works on reproductive physiology in cetaceans with special reference to dolphins from the following aspects: estrous cycle in female dolphins, hormonal profiles during pregnancy, testosterone levels and seasonality in testicular activity, ovulation induction and sperm collection and freezing.

  11. PHYSIOLOGIC BASIS OF NASAL OPERATIONS

    Science.gov (United States)

    Hilding, A. C.

    1950-01-01

    To be successful, intranasal operations must be so designed as to restore the normal physiologic function of the nose. It is impossible with impunity to operate upon the interior of the nose as though it were simply an air flue and on the sinuses as though they were boxes. PMID:15400563

  12. Physiological Monitoring in Diving Mammals

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Physiological Monitoring in Diving Mammals Andreas...825-2025 email: andreas.fahlman@tamucc.edu Peter L. Tyack School of Biology Sea Mammal Research Unit Scottish Oceans Institute...OBJECTIVES This project is separated into three aims: Aim 1: Develop a new generation of tags/data logger for marine mammals that will

  13. Teaching Physiology of Exercise to Reluctant Physical Educators

    Science.gov (United States)

    Strawbridge, Marilyn

    2012-01-01

    Exercise physiology seems to be a course that students love or hate. Many physical education students and others involved in the related areas of health, teaching, recreation, dance, athletic training, fitness, and motor learning and development find this course a requirement at some point in their curriculum. Inquiry-based learning is an…

  14. Vesicle associated membrane protein (VAMP)-7 and VAMP-8, but not VAMP-2 or VAMP-3, are required for activation-induced degranulation of mature human mast cells.

    Science.gov (United States)

    Sander, Leif E; Frank, Simon P C; Bolat, Seza; Blank, Ulrich; Galli, Thierry; Bigalke, Hans; Bischoff, Stephan C; Lorentz, Axel

    2008-03-01

    Mediator release from mast cells (MC) is a crucial step in allergic and non-allergic inflammatory disorders. However, the final events in response to activation leading to membrane fusion and thereby facilitating degranulation have hitherto not been analyzed in human MC. Soluble N-ethyl-maleimide-sensitive factor attachment protein receptors (SNARE) represent a highly conserved family of proteins that have been shown to mediate intracellular membrane fusion events. Here, we show that mature MC isolated from human intestinal tissue express soluble N-ethylmaleide sensitive factor attachment protein (SNAP)-23, Syntaxin (STX)-1B, STX-2, STX-3, STX-4, and STX-6 but not SNAP-25. Furthermore, we found that primary human MC express substantial amounts of vesicle associated membrane protein (VAMP)-3, VAMP-7 and VAMP-8 and, in contrast to previous reports about rodent MC, only low levels of VAMP-2. Furthermore, VAMP-7 and VAMP-8 were found to translocate to the plasma membrane and interact with SNAP-23 and STX-4 upon activation. Inhibition of SNAP-23, STX-4, VAMP-7 or VAMP-8, but not VAMP-2 or VAMP-3, resulted in a markedly reduced high-affinity IgE receptor-mediated histamine release. In summary, our data show that mature human MC express a specific pattern of SNARE and that VAMP-7 and VAMP-8, but not VAMP-2, are required for rapid degranulation.

  15. Network Physiology: Mapping interactions between complex physiological systems

    OpenAIRE

    Ivanov, Plamen Ch.

    2016-01-01

    The human organism is an integrated network where multi-component organ systems, each with its own regulatory mechanisms, continuously interact to optimize and coordinate their function. Organ-to-organ interactions occur at multiple levels and spatiotemporal time scales to produce distinct physiologic states: wake and sleep; light and deep sleep; consciousness and unconsciousness. Disrupting organ communications can lead to dysfunction of individual systems or to collapse of the entire organ...

  16. A conceptual framework for the emerging discipline of conservation physiology

    Science.gov (United States)

    Coristine, Laura E.; Robillard, Cassandra M.; Kerr, Jeremy T.; O'Connor, Constance M.; Lapointe, Dominique; Cooke, Steven J.

    2014-01-01

    Current rates of biodiversity decline are unprecedented and largely attributed to anthropogenic influences. Given the scope and magnitude of conservation issues, policy and management interventions must maximize efficiency and efficacy. The relatively new field of conservation physiology reveals the physiological mechanisms associated with population declines, animal–environment relationships and population or species tolerance thresholds, particularly where these relate to anthropogenic factors that necessitate conservation action. We propose a framework that demonstrates an integrative approach between physiology, conservation and policy, where each can inform the design, conduct and implementation of the other. Each junction of the conservation physiology process has the capacity to foster dialogue that contributes to effective implementation, monitoring, assessment and evaluation. This approach enables effective evaluation and implementation of evidence-based conservation policy and management decisions through a process of ongoing refinement, but may require that scientists (from the disciplines of both physiology and conservation) and policy-makers bridge interdisciplinary knowledge gaps. Here, we outline a conceptual framework that can guide and lead developments in conservation physiology, as well as promote innovative research that fosters conservation-motivated policy. PMID:27293654

  17. Social-physiological compliance as a determinant of team performance.

    Science.gov (United States)

    Henning, R A; Boucsein, W; Gil, M C

    2001-04-01

    A cybernetic model of behavior predicts that team performance may depend on physiological compliance among participants. This laboratory study tested if compliance in electrodermal activity (EDA), heart rate or breathing in two-person teams (N=16) was predictive of team performance or coordination in a continuous tracking task simulating teleoperation. Visual contact among participants was manipulated. Physiological compliance was scored with weighted coherence and cross correlation. Separate multiple regression analyses revealed that the task completion time was predicted by coherence measures for EDA and heart, but only at a trend level for breathing. Task completion time was also predicted by heart cross correlation. Team tracking error was predicted by coherence measures for EDA, heart and breathing, and also heart cross correlation. While social-visual contact did not have an impact, physiological compliance was predictive of improved performance, with coherence robust over all three physiological measures. Heart cross correlation showed the strongest predictive relationships. These results provide evidence that physiological compliance among team members may benefit team performance. While further study is needed, physiological compliance may someday provide a needed tool for the study of team work, and an objective means to guide the ergonomic design of complex sociotechnical systems requiring a high degree of team proficiency.

  18. Development of concept-based physiology lessons for biomedical engineering undergraduate students.

    Science.gov (United States)

    Nelson, Regina K; Chesler, Naomi C; Strang, Kevin T

    2013-06-01

    Physiology is a core requirement in the undergraduate biomedical engineering curriculum. In one or two introductory physiology courses, engineering students must learn physiology sufficiently to support learning in their subsequent engineering courses and careers. As preparation for future learning, physiology instruction centered on concepts may help engineering students to further develop their physiology and biomedical engineering knowledge. Following the Backward Design instructional model, a series of seven concept-based lessons was developed for undergraduate engineering students. These online lessons were created as prerequisite physiology training to prepare students to engage in a collaborative engineering challenge activity. This work is presented as an example of how to convert standard, organ system-based physiology content into concept-based content lessons.

  19. Applied physiology of female soccer players.

    Science.gov (United States)

    Davis, J A; Brewer, J

    1993-09-01

    Women's soccer is in its infancy as a sport and research into its physiological demands and the physical characteristics of players is somewhat limited. There is now an increasing demand for scientific investigation of the female game and of the players, match analysis and role variations requiring particular attention. Current research suggests that the demands of the game for women are similar to those placed on male players. Women are reported to cover a similar distance (mean 8471m) to their male counterparts during a game and much the same proportions of the game appear to be devoted to exercise of varying intensities. Furthermore, female and male players appear to tax the aerobic and anaerobic energy systems to a similar level. The physical and physiological characteristics of female soccer players are comparable with those of other female games players and are more favourable than average for the population. Mean body fat percentages of between 19.7 and 22.0% and VO2max values of between 47.1 and 57.6 ml/kg/min have been reported for elite female players, while faster than average sprint times are also characteristic of them.

  20. Pregnancy: Comparison among Physiological and Pathological States

    Directory of Open Access Journals (Sweden)

    Angela Lucariello

    2014-01-01

    Full Text Available The WFS1 gene, encoding a transmembrane glycoprotein of the endoplasmic reticulum called wolframin, is mutated in Wolfram syndrome, an autosomal recessive disorder defined by the association of diabetes mellitus, optic atrophy, and further organ abnormalities. Disruption of the WFS1 gene in mice causes progressive β-cell loss in the pancreas and impaired stimulus-secretion coupling in insulin secretion. However, little is known about the physiological functions of this protein. We investigated the immunohistochemical expression of wolframin in human placenta throughout pregnancy in normal women and diabetic pregnant women. In normal placenta, there was a modulation of wolframin throughout pregnancy with a strong level of expression during the first trimester and a moderate level in the third trimester of gestation. In diabetic women, wolframin expression was strongly reduced in the third trimester of gestation. The pattern of expression of wolframin in normal placenta suggests that this protein may be required to sustain normal rates of cytotrophoblast cell proliferation during the first trimester of gestation. The decrease in wolframin expression in diabetic placenta suggests that this protein may participate in maintaining the physiologic glucose homeostasis in this organ.

  1. Physiological description of multivariate interdependencies between process parameters, morphology and physiology during fed-batch penicillin production.

    Science.gov (United States)

    Posch, Andreas E; Herwig, Christoph

    2014-01-01

    Optimization of productivity and economics of industrial bioprocesses requires characterization of interdependencies between process parameters and process performance. In the case of penicillin production, as in other processes, process performance is often closely interlinked with the physiology and morphology of the organism used for production. This study presents a systematic approach to efficiently characterize the physiological effects of multivariate interdependencies between bioprocess design parameters (spore inoculum concentration, pO2 control level and substrate feed rate), morphology, and physiology. Method development and application was performed using the industrial model process of penicillin production. Applying traditional, statistical bioprocess analysis, multivariate correlations of raw bioprocess design parameters (high spore inoculum concentration, low pO2 control as well as reduced glucose feeding) and pellet morphology were identified. A major drawback of raw design parameter correlation models; however, is the lack of transferability across different process scales and regimes. In this context, morphological and physiological bioprocess modeling based on scalable physiological parameters is introduced. In this study, raw parameter effects on pellet morphology were efficiently summarized by the physiological parameter of the biomass yield per substrate. Finally, for the first time to our knowledge, the specific growth rate per spore was described as time-independent determinant for switching from pellet to disperse growth during penicillin production and thus introduced as a novel, scalable key process parameter for pellet morphology and process performance.

  2. Anatomy and physiology of cisternostomy

    Institute of Scientific and Technical Information of China (English)

    Iype Cherian; Giovanni Grasso; Antonio Bernardo; Sunil Munakomi

    2016-01-01

    Cisternostomy is defined as opening the basal cisterns to atmospheric pressure.This technique helps to reduce the intracranial pressure in severe head trauma as well as other conditions when the so-called sudden "brain swelling" troubles the surgeon.We elaborated the surgical anatomy of this procedure as well as the proposed physiology of how cisternostomy works.This novel technique may change the current trends in neurosurgery.

  3. [C-peptide physiological effects].

    Science.gov (United States)

    Shpakov, A O; Granstrem, O K

    2013-02-01

    In the recent years there were numerous evidences that C-peptide, which was previously considered as a product of insulin biosynthesis, is one of the key regulators of physiological processes. C-peptide via heterotrimeric G(i/o) protein-coupled receptors activates a wide range of intracellular effector proteins and transcription factors and, thus, controls the inflammatory and neurotrophic processes, pain sensitivity, cognitive function, macro- and microcirculation, glomerular filtration. These effects of C-peptide are mainly expressed in its absolute or relative deficiency occurred in type 1 diabetes mellitus and they are less pronounced when the level of C-peptide is close to normal. Replacement therapy with C-peptide prevents many complications of type 1 diabetes, such as atherosclerosis, diabetic peripheral neuropathy, and nephropathy. C-peptide interacts with the insulin hexamer complexes and induces their dissociation and, as a result, regulates the functional activity of the insulin signaling system. At the same time, C-peptide at the concentrations above physiological may demonstrate pro-inflammatory effects on the endothelial cells and cause atherosclerotic changes in the vessels, which should be considered in the study of pathogenic mechanisms of complications of type 2 diabetes mellitus, where the level of C peptide is increased, as well as in the development of approaches for C-peptide application in clinic. This review is devoted contemporary achievements and unsolved problems in the study of C-peptide, as an important regulator of physiological and biochemical processes.

  4. Neuronal responses to physiological stress

    Directory of Open Access Journals (Sweden)

    Konstantinos eKagias

    2012-10-01

    Full Text Available Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. Physiological stress can be divided into three different aspects: environmental stress, intrinsic developmental stress and aging. Throughout life all living organisms are challenged by changes in the environment. Fluctuations in oxygen levels, temperature and redox state for example, trigger molecular events that enable an organism to adapt, survive and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner chemistry during normal development. For example, conditions such as intrinsic hypoxia and oxidative stress, which result from an increase in tissue mass, have to be confronted by developing embryos in order to complete their development. Finally, organisms face the challenge of stochastic accumulation of molecular damage during aging that results in decline and eventual death. Studies have shown that the nervous system plays a pivotal role in responding to stress. Neurons not only receive and process information from the environment but also actively respond to various stresses to promote survival. These responses include changes in the expression of molecules such as transcription factors and microRNAs that regulate stress resistance and adaptation. Moreover, both intrinsic and extrinsic stresses have a tremendous impact on neuronal development and maintenance with implications in many diseases. Here, we review the responses of neurons to various physiological stressors at the molecular and cellular level.

  5. Physiology of psychogenic movement disorders.

    Science.gov (United States)

    Hallett, Mark

    2010-08-01

    Psychogenic movement disorders (PMDs) are common, but their physiology is largely unknown. In most situations, the movement is involuntary, but in a minority, when the disorder is malingering or factitious, the patient is lying and the movement is voluntary. Physiologically, we cannot tell the difference between voluntary and involuntary. The Bereitschaftspotential (BP) is indicative of certain brain mechanisms for generating movement, and is seen with ordinarily voluntary movements, but by itself does not indicate that a movement is voluntary. There are good clinical neurophysiological methods available to determine whether myoclonus or tremor is a PMD. For example, psychogenic myoclonus generally has a BP, and psychogenic stimulus-sensitive myoclonus has a variable latency with times similar to normal reaction times. Psychogenic tremor will have variable frequency over time, be synchronous in the two arms, and might well be entrained with voluntary rhythmic movements. These facts suggest that PMDs share voluntary mechanisms for movement production. There are no definitive tests to differentiate psychogenic dystonia from organic dystonia, although one has been recently reported. Similar physiological abnormalities are seen in both groups. The question arises as to how a movement can be produced with voluntary mechanisms, but not be considered voluntary.

  6. Dynamical compensation in physiological circuits.

    Science.gov (United States)

    Karin, Omer; Swisa, Avital; Glaser, Benjamin; Dor, Yuval; Alon, Uri

    2016-11-08

    Biological systems can maintain constant steady-state output despite variation in biochemical parameters, a property known as exact adaptation. Exact adaptation is achieved using integral feedback, an engineering strategy that ensures that the output of a system robustly tracks its desired value. However, it is unclear how physiological circuits also keep their output dynamics precise-including the amplitude and response time to a changing input. Such robustness is crucial for endocrine and neuronal homeostatic circuits because they need to provide a precise dynamic response in the face of wide variation in the physiological parameters of their target tissues; how such circuits compensate their dynamics for unavoidable natural fluctuations in parameters is unknown. Here, we present a design principle that provides the desired robustness, which we call dynamical compensation (DC). We present a class of circuits that show DC by means of a nonlinear feedback loop in which the regulated variable controls the functional mass of the controlling endocrine or neuronal tissue. This mechanism applies to the control of blood glucose by insulin and explains several experimental observations on insulin resistance. We provide evidence that this mechanism may also explain compensation and organ size control in other physiological circuits.

  7. Software requirements

    CERN Document Server

    Wiegers, Karl E

    2003-01-01

    Without formal, verifiable software requirements-and an effective system for managing them-the programs that developers think they've agreed to build often will not be the same products their customers are expecting. In SOFTWARE REQUIREMENTS, Second Edition, requirements engineering authority Karl Wiegers amplifies the best practices presented in his original award-winning text?now a mainstay for anyone participating in the software development process. In this book, you'll discover effective techniques for managing the requirements engineering process all the way through the development cy

  8. General lighting requirements for photosynthesis

    Science.gov (United States)

    Geiger, Donald R.

    1994-01-01

    This paper presents data that suggests some criteria for evaluating growth chamber and greenhouse lighting. A review of the general lighting requirements for photosynthesis reveals that four aspects of light are important: irradiance, quality, timing, and duration. Effective lighting should produce plants that perform according to the goals of the project. For example, for physiological studies the plants probably should exhibit morphology and physiology similar to that found in field-grown plants. For other projects the criteria will obviously be set according to the reason for raising the plants.

  9. Conservation physiology for applied management of marine fish: an overview with perspectives on the role and value of telemetry

    OpenAIRE

    Metcalfe, J.D.; Le Quesne, W.J.F.; Cheung, W W L; Righton, D. A.

    2012-01-01

    Physiological studies focus on the responses of cells, tissues and individuals to stressors, usually in laboratory situations. Conservation and management, on the other hand, focus on populations. The field of conservation physiology addresses the question of how abiotic drivers of physiological responses at the level of the individual alter requirements for successful conservation and management of populations. To achieve this, impacts of physiological effects at the individual level need to...

  10. Physiologic Status Monitoring via the Gastrointestinal Tract.

    Science.gov (United States)

    Traverso, G; Ciccarelli, G; Schwartz, S; Hughes, T; Boettcher, T; Barman, R; Langer, R; Swiston, A

    2015-01-01

    Reliable, real-time heart and respiratory rates are key vital signs used in evaluating the physiological status in many clinical and non-clinical settings. Measuring these vital signs generally requires superficial attachment of physically or logistically obtrusive sensors to subjects that may result in skin irritation or adversely influence subject performance. Given the broad acceptance of ingestible electronics, we developed an approach that enables vital sign monitoring internally from the gastrointestinal tract. Here we report initial proof-of-concept large animal (porcine) experiments and a robust processing algorithm that demonstrates the feasibility of this approach. Implementing vital sign monitoring as a stand-alone technology or in conjunction with other ingestible devices has the capacity to significantly aid telemedicine, optimize performance monitoring of athletes, military service members, and first-responders, as well as provide a facile method for rapid clinical evaluation and triage.

  11. Energy requirements

    NARCIS (Netherlands)

    Hulzebos, Christian V.; Sauer, Pieter J. J.

    2007-01-01

    The determination of the appropriate energy and nutritional requirements of a newborn infant requires a clear goal of the energy and other compounds to be administered, valid methods to measure energy balance and body composition, and knowledge of the neonatal metabolic capacities. Providing an appr

  12. Energy requirements

    NARCIS (Netherlands)

    Hulzebos, Christian V.; Sauer, Pieter J. J.

    The determination of the appropriate energy and nutritional requirements of a newborn infant requires a clear goal of the energy and other compounds to be administered, valid methods to measure energy balance and body composition, and knowledge of the neonatal metabolic capacities. Providing an

  13. Guidelines for Undergraduate Exercise Physiology in a Physical Education Teacher Education Program. Guidance Document

    Science.gov (United States)

    National Association for Sport and Physical Education, 2006

    2006-01-01

    A course in Exercise Physiology is a common requirement among undergraduate students preparing for a career in physical education, adult fitness, or athletic training. Often, such courses are taught to an assortment of students from a variety of disciplines (Van Donselaar & Leslie, 1990) with an emphasis on physiological principles applied to…

  14. A Case of Snare Conbine With Cola in Treatment of Huge Gastric Calculus Under Endoscopy%内镜下圈套器联合可乐治疗巨大胃结石1例

    Institute of Scientific and Technical Information of China (English)

    王疆

    2016-01-01

    目的:报道口服可乐治疗巨大胃结石成功实例1例,探讨可乐治疗胃结石的可行性。方法内镜下圈套器切割部分胃结石,使结石内部暴露,有利于充分接触可乐,然后口服可乐1周,并同时服用质子泵抑制剂,胃肠动力剂。结果1周后复查胃镜,患者胃结石消失。结论口服可乐结合内镜治疗胃结石患者依从性好,经济负担小,疗效显著。%Objective To analyze the feasibility of treating gastric calculus with cola by reporting a case of successful treatment of it with oral cola. MethodsPart of the gastric calculus was cut with the application of endoscopic snare to enable the gastric calculus to be fully exposed to cola which was administered as oral formulation for a week; meanwhile, proton-pump inhibitors and gastrointestinal mobility agents were taken.ResultThe disappearance of the gastric calculus was conifrmed by follow-up gastroscopy one week later. Conclusion Endoscopic treatment of the gastric calculus in combination with oral cola is good compliance, affordable treatment fee, and good clinical effects.

