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Sample records for intracellular compartments contributes

  1. The contribution of TWIK-1 channels to astrocyte K+ current is limited by retention in intracellular compartments

    PubMed Central

    Wang, Wei; Putra, Adhytia; Schools, Gary P.; Ma, Baofeng; Chen, Haijun; Kaczmarek, Leonard K.; Barhanin, Jacques; Lesage, Florian; Zhou, Min

    2013-01-01

    TWIK-1 two-pore domain K+ channels are expressed abundantly in astrocytes. In the present study, we examined the extent to which TWIK-1 contributes to the linear current-voltage (I–V) relationship (passive) K+ membrane conductance, a dominant electrophysiological feature of mature hippocampal astrocytes. Astrocytes from TWIK-1 knockout mice have a more negative resting potential than those from wild type animals and a reduction in both inward rectification and Cs+ permeability. Nevertheless, the overall whole-cell passive conductance is not altered significantly in TWIK-1 knockout astrocytes. The expression of Kir4.1 and TREK-1, two other major astrocytic K+ channels, or of other two-pore K+ channels is not altered in TWIK-1 knockout mice, suggesting that the mild effect of TWIK-1 knockout does not result from compensation by these channels. Fractionation experiments showed that TWIK-1 is primarily localized in intracellular cytoplasmic fractions (55%) and mildly hydrophobic internal compartment fractions (41%), with only 5% in fractions containing plasma membranes. Our study revealed that TWIK-1 proteins are mainly located in the intracellular compartments of hippocampal astrocyte under physiological condition, therefore a minimal contribution of TWIK-1 channels to whole-cell currents is likely attributable to a relatively low level presence of channels in the plasma membrane. PMID:24368895

  2. Leishmania hijacking of the macrophage intracellular compartments.

    PubMed

    Liévin-Le Moal, Vanessa; Loiseau, Philippe M

    2016-02-01

    Leishmania spp., transmitted to humans by the bite of the sandfly vector, are responsible for the three major forms of leishmaniasis, cutaneous, diffuse mucocutaneous and visceral. Leishmania spp. interact with membrane receptors of neutrophils and macrophages. In macrophages, the parasite is internalized within a parasitophorous vacuole and engages in a particular intracellular lifestyle in which the flagellated, motile Leishmania promastigote metacyclic form differentiates into non-motile, metacyclic amastigote form. This phenomenon is induced by Leishmania-triggered events leading to the fusion of the parasitophorous vacuole with vesicular members of the host cell endocytic pathway including recycling endosomes, late endosomes and the endoplasmic reticulum. Maturation of the parasitophorous vacuole leads to the intracellular proliferation of the Leishmania amastigote forms by acquisition of host cell nutrients while escaping host defense responses. © 2015 FEBS.

  3. Aquaporin-2 (AQP2): its intracellular compartment and trafficking.

    PubMed

    Takata, K

    2006-10-30

    Aquaporins (AQPs) are membrane proteins serving in the transfer of water and small solutes across cellular membranes. At least 7 isoforms, namely AQP1, AQP2, AQP3, AQP4, AQP6, AQP7 and AQP11 are expressed in the kidney. Among them, AQP2 plays a pivotal role in the concentration of urine. AQP2 is expressed in the principal cells of the collecting ducts. It is localized in the intracellular compartment and is translocated to the cell surface upon anti-diuretic hormone stimulation. Analyses in cultured cells expressing AQP2 have provided clues to the trafficking of AQP2. AQP2 resides in the subapical vesicles, some of which are Rab11-positive, suggesting their close relationship with apical recycling endosomes. Upon stimulation with forskolin, AQP2 is translocated to the cell surface. After washout, AQP2 is endocytosed to early endosomes and then transferred to the apical storage compartment. Some of AQP2 is excreted as exosomes. Actin cytoskeleton plays important roles in the trafficking of AQP2. Analyses of molecules found in AQP2-containing vesicles will shed light on the mechanism of AQP2 translocation.

  4. Uptake of heavy metals to the extracellular and intracellular compartments in three species of aquatic bryophyte.

    PubMed

    Vázquez, M D; López, J; Carballeira, A

    1999-09-01

    Shoot tips of Fontinalis antipyretica, Scapania undulata, and Fissidens polyphyllus were maintained for 60 min with solutions containing 0, 1, 10, 50, 100, or 200 ppm of Cd, Co, Cu, Ni, Pb, or Zn. A sequential extraction procedure was then used to estimate the amounts of the corresponding metal, and of K and Mg, in the extracellular compartment (extraction with NiCl(2) or EDTA), the intracellular compartment (subsequent extraction with cold dilute HNO(3)), and the particulate fraction (subsequent extraction with hot concentrated HNO(3)). In most cases more metal was taken up to the extracellular compartment than to the intracellular compartment, while particulate-fraction content was negligible. The relationship between metal concentration in the water and metal content in the extracellular compartment was well modeled with a Michaelis-Menten-type equation. Results suggest that in S. undulata extracellular cation-binding sites have a high metal affinity, while in F. polyphyllus it is relatively low. However, postincubation intracellular contents were highest in the latter species. The ranking of the six metals by amounts taken up into the intracellular compartment was the same for all three bryophyte species. Uptake of heavy metals led to considerable losses of intracellular K (probably due to effects on plasma membrane properties), and of extracellular Mg (probably due to displacement from cation-binding sites). Losses of intracellular K were most marked in S. undulata, followed by F. antipyretica. By contrast, S. undulata was the species from which losses of extracellular Mg were lowest.

  5. Intracellular plant microbe associations: secretory pathways and the formation of perimicrobial compartments.

    PubMed

    Ivanov, Sergey; Fedorova, Elena; Bisseling, Ton

    2010-08-01

    Plants can establish intracellular interactions with symbiotic as well as pathogenic microbes. Such intracellular accommodation of microbes always involves the formation of a host membrane compartment--the interface between the cytoplasm of the host and the microbe. These are the so-called perimicrobial compartments. In this review we will focus on the rhizobial legume symbiosis in which the microbes are hosted in organelle-like compartments, which are named symbiosomes. The signaling events leading to infection and symbiosome formation are discussed. Further the role of the host cell endomembrane system in symbiosome formation is described and compared with the processes involved in arbuscule and haustorium formation during the interaction of plants and biotrophic fungi.

  6. Investigating the robustness of the classical enzyme kinetic equations in small intracellular compartments

    PubMed Central

    2009-01-01

    Background Classical descriptions of enzyme kinetics ignore the physical nature of the intracellular environment. Main implicit assumptions behind such approaches are that reactions occur in compartment volumes which are large enough so that molecular discreteness can be ignored and that molecular transport occurs via diffusion. Though these conditions are frequently met in laboratory conditions, they are not characteristic of the intracellular environment, which is compartmentalized at the micron and submicron scales and in which active means of transport play a significant role. Results Starting from a master equation description of enzyme reaction kinetics and assuming metabolic steady-state conditions, we derive novel mesoscopic rate equations which take into account (i) the intrinsic molecular noise due to the low copy number of molecules in intracellular compartments (ii) the physical nature of the substrate transport process, i.e. diffusion or vesicle-mediated transport. These equations replace the conventional macroscopic and deterministic equations in the context of intracellular kinetics. The latter are recovered in the limit of infinite compartment volumes. We find that deviations from the predictions of classical kinetics are pronounced (hundreds of percent in the estimate for the reaction velocity) for enzyme reactions occurring in compartments which are smaller than approximately 200 nm, for the case of substrate transport to the compartment being mediated principally by vesicle or granule transport and in the presence of competitive enzyme inhibitors. Conclusion The derived mesoscopic rate equations describe subcellular enzyme reaction kinetics, taking into account, for the first time, the simultaneous influence of both intrinsic noise and the mode of transport. They clearly show the range of applicability of the conventional deterministic equation models, namely intracellular conditions compatible with diffusive transport and simple enzyme

  7. Delivery of rifampicin-chitin nanoparticles into the intracellular compartment of polymorphonuclear leukocytes.

    PubMed

    Smitha, K T; Nisha, N; Maya, S; Biswas, Raja; Jayakumar, R

    2015-03-01

    Polymorphonuclear leukocytes (PMNs) provide the primary host defence against invading pathogens by producing reactive oxygen species (ROS) and microbicidal products. However, few pathogens can survive for a prolonged period of time within the PMNs. Additionally their intracellular lifestyle within the PMNs protect themselves from the additional lethal action of host immune systems such as antibodies and complements. Antibiotic delivery into the intracellular compartments of PMNs is a major challenge in the field of infectious diseases. In order to deliver antibiotics within the PMNs and for the better treatment of intracellular bacterial infections we synthesized rifampicin (RIF) loaded amorphous chitin nanoparticles (RIF-ACNPs) of 350±50 nm in diameter. RIF-ACNPs nanoparticles are found to be non-hemolytic and non-toxic against a variety of host cells. The release of rifampicin from the prepared nanoparticles was ∼60% in 24 h, followed by a sustained pattern till 72 h. The RIF-ACNPs nanoparticles showed 5-6 fold enhanced delivery of RIF into the intracellular compartments of PMNs. The RIF-ACNPs showed anti-microbial activity against Escherichia coli, Staphylococcus aureus and a variety of other bacteria. In summary, our results suggest that RIF-ACNPs could be used to treat a variety of intracellular bacterial infections. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Ca(2+) transport into an intracellular acidic compartment of Candida parapsilosis.

    PubMed

    Milani, G; Schereiber, A Z; Vercesi, A E

    2001-06-29

    In this report, we study Ca2+ transport in permeabilized Candida parapsilosis spheroplasts prepared by a new technique using lyticase. An intracellular non-mitochondrial Ca2+ uptake pathway, insensitive to orthovanadate and sensitive to the V-H(+)-ATPase inhibitor bafilomycin A(1), nigericin and carbonyl cyanide p-trifluoromethoxyphenylhydrazone was characterized. Acidification of the compartment in which Ca2+ accumulated was followed using the fluorescent dye acridine orange. Acidification was stimulated by the Ca2+ chelator EGTA and inhibited by Ca2+. These results, when added to the observation that Ca2+ induces alkalization of a cellular compartment, provide evidence for the presence of a Ca2+/nH(+) antiporter in the acid compartment membrane. Interestingly, like in acidocalcisomes of trypanosomatids, the antioxidant 3,5-dibutyl-4-hydroxytoluene inhibits the V-H(+)-ATPase. In addition, the antifungal agent ketoconazole promoted a fast alkalization of the acidic compartment. Ketoconazole effects were dose-dependent and occurred in a concentration range close to that attained in the plasma of patients treated with this drug.

  9. Organization and regulation of intracellular plasma membrane-connected HIV-1 assembly compartments in macrophages

    PubMed Central

    2013-01-01

    Background In HIV-1-infected human monocyte-derived macrophages (MDMs), virus particles assemble primarily on intracellularly sequestered plasma membrane domains termed intracellular plasma membrane-connected compartments (IPMCs). Despite their clear role in virus formation, little is known of the organization, composition, dynamics or function of these compartments. Results We have used amphipathic membrane dyes to reveal the complex three-dimensional structure of IPMCs in whole MDMs and to visualize connections between IPMCs and the cell surface. The observation of similar IPMC structures in both infected and uninfected cells indicates that these compartments are not induced by virus infection, but are present constitutively in MDMs. By expressing a phospholipase Cδ pleckstrin homology domain linked to green fluorescent protein, we demonstrate that IPMCs contain phosphatidylinositol 4,5-bisphosphate. Live cell imaging of cells expressing this probe shows that IPMCs are dynamic, but relatively stable, sub-domains of the plasma membrane. As recent electron microscopy studies indicated that portions of IPMCs are coated with β2 integrin-containing focal adhesion-like complexes linked to actin, we investigated whether the actin cytoskeleton is required for the organization of IPMCs. In MDMs treated with the actin polymerization inhibitor latrunculin, the normally compact IPMCs dispersed into smaller structures that remained connected to the plasma membrane. Moreover, latrunculin enhanced the release of preformed, mature HIV-1 particles from infected MDMs. Conclusions IPMCs are constitutive features of MDMs that are continuous with the plasma membrane and are used as unique sites for the assembly of new virions following infection by HIV-1. A functionally intact actin cytoskeleton is required to maintain the organization of the IPMCs and, in HIV-1-infected cells, perturbation of the actin cytoskeleton influences both the organization of the compartment and the

  10. Automatic Quantification of the Number of Intracellular Compartments in Arabidopsis thaliana Root Cells

    PubMed Central

    Bayle, Vincent; Platre, Matthieu Pierre; Jaillais, Yvon

    2017-01-01

    In the era of quantitative biology, it is increasingly required to quantify confocal microscopy images. If possible, quantification should be performed in an automatic way, in order to avoid bias from the experimenter, to allow the quantification of a large number of samples, and to increase reproducibility between laboratories. In this protocol, we describe procedures for automatic counting of the number of intracellular compartments in Arabidopsis root cells, which can be used for example to study endocytosis or secretory trafficking pathways and to compare membrane organization between different genotypes or treatments. While developed for Arabidopsis roots, this method can be used on other tissues, cell types and plant species. PMID:28255574

  11. Gamma-secretase subunits associate in intracellular membrane compartments in Arabidopsis thaliana.

    PubMed

    Smolarkiewicz, Michalina; Skrzypczak, Tomasz; Michalak, Michał; Leśniewicz, Krzysztof; Walker, J Ross; Ingram, Gwyneth; Wojtaszek, Przemysław

    2014-07-01

    Gamma-secretase is a multisubunit complex with intramembrane proteolytic activity. In humans it was identified in genetic screens of patients suffering from familial forms of Alzheimer's disease, and since then it was shown to mediate cleavage of more than 80 substrates, including amyloid precursor protein or Notch receptor. Moreover, in animals, γ-secretase was shown to be involved in regulation of a wide range of cellular events, including cell signalling, regulation of endocytosis of membrane proteins, their trafficking, and degradation. Here we show that genes coding for γ-secretase homologues are present in plant genomes. Also, amino acid motifs crucial for γ-secretase activity are conserved in plants. Moreover, all γ-secretase subunits: PS1/PS2, APH-1, PEN-2, and NCT colocalize and interact with each other in Arabidopsis thaliana protoplasts. The intracellular localization of γ-secretase subunits in Arabidopsis protoplasts revealed a distribution in endomembrane system compartments that is consistent with data from animal studies. Together, our data may be considered as a starting point for analysis of γ-secretase in plants. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  12. Self-assembled hydrogel fibers for sensing the multi-compartment intracellular milieu.

    PubMed

    Vemula, Praveen Kumar; Kohler, Jonathan E; Blass, Amy; Williams, Miguel; Xu, Chenjie; Chen, Lynna; Jadhav, Swapnil R; John, George; Soybel, David I; Karp, Jeffrey M

    2014-03-26

    Targeted delivery of drugs and sensors into cells is an attractive technology with both medical and scientific applications. Existing delivery vehicles are generally limited by the complexity of their design, dependence on active transport, and inability to function within cellular compartments. Here, we developed self-assembled nanofibrous hydrogel fibers using a biologically inert, low-molecular-weight amphiphile. Self-assembled nanofibrous hydrogels offer unique physical/mechanical properties and can easily be loaded with a diverse range of payloads. Unlike commercially available E. coli membrane particles covalently bound to the pH reporting dye pHrodo, pHrodo encapsulated in self-assembled hydrogel-fibers internalizes into macrophages at both physiologic (37°C) and sub-physiologic (4°C) temperatures through an energy-independent, passive process. Unlike dye alone or pHrodo complexed to E. coli, pHrodo-SAFs report pH in both the cytoplasm and phagosomes, as well the nucleus. This new class of materials should be useful for next-generation sensing of the intracellular milieu.

  13. Self-assembled hydrogel fibers for sensing the multi-compartment intracellular milieu

    NASA Astrophysics Data System (ADS)

    Vemula, Praveen Kumar; Kohler, Jonathan E.; Blass, Amy; Williams, Miguel; Xu, Chenjie; Chen, Lynna; Jadhav, Swapnil R.; John, George; Soybel, David I.; Karp, Jeffrey M.

    2014-03-01

    Targeted delivery of drugs and sensors into cells is an attractive technology with both medical and scientific applications. Existing delivery vehicles are generally limited by the complexity of their design, dependence on active transport, and inability to function within cellular compartments. Here, we developed self-assembled nanofibrous hydrogel fibers using a biologically inert, low-molecular-weight amphiphile. Self-assembled nanofibrous hydrogels offer unique physical/mechanical properties and can easily be loaded with a diverse range of payloads. Unlike commercially available E. coli membrane particles covalently bound to the pH reporting dye pHrodo, pHrodo encapsulated in self-assembled hydrogel-fibers internalizes into macrophages at both physiologic (37°C) and sub-physiologic (4°C) temperatures through an energy-independent, passive process. Unlike dye alone or pHrodo complexed to E. coli, pHrodo-SAFs report pH in both the cytoplasm and phagosomes, as well the nucleus. This new class of materials should be useful for next-generation sensing of the intracellular milieu.

  14. Regulation of intracellular cyclic AMP in skeletal muscle cells involves the efflux of cyclic nucleotide to the extracellular compartment

    PubMed Central

    Godinho, Rosely Oliveira; Costa-Jr, Valter Luiz

    2003-01-01

    This report analyses the intracellular and extracellular accumulation of cyclic AMP in primary rat skeletal muscle cultures, after direct and receptor-dependent stimulation of adenylyl cyclase (AC). Isoprenaline, calcitonin gene-related peptide (CGRP) and forskolin induced a transient increase in the intracellular cyclic AMP that peaked 5 min after onset stimulation. Under stimulation with isoprenaline or CGRP, the intracellular cyclic AMP initial rise was followed by an exponential decline, reaching 46 and 52% of peak levels in 10 min, respectively. Conversely, the forskolin-dependent accumulation of intracellular cyclic AMP decreased slowly and linearly, reaching 49% of the peak level in 30 min. The loss of intracellular cyclic AMP from peak levels, induced by direct or receptor-induced activation of AC, was followed by an increase in the extracellular cyclic AMP. This effect was independent on PDEs, since it was obtained in the presence of 3-isobutyl-1-methylxanthine (IBMX). Besides, in isoprenaline treated cells, the beta-adrenoceptor antagonist propranolol reduced both intra- and extracellular accumulation of cyclic AMP, whereas the organic anion transporter inhibitor probenecid reduced exclusively the extracellular accumulation. Together our data show that direct or receptor-dependent activation of skeletal muscle AC results in a transient increase in the intracellular cyclic AMP, despite the continuous presence of the stimulus. The temporal declining of intracellular cyclic AMP was not dependent on the cyclic AMP breakdown but associated to the efflux of cyclic nucleotide to the extracellular compartment, by an active transport since it was prevented by probenecid. PMID:12642402

  15. Trafficking of major histocompatibility complex class II molecules through intracellular compartments containing HLA-DM.

    PubMed

    Robbins, N F; Hammond, C; Denzin, L K; Pan, M; Cresswell, P

    1996-01-01

    The endosomal site(s) where MHC class II molecules become competent to bind antigenic peptide has not been completely characterized. We identified endocytic compartments through which newly synthesized MHC class II molecules move prior to their expression on the plasma membrane. The compartments co-sediment with lysosomes in the most dense regions of Percoll gradients. The appearance of proteolytic fragments of the invariant chain (I chain), namely leupeptin-induced proteins (LIPs) and class-II-associated invariant chain peptides (CLIP), in this region of the gradient suggests that the release of MHC class II molecules from I chain association occurs within these vesicles. The formation of SDS-stable alpha beta dimers indicated that MHC class II molecules contained within these compartments are receptive to peptide binding. A majority of the HLA-DM protein was found in the same region of the Percoll gradient, consistent with its established function in MHC class-II-restricted antigen presentation. Immunoelectron micrographs of dense-sedimenting compartments indicated that I chain, MHC class II, and DM molecules are contained within both multivesicular and multilamellar vesicles. The final stages of I chain dissociation from MHC class II molecules and DM-mediated peptide loading probably occur in these compartments.

  16. Physiological Intracellular Crowdedness is Defined by the Perimeter-to-Area Ratio of Sub-Cellular Compartments

    PubMed Central

    Hiroi, Noriko; Okuhara, Takahiro; Kubojima, Takeshi; Iba, Keisuke; Tabira, Akito; Yamashita, Shuji; Okada, Yasunori; Kobayashi, Tetsuya J.; Funahashi, Akira

    2012-01-01

    The intracellular environment is known to be a crowded and inhomogeneous space. Such an in vivo environment differs from a well-diluted, homogeneous environment for biochemical reactions. However, the effects of both crowdedness and the inhomogeneity of environment on the behavior of a mobile particle have not yet been investigated sufficiently. As described in this paper, we constructed artificial reaction spaces with fractal models, which are assumed to be non-reactive solid obstacles in a reaction space with crevices that function as operating ranges for mobile particles threading the space. Because of the homogeneity of the structures of artificial reaction spaces, the models succeeded in reproducing the physiological fractal dimension of solid structures with a smaller number of non-reactive obstacles than in the physiological condition. This incomplete compatibility was mitigated when we chose a suitable condition of a perimeter-to-area ratio of the operating range to our model. Our results also show that a simulation space is partitioned into convenient reaction compartments as an in vivo environment with the exact amount of solid structures estimated from TEM images. The characteristics of these compartments engender larger mean square displacement of a mobile particle than that of particles in smaller compartments. Subsequently, the particles start to show confined particle-like behavior. These results are compatible with our previously presented results, which predicted that a physiological environment would produce quick response and slow exhaustion reactions. PMID:22936917

  17. Designer amphiphilic proteins as building blocks for the intracellular formation of organelle-like compartments

    NASA Astrophysics Data System (ADS)

    Huber, Matthias C.; Schreiber, Andreas; von Olshausen, Philipp; Varga, Balázs R.; Kretz, Oliver; Joch, Barbara; Barnert, Sabine; Schubert, Rolf; Eimer, Stefan; Kele, Péter; Schiller, Stefan M.

    2015-01-01

    Nanoscale biological materials formed by the assembly of defined block-domain proteins control the formation of cellular compartments such as organelles. Here, we introduce an approach to intentionally ‘program’ the de novo synthesis and self-assembly of genetically encoded amphiphilic proteins to form cellular compartments, or organelles, in Escherichia coli. These proteins serve as building blocks for the formation of artificial compartments in vivo in a similar way to lipid-based organelles. We investigated the formation of these organelles using epifluorescence microscopy, total internal reflection fluorescence microscopy and transmission electron microscopy. The in vivo modification of these protein-based de novo organelles, by means of site-specific incorporation of unnatural amino acids, allows the introduction of artificial chemical functionalities. Co-localization of membrane proteins results in the formation of functionalized artificial organelles combining artificial and natural cellular function. Adding these protein structures to the cellular machinery may have consequences in nanobiotechnology, synthetic biology and materials science, including the constitution of artificial cells and bio-based metamaterials.

  18. Designer amphiphilic proteins as building blocks for the intracellular formation of organelle-like compartments.

    PubMed

    Huber, Matthias C; Schreiber, Andreas; von Olshausen, Philipp; Varga, Balázs R; Kretz, Oliver; Joch, Barbara; Barnert, Sabine; Schubert, Rolf; Eimer, Stefan; Kele, Péter; Schiller, Stefan M

    2015-01-01

    Nanoscale biological materials formed by the assembly of defined block-domain proteins control the formation of cellular compartments such as organelles. Here, we introduce an approach to intentionally 'program' the de novo synthesis and self-assembly of genetically encoded amphiphilic proteins to form cellular compartments, or organelles, in Escherichia coli. These proteins serve as building blocks for the formation of artificial compartments in vivo in a similar way to lipid-based organelles. We investigated the formation of these organelles using epifluorescence microscopy, total internal reflection fluorescence microscopy and transmission electron microscopy. The in vivo modification of these protein-based de novo organelles, by means of site-specific incorporation of unnatural amino acids, allows the introduction of artificial chemical functionalities. Co-localization of membrane proteins results in the formation of functionalized artificial organelles combining artificial and natural cellular function. Adding these protein structures to the cellular machinery may have consequences in nanobiotechnology, synthetic biology and materials science, including the constitution of artificial cells and bio-based metamaterials.

  19. Intracellular lumen formation in Drosophila proceeds via a novel subcellular compartment.

    PubMed

    Nikolova, Linda S; Metzstein, Mark M

    2015-11-15

    Cellular tubes have diverse morphologies, including multicellular, unicellular and subcellular architectures. Subcellular tubes are found prominently within the vertebrate vasculature, the insect breathing system and the nematode excretory apparatus, but how such tubes form is poorly understood. To characterize the cellular mechanisms of subcellular tube formation, we have refined methods of high pressure freezing/freeze substitution to prepare Drosophila larvae for transmission electron microscopic (TEM) analysis. Using our methods, we have found that subcellular tube formation may proceed through a previously undescribed multimembrane intermediate composed of vesicles bound within a novel subcellular compartment. We have also developed correlative light/TEM procedures to identify labeled cells in TEM-fixed larval samples. Using this technique, we have found that Vacuolar ATPase (V-ATPase) and the V-ATPase regulator Rabconnectin-3 are required for subcellular tube formation, probably in a step resolving the intermediate compartment into a mature lumen. In general, our ultrastructural analysis methods could be useful for a wide range of cellular investigations in Drosophila larvae.

  20. Essentially All Excess Fibroblast Cholesterol Moves from Plasma Membranes to Intracellular Compartments

    PubMed Central

    Lange, Yvonne; Ye, Jin; Steck, Theodore L.

    2014-01-01

    It has been shown that modestly increasing plasma membrane cholesterol beyond its physiological set point greatly increases the endoplasmic reticulum and mitochondrial pools, thereby eliciting manifold feedback responses that return cell cholesterol to its resting state. The question arises whether this homeostatic mechanism reflects the targeting of cell surface cholesterol to specific intracellular sites or its general equilibration among the organelles. We now show that human fibroblast cholesterol can be increased as much as two-fold from 2-hydroxypropyl-β-cyclodextrin without changing the size of the cell surface pool. Rather, essentially all of the added cholesterol disperses rapidly among cytoplasmic membranes, increasing their overall cholesterol content by as much as five-fold. We conclude that the level of plasma membrane cholesterol is normally at capacity and that even small increments above this physiological set point redistribute essentially entirely to intracellular membranes, perhaps down their chemical activity gradients. PMID:25014655

  1. A Thapsigargin-Resistant Intracellular Calcium Sequestering Compartment in Rat Brain

    DTIC Science & Technology

    2000-03-31

    SERCA-like Ca2+IMg2+-ATPase insensitive to TG inhibition has been isolated and cloned from the ciliated protozoan, Paramecium tetraurelia [54,72]. This...segment, may account for the TG-I Ca2+ uptake. Indeed, a novel SERCA isoform was recently discovered in paramecium that displays a unique intracellular...Kissmehl, R. and Plattner, H., Molecular characterization of a sarco(endo)plasmic reticulum Ca2+- ATPase gene from Paramecium tetraurelia and localization

  2. LINGO-1 protein interacts with the p75 neurotrophin receptor in intracellular membrane compartments.

    PubMed

    Meabon, James S; De Laat, Rian; Ieguchi, Katsuaki; Wiley, Jesse C; Hudson, Mark P; Bothwell, Mark

    2015-04-10

    Axon outgrowth inhibition in response to trauma is thought to be mediated via the binding of myelin-associated inhibitory factors (e.g. Nogo-66, myelin-associated glycoprotein, oligodendrocyte myelin glycoprotein, and myelin basic protein) to a putative tripartite LINGO-1·p75(NTR)·Nogo-66 receptor (NgR) complex at the cell surface. We found that endogenous LINGO-1 expression in neurons in the cortex and cerebellum is intracellular. Mutation or truncation of the highly conserved LINGO-1 C terminus altered this intracellular localization, causing poor intracellular retention and increased plasma membrane expression. p75(NTR) associated predominantly with natively expressed LINGO-1 containing immature N-glycans, characteristic of protein that has not completed trans-Golgi-mediated processing, whereas mutant forms of LINGO-1 with enhanced plasma membrane expression did not associate with p75(NTR). Co-immunoprecipitation experiments demonstrated that LINGO-1 and NgR competed for binding to p75(NTR) in a manner that is difficult to reconcile with the existence of a LINGO-1·p75(NTR)·NgR ternary complex. These findings contradict models postulating functional LINGO-1·p75(NTR)·NgR complexes in the plasma membrane.

  3. Insulin stimulates actin comet tails on intracellular GLUT4-containing compartments in differentiated 3T3L1 adipocytes.

    PubMed

    Kanzaki, M; Watson, R T; Khan, A H; Pessin, J E

    2001-12-28

    Incubation of isolated GLUT4-containing vesicles with Xenopus oocyte extracts resulted in a guanosine 5'-[gamma-thio]triphosphate (GTP gamma S) and sodium orthovanadate stimulation of actin comet tails. The in vitro actin-based GLUT4 vesicle motility was inhibited by both latrunculin B and a dominant-interfering N-WASP mutant, N-WASP/Delta VCA. Preparations of gently sheared (broken) 3T3L1 adipocytes also displayed GTP gamma S and sodium orthovanadate stimulation of actin comet tails on GLUT4 intracellular compartments. Furthermore, insulin pretreatment of intact adipocytes prior to gently shearing also resulted in a marked increase in actin polymerization and actin comet tailing on GLUT4 vesicles. In addition, the insulin stimulation of actin comet tails was completely inhibited by Clostridum difficile toxin B, demonstrating a specific role for a Rho family member small GTP-binding protein. Expression of N-WASP/Delta VCA in intact cells had little effect on adipocyte cortical actin but partially inhibited insulin-stimulated GLUT4 translocation. Taken together, these data demonstrate that insulin can induce GLUT4 vesicle actin comet tails that are necessary for the efficient translocation of GLUT4 from intracellular storage sites to the plasma membrane.

  4. Muscles that do not cross the knee contribute to the knee adduction moment and tibiofemoral compartment loading during gait.

    PubMed

    Sritharan, Prasanna; Lin, Yi-Chung; Pandy, Marcus G

    2012-10-01

    The aims of this study were to evaluate and explain the individual muscle contributions to the medial and lateral knee compartment forces during gait, and to determine whether these quantities could be inferred from their contributions to the external knee adduction moment. Gait data from eight healthy male subjects were used to compute each individual muscle contribution to the external knee adduction moment, the net tibiofemoral joint reaction force, and reaction moment. The individual muscle contributions to the medial and lateral compartment forces were then found using a least-squares approach. While knee-spanning muscles were the primary contributors, non-knee-spanning muscles (e.g., the gluteus medius) also contributed substantially to the medial compartment compressive force. Furthermore, knee-spanning muscles tended to compress both compartments, while most non-knee-spanning muscles tended to compress the medial compartment but unload the lateral compartment. Muscle contributions to the external knee adduction moment, particularly those from knee-spanning muscles, did not accurately reflect their tendencies to compress or unload the medial compartment. This finding may further explain why gait modifications may reduce the knee adduction moment without necessarily decreasing the medial compartment force.

  5. Mercury-pollution induction of intracellular lipid accumulation and lysosomal compartment amplification in the benthic foraminifer Ammonia parkinsoniana

    DOE PAGES

    Frontalini, Fabrizio; Curzi, Davide; Cesarini, Erica; ...

    2016-09-07

    In this study, heavy metals such as mercury (Hg) pose a significant health hazard through bioaccumulation and biomagnification. By penetrating cell membranes, heavy metal ions may lead to pathological conditions. Here we examined the responses of Ammonia parkinsoniana, a benthic foraminiferan, to different concentrations of Hg in the artificial sea water. Confocal images of untreated and treated specimens using fluorescent probes (Nile Red and Acridine Orange) provided an opportunity for visualizing the intracellular lipid accumulation and acidic compartment regulation. With increased Hg over time, we observed an increased number of lipid droplets, which may have acted as a detoxifying organellemore » where Hg is sequestered and biologically inactivated. Further, Hg seems to promote the proliferation of lysosomes both in terms of number and dimension that, at the highest level of Hg, resulted in cell death. We report, for the first time, the presence of Hg within the foraminiferal cell: at the basal part of pores, in the organic linings of the foramen/septa, and as cytoplasmic accumulations.« less

  6. Mercury-Pollution Induction of Intracellular Lipid Accumulation and Lysosomal Compartment Amplification in the Benthic Foraminifer Ammonia parkinsoniana.

    PubMed

    Frontalini, Fabrizio; Curzi, Davide; Cesarini, Erica; Canonico, Barbara; Giordano, Francesco M; De Matteis, Rita; Bernhard, Joan M; Pieretti, Nadia; Gu, Baohua; Eskelsen, Jeremy R; Jubb, Aaron M; Zhao, Linduo; Pierce, Eric M; Gobbi, Pietro; Papa, Stefano; Coccioni, Rodolfo

    2016-01-01

    Heavy metals such as mercury (Hg) pose a significant health hazard through bioaccumulation and biomagnification. By penetrating cell membranes, heavy metal ions may lead to pathological conditions. Here we examined the responses of Ammonia parkinsoniana, a benthic foraminiferan, to different concentrations of Hg in the artificial sea water. Confocal images of untreated and treated specimens using fluorescent probes (Nile Red and Acridine Orange) provided an opportunity for visualizing the intracellular lipid accumulation and acidic compartment regulation. With increased Hg over time, we observed an increased number of lipid droplets, which may have acted as a detoxifying organelle where Hg is sequestered and biologically inactivated. Further, Hg seems to promote the proliferation of lysosomes both in terms of number and dimension that, at the highest level of Hg, resulted in cell death. We report, for the first time, the presence of Hg within the foraminiferal cell: at the basal part of pores, in the organic linings of the foramen/septa, and as cytoplasmic accumulations.

  7. Mercury-Pollution Induction of Intracellular Lipid Accumulation and Lysosomal Compartment Amplification in the Benthic Foraminifer Ammonia parkinsoniana

    PubMed Central

    Curzi, Davide; Cesarini, Erica; Canonico, Barbara; Giordano, Francesco M.; De Matteis, Rita; Bernhard, Joan M.; Pieretti, Nadia; Gu, Baohua; Eskelsen, Jeremy R.; Jubb, Aaron M.; Zhao, Linduo; Pierce, Eric M.; Gobbi, Pietro; Papa, Stefano; Coccioni, Rodolfo

    2016-01-01

    Heavy metals such as mercury (Hg) pose a significant health hazard through bioaccumulation and biomagnification. By penetrating cell membranes, heavy metal ions may lead to pathological conditions. Here we examined the responses of Ammonia parkinsoniana, a benthic foraminiferan, to different concentrations of Hg in the artificial sea water. Confocal images of untreated and treated specimens using fluorescent probes (Nile Red and Acridine Orange) provided an opportunity for visualizing the intracellular lipid accumulation and acidic compartment regulation. With increased Hg over time, we observed an increased number of lipid droplets, which may have acted as a detoxifying organelle where Hg is sequestered and biologically inactivated. Further, Hg seems to promote the proliferation of lysosomes both in terms of number and dimension that, at the highest level of Hg, resulted in cell death. We report, for the first time, the presence of Hg within the foraminiferal cell: at the basal part of pores, in the organic linings of the foramen/septa, and as cytoplasmic accumulations. PMID:27603511

  8. Plant defensin AhPDF1.1 is not secreted in leaves but it accumulates in intracellular compartments.

    PubMed

    Oomen, Ronald J F J; Séveno-Carpentier, Emilie; Ricodeau, Nicolas; Bournaud, Caroline; Conéjéro, Geneviève; Paris, Nadine; Berthomieu, Pierre; Marquès, Laurence

    2011-10-01

    • Apart from their antifungal role, plant defensins have recently been shown to be involved in abiotic stress tolerance or in inhibition of root growth when added in plant culture medium. We studied the subcellular localization of these proteins, which may account for these different roles. • Stable and transient expression of AhPDF1.1::GFP (green fluorescent protein) fusion proteins were analysed in yeast and plants. Functional tests established that the GFP tag did not alter the action of the defensin. Subcellular localization of AhPDF1.1 was characterized: by imaging AhPDF1.1::GFP together with organelle markers; and by immunolabelling AhPDF1.1 in Arabidopsis halleri and Arabidopsis thaliana leaves using a polyclonal serum. • All our independent approaches demonstrated that AhPDF1.1 is retained in intracellular compartments on the way to the lytic vacuole, instead of being addressed to the apoplasm. • These findings challenge the commonly accepted idea of secretion of defensins. The subcellular localization highlighted in this study could partly explain the dual role of plant defensins on plant cells and is of major importance to unravel the mechanisms of action of these proteins at the cellular level. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  9. A T4SS Effector Targets Host Cell Alpha-Enolase Contributing to Brucella abortus Intracellular Lifestyle

    PubMed Central

    Marchesini, María I.; Morrone Seijo, Susana M.; Guaimas, Francisco F.; Comerci, Diego J.

    2016-01-01

    Brucella abortus, the causative agent of bovine brucellosis, invades and replicates within cells inside a membrane-bound compartment known as the Brucella containing vacuole (BCV). After trafficking along the endocytic and secretory pathways, BCVs mature into endoplasmic reticulum-derived compartments permissive for bacterial replication. Brucella Type IV Secretion System (VirB) is a major virulence factor essential for the biogenesis of the replicative organelle. Upon infection, Brucella uses the VirB system to translocate effector proteins from the BCV into the host cell cytoplasm. Although the functions of many translocated proteins remain unknown, some of them have been demonstrated to modulate host cell signaling pathways to favor intracellular survival and replication. BPE123 (BAB2_0123) is a B. abortus VirB-translocated effector protein recently identified by our group whose function is yet unknown. In an attempt to identify host cell proteins interacting with BPE123, a pull-down assay was performed and human alpha-enolase (ENO-1) was identified by LC/MS-MS as a potential interaction partner of BPE123. These results were confirmed by immunoprecipitation assays. In bone-marrow derived macrophages infected with B. abortus, ENO-1 associates to BCVs in a BPE123-dependent manner, indicating that interaction with translocated BPE123 is also occurring during the intracellular phase of the bacterium. Furthermore, ENO-1 depletion by siRNA impaired B. abortus intracellular replication in HeLa cells, confirming a role for α-enolase during the infection process. Indeed, ENO-1 activity levels were enhanced upon B. abortus infection of THP-1 macrophagic cells, and this activation is highly dependent on BPE123. Taken together, these results suggest that interaction between BPE123 and host cell ENO-1 contributes to the intracellular lifestyle of B. abortus. PMID:27900285

  10. A T4SS Effector Targets Host Cell Alpha-Enolase Contributing to Brucella abortus Intracellular Lifestyle.

    PubMed

    Marchesini, María I; Morrone Seijo, Susana M; Guaimas, Francisco F; Comerci, Diego J

    2016-01-01

    Brucella abortus, the causative agent of bovine brucellosis, invades and replicates within cells inside a membrane-bound compartment known as the Brucella containing vacuole (BCV). After trafficking along the endocytic and secretory pathways, BCVs mature into endoplasmic reticulum-derived compartments permissive for bacterial replication. Brucella Type IV Secretion System (VirB) is a major virulence factor essential for the biogenesis of the replicative organelle. Upon infection, Brucella uses the VirB system to translocate effector proteins from the BCV into the host cell cytoplasm. Although the functions of many translocated proteins remain unknown, some of them have been demonstrated to modulate host cell signaling pathways to favor intracellular survival and replication. BPE123 (BAB2_0123) is a B. abortus VirB-translocated effector protein recently identified by our group whose function is yet unknown. In an attempt to identify host cell proteins interacting with BPE123, a pull-down assay was performed and human alpha-enolase (ENO-1) was identified by LC/MS-MS as a potential interaction partner of BPE123. These results were confirmed by immunoprecipitation assays. In bone-marrow derived macrophages infected with B. abortus, ENO-1 associates to BCVs in a BPE123-dependent manner, indicating that interaction with translocated BPE123 is also occurring during the intracellular phase of the bacterium. Furthermore, ENO-1 depletion by siRNA impaired B. abortus intracellular replication in HeLa cells, confirming a role for α-enolase during the infection process. Indeed, ENO-1 activity levels were enhanced upon B. abortus infection of THP-1 macrophagic cells, and this activation is highly dependent on BPE123. Taken together, these results suggest that interaction between BPE123 and host cell ENO-1 contributes to the intracellular lifestyle of B. abortus.

  11. Bem3, a Cdc42 GTPase-activating protein, traffics to an intracellular compartment and recruits the secretory Rab GTPase Sec4 to endomembranes

    PubMed Central

    Mukherjee, Debarati; Sen, Arpita; Boettner, Douglas R.; Fairn, Gregory D.; Schlam, Daniel; Bonilla Valentin, Fernando J.; Michael McCaffery, J.; Hazbun, Tony; Staiger, Chris J.; Grinstein, Sergio; Lemmon, Sandra K.; Claudio Aguilar, R.

    2013-01-01

    Summary Cell polarity is essential for many cellular functions including division and cell-fate determination. Although RhoGTPase signaling and vesicle trafficking are both required for the establishment of cell polarity, the mechanisms by which they are coordinated are unclear. Here, we demonstrate that the yeast RhoGAP (GTPase activating protein), Bem3, is targeted to sites of polarized growth by the endocytic and recycling pathways. Specifically, deletion of SLA2 or RCY1 led to mislocalization of Bem3 to depolarized puncta and accumulation in intracellular compartments, respectively. Bem3 partitioned between the plasma membrane and an intracellular membrane-bound compartment. These Bem3-positive structures were polarized towards sites of bud emergence and were mostly observed during the pre-mitotic phase of apical growth. Cell biological and biochemical approaches demonstrated that this intracellular Bem3 compartment contained markers for both the endocytic and secretory pathways, which were reminiscent of the Spitzenkörper present in the hyphal tips of growing fungi. Importantly, Bem3 was not a passive cargo, but recruited the secretory Rab protein, Sec4, to the Bem3-containing compartments. Moreover, Bem3 deletion resulted in less efficient localization of Sec4 to bud tips during early stages of bud emergence. Surprisingly, these effects of Bem3 on Sec4 were independent of its GAP activity, but depended on its ability to efficiently bind endomembranes. This work unveils unsuspected and important details of the relationship between vesicle traffic and elements of the cell polarity machinery: (1) Bem3, a cell polarity and peripherally associated membrane protein, relies on vesicle trafficking to maintain its proper localization; and (2) in turn, Bem3 influences secretory vesicle trafficking. PMID:23943876

  12. Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane

    PubMed Central

    Monet, Michael; Birgy-Barelli, Eléonore; Léna, Isabelle; Counillon, Laurent

    2015-01-01

    Endosomal acidification is critical for a wide range of processes, such as protein recycling and degradation, receptor desensitization, and neurotransmitter loading in synaptic vesicles. This acidification is described to be mediated by proton ATPases, coupled to ClC chloride transporters. Highly-conserved electroneutral protons transporters, the Na+/H+ exchangers (NHE) 6, 7 and 9 are also expressed in these compartments. Mutations in their genes have been linked with human cognitive and neurodegenerative diseases. Paradoxically, their roles remain elusive, as their intracellular localization has prevented detailed functional characterization. This manuscript shows a method to solve this problem. This consists of the selection of mutant cell lines, capable of surviving acute cytosolic acidification by retaining intracellular NHEs at the plasma membrane. It then depicts two complementary protocols to measure the ion selectivity and activity of these exchangers: (i) one based on intracellular pH measurements using fluorescence video microscopy, and (ii) one based on the fast kinetics of lithium uptake. Such protocols can be extrapolated to measure other non-electrogenic transporters. Furthermore, the selection procedure presented here generates cells with an intracellular retention defective phenotype. Therefore these cells will also express other vesicular membrane proteins at the plasma membrane. The experimental strategy depicted here may therefore constitute a potentially powerful tool to study other intracellular proteins that will be then expressed at the plasma membrane together with the vesicular Na+/H+ exchangers used for the selection. PMID:25867523

  13. Disproportionate Contributions of Select Genomic Compartments and Cell Types to Genetic Risk for Coronary Artery Disease

    PubMed Central

    Won, Hong-Hee; Natarajan, Pradeep; Dobbyn, Amanda; Jordan, Daniel M.; Roussos, Panos; Lage, Kasper; Raychaudhuri, Soumya

    2015-01-01

    Large genome-wide association studies (GWAS) have identified many genetic loci associated with risk for myocardial infarction (MI) and coronary artery disease (CAD). Concurrently, efforts such as the National Institutes of Health (NIH) Roadmap Epigenomics Project and the Encyclopedia of DNA Elements (ENCODE) Consortium have provided unprecedented data on functional elements of the human genome. In the present study, we systematically investigate the biological link between genetic variants associated with this complex disease and their impacts on gene function. First, we examined the heritability of MI/CAD according to genomic compartments. We observed that single nucleotide polymorphisms (SNPs) residing within nearby regulatory regions show significant polygenicity and contribute between 59–71% of the heritability for MI/CAD. Second, we showed that the polygenicity and heritability explained by these SNPs are enriched in histone modification marks in specific cell types. Third, we found that a statistically higher number of 45 MI/CAD-associated SNPs that have been identified from large-scale GWAS studies reside within certain functional elements of the genome, particularly in active enhancer and promoter regions. Finally, we observed significant heterogeneity of this signal across cell types, with strong signals observed within adipose nuclei, as well as brain and spleen cell types. These results suggest that the genetic etiology of MI/CAD is largely explained by tissue-specific regulatory perturbation within the human genome. PMID:26509271

  14. Contribution of inflammation to cellular injury in compartment syndrome in an experimental rodent model.

    PubMed

    Lawendy, A-R; Bihari, A; Sanders, D W; McGarr, G; Badhwar, A; Cepinskas, G

    2015-04-01

    Compartment syndrome, a devastating consequence of limb trauma, is characterised by severe tissue injury and microvascular perfusion deficits. We hypothesised that leucopenia might provide significant protection against microvascular dysfunction and preserve tissue viability. Using our clinically relevant rat model of compartment syndrome, microvascular perfusion and tissue injury were directly visualised by intravital video microscopy in leucopenic animals. We found that while the tissue perfusion was similar in both groups (38.8% (standard error of the mean (sem) 7.1), 36.4% (sem 5.7), 32.0% (sem 1.7), and 30.5% (sem 5.35) continuously-perfused capillaries at 45, 90, 120 and 180 minutes compartment syndrome, respectively versus 39.2% (sem 8.6), 43.5% (sem 8.5), 36.6% (sem 1.4) and 50.8% (sem 4.8) at 45, 90, 120 and 180 minutes compartment syndrome, respectively in leucopenia), compartment syndrome-associated muscle injury was significantly decreased in leucopenic animals (7.0% (sem 2.0), 7.0%, (sem 1.0), 9.0% (sem 1.0) and 5.0% (sem 2.0) at 45, 90, 120 and 180 minutes of compartment syndrome, respectively in leucopenia group versus 18.0% (sem 4.0), 23.0% (sem 4.0), 32.0% (sem 7.0), and 20.0% (sem 5.0) at 45, 90, 120 and 180 minutes of compartment syndrome in control, p = 0.0005). This study demonstrates that the inflammatory process should be considered central to the understanding of the pathogenesis of cellular injury in compartment syndrome. ©2015 The British Editorial Society of Bone & Joint Surgery.

  15. Localization of outer surface proteins A and B in both the outer membrane and intracellular compartments of Borrelia burgdorferi.

    PubMed Central

    Brusca, J S; McDowall, A W; Norgard, M V; Radolf, J D

    1991-01-01

    Borrelia burgdorferi B31 with and without outer membranes contained nearly identical amounts of outer surface proteins A and B. The majority of each immunogen also was localized intracellularly by immunocryoultramicrotomy. These results are inconsistent with the widely held belief that outer surface proteins A and B are exclusively outer membrane proteins. Images FIG. 1 FIG. 2 FIG. 3 PMID:1744059

  16. Anomalous bilateral contribution of extensor pollicis longus and muscle fusion of the first compartment of the wrist

    PubMed Central

    Rosa, Rodrigo César; de Oliveira, Kennedy Martinez; Léo, Jorge Alfredo; Elias, Bruno Adriano Borges; dos Santos, Paulo Ricardo; de Santiago, Hildemberg Agostinho Rocha

    2016-01-01

    Knowledge of the anatomical variations of the muscles of the first dorsal compartments of the wrist is clinically relevant to De Quervain's tenosynovitis and to reconstructive surgeries. In the literature, there are many reports of the presence of multiple insertion tendons in the first dorsal compartment of the wrist, but few reports describe occurrences of fusion and muscle contributions. This case report describes an anomalous bilateral contribution of the extensor pollicis longus. This anomalous contribution was found through a slender auxiliary tendon that crossed laterally under the extensor retinaculum, entered the first dorsal compartment of the wrist and merged with the tendon of the extensor pollicis brevis muscle. In the same cadaver in which this contribution was present, there was atypical muscle fusion of the abductor pollicis longus muscle and extensor pollicis brevis muscle. In conclusion, anomalous bilateral contribution of the extensor pollicis longus muscle and atypical muscle fusion, concomitant with a variant insertion pattern, are the highlight of this case report. Furthermore, it is concluded that additional tendons may be effectively used in reconstructive surgeries, but that there is a need for knowledge of the possible numerical and positional variations of these tendons, with a view to making more effective surgical plans. PMID:27069895

  17. Anomalous bilateral contribution of extensor pollicis longus and muscle fusion of the first compartment of the wrist.

    PubMed

    Rosa, Rodrigo César; de Oliveira, Kennedy Martinez; Léo, Jorge Alfredo; Elias, Bruno Adriano Borges; Dos Santos, Paulo Ricardo; de Santiago, Hildemberg Agostinho Rocha

    2016-01-01

    Knowledge of the anatomical variations of the muscles of the first dorsal compartments of the wrist is clinically relevant to De Quervain's tenosynovitis and to reconstructive surgeries. In the literature, there are many reports of the presence of multiple insertion tendons in the first dorsal compartment of the wrist, but few reports describe occurrences of fusion and muscle contributions. This case report describes an anomalous bilateral contribution of the extensor pollicis longus. This anomalous contribution was found through a slender auxiliary tendon that crossed laterally under the extensor retinaculum, entered the first dorsal compartment of the wrist and merged with the tendon of the extensor pollicis brevis muscle. In the same cadaver in which this contribution was present, there was atypical muscle fusion of the abductor pollicis longus muscle and extensor pollicis brevis muscle. In conclusion, anomalous bilateral contribution of the extensor pollicis longus muscle and atypical muscle fusion, concomitant with a variant insertion pattern, are the highlight of this case report. Furthermore, it is concluded that additional tendons may be effectively used in reconstructive surgeries, but that there is a need for knowledge of the possible numerical and positional variations of these tendons, with a view to making more effective surgical plans.

  18. Probing the metabolic water contribution to intracellular water using oxygen isotope ratios of PO4

    PubMed Central

    Li, Hui; Yu, Chan; Wang, Fei; Chang, Sae Jung; Yao, Jun; Blake, Ruth E.

    2016-01-01

    Knowledge of the relative contributions of different water sources to intracellular fluids and body water is important for many fields of study, ranging from animal physiology to paleoclimate. The intracellular fluid environment of cells is challenging to study due to the difficulties of accessing and sampling the contents of intact cells. Previous studies of multicelled organisms, mostly mammals, have estimated body water composition—including metabolic water produced as a byproduct of metabolism—based on indirect measurements of fluids averaged over the whole organism (e.g., blood) combined with modeling calculations. In microbial cells and aquatic organisms, metabolic water is not generally considered to be a significant component of intracellular water, due to the assumed unimpeded diffusion of water across cell membranes. Here we show that the 18O/16O ratio of PO4 in intracellular biomolecules (e.g., DNA) directly reflects the O isotopic composition of intracellular water and thus may serve as a probe allowing direct sampling of the intracellular environment. We present two independent lines of evidence showing a significant contribution of metabolic water to the intracellular water of three environmentally diverse strains of bacteria. Our results indicate that ∼30–40% of O in PO4 comprising DNA/biomass in early stationary phase cells is derived from metabolic water, which bolsters previous results and also further suggests a constant metabolic water value for cells grown under similar conditions. These results suggest that previous studies assuming identical isotopic compositions for intracellular/extracellular water may need to be reconsidered. PMID:27170190

  19. Probing the metabolic water contribution to intracellular water using oxygen isotope ratios of PO4.

    PubMed

    Li, Hui; Yu, Chan; Wang, Fei; Chang, Sae Jung; Yao, Jun; Blake, Ruth E

    2016-05-24

    Knowledge of the relative contributions of different water sources to intracellular fluids and body water is important for many fields of study, ranging from animal physiology to paleoclimate. The intracellular fluid environment of cells is challenging to study due to the difficulties of accessing and sampling the contents of intact cells. Previous studies of multicelled organisms, mostly mammals, have estimated body water composition-including metabolic water produced as a byproduct of metabolism-based on indirect measurements of fluids averaged over the whole organism (e.g., blood) combined with modeling calculations. In microbial cells and aquatic organisms, metabolic water is not generally considered to be a significant component of intracellular water, due to the assumed unimpeded diffusion of water across cell membranes. Here we show that the (18)O/(16)O ratio of PO4 in intracellular biomolecules (e.g., DNA) directly reflects the O isotopic composition of intracellular water and thus may serve as a probe allowing direct sampling of the intracellular environment. We present two independent lines of evidence showing a significant contribution of metabolic water to the intracellular water of three environmentally diverse strains of bacteria. Our results indicate that ∼30-40% of O in PO4 comprising DNA/biomass in early stationary phase cells is derived from metabolic water, which bolsters previous results and also further suggests a constant metabolic water value for cells grown under similar conditions. These results suggest that previous studies assuming identical isotopic compositions for intracellular/extracellular water may need to be reconsidered.

  20. Probing the metabolic water contribution to intracellular water using oxygen isotope ratios of PO4

    NASA Astrophysics Data System (ADS)

    Li, Hui; Yu, Chan; Wang, Fei; Chang, Sae Jung; Yao, Jun; Blake, Ruth E.

    2016-05-01

    Knowledge of the relative contributions of different water sources to intracellular fluids and body water is important for many fields of study, ranging from animal physiology to paleoclimate. The intracellular fluid environment of cells is challenging to study due to the difficulties of accessing and sampling the contents of intact cells. Previous studies of multicelled organisms, mostly mammals, have estimated body water composition—including metabolic water produced as a byproduct of metabolism—based on indirect measurements of fluids averaged over the whole organism (e.g., blood) combined with modeling calculations. In microbial cells and aquatic organisms, metabolic water is not generally considered to be a significant component of intracellular water, due to the assumed unimpeded diffusion of water across cell membranes. Here we show that the 18O/16O ratio of PO4 in intracellular biomolecules (e.g., DNA) directly reflects the O isotopic composition of intracellular water and thus may serve as a probe allowing direct sampling of the intracellular environment. We present two independent lines of evidence showing a significant contribution of metabolic water to the intracellular water of three environmentally diverse strains of bacteria. Our results indicate that ˜30-40% of O in PO4 comprising DNA/biomass in early stationary phase cells is derived from metabolic water, which bolsters previous results and also further suggests a constant metabolic water value for cells grown under similar conditions. These results suggest that previous studies assuming identical isotopic compositions for intracellular/extracellular water may need to be reconsidered.

  1. Intracellular Tenofovir and Emtricitabine Anabolites in Genital, Rectal, and Blood Compartments from First Dose to Steady State.

    PubMed

    Seifert, Sharon M; Chen, Xinhui; Meditz, Amie L; Castillo-Mancilla, Jose R; Gardner, Edward M; Predhomme, Julie A; Clayton, Carolyn; Austin, Gregory; Palmer, Brent E; Zheng, Jia-Hua; Klein, Brandon; Kerr, Becky J; Guida, L Anthony; Rower, Caitlin; Rower, Joseph E; Kiser, Jennifer J; Bushman, Lane R; MaWhinney, Samantha; Anderson, Peter L

    The pharmacokinetics (PK) of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP), the active anabolites of tenofovir disoproxil fumarate (TDF), and emtricitabine (FTC) in blood, genital, and rectal compartments was determined in HIV-positive and seronegative adults who undertook a 60-day intensive PK study of daily TDF/FTC (plus efavirenz in HIV positives). Lymphocyte cell sorting, genital, and rectal sampling occurred once per subject, at staggered visits. Among 19 HIV-positive (3 female) and 21 seronegative (10 female) adults, TFV-DP in peripheral blood mononuclear cells (PBMC) accumulated 8.6-fold [95% confidence interval (CI): 7.2-10] from first-dose to steady-state concentration (Css) versus 1.7-fold (95% CI: 1.5-1.9) for FTC-TP. Css was reached in ∼11 and 3 days, respectively. Css values were similar between HIV-negative and HIV-positive individuals. Css TFV-DP in rectal mononuclear cells (1,450 fmol/10(6) cells, 898-2,340) was achieved in 5 days and was >10 times higher than PBMC (95 fmol/10(6) cells, 85-106), seminal cells (22 fmol/10(6) cells, 6-79), and cervical cells (111 fmol/10(6) cells, 64-194). FTC-TP Css was highest in PBMC (5.7 pmol/10(6) cells, 5.2-6.1) and cervical cells (7 pmol/10(6) cells, 2-19) versus rectal (0.8 pmol/10(6) cells, 0.6-1.1) and seminal cells (0.3 pmol/10(6) cells, 0.2-0.5). Genital drug concentrations on days 1-7 overlapped with estimated Css, but accumulation characteristics were based on limited data. TFV-DP and FTC-TP in cell sorted samples were highest and achieved most rapidly in CD14(+) compared with CD4(+), CD8(+), and CD19(+) cells. Together, these findings demonstrate cell-type and tissue-dependent cellular pharmacology, preferential accumulation of TFV-DP in rectal mononuclear cells, and rapid distribution into rectal and genital compartments.

  2. Acetylation of TUG protein promotes the accumulation of GLUT4 glucose transporters in an insulin-responsive intracellular compartment.