  15. Physiological Parameters Database for Older Adults

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Physiological Parameters Database for Older Adults is available for download and contains physiological parameters values for healthy older human adults (age 60...

  16. Psycho-physiological response of soldiers in urban combat

    Directory of Open Access Journals (Sweden)

    Vicente J. Clemente-Suárez

    2013-05-01

    Full Text Available Current armed conflicts are asymmetrical and are developed m urban areas. These new requirements have not been studied for current literature. The aim of this study was to analyse changes in cortical arousal, blood lactate, muscle strength, autonomic modulation and rate of perceived exertion in a simulated urban combat. We analyzed 20 soldiers before and after an urban combat simulation. The results showed how urban combat produced high sympathetic nervous system activation, increasing the muscle strength, heart rate and blood lactate concentration of the soldiers. Despite this effort, rate of perceived exertion were not consistent with the physiological response that soldiers presented, the rate of perceived exertion was lower than the physiological response evaluated. Furthermore, the information processing and cortical arousal decreased after the urban combat simulation. These results have showed the psycho-physiological response of soldiers in combat, helping to better understanding and enabling an improvement of current training methods of soldiers.

  17. Upper gastrointestinal physiology and diseases.

    Science.gov (United States)

    Waldum, Helge L; Kleveland, Per M; Fossmark, Reidar

    2015-06-01

    Nordic research on physiology and pathophysiology of the upper gastrointestinal tract has flourished during the last 50 years. Swedish surgeons and physiologists were in the frontline of research on the regulation of gastric acid secretion. This research finally led to the development of omeprazole, the first proton pump inhibitor. When Swedish physiologists developed methods allowing the assessment of acid secretion in isolated oxyntic glands and isolated parietal cells, the understanding of mechanisms by which gastric acid secretion is regulated took a great step forward. Similarly, in Trondheim, Norway, the acid producing isolated rat stomach model combined with a sensitive and specific method for determination of histamine made it possible to evaluate this regulation qualitatively as well as quantitatively. In Lund, Sweden, the identification of the enterochromaffin-like cell as the cell taking part in the regulation of acid secretion by producing and releasing histamine was of fundamental importance both physiologically and clinically. Jorpes and Mutt established a center at Karolinska Institutet in Stockholm for the purification of gastrointestinal hormones in the 1960s, and Danes followed up this work by excelling in the field of determination and assessment of biological role of gastrointestinal hormones. A Finnish group was for a long period in the forefront of research on gastritis, and the authors' own studies on the classification of gastric cancer and the role of gastrin in the development of gastric neoplasia are of importance. It can, accordingly, be concluded that Nordic researchers have been central in the research on area of the upper gastrointestinal physiology and diseases.

  18. Fish cardiovascular physiology and disease.

    Science.gov (United States)

    Sherrill, Johanna; Weber, E Scott; Marty, Gary D; Hernandez-Divers, Stephen

    2009-01-01

    Fish patients with cardiovascular disorders present a challenge in terms of diagnostic evaluation and therapeutic options. Veterinarians can approach these cases in fish using methods similar to those employed for other companion animals. Clinicians who evaluate and treat fish in private, aquarium, zoologic, or aquaculture settings need to rely on sound clinical judgment after thorough historical and physical evaluation. Pharmacokinetic data and treatments specific to cardiovascular disease in fish are limited; thus, drug types and dosages used in fish are largely empiric. Fish cardiovascular anatomy, physiology, diagnostic evaluation, monitoring, common diseases, cardiac pathologic conditions, formulary options, and comprehensive references are presented with the goal of providing fish veterinarians with clinically relevant tools.

  19. Physiologic mastectomy via flank laparotomy.

    Science.gov (United States)

    Allen, Andrew J; Barrington, George M; Parish, Steve M

    2008-11-01

    Physiologic mastectomy can be used as a salvage procedure in cases of chronic suppurative mastitis, gangrenous mastitis, or chronic, severe mastitis associated with organisms liberating endotoxin or exotoxin. The surgical technique involves ligation of the major arterial blood supply (external pudendal artery) to the corresponding half of the mammary gland, which results in decreased systemic absorption of toxins and gland atrophy. The technique is performed with the cow standing, and it is relatively atraumatic. This procedure is a simple, yet effective alternative to radical mastectomy for unresponsive mastitis cases in genetically or otherwise valuable cattle.

  20. Bengt Saltin and exercise physiology: a perspective.

    Science.gov (United States)

    Joyner, Michael J

    2017-01-01

    This perspective highlights some of the key contributions of Professor Bengt Saltin (1935-2014) to exercise physiology. The emergence of exercise physiology from work physiology as his career began is discussed as are his contributions in a number of areas. Saltin's open and question-based style of leadership is a model for the future of our field.

  1. A New Model of Master of Philosophy in Physiological Sciences

    Science.gov (United States)

    Ahmad, HR; Arain, FM; Khan, NA

    2016-01-01

    The objectives of Master of Philosophy (MPhil) in Physiological Sciences are: 1) to describe the new ways in which anatomy, biochemistry and physiology on one hand, and microbiology, pathology and pharmacology on other hand meet their functional requirements through multidisciplinary integrated concepts; 2) to elucidate relationships between cell biology, molecular biology and molecular genetics by connecting dots of how cell functions are driven by molecules and being controlled by genes. This forms the basis of cell, molecular and genetics [CMG] module upon which 7 multidisciplinary modules of Physiological Sciences follow; 3) these 24 credit hours provide the physiological basis for PhD studies as well as faculty development to enhance learning abilities of medical student; 4) the modules constitute Cardio- Respiratory Physiological Sciences, GI and Renal Physiological Sciences, Neurosciences, Endo-Reproductive Physiological Sciences.; 5) it has integrated microbiology, pathology and pharmacology in a unique way through CMG of microbes leading to associated pathology and mechanisms of prescribed drugs; 6) it has additional synopsis and thesis friendly course work leading to comprehensive examinations; 7) the year two deals with research work of 6 credit hours leading to defense of thesis; 8) The MPhil in Physiological Sciences is fundamentally different from what is being offered elsewhere. It prepares and offers a good spring board to dovetail PhD studies as well as faculty and institutional development. This is the first study that deals with innovative programmes in research, learning and education in the field of physiological sciences. This broad-based MPhil would make its recipients competent, critical, confident and productive learner. This is a completely unique design of a curriculum that has no comparable examples elsewhere. Our mission is to educate graduate students in the field of Physiological Sciences such that they have a complete grasp over the

  2. Requirements dilemma

    OpenAIRE

    2006-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Knowing ‘what’ to build is an integral part of an Information System Development, and it is generally understood that this, which is known as Requirements, is achievable through a process of understanding, communication and management. It is currently maintained by the Requirements theorists that successful system design clarifies the interrelations between information and its representations...

  3. Infrared thermography: A non-invasive window into thermal physiology.

    Science.gov (United States)

    Tattersall, Glenn J

    2016-12-01

    Infrared thermography is a non-invasive technique that measures mid to long-wave infrared radiation emanating from all objects and converts this to temperature. As an imaging technique, the value of modern infrared thermography is its ability to produce a digitized image or high speed video rendering a thermal map of the scene in false colour. Since temperature is an important environmental parameter influencing animal physiology and metabolic heat production an energetically expensive process, measuring temperature and energy exchange in animals is critical to understanding physiology, especially under field conditions. As a non-contact approach, infrared thermography provides a non-invasive complement to physiological data gathering. One caveat, however, is that only surface temperatures are measured, which guides much research to those thermal events occurring at the skin and insulating regions of the body. As an imaging technique, infrared thermal imaging is also subject to certain uncertainties that require physical modelling, which is typically done via built-in software approaches. Infrared thermal imaging has enabled different insights into the comparative physiology of phenomena ranging from thermogenesis, peripheral blood flow adjustments, evaporative cooling, and to respiratory physiology. In this review, I provide background and guidelines for the use of thermal imaging, primarily aimed at field physiologists and biologists interested in thermal biology. I also discuss some of the better known approaches and discoveries revealed from using thermal imaging with the objective of encouraging more quantitative assessment.

  4. Detection of essential hypertension with physiological signals from wearable devices.

    Science.gov (United States)

    Ghosh, Arindam; Torres, Juan Manuel Mayor; Danieli, Morena; Riccardi, Giuseppe

    2015-08-01

    Early detection of essential hypertension can support the prevention of cardiovascular disease, a leading cause of death. The traditional method of identification of hypertension involves periodic blood pressure measurement using brachial cuff-based measurement devices. While these devices are non-invasive, they require manual setup for each measurement and they are not suitable for continuous monitoring. Research has shown that physiological signals such as Heart Rate Variability, which is a measure of the cardiac autonomic activity, is correlated with blood pressure. Wearable devices capable of measuring physiological signals such as Heart Rate, Galvanic Skin Response, Skin Temperature have recently become ubiquitous. However, these signals are not accurate and are prone to noise due to different artifacts. In this paper a) we present a data collection protocol for continuous non-invasive monitoring of physiological signals from wearable devices; b) we implement signal processing techniques for signal estimation; c) we explore how the continuous monitoring of these physiological signals can be used to identify hypertensive patients; d) We conduct a pilot study with a group of normotensive and hypertensive patients to test our techniques. We show that physiological signals extracted from wearable devices can distinguish between these two groups with high accuracy.

  5. Electrocyte physiology: 50 years later.

    Science.gov (United States)

    Markham, Michael R

    2013-07-01

    Weakly electric gymnotiform and mormyrid fish generate and detect weak electric fields to image their worlds and communicate. These multi-purpose electric signals are generated by electrocytes, the specialized electric organ (EO) cells that produce the electric organ discharge (EOD). Just over 50 years ago the first experimental analyses of electrocyte physiology demonstrated that the EOD is produced and shaped by the timing and waveform of electrocyte action potentials (APs). Electrocytes of some species generate a single AP from a distinct region of excitable membrane, and this AP waveform determines EOD waveform. In other species, electrocytes possess two independent regions of excitable membrane that generate asynchronous APs with different waveforms, thereby increasing EOD complexity. Signal complexity is further enhanced in some gymnotiforms by the spatio-temporal activation of distinct EO regions with different electrocyte properties. For many mormyrids, additional EOD waveform components are produced by APs that propagate along stalks that connect postsynaptic regions to the main body of the electrocyte. I review here the history of research on electrocyte physiology in weakly electric fish, as well as recent discoveries of key phenomena not anticipated during early work in this field. Recent areas of investigation include the regulation of electrocyte activity by steroid and peptide hormones, the molecular evolution of electrocyte ion channels, and the evolutionary selection of ion channels expressed in excitable cells. These emerging research areas have generated renewed interest in electrocyte function and clear future directions for research addressing a broad range of new and important questions.

  6. The glycemic index: physiological significance.

    Science.gov (United States)

    Esfahani, Amin; Wong, Julia M W; Mirrahimi, Arash; Srichaikul, Korbua; Jenkins, David J A; Kendall, Cyril W C

    2009-08-01

    The glycemic index (GI) is a physiological assessment of a food's carbohydrate content through its effect on postprandial blood glucose concentrations. Evidence from trials and observational studies suggests that this physiological classification may have relevance to those chronic Western diseases associated with overconsumption and inactivity leading to central obesity and insulin resistance. The glycemic index classification of foods has been used as a tool to assess potential prevention and treatment strategies for diseases where glycemic control is of importance, such as diabetes. Low GI diets have also been reported to improve the serum lipid profile, reduce C-reactive protein (CRP) concentrations, and aid in weight control. In cross-sectional studies, low GI or glycemic load diets (mean GI multiplied by total carbohydrate) have been associated with higher levels of high-density lipoprotein cholesterol (HDL-C), with reduced CRP concentrations, and, in cohort studies, with decreased risk of developing diabetes and cardiovascular disease. In addition, some case-control and cohort studies have found positive associations between dietary GI and risk of various cancers, including those of the colon, breast, and prostate. Although inconsistencies in the current findings still need to be resolved, sufficient positive evidence, especially with respect to renewed interest in postprandial events, suggests that the glycemic index may have a role to play in the treatment and prevention of chronic diseases.

  7. Physiological Effects of Touching Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

    Full Text Available This study aimed to clarify the physiological effects of touching wood with the palm, in comparison with touching other materials on brain activity and autonomic nervous activity. Eighteen female university students (mean age, 21.7  ±  1.6 years participated in the study. As an indicator of brain activity, oxyhemoglobin (oxy-Hb concentrations were measured in the left/right prefrontal cortex using near-infrared time-resolved spectroscopy. Heart rate variability (HRV was used as an indicator of autonomic nervous activity. The high-frequency (HF component of HRV, which reflected parasympathetic nervous activity, and the low-frequency (LF/HF ratio, which reflected sympathetic nervous activity, were measured. Plates of uncoated white oak, marble, tile, and stainless steel were used as tactile stimuli. After sitting at rest with their eyes closed, participants touched the materials for 90 s. As a result, tactile stimulation with white oak significantly (1 decreased the oxy-Hb concentration in the left/right prefrontal cortex relative to marble, tile, and stainless steel and (2 increased ln(HF-reflected parasympathetic nervous activity relative to marble and stainless steel. In conclusion, our study revealed that touching wood with the palm calms prefrontal cortex activity and induces parasympathetic nervous activity more than other materials, thereby inducing physiological relaxation.

  8. Network Physiology: How Organ Systems Dynamically Interact.

    Science.gov (United States)

    Bartsch, Ronny P; Liu, Kang K L; Bashan, Amir; Ivanov, Plamen Ch

    2015-01-01

    We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS), we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  9. Network Physiology: How Organ Systems Dynamically Interact.

    Directory of Open Access Journals (Sweden)

    Ronny P Bartsch

    Full Text Available We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS, we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  10. Endocrine FGFs: evolution, physiology, pathophysiology, and pharmacotherapy

    Directory of Open Access Journals (Sweden)

    Nobuyuki eItoh

    2015-09-01

    Full Text Available The human fibroblast growth factor (FGF family comprises 22 structurally related polypeptides that play crucial roles in neuronal functions, development, and metabolism. FGFs are classified as intracrine, paracrine, and endocrine FGFs based on their action mechanisms. Paracrine and endocrine FGFs are secreted signaling molecules by acting via cell-surface FGF receptors (FGFRs. Paracrine FGFs require heparan sulfate as a co-factor for FGFRs. In contrast, endocrine FGFs, comprising FGF19, FGF21, and FGF23, require α−Klotho or β−Klotho as a co-factor for FGFRs. Endocrine FGFs, which are specific to vertebrates, lost heparan sulfate-binding affinity and acquired a systemic signaling system with αKlotho or βKlotho during early vertebrate evolution. The phenotypes of endocrine FGF knockout mice indicate that they play roles in metabolism including bile acid, energy, and phosphate/active vitamin D metabolism. Accumulated evidence for the involvement of endocrine FGFs in human genetic and metabolic diseases also indicates their pathophysiological roles in metabolic diseases, potential risk factors for metabolic diseases, and useful biomarkers for metabolic diseases. The therapeutic utility of endocrine FGFs is currently being developed. These findings provide new insights into the physiological and pathophysiological roles of endocrine FGFs and potential diagnostic and therapeutic strategies for metabolic diseases.

  11. NASA Exercise Physiology and Countermeasures Project Overview

    Science.gov (United States)

    Loerch, Linda; Ploutz-Snyder, Lori

    2009-01-01

    Efficient exercise countermeasures are necessary to offset or minimize spaceflight-induced deconditioning and to maximize crew performance of mission tasks. These countermeasure protocols should use the fewest crew and vehicle resources. NASA s Exercise Physiology and Countermeasures (ExPC) Project works to identify, collect, interpret, and summarize evidence that results in effective exercise countermeasure protocols which protect crew health and performance during International Space Station (ISS) and future exploration-class missions. The ExPC and NASA s Human Research Program are sponsoring multiple studies to evaluate and improve the efficacy of spaceflight exercise countermeasures. First, the Project will measure maximal aerobic capacity (VO2max) during cycle ergometry before, during, and after ISS missions. Second, the Project is sponsoring an evaluation of a new prototype harness that offers improved comfort and increased loading during treadmill operations. Third, the Functional Tasks Test protocol will map performance of anticipated lunar mission tasks with physiologic systems before and after short and long-duration spaceflight, to target system contributions and the tailoring of exercise protocols to maximize performance. In addition to these studies that are actively enrolling crewmember participants, the ExPC is planning new studies that include an evaluation of a higher-intensity/lower-volume exercise countermeasure protocol aboard the ISS using the Advanced Resistive Exercise Device and second-generation treadmill, studies that evaluate bone loading during spaceflight exercise, and ground-based studies that focus on fitness for duty standards required to complete lunar mission tasks and for which exercise protocols need to protect. Summaries of these current and future studies and strategies will be provided to international colleagues for knowledge sharing and possible collaboration.

  12. Physiological hydrostatic pressure protects endothelial monolayer integrity.

    Science.gov (United States)

    Müller-Marschhausen, K; Waschke, J; Drenckhahn, D

    2008-01-01

    Endothelial monolayer integrity is required to maintain endothelial barrier functions and has found to be impaired in several disorders like inflammatory edema, allergic shock, or artherosclerosis. Under physiologic conditions in vivo, endothelial cells are exposed to mechanical forces such as hydrostatic pressure, shear stress, and cyclic stretch. However, insight into the effects of hydrostatic pressure on endothelial cell biology is very limited at present. Therefore, in this study, we tested the hypothesis that physiological hydrostatic pressure protects endothelial monolayer integrity in vitro. We investigated the protective efficacy of hydrostatic pressure in microvascular myocardial endothelial (MyEnd) cells and macrovascular pulmonary artery endothelial cells (PAECs) by the application of selected pharmacological agents known to alter monolayer integrity in the absence or presence of hydrostatic pressure. In both endothelial cell lines, extracellular Ca(2+) depletion by EGTA was followed by a loss of vascular-endothelial cadherin (VE-caherin) immunostaining at cell junctions. However, hydrostatic pressure (15 cmH(2)O) blocked this effect of EGTA. Similarly, cytochalasin D-induced actin depolymerization and intercellular gap formation and cell detachment in response to the Ca(2+)/calmodulin antagonist trifluperazine (TFP) as well as thrombin-induced cell dissociation were also reduced by hydrostatic pressure. Moreover, hydrostatic pressure significantly reduced the loss of VE-cadherin-mediated adhesion in response to EGTA, cytochalasin D, and TFP in MyEnd cells as determined by laser tweezer trapping using VE-cadherin-coated microbeads. In caveolin-1-deficient MyEnd cells, which lack caveolae, hydrostatic pressure did not protect monolayer integrity compromised by EGTA, indicating that caveolae-dependent mechanisms are involved in hydrostatic pressure sensing and signaling.

  13. Sufficient protein quality of food aid varies with the physiologic status of recipients

    Science.gov (United States)

    Protein quality scores use the amino acid (AA) requirements of a healthy North American child. AA requirements vary with physiologic status. We estimated AA requirements for healthy North American children, children with environmental enteric dysfunction, children recovering from wasting, and childr...

  14. Neuronal responses to physiological stress

    DEFF Research Database (Denmark)

    Kagias, Konstantinos; Nehammer, Camilla; Pocock, Roger David John

    2012-01-01

    by changes in the environment. Fluctuations in oxygen levels, temperature, and redox state for example, trigger molecular events that enable an organism to adapt, survive, and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner...... include changes in the expression of molecules such as transcription factors and microRNAs that regulate stress resistance and adaptation. Moreover, both intrinsic and extrinsic stresses have a tremendous impact on neuronal development and maintenance with implications in many diseases. Here, we review......Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. It can be divided into three different aspects: environmental stress, intrinsic developmental stress, and aging. Throughout life all living organisms are challenged...

  15. CH2 - Lighting and Physiology

    Directory of Open Access Journals (Sweden)

    Sergio Altomonte

    2012-11-01

    Full Text Available This paper explains the designed performances of the new CH2 building in Melbourne, Australia. CH2 is an environmentally significant project that involves biomimicry of natural systems to produce indoor conditions that are conducive to user comfort, health and productivity. This paper focuses on lighting and physiology and examines the solutions chosen for artificial and natural lighting and the likely effects these will have on building occupants. The purpose of the paper is to critically comment on the adopted strategy and, cognisance of contemporary thinking in lighting design, to judge the effectiveness of this aspect of the project with a view to later verification and post-occupancy review. The paper concludes that CH2 is an exemplar of lighting innovation that provides valuable lessons to designers of office buildings, particularly in the Melbourne CSD.

  16. Children's physiological responses to childcare.

    Science.gov (United States)

    Vermeer, Harriet J; Groeneveld, Marleen G

    2017-06-01

    This review focuses on children's physiological responses to out-of-home childcare. The finding that children's cortisol levels are higher at childcare than at home has been well-replicated. Here we summarize recent evidence examining possible correlates of elevated cortisol levels. Reviewed studies suggest that childcare quality matters, whereas group sizes and type of care do not. As for child characteristics, elevated cortisol at childcare is more pronounced in toddlers than in infants, and in inhibited and aggressive children. We discuss recent advances focusing on hair cortisol analysis and immunomarkers of stress, and suggest that there is a need for experimental and longitudinal studies to examine causal relations and possible negative long-term consequences for children's health and development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. CH2 - Lighting and Physiology

    Directory of Open Access Journals (Sweden)

    Sergio Altomonte

    2012-11-01

    Full Text Available This paper explains the designed performances of the new CH2 building in Melbourne, Australia. CH2 is an environmentally significant project that involves biomimicry of natural systems to produce indoor conditions that are conducive to user comfort, health and productivity. This paper focuses on lighting and physiology and examines the solutions chosen for artificial and natural lighting and the likely effects these will have on building occupants. The purpose of the paper is to critically comment on the adopted strategy and, cognisance of contemporary thinking in lighting design, to judge the effectiveness of this aspect of the project with a view to later verification and post-occupancy review. The paper concludes that CH2 is an exemplar of lighting innovation that provides valuable lessons to designers of office buildings, particularly in the Melbourne CSD.

  18. Ventricular hypertrophy--physiological mechanisms.

    Science.gov (United States)

    Vaughan Williams, E M

    1986-01-01

    Adult cardiac myocytes are incapable of mitosis. Dead cells are replaced by connective tissue so that after myocardial infarction (MI), function can only be restored by compensatory hypertrophy of the surviving myocardium. In physiological hypertrophy in response to exercise, high altitude, or mild hypertension, additional myoplasm expands cell diameter in an orderly fashion; Z-lines are in register and the normal ratio of volume densities of contractile elements, mitochondria, and capillaries is conserved. In hypertrophy induced by aortic or pulmonary artery banding or by experimental or congenital hypertension, the borderline between physiological and pathological hypertrophy may be crossed, causing disorganization of fibers and an unfavourable contractile element to capillary ratio. There was, therefore, a need for a graded model of hypertrophy, which involves simulating an altitude of 6,000 m at sea level by supplying rabbits with appropriate nitrogen/oxygen mixtures. In this environment, 50% right ventricular hypertrophy can be achieved without alteration of left ventricular weight or hematocrit. Longer exposures produced 100% right ventricular hypertrophy, with only moderate increases in hematocrit and left ventricular weight. It is well known that adrenergic stimulation causes cardiac hypertrophy, and it has been suggested that release of a trophic factor from sympathetic nerves, either noradrenaline or a protein, might be a necessary stimulus for growth. If so, long-term treatment of post-MI patients with beta-adrenergic blocking agents could inhibit a desirable compensatory hypertrophy of the surviving myocardium. In the above model it has been found, however, that neither beta-blockade nor chemical sympathectomy with guanethidine or 6-hydroxydopamine had any effect on the hypertrophy, nor did treatment with verapamil or nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Fruit Calcium: Transport and Physiology

    Directory of Open Access Journals (Sweden)

    Bradleigh eHocking

    2016-04-01

    Full Text Available Calcium has well-documented roles in plant signaling, water relations and cell wall interactions. Significant research into how calcium impacts these individual processes in various tissues has been carried out; however, the influence of calcium on fruit ripening has not been thoroughly explored. Here, we review the current state of knowledge on how calcium may impact fruit development, physical traits and disease susceptibility through facilitating developmental and stress response signaling, stabilizing membranes, influencing water relations and modifying cell wall properties through cross-linking of de-esterified pectins. We explore the involvement of calcium in hormone signaling integral to ripening and the physiological mechanisms behind common disorders that have been associated with fruit calcium deficiency (e.g. blossom end rot in tomatoes or bitter pit in apples. This review works towards an improved understanding of how the many roles of calcium interact to influence fruit ripening, and proposes future research directions to fill knowledge gaps. Specifically, we focus mostly on grapes and present a model that integrates existing knowledge around these various functions of calcium in fruit, which provides a basis for understanding the physiological impacts of sub-optimal calcium nutrition in grapes. Calcium accumulation and distribution in fruit is shown to be highly dependent on water delivery and cell wall interactions in the apoplasm. Localized calcium deficiencies observed in particular species or varieties can result from differences in xylem morphology, fruit water relations and pectin composition, and can cause leaky membranes, irregular cell wall softening, impaired hormonal signaling and aberrant fruit development. We propose that the role of apoplasmic calcium-pectin crosslinking, particularly in the xylem, is an understudied area that may have a key influence on fruit water relations. Furthermore, we believe that improved

  20. A consideration of the paradigm of exercise physiology.

    Science.gov (United States)

    Kilgore, J L; Baker, J S; Davies, B

    2014-01-01

    Exercise physiology, in terms of the history of biological sciences, is quite young and has a rather tumultuous history - as it spans physical education, health & medicine, sport science, and biology. This has led to the development of differing definitions, research approaches, practices and goals. This is easily seen in the presence of competing and non-universally adopted definitions of fitness. Such internal inconsistencies portray to the outside world a discipline experiencing the problems associated with a changing paradigm. Every science requires the presence of a paradigm that both describes and guides the evolution of thinking, experimentation, and the application of such. It is argued here that exercise physiology has been operating without benefit of a satisfactory and relevant paradigm. A further proposition is that the required disciplinary definitions derived from an articulated paradigm are also absent. A paradigmatic scheme based on biological dogma is presented along with proposed definitions.

  1. Translational physiology: from molecules to public health.

    Science.gov (United States)

    Seals, Douglas R

    2013-07-15

    The term 'translational research' was coined 20 years ago and has become a guiding influence in biomedical research. It refers to a process by which the findings of basic research are extended to the clinical research setting (bench to bedside) and then to clinical practice and eventually health policy (bedside to community). It is a dynamic, multidisciplinary research approach. The concept of translational physiology applies the translational research model to the physiological sciences. It differs from the traditional areas of integrative and clinical physiology by its broad investigative scope of basic research to community health. Translational physiology offers exciting opportunities, but presently is under-developed and -utilized. A key challenge will be to expand physiological research by extending investigations to communities of patients and healthy (or at risk) individuals. This will allow bidirectional physiological investigation throughout the translational continuum: basic research observations can be studied up to the population level, and mechanisms can be assessed by 'reverse translation' in clinical research settings and preclinical models based on initial observations made in populations. Examples of translational physiology questions, experimental approaches, roadblocks and strategies for promotion are discussed. Translational physiology provides a novel framework for physiology programs and an investigational platform for physiologists to study function from molecular events to public health. It holds promise for enhancing the completeness and societal impact of our work, while further solidifying the critical role of physiology in the biomedical research enterprise.

  2. GFR estimation: from physiology to public health.

    Science.gov (United States)

    Levey, Andrew S; Inker, Lesley A; Coresh, Josef

    2014-05-01

    Estimating glomerular filtration rate (GFR) is essential for clinical practice, research, and public health. Appropriate interpretation of estimated GFR (eGFR) requires understanding the principles of physiology, laboratory medicine, epidemiology, and biostatistics used in the development and validation of GFR estimating equations. Equations developed in diverse populations are less biased at higher GFRs than equations developed in chronic kidney disease (CKD) populations and are more appropriate for general use. Equations that include multiple endogenous filtration markers are more precise than equations including a single filtration marker. The CKD-EPI (CKD Epidemiology Collaboration) equations are the most accurate GFR estimating equations that have been evaluated in large diverse populations and are applicable for general clinical use. The 2009 CKD-EPI creatinine equation is more accurate in estimating GFR and prognosis than the 2006 MDRD (Modification of Diet in Renal Disease) Study equation and provides lower estimates of prevalence of decreased eGFR. It is useful as a "first test" for decreased eGFR and should replace the MDRD Study equation for routine reporting of serum creatinine-based eGFR by clinical laboratories. The 2012 CKD-EPI cystatin C equation is as accurate as the 2009 CKD-EPI creatinine equation in estimating GFR, does not require specification of race, and may be more accurate in patients with decreased muscle mass. The 2012 CKD-EPI creatinine-cystatin C equation is more accurate than the 2009 CKD-EPI creatinine and 2012 CKD-EPI cystatin C equations and is useful as a confirmatory test for decreased eGFR as determined by serum creatinine-based eGFR. Further improvement in GFR estimating equations will require development in more broadly representative populations, including diverse racial and ethnic groups, use of multiple filtration markers, and evaluation using statistical techniques to compare eGFR to "true GFR."

  3. New Reaction Timer for Physiological and Psychological Studies

    Directory of Open Access Journals (Sweden)

    A. K. Gupta

    1983-07-01

    Full Text Available In physiological and psychological measurements, the response to some form of external stimulus is required. The instrumentation used for the measurement of Reaction Time is vital part of the main instrument system. Instrument design reported here is suitable for the measurement of Reaction. Time under environmental stress. The stimulus are visual (flash of light andauditory tone. This instrument is solidstate, portable and can be used with any electronic timer.

  4. Wearable Brain Imaging with Multi-Modal Physiological Recording.

    Science.gov (United States)

    Strangman, Gary E; Ivkovic, Vladimir; Zhang, Quan

    2017-07-13

    The brain is a central component of cognitive and physical human performance. Measures including functional brain activation, cerebral perfusion, cerebral oxygenation, evoked electrical responses, and resting hemodynamic and electrical activity are all related to, or can predict health status or performance decrements. However, measuring brain physiology typically requires large, stationary machines that are not suitable for mobile or self-monitoring. Moreover, when individuals are ambulatory, systemic physiological fluctuations-e.g., in heart rate, blood pressure, skin perfusion and more-can interfere with non-invasive brain measurements. In efforts to address the physiological monitoring and performance assessment needs for astronauts during spaceflight, we have developed easy-to-use, wearable prototypes- NINscan, for near-infrared scanning-that can collect synchronized multi-modal physiology data, including hemodynamic deep-tissue imaging (including brain and muscles), electroencephalography, electrocardiography, electromyography, electrooculography, accelerometry, gyroscopy, pressure, respiration and temperature measurements. Given their self-contained and portable nature, these devices can be deployed in a much broader range of settings-including austere environments-thereby enabling a wider range of novel medical and research physiology applications. We review these, including high-altitude assessments, self-deployable multi-modal e.g., (polysomnographic) recordings in remote or low-resource environments, fluid shifts in variable-gravity or spaceflight analog environments, intra-cranial brain motion during high-impact sports, and long-duration monitoring for clinical symptom-capture in various clinical conditions. In addition to further enhancing sensitivity and miniaturization, advanced computational algorithms could help support real-time feedback and alerts regarding performance and health. Copyright © 2017, Journal of Applied Physiology.

  5. System identification of physiological systems using short data segments.

    Science.gov (United States)

    Ludvig, Daniel; Perreault, Eric J

    2012-12-01

    System identification of physiological systems poses unique challenges, especially when the structure of the system under study is uncertain. Nonparametric techniques can be useful for identifying system structure, but these typically assume stationarity and require large amounts of data. Both of these requirements are often not easily obtained in the study of physiological systems. Ensemble methods for time-varying nonparametric estimation have been developed to address the issue of stationarity, but these require an amount of data that can be prohibitive for many experimental systems. To address this issue, we developed a novel algorithm that uses multiple short data segments. Using simulation studies, we showed that this algorithm produces system estimates with lower variability than previous methods when limited data are present. Furthermore, we showed that the new algorithm generates time-varying system estimates with lower total error than an ensemble method. Thus, this algorithm is well suited for the identification of physiological systems that vary with time or from which only short segments of stationary data can be collected.

  6. The Physiologic Effects of Pneumoperitoneum in the Morbidly Obese

    Science.gov (United States)

    Nguyen, Ninh T.; Wolfe, Bruce M.

    2005-01-01

    Objective: To review the physiologic effects of carbon dioxide (CO2) pneumoperitoneum in the morbidly obese. Summary Background Data: The number of laparoscopic bariatric operations performed in the United States has increased dramatically over the past several years. Laparoscopic bariatric surgery requires abdominal insufflation with CO2 and an increase in the intraabdominal pressure up to 15 mm Hg. Many studies have demonstrated the adverse consequences of pneumoperitoneum; however, few studies have examined the physiologic effects of pneumoperitoneum in the morbidly obese. Methods: A MEDLINE search from 1994 to 2003 was performed using the key words morbid obesity, laparoscopy, bariatric surgery, pneumoperitoneum, and gastric bypass. The authors reviewed papers evaluating the physiologic effects of pneumoperitoneum in morbidly obese subjects undergoing laparoscopy. The topics examined included alteration in acid-base balance, hemodynamics, femoral venous flow, and hepatic, renal, and cardiorespiratory function. Results: Physiologically, morbidly obese patients have a higher intraabdominal pressure at 2 to 3 times that of nonobese patients. The adverse consequences of pneumoperitoneum in morbidly obese patients are similar to those observed in nonobese patients. Laparoscopy in the obese can lead to systemic absorption of CO2 and increased requirements for CO2 elimination. The increased intraabdominal pressure enhances venous stasis, reduces intraoperative portal venous blood flow, decreases intraoperative urinary output, lowers respiratory compliance, increases airway pressure, and impairs cardiac function. Intraoperative management to minimize the adverse changes include appropriate ventilatory adjustments to avoid hypercapnia and acidosis, the use of sequential compression devices to minimizes venous stasis, and optimize intravascular volume to minimize the effects of increased intraabdominal pressure on renal and cardiac function. Conclusions: Morbidly obese

  7. Are functional foods redefining nutritional requirements?

    Science.gov (United States)

    Jones, Peter J; Varady, Krista A

    2008-02-01

    Functional foods are increasing in popularity owing to their ability to confer health and physiological benefits. Nevertheless, the notion that functional foods improve health when providing nutrients at levels above and beyond existing recommended intakes is inconsistent with the definition of requirement. This disparity highlights the need for an alternative definition of nutrient requirement. The present objective is to examine distinctions between optimization of health, as defined by what we currently deem as required intakes, versus adding physiological benefit using bioactive agents found in functional foods. Presently, requirement is defined as the lowest amount of intake of a nutrient that will maintain a defined level of nourishment for a specific indicator of adequacy. In contrast, functional foods are described as ingredients that are not necessary for body function, yet provide added physiological benefit that confer better overall health. Plant sterols are one example of such an ingredient. Plant sterols lower plasma cholesterol concentrations, and may thus be considered essential nutrients in physiological situations where circulating cholesterol concentrations are high. Similarly, intakes of omega-3 fats beyond existing requirement may confer additional health benefits such as hypolipidemic and anti-diabetic effects. These examples underscore the inconsistencies between what is defined as a nutrient requirement versus what is identified as a health benefit of a functional food. Such discrepancies emphasize the need for a more all-encompassing definition of a nutrient requirement; that is, one that moves beyond the prevention of overt deficiency to encompass improved health and disease risk reduction.

  8. Intragroup Emotions: Physiological Linkage and Social Presence

    Science.gov (United States)

    Järvelä, Simo; Kätsyri, Jari; Ravaja, Niklas; Chanel, Guillaume; Henttonen, Pentti

    2016-01-01

    We investigated how technologically mediating two different components of emotion—communicative expression and physiological state—to group members affects physiological linkage and self-reported feelings in a small group during video viewing. In different conditions the availability of second screen text chat (communicative expression) and visualization of group level physiological heart rates and their dyadic linkage (physiology) was varied. Within this four person group two participants formed a physically co-located dyad and the other two were individually situated in two separate rooms. We found that text chat always increased heart rate synchrony but HR visualization only with non-co-located dyads. We also found that physiological linkage was strongly connected to self-reported social presence. The results encourage further exploration of the possibilities of sharing group member's physiological components of emotion by technological means to enhance mediated communication and strengthen social presence. PMID:26903913

  9. Intragroup emotions: physiological linkage and social presence

    Directory of Open Access Journals (Sweden)

    Simo eJärvelä

    2016-02-01

    Full Text Available We investigated how technologically mediating two different components of emotion – communicative expression and physiological state – to group members affects physiological linkage and self-reported feelings in a small group during video viewing. In different conditions the availability of second screen text chat (communicative expression and visualization of group level physiological heart rates and their dyadic linkage (physiology was varied. Within this four person group two participants formed a physically co-located dyad and the other two were individually situated in two separate rooms. We found that text chat always increased heart rate synchrony but HR visualization only with non-co-located dyads. We also found that physiological linkage was strongly connected to self-reported social presence. The results encourage further exploration of the possibilities of sharing group member’s physiological components of emotion by technological means to enhance mediated communication and strengthen social presence.

  10. Wireless Sensor Network for Wearable Physiological Monitoring

    OpenAIRE

    P. S. Pandian; K. P. Safeer; Pragati Gupta; D. T. Shakunthala; B. S. Sundersheshu; V. C. Padaki

    2008-01-01

    Wearable physiological monitoring system consists of an array of sensors embedded into the fabric of the wearer to continuously monitor the physiological parameters and transmit wireless to a remote monitoring station. At the remote monitoring station the data is correlated to study the overall health status of the wearer. In the conventional wearable physiological monitoring system, the sensors are integrated at specific locations on the vest and are interconnected to the wearable data acqui...

  11. Use of a physiological profile to document motor impairment in ageing and in clinical groups.

    Science.gov (United States)

    Lord, S R; Delbaere, K; Gandevia, S C

    2016-08-15

    Ageing decreases exercise performance and is frequently accompanied by reductions in cognitive performance. Deterioration in the physiological capacity to stand, locomote and exercise can manifest itself as falling over and represents a significant deterioration in sensorimotor control. In the elderly, falling leads to serious morbidity and mortality with major societal costs. Measurement of a suite of physiological capacities that are required for successful motor performance (including vision, muscle strength, proprioception and balance) has been used to produce a physiological profile assessment (PPA) which has been tracked over the age spectrum and in different diseases (e.g. multiple sclerosis, Parkinson's disease). As well as measures of specific physiological capacities, the PPA generates an overall 'score' which quantitatively measures an individual's cumulative risk of falling. The present review collates data from the PPA (and the physiological capacities it measures) as well as its use in strategies to reduce falls in the elderly and those with different diseases. We emphasise that (i) motor impairment arises via reductions in a wide range of sensorimotor abilities; (ii) the PPA approach not only gives a snapshot of the physiological capacity of an individual, but it also gives insight into the deficits among groups of individuals with particular diseases; and (iii) deficits in seemingly restricted and disparate physiological domains (e.g. vision, strength, cognition) are funnelled into impairments in tasks requiring upright balance. Motor impairments become more prevalent with ageing but careful physiological measurement and appropriate interventions offer a way to maximise health across the lifespan.

  12. Auditory pathways: anatomy and physiology.

    Science.gov (United States)

    Pickles, James O

    2015-01-01

    This chapter outlines the anatomy and physiology of the auditory pathways. After a brief analysis of the external, middle ears, and cochlea, the responses of auditory nerve fibers are described. The central nervous system is analyzed in more detail. A scheme is provided to help understand the complex and multiple auditory pathways running through the brainstem. The multiple pathways are based on the need to preserve accurate timing while extracting complex spectral patterns in the auditory input. The auditory nerve fibers branch to give two pathways, a ventral sound-localizing stream, and a dorsal mainly pattern recognition stream, which innervate the different divisions of the cochlear nucleus. The outputs of the two streams, with their two types of analysis, are progressively combined in the inferior colliculus and onwards, to produce the representation of what can be called the "auditory objects" in the external world. The progressive extraction of critical features in the auditory stimulus in the different levels of the central auditory system, from cochlear nucleus to auditory cortex, is described. In addition, the auditory centrifugal system, running from cortex in multiple stages to the organ of Corti of the cochlea, is described.

  13. Physiologic amputation: a case study.

    Science.gov (United States)

    Long, Jeri; Hall, Virginia

    2014-03-01

    Acute limb ischemia is a complication of severe peripheral arterial disease that can be a threatening limb as well as life. Multiple procedures exist today to help revascularize extremities; however, even with the latest technologies, surgical amputation of the limb may still be necessary. Cryoamputation, or physiologic amputation, is a method used to treat patients who are hemodynamically unstable for the operating room and who are in need of urgent amputation owing to arterial ischemia. This procedure is used in the rare instance where not only a persons' limb is threatened, but also their life. This is a case study regarding one patient who presented to the hospital with limb-threatening ischemia who became hemodynamically unstable owing to the rhabdomyolysis associated with the ischemia of his lower extremity. Cryoamputation was used to stabilize the patient and prevent further deterioration, so that he could safely undergo surgical amputation of the limb without an increase in mortality risk. Cryoamputation must be followed by formal surgical amputation when the patient is hemodynamically stabilized. It is not a limb salvaging, procedure but it is a life-saving procedure. This case study demonstrates the usefulness of the procedure and discusses the technique used for cryoamputation.