    PubMed

    Belman, Jonathan P; Bian, Rachel R; Habtemichael, Estifanos N; Li, Don T; Jurczak, Michael J; Alcázar-Román, Abel; McNally, Leah J; Shulman, Gerald I; Bogan, Jonathan S

    2015-02-13

    Insulin causes the exocytic translocation of GLUT4 glucose transporters to stimulate glucose uptake in fat and muscle. Previous results support a model in which TUG traps GLUT4 in intracellular, insulin-responsive vesicles termed GLUT4 storage vesicles (GSVs). Insulin triggers TUG cleavage to release the GSVs; GLUT4 then recycles through endosomes during ongoing insulin exposure. The TUG C terminus binds a GSV anchoring site comprising Golgin-160 and possibly other proteins. Here, we report that the TUG C terminus is acetylated. The TUG C-terminal peptide bound the Golgin-160-associated protein, ACBD3 (acyl-CoA-binding domain-containing 3), and acetylation reduced binding of TUG to ACBD3 but not to Golgin-160. Mutation of the acetylated residues impaired insulin-responsive GLUT4 trafficking in 3T3-L1 adipocytes. ACBD3 overexpression enhanced the translocation of GSV cargos, GLUT4 and insulin-regulated aminopeptidase (IRAP), and ACBD3 was required for intracellular retention of these cargos in unstimulated cells. Sirtuin 2 (SIRT2), a NAD(+)-dependent deacetylase, bound TUG and deacetylated the TUG peptide. SIRT2 overexpression reduced TUG acetylation and redistributed GLUT4 and IRAP to the plasma membrane in 3T3-L1 adipocytes. Mutation of the acetylated residues in TUG abrogated these effects. In mice, SIRT2 deletion increased TUG acetylation and proteolytic processing. During glucose tolerance tests, glucose disposal was enhanced in SIRT2 knock-out mice, compared with wild type controls, without any effect on insulin concentrations. Together, these data support a model in which TUG acetylation modulates its interaction with Golgi matrix proteins and is regulated by SIRT2. Moreover, acetylation of TUG enhances its function to trap GSVs within unstimulated cells and enhances insulin-stimulated glucose uptake.

  3. Facile Synthesis of pH-sensitive Germanium Nanocrystals with High Quantum Yield for Intracellular Acidic Compartment Imaging.

    PubMed

    Li, Feng; Wang, Jing; Sun, Shuqing; Wang, Hai; Tang, Zhiyong; Nie, Guangjun

    2015-04-24

    A green-light emitting germanium nanocrystal-based biosensor to monitor lysosomal pH changes is developed. The Ge nanocrystals are synthesized in an aqueous solution with a significantly enhanced photoluminescence quantum yield of 26%. This synthesis involves a facile solution based route which avoided the use of toxic or environmentally unfriendly agents. Importantly, the photoluminescence intensity of the synthesized Ge nanocrystals is particularly sensitive to changes in pH between 5 and 6. When incubated with cultured cells, the nanocrystals are internalized and subsequently translocated via the lysosomal pathway, and the Ge nanocrystals' fluorescence are greatly enhanced, even when the lysosomal pH is only slightly increased. These results reveal that the Ge nanocrystals possess high pH sensitivity compared to a commercially available dye, LysoSensor Green DND-189. The fluorescent properties of the Ge nanocrystals are demonstrated to be dependent on both the crystal form and their surface chemistry. The superior fluorescence properties and bioapplicability of the Ge nanocrystals makes them a promising intracellular bioimaging probe for monitoring various pH-sensitive processes in cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Drug resistance to paclitaxel is not only associated with ABCB1 mRNA expression but also with drug accumulation in intracellular compartments in human lung cancer cell lines.

    PubMed

    Shimomura, Masanori; Yaoi, Takeshi; Itoh, Kyoko; Kato, Daishiro; Terauchi, Kunihiko; Shimada, Junichi; Fushiki, Shinji

    2012-04-01

    In order to clarify the mechanisms of resistance to paclitaxel in lung cancer, three human lung cancer cell lines which exhibit different sensitivity to paclitaxel were investigated from the following viewpoints: overexpression of ATP-binding cassette, sub-family B, member 1 (ABCB1), mutations on paclitaxel binding site of β-tubulin genes, quantity of polymerized tubulin and the intracellular localization of paclitaxel. ABCB1 expression was evaluated by real-time RT-PCR. No correlations were noted between the ABCB1 expression in the sensitive and resistant cell lines at the mRNA level. No mutations on the paclitaxel binding site of the β-tubulin genes were detected in either the resistant or sensitive cells. Live cell images obtained by confocal laser microscopy revealed that the resistant cell line, RERF-LC-KJ, had more accumulation of Oregon Green® 488 conjugated paclitaxel in the lysosomal and extra-lysosomal compartments of cytoplasm than other cell lines. The results obtained in this study indicated that the changes in the subcellular localization could contribute to the production of paclitaxel resistance in lung cancer cell lines. Further studies should be conducted to elucidate the molecular mechanisms that differentiate the intracellular localization of paclitaxel.

  5. Drug resistance to paclitaxel is not only associated with ABCB1 mRNA expression but also with drug accumulation in intracellular compartments in human lung cancer cell lines

    PubMed Central

    SHIMOMURA, MASANORI; YAOI, TAKESHI; ITOH, KYOKO; KATO, DAISHIRO; TERAUCHI, KUNIHIKO; SHIMADA, JUNICHI; FUSHIKI, SHINJI

    2012-01-01

    In order to clarify the mechanisms of resistance to paclitaxel in lung cancer, three human lung cancer cell lines which exhibit different sensitivity to paclitaxel were investigated from the following viewpoints: overexpression of ATP-binding cassette, sub-family B, member 1 (ABCB1), mutations on paclitaxel binding site of β-tubulin genes, quantity of polymerized tubulin and the intracellular localization of paclitaxel. ABCB1 expression was evaluated by real-time RT-PCR. No correlations were noted between the ABCB1 expression in the sensitive and resistant cell lines at the mRNA level. No mutations on the paclitaxel binding site of the β-tubulin genes were detected in either the resistant or sensitive cells. Live cell images obtained by confocal laser microscopy revealed that the resistant cell line, RERF-LC-KJ, had more accumulation of Oregon Green® 488 conjugated paclitaxel in the lysosomal and extra-lysosomal compartments of cytoplasm than other cell lines. The results obtained in this study indicated that the changes in the subcellular localization could contribute to the production of paclitaxel resistance in lung cancer cell lines. Further studies should be conducted to elucidate the molecular mechanisms that differentiate the intracellular localization of paclitaxel. PMID:22179563

  6. Optical oximetry of volume-oscillating vascular compartments: contributions from oscillatory blood flow

    NASA Astrophysics Data System (ADS)

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Fantini, Sergio

    2016-10-01

    We present a quantitative analysis of dynamic diffuse optical measurements to obtain oxygen saturation of hemoglobin in volume oscillating compartments. We used a phasor representation of oscillatory hemodynamics at the heart rate and respiration frequency to separate the oscillations of tissue concentrations of oxyhemoglobin (O) and deoxyhemoglobin (D) into components due to blood volume (subscript V) and blood flow (subscript F): O=OV+OF, D=DV+DF. This is achieved by setting the phase angle Arg(OF)-Arg(O), which can be estimated by a hemodynamic model that we recently developed. We found this angle to be -72 deg for the cardiac pulsation at 1 Hz, and -7 deg for paced breathing at 0.1 Hz. Setting this angle, we can obtain the oxygen saturation of hemoglobin of the volume-oscillating vascular compartment, SV=|OV|/(|OV|+|DV|). We demonstrate this approach with cerebral near-infrared spectroscopy measurements on healthy volunteers at rest (n=4) and during 0.1 Hz paced breathing (n=3) with a 24-channel system. Rest data at the cardiac frequency were used to calculate the arterial saturation, S(a); over all subjects and channels, we found ==0.96±0.02. In the case of paced breathing, we found =0.66±0.14, which reflects venous-dominated hemodynamics at the respiratory frequency.

  7. The N-terminal segment of endothelin-converting enzyme (ECE)-1b contains a di-leucine motif that can redirect neprilysin to an intracellular compartment in Madin-Darby canine kidney (MDCK) cells.

    PubMed

    Cailler, F; Zappulla, J P; Boileau, G; Crine, P

    1999-07-01

    Endothelin-converting enzyme (ECE)-1 is a membrane-bound metallopeptidase of the neprilysin (NEP) family. ECE-1 is responsible for the conversion of inactive big-endothelins into active endothelins. Three different isoforms of human ECE-1 (ECE-1a, ECE-1b and ECE-1c) have been identified. They differ in their N-terminal cytosolic regions, have distinct tissue distribution and intracellular localization. ECE-1a and ECE-1c are both located at the cell surface whereas ECE-1b is targeted to an intracellular compartment. To better understand the nature of the signal responsible for the targeting of ECE-1b to the intracellular compartment, we have constructed several ECE/NEP chimaeric proteins and expressed them by transfection into Madin-Darby canine kidney (MDCK) cells. This allowed us to identify a nine amino acid segment in the cytosolic tail of ECE-1b that is sufficient to relocate NEP from the cell surface to an intracellular compartment. Site-directed mutagenesis on these chimaeras led to the identification of two leucine residues as part of the intracellular retention signal.

  8. Optical oximetry of volume-oscillating vascular compartments: contributions from oscillatory blood flow

    PubMed Central

    Kainerstorfer, Jana M.; Sassaroli, Angelo; Fantini, Sergio

    2016-01-01

    Abstract. We present a quantitative analysis of dynamic diffuse optical measurements to obtain oxygen saturation of hemoglobin in volume oscillating compartments. We used a phasor representation of oscillatory hemodynamics at the heart rate and respiration frequency to separate the oscillations of tissue concentrations of oxyhemoglobin (O) and deoxyhemoglobin (D) into components due to blood volume (subscript V) and blood flow (subscript F): O=OV+OF, D=DV+DF. This is achieved by setting the phase angle Arg(OF)−Arg(O), which can be estimated by a hemodynamic model that we recently developed. We found this angle to be −72  deg for the cardiac pulsation at 1 Hz, and −7  deg for paced breathing at 0.1 Hz. Setting this angle, we can obtain the oxygen saturation of hemoglobin of the volume-oscillating vascular compartment, SV=|OV|/(|OV|+|DV|). We demonstrate this approach with cerebral near-infrared spectroscopy measurements on healthy volunteers at rest (n=4) and during 0.1 Hz paced breathing (n=3) with a 24-channel system. Rest data at the cardiac frequency were used to calculate the arterial saturation, S(a); over all subjects and channels, we found 〈SV〉=〈S(a)〉=0.96±0.02. In the case of paced breathing, we found 〈SV〉=0.66±0.14, which reflects venous-dominated hemodynamics at the respiratory frequency. PMID:26926870

  9. Mercury-pollution induction of intracellular lipid accumulation and lysosomal compartment amplification in the benthic foraminifer Ammonia parkinsoniana

    SciTech Connect

    Frontalini, Fabrizio; Curzi, Davide; Cesarini, Erica; Canonico, Barbara; Giordano, Francesco M.; De Matteis, Rita; Bernhard, Joan M.; Pieretti, Nadia; Gu, Baohua; Eskelsen, Jeremy R.; Jubb, Aaron M.; Zhao, Linduo; Pierce, Eric M.; Gobbi, Pietro; Papa, Stefano; Coccioni, Rodolfo; Hu, Yi

    2016-09-07

    In this study, heavy metals such as mercury (Hg) pose a significant health hazard through bioaccumulation and biomagnification. By penetrating cell membranes, heavy metal ions may lead to pathological conditions. Here we examined the responses of Ammonia parkinsoniana, a benthic foraminiferan, to different concentrations of Hg in the artificial sea water. Confocal images of untreated and treated specimens using fluorescent probes (Nile Red and Acridine Orange) provided an opportunity for visualizing the intracellular lipid accumulation and acidic compartment regulation. With increased Hg over time, we observed an increased number of lipid droplets, which may have acted as a detoxifying organelle where Hg is sequestered and biologically inactivated. Further, Hg seems to promote the proliferation of lysosomes both in terms of number and dimension that, at the highest level of Hg, resulted in cell death. We report, for the first time, the presence of Hg within the foraminiferal cell: at the basal part of pores, in the organic linings of the foramen/septa, and as cytoplasmic accumulations.

  10. Contribution of intracellular negative ion capacity to Donnan effect across the membrane in alkaliphilic Bacillus spp.

    PubMed

    Goto, Toshitaka; Hirabayashi, Toshinao; Morimoto, Hajime; Yamazaki, Koji; Inoue, Norio; Matsuyama, Hidetoshi; Yumoto, Isao

    2016-02-01

    To elucidate the energy production mechanism of alkaliphiles, the relationship between the H(+) extrusion rate by the respiratory chain and the corresponding ATP synthesis rate was determined in the facultative alkaliphile Bacillus cohnii YN-2000 and compared with those in the obligate alkaliphile Bacillus clarkii DSM 8720(T) and the neutralophile Bacillus subtilis IAM 1026. Under high aeration condition, much higher ATP synthesis rates and larger Δψ in the alkaliphilic Bacillus spp. grown at pH 10 than those in the neutralophilic B. subtilis grown at pH 7 were observed. This high ATP productivity could be attributed to the larger Δψ in alkaliphiles than in B. subtilis because the H(+) extrusion rate in alkaliphiles cannot account for the high ATP productivity. However, the large Δψ in the alkaliphiles could not be explained only by the H(+) translocation rate in the respiratory chain in alkaliphiles. There is a possibility that the Donnan effect across the membrane has the potential to contribute to the large Δψ. To estimate the contribution of the Donnan effect to the large Δψ in alkaliphilic Bacillus spp. grown at pH 10, intracellular negative ion capacity was examined. The intracellular negative ion capacities in alkaliphiles grown at pH 10 under high aeration condition corresponding to their intracellular pH (pH 8.1) were much higher than those in alkaliphiles grown under low aeration condition. A proportional relationship is revealed between the negative ion capacity and Δψ in alkaliphiles grown under different aeration conditions. This relationship strongly suggests that the intracellular negative ion capacity contributes to the formation of Δψ through the Donnan effect in alkaliphilic Bacillus spp. grown at pH 10.

  11. The multidrug transporter MATE1 sequesters OCs within an intracellular compartment that has no influence on OC secretion in renal proximal tubules.

    PubMed

    Martínez-Guerrero, L J; Evans, K K; Dantzler, W H; Wright, S H

    2016-01-01

    Secretion of organic cations (OCs) across renal proximal tubules (RPTs) involves basolateral OC transporter (OCT)2-mediated uptake from the blood followed by apical multidrug and toxin extruder (MATE)1/2-mediated efflux into the tubule filtrate. Whereas OCT2 supports electrogenic OC uniport, MATE is an OC/H(+) exchanger. As assessed by epifluorescence microscopy, cultured Chinese hamster ovary (CHO) cells that stably expressed human MATE1 accumulated the fluorescent OC N,N,N-trimethyl-2-[methyl(7-nitrobenzo[c][l,2,5]oxadiazol-4-yl)amino]ethanaminium (NBD-MTMA) in the cytoplasm and in a smaller, punctate compartment; accumulation in human OCT2-expressing cells was largely restricted to the cytoplasm. A second intracellular compartment was also evident in the multicompartmental kinetics of efflux of the prototypic OC [(3)H]1-methyl-4-phenylpyridinium (MPP) from MATE1-expressing CHO cells. Punctate accumulation of NBD-MTMA was markedly reduced by coexposure of MATE1-expressing cells with 5 μM bafilomycin (BAF), an inhibitor of V-type H(+)-ATPase, and accumulation of [(3)H]MPP and [(3)H]NBD-MTMA was reduced by >30% by coexposure with 5 μM BAF. BAF had no effect on the initial rate of MATE1-mediated uptake of NBD-MTMA, suggesting that the influence of BAF was a secondary effect involving inhibition of V-type H(+)-ATPase. The accumulation of [(3)H]MPP by isolated single nonperfused rabbit RPTs was also reduced >30% by coexposure to 5 μM BAF, suggesting that the native expression in RPTs of MATE protein within endosomes can increase steady-state OC accumulation. However, the rate of [(3)H]MPP secretion by isolated single perfused rabbit RPTs was not affected by 5 μM BAF, suggesting that vesicles loaded with OCs(+) are not likely to recycle into the apical plasma membrane at a rate sufficient to provide a parallel pathway for OC secretion. Copyright © 2016 the American Physiological Society.

  12. Intracellular Proton Conductance of the Hepatitis C Virus p7 Protein and Its Contribution to Infectious Virus Production

    PubMed Central

    Wozniak, Ann L.; Griffin, Stephen; Rowlands, David; Harris, Mark; Yi, MinKyung; Lemon, Stanley M.; Weinman, Steven A.

    2010-01-01

    The hepatitis C virus (HCV) p7 protein is critical for virus production and an attractive antiviral target. p7 is an ion channel when reconstituted in artificial lipid bilayers, but channel function has not been demonstrated in vivo and it is unknown whether p7 channel activity plays a critical role in virus production. To evaluate the contribution of p7 to organelle pH regulation and virus production, we incorporated a fluorescent pH sensor within native, intracellular vesicles in the presence or absence of p7 expression. p7 increased proton (H+) conductance in vesicles and was able to rapidly equilibrate H+ gradients. This conductance was blocked by the viroporin inhibitors amantadine, rimantadine and hexamethylene amiloride. Fluorescence microscopy using pH indicators in live cells showed that both HCV infection and expression of p7 from replicon RNAs reduced the number of highly acidic (pH<5) vesicles and increased lysosomal pH from 4.5 to 6.0. These effects were not present in uninfected cells, sub-genomic replicon cells not expressing p7, or cells electroporated with viral RNA containing a channel-inactive p7 point mutation. The acidification inhibitor, bafilomycin A1, partially restored virus production to cells electroporated with viral RNA containing the channel inactive mutation, yet did not in cells containing p7-deleted RNA. Expression of influenza M2 protein also complemented the p7 mutant, confirming a requirement for H+ channel activity in virus production. Accordingly, exposure to acid pH rendered intracellular HCV particles non-infectious, whereas the infectivity of extracellular virions was acid stable and unaffected by incubation at low pH, further demonstrating a key requirement for p7-induced loss of acidification. We conclude that p7 functions as a H+ permeation pathway, acting to prevent acidification in otherwise acidic intracellular compartments. This loss of acidification is required for productive HCV infection, possibly through

  13. Intracellular proadrenomedullin-derived peptides decorate the microtubules and contribute to cytoskeleton function.

    PubMed

    Sackett, Dan L; Ozbun, Laurent; Zudaire, Enrique; Wessner, Lisa; Chirgwin, John M; Cuttitta, Frank; Martínez, Alfredo

    2008-06-01

    Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are secretory hormones, but it is not unusual to find them in intracellular compartments. Using yeast-2 hybrid technology, we found interactions between AM and several microtubule-associated proteins (MAPs), and between PAMP and tubulin. Expression of fluorescent-tagged AM and PAMP as well as immunofluorescence for the native peptides showed a complete decoration of the microtubules and colocalization with other MAPs. PAMP, but not AM, bound to tubulin in vitro and destabilized tubulin polymerization. Down-regulation of the gene coding for both AM and PAMP through small interfering RNA technology resulted in morphological changes, microtubule stabilization, increase in posttranslational modifications of tubulin such as acetylation and detyrosination, reduction in cell motility, and partial arrest at the G2 phase of the cell cycle, when compared with cells transfected with the same vector carrying a scrambled sequence. These results show that PAMP is a novel MAP, whereas AM may be exerting more subtle effects in regulating cytoskeleton function.

  14. Direct Visualization of Peptide/MHC Complexes at the Surface and in the Intracellular Compartments of Cells Infected In Vivo by Leishmania major

    PubMed Central

    Cazareth, Julie; Hoebeke, Johan; Lippuner, Christoph; Davalos-Misslitz, Ana; Aebischer, Toni; Muller, Sylviane; Glaichenhaus, Nicolas; Mougneau, Evelyne

    2010-01-01

    Protozoa and bacteria infect various types of phagocytic cells including macrophages, monocytes, dendritic cells and eosinophils. However, it is not clear which of these cells process and present microbial antigens in vivo and in which cellular compartments parasite peptides are loaded onto Major Histocompatibility Complex molecules. To address these issues, we have infected susceptible BALB/c (H-2d) mice with a recombinant Leishmania major parasite expressing a fluorescent tracer. To directly visualize the antigen presenting cells that present parasite-derived peptides to CD4+ T cells, we have generated a monoclonal antibody that reacts to an antigenic peptide derived from the parasite LACK antigen bound to I-Ad Major Histocompatibility Complex class II molecule. Immunogold electron microscopic analysis of in vivo infected cells showed that intracellular I-Ad/LACK complexes were present in the membrane of amastigote-containing phagosomes in dendritic cells, eosinophils and macrophages/monocytes. In both dendritic cells and macrophages, these complexes were also present in smaller vesicles that did not contain amastigote. The presence of I-Ad/LACK complexes at the surface of dendritic cells, but neither on the plasma membrane of macrophages nor eosinophils was independently confirmed by flow cytometry and by incubating sorted phagocytes with highly sensitive LACK-specific hybridomas. Altogether, our results suggest that peptides derived from Leishmania proteins are loaded onto Major Histocompatibility Complex class II molecules in the phagosomes of infected phagocytes. Although these complexes are transported to the cell surface in dendritic cells, therefore allowing the stimulation of parasite-specific CD4+ T cells, this does not occur in other phagocytic cells. To our knowledge, this is the first study in which Major Histocompatibility Complex class II molecules bound to peptides derived from a parasite protein have been visualized within and at the surface of

  15. Hydro-Alcoholic Cinnamon Extract, Enhances Glucose Transporter Isotype-4 Translocation from Intracellular Compartments into the Cytoplasmic Membrane of C2C12 Myotubes.

    PubMed

    Absalan, Abdorrahim; Mohiti-Ardakani, Javad; Hadinedoushan, Hossein; Khalili, Mohammad Ali

    2012-10-01

    Cinnamon has been used as an anti-diabetic agent for centuries but only in recent few years its mechanism of action has been under investigation. Previous studies showed that cinnamon might exert its anti-diabetic effect via increasing glucose transporter isotype-4 (GLUT4) gene and glycoprotein contents in fat cells. To study if hydro-alcoholic cinnamon extract (HACE) enhances GLUT4 translocation from intracellular compartments of nuclear or endoplasmic reticulum membranes (N/ER) into the cytoplasmic membrane (CM). C2C12 myoblastic cell line were seeded in DMEM plus 20 % FBS and differentiated to myotubes using 2 % horse serum. After myotubes formation, 100 or 1,000 μg/ml HACE, as intervention, and as control 1 % DMSO were added for 3 h. Cells were washed and homogenized followed by ultracentrifuge fractionation, protein separation by SDS-PAGE and GLUT4 detection using semi-quantitative Western blotting. Data analysis was done by two-independent samples t test for comparison of mean ± SD of GLUT4 percent in categories. GLUT4 contents were higher in CM of groups 100 and 1,000 μg/ml HACE and lower in 1 % DMSO treated myotubes (CI = 0.95, P < 0.05). For N/ER reverse results were obtained (CI = 0.95, P < 0.05). As our results have shown HACE induces GLUT4 translocation from intra-cell into cell surface. We conclude that cinnamon maybe a choice of type-2 diabetes mellitus treatment because its extract enhances GLUT4 contents in CM where it facilitates glucose entrance into the cell. However it is necessary to trace the signaling pathways which are activated by HACE in muscular tissue.

  16. Raised Intracellular Calcium Contributes to Ischemia-Induced Depression of Evoked Synaptic Transmission

    PubMed Central

    Jalini, Shirin; Ye, Hui; Tonkikh, Alexander A.; Charlton, Milton P.; Carlen, Peter L.

    2016-01-01

    Oxygen-glucose deprivation (OGD) leads to depression of evoked synaptic transmission, for which the mechanisms remain unclear. We hypothesized that increased presynaptic [Ca2+]i during transient OGD contributes to the depression of evoked field excitatory postsynaptic potentials (fEPSPs). Additionally, we hypothesized that increased buffering of intracellular calcium would shorten electrophysiological recovery after transient ischemia. Mouse hippocampal slices were exposed to 2 to 8 min of OGD. fEPSPs evoked by Schaffer collateral stimulation were recorded in the stratum radiatum, and whole cell current or voltage clamp recordings were performed in CA1 neurons. Transient ischemia led to increased presynaptic [Ca2+]i, (shown by calcium imaging), increased spontaneous miniature EPSP/Cs, and depressed evoked fEPSPs, partially mediated by adenosine. Buffering of intracellular Ca2+ during OGD by membrane-permeant chelators (BAPTA-AM or EGTA-AM) partially prevented fEPSP depression and promoted faster electrophysiological recovery when the OGD challenge was stopped. The blocker of BK channels, charybdotoxin (ChTX), also prevented fEPSP depression, but did not accelerate post-ischemic recovery. These results suggest that OGD leads to elevated presynaptic [Ca2+]i, which reduces evoked transmitter release; this effect can be reversed by increased intracellular Ca2+ buffering which also speeds recovery. PMID:26934214

  17. Raised Intracellular Calcium Contributes to Ischemia-Induced Depression of Evoked Synaptic Transmission.

    PubMed

    Jalini, Shirin; Ye, Hui; Tonkikh, Alexander A; Charlton, Milton P; Carlen, Peter L

    2016-01-01

    Oxygen-glucose deprivation (OGD) leads to depression of evoked synaptic transmission, for which the mechanisms remain unclear. We hypothesized that increased presynaptic [Ca2+]i during transient OGD contributes to the depression of evoked field excitatory postsynaptic potentials (fEPSPs). Additionally, we hypothesized that increased buffering of intracellular calcium would shorten electrophysiological recovery after transient ischemia. Mouse hippocampal slices were exposed to 2 to 8 min of OGD. fEPSPs evoked by Schaffer collateral stimulation were recorded in the stratum radiatum, and whole cell current or voltage clamp recordings were performed in CA1 neurons. Transient ischemia led to increased presynaptic [Ca2+]i, (shown by calcium imaging), increased spontaneous miniature EPSP/Cs, and depressed evoked fEPSPs, partially mediated by adenosine. Buffering of intracellular Ca2+ during OGD by membrane-permeant chelators (BAPTA-AM or EGTA-AM) partially prevented fEPSP depression and promoted faster electrophysiological recovery when the OGD challenge was stopped. The blocker of BK channels, charybdotoxin (ChTX), also prevented fEPSP depression, but did not accelerate post-ischemic recovery. These results suggest that OGD leads to elevated presynaptic [Ca2+]i, which reduces evoked transmitter release; this effect can be reversed by increased intracellular Ca2+ buffering which also speeds recovery.

  18. Modulation of the expression of an apical plasma membrane protein of Madin-Darby canine kidney epithelial cells: cell-cell interactions control the appearance of a novel intracellular storage compartment

    PubMed Central

    1987-01-01

    Experimental conditions that abolish or reduce to a minimum intercellular contacts between Madin-Darby canine kidney epithelial cells result in the appearance of an intracellular storage compartment for apical membrane proteins. Subconfluent culture, incubation in 1-5 microM Ca++, or inclusion of dissociated cells within agarose or collagen gels all caused the intracellular accumulation of a 184-kD apical membrane protein within large (0.5-5 micron) vacuoles, rich in microvilli. Influenza virus hemagglutinin, an apically targeted viral glycoprotein, is concentrated within these structures but the basolateral glycoprotein G of vesicular stomatitis virus and a cellular basolateral 63-kD membrane protein of Madin-Darby canine kidney cells were excluded. This novel epithelial organelle (VAC), which we designate the vacuolar apical compartment, may play an as yet unrecognized role in the biogenesis of the apical plasma membrane during the differentiation of normal epithelia. PMID:3553208

  19. Analyzing panel acoustic contributions toward the sound field inside the passenger compartment of a full-size automobile.

    PubMed

    Wu, Sean F; Moondra, Manmohan; Beniwal, Ravi

    2015-04-01

    The Helmholtz equation least squares (HELS)-based nearfield acoustical holography (NAH) is utilized to analyze panel acoustic contributions toward the acoustic field inside the interior region of an automobile. Specifically, the acoustic power flows from individual panels are reconstructed, and relative contributions to sound pressure level and spectrum at any point of interest are calculated. Results demonstrate that by correlating the acoustic power flows from individual panels to the field acoustic pressure, one can correctly locate the panel allowing the most acoustic energy transmission into the vehicle interior. The panel on which the surface acoustic pressure amplitude is the highest should not be used as indicative of the panel responsible for the sound field in the vehicle passenger compartment. Another significant advantage of this HELS-based NAH is that measurements of the input data only need to be taken once by using a conformal array of microphones in the near field, and ranking of panel acoustic contributions to any field point can be readily performed. The transfer functions between individual panels of any vibrating structure to the acoustic pressure anywhere in space are calculated not measured, thus significantly reducing the time and effort involved in panel acoustic contributions analyses.

  20. Contributions of Unique Intracellular Domains to Switchlike Biosensing by Toll-like Receptor 4*

    PubMed Central

    Daringer, Nichole M.; Schwarz, Kelly A.; Leonard, Joshua N.

    2015-01-01

    Toll-like receptors (TLRs) mediate immune recognition of both microbial infections and tissue damage. Aberrant TLR signaling promotes disease; thus, understanding the regulation of TLR signaling is of medical relevance. Although downstream mediators of TLR signaling have been identified, the detailed mechanism by which ligand binding-mediated dimerization induces downstream signaling remains poorly understood. Here, we investigate this question for TLR4, which mediates responsiveness to bacterial LPS and drives inflammatory disease. TLR4 exhibits structural and functional features that are unique among TLRs, including responsiveness to a wide variety of ligands. However, the connection between these structural features and the regulation of signaling is not clear. Here, we investigated how the unique intracellular structures of TLR4 contribute to receptor signaling. Key conclusions include the following. 1) The unique intracellular linker of TLR4 is important for achieving LPS-inducible signaling via Toll/IL-1 receptor (TIR) domain-containing adapter-inducing interferon-β (TRIF) but less so for signaling via myeloid differentiation primary response 88 (MyD88). 2) Membrane-bound TLR4 TIR domains were sufficient to induce signaling. However, introducing long, flexible intracellular linkers neither induced constitutive signaling nor ablated LPS-inducible signaling. Thus, the initiation of TLR4 signaling is regulated by a mechanism that does not require tight geometric constraints. Together, these observations necessitate refining the model of TLR4 signal initiation. We hypothesize that TLR4 may interact with an inhibitory partner in the absence of ligand, via both TIR and extracellular domains of TLR4. In this speculative model, ligand binding induces dissociation of the inhibitory partner, triggering spontaneous, switchlike TIR domain homodimerization to initiate downstream signaling. PMID:25694428

  1. Intracellular proteoglycans.

    PubMed Central

    Kolset, Svein Olav; Prydz, Kristian; Pejler, Gunnar

    2004-01-01

    Proteoglycans (PGs) are proteins with glycosaminoglycan chains, are ubiquitously expressed and have a wide range of functions. PGs in the extracellular matrix and on the cell surface have been the subject of extensive structural and functional studies. Less attention has so far been given to PGs located in intracellular compartments, although several reports suggest that these have biological functions in storage granules, the nucleus and other intracellular organelles. The purpose of this review is, therefore, to present some of these studies and to discuss possible functions linked to PGs located in different intracellular compartments. Reference will be made to publications relevant for the topics we present. It is beyond the scope of this review to cover all publications on PGs in intracellular locations. PMID:14759226

  2. Comparative contribution of CD1 on the development of CD4+ and CD8+ T cell compartments.

    PubMed

    Wang, B; Chun, T; Wang, C R

    2000-01-15

    CD1 molecules are MHC class I-like glycoproteins whose expression is essential for the development of a unique subset of T cells, the NK T cells. To evaluate to what extent CD1 contributes to the development of CD4+ and CD8+ T cells, we generated CD1oIIo and CD1oTAPo mice and compared the generation of T cells in these double-mutant mice and IIo or TAPo mice. FACS analysis showed that the number of CD4+ T cells in CD1oIIo mice was reduced significantly compared with the corresponding population in IIo mice. Both CD4+ NK1.1+ and the CD4+ NK1.1- population were reduced in CD1oIIo mice, suggesting that CD1 can select not only CD4+ NK1.1+ T cells but also some NK1.1- CD4+ T cells. Functional analysis showed that the residual CD4+ cells in CD1oIIo can secrete large amounts of IFN-gamma and a significant amount of IL-4 during primary stimulation with anti-CD3, suggesting that this population may be enriched for NK T cells restricted by other class I molecules. In contrast to the CD4+ population, no significant differences in the CD8+ T cell compartment can be detected between TAPo and CD1oTAPo mice in all lymphoid tissues tested, including intestinal intraepithelial lymphocytes. Our data suggest that, unlike other MHC class I molecules, CD1 does not contribute in a major way to the development of CD8+ T cells.

  3. Traffic into the prevacuolar/endosomal compartment of Saccharomyces cerevisiae: a VPS45-dependent intracellular route and a VPS45-independent, endocytic route.

    PubMed

    Bryant, N J; Piper, R C; Gerrard, S R; Stevens, T H

    1998-05-01

    The vps (vacuolar protein sorting) mutants have been used to dissect and characterize the vacuolar biogenesis pathway in the yeast Saccharomyces cerevisiae. The vps mutants were isolated through their loss of ability to correctly sort the vacuolar hydrolase CPY, which travels from Golgi membranes to the vacuole through a prevacuolar compartment. Over 50 VPS genes have been divided into 6 classes according to vacuolar morphology. Mutations in any one of the class E VPS genes, such as VPS27, lead to an exaggerated form of the prevacuolar compartment. This class E compartment contains endocytosed proteins as well as proteins en route to the vacuole, and is thus taken to represent an intersection point between the endocytic and biosynthetic pathways. Mutations in the class D gene VPS45 can be used to define a second transport intermediate along the vacuolar biogenesis pathway, Golgi-derived transport vesicles carrying vacuolar membrane proteins on their way to the vacuole. Here we demonstrate that the Sec1p-like protein Vps45p is required for the fusion of Golgi-derived vesicles with the prevacuolar compartment indicating that VPS45 functions before VPS27 in the vacuolar biogenesis pathway. In addition, we show that VPS45 function is not required for the delivery of endocytosed proteins to the prevacuolar compartment from the plasma membrane suggesting that the function of Vps45p is restricted to a single vesicular pathway.

  4. Distinct intracellular Ca(2+) dynamics regulate apical constriction and differentially contribute to neural tube closure.

    PubMed

    Suzuki, Makoto; Sato, Masanao; Koyama, Hiroshi; Hara, Yusuke; Hayashi, Kentaro; Yasue, Naoko; Imamura, Hiromi; Fujimori, Toshihiko; Nagai, Takeharu; Campbell, Robert E; Ueno, Naoto

    2017-04-01

    Early in the development of the central nervous system, progenitor cells undergo a shape change, called apical constriction, that triggers the neural plate to form a tubular structure. How apical constriction in the neural plate is controlled and how it contributes to tissue morphogenesis are not fully understood. In this study, we show that intracellular calcium ions (Ca(2+)) are required for Xenopus neural tube formation and that there are two types of Ca(2+)-concentration changes, a single-cell and a multicellular wave-like fluctuation, in the developing neural plate. Quantitative imaging analyses revealed that transient increases in Ca(2+) concentration induced cortical F-actin remodeling, apical constriction and accelerations of the closing movement of the neural plate. We also show that extracellular ATP and N-cadherin (cdh2) participate in the Ca(2+)-induced apical constriction. Furthermore, our mathematical model suggests that the effect of Ca(2+) fluctuations on tissue morphogenesis is independent of fluctuation frequency and that fluctuations affecting individual cells are more efficient than those at the multicellular level. We propose that distinct Ca(2+) signaling patterns differentially modulate apical constriction for efficient epithelial folding and that this mechanism has a broad range of physiological outcomes. © 2017. Published by The Company of Biologists Ltd.

  5. Arabidopsis GPAT9 contributes to synthesis of intracellular glycerolipids but not surface lipids

    PubMed Central

    Singer, Stacy D.; Chen, Guanqun; Mietkiewska, Elzbieta; Tomasi, Pernell; Jayawardhane, Kethmi; Dyer, John M.; Weselake, Randall J.

    2016-01-01

    GLYCEROL-3-PHOSPHATE ACYLTRANSFERASE (GPAT) genes encode enzymes involved in glycerolipid biosynthesis in plants. Ten GPAT homologues have been identified in Arabidopsis. GPATs 4–8 have been shown to be involved in the production of extracellular lipid barrier polyesters. Recently, GPAT9 was reported to be essential for triacylglycerol (TAG) biosynthesis in developing Arabidopsis seeds. The enzymatic properties and possible functions of GPAT9 in surface lipid, polar lipid and TAG biosynthesis in non-seed organs, however, have not been investigated. Here we show that Arabidopsis GPAT9 exhibits sn-1 acyltransferase activity with high specificity for acyl-coenzyme A, thus providing further evidence that this GPAT is involved in storage lipid biosynthesis. We also confirm a role for GPAT9 in seed oil biosynthesis and further demonstrate that GPAT9 contributes to the biosynthesis of both polar lipids and TAG in developing leaves, as well as lipid droplet production in developing pollen grains. Conversely, alteration of constitutive GPAT9 expression had no obvious effects on surface lipid biosynthesis. Taken together, these studies expand our understanding of GPAT9 function to include modulation of several different intracellular glycerolipid pools in plant cells. PMID:27325892

  6. Phosphatidylinositol-specific phospholipase C from Listeria monocytogenes contributes to intracellular survival and growth of Listeria innocua.

    PubMed Central

    Schwan, W R; Demuth, A; Kuhn, M; Goebel, W

    1994-01-01

    Listeria monocytogenes is a facultative intracellular organism that is capable of replicating within macrophage and macrophage-like cells. The species secretes a phosphatidylinositol-specific phospholipase C (PI-PLC) encoded by the plcA gene. A plcA gene from L. monocytogenes was cloned downstream of a gram-positive promoter in the plasmid pWS2-2. To determine what effect plcA would have on intracellular survival when introduced into Listeria innocua, a species that does not growth intracellularly or contain plcA, transformation with the recombinant pWS2-2 plasmid was performed. Phospholipase C activity in Listeria innocua/pWS2-2 was confirmed on a brain heart infusion-phosphatidylinositol agar plate, whereas wild-type L. innocua did not produce PI-PLC activity. Intracellular growth of L. innocua/pWS2-2 was subsequently measured in the macrophage-like cell line J774 by Giemsa staining and viable count determinations at specific time points following infection. The J774 cells infected with wild-type L. innocua showed a falling viable count through 8 h postinfection. Although J774 cells infected with L. innocua/pWS2-2 also initially displayed reduced viable counts, the viable count rose after 6 h postinfection and increased further at 8 h postinfection before a subsequent decline again at 16 h postinfection. Giemsa staining revealed fewer than 6 bacteria in individual macrophage cells at 2 h postinfection, and yet approximately 15% of the J774 cells had 6 to 12 bacteria localized to one area of the macrophage cell after 6 h; moreover, electron micrographs showed that the L. innocua/pWS2-2 cells were replicating inside the phagosome of the host cell. Furthermore, Thoria Sol labeling demonstrated that lysosomes had fused with these phagosomes, and acridine orange staining revealed that the compartments were acidified. These results demonstrate that L. innocua cells transformed with the plasmid-borne plcA gene, and expressing functional PI-PLC, are able to grow

  7. The impact of pH inhomogeneities on CHO cell physiology and fed-batch process performance - two-compartment scale-down modelling and intracellular pH excursion.

    PubMed

    Brunner, Matthias; Braun, Philipp; Doppler, Philipp; Posch, Christoph; Behrens, Dirk; Herwig, Christoph; Fricke, Jens

    2017-01-12

    Due to high mixing times and base addition from top of the vessel, pH inhomogeneities are most likely to occur during large-scale mammalian processes. The goal of this study was to set-up a scale-down model of a 10-12 m(3) stirred tank bioreactor and to investigate the effect of pH perturbations on CHO cell physiology and process performance. Short-term changes in extracellular pH are hypothesized to affect intracellular pH and thus cell physiology. Therefore, batch fermentations, including pH shifts to 9.0 and 7.8, in regular one-compartment systems are conducted. The short-term adaption of the cells intracellular pH are showed an immediate increase due to elevated extracellular pH. With this basis of fundamental knowledge, a two-compartment system is established which is capable of simulating defined pH inhomogeneities. In contrast to state-of-the-art literature, the scale-down model is included parameters (e.g. volume of the inhomogeneous zone) as they might occur during large-scale processes. pH inhomogeneity studies in the two-compartment system are performed with simulation of temporary pH zones of pH 9.0. The specific growth rate especially during the exponential growth phase is strongly affected resulting in a decreased maximum viable cell density and final product titer. The gathered results indicate that even short-term exposure of cells to elevated pH values during large-scale processes can affect cell physiology and overall process performance. In particular, it could be shown for the first time that pH perturbations, which might occur during the early process phase, have to be considered in scale-down models of mammalian processes.

  8. Mechanical Contributions of the Cortical and Trabecular Compartments Contribute to Differences in Age-Related Changes in Vertebral Body Strength in Men and Women Assessed by QCT-Based Finite Element Analysis

    PubMed Central

    Christiansen, Blaine A; Kopperdahl, David L; Kiel, Douglas P; Keaveny, Tony M; Bouxsein, Mary L

    2011-01-01

    The biomechanical mechanisms underlying sex-specific differences in age-related vertebral fracture rates are ill defined. To gain insight into this issue, we used finite element analysis of clinical computed tomography (CT) scans of the vertebral bodies of L3 and T10 of young and old men and women to assess age- and sex-related differences in the strength of the whole vertebra, the trabecular compartment, and the peripheral compartment (the outer 2 mm of vertebral bone, including the thin cortical shell). We sought to determine whether structural and geometric changes with age differ in men and women, making women more susceptible to vertebral fractures. As expected, we found that vertebral strength decreased with age 2-fold more in women than in men. The strength of the trabecular compartment declined significantly with age for both sexes, whereas the strength of the peripheral compartment decreased with age in women but was largely maintained in men. The proportion of mechanical strength attributable to the peripheral compartment increased with age in both sexes and at both vertebral levels. Taken together, these results indicate that men and women lose vertebral bone differently with age, particularly in the peripheral (cortical) compartment. This differential bone loss explains, in part, a greater decline in bone strength in women and may contribute to the higher incidence of vertebral fractures among women than men. © 2011 American Society for Bone and Mineral Research. PMID:21542000

  9. Contribution of elevated intracellular calcium to pulmonary arterial myocyte alkalinization during chronic hypoxia

    PubMed Central

    Luke, Trevor; Shimoda, Larissa A.

    2016-01-01

    Abstract In the lung, exposure to chronic hypoxia (CH) causes pulmonary hypertension, a debilitating disease. Development of this condition arises from increased muscularity and contraction of pulmonary vessels, associated with increases in pulmonary arterial smooth muscle cell (PASMC) intracellular pH (pHi) and Ca2+ concentration ([Ca2+]i). In this study, we explored the interaction between pHi and [Ca2+]i in PASMCs from rats exposed to normoxia or CH (3 weeks, 10% O2). PASMC pHi and [Ca2+]i were measured with fluorescent microscopy and the dyes BCECF and Fura-2. Both pHi and [Ca2+]i levels were elevated in PASMCs from hypoxic rats. Exposure to KCl increased [Ca2+]i and pHi to a similar extent in normoxic and hypoxic PASMCs. Conversely, removal of extracellular Ca2+ or blockade of Ca2+ entry with NiCl2 or SKF 96365 decreased [Ca2+]i and pHi only in hypoxic cells. Neither increasing pHi with NH4Cl nor decreasing pHi by removal of bicarbonate impacted PASMC [Ca2+]i. We also examined the roles of Na+/Ca2+ exchange (NCX) and Na+/H+ exchange (NHE) in mediating the elevated basal [Ca2+]i and Ca2+-dependent changes in PASMC pHi. Bepridil, dichlorobenzamil, and KB-R7943, which are NCX inhibitors, decreased resting [Ca2+]i and pHi only in hypoxic PASMCs and blocked the changes in pHi induced by altering [Ca2+]i. Exposure to ethyl isopropyl amiloride, an NHE inhibitor, decreased resting pHi and prevented changes in pHi due to changing [Ca2+]i. Our findings indicate that, during CH, the elevation in basal [Ca2+]i may contribute to the alkaline shift in pHi in PASMCs, likely via mechanisms involving reverse-mode NCX and NHE. PMID:27076907

  10. Intracellular pH (pHin) and cytosolic calcium ([Ca2+]cyt) regulation via ATPases: studies in cell populations, single cells, and subcellular compartments

    NASA Astrophysics Data System (ADS)

    Rojas, Jose D.; Sanka, Shankar C.; Gyorke, Sandor; Wesson, Donald E.; Minta, Akwasi; Martinez-Zaguilan, Raul

    1999-07-01

    Changes in pHin and (Ca2+)cyt are important in the signal transduction mechanisms leading to many physiological responses including cell growth, motility, secretion/exocytosis, etc. The concentrations of these ions are regulated via primary and secondary ion transporting mechanisms. In diabetes, specific pH and Ca2+ regulatory mechanism might be altered. To study these ions, we employ fluorescence spectroscopy, and cell imagin spectroscopy/confocal microscopy. pH and Ca2+ indicators are loaded in the cytosol with acetoxymethyl ester forms of dyes, and in endosomal/lysosomal (E/L) compartments by overnight incubation of cells with dextran- conjugated ion fluorescent probes. We focus on specific pH and Ca2+ regulatory systems: plasmalemmal vacuolar- type H+-ATPases (pm V-ATPases) and sarcoplasmic/endoplasmic reticulum Ca2+-ATPases (SERCA). As experimental models, we employ vascular smooth muscle (VSM) and microvascular endothelial cells. We have chosen these cells because they are important in blood flow regulation and in angiogenesis. These processes are altered in diabetes. In many cell types, ion transport processes are dependent on metabolism of glucose for maximal activity. Our main findings are: (a) glycolysis coupling the activity of SERCA is required for cytosolic Ca2+ homeostasis in both VSM and microvascular endothelial cells; (b) E/L compartments are important for pH and Ca2+ regulation via H+-ATPases and SERCA, respectively; and (c) pm-V- ATPases are important for pHin regulation in microvascular endothelial cells.

  11. Compartment syndromes

    NASA Technical Reports Server (NTRS)

    Mubarak, S. J.; Pedowitz, R. A.; Hargens, A. R.

    1989-01-01

    The compartment syndrome is defined as a condition in which high pressure within a closed fascial space (muscle compartment) reduces capillary blood perfusion below the level necessary for tissue viability'. This condition occurs in acute and chronic (exertional) forms, and may be secondary to a variety of causes. The end-result of an extended period of elevated intramuscular pressure may be the development of irreversible tissue injury and Volkmann's contracture. The goal of treatment of the compartment syndrome is the reduction of intracompartmental pressure thus facilitating reperfusion of ischaemic tissue and this goal may be achieved by decompressive fasciotomy. Controversy exists regarding the critical pressure-time thresholds for surgical decompression and the optimal diagnostic methods of measuring intracompartmental pressures. This paper will update and review some current knowledge regarding the pathophysiology, aetiology, diagnosis, and treatment of the acute compartment syndrome.

  12. Compartment syndromes

    NASA Technical Reports Server (NTRS)

    Mubarak, S. J.; Pedowitz, R. A.; Hargens, A. R.

    1989-01-01

    The compartment syndrome is defined as a condition in which high pressure within a closed fascial space (muscle compartment) reduces capillary blood perfusion below the level necessary for tissue viability'. This condition occurs in acute and chronic (exertional) forms, and may be secondary to a variety of causes. The end-result of an extended period of elevated intramuscular pressure may be the development of irreversible tissue injury and Volkmann's contracture. The goal of treatment of the compartment syndrome is the reduction of intracompartmental pressure thus facilitating reperfusion of ischaemic tissue and this goal may be achieved by decompressive fasciotomy. Controversy exists regarding the critical pressure-time thresholds for surgical decompression and the optimal diagnostic methods of measuring intracompartmental pressures. This paper will update and review some current knowledge regarding the pathophysiology, aetiology, diagnosis, and treatment of the acute compartment syndrome.

  13. Peptide and RNA contributions to iron-sulphur chemical gardens as life's first inorganic compartments, catalysts, capacitors and condensers.

    PubMed

    McGlynn, Shawn E; Kanik, Isik; Russell, Michael J

    2012-06-28

    Hydrothermal chimneys and compartments comprising transition metal sulphides and associated minerals have been proposed as likely locations for the beginnings of life. In laboratory simulations of off-axis alkaline springs, it is shown that the interaction of a simulated alkaline sulphide-bearing submarine vent solution with a primeval anoxic iron-bearing ocean leads to the formation of chimney structures reminiscent of chemical gardens. These chimneys display periodicity in their deposition and exhibit diverse morphologies and mineralogies, affording the possibilities of catalysis and molecular sequestration. The addition of peptides and RNA to the alkaline solution modifies the elemental stoichiometry of the chimneys-perhaps indicating the very initial stage of the organic takeover on the way to living cells by charged organic polymers potentially synthesized in this same environment.

  14. Water compartments in cells.

    PubMed

    Fullerton, Gary D; Cameron, Ivan L

    2007-01-01

    Human experience in the macrobiological world leads scientists to visualize water compartments in cells analogous to the bladder in the human pelvis or ventricles in the brain. While such water-filled cellular compartments likely exist, the volume contributions are insignificant relative to those of biomolecular hydration compartments. The purpose of this chapter is to identify and categorize the molecular water compartments caused by proteins, the primary macromolecular components of cells. The categorical changes in free energy of water molecules on proteins cause these compartments to play dominant roles in osmoregulation and provide important adjuncts to fundamental understanding of osmosensing and osmosignaling mechanisms. Water compartments possess differences in molecular motion, enthalpy, entropy, freezing point depression, and other properties because of electrostatic interaction of polar water molecules with electric fields generated by covalently bound pairs of opposite charge caused by electronegative oxygen and nitrogen atoms of the protein. Macromolecules, including polypeptides, polynucleotides, and polysaccharides, are stiff molecular chains with restricted folding capacities due to inclusion of rigid ring structures or double amide bonds in the backbone sequence. This creates "irreducible spatial charge separation" between positive and negative partial charges, causing elevated electrostatic energy. In the fully hydrated in vivo state of living cells the high dielectric coefficient of water reduces protein electrostatic free energy by providing polar "water bridge networks" between charges, thereby creating four measurably different compartments of bound water with distinct free energy differences.

  15. An SREBP Responsive micro-RNA Operon Contributes to a Regulatory Loop for Intracellular Lipid Homeostasis

    PubMed Central

    Jeon, Tae-Il; Esquejo, Ryan M.; Roqueta-Rivera, Manuel; Phelan, Peter E.; Moon, Young-Ah; Govindarajan, Subramaniam S.; Esau, Christine C.; Osborne, Timothy F.

    2013-01-01

    Sterol regulatory element binding proteins (SREBPs) have evolved as a focal point for linking lipid synthesis with other pathways that regulate cell growth and survival. Here, we have uncovered a polycistrionic micro-RNA locus that is activated directly by SREBP-2. Two of the encoded miRs, miR-182 and miR-96, negatively regulate expression of Fbxw7 and Insig-2 respectively, and both are known to negatively affect nuclear SREBP accumulation. Direct manipulation of this miR pathway alters nuclear SREBP levels and endogenous lipid synthesis. Thus, we have uncovered a new mechanism for regulation of intracellular lipid metabolism mediated by the concerted action of a pair of miRs that are expressed from the same SREBP-2 regulated miR locus and each targets a different protein of the multi-step pathway that regulates SREBP function. These studies reveal a miR “operon” analogous to the classic model for genetic control in bacterial regulatory systems. PMID:23823476

  16. TRPV1: Contribution to Retinal Ganglion Cell Apoptosis and Increased Intracellular Ca2+ with Exposure to Hydrostatic Pressure

    PubMed Central

    Sappington, Rebecca M.; Sidorova, Tatiana; Long, Daniel J.; Calkins, David J.

    2013-01-01

    Purpose Elevated hydrostatic pressure induces retinal ganglion cell (RGC) apoptosis in culture. The authors investigated whether the transient receptor potential vanilloid 1 (TRPV1) channel, which contributes to pressure sensing and Ca2+-dependent cell death in other systems, also contributes to pressure-induced RGC death and whether this contribution involves Ca2+. Methods trpv1 mRNA expression in RGCs was probed with the use of PCR and TRPV1 protein localization through immunocytochemistry. Subunit-specific antagonism (iodo-resiniferatoxin) and agonism (capsaicin) were used to probe how TRPV1 activation affects the survival of isolated RGCs at ambient and elevated hydrostatic pressure (+70 mm Hg). Finally, for RGCs under pressure, the authors tested whether EGTA chelation of Ca2+ improves survival and whether, with the Ca2+ dye Fluo-4 AM, TRPV1 contributes to increased intracellular Ca2+. Results RGCs express trpv1 mRNA, with robust TRPV1 protein localization to the cell body and axon. For isolated RGCs under pressure, TRPV1 antagonism increased cell density and reduced apoptosis to ambient levels (P ≤ 0.05), whereas for RGCs at ambient pressure, TRPV1 agonism reduced density and increased apoptosis to levels for elevated pressure (P ≤ 0.01). Chelation of extracellular Ca2+ reduced RGC apoptosis at elevated pressure by nearly twofold (P ≤ 0.01). Exposure to elevated hydrostatic pressure induced a fourfold increase in RGC intracellular Ca2+ that was reduced by half with TRPV1 antagonism. Finally, in the DBA/2 mouse model of glaucoma, levels of TRPV1 in RGCs increased with elevated IOP. Conclusions RGC apoptosis induced by elevated hydrostatic pressure arises substantially through TRPV1, likely through the influx of extracellular Ca2+. PMID:18952924

  17. Modulation of Intracellular Restriction Factors Contributes to Methamphetamine-Mediated Enhancement of Acquired Immune Deficiency Syndrome Virus Infection of Macrophages

    PubMed Central

    Wang, Xu; Wang, Yizhong; Ye, Li; Li, Jieliang; Zhou, Yu; Sakarcan, Sinem; Ho, Wenzhe

    2014-01-01

    Epidemiological studies have demonstrated that the use of methamphetamine (METH), a sympathomimetic stimulant, is particularly common among patients infected with HIV. In vitro studies have determined that METH enhances HIV infection of CD4+ T cells, monocyte-derived dendritic cells, and macrophages. In addition, animal studies have also showed that METH treatment increases brain viral load of SIV-infected monkeys and promotes HIV replication and viremia in HIV/hu-CycT1 transgenic mice. However, the mechanisms (s) of METH actions on HIV remain to be determined. In this study, we investigated the impact of METH on intracellular restriction factors against HIV and SIV. We demonstrated that METH treatment of human blood mononuclear phagocytes significantly affected the expression of anti-HIV microRNAs and several key elements (RIG-I, IRF-3/5, SOCS-2, 3 and PIAS-1, 3, X, Y) in the type I IFN pathway. The suppression of these innate restriction factors was associated with a reduced production of type I IFNs and the enhancement of HIV or SIV infection of macrophages. These findings indicate that METH use impairs intracellular innate antiviral mechanism(s) in macrophages, contributing to cell susceptibility to the acquired immune deficiency syndrome (AIDS) virus infection. PMID:22591364

  18. Contribution of the late sodium current to intracellular sodium and calcium overload in rabbit ventricular myocytes treated by anemone toxin.

    PubMed

    Kornyeyev, Dmytro; El-Bizri, Nesrine; Hirakawa, Ryoko; Nguyen, Steven; Viatchenko-Karpinski, Serge; Yao, Lina; Rajamani, Sridharan; Belardinelli, Luiz

    2016-02-01

    Pathological enhancement of late Na(+) current (INa) can potentially modify intracellular ion homeostasis and contribute to cardiac dysfunction. We tested the hypothesis that modulation of late INa can be a source of intracellular Na(+) ([Na(+)]i) overload. Late INa was enhanced by exposing rabbit ventricular myocytes to Anemonia sulcata toxin II (ATX-II) and measured using whole cell patch-clamp technique. [Na(+)]i was determined with fluorescent dye Asante NaTRIUM Green-2 AM. Pacing-induced changes in the dye fluorescence measured at 37°C were more pronounced in ATX-II-treated cells than in control (dye washout prevented calibration). At 22-24°C, resting [Na(+)]i was 6.6 ± 0.8 mM. Treatment with 5 nM ATX-II increased late INa 8.7-fold. [Na(+)]i measured after 2 min of electrical stimulation (1 Hz) was 10.8 ± 1.5 mM and 22.1 ± 1.6 mM (P < 0.001) in the absence and presence of 5 nM ATX-II, respectively. Inhibition of late INa with GS-967 (1 μM) prevented Na(+) i accumulation. A strong positive correlation was observed between the late INa and the pacing-induced increase of [Na(+)]i (R(2) = 0.88) and between the rise in [Na(+)]i and the increases in cytosolic Ca(2+) (R(2) = 0.96). ATX-II, tetrodotoxin, or GS-967 did not affect [Na(+)]i in quiescent myocytes suggesting that late INa was solely responsible for triggering the ATX-II effect on [Na(+)]i. Experiments with pinacidil and E4031 indicate that prolongation of the action potential contributes to as much as 50% of the [Na(+)]i overload associated with the increase in late INa caused by ATX-II. Enhancement of late INa can cause intracellular Na(+) overload in ventricular myocytes. Copyright © 2016 the American Physiological Society.

  19. Intracellular calcium release through IP3R or RyR contributes to secondary axonal degeneration.

    PubMed

    Orem, Ben C; Pelisch, Nicolas; Williams, Joshua; Nally, Jacqueline M; Stirling, David P

    2017-10-01

    Severed CNS axons often retract or dieback away from the injury site and fail to regenerate. The precise mechanisms underlying acute axonal dieback and secondary axonal degeneration remain poorly understood. Here we investigate the role of Ca(2+) store mediated intra-axonal Ca(2+) release in acute axonal dieback and secondary axonal degeneration. To differentiate between primary (directly transected) and "bystander" axonal injury (axons spared by the initial injury but then succumb to secondary degeneration) in real-time we use our previously published highly focal laser-induced spinal cord injury (LiSCI) ex vivo model. Ascending spinal cord dorsal column axons that express YFP were severed using an 800 nm laser pulse while being imaged continuously using two-photon excitation microscopy. We inhibited two major intra-axonal Ca(2+) store channels, ryanodine receptors (RyR) and IP3R, with ryanodine or 2-APB, respectively, to individually determine their role in axonal dieback and secondary axonal degeneration. Each antagonist was dissolved in artificial CSF and applied 1h post-injury alone or in combination, and continuously perfused for the remainder of the imaging session. Initially following LiSCI, transected axons retracted equal distances both distal and proximal to the lesion. However, by 4h after injury, the distal axonal segments that are destined for Wallerian degeneration had significantly retracted further than their proximal counterparts. We also found that targeting either RyR or IP3R using pharmacological and genetic approaches significantly reduced proximal axonal dieback and "bystander" secondary degeneration of axons compared to vehicle controls at 6h post-injury. Combined treatment effects on secondary axonal degeneration were similar to either drug in isolation. Together, these results suggest that intra-axonal Ca(2+) store mediated Ca(2+) release through RyR or IP3R contributes to secondary axonal degeneration following SCI. Copyright © 2017

  20. Contribution of Host Intracellular Transport Machineries to Intercellular Movement of Turnip Mosaic Virus

    PubMed Central

    Nelson, Richard S.; Zheng, Huanquan; Laliberté, Jean-François

    2013-01-01

    The contribution of different host cell transport systems in the intercellular movement of turnip mosaic virus (TuMV) was investigated. To discriminate between primary infections and secondary infections associated with the virus intercellular movement, a gene cassette expressing GFP-HDEL was inserted adjacent to a TuMV infectious cassette expressing 6K2:mCherry, both within the T-DNA borders of the binary vector pCambia. In this system, both gene cassettes were delivered to the same cell by a single binary vector and primary infection foci emitted green and red fluorescence while secondarily infected cells emitted only red fluorescence. Intercellular movement was measured at 72 hours post infiltration and was estimated to proceed at an average rate of one cell being infected every three hours over an observation period of 17 hours. To determine if the secretory pathway were important for TuMV intercellular movement, chemical and protein inhibitors that blocked both early and late secretory pathways were used. Treatment with Brefeldin A or Concanamycin A or expression of ARF1 or RAB-E1d dominant negative mutants, all of which inhibit pre- or post-Golgi transport, reduced intercellular movement by the virus. These treatments, however, did not inhibit virus replication in primary infected cells. Pharmacological interference assays using Tyrphostin A23 or Wortmannin showed that endocytosis was not important for TuMV intercellular movement. Lack of co-localization by endocytosed FM4-64 and Ara7 (AtRabF2b) with TuMV-induced 6K2-tagged vesicles further supported this conclusion. Microfilament depolymerizing drugs and silencing expression of myosin XI-2 gene, but not myosin VIII genes, also inhibited TuMV intercellular movement. Expression of dominant negative myosin mutants confirmed the role played by myosin XI-2 as well as by myosin XI-K in TuMV intercellular movement. Using this dual gene cassette expression system and transport inhibitors, components of the secretory

  1. Contribution of forensic autopsy to scene reconstruction in mass fire casualties: a case of alleged arson on a floor consisting of small compartments in a building.

    PubMed

    Michiue, Tomomi; Ishikawa, Takaki; Oritani, Shigeki; Maeda, Hitoshi

    2015-01-01

    A fire is an important cause of mass disasters, involving various forensic issues. Before dawn on an early morning, 16 male visitors in their twenties to sixties were killed in a possibly incendiary fire at a 'private video parlor' consisting of small compartments in a building. The main causes of death as determined by forensic autopsy were acute carbon monoxide (CO) intoxication for all of the 15 found-dead victims, and hypoxic-ischemic encephalopathy following acute CO intoxication for a victim who died in hospital. Burns were mild (<20% of body surface) in most victims, except for three victims found between the entrance and the estimated fire-outbreak site; thus, identification was completed without difficulty, supported by DNA analysis. Blood carboxyhemoglobin saturation (COHb) was higher for victims found dead in the inner area. Blood cyanide levels were sublethal, moderately correlated to COHb, but were higher in victims found around the estimated fire-outbreak site. There was no evidence of thinner, alcohol or drug abuse, or an attack of disease as a possible cause of an accidental fire outbreak. These observations contribute to evidence-based reconstruction of the fire disaster, and suggest how deaths could have been prevented by appropriate disaster measures. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. An intracellular modulation of free radical production could contribute to the beneficial effects of metformin towards oxidative stress.

    PubMed

    Bonnefont-Rousselot, D; Raji, B; Walrand, S; Gardès-Albert, M; Jore, D; Legrand, A; Peynet, J; Vasson, M P

    2003-05-01

    Metformin (dimethylbiguanide) is an antihyperglycemic agent used in type 2 diabetes. Beyond its action on glycemic control, metformin exhibits other intrinsic effects that could play a role in prevention against diabetes complications. Some studies thus reported an improvement in the antioxidant status in patients treated with metformin. This might be in part related to its property to limit formation of advanced glycation end products (AGEs) and to decrease the overproduction of free radicals in diabetic subjects. The aim of this study was to investigate the in vitro ability of metformin to modulate the action of reactive oxygen species (ROS) generated either by water gamma radiolysis or by stimulated human leukocytes. Our results showed that metformin at pharmacologically relevant concentrations was in vitro able to scavenge hydroxyl ((.)OH) but not superoxide (O(.-)(2)) free radicals and that hydrogen peroxide did not react with metformin. Nevertheless, when polymorphonuclear cells (PMN) are stimulated by phorbol myristate acetate (PMA), or above all by formyl methionine leucyl phenylalanine (fMLP), a systematic (although nonsignificant) decrease of the ROS-induced chimiluminescence (CL) was observed. These results suggest that metformin could directly scavenge ROS or indirectly act by modulating the intracellular production of superoxide anion, of which NADPH oxidase constitutes the major source. This could contribute to the additional benefits of metformin, especially those related to the improvement in the cardiovascular outcomes in diabetes. Copyright 2003 Elsevier Inc. All rights reserved.

  3. Inducible astrocytic glucose transporter-3 contributes to the enhanced storage of intracellular glycogen during reperfusion after ischemia.

    PubMed

    Iwabuchi, Sadahiro; Kawahara, Koichi

    2011-08-01

    Glucose is a necessary source of energy to sustain cell activities and homeostasis in the brain, and enhanced glucose transporter (GLUT) activities are protective of cells during energy depletion including brain ischemia. Here we investigated whether and if so how the astrocytic expression of GLUTs crucial for the uptake of glucose changes in ischemic conditions. Under physiological conditions, cultured astrocytes primarily expressed GLUT1, and GLUT3 was only detected at extremely low levels. However, exposure to ischemic stress increased the expression of not only GLUT1 but also GLUT3. During ischemia, cultured astrocytes significantly increased production of the transcription factor nuclear factor-κB (NF-κB), leading to an increase in GLUT3 expression. Moreover, astrocytic GLUT3 was responsible for the enhanced storage of intracellular glucose during reperfusion, resulting in increased resistance to lethal ischemic stress. These results suggested that astrocytes promptly increase GLUT3 production in situations such as ischemia, and much glucose is quickly taken up, possibly contributing to the protection of astrocytes from ischemic damage.

  4. Intra-endosomal trafficking mediated by lysobisphosphatidic acid contributes to intracellular release of phosphorothioate-modified antisense oligonucleotides

    PubMed Central

    Sun, Hong; Tanowitz, Michael; Liang, Xue-hai; Crooke, Stanley T.

    2017-01-01

    Abstract Antisense oligonucleotides (ASOs) with phosphorothioate (PS) linkages are broadly used as research tools and therapeutic agents. Chemically modified PS-ASOs can mediate efficient target reduction by site-specific cleavage of RNA through RNase H1. PS-ASOs are known to be internalized via a number of endocytotic pathways and are released from membrane-enclosed endocytotic organelles, mainly late endosomes (LEs). This study was focused on the details of PS-ASO trafficking through endocytic pathways. It was found that lysobisphosphatidic acid (LBPA) is required for release of PS-ASOs from LEs. PS-ASOs exited early endosomes (EEs) rapidly after internalization and became co-localized with LBPA by 2 hours in LEs. Inside LEs, PS-ASOs and LBPA were co-localized in punctate, dot-like structures, likely intraluminal vesicles (ILVs). Deactivation of LBPA using anti-LBPA antibody significantly decreased PS-ASO activities without affecting total PS-ASO uptake. Reduction of Alix also substantially decreased PS-ASO activities without affecting total PS-ASO uptake. Furthermore, Alix reduction decreased LBPA levels and limited co-localization of LBPA with PS-ASOs at ILVs inside LEs. Thus, the fusion properties of ILVs, which are supported by LBPA, contribute to PS-ASO intracellular release from LEs. PMID:28379543

  5. Intra-endosomal trafficking mediated by lysobisphosphatidic acid contributes to intracellular release of phosphorothioate-modified antisense oligonucleotides.

    PubMed

    Wang, Shiyu; Sun, Hong; Tanowitz, Michael; Liang, Xue-Hai; Crooke, Stanley T

    2017-05-19

    Antisense oligonucleotides (ASOs) with phosphorothioate (PS) linkages are broadly used as research tools and therapeutic agents. Chemically modified PS-ASOs can mediate efficient target reduction by site-specific cleavage of RNA through RNase H1. PS-ASOs are known to be internalized via a number of endocytotic pathways and are released from membrane-enclosed endocytotic organelles, mainly late endosomes (LEs). This study was focused on the details of PS-ASO trafficking through endocytic pathways. It was found that lysobisphosphatidic acid (LBPA) is required for release of PS-ASOs from LEs. PS-ASOs exited early endosomes (EEs) rapidly after internalization and became co-localized with LBPA by 2 hours in LEs. Inside LEs, PS-ASOs and LBPA were co-localized in punctate, dot-like structures, likely intraluminal vesicles (ILVs). Deactivation of LBPA using anti-LBPA antibody significantly decreased PS-ASO activities without affecting total PS-ASO uptake. Reduction of Alix also substantially decreased PS-ASO activities without affecting total PS-ASO uptake. Furthermore, Alix reduction decreased LBPA levels and limited co-localization of LBPA with PS-ASOs at ILVs inside LEs. Thus, the fusion properties of ILVs, which are supported by LBPA, contribute to PS-ASO intracellular release from LEs. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major

    PubMed Central

    Ricci-Azevedo, Rafael; Oliveira, Aline Ferreira; Conrado, Marina C. A. V.; Carvalho, Fernanda Caroline; Roque-Barreira, Maria Cristina

    2016-01-01

    ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1) immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS), form neutrophil extracellular traps (NETs) and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF) and interleukin-1beta (IL-1β) release; otherwise, transforming growth factor-beta (TGF-β) production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be considered an

  7. Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major.

    PubMed

    Ricci-Azevedo, Rafael; Oliveira, Aline Ferreira; Conrado, Marina C A V; Carvalho, Fernanda Caroline; Roque-Barreira, Maria Cristina

    2016-04-01

    ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1) immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS), form neutrophil extracellular traps (NETs) and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF) and interleukin-1beta (IL-1β) release; otherwise, transforming growth factor-beta (TGF-β) production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be considered an

  8. MDMA causes a redistribution of serotonin transporter from the cell surface to the intracellular compartment by a mechanism independent of phospho-p38-mitogen activated protein kinase activation.

    PubMed

    Kivell, B; Day, D; Bosch, P; Schenk, S; Miller, J

    2010-06-16

    3,4-methylenedioxymethamphetamine (MDMA) causes long-term serotonin depletion and reduced serotonin transporter (SERT) function in humans and in animal models. Using quantitative Western blotting and real-time PCR, we have shown that total SERT protein in the striatum and nucleus accumbens and mRNA levels in the dorsal raphe nucleus were not significantly changed following MDMA exposure in rats (4 x 2 h i.p. injections, 10 mg/kg each). In mouse neuroblastoma (N(2)A) cells transiently expressing green fluorescent protein-tagged human SERT (GFP-hSERT), we have shown redistribution of SERT from the cell surface to intracellular vesicles on exposure to MDMA using cell surface biotinylation, total internal reflection fluorescence microscopy (TIRFM) and live-cell confocal microscopy. To investigate the mechanism responsible for SERT redistribution, we used specific antibodies to phospho-p38-mitogen activated protein kinase (p38 MAPK), a known signalling pathway involved in SERT membrane expression. We found that p38 MAPK activation was not involved in the MDMA-induced redistribution of SERT from the cell-surface to the cell interior. A loss of SERT from the cell surface on acute exposure to MDMA may contribute to the decreased SERT function seen in rats exposed to MDMA.

  9. Glycosyl chains and 25-hydroxycholesterol contribute to the intracellular transport of amyloid beta (Aβ-42) in Jurkat T cells.

    PubMed

    Sharma, Neha; Baek, KeangOK; Phan, Huong T T; Shimokawa, Naofumi; Takagi, Masahiro

    2017-06-01

    Amyloid beta (Aβ) is a peptide responsible for the development of Alzheimer's disease (AD). Misfolding and accumulation of endogenous Aβ can lead to neural cell apoptosis through endoplasmic reticulum (ER) stress. Added exogenous Aβ can also result in ER stress, leading to neurotoxicity and apoptosis, which is identical to that caused by the endogenous peptide. We have speculated that the endocytic transport of Aβ causes ER stress and have previously shown that the oxysterol, in particular, 7-ketocholesterol (7-keto) induces more surface interaction between Aβ-42 and Jurkat cells than cholesterol. However, the interaction was not enough to induce intracellular transfer of the peptide. In this study, we investigated the effect of another oxysterol, 25-hydroxycholesterol (25-OH) on the membrane raft-dependent transport of Aβ-42 in Jurkat cells. Interestingly, intracellular transfer of Aβ-42 was observed in the presence of 25-OH only after the inclusion of cholera toxin B subunit (CT-B), a marker used to detect the raft domain. We speculated that 25-OH can induce intracellular movement of Aβ peptides. Furthermore, CT-B together with GM1 provided negative curvature, which resulted in the intracellular transport of Aβ-42. Notably, we used a protofibrillar species of Aβ-42 in this study. We have shown that the transport was microtubule-dependent since it could not be observed in depolymerized microtubules. These results demonstrate that oxysterols and glycosyl chains are important factors affecting intracellular transport. These compounds are also associated with aging and advanced glycation are risk factors for AD. Thus, this study should further understanding of the pathology of AD.

  10. Evolution of intracellular compartmentalization.

    PubMed

    Diekmann, Yoan; Pereira-Leal, José B

    2013-01-15

    Cells compartmentalize their biochemical functions in a variety of ways, notably by creating physical barriers that separate a compartment via membranes or proteins. Eukaryotes have a wide diversity of membrane-based compartments, many that are lineage- or tissue-specific. In recent years, it has become increasingly evident that membrane-based compartmentalization of the cytosolic space is observed in multiple prokaryotic lineages, giving rise to several types of distinct prokaryotic organelles. Endosymbionts, previously believed to be a hallmark of eukaryotes, have been described in several bacteria. Protein-based compartments, frequent in bacteria, are also found in eukaryotes. In the present review, we focus on selected intracellular compartments from each of these three categories, membrane-based, endosymbiotic and protein-based, in both prokaryotes and eukaryotes. We review their diversity and the current theories and controversies regarding the evolutionary origins. Furthermore, we discuss the evolutionary processes acting on the genetic basis of intracellular compartments and how those differ across the domains of life. We conclude that the distinction between eukaryotes and prokaryotes no longer lies in the existence of a compartmentalized cell plan, but rather in its complexity.

  11. Fractal-like kinetics of intracellular enzymatic reactions: a chemical framework of endotoxin tolerance and a possible non-specific contribution of macromolecular crowding to cross-tolerance.

    PubMed

    Vasilescu, Catalin; Olteanu, Mircea; Flondor, Paul; Calin, George A

    2013-09-14

    The response to endotoxin (LPS), and subsequent signal transduction lead to the production of cytokines such as tumor necrosis factor-α (TNF-α) by innate immune cells. Cells or organisms pretreated with endotoxin enter into a transient state of hyporesponsiveness, referred to as endotoxin tolerance (ET) which represents a particular case of negative preconditioning. Despite recent progress in understanding the molecular basis of ET, there is no consensus yet on the primary mechanism responsible for ET and for the more complex cases of cross tolerance. In this study, we examined the consequences of the macromolecular crowding (MMC) and of fractal-like kinetics (FLK) of intracellular enzymatic reactions on the LPS signaling machinery. We hypothesized that this particular type of enzyme kinetics may explain the development of ET phenomenon. Our aim in the present study was to characterize the chemical kinetics framework in ET and determine whether fractal-like kinetics explains, at least in part, ET. We developed an ordinary differential equations (ODE) mathematical model that took into account the links between the MMC and the LPS signaling machinery leading to ET. We proposed that the intracellular fractal environment (MMC) contributes to ET and developed two mathematical models of enzyme kinetics: one based on Kopelman's fractal-like kinetics framework and the other based on Savageau's power law model. Kopelman's model provides a good image of the potential influence of a fractal intracellular environment (MMC) on ET. The Savageau power law model also partially explains ET. The computer simulations supported the hypothesis that MMC and FLK may play a role in ET. The model highlights the links between the organization of the intracellular environment, MMC and the LPS signaling machinery leading to ET. Our FLK-based model does not minimize the role of the numerous negative regulatory factors. It simply draws attention to the fact that macromolecular crowding can

  12. Intracellular ROS

    PubMed Central

    Leshem, Yehoram

    2007-01-01

    Intracellular localization of stress induced reactive oxygen species (ROS) has emerged as an important aspect towards understanding of cellular responses to environmental stimuli. Our recent study published in the PNAS (103:18008–13)1 shows that NaCl-induced ROS appear within endosomes on the way to tonoplast as part of the vacuolar vesicle trafficking. In addition to showing ROS damage to the tonoplast, this finding may shed light upon recently reported aspects of root water relations during salt stress, suggesting a new signaling role for intracellular ROS in Arabidopsis root cells, during salt stress: ROS that are compartmentalized in endosomes are delivered by the vacuolar vesicle trafficking pathway to the tonoplast, resulting in oxidative gating of TIPs water channels. The closure of the tonoplast aquaporins contributes to the observed reduction in root hydraulic conductivity during salt stress. PMID:19704741

  13. β adrenergic receptor/cAMP/PKA signaling contributes to the intracellular Ca(2+) release by tentacle extract from the jellyfish Cyanea capillata.

    PubMed

    Wang, Qianqian; Zhang, Hui; Wang, Bo; Wang, Chao; Xiao, Liang; Zhang, Liming

    2017-07-25

    Intracellular Ca(2+) overload induced by extracellular Ca(2+) entry has previously been confirmed to be an important mechanism for the cardiotoxicity as well as the acute heart dysfunction induced by jellyfish venom, while the underlying mechanism remains to be elucidated. Under extracellular Ca(2+)-free or Ca(2+)-containing conditions, the Ca(2+) fluorescence in isolated adult mouse cardiomyocytes pre-incubated with tentacle extract (TE) from the jellyfish Cyanea capillata and β blockers was scanned by laser scanning confocal microscope. Then, the cyclic adenosine monophosphate (cAMP) concentration and protein kinase A (PKA) activity in primary neonatal rat ventricular cardiomyocytes were determined by ELISA assay. Furthermore, the effect of propranolol against the cardiotoxicity of TE was evaluated in Langendorff-perfused rat hearts and intact rats. The increase of intracellular Ca(2+) fluorescence signal by TE was significantly attenuated and delayed when the extracellular Ca(2+) was removed. The β adrenergic blockers, including propranolol, atenolol and esmolol, partially inhibited the increase of intracellular Ca(2+) in the presence of 1.8 mM extracellular Ca(2+) and completely abolished the Ca(2+) increase under an extracellular Ca(2+)-free condition. Both cAMP concentration and PKA activity were stimulated by TE, and were inhibited by the β adrenergic blockers. Cardiomyocyte toxicity of TE was antagonized by β adrenergic blockers and the PKA inhibitor H89. Finally, the acute heart dysfuction by TE was antagonized by propranolol in Langendorff-perfused rat hearts and intact rats. Our findings indicate that β adrenergic receptor/cAMP/PKA signaling contributes to the intracellular Ca(2+) overload through intracellular Ca(2+) release by TE from the jellyfish C. capillata.

  14. ZIP7-mediated intracellular zinc transport contributes to aberrant growth factor signaling in antihormone-resistant breast cancer Cells.

    PubMed

    Taylor, Kathryn M; Vichova, Petra; Jordan, Nicola; Hiscox, Stephen; Hendley, Rhiannon; Nicholson, Robert I

    2008-10-01

    Antiestrogens such as tamoxifen are the mainstay of treatment for estrogen receptor-positive breast cancer. However, their effectiveness is limited by the development of endocrine resistance, allowing tumor regrowth and progression. Importantly, in vitro MCF7 cell models of acquired tamoxifen resistance (TamR cells) display an aggressive, invasive phenotype in which activation of epithelial growth factor receptor/IGF-I receptor/Src signaling plays a critical role. In this study, we report that TamR cells have increased levels of zinc and zinc transporter, ZIP7 [solute carrier family 39 (zinc transporter) member 7, also known as SLC39A7], resulting in an enhanced response to exogenous zinc, which is manifested as a greatly increased growth factor receptor activation, leading to increased growth and invasion. Removal of ZIP7, using small interfering RNA, destroys this activation of epithelial growth factor receptor/IGF-I receptor/Src signaling by reducing intracellular zinc levels. Similarly, it also blocks the activation of HER2, -3, and -4. These data suggest that intracellular zinc levels may be a critical factor in determining growth factor responses and that the targeting of zinc transporters may have novel therapeutic implications. We show that ZIP7 is a critical component in the redistribution of zinc from intracellular stores to the cytoplasm and, as such, is essential for the zinc-induced inhibition of phosphatases, which leads to activation of growth factor receptors. Removal of ZIP7 therefore offers a means through which zinc-induced activation of growth factor receptors may be effectively suppressed and provides a mechanism of targeting multiple growth factor pathways, increasing tumor kill, and preventing further development of resistance in breast cancer.

  15. Compartment-specific Control of Reactive Oxygen Species Scavenging by Antioxidant Pathway Enzymes.

    PubMed

    Dey, Swati; Sidor, Agnieszka; O'Rourke, Brian

    2016-05-20

    Oxidative stress arises from an imbalance in the production and scavenging rates of reactive oxygen species (ROS) and is a key factor in the pathophysiology of cardiovascular disease and aging. The presence of parallel pathways and multiple intracellular compartments, each having its own ROS sources and antioxidant enzymes, complicates the determination of the most important regulatory nodes of the redox network. Here we quantified ROS dynamics within specific intracellular compartments in the cytosol and mitochondria and determined which scavenging enzymes exert the most control over antioxidant fluxes in H9c2 cardiac myoblasts. We used novel targeted viral gene transfer vectors expressing redox-sensitive GFP fused to sensor domains to measure H2O2 or oxidized glutathione. Using genetic manipulation in heart-derived H9c2 cells, we explored the contribution of specific antioxidant enzymes to ROS scavenging and glutathione redox potential within each intracellular compartment. Our findings reveal that antioxidant flux is strongly dependent on mitochondrial substrate catabolism, with availability of NADPH as a major rate-controlling step. Moreover, ROS scavenging by mitochondria significantly contributes to cytoplasmic ROS handling. The findings provide fundamental information about the control of ROS scavenging by the redox network and suggest novel interventions for circumventing oxidative stress in cardiac cells.

  16. Examination of the Staphylococcus aureus Nitric Oxide Reductase (saNOR) Reveals its Contribution to Modulating Intracellular NO Levels and Cellular Respiration

    PubMed Central

    Lewis, A. M.; Matzdorf, S.S.; Endres, J. L.; Windham, I.H.; Bayles, K. W.; Rice, K. C.

    2015-01-01

    Staphylococcus aureus nitrosative stress resistance is due in part to flavohemoprotein (Hmp). Although hmp is present in all sequenced S. aureus genomes, 37% of analyzed strains also contain nor, encoding a predicted quinol-type NO reductase (saNOR). DAF-FM staining of NO-challenged wild-type, nor, hmp, and nor hmp mutant biofilms suggested that Hmp may have a greater contribution to intracellular NO detoxification relative to saNOR. However, saNOR still had a significant impact on intracellular NO levels, and complemented NO detoxification in a nor hmp mutant. When grown as NO-challenged static (low-oxygen) cultures, hmp and nor hmp mutants both experienced a delay in growth initiation, whereas the nor mutant's ability to initiate growth was comparable to the wild-type strain. However, saNOR contributed to cell respiration in this assay once growth had resumed, as determined by membrane potential and respiratory activity assays. Expression of nor was upregulated during low-oxygen growth and dependent on SrrAB, a two-component system that regulates expression of respiration and nitrosative stress resistance genes. High-level nor promoter activity was also detectable in a cell subpopulation near the biofilm substratum. These results suggest that saNOR contributes to NO-dependent respiration during nitrosative stress, possibly conferring an advantage to nor+ strains in vivo. PMID:25651868

  17. An Na(+)-independent short-chain fatty acid transporter contributes to intracellular pH regulation in murine colonocytes

    PubMed Central

    1995-01-01

    Short-chain fatty acids (SCFAs) are the major anions in the colonic lumen. Experiments studied how intracellular pH (pHi) of isolated colonocytes was affected by exposure to SCFAs normally found in the colon. Isolated crypt fragments were loaded with SNARF-1 (a fluorescent dye with pH-sensitive excitation and emission spectra) and studied in a digital imaging microscope. Intracellular pH was measured in individual colonocytes as the ratio of fluorescence intensity in response to alternating excitation wavelengths (575/505 nm). After exposure to 65 mM acetate, propionate, n-butyrate, or iso-butyrate in isosmotic Na(+)- free media (substituted with tetramethylammonia), all colonocytes acidified rapidly and then > 90% demonstrated a pHi alkalinization (Na(+)-independent pHi recovery). Upon subsequent removal of the SCFA, pHi alkalinized beyond the starting pHi (a pHi overshoot). Using propionate as a test SCFA, experiments demonstrate that the acidification and pHi overshoot are explained by transmembrane influx and efflux of nonionized SCFA, respectively. The basis for the pHi overshoot is shown to be accumulation of propionate during pHi alkalinization. The Na(+)-independent pHi recovery (a) demonstrates saturable propionate activation kinetics; (b) demonstrates substrate specificity for unmodified aliphatic carbon chains; (c) occurs after exposure to SCFAs of widely different metabolic activity, (d) is electroneutral; and (e) is not inhibited by changes in the K+ gradient, Cl- gradient or addition of the anion transport inhibitors DIDS (1 mM), SITS (1 mM), alpha-cyano-4-hydroxycinnamate (4 mM), or probenicid (1 mM). Results suggest that most mouse colonocytes have a previously unreported SCFA transporter which mediates Na(+)-independent pHi recovery. PMID:7658194

  18. Two Outer Membrane Proteins Contribute to Caulobacter crescentus Cellular Fitness by Preventing Intracellular S-Layer Protein Accumulation

    DOE PAGES

    Overton, K. Wesley; Park, Dan M.; Yung, Mimi C.; ...

    2016-09-23

    Surface layers, or S-layers, are two-dimensional protein arrays that form the outermost layer of many bacteria and archaea. They serve several functions, including physical protection of the cell from environmental threats. The high abundance of S-layer proteins necessitates a highly efficient export mechanism to transport the S-layer protein from the cytoplasm to the cell exterior.Caulobacter crescentusis unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaFaand RsaFb, which together with other components form a type I protein translocation pathway for S-layer export. These proteins have homology toEscherichia coliTolC, the outer membrane channel of multidrug efflux pumps. Heremore » we provide evidence that, unlike TolC, RsaFaand RsaFbare not involved in either the maintenance of membrane stability or the active export of antimicrobial compounds. Rather, RsaFaand RsaFbare required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaFaand RsaFbled to a general growth defect and lowered cellular fitness. Using Western blotting, transmission electron microscopy, and transcriptome sequencing (RNA-seq), we show that loss of both RsaFaand RsaFbled to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein misfolding and degradation pathways. These findings provide new insight into the requirement for RsaFaand RsaFbin cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels inC. crescentus. IMPORTANCEDecreased growth rate and reduced cell fitness are common side effects of protein production in overexpression systems. Inclusion bodies typically form inside the cell, largely due to a lack of sufficient export machinery to transport the overexpressed proteins to the extracellular environment. This phenomenon can

  19. Reduced stability and intracellular transport of dsRNA contribute to poor RNAi response in lepidopteran insects.

    PubMed

    Shukla, Jayendra Nath; Kalsi, Megha; Sethi, Amit; Narva, Kenneth E; Fishilevich, Elane; Singh, Satnam; Mogilicherla, Kanakachari; Palli, Subba Reddy

    2016-07-02

    RNA interference (RNAi) has become a widely used reverse genetic tool to study gene function in eukaryotic organisms and is being developed as a technology for insect pest management. The efficiency of RNAi varies among organisms. Insects from different orders also display differential efficiency of RNAi, ranging from highly efficient (coleopterans) to very low efficient (lepidopterans). We investigated the reasons for varying RNAi efficiency between lepidopteran and coleopteran cell lines and also between the Colorado potato beetle, Leptinotarsa decemlineata and tobacco budworm, Heliothis virescens. The dsRNA either injected or fed was degraded faster in H. virescens than in L. decemlineata. Both lepidopteran and coleopteran cell lines and tissues efficiently took up the dsRNA. Interestingly, the dsRNA administered to coleopteran cell lines and tissues was taken up and processed to siRNA whereas the dsRNA was taken up by lepidopteran cell lines and tissues but no siRNA was detected in the total RNA isolated from these cell lines and tissues. The data included in this paper showed that the degradation and intracellular transport of dsRNA are the major factors responsible for reduced RNAi efficiency in lepidopteran insects.

  20. An SREBP-responsive microRNA operon contributes to a regulatory loop for intracellular lipid homeostasis.

    PubMed

    Jeon, Tae-Il; Esquejo, Ryan M; Roqueta-Rivera, Manuel; Phelan, Peter E; Moon, Young-Ah; Govindarajan, Subramaniam S; Esau, Christine C; Osborne, Timothy F

    2013-07-02

    Sterol regulatory element-binding proteins (SREBPs) have evolved as a focal point for linking lipid synthesis with other pathways that regulate cell growth and survival. Here, we have uncovered a polycistrionic microRNA (miRNA) locus that is activated directly by SREBP-2. Two of the encoded miRNAs, miR-182 and miR-96, negatively regulate the expression of Fbxw7 and Insig-2, respectively, and both are known to negatively affect nuclear SREBP accumulation. Direct manipulation of this miRNA pathway alters nuclear SREBP levels and endogenous lipid synthesis. Thus, we have uncovered a mechanism for the regulation of intracellular lipid metabolism mediated by the concerted action of a pair of miRNAs that are expressed from the same SREBP-2-regulated miRNA locus, and each targets a different protein of the multistep pathway that regulates SREBP function. These studies reveal an miRNA "operon" analogous to the classic model for genetic control in bacterial regulatory systems. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Reduced stability and intracellular transport of dsRNA contribute to poor RNAi response in lepidopteran insects

    PubMed Central

    Shukla, Jayendra Nath; Kalsi, Megha; Sethi, Amit; Narva, Kenneth E.; Fishilevich, Elane; Singh, Satnam; Mogilicherla, Kanakachari; Palli, Subba Reddy

    2016-01-01

    ABSTRACT RNA interference (RNAi) has become a widely used reverse genetic tool to study gene function in eukaryotic organisms and is being developed as a technology for insect pest management. The efficiency of RNAi varies among organisms. Insects from different orders also display differential efficiency of RNAi, ranging from highly efficient (coleopterans) to very low efficient (lepidopterans). We investigated the reasons for varying RNAi efficiency between lepidopteran and coleopteran cell lines and also between the Colorado potato beetle, Leptinotarsa decemlineata and tobacco budworm, Heliothis virescens. The dsRNA either injected or fed was degraded faster in H. virescens than in L. decemlineata. Both lepidopteran and coleopteran cell lines and tissues efficiently took up the dsRNA. Interestingly, the dsRNA administered to coleopteran cell lines and tissues was taken up and processed to siRNA whereas the dsRNA was taken up by lepidopteran cell lines and tissues but no siRNA was detected in the total RNA isolated from these cell lines and tissues. The data included in this paper showed that the degradation and intracellular transport of dsRNA are the major factors responsible for reduced RNAi efficiency in lepidopteran insects. PMID:27245473

  2. Two Outer Membrane Proteins Contribute to Caulobacter crescentus Cellular Fitness by Preventing Intracellular S-Layer Protein Accumulation

    SciTech Connect

    Overton, K. Wesley; Park, Dan M.; Yung, Mimi C.; Dohnalkova, Alice C.; Smit, John; Jiao, Yongqin

    2016-09-23

    Surface layers, or S-layers, are two-dimensional protein arrays that form the outermost layer of many bacteria and archaea. They serve several functions, including physical protection of the cell from environmental threats. The high abundance of S-layer proteins necessitates a highly efficient export mechanism to transport the S-layer protein from the cytoplasm to the cell exterior.Caulobacter crescentusis unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaFaand RsaFb, which together with other components form a type I protein translocation pathway for S-layer export. These proteins have homology toEscherichia coliTolC, the outer membrane channel of multidrug efflux pumps. Here we provide evidence that, unlike TolC, RsaFaand RsaFbare not involved in either the maintenance of membrane stability or the active export of antimicrobial compounds. Rather, RsaFaand RsaFbare required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaFaand RsaFbled to a general growth defect and lowered cellular fitness. Using Western blotting, transmission electron microscopy, and transcriptome sequencing (RNA-seq), we show that loss of both RsaFaand RsaFbled to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein misfolding and degradation pathways. These findings provide new insight into the requirement for RsaFaand RsaFbin cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels inC. crescentus.

  3. Two Outer Membrane Proteins Contribute to Caulobacter crescentus Cellular Fitness by Preventing Intracellular S-Layer Protein Accumulation

    SciTech Connect

    Overton, K. Wesley; Park, Dan M.; Yung, Mimi C.; Dohnalkova, Alice C.; Smit, John; Jiao, Yongqin; Parales, R. E.

    2016-09-23

    ABSTRACT

    Surface layers, or S-layers, are two-dimensional protein arrays that form the outermost layer of many bacteria and archaea. They serve several functions, including physical protection of the cell from environmental threats. The high abundance of S-layer proteins necessitates a highly efficient export mechanism to transport the S-layer protein from the cytoplasm to the cell exterior.Caulobacter crescentusis unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaFaand RsaFb, which together with other components form a type I protein translocation pathway for S-layer export. These proteins have homology toEscherichia coliTolC, the outer membrane channel of multidrug efflux pumps. Here we provide evidence that, unlike TolC, RsaFaand RsaFbare not involved in either the maintenance of membrane stability or the active export of antimicrobial compounds. Rather, RsaFaand RsaFbare required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaFaand RsaFbled to a general growth defect and lowered cellular fitness. Using Western blotting, transmission electron microscopy, and transcriptome sequencing (RNA-seq), we show that loss of both RsaFaand RsaFbled to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein misfolding and degradation pathways. These findings provide new insight into the requirement for RsaFaand RsaFbin cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels inC. crescentus

  4. Two Outer Membrane Proteins Contribute to Caulobacter crescentus Cellular Fitness by Preventing Intracellular S-Layer Protein Accumulation

    SciTech Connect

    Overton, K. Wesley; Park, Dan M.; Yung, Mimi C.; Dohnalkova, Alice C.; Smit, John; Jiao, Yongqin

    2016-09-23

    Surface layers, or S-layers, are two-dimensional protein arrays that form the outermost layer of many bacteria and archaea. They serve several functions, including physical protection of the cell from environmental threats. The high abundance of S-layer proteins necessitates a highly efficient export mechanism to transport the S-layer protein from the cytoplasm to the cell exterior.Caulobacter crescentusis unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaFaand RsaFb, which together with other components form a type I protein translocation pathway for S-layer export. These proteins have homology toEscherichia coliTolC, the outer membrane channel of multidrug efflux pumps. Here we provide evidence that, unlike TolC, RsaFaand RsaFbare not involved in either the maintenance of membrane stability or the active export of antimicrobial compounds. Rather, RsaFaand RsaFbare required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaFaand RsaFbled to a general growth defect and lowered cellular fitness. Using Western blotting, transmission electron microscopy, and transcriptome sequencing (RNA-seq), we show that loss of both RsaFaand RsaFbled to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein misfolding and degradation pathways. These findings provide new insight into the requirement for RsaFaand RsaFbin cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels inC. crescentus.

  5. Compartmented electrode structure

    DOEpatents

    Vissers, Donald R.; Shimotake, Hiroshi; Gay, Eddie C.; Martino, Fredric J.

    1977-06-14

    Electrodes for secondary electrochemical cells are provided with compartments for containing particles of the electrode reactant. The compartments are defined by partitions that are generally impenetrable to the particles of reactant and, in some instances, to the liquid electrolyte used in the cell. During cycling of the cell, reactant material initially loaded into a particular compartment is prevented from migrating and concentrating within the lower portion of the electrode or those portions of the electrode that exhibit reduced electrical resistance.

  6. Contribution of sarcolemmal sodium-calcium exchange and intracellular calcium release to force development in isolated canine ventricular muscle

    PubMed Central

    1992-01-01

    frequency in 70 mM [Na+]o was not a consequence of a decreased rate of refilling of a releasable pool of Ca2+ within the cell. These results demonstrate that frequency-dependent changes of contractile strength and intracellular Ca2+ loading in 140 mM [Na+]o require the presence of a functional sarcolemmal Na(+)-Ca2+ exchange process. The possibility that the negative staircase in 70 mM [Na+]o is related to inhibition of Ca(2+)-induced release of Ca2+ from the SR by various cellular mechanisms is discussed. PMID:1640221

  7. Compartment Syndrome in Children.

    PubMed

    Hosseinzadeh, Pooya; Hayes, Christopher B

    2016-07-01

    Compartment syndrome in children can present differently than adults. Increased analgesic need should be considered the first sign of evolving compartment syndrome in children. Children with supracondylar humerus fractures, floating elbow injuries, operatively treated forearm fractures, and tibia fractures are at high risk for developing compartment syndrome. Elbow flexion beyond 90° in supracondylar humerus fractures and closed treatment of forearm fractures in floating elbow injuries are associated with increased risk of compartment syndrome. Prompt diagnosis and treatment with fasciotomy in children result in excellent long-term outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Intracellular Ca2+ release through ryanodine receptors contributes to AMPA receptor-mediated mitochondrial dysfunction and ER stress in oligodendrocytes

    PubMed Central

    Ruiz, A; Matute, C; Alberdi, E

    2010-01-01

    Overactivation of ionotropic glutamate receptors in oligodendrocytes induces cytosolic Ca2+ overload and excitotoxic death, a process that contributes to demyelination and multiple sclerosis. Excitotoxic insults cause well-characterized mitochondrial alterations and endoplasmic reticulum (ER) dysfunction, which is not fully understood. In this study, we analyzed the contribution of ER-Ca2+ release through ryanodine receptors (RyRs) and inositol triphosphate receptors (IP3Rs) to excitotoxicity in oligodendrocytes in vitro. First, we observed that oligodendrocytes express all previously characterized RyRs and IP3Rs. Blockade of Ca2+-induced Ca2+ release by TMB-8 following α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor-mediated insults attenuated both oligodendrocyte death and cytosolic Ca2+ overload. In turn, RyR inhibition by ryanodine reduced as well the Ca2+ overload whereas IP3R inhibition was ineffective. Furthermore, AMPA-triggered mitochondrial membrane depolarization, oxidative stress and activation of caspase-3, which in all instances was diminished by RyR inhibition. In addition, we observed that AMPA induced an ER stress response as revealed by α subunit of the eukaryotic initiation factor 2α phosphorylation, overexpression of GRP chaperones and RyR-dependent cleavage of caspase-12. Finally, attenuating ER stress with salubrinal protected oligodendrocytes from AMPA excitotoxicity. Together, these results show that Ca2+ release through RyRs contributes to cytosolic Ca2+ overload, mitochondrial dysfunction, ER stress and cell death following AMPA receptor-mediated excitotoxicity in oligodendrocytes. PMID:21364659

  9. Upregulation of arginase activity contributes to intracellular ROS production induced by high glucose in H9c2 cells.

    PubMed

    Zhou, Lu; Sun, Chuan-Bo; Liu, Chao; Fan, Yue; Zhu, Hong-Yi; Wu, Xiao-Wei; Hu, Liang; Li, Qing-Ping

    2015-01-01

    Arginase is upregulated in some tissues under diabetes states. Arginase can compete with nitroxide synthase (NOS) for the common substrate L-arginine and thus increases oxidative stress by NOS uncoupling. We want to analyze whether arginase is upregulated and contribute to oxidative stress in H9c2 cells during high glucose treatment. H9c2 cells were cultured in normal or high glucose DMEM. Arginase activity increased in parallel with increased cell death and oxidative stress. Arginase inhibitor N ω-hydroxy-nor-l-arginine (nor-NOHA) and NOS inhibitor N ω-nitro-l-arginine methyl ester (L-NAME) could reverse these effects. Despite of upregulated NOS activity, NO production was impaired which could be preserved by nor-NOHA, suggesting a decreased substrate availability of NOS due to increased arginase activity. L-arginine supplementation decreased superoxide production while it could not protect cells from death. Upregulated arginase activity in H9c2 treated with high glucose can cause NOS uncoupling and subsequently reactive oxygen species augmentation and cell death. These findings suggest that arginase will be a novel therapeutic target for treatment of diabetic cardiomyopathy.

  10. Single compartment drug delivery

    PubMed Central

    Cima, Michael J.; Lee, Heejin; Daniel, Karen; Tanenbaum, Laura M.; Mantzavinou, Aikaterini; Spencer, Kevin C.; Ong, Qunya; Sy, Jay C.; Santini, John; Schoellhammer, Carl M.; Blankschtein, Daniel; Langer, Robert S.

    2014-01-01

    Drug design is built on the concept that key molecular targets of disease are isolated in the diseased tissue. Systemic drug administration would be sufficient for targeting in such a case. It is, however, common for enzymes or receptors that are integral to disease to be structurally similar or identical to those that play important biological roles in normal tissues of the body. Additionally, systemic administration may not lead to local drug concentrations high enough to yield disease modification because of rapid systemic metabolism or lack of sufficient partitioning into the diseased tissue compartment. This review focuses on drug delivery methods that physically target drugs to individual compartments of the body. Compartments such as the bladder, peritoneum, brain, eye and skin are often sites of disease and can sometimes be viewed as “privileged,” since they intrinsically hinder partitioning of systemically administered agents. These compartments have become the focus of a wide array of procedures and devices for direct administration of drugs. We discuss the rationale behind single compartment drug delivery for each of these compartments, and give an overview of examples at different development stages, from the lab bench to phase III clinical trials to clinical practice. We approach single compartment drug delivery from both a translational and a technological perspective. PMID:24798478

  11. Intracellular protein topogenesis

    PubMed Central

    Blobel, Günter

    1980-01-01

    Concurrently with or shortly after their synthesis on ribosomes, numerous specific proteins are unidirectionally translocated across or asymmetrically integrated into distinct cellular membranes. Thereafter, subpopulations of these proteins need to be sorted from each other and routed for export or targeted to other intracellular membranes or compartments. It is hypothesized here that the information for these processes, termed “protein topogenesis,” is encoded in discrete “topogenic” sequences that constitute a permanent or transient part of the polypeptide chain. The repertoire of distinct topogenic sequences is predicted to be relatively small because many different proteins would be topologically equivalent—i.e., targeted to the same intracellular address. The information content of topogenic sequences would be decoded and processed by distinct effectors. Four types of topogenic sequences could be distinguished: signal sequences, stop-transfer sequences, sorting sequences, and insertion sequences. Signal sequences initiate translocation of proteins across specific membranes. They would be decoded and processed by protein translocators that, by virtue of their signal sequence-specific domain and their unique location in distinct cellular membranes, effect unidirectional translocation of proteins across specific cellular membranes. Stop-transfer sequences interrupt the translocation process that was previously initiated by a signal sequence and, by excluding a distinct segment of the polypeptide chain from translocation, yield asymmetric integration of proteins into translocation-competent membranes. Sorting sequences would act as determinants for posttranslocational traffic of subpopulations of proteins, originating in translocation-competent donor membranes (and compartments) and going to translocation-incompetent receiver membranes (and compartments). Finally, insertion sequences initiate unilateral integration of proteins into the lipid bilayer

  12. N-methyl-D-aspartate receptors in human erythroid precursor cells and in circulating red blood cells contribute to the intracellular calcium regulation.

    PubMed

    Makhro, Asya; Hänggi, Pascal; Goede, Jeroen S; Wang, Jue; Brüggemann, Andrea; Gassmann, Max; Schmugge, Markus; Kaestner, Lars; Speer, Oliver; Bogdanova, Anna

    2013-12-01

    The presence of N-methyl-d-aspartate receptor (NMDAR) was previously shown in rat red blood cells (RBCs) and in a UT-7/Epo human myeloid cell line differentiating into erythroid lineage. Here we have characterized the subunit composition of the NMDAR and monitored its function during human erythropoiesis and in circulating RBCs. Expression of the NMDARs subunits was assessed in erythroid progenitors during ex vivo erythropoiesis and in circulating human RBCs using quantitative PCR and flow cytometry. Receptor activity was monitored using a radiolabeled antagonist binding assay, live imaging of Ca(2+) uptake, patch clamp, and monitoring of cell volume changes. The receptor tetramers in erythroid precursor cells are composed of the NR1, NR2A, 2C, 2D, NR3A, and 3B subunits of which the glycine-binding NR3A and 3B and glutamate-binding NR2C and 2D subunits prevailed. Functional receptor is required for survival of erythroid precursors. Circulating RBCs retain a low number of the receptor copies that is higher in young cells compared with mature and senescent RBC populations. In circulating RBCs the receptor activity is controlled by plasma glutamate and glycine. Modulation of the NMDAR activity in RBCs by agonists or antagonists is associated with the alterations in whole cell ion currents. Activation of the receptor results in the transient Ca(2+) accumulation, cell shrinkage, and alteration in the intracellular pH, which is associated with the change in hemoglobin oxygen affinity. Thus functional NMDARs are present in erythroid precursor cells and in circulating RBCs. These receptors contribute to intracellular Ca(2+) homeostasis and modulate oxygen delivery to peripheral tissues.

  13. DNA Virus Replication Compartments

    PubMed Central

    Schmid, Melanie; Speiseder, Thomas; Dobner, Thomas

    2014-01-01

    Viruses employ a variety of strategies to usurp and control cellular activities through the orchestrated recruitment of macromolecules to specific cytoplasmic or nuclear compartments. Formation of such specialized virus-induced cellular microenvironments, which have been termed viroplasms, virus factories, or virus replication centers, complexes, or compartments, depends on molecular interactions between viral and cellular factors that participate in viral genome expression and replication and are in some cases associated with sites of virion assembly. These virus-induced compartments function not only to recruit and concentrate factors required for essential steps of the viral replication cycle but also to control the cellular mechanisms of antiviral defense. In this review, we summarize characteristic features of viral replication compartments from different virus families and discuss similarities in the viral and cellular activities that are associated with their assembly and the functions they facilitate for viral replication. PMID:24257611

  14. Chronic Exertional Compartment Syndrome.

    PubMed

    Braver, Richard T

    2016-04-01

    Increased tissue pressure within a fascial compartment may be the result from any increase in volume within its contents, or any decrease in size of the fascial covering or its distensibility. This may lead to symptoms of leg tightness, pain or numbness brought about by exercise. There are multiple differential diagnoses of exercise induced leg pain and the proper diagnoses of chronic exertional compartment syndrome (CECS) is made by a careful history and by exclusion of other maladies and confirmed by compartment syndrome testing as detailed in this text. Surgical fasciotomies for the anterior, lateral, superficial and deep posterior compartments are described in detail along with ancillary procedures for chronic shin splints that should allow the athlete to return to competitive activity. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Chronic Exertional Compartment Syndrome

    MedlinePlus

    ... through the pain; that can lead to permanent muscle or nerve damage. Sometimes chronic exertional compartment syndrome is mistaken for shin splints, a more common cause of leg pain in young people who do a lot of vigorous weight- ...

  16. Atraumatic painless compartment syndrome.

    PubMed

    Blanchard, Scott; Griffin, Gregory D; Simon, Erin L

    2013-12-01

    Acute compartment syndrome is a time-sensitive diagnosis and surgical emergency because it poses a threat to life and the limbs. It is defined by Matsen et al (Surg Gynecol Obstet. 1978;147(6):943–949) as "a condition in which increased pressure within a limited space compromises the circulation and function of the tissues within that space." The most common cause of compartment syndrome is traumatic injury. A variety of other conditions such as vascular injuries, bleeding disorders, thrombosis, fasciitis, gas gangrene, rhabdomyolysis, prolonged limb compression, cellulitis, and nephrotic syndrome may also cause compartment syndrome. Patients who are elderly, have preexisting nerve damage, or have psychopathology may have an atypical presentation. This case highlights the first report of a 75-year-old woman who developed painless bilateral compartment syndrome in the absence of traumatic injury.

  17. Acute compartment syndrome.

    PubMed

    Via, Alessio Giai; Oliva, Francesco; Spoliti, Marco; Maffulli, Nicola

    2015-01-01

    acute compartment syndrome (ACS) is one of the few true emergencies in orthopedics and traumatology. It is a painful condition caused by the increase interstitial pressure (intracompart-mental pressure - ICP) within a closed osteofascial compartment which impair local circulation. It occurs most often in the legs, but it can affects also the arms, hands, feet, and buttocks. It usually develops after a severe injury such as fractures or crush injury, but it can also occurs after a relatively minor injury and it may be iatrogenic. Uncommon causes of ACS have been also described, that suggest surgeons to pay great attention to this serious complication. Diagnosing ACS is difficult in clinical practice, even among expert surgeons. Currently, the diagnosis is made on the basis of physical examination and repeated ICP measures. ICP higher than 30 mmHg of diastolic blood pressure is significant of compartment syndrome. Once diagnosis is made, fasciotomy to release the affected compartment should be performed as early as possible because delayed decompression would lead to irreversible ischemic damage to muscles and peripheral nerves. acute compartment syndrome is a surgical emergency. There is still little consensus among authors about diagnosis and treatment of these serious condition, in particular about the ICP at which fasciotomy is absolutely indicated and the timing of wound closure. New investigations are needed in order to improve diagnosis and treatment of ACS.

  18. Psoas compartment block.

    PubMed

    Brooks, D M

    2000-05-01

    The psoas compartment acts as a conduit for the nerve roots of the lumbar plexus. Originating at approximately the 12th thoracic vertebrae, this potential compartment continues on caudally, bordered posterolaterally by fascia of the quadratus lumborum and iliacus muscles, medially by the fascia of the psoas major muscle, and anteriorly by the transversalis fascia. This natural "gutter" acts as a repository for local anesthetic agents and provides an excellent method of unilateral anterior lower extremity anesthesia. After elicitation of a motor evoked response in the muscles of the anterior thigh, 30 to 40 milliliters of local anesthetic is incrementally injected into the compartment. Spread of the anesthetic to all roots of the plexus occurs in 15 to 20 minutes. Profound sensory and motor blockade can be achieved providing surgical anesthesia as well as long duration postoperative pain relief.

  19. Rab5 activity regulates GLUT4 sorting into insulin-responsive and non-insulin-responsive endosomal compartments: a potential mechanism for development of insulin resistance.

    PubMed

    Tessneer, Kandice L; Jackson, Robert M; Griesel, Beth A; Olson, Ann Louise

    2014-09-01

    Glucose transporter isoform 4 (GLUT4) is the insulin-responsive glucose transporter mediating glucose uptake in adipose and skeletal muscle. Reduced GLUT4 translocation from intracellular storage compartments to the plasma membrane is a cause of peripheral insulin resistance. Using a chronic hyperinsulinemia (CHI)-induced cell model of insulin resistance and Rab5 mutant overexpression, we determined these manipulations altered endosomal sorting of GLUT4, thus contributing to the development of insulin resistance. We found that CHI induced insulin resistance in 3T3-L1 adipocytes by retaining GLUT4 in a Rab5-activity-dependent compartment that is unable to equilibrate with the cell surface in response to insulin. Furthermore, CHI-mediated retention of GLUT4 in this non-insulin-responsive compartment impaired filling of the transferrin receptor (TfR)-positive and TfR-negative insulin-responsive storage compartments. Our data suggest that hyperinsulinemia may inhibit GLUT4 by chronically maintaining GLUT4 in the Rab5 activity-dependent endosomal pathway and impairing formation of the TfR-negative and TfR-positive insulin-responsive GLUT4 pools. This model suggests that an early event in the development of insulin-resistant glucose transport in adipose tissue is to alter the intracellular localization of GLUT4 to a compartment that does not efficiently equilibrate with the cell surface when insulin levels are elevated for prolonged periods of time.

  20. Relationship between nutrition, weight change, and fluid compartments in preterm infants during the first week of life.

    PubMed

    Heimler, R; Doumas, B T; Jendrzejczak, B M; Nemeth, P B; Hoffman, R G; Nelin, L D

    1993-01-01

    This study was conducted to investigate the redistribution of fluid compartments and to examine the factors contributing to the variability of early weight loss in premature infants. Fourteen preterm infants (mean +/- SD: birth weight, 1473 +/- 342 gm; gestational age, 30.7 +/- 2.4 weeks) were studied at 1 and 7 days of age. Total body water was measured by deuterium oxide dilution, extracellular volume by bromide dilution, and intracellular volume by the difference between total body water and extracellular volume. There were significant changes in body fluid distribution per concurrent weight from birth to age 1 week. Extracellular volume decreased by 11%, and intracellular volume increased by 8.5% with no change in total body water. Infants were then grouped according to postnatal weight loss (group 1 (n = 7) > 10% and group 2 (n = 7) < 5% of birth weight). In group 1 there was a significant loss of both weight (mean +/- SD: 15.6% +/- 3.7%) and extracellular volume (15.9% +/- 9% of birth weight), with no change in intracellular volume. In group 2 there was no significant weight loss (1.4% +/- 1.8%), but a significant loss of extracellular volume (13.0% +/- 5.4% of birth weight) and a significant increase in intracellular volume. Other differences between the groups were a lower energy intake in group 1 than in group 2 (mean +/- SD: 177 +/- 46 vs 269 +/- 45 kilojoules/kg per day; p < 0.005) and a higher physiologic stability index in group 1 (p < 0.05). We conclude that significant postnatal weight loss as a result of the contraction of the extracellular compartment occurs only in less stable infants whose energy intake is inadequate. With adequate energy intake, weight loss is minimal because of the expansion of the intracellular compartment, which may be related to the onset of growth.

  1. Neonatal compartment syndrome.

    PubMed

    Martin, B; Treharne, L

    2016-09-01

    A term neonate was born with a grossly swollen and discoloured left hand and forearm. He was transferred from the local hospital to the plastic surgical unit, where a diagnosis of compartment syndrome was made and he underwent emergency forearm fasciotomies at six hours of age. Following serial debridements of necrotic tissue, he underwent split-thickness skin grafting of the resultant defects of his forearm, hand and digits. At the clinic follow-up appointment two months after the procedure, he was found to have developed severe flexion contractures despite regular outpatient hand therapy and splintage. He has had further reconstruction with contracture release, use of artificial dermal matrix, and K-wire fixation of the thumb and wrist. Despite this, the long term outcome is likely to be an arm with poor function. The key learning point from this case is that despite prompt transfer, diagnosis and appropriate surgical management, the outcome for neonatal compartment syndrome may still be poor.

  2. Identification of two distinct intracellular sites that contribute to the modulation of multidrug resistance in P388/ADR cells expressing P-glycoprotein.

    PubMed

    Mayer, Lawrence D; Lim, Kye-Taek; Hartley, Daria

    2002-01-01

    Although the ability of chemosensitizers to modulate P-glycoprotein (PGP)-based multidrug resistance (MDR) has been extensively studied, relatively little is known about the cellular pharmacology of the PGP inhibitors themselves in MDR cells. The studies described here have correlated the in vitro accumulation and retention properties of verapamil (VRP) in murine P388 (sensitive) and P388/ADR (MDR) cells with doxorubicin (DOX) uptake and cytotoxicity modulation characteristics in order to better understand VRP-tumor cell interactions that give rise to MDR modulation. VRP is rapidly taken up by DOX-sensitive and -resistant P388 cells where greater than 50% maximal VRP uptake occurs within 10 min of initial exposure at 37 degrees C. Whereas chemosensitization and DOX uptake in P388/ADR cells increase with increasing VRP concentration until a plateau is achieved at approximately 5 microM VRP, cellular modulator levels increase proportionally with increasing VPR concentrations beyond 20 microM. Subsequent to removal of noncell-associated modulator, VRP levels in both sensitive and resistant cells rapidly fall below 10% of those obtained at uptake equilibrium. However, a residual amount of VRP remains associated with the cells for extended time periods after the cells are washed. Pulse exposures of P388/ADR cells to high concentrations of VRP (50-100 microM) are capable of providing extended cell-associated VRP levels comparable to those obtained with continuous exposure at biologically active VRP concentrations (1-3 microM) and this leads to chemosensitization. These results are consistent with the existence of high- and low-affinity intracellular VRP pools in P388 MDR cells, both of which can contribute to the reversal of drug resistance. It is suggested that these properties should be taken into consideration during the design and evaluation of preclinical in vivo MDR models where pulsed exposure to high concentrations of resistance modulators often occurs. Special

  3. Mathematical Model for the Contribution of Individual Organs to Non-Zero Y-Intercepts in Single and Multi-Compartment Linear Models of Whole-Body Energy Expenditure

    PubMed Central

    Kaiyala, Karl J.

    2014-01-01

    Mathematical models for the dependence of energy expenditure (EE) on body mass and composition are essential tools in metabolic phenotyping. EE scales over broad ranges of body mass as a non-linear allometric function. When considered within restricted ranges of body mass, however, allometric EE curves exhibit ‘local linearity.’ Indeed, modern EE analysis makes extensive use of linear models. Such models typically involve one or two body mass compartments (e.g., fat free mass and fat mass). Importantly, linear EE models typically involve a non-zero (usually positive) y-intercept term of uncertain origin, a recurring theme in discussions of EE analysis and a source of confounding in traditional ratio-based EE normalization. Emerging linear model approaches quantify whole-body resting EE (REE) in terms of individual organ masses (e.g., liver, kidneys, heart, brain). Proponents of individual organ REE modeling hypothesize that multi-organ linear models may eliminate non-zero y-intercepts. This could have advantages in adjusting REE for body mass and composition. Studies reveal that individual organ REE is an allometric function of total body mass. I exploit first-order Taylor linearization of individual organ REEs to model the manner in which individual organs contribute to whole-body REE and to the non-zero y-intercept in linear REE models. The model predicts that REE analysis at the individual organ-tissue level will not eliminate intercept terms. I demonstrate that the parameters of a linear EE equation can be transformed into the parameters of the underlying ‘latent’ allometric equation. This permits estimates of the allometric scaling of EE in a diverse variety of physiological states that are not represented in the allometric EE literature but are well represented by published linear EE analyses. PMID:25068692

  4. Mathematical model for the contribution of individual organs to non-zero y-intercepts in single and multi-compartment linear models of whole-body energy expenditure.