  14. Physiological demands of competitive basketball.

    Science.gov (United States)

    Narazaki, K; Berg, K; Stergiou, N; Chen, B

    2009-06-01

    The aim of this study was to assess physiological demands of competitive basketball by measuring oxygen consumption (VO2) and other variables during practice games. Each of 12 players (20.4 +/- 1.1 years) was monitored in a 20-min practice game, which was conducted in the same way as actual games with the presence of referees and coaches. VO2 was measured by a portable system during the game and blood lactate concentration (LA) was measured in brief breaks. Subjects were also videotaped for time-motion analysis. Female and male players demonstrated respective VO2 of 33.4 +/- 4.0 and 36.9 +/- 2.6 mL/kg/min and LA of 3.2 +/- 0.9 and 4.2 +/- 1.3 mmol/L in the practice games (P>0.05). They spent 34.1% of play time running and jumping, 56.8% walking, and 9.0% standing. Pre-obtained VO(2max) was correlated to VO(2) during play (r=0.673) and to percent of duration for running and jumping (r=0.935 and 0.962 for females and males, respectively). This study demonstrated a greater oxygen uptake for competitive basketball than that estimated based on a previous compendium. The correlation between aerobic capacity and activity level suggests the potential benefit of aerobic conditioning in basketball.

  15. Obesity and Asthma: Physiological Perspective

    Directory of Open Access Journals (Sweden)

    Bill Brashier

    2013-01-01

    Full Text Available Obesity induces some pertinent physiological changes which are conducive to either development of asthma or cause of poorly controlled asthma state. Obesity related mechanical stress forces induced by abdominal and thoracic fat generate stiffening of the lungs and diaphragmatic movements to result in reduction of resting lung volumes such as functional residual capacity (FRC. Reduced FRC is primarily an outcome of decreased expiratory reserve volume, which pushes the tidal breathing more towards smaller high resistance airways, and consequentially results in expiratory flow limitation during normal breathing in obesity. Reduced FRC also induces plastic alteration in the small collapsible airways, which may generate smooth muscle contraction resulting in increased small airway resistance, which, however, is not picked up by spirometric lung volumes. There is also a possibility that chronically reduced FRC may generate permanent adaptation in the very small airways; therefore, the airway calibres may not change despite weight reduction. Obesity may also induce bronchodilator reversibility and diurnal lung functional variability. Obesity is also associated with airway hyperresponsiveness; however, the mechanism of this is not clear. Thus, obesity has effects on lung function that can generate respiratory distress similar to asthma and may also exaggerate the effects of preexisting asthma.

  16. Wearable Systems for Service based on Physiological Signals.

    Science.gov (United States)

    Ryoo, Dong-Wan; Kim, Young-Sung; Lee, Jeun-Woo

    2005-01-01

    Many researches for useful status information on humans have been done using the bio-signals. The bio-signal acquisition systems can be used to connect a user and a ubiquitous computing environment. The ubiquitous computing environment has to give various services anywhere, anytime. Consequently, ubiquitous computing requires new technology, such as a new user interface, dynamic service mechanism based on context and mobility support, which is different from technology used in desktop environment. To do this, we developed a wearable system, which can sense physiological data, determine emotional status and execute service based on the emotion. In this paper, we described wearable systems for personalized service based on physiological signals. The wearable system is composed of three subsystems, the physiological data sensing subsystem, the human status awareness subsystem and the service management subsystem. The physiological data sensing subsystem senses PPG, GSR and SKT signals from the data glove and sends the data to a wearable system using Bluetooth. The human status awareness subsystem in the wearable system receives the data from bio-sensors and determines emotional status using nonlinear mapping and rule-base. After determining emotion, the service management subsystem activates proper service automatically, and the service management subsystem can provide personalized service for users based on acquired bio-signals. Also, we presented various feature extraction using bio-signals such as PPG, GSR, SKT considering mobility, and emotion recognition of human status for the ubiquitous computing service.

  17. Physiological consequences of repeated exposures to conditioned fear.

    Science.gov (United States)

    Thompson, Robert S; Strong, Paul V; Fleshner, Monika

    2012-06-01

    Activation of the stress response evokes a cascade of physiological reactions that may be detrimental when repeated or chronic, and when triggered after exposure to psychological/emotional stressors. Investigation of the physiological mechanisms responsible for the health damaging effects requires animal paradigms that repeatedly evoke a response to psychological/emotional stressors. To this end, adult male Sprague Dawley rats were repeatedly exposed (2X per day for 20 days) to a context that they were conditioned to fear (conditioned fear test, CFT). Repeated exposure to CFT produced body weight loss, adrenal hypertrophy, thymic involution, and basal corticosterone elevation. In vivo biotelemetry measures revealed that CFT evokes sympathetic nervous system driven increases in heart rate (HR), mean arterial pressure (MAP), and core body temperature. Extinction of behavioral (freezing) and physiological responses to CFT was prevented using minimal reinstatement footshock. MAP responses to the CFT did not diminish across 20 days of exposure. In contrast, HR and cardiac contractility responses declined by day 15, suggesting a shift toward vascular-dominated MAP (a pre-clinical marker of CV dysfunction). Flattened diurnal rhythms, common to stress-related mood/anxiety disorders, were found for most physiological measures. Thus, repeated CFT produces adaptations indicative of the health damaging effects of psychological/emotional stress.

  18. Physiological Consequences of Repeated Exposures to Conditioned Fear

    Directory of Open Access Journals (Sweden)

    Robert S. Thompson

    2012-05-01

    Full Text Available Activation of the stress response evokes a cascade of physiological reactions that may be detrimental when repeated or chronic, and when triggered after exposure to psychological/emotional stressors. Investigation of the physiological mechanisms responsible for the health damaging effects requires animal paradigms that repeatedly evoke a response to psychological/emotional stressors. To this end, adult male Sprague Dawley rats were repeatedly exposed (2X per day for 20 days to a context that they were conditioned to fear (conditioned fear test, CFT. Repeated exposure to CFT produced body weight loss, adrenal hypertrophy, thymic involution, and basal corticosterone elevation. In vivo biotelemetry measures revealed that CFT evokes sympathetic nervous system driven increases in heart rate (HR, mean arterial pressure (MAP, and core body temperature. Extinction of behavioral (freezing and physiological responses to CFT was prevented using minimal reinstatement footshock. MAP responses to the CFT did not diminish across 20 days of exposure. In contrast, HR and cardiac contractility responses declined by day 15, suggesting a shift toward vascular-dominated MAP (a pre-clinical marker of CV dysfunction. Flattened diurnal rhythms, common to stress-related mood/anxiety disorders, were found for most physiological measures. Thus, repeated CFT produces adaptations indicative of the health damaging effects of psychological/emotional stress.

  19. Physiological Responses to Thermal Stress and Exercise

    Science.gov (United States)

    Iyota, Hiroyuki; Ohya, Akira; Yamagata, Junko; Suzuki, Takashi; Miyagawa, Toshiaki; Kawabata, Takashi

    The simple and noninvasive measuring methods of bioinstrumentation in humans is required for optimization of air conditioning and management of thermal environments, taking into consideration the individual specificity of the human body as well as the stress conditions affecting each. Changes in human blood circulation were induced with environmental factors such as heat, cold, exercise, mental stress, and so on. In this study, the physiological responses of human body to heat stress and exercise were investigated in the initial phase of the developmental research. We measured the body core and skin temperatures, skin blood flow, and pulse wave as the indices of the adaptation of the cardiovascular system. A laser Doppler skin blood flowmetry using an optical-sensor with a small portable data logger was employed for the measurement. These results reveal the heat-stress and exercise-induced circulatory responses, which are under the control of the sympathetic nerve system. Furthermore, it was suggested that the activity of the sympathetic nervous system could be evaluated from the signals of the pulse wave included in the signals derived from skin blood flow by means of heart rate variability assessments and detecting peak heights of velocity-plethysmogram.

  20. Physiological and pathological implications of cholesterol.

    Science.gov (United States)

    Cortes, Victor A; Busso, Dolores; Maiz, Alberto; Arteaga, Antonio; Nervi, Flavio; Rigotti, Attilio

    2014-01-01

    Cholesterol has evolved to fulfill sophisticated biophysical, cell signaling and endocrine requirements of animal systems. At a cellular level, cholesterol is found in membranes, where it increases both bilayer stiffness and impermeability to water and ions. Furthermore, cholesterol is integrated into specialized lipid-protein membrane microdomains with critical topographical and signaling functions. At an organismal level, cholesterol is the precursor for all steroid hormones, including gluco- and mineralo-corticoids, sex hormones and vitamin D, all of which regulate carbohydrate, sodium, reproductive and bone homeostasis, respectively. This sterol is also the precursor for bile acids, which are important for intestinal absorption of dietary lipids as well as energy and glucose metabolic regulation. Importantly, complex mechanisms maintain cholesterol within physiological ranges and the disregulation of these mechanisms results in embryonic or adult diseases, caused by either excessive or reduced tissue cholesterol levels. The causative role of cholesterol in these diseases has been demonstrated by diverse genetic and pharmacologic animal models that are commented in this review.

  1. Assessment of acute physiological demand for soccer

    Directory of Open Access Journals (Sweden)

    Daniel Barbosa Coelho

    2013-09-01

    Full Text Available Soccer is a sport practiced worldwide, on all continents. It is considered an intermittent activity of high intensity and long duration, in which movements that require great strength and speed, such as jumps and sprints, result in high levels of muscle microtrauma, hampering athletes’ training and recovery. The present study aimed to evaluate the magnitude of changes in different markers of physiological demand resulting from a soccer match in healthy individuals. Ten healthy male physical education students participated in the study and were evaluated in two matches: the semi-final and final games of the college tournament at the federal university where they studied. Blood samples were collected from each volunteer pre- and post-match. Cortisol, IL-6 and CK concentrations were increased after the match (p < 0.05. Testosterone and alpha-actin concentrations did not change. Our results indicate that changes in some of the acute response markers evaluated in players before and after competitive soccer matches provide important information for planning training or recovery, as well as nutritional strategies for improving performance.

  2. Physiological and molecular aspects of cobalamin transport.

    Science.gov (United States)

    Fedosov, Sergey N

    2012-01-01

    Minute doses of a complex cofactor cobalamin (Cbl, vitamin B12) are essential for metabolism. The nutritional chain for humans includes: (1) production of Cbl by bacteria in the intestinal tract of herbivores; (2) accumulation of the absorbed Cbl in animal tissues; (3) consumption of food of animal origin. Most biological sources contain both Cbl and its analogues, i.e. Cbl-resembling compounds physiologically inactive in animal cells. Selective assimilation of the true vitamin requires an interplay between three transporting proteins - haptocorrin (HC), intrinsic factor (IF), transcobalamin (TC) - and several receptors. HC is present in many biological fluids, including gastric juice, where it assists in disposal of analogues. Gastric IF selectively binds dietary Cbl and enters the intestinal cells via receptor-mediated endocytosis. Absorbed Cbl is transmitted to TC and delivered to the tissues with blood flow. The complex transport system guarantees a very efficient uptake of the vitamin, but failure at any link causes Cbl-deficiency. Early detection of a negative B12 balance is highly desirable to prevent irreversible neurological damages, anaemia and death in aggravated cases. The review focuses on the molecular mechanisms of cobalamin transport with emphasis on interaction of corrinoids with the specific proteins and protein-receptor recognition. The last section briefly describes practical aspects of recent basic research concerning early detection of B12-related disorders, medical application of Cbl-conjugates, and purification of corrinoids from biological samples.

  3. Effect of Metformin on v-SNAREs expression in Human omental Adipocytes%二甲双胍对人网膜脂肪细胞中v-SNAREs家族表达的影响

    Institute of Scientific and Technical Information of China (English)

    丁跃; 刘云峰; 章毅; 杨静

    2015-01-01

    目的:观察二甲双胍对人成熟脂肪细胞中囊泡相关可溶性N-乙酰基亚胺敏感因子附着蛋白受体(vescical-souble N-ethymaleimide sensitive factor attachment proteins receptor, v-SNAREs)家族成员VAMP2、3、4、5、7、8表达的影响。方法:诱导分化人前脂肪细胞为成熟脂肪细胞,并用油红O染色证明。给予不同浓度二甲双胍(0mM,1mM,10mM)干预24小时后,运用实时荧光相对定量PCR技术检测脂肪细胞VAMP2、3、4、5、7、8的mRNA基因水平。结果:与对照组(0mM二甲双胍)相比,1mM二甲双胍上调脂肪细胞VAMP4,5,8水平(分别P<0.05,P<0.05,P<0.05,),下调VAMP3、7水平(分别P<0.05,P<0.01),对VAMP2表达的差异无统计学意义;与对照组相比10mM二甲双胍上调脂肪细胞VAMP4、5、8水平(分别P<0.01,P<0.01,P<0.01),下调VAMP7水平(P<0.01),VAMP2、3表达差异无统计学意义。10mM二甲双胍干预组与1mM组比较, VAMP3、4、5、8表达水平升高(P<0.05,P<0.05,P<0.05,P<0.01),VAMP2、7表达差异无统计学意义。结论:二甲双胍可上调VAMP4,5,8的表达,可下调VAMP3、7的表达,且具有一定的剂量依赖效应,对VAMP2的表达无影响,显示二甲双胍可能通过对v-SNAREs家族表达的调节而参与对脂肪细胞GLUT4转运的调节。%Objective:To observe the effects of metformin on the expression of vesicle-associated membrane proteins (VAMP2,3,4,7,8) which the subfailmilies of vescical-souble N-ethymaleimide sensitive factor attachment proteins receptor (v-SNAREs) in human omental adipocytes. Method:Induce human preadipocytes into mature adipocytes and proofed by oil red O staining. Twenty-four hours after giving different concentration metfomin ( 0mM, 1mM, 10mM) intervention, we using real-time PCR technology to detect the mRNA expression of VAMP2,3,4,5,7,8.Results The levels of VAMP4,5,8 in 1mM metformin group was increased compared with

  4. Physiological factors influencing capillary growth.

    Science.gov (United States)

    Egginton, S

    2011-07-01

    (1) Angiogenesis (growth of new capillaries from an existing capillary bed) may result from a mismatch in microvascular supply and metabolic demand (metabolic error signal). Krogh examined the distribution and number of capillaries to explore the correlation between O(2) delivery and O(2) consumption. Subsequently, the heterogeneity in angiogenic response within a muscle has been shown to reflect either differences in fibre type composition or mechanical load. However, local control leads to targetted angiogenesis in the vicinity of glycolytic fibre types following muscle stimulation, or oxidative fibres following endurance training, while heterogeneity of capillary spacing is maintained during ontogenetic growth. (2) Despite limited microscopy resolution and lack of specific markers, Krogh's interest in the structure of the capillary wall paved the way for understanding the mechanisms of capillary growth. Angiogenesis may be influenced by the response of perivascular or stromal cells (fibroblasts, macrophages and pericytes) to altered activity, likely acting as a source for chemical signals modulating capillary growth such as vascular endothelial growth factor. In addition, haemodynamic factors such as shear stress and muscle stretch play a significant role in adaptive remodelling of the microcirculation. (3) Most indices of capillarity are highly dependent on fibre size, resulting in possible bias because of scaling. To examine the consequences of capillary distribution, it is therefore helpful to quantify the area of tissue supplied by individual capillaries. This allows the spatial limitations inherent in most models of tissue oxygenation to be overcome generating an alternative approach to Krogh's tissue cylinder, the capillary domain, to improve descriptions of intracellular oxygen diffusion. © 2010 The Author. Acta Physiologica © 2010 Scandinavian Physiological Society.

  5. Aristotle on physiology of logos

    Directory of Open Access Journals (Sweden)

    Benéitez Prudencio, José Javier

    2011-06-01

    Full Text Available This paper presents a view of Aristotle’s understanding of the relation of human intellect to human body. Given that for Aristotle intellect is a ‘psychic’ capacity or power: does Aristotle think of human understanding as a part or aspect of form (ειδος of the human body, in the way that the other powers (i.e. sensitive and nutritive are both parts of the form of an animal body? This question is still in dispute, but the objective in my inquiry is to justify the possibilities of an Aristotelian’s physiology of mind or thought.

    El presente artículo trata de estudiar la relación del entendimiento humano con el cuerpo en el pensamiento aristotélico. Dado que para Aristóteles la inteligencia constituye una capacidad o facultad ‘psíquica’, podríamos preguntarnos si no piensa, entonces, que sea una parte o un aspecto de la forma (ειδος del cuerpo humano, de la misma manera que se da esta relación con los otras facultades (así, por ejemplo, con la sensación y la nutrición. La cuestión es motivo todavía de disputa. El objetivo de mi investigación radica en justificar las posibilidades de una fisiología aristotélica de la mente o del pensamiento.

  6. Cardiac anatomy and physiology: a review.

    Science.gov (United States)

    Gavaghan, M

    1998-04-01

    This article reviews the normal anatomy and physiology of the heart. Understanding the normal anatomic and physiologic relationships described in this article will help perioperative nurses care for patients who are undergoing cardiac procedures. Such knowledge also assists nurses in educating patients about cardiac procedures and about activities that can prevent, reverse, or improve cardiac illness.

  7. Teaching Stress Physiology Using Zebrafish ("Danio Rerio")

    Science.gov (United States)

    Cooper, Michael; Dhawale, Shree; Mustafa, Ahmed

    2009-01-01

    A straightforward and inexpensive laboratory experiment is presented that investigates the physiological stress response of zebrafish after a 5 degree C increase in water temperature. This experiment is designed for an undergraduate physiology lab and allows students to learn the scientific method and relevant laboratory techniques without causing…

  8. Physiological Coping: A Model for Teaching Pathophysiology

    Science.gov (United States)

    Porth, Carol M.

    1977-01-01

    The author discusses the use of a teaching model she developed for use in a pathophysiology. The model is based on the physiological component of C. Roy's adaptation model, which encourages students to look for physiological cues and apply relevant knowledge in patient care through a problem-solving approach. (TA)

  9. Physiology and biochemistry of honey bees

    Science.gov (United States)

    Despite their tremendous economic importance, honey bees are not a typical model system for studying general questions of insect physiology. This is primarily due to the fact that honey bees live in complex social settings which impact their physiological and biochemical characteristics. Not surpris...

  10. Towards Individualized Physiology Lecturing in Africa

    African Journals Online (AJOL)

    Dr Olaleye Samuel

    physiology slides, animations, diagrams and problem illustrations and real life case films in digital form. ... Patient-based physiology learning. Ripatti and Hänninen ... source leaving still a deeper cognitive understanding aside. This is to ... throughout the whole school time. ... now the on-line computerized systems provide.

  11. Physiological Bases of Bulimia, and Antidepressant Treatment.

    Science.gov (United States)

    Getzfeld, Andrew R.

    This paper reviews the literature on the physiological causes of bulimia and investigates the rationale behind the usage of antidepressant medication in the treatment of bulimia nervosa. No definite conclusions can be stated regarding the physiology of bulimia, but a number of hypotheses are suggested. It appears that the hypothalamus is involved…

  12. Wireless Sensor Network for Wearable Physiological Monitoring

    Directory of Open Access Journals (Sweden)

    P. S. Pandian

    2008-05-01

    Full Text Available Wearable physiological monitoring system consists of an array of sensors embedded into the fabric of the wearer to continuously monitor the physiological parameters and transmit wireless to a remote monitoring station. At the remote monitoring station the data is correlated to study the overall health status of the wearer. In the conventional wearable physiological monitoring system, the sensors are integrated at specific locations on the vest and are interconnected to the wearable data acquisition hardware by wires woven into the fabric. The drawbacks associated with these systems are the cables woven in the fabric pickup noise such as power line interference and signals from nearby radiating sources and thereby corrupting the physiological signals. Also repositioning the sensors in the fabric is difficult once integrated. The problems can be overcome by the use of physiological sensors with miniaturized electronics to condition, process, digitize and wireless transmission integrated into the single module. These sensors are strategically placed at various locations on the vest. Number of sensors integrated into the fabric form a network (Personal Area Network and interacts with the human system to acquire and transmit the physiological data to a wearable data acquisition system. The wearable data acquisition hardware collects the data from various sensors and transmits the processed data to the remote monitoring station. The paper discusses wireless sensor network and its application to wearable physiological monitoring and its applications. Also the problems associated with conventional wearable physiological monitoring are discussed.