    PubMed

    Kaiyala, Karl J

    2014-01-01

    Mathematical models for the dependence of energy expenditure (EE) on body mass and composition are essential tools in metabolic phenotyping. EE scales over broad ranges of body mass as a non-linear allometric function. When considered within restricted ranges of body mass, however, allometric EE curves exhibit 'local linearity.' Indeed, modern EE analysis makes extensive use of linear models. Such models typically involve one or two body mass compartments (e.g., fat free mass and fat mass). Importantly, linear EE models typically involve a non-zero (usually positive) y-intercept term of uncertain origin, a recurring theme in discussions of EE analysis and a source of confounding in traditional ratio-based EE normalization. Emerging linear model approaches quantify whole-body resting EE (REE) in terms of individual organ masses (e.g., liver, kidneys, heart, brain). Proponents of individual organ REE modeling hypothesize that multi-organ linear models may eliminate non-zero y-intercepts. This could have advantages in adjusting REE for body mass and composition. Studies reveal that individual organ REE is an allometric function of total body mass. I exploit first-order Taylor linearization of individual organ REEs to model the manner in which individual organs contribute to whole-body REE and to the non-zero y-intercept in linear REE models. The model predicts that REE analysis at the individual organ-tissue level will not eliminate intercept terms. I demonstrate that the parameters of a linear EE equation can be transformed into the parameters of the underlying 'latent' allometric equation. This permits estimates of the allometric scaling of EE in a diverse variety of physiological states that are not represented in the allometric EE literature but are well represented by published linear EE analyses.

  5. Intracellular precipitation of hydroxyapatite mineral and implications for pathologic calcification.

    PubMed

    Azari, Fereshteh; Vali, Hojatollah; Guerquin-Kern, Jean-Luc; Wu, Ting-Di; Croisy, Alain; Sears, S Kelly; Tabrizian, Maryam; McKee, Marc D

    2008-06-01

    In contrast to physiologic biomineralization occurring in bones, teeth and otoconia in vertebrates, calcification of soft tissues occurs in many pathologic conditions. Although similarities have been noted between the two processes, and despite the important clinical consequences of ectopic calcification, the molecular mechanisms regulating ectopic calcification are poorly understood. Although calcification is mainly extracellular, intracellular calcification has been reported and might indeed contribute to pathologic calcification of soft tissues. To better understand the process of intracellular calcification as a potential origin for pathologic calcification, and to examine the role of proteoglycans in this process, we investigated a pattern of intracellular nucleation and growth of hydroxyapatite in Madin-Darby Canine Kidney (MDCK) epithelial cells using electron microscopy, secondary ion mass spectroscopy (NanoSIMS), cytochemical staining, immunolabeling and biochemical analysis. We report here that under mineralizing cell culture conditions where beta-glycerophosphate (betaGP) was added as an exogenous organic source of phosphate, betaGP-cleaving alkaline phosphatase activity increased and hydroxyapatite crystals subsequently nucleated within intracellular, membrane-bounded compartments. The small, leucine-rich proteoglycan decorin was also upregulated and associated with mineral in these cultures. Such information provides insight into the mechanisms leading to pathologic calcification and describes a process whereby hydroxyapatite deposition in cells might lead to ectopic calcification.

  6. Nanovehicular Intracellular Delivery Systems

    PubMed Central

    PROKOP, ALES; DAVIDSON, JEFFREY M.

    2013-01-01

    This article provides an overview of principles and barriers relevant to intracellular drug and gene transport, accumulation and retention (collectively called as drug delivery) by means of nanovehicles (NV). The aim is to deliver a cargo to a particular intracellular site, if possible, to exert a local action. Some of the principles discussed in this article apply to noncolloidal drugs that are not permeable to the plasma membrane or to the blood–brain barrier. NV are defined as a wide range of nanosized particles leading to colloidal objects which are capable of entering cells and tissues and delivering a cargo intracelullarly. Different localization and targeting means are discussed. Limited discussion on pharmacokinetics and pharmacodynamics is also presented. NVs are contrasted to micro-delivery and current nanotechnologies which are already in commercial use. Newer developments in NV technologies are outlined and future applications are stressed. We also briefly review the existing modeling tools and approaches to quantitatively describe the behavior of targeted NV within the vascular and tumor compartments, an area of particular importance. While we list “elementary” phenomena related to different level of complexity of delivery to cancer, we also stress importance of multi-scale modeling and bottom-up systems biology approach. PMID:18200527

  7. Neonatal compartment syndrome

    PubMed Central

    Martin, B; Treharne, L

    2016-01-01

    A term neonate was born with a grossly swollen and discoloured left hand and forearm. He was transferred from the local hospital to the plastic surgical unit, where a diagnosis of compartment syndrome was made and he underwent emergency forearm fasciotomies at six hours of age. Following serial debridements of necrotic tissue, he underwent split-thickness skin grafting of the resultant defects of his forearm, hand and digits. At the clinic follow-up appointment two months after the procedure, he was found to have developed severe flexion contractures despite regular outpatient hand therapy and splintage. He has had further reconstruction with contracture release, use of artificial dermal matrix, and K-wire fixation of the thumb and wrist. Despite this, the long term outcome is likely to be an arm with poor function. The key learning point from this case is that despite prompt transfer, diagnosis and appropriate surgical management, the outcome for neonatal compartment syndrome may still be poor. PMID:27138850

  8. Intracellular shunting of O{sub 2}{sup −} contributes to charge compensation and preservation of neutrophil respiratory burst in the absence of voltage-gated proton channel activity

    SciTech Connect

    Decleva, Eva; Menegazzi, Renzo; Fasolo, Alba; Defendi, Federica

    2013-07-15

    depolarization and pH{sub i} decrease. • Intracellular shunting of O{sub 2}{sup −} contributes to charge compensation in neutrophils.

  9. Regulation of intracellular heme trafficking revealed by subcellular reporters

    PubMed Central

    Yuan, Xiaojing; Rietzschel, Nicole; Walter Nuno, Ana Beatriz; Hanna, David A.; Phillips, John D.; Raven, Emma L.; Reddi, Amit R.; Hamza, Iqbal

    2016-01-01

    Heme is an essential prosthetic group in proteins that reside in virtually every subcellular compartment performing diverse biological functions. Irrespective of whether heme is synthesized in the mitochondria or imported from the environment, this hydrophobic and potentially toxic metalloporphyrin has to be trafficked across membrane barriers, a concept heretofore poorly understood. Here we show, using subcellular-targeted, genetically encoded hemoprotein peroxidase reporters, that both extracellular and endogenous heme contribute to cellular labile heme and that extracellular heme can be transported and used in toto by hemoproteins in all six subcellular compartments examined. The reporters are robust, show large signal-to-background ratio, and provide sufficient range to detect changes in intracellular labile heme. Restoration of reporter activity by heme is organelle-specific, with the Golgi and endoplasmic reticulum being important sites for both exogenous and endogenous heme trafficking. Expression of peroxidase reporters in Caenorhabditis elegans shows that environmental heme influences labile heme in a tissue-dependent manner; reporter activity in the intestine shows a linear increase compared with muscle or hypodermis, with the lowest heme threshold in neurons. Our results demonstrate that the trafficking pathways for exogenous and endogenous heme are distinct, with intrinsic preference for specific subcellular compartments. We anticipate our results will serve as a heuristic paradigm for more sophisticated studies on heme trafficking in cellular and whole-animal models. PMID:27528661

  10. Detection of functional class II-associated antigen: role of a low density endosomal compartment in antigen processing

    PubMed Central

    1995-01-01

    We have developed a functional assay to identify processed antigen in subcellular fractions from antigen-presenting cells; stimulatory activity in this assay may be caused by either free peptide fragments or by complexes of peptide fragments and class II molecules present on organellar membrane sheets and vesicles. In addition, we have developed a functional assay to identify proteolytic activity in subcellular fractions capable of generating antigenic peptides from intact proteins. These techniques permit the direct identification of intracellular sites of antigen processing and class II association. Using a murine B cell line stably transfected with a phosphorylcholine (PC)-specific membrane-bound immunoglobulin (Ig), we show that PC- conjugated antigens are rapidly internalized and efficiently degraded to generate processed antigen within an early low density compartment. Proteolytic activity capable of generating antigenic peptide fragments from intact proteins is found within low density endosomes and a dense compartment consistent with lysosomes. However, neither processed peptide nor peptide-class II complexes are detected in lysosomes from antigen-pulsed cells. Furthermore, blocking the intracellular transport of internalized antigen from the low density endosome to lysosomes does not inhibit the generation of processed antigen. Therefore, antigens internalized in association with membrane Ig on B cells can be efficiently processed in low density endosomal compartments without the contribution of proteases present within denser organelles. PMID:7722450

  11. The effect of extracellular weak acids and bases on the intracellular buffering power of snail neurones.

    PubMed Central

    Szatkowski, M S

    1989-01-01

    1. Intracellular pH (pHi) was measured in snail neurones using pH-sensitive glass microelectrodes. The influence of externally applied weak acids and bases on the total intracellular buffering power (beta T) was investigated by monitoring the pHi changes caused by the intracellular ionophoretic injection of HCl. 2. In the absence of weak acids or bases a reduction in the extracellular HEPES concentration had no effect on pHi or on beta T. It did, however, reduce slightly the rate of pHi recovery following HCl injection. 3. The presence of CO2 greatly increased beta T. However, as predicted for an open buffer system, the contributions to intracellular buffering by CO2 (beta CO2) decreased as pHi decreased. 4. When added to the superfusate, procaine, 4-aminopyridine, trimethylamine and NH4Cl (1-10 mM) all increased steady-state pHi. Procaine was fastest at increasing pHi and 4-aminopyridine the slowest. All four of these weak bases increased beta T. 5. The intracellular buffering action by these weak bases varied. HCl injection in the presence of procaine usually resulted in steady-state pHi changes with no pHi transients. In the presence of the other three weak bases HCl injections resulted in intracellular acidifications which were followed by pHi recovery-like transients. However, these were not blocked by SITS (4-acetamido-4'-isothiocyanatostilbene-2,2'-disulphonic acid) or by CaCl2 and I thus conclude that these transients were as a result of slow or incomplete intracellular buffering by the weak bases. 6. In many cells there was a good correlation between the measured contributions to intracellular buffering by the weak bases (beta base) and those predicted assuming a simple two-compartment open system. In all cases, as predicted, beta base increased as pHi decreased. 7. I found a clear relationship between the concentration of external buffer (HEPES) and the rate at which weak bases, applied to the superfusate, were able to increase pHi. The greater the

  12. Targeted intracellular delivery of therapeutics: an overview.

    PubMed

    Rawat, A; Vaidya, B; Khatri, K; Goyal, A K; Gupta, P N; Mahor, S; Paliwal, R; Rai, S; Vyas, S P

    2007-09-01

    During the last decade, intracellular drug delivery has become an emerging area of research in the medical and pharmaceutical field. Many therapeutic agents such as drugs and DNA/oligonucleotides can be delivered not just to the cell but also to a particular compartment of that cell to achieve better activity e.g. proapoptotic drugs to the mitochondria, antibiotics and enzymes to the lysosomes and various anticancer drugs and gene to the nucleus. The lipidic nature of biological membrans is the major obstacle to the intracellular delivery of macromolecular and ionic drugs. Additionally, after endocytosis, the lysosome, the major degradation compartment, needs to be avoided for better activity. To avoid these problems, various carriers have been investigated for efficient intracellular delivery, either by direct entry to cytoplasm or by escaping the endosomal compartment. These include cell penetrating peptides, and carrier systems such as liposomes, cationic lipids and polymers, polymeric nanoparticles, etc. Various properties of these carriers, including size, surface charge, composition and the presence of cell specific ligands, alter their efficacy and specificity towards particular cells. This review summarizes various aspects of targeted intracellular delivery of therapeutics including pathways, mechanisms and approaches. Various carrier constructs having potential for targeted intracellular delivery are also been discussed.

  13. Compartment Syndrome of the Hand.

    PubMed

    Oak, Nikhil R; Abrams, Reid A

    2016-07-01

    Hand compartment syndrome has many etiologies; untreated, it has dire functional consequences. Intracompartmental pressure exceeding capillary filling pressure causes decreased tissue perfusion resulting in progressive ischemic death of compartment contents. Clinical findings can evolve. Serial physical examinations are recommended and, if equivocal, interstitial pressure monitoring is indicated. Definitive management is emergent fasciotomies with incisions designed to decompress the involved hand compartments, which could include the thenar, hypothenar, and interosseous compartments, and the carpal tunnel. Careful wound care, edema management, splinting, and hand therapy are critical. Therapy should start early postoperatively, possibly before wound closure. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Intracellular microlasers

    NASA Astrophysics Data System (ADS)

    Humar, Matjaž; Hyun Yun, Seok

    2015-09-01

    Optical microresonators, which confine light within a small cavity, are widely exploited for various applications ranging from the realization of lasers and nonlinear devices to biochemical and optomechanical sensing. Here we use microresonators and suitable optical gain materials inside biological cells to demonstrate various optical functions in vitro including lasing. We explore two distinct types of microresonator—soft and hard—that support whispering-gallery modes. Soft droplets formed by injecting oil or using natural lipid droplets support intracellular laser action. The laser spectra from oil-droplet microlasers can chart cytoplasmic internal stress (˜500 pN μm-2) and its dynamic fluctuations at a sensitivity of 20 pN μm-2 (20 Pa). In a second form, whispering-gallery modes within phagocytized polystyrene beads of different sizes enable individual tagging of thousands of cells easily and, in principle, a much larger number by multiplexing with different dyes.

  15. The contribution of both oxygen and nitrogen intermediates to the intracellular killing mechanisms of C1q-opsonized Listeria monocytogenes by the macrophage-like IC-21 cell line

    PubMed Central

    Álvarez-Domínguez, C; Carrasco-Marín, E; López-Mato, P; Leyva-Cobián, F

    2000-01-01

    Listeria monocytogenes is a facultative intracellular pathogen which is internalized by host mammalian cells upon binding to their surface. Further listerial growth occurs in the cytosol after escape from the phagosomal–endosomal compartment. We have previously reported that C1q is able to potentiate L. monocytogenes phagocytosis upon bacterial opsonization by ingestion through C1q-binding structures. In this report, we analysed the post-phagocytic events upon internalization of C1q-opsonized L. monocytogenes and found an induction of macrophage (Mφ)-like IC-21 cell bactericidal mechanisms displayed by the production of oxygen and nitrogen metabolites. Both types of molecules are effective in L. monocytogenes killing. Further analysis of the cellular responses promoted by interaction of C1q with its surface binding structures, leads us to consider C1q as a collaborative molecule involved in Mφ activation. Upon interaction with surface binding structures, C1q was able to trigger and/or amplify the production of reactive oxygen and nitrogen intermediates induced by stimuli such as interferon-γ and L. monocytogenes phagocytosis. PMID:11012757

  16. The contribution of both oxygen and nitrogen intermediates to the intracellular killing mechanisms of C1q-opsonized Listeria monocytogenes by the macrophage-like IC-21 cell line.

    PubMed

    Alvarez-Domínguez, C; Carrasco-Marín, E; López-Mato, P; Leyva-Cobián, F

    2000-09-01

    Listeria monocytogenes is a facultative intracellular pathogen which is internalized by host mammalian cells upon binding to their surface. Further listerial growth occurs in the cytosol after escape from the phagosomal-endosomal compartment. We have previously reported that C1q is able to potentiate L. monocytogenes phagocytosis upon bacterial opsonization by ingestion through C1q-binding structures. In this report, we analysed the post-phagocytic events upon internalization of C1q-opsonized L. monocytogenes and found an induction of macrophage (Mphi)-like IC-21 cell bactericidal mechanisms displayed by the production of oxygen and nitrogen metabolites. Both types of molecules are effective in L. monocytogenes killing. Further analysis of the cellular responses promoted by interaction of C1q with its surface binding structures, leads us to consider C1q as a collaborative molecule involved in Mphi activation. Upon interaction with surface binding structures, C1q was able to trigger and/or amplify the production of reactive oxygen and nitrogen intermediates induced by stimuli such as interferon-gamma and L. monocytogenes phagocytosis.

  17. COMPARTMENTED REACTOR FUEL ELEMENT

    DOEpatents

    Cain, F.M. Jr.

    1962-09-11

    A method of making a nuclear reactor fuel element of the elongated red type is given wherein the fissionable fuel material is enclosed within a tubular metal cladding. The method comprises coating the metal cladding tube on its inside wall with a brazing alloy, inserting groups of cylindrical pellets of fissionable fuel material into the tube with spacing members between adjacent groups of pellets, sealing the ends of the tubes to leave a void space therewithin, heating the tube and its contents to an elevated temperature to melt the brazing alloy and to expand the pellets to their maximum dimensions under predetermined operating conditions thereby automatically positioning the spacing members along the tube, and finally cooling the tube to room temperature whereby the spacing disks become permanently fixed at their edges in the brazing alloy and define a hermetically sealed compartment for each fl group of fuel pellets. Upon cooling, the pellets contract thus leaving a space to accommodate thermal expansion of the pellets when in use in a reactor. The spacing members also provide lateral support for the tubular cladding to prevent collapse thereof when subjected to a reactor environment. (AEC)

  18. Contribution of mitochondria to the removal of intracellular Ca2+ induced by caffeine and rapid cooling at low temperatures in ferret ventricular muscles.

    PubMed

    Tanaka, E; Kurihara, S

    1997-06-01

    We investigated the role of mitochondria in the removal of intracellular Ca2+ which was increased by caffeine (15 mM, Caf), rapid lowering of the solution temperature from 30 to 4 degrees C (rapid cooling, RC), and electrical stimulation (0.07 Hz, ES). For this purpose, the intracellular Ca2+ concentration ([Ca2+]i) was measured using aequorin from the superficial cells of ferret papillary muscles. The three maneuvers induced transient changes in [Ca2+]i with different time courses. The decay time of the aequorin light signal (DT) in the Caf-induced Ca2+ release was significantly prolonged by the inhibitors for Na+-Ca2+ exchanger (Ni2+, Na+-free solution) at higher temperatures (> or = 12 degrees C). In the caffeine application at lower temperatures (< or = 12 degrees C), the inhibitors for mitochondria (ruthenium red, NaN3) significantly prolonged the DT but other inhibitors were ineffective. In the RC-induced Ca2+ release, DT was significantly prolonged by the mitochondrial inhibitors but other inhibitors were not effective. In the ES-induced Ca2+ release, each inhibitor for the sarcoplasmic reticulum (SR) (thapsigargin and 2,5-di(tert-butyl)-1,4-benzohydroquinone) prolonged the DT at all temperatures. The inhibitors for Na+-Ca2+ exchanger slightly prolonged the DT only at higher temperatures, and the mitochondrial inhibitors did not alter the DT at any temperature. These results suggest that mitochondria substantially transport Ca2+ when the Ca2+ uptake by the SR and Na+-Ca2+ exchanger are inhibited and [Ca2+]i is increased with a slower time course.

  19. A case of delayed presentation of thigh compartment syndrome.

    PubMed

    Wardi, Gabriel; Görtz, Simon; Snyder, Brian

    2014-05-01

    Thigh compartment syndrome is a rare and devastating process. It generally occurs within hours to days of a traumatic event, although cases have been reported nearly 2 weeks after the initial event. To evaluate the literature describing the timing between inciting event and presentation of thigh compartment syndromes, with a focus on delayed presentations of this rare condition. To describe the unique properties of thigh compartments, and finally, to review the anatomy and techniques needed to measure the compartment pressures of the thigh. A case of a 54-year-old man is presented. He sustained trauma to his thigh 17 days prior to presenting to our ED with severe, sudden-onset pain in his right thigh. Compartment pressures were measured and confirmed the diagnosis of compartment syndrome caused by two large intramuscular hematomas. No other contributing events were identified. Compartment syndrome in the thigh should be considered in patients with a concerning examination and a history of recent trauma. This particular case represents the longest reported time between injury and development of a thigh compartment syndrome. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Neurovascular impairment and compartment syndrome.

    PubMed

    Wright, Elizabeth

    2009-04-01

    Compartment syndrome is a potential complication of musculoskeletal trauma and surgery. Early identification of compartment syndrome is critical because, if left untreated, it may result in limb loss or death. Nurses routinely perform neurovascular observations as a part of the patient's essential care in hospital. However, there is limited literature on the assessment and early identification of compartment syndrome in children, although most authors agree on assessment criteria such as pain, warmth, colour, movement, sensation and pulses. Improved approaches to assessment and early recognition may be required so that effective action can be taken to reduce the severity of the outcome.

  1. [Compartment syndrome following adder bites].

    PubMed

    Roed, Casper; Bayer, Lasse; Lebech, Anne-Mette Kjaer; Poulsen, Jesper Brøndum; Katzenstein, Terese

    2009-01-26

    Bites from the adder, Vipera Berus, can have serious clinical consequences due to systemic effects. Meanwhile, the local swelling calls for attention as well. Two cases of seven- and eleven-year-old boys are reported. The first patient was bitten in the 5th toe, the second in the thumb. Both developed fasciotomy-requiring compartment syndrome of the lower and upper limb, respectively. Recognition of this most seldom complication of an adder bite is vital to save the limb. We recommend that the classical signs and symptoms of compartment syndrome serve as indication for surgery. However, compartment pressure measurement can be helpful in the assessment of children.

  2. Intra-abdominal hypertension and abdominal compartment syndrome.

    PubMed

    Early, Gerald L; Wesp, Julie; Augustin, Stanley M

    2012-01-01

    Abdominal compartment syndrome (ACS) is seen with increasing frequency in the critically-ill. Elevated intraabdominal pressures interfere with vital organ function and contribute to mortality. Prevention, when possible and early recognition of occurrence with timely therapy will improve survival. Measurement of bladder pressures plays a critical role in diagnosis and guiding therapy. Treatment includes non-invasive and invasive methodologies designed to decrease the volume of abdominal contents and invasive methods to increase the compartment dimensions.

  3. Simplest relationship between local field potential and intracellular signals in layered neural tissue.

    PubMed

    Chizhov, Anton V; Sanchez-Aguilera, Alberto; Rodrigues, Serafim; de la Prida, Liset Menendez

    2015-12-01

    The relationship between the extracellularly measured electric field potential resulting from synaptic activity in an ensemble of neurons and intracellular signals in these neurons is an important but still open question. Based on a model neuron with a cylindrical dendrite and lumped soma, we derive a formula that substantiates a proportionality between the local field potential and the total somatic transmembrane current that emerges from the difference between the somatic and dendritic membrane potentials. The formula is tested by intra- and extracellular recordings of evoked synaptic responses in hippocampal slices. Additionally, the contribution of different membrane currents to the field potential is demonstrated in a two-population mean-field model. Our formalism, which allows for a simple estimation of unknown dendritic currents directly from somatic measurements, provides an interpretation of the local field potential in terms of intracellularly measurable synaptic signals. It is also applicable to the study of cortical activity using two-compartment neuronal population models.

  4. Simplest relationship between local field potential and intracellular signals in layered neural tissue

    NASA Astrophysics Data System (ADS)

    Chizhov, Anton V.; Sanchez-Aguilera, Alberto; Rodrigues, Serafim; de la Prida, Liset Menendez

    2015-12-01

    The relationship between the extracellularly measured electric field potential resulting from synaptic activity in an ensemble of neurons and intracellular signals in these neurons is an important but still open question. Based on a model neuron with a cylindrical dendrite and lumped soma, we derive a formula that substantiates a proportionality between the local field potential and the total somatic transmembrane current that emerges from the difference between the somatic and dendritic membrane potentials. The formula is tested by intra- and extracellular recordings of evoked synaptic responses in hippocampal slices. Additionally, the contribution of different membrane currents to the field potential is demonstrated in a two-population mean-field model. Our formalism, which allows for a simple estimation of unknown dendritic currents directly from somatic measurements, provides an interpretation of the local field potential in terms of intracellularly measurable synaptic signals. It is also applicable to the study of cortical activity using two-compartment neuronal population models.

  5. Compartment-Specific Phosphorylation of Squid Neurofilaments.

    PubMed

    Grant, Philip; Pant, Harish C

    2016-01-01

    Studies of the giant axon and synapse of third-order neurons in the squid stellate ganglion have provided a vast literature on neuronal physiology and axon transport. Large neuronal size also lends itself to comparative biochemical studies of cell body versus axon. These have focused on the regulation of synthesis, assembly, posttranslational modification and function of neuronal cytoskeletal proteins (microtubules (MTs) and neurofilaments (NFs)), the predominant proteins in axoplasm. These contribute to axonal organization, stability, transport, and impulse transmission responsible for rapid contractions of mantle muscles underlying jet propulsion. Studies of vertebrate NFs have established an extensive literature on NF structure, organization, and function; studies of squid NFs, however, have made it possible to compare compartment-specific regulation of NF synthesis, assembly, and function in soma versus axoplasm. Since NFs contain over 100 eligible sites for phosphorylation by protein kinases, the compartment-specific patterns of phosphorylation have been a primary focus of biochemical studies. We have learned that NF phosphorylation is tightly compartmentalized; extensive phosphorylation occurs only in the axonal compartment in squid and in vertebrate neurons. This extensive phosphorylation plays a key role in organizing NFs, in association with microtubules (MTs), into a stable, dynamic functional lattice that supports axon growth, diameter, impulse transmission, and synaptic activity. To understand how cytoskeletal phosphorylation is topographically regulated, the kinases and phosphatases, bound to NFs isolated from cell bodies and axoplasm, have also been studied. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Dual-Compartment Inflatable Suitlock

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.; Guirgis, Peggy L.; Boyle, Robert M.

    2013-01-01

    There is a need for an improvement over current NASA Extravehicular Activity (EVA) technology. The technology must allow the capacity for quicker, more efficient egress/ingress, allow for shirtsleeve suit maintenance, be compact in transport, and be applicable to environments ranging from planetary surface (partial-g) to orbital or deep space zero-g environments. The technology must also be resistant to dust and other foreign contaminants that may be present on or around a planetary surface. The technology should be portable, and be capable of docking with a variety of habitats, ports, stations, vehicles, and other pressurized modules. The Dual-Compartment Inflatable Suitlock (DCIS) consists of three hard inline bulkheads, separating two cylindrical membrane-walled compartments. The Inner Bulkhead can be fitted with a variety of hatch types, docking flanges, and mating hardware, such as the Common Berthing Mechanism (CBM), for the purpose of mating with vehicles, habitats, and other pressurized modules. The Inner Bulkhead and Center Bulkhead function as the end walls of the Inner Compartment, which during operations, would stay pressurized, either matching the pressure of the habitat or acting as a lower-pressure transitional volume. The Inner Compartment contains donning/doffing fixtures and inner suit-port hatches. The Center Bulkhead has two integrated suit-ports along with a maintenance hatch. The Center Bulkhead and Outer Bulkhead function as the end walls of the Outer Compartment, which stays at vacuum during normal operations. This allows the crewmember to quickly don a suit, and egress the suitlock without waiting for the Outer Compartment to depressurize. The Outer Compartment can be pressurized infrequently for both nominal and off-nominal suit maintenance tasks, allowing shirtsleeve inspections and maintenance/repair of the environmental suits. The Outer Bulkhead has a pressure-assisted hatch door that stays open and stowed during EVA operations, but can

  7. Dual-Compartment Inflatable Suitlock

    NASA Technical Reports Server (NTRS)

    Howe, Scott; Kennedy, Kriss J.; Guirgis, Peggy L.

    2012-01-01

    A paper discusses a dual-compartment inflatable suitlock (DCIS) for Extra - vehicular Activity (EVA) that will allow for dust control, suit maintenance, and efficient EVA egress/ingress. The expandable (inflatable technologies) aspect of the design will allow the unit to stow in a compact package for transport. The DCIS consists of three hard, in line bulkheads, separating two cylindrical membrane-walled compartments. The inner bulkhead can be fitted with a variety of hatch types, docking flanges, and mating hardware, such as the common berthing mechanism (CBM), for the purpose of mating with vehicles, habitats, and other pressurized modules. The inner bulkhead and center bulkhead function as the end walls of the inner compartment, which, during operations, would stay pressurized, either matching the pressure of the habitat or acting as a lower-pressure transitional volume. The suited crewmember can quickly don a suit, and egress the suitlock without waiting for the compartment to depressurize. The outer compartment can be pressurized infrequently, when a long dwell time is expected prior to the next EVA, or during off-nominal suit maintenance tasks, allowing shirtsleeve inspections and maintenance of the space suits. The outer bulkhead has a pressure-assisted hatch door that stays open and stowed routinely, but can be closed for suit maintenance and pressurization as needed.

  8. Human immunodeficiency virus type 1 Gag proteins are processed in two cellular compartments.

    PubMed Central

    Kaplan, A H; Swanstrom, R

    1991-01-01

    The structural proteins of the retroviral capsid are translated as a polyprotein (the Gag precursor) that is cleaved by a virally encoded protease. Processing of the human immunodeficiency virus type 1 Gag precursor Pr55 was analyzed through a combination of pulse-chase labeling, cell fractionation, and immunoprecipitation. We observed a membrane-associated processing pathway for the Gag precursor that gives rise to virions. In addition, we found that a significant amount of processing occurs in the cytoplasm of infected cells resulting in the intracellular accumulation of appropriately processed viral proteins. This observation suggests the viral protease is active in the cytoplasmic compartment of the cell. Processing of the Gag protein was blocked in both compartments by the addition of a viral protease inhibitor. A comparison of the amount of cytoplasmic processing seen in lytically infected cells with that seen in chronically infected cells showed that cytoplasmic processing was associated with the lytic infection. These observations raise the possibility that activation of the human immunodeficiency virus type 1 protease in the cytoplasm of lytically infected cells might result in the cleavage of cellular proteins and thus contribute to cytotoxicity. Images PMID:2034693

  9. Corynebacterium diphtheriae putative tellurite-resistance protein (CDCE8392_0813) contributes to the intracellular survival in human epithelial cells and lethality of Caenorhabditis elegans

    PubMed Central

    dos Santos, Louisy Sanches; Antunes, Camila Azevedo; dos Santos, Cintia Silva; Pereira, José Augusto Adler; Sabbadini, Priscila Soares; de Luna, Maria das Graças; Azevedo, Vasco; Hirata, Raphael; Burkovski, Andreas; Asad, Lídia Maria Buarque de Oliveira; Mattos-Guaraldi, Ana Luíza

    2015-01-01

    Corynebacterium diphtheriae, the aetiologic agent of diphtheria, also represents a global medical challenge because of the existence of invasive strains as causative agents of systemic infections. Although tellurite (TeO32-) is toxic to most microorganisms, TeO32--resistant bacteria, including C. diphtheriae, exist in nature. The presence of TeO32--resistance (TeR) determinants in pathogenic bacteria might provide selective advantages in the natural environment. In the present study, we investigated the role of the putative TeR determinant (CDCE8392_813gene) in the virulence attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in the LDCIC-L1 mutant increased susceptibility to TeO32- and reactive oxygen species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1 mutant also showed a decrease in both the lethality of Caenorhabditis elegans and the survival inside of human epithelial cells compared to wild-type strain. Conversely, the haemagglutinating activity and adherence to and formation of biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813 gene. In conclusion, the CDCE8392_813 gene contributes to the TeR and pathogenic potential of C. diphtheriae. PMID:26107188

  10. Corynebacterium diphtheriae putative tellurite-resistance protein (CDCE8392_0813) contributes to the intracellular survival in human epithelial cells and lethality of Caenorhabditis elegans.

    PubMed

    Santos, Louisy Sanches Dos; Antunes, Camila Azevedo; Santos, Cintia Silva Dos; Pereira, José Augusto Adler; Sabbadini, Priscila Soares; Luna, Maria das Graças de; Azevedo, Vasco; Hirata Júnior, Raphael; Burkovski, Andreas; Asad, Lídia Maria Buarque de Oliveira; Mattos-Guaraldi, Ana Luíza

    2015-08-01

    Corynebacterium diphtheriae, the aetiologic agent of diphtheria, also represents a global medical challenge because of the existence of invasive strains as causative agents of systemic infections. Although tellurite (TeO32-) is toxic to most microorganisms, TeO32--resistant bacteria, including C. diphtheriae, exist in nature. The presence of TeO32--resistance (TeR) determinants in pathogenic bacteria might provide selective advantages in the natural environment. In the present study, we investigated the role of the putative TeR determinant (CDCE8392_813gene) in the virulence attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in the LDCIC-L1 mutant increased susceptibility to TeO32- and reactive oxygen species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1 mutant also showed a decrease in both the lethality of Caenorhabditis elegans and the survival inside of human epithelial cells compared to wild-type strain. Conversely, the haemagglutinating activity and adherence to and formation of biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813 gene. In conclusion, the CDCE8392_813 gene contributes to the TeR and pathogenic potential of C. diphtheriae.

  11. Metabolic coupling in urothelial bladder cancer compartments and its correlation to tumor aggressiveness

    PubMed Central

    Afonso, Julieta; Santos, Lúcio L.; Morais, António; Amaro, Teresina; Longatto-Filho, Adhemar; Baltazar, Fátima

    2016-01-01

    abstract Monocarboxylate transporters (MCTs) are vital for intracellular pH homeostasis by extruding lactate from highly glycolytic cells. These molecules are key players of the metabolic reprogramming of cancer cells, and evidence indicates a potential contribution in urothelial bladder cancer (UBC) aggressiveness and chemoresistance. However, the specific role of MCTs in the metabolic compartmentalization within bladder tumors, namely their preponderance on the tumor stroma, remains to be elucidated. Thus, we evaluated the immunoexpression of MCTs in the different compartments of UBC tissue samples (n = 111), assessing the correlations among them and with the clinical and prognostic parameters. A significant decrease in positivity for MCT1 and MCT4 occurred from normoxic toward hypoxic regions. Significant associations were found between the expression of MCT4 in hypoxic tumor cells and in the tumor stroma. MCT1 staining in normoxic tumor areas, and MCT4 staining in hypoxic regions, in the tumor stroma and in the blood vessels were significantly associated with UBC aggressiveness. MCT4 concomitant positivity in hypoxic tumor cells and in the tumor stroma, as well as positivity in each of these regions concomitant with MCT1 positivity in normoxic tumor cells, was significantly associated with an unfavourable clinicopathological profile, and predicted lower overall survival rates among patients receiving platinum-based chemotherapy. Our results point to the existence of a multi-compartment metabolic model in UBC, providing evidence of a metabolic coupling between catabolic stromal and cancer cells’ compartments, and the anabolic cancer cells. It is urgent to further explore the involvement of this metabolic coupling in UBC progression and chemoresistance. PMID:26636903

  12. Role of Repeat Muscle Compartment Pressure Measurements in Chronic Exertional Compartment Syndrome of the Lower Leg.

    PubMed

    van Zantvoort, Aniek P M; de Bruijn, Johan A; Winkes, Michiel B; Hoogeveen, Adwin R; Teijink, Joep A W; Scheltinga, Marc R

    2017-06-01

    The diagnostic gold standard for diagnosing chronic exertional compartment syndrome (CECS) is a dynamic intracompartmental pressure (ICP) measurement of the muscle. The potential role of a repeat ICP (re-ICP) measurement in patients with persistent lower leg symptoms after surgical decompression or with ongoing symptoms after an earlier normal ICP is unknown. To study whether re-ICP measurements in patients with persistent CECS-like symptoms of the lower leg may contribute to the diagnosis of CECS after both surgical decompression and a previously normal ICP measurement. Case series; Level of evidence, 4. Charts of patients who underwent re-ICP measurement of lower leg compartments (anterior [ant], deep posterior [dp], and/or lateral [lat] compartments) between 2001 and 2013 were retrospectively studied. CECS was diagnosed on the basis of generally accepted cutoff pressures for newly onset CECS (Pedowitz criteria: ICP at rest ≥15 mmHg, ≥30 mmHg after 1 minute, or ≥20 mmHg 5 minutes after a provocative test). Factors predicting recurrent CECS after surgery or after a previously normal ICP measurement were analyzed. A total of 1714 ICP measurements were taken in 1513 patients with suspected CECS over a 13-year observation period. In all, 201 (12%) tests were re-ICP measurements for persistent lower leg symptoms. Based on the proposed ICP cutoff values, CECS recurrence was diagnosed in 16 of 62 previously operated compartments (recurrence rate, 26%; 53 patients [64% female]; median age, 24 years; age range, 15-78 years). Recurrence rates were not different among the 3 lower leg CECS compartments (ant-CECS, 17%; dp-CECS, 33%; lat-CECS, 30%; χ(2) = 1.928, P = .381). Sex (χ(2) = 0.058, P = .810), age (U = 378, z = 1.840, P = .066), bilaterality (χ(2) = 0.019, P = .889), and prefasciotomy ICP did not predict recurrence. Re-ICP measurements evaluating 20 compartments with previously normal ICP measurements (15 patients [53% female]; mean age, 31 ± 10 years

  13. Role of Repeat Muscle Compartment Pressure Measurements in Chronic Exertional Compartment Syndrome of the Lower Leg

    PubMed Central

    van Zantvoort, Aniek P. M.; de Bruijn, Johan A.; Winkes, Michiel B.; Hoogeveen, Adwin R.; Teijink, Joep A. W.; Scheltinga, Marc R.

    2017-01-01

    Background: The diagnostic gold standard for diagnosing chronic exertional compartment syndrome (CECS) is a dynamic intracompartmental pressure (ICP) measurement of the muscle. The potential role of a repeat ICP (re-ICP) measurement in patients with persistent lower leg symptoms after surgical decompression or with ongoing symptoms after an earlier normal ICP is unknown. Purpose: To study whether re-ICP measurements in patients with persistent CECS-like symptoms of the lower leg may contribute to the diagnosis of CECS after both surgical decompression and a previously normal ICP measurement. Study Design: Case series; Level of evidence, 4. Methods: Charts of patients who underwent re-ICP measurement of lower leg compartments (anterior [ant], deep posterior [dp], and/or lateral [lat] compartments) between 2001 and 2013 were retrospectively studied. CECS was diagnosed on the basis of generally accepted cutoff pressures for newly onset CECS (Pedowitz criteria: ICP at rest ≥15 mmHg, ≥30 mmHg after 1 minute, or ≥20 mmHg 5 minutes after a provocative test). Factors predicting recurrent CECS after surgery or after a previously normal ICP measurement were analyzed. Results: A total of 1714 ICP measurements were taken in 1513 patients with suspected CECS over a 13-year observation period. In all, 201 (12%) tests were re-ICP measurements for persistent lower leg symptoms. Based on the proposed ICP cutoff values, CECS recurrence was diagnosed in 16 of 62 previously operated compartments (recurrence rate, 26%; 53 patients [64% female]; median age, 24 years; age range, 15-78 years). Recurrence rates were not different among the 3 lower leg CECS compartments (ant-CECS, 17%; dp-CECS, 33%; lat-CECS, 30%; χ2 = 1.928, P = .381). Sex (χ2 = 0.058, P = .810), age (U = 378, z = 1.840, P = .066), bilaterality (χ2 = 0.019, P = .889), and prefasciotomy ICP did not predict recurrence. Re-ICP measurements evaluating 20 compartments with previously normal ICP measurements (15

  14. Exploring Water-Tight Compartments.

    ERIC Educational Resources Information Center

    Fishman, Steve

    John Dewey employed the phrase "water-tight compartments" to mark deficiencies of integration within an individual's personality. For Dewey, the self is complex, but a strong personality integrates its various habits so that they reinforce rather than conflict with one another. Dewey's focus on this problem of personality has relevance…

  15. Subcellular storage compartments of bacteriopheophorbide sensitizers

    NASA Astrophysics Data System (ADS)

    Moser, Joerg G.; Dembeck, U.; Hubert, M.; Spengler, Bernhard; Bayer, Rainer; Wagner, Birgit

    1994-03-01

    Fluorescence colocalization with the Golgi specific stain, NBD-ceramide, and the mitochondrial localizing stain, Rhodamine 123, confirmed the earlier assumption that the Golgi apparatus is one of the prominent storage compartments for bacteriopheophorbide esters in OAT 75 SCLC cells and several amelanotic melanoma cell lines (A375, Melur SP18, SkAMel 25). Furthermore, a diffuse staining of mitochondria, of non-structured cytoplasm, and an additional storage in melanine vesicles of the amelanotic melanoma cells suggests further storage compartments with quantitatively different contributions to the phototoxicity of bacteriochlorophyll-derived photosensitizers. Independent observations of early phototoxic effects on microfilamentous networks, enzymatic activities (succinate dehydrogenase, lactate dehydrogenase), and redistribution phenomena following primary uptake of the sensitizers let us assume that only a part of the 108 molecules taken up by a cell contribute directly to phototoxicity. Thus it may be asked if a proper subcellular positioning of only a few sensitizer molecules may have similar phototoxic effects as the huge amounts stored at apparently ineffective sites.

  16. Computer model of unstirred layer and intracellular pH changes. Determinants of unstirred layer pH.

    PubMed

    Marrannes, Roger

    2013-06-01

    Transmembrane acid-base fluxes affect the intracellular pH and unstirred layer pH around a superfused biological preparation. In this paper the factors influencing the unstirred layer pH and its gradient are studied. An analytical expression of the unstirred layer pH gradient in steady state is derived as a function of simultaneous transmembrane fluxes of (weak) acids and bases with the dehydration reaction of carbonic acid in equilibrium. Also a multicompartment computer model is described consisting of the extracellular bulk compartment, different unstirred layer compartments and the intracellular compartment. With this model also transient changes and the influence of carbonic anhydrase (CA) can be studied. The analytical expression and simulations with the multicompartment model demonstrate that in steady state the unstirred layer pH and its gradient are influenced by the size and type of transmembrane flux of acids and bases, their dissociation constant and diffusion coefficient, the concentration, diffusion coefficient and type of mobile buffers and the activity and location of CA. Similar principles contribute to the amplitude of the unstirred layer pH transients. According to these models an immobile buffer does not influence the steady-state pH, but reduces the amplitude of pH transients especially when these are fast. The unstirred layer pH provides useful information about transmembrane acid-base fluxes. This paper gives more insight how the unstirred layer pH and its transients can be interpreted. Methodological issues are discussed.

  17. Toward Intracellular Targeted Delivery of Cancer Therapeutics

    PubMed Central

    Pandya, Hetal; Debinski, Waldemar

    2013-01-01

    A number of anti-cancer drugs have their targets localized to particular intracellular compartments. These drugs reach the targets mainly through diffusion, dependent on biophysical and biochemical forces that allow cell penetration. This means that both cancer cells and normal cells will be subjected to such diffusion; hence many of these drugs, like chemotherapeutics, are potentially toxic and the concentration achieved at the site of their action is often suboptimal. The same relates to radiation that indiscriminately affects normal and diseased cells. However, nature-designed systems enable compounds present in the extracellular environment to end up inside the cell and even travel to more specific intracellular compartments. For example, viruses and bacterial toxins can more or less specifically recognize eukaryotic cells, enter these cells, and direct some protein portions to designated intracellular areas. These phenomena have led to creative thinking, such as employing viruses or bacterial toxins for cargo delivery to cells and, more specifically, to cancer cells. Proteins can be genetically engineered in order to not only mimic what viruses and bacterial toxins can do, but also to add new functions, extending or changing the intracellular routes. It is possible to make conjugates or, more preferably, single-chain proteins that recognize cancer cells and deliver cargo inside the cells, even to the desired subcellular compartment. These findings offer new opportunities to deliver drugs/labels only to cancer cells and only to their site of action within the cells. The development of such dual-specificity vectors for targeting cancer cells is an attractive and potentially safer and more efficacious way of delivering drugs. We provide examples of this approach for delivering brain cancer therapeutics, using a specific biomarker on glioblastoma tumor cells. PMID:22671766

  18. Emerging Technologies and Their Applications in Lipid Compartment Measurement

    PubMed Central

    Heymsfield, Steven B.; Hu, Houchun Harry; Shen, Wei; Carmichael, Owen

    2015-01-01

    Non-Communicable diseases (NCDs), including obesity, are emerging as the major health concern of the 21st century. Excess adiposity and related NCD metabolic disturbances have stimulated development of new lipid compartment measurement technologies to help us understand cellular energy exchange, to refine phenotypes, and to develop predictive markers of adverse clinical outcomes. Recent advances now allow for quantification of multiple intracellular lipid and adipose tissue compartments that can be evaluated across the human lifespan. With magnetic resonance methods leading the way, newer approaches will give molecular structural and metabolic information beyond the laboratory in real-world settings. The union between these new technologies and the growing NCD population is creating an exciting interface advancing our understanding of chronic disease mechanisms. PMID:26596676

  19. Small Peptide Recognition Sequence for Intracellular Sorting

    PubMed Central

    Pandey, Kailash N.

    2010-01-01

    Increasing evidence indicate that complex arrays of short signals and recognition peptide sequence ensure accurate trafficking and distribution of transmembrane receptors and/or proteins and their ligands into intracellular compartments. Internalization and subsequent trafficking of cell-surface receptors into the cell interior is mediated by specific short-sequence peptide signals within the cytoplasmic domains of these receptor proteins. The short signals usually consist of small linear amino acid sequences, which are recognized by adaptor coat proteins along the endocytic and sorting pathways. In recent years, much has been learned about the function and mechanisms of endocytic pathways responsible for the trafficking and molecular sorting of membrane receptors and their ligands into intracellular compartments, however, the significance and scope of the short sequence motifs in these cellular events is not well understood. Here a particular emphasis has been given to the functions of short-sequence signal motifs responsible for the itinerary and destination of membrane receptors and proteins moving into subcellular compartments. PMID:20817434

  20. The Orbital Workshop Shower Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This photograph shows technicians performing a checkout of the Metabolic Analyzer (center background) and the Ergometer (foreground) in the Orbital Workshop (OWS). The shower compartment is at right. The Ergometer (Skylab Experiment M171) evaluated man's metabolic effectiveness and cost of work in space environment. Located in the experiment and work area of the OWS, the shower compartment was a cylindrical cloth enclosure that was folded flat when not in use. The bottom ring of the shower was fastened to the floor and contained foot restraints. The upper ring contained the shower head and hose. To use the shower, the astronaut filled a pressurized portable bottle with heated water and attached the bottle to the ceiling. A flexible hose cornected the water bottle to a handheld shower head. The astronaut pulled the cylindrical shower wall up into position and bathed, using liquid soap. Both soap and water were carefully rationed, having been premeasured for economical use.

  1. Functional Analysis of the Hydrophilic Loop in Intracellular Trafficking of Arabidopsis PIN-FORMED Proteins.

    PubMed

    Ganguly, Anindya; Park, Minho; Kesawat, Mahipal Singh; Cho, Hyung-Taeg

    2014-04-01

    Different PIN-FORMED proteins (PINs) contribute to intercellular and intracellular auxin transport, depending on their distinctive subcellular localizations. Arabidopsis thaliana PINs with a long hydrophilic loop (HL) (PIN1 to PIN4 and PIN7; long PINs) localize predominantly to the plasma membrane (PM), whereas short PINs (PIN5 and PIN8) localize predominantly to internal compartments. However, the subcellular localization of the short PINs has been observed mostly for PINs ectopically expressed in different cell types, and the role of the HL in PIN trafficking remains unclear. Here, we tested whether a long PIN-HL can provide its original molecular cues to a short PIN by transplanting the HL. The transplanted long PIN2-HL was sufficient for phosphorylation and PM trafficking of the chimeric PIN5:PIN2-HL but failed to provide the characteristic polarity of PIN2. Unlike previous observations, PIN5 showed clear PM localization in diverse cell types where PIN5 is natively or ectopically expressed and even polar PM localization in one cell type. Furthermore, in the root epidermis, the subcellular localization of PIN5 switched from PM to internal compartments according to the developmental stage. Our results suggest that the long PIN-HL is partially modular for the trafficking behavior of PINs and that the intracellular trafficking of PIN is plastic depending on cell type and developmental stage.

  2. Glucose transporter 4: cycling, compartments and controversies

    PubMed Central

    Dugani, Chandrasagar B; Klip, Amira

    2005-01-01

    Insulin promotes glucose uptake into muscle and adipose tissues through glucose transporter 4 (GLUT4). In unstimulated cells, rapid endocytosis, slow exocytosis and dynamic or static retention cause GLUT4 to concentrate in early recycling endosomes, the trans-Golgi network and vesicle-associated protein 2-containing vesicles. The coordinated action of phosphatidylinositol 3-kinase effectors, protein kinase Akt, atypical protein kinase C (aPKC) and Akt substrate of 160-kDa (AS160), regulates the GLUT4 cycle by affecting its translocation, fusion with the plasma membrane, internalization and sorting. We review the evidence that supports such cycling, evaluate current models proposing static or dynamic retention, and highlight how distinct steps of GLUT4 transport are regulated by insulin signals. In particular, fusion seems to be regulated by aPKC (via munc18) and Akt (via syntaxin4-interacting protein (synip)). AS160 participates in GLUT4 intracellular retention, and possibly fusion, through candidate ras-related GTP-binding protein (Rab)2, Rab8, Rab10 and/or Rab14. The localization of the insulin-sensitive GLUT4 compartment and the precise target of insulin-derived signals remain open for future investigation. PMID:16319959

  3. The Orbital Workshop Sleep Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This wide-angle view is of the Orbital Workshop (OWS) sleep compartment, located in the lower level of the OWS. Each crewman was assigned a small space for sleeping and zipped themselves into sleeping bags stretched against the wall. Because of the absence of gravity, sleeping comfort was achieved in any position relative to the spacecraft; body support was not necessary. Sleeping could be accommodated quite comfortably in a bag that held the body at a given place in Skylab.

  4. σS Controls Multiple Pathways Associated with Intracellular Multiplication of Legionella pneumophila▿ †

    PubMed Central

    Hovel-Miner, Galadriel; Pampou, Sergey; Faucher, Sebastien P.; Clarke, Margaret; Morozova, Irina; Morozov, Pavel; Russo, James J.; Shuman, Howard A.; Kalachikov, Sergey

    2009-01-01

    Legionella pneumophila is the causative agent of the severe and potentially fatal pneumonia Legionnaires' disease. L. pneumophila is able to replicate within macrophages and protozoa by establishing a replicative compartment in a process that requires the Icm/Dot type IVB secretion system. The signals and regulatory pathways required for Legionella infection and intracellular replication are poorly understood. Mutation of the rpoS gene, which encodes σS, does not affect growth in rich medium but severely decreases L. pneumophila intracellular multiplication within protozoan hosts. To gain insight into the intracellular multiplication defect of an rpoS mutant, we examined its pattern of gene expression during exponential and postexponential growth. We found that σS affects distinct groups of genes that contribute to Legionella intracellular multiplication. We demonstrate that rpoS mutants have a functional Icm/Dot system yet are defective for the expression of many genes encoding Icm/Dot-translocated substrates. We also show that σS affects the transcription of the cpxR and pmrA genes, which encode two-component response regulators that directly affect the transcription of Icm/Dot substrates. Our characterization of the L. pneumophila small RNA csrB homologs, rsmY and rsmZ, introduces a link between σS and the posttranscriptional regulator CsrA. We analyzed the network of σS-controlled genes by mutational analysis of transcriptional regulators affected by σS. One of these, encoding the L. pneumophila arginine repressor homolog gene, argR, is required for maximal intracellular growth in amoebae. These data show that σS is a key regulator of multiple pathways required for L. pneumophila intracellular multiplication. PMID:19218380

  5. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to be... controls, call buttons, electrical outlets, etc.) shall be mounted no more than 48 inches, and no less than...

  6. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to be... controls, call buttons, electrical outlets, etc.) shall be mounted no more than 48 inches, and no less than...

  7. Method and apparatus to assess compartment syndrome

    NASA Technical Reports Server (NTRS)

    Ueno, Toshiaki (Inventor); Hargens, Alan R. (Inventor); Yost, William T. (Inventor)

    2008-01-01

    A method and apparatus for measuring pressure buildup in a body compartment that encases muscular tissue. The method includes assessing the body compartment configuration and identifying the effect of pulsatile components on at least one compartment dimension. This process is used in preventing tissue necrosis, and in decisions of whether to perform surgery on the body compartment for prevention of Compartment Syndrome. An apparatus is used for measuring excess pressure in the body compartment having components for imparting ultrasonic waves such as a transducer, placing the transducer to impart the ultrasonic waves, capturing the reflected imparted ultrasonic waves, and converting them to electrical signals, a pulsed phase-locked loop device for assessing a body compartment configuration and producing an output signal, and means for mathematically manipulating the output signal to thereby categorize pressure build-up in the body compartment from the mathematical manipulations.

  8. Orbiter Crew Compartment Integration-Stowage

    NASA Technical Reports Server (NTRS)

    Morgan, L. Gary

    2007-01-01

    This viewgraph presentation describes the Orbiter Crew Compartment Integration (CCI) stowage. The evolution of orbiter crew compartment stowage volume is also described, along with photographs presented of the on-orbit volume stowage capacity.

  9. The cell outgrowth secretory endosome (COSE): a specialized compartment involved in neuronal morphogenesis.

    PubMed

    Alberts, Philipp; Galli, Thierry

    2003-10-01

    The role of intracellular membrane trafficking in cellular morphogenesis is still unclear. We propose here a prominent function of a recently identified compartment that we propose to call the cell outgrowth secretory endosome (COSE), the exocytosis of which is controlled by the v-SNARE TIVAMP and by cell-cell adhesion.

  10. 14 CFR 29.771 - Pilot compartment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment. 29.771 Section 29.771... Pilot compartment. For each pilot compartment— (a) The compartment and its equipment must allow each pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  11. 14 CFR 27.771 - Pilot compartment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment. 27.771 Section 27.771... Pilot compartment. For each pilot compartment— (a) The compartment and its equipment must allow each pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  12. 14 CFR 23.771 - Pilot compartment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment. 23.771 Section 23.771... Cargo Accommodations § 23.771 Pilot compartment. For each pilot compartment— (a) The compartment and its equipment must allow each pilot to perform his duties without unreasonable concentration or fatigue; (b...

  13. 14 CFR 23.771 - Pilot compartment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pilot compartment. 23.771 Section 23.771... Cargo Accommodations § 23.771 Pilot compartment. For each pilot compartment— (a) The compartment and its equipment must allow each pilot to perform his duties without unreasonable concentration or fatigue; (b...

  14. 14 CFR 25.771 - Pilot compartment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment. 25.771 Section 25.771... Pilot compartment. (a) Each pilot compartment and its equipment must allow the minimum flight crew... pilot, the airplane must be controllable with equal safety from either pilot seat. (d) The pilot...

  15. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  16. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Sleeping compartments. 1192.127 Section 1192.127 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS... Intercity Rail Cars and Systems § 1192.127 Sleeping compartments. (a) Sleeping compartments required to...

  17. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  18. 14 CFR 25.787 - Stowage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Personnel and Cargo Accommodations § 25.787 Stowage compartments. (a) Each compartment for the stowage of cargo, baggage, carry-on articles, and... to compartments located below, or forward, of all occupants in the airplane. If the airplane has a...

  19. 14 CFR 25.787 - Stowage compartments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Personnel and Cargo Accommodations § 25.787 Stowage compartments. (a) Each compartment for the stowage of cargo, baggage, carry-on articles, and... to compartments located below, or forward, of all occupants in the airplane. If the airplane has a...

  20. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  1. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Sleeping compartments. 38.127 Section 38.127... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a) Sleeping compartments required to be accessible shall be designed so as to allow a person using...

  2. Evolution of intracellular pathogens.

    PubMed

    Casadevall, Arturo

    2008-01-01

    The evolution of intracellular pathogens is considered in the context of ambiguities in basic definitions and the diversity of host-microbe interactions. Intracellular pathogenesis is a subset of a larger world of host-microbe interactions that includes amoeboid predation and endosymbiotic existence. Intracellular pathogens often reveal genome reduction. Despite the uniqueness of each host-microbe interaction, there are only a few general solutions to the problem of intracellular survival, especially in phagocytic cells. Similarities in intracellular pathogenic strategies between phylogenetically distant microbes suggest convergent evolution. For discerning such patterns, it is useful to consider whether the microbe is acquired from another host or directly from the environment. For environmentally acquired microbes, biotic pressures, such as amoeboid predators, may select for the capacity for virulence. Although often viewed as a specialized adaptation, the capacity for intracellular survival may be widespread among microbes, thus questioning whether the intracellular lifestyle warrants a category of special distinctiveness.

  3. Neutral buoyancy testing of a shuttle orbiter crew compartment

    NASA Technical Reports Server (NTRS)

    Rosener, A. A.; Stephenson, M. L.

    1973-01-01

    The architectural and man-machine aspects of a shuttle orbiter crew compartment were examined. All phases of the Orbiter's flight mode from launch through zero gravity, reentry, and ferry flight are considered. The data provides an initial design criteria that treats the crew compartment as a total system and provides data that has a direct contribution to the development of flight hardware. Primary interest was centered on the design of the galley, hygiene facility, passenger couches, airlock, work station, and flight deck access. The man-machine interface emphasis was placed on identifying and developing solutions for problems in mobility/restraint, ingress/egress, accessibility, and volume utilization.

  4. Photoactivatable Drug-Caged Fluorophore Conjugate Allows Direct Quantification of Intracellular Drug Transport

    PubMed Central

    Kohler, Rainer H.; Weissleder, Ralph

    2013-01-01

    We report here a method that utilizes photoactivatable drug-caged fluorophore conjugate to quantify intracellular drug trafficking processes at single cell resolution. Photoactivation is performed in labeled cellular compartments to visualize intracellular drug exchange at physiologic conditions, without the need for washing, facilitating its translation to in vivo cancer models. PMID:24135896

  5. Hypothyroid-induced acute compartment syndrome in all extremities

    PubMed Central

    Musielak, Matthew C.; Chae, Jung Hee

    2016-01-01

    Acute compartment syndrome (ACS) is an uncommon complication of uncontrolled hypothyroidism. If unrecognized, this can lead to ischemia, necrosis and potential limb loss. A 49-year-old female presented with the sudden onset of bilateral lower and upper extremity swelling and pain. The lower extremity anterior compartments were painful and tense. The extensor surface of the upper extremities exhibited swelling and pain. Motor function was intact, however, limited due to pain. Bilateral lower extremity fasciotomies were performed. Postoperative Day 1, upper extremity motor function decreased significantly and paresthesias occurred. She therefore underwent bilateral forearm fasciotomies. The pathogenesis of hypothyroidism-induced compartment syndrome is unclear. Thyroid-stimulating hormone-induced fibroblast activation results in increased glycosaminoglycan deposition. The primary glycosaminoglycan in hypothyroid myxedematous changes is hyaluronic acid, which binds water causing edema. This increases vascular permeability, extravasation of proteins and impaired lymphatic drainage. These contribute to increased intra-compartmental pressure and subsequent ACS. PMID:28003319

  6. Acute Compartment Syndrome of the Leg.

    PubMed

    Konda, Sanjit R; Kester, Benjamin S; Fisher, Nina; Behery, Omar A; Crespo, Alexander M; Egol, Kenneth A

    2017-08-01

    Acute compartment syndrome (ACS) is well known among orthopaedic surgeons. The timely diagnosis and management of ACS is crucial to avoiding its sequelae, including renal failure, ischemic contractures, and limb loss. Despite its relative importance, ACS poses a challenge to many residents and clinicians as diagnosis relies largely on clinical judgment. Timely diagnosis and thorough compartment release are essential to optimizing outcomes in ACS. This video highlights a clinical case in which compartment syndrome of the leg was considered, diagnosed, and surgically managed. This video will present the indications for compartment release and a video-guided demonstration of compartment checks using an arterial line transducer, a 4-compartment fasciotomy with 2 incisions, and temporizing vessel loop closure. Compartment syndrome can be a devastating complication of common fractures. It is essential that orthopaedic practitioners understand the immediacy of intervention. We have a responsibility to provide timely, accurate diagnosis along with expedient surgical management.

  7. RAB24 facilitates clearance of autophagic compartments during basal conditions

    PubMed Central

    Ylä-Anttila, Päivi; Mikkonen, Elisa; Happonen, Kaisa E; Holland, Petter; Ueno, Takashi; Simonsen, Anne; Eskelinen, Eeva-Liisa

    2015-01-01

    RAB24 belongs to a family of small GTPases and has been implicated to function in autophagy. Here we confirm the intracellular localization of RAB24 to autophagic vacuoles with immuno electron microscopy and cell fractionation, and show that prenylation and guanine nucleotide binding are necessary for the targeting of RAB24 to autophagic compartments. Further, we show that RAB24 plays a role in the maturation and/or clearance of autophagic compartments under nutrient-rich conditions, but not during short amino acid starvation. Quantitative electron microscopy shows an increase in the numbers of late autophagic compartments in cells silenced for RAB24, and mRFP-GFP-LC3 probe and autophagy flux experiments indicate that this is due to a hindrance in their clearance. Formation of autophagosomes is shown to be unaffected by RAB24-silencing with siRNA. A defect in aggregate clearance in the absence of RAB24 is also shown in cells forming polyglutamine aggregates. This study places RAB24 function in the termination of the autophagic process under nutrient-rich conditions. PMID:26325487

  8. [Fascia compartment syndrome of the iliac-psoas compartment].

    PubMed

    Klammer, A

    1983-01-01

    The iliacus compression syndrome has a kind of exceptional position--as to genesis, development and therapy--in comparison with the other compartment-compression syndromes of the limbs. Indeed there exist similar pathophysiological, rules, but the special anatomic facts enlarge the etiological, differential-diagnostic and therapeutic spectrum. Thus, concerning the frequency of causes, not the trauma but the spontaneous bleeding in coagulation disturbances takes the first place, and unusual causes, such as rupturing aortic aneurysms, have to be included in the differential diagnostic discussion. The finest diagnostic sign besides pain is the palsy of the Nervus Femoralis. As to the treatment, operative measures are possible. The exact knowledge of the anatomy is important for the understanding of the specialties mentioned above.

  9. Intracellular protein transport to the thyrocyte plasma membrane: potential implications for thyroid physiology.

    PubMed

    Arvan, P; Kim, P S; Kuliawat, R; Prabakaran, D; Muresan, Z; Yoo, S E; Abu Hossain, S

    1997-02-01

    We present a snapshot of developments in epithelial biology that may prove helpful in understanding cellular aspects of the machinery designed for the synthesis of thyroid hormones on the thyroglobulin precursor. The functional unit of the thyroid gland is the follicle, delimited by a monolayer of thyrocytes. Like the cells of most simple epithelia, thyrocytes exhibit specialization of the cell surface that confronts two different extracellular environments-apical and basolateral, which are separated by tight junctions. Specifically, the basolateral domain faces the interstitium/bloodstream, while the apical domain is in contact with the lumen that is the primary target for newly synthesized thyroglobulin secretion and also serves as a storage depot for previously secreted protein. Thyrocytes use their polarity in several important ways, such as for maintaining basolaterally located iodide uptake and T4 deiodination, as well apically located iodide efflux and iodination machinery. The mechanisms by which this organization is established, fall in large part under the more general cell biological problem of intracellular sorting and trafficking of different proteins en route to the cell surface. Nearly all exportable proteins begin their biological life after synthesis in an intracellular compartment known as the endoplasmic reticulum (ER), upon which different degrees of difficulty may be encountered during nascent polypeptide folding and initial export to the Golgi complex. In these initial stages, ER molecular chaperones can assist in monitoring protein folding and export while themselves remaining as resident proteins of the thyroid ER. After export from the ER, most subsequent sorting for protein delivery to apical or basolateral surfaces of thyrocytes occurs within another specialized intracellular compartment known as the trans-Golgi network. Targeting information encoded in secretory proteins and plasma membrane proteins can be exposed or buried at different

  10. Duality of the murine CD8 compartment

    PubMed Central

    Genolet, Raphaël; Leignadier, Julie; Østerås, Magne; Farinelli, Laurent; Stevenson, Brian J.; Luescher, Immanuel F.

    2014-01-01

    CD8αβ plays crucial roles in the thymic selection, differentiation, and activation of some, but not all, CD8+ T cells, whereas CD8αα does not. To investigate these roles, we produced mice that expressed transgene P14 T-cell receptor β (TCRβ) chain and CD8β or did not (WT and KO mice, respectively). The primary CD8+ T-cell response to acute lymphocytic choriomeningitis virus (LCMV) infection was predominantly Db/GP33 specific and CD8 independent in KO mice and was mostly CD8 dependent in WT mice. Cytotoxic T lymphocytes (CTL) from KO mice failed to mobilize intracellular Ca2+ and to kill via perforin/granzyme. Their strong Fas/FasL-mediated cytotoxicity and IFN-γ response were signaled via a Ca2+-independent, PI3K-dependent pathway. This was also true for 15–20% of CD8-independent CTL found in WT mice. Conversely, the perforin/granzyme-mediated killing and IFN-γ response of CD8-dependent CTL were signaled via a Ca2+, p56lck, and nuclear factor of activated T cells-dependent pathway. Deep sequencing of millions of TCRα chain transcripts revealed that the TCR repertoires of preimmune CD8+ T cells were highly diverse, but those of LCMV Db/GP33-specific CTL, especially from KO mice, were narrow. The immune repertoires exhibited biased use of Vα segments that encoded different complementary-determining region 1α (CDR1α) and CDR2α sequences. We suggest that TCR from WT CD8-independent T cells may engage MHC–peptide complexes in a manner unfavorable for efficient CD8 engagement and Ca2+ signaling but permissive for Ca2+-independent, PI3K-dependent signaling. This duality of the CD8 compartment may provide organisms with broader protective immunity. PMID:24594598

  11. Acute compartment syndrome caused by uncontrolled hypothyroidism.

    PubMed

    Modi, Anar; Amin, Hari; Salzman, Matthew; Morgan, Farah

    2017-06-01

    Acute compartment syndrome is increased tissue pressure exceeding perfusion pressure in a closed compartment resulting in nerve and muscle ischemia. Common precipitating causes are crush injuries, burns, substance abuse, osseous or vascular limb trauma. This is a case of 42year old female with history of hypothyroidism who presented to emergency room with acute onset of severe pain and swelling in right lower extremity. Physical examination was concerning for acute compartment syndrome of right leg which was confirmed by demonstration of elevated compartmental pressures. No precipitating causes were readily identified. Further laboratory testing revealed uncontrolled hypothyroidism. Management included emergent fasciotomy and initiating thyroid hormone replacement. This case represents a rare association between acute compartment syndrome and uncontrolled hypothyroidism. We also discuss the pathogenesis of compartment syndrome in hypothyroid patients and emphasize the importance of evaluating for less common causes, particularly in setting of non-traumatic compartment syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Independent Active Contraction of Extraocular Muscle Compartments

    PubMed Central

    Shin, Andrew; Yoo, Lawrence; Demer, Joseph L.

    2015-01-01

    Purpose. Intramuscular innervation of horizontal rectus extraocular muscle (EOMs) is segregated into superior and inferior (transverse) compartments, whereas all EOMs are also divided into global (GL) and orbital (OL) layers with scleral and pulley insertions, respectively. Mechanical independence between both types of compartments has been demonstrated during passive tensile loading. We examined coupling between EOM compartments during active, ex vivo contraction. Methods. Fresh bovine EOMs were removed, and one compartment of each was coated with hydrophobic petrolatum. Contraction of the uncoated compartment was induced by immersion in a solution of 50 mM CaCl2 at 38°C labeled with sodium fluorescein dye, whereas tensions in both compartments were monitored by strain gauges. Control experiments omitted petrolatum so that the entire EOM contracted. After physiological experiments, EOMs were sectioned transversely to demonstrate specificity of CaCl2 permeation by yellow fluorescence dye excited by blue light. Results. In control experiments without petrolatum, both transverse and GL and OL compartments contracted similarly. Selective compartmental omission of petrolatum caused markedly independent compartmental contraction whether measured at the GL or the OL insertions or for transverse compartments at the scleral insertion. Although some CaCl2 spread occurred, mean (±SD) tension in the coated compartments averaged only 10.5 ± 3.3% and 6.0 ± 1.5% in GL/OL and transverse compartments, respectively relative to uncoated compartments. Fluorescein penetration confirmed selective CaCl2 permeation. Conclusions. These data confirm passive tensile findings of mechanical independence of EOM compartments and extend results to active contraction. EOMs behave actively as if composed of mechanically independent parallel fiber bundles having different insertional targets, consistent with the active pulley and transverse compartmental hypotheses. PMID:25503460

  13. Abdominal Compartment Syndrome After Hip Arthroscopy

    DTIC Science & Technology

    2010-01-01

    K. Intra- abdominal compartment syndrome as a complication of ruptured abdomi- nal aortic aneurysm repair. Am Surg 1989;55:396-402. 6. Sugrue M...00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Abdominal Compartment Syndrome After Hip Arthroscopy 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Author’s personal copy Case Report Abdominal Compartment Syndrome After

  14. Can intramuscular glucose levels diagnose compartment syndrome?

    PubMed

    Doro, Christopher J; Sitzman, Thomas J; O'Toole, Robert V

    2014-02-01

    Compartment syndrome is difficult to diagnose, particularly in patients who are not able to undergo adequate clinical examination. Current methods rely on pressure measurements within the compartment, have high false-positive rates, and do not reliably indicate presence of muscle ischemia. We hypothesized that measurement of intramuscular glucose and oxygen can identify compartment syndrome with high sensitivity and specificity. Compartment syndrome was created in 12 anesthetized adult mixed-sex beagles, in the craniolateral compartment of a lower leg, by infusion of lactated Ringer's solution with normal serum concentration of glucose. The contralateral leg served as a control. Hydrostatic pressure, oxygen tension, and glucose concentration were recorded with commercially available probes. Compartment syndrome was maintained for 8 hours, and the animals were recovered. Two weeks later, compartment and control legs underwent muscle biopsy. Specimens were reviewed by a blinded pathologist. Within 15 minutes of creating compartment syndrome, glucose concentration and oxygen tension in the experimental limb were significantly lower than in the control limb (glucose, p = 0.02; oxygen, p = 0.007; two-tailed t test). Intramuscular glucose concentration of less than 97 mg/dL was 100% sensitive (95% confidence interval [CI], 73-100%) and 75% specific (95% CI, 40-94%) for the presence of compartment syndrome. Partial pressure of oxygen less than 30 mm Hg was 100% sensitive (95% CI, 72-100%) and 100% specific (95% CI, 69-100%) for the presence of compartment syndrome. Pathology confirmed compartment syndrome in all experimental limbs. Our results show that intramuscular glucose concentration and partial pressure of oxygen rapidly identify muscle ischemia with high sensitivity and specificity after experimentally created compartment syndrome in this animal model.

  15. Compartment syndrome after tibial plateau fracture.

    PubMed

    Pitta, Guilherme Benjamin Brandão; Dos Santos, Thays Fernanda Avelino; Dos Santos, Fernanda Thaysa Avelino; da Costa Filho, Edelson Moreira

    2014-01-01

    Fractures of the tibial plateau are relatively rare, representing around 1.2% of all fractures. The tibia, due to its subcutaneous location and poor muscle coverage, is exposed and suffers large numbers of traumas, not only fractures, but also crush injuries and severe bruising, among others, which at any given moment, could lead compartment syndrome in the patient. The case is reported of a 58-year-old patient who, following a tibial plateau fracture, presented compartment syndrome of the leg and was submitted to decompressive fasciotomy of the four right compartments. After osteosynthesis with internal fixation of the tibial plateau using an L-plate, the patient again developed compartment syndrome.

  16. Synergism between upregulation of Rab7 and inhibition of autophagic degradation caused by mycoplasma facilitates intracellular mycoplasma infection.

    PubMed

    Hu, Xiaopeng; Yu, Jie; Zhou, Xiang; Li, Zhaoming; Xia, Yun; Luo, Zhiyong; Wu, Yaqun

    2014-03-01

    Following fusion of a mycoplasma with a host cell membrane, the inserted components of mycoplasma may then be transported through the endocytic pathway. However, the effects of mycoplasmas on the host cell endomembrane system are largely unknown. In this study, mycoplasma‑induced changes in the dynamics of endocytic and autophagic systems were investigated. Endocytosis and autophagy are two major processes involved in the survival of intracellular prokaryotic pathogens. It was found that, immediately following infection, mycoplasmas induce endocytosis in the host cell; however, in the long term the mycoplasmas suppress turnover of the components of the endocytic pathway. Immunofluorescence microscopy revealed that Rab7 and LC3‑II are recruited to the intracellular mycoplasma‑containing compartments. Western blot analysis and quantitative reverse transcription-polymerase chain reaction (qPCR) showed that mycoplasmas increase expression of Rab7 by upregulating transcription, but increase levels of LC3‑II and p62 by post‑translational regulation. Furthermore, it was demonstrated that mycoplasma infection causes inhibition of autophagic degradation of LC3‑II and p62. In addition, it was found that upregulation of Rab7 and inhibition of autophagic degradation synergistically contributes to intracellular mycoplasma accumulation. In conclusion, these findings suggest that mycoplasmas may manipulate host cell endosomal and autophagic systems in order to facilitate intracellular infection.

  17. Compartment syndrome: A quantitative study of high-energy phosphorus compounds using sup 31 P-magnetic resonance spectroscopy

    SciTech Connect

    Heppenstall, R.B.; Sapega, A.A.; Izant, T.; Fallon, R.; Shenton, D.; Park, Y.S.; Chance, B. )

    1989-08-01

    The purpose of this study was to quantitate the intracellular high-energy phosphate compounds during 6 hours of tissue ischemia in the anterior tibial compartment of beagles subjected to an induced traumatized compartment syndrome. The goal of this work was to provide clinicians with objective criteria to augment clinical judgment regarding surgical intervention in the impending compartment syndrome. A beagle model was utilized in which the Delta pressure (difference between the mean arterial pressure and compartment pressure) could be controlled. The model, in conjunction with {sup 31}P-magnetic resonance spectroscopy (MRS), allowed a measure of high-energy phosphate compounds and pH in the compartment at various Delta pressures. The extent of ischemic metabolic insult in the compartment was then quantitated. Our data suggest the following: (1) lower Delta pressures result in a proportionally greater drop in the intracellular phosphocreatine ratio and pH; (2) at lower Delta pressures, there is proportionally greater decline in the percentage recovery post-fasciotomy; (3) blood pressure is extremely important and periods of hypotension may result in increased muscle damage at lower compartment pressures.

  18. Coupling mechanical forces to electrical signaling: molecular motors and the intracellular transport of ion channels.

    PubMed

    Barry, Joshua; Gu, Chen

    2013-04-01

    Proper localization of various ion channels is fundamental to neuronal functions, including postsynaptic potential plasticity, dendritic integration, action potential initiation and propagation, and neurotransmitter release. Microtubule-based forward transport mediated by kinesin motors plays a key role in placing ion channel proteins to correct subcellular compartments. PDZ- and coiled-coil-domain proteins function as adaptor proteins linking ionotropic glutamate and GABA receptors to various kinesin motors, respectively. Recent studies show that several voltage-gated ion channel/transporter proteins directly bind to kinesins during forward transport. Three major regulatory mechanisms underlying intracellular transport of ion channels are also revealed. These studies contribute to understanding how mechanical forces are coupled to electrical signaling and illuminating pathogenic mechanisms in neurodegenerative diseases.

  19. Intracellular Parasite Invasion Strategies

    NASA Astrophysics Data System (ADS)

    Sibley, L. D.

    2004-04-01

    Intracellular parasites use various strategies to invade cells and to subvert cellular signaling pathways and, thus, to gain a foothold against host defenses. Efficient cell entry, ability to exploit intracellular niches, and persistence make these parasites treacherous pathogens. Most intracellular parasites gain entry via host-mediated processes, but apicomplexans use a system of adhesion-based motility called ``gliding'' to actively penetrate host cells. Actin polymerization-dependent motility facilitates parasite migration across cellular barriers, enables dissemination within tissues, and powers invasion of host cells. Efficient invasion has brought widespread success to this group, which includes Toxoplasma, Plasmodium, and Cryptosporidium.

  20. Digital Microscopy Assessment of Angiogenesis in Different Breast Cancer Compartments

    PubMed Central

    Rogojanu, Radu; Croitoru, Camelia; Jitaru, Daniela; Tarniceriu, Cristina; Carasevici, Eugen

    2013-01-01

    Background/Aim. Tumour angiogenesis defined by microvessel density (MVD) is generally accepted as a prognostic factor in breast cancer. However, due to variability of measurement systems and cutoffs, it is questionable to date whether it contributes to predictive outline. Our study aims to grade vascular heterogeneity by comparing clear-cut compartments: tumour associated stroma (TAS), tumour parenchyma, and tumour invasive front. Material and Methods. Computerized vessel area measurement was performed using a tissue cytometry system (TissueFAXS) on slides originated from 50 patients with breast cancer. Vessels were marked using immunohistochemistry with CD34. Regions of interest were manually defined for each tumour compartment. Results. Tumour invasive front vascular endothelia area was 2.15 times higher than that in tumour parenchyma and 4.61 times higher than that in TAS (P < 0.002). Worth to mention that the lymph node negative subgroup of patients show a slight but constant increase of vessel index in all examined compartments of breast tumour. Conclusion. Whole slide digital examination and region of interest (ROI) analysis are a valuable tool in scoring angiogenesis markers and disclosing their prognostic capacity. Our study reveals compartments' variability of vessel density inside the tumour and highlights the propensity of invasive front to associate an active process of angiogenesis with potential implications in adjuvant therapy. PMID:24073397

  1. Internalized compartments encapsulated nanogels for targeted drug delivery

    NASA Astrophysics Data System (ADS)

    Yu, Jicheng; Zhang, Yuqi; Sun, Wujin; Wang, Chao; Ranson, Davis; Ye, Yanqi; Weng, Yuyan; Gu, Zhen

    2016-04-01

    Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The resulting nanogels loaded with doxorubicin (DOX) displayed enhanced internalization efficiency to the source cells through a specific homotypic affinity in vitro. However, when treated with the non-source cells, the EM-NGs exhibited insignificant difference in therapeutic efficiency compared to a bare HA nanogel with DOX. This study illustrates the potential of utilizing an internalized compartments encapsulated formulation for targeted cancer therapy, and offers guidelines for developing a natural particulate-inspired drug delivery system.Drug delivery systems inspired by natural particulates hold great promise for targeted cancer therapy. An endosome formed by internalization of plasma membrane has a massive amount of membrane proteins and receptors on the surface, which is able to specifically target the homotypic cells. Herein, we describe a simple method to fabricate an internalized compartments encapsulated nanogel with endosome membrane components (EM-NG) from source cancer cells. Following intracellular uptake of methacrylated hyaluronic acid (m-HA) adsorbed SiO2/Fe3O4 nanoparticles encapsulating a crosslinker and a photoinitiator, EM-NG was readily prepared through in situ crosslinking initiated under UV irradiation after internalization. The

  2. Chronic exertional compartment syndrome of the superficial posterior compartment: Soleus syndrome.

    PubMed

    Gross, Christopher E; Parekh, Bela J; Adams, Samuel B; Parekh, Selene G

    2015-01-01

    Chronic exertional compartment syndrome (CECS) represents the second most-common cause of exertional leg pain with incidence of 27-33%. CECS of the superficial posterior compartment, or soleus syndrome, is rare and has only been discussed briefly in the literature. We discuss the management of two patients with bilateral soleus syndrome or CECS of the superficial posterior compartment.

  3. 36 CFR 1192.127 - Sleeping compartments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Sleeping compartments. 1192.127 Section 1192.127 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS... compartment. (c) Controls and operating mechanisms (e.g., heating and air conditioning controls, lighting...

  4. Compartmented mode workstation (CMW) comparisons

    SciTech Connect

    Tolliver, J.S.

    1995-12-31

    As the Compartmented Mode Workstation (CMW) market has matured, several vendors have released new versions of their CMW operating systems. These include a new version from SecureWare (CMW + Version 2.4), and Sun`s CMW 1.1 (also known as Trusted Solaris 1.1). EC is now shipping MLS+ 3.0 for DEC Alpha platforms. Relatively new entries in the market include Loral B1/CMW for IBM RS/6000 platforms and a SecureWare-based CMW for HP platforms (HP-UX 10.09). With all these choices it is time for a comparative analysis of the features offered by the various vendors. The authors have three of the above five CMW systems plus HP-UX BLS 9.09, which is a multilevel secure operating system (OS) targeted at the B1 level but not a CMW. Each is unique in sometimes obvious, sometimes subtle ways, a situation that requires knowing and keeping straight a variety of commands to do the same thing on each system. Some vendors offer extensive GUI tools for system administration; some require entering command-line commands for certain system administration tasks. They examine the differences in system installation, system administration, and system operating among the systems. They look at trusted networking among the various systems and differences in the network databases and label encodings files. They examine the user interface on the various systems from logging in to logging out.

  5. [Reiteration on abdominal compartment syndrome].

    PubMed

    Xia, Guang-Xia

    2008-04-01

    Since we called for the attention of the occurrence of abdominal compartment syndrome in 2002, forty cases of this complication have been recognized and reported by six burn units in this journal, including three cases accompanied with massive pleural effusion (1601 - 3240 mL). Most cases emerged after "aggressive" fluid resuscitation, especially after massive infusion of crystalloid fluid. The idea "more fluid no harm" should be corrected. The goal of early fluid resuscitation in burn is to correct the hypovolemia and cell hypoxia, and circulating fluid just serves as a carrier in bringing O2 to the cells and carrying out CO2 and other metabolites from tissues. In face of "leaking while infusing", heavy accumulation of fluid in the third spaces may worsen the cell hypoxia. Some of the parameters we get from invasive monitoring systems can be misleading. Now, the trend of overloading should be prevented, and it behaves us to study the regime of lower fluid volume with proper contents in burn shock resuscitation.

  6. Spontaneous Extensor Carpi Ulnaris Compartment Syndrome.

    PubMed

    Stewart, Sarah K; Singleton, James A G

    2016-06-01

    We report a case of isolated compartment syndrome within the extensor carpi ulnaris (ECU) compartment in the forearm of a 40-year-old diabetic man. Magnetic resonance imaging of his forearm showed isolated changes in the ECU muscle belly; compartment syndrome was confirmed on manometry. In view of the short history of symptoms and his diabetic status, the patient was managed conservatively. Twenty-four hours after onset of the symptoms, the pain and swelling resolved and he was able to be discharged. To date, 3 cases of ECU compartment syndrome secondary to trauma have been reported. This report illustrates a case of confirmed compartment syndrome without antecedent trauma, highly unusual in terms of both its etiology and its anatomical location. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  7. Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms.

    PubMed

    Pareja, Maria Eugenia Mansilla; Colombo, Maria I

    2013-01-01

    Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance.

  8. Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms

    PubMed Central

    Mansilla Pareja, Maria Eugenia; Colombo, Maria I.

    2013-01-01

    Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance. PMID:24137567

  9. Recurrent Lower-Extremity Compartment Syndrome after Four-Compartment Fasciotomy Secondary to Acute Limb Ischemia.

    PubMed

    Kerkar, Ashwini P; Farber, Alik; Kalish, Jeffrey A; Siracuse, Jeffrey J

    2016-01-01

    Lower-extremity compartment syndrome is a limb-threatening event necessitating emergent treatment using fasciotomy. Recurrent compartment syndrome is rare and has only been reported after trauma and in conjunction with underlying connective tissue disorders. In this report, we present a case of recurrent lower-extremity compartment syndrome caused by ischemia-reperfusion injury, in a patient previously treated with adequate 4-compartment fasciotomies. As such, this is the first reported case of recurrent compartment syndrome in the setting of ischemia-reperfusion injury that required treatment with 4-compartment fasciotomies on both occasions. This case demonstrates that fasciotomy is not protective against the development of recurrent compartment syndrome due to ischemia-reperfusion injury and that patients at high risk require monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Membrane contact sites between pathogen-containing compartments and host organelles.

    PubMed

    Dumoux, Maud; Hayward, Richard D

    2016-08-01

    Intracellular pathogens survive and replicate within specialised membrane-bound compartments that can be considered as pseudo-organelles. Using the obligate intracellular bacterium Chlamydia as an illustrative example, we consider the modes of lipid transport between pathogen-containing compartments and host organelles, including the formation of static membrane contact sites. We discuss how lipid scavenging can be mediated via the reprogramming of cellular transporters at these interfaces and describe recent data suggesting that pathogen effectors modulate the formation of specific membrane contacts. Further study of these emerging mechanisms is likely to yield new insights into the cell biology of lipid transport and organelle communication, which highlights potential new targets and strategies for future therapeutics. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Description of glucose transport in isolated bovine mammary epithelial cells by a three-compartment model.

    PubMed

    Xiao, Changting; Quinton, V Margaret; Cant, John P

    2004-04-01

    Initial rates of glucose entry into isolated bovine mammary epithelial cells display moderate degrees of asymmetry and cooperative interactions between export and import sites. The present study examined the hypothesis that these kinetic features are due to compartmentalization of intracellular glucose. Net uptake of 3-O-methyl-d-[1-(3)H]glucose (3-OMG) by isolated bovine mammary epithelial cells was measured at 37 degrees C. The time course of 3-OMG net uptake was better fitted by a double-exponential equation than by a single- or triple-exponential equation. Compartmental analysis of the time course curve suggested that translocated 3-OMG is distributed into two compartments with fractional volumes of 32.6 +/- 5.7% and 67.4 +/- 5.7%, respectively. The results support the view that glucose transport in bovine mammary epithelial cells is a multistep process consisting of two serial steps: fast, carrier-mediated, symmetric translocation of sugar across the cell plasma membrane into a small compartment and subsequent slow exchange of posttranslocated sugar between two intracellular compartments. A three-compartment model of this system successfully simulated the observed time course of 3-OMG net uptake and the observed dependence of unidirectional entry rates on intra- and extracellular 3-OMG concentrations. Simulations indicated that backflux of radiolabeled sugar from the small compartment to extracellular space during 15 s of incubation gives rise to the apparent asymmetry, trans-stimulation, and cooperativity of mammary glucose transport kinetics. The fixed-site carrier model overestimated the rate of glucose accumulation in cells, and its features can be accounted for by the compartmentalization of intracellular sugar.

  12. Abdominal compartment syndrome: a concise clinical review.

    PubMed

    An, Gary; West, Michael A

    2008-04-01

    There has been an increased awareness of the presence and clinical importance of abdominal compartment syndrome. It is now appreciated that elevations of abdominal pressure occur in a wide variety of critically ill patients. Full-blown abdominal compartment syndrome is a clinical syndrome characterized by progressive intra-abdominal organ dysfunction resulting from elevated intra-abdominal pressure. This review provides a current, clinically focused approach to the diagnosis and management of abdominal compartment syndrome, with a particular emphasis on intensive care. Source data were obtained from a PubMed search of the medical literature, with an emphasis on the time period after 2000. PubMed "related articles" search strategies were likewise employed frequently. Additional information was derived from the Web site of the World Society of the Abdominal Compartment Syndrome (http://www.wsacs.org). The detrimental impact of elevated intra-abdominal pressure, progressing to abdominal compartment syndrome, is recognized in both surgical and medical intensive care units. The recent international abdominal compartment syndrome consensus conference has helped to define, characterize, and raise awareness of abdominal compartment syndrome. Because of the frequency of this condition, routine measurement of intra-abdominal pressure should be performed in high-risk patients in the intensive care unit. Evidence-based interventions can be used to minimize the risk of developing elevated intra-abdominal pressure and to aggressively treat intra-abdominal hypertension when identified. Surgical decompression remains the gold standard for rapid, definitive treatment of fully developed abdominal compartment syndrome, but nonsurgical measures can often effectively affect lesser degrees of intra-abdominal hypertension and abdominal compartment syndrome.

  13. Contrast media-induced compartment syndrome.

    PubMed

    Wilson, Bettye G

    2011-01-01

    Intravascular (IV) contrast media are essential in many cases to enhance the diagnostic capabilities of medical imaging procedures. Much is known about the indications, contraindications, and adverse events associated with their use. This Directed Reading focuses on extravasation and IV contrast media-induced compartment syndrome, a less frequent, although serious, adverse event. In addition to describing the compartments within the forearm, wrist, and hand, the article explains how compartment syndrome develops, techniques used to treat the condition, and prevention strategies. ©2011 by the American Society of Radiologic Technologists.

  14. An intracellular nanotrap redirects proteins and organelles in live bacteria.

    PubMed

    Borg, Sarah; Popp, Felix; Hofmann, Julia; Leonhardt, Heinrich; Rothbauer, Ulrich; Schüler, Dirk

    2015-01-13

    Owing to their small size and enhanced stability, nanobodies derived from camelids have previously been used for the construction of intracellular "nanotraps," which enable redirection and manipulation of green fluorescent protein (GFP)-tagged targets within living plant and animal cells. By taking advantage of intracellular compartmentalization in the magnetic bacterium Magnetospirillum gryphiswaldense, we demonstrate that proteins and even entire organelles can be retargeted also within prokaryotic cells by versatile nanotrap technology. Expression of multivalent GFP-binding nanobodies on magnetosomes ectopically recruited the chemotaxis protein CheW1-GFP from polar chemoreceptor clusters to the midcell, resulting in a gradual knockdown of aerotaxis. Conversely, entire magnetosome chains could be redirected from the midcell and tethered to one of the cell poles. Similar approaches could potentially be used for building synthetic cellular structures and targeted protein knockdowns in other bacteria. Intrabodies are commonly used in eukaryotic systems for intracellular analysis and manipulation of proteins within distinct subcellular compartments. In particular, so-called nanobodies have great potential for synthetic biology approaches because they can be expressed easily in heterologous hosts and actively interact with intracellular targets, for instance, by the construction of intracellular "nanotraps" in living animal and plant cells. Although prokaryotic cells also exhibit a considerable degree of intracellular organization, there are few tools available equivalent to the well-established methods used in eukaryotes. Here, we demonstrate the ectopic retargeting and depletion of polar membrane proteins and entire organelles to distinct compartments in a magnetotactic bacterium, resulting in a gradual knockdown of magneto-aerotaxis. This intracellular nanotrap approach has the potential to be applied in other bacteria for building synthetic cellular structures

  15. Chlamydial Intracellular Survival Strategies

    PubMed Central

    Bastidas, Robert J.; Elwell, Cherilyn A.; Engel, Joanne N.

    2013-01-01

    Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen and the causative agent of blinding trachoma. Although Chlamydia is protected from humoral immune responses by residing within remodeled intracellular vacuoles, it still must contend with multilayered intracellular innate immune defenses deployed by its host while scavenging for nutrients. Here we provide an overview of Chlamydia biology and highlight recent findings detailing how this vacuole-bound pathogen manipulates host–cellular functions to invade host cells and maintain a replicative niche. PMID:23637308

  16. Compartment syndrome after tibial plateau fracture☆

    PubMed Central

    Pitta, Guilherme Benjamin Brandão; dos Santos, Thays Fernanda Avelino; dos Santos, Fernanda Thaysa Avelino; da Costa Filho, Edelson Moreira

    2014-01-01

    Fractures of the tibial plateau are relatively rare, representing around 1.2% of all fractures. The tibia, due to its subcutaneous location and poor muscle coverage, is exposed and suffers large numbers of traumas, not only fractures, but also crush injuries and severe bruising, among others, which at any given moment, could lead compartment syndrome in the patient. The case is reported of a 58-year-old patient who, following a tibial plateau fracture, presented compartment syndrome of the leg and was submitted to decompressive fasciotomy of the four right compartments. After osteosynthesis with internal fixation of the tibial plateau using an L-plate, the patient again developed compartment syndrome. PMID:26229779

  17. 49 CFR 38.127 - Sleeping compartments.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SPECIFICATIONS FOR TRANSPORTATION VEHICLES Intercity Rail Cars and Systems § 38.127 Sleeping compartments. (a...., heating and air conditioning controls, lighting controls, call buttons, electrical outlets, etc.) shall be...

  18. [Acute compartment syndrome following snake bite].

    PubMed

    Wagner, H E; Barbier, P; Frey, H P; Janggen, F M; Rothen, H U

    1986-04-01

    The experience with snake bites, causing local complications is discussed. Whenever systemic envenomation occurs, antivenin is the treatment of choice. Tissue necroses are treated by early debridement and a possible closed compartment syndrome demands the open fasciotomy.

  19. Aircraft Cargo Compartment Fire Test Simulation Program

    NASA Technical Reports Server (NTRS)

    Blumke, R. E.

    1977-01-01

    The objective of the test was to assess fire containment and fire extinguishment in the cargo by reducing the ventilation through the cargo compartment. Parameters which were measured included ignition time, burnthrough time, and physical damage to the cargo liner, composition of selected combustible gases, temperature-time histories, heat flux, and detector response. The ignitor load was made of a typical cargo consisting of filled cardboard cartons occupying 50% of the compartment volume.

  20. Mapping intracellular mechanics on micropatterned substrates

    PubMed Central

    Mandal, Kalpana; Asnacios, Atef; Goud, Bruno; Manneville, Jean-Baptiste

    2016-01-01

    The mechanical properties of cells impact on their architecture, their migration, intracellular trafficking, and many other cellular functions and have been shown to be modified during cancer progression. We have developed an approach to map the intracellular mechanical properties of living cells by combining micropatterning and optical tweezers-based active microrheology. We optically trap micrometer-sized beads internalized in cells plated on crossbow-shaped adhesive micropatterns and track their displacement following a step displacement of the cell. The local intracellular complex shear modulus is measured from the relaxation of the bead position assuming that the intracellular microenvironment of the bead obeys power-law rheology. We also analyze the data with a standard viscoelastic model and compare with the power-law approach. We show that the shear modulus decreases from the cell center to the periphery and from the cell rear to the front along the polarity axis of the micropattern. We use a variety of inhibitors to quantify the spatial contribution of the cytoskeleton, intracellular membranes, and ATP-dependent active forces to intracellular mechanics and apply our technique to differentiate normal and cancer cells. PMID:27799529

  1. Intracellular Trafficking of the Pyridoxal Cofactor. Implications for Health and Metabolic Disease*

    PubMed Central

    Whittaker, James W.

    2016-01-01

    The importance of the vitamin B6-derived pyridoxal cofactor for human health has been established through more than 70 years of intensive biochemical research, revealing its fundamental roles in metabolism. B6 deficiency, resulting from nutritional limitation or impaired uptake from dietary sources, is associated with epilepsy, neuromuscular disease and neurodegeneration. Hereditary disorders of B6 processing are also known, and genetic defects in pathways involved in transport of B6 into the cell and its transformation to the pyridoxal-5′-phosphate enzyme cofactor can contribute to cardiovascular disease by interfering with homocysteine metabolism and the biosynthesis of vasomodulatory polyamines. Compared to the processes involved in cellular uptake and processing of the B6 vitamers, trafficking of the PLP cofactor across intracellular membranes is very poorly understood, even though the availability of PLP within subcellular compartments (particularly the mitochondrion) may have important health implications. The aim of this review is to concisely summarize the state of current knowledge of intracellular trafficking of PLP and to identify key directions for future research. PMID:26619753

  2. Intracellular Voyeurism: Examining the Modulation of Host Cell Activities bySalmonella enterica Serovar Typhimurium.

    PubMed

    Szeto, Jason; Brumell, John H

    2005-11-01

    Salmonella spp. can infect host cells by gaining entry through phagocytosis or by inducing host cell membrane ruffling that facilitates bacterial uptake. With its wide host range, Salmonella enterica serovar Typhimurium has proven to be an important model organism for studying intracellular bacterial pathogenesis. Upon entry into host cells, serovar Typhimurium typically resides within a membrane-bound compartment termed the Salmonella-containing vacuole (SCV). From the SCV, serovar Typhimurium can inject several effector proteins that subvert many normal host cell systems, including endocytic trafficking, cytoskeletal rearrangements, lipid signaling and distribution, and innate and adaptive host defenses. The study of these intracellular events has been made possible through the use of various imaging techniques, ranging from classic methods of transmission electron microscopy to advanced livecell fluorescence confocal microscopy. In addition, DNA microarrays have now been used to provide a "snapshot" of global gene expression in serovar Typhimurium residing within the infected host cell. This review describes key aspects of Salmonella-induced subversion of host cell activities, providing examples of imaging that have been used to elucidate these events. Serovar Typhimurium engages specific host cell machinery from initial contact with the host cell to replication within the SCV. This continuous interaction with the host cell has likely contributed to the extensive arsenal that serovar Typhimurium now possesses, including two type III secretion systems, a range of ammunition in the form of TTSS effectors, and a complex genetic regulatory network that coordinates the expression of hundreds of virulence factors.

  3. Independent Passive Mechanical Behavior of Bovine Extraocular Muscle Compartments

    PubMed Central

    Shin, Andrew; Yoo, Lawrence; Chaudhuri, Zia; Demer, Joseph L.

    2012-01-01

    Purpose. Intramuscular innervation of horizontal rectus extraocular muscles (EOMs) is segregated into superior and inferior (transverse) compartments, while all EOMs are also divided into global (GL) and orbital (OL) layers with scleral and pulley insertions, respectively. We sought evidence of potential independent action by examining passive mechanical coupling between EOM compartments. Methods. Putative compartments of each of the six whole bovine anatomical EOMs were separately clamped to a physiologically controlled, dual channel microtensile load cell (5-mN force resolution) driven by independent, high-speed, linear motors having 20-nm position resolution. One channel at a time was extended or retracted by 3 to 5 mm, with the other channel stationary. Fiducials distributed on the EOM global surface enabled optical tracking of local deformation. Loading rates of 5 to 100 mm/sec were applied to explore speeds from slow vergence to saccades. Control loadings employed transversely loaded EOM and isotropic latex. Results. All EOM bellies and tendons exhibited substantial compartmental independence when loaded in the physiologic direction, both between OL and GL, and for arbitrary transverse parsings of EOM width ranging from 60%:40% to 80%:20%. Intercompartmental force coupling in the physiologic direction was less than or equal to 10% in all six EOMS even for saccadic loading rates. Coupling was much higher for nonphysiologic transverse EOM loading and isotropic latex. Optical tracking demonstrated independent strain distribution between EOM compartments. Conclusions. Substantial mechanical independence exists among physiologically loaded fiber bundles in bovine EOMs and tendons, providing biomechanical support for the proposal that differential compartmental function in horizontal rectus EOMs contributes to novel torsional and vertical actions. PMID:23188730

  4. Anatomic Landmarks for the First Dorsal Compartment

    PubMed Central

    Hazani, Ron; Engineer, Nitin J.; Cooney, Damon; Wilhelmi, Bradon J.

    2008-01-01

    Objective: Knowledge of anatomic landmarks for the first dorsal compartment can assist clinicians with management of de Quervain's disease. The radial styloid, the scaphoid tubercle, and Lister's tubercle can be used as superficial landmarks for the first dorsal compartment. Methods: Thirty-two cadaveric wrists were dissected, and measurements were taken from the predetermined landmarks to the extensor retinaculum. The compartments were also inspected for variability of the abductor pollicis longus tendon and intracompartmental septations. Results: The average length of the extensor retinaculum from its proximal to distal extent measured approximately 2.2 cm. The distal aspect of the radial styloid was 0.3 cm distal to the distal aspect of the extensor retinaculum, and the distance between the distal aspect of the extensor retinaculum and the APL-Lister's-Scaphoid juncture was approximately 0.5 cm. A separate compartment for the extensor pollicis brevis was noted in 35% of the specimens. The abductor pollicis longus tendon demonstrated great variability with 1, 2, 3, or 4 slips in 9%, 30%, 43%, or 26% of the specimens, respectively. Conclusion: The superficial bony prominences of the radial wrist can be used reliably as anatomic landmarks for the first dorsal compartment. PMID:19092992

  5. Compartment syndrome in infants and toddlers.

    PubMed

    Broom, Alexander; Schur, Mathew D; Arkader, Alexandre; Flynn, John; Gornitzky, Alex; Choi, Paul D

    2016-10-01

    To study the cause, diagnosis, treatment and outcome of acute compartment syndrome in infants and toddlers aged <3 years. Fifteen patients aged <3 years with acute compartment syndrome were identified from two large pediatric trauma centers over a fifteen-year period. All children underwent fasciotomy. The mechanism of injury, time of injury, time to diagnosis, compartment pressures, time to fasciotomy, and outcome at the time of the latest follow-up were recorded. Nine (60 %) of fifteen patients developed compartment syndrome secondary to trauma, four (4/15, 27 %) due to infection, and two (2/15, 13 %) due to intravenous infiltration. The average time from injury or hospital admission to fasciotomy was 31.8 h (range 2.9-136.3 h). In general, the functional outcome was excellent at the latest follow-up with thirteen (13/15, 87 %) patients having an excellent outcome. No cases of Volkmann's ischemia were noted at the time of fasciotomy, even when performed as late as 5 days after injury. Compared to the general pediatric population, the diagnosis of compartment syndrome in infants and toddlers may be further delayed, i.e., >24 h after injury. Despite delays in diagnosis and time to treatment, the present study shows that outcomes in infants and toddlers remain favorable even when fasciotomy is performed 48-72 h after injury. Case series, level IV.

  6. Anomalous dynamics in intracellular transport

    NASA Astrophysics Data System (ADS)

    Dinner, Aaron

    2013-03-01

    This talk will describe quantitative analyses of particle tracking data for systems with cytoskeletally associated molecular motors to better understand the motions contributing to intracellular transport and, more generally, means for characterizing systems far from equilibrium. In particular, we have studied the motions of insulin-containing vesicles (granules) in a pancreatic beta cell line. We find subdiffusive behavior with correlations in both space and time. These data can be modeled by subordinating an ergodic random walk process to a non-ergodic one. We relate the dynamics to the underlying microtubule structure by imaging in the presence of the drug vinblastine. Our results provide a simple physical mechanism for how diverse pools of insulin granules and, in turn, biphasic secretion could arise. Time permitting, these dynamics will be compared with those of actomyosin assemblies.

  7. Post-dialysis urea concentration: comparison between one- compartment model and two-compartment model

    NASA Astrophysics Data System (ADS)

    Tamrin, N. S. Ahmad; Ibrahim, N.

    2014-11-01

    The reduction of the urea concentration in blood can be numerically projected by using one-compartment model and two-compartment model with no variation in body fluid. This study aims to compare the simulated values of post-dialysis urea concentration for both models with the clinical data obtained from the hospital. The clinical assessment of adequacy of a treatment is based on the value of Kt/V. Further, direct calculation using clinical data and one-compartment model are presented in the form of ratio. It is found that the ratios of postdialysis urea concentration simulated using two-compartment model are higher compared to the ratios of post-dialysis urea concentration using one-compartment model. In addition, most values of post-dialysis urea concentration simulated using two-compartment model are much closer to the clinical data compared to values simulated using one-compartment model. Kt/V values calculated directly using clinical data are found to be higher than Kt/V values derived from one-compartment model.

  8. Compartment Syndrome of the Leg Associated With Fracture: An Algorithm to Avoid Releasing the Posterior Compartments.

    PubMed

    Tornetta, Paul; Puskas, Brian L; Wang, Kevin

    2016-07-01

    The purpose of this study is to report on a prospective series of patients in whom an algorithm was used to attempt to avoid releasing the posterior compartments in patients with lower leg compartment syndrome (CS) and the safety of such a practice. Prospective cohort study. Level 1 trauma center. A consecutive series of 39 patients was managed by one surgeon for CS using the reported protocol. Patients diagnosed with a CS of the leg were managed with a single operative protocol. After a standard anterior and lateral compartment release through a full-length lateral incision was performed, the superficial and deep posterior compartments were measured with the heel resting on a bolster. Using the preoperative diastolic blood pressure, a ΔP < 30 was considered to be a positive finding warranting a separate medial incision for release of the posterior compartments. If the ΔP was ≥30, the posterior compartments were not released. Need for medial release or development of posterior CS or sequelae. A consecutive series of 39 patients were managed by 1 surgeon for CS using the described protocol. Two patients with an isolated posterior CS were excluded. The other 37 had clinical symptoms or compartment pressures consistent with anterior compartment involvement. Of 37 patients, 21 had (57%) symptoms suggesting posterior compartment involvement. The preoperative pressure measurements averaged 41 mm Hg with an average ΔP of 38. After full-length release of the anterior and lateral compartments, only 3/37 (8%) required a posterior release for a ΔP of <30 mm Hg. The lowest ΔP in the posterior compartments of the remaining 34 patients averaged 59 (32-86). The compartment pressures in the superficial and deep posterior compartments decreased by 22 mm Hg and 24 mm Hg, respectively, after the anterolateral release. None of the patients who had only an anterolateral release developed sequelae of a missed posterior CS. The use of the reported algorithm is effective in

  9. Intracellular Calcium Dysregulation: Implications for Alzheimer's Disease

    PubMed Central

    Magi, Simona; Castaldo, Pasqualina; Macrì, Maria Loredana; Maiolino, Marta; Matteucci, Alessandra; Bastioli, Guendalina; Gratteri, Santo; Lariccia, Vincenzo

    2016-01-01

    Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by progressive neuronal loss. AD is associated with aberrant processing of the amyloid precursor protein, which leads to the deposition of amyloid-β plaques within the brain. Together with plaques deposition, the hyperphosphorylation of the microtubules associated protein tau and the formation of intraneuronal neurofibrillary tangles are a typical neuropathological feature in AD brains. Cellular dysfunctions involving specific subcellular compartments, such as mitochondria and endoplasmic reticulum (ER), are emerging as crucial players in the pathogenesis of AD, as well as increased oxidative stress and dysregulation of calcium homeostasis. Specifically, dysregulation of intracellular calcium homeostasis has been suggested as a common proximal cause of neural dysfunction in AD. Aberrant calcium signaling has been considered a phenomenon mainly related to the dysfunction of intracellular calcium stores, which can occur in both neuronal and nonneuronal cells. This review reports the most recent findings on cellular mechanisms involved in the pathogenesis of AD, with main focus on the control of calcium homeostasis at both cytosolic and mitochondrial level. PMID:27340665

  10. Local intracellular ion measurements with luminescent indicators using confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Opitz, N.; Merten, E.; Acker, H.

    1995-09-01

    Ion sensitive fluoroprobes such as BCECF (pH) and FURA-II (Ca2+) are frequently used indicators for determination of ion activities in single cells and subcellular compartments, e.g. by video enhanced or video intensified microscopy. Moreover, using confocal laser scanning microscopy (CLSM) with its inherent potential for noninvasive optical sectioning of cells and tissues and subsequent 3D image reconstruction, intracellular ion topographies can be monitored via pseudocolor encoded ratio imaging from pixel to pixel enabling in vivo measurements of dynamic intracellular processes. Regardless of the degree of spatial resolution, reliable qualtitative determinations essentially depend on accurate calibration of the intracellularly entrapped fluoroprobe. Calibration is either established on the basis of a whole cell or within a more or less extended subcellular compartment and the characteristics are displayed as concentration encoded pseudocolor bar within the image frame. This calibration is assumed to be valid for other cellular compartments and, in case of ion imaging, it is even thought to be valid for every single pixel of the complete pixel field. However, the assumption of a topographically invariant intracellular calibration requires a reliable behavior of the intracellularly applied indicator. This intracellular integrity of the dyes often does not seem to exist since intracellular calibration curves considerably deviate from in vitro calibration characteristics. Deviations may be due to intracellular interactions of indicator molecules with cytoplasmic macromolecules, e.g. proteins, resulting in spectral distortions and/or sensitivity deficits as demonstrated by the indicators BCECF and FURA-RED (a FURA-II analogue) or to intracellular redistribution of the indicator as exemplified by pH measurements using carboxy-SNARF-1. Consequences of these investigations as well as further potential interferences are discussed with special respect to ion imaging

  11. Space Shuttle crew compartment debris-contamination

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Villarreal, Leopoldo J.

    1992-01-01

    Remedial actions undertaken to reduce debris during manned flights and ground turnaround operations at Kennedy Space Center and Palmdale are addressed. They include redesign of selected ground support equipment and Orbiter hardware to reduce particularization/debris generation; development of new detachable filters for air-cooled avionics boxes; application of tape-on screens to filter debris; and implementation of new Orbiter maintenance and turnaround procedures to clean filters and the crew compartment. Most of these steps were implemented before the return-to-flight of STS-26 in September 1988 which resulted in improved crew compartment habitability and less potential for equipment malfunction.

  12. AFT view of the Transfer Compartment

    NASA Image and Video Library

    2012-04-22

    ISS030-E-241385 (22 April 2012) --- Photographed from the transfer compartment between the Zarya Functional Cargo Block (FGB) and the Zvezda Service Module of the International Space Station, Russian cosmonauts Anton Shkaplerov (left), Oleg Kononenko (right) and Anatoly Ivanishin, all Expedition 30 flight engineers, monitor data at the manual TORU docking system controls in Zvezda during approach and docking operations of the unpiloted ISS Progress 47 resupply vehicle. Progress 47 docked automatically to the Pirs Docking Compartment via the Kurs automated rendezvous system at 10:39 a.m. (EDT) on April 22, 2012.

  13. AFT view of the Transfer Compartment

    NASA Image and Video Library

    2012-04-22

    ISS030-E-241386 (22 April 2012) --- Photographed from the transfer compartment between the Zarya Functional Cargo Block (FGB) and the Zvezda Service Module of the International Space Station, Russian cosmonauts Anton Shkaplerov (left), Oleg Kononenko (right) and Anatoly Ivanishin, all Expedition 30 flight engineers, monitor data at the manual TORU docking system controls in Zvezda during approach and docking operations of the unpiloted ISS Progress 47 resupply vehicle. Progress 47 docked automatically to the Pirs Docking Compartment via the Kurs automated rendezvous system at 10:39 a.m. (EDT) on April 22, 2012.

  14. [The perichromatin compartment of the cell nucleus].

    PubMed

    Bogoliubov, D S

    2014-01-01

    In this review, the data on the structure and composition of the perichromatin compartment, a special border area between the condensed chromatin and the interchromatin space of the cell nucleus, are discussed in the light of the concept of nuclear functions in complex nuclear architectonics. Morphological features, molecular composition and functions of main extrachromosomal structures of the perichromatin compartment, perichromatin fibrils (PFs) and perichromatin granules (PGs) including nuclear stress-bodies (nSBs) that are derivates of the PGs under heat shock, are presented. A special attention was paid to the features of the molecular compositions of PFs and PGs in different cell types and at different physiological conditions.

  15. New insights into the intracellular distribution pattern of cationic amphiphilic drugs

    PubMed Central

    Vater, Magdalena; Möckl, Leonhard; Gormanns, Vanessa; Schultz Fademrecht, Carsten; Mallmann, Anna M.; Ziegart-Sadowska, Karolina; Zaba, Monika; Frevert, Marie L.; Bräuchle, Christoph; Holsboer, Florian; Rein, Theo; Schmidt, Ulrike; Kirmeier, Thomas

    2017-01-01

    Cationic amphiphilic drugs (CADs) comprise a wide variety of different substance classes such as antidepressants, antipsychotics, and antiarrhythmics. It is well recognized that CADs accumulate in certain intracellular compartments leading to specific morphological changes of cells. So far, no adequate technique exists allowing for ultrastructural analysis of CAD in intact cells. Azidobupramine, a recently described multifunctional antidepressant analogue, allows for the first time to perform high-resolution studies of CADs on distribution pattern and morphological changes in intact cells. We showed here that the intracellular distribution pattern of azidobupramine strongly depends on drug concentration and exposure time. The mitochondrial compartment (mDsRed) and the late endo-lysosomal compartment (CD63-GFP) were the preferred localization sites at low to intermediate concentrations (i.e. 1 μM, 5 μM). In contrast, the autophagosomal compartment (LC3-GFP) can only be reached at high concentrations (10 μM) and long exposure times (72 hrs). At the morphological level, LC3-clustering became only prominent at high concentrations (10 μM), while changes in CD63 pattern already occurred at intermediate concentrations (5 μM). To our knowledge, this is the first study that establishes a link between intracellular CAD distribution pattern and morphological changes. Therewith, our results allow for gaining deeper understanding of intracellular effects of CADs. PMID:28281674

  16. New insights into the intracellular distribution pattern of cationic amphiphilic drugs.

    PubMed

    Vater, Magdalena; Möckl, Leonhard; Gormanns, Vanessa; Schultz Fademrecht, Carsten; Mallmann, Anna M; Ziegart-Sadowska, Karolina; Zaba, Monika; Frevert, Marie L; Bräuchle, Christoph; Holsboer, Florian; Rein, Theo; Schmidt, Ulrike; Kirmeier, Thomas

    2017-03-10

    Cationic amphiphilic drugs (CADs) comprise a wide variety of different substance classes such as antidepressants, antipsychotics, and antiarrhythmics. It is well recognized that CADs accumulate in certain intracellular compartments leading to specific morphological changes of cells. So far, no adequate technique exists allowing for ultrastructural analysis of CAD in intact cells. Azidobupramine, a recently described multifunctional antidepressant analogue, allows for the first time to perform high-resolution studies of CADs on distribution pattern and morphological changes in intact cells. We showed here that the intracellular distribution pattern of azidobupramine strongly depends on drug concentration and exposure time. The mitochondrial compartment (mDsRed) and the late endo-lysosomal compartment (CD63-GFP) were the preferred localization sites at low to intermediate concentrations (i.e. 1 μM, 5 μM). In contrast, the autophagosomal compartment (LC3-GFP) can only be reached at high concentrations (10 μM) and long exposure times (72 hrs). At the morphological level, LC3-clustering became only prominent at high concentrations (10 μM), while changes in CD63 pattern already occurred at intermediate concentrations (5 μM). To our knowledge, this is the first study that establishes a link between intracellular CAD distribution pattern and morphological changes. Therewith, our results allow for gaining deeper understanding of intracellular effects of CADs.

  17. 24 CFR 3280.111 - Toilet compartments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Planning Considerations § 3280.111... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Toilet compartments. 3280.111 Section 3280.111 Housing and Urban Development Regulations Relating to Housing and Urban Development...

  18. Gluteal Compartment Syndrome Secondary to Pelvic Trauma

    PubMed Central

    Taype Zamboni, Danilo E. R.; Carabelli, Guido S.; Barla, Jorge D.; Sancineto, Carlos F.

    2016-01-01

    Gluteal compartment syndrome (GCS) is extremely rare when compared to compartment syndrome in other anatomical regions, such as the forearm or the lower leg. It usually occurs in drug users following prolonged immobilization due to loss of consciousness. Another possible cause is trauma, which is rare and has only few reports in the literature. Physical examination may show tense and swollen buttocks and severe pain caused by passive range of motion. We present the case of a 70-year-old man who developed GCS after prolonged anterior-posterior pelvis compression. The physical examination revealed swelling, scrotal hematoma, and left ankle extension weakness. An unstable pelvic ring injury was diagnosed and the patient was taken to surgery. Measurement of the intracompartmental pressure was measured in the operating room, thereby confirming the diagnosis. Emergent fasciotomy was performed to decompress the three affected compartments. Trauma surgeons must be aware of the possibility of gluteal compartment syndrome in patients who have an acute pelvic trauma with buttock swelling and excessive pain of the gluteal region. Any delay in diagnosis or treatment can be devastating, causing permanent disability, irreversible loss of gluteal muscles, sciatic nerve palsy, kidney failure, or even death. PMID:27579205

  19. 14 CFR 25.771 - Pilot compartment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Pilot compartment. 25.771 Section 25.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... (established under § 25.1523) to perform their duties without unreasonable concentration or fatigue. (b) The...

  20. 14 CFR 29.771 - Pilot compartment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Pilot compartment. 29.771 Section 29.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  1. 14 CFR 23.771 - Pilot compartment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Pilot compartment. 23.771 Section 23.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... equipment must allow each pilot to perform his duties without unreasonable concentration or fatigue; (b...

  2. 14 CFR 23.771 - Pilot compartment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Pilot compartment. 23.771 Section 23.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... equipment must allow each pilot to perform his duties without unreasonable concentration or fatigue; (b...

  3. 14 CFR 27.771 - Pilot compartment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Pilot compartment. 27.771 Section 27.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  4. 14 CFR 29.771 - Pilot compartment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Pilot compartment. 29.771 Section 29.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  5. 14 CFR 25.771 - Pilot compartment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Pilot compartment. 25.771 Section 25.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... (established under § 25.1523) to perform their duties without unreasonable concentration or fatigue. (b) The...

  6. 14 CFR 23.771 - Pilot compartment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Pilot compartment. 23.771 Section 23.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... equipment must allow each pilot to perform his duties without unreasonable concentration or fatigue; (b...

  7. 14 CFR 27.771 - Pilot compartment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Pilot compartment. 27.771 Section 27.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  8. 14 CFR 29.771 - Pilot compartment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Pilot compartment. 29.771 Section 29.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  9. 14 CFR 25.771 - Pilot compartment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Pilot compartment. 25.771 Section 25.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... (established under § 25.1523) to perform their duties without unreasonable concentration or fatigue. (b) The...

  10. 14 CFR 27.771 - Pilot compartment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Pilot compartment. 27.771 Section 27.771 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... pilot to perform his duties without unreasonable concentration or fatigue; (b) If there is provision for...