  13. Physiological Activity and Attitudes toward Disabled Persons.

    Science.gov (United States)

    Wesolowski, Michael D.; Deichmann, John

    1980-01-01

    Investigated whether physiological reactions of college students viewing videotapes showing three scene types (disabled people, able-bodied people, and neutral scenes) could be discriminated by scene type. Participants for the study were selected by their scores on the Attitudes toward Disabled Persons (ATDP) Scale. Physiological measures showed…

  14. Physiological characteristics of an aging Olympic athlete

    DEFF Research Database (Denmark)

    Nybo, Lars; Schmidt, Jakob Friis; Fritzdorf, Stephen;

    2014-01-01

    To investigate the physiological basis of continued world-class performance of a world-class rower who won medals (3 gold and 2 bronze) at five consecutive Olympic Games.......To investigate the physiological basis of continued world-class performance of a world-class rower who won medals (3 gold and 2 bronze) at five consecutive Olympic Games....

  15. Human physiologically based pharmacokinetic model for propofol

    Directory of Open Access Journals (Sweden)

    Schnider Thomas W

    2005-04-01

    Full Text Available Abstract Background Propofol is widely used for both short-term anesthesia and long-term sedation. It has unusual pharmacokinetics because of its high lipid solubility. The standard approach to describing the pharmacokinetics is by a multi-compartmental model. This paper presents the first detailed human physiologically based pharmacokinetic (PBPK model for propofol. Methods PKQuest, a freely distributed software routine http://www.pkquest.com, was used for all the calculations. The "standard human" PBPK parameters developed in previous applications is used. It is assumed that the blood and tissue binding is determined by simple partition into the tissue lipid, which is characterized by two previously determined set of parameters: 1 the value of the propofol oil/water partition coefficient; 2 the lipid fraction in the blood and tissues. The model was fit to the individual experimental data of Schnider et. al., Anesthesiology, 1998; 88:1170 in which an initial bolus dose was followed 60 minutes later by a one hour constant infusion. Results The PBPK model provides a good description of the experimental data over a large range of input dosage, subject age and fat fraction. Only one adjustable parameter (the liver clearance is required to describe the constant infusion phase for each individual subject. In order to fit the bolus injection phase, for 10 or the 24 subjects it was necessary to assume that a fraction of the bolus dose was sequestered and then slowly released from the lungs (characterized by two additional parameters. The average weighted residual error (WRE of the PBPK model fit to the both the bolus and infusion phases was 15%; similar to the WRE for just the constant infusion phase obtained by Schnider et. al. using a 6-parameter NONMEM compartmental model. Conclusion A PBPK model using standard human parameters and a simple description of tissue binding provides a good description of human propofol kinetics. The major advantage of a

  16. Preemptive analgesia I: physiological pathways and pharmacological modalities.

    LENUS (Irish Health Repository)

    Kelly, D J

    2012-02-03

    PURPOSE: This two-part review summarizes the current knowledge of physiological mechanisms, pharmacological modalities and controversial issues surrounding preemptive analgesia. SOURCE: Articles from 1966 to present were obtained from the MEDLINE databases. Search terms included: analgesia, preemptive; neurotransmitters; pain, postoperative; hyperalgesia; sensitization, central nervous system; pathways, nociception; anesthetic techniques; analgesics, agents. Principal findings: The physiological basis of preemptive analgesia is complex and involves modification of the pain pathways. The pharmacological modalities available may modify the physiological responses at various levels. Effective preemptive analgesic techniques require multi-modal interception of nociceptive input, increasing threshold for nociception, and blocking or decreasing nociceptor receptor activation. Although the literature is controversial regarding the effectiveness of preemptive analgesia, some general recommendations can be helpful in guiding clinical care. Regional anesthesia induced prior to surgical trauma and continued well into the postoperative period is effective in attenuating peripheral and central sensitization. Pharmacologic agents such as NSAIDs (non-steroidal anti-inflammatory drugs) opioids, and NMDA (N-methyl-D-aspartate) - and alpha-2-receptor antagonists, especially when used in combination, act synergistically to decrease postoperative pain. CONCLUSION: The variable patient characteristics and timing of preemptive analgesia in relation to surgical noxious input requires individualization of the technique(s) chosen. Multi-modal analgesic techniques appear most effective.

  17. Alterations in physiology and anatomy during pregnancy.

    Science.gov (United States)

    Tan, Eng Kien; Tan, Eng Loy

    2013-12-01

    Pregnant women undergo profound anatomical and physiological changes so that they can cope with the increased physical and metabolic demands of their pregnancies. The cardiovascular, respiratory, haematological, renal, gastrointestinal and endocrine systems all undergo important physiological alterations and adaptations needed to allow development of the fetus and to allow the mother and fetus to survive the demands of childbirth. Such alterations in anatomy and physiology may cause difficulties in interpreting signs, symptoms, and biochemical investigations, making the clinical assessment of a pregnant woman inevitably confusing but challenging. Understanding these changes is important for every practicing obstetrician, as the pathological deviations from the normal physiological alterations may not be clear-cut until an adverse outcome has resulted. Only with a sound knowledge of the physiology and anatomy changes can the care of an obstetric parturient be safely optimized for a better maternal and fetal outcome.

  18. Correlations between tests of aging in Hiroshima subjects: an attempt to define physiologic age

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, J.W.; Hashizume, Asaji; Jablon, Seymour

    1964-12-01

    Nine physiologic functions which change with age were measured in 437 subjects during their regular visits to the Atomic Bomb Casualty Commission clinic in Hiroshima, Japan. This pilot study was undertaken to determine the feasibility of collecting such data in a population sample physiologic age score. Tests conducted consisted of: skin elasticity, systolic blood pressure, vital capacity, hand grip strength, light extinction time, vibrometer, visual activity, audiometry, and serum cholesterol. The study demonstrated that adequate sample data could be obtained, and that statistical treatment could construct a physiologic age for individual subjects. However, the tests were of limited value below age 40, and the validation of the concept of physiologic age requires eventual correlation with mortality. Since the ABCC program includes a highly accurate mortality survey, it is hoped that data on physiologic aging can be collected and eventually related to mortality. 11 references, 3 figures, 6 tables.

  19. The Effects Of An Exercise Physiology Program on Physical Fitness Variables, Body Satisfaction, and Physiology Knowledge.

    Science.gov (United States)

    Perry, Arlette C.; Rosenblatt, Evelyn S.; Kempner, Lani; Feldman, Brandon B.; Paolercio, Maria A.; Van Bemden, Angie L.

    2002-01-01

    Examined the effects of an exercise physiology program on high school students' physical fitness, body satisfaction, and physiology knowledge. Intervention students received exercise physiology theory and active aerobic and resistance exercise within their biology course. Data from student surveys and measurements indicated that the integrated…

  20. A graphical simulation software for instruction in cardiovascular mechanics physiology

    Directory of Open Access Journals (Sweden)

    Wenger Roland H

    2011-01-01

    Full Text Available Abstract Background Computer supported, interactive e-learning systems are widely used in the teaching of physiology. However, the currently available complimentary software tools in the field of the physiology of cardiovascular mechanics have not yet been adapted to the latest systems software. Therefore, a simple-to-use replacement for undergraduate and graduate students' education was needed, including an up-to-date graphical software that is validated and field-tested. Methods Software compatible to Windows, based on modified versions of existing mathematical algorithms, has been newly developed. Testing was performed during a full term of physiological lecturing to medical and biology students. Results The newly developed CLabUZH software models a reduced human cardiovascular loop containing all basic compartments: an isolated heart including an artificial electrical stimulator, main vessels and the peripheral resistive components. Students can alter several physiological parameters interactively. The resulting output variables are printed in x-y diagrams and in addition shown in an animated, graphical model. CLabUZH offers insight into the relations of volume, pressure and time dependency in the circulation and their correlation to the electrocardiogram (ECG. Established mechanisms such as the Frank-Starling Law or the Windkessel Effect are considered in this model. The CLabUZH software is self-contained with no extra installation required and runs on most of today's personal computer systems. Conclusions CLabUZH is a user-friendly interactive computer programme that has proved to be useful in teaching the basic physiological principles of heart mechanics.

  1. Predicting physiological capacity of human load carriage - a review.

    Science.gov (United States)

    Drain, Jace; Billing, Daniel; Neesham-Smith, Daniel; Aisbett, Brad

    2016-01-01

    This review article aims to evaluate a proposed maximum acceptable work duration model for load carriage tasks. It is contended that this concept has particular relevance to physically demanding occupations such as military and firefighting. Personnel in these occupations are often required to perform very physically demanding tasks, over varying time periods, often involving load carriage. Previous research has investigated concepts related to physiological workload limits in occupational settings (e.g. industrial). Evidence suggests however, that existing (unloaded) workload guidelines are not appropriate for load carriage tasks. The utility of this model warrants further work to enable prediction of load carriage durations across a range of functional workloads for physically demanding occupations. If the maximum duration for which personnel can physiologically sustain a load carriage task could be accurately predicted, commanders and supervisors could better plan for and manage tasks to ensure operational imperatives were met whilst minimising health risks for their workers.

  2. Elite futsal refereeing: Activity profile and physiological demands

    DEFF Research Database (Denmark)

    Rebelo, António N.; Ascensão, António A.; Magalhães, José F.

    2011-01-01

    Rebelo, AN, Ascensão, AA, Magalhães, JF, Bischoff, R, Bendiksen, M, and Krustrup, P. Elite futsal refereeing: activity profile and physiological demands. J Strength Cond Res 24(X): 000-000, 2010-The purpose of this study was to determine the physiological demands and to establish the relationship...... between activity profile and endurance capacity of futsal referees. Eighteen elite futsal referees (33.0 ± 5.1 years, 173 ± 5 cm, and 73.2 ± 8.4 kg) were studied. Video filming (n = 18) and heart rate (HR) recordings were performed throughout games. Blood lactate (n = 14) was determined at rest and after....... Considering the data obtained in the present study, the use of match-specific intermittent fitness tests to evaluate futsal referees seems to be required....

  3. An Improved Method of Presenting Laboratory Demonstrations in Physiology and Pharmacology.

    Science.gov (United States)

    Sims, Michael H.; Oliver, Jack W.

    1979-01-01

    The use of a laboratory demonstration and discussion period in physiology and pharmacology instruction at the Univeristy of Tennessee College of Veterinary Medicine is described. The advantages for instruction include lower costs, fewer personnel and animals required, less time required in the curriculum, and increased student attention in class.…

  4. Determinants of physiological and perceived physiological stress reactivity in children and adolescents.

    Directory of Open Access Journals (Sweden)

    Brittany E Evans

    Full Text Available AIMS: Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. METHOD: In a stratified sample of 363 children (7-12 years and 344 adolescents (13-20 years from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. RESULTS: Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. CONCLUSIONS: As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness.

  5. Quantitative Circulatory Physiology: an integrative mathematical model of human physiology for medical education.

    Science.gov (United States)

    Abram, Sean R; Hodnett, Benjamin L; Summers, Richard L; Coleman, Thomas G; Hester, Robert L

    2007-06-01

    We have developed Quantitative Circulatory Physiology (QCP), a mathematical model of integrative human physiology containing over 4,000 variables of biological interactions. This model provides a teaching environment that mimics clinical problems encountered in the practice of medicine. The model structure is based on documented physiological responses within peer-reviewed literature and serves as a dynamic compendium of physiological knowledge. The model is solved using a desktop, Windows-based program, allowing students to calculate time-dependent solutions and interactively alter over 750 parameters that modify physiological function. The model can be used to understand proposed mechanisms of physiological function and the interactions among physiological variables that may not be otherwise intuitively evident. In addition to open-ended or unstructured simulations, we have developed 30 physiological simulations, including heart failure, anemia, diabetes, and hemorrhage. Additional stimulations include 29 patients in which students are challenged to diagnose the pathophysiology based on their understanding of integrative physiology. In summary, QCP allows students to examine, integrate, and understand a host of physiological factors without causing harm to patients. This model is available as a free download for Windows computers at http://physiology.umc.edu/themodelingworkshop.

  6. Diving physiology of seabirds and marine mammals: Relevance, challenges and some solutions for field studies.

    Science.gov (United States)

    Andrews, Russel D; Enstipp, Manfred R

    2016-12-01

    To fully understand how diving seabirds and marine mammals balance the potentially conflicting demands of holding their breath while living their lives underwater (and maintaining physiological homeostasis during exercise, feeding, growth, and reproduction), physiological studies must be conducted with animals in their natural environments. The purpose of this article is to review the importance of making physiological measurements on diving animals in field settings, while acknowledging the challenges and highlighting some solutions. The most extreme divers are great candidates for study, especially in a comparative and mechanistic context. However, physiological data are also required of a wide range of species for problems relating to other disciplines, in particular ecology and conservation biology. Physiological data help with understanding and predicting the outcomes of environmental change, and the direct impacts of anthropogenic activities. Methodological approaches that have facilitated the development of field-based diving physiology include the isolated diving hole protocol and the translocation paradigm, and while there are many techniques for remote observation, animal-borne biotelemetry, or "biologging", has been critical. We discuss issues related to the attachment of instruments, the retrieval of data and sensing of physiological variables, while also considering negative impacts of tagging. This is illustrated with examples from a variety of species, and an in-depth look at one of the best studied and most extreme divers, the emperor penguin (Aptenodytes forsteri). With a variety of approaches and high demand for data on the physiology of diving seabirds and marine mammals, the future of field studies is bright.

  7. [Claude Bernard, founder of experimental physiology].

    Science.gov (United States)

    Ren, Y; Li, X; Xu, W

    2001-07-01

    Claude Bernard was a famous French physiologist and philosopher in the 19th century. His experimental researches almost involved all fields of physiology. It is generally recognized by physiologists that in the research of Bernard in the digestion of pancreas, glucogenesis in the liver, and the vasomotor mechanism and the mechanism of action of curari and carbon monoxide were all at the lead. His researches established the foundation for modern physiology, modern biochemistry and the works of Pavlov, and were the initiation of experimental physiology.

  8. Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy.

    Science.gov (United States)

    Dallmann, André; Ince, Ibrahim; Meyer, Michaela; Willmann, Stefan; Eissing, Thomas; Hempel, Georg

    2017-04-11

    In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues. The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues. A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility. The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions. The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding

  9. Phosphorylation of αSNAP is Required for Secretory Organelle Biogenesis in Toxoplasma gondii.

    Science.gov (United States)

    Stewart, Rebecca J; Ferguson, David J P; Whitehead, Lachlan; Bradin, Clare H; Wu, Hong J; Tonkin, Christopher J

    2016-02-01

    Upon infection, apicomplexan parasites quickly invade host cells and begin a replicative cycle rapidly increasing in number over a short period of time, leading to tissue lysis and disease. The secretory pathway of these highly polarized protozoan parasites tightly controls, in time and space, the biogenesis of specialized structures and organelles required for invasion and intracellular survival. In other systems, regulation of protein trafficking can occur by phosphorylation of vesicle fusion machinery. Previously, we have shown that Toxoplasma gondii αSNAP - a protein that controls the disassembly of cis-SNARE complexes--is phosphorylated. Here, we show that this post-translational modification is required for the correct function of αSNAP in controlling secretory traffic. We demonstrate that during intracellular development conditional expression of a non-phosphorylatable form of αSNAP results in Golgi fragmentation and vesiculation of all downstream secretory organelles. In addition, we show that the vestigial plastid (termed apicoplast), although reported not to be reliant on Golgi trafficking for biogenesis, is also affected upon overexpression of αSNAP and is much more sensitive to the levels of this protein than targeting to other organelles. This work highlights the importance of αSNAP and its phosphorylation in Toxoplasma organelle biogenesis and exposes a hereto fore-unexplored mechanism of regulation of vesicle fusion during secretory pathway trafficking in apicomplexan parasites.

  10. Developing legally defensible physiological employment standards for prominent physically demanding public safety occupations: a Canadian perspective.

    Science.gov (United States)

    Jamnik, V; Gumienak, R; Gledhill, N

    2013-10-01

    Canadian court decisions and human rights legislation impose strict legal criteria for developing applicant and incumbent physiological employment standards to qualify as a bona fide occupational requirement. These legal criteria compel researchers and employers to ensure that the standards are criterion-based and validly linked to the critical life threatening physically demanding tasks of the occupation, and this has led to the establishment of a systematic research process template to ensure this connection. Validation of job-related physiological employment standards is achieved using both construct and content procedures and reliability is established via test-retest procedures. The 1999 Supreme Court of Canada Meiorin Decision also obliges employers to demonstrate that it is impossible to accommodate an individual applicant or employee who is adversely impacted by lowering the physiological employment standards without imposing undue hardship on the employer. Recent evidence has demonstrated convincingly that familiarization opportunities, motivational feedback/coaching during test performance, and participation in a 6-week job-specific physical fitness training program can overcome the adverse impact of a physiological employment standards on a sub-group of participants, thereby providing "de facto" accommodation. In this article, the authors review the physiological employment standards for prominent Canadian physically demanding public safety occupations; police, correctional officers, nuclear emergency personnel, structural fire fighters, and wildland fire fighters, to illustrate the steps, challenges, and solutions involved in developing and implementing physiological employment standards designed to meet the requirements to qualify as a bona fide occupational requirement.

  11. Nutrition and human physiological adaptations to space flight

    Science.gov (United States)

    Lane, H. W.; LeBlanc, A. D.; Putcha, L.; Whitson, P. A.

    1993-01-01

    Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastro-intestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures.

  12. An Author's Philosophy of Physiology Textbook Writing.

    Science.gov (United States)

    Guyton, Arthur C.

    1998-01-01

    Discusses the factors that have determined the author's approach to writing medical physiology textbooks. Reviews the author's career and the events surrounding the development of each textbook. Explains the motivation behind critical decisions made during the authoring process. (DDR)

  13. Three-dimensional printing physiology laboratory technology.

    Science.gov (United States)

    Sulkin, Matthew S; Widder, Emily; Shao, Connie; Holzem, Katherine M; Gloschat, Christopher; Gutbrod, Sarah R; Efimov, Igor R

    2013-12-01

    Since its inception in 19th-century Germany, the physiology laboratory has been a complex and expensive research enterprise involving experts in various fields of science and engineering. Physiology research has been critically dependent on cutting-edge technological support of mechanical, electrical, optical, and more recently computer engineers. Evolution of modern experimental equipment is constrained by lack of direct communication between the physiological community and industry producing this equipment. Fortunately, recent advances in open source technologies, including three-dimensional printing, open source hardware and software, present an exciting opportunity to bring the design and development of research instrumentation to the end user, i.e., life scientists. Here we provide an overview on how to develop customized, cost-effective experimental equipment for physiology laboratories.

  14. Neuroticism, Extraversion, Conscientiousness and Stress: Physiological Correlates

    NARCIS (Netherlands)

    Brouwer, Anne-Marie; van Schaik, Martin G.; Korteling, J.E. (Hans); van Erp, Johannes Bernardus Fransiscus; Toet, Alexander

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  15. Neuroticism, extraversion, conscientiousness and stress : Physiological correlates

    NARCIS (Netherlands)

    Brouwer, A.M.; Schaik, M.G. van; Korteling, J.E.; Erp, J.B.F. van; Toet, A.

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  16. Neuromodulators: available agents, physiology, and anatomy.

    Science.gov (United States)

    Nettar, Kartik; Maas, Corey

    2011-12-01

    Neuromodulators have risen to the forefront of aesthetic medicine. By reversibly relaxing target muscles, neuromodulators exhibit their effect by softening hyperfunctional lines. An understanding of their physiology, relevant facial anatomy, and current agents is imperative for a successful aesthetic practice.

  17. Neuroticism, extraversion, conscientiousness and stress : Physiological correlates

    NARCIS (Netherlands)

    Brouwer, A.M.; Schaik, M.G. van; Korteling, J.E.; Erp, J.B.F. van; Toet, A.

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  18. Some Recent Advances in Plant Physiology

    Science.gov (United States)

    Stafford, G. A.

    1972-01-01

    A popular review of plant physiological research, emphasizing those apsects of plant metabolism where there has been a recent shift in emphasis that is not yet reflected in secondary school advanced texts. (AL)

  19. Neuroticism, Extraversion, Conscientiousness and Stress: Physiological Correlates

    NARCIS (Netherlands)

    Brouwer, Anne-Marie; Schaik, van Martin G.; Korteling, J.E. (Hans); Erp, van Jan B.F.; Toet, Alexander

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  20. PHYSIOLOGICAL RESPONSES OF MEN DURING SLEEP DEPRIVATION,

    Science.gov (United States)

    The effects of 84 hours of sleep deprivation were examined in a group of six young men and compared with a group of six controls. Subjects were... sleep deprivation , physiological regulating systems are relatively unaffected by sleep loss. (Author)

  1. Physiology of the fetal and transitional circulation.

    Science.gov (United States)

    Finnemore, Anna; Groves, Alan

    2015-08-01

    The fetal circulation is an entirely transient event, not replicated at any point in later life, and functionally distinct from the pediatric and adult circulations. Understanding of the physiology of the fetal circulation is vital for accurate interpretation of hemodynamic assessments in utero, but also for management of circulatory compromise in premature infants, who begin extrauterine life before the fetal circulation has finished its maturation. This review summarizes the key classical components of circulatory physiology, as well as some of the newer concepts of physiology that have been appreciated in recent years. The immature circulation has significantly altered function in all aspects of circulatory physiology. The mechanisms and significance of these differences are also discussed, as is the impact of these alterations on the circulatory transition of infants born prematurely.