  11. High-Throughput Intracellular Antimicrobial Susceptibility Testing of Legionella pneumophila

    PubMed Central

    Chiaraviglio, Lucius

    2015-01-01

    Legionella pneumophila is a Gram-negative opportunistic human pathogen that causes a severe pneumonia known as Legionnaires' disease. Notably, in the human host, the organism is believed to replicate solely within an intracellular compartment, predominantly within pulmonary macrophages. Consequently, successful therapy is predicated on antimicrobials penetrating into this intracellular growth niche. However, standard antimicrobial susceptibility testing methods test solely for extracellular growth inhibition. Here, we make use of a high-throughput assay to characterize intracellular growth inhibition activity of known antimicrobials. For select antimicrobials, high-resolution dose-response analysis was then performed to characterize and compare activity levels in both macrophage infection and axenic growth assays. Results support the superiority of several classes of nonpolar antimicrobials in abrogating intracellular growth. Importantly, our assay results show excellent correlations with prior clinical observations of antimicrobial efficacy. Furthermore, we also show the applicability of high-throughput automation to two- and three-dimensional synergy testing. High-resolution isocontour isobolograms provide in vitro support for specific combination antimicrobial therapy. Taken together, findings suggest that high-throughput screening technology may be successfully applied to identify and characterize antimicrobials that target bacterial pathogens that make use of an intracellular growth niche. PMID:26392509

  12. Extraocular Muscle Compartments in Superior Oblique Palsy

    PubMed Central

    Suh, Soh Youn; Clark, Robert A.; Le, Alan; Demer, Joseph L.

    2016-01-01

    Purpose To investigate changes in volumes of extraocular muscle (EOM) compartments in unilateral superior oblique (SO) palsy using magnetic resonance imaging (MRI). Methods High-resolution, surface-coil MRI was obtained in 19 patients with unilateral SO palsy and 19 age-matched orthotropic control subjects. Rectus EOMs and the SO were divided into two anatomic compartments for volume analysis in patients with unilateral SO palsy, allowing comparison of total compartmental volumes versus controls. Medial and lateral compartmental volumes of the SO muscle were compared in patients with isotropic (round shape) versus anisotropic (elongated shape) SO atrophy. Results The medial and lateral compartments of the ipsilesional SO muscles were equally atrophic in isotropic SO palsy, whereas the lateral compartment was significantly smaller than the medial in anisotropic SO palsy (P = 0.01). In contrast to the SO, there were no differential compartmental volume changes in rectus EOMs; however, there was significant total muscle hypertrophy in the ipsilesional inferior rectus (IR) and lateral rectus (LR) muscles and contralesional superior rectus (SR) muscles. Medial rectus (MR) volume was normal both ipsi- and contralesionally. Conclusions A subset of patients with SO palsy exhibit selective atrophy of the lateral, predominantly vertically acting SO compartment. Superior oblique atrophy is associated with whole-muscle volume changes in the ipsilesional IR, ipsilesional LR, and contralesional SR; however, SO muscle atrophy is not associated with compartmentally selective volume changes in the rectus EOMs. Selective compartmental SO pathology may provide an anatomic mechanism that explains some of the variability in clinical presentations of SO palsy. PMID:27768791

  13. Annexin A6 in the liver: From the endocytic compartment to cellular physiology.

    PubMed

    Enrich, Carlos; Rentero, Carles; Grewal, Thomas

    2016-10-27

    Annexin A6 (AnxA6) belongs to the conserved annexin family - a group of Ca(2+)-dependent membrane binding proteins. AnxA6 is the largest of all annexins and highly expressed in smooth muscle, hepatocytes, endothelial cells and cardiomyocytes. Upon activation, AnxA6 binds to negatively charged phospholipids in a wide range of intracellular localizations, in particular the plasma membrane, late endosomes/pre-lysosomes, but also synaptic vesicles and sarcolemma. In these cellular sites, AnxA6 is believed to contribute to the organization of membrane microdomains, such as cholesterol-rich lipid rafts and confer multiple regulatory functions, ranging from vesicle fusion, endocytosis and exocytosis to programmed cell death and muscle contraction. Growing evidence supports that Ca(2+) and Ca(2+)-binding proteins control endocytosis and autophagy. Their regulatory role seems to operate at the level of the signalling pathways that initiate autophagy or at later stages, when autophagosomes fuse with endolysosomal compartments. The convergence of the autophagic and endocytic vesicles to lysosomes shares several features that depend on Ca(2+) originating from lysosomes/late endosomes and seems to depend on proteins that are subsequently activated by this cation. However, the involvement of Ca(2+) and its effector proteins in these autophagic and endocytic stages still remains poorly understood. Although AnxA6 makes up almost 0.25% of total protein in the liver, little is known about its function in hepatocytes. Within the endocytic route, we identified AnxA6 in endosomes and autophagosomes of hepatocytes. Hence, AnxA6 and possibly other annexins might represent new Ca(2+) effectors that regulate converging steps of autophagy and endocytic trafficking in hepatocytes. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.

  14. The longest telomeres: a general signature of adult stem cell compartments

    PubMed Central

    Flores, Ignacio; Canela, Andres; Vera, Elsa; Tejera, Agueda; Cotsarelis, George; Blasco, María A.

    2008-01-01

    Identification of adult stem cells and their location (niches) is of great relevance for regenerative medicine. However, stem cell niches are still poorly defined in most adult tissues. Here, we show that the longest telomeres are a general feature of adult stem cell compartments. Using confocal telomere quantitative fluorescence in situ hybridization (telomapping), we find gradients of telomere length within tissues, with the longest telomeres mapping to the known stem cell compartments. In mouse hair follicles, we show that cells with the longest telomeres map to the known stem cell compartments, colocalize with stem cell markers, and behave as stem cells upon treatment with mitogenic stimuli. Using K15-EGFP reporter mice, which mark hair follicle stem cells, we show that GFP-positive cells have the longest telomeres. The stem cell compartments in small intestine, testis, cornea, and brain of the mouse are also enriched in cells with the longest telomeres. This constitutes the description of a novel general property of adult stem cell compartments. Finally, we make the novel finding that telomeres shorten with age in different mouse stem cell compartments, which parallels a decline in stem cell functionality, suggesting that telomere loss may contribute to stem cell dysfunction with age. PMID:18283121

  15. Application of separable parameter space techniques to multi-tracer PET compartment modeling

    PubMed Central

    Zhang, Jeff L; Morey, A Michael; Kadrmas, Dan J

    2016-01-01

    Multi-tracer positron emission tomography (PET) can image two or more tracers in a single scan, characterizing multiple aspects of biological functions to provide new insights into many diseases. The technique uses dynamic imaging, resulting in time-activity curves that contain contributions from each tracer present. The process of separating and recovering separate images and/or imaging measures for each tracer requires the application of kinetic constraints, which are most commonly applied by fitting parallel compartment models for all tracers. Such multi-tracer compartment modeling presents challenging nonlinear fits in multiple dimensions. This work extends separable parameter space kinetic modeling techniques, previously developed for fitting single-tracer compartment models, to fitting multi-tracer compartment models. The multi-tracer compartment model solution equations were reformulated to maximally separate the linear and nonlinear aspects of the fitting problem, and separable least-squares techniques were applied to effectively reduce the dimensionality of the nonlinear fit. The benefits of the approach are then explored through a number of illustrative examples, including characterization of separable parameter space multi-tracer objective functions and demonstration of exhaustive search fits which guarantee the true global minimum to within arbitrary search precision. Iterative gradient-descent algorithms using Levenberg–Marquardt were also tested, demonstrating improved fitting speed and robustness as compared to corresponding fits using conventional model formulations. The proposed technique overcomes many of the challenges in fitting simultaneous multi-tracer PET compartment models. PMID:26788888

  16. Acute exertional anterior compartment syndrome in an adolescent female.

    PubMed

    Fehlandt, A; Micheli, L

    1995-01-01

    Acute compartment syndromes usually occur as a complication of major trauma. While the chronic exertional anterior tibial compartment syndrome is well described in the sports medicine literature, reports of acute tibial compartment syndromes due to physical exertion, or repetitive microtrauma, are rare. The case of an adolescent female who developed an acute anterior compartment syndrome from running in a soccer game is described in this report. Failure to recognize the onset of an acute exertional compartment syndrome may lead to treatment delay and serious complications. Whereas the chronic exertional anterior compartment syndrome is characterized by pain that diminishes with the cessation of exercise, the onset of the acute exertional anterior compartment syndrome is heralded by pain that continues, or increases, after exercise has stopped. Compartment pressure measurement confirms the clinical diagnosis and helps guide treatment. True compartment syndromes require urgent fasciotomy.

  17. Overuse injuries: tendinopathies, stress fractures, compartment syndrome, and shin splints.

    PubMed

    Wilder, Robert P; Sethi, Shikha

    2004-01-01

    Approximately 50% of all sports injuries are secondary to overuse and result from repetitive microtrauma that causes local tissue damage. Injuries are most likely with changes in mode, intensity, or duration of training and can accumulate before symptoms appear. Intrinsic factors contributing to injuries are individual bio-mechanical abnormalities such as malalignments, muscle imbalance, inflexibility, weakness, and instability. Contributing extrinsic (avoidable) factors include poor technique, improper equipment, and improper changes in duration or frequency of activity. Injuries are often related to biomechanical abnormalities removed from the specific injury site, requiring evaluation of the entire kinetic chain. This article discusses common overuse injuries of the lower leg, ankle, and foot: tendinopathies, stress fractures, chronic exertional compartment syndrome, and shin splints.

  18. Extracellular Tau Oligomers Induce Invasion of Endogenous Tau into the Somatodendritic Compartment and Axonal Transport Dysfunction

    PubMed Central

    Swanson, Eric; Breckenridge, Leigham; McMahon, Lloyd; Som, Sreemoyee; McConnell, Ian; Bloom, George S.

    2017-01-01

    Aggregates composed of the microtubule associated protein, tau, are a hallmark of Alzheimer’s disease and non-Alzheimer’s tauopathies. Extracellular tau can induce the accumulation and aggregation of intracellular tau, and tau pathology can be transmitted along neural networks over time. There are six splice variants of central nervous system tau, and various oligomeric and fibrillar forms are associated with neurodegeneration in vivo. The particular extracellular forms of tau capable of transferring tau pathology from neuron to neuron remain ill defined, however, as do the consequences of intracellular tau aggregation on neuronal physiology. The present study was undertaken to compare the effects of extracellular tau monomers, oligomers, and filaments comprising various tau isoforms on the behavior of cultured neurons. We found that 2N4R or 2N3R tau oligomers provoked aggregation of endogenous intracellular tau much more effectively than monomers or fibrils, or of oligomers made from other tau isoforms, and that a mixture of all six isoforms most potently provoked intracellular tau accumulation. These effects were associated with invasion of tau into the somatodendritic compartment. Finally, we observed that 2N4R oligomers perturbed fast axonal transport of membranous organelles along microtubules. Intracellular tau accumulation was often accompanied by increases in the run length, run time and instantaneous velocity of membranous cargo. This work indicates that extracellular tau oligomers can disrupt normal neuronal homeostasis by triggering axonal tau accumulation and loss of the polarized distribution of tau, and by impairing fast axonal transport. PMID:28482642

  19. Extracellular Tau Oligomers Induce Invasion of Endogenous Tau into the Somatodendritic Compartment and Axonal Transport Dysfunction.

    PubMed

    Swanson, Eric; Breckenridge, Leigham; McMahon, Lloyd; Som, Sreemoyee; McConnell, Ian; Bloom, George S

    2017-01-01

    Aggregates composed of the microtubule associated protein, tau, are a hallmark of Alzheimer's disease and non-Alzheimer's tauopathies. Extracellular tau can induce the accumulation and aggregation of intracellular tau, and tau pathology can be transmitted along neural networks over time. There are six splice variants of central nervous system tau, and various oligomeric and fibrillar forms are associated with neurodegeneration in vivo. The particular extracellular forms of tau capable of transferring tau pathology from neuron to neuron remain ill defined, however, as do the consequences of intracellular tau aggregation on neuronal physiology. The present study was undertaken to compare the effects of extracellular tau monomers, oligomers, and filaments comprising various tau isoforms on the behavior of cultured neurons. We found that 2N4R or 2N3R tau oligomers provoked aggregation of endogenous intracellular tau much more effectively than monomers or fibrils, or of oligomers made from other tau isoforms, and that a mixture of all six isoforms most potently provoked intracellular tau accumulation. These effects were associated with invasion of tau into the somatodendritic compartment. Finally, we observed that 2N4R oligomers perturbed fast axonal transport of membranous organelles along microtubules. Intracellular tau accumulation was often accompanied by increases in the run length, run time and instantaneous velocity of membranous cargo. This work indicates that extracellular tau oligomers can disrupt normal neuronal homeostasis by triggering axonal tau accumulation and loss of the polarized distribution of tau, and by impairing fast axonal transport.

  20. The estimated sensitivity and specificity of compartment pressure monitoring for acute compartment syndrome.

    PubMed

    McQueen, Margaret M; Duckworth, Andrew D; Aitken, Stuart A; Court-Brown, Charles M

    2013-04-17

    The aim of our study was to document the estimated sensitivity and specificity of continuous intracompartmental pressure monitoring for the diagnosis of acute compartment syndrome. From our prospective trauma database, we identified all patients who had sustained a tibial diaphyseal fracture over a ten-year period. A retrospective analysis of 1184 patients was performed to record and analyze the documented use of continuous intracompartmental pressure monitoring and the use of fasciotomy. A diagnosis of acute compartment syndrome was made if there was escape of muscles at fasciotomy and/or color change in the muscles or muscle necrosis intraoperatively. A diagnosis of acute compartment syndrome was considered incorrect if it was possible to close the fasciotomy wounds primarily at forty-eight hours. The absence of acute compartment syndrome was confirmed by the absence of neurological abnormality or contracture at the time of the latest follow-up. Of 979 monitored patients identified, 850 fit the inclusion criteria with a mean age of thirty-eight years (range, twelve to ninety-four years), and 598 (70.4%) were male (p < 0.001). A total of 152 patients (17.9%) underwent fasciotomy for the treatment of acute compartment syndrome: 141 had acute compartment syndrome (true positives), six did not have it (false positives), and five underwent fasciotomy despite having a normal differential pressure reading, with subsequent operative findings consistent with acute compartment syndrome (false negatives). Of the 698 patients (82.1%) who did not undergo fasciotomy, 689 had no evidence of any late sequelae of acute compartment syndrome (true negatives) at a mean follow-up time of fifty-nine weeks. The estimated sensitivity of intracompartmental pressure monitoring for suspected acute compartment syndrome was 94%, with an estimated specificity of 98%, an estimated positive predictive value of 93%, and an estimated negative predictive value of 99%. The estimated sensitivity and

  1. A cell-penetrating bispecific antibody for therapeutic regulation of intracellular targets.

    PubMed

    Weisbart, Richard H; Gera, Joseph F; Chan, Grace; Hansen, James E; Li, Erica; Cloninger, Cheri; Levine, Arnold J; Nishimura, Robert N

    2012-10-01

    The therapeutic use of antibodies is restricted by the limited access of antibodies to intracellular compartments. To overcome this limitation, we developed a cell-penetrating monoclonal antibody, mAb 3E10, as an intracellular delivery vehicle for the intracellular and intranuclear delivery of antibodies constructed as bispecific single-chain Fv fragments. Because MDM2 is an important target in cancer therapy, we selected monoclonal antibody (mAb) 3G5 for intracellular transport. mAb 3G5 binds MDM2 and blocks binding of MDM2 to p53. Here, we show that the resulting 3E10-3G5 bispecific antibody retains cell-penetrating and MDM2-binding activity, increases tumor p53 levels, and inhibits growth of MDM2-addicted tumors. The use of cell-penetrating bispecific antibodies in targeted molecular therapy will significantly broaden the spectrum of accessible intracellular targets and may have a profound impact in cancer therapy.

  2. Determination of intracellular nitrate.

    PubMed Central

    Romero, J M; Lara, C; Guerrero, M G

    1989-01-01

    A sensitive procedure has been developed for the determination of intracellular nitrate. The method includes: (i) preparation of cell lysates in 2 M-H3PO4 after separation of cells from the outer medium by rapid centrifugation through a layer of silicone oil, and (ii) subsequent nitrate analysis by ion-exchange h.p.l.c. with, as mobile phase, a solution containing 50 mM-H3PO4 and 2% (v/v) tetrahydrofuran, adjusted to pH 1.9 with NaOH. The determination of nitrate is subjected to interference by chloride and sulphate when present in the samples at high concentrations. Nitrite also interferes, but it is easily eliminated by treatment of the samples with sulphamic acid. The method has been successfully applied to the study of nitrate transport in the unicellular cyanobacterium Anacystis nidulans. PMID:2497740

  3. Intracellular Oscillations and Waves

    NASA Astrophysics Data System (ADS)

    Beta, Carsten; Kruse, Karsten

    2017-03-01

    Dynamic processes in living cells are highly organized in space and time. Unraveling the underlying molecular mechanisms of spatiotemporal pattern formation remains one of the outstanding challenges at the interface between physics and biology. A fundamental recurrent pattern found in many different cell types is that of self-sustained oscillations. They are involved in a wide range of cellular functions, including second messenger signaling, gene expression, and cytoskeletal dynamics. Here, we review recent developments in the field of cellular oscillations and focus on cases where concepts from physics have been instrumental for understanding the underlying mechanisms. We consider biochemical and genetic oscillators as well as oscillations that arise from chemo-mechanical coupling. Finally, we highlight recent studies of intracellular waves that have increasingly moved into the focus of this research field.

  4. SERS-based monitoring of the intracellular pH in endothelial cells: the influence of the extracellular environment and tumour necrosis factor-α.

    PubMed

    Jaworska, Aleksandra; Jamieson, Lauren E; Malek, Kamilla; Campbell, Colin J; Choo, Jaebum; Chlopicki, Stefan; Baranska, Malgorzata

    2015-04-07

    The intracellular pH plays an important role in various cellular processes. In this work, we describe a method for monitoring of the intracellular pH in endothelial cells by using surface enhanced Raman spectroscopy (SERS) and 4-mercaptobenzoic acid (MBA) anchored to gold nanoparticles as pH-sensitive probes. Using the Raman microimaging technique, we analysed changes in intracellular pH induced by buffers with acid or alkaline pH, as well as in endothelial inflammation induced by tumour necrosis factor-α (TNFα). The targeted nanosensor enabled spatial pH measurements revealing distinct changes of the intracellular pH in endosomal compartments of the endothelium. Altogether, SERS-based analysis of intracellular pH proves to be a promising technique for a better understanding of intracellular pH regulation in various subcellular compartments.

  5. compartment transfer rates in horizontal flow constructed wetlands

    NASA Astrophysics Data System (ADS)

    Maier, Uli; Oswald, Sascha; Thullner, Martin; Grathwohl, Peter

    2010-05-01

    A conceptual computer model has been constructed to simulate the compartment transfer rates in horizontal flow constructed wetlands. The model accounts for flow and transport in the variably saturated porous medium as well as biogeochemical change reactions. The most concentrated contaminants such as BTEX, MTBE and gasoline hydrocarbons and dissolved as well as mineral phase electron acceptors are considered. Also of major interest are reduced species with high oxygen demand such as ammonium. The influence of marsh plants on microbial activity, gas transport, water balance and contaminant fate in general is matter of current investigation. The constructed wetlands consist of a coarse sand or fine gravel porous medium. Marsh plants were introduced after installation, however, a number of control basins are operated unplanted. Water levels and through flow rates are adjusted to optimize the remediation efficiency. The system is likely to be neither reaction nor mixing limited, thus both, values of dispersivity and degradation kinetics may be crucial for remediation efficiency. Biogeochemical modelling is able to delineate in detail (i) the zonation of processes, (ii) temporal variation (breakthrough curves) and (iii) mass balance information. The contributions of biodegradation and volatilisation and the influence of plants (compartment transfer) can generally best be evaluated by the component's mass balance. More efficient mixing is expected in the wetlands with open water body which leads to both, more biodegradation and volatilisation. An important task is to quantify the role of plants and root systems for contaminant attenuation in constructed wetlands. The long term goal of investigation is to allow for predictions for the design of large scale compartment transfer wetlands that may be applied to remediate the site as a whole.

  6. Interaction of Salmonella enterica Serotype Typhimurium with Dendritic Cells Is Defined by Targeting to Compartments Lacking Lysosomal Membrane Glycoproteins

    PubMed Central

    García-Del Portillo, Francisco; Jungnitz, Heidrun; Rohde, Manfred; Guzmán, Carlos A.

    2000-01-01

    Dendritic cells (DCs) play a central role in the generation of acquired immunity to infections by pathogenic microorganisms. Salmonella enterica serotype Typhimurium is known to survive and proliferate intracellularly within macrophages and nonphagocytic cells, but no data exist on how this pathogen interacts with DCs. In this report, we show the capacity of serotype Typhimurium to survive within the established mouse DC line CB1. In contrast to the case for the macrophage model, the compartments of DCs containing serotype Typhimurium are devoid of lysosomal membrane glycoproteins and the PhoPQ two-component regulatory system is not essential for pathogen intracellular survival. PMID:10768999

  7. Acidic NAADP-releasable Ca(2+) compartments in the megakaryoblastic cell line MEG01.

    PubMed

    Dionisio, Natalia; Albarrán, Letizia; López, José J; Berna-Erro, Alejandro; Salido, Ginés M; Bobe, Régis; Rosado, Juan A

    2011-08-01

    A novel family of intracellular Ca(2+)-release channels termed two-pore channels (TPCs) has been presented as the receptors of NAADP (nicotinic acid adenine dinucleotide phosphate), the most potent Ca(2+) mobilizing intracellular messenger. TPCs have been shown to be exclusively localized to the endolysosomal system mediating NAADP-evoked Ca(2+) release from the acidic compartments. The present study is aimed to investigate NAADP-mediated Ca(2+) release from intracellular stores in the megakaryoblastic cell line MEG01. Changes in cytosolic and intraluminal free Ca(2+) concentrations were registered by fluorimetry using fura-2 and fura-ff, respectively; TPC expression was detected by PCR. Treatment of MEG01 cells with the H(+)/K(+) ionophore nigericin or the V-type H(+)-ATPase selective inhibitor bafilomycin A1 revealed the presence of acidic Ca(2+) stores in these cells, sensitive to the SERCA inhibitor 2,5-di-(tert-butyl)-1,4-hydroquinone (TBHQ). NAADP releases Ca(2+) from acidic lysosomal-like Ca(2+) stores in MEG01 cells probably mediated by the activation of TPC1 and TPC2 as demonstrated by TPC1 and TPC2 expression silencing and overexpression. Ca(2+) efflux from the acidic lysosomal-like Ca(2+) stores or the endoplasmic reticulum (ER) results in ryanodine-sensitive activation of Ca(2+)-induced Ca(2+) release (CICR) from the complementary Ca(2+) compartment. Our results show for the first time NAADP-evoked Ca(2+) release from acidic compartments through the activation of TPC1 and TPC2, and CICR, in a megakaryoblastic cell line. 2011 Elsevier B.V. All rights reserved.

  8. Raised intracompartmental pressure and compartment syndromes.

    PubMed

    Mars, M; Hadley, G P

    1998-07-01

    Raised intracompartmental pressure (ICP) has become recognized as the final common pathway of a variety of pathologies which lead to failure of the microcirculation with resultant tissue hypoxia and cell death. While commonly seen after trauma, either accidental or operative, raised ICP may result from either an increase in the volume of tissue within a closed osseo-fascial or fascial compartment or by the application of an external force compressing a compartment, and it is associated with a wide variety of insults. The advent of reproducible techniques of measuring ICP has added science to a well-recognized clinical picture and allowed a rational approach to management. Controversies still remain, particularly in regard to the level of pressure at which intervention becomes mandatory, and the role of prophylactic interventions. This review attempts to present current thinking on the pathophysiology of the microcirculation and the background to these controversies.

  9. Compartment syndrome in patients with haemophilia

    PubMed Central

    Donaldson, James; Goddard, Nicholas

    2015-01-01

    Background Acute compartment syndrome (ACS) is an uncommon but potentially devastating condition. Methods and results There are scattered case reports and case series in the literature of ACS in persons with haemophilia (PWH), and even fewer in PWH and inhibitors. The management of compartment syndrome in these scenarios is controversial and often anecdotal. In addition haematological outcomes are frequently quoted but functional outcomes are generally overlooked. This article aims to provide an overview of ACS and its contemporary management. We also review the literature and outcomes of patients with haemophilia who develop ACS in an effort to assess the best treatment modality. Conclusion In the majority of cases ACS settles with normalisation of the clotting cascade. Specialist haematological input is mandatory before surgical intervention should be considered, especially in PWH and inhibitors. PMID:26566325

  10. Are hydrodynamic interactions screened in spherically confined micro-compartments?

    NASA Astrophysics Data System (ADS)

    Aponte-Rivera, Christian; Zia, Roseanna

    2016-11-01

    We study diffusion of hydrodynamically interacting particles confined by a spherical cavity via dynamic simulation, as a model for intracellular transport. Previous models of 3D confined transport typically assume that hydrodynamic interactions are screened and thus can be neglected, but such assumptions lead to qualitative errors in predictive models. Recent studies show that crowding does not screen hydrodynamic entrainment of freely diffusing particles in unbound suspensions, and that diffusing near a planar wall can weaken (but does not screen) hydrodynamic entrainment. Biophysical and other confined suspensions are crowded, watery compartments, suggesting a role of both crowding and confinement in hydrodynamic entrainment. In the present work, we utilize our new computational framework to study the effect of 3D micro-confinement on particle entrainment, and whether such entrainment is algebraically screened. We measure the hydrodynamic entrainment of one particle in the flow induced by another, in suspensions of arbitrary concentration. We find that the strength of entrainment varies spatially in the cavity, changes qualitatively with the size of the confined particles relative to the enclosure, but varies only quantitatively with the concentration of particles.

  11. Decompressive laparotomy for abdominal compartment syndrome

    PubMed Central

    Kimball, E.; Malbrain, M.; Nesbitt, I.; Cohen, J.; Kaloiani, V.; Ivatury, R.; Mone, M.; Debergh, D.; Björck, M.

    2016-01-01

    Background The effect of decompressive laparotomy on outcomes in patients with abdominal compartment syndrome has been poorly investigated. The aim of this prospective cohort study was to describe the effect of decompressive laparotomy for abdominal compartment syndrome on organ function and outcomes. Methods This was a prospective cohort study in adult patients who underwent decompressive laparotomy for abdominal compartment syndrome. The primary endpoints were 28‐day and 1‐year all‐cause mortality. Changes in intra‐abdominal pressure (IAP) and organ function, and laparotomy‐related morbidity were secondary endpoints. Results Thirty‐three patients were included in the study (20 men). Twenty‐seven patients were surgical admissions treated for abdominal conditions. The median (i.q.r.) Acute Physiology And Chronic Health Evaluation (APACHE) II score was 26 (20–32). Median IAP was 23 (21–27) mmHg before decompressive laparotomy, decreasing to 12 (9–15), 13 (8–17), 12 (9–15) and 12 (9–14) mmHg after 2, 6, 24 and 72 h. Decompressive laparotomy significantly improved oxygenation and urinary output. Survivors showed improvement in organ function scores, but non‐survivors did not. Fourteen complications related to the procedure developed in eight of the 33 patients. The abdomen could be closed primarily in 18 patients. The overall 28‐day mortality rate was 36 per cent (12 of 33), which increased to 55 per cent (18 patients) at 1 year. Non‐survivors were no different from survivors, except that they tended to be older and on mechanical ventilation. Conclusion Decompressive laparotomy reduced IAP and had an immediate effect on organ function. It should be considered in patients with abdominal compartment syndrome. PMID:26891380

  12. Dynamic GLUT4 sorting through a syntaxin-6 compartment in muscle cells is derailed by insulin resistance-causing ceramide

    PubMed Central

    Foley, Kevin P.; Klip, Amira

    2014-01-01

    ABSTRACT GLUT4 constitutively recycles between the plasma membrane and intracellular depots. Insulin shifts this dynamic equilibrium towards the plasma membrane by recruiting GLUT4 to the plasma membrane from insulin-responsive vesicles. Muscle is the primary site for dietary glucose deposition; however, how GLUT4 sorts into insulin-responsive vesicles, and if and how insulin resistance affects this process, is unknown. In L6 myoblasts stably expressing myc-tagged GLUT4, we analyzed the intracellular itinerary of GLUT4 as it internalizes from the cell surface and examined if such sorting is perturbed by C2-ceramide, a lipid metabolite causing insulin resistance. Surface-labeled GLUT4myc that internalized for 30 min accumulated in a Syntaxin-6 (Stx6)- and Stx16-positive perinuclear sub-compartment devoid of furin or internalized transferrin, and displayed insulin-responsive re-exocytosis. C2-ceramide dispersed the Stx6-positive sub-compartment and prevented insulin-responsive re-exocytosis of internalized GLUT4myc, even under conditions not affecting insulin-stimulated signaling towards Akt. Microtubule disruption with nocodazole prevented pre-internalized GLUT4myc from reaching the Stx6-positive perinuclear sub-compartment and from undergoing insulin-responsive exocytosis. Removing nocodazole allowed both parameters to recover, suggesting that the Stx6-positive perinuclear sub-compartment was required for GLUT4 insulin-responsiveness. Accordingly, Stx6 knockdown inhibited by ∼50% the ability of internalized GLUT4myc to undergo insulin-responsive re-exocytosis without altering its overall perinuclear accumulation. We propose that Stx6 defines the insulin-responsive compartment in muscle cells. Our data are consistent with a model where ceramide could cause insulin resistance by altering intracellular GLUT4 sorting. PMID:24705014

  13. Dynamic GLUT4 sorting through a syntaxin-6 compartment in muscle cells is derailed by insulin resistance-causing ceramide.

    PubMed

    Foley, Kevin P; Klip, Amira

    2014-04-04

    GLUT4 constitutively recycles between the plasma membrane and intracellular depots. Insulin shifts this dynamic equilibrium towards the plasma membrane by recruiting GLUT4 to the plasma membrane from insulin-responsive vesicles. Muscle is the primary site for dietary glucose deposition; however, how GLUT4 sorts into insulin-responsive vesicles, and if and how insulin resistance affects this process, is unknown. In L6 myoblasts stably expressing myc-tagged GLUT4, we analyzed the intracellular itinerary of GLUT4 as it internalizes from the cell surface and examined if such sorting is perturbed by C2-ceramide, a lipid metabolite causing insulin resistance. Surface-labeled GLUT4myc that internalized for 30 min accumulated in a Syntaxin-6 (Stx6)- and Stx16-positive perinuclear sub-compartment devoid of furin or internalized transferrin, and displayed insulin-responsive re-exocytosis. C2-ceramide dispersed the Stx6-positive sub-compartment and prevented insulin-responsive re-exocytosis of internalized GLUT4myc, even under conditions not affecting insulin-stimulated signaling towards Akt. Microtubule disruption with nocodazole prevented pre-internalized GLUT4myc from reaching the Stx6-positive perinuclear sub-compartment and from undergoing insulin-responsive exocytosis. Removing nocodazole allowed both parameters to recover, suggesting that the Stx6-positive perinuclear sub-compartment was required for GLUT4 insulin-responsiveness. Accordingly, Stx6 knockdown inhibited by ∼50% the ability of internalized GLUT4myc to undergo insulin-responsive re-exocytosis without altering its overall perinuclear accumulation. We propose that Stx6 defines the insulin-responsive compartment in muscle cells. Our data are consistent with a model where ceramide could cause insulin resistance by altering intracellular GLUT4 sorting.

  14. Clathrin-coated, Golgi-related compartment of the insulin secreting cell accumulates proinsulin in the presence of monensin

    SciTech Connect

    Orci, L.; Halban, P.; Amherdt, M.; Ravazzola, M.; Vassalli, J.D.; Perrelet, A.

    1984-11-01

    When the intracellular transit of /sup 3/H-labeled (pro)-insulin polypeptides is perturbed by monensin in the pancreatic B-cell, proinsulin conversion is impaired and the radioactive peptides accumulate in a clathrin-coated membrane compartment related to the Golgi apparatus. Clathrin was demonstrated by immunocytochemistry using the postembedding protein A-gold technique. The coated compartment, which is dilated by monensin, comprises Golgi cisternae with condensing secretory material and newly formed secretory granules; under monensin block, the noncoated (storage) secretory granules do not become significantly labeled. These data suggest that an unperturbed passage through a Golgi-related, clathrin-coated membrane compartment which subsequently matures into noncoated secretory granules is needed for the normal processing of (pro)insulin polypeptides.

  15. NMR quantification of diffusional exchange in cell suspensions with relaxation rate differences between intra and extracellular compartments

    PubMed Central

    Eriksson, Stefanie; Elbing, Karin; Söderman, Olle; Lindkvist-Petersson, Karin; Topgaard, Daniel

    2017-01-01

    Water transport across cell membranes can be measured non-invasively with diffusion NMR. We present a method to quantify the intracellular lifetime of water in cell suspensions with short transverse relaxation times, T2, and also circumvent the confounding effect of different T2 values in the intra- and extracellular compartments. Filter exchange spectroscopy (FEXSY) is specifically sensitive to exchange between compartments with different apparent diffusivities. Our investigation shows that FEXSY could yield significantly biased results if differences in T2 are not accounted for. To mitigate this problem, we propose combining FEXSY with diffusion-relaxation correlation experiment, which can quantify differences in T2 values in compartments with different diffusivities. Our analysis uses a joint constrained fitting of the two datasets and considers the effects of diffusion, relaxation and exchange in both experiments. The method is demonstrated on yeast cells with and without human aquaporins. PMID:28493928

  16. [Arthritis of the Medial Knee Joint Compartment].

    PubMed

    Matziolis, G; Röhner, E

    2015-10-01

    23 % of all persons older than 65 years suffer from osteoarthritis of the medial compartment of the knee joint, a very common situation in orthopaedic practice 1. As a result of the demographic trend the number of patients is expected to increase in the future. Based on specific joint biomechanics and kinematics the medial knee joint compartment is more frequently affected than the lateral. Only an understanding of the functional anatomy and underlying pathology allows a critical evaluation of different available conservative and operative treatment options. This article gives an overview of diagnostic and therapeutic strategies of osteoarthritis of the medial knee joint. Frequently performed surgeries, e.g. high tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) will be presented in a comparative manner. The actual scientific evidence will be given with the goal of an evidence based therapy that is adopted to stage and pathology of osteoarthritis of the medial compartment of the knee joint. Georg Thieme Verlag KG Stuttgart · New York.

  17. Bacterial translocation - impact on the adipocyte compartment.

    PubMed

    Kruis, Tassilo; Batra, Arvind; Siegmund, Britta

    2014-01-06

    Over the last decade it became broadly recognized that adipokines and thus the fat tissue compartment exert a regulatory function on the immune system. Our own group described the pro-inflammatory function of the adipokine leptin within intestinal inflammation in a variety of animal models. Following-up on this initial work, the aim was to reveal stimuli and mechanisms involved in the activation of the fat tissue compartment and the subsequent release of adipokines and other mediators paralleled by the infiltration of immune cells. This review will summarize the current literature on the possible role of the mesenteric fat tissue in intestinal inflammation with a focus on Crohn's disease (CD). CD is of particular interest in this context since the transmural intestinal inflammation has been associated with a characteristic hypertrophy of the mesenteric fat, a phenomenon called "creeping fat." The review will address three consecutive questions: (i) What is inducing adipocyte activation, (ii) which factors are released after activation and what are the consequences for the local fat tissue compartment and infiltrating cells; (iii) do the answers generated before allow for an explanation of the role of the mesenteric fat tissue within intestinal inflammation? With this review we will provide a working model indicating a close interaction in between bacterial translocation, activation of the adipocytes, and subsequent direction of the infiltrating immune cells. In summary, the models system mesenteric fat indicates a unique way how adipocytes can directly interact with the immune system.

  18. Perfluoroalkyl acid distribution in various plant compartments ...

    EPA Pesticide Factsheets

    Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var.dulce), tomato (Lycopersicon lycopersicum), and sugar snap pea (Pisum sativum var. macrocarpon) from an industrially impacted biosolids-amended soil, a municipal biosolids­ amended soil, and a control soil. Individual concentrations of PFAAs, on a dry weight basis, in mature, edible portions of crops grown in soil amended with PFAA industrially impacted biosolids were highest for perfluorooctanoate (PFOA; 67 ng/g) in radish root, perfluorobutanoate (PFBA;232 ng/g) in celery shoot, and PFBA (150 ng/g) in pea fruit. Comparatively, PFAA concentrations in edible compartments of crops grown in the municipal biosolids-amended soil and in the control soil were less than 25 ng/g. Bioaccumulation factors (BAFs) were calculated for the root, shoot, and fruit compartments (as applicable) of all crops grown in the industrially impacted soil. BAFs were highest for PFBA in the shoots of all crops, as well as in the fruit compartment of pea. Root­ soil concentration factors (RCFs) for tomato and pea were independent of PFAA chain length, while radish and celery RCFs showed a slight decrease with increasing chain length. Shoot-soil concentration factors (SCFs) for all crops showed a decrease with incre

  19. Intracellular routing of cytotoxic pancreatic-type ribonucleases.

    PubMed

    Benito, Antoni; Vilanova, Maria; Ribó, Marc

    2008-06-01

    In addition to their ribonucleolytic activity, several ribonucleases (RNases) play important roles in other specific biological activities, such as dendritic cell activation, certain pollen-induced allergies, blood vessel formation and defense against parasitic or microbial infections. Among these diverse actions, cytotoxic activity, which relies in most cases on ribonucleolytic activity, has attracted a considerable attention because of the potential for using RNases as therapeutic agents for the treatment of different malignancies. In addition to use naturally existing RNases, major efforts have been made in the development of engineered variants, which display more potent cytotoxic activity and greater selectivity for malignant cells. This review focuses on the molecular and cellular aspects of the internalization, intracellular trafficking and final sorting of cytotoxic RNases. Knowledge about the strategies used by these promising toxins provides us with essential information about the mechanisms that can be used to gain access to different subcellular compartments and intracellular sorting.

  20. Isolated medial foot compartment syndrome after ankle sprain.

    PubMed

    Cortina, Josep; Amat, Carles; Selga, Jordi; Corona, Pablo Salvador

    2014-03-01

    Foot compartment syndrome is a serious potential complication of foot crush injury, fractures, surgery, and vascular injury. An acute compartment syndrome isolated to the medial compartment of the foot after suffering an ankle sprain is a rare complication. We report the case of a 31-year-old man who developed a medial foot compartment syndrome after suffering a deltoid ligament rupture at ankle while playing football. The patient underwent a medial compartment fasciotomy with resolution of symptoms. Compartment syndromes of the foot are rare and have been reported to occur after severe trauma. But, there are some reports in the literature of acute exertional compartment syndrome. In our case, the compartment syndrome appeared after an ankle sprain without vascular injuries associated. Copyright © 2013 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  1. 14 CFR 29.787 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 29.787 Cargo and baggage compartments. (a) Each cargo and baggage compartment must be...

  2. 14 CFR 27.787 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 27.787 Cargo and baggage compartments. (a) Each cargo and baggage compartment must be...

  3. Inhibition of intracellular pH control and relationship to cytotoxicity of chlorambucil and vinblastine.

    PubMed Central

    Parkins, C. S.; Chadwick, J. A.; Chaplin, D. J.

    1996-01-01

    The uptake and cytotoxicity of weakly acidic or basic chemotherapeutic agents is determined in part by passive diffusion along the pH gradient between the intracellular and extracellular compartments. In vivo it is known that tumour extracellular pH is more acidic than intracellular pH. Using CaNT murine tumour cells in vitro, we found the cytotoxicity of chlorambucil (a weak acid) increased as the extracellular pH of the culture medium (pHmed) was acidified. The cytotoxicity of vinblastine shows a reverse pH relationship with reduced cytotoxicity as pHmed was acidified. Chlorambucil cytotoxicity increased at acidic pHmed because the weak acidic function is ionised to a lesser extent at acidic pH and, therefore, favours drug uptake into the relatively neutral intracellular compartment. Vinblastine cytotoxicity decreased at acidic pHmed because the weak basic function is ionised to a greater extent at acidic pH and therefore does not favour drug uptake into the relatively neutral intracellular compartment. Using a combination of an inhibitor of the cell membrane proton pump, amiloride, and the ionophore, nigericin, the intracellular compartment can be acidified. This results in a time-dependent increase in sensitivity of the cells to low pHmed with significant cytotoxicity after 6 h exposure to pHmed = 6.2 and suggests that there is potential for direct tumour cytotoxicity in vivo if the tumour extracellular pH were equally acidic. An indirect effect of intracellular acidification is to alter the distribution of drugs between the extra- and intracellular compartment by reducing the pH gradient across the cell membrane. In response to intracellular acidification, the cytotoxicity of chlorambucil was reduced and that for vinblastine was increased. Inhibition of cellular pH control may result in direct cytotoxicity by acidification due to inhibition of proton efflux or indirectly by resulting in differential uptake of chemotherapeutic agents with weak acidic or basic

  4. Intracellular microbes and haemophagocytosis.

    PubMed

    Silva-Herzog, Eugenia; Detweiler, Corrella S

    2008-11-01

    Haemophagocytosis (hemophagocytosis) is the phenomenon of activated macrophage consumption of red and white blood cells, including professional phagocytes and lymphocytes. It can occur in patients with severe cases of intracellular microbial infection, including avian influenza, leishmaniasis, tuberculosis and typhoid fever. While well-known to physicians since at least the mid-1800s, haemophagocytosis has been little studied due to a paucity of tractable animal and cell culture models. Recently, haemophagocytosis has been described in a mouse model of typhoid fever, and it was noted that the infectious agent, Salmonella enterica, resides within haemophagocytic macrophages in mice. In addition, a cell culture model for haemophagocytosis revealed that S. enterica preferentially replicate in haemophagocytic macrophages. This review describes how, at the molecular and cellular levels, S. enterica may promote and take advantage of haemophagocytosis to establish long-term systemic infections in mammals. The role, relevance and possible molecular mechanisms of haemophagocytosis are discussed within the context of other microbial infections and of genetic deficiencies in which haemophagocytosis occurs and is associated with morbidity.

  5. Intracellular Sterol Dynamics

    PubMed Central

    Mesmin, Bruno; Maxfield, Frederick R.

    2009-01-01

    We review the cellular mechanisms implicated in cholesterol trafficking and distribution. Recent studies have provided new information about the distribution of sterols within cells, including analysis of its transbilayer distribution. The cholesterol interaction with other lipids and its engagement in various trafficking processes will determine its proper level in a specific membrane; making the cholesterol distribution uneven among the various intracellular organelles. The cholesterol content is important since cholesterol plays an essential role in membranes by controlling their physicochemical properties as well as key cellular events such as signal transduction and protein trafficking. Cholesterol movement between cellular organelles is highly dynamic, and can be achieved by vesicular and non-vesicular processes. Various studies have analyzed the proteins that play a significant role in these processes, giving us new information about the relative importance of these two trafficking pathways in cholesterol transport. Although still poorly characterized in many trafficking routes, several potential sterol transport proteins have been described in detail; as a result, molecular mechanisms for sterol transport among membranes start to be appreciated. PMID:19286471

  6. Multivariate profiling of neurodegeneration-associated changes in a subcellular compartment of neurons via image processing.

    PubMed

    Kumarasamy, Saravana K; Wang, Yunshi; Viswanathan, Vignesh; Kraut, Rachel S

    2008-11-14

    Dysfunction in the endolysosome, a late endosomal to lysosomal degradative intracellular compartment, is an early hallmark of some neurodegenerative diseases, in particular Alzheimer's disease. However, the subtle morphological changes in compartments of affected neurons are difficult to quantify quickly and reliably, making this phenotype inaccessible as either an early diagnostic marker, or as a read-out for drug screening. We present a method for automatic detection of fluorescently labeled endolysosomes in degenerative neurons in situ. The Drosophila blue cheese (bchs) mutant was taken as a genetic neurodegenerative model for direct in situ visualization and quantification of endolysosomal compartments in affected neurons. Endolysosomal compartments were first detected automatically from 2-D image sections using a combination of point-wise multi-scale correlation and normalized correlation operations. This detection algorithm performed well at recognizing fluorescent endolysosomes, unlike conventional convolution methods, which are confounded by variable intensity levels and background noise. Morphological feature differences between endolysosomes from wild type vs. degenerative neurons were then quantified by multivariate profiling and support vector machine (SVM) classification based on compartment density, size and contrast distribution. Finally, we ranked these distributions according to their profiling accuracy, based on the backward elimination method. This analysis revealed a statistically significant difference between the neurodegenerative phenotype and the wild type up to a 99.9% confidence interval. Differences between the wild type and phenotypes resulting from overexpression of the Bchs protein are detectable by contrast variations, whereas both size and contrast variations distinguish the wild type from either of the loss of function alleles bchs1 or bchs58. In contrast, the density measurement differentiates all three bchs phenotypes (loss of

  7. 14 CFR 23.773 - Pilot compartment view.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment view. 23.773 Section 23... Personnel and Cargo Accommodations § 23.773 Pilot compartment view. (a) Each pilot compartment must be— (1) Arranged with sufficiently extensive, clear and undistorted view to enable the pilot to safely taxi...

  8. 14 CFR 25.772 - Pilot compartment doors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment doors. 25.772 Section 25... § 25.772 Pilot compartment doors. For an airplane that has a lockable door installed between the pilot... pilot compartment if the cockpit door becomes jammed. (c) There must be an emergency means to enable a...

  9. 14 CFR 23.773 - Pilot compartment view.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pilot compartment view. 23.773 Section 23... Personnel and Cargo Accommodations § 23.773 Pilot compartment view. (a) Each pilot compartment must be— (1) Arranged with sufficiently extensive, clear and undistorted view to enable the pilot to safely taxi...

  10. 14 CFR 27.773 - Pilot compartment view.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment view. 27.773 Section 27... § 27.773 Pilot compartment view. (a) Each pilot compartment must be free from glare and reflections that could interfere with the pilot's view, and designed so that— (1) Each pilot's view is sufficiently...

  11. 14 CFR 25.772 - Pilot compartment doors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pilot compartment doors. 25.772 Section 25... § 25.772 Pilot compartment doors. For an airplane that has a lockable door installed between the pilot... pilot compartment if the cockpit door becomes jammed. (c) There must be an emergency means to enable a...

  12. 14 CFR 29.773 - Pilot compartment view.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pilot compartment view. 29.773 Section 29... Accommodations § 29.773 Pilot compartment view. (a) Nonprecipitation conditions. For nonprecipitation conditions, the following apply: (1) Each pilot compartment must be arranged to give the pilots a sufficiently...

  13. 14 CFR 29.773 - Pilot compartment view.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pilot compartment view. 29.773 Section 29... Accommodations § 29.773 Pilot compartment view. (a) Nonprecipitation conditions. For nonprecipitation conditions, the following apply: (1) Each pilot compartment must be arranged to give the pilots a sufficiently...

  14. 14 CFR 25.365 - Pressurized compartment loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Pressurized compartment loads. 25.365... an engine disintegration; (2) Any opening in any pressurized compartment up to the size Ho in square... small compartment. The size Ho must be computed by the following formula: Ho=PAs where,...

  15. 46 CFR 169.627 - Compartments containing diesel fuel tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compartments containing diesel fuel tanks. 169.627... SCHOOL VESSELS Machinery and Electrical Ventilation § 169.627 Compartments containing diesel fuel tanks. Unless they are adequately ventilated, enclosed compartments or spaces containing diesel fuel tanks and...

  16. Compartment Syndrome of the Hand: A Little Thought about Diagnosis

    PubMed Central

    Reichman, Eric F.

    2016-01-01

    Compartment syndrome of the forearm is a well described entity but there have been relatively few case reports in the emergency medicine literature of hand compartment syndromes (HCS). Prompt recognition and treatment of this potential limb threat are essential to minimize morbidity and mortality. Presented is a case of a documented hand compartment syndrome following a motor vehicle collision. PMID:27293917

  17. Analysis of the Relative Contribution of Phagocytosis, LC3-Associated Phagocytosis, and Canonical Autophagy During Helicobacter pylori Infection of Macrophages.

    PubMed

    Deen, Nadia S; Gong, Lan; Naderer, Thomas; Devenish, Rodney J; Kwok, Terry

    2015-12-01

    Previous findings have suggested that Helicobacter pylori induces autophagic processes and subsequently takes refuge in autophagosomes, thereby contributing to persistent infection. Recently, a noncanonical form of autophagy, LC3 (microtubule-associated protein 1 light chain 3)-associated phagocytosis (LAP), has been shown to be required for efficient clearance of some intracellular bacteria. Whether H. pylori infection induces LAP had not been examined previously. In this study, we determined the extent to which H. pylori infection induces canonical autophagy or LAP in macrophages, and the involvement of the H. pylori cag pathogenicity island (cagPAI) with these processes. Immunofluorescence confocal microscopy was used to analyze the formation of GFP-LC3 puncta and their colocalization with H. pylori. Transmission electron microscopy was used to detect the ultrastructure of H. pylori-containing compartments. The majority of intracellular bacteria (85-95%) were found in phagosomes that were LC3-negative, with a small proportion (4-14%) appearing "free" in the cytosol. Only a very small percentage (0.5-6%) of intracellular H. pylori was sequestered in autophagosomes. Furthermore, no statistically significant difference in the relative distribution of H. pylori in the various compartments was observed between wild-type and cagPAI-mutant bacteria. In macrophages, H. pylori infection does not induce LAP, but can induce canonical autophagy, which entraps a very small fraction of intracellular bacteria. We propose that this subpopulation of intracellular H. pylori might have escaped from phagosomes into the cytosol before being sequestered by autophagosomes. The cagPAI of H. pylori has only minor influence, if any, on the extent of these processes. © 2015 John Wiley & Sons Ltd.

  18. Continuous monitoring of plasma, interstitial, and intracellular fluid volumes in dialyzed patients by bioimpedance and hematocrit measurements.

    PubMed

    Jaffrin, Michel Y; Fenech, Marianne; de Fremont, Jean-François; Tolani, Michel

    2002-01-01

    Bioimpedance spectroscopy (BIS) permits evaluation of extra- and intracellular fluid volumes in patients. We wished to examine whether this technique, used in combination with hematocrit measurement, can reliably monitor fluid transfers during dialysis. Ankle to wrist BIS measurements were collected during 21 dialysis runs while hematocrit was continuously monitored in the blood line by an optical device. Extracellular (ECW) and intracellular (ICW) water volumes were calculated using Hanai's electrical model of suspensions. Plasma volume variations were calculated from hematocrit, and changes in interstitial volume were calculated as the difference between ECW and plasma volume changes. Because accuracy of ICW was too low, changes in ICW were calculated as the difference between ultrafiltered volume and ECW changes. Total body water (TBW) volumes calculated pre- and postdialysis were, respectively, 3.25+/-3.2 and 1.95+/-2.5 liters lower on average than TBW given by Watson et al.'s correlation. Average decreases in fluid compartments expressed as percentage of ultrafiltered volume were as follows: plasma, 18%; interstitial, 28%, and ICW, 54%. When the ultrafiltered volume was increased in a patient in successive runs, the relative contributions of ICW and interstitial fluid were augmented so as to reduce the relative drop in plasma volume.

  19. Mechanisms of intracellular ice formation.

    PubMed Central

    Muldrew, K; McGann, L E

    1990-01-01

    The phenomenon of intracellular freezing in cells was investigated by designing experiments with cultured mouse fibroblasts on a cryomicroscope to critically assess the current hypotheses describing the genesis of intracellular ice: (a) intracellular freezing is a result of critical undercooling; (b) the cytoplasm is nucleated through aqueous pores in the plasma membrane; and (c) intracellular freezing is a result of membrane damage caused by electrical transients at the ice interface. The experimental data did not support any of these theories, but was consistent with the hypothesis that the plasma membrane is damaged at a critical gradient in osmotic pressure across the membrane, and intracellular freezing occurs as a result of this damage. An implication of this hypothesis is that mathematical models can be used to design protocols to avoid damaging gradients in osmotic pressure, allowing new approaches to the preservation of cells, tissues, and organs by rapid cooling. PMID:2306499

  20. Nutrient salvaging and metabolism by the intracellular pathogen Legionella pneumophila.

    PubMed

    Fonseca, Maris V; Swanson, Michele S

    2014-01-01

    The Gram-negative bacterium Legionella pneumophila is ubiquitous in freshwater environments as a free-swimming organism, resident of biofilms, or parasite of protozoa. If the bacterium is aerosolized and inhaled by a susceptible human host, it can infect alveolar macrophages and cause a severe pneumonia known as Legionnaires' disease. A sophisticated cell differentiation program equips L. pneumophila to persist in both extracellular and intracellular niches. During its life cycle, L. pneumophila alternates between at least two distinct forms: a transmissive form equipped to infect host cells and evade lysosomal degradation, and a replicative form that multiplies within a phagosomal compartment that it has retooled to its advantage. The efficient changeover between transmissive and replicative states is fundamental to L. pneumophila's fitness as an intracellular pathogen. The transmission and replication programs of L. pneumophila are governed by a number of metabolic cues that signal whether conditions are favorable for replication or instead trigger escape from a spent host. Several lines of experimental evidence gathered over the past decade establish strong links between metabolism, cellular differentiation, and virulence of L. pneumophila. Herein, we focus on current knowledge of the metabolic components employed by intracellular L. pneumophila for cell differentiation, nutrient salvaging and utilization of host factors. Specifically, we highlight the metabolic cues that are coupled to bacterial differentiation, nutrient acquisition systems, and the strategies utilized by L. pneumophila to exploit host metabolites for intracellular replication.

  1. Characterization of peptides bound to extracellular and intracellular HLA-DR1 molecules.

    PubMed

    Max, H; Halder, T; Kropshofer, H; Kalbus, M; Müller, C A; Kalbacher, H

    1993-11-01

    Exogenous antigens are internalized by antigen-processing cells and processed within vesicular compartments to produce antigenic peptides that bind to newly synthesized MHC II molecules. These MHC class II peptide complexes are displayed at the plasma membrane and stimulate specific CD4+ T cells. In the present study, we established a method to isolate intracellular MHC molecules in a preparative scale (2-3 mg HLA-DR1) from endosomal compartments by Percoll density-gradient centrifugation. Peptides associated with HLA-DR1 in these intracellular fractions were released, purified by microbore HPLC, characterized by sequencing, and compared with the amino acid composition of peptides derived from MHC class II molecules obtained by solubilization of the plasma membrane. The binding affinity of these MHC fractions was analyzed by our highly sensitive binding assay using different DR1-restricted IM and Ii peptides. The results indicate that (a) intracellular MHC molecules show higher peptide-binding capacity, (b) peptides that are about 18-25 amino acids long need only a core region of 11 amino acids for binding, (c) specific positions of the peptides are important for DR1 binding, (d) most of the naturally processed peptides show a proline at position 2 or 3 that may represent a stop signal for trimming, and (e) Ii peptides are very abundant in DR1 peptide pools derived from intracellular compartments.

  2. Lower limb compartment syndrome by reperfusion injury after treatment of arterial thrombosis post-laparoscopic radical hysterectomy and pelvic lymph node dissection for cervical cancer

    PubMed Central

    Yeon, Jihee; Jung, Ye Won; Yang, Shin Seok; Kang, Byung Hun; Lee, Mina; Ko, Young Bok; Yang, Jung Bo; Lee, Ki Hwan

    2017-01-01

    Compartment syndrome is a clinical condition associated with decreased blood circulation that can lead to swelling of tissue in limited space. Several factors including lithotomy position, prolonged surgery, intermittent pneumatic compressor, and reperfusion after treatment of arterial thrombosis may contribute to compartment syndrome. However, compartment syndrome rarely occurs after gynecologic surgery. In this case, the patient was diagnosed as compartment syndrome due to reperfusion injury after treatment of arterial thrombosis, which occurred after laparoscopic radical hysterectomy and pelvic lymph node dissection for cervical cancer. Despite its rarity, prevention and identifying the risk factors of complication should be performed perioperatively; furthermore, gynecologist should be aware of the possibility of complications. PMID:28344966

  3. Lower limb compartment syndrome by reperfusion injury after treatment of arterial thrombosis post-laparoscopic radical hysterectomy and pelvic lymph node dissection for cervical cancer.

    PubMed

    Yeon, Jihee; Jung, Ye Won; Yang, Shin Seok; Kang, Byung Hun; Lee, Mina; Ko, Young Bok; Yang, Jung Bo; Lee, Ki Hwan; Yoo, Heon Jong

    2017-03-01

    Compartment syndrome is a clinical condition associated with decreased blood circulation that can lead to swelling of tissue in limited space. Several factors including lithotomy position, prolonged surgery, intermittent pneumatic compressor, and reperfusion after treatment of arterial thrombosis may contribute to compartment syndrome. However, compartment syndrome rarely occurs after gynecologic surgery. In this case, the patient was diagnosed as compartment syndrome due to reperfusion injury after treatment of arterial thrombosis, which occurred after laparoscopic radical hysterectomy and pelvic lymph node dissection for cervical cancer. Despite its rarity, prevention and identifying the risk factors of complication should be performed perioperatively; furthermore, gynecologist should be aware of the possibility of complications.

  4. Intracellular Acidosis Enhances the Excitability of Working Muscle

    NASA Astrophysics Data System (ADS)

    Pedersen, Thomas H.; Nielsen, Ole B.; Lamb, Graham D.; Stephenson, D. George

    2004-08-01

    Intracellular acidification of skeletal muscles is commonly thought to contribute to muscle fatigue. However, intracellular acidosis also acts to preserve muscle excitability when muscles become depolarized, which occurs with working muscles. Here, we show that this process may be mediated by decreased chloride permeability, which enables action potentials to still be propagated along the internal network of tubules in a muscle fiber (the T system) despite muscle depolarization. These results implicate chloride ion channels in muscle function and emphasize that intracellular acidosis of muscle has protective effects during muscle fatigue.

  5. Intracellular acidosis enhances the excitability of working muscle.

    PubMed

    Pedersen, Thomas H; Nielsen, Ole B; Lamb, Graham D; Stephenson, D George

    2004-08-20

    Intracellular acidification of skeletal muscles is commonly thought to contribute to muscle fatigue. However, intracellular acidosis also acts to preserve muscle excitability when muscles become depolarized, which occurs with working muscles. Here, we show that this process may be mediated by decreased chloride permeability, which enables action potentials to still be propagated along the internal network of tubules in a muscle fiber (the T system) despite muscle depolarization. These results implicate chloride ion channels in muscle function and emphasize that intracellular acidosis of muscle has protective effects during muscle fatigue.

  6. Unloader Braces for Medial Compartment Knee Osteoarthritis

    PubMed Central

    Ramsey, Dan K.; Russell, Mary E.

    2009-01-01

    Background: For persons with unicompartment knee osteoarthritis (OA), off-unloader braces are a mechanical intervention designed to reduce pain, improve physical function, and possibly slow disease progression. Pain relief is thought to be mediated by distracting the involved compartment via external varus or valgus forces applied to the knee. In so doing, tibiofemoral alignment is improved, and load is shifted off the degenerative compartment, where exposure to potentially damaging and provocative mechanical stresses are reduced. Objectives: To provide a synopsis of the evidence documented in the scientific literature concerning the efficacy of off-loader knee braces for improving symptomatology associated with painful disabling medial compartment knee OA. Search Strategy: Relevant peer-reviewed publications were retrieved from a MEDLINE search using the terms with the reference terms osteoarthritis, knee, and braces (per Medical Subject Headings), plus a manual search of bibliographies from original and review articles and appropriate Internet resources. Results: For persons with combined unicompartment knee OA and mild to moderate instability, the strength of recommendation reported by the Osteoarthritis Research Society International in the ability of off-loader knee braces to reduce pain, improve stability, and diminish the risk of falling was 76% (95% confidence interval, 69%-83%). The more evidence the treatment is effective, the higher the percentage. Conclusions: Given the encouraging evidence that off-loader braces are effective in mediating pain relief in conjunction with knee OA and malalignment, bracing should be fully used before joint realignment or replacement surgery is considered. With the number of patients with varus deformities and knee pain predicted to increase as the population ages, a reduction of patient morbidity for this widespread chronic condition in combination with this treatment modality could have a positive impact on health care

  7. On the interaction between respiratory compartments during passive expiration in ARDS patients.

    PubMed

    Chelucci, Gian-Luca; Locchi, Fabrizio; Zin, Walter A

    2005-01-15

    Relaxed expiratory volume-time profile has been frequently analysed by fitting exponential functions of time to one- or two-compartment models. In the latter case, the two exponential constants are assumed as representing the time constants of both compartments. Least-square fittings on the experimental data of five consecutive mechanically ventilated supine patients with acute respiratory distress syndrome (ARDS) were performed using rate-constants (flow/volume ratio) as parameters in order to obtain the model matching. Passive expiratory volume-time curves were recorded under PEEP = 0 and 13.6 +/- 3.3 S.D. cmH2O conditions. Model matching was optimal with significant, reliable parameter values. As a result, the use of a PEEP in ARDS patients: (a) delayed expiration; (b) decreased the percentage initial volume contribution of the slow-emptying compartment; and, (c) modified the interaction between compartments. The volume-time profile of the second compartment was found to increase at the beginning of expiration, and, then, progressively decayed towards zero, showing a maximum, although the overall curve decreased throughout expiration.

  8. Utility of Doppler ultrasonography for diagnosing and assessing treatment effects in liver compartment syndrome.

    PubMed

    Ando, Yusuke; Ishigami, Masatoshi; Ishizu, Yoji; Kuzuya, Teiji; Honda, Takashi; Hayashi, Kazuhiko; Ishikawa, Tetsuya; Goto, Hidemi; Hirooka, Yoshiki

    2017-06-01

    Liver compartment syndrome is a life-threatening complication of hepatic subcapsular hematoma; diagnosis and assessment of treatment effects are therefore important. We report a rare case of liver compartment syndrome due to spontaneous hepatic subcapsular hematoma without any underlying conditions, in which Doppler ultrasonography (US) proved useful in both diagnosis and assessment of treatment effects. A 32-year-old woman experienced sudden epigastralgia and was diagnosed with hepatic subcapsular hematoma in the right lobe, based on contrast-enhanced computed tomography. Hepatic arteriography showed active hemorrhage and Doppler US showed retrograde flow in the right portal vein. From these findings, we diagnosed hepatic subcapsular hematoma complicated with liver compartment syndrome, and performed embolization of the bleeding point and percutaneous hematoma drainage. After these medical procedures, normalized antegrade flow in the right portal vein was observed on Doppler US. No underlying conditions contributing to hematoma were identified. In this case, Doppler US was useful for both diagnosis and assessment of treatment effects in liver compartment syndrome. When we examine patients with hepatic subcapsular hematoma, Doppler US should be used to diagnose the presence of liver compartment syndrome and assess treatment effects.

  9. Microspectroscopy of the photosynthetic compartment of algae.

    PubMed

    Evangelista, Valtere; Frassanito, Anna Maria; Passarelli, Vincenzo; Barsanti, Laura; Gualtieri, Paolo

    2006-01-01

    We performed microspectroscopic evaluation of the pigment composition of the photosynthetic compartments of algae belonging to different taxonomic divisions and higher plants. The feasibility of microspectroscopy for discriminating among species and/or phylogenetic groups was tested on laboratory cultures. Gaussian bands decompositions and a fitting algorithm, together with fourth-derivative transformation of absorbance spectra, provided a reliable discrimination among chlorophylls a, b and c, phycobiliproteins and carotenoids. Comparative analysis of absorption spectra highlighted the evolutionary grouping of the algae into three main lineages in accordance with the most recent endosymbiotic theories.

  10. [Intraabdominal hypertension and abdominal compartment syndrome].

    PubMed

    Sonne, Morten; Hillingsø, Jens

    2008-02-11

    Intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are rare conditions with high mortality. IAH is an intraabdominal pressure (IAP) above 12 mmHg and ACS an IAP above 20 mmHg with evidence of organ dysfunction. IAP is measured indirectly via the bladder or stomach. Various medical and surgical conditions increase the intraabdominal volume. When the content exceeds the compliance of the abdominal wall, the IAP rises. Increased IAP affects the functioning of the brain, lungs, circulation, kidneys, and bowel. The treatment of ACS is a reduction of IAP.

  11. Actin: its cumbersome pilgrimage through cellular compartments

    PubMed Central

    Schleicher, Michael

    2008-01-01

    In this article, we follow the history of one of the most abundant, most intensely studied proteins of the eukaryotic cells: actin. We report on hallmarks of its discovery, its structural and functional characterization and localization over time, and point to present days’ knowledge on its position as a member of a large family. We focus on the rather puzzling number of diverse functions as proposed for actin as a dual compartment protein. Finally, we venture on some speculations as to its origin. PMID:18438682

  12. Acute compartment syndrome of forearm and hand

    PubMed Central

    Chandraprakasam, T.; Kumar, R. Ashok

    2011-01-01

    The diagnosis and treatment of the acute compartment syndrome is of paramount importance. Unless the viscious cycle is intervened at an appropriately early time it will result in irreversible damage leading to disability. In this review article we are discussing the basic pathophysiological process through which the various aetiological factors causing increased compartmental pressure lead to the progressive death of muscles and nerves. We also discuss the various clinical features that aid in the diagnosis and the role of intracompartmental pressure measurements. Finally we hope to ascertain the basic principles and the surgical techniques for treating this condition effectively. PMID:22022031

  13. Cell-penetrating peptides with intracellular organelle targeting.

    PubMed

    Cerrato, Carmine Pasquale; Künnapuu, Kadri; Langel, Ülo

    2017-02-01

    One of the major limiting steps in order to have an effective drug is the passage through one or more cell membranes to reach its site of action. To reach the action-site, the specific macromolecules are required to be delivered specifically to the cell compartment/organelle in their (pre)active form. Areas covered: In this review, we will discuss cell-penetrating peptides (CPPs) developed in the last decade to transport small RNA/DNA, plasmids, antibodies, and nanoparticles into specific sites of the cell. The article describes CPPs in complex with cargo molecules that target specific intracellular organelles and their potential for pharmacological or clinical use. Expert opinion: Organelle targeting is the ultimate goal to ensure selective delivery to the site of action in the cells. CPP technologies represent an important strategy to address drug delivery to specific intracellular compartments by covalent conjugation to targeting sequences, potentially enabling strategies to combat genomic diseases as well as infections, cancer, neurodegenerative and hereditary diseases. They have proven to be successful in delivering various therapeutic agents into cells however, further in vivo experiments and clinical trials are required to demonstrate the efficacy of this technology.

  14. Emerging intracellular receptors for hemorrhagic fever viruses.

    PubMed

    Jae, Lucas T; Brummelkamp, Thijn R

    2015-07-01

    Ebola virus and Lassa virus belong to different virus families that can cause viral hemorrhagic fever, a life-threatening disease in humans with limited treatment options. To infect a target cell, Ebola and Lassa viruses engage receptors at the cell surface and are subsequently shuttled into the endosomal compartment. Upon arrival in late endosomes/lysosomes, the viruses trigger membrane fusion to release their genome into the cytoplasm. Although contact sites at the cell surface were recognized for Ebola virus and Lassa virus, it was postulated that Ebola virus requires a critical receptor inside the cell. Recent screens for host factors identified such internal receptors for both viruses: Niemann-Pick disease type C1 protein (NPC1) for Ebola virus and lysosome-associated membrane protein 1 (LAMP1) for Lassa virus. A cellular trigger is needed to permit binding of the viral envelope protein to these intracellular receptors. This 'receptor switch' represents a previously unnoticed step in virus entry with implications for host-pathogen interactions and viral tropism.

  15. Ultrasonic Apparatus and Method to Assess Compartment Syndrome

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Ueno, Toshiaki (Inventor); Hargens, Alan R. (Inventor)

    2009-01-01

    A process and apparatus for measuring pressure buildup in a body compartment that encases muscular tissue. The method includes assessing the body compartment configuration and identifying the effect of pulsatible components on compartment dimensions and muscle tissue characteristics. This process is used in preventing tissue necrosis, and in decisions of whether to perform surgery on the body compartment for prevention of Compartment Syndrome. An apparatus is used for measuring pressure build-up in the body compartment having components for imparting ultrasonic waves such as a transducer, placing the transducer to impart the ultrasonic waves, capturing the imparted ultrasonic waves, mathematically manipulating the captured ultrasonic waves and categorizing pressure build-up in the body compartment from the mathematical manipulations.

  16. Supraspinatus and infraspinatus compartment syndrome following scapular fracture

    PubMed Central

    Kenny, Ryan M.; Beiser, Christopher W.; Patel, Arun

    2013-01-01

    Acute compartment syndrome occurs when pressure within a confined fascial space rises to a level impairing microvascular perfusion to surrounding tissues.[1234567] The majority of the reported literature is based on lower extremity compartment syndrome, but any muscle group within an osteofascial compartment has the potential to develop compartment syndrome. We report a case of a 64-year-old male who developed an acute compartment syndrome of both the supraspinatus and infraspinatus after sustaining a severely comminuted scapula fracture. Diagnosis of compartment syndrome was made after intracompartmental pressure measurements of the supraspinatus and infraspinatus revealed pressures within 30 mmHg of the diastolic blood pressure, prompting emergency decompressive fasciotomy. At final follow-up, the examination revealed full shoulder strength with near-full range of motion. There were no signs of sequelae from compartment syndrome at any point. Few case reports describe compartment syndrome of the periscapular fascial compartments. However, these cases were either retrospectively diagnosed[89] or diagnosed via magnetic resonance imaging (MRI) findings and lab values.[910] Surgical management of acute compartment syndrome of the supraspinatus has been reported in only one other case.[10] To our knowledge, we report the only case of a patient with acute compartment syndrome of both the supraspinatus and infraspinatus compartments treated with emergent decompressive fasciotomy. Due to the devastating complications and functional loss of a missed diagnosis of compartment syndrome, a high index of clinical suspicion for developing compartment syndrome must be maintained in every fracture setting, regardless of anatomic location or rarity of reported cases. PMID:23858293

  17. Supraspinatus and infraspinatus compartment syndrome following scapular fracture.

    PubMed

    Kenny, Ryan M; Beiser, Christopher W; Patel, Arun

    2013-01-01

    Acute compartment syndrome occurs when pressure within a confined fascial space rises to a level impairing microvascular perfusion to surrounding tissues.[1234567] The majority of the reported literature is based on lower extremity compartment syndrome, but any muscle group within an osteofascial compartment has the potential to develop compartment syndrome. We report a case of a 64-year-old male who developed an acute compartment syndrome of both the supraspinatus and infraspinatus after sustaining a severely comminuted scapula fracture. Diagnosis of compartment syndrome was made after intracompartmental pressure measurements of the supraspinatus and infraspinatus revealed pressures within 30 mmHg of the diastolic blood pressure, prompting emergency decompressive fasciotomy. At final follow-up, the examination revealed full shoulder strength with near-full range of motion. There were no signs of sequelae from compartment syndrome at any point. Few case reports describe compartment syndrome of the periscapular fascial compartments. However, these cases were either retrospectively diagnosed[89] or diagnosed via magnetic resonance imaging (MRI) findings and lab values.[910] Surgical management of acute compartment syndrome of the supraspinatus has been reported in only one other case.[10] To our knowledge, we report the only case of a patient with acute compartment syndrome of both the supraspinatus and infraspinatus compartments treated with emergent decompressive fasciotomy. Due to the devastating complications and functional loss of a missed diagnosis of compartment syndrome, a high index of clinical suspicion for developing compartment syndrome must be maintained in every fracture setting, regardless of anatomic location or rarity of reported cases.

  18. Determination of Intracellular Vitrification Temperatures for Unicellular Micro Organisms under Conditions Relevant for Cryopreservation.

    PubMed

    Fonseca, Fernanda; Meneghel, Julie; Cenard, Stéphanie; Passot, Stéphanie; Morris, G John

    2016-01-01

    During cryopreservation ice nucleation and crystal growth may occur within cells or the intracellular compartment may vitrify. Whilst previous literature describes intracellular vitrification in a qualitative manner, here we measure the intracellular vitrification temperature of bacteria and yeasts under conditions relevant to cryopreservation, including the addition of high levels of permeating and nonpermeating additives and the application of rapid rates of cooling. The effects of growth conditions that are known to modify cellular freezing resistance on the intracellular vitrification temperature are also examined. For bacteria a plot of the activity on thawing against intracellular glass transition of the maximally freeze-concentrated matrix (Tg') shows that cells with the lowest value of intracellular Tg' survive the freezing process better than cells with a higher intracellular Tg'. This paper demonstrates the role of the physical state of the intracellular environment in determining the response of microbial cells to preservation and could be a powerful tool to be manipulated to allow the optimization of methods for the preservation of microorganisms.

  19. Determination of Intracellular Vitrification Temperatures for Unicellular Micro Organisms under Conditions Relevant for Cryopreservation

    PubMed Central

    Fonseca, Fernanda; Meneghel, Julie; Cenard, Stéphanie; Passot, Stéphanie; Morris, G. John

    2016-01-01

    During cryopreservation ice nucleation and crystal growth may occur within cells or the intracellular compartment may vitrify. Whilst previous literature describes intracellular vitrification in a qualitative manner, here we measure the intracellular vitrification temperature of bacteria and yeasts under conditions relevant to cryopreservation, including the addition of high levels of permeating and nonpermeating additives and the application of rapid rates of cooling. The effects of growth conditions that are known to modify cellular freezing resistance on the intracellular vitrification temperature are also examined. For bacteria a plot of the activity on thawing against intracellular glass transition of the maximally freeze-concentrated matrix (Tg’) shows that cells with the lowest value of intracellular Tg’ survive the freezing process better than cells with a higher intracellular Tg’. This paper demonstrates the role of the physical state of the intracellular environment in determining the response of microbial cells to preservation and could be a powerful tool to be manipulated to allow the optimization of methods for the preservation of microorganisms. PMID:27055246

  20. Remote detection of pressure compartments. Topical report

    SciTech Connect

    Surdam, R.C.; Boyd, N.; Jiao, Z.; Maucione, D.; Kubicheck, S.

    1996-02-01

    A significant portion of the Cretaceous shale section in the Rocky Mountain Laramide Basins (RMLB) is anomalously pressured and gas saturated. The top of the anomalously pressured zone is identified by marked increases in sonic transit time, hydrocarbon production index (P.I.), clay diagenesis (smectite to illite), and vitrinite reflectance gradients. The driving mechanism of anomalous pressure development and compartmentalization is the generation and storage of liquid hydrocarbons that subsequently partially react to gas, converting the fluid-flow system to a multiphase regime in which capillarity controls permeability; the result is elevated displacement pressure within the shales. Sandstone reservoirs within this anomalously pressured shale section are subdivided stratigraphically and diagenetically into relatively small, isolated pressure or fluid-flow compartments. The saturation of these compartments with hydrocarbons and the subsequent oil-to-gas reaction causes explusion of a significant portion of the free water, resulting in anomalously pressured gas accumulations characterized by depletion drive. The determination of the position and configuration of the pressure boundary between normal and anomalously pressured regimes and the detection and delineation of porosity/permeability `sweet spots` below this boundary are the two most important elements in exploring for basin center gas in the RMLB.

  1. Plasma bupivacaine concentrations following psoas compartment block.

    PubMed

    Odoom, J A; Zuurmond, W W; Sih, I L; Bovill, J; Osterlöf, G; Oosting, H V

    1986-02-01

    Fourteen patients undergoing hip replacement surgery under psoas compartment block combined with general anaesthesia were studied. Group 1 (n = 7) received plain and Group 2 (n = 7) received 0.25% bupivacaine with adrenaline. The mean maximum peak concentrations were 1.93 (SEM 0.46) micrograms/ml and 1.04 (SEM 0.19) micrograms/ml at 10 minutes in groups 1 and 2 respectively. Bupivacaine concentrations were higher at all times in the group which received plain than the group receiving solution containing adrenaline. These differences were statistically significant at 10, 15 (p less than 0.05) and 30 minutes (p less than 0.025). The highest recorded plasma bupivacaine concentration was 4.54 micrograms/ml in one patient receiving plain bupivacaine. No patient developed any signs of toxic symptoms. The duration of analgesia was longer (p less than 0.005) in the group receiving bupivacaine with adrenaline. Bupivacaine 0.25% with adrenaline 1:200 000 is safe for psoas compartment block, and is recommended for hip surgery.

  2. Biodistribution of titanium dioxide from biologic compartments.

    PubMed

    Olmedo, Daniel G; Tasat, Deborah R; Guglielmotti, María Beatriz; Cabrini, Rómulo Luis

    2008-09-01

    The layer of titanium dioxide (TiO(2)) of the implant is chronically exposed to the internal electrolyte milieu in the peri-implant biological compartment. Corrosion results from electrochemical attack and ensuing gradual degradation of the metallic materials and is thus of biological interest when these biomaterials are employed in clinical implantology. Herein we evaluated and compared the chronic effect and the biodistribution of TiO(2) administered subcutaneously or intraperitoneally. We propose that the compartmentalization of titanium in the area of subcutaneous injection would reproduce the biological compartment of the implant and its microenvironment from which metal ions could be released and migrate systemically. Potential TiO(2) deposits were identified and characterized in skin, liver and lung by histological and EDX analyses. After both treatments, the skin, liver, and lungs exhibited histological evidence of TiO(2) deposits. In order to characterize in situ macrophage-like cells, tissue sections were immunohistochemically stained for CD68. Tissue specimens from all organs assayed showed positive staining for anti-macrophage monoclonal antibody CD68 (PGM1). Despite the compartmentalization of titanium within nodular areas in rats treated subcutaneously, systemic migration occurred. We concluded that systemic migration of TiO(2) occurred regardless of the administration route.

  3. Multi-compartment microscopic diffusion imaging.

    PubMed

    Kaden, Enrico; Kelm, Nathaniel D; Carson, Robert P; Does, Mark D; Alexander, Daniel C

    2016-10-01

    This paper introduces a multi-compartment model for microscopic diffusion anisotropy imaging. The aim is to estimate microscopic features specific to the intra- and extra-neurite compartments in nervous tissue unconfounded by the effects of fibre crossings and orientation dispersion, which are ubiquitous in the brain. The proposed MRI method is based on the Spherical Mean Technique (SMT), which factors out the neurite orientation distribution and thus provides direct estimates of the microscopic tissue structure. This technique can be immediately used in the clinic for the assessment of various neurological conditions, as it requires only a widely available off-the-shelf sequence with two b-shells and high-angular gradient resolution achievable within clinically feasible scan times. To demonstrate the developed method, we use high-quality diffusion data acquired with a bespoke scanner system from the Human Connectome Project. This study establishes the normative values of the new biomarkers for a large cohort of healthy young adults, which may then support clinical diagnostics in patients. Moreover, we show that the microscopic diffusion indices offer direct sensitivity to pathological tissue alterations, exemplified in a preclinical animal model of Tuberous Sclerosis Complex (TSC), a genetic multi-organ disorder which impacts brain microstructure and hence may lead to neurological manifestations such as autism, epilepsy and developmental delay. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Multi-compartment microscopic diffusion imaging

    PubMed Central

    Kaden, Enrico; Kelm, Nathaniel D.; Carson, Robert P.; Does, Mark D.; Alexander, Daniel C.

    2017-01-01

    This paper introduces a multi-compartment model for microscopic diffusion anisotropy imaging. The aim is to estimate microscopic features specific to the intra- and extra-neurite compartments in nervous tissue unconfounded by the effects of fibre crossings and orientation dispersion, which are ubiquitous in the brain. The proposed MRI method is based on the Spherical Mean Technique (SMT), which factors out the neurite orientation distribution and thus provides direct estimates of the microscopic tissue structure. This technique can be immediately used in the clinic for the assessment of various neurological conditions, as it requires only a widely available off-the-shelf sequence with two b-shells and high-angular gradient resolution achievable within clinically feasible scan times. To demonstrate the developed method, we use high-quality diffusion data acquired with a bespoke scanner system from the Human Connectome Project. This study establishes the normative values of the new biomarkers for a large cohort of healthy young adults, which may then support clinical diagnostics in patients. Moreover, we show that the microscopic diffusion indices offer direct sensitivity to pathological tissue alterations, exemplified in a preclinical animal model of Tuberous Sclerosis Complex (TSC), a genetic multi-organ disorder which impacts brain microstructure and hence may lead to neurological manifestations such as autism, epilepsy and developmental delay. PMID:27282476

  5. Dynamics of Major Histocompatibility Complex Class II Compartments during B Cell Receptor–mediated Cell Activation

    PubMed Central

    Lankar, Danielle; Vincent-Schneider, Hélène; Briken, Volker; Yokozeki, Takeaki; Raposo, Graça; Bonnerot, Christian

    2002-01-01

    Antigen recognition by clonotypic B cell receptor (BcR) is the first step of B lymphocytes differentiation into plasmocytes. This B cell function is dependent on efficient major histocompatibility complex (MHC) class II–restricted presentation of BcR-bound antigens. In this work, we analyzed the subcellular mechanisms underlying antigen presentation after BcR engagement on B cells. In quiescent B cells, we found that MHC class II molecules mostly accumulated at the cell surface and in an intracellular pool of tubulovesicular structures, whereas H2-M molecules were mostly detected in distinct lysosomal compartments devoid of MHC class II. BcR stimulation induced the transient intracellular accumulation of MHC class II molecules in newly formed multivesicular bodies (MVBs), to which H2-M was recruited. The reversible downregulation of cathepsin S activity led to the transient accumulation of invariant chain–MHC class II complexes in MVBs. A few hours after BcR engagement, cathepsin S activity increased, the p10 invariant chain disappeared, and MHC class II–peptide complexes arrived at the plasma membrane. Thus, BcR engagement induced the transient formation of antigen-processing compartments, enabling antigen-specific B cells to become effective antigen-presenting cells. PMID:11854359

  6. Raised compartment pressures are frequently observed with tibial shaft fractures despite the absence of compartment syndrome: A prospective cohort study.

    PubMed

    Ho, Kelvin Lor Kah; Sing, Nicholas Yeoh Ching; Wong, Khai Phang; Huat, Andy Wee Teck

    2017-01-01

    To measure the intracompartmental pressures surrounding tibial fractures not exhibiting any clinical evidence of compartment syndrome. Our hypothesis was that pressures often exceed the recommended threshold of fasciotomy despite the absence of compartment syndrome, and hence diagnosis based on pressure measurements alone is unreliable. Thirteen consecutive patients with closed tibial shaft fractures without clinical suspicion of compartment syndrome, and who were planned for intramedullary nailing, were prospectively enrolled. Compartment pressures ( P) in all four compartments of the affected leg were measured at the start of surgery and immediately after tibial reaming, and differential pressures (delta P) were calculated based on the diastolic blood pressure prior to induction of anaesthesia. No patients required reoperation in the post-operative period, as a result of an undiagnosed compartment syndrome. Using commonly quoted threshold pressure criteria, 62% (using P > 30 mmHg) and 23% of patients (using delta P < 30 mmHg) have been incorrectly diagnosed with compartment syndrome. We conclude that raised compartment pressures are frequently seen in patients with tibial shaft fractures; but in most cases, it does not equate to the presence of compartment syndrome. Diagnosis of compartment syndrome based on intracompartmental pressure measurements alone may result in unnecessary fasciotomies in a sizeable number of patients. Compartment syndrome remains a clinical diagnosis, and one which always needs to be considered when managing tibial fractures.

  7. Prediction of intracellular exposure bridges the gap between target- and cell-based drug discovery

    PubMed Central

    Gordon, Laurie J.; Wayne, Gareth J.; Almqvist, Helena; Axelsson, Hanna; Seashore-Ludlow, Brinton; Treyer, Andrea; Lundbäck, Thomas; West, Andy; Hann, Michael M.; Artursson, Per

    2017-01-01

    Inadequate target exposure is a major cause of high attrition in drug discovery. Here, we show that a label-free method for quantifying the intracellular bioavailability (Fic) of drug molecules predicts drug access to intracellular targets and hence, pharmacological effect. We determined Fic in multiple cellular assays and cell types representing different targets from a number of therapeutic areas, including cancer, inflammation, and dementia. Both cytosolic targets and targets localized in subcellular compartments were investigated. Fic gives insights on membrane-permeable compounds in terms of cellular potency and intracellular target engagement, compared with biochemical potency measurements alone. Knowledge of the amount of drug that is locally available to bind intracellular targets provides a powerful tool for compound selection in early drug discovery. PMID:28701380

  8. Insider trading: Extracellular matrix proteins and their non-canonical intracellular roles.

    PubMed

    Hellewell, Andrew L; Adams, Josephine C

    2016-01-01

    In metazoans, the extracellular matrix (ECM) provides a dynamic, heterogeneous microenvironment that has important supportive and instructive roles. Although the primary site of action of ECM proteins is extracellular, evidence is emerging for non-canonical intracellular roles. Examples include osteopontin, thrombospondins, IGF-binding protein 3 and biglycan, and relate to roles in transcription, cell-stress responses, autophagy and cancer. These findings pose conceptual problems on how proteins signalled for secretion can be routed to the cytosol or nucleus, or can function in environments with diverse redox, pH and ionic conditions. We review evidence for intracellular locations and functions of ECM proteins, and current knowledge of the mechanisms by which they may enter intracellular compartments. We evaluate the experimental methods that are appropriate to obtain rigorous evidence for intracellular localisation and function. Better insight into this under-researched topic is needed to decipher the complete spectrum of physiological and pathological roles of ECM proteins.

  9. Changes in body fluid compartments during a 28-day bed rest

    NASA Technical Reports Server (NTRS)

    Fortney, Suzanne M.; Hyatt, Kenneth H.; Davis, John E.; Vogel, John M.

    1991-01-01

    Serial isotope measurements were used to obtain measurements of the body fluid responses of 10 22-29-year-old men during 28 d of simulated microgravity (bed rest). The subjects were maintained on a controlled metabolic diet for 7 d before the study, during 14 d of ambulatory control, 28 d of horizontal bed rest, and 14 d of ambulant recovery. Fluid compartments were measured on control days 1 and 9, bed rest days 2, 14, and 28, and recovery days 7 and 14. By day 2 of bed rest, plasma volume and extracellular volume (ECV) decreased significantly by an average 209 and 533 ml, respectively. Red cell volume and total body water (TBW) decreased more slowly, with average losses of 128 and 1316 ml, respectively, after 28 d of bed rest. Early in the bed rest, TBW loss was mostly from the ECV. Thereafter, the TBW deficit was derived from the intracellular compartment, which decreased an average of 838 ml after 28 d. These results suggest losses from all fluid compartments during bed rest, with no evidence of restoration of ECV after 1-2 weeks.

  10. A novel choline cotransporter sequestration compartment in cholinergic neurons revealed by selective endosomal ablation.

    PubMed

    Ivy, Michael T; Newkirk, Robert F; Wang, Yilun; Townsel, James G

    2010-03-01

    The sodium-dependent, high affinity choline transporter - choline cotransporter - (ChCoT, aka: cho-1, CHT1, CHT) undergoes constitutive and regulated trafficking between the plasma membrane and cytoplasmic compartments. The pathways and regulatory mechanisms of this trafficking are not well understood. We report herein studies involving selective endosomal ablation to further our understanding of the trafficking of the ChCoT. Selective ablation of early sorting and recycling endosomes resulted in a decrease of approximately 75% of [3H]choline uptake and approximately 70% of [3H]hemicholinium-3 binding. Western blot analysis showed that ablation produced a similar decrease in ChCoTs in the plasma membrane subcellular fraction. The time frame for this loss was approximately 2 h which has been shown to be the constitutive cycling time for ChCoTs in this tissue. Ablation appears to be dependent on the intracellular cycling of transferrin-conjugated horseradish peroxidase and the selective deposition of transferrin-conjugated horseradish peroxidase in early endosomes, both sorting and recycling. Ablated brain slices retained their capacity to recruit via regulated trafficking ChCoTs to the plasma membrane. This recruitment of ChCoTs suggests that the recruitable compartment is distinct from the early endosomes. It will be necessary to do further studies to identify the novel sequestration compartment supportive of the ChCoT regulated trafficking.

  11. Is bioelectrical impedance spectroscopy accurate in estimating total body water and its compartments in elite athletes?

    PubMed

    Matias, Catarina N; Santos, Diana A; Gonçalves, Ezequiel M; Fields, David A; Sardinha, Luís B; Silva, Analiza M

    2013-03-01

    Bioelectrical impedance spectroscopy (BIS) provides an affordable assessment of the body's various water compartments: total body water (TBW), extracellular water (ECW) and intracellular water (ICW). However, little is known of its validity in athletes. To validate TBW, ECW and ICW by BIS in elite male and female Portuguese athletes using dilution techniques (i.e. deuterium and bromide dilution) as criterion methods. Sixty-two athletes (18.5 ± 4.1 years) had TBW, ECW and ICW assessed by BIS during their respective pre-season. BIS significantly under-estimated TBW by 1.0 ± 1.7 kg and ICW by 0.9 ± 1.9 kg in relation to the criterion methods, with no differences observed for ECW. The values for the concordance correlation coefficient were 0.98 for TBW and ECW and 0.95 for ICW. Bland-Altman analyses revealed no bias for the various water compartments, with the 95% confidence intervals ranging from - 4.8 to 2.6 kg for TBW, - 1.5 to 1.6 kg for ECW and - 4.5 to 2.7 kg for ICW. Overall, these findings demonstrate the validity of BIS as a valid tool in the assessment of TBW and its compartments in both male and female athletes.

  12. INTRACELLULAR SIGNALING AND DEVELOPMENTAL NEUROTOXICITY.

    EPA Science Inventory

    A book chapter in ?Molecular Toxicology: Transcriptional Targets? reviewed the role of intracellular signaling in the developmental neurotoxicity of environmental chemicals. This chapter covered a number of aspects including the development of the nervous system, role of intrace...

  13. INTRACELLULAR SIGNALING AND DEVELOPMENTAL NEUROTOXICITY.

    EPA Science Inventory

    A book chapter in ?Molecular Toxicology: Transcriptional Targets? reviewed the role of intracellular signaling in the developmental neurotoxicity of environmental chemicals. This chapter covered a number of aspects including the development of the nervous system, role of intrace...

  14. Examination of Listeria monocytogenes intracellular gene expression by using the green fluorescent protein of Aequorea victoria.

    PubMed

    Freitag, N E; Jacobs, K E

    1999-04-01

    The ActA protein of Listeria monocytogenes is an essential virulence factor and is required for intracellular bacterial motility and cell-to-cell spread. plcB, cotranscribed with actA, encodes a broad-specificity phospholipase C that contributes to lysis of host cell vacuoles and cell-to-cell spread. Construction of a transcriptional fusion between actA-plcB and the green fluorescent protein gene of Aequorea victoria has facilitated the detailed examination of patterns of actA/plcB expression within infected tissue culture cells. actA/plcB expression began approximately 30 min postinfection and was dependent upon entry of L. monocytogenes into the host cytosol. L. monocytogenes Deltahly mutants, which are unable to escape from host cell vacuoles, did not express actA/plcB at detectable levels within infected tissue culture cells; however, complementation of the hly defect allowed entry of the bacteria into the host cytoplasm and subsequent actA/plcB expression. These results emphasize the ability of L. monocytogenes to sense the different host cell compartment environments encountered during the course of infection and to regulate virulence gene expression in response.

  15. Multifaceted plasma membrane Ca(2+) pumps: From structure to intracellular Ca(2+) handling and cancer.

    PubMed

    Padányi, Rita; Pászty, Katalin; Hegedűs, Luca; Varga, Karolina; Papp, Béla; Penniston, John T; Enyedi, Ágnes

    2016-06-01

    Plasma membrane Ca(2+) ATPases (PMCAs) are intimately involved in the control of intracellular Ca(2+) concentration. They reduce Ca(2+) in the cytosol not only by direct ejection, but also by controlling the formation of inositol-1,4,5-trisphosphate and decreasing Ca(2+) release from the endoplasmic reticulum Ca(2+) pool. In mammals four genes (PMCA1-4) are expressed, and alternative RNA splicing generates more than twenty variants. The variants differ in their regulatory characteristics. They localize into highly specialized membrane compartments and respond to the incoming Ca(2+) with distinct temporal resolution. The expression pattern of variants depends on cell type; a change in this pattern can result in perturbed Ca(2+) homeostasis and thus altered cell function. Indeed, PMCAs undergo remarkable changes in their expression pattern during tumorigenesis that might significantly contribute to the unbalanced Ca(2+) homeostasis of cancer cells. This article is part of a Special Issue entitled: Calcium and Cell Fate. Guest Editors: Jacques Haiech, Claus Heizmann, Joachim Krebs, Thierry Capiod and Olivier Mignen. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Metallothionein is crucial for safe intracellular copper storage and cell survival at normal and supra-physiological exposure levels.

    PubMed Central

    Tapia, Lucía; González-Agüero, Mauricio; Cisternas, Mónica F; Suazo, Miriam; Cambiazo, Verónica; Uauy, Ricardo; González, Mauricio

    2004-01-01

    MTs (metallothioneins) increase the resistance of cells to exposure to high Cu (copper) levels. Characterization of the MT-Cu complex suggests that MT has an important role in the cellular storage and/or delivery of Cu ions to cuproenzymes. In this work we investigate how these properties contribute to Cu homoeostasis by evaluating the uptake, accumulation and efflux of Cu in wild-type and MT I/II null rat fibroblast cell lines. We also assessed changes in the expression of Cu metabolism-related genes in response to Cu exposure. At sub-physiological Cu levels (0.4 microM), the metal content was not dependent on MT; however, when extracellular Cu was increased to physiological levels (10 microM), MTs were required for the cell's ability to accumulate the metal. The subcellular localization of the accumulated metal in the cytoplasm was MT-dependent. Following supra-physiological Cu exposure (>50 microM), MT null cells had a decreased capacity for Cu storage and an elevated sensitivity to a minor increment in intracellular metal levels, suggesting that intracellular Cu toxicity is due not to the metal content but to the interactions of the metal with cellular components. Moreover, MT null cells failed to show increased levels of mRNAs encoding MT I, SOD1 (superoxide dismutase 1) and Ccs1 (Cu chaperone for SOD) in response to Cu exposure. These results support a role for MT in the storage of Cu in a safe compartment and in sequestering an intracellular excess of Cu in response to supra-physiological Cu exposure. Gene expression analysis suggests the necessity of having MT as part of the signalling pathway that induces gene expression in response to Cu. PMID:14627437

  17. Contribution of Malic Enzyme, Pyruvate Kinase, Phosphoenolpyruvate Carboxylase, and the Krebs Cycle to Respiration and Biosynthesis and to Intracellular pH Regulation during Hypoxia in Maize Root Tips Observed by Nuclear Magnetic Resonance Imaging and Gas Chromatography-Mass Spectrometry1

    PubMed Central

    Edwards, Shaune; Nguyen, Bich-Ty; Do, Binh; Roberts, Justin K.M.

    1998-01-01

    In vivo pyruvate synthesis by malic enzyme (ME) and pyruvate kinase and in vivo malate synthesis by phosphoenolpyruvate carboxylase and the Krebs cycle were measured by 13C incorporation from [1-13C]glucose into glucose-6-phosphate, alanine, glutamate, aspartate, and malate. These metabolites were isolated from maize (Zea mays L.) root tips under aerobic and hypoxic conditions. 13C-Nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry were used to discern the positional isotopic distribution within each metabolite. This information was applied to a simple precursor-product model that enabled calculation of specific metabolic fluxes. In respiring root tips, ME was found to contribute only approximately 3% of the pyruvate synthesized, whereas pyruvate kinase contributed the balance. The activity of ME increased greater than 6-fold early in hypoxia, and then declined coincident with depletion of cytosolic malate and aspartate. We found that in respiring root tips, anaplerotic phosphoenolpyruvate carboxylase activity was high relative to ME, and therefore did not limit synthesis of pyruvate by ME. The significance of in vivo pyruvate synthesis by ME is discussed with respect to malate and pyruvate utilization by isolated mitochondria and intracellular pH regulation under hypoxia. PMID:9501140

  18. Linear Peptides in Intracellular Applications.

    PubMed

    Zuconelli, Cristiane R; Brock, Roland; Adjobo-Hermans, Merel J W

    2017-01-01

    To this point, efforts to develop therapeutic peptides for intracellular applications were guided by the perception that unmodified linear peptides are highly unstable and therefore structural modifications are required to reduce proteolytic breakdown. Largely, this concept is a consequence of the fact that most research on intracellular peptides hitherto has focused on peptide degradation in the context of antigen processing, rather than on peptide stability. Interestingly, inside cells, endogenous peptides lacking any chemical modifications to enhance stability escape degradation to the point that they may even modulate intracellular signaling pathways. In addition, many unmodified synthetic peptides designed to interfere with intracellular signaling, following introduction into cells, have the expected activity demonstrating that biologically relevant concentrations can be reached. This review provides an overview of results and techniques relating to the exploration and application of linear, unmodified peptides. After an introduction to intracellular peptide turnover, the review mentions examples for synthetic peptides as modulators of intracellular signaling, introduces endogenous peptides with bioactivity, techniques to measure peptide stability, and peptide delivery. Future experiments should elucidate the rules needed to predict promising peptide candidates. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Functional genomics of intracellular bacteria.

    PubMed

    de Barsy, Marie; Greub, Gilbert

    2013-07-01

    During the genomic era, a large amount of whole-genome sequences accumulated, which identified many hypothetical proteins of unknown function. Rapidly, functional genomics, which is the research domain that assign a function to a given gene product, has thus been developed. Functional genomics of intracellular pathogenic bacteria exhibit specific peculiarities due to the fastidious growth of most of these intracellular micro-organisms, due to the close interaction with the host cell, due to the risk of contamination of experiments with host cell proteins and, for some strict intracellular bacteria such as Chlamydia, due to the absence of simple genetic system to manipulate the bacterial genome. To identify virulence factors of intracellular pathogenic bacteria, functional genomics often rely on bioinformatic analyses compared with model organisms such as Escherichia coli and Bacillus subtilis. The use of heterologous expression is another common approach. Given the intracellular lifestyle and the many effectors that are used by the intracellular bacteria to corrupt host cell functions, functional genomics is also often targeting the identification of new effectors such as those of the T4SS of Brucella and Legionella.

  20. Using targeted variants of aequorin to measure Ca2+ levels in intracellular organelles.

    PubMed

    Granatiero, Veronica; Patron, Maria; Tosatto, Anna; Merli, Giulia; Rizzuto, Rosario

    2014-01-01

    Aequorin is a Ca(2+)-sensitive photoprotein isolated from the jellyfish Aequorea victoria. It is an ideal probe for measuring Ca(2+) concentration ([Ca(2+)]) in intracellular organelles because it can be modified to include specific targeting sequences. On the binding of Ca(2+) to three high-affinity sites in aequorin, an irreversible reaction occurs in which the prosthetic group coelenterazine is released and a photon is emitted. This protocol presents procedures for expressing, targeting, and reconstituting aequorin in intact and permeabilized mammalian cells and describes how to use this photoprotein to measure intracellular [Ca(2+)] in various subcellular compartments.

  1. Cancer-Selective Apoptotic Effects of Extracellular and Intracellular Par-4

    PubMed Central

    Bhattarai, Tripti Shrestha; Rangnekar, Vivek M.

    2010-01-01

    Selectivity toward cancer cells is the most desirable element in cancer therapeutics. Par-4 is a cancer cell-selective pro-apoptotic protein that functions intracellularly in the cytoplasmic and nuclear compartments, as a tumor suppressor. Moreover, recent findings indicate that the Par-4 protein is secreted by cells, and extracellular Par-4 induces cancer cell-specific apoptosis by interaction with the cell-surface receptor GRP78. This review describes the mechanisms underlying the apoptotic effects of both extracellular and intracellular Par-4 acting via its effector domain SAC. PMID:20440265

  2. Extracellular matrix stiffness and architecture govern intracellular rheology in cancer.

    PubMed

    Baker, Erin L; Bonnecaze, Roger T; Zaman, Muhammad H

    2009-08-19

    Little is known about the complex interplay between the extracellular mechanical environment and the mechanical properties that characterize the dynamic intracellular environment. To elucidate this relationship in cancer, we probe the intracellular environment using particle-tracking microrheology. In three-dimensional (3D) matrices, intracellular effective creep compliance of prostate cancer cells is shown to increase with increasing extracellular matrix (ECM) stiffness, whereas modulating ECM stiffness does not significantly affect the intracellular mechanical state when cells are attached to two-dimensional (2D) matrices. Switching from 2D to 3D matrices induces an order-of-magnitude shift in intracellular effective creep compliance and apparent elastic modulus. However, for a given matrix stiffness, partial blocking of beta1 integrins mitigates the shift in intracellular mechanical state that is invoked by switching from a 2D to 3D matrix architecture. This finding suggests that the increased cell-matrix engagement inherent to a 3D matrix architecture may contribute to differences observed in viscoelastic properties between cells attached to 2D matrices and cells embedded within 3D matrices. In total, our observations show that ECM stiffness and architecture can strongly influence the intracellular mechanical state of cancer cells.

  3. Getting across the plasma membrane and beyond: intracellular uses of colloidal semiconductor nanocrystals.

    PubMed

    Luccardini, Camilla; Yakovlev, Aleksey; Gaillard, Stéphane; van 't Hoff, Marcel; Alberola, Alicia Piera; Mallet, Jean-Maurice; Parak, Wolfgang J; Feltz, Anne; Oheim, Martin

    2007-01-01

    Semiconductor nanocrystals (NCs) are increasingly being used as photoluminescen markers in biological imaging. Their brightness, large Stokes shift, and high photostability compared to organic fluorophores permit the exploration of biological phenomena at the single-molecule scale with superior temporal resolution and spatial precision. NCs have predominantly been used as extracellular markers for tagging and tracking membrane proteins. Successful internalization and intracellular labelling with NCs have been demonstrated for both fixed immunolabelled and live cells. However, the precise localization and subcellular compartment labelled are less clear. Generally, live cell studies are limited by the requirement of fairly invasive protocols for loading NCs and the relatively large size of NCs compared to the cellular machinery, along with the subsequent sequestration of NCs in endosomal/lysosomal compartments. For long-period observation the potential cytotoxicity of cytoplasmically loaded NCs must be evaluated. This review focuses on the challenges of intracellular uses of NCs.

  4. Functions of Intracellular Retinoid Binding-Proteins

    PubMed Central

    2017-01-01

    Multiple binding and transport proteins facilitate many aspects of retinoid biology through effects on retinoid transport, cellular uptake, metabolism, and nuclear delivery. These include the serum retinol binding protein sRBP (aka Rbp4), the plasma membrane sRBP receptor Stra6, and the intracellular retinoid binding-proteins such as cellular retinol-binding proteins (CRBP) and cellular retinoic acid binding-proteins (CRABP). sRBP transports the highly lipophilic retinol through an aqueous medium. The major intracellular retinol-binding protein, CRBP1, likely enhances efficient retinoid use by providing a sink to facilitate retinol uptake from sRBP through the plasma membrane or via Stra6, delivering retinol or retinal to select enzymes that generate retinyl esters or retinoic acid, and protecting retinol/retinal from excess catabolism or opportunistic metabolism. Intracellular retinoic acid binding-proteins (CRABP1 and 2, and FABP5) seem to have more diverse functions distinctive to each, such as directing retinoic acid to catabolism, delivering retinoic acid to specific nuclear receptors, and generating non-canonical actions. Gene ablation of intracellular retinoid binding-proteins does not cause embryonic lethality or gross morphological defects. Metabolic and functional defects manifested in knockouts of CRBP1, CRBP2 and CRBP3, however, illustrate their essentiality to health, and in the case of CRBP2, to survival during limited dietary vitamin A. Future studies should continue to address the specific molecular interactions that occur between retinoid binding-proteins and their targets and their precise physiologic contributions to retinoid homeostasis and function. PMID:27830500

  5. The Orbital Workshop Waste Management Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This image is a wide-angle view of the Orbital Workshop waste management compartment. The waste management facilities presented a unique challenge to spacecraft designers. In addition to collection of liquid and solid human wastes, there was a medical requirement to dry all solid human waste products and to return the residue to Earth for examination. Liquid human waste (urine) was frozen for return to Earth. Total quantities of each astronaut's liquid and solid wastes were precisely measured. Cabin air was drawn into the toilet, shown on the wall at right in this photograph, and over the waste products to generate a flow of the waste in the desired direction. The air was then filtered for odor control and antiseptic purposes prior to being discharged back into the cabin.

  6. The Orbital Workshop Waste Management Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This image is a wide-angle view of the Orbital Workshop waste management compartment. The waste management facilities presented a unique challenge to spacecraft designers. In addition to collection of liquid and solid human wastes, there was a medical requirement to dry all solid human waste products and to return the residue to Earth for examination. Liquid human waste (urine) was frozen for return to Earth. Total quantities of each astronaut's liquid and solid wastes were precisely measured. Cabin air was drawn into the toilet, shown on the wall at right in this photograph, and over the waste products to generate a flow of the waste in the desired direction. The air was then filtered for odor control and antiseptic purposes prior to being discharged back into the cabin.

  7. Compartment syndrome and regional anaesthesia: Critical review.

    PubMed

    Klucka, Jozef; Stourac, Petr; Stouracova, Alena; Masek, Michal; Repko, Martin

    2017-05-24

    Acute compartment syndrome (ACS) is a potential orthopaedic/traumatology emergency. Without prompt, precise diagnosis and immediate treatment with surgical decompressive fasciotomy it can lead to neurological dysfunction and disability. The role of regional anaesthesia (RA) in patients at risk for ACS/ and in those with developed ACS is controversial. The aim of this critical review was to answer the question, whether regional anaesthesia can delay the diagnosis. The authors use an evidence-based approach to discuss these high risk patients in considering RA as a method of choice for effective analgesia. To the date of data collection, there was no single case report identified where RA alone led to delay in ACS diagnosis and surgical treatment. In four clinical cases, epidural analgesia can be associated with delayed ACS diagnosis. Frequent clinical evaluation and breakthrough pain despite a functional RA in combination with intracompartment pressure measurement remains the keystone of recommended management for patients at risk of ACS.

  8. Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development.

    PubMed

    Peremyslov, Valera V; Cole, Rex A; Fowler, John E; Dolja, Valerian V

    2015-01-01

    Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI), cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors) and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6-1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development.

  9. Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development

    PubMed Central

    Peremyslov, Valera V.; Cole, Rex A.; Fowler, John E.; Dolja, Valerian V.

    2015-01-01

    Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI), cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors) and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6–1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development. PMID:26426395

  10. Production of compartmented cultures of rat sympathetic neurons.

    PubMed

    Campenot, Robert B; Lund, Karen; Mok, Sue-Ann

    2009-01-01

    The compartmented culture, in which primary neurons plated in a proximal compartment send their axons under silicone grease barriers and into left and right distal compartments, has enhanced the experimental capabilities of neuronal cultures. Treatments can be applied separately to cell bodies/proximal axons or distal axons, and cell bodies/proximal axons and distal axons can be separately harvested and analyzed. Distal axons can be axotomized, and the neurons can be studied while their axons regenerate. Construction of the culture dishes requires 3 h for 48 cultures, and preparing the neurons also requires 3 h. Compartmented cultures provide enough cellular material for biochemical analyses such as immunoblotting. The uses of compartmented cultures have included studies of neurotrophic factor retrograde signaling, axonal transport, and axonal protein and lipid biosynthesis. Here we focus on sympathetic neurons cultured from neonatal rats and provide protocols for the production and some of the uses of compartmented cultures.

  11. Siglec-1 initiates formation of the virus-containing compartment and enhances macrophage-to-T cell transmission of HIV-1

    PubMed Central

    Beeman, Neal; Ding, Lingmei; Melikyan, Gregory B.

    2017-01-01

    HIV-1 particles assemble and bud from the plasma membrane of infected T lymphocytes. Infected macrophages, in contrast, accumulate particles within an apparent intracellular compartment known as the virus-containing compartment or VCC. Many aspects of the formation and function of the VCC remain unclear. Here we demonstrate that VCC formation does not actually require infection of the macrophage, but can be reproduced through the exogenous addition of non-infectious virus-like particles or infectious virions to macrophage cultures. Particles were captured by Siglec-1, a prominent cell surface lectin that attaches to gangliosides on the lipid envelope of the virus. VCCs formed within infected macrophages were readily targeted by the addition of ganglioside-containing virus-like particles to the extracellular media. Depletion of Siglec-1 from the macrophage or depletion of gangliosides from viral particles prevented particle uptake into the VCC and resulted in substantial reductions of VCC volume. Furthermore, Siglec-1-mediated virion capture and subsequent VCC formation was required for efficient trans-infection of autologous T cells. Our results help to define the nature of this intracellular compartment, arguing that it is a compartment formed by particle uptake from the periphery, and that this compartment can readily transmit virus to target T lymphocytes. Inhibiting or eliminating the VCC may be an important component of strategies to reduce HIV transmission and to eradicate HIV reservoirs. PMID:28129379

  12. Simultaneous intracellular chloride and pH measurements using a GFP-based sensor.

    PubMed

    Arosio, Daniele; Ricci, Fernanda; Marchetti, Laura; Gualdani, Roberta; Albertazzi, Lorenzo; Beltram, Fabio

    2010-07-01

    Chloride and protons perform important closely related roles in many cellular responses. Here we developed a ratiometric biosensor, ClopHensor, based on a highly chloride-sensitive Aequorea victoria GFP variant that is suited for the combined real-time optical detection of pH changes and chloride fluxes in live cells. We detected high chloride concentration in large dense-core exocytosis granules by targeting ClopHensor to these intracellular compartments.

  13. Intracellular Nanoparticle Aggregation as a Mechanism for Inducing Apoptosis in Breast Cancer Cells

    DTIC Science & Technology

    2010-09-01

    Viral nanoparticles as tools for intravital vascular imaging . Nature Medicine, 2006. 12(3): p. 354-360. 16. Speelmans, G., et al., Transport Studies of...hydrodynamic diameter of 25.4 ± 0.4 nm and TEM images showing distinct nanoparticles. Task 2: Coupling of chemotherapeutic molecules to protein...examined. The images indicate cellular uptake and an accumulation of D381C-AF532M within intracellular compartments, but minimal uptake of free AF532M

  14. An Update on the Anatomy of the Forehead Compartments.

    PubMed

    Cotofana, Sebastian; Mian, Asima; Sykes, Jonathan M; Redka-Swoboda, Wolfgang; Ladinger, Andrea; Pavicic, Tatjana; Schenck, Thilo L; Benslimane, Fahd; Ingallina, Fabio; Schlattau, Alexander

    2017-04-01

    The forehead is one of the most frequent locations for neuromodulator and soft tissue filler applications; however, the underlying anatomy is still poorly understood. Thus far, the presence of deep forehead compartments has not been confirmed. Twenty Caucasian cephalic specimens, 15 fresh frozen (six female and nine male) and five with formalin-phenol embalmment (three female and two male) were investigated using contrast-enhanced computed tomographic scans, dye injections, and anatomical dissections. Three superficial (one central and two lateral) and three deep (one central and two lateral) forehead compartments were identified. The superficial fat compartments were found within the subcutaneous fat tissue (layer 2) and measured 2.1 × 4.6 mm for the superficial central forehead compartments and the right superficial lateral forehead compartments and 2.6 × 3.2 cm for the left superficial lateral forehead compartments, with a mean volume of 2.5, 3.1, and 3.4 cc, respectively. The deep fat compartments were identified deep to the frontalis muscle but superficial to the periosteum with an extent of 6.4 × 5.9 cm for the deep central forehead compartments, 2.6 × 5.8 cm for the right deep lateral forehead compartments, and 2.7 × 5.8 cm for the left deep lateral forehead compartments, and a mean volume of 9.1, 1.6, and 1.4 cc, respectively. The results presented in this study increase the understanding of the forehead anatomy. Understanding the presence of the superficial and the deep forehead compartments allows one to change the signs of frontal aging. The deep forehead compartments are in general avascular planes and permit blunt dissection for access to the supraorbital region.

  15. Vehicle hydraulic system that provides heat for passenger compartment

    DOEpatents

    Bartley, Bradley E.; Blass, James R.; Gibson, Dennis H.

    2001-01-01

    A vehicle includes a vehicle housing which defines a passenger compartment. Attached to the vehicle housing is a hydraulic system, that includes a hydraulic fluid which flows through at least one passageway within the hydraulic system. Also attached to the vehicle housing is a passenger compartment heating system. The passenger compartment heating system includes a heat exchanger, wherein a portion of the heat exchanger is a segment of the at least one passageway of the hydraulic system.

  16. Compartment syndrome after hypocalcemic tetany: a case report.

    PubMed

    Luzzi, Richard; Burghardt, Rolf D; Herzenberg, John E; Zuckerberg, Aaron L

    2008-09-01

    Compartment syndrome results from pathologically elevated muscle tissue pressure within a closed space. It is almost always related to either trauma or reperfusion after loss of arterial inflow from occlusion of a major blood vessel. We present an unusual case of nontraumatic and nonvascular compartment syndrome after hypocalcemia-induced sustained tetany in a 2-year-10-month-old male child after a neuroblastoma tumor resection. This particular cause of compartment syndrome has been described only once before in an adult patient.

  17. ClC-3 expression enhances etoposide resistance by increasing acidification of the late endocytic compartment.

    PubMed

    Weylandt, Karsten H; Nebrig, Maxim; Jansen-Rosseck, Nils; Amey, Joanna S; Carmena, David; Wiedenmann, Bertram; Higgins, Christopher F; Sardini, Alessandro

    2007-03-01

    Resistance to anticancer drugs and consequent failure of chemotherapy is a complex problem severely limiting therapeutic options in metastatic cancer. Many studies have shown a role for drug efflux pumps of the ATP-binding cassette transporters family in the development of drug resistance. ClC-3, a member of the CLC family of chloride channels and transporters, is expressed in intracellular compartments of neuronal cells and involved in vesicular acidification. It has previously been suggested that acidification of intracellular organelles can promote drug resistance by increasing drug sequestration. Therefore, we hypothesized a role for ClC-3 in drug resistance. Here, we show that ClC-3 is expressed in neuroendocrine tumor cell lines, such as BON, LCC-18, and QGP-1, and localized in intracellular vesicles co-labeled with the late endosomal/lysosomal marker LAMP-1. ClC-3 overexpression increased the acidity of intracellular vesicles, as assessed by acridine orange staining, and enhanced resistance to the chemotherapeutic drug etoposide by almost doubling the IC(50) in either BON or HEK293 cell lines. Prevention of organellar acidification, by inhibition of the vacuolar H(+)-ATPase, reduced etoposide resistance. No expression of common multidrug resistance transporters, such as P-glycoprotein or multidrug-related protein-1, was detected in either the BON parental cell line or the derivative clone overexpressing ClC-3. The probable mechanism of enhanced etoposide resistance can be attributed to the increase of vesicular acidification as consequence of ClC-3 overexpression. This study therefore provides first evidence for a role of intracellular CLC proteins in the modulation of cancer drug resistance.

  18. The myofascial compartments of the foot: a cadaver study.

    PubMed

    Ling, Z X; Kumar, V P

    2008-08-01

    Compartment syndrome of the foot requires urgent surgical treatment. Currently, there is still no agreement on the number and location of the myofascial compartments of the foot. The aim of this cadaver study was to provide an anatomical basis for surgical decompression in the event of compartment syndrome. We found that there were three tough vertical fascial septae that extended from the hindfoot to the midfoot on the plantar aspect of the foot. These septae separated the posterior half of the foot into three compartments. The medial compartment containing the abductor hallucis was surrounded medially by skin and subcutaneous fat and laterally by the medial septum. The intermediate compartment, containing the flexor digitorum brevis and the quadratus plantae more deeply, was surrounded by the medial septum medially, the intermediate septum laterally and the main plantar aponeurosis on its plantar aspect. The lateral compartment containing the abductor digiti minimi was surrounded medially by the intermediate septum, laterally by the lateral septum and on its plantar aspect by the lateral band of the main plantar aponeurosis. No distinct myofascial compartments exist in the forefoot. Based on our findings, in theory, fasciotomy of the hindfoot compartments through a modified medial incision would be sufficient to decompress the foot.

  19. Acute exercise-induced bilateral thigh compartment syndrome.

    PubMed

    Boland, Michael R; Heck, Chris

    2009-03-01

    Acute compartment syndrome of the thigh is rare due to the space's ability to accommodate large volumes of fluid and, with the exception of the lateral septum, its thin compliant linings. This article describes a case of bilateral exercise-induced severe compartment syndrome treated with anterior and posterior fasciotomies. A 29-year-old man was admitted to intensive care with myoglobinuria. His left thigh was evaluated 18 hours later for compartment syndrome. The patient reported that 14 hours prior to initial presentation, he had participated in a 1-hour session of vigorous basketball. He gradually developed bilateral moderately severe thigh pain and tea-colored urine. Physical examination revealed pain secondary to passive stretch of both knees at 20 degrees flexion, plus firm anterior and posterior compartments to palpation. A handheld pressure monitor revealed the following compartment pressures: left anterior 80 mm Hg; left posterior 75 mm Hg; right anterior 45 mm Hg; and right posterior 50 mm Hg. Bilateral emergent anterior and posterior compartment fasciotomies were performed. The patient developed a significant severe distal motor and sensory neurological deficit on the left side, which recovered to 3/5 motor strength and protective sensation. At 6-month follow-up, he ambulated with the assistance of a left ankle foot orthosis. Acute severe compartment syndrome can occur following vigorous exercise. We recommend fasciotomies after exercise-induced acute compartment syndrome rather than initial observation because of the severity of morbidity associated with undertreated compartment syndrome.