  2. Reproductive physiology of the male camelid.

    Science.gov (United States)

    Bravo, P W; Johnson, L W

    1994-07-01

    The physiology of reproduction with emphasis on endocrinology of llamas and alpacas is addressed. Information regarding male anatomy, puberty, testicular function, semen description, and sexual behavior is also included.

  3. An Author's Philosophy of Physiology Textbook Writing.

    Science.gov (United States)

    Guyton, Arthur C.

    1998-01-01

    Discusses the factors that have determined the author's approach to writing medical physiology textbooks. Reviews the author's career and the events surrounding the development of each textbook. Explains the motivation behind critical decisions made during the authoring process. (DDR)

  4. Neuroticism, Extraversion, Conscientiousness and Stress: Physiological Correlates

    NARCIS (Netherlands)

    Brouwer, Anne-Marie; van Schaik, Martin G.; Korteling, J.E. (Hans); van Erp, Johannes Bernardus Fransiscus; Toet, Alexander

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming

  5. Physiological responses induced by pleasant stimuli.

    Science.gov (United States)

    Watanuki, Shigeki; Kim, Yeon-Kyu

    2005-01-01

    The specific physiological responses induced by pleasant stimuli were investigated in this study. Various physiological responses of the brain (encephaloelectrogram; EEG), autonomic nervous system (ANS), immune system and endocrine system were monitored when pleasant stimuli such as odors, emotional pictures and rakugo, a typical Japanese comical story-telling, were presented to subjects. The results revealed that (i) EEG activities of the left frontal brain region were enhanced by a pleasant odor; (ii) emotional pictures related to primitive element such as nudes and erotic couples elevated vasomotor sympathetic nervous activity; and (iii) an increase in secretory immunoglobulin A (s-IgA) and a decrease in salivary cortisol (s-cortisol) were induced by rakugo-derived linguistic pleasant emotion. Pleasant emotion is complicated state. However, by considering the evolutionary history of human being, it is possible to assess and evaluate pleasant emotion from certain physiological responses by appropriately summating various physiological parameters.

  6. A physiological review of American football.

    Science.gov (United States)

    Pincivero, D M; Bompa, T O

    1997-04-01

    American football has been one of the most popular sports in North America within the past century and has recently received support and increased participation from European nations. Two of the biggest concerns regarding participation in American football are the high incidence of injury and the physical demand for preparation. A basic understanding of the physiological systems utilised in the sport of football is necessary in order to develop optimal training programmes geared specifically for preparation as well as the requirements of individual field positions. Previously, it has been assumed that football relies primarily on an anaerobic source of energy for adenosine triphosphate (ATP) resynthesis with approximately 90% coming from the phosphocreatine (PCr) energy system. In lieu of research conducted specifically with football players, it appears that the energy contribution from the anaerobic glycolytic pathway in this sport has been underestimated. The elevated blood lactate levels observed in football players following game participation cast doubt on this hypothesis. Identifying position specific characteristics may also enhance the development of training programmes based on the requirements of the different positions. It appears that offensive and defensive linemen are generally larger, have higher levels of percent body fat and have greater absolute strength scores than all other positions. Offensive backs, defensive backs and wide receivers tend to display the lowest percentages of body fat, lower absolute strength scores, fastest times over 5, 10, 40 and 300m and the highest relative VO2max values. Linebackers appeared to represent a transition group mid way between the backs and linemen for size, body composition, strength, speed and endurance as well as positional duties. Findings within the literature suggest that a lack of cardiovascular development of university and professional football players may prove to be a hindrance to performance with

  7. Physiological, Psychological, and Social Effects of Noise

    Science.gov (United States)

    Kryter, K. D.

    1984-01-01

    The physiological, and behavioral effects of noise on man are investigated. Basic parameters such as definitions of noise, measuring techniques of noise, and the physiology of the ear are presented prior to the development of topics on hearing loss, speech communication in noise, social effects of noise, and the health effects of noise pollution. Recommendations for the assessment and subsequent control of noise is included.

  8. Physiological and Growth Characteristics of Shewanella Species

    Science.gov (United States)

    2016-05-01

    282–287. 29. Dawood B. 1998. Corrosion-enhancing potential of Shewanella putrefaciens isolated from industrial cooling waters. J Appl Microbiol. 84...AFCEC-CX-TY-TR-2016-0016 PHYSIOLOGICAL AND GROWTH CHARACTERISTICS OF SHEWANELLA SPECIES Karen Farrington, D. Matthew Eby, Susan Sizemore...Technical Report 01 March 2012 - 01 March 2014 Physiological and growth characteristics of Shewanella species FA4819-11-C-0003 Karen Farrington (1

  9. Phage Therapy: Eco-Physiological Pharmacology

    OpenAIRE

    Abedon, Stephen T.

    2014-01-01

    Bacterial virus use as antibacterial agents, in the guise of what is commonly known as phage therapy, is an inherently physiological, ecological, and also pharmacological process. Physiologically we can consider metabolic properties of phage infections of bacteria and variation in those properties as a function of preexisting bacterial states. In addition, there are patient responses to pathogenesis, patient responses to phage infections of pathogens, and also patient responses to phage virio...

  10. Computers in Some Branches of Applied Physiology .

    Directory of Open Access Journals (Sweden)

    S.S. Verma

    1994-04-01

    Full Text Available This paper reviews the applications of computers in the evaluation of different types of problems occuring in some branches of applied physiology. The recent applications of computers to perform advanced multivariate regression analysis for developing regression models in applied physiology are also highlighted. The regression models are practical significance for screening personnel in defence services, mines, industrial works, sports and the like.

  11. Coronary physiology assessment in the catheterization laboratory

    Institute of Scientific and Technical Information of China (English)

    Felipe; Díez-delhoyo; Enrique; Gutiérrez-Iba?es; Gerard; Loughlin; Ricardo; Sanz-Ruiz; María; Eugenia; Vázquez-álvarez; Fernando; Sarnago-Cebada; Rocío; Angulo-Llanos; Ana; Casado-Plasencia; Jaime; Elízaga; Francisco; Fernández; Avilés; Diáz

    2015-01-01

    Physicians cannot rely solely on the angiographic appearance of epicardial coronary artery stenosis when evaluating patients with myocardial ischemia. Instead, sound knowledge of coronary vascular physiology and of the methods currently available for its characterization can improve the diagnostic and prognostic accuracy of invasive assessment of the coronary circulation, and help improve clinical decision-making. In this article we summarize the current methods available for a thorough assessment of coronary physiology.

  12. Anatomy and physiology of the stomach.

    Science.gov (United States)

    Soybel, David I

    2005-10-01

    In this article, key concepts in gastric anatomy and physiology are reviewed. Attention is given to historical development of concepts of acid secretion, to the role of stomach in digestion, and to the mechanisms that protect gastric mucosa from acid and hostile luminal conditions. Evolving ideas that may influence understand-ing of the physiologic consequences of emerging therapeutics, and procedures that target anatomy or function of the stomach are also reviewed.

  13. Flight physiology training experiences and perspectives: survey of 117 pilots.

    Science.gov (United States)

    Patrão, Luís; Zorro, Sara; Silva, Jorge; Castelo-Branco, Miguel; Ribeiro, João

    2013-06-01

    Human factors and awareness of flight physiology play a crucial role in flight safety. Even so, international legislation is vague relative to training requirements in hypoxia and altitude physiology. Based on a previously developed survey, an adapted questionnaire was formulated and released online for Portuguese pilots. Specific questions regarding the need for pilot attention monitoring systems were added to the original survey. There were 117 pilots, 2 of whom were women, who completed the survey. Most of the pilots had a light aviation license and flew in unpressurized cabins at a maximum ceiling of 10,000 ft (3048 m). The majority of the respondents never experienced hypoxic symptoms. In general, most of the individuals agreed with the importance of an introductory hypoxia course without altitude chamber training (ACT) for all pilot populations, and with a pilot monitoring system in order to increase flight safety. Generally, most of the pilots felt that hypoxia education and training for unpressurized aircraft is not extensive enough. However, almost all the respondents were willing to use a flight physiology monitoring system in order to improve flight safety.

  14. Reflexology: its effects on physiological anxiety signs and sedation needs.

    Science.gov (United States)

    Akin Korhan, Esra; Khorshid, Leyla; Uyar, Mehmet

    2014-01-01

    To investigate whether reflexology has an effect on the physiological signs of anxiety and level of sedation in patients receiving mechanically ventilated support, a single blinded, randomized controlled design with repeated measures was used in the intensive care unit of a university hospital in Turkey. Patients (n = 60) aged between 18 and 70 years and were hospitalized in the intensive care unit and receiving mechanically ventilated support. Participants were randomized to a control group or an intervention group. The latter received 30 minutes of reflexology therapy on their feet, hands, and ears for 5 days. Subjects had vital signs taken immediately before the intervention and at the 10th, 20th, and 30th minutes of the intervention. In the collection of the data, "American Association of Critical-Care Nurses Sedation Assessment Scale" was used. The reflexology therapy group had a significantly lower heart rate, systolic blood pressure, diastolic blood pressure, and respiratory rate than the control group. A statistically significant difference was found between the averages of the scores that the patients included in the experimental and control groups received from the agitation, anxiety, sleep, and patient-ventilator synchrony subscales of the American Association of Critical-Care Nurses Sedation Assessment Scale. Reflexology can serve as an effective method of decreasing the physiological signs of anxiety and the required level of sedation in patients receiving mechanically ventilated support. Nurses who have appropriate training and certification may include reflexology in routine care to reduce the physiological signs of anxiety of patients receiving mechanical ventilation.

  15. CaMKII in sinoatrial node physiology and dysfunction

    Directory of Open Access Journals (Sweden)

    Yuejin eWu

    2014-03-01

    Full Text Available The calcium and calmodulin dependent protein kinase II (CaMKII is present in sinoatrial node (SAN pacemaker cells and is required for physiological fight or flight SAN beating rate responses. Inhibition of CaMKII in SAN does not affect baseline heart rate, but reduces heart rate increases in response to physiological stress. CaMKII senses intracellular calcium (Ca2+ changes, oxidation status and hyperglycemia to phosphorylate substrates that regulate Ca2+-sensitive proteins, such as L-type Ca2+ channels, phospholamban (PLN, and cardiac ryanodine receptors (RyR2. All of these substrates are involved in the SAN pacemaking mechanism. Excessive CaMKII activity, as occurs under pathological conditions such as heart failure, ischemia and diabetes, can promote intracellular Ca2+ overload and reactive oxygen species (ROS production. Oxidation of CaMKII (ox-CaMKII locks CaMKII into a constitutively active configuration that contributes to SAN cell apoptosis and fibrosis. This ox-CaMKII-mediated loss of functional SAN cells contributes to sinoatrial node dysfunction (SND and sudden death. Thus, CaMKII has emerged as a central regulator of physiological SAN responses and a key determinant of SND.

  16. Physiological characteristics of top level off-road motorcyclists.

    Science.gov (United States)

    Gobbi, A W; Francisco, R A; Tuy, B; Kvitne, R S

    2005-12-01

    The study aims to analyse the physiological characteristics of top level off-road motocross, enduro, and desert rally motorcyclists to facilitate the design of a specific training program. Twenty seven off-road top level riders participated in this study which measured anthropometric data, maximum aerobic power with incremental tests of both arms and legs, isokinetic dynamometry of the knee and elbow, handgrip strength, heart rate, and blood lactate concentrations during competition. The physical demands of the various races appear to influence the development of distinct musculoskeletal characteristics, as well as aerobic and anaerobic metabolism. Motocross riders have more muscle mass, higher isokinetic handgrip strength, and greater aerobic power than enduro and desert rally riders. However, there are no significant anthropometric and physiological differences between desert rally and enduro riders. Desert rally riders tend to be overweight with maximum aerobic power similar to that of healthy individuals. The mechanical characteristics of the motorcycle and the technical and tactical skills of the riders seem to be more important for race success than the metabolic capabilities of the rider. Desert rally and enduro riders present similar anthropometric and physiological characteristics. Both have a maximum aerobic power similar to that of healthy normal individuals, although desert rally riders tend to be overweight. Motocross riders on the other hand, have more muscle mass, more strength, and greater aerobic power. The differences observed suggest the need for a specific training program to address the requirements of different riders to reduce the possibility of injury.

  17. Using situational physiology in a didactic lecture setting.

    Science.gov (United States)

    Richardson, D

    1996-12-01

    This project used the approach of "human situations" to teach about the cardiovascular system within an undergraduate physiology course (PGY 412). About two-thirds of the students had previously taken a college-level physiology course (sophisticated), whereas one-third had not (naive). Nine didactic lectures were organized around the common human situations of orthostasis, blood donation, and exercise. For acceptance evaluation, the students were given a questionnaire consisting of six expectation statements (e.g., compared with other life science courses, I expect that I will better understand the material) and asked to rate the degree to which they agreed with each statement on a scale of 1 to 5. On completion of the lectures, the students were given a questionnaire asking them to compare experiences with expectations. Experiences were significantly less than expectations for naive (P didactic lectures. There were no significant differences between present and previous scores (77 vs. 79%; P > 0.16). Furthermore, there were no significant differences between naive and sophisticated students in cardiovascular examination scores (P > 0.608) or in total course scores (P > 0.523). These results indicate that didactic lectures based on situational physiology will yield a performance outcome equivalent to traditional lectures. However, naive students may have difficulty with the procedure and require extra attention.

  18. The Physiological Foundation of the Wealth of Nations

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Strulik, Holger

    2015-01-01

    In the present paper we advance a theory of pre-industrial growth where body size and population size are endogenously determined. Despite the fact that parents invest in both child quantity and productivity enhancing child quality, a take-off does not occur due to a key “physiological check......”: if human body size rises, subsistence requirements will increase. This mechanism turns out to be instrumental in explaining why income stagnates near an endogenously determined subsistence boundary. Key predictions of the model are examined using data for ethnic groups as well as for sub-national regions....

  19. The Endoplasmic Reticulum Stress Sensor Inositol-Requiring Enzyme 1α Augments Bacterial Killing through Sustained Oxidant Production.

    Science.gov (United States)

    Abuaita, Basel H; Burkholder, Kristin M; Boles, Blaise R; O'Riordan, Mary X

    2015-07-14

    Bacterial infection can trigger cellular stress programs, such as the unfolded protein response (UPR), which occurs when misfolded proteins accumulate within the endoplasmic reticulum (ER). Here, we used the human pathogen methicillin-resistant Staphylococcus aureus (MRSA) as an infection model to probe how ER stress promotes antimicrobial function. MRSA infection activated the most highly conserved unfolded protein response sensor, inositol-requiring enzyme 1α (IRE1α), which was necessary for robust bacterial killing in vitro and in vivo. The macrophage IRE1-dependent bactericidal activity required reactive oxygen species (ROS). Viable MRSA cells excluded ROS from the nascent phagosome and strongly triggered IRE1 activation, leading to sustained generation of ROS that were largely Nox2 independent. In contrast, dead MRSA showed early colocalization with ROS but was a poor activator of IRE1 and did not trigger sustained ROS generation. The global ROS stimulated by IRE1 signaling was necessary, but not sufficient, for MRSA killing, which also required the ER resident SNARE Sec22B for accumulation of ROS in the phagosomal compartment. Taken together, these results suggest that IRE1-mediated persistent ROS generation might act as a fail-safe mechanism to kill bacterial pathogens that evade the initial macrophage oxidative burst. Cellular stress programs have been implicated as important components of the innate immune response to infection. The role of the IRE1 pathway of the ER stress response in immune secretory functions, such as antibody production, is well established, but its contribution to innate immunity is less well defined. Here, we show that infection of macrophages with viable MRSA induces IRE1 activation, leading to bacterial killing. IRE1-dependent bactericidal activity required generation of reactive oxygen species in a sustained manner over hours of infection. The SNARE protein Sec22B, which was previously demonstrated to control ER

  20. The physiology of keystroke dynamics

    Science.gov (United States)

    Jenkins, Jeffrey; Nguyen, Quang; Reynolds, Joseph; Horner, William; Szu, Harold

    2011-06-01

    A universal implementation for most behavioral Biometric systems is still unknown since some behaviors aren't individual enough for identification. Habitual behaviors which are measurable by sensors are considered 'soft' biometrics (i.e., walking style, typing rhythm), while physical attributes (i.e., iris, fingerprint) are 'hard' biometrics. Thus, biometrics can aid in the identification of a human not only in cyberspace but in the world we live in. Hard biometrics have proven to be a rather successful form of identification, despite a large amount of individual signatures to keep track of. Virtually all soft biometric strategies, however, share a common pitfall. Instead of the classical pass/fail decision based on the measurements used by hard biometrics, a confidence threshold is imposed, increasing False Alarm and False Rejection Rates. This unreliability is a major roadblock for large scale system integration. Common computer security requires users to log-in with a six or more digit PIN (Personal Identification Number) to access files on the disk. Commercially available Keystroke Dynamics (KD) software can separately calculate and keep track of the mean and variance for each time travelled between each key (air time), and the time spent pressing each key (touch time). Despite its apparent utility, KD is not yet a robust, fault-tolerant system. We begin with a simple question: how could a pianist quickly control so many different finger and wrist movements to play music? What information, if any, can be gained from analyzing typing behavior over time? Biology has shown us that the separation of arm and finger motion is due to 3 long nerves in each arm; regulating movement in different parts of the hand. In this paper we wish to capture the underlying behavioral information of a typist through statistical memory and non-linear dynamics. Our method may reveal an inverse Compressive Sensing mapping; a unique individual signature.

  1. Suppression of enhanced physiological tremor via stochastic noise: initial observations.

    Directory of Open Access Journals (Sweden)

    Carlos Trenado

    Full Text Available Enhanced physiological tremor is a disabling condition that arises because of unstable interactions between central tremor generators and the biomechanics of the spinal stretch reflex. Previous work has shown that peripheral input may push the tremor-related spinal and cortical systems closer to anti-phase firing, potentially leading to a reduction in tremor through phase cancellation. The aim of the present study was to investigate whether peripherally applied mechanical stochastic noise can attenuate enhanced physiological tremor and improve motor performance. Eight subjects with enhanced physiological tremor performed a visuomotor task requiring the right index finger to compensate a static force generated by a manipulandum to which Gaussian noise (3-35 Hz was applied. The finger position was displayed on-line on a monitor as a small white dot which the subjects had to maintain in the center of a larger green circle. Electromyogram (EMG from the active hand muscles and finger position were recorded. Performance was measured by the mean absolute deviation of the white dot from the zero position. Tremor was identified by the acceleration in the frequency range 7-12 Hz. Two different conditions were compared: with and without superimposed noise at optimal amplitude (determined at the beginning of the experiment. The application of optimum noise reduced tremor (accelerometric amplitude and EMG activity and improved the motor performance (reduced mean absolute deviation from zero. These data provide the first evidence of a significant reduction of enhanced physiological tremor in the human sensorimotor system due to application of external stochastic noise.

  2. Suppression of enhanced physiological tremor via stochastic noise: initial observations.

    Science.gov (United States)

    Trenado, Carlos; Amtage, Florian; Huethe, Frank; Schulte-Mönting, Jürgen; Mendez-Balbuena, Ignacio; Baker, Stuart N; Baker, Mark; Hepp-Reymond, Marie-Claude; Manjarrez, Elias; Kristeva, Rumyana

    2014-01-01

    Enhanced physiological tremor is a disabling condition that arises because of unstable interactions between central tremor generators and the biomechanics of the spinal stretch reflex. Previous work has shown that peripheral input may push the tremor-related spinal and cortical systems closer to anti-phase firing, potentially leading to a reduction in tremor through phase cancellation. The aim of the present study was to investigate whether peripherally applied mechanical stochastic noise can attenuate enhanced physiological tremor and improve motor performance. Eight subjects with enhanced physiological tremor performed a visuomotor task requiring the right index finger to compensate a static force generated by a manipulandum to which Gaussian noise (3-35 Hz) was applied. The finger position was displayed on-line on a monitor as a small white dot which the subjects had to maintain in the center of a larger green circle. Electromyogram (EMG) from the active hand muscles and finger position were recorded. Performance was measured by the mean absolute deviation of the white dot from the zero position. Tremor was identified by the acceleration in the frequency range 7-12 Hz. Two different conditions were compared: with and without superimposed noise at optimal amplitude (determined at the beginning of the experiment). The application of optimum noise reduced tremor (accelerometric amplitude and EMG activity) and improved the motor performance (reduced mean absolute deviation from zero). These data provide the first evidence of a significant reduction of enhanced physiological tremor in the human sensorimotor system due to application of external stochastic noise.

  3. The Routing Algorithm Based on Fuzzy Logic Applied to the Individual Physiological Monitoring Wearable Wireless Sensor Network

    OpenAIRE

    Jie Jiang; Yun Liu; Fuxing Song; Ronghao Du; Mengsen Huang

    2015-01-01

    In recent years, the research of individual wearable physiological monitoring wireless sensor network is in the primary stage. The monitor of physiology and geographical position used in wearable wireless sensor network requires performances such as real time, reliability, and energy balance. According to these requirements, this paper introduces a design of individual wearable wireless sensor network monitoring system; what is more important, based on this background, this paper improves the...

  4. Database of Physiological Parameters for Early Life Rats and Mice

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Database of Physiological Parameters for Early Life Rats and Mice provides information based on scientific literature about physiological parameters. Modelers...

  5. Physiological and Behavioral Stress and Anxiety in Children with Autism Spectrum Disorders during Routine Oral Care

    Directory of Open Access Journals (Sweden)

    Leah I. Stein

    2014-01-01

    Full Text Available Background. Children with autism spectrum disorders (ASD commonly exhibit uncooperative behaviors which impede oral care. Previous studies have utilized dentist-report measures of uncooperative behaviors in children with ASD but none have utilized an objective measure of children’s behavior or a physiological measure of distress. This study investigated behavioral and physiological distress in children with ASD during routine oral care and examined factors associated with this distress. Methods. Participants were 44 children (n=22 typical, n=22 ASD aged 6–12 receiving routine dental cleanings. Behavioral and physiological measures of stress and anxiety were collected during dental cleanings. Results. Children with ASD exhibited greater distress, compared to the typical group, on dentist-report and researcher-coded measures of overt distress behaviors and on physiological measures. Correlations between physiological and behavioral measures of distress were found in the ASD but not in the typical group. Behavioral distress was correlated with age in the typical group and with expressive communication ability and sensory processing difficulties in the ASD group; physiological distress was correlated with parent-report of anxiety in the typical group and sensory processing difficulties in the ASD group. Conclusions. Novel strategies may be required to decrease behavioral and physiological distress in children with ASD in the dental clinic.

  6. Physiological responses to daily light exposure

    Science.gov (United States)

    Yang, Yefeng; Yu, Yonghua; Yang, Bo; Zhou, Hong; Pan, Jinming

    2016-04-01

    Long daylength artificial light exposure associates with disorders, and a potential physiological mechanism has been proposed. However, previous studies have examined no more than three artificial light treatments and limited metabolic parameters, which have been insufficient to demonstrate mechanical responses. Here, comprehensive physiological response curves were established and the physiological mechanism was strengthened. Chicks were illuminated for 12, 14, 16, 18, 20, or 22 h periods each day. A quadratic relationship between abdominal adipose weight (AAW) and light period suggested that long-term or short-term light exposure could decrease the amount of AAW. Quantitative relationships between physiological parameters and daily light period were also established in this study. The relationships between triglycerides (TG), cholesterol (TC), glucose (GLU), phosphorus (P) levels and daily light period could be described by quadratic regression models. TG levels, AAW, and BW positively correlated with each other, suggesting long-term light exposure significantly increased AAW by increasing TG thus resulting in greater BW. A positive correlation between blood triiodothyronine (T3) levels and BW suggested that daily long-term light exposure increased BW by thyroid hormone secretion. Though the molecular pathway remains unknown, these results suggest a comprehensive physiological mechanism through which light exposure affects growth.

  7. Epigenetics and transgenerational transfer: a physiological perspective.

    Science.gov (United States)

    Ho, D H; Burggren, W W

    2010-01-01

    Epigenetics, the transgenerational transfer of phenotypic characters without modification of gene sequence, is a burgeoning area of study in many disciplines of biology. However, the potential impact of this phenomenon on the physiology of animals is not yet broadly appreciated, in part because the phenomenon of epigenetics is not typically part of the design of physiological investigations. Still enigmatic and somewhat ill defined is the relationship between the overarching concept of epigenetics and interesting transgenerational phenomena (e.g. 'maternal/parental effects') that alter the physiological phenotype of subsequent generations. The lingering effect on subsequent generations of an initial environmental disturbance in parent animals can be profound, with genes continuing to be variously silenced or expressed without an associated change in gene sequence for many generations. Known epigenetic mechanisms involved in this phenomenon include chromatin remodeling (DNA methylation and histone modification), RNA-mediated modifications (non-coding RNA and microRNA), as well as other less well studied mechanisms such as self-sustaining loops and structural inheritance. In this review we: (1) discuss how the concepts of epigenetics and maternal effects both overlap with, and are distinct from, each other; (2) analyze examples of existing animal physiological studies based on these concepts; and (3) offer a construct by which to integrate these concepts into the design of future investigations in animal physiology.

  8. Feeding behavior and physiological responses of sheep grazing in the semi-arid

    Directory of Open Access Journals (Sweden)

    Carolyny Batista Lima

    2014-01-01

    Full Text Available Sheep farming is an important social and economic support for the population living in semi-arid zones. These climatic conditions in these regions - a high radiant heat load, especially - may require adjustments in physiology and behavior of the animal to enable their survival. The increased respiratory rate and rectal temperature, with seeking behavioral patterns reduced grazing time and increased idle time are recurrent in the literature as the main physiological and behavioral responses of sheep grazing in high radiant heat load environments. The presence of shadow, natural or artificial, can encourage and facilitate thermolysis physiological adjustments sheep without harm, predominantly, your metabolism. Thus, the objective of compiling information on the main patterns of behavior, as well as major physiological responses of sheep grazing in semi-arid zones.

  9. Signals and Systems in Biomedical Engineering Signal Processing and Physiological Systems Modeling

    CERN Document Server

    Devasahayam, Suresh R

    2013-01-01

    The use of digital signal processing is ubiquitous in the field of physiology and biomedical engineering. The application of such mathematical and computational tools requires a formal or explicit understanding of physiology. Formal models and analytical techniques are interlinked in physiology as in any other field. This book takes a unitary approach to physiological systems, beginning with signal measurement and acquisition, followed by signal processing, linear systems modelling, and computer simulations. The signal processing techniques range across filtering, spectral analysis and wavelet analysis. Emphasis is placed on fundamental understanding of the concepts as well as solving numerical problems. Graphs and analogies are used extensively to supplement the mathematics. Detailed models of nerve and muscle at the cellular and systemic levels provide examples for the mathematical methods and computer simulations. Several of the models are sufficiently sophisticated to be of value in understanding real wor...

  10. Syntaxin 8 is required for efficient lytic granule trafficking in cytotoxic T lymphocytes.

    Science.gov (United States)

    Bhat, Shruthi S; Friedmann, Kim S; Knörck, Arne; Hoxha, Cora; Leidinger, Petra; Backes, Christina; Meese, Eckart; Keller, Andreas; Rettig, Jens; Hoth, Markus; Qu, Bin; Schwarz, Eva C

    2016-07-01

    Cytotoxic T lymphocytes (CTL) eliminate pathogen-infected and cancerous cells mainly by polarized secretion of lytic granules (LG, containing cytotoxic molecules like perforin and granzymes) at the immunological synapse (IS). Members of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) family are involved in trafficking (generation, transport and fusion) of vesicles at the IS. Syntaxin 8 (Stx8) is expressed in LG and colocalizes with the T cell receptor (TCR) upon IS formation. Here, we report the significance of Stx8 for human CTL cytotoxicity. We found that Stx8 mostly localized in late, recycling endosomal and lysosomal compartments with little expression in early endosomal compartments. Down-regulation of Stx8 by siRNA resulted in reduced cytotoxicity. We found that following perforin release of the pre-existing pool upon target cell contact, Stx8 down-regulated CTL regenerate perforin pools less efficiently and thus release less perforin compared to control CTL. CD107a degranulation, real-time and end-point population cytotoxicity assays, and high resolution microscopy support our conclusion that Stx8 is required for proper and timely sorting and trafficking of cytotoxic molecules to functional LG through the endosomal pathway in human CTL.

  11. Cell volume regulation: physiology and pathophysiology

    DEFF Research Database (Denmark)

    Lambert, I H; Hoffmann, E K; Pedersen, Stine Helene Falsig

    2008-01-01

    not only under physiological conditions, e.g. following accumulation of nutrients, during epithelial absorption/secretion processes, following hormonal/autocrine stimulation, and during induction of apoptosis, but also under pathophysiological conditions, e.g. hypoxia, ischaemia and hyponatremia....../hypernatremia. On the other hand, it has recently become clear that an increase or reduction in cell volume can also serve as a specific signal in the regulation of physiological processes such as transepithelial transport, cell migration, proliferation and death. Although the mechanisms by which cell volume perturbations...... are sensed are still far from clear, significant progress has been made with respect to the nature of the sensors, transducers and effectors that convert a change in cell volume into a physiological response. In the present review, we summarize recent major developments in the field, and emphasize...

  12. Financial Anxiety, Physiological Arousal, and Planning Intention

    Directory of Open Access Journals (Sweden)

    John Grable

    2014-12-01

    Full Text Available Results from this exploratory clinical study indicate that financial anxiety—holding an unhealthy attitude about one’s financial situation—and physiological arousal—the physical precursor to behavior—play important roles in shaping consumer intention to engage in future financial planning activity. Findings suggest that those who are most likely to engage the services of a financial adviser exhibit low levels of financial anxiety and moderate to high levels of physiological arousal. The least likely to seek the help of a financial adviser are those who exhibit high financial anxiety and low physiological arousal. Results support findings documented in the literature that high anxiety levels often lead to a form of self-imposed helplessness. In order to move those experiencing financial anxiety towards financial solutions, financial advisers ought to take steps to simultaneously reduce financial stressors and stimulate arousal as a way to promote behavioral change and help seeking.

  13. From growth physiology to systems biology.

    Science.gov (United States)

    Schaechter, Moselio

    2006-09-01

    As it focuses on the integrated behavior of the entire cell, systems biology is a powerful extension of growth physiology. Here, I briefly trace some of the origins of modern-day bacterial growth physiology and its relevance to systems biology. I describe how growth physiology emerged from the foggy picture of the growth curve as a self-contained entity. For this insight, we can thank Henrici, Hershey, Monod, Maaløe, and others. As a result of their work, growth rate is understood to be the unitary manifestation of the response to nutritional conditions and to the control condition for studies on the effect of environmental stresses. For this response to be usefully reproducible, cultures must be in the steady state known as balanced growth. I point out that present-day experimenters are not always aware of this imperative and thus do not always use conditions that ensure the balanced growth of their control cultures.

  14. New concept of physiologic anchorage control

    Directory of Open Access Journals (Sweden)

    Tian-Min Xu

    2015-01-01

    Full Text Available Molar anchorage loss in extraction case is believed due to the reaction of mechanical force applied to retract anterior teeth. While it may be close to truth in adult patients, it is certainly not true in adolescents. Studies on molar growth show upper molar move forward as mandible growing forward, probably through intercuspation force. Hence, for adolescents, molar anchorage loss shall consist of two parts. One is from retraction force - mechanical anchorage loss; another from biologic force - physiologic anchorage loss. Since physiologic anchorage loss is caused by the continuous biologic force, the strategy of physiologic anchorage control (PAC is different from the strategy of mechanical anchorage control. A new PAC method is introduced in this article that can reduce the headgear and temporary anchorage device used as sagittal anchorage dramatically in orthodontic clinic.

  15. Improving the physiological realism of experimental models.

    Science.gov (United States)

    Vinnakota, Kalyan C; Cha, Chae Y; Rorsman, Patrik; Balaban, Robert S; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A; Jeneson, Jeroen A L

    2016-04-06

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these models rely on the analysis and integration of experimental data. As such, the success of VPH depends on the availability of physiologically realistic experimental models (E-Models) of human organ function that can be parametrized to test the numerical models. Here, the current state of suitable E-models, ranging from in vitro non-human cell organelles to in vivo human organ systems, is discussed. Specifically, challenges and recent progress in improving the physiological realism of E-models that may benefit the VPH project are highlighted and discussed using examples from the field of research on cardiovascular disease, musculoskeletal disorders, diabetes and Parkinson's disease.

  16. [The role of physiology in modern surgery].

    Science.gov (United States)

    2006-04-01

    Through the analysis of recent achievements in the field of surgery we have demonstrated convincingly that physiological studies in both humans and animal models are the keystone of modern surgery. Physiological studies of blood circulation, respiration, digestion and other functions have laid the foundations for major fields of surgery. Their role is the most evident in the development of cardiac surgery. Notably, one of the outstanding breakthroughs in the medical science of the 20th century--the extracorporeal blood circulation--was made by the Russian physiologist S. S. Bryukhovenko. We have shown that noninvasive diagnostic procedures such as echocardiography are of outmost significance on all stages of the surgical treatment (pre- and intraoperational diagnostics and medical rehabilitation). The great impact of physiology on the development of surgery has also led to the progress of related fields of medicine--anesthesiology, intensive care, functional diagnostics, transplantation, rehabilitation, and many others.

  17. Physiologic basis for understanding quantitative dehydration assessment.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W; Charkoudian, Nisha; Sawka, Michael N

    2013-03-01

    Dehydration (body water deficit) is a physiologic state that can have profound implications for human health and performance. Unfortunately, dehydration can be difficult to assess, and there is no single, universal gold standard for decision making. In this article, we review the physiologic basis for understanding quantitative dehydration assessment. We highlight how phenomenologic interpretations of dehydration depend critically on the type (dehydration compared with volume depletion) and magnitude (moderate compared with severe) of dehydration, which in turn influence the osmotic (plasma osmolality) and blood volume-dependent compensatory thresholds for antidiuretic and thirst responses. In particular, we review new findings regarding the biological variation in osmotic responses to dehydration and discuss how this variation can help provide a quantitative and clinically relevant link between the physiology and phenomenology of dehydration. Practical measures with empirical thresholds are provided as a starting point for improving the practice of dehydration assessment.

  18. [Autopharmacology, sloths and physiology. Opinions on certain historical aspects and potential developments in physiology in Liege].

    Science.gov (United States)

    Damas, J

    2001-07-01

    We recall the works of Bacq, Lecomte and Goffart, three physiologists from the University of Liège, on neurohumoral transmission, autacoids, sloths and monkeys in order to stress first that Physiology is a natural science of its own, and secondly that physiological studies aim at the understanding of the general mechanisms concurring to homeostasis.

  19. The XIIIth International Physiological Congress in Boston in 1929: American Physiology Comes of Age

    Science.gov (United States)

    Rall, Jack A.

    2016-01-01

    In the 19th century, the concept of experimental physiology originated in France with Claude Bernard, evolved in Germany stimulated by the teaching of Carl Ludwig, and later spread to Britain and then to the United States. The goal was to develop a physicochemical understanding of physiological phenomena. The first International Physiological…

  20. [Space physiology and psychology: long missions].

    Science.gov (United States)

    Lazorthes, G

    1989-06-01

    Until now spatial physiology and medicine concern mainly disturbances caused by life in microgravity during short stay (days, weeks). Neuro-sensorial, cardiovascular, osteo-muscular manifestations are well known; their prophylaxis is in great part established. It is shortly speak of them. Consequence of long stay (months or years) are not so well known; they are physiologic and psychologic. These long flights are now rare but they would probably be more numerous in next future. Authors present successively physics dangers: radiations, meteorites, composition of screw, number and selective tests, alimentation, fry time, habitation, biologic rhythms, psychism... We meet the same psychologic problems as great explorations have known.

  1. Signal Processing of Random Physiological Signals

    CERN Document Server

    Lessard, Charles

    2006-01-01

    Signal Processing of Random Physiological Signals presents the most widely used techniques in signal and system analysis. Specifically, the book is concerned with methods of characterizing signals and systems. Author Charles Lessard provides students and researchers an understanding of the time and frequency domain processes which may be used to evaluate random physiological signals such as brainwave, sleep, respiratory sounds, heart valve sounds, electromyograms, and electro-oculograms.Another aim of the book is to have the students evaluate actual mammalian data without spending most or all

  2. Physiological Disorders in Closed, Controlled Environment Crops

    Science.gov (United States)

    Wheeler, Raymond M.; Morrow, Robert C.

    2010-01-01

    This slide presentation reviews some of the physiological disorders that affect crops grown in closed controlled environments. A physiological disorder is understood to be a problem resulting from the influence of environmental and horticultural factors on plan development other than a problem caused by a pathogen or some other abiotic cause. The topics that are addressed are: (1) Calcium-Related Disorders (2) Oedema (Intumescence) (3) Long-Photoperiod Injury (4) Light Spectral Quality Effects (5) Super-Elevated CO2 Injuries (6) Ethylene (7) Other Disorders (8) Considerations for Closed Space Environments. Views of plant with the disorders are shown.

  3. Cardiovascular physiology and diseases of amphibians.

    Science.gov (United States)

    Heinz-Taheny, Kathleen M

    2009-01-01

    The class Amphibia includes three orders of amphibians: the anurans (frogs and toads), urodeles (salamanders, axolotls, and newts), and caecilians. The diversity of lifestyles across these three orders has accompanying differences in the cardiovascular anatomy and physiology allowing for adaptations to aquatic or terrestrial habitats, pulmonic or gill respiration, hibernation, and body elongation (in the caecilian). This article provides a review of amphibian cardiovascular anatomy and physiology with discussion of unique species adaptations. In addition, amphibians as cardiovascular animal models and commonly encountered natural diseases are covered.

  4. Concepts of Human Physiology in Ayurveda

    OpenAIRE

    Patwardhan, Dr. Kishor

    2008-01-01

    ‘Human Physiology’, or the study of functional aspects of human body, is designated by the term ‘Śarīra Vicaya’ in Ayurvedic literature. The word ‘Vicaya’ means the special or detailed knowledge. Detailed knowledge of normal human body i.e., ‘Śarīra’, is considered helpful in understanding the factors influencing the health. Though most of the basic concepts of human physiology explained in Ayurveda are strikingly similar to the concepts of modern physiology, some concepts like ‘Ātmā’, ‘Ma...

  5. Emission Computed Tomography: A New Technique for the Quantitative Physiologic Study of Brain and Heart in Vivo

    Science.gov (United States)

    Phelps, M. E.; Hoffman, E. J.; Huang, S. C.; Schelbert, H. R.; Kuhl, D. E.

    1978-01-01

    Emission computed tomography can provide a quantitative in vivo measurement of regional tissue radionuclide tracer concentrations. This facility when combined with physiologic models and radioactively labeled physiologic tracers that behave in a predictable manner allow measurement of a wide variety of physiologic variables. This integrated technique has been referred to as Physiologic Tomography (PT). PT requires labeled compounds which trace physiologic processes in a known and predictable manner, and physiologic models which are appropriately formulated and validated to derive physiologic variables from ECT data. In order to effectively achieve this goal, PT requires an ECT system that is capable of performing truly quantitative or analytical measurements of tissue tracer concentrations and which has been well characterized in terms of spatial resolution, sensitivity and signal to noise ratios in the tomographic image. This paper illustrates the capabilities of emission computed tomography and provides examples of physiologic tomography for the regional measurement of cerebral and myocardial metabolic rate for glucose, regional measurement of cerebral blood volume, gated cardiac blood pools and capillary perfusion in brain and heart. Studies on patients with stroke and myocardial ischemia are also presented.

  6. Task Differences, Stylistic Characteristics and Physiological Arousal.

    Science.gov (United States)

    1983-08-01

    responses in Type A and B subjects. Journal of Applied Social Psychology , 1979, 9, 209-228. Dembroski, T. M., MacDougall, J. M. and Shields, J. L...C. and Denson, A. L. Information load stress, risk taking and physiological responsivity in a visual-motor task. Journal of Applied Social Psychology , 1983

  7. The Physiology of Fear and Sound

    DEFF Research Database (Denmark)

    Garner, Tom Alexander; Grimshaw, Mark

    2013-01-01

    The potential value of a looping biometric feedback system as a key component of adaptive computer video games is significant. Psychophysiological measures are essential to the development of an automated emotion recognition program, capable of interpreting physiological data into models of affec...

  8. Physiologic and pharmacokinetic changes in pregnancy.

    Science.gov (United States)

    Costantine, Maged M

    2014-01-01

    Physiologic changes in pregnancy induce profound alterations to the pharmacokinetic properties of many medications. These changes affect distribution, absorption, metabolism, and excretion of drugs, and thus may impact their pharmacodynamic properties during pregnancy. Pregnant women undergo several adaptations in many organ systems. Some adaptations are secondary to hormonal changes in pregnancy, while others occur to support the gravid woman and her developing fetus. Some of the changes in maternal physiology during pregnancy include, for example, increased maternal fat and total body water, decreased plasma protein concentrations, especially albumin, increased maternal blood volume, cardiac output, and blood flow to the kidneys and uteroplacental unit, and decreased blood pressure. The maternal blood volume expansion occurs at a larger proportion than the increase in red blood cell mass, which results in physiologic anemia and hemodilution. Other physiologic changes include increased tidal volume, partially compensated respiratory alkalosis, delayed gastric emptying and gastrointestinal motility, and altered activity of hepatic drug metabolizing enzymes. Understating these changes and their profound impact on the pharmacokinetic properties of drugs in pregnancy is essential to optimize maternal and fetal health.

  9. The concept of function in modern physiology.

    Science.gov (United States)

    Roux, Etienne

    2014-06-01

    An overview of the scientific literature shows that the concept of function is central in physiology. However, the concept itself is not defined by physiologists. On the other hand, the teleological, namely, the 'goal-directed' dimension of function, and its subsequent explanatory relevance, is a philosophical problem. Intuitively, the function of a trait in a system explains why this trait is present, but, in the early 1960s, Ernest Nagel and Carl Hempel have shown that this inference cannot be logically founded. However, they showed that self-regulated systems are teleological. According to the selectionist theories, the function of an item is its effect that has been selected by natural selection, a process that explains its presence. As they restrict the functional attribution of a trait to its past selective value and not its current properties, these theories are inconsistent with the concept of function in physiology. A more adequate one is the causal role theory, for which a function of a trait in a system is its causal contribution to the functional capacity of the system. However, this leaves unsolved the question of the 'surplus meaning' of the teleological dimension of function. The significance of considering organisms as 'purpose-like' (teleological) systems may reside not in its explanatory power but in its methodological fruitfulness in physiology. In this view, the teleological dimension of physiological functions is convergent to but not imported from, the teleological dimension of evolutionary biology.

  10. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY:

    Science.gov (United States)

    Twenty-one participants from Europe, North America and China convened in Chongqing, China, October 12-14, 2005, for the Eighth International Symposium in Fish Physiology, Toxicology and Water Quality. The subject of the meeting was "Hypoxia in vertebrates: Comparisons of terrestr...

  11. Anatomy and physiology of genital organs - women.

    Science.gov (United States)

    Graziottin, Alessandra; Gambini, Dania

    2015-01-01

    "Anatomy is destiny": Sigmund Freud viewed human anatomy as a necessary, although not a sufficient, condition for understanding the complexity of human sexual function with a solid biologic basis. The aim of the chapter is to describe women's genital anatomy and physiology, focusing on women's sexual function with a clinically oriented vision. Key points include: embryology, stressing that the "female" is the anatomic "default" program, differentiated into "male" only in the presence of androgens at physiologic levels for the gestational age; sex determination and sex differentiation, describing the interplay between anatomic and endocrine factors; the "clitoral-urethral-vaginal" complex, the most recent anatomy reading of the corpora cavernosa pattern in women; the controversial G spot; the role of the pelvic floor muscles in modulating vaginal receptivity and intercourse feelings, with hyperactivity leading to introital dyspareunia and contributing to provoked vestibulodynia and recurrent postcoital cystitis, whilst lesions during delivery reduce vaginal sensations, genital arousability, and orgasm; innervation, vessels, bones, ligaments; and the physiology of women's sexual response. Attention to physiologic aging focuses on "low-grade inflammation," genital and systemic, with its impact on women sexual function, especially after the menopause, if the woman does not or cannot use hormone replacement therapy.

  12. Physiologic and Pharmacokinetic Changes in Pregnancy

    Directory of Open Access Journals (Sweden)

    Maged eCostantine

    2014-04-01

    Full Text Available Physiologic changes in pregnancy induce profound alterations to the pharmacokinetic properties of many medications. These changes affect distribution, absorption, metabolism, and excretion of drugs, and thus may impact their pharmacodynamic properties during pregnancy. Pregnant women undergo several adaptations in many organ systems. Some adaptations are secondary to hormonal changes in pregnancy, while others occur to support the gravid woman and her developing fetus. Some of the changes in maternal physiology during pregnancy include, for example, increased maternal fat and total body water, decreased plasma protein concentrations, especially albumin, increased maternal blood volume, cardiac output and blood flow to the kidneys and uteroplacental unit, and decreased blood pressure. The maternal blood volume expansion occurs at a larger proportion than the increase in red blood cell mass, which results in physiologic anemia and hemodilution. Other physiologic changes include increased tidal volume, partially compensated respiratory alkalosis, delayed gastric emptying and gastrointestinal motility, and altered activity of hepatic drug metabolizing enzymes. Understating these changes and their profound impact on the pharmacokinetic properties of drugs in pregnancy is essential to optimize maternal and fetal health.

  13. Electromyography physiology engineering and noninvasive applications

    CERN Document Server

    Parker, Philip; John Wiley & Sons

    2004-01-01

    "Featuring contributions from key innovators working in the field today, Electromyography reveals the broad applications of EMG data in areas as diverse as neurology, ergonomics, exercise physiology, rehabilitation, movement analysis, biofeedback, and myoelectric control of prostheses." "Electromyography offers physiologists, medical professionals, and students in biomedical engineering a new window into the possibilities of this technology."--Jacket.

  14. [Immune response genes products in human physiology].

    Science.gov (United States)

    Khaitov, R M; Alekseev, L P

    2012-09-01

    Current data on physiological role of human immune response genes' proteomic products (antigens) are discussed. The antigens are specified by a very high level of diversity that mediates a wide specter ofphysiological functions. They actually provide integrity and biological stability of human as species. These data reveal new ideas on many pathological processes as well as drafts new approaches for prophylaxis and treatment.

  15. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

    Vinnakota, Kalyan C.; Cha, Chae Y.; Rorsman, Patrik; Balaban, Robert S.; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A.; Jeneson, Jeroen A. L.

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these

  16. Physiological Disorders of Pear Shoot Cultures

    Science.gov (United States)

    Physiological disorders are some of the most difficult challenges in micropropagation. Little is known of the causes of plant growth disorders which include callus formation, hyperhydricity, shoot tip necrosis, leaf lesions, epinasty, fasciation and hypertrophy. During our study of mineral nutritio...

  17. Physiological considerations in radionuclide urodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, T.K.; Fink, S.; Burger, R.H.; Netto, I.C.; Palmer, J.D. (V.A. Medical Center, Hamptom, VA (USA))

    1989-01-01

    Radionuclear imaging of micturition (RNIM) (Nuclear Uroflowmetry, Voiding Nuclear Cystogram) measures bladder volumes, bladder emptying times, and urinary flow rates. These data help to differentiate normal subjects from those with obstructive uropathy or neuromuscular failure and to quantify the deficit. We discuss the physiological considerations of importance to physicians ordering and interpreting this convenient and noninvasive diagnostic procedure. 39 references.

  18. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY

    Science.gov (United States)

    Scientists from ten countries presented papers at the Fifth International Symposium on Fish Physiology, Toxicology, and Water Quality, which was held on the campus of the city University of Hong Kong on November 10-13, 1998. These Proceedings include 23 papers presented in sessi...

  19. Supporting Placement Supervision in Clinical Exercise Physiology

    Science.gov (United States)

    Sealey, Rebecca M.; Raymond, Jacqueline; Groeller, Herb; Rooney, Kieron; Crabb, Meagan; Watt, Kerrianne

    2015-01-01

    The continued engagement of the professional workforce as supervisors is critical for the sustainability and growth of work-integrated learning activities in university degrees. This study investigated factors that influence the willingness and ability of clinicians to continue to supervise clinical exercise physiology work-integrated learning…

  20. Preparing Prospective Physical Educators in Exercise Physiology.

    Science.gov (United States)

    Bulger, Sean M.; Mohr, Derek J.; Carson, Linda M.; Robert, Darren L.; Wiegand, Robert L.

    2000-01-01

    Addresses the need for continued assessment of course content and instructional methods employed within physical education teacher education programs to deliver theoretical and applied information from the foundational subdiscipline of exercise physiology, describing an innovative course at one university (Exercise for School-Aged Children) which…

  1. Myths and Truths from Exercise Physiology

    Science.gov (United States)

    Kieffer, H. Scott

    2008-01-01

    This article addresses some of the common myths in the field of exercise physiology. Some of the myths are misconstrued facts that have developed over time, such as the myth of localized fat reduction. Other myths are unproved or collective beliefs used to justify a social institution; we see this occur in the form of "fitness fads." Society is…

  2. Challenges in Exercise Physiology Research and Education

    Science.gov (United States)

    Ji, Li Li; Diffee, Gary; Schrage, William

    2008-01-01

    Similar to other subdisciplines in kinesiology, exercise physiology (EP) as a field is facing challenges in both research (creation and dissemination of new knowledge) and education (classroom instruction and student mentoring). In the current communication, we will learn from the history, analyze the current status of the field, and provide some…

  3. Teaching Physics in a Physiologically Meaningful Manner

    Science.gov (United States)

    Plomer, Michael; Jessen, Karsten; Rangelov, Georgi; Meyer, Michael

    2010-01-01

    The learning outcome of a physics laboratory course for medical students was examined in an interdisciplinary field study and discussed for the electrical physiology ("Propagation of Excitation and Nerve Cells"). At the Ludwig-Maximilians-University of Munich (LMU) at a time about 300 medicine students were assessed in two successive…

  4. Experienced and physiological fatigue in neuromuscular disorders.

    NARCIS (Netherlands)

    Schillings, M.L.; Kalkman, J.S.; Janssen, H.M.; Engelen, B.G.M. van; Bleijenberg, G.; Zwarts, M.J.

    2007-01-01

    OBJECTIVE: Fatigue has been described as a typical symptom of neurological diseases. It might be caused both by changes at the peripheral and at the central level. This study measured the level of experienced fatigue and physiological correlates of fatigue in three genetically defined neuromuscular

  5. Mechanisms of physiological and epileptic HFO generation

    NARCIS (Netherlands)

    Jefferys, J.G.; Menendez de la Prida, L.; Wendling, F.; Bragin, A.; Avoli, M.; Timofeev, I.; Lopes da Silva, F.H.

    2012-01-01

    High frequency oscillations (HFO) have a variety of characteristics: band-limited or broad-band, transient burst-like phenomenon or steady-state. HFOs may be encountered under physiological or under pathological conditions (pHFO). Here we review the underlying mechanisms of oscillations, at the leve

  6. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

    Vinnakota, Kalyan C.; Cha, Chae Y.; Rorsman, Patrik; Balaban, Robert S.; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A.; Jeneson, Jeroen A. L.

    2016-01-01

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these m

  7. Physiological consequences : Cardiopulmonary, vestibular, and sensory aspects

    NARCIS (Netherlands)

    Welsch, H.; Albery, W.; Banks, R.D.; Bles, W.

    2000-01-01

    Discussing the physiological consequences of enhanced fighter manoeuvrability (EFM), aspects of cardiopulmonary reactions will be seen during high G manoeuvres, especially the combination of negative G-load followed by high G-onset manoeuvres ("push-pull"). The aircraft's capability to reach high al

  8. The concept of function in modern physiology

    Science.gov (United States)

    Roux, Etienne

    2014-01-01

    An overview of the scientific literature shows that the concept of function is central in physiology. However, the concept itself is not defined by physiologists. On the other hand, the teleological, namely, the ‘goal-directed’ dimension of function, and its subsequent explanatory relevance, is a philosophical problem. Intuitively, the function of a trait in a system explains why this trait is present, but, in the early 1960s, Ernest Nagel and Carl Hempel have shown that this inference cannot be logically founded. However, they showed that self-regulated systems are teleological. According to the selectionist theories, the function of an item is its effect that has been selected by natural selection, a process that explains its presence. As they restrict the functional attribution of a trait to its past selective value and not its current properties, these theories are inconsistent with the concept of function in physiology. A more adequate one is the causal role theory, for which a function of a trait in a system is its causal contribution to the functional capacity of the system. However, this leaves unsolved the question of the ‘surplus meaning’ of the teleological dimension of function. The significance of considering organisms as ‘purpose-like’ (teleological) systems may reside not in its explanatory power but in its methodological fruitfulness in physiology. In this view, the teleological dimension of physiological functions is convergent to but not imported from, the teleological dimension of evolutionary biology. PMID:24882809

  9. Physiology and molecular biology of petal senescence

    NARCIS (Netherlands)

    Doorn, van W.G.; Woltering, E.J.

    2008-01-01

    Petal senescence is reviewed, with the main emphasis on gene expression in relation to physiological functions. Autophagy seems to be the major mechanism for large-scale degradation of macromolecules, but it is still unclear if it contributes to cell death. Depending on the species, petal senescence

  10. Physiology and molecular biology of petal senescence

    NARCIS (Netherlands)

    Doorn, van W.G.; Woltering, E.J.

    2008-01-01

    Petal senescence is reviewed, with the main emphasis on gene expression in relation to physiological functions. Autophagy seems to be the major mechanism for large-scale degradation of macromolecules, but it is still unclear if it contributes to cell death. Depending on the species, petal senescence

  11. [Heat and Fever in ancient Greek physiology].

    Science.gov (United States)

    Yeo, In-Sok

    2009-12-01

    This paper aims at clarifying the relationship of physiological heat and pathological heat(fever) using the theoretical scheme of Georges Canguilhem as is argued in his famous book The Normal and the Pathologic. Ancient authors had presented various views on the innate heat and pathological heat. Some argued that there is only pathological heat while others, like Galen, distinguished two different kinds of heat. Galen was the first medial author who had the clear notion of the relationship between the normal heat and the pathological heat. He conceptualized their difference as the heat conforming to nature (kata phusin) and the heat against nature (para phusin). However, the Peripatetic authors, such as ps-Alexander Aphrodisias, who laid more emphasis on physiology tended to regard pathology in continuation with physiology as Claude Bernard attempted to do it. Therefore, Canguilhem's theoretical scheme turns out to be very useful in analysing the relationship of normal heat and pathological heat as is manifested in ancient Greek physiology.

  12. Anatomy and Physiology. Revised Teacher Edition.

    Science.gov (United States)

    Hartman, Danene; And Others

    This curriculum guide contains 14 units of instruction for a course in anatomy and physiology for surgical technology students. The units cover the following topics: (1) organization of the body; (2) cells, tissues, and membranes; (3) integumentary system; (4) skeletal system; (5) muscular system; (6) nervous system; (7) special sense organs; (8)…

  13. Physiological functions of MTA family of proteins.

    Science.gov (United States)

    Sen, Nirmalya; Gui, Bin; Kumar, Rakesh

    2014-12-01

    Although the functional significance of the metastasic tumor antigen (MTA) family of chromatin remodeling proteins in the pathobiology of cancer is fairly well recognized, the physiological role of MTA proteins continues to be an understudied research area and is just beginning to be recognized. Similar to cancer cells, MTA1 also modulates the expression of target genes in normal cells either by acting as a corepressor or coactivator. In addition, physiological functions of MTA proteins are likely to be influenced by its differential expression, subcellular localization, and regulation by upstream modulators and extracellular signals. This review summarizes our current understanding of the physiological functions of the MTA proteins in model systems. In particular, we highlight recent advances of the role MTA proteins play in the brain, eye, circadian rhythm, mammary gland biology, spermatogenesis, liver, immunomodulation and inflammation, cellular radio-sensitivity, and hematopoiesis and differentiation. Based on the growth of knowledge regarding the exciting new facets of the MTA family of proteins in biology and medicine, we speculate that the next burst of findings in this field may reveal further molecular regulatory insights of non-redundant functions of MTA coregulators in the normal physiology as well as in pathological conditions outside cancer.

  14. Evolutionary plant physiology: Charles Darwin's forgotten synthesis

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J.

    2009-11-01

    Charles Darwin dedicated more than 20 years of his life to a variety of investigations on higher plants (angiosperms). It has been implicitly assumed that these studies in the fields of descriptive botany and experimental plant physiology were carried out to corroborate his principle of descent with modification. However, Darwin’s son Francis, who was a professional plant biologist, pointed out that the interests of his father were both of a physiological and an evolutionary nature. In this article, we describe Darwin’s work on the physiology of higher plants from a modern perspective, with reference to the following topics: circumnutations, tropisms and the endogenous oscillator model; the evolutionary patterns of auxin action; the root-brain hypothesis; phloem structure and photosynthesis research; endosymbioses and growth-promoting bacteria; photomorphogenesis and phenotypic plasticity; basal metabolic rate, the Pfeffer-Kleiber relationship and metabolic optimality theory with respect to adaptive evolution; and developmental constraints versus functional equivalence in relationship to directional natural selection. Based on a review of these various fields of inquiry, we deduce the existence of a Darwinian (evolutionary) approach to plant physiology and define this emerging scientific discipline as the experimental study and theoretical analysis of the functions of green, sessile organisms from a phylogenetic perspective.

  15. Physiological Sociology. Endocrine Correlates of Status Behaviors,

    Science.gov (United States)

    1975-01-01

    Behavior. J. Spuhler (Ed.). Chicago: Aldine Press, pp. 135-170, 1967. Hare, R. D. Psychopathy ’ Theory and Research. New York: Wiley-Interscience, 1970...Hare, R. D. Psychophathy and physiological responses to adrenalin. J. Abnorm. Psychol. 79:138-147, 1972. Hare, R. D. and Quinn, M. J. Psychopathy and

  16. From Dietary Fiber to Host Physiology

    DEFF Research Database (Denmark)

    Koh, Ara; De Vadder, Filipe; Kovatcheva-Datchary, Petia

    2016-01-01

    A compelling set of links between the composition of the gut microbiota, the host diet, and host physiology has emerged. Do these links reflect cause-and-effect relationships, and what might be their mechanistic basis? A growing body of work implicates microbially produced metabolites as crucial...

  17. Physiological basis for residual feed intake

    National Research Council Canada - National Science Library

    Herd, R. M; Arthur, P. F

    2009-01-01

    ...{at}dpi.nsw.gov.au Residual feed intake (RFI) is a measure of feed efficiency that is independent of level of production, such as size and growth rate in beef cattle, and thus is a useful new trait for studying the physiological mechanisms...

  18. Physiology of Exercise in the Cold

    Science.gov (United States)

    1991-01-01

    working i 25.5"C water, Rapp GM. Convection coefficients of man in a forensic area ofbreathing air or helium tri-mix. Jourial of Applied Physiology thermal...Jones RJ, Lahiri A, Cashman PMM, Dore C, Raftery EB. Left man at rest and during exercise. Medicina dello Sport 24: 223- ventricular function during

  19. Using measures of single-cell physiology and physiological state to understand organismic aging.

    Science.gov (United States)

    Mendenhall, Alexander; Driscoll, Monica; Brent, Roger

    2016-02-01

    Genetically identical organisms in homogeneous environments have different lifespans and healthspans. These differences are often attributed to stochastic events, such as mutations and 'epimutations', changes in DNA methylation and chromatin that change gene function and expression. But work in the last 10 years has revealed differences in lifespan- and health-related phenotypes that are not caused by lasting changes in DNA or identified by modifications to DNA or chromatin. This work has demonstrated persistent differences in single-cell and whole-organism physiological states operationally defined by values of reporter gene signals in living cells. While some single-cell states, for example, responses to oxygen deprivation, were defined previously, others, such as a generally heightened ability to make proteins, were, revealed by direct experiment only recently, and are not well understood. Here, we review technical progress that promises to greatly increase the number of these measurable single-cell physiological variables and measureable states. We discuss concepts that facilitate use of single-cell measurements to provide insight into physiological states and state transitions. We assert that researchers will use this information to relate cell level physiological readouts to whole-organism outcomes, to stratify aging populations into groups based on different physiologies, to define biomarkers predictive of outcomes, and to shed light on the molecular processes that bring about different individual physiologies. For these reasons, quantitative study of single-cell physiological variables and state transitions should provide a valuable complement to genetic and molecular explanations of how organisms age.

  20. "Physiology in the News": Using Press Releases to Enhance Lay Communication and Introduce Current Physiology Research to Undergraduates

    Science.gov (United States)

    Kelly, Kevin L.; Poteracki, James M.; Steury, Michael D.; Wehrwein, Erica A.

    2015-01-01

    Michigan State University's senior-level undergraduate physiology capstone laboratory uses a simple exercise termed "Physiology in the News," to help students explore the current research within the field of physiology while also learning to communicate science in lay terms. "Physiology in the News" is an activity that charges…