  20. Coping with the diagnostic complexities of the compartment syndrome

    NASA Technical Reports Server (NTRS)

    Mubarak, S. J.; Hargens, A. R.; Karkal, S. S.

    1988-01-01

    This review recognizes that, given the various complexities associated with the condition, no pat answers can be given to fit every patient with the compartment syndrome. The authors first give a definition of the syndrome, together with a brief account of how this self-perpetuating pathologic cycle is triggered. Next, they delineate specific anatomical features of compartments that are likely to be involved, and follow this with an inventory of symptoms and signs to look for in suspected cases. After sorting out the entities that can mimic the compartment syndrome, the authors describe three essential techniques of measuring tissue pressure, which can prove invaluable in diagnosing the compartment syndrome.

  1. Central compartment neck dissection for thyroid cancer. Technical considerations.

    PubMed

    Pai, Sara I; Tufano, Ralph P

    2008-01-01

    The central compartment of the neck is a common site of local metastasis for thyroid carcinoma. Therefore, knowledge of the surgical techniques employed during a central compartment neck dissection is important to master for any surgeon who manages thyroid cancer patients. We review the anatomical boundaries of the central compartment of the neck as well as discuss the lymphatic drainage patterns of the thyroid gland. We advocate standardization of the surgical approach to the central compartment in order to minimize morbidity and ensure comprehensive removal of all lymph nodes when indicated, which can reduce the need for reoperative dissections. Copyright 2008 S. Karger AG, Basel.

  2. Lateral canthotomy and cantholysis: emergency management of orbital compartment syndrome.

    PubMed

    Rowh, Adam D; Ufberg, Jacob W; Chan, Theodore C; Vilke, Gary M; Harrigan, Richard A

    2015-03-01

    Orbital compartment syndrome is a sight-threatening emergency. Vision may be preserved when timely intervention is performed. To present a case of orbital compartment syndrome caused by traumatic retrobulbar hemorrhage and the procedure of lateral canthotomy and cantholysis, reviewed with photographic illustration. Lateral canthotomy and cantholysis are readily performed at the bedside with simple instruments. The procedure may prevent irreversible blindness in cases of acute orbital compartment syndrome. Emergency physicians should be familiar with lateral canthotomy and cantholysis in the management of orbital compartment syndrome to minimize the chance of irreversible visual loss. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Compartment Syndrome After Varicose Vein Surgery Evidenced by CT Images.

    PubMed

    Wang, Sheng-Min; Kim, Maru

    2016-03-01

    A 21-year-old man developed compartment syndrome after a varicose vein surgery. Because of a lack of appropriate diagnostic apparatus, it was not possible to measure calf pressure. The only diagnostic tool available was computed tomography (CT). With the aid of CT, faster diagnosis of the compartment syndrome was possible, leading to appropriate management. By providing unique CT images of a patient before and after having compartment syndrome and after a fasciotomy, this study could add valuable references for diagnosis of compartment syndrome using CT. © The Author(s) 2014.

  4. Femoral vessel entrapment and compartment syndromes following snakebite.

    PubMed

    Blaylock, Roger S

    2003-08-01

    A 15-year-old patient who had been bitten on the ankle by a snake presented with swelling extending to the chest wall, with significant haemostatic abnormalities. Compartment and femoral vessel entrapment syndromes are presented. Compartment syndrome is easily mimicked by snakebite without a compartment syndrome. Current measurement of intracompartmental pressure, diastolic or mean arterial blood pressure and resulting equations used to determine the need for fasciotomy do not take into account regional venous or arterial pressures. Combined vessel entrapment and compartment syndromes due to snakebite warrant urgent surgery once hypovolaemia and coagulopathy have been controlled.

  5. Soft tissue vibrations within one soft tissue compartment.

    PubMed

    Boyer, Katherine A; Nigg, Benno M

    2006-01-01

    The concept of muscle tuning suggests that vibrations of the soft tissue compartments of the leg initiated by impacts are minimized by muscular activity prior to heel-strike of heel-toe running. For the quantification of muscle tuning it has been assumed (1) that the soft tissue compartment acts as one lumped mass and (2) that vibration energy dissipation does occur within one muscle. The purpose of this study was to test these two assumptions. It was hypothesized that (H1) the movement of the soft tissue compartment is not homogeneous, (H2) the vibration frequencies for different muscles within one soft tissue compartment are different and (3) attenuation of vibration movement within one muscle does occur. Soft tissue vibrations were measured using accelerometers on four locations on the quadriceps soft tissue compartment during heel-toe running. There were differences in the peak soft tissue acceleration and time of peak acceleration between accelerometer locations. The dominant frequency was similar throughout the soft tissue compartment, however; there was an attenuation of high-frequency vibration energy between distal and proximal points overlying one muscle. This evidence suggests that accelerometer placement is important when quantifying the acceleration magnitude and timing of peak soft tissue compartment but not when estimating the resonant vibration characteristics of a soft tissue compartment. It also provides initial evidence to support the idea that vibration control through muscle tuning may be achieved through changes in energy dissipating properties within the soft tissue compartment.

  6. Intracellular delivery of phosphoinositides and inositol phosphates using polyamine carriers

    PubMed Central

    Ozaki, Shoichiro; DeWald, Daryll B.; Shope, Joseph C.; Chen, Jian; Prestwich, Glenn D.

    2000-01-01

    Phosphoinositide signaling regulates events in endocytosis and exocytosis, vesicular trafficking of proteins, transduction of extracellular signals, remodeling of the actin cytoskeleton, regulation of calcium flux, and apoptosis. Obtaining mechanistic insights in living cells is impeded by the membrane impermeability of these anionic lipids. We describe a carrier system for intracellular delivery of phosphoinositide polyphosphates (PIPns) and fluorescently labeled PIPns into living cells, such that intracellular localization can be directly observed. Preincubation of PIPns or inositol phosphates with carrier polyamines produced complexes that entered mammalian, plant, yeast, bacterial, and protozoal cells in seconds to minutes via a nonendocytic mechanism. Time-dependent transit of both PIPns and the carrier to specific cytosolic and nuclear compartments was readily visualized by fluorescence microscopy. Platelet-derived growth factor treatment of NIH 3T3 fibroblasts containing carrier-delivered phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2]-7-nitrobenz-2-oxa-1,3-diazole resulted in the redistribution of the fluorescent signal, suggesting that fluorescent PtdIns(4,5)P2 was a substrate for phospholipase C. We also observed a calcium flux in NIH 3T3 cells when complexes of carrier and PtdIns(4,5)P2 or inositol 1,4,5-trisphosphate were added extracellularly. This simple intracellular delivery system allows for the efficient translocation of biologically active PIPns, inositol phosphates, and their fluorescent derivatives into living cells in a physiologically relevant context. PMID:11005844

  7. Leelamine mediates cancer cell death through inhibition of intracellular cholesterol transport

    PubMed Central

    Kuzu, Omer F.; Gowda, Raghavendra; Sharma, Arati; Robertson, Gavin P.

    2015-01-01

    Leelamine is a promising compound for the treatment of cancer; however, the molecular mechanisms leading to leelamine-mediated cell death have not been identified. This report shows that leelamine is a weakly basic amine with lysosomotropic properties, leading to its accumulation inside acidic organelles such as lysosomes. This accumulation leads to homeostatic imbalance in the lysosomal endosomal cell compartments that disrupts autophagic flux and intracellular cholesterol trafficking as well as receptor-mediated endocytosis. Electron micrographs of leelamine-treated cancer cells displayed accumulation of autophagosomes, membrane whorls, and lipofuscin-like structures, indicating disruption of lysosomal cell compartments. Early in the process, leelamine-mediated killing was a caspase-independent event triggered by cholesterol accumulation, as depletion of cholesterol using β-cyclodextrin treatment attenuated the cell death and restored the subcellular structures identified by electron microscopy. Protein microarray–based analyses of the intracellular signaling cascades showed alterations in RTK–AKT/STAT/MAPK signaling cascades, which was subsequently confirmed by Western blotting. Inhibition of Akt, Erk, and Stat signaling, together with abnormal deregulation of receptor tyrosine kinases, was caused by the inhibition of receptor-mediated endocytosis. This study is the first report demonstrating that leelamine is a lysosomotropic, intracellular cholesterol transport inhibitor with potential chemotherapeutic properties leading to inhibition of autophagic flux and induction of cholesterol accumulation in lysosomal/endosomal cell compartments. Importantly, the findings of this study show the potential of leelamine to disrupt cholesterol homeostasis for treatment of advanced-stage cancers. PMID:24688051

  8. Intramuscular compartment pressure measurement in chronic exertional compartment syndrome: new and improved diagnostic criteria.

    PubMed

    Roscoe, David; Roberts, Andrew J; Hulse, David

    2015-02-01

    Patients with chronic exertional compartment syndrome (CECS) have pain during exercise that subsides with rest. Diagnosis is usually confirmed by intramuscular compartment pressure (IMCP) measurement. Controversy exists regarding the accuracy of existing diagnostic criteria. (1) To compare dynamic IMCP measurement and anthropometric factors between patients with CECS and asymptomatic controls and (2) to establish the diagnostic utility of dynamic IMCP measurement. Cohort study (diagnosis); Level of evidence, 2. A total of 40 men aged 21 to 40 years were included in the study: 20 with symptoms of CECS of the anterior compartment and 20 asymptomatic controls. Diagnoses other than CECS were excluded with rigorous inclusion criteria and magnetic resonance imaging. The IMCP was measured continuously before, during, and after participants exercised on a treadmill, wearing identical footwear and carrying a 15-kg load. Pain experienced by study subjects increased incrementally as the study progressed (P < .001). Pain levels experienced by the case group during each phase of the exercise were significantly different (P = .021). Subjects had higher IMCP immediately upon standing at rest compared with controls (23.8 mm Hg [controls] vs 35.5 mm Hg [subjects]; P = .006). This relationship persisted throughout the exercise protocol, with the greatest difference corresponding to the period of maximal tolerable pain (68.7 mm Hg [controls] vs 114 mm Hg [subjects]; P < .001). Sensitivity and specificity were consistently higher than the existing criteria with improved diagnostic value (sensitivity = 63%, specificity = 95%; likelihood ratio = 12.5 [95% CI, 3.2-49]). Anterior compartment IMCP is elevated immediately upon standing at rest in subjects with CECS. In patients with symptoms consistent with CECS, diagnostic utility of IMCP measurement is improved when measured continuously during exercise. A cutoff of 105 mm Hg in phase 2 provides better diagnostic accuracy than do the

  9. The Epidermis Comprises Autonomous Compartments Maintained by Distinct Stem Cell Populations

    PubMed Central

    Page, Mahalia E.; Lombard, Patrick; Ng, Felicia; Göttgens, Berthold; Jensen, Kim B.

    2013-01-01

    Summary The complex anatomy of the epidermis contains multiple adult stem cell populations, but the extent to which they functionally overlap during homeostasis, wound healing, and tumor initiation remains poorly defined. Here, we demonstrate that Lrig1+ve cells are highly proliferative epidermal stem cells. Long-term clonal analysis reveals that Lrig1+ve cells maintain the upper pilosebaceous unit, containing the infundibulum and sebaceous gland as independent compartments, but contribute to neither the hair follicle nor the interfollicular epidermis, which are maintained by distinct stem cell populations. In contrast, upon wounding, stem cell progeny from multiple compartments acquire lineage plasticity and make permanent contributions to regenerating tissue. We further show that oncogene activation in Lrig1+ve cells drives hyperplasia but requires auxiliary stimuli for tumor formation. In summary, our data demonstrate that epidermal stem cells are lineage restricted during homeostasis and suggest that compartmentalization may constitute a conserved mechanism underlying epithelial tissue maintenance. PMID:23954751

  10. Creatine Supplementation and Anterior Compartment Pressure During Exercise in the Heat in Dehydrated Men

    PubMed Central

    Hile, Amy M; Anderson, Jeffrey M; Fiala, Kelly A; Stevenson, J. Herb; Casa, Douglas J; Maresh, Carl M

    2006-01-01

    Context: Theoretically, the risk of compartment syndrome is increased during creatine monohydrate (CrM) supplementation because of intracellular fluid retention in muscle cells and the overall increased size of the muscle tissue. Whether this change in intracellular fluid is associated with an increase in anterior compartment pressure in the lower leg when subjects are under thermal stress is unknown. Objective: To assess the influence of CrM on the resting and postexercise anterior compartment pressure of the lower leg in mildly to moderately dehydrated males exercising in the heat. Design: Double-blind, randomized, crossover design. Setting: Human Performance Laboratory. Patients or Other Participants: Eleven well-trained, non– heat-acclimated, healthy males (age = 22 ± 2 years, height = 181.1 ± 7 cm, mass = 78.4 ± 4.2 kg, V̇o2max = 50.5 ± 3.4 mL·kg−1·min−1). Intervention(s): Subjects were supplemented with 21.6 g/d of CrM or placebo for 7 days. On day 7, they performed 2 hours of submaximal exercise, alternating 30 minutes of walking with 30 minutes of cycling in the heat, resulting in approximately 2% dehydration. This was followed by an 80-minute heat tolerance test (temperature = 33.5 ± 0.5°C, humidity = 41.0 ± 12%), which included 12 repetitions of a 3-minute walk (pace = 4.0 ± 0.1 miles/h, intensity = 37.1 ± 6.1% V̇o2max) alternating with a 1-minute, high-intensity run (pace = 11.8 ± 0.4 miles/h, intensity = 115.0 ± 5.6% V̇o2max), resulting in an additional 2% decrease in body weight. Main Outcome Measures: Before supplementation and on day 7 of supplementation, anterior compartment pressure was measured at rest, after dehydration, and at 1, 3, 5, 10, 15, and 60 minutes after the heat tolerance test. Analysis of variance with repeated measures was calculated to compare differences within the trials and time points and to identify any interaction between trial and time. Results: The CrM intake was associated with an increase in body

  11. Uptake and intracellular traffic of siRNA dendriplexes in glioblastoma cells and macrophages

    PubMed Central

    Perez, Ana Paula; Cosaka, Maria Luz; Romero, Eder Lilia; Morilla, Maria Jose

    2011-01-01

    Background Gene silencing using small interfering RNA (siRNA) is a promising new therapeutic approach for glioblastoma. The endocytic uptake and delivery of siRNA to intracellular compartments could be enhanced by complexation with polyamidoamine dendrimers. In the present work, the uptake mechanisms and intracellular traffic of siRNA/generation 7 dendrimer complexes (siRNA dendriplexes) were screened in T98G glioblastoma and J774 macrophages. Methods The effect of a set of chemical inhibitors of endocytosis on the uptake and silencing capacity of dendriplexes was determined by flow cytometry. Colocalization of fluorescent dendriplexes with endocytic markers and occurrence of intracellular dissociation were assessed by confocal laser scanning microscopy. Results Uptake of siRNA dendriplexes by T98G cells was reduced by methyl-β-cyclodextrin, and genistein, and cytochalasine D, silencing activity was reduced by genistein; dendriplexes colocalized with cholera toxin subunit B. Therefore, caveolin-dependent endocytosis was involved both in the uptake and silencing activity of siRNA dendriplexes. On the other hand, uptake of siRNA dendriplexes by J774 cells was reduced by methyl-β-cyclodextrin, genistein, chlorpromazine, chloroquine, cytochalasine D, and nocodazole, the silencing activity was not affected by chlorpromazine, genistein or chloroquine, and dendriplexes colocalized with transferrin and cholera toxin subunit B. Thus, both clathrin-dependent and caveolin-dependent endocytosis mediated the uptake and silencing activity of the siRNA dendriplexes. SiRNA dendriplexes were internalized at higher rates by T98G but induced lower silencing than in J774 cells. SiRNA dendriplexes showed relatively slow dissociation kinetics, and their escape towards the cytosol was not mediated by acidification independently of the uptake pathway. Conclusion The extent of cellular uptake of siRNA dendriplexes was inversely related to their silencing activity. The higher silencing

  12. Dopamine modulated ionic permeability in mesoporous silica sphere based biomimetic compartment.

    PubMed

    Liu, Wei; Yang, Xiaohai; He, Dinggeng; He, Leiliang; Li, Li; Liu, Yu; Liu, Jianbo; Wang, Kemin

    2016-06-01

    The building of artificial systems with similar structure and function as cellular compartments will expand our understanding of compartmentalization related biological process and facilitate the construction of biomimetic highly functional structures. Herein, surface phenylboronic acid functionalized mesoporous silica sphere was developed as a biomimetic dopamine gated compartment, in which the ionic permeability can be well modulated through the dopamine-binding induced charge reversal. As the phenylboronic acid is negatively charged, the negatively charged 1, 3, 6, 8-pyrenetetrasulfonic acid (TPSA) was hindered from permeation into the biomimetic compartment. However, the presence of dopamine and its binding with phenylboronic acid reversed the gatekeeper shell from negative to positive charged and gated the permeation of TPSA into the interior. The dopamine gated permeation phenomenon resembles that in biological system, and thus the phenylboronic acid functionalized mesoporous silica sphere was taken as a simple model for dopamine gated ion channel decorated biological compartment. It will also contribute to the development of artificial cell and responsive nanoreactor.

  13. A two-compartment population pharmacokinetic-pharmacodynamic model of digoxin in adults, with implications for dosage.

    PubMed

    Jelliffe, Roger W; Milman, Mark; Schumitzky, Alan; Bayard, David; Van Guilder, Michael

    2014-06-01

    A population pharmacokinetic/pharmacodynamic model of digoxin in adult subjects was originally developed by Reuning et al in 1973. They clearly described the 2-compartment behavior of digoxin, the lack of correlation of effect with serum concentrations, and the close correlation of the observed inotropic effect of digoxin with the calculated amount of drug present in the peripheral nonserum compartment. Their model seemed most attractive for clinical use. However, to make it more applicable for maximally precise dosage, its model parameter values (means and SD's) were converted into discrete model parameter distributions using a computer program developed especially for this purpose using the method of maximum entropy. In this way, the parameter distributions became discrete rather than continuous, suitable for use in developing maximally precise digoxin dosage regimens, individualized to an adult patient's age, gender, body weight, and renal function, to achieve desired specific target goals either in the central (serum) compartment or in the peripheral (effect) compartment using the method of multiple model dosage design. Some illustrative clinical applications of this model are presented and discussed. This model with a peripheral compartment reflecting clinical effect has contributed significantly to an improved understanding of the clinical behavior of digoxin in patients than is possible with models having only a single compartment, and to the improved management of digoxin therapy for more than 20 years.

  14. Birbeck Granules Are Subdomains of Endosomal Recycling Compartment in Human Epidermal Langerhans Cells, Which Form Where Langerin Accumulates

    PubMed Central

    Mc Dermott, Ray; Ziylan, Umit; Spehner, Danièle; Bausinger, Huguette; Lipsker, Dan; Mommaas, Mieke; Cazenave, Jean-Pierre; Raposo, Graça; Goud, Bruno; de la Salle, Henri; Salamero, Jean; Hanau, Daniel

    2002-01-01

    Birbeck granules are unusual rod-shaped structures specific to epidermal Langerhans cells, whose origin and function remain undetermined. We investigated the intracellular location and fate of Langerin, a protein implicated in Birbeck granule biogenesis, in human epidermal Langerhans cells. In the steady state, Langerin is predominantly found in the endosomal recycling compartment and in Birbeck granules. Langerin internalizes by classical receptor-mediated endocytosis and the first Birbeck granules accessible to endocytosed Langerin are those connected to recycling endosomes in the pericentriolar area, where Langerin accumulates. Drug-induced inhibition of endocytosis results in the appearance of abundant open-ended Birbeck granule-like structures appended to the plasma membrane, whereas inhibition of recycling induces Birbeck granules to merge with a tubular endosomal network. In mature Langerhans cells, Langerin traffic is abolished and the loss of internal Langerin is associated with a concomitant depletion of Birbeck granules. Our results demonstrate an exchange of Langerin between early endosomal compartments and the plasma membrane, with dynamic retention in the endosomal recycling compartment. They show that Birbeck granules are not endocytotic structures, rather they are subdomains of the endosomal recycling compartment that form where Langerin accumulates. Finally, our results implicate ADP-ribosylation factor proteins in Langerin trafficking and the exchange between Birbeck granules and other endosomal membranes. PMID:11809842

  15. 14 CFR 29.855 - Cargo and baggage compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Cargo and baggage compartments. 29.855 Section 29.855 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...) They cannot be damaged by the movement of cargo in the compartment; and (2) Their breakage or failure...

  16. 14 CFR 27.855 - Cargo and baggage compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Cargo and baggage compartments. 27.855 Section 27.855 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... by the movement of cargo in the compartment; and (2) Their breakage or failure will not create a fire...

  17. 14 CFR 25.855 - Cargo or baggage compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Cargo or baggage compartments. 25.855 Section 25.855 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... movement of cargo in the compartment, and (2) Their breakage or failure will not create a fire hazard. (f...

  18. 14 CFR 27.855 - Cargo and baggage compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Cargo and baggage compartments. 27.855 Section 27.855 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... by the movement of cargo in the compartment; and (2) Their breakage or failure will not create a fire...

  19. Acute compartment syndrome of the thigh after weight training.

    PubMed Central

    Bidwell, J P; Gibbons, C E; Godsiff, S

    1996-01-01

    Compartment syndrome of the thigh is a rare but serious condition that is normally associated with closed trauma or compressive injury. A case of acute compartment syndrome of the thigh occurred in a 16 year old boy after intensive weight training. There was no evidence of muscle tear or focal haemorrhage during subsequent fasciotomy. PMID:8889126

  20. 14 CFR 25.857 - Cargo compartment classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... access provisions are being used, no hazardous quantity of smoke, flames, or extinguishing agent, will enter any compartment occupied by the crew or passengers; (3) There is a separate approved smoke... compartment but in which— (1) There is a separate approved smoke detector or fire detector system to give...

  1. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the engine...

  2. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the engine...

  3. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the engine...

  4. 14 CFR 25.855 - Cargo or baggage compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Fire Protection § 25... attached to) the airplane structure. (c) Ceiling and sidewall liner panels of Class C compartments must.... (d) All other materials used in the construction of the cargo or baggage compartment must meet...

  5. 14 CFR 25.855 - Cargo or baggage compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Fire Protection § 25... attached to) the airplane structure. (c) Ceiling and sidewall liner panels of Class C compartments must.... (d) All other materials used in the construction of the cargo or baggage compartment must meet...

  6. 14 CFR 23.1192 - Engine accessory compartment diaphragm.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine accessory compartment diaphragm. 23... Powerplant Powerplant Fire Protection § 23.1192 Engine accessory compartment diaphragm. For aircooled radial engines, the engine power section and all portions of the exhaust sytem must be isolated from the...

  7. Fungal community assemblage of different soil compartments in mangrove ecosystem.

    PubMed

    Sanka Loganathachetti, Dinesh; Poosakkannu, Anbu; Muthuraman, Sundararaman

    2017-08-17

    The fungal communities of different soil compartments in mangrove ecosystem are poorly studied. We sequenced the internal transcribed spacer (ITS) regions to characterize the fungal communities in Avicennia marina root-associated soils (rhizosphere and pneumatophore) and bulk soil compartments. The rhizosphere but not pneumatophore soil compartment had significantly lower fungal species richness than bulk soil. However, bulk soil fungal diversity (Shannon diversity index) was significantly higher than both pneumatophore and rhizosphere soil compartments. The different soil compartments significantly affected the fungal community composition. Pairwise sample analyses showed that bulk soil microbial community composition significantly different from rhizosphere and pneumatophore soil compartments. There was, however no significant difference observed between rhizosphere and pneumatophore soil fungal community composition and they shared relatively more OTUs between them. Further, there was a significant correlation observed between fungal community compositional changes and carbon or nitrogen availability of different soil compartments. These results suggest that few characteristics such as fungal richness and taxa abundance of rhizosphere and pneumatophore soil compartments were significantly different in mangrove ecosystem.

  8. 9 CFR 354.241 - Cleaning of rooms and compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Maintenance of... compartments. Rooms, compartments, or other parts of the official plant shall be kept clean and in sanitary... light fixtures in the official plant shall be kept clean. (c) All docks and rooms shall be kept clean...

  9. Chronic Exertional Compartment Syndrome in a Healthy Young Man.

    PubMed

    Joubert, Sonia V; Duarte, Manuel A

    2016-06-01

    The purpose of this case report is to describe a patient who presented with symptoms of exercise-induced compartment syndrome and was later referred for bilateral fasciotomy surgery. A 21-year-old patient presented for chiropractic care with the inability to run due to foot paresthesia and weakness. An exertion test and compartment pressure test diagnosed exercise-induced compartment syndrome. Exertion test and compartment pressure test were used to identify and diagnose exercise-induced compartment syndrome. The patient was diagnosed with exercise-induced compartment syndrome. He was treated conservatively and referred for additional testing. The orthopedic surgeon requested that 12 weeks of conservative care be provided prior to testing; treatment consisted of chiropractic care and rehabilitation exercises. Following the 12 weeks of treatment, the patient did not significantly respond to conservative care. A compartment pressure test confirmed the initial diagnosis of exercise-induced compartment syndrome. The patient underwent a unilateral fasciotomy surgery and recovered fully. Following the surgery, the patient returned to the chiropractic clinic with the same presentation in the contralateral leg. The same protocol of management resulted in the same outcome. Two years after surgical intervention, the patient continues to maintain an active lifestyle, able to run 2 to 3 miles per day without any exacerbations or symptomatology. Clinical awareness, a detailed history, and thorough examination with reproduction of symptomatology are necessary to form a proper diagnosis and treatment plan for these patients. Therefore, multidisciplinary medical communication would prove to be the most beneficial approach for the patient.

  10. Spontaneous Compartment Syndrome of the Hand in Systemic Sclerosis.

    PubMed

    Tanagho, Andy; Hatab, Sameh; Youssef, Sally; Ansara, Sameh

    2015-09-01

    Compartment syndrome refers to a condition of compromised circulation within a limited space due to increased pressure within that space. The reduced tissue perfusion results in reduced venous drainage, leading to increased interstitial tissue pressure and subsequent compromised arterial flow. Although not as common as compartment syndrome of the leg and forearm, compartment syndrome of the hand is not rare and can lead to devastating sequelae as a result of tissue necrosis. Compartment syndrome of the hand has several etiologies, including trauma, arterial injury, thermal injury, and constrictive bandaging. The cardinal clinical sign is pain that is aggravated by passive stretching of the muscles within the involved compartments. Extremity function is usually restored with expeditious fasciotomy of the involved myofascial compartments, and complications, such as intrinsic muscular dysfunction and Volkmann's ischemic contracture, can usually be prevented. There are no reported cases of compartment syndrome of the hand in patients with systemic sclerosis or Raynaud's phenomenon. Systemic sclerosis is a form of scleroderma that affects the skin and internal organs. The limited cutaneous subset affects the skin of the extremities but is associated with a set of characteristic features that includes calcinosis, Raynaud's phenomenon, esophageal involvement, sclerodactyly, and telangiectasia. This report describes an unusual case of a patient who had spontaneous compartment syndrome of the hand. The patient's concomitant limited cutaneous systemic sclerosis may have played a role in this unusual occurrence. The diagnosis was based on the clinical picture, and the symptoms resolved after surgical decompression. Copyright 2015, SLACK Incorporated.

  11. Radiographic predictors of compartment syndrome in tibial plateau fractures.

    PubMed

    Ziran, Bruce H; Becher, Stephen John

    2013-11-01

    The purpose of this article was to evaluate the relationship of radiographic features of tibial plateau fractures to the development of compartment syndrome. We hypothesized that the direction and degree of initial displacement of the femur on the tibia, and the amount of tibial widening (TW), were correlated with the development of compartment syndrome. Retrospective case-control study. Single level 1 trauma center. Retrospective evaluation of 158 patients with 162 plateau fractures. Grouping with and without compartment syndrome. The following data were obtained: age, sex, Schatzker and OTA/AO classification, open/closed status, TW, and femoral displacement (FD). A univariate statistical and a logistical regression analysis were performed to determine significance. The overall rate of compartment syndrome was 11%. Univariate analysis found both the TW and FD to be significant with respect to development of compartment syndrome (P < 0.05). Higher Schatzker (IV-VI) and OTA/AO grades were also correlated (P < 0.05) with increased incidence of compartment syndrome. Logistic regression found FD and Schatzker grade to be significant. Our study is the first to identify easily obtained radiographic parameters that correlate to the occurrence compartment syndrome. There may also be a relationship between TW and FD, as noted by regression result. This study helps to assess which patients with a fracture are at higher risk for developing a compartment syndrome. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  12. 7 CFR 58.510 - Rooms and compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Rooms and Compartments § 58... avoided. Rooms, compartments, coolers, and dry storage space in which any raw material, packaging or...

  13. 7 CFR 58.510 - Rooms and compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Rooms and Compartments § 58... avoided. Rooms, compartments, coolers, and dry storage space in which any raw material, packaging or...

  14. 7 CFR 58.510 - Rooms and compartments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Rooms and Compartments § 58... avoided. Rooms, compartments, coolers, and dry storage space in which any raw material, packaging or...

  15. 7 CFR 58.510 - Rooms and compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Rooms and Compartments § 58... avoided. Rooms, compartments, coolers, and dry storage space in which any raw material, packaging or...

  16. 7 CFR 58.510 - Rooms and compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General Specifications for Dairy Plants Approved for USDA Inspection and Grading Service 1 Rooms and Compartments § 58... avoided. Rooms, compartments, coolers, and dry storage space in which any raw material, packaging or...

  17. 49 CFR 179.220-9 - Compartment tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Compartment tanks. 179.220-9 Section 179.220-9... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-9 Compartment tanks....

  18. 14 CFR 121.314 - Cargo and baggage compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the certificate holder for operation under this part that has at least one Class D compartment that...: (a) Each Class C or Class D compartment, as defined in § 25.857 of this Chapter in effect on June 16... capability of the liner to safely contain a fire. (c) After March 19, 2001, each Class D...

  19. Superdiffusion dominates intracellular particle motion in the supercrowded cytoplasm of pathogenic Acanthamoeba castellanii

    NASA Astrophysics Data System (ADS)

    Reverey, Julia F.; Jeon, Jae-Hyung; Bao, Han; Leippe, Matthias; Metzler, Ralf; Selhuber-Unkel, Christine

    2015-06-01

    Acanthamoebae are free-living protists and human pathogens, whose cellular functions and pathogenicity strongly depend on the transport of intracellular vesicles and granules through the cytosol. Using high-speed live cell imaging in combination with single-particle tracking analysis, we show here that the motion of endogenous intracellular particles in the size range from a few hundred nanometers to several micrometers in Acanthamoeba castellanii is strongly superdiffusive and influenced by cell locomotion, cytoskeletal elements, and myosin II. We demonstrate that cell locomotion significantly contributes to intracellular particle motion, but is clearly not the only origin of superdiffusivity. By analyzing the contribution of microtubules, actin, and myosin II motors we show that myosin II is a major driving force of intracellular motion in A. castellanii. The cytoplasm of A. castellanii is supercrowded with intracellular vesicles and granules, such that significant intracellular motion can only be achieved by actively driven motion, while purely thermally driven diffusion is negligible.

  20. Compartment in vertical flow reactor for ferruginous mine water

    NASA Astrophysics Data System (ADS)

    Hur, Won; Cheong, Young-Wook; Yim, Gil-Jae; Ji, Sang-Woo; Hong, Ji-Hye

    2014-05-01

    Mine effluents contain varying concentrations of ferrous ion along with other metal ions. Fe(II) that quickly oxidizes to form precipitates in the presence of oxygen under net alkaline or neutral conditions. Thus, passive treatment methods are designed for the mine water to reside in an open containment area so as to allow simultaneous oxidation and precipitation of Fe(II), such as in a lagoon or an oxidation pond. A vertical flow reactor (VFR) was also suggested to remediate ferruginous mine drainage passing down through an accreting bed of ochre. However, VFR has a limited operation time until the system begins to overflow. It was also demonstrated that two-compartment VFR has a longer operation time than single compartment VFR of same size. In this study, a mathematical model was developed as a part of efforts to explore the operation of VFR, showing dynamic changes in head differences, ochre depth and Fe(II)/Fe(III) concentration in the effluent flow. The analysis shows that Fe(II) oxidation and ochre formation should be balanced with permeability of ochre bed to maximize VFR operation time and minimize residual Fe(II) in the effluent. The model demonstrates that two compartment VFR can have a longer operation time than a single-compartment VFR and that an optimum compartment ratio exists that maximize VFR operation time. Accelerated Fe(II) oxidation significantly affects the optimum ratio of compartment area and reduced residual Fe(II) in the effluent. VFR operation time can be significantly prolonged by increasing the rate of ochre formation not by accelerated Fe(II) oxidation. Taken together, ochre forms largely in the first compartment while overflowed mine water with reduced iron contents is efficiently filtered in the second compartment. These results provide us a better understanding of VFR operation and optimum design criteria for maximum operation time in a two-compartment VFR. Rapid ochre accretion in the first compartment maintains constant hydraulic

  1. Contamination control of the space shuttle Orbiter crew compartment

    NASA Technical Reports Server (NTRS)

    Bartelson, Donald W.

    1986-01-01

    Effective contamination control as applied to manned space flight environments is a discipline characterized and controlled by many parameters. An introduction is given to issues involving Orbiter crew compartment contamination control. An effective ground processing contamination control program is an essential building block to a successful shuttle mission. Personnel are required to don cleanroom-grade clothing ensembles before entering the crew compartment and follow cleanroom rules and regulations. Prior to crew compartment entry, materials and equipment must be checked by an orbiter integrity clerk stationed outside the white-room entrance for compliance to program requirements. Analysis and source identification of crew compartment debris studies have been going on for two years. The objective of these studies is to determine and identify particulate generating materials and activities in the crew compartment. Results show a wide spectrum of many different types of materials. When source identification is made, corrective action is implemented to minimize or curtail further contaminate generation.

  2. Bilaterally Symmetrical Lower Extremity Compartment Syndrome following Massive Transfusion.

    PubMed

    Karaoren, Gulsah; Bakan, Nurten; Tomruk, Senay Goksu; Topaç, Zelin; Kurtulmuş, Tuhan; Irkören, Saime

    2016-01-01

    Compartment syndrome is a serious condition characterized by raised intracompartmental pressure, which develops following trauma. Well leg compartment syndrome (WLCS) is a term reserved for compartment syndrome in a nontraumatic setting, usually resulting from prolonged lithotomy position during surgery. In literature, 8 cases have been reported regarding well leg compartment syndrome in a supine position and bilateral symmetrical involvement was observed in only 2 cases. In WLCS etiology, lengthy surgery, lengthy hypotension, and extremity malpositioning have been held responsible but one of the factors with a role in the etiology may have been the tissue oedema and impaired microcirculation formed from the effect of vasoactive mediators expressed into the circulation associated with the massive blood transfusion. The case is presented here regarding symmetrical lower extremity compartment syndrome after surgery in which massive transfusion was made for gross haemorrhage from an abdominal injury. In conclusion, blood transfusion applied at the required time is life-saving but potential risks must always be considered.

  3. The effects of interaction compartments on stability for competitive systems.

    PubMed

    Rozdilsky, Ian D; Stone, Lewi; Solow, Andrew

    2004-03-21

    The interactions between species are unlikely to be randomly arranged, and there is increasing evidence that most interactions occur within small species sub-groups, or compartments, that do not strongly interact with one another. We examine whether arranging the interactions of a competitive system into compartments influences the system properties of linear stability, feasibility, reactivity, and biomass stability, thereby altering the likelihood of species persistence. Model Lotka-Volterra systems of diffuse competition were analysed with interactions arranged randomly and in compartments. It was found, using a variety of dynamical measures, that arranging interactions into compartments enhances the likelihood of species persistence. Since many natural competitive systems appear to have interactions arranged within compartments, this may be an outcome of the positive attributes that this form of organization offers.

  4. Senescence-inducible cell wall and intracellular purple acid phosphatases: implications for phosphorus remobilization in Hakea prostrata (Proteaceae) and Arabidopsis thaliana (Brassicaceae)

    PubMed Central

    Shane, Michael W.; Stigter, Kyla; Fedosejevs, Eric T.; Plaxton, William C.

    2014-01-01

    Despite its agronomic importance, the metabolic networks mediating phosphorus (P) remobilization during plant senescence are poorly understood. Highly efficient P remobilization (~85%) from senescing leaves and proteoid roots of harsh hakea (Hakea prostrata), a native ‘extremophile’ plant of south-western Australia, was linked with striking up-regulation of cell wall-localized and intracellular acid phosphatase (APase) and RNase activities. Non-denaturing PAGE followed by in-gel APase activity staining revealed senescence-inducible 120kDa and 60kDa intracellular APase isoforms, whereas only the 120kDa isoform was detected in corresponding cell wall fractions. Kinetic and immunological properties of the 120kDa and 60kDa APases partially purified from senescing leaves indicated that they are purple acid phosphatases (PAPs). Results obtained with cell wall-targeted hydrolases of harsh hakea were corroborated using Arabidopsis thaliana in which an ~200% increase in cell wall APase activity during leaf senescence was paralleled by accumulation of immunoreactive 55kDa AtPAP26 polypeptides. Senescing leaves of an atpap26 T-DNA insertion mutant displayed a >90% decrease in cell wall APase activity. Previous research established that senescing leaves of atpap26 plants exhibited a similar reduction in intracellular (vacuolar) APase activity, while displaying markedly impaired P remobilization efficiency and delayed senescence. It is hypothesized that up-regulation and dual targeting of PAPs and RNases to the cell wall and vacuolar compartments make a crucial contribution to highly efficient P remobilization that dominates the P metabolism of senescing tissues of harsh hakea and Arabidopsis. To the best of the authors’ knowledge, the apparent contribution of cell wall-targeted hydrolases to remobilizing key macronutrients such as P during senescence has not been previously suggested. PMID:25170100

  5. Senescence-inducible cell wall and intracellular purple acid phosphatases: implications for phosphorus remobilization in Hakea prostrata (Proteaceae) and Arabidopsis thaliana (Brassicaceae).

    PubMed

    Shane, Michael W; Stigter, Kyla; Fedosejevs, Eric T; Plaxton, William C

    2014-11-01

    Despite its agronomic importance, the metabolic networks mediating phosphorus (P) remobilization during plant senescence are poorly understood. Highly efficient P remobilization (~85%) from senescing leaves and proteoid roots of harsh hakea (Hakea prostrata), a native 'extremophile' plant of south-western Australia, was linked with striking up-regulation of cell wall-localized and intracellular acid phosphatase (APase) and RNase activities. Non-denaturing PAGE followed by in-gel APase activity staining revealed senescence-inducible 120kDa and 60kDa intracellular APase isoforms, whereas only the 120kDa isoform was detected in corresponding cell wall fractions. Kinetic and immunological properties of the 120kDa and 60kDa APases partially purified from senescing leaves indicated that they are purple acid phosphatases (PAPs). Results obtained with cell wall-targeted hydrolases of harsh hakea were corroborated using Arabidopsis thaliana in which an ~200% increase in cell wall APase activity during leaf senescence was paralleled by accumulation of immunoreactive 55kDa AtPAP26 polypeptides. Senescing leaves of an atpap26 T-DNA insertion mutant displayed a >90% decrease in cell wall APase activity. Previous research established that senescing leaves of atpap26 plants exhibited a similar reduction in intracellular (vacuolar) APase activity, while displaying markedly impaired P remobilization efficiency and delayed senescence. It is hypothesized that up-regulation and dual targeting of PAPs and RNases to the cell wall and vacuolar compartments make a crucial contribution to highly efficient P remobilization that dominates the P metabolism of senescing tissues of harsh hakea and Arabidopsis. To the best of the authors' knowledge, the apparent contribution of cell wall-targeted hydrolases to remobilizing key macronutrients such as P during senescence has not been previously suggested. © The Author 2014. Published by Oxford University Press on behalf of the Society for

  6. A human cadaver fascial compartment pressure measurement model.

    PubMed

    Messina, Frank C; Cooper, Dylan; Huffman, Gretchen; Bartkus, Edward; Wilbur, Lee

    2013-10-01

    Fresh human cadavers provide an effective model for procedural training. Currently, there are no realistic models to teach fascial compartment pressure measurement. We created a human cadaver fascial compartment pressure measurement model and studied its feasibility with a pre-post design. Three faculty members, following instructions from a common procedure textbook, used a standard handheld intra-compartment pressure monitor (Stryker(®), Kalamazoo, MI) to measure baseline pressures ("unembalmed") in the anterior, lateral, deep posterior, and superficial posterior compartments of the lower legs of a fresh human cadaver. The right femoral artery was then identified by superficial dissection, cannulated distally towards the lower leg, and connected to a standard embalming machine. After a 5-min infusion, the same three faculty members re-measured pressures ("embalmed") of the same compartments on the cannulated right leg. Unembalmed and embalmed readings for each compartment, and baseline readings for each leg, were compared using a two-sided paired t-test. The mean baseline compartment pressures did not differ between the right and left legs. Using the embalming machine, compartment pressure readings increased significantly over baseline for three of four fascial compartments; all in mm Hg (±SD): anterior from 40 (±9) to 143 (±44) (p = 0.08); lateral from 22 (±2.5) to 160 (±4.3) (p < 0.01); deep posterior from 34 (±7.9) to 161 (±15) (p < 0.01); superficial posterior from 33 (±0) to 140 (±13) (p < 0.01). We created a novel and measurable fascial compartment pressure measurement model in a fresh human cadaver using a standard embalming machine. Set-up is minimal and the model can be incorporated into teaching curricula. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Functional outcome of tibial fracture with acute compartment syndrome and correlation to deep posterior compartment pressure

    PubMed Central

    Goyal, Saumitra; Naik, Monappa A; Tripathy, Sujit Kumar; Rao, Sharath K

    2017-01-01

    AIM To measure single baseline deep posterior compartment pressure in tibial fracture complicated by acute compartment syndrome (ACS) and to correlate it with functional outcome. METHODS Thirty-two tibial fractures with ACS were evaluated clinically and the deep posterior compartment pressure was measured. Urgent fasciotomy was needed in 30 patients. Definite surgical fixation was performed either primarily or once fasciotomy wound was healthy. The patients were followed up at 3 mo, 6 mo and one year. At one year, the functional outcome [lower extremity functional scale (LEFS)] and complications were assessed. RESULTS Three limbs were amputated. In remaining 29 patients, the average times for clinical and radiological union were 25.2 ± 10.9 wk (10 to 54 wk) and 23.8 ± 9.2 wk (12 to 52 wk) respectively. Nine patients had delayed union and 2 had nonunion who needed bone grafting to augment healing. Most common complaint at follow up was ankle stiffness (76%) that caused difficulty in walking, running and squatting. Of 21 patients who had paralysis at diagnosis, 13 (62%) did not recover and additional five patients developed paralysis at follow-up. On LEFS evaluation, there were 14 patients (48.3%) with severe disability, 10 patients (34.5%) with moderate disability and 5 patients (17.2%) with minimal disability. The mean pressures in patients with minimal disability, moderate disability and severe disability were 37.8, 48.4 and 58.79 mmHg respectively (P < 0.001). CONCLUSION ACS in tibial fractures causes severe functional disability in majority of patients. These patients are prone for delayed union and nonunion; however, long term disability is mainly because of severe soft tissue contracture. Intra-compartmental pressure (ICP) correlates with functional disability; patients with relatively high ICP are prone for poor functional outcome. PMID:28567342

  8. Functional outcome of tibial fracture with acute compartment syndrome and correlation to deep posterior compartment pressure.

    PubMed

    Goyal, Saumitra; Naik, Monappa A; Tripathy, Sujit Kumar; Rao, Sharath K

    2017-05-18

    To measure single baseline deep posterior compartment pressure in tibial fracture complicated by acute compartment syndrome (ACS) and to correlate it with functional outcome. Thirty-two tibial fractures with ACS were evaluated clinically and the deep posterior compartment pressure was measured. Urgent fasciotomy was needed in 30 patients. Definite surgical fixation was performed either primarily or once fasciotomy wound was healthy. The patients were followed up at 3 mo, 6 mo and one year. At one year, the functional outcome [lower extremity functional scale (LEFS)] and complications were assessed. Three limbs were amputated. In remaining 29 patients, the average times for clinical and radiological union were 25.2 ± 10.9 wk (10 to 54 wk) and 23.8 ± 9.2 wk (12 to 52 wk) respectively. Nine patients had delayed union and 2 had nonunion who needed bone grafting to augment healing. Most common complaint at follow up was ankle stiffness (76%) that caused difficulty in walking, running and squatting. Of 21 patients who had paralysis at diagnosis, 13 (62%) did not recover and additional five patients developed paralysis at follow-up. On LEFS evaluation, there were 14 patients (48.3%) with severe disability, 10 patients (34.5%) with moderate disability and 5 patients (17.2%) with minimal disability. The mean pressures in patients with minimal disability, moderate disability and severe disability were 37.8, 48.4 and 58.79 mmHg respectively (P < 0.001). ACS in tibial fractures causes severe functional disability in majority of patients. These patients are prone for delayed union and nonunion; however, long term disability is mainly because of severe soft tissue contracture. Intra-compartmental pressure (ICP) correlates with functional disability; patients with relatively high ICP are prone for poor functional outcome.

  9. Phosphorylation-mediated RNA/peptide complex coacervation as a model for intracellular liquid organelles.

    PubMed

    Aumiller, William M; Keating, Christine D

    2016-02-01

    Biological cells are highly organized, with numerous subcellular compartments. Phosphorylation has been hypothesized as a means to control the assembly/disassembly of liquid-like RNA- and protein-rich intracellular bodies, or liquid organelles, that lack delimiting membranes. Here, we demonstrate that charge-mediated phase separation, or complex coacervation, of RNAs with cationic peptides can generate simple model liquid organelles capable of reversibly compartmentalizing biomolecules. Formation and dissolution of these liquid bodies was controlled by changes in peptide phosphorylation state using a kinase/phosphatase enzyme pair. The droplet-generating phase transition responded to modification of even a single serine residue. Electrostatic interactions between the short cationic peptides and the much longer polyanionic RNAs drove phase separation. Coacervates were also formed on silica beads, a primitive model for localization at specific intracellular sites. This work supports phosphoregulation of complex coacervation as a viable mechanism for dynamic intracellular compartmentalization in membraneless organelles.

  10. Phosphorylation-mediated RNA/peptide complex coacervation as a model for intracellular liquid organelles

    NASA Astrophysics Data System (ADS)

    Aumiller, William M.; Keating, Christine D.

    2016-02-01

    Biological cells are highly organized, with numerous subcellular compartments. Phosphorylation has been hypothesized as a means to control the assembly/disassembly of liquid-like RNA- and protein-rich intracellular bodies, or liquid organelles, that lack delimiting membranes. Here, we demonstrate that charge-mediated phase separation, or complex coacervation, of RNAs with cationic peptides can generate simple model liquid organelles capable of reversibly compartmentalizing biomolecules. Formation and dissolution of these liquid bodies was controlled by changes in peptide phosphorylation state using a kinase/phosphatase enzyme pair. The droplet-generating phase transition responded to modification of even a single serine residue. Electrostatic interactions between the short cationic peptides and the much longer polyanionic RNAs drove phase separation. Coacervates were also formed on silica beads, a primitive model for localization at specific intracellular sites. This work supports phosphoregulation of complex coacervation as a viable mechanism for dynamic intracellular compartmentalization in membraneless organelles.

  11. Shigella subverts the host recycling compartment to rupture its vacuole.

    PubMed

    Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

    2014-10-08

    Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P₂ into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion.

  12. Single Cell Measurements of Vacuolar Rupture Caused by Intracellular Pathogens

    PubMed Central

    Danckaert, Anne; Simeone, Roxane; Brosch, Roland; Enninga, Jost; Bobard, Alexandre

    2013-01-01

    Shigella flexneri are pathogenic bacteria that invade host cells entering into an endocytic vacuole. Subsequently, the rupture of this membrane-enclosed compartment allows bacteria to move within the cytosol, proliferate and further invade neighboring cells. Mycobacterium tuberculosis is phagocytosed by immune cells, and has recently been shown to rupture phagosomal membrane in macrophages. We developed a robust assay for tracking phagosomal membrane disruption after host cell entry of Shigella flexneri or Mycobacterium tuberculosis. The approach makes use of CCF4, a FRET reporter sensitive to β-lactamase that equilibrates in the cytosol of host cells. Upon invasion of host cells by bacterial pathogens, the probe remains intact as long as the bacteria reside in membrane-enclosed compartments. After disruption of the vacuole, β-lactamase activity on the surface of the intracellular pathogen cleaves CCF4 instantly leading to a loss of FRET signal and switching its emission spectrum. This robust ratiometric assay yields accurate information about the timing of vacuolar rupture induced by the invading bacteria, and it can be coupled to automated microscopy and image processing by specialized algorithms for the detection of the emission signals of the FRET donor and acceptor. Further, it allows investigating the dynamics of vacuolar disruption elicited by intracellular bacteria in real time in single cells. Finally, it is perfectly suited for high-throughput analysis with a spatio-temporal resolution exceeding previous methods. Here, we provide the experimental details of exemplary protocols for the CCF4 vacuolar rupture assay on HeLa cells and THP-1 macrophages for time-lapse experiments or end points experiments using Shigella flexneri as well as multiple mycobacterial strains such as Mycobacterium marinum, Mycobacterium bovis, and Mycobacterium tuberculosis. PMID:23792688

  13. Insight into nanoparticle cellular uptake and intracellular targeting.

    PubMed

    Yameen, Basit; Choi, Won Il; Vilos, Cristian; Swami, Archana; Shi, Jinjun; Farokhzad, Omid C

    2014-09-28

    Collaborative efforts from the fields of biology, materials science, and engineering are leading to exciting progress in the development of nanomedicines. Since the targets of many therapeutic agents are localized in subcellular compartments, modulation of nanoparticle-cell interactions for efficient cellular uptake through the plasma membrane and the development of nanomedicines for precise delivery to subcellular compartments remain formidable challenges. Cellular internalization routes determine the post-internalization fate and intracellular localization of nanoparticles. This review highlights the cellular uptake routes most relevant to the field of non-targeted nanomedicine and presents an account of ligand-targeted nanoparticles for receptor-mediated cellular internalization as a strategy for modulating the cellular uptake of nanoparticles. Ligand-targeted nanoparticles have been the main impetus behind the progress of nanomedicines towards the clinic. This strategy has already resulted in remarkable progress towards effective oral delivery of nanomedicines that can overcome the intestinal epithelial barrier. A detailed overview of the recent developments in subcellular targeting as a novel platform for next-generation organelle-specific nanomedicines is also provided. Each section of the review includes prospects, potential, and concrete expectations from the field of targeted nanomedicines and strategies to meet those expectations.

  14. Intracellular processing of the Newcastle disease virus fusion glycoprotein

    SciTech Connect

    Morrison, T.; Ward, L.J.; Semerjian, A.

    1985-03-01

    The fusion glycoprotein (Fo) of Newcastle disease virus is cleaved at an intracellular site into F1 and F2. This result was confirmed by comparing the transit time of the fusion protein to the cell surface with the time course of cleavage of Fo. The time required for cleavage of half of the pulse-labeled Fo protein is ca. 40 min faster than the half time of the transit of the fusion protein to the cell surface. To determine the cell compartment in which cleavage occurs, use was made of inhibitors which block glycoprotein migration at specific points and posttranslational modifications known to occur in specific cell membranes. Cleavage of Fo is inhibited by carbonyl cyanide m-chlorophenylhydrazone; thus, cleavage does not occur in the rough endoplasmic reticulum. Monensin blocks the incorporation of Newcastle disease virus glycoproteins into virions and blocks the cleavage of the fusion glycoprotein. However, Fo cannot be radioactively labeled with (/sup 3/H) fucose, whereas F1 is readily labeled. These results argue that cleavage occurs in the trans Golgi membranes or in a cell compartment occupied by glycoproteins quite soon after their transit through the trans Golgi membranes. The implications of the results presented for the transit times of the fusion protein between subcellular organelles are discussed.

  15. Insight into nanoparticle cellular uptake and intracellular targeting

    PubMed Central

    Yameen, Basit; Choi, Won Il; Vilos, Cristian; Swami, Archana; Shi, Jinjun; Farokhzad, Omid C.

    2014-01-01

    Collaborative efforts from the fields of biology, materials science, and engineering are leading to exciting progress in the development of nanomedicines. Since the targets of many therapeutic agents are localized in subcellular compartments, modulation of nanoparticle-cell interactions for an efficient cellular uptake through the plasma membrane, and the development of nanomedicines for precise delivery to subcellular compartments remain formidable challenges. The cellular internalization routes have a determining effect on the post-internalization fate and intracellular localization of nanoparticles. This review highlights the cellular uptake routes most relevant to the field of non-targeted nanomedicine, and presents an account of ligand targeted nanoparticles for receptor mediated cellular internalization as a strategy for modulating the cellular uptake of nanoparticles. Ligand targeted nanoparticles have been the main impetus behind the progress of nanomedicines towards the clinic. This strategy has even resulted in a remarkable development towards effective oral delivery of nanomedicines that can overcome the intestinal epithelial cellular barrier. A detailed overview of the recent developments towards subcellular targeting that is emerging as a platform for the next generation organelle specific nanomedicines is also provided. Each section of the review includes prospect, potential, and concrete expectations from the field of targeted nanomedicines and strategies to meet those expectations. PMID:24984011

  16. Early Intracellular Trafficking of Granulibacter bethesdensis in Human Macrophages.

    PubMed

    Chu, Jessica; Smelkinson, Margery G; Dorward, David W; Zarember, Kol A; Gallin, John I

    2017-06-01

    Granulibacter bethesdensis is a Gram-negative bacterium that infects patients with chronic granulomatous disease (CGD), a primary immunodeficiency marked by a defect in NOX2, the phagocyte NADPH oxidase. Previous studies have shown that NOX2 is essential for killing of G. bethesdensis by neutrophils and monocytes and that the bacteriostatic activity of monocyte-derived macrophages (MDM) requires NOX2 and gamma interferon (IFN-γ) pretreatment. To determine whether G. bethesdensis evades phagolysosomal killing, a host defense pathway intact in both normal and CGD MDM, or whether it occupies a distinct intracellular niche in CGD MDM, we assessed the trafficking patterns of this organism. We observed colocalization of G. bethesdensis with an early endosome antigen 1 (EEA1)-positive compartment, followed by colocalization with lysosome-associated membrane protein 1 (LAMP1)-positive and LysoTracker-positive late phagosomes; these characteristics were similar in both normal and CGD MDM. Despite localization to acidified late phagosomes, viable G. bethesdensis cells were recovered from viable MDM in numbers greater than in the initial input up to 6 days after infection. G. bethesdensis remains, and in some cases appears to divide, within a membrane-bound compartment for the entire 6-day time course. These findings indicate that this organism resists both oxygen-dependent and oxygen-independent phagolysosomal antimicrobial systems of human macrophages. Copyright © 2017 American Society for Microbiology.

  17. Compartment syndrome causes systemic inflammation in a rat.

    PubMed

    Lawendy, A-R; Bihari, A; Sanders, D W; Badhwar, A; Cepinskas, G

    2016-08-01

    Compartment syndrome results from increased intra-compartmental pressure (ICP) causing local tissue ischaemia and cell death, but the systemic effects are not well described. We hypothesised that compartment syndrome would have a profound effect not only on the affected limb, but also on remote organs. Using a rat model of compartment syndrome, its systemic effects on the viability of hepatocytes and on inflammation and circulation were directly visualised using intravital video microscopy. We found that hepatocellular injury was significantly higher in the compartment syndrome group (192 PI-labelled cells/10(-1) mm(3), standard error of the mean (sem) 51) compared with controls (30 PI-labelled cells/10(-1) mm(3), sem 12, p < 0.01). The number of adherent venular white blood cells was significantly higher for the compartment syndrome group (5 leukocytes/30s/10 000 μm(2), sem 1) than controls (0.2 leukocytes/30 s/10 000 μm(2), sem 0.2, p < 0.01). Volumetric blood flow was not significantly different between the two groups, although there was an increase in the heterogeneity of perfusion. Compartment syndrome can be accompanied by severe systemic inflammation and end organ damage. This study provides evidence of the relationship between compartment syndrome in a limb and systemic inflammation and dysfunction in a remote organ. Cite this article: Bone Joint J 2016; 98-B:1132-7. ©2016 The British Editorial Society of Bone & Joint Surgery.

  18. Endocytosis and intracellular traffic of cholesterol-PDMAEMA liposome complexes in human epithelial-like cells.

    PubMed

    Szymanowski, F; Hugo, A A; Alves, P; Simões, P N; Gómez-Zavaglia, A; Pérez, Pablo F

    2017-08-01

    Liposomes are generally used as delivery systems, as they are capable of encapsulating a wide variety of molecules (i.e. plasmids, recombinant proteins, therapeutic drugs). However, liposomal drug delivery have to fulfill different requirements, such as the effective internalization by the target cells and avoidance of the degradative activity of the intracellular compartments. The use of polymer lipid complexes (PLCs), by including different polymers in the liposome formulation, could improve internalization and intracellular release of drugs. The aim of the present work is to study the mechanisms of cellular uptaking and the intracellular trafficking of PLCs formed with cholesterol-poly(2-(dimethylamino)ethyl methacrylate) CHO-PDMAEMA and lecithin (LC CHO-PD). Calcein-loaded liposomes were used to determine cellular uptake and intracellular localization by flow cytometry and confocal microscopy. Incorporation of CHO-PDMAEMA to lecithin liposomes enhanced the internalization capacity of PLCs. Internalization of PLCs by human epithelial-like cells (HEK-293) diminished at 4°C, suggesting uptake by endocytosis. PLCs showed no co-localization with acidic compartments after internalization. Experiments with endocytosis inhibitors and co-localization of liposomes and albumin, suggested the caveolae endocytic pathway as the most probable route for intracellular trafficking of PLCs. In this work, we demonstrated an efficient uptake of LC CHO-PDs by human epithelial-like cells (HEK-293) through the non-degradative caveolae endocytic pathway. The mode of internalization and the intracellular fate of liposomes under study, suggest a promising use of LC CHO-PDs as drug delivery systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Patterns of intracellular compartmentalization, trafficking and acidification of 5'-fluorescein labeled phosphodiester and phosphorothioate oligodeoxynucleotides in HL60 cells.

    PubMed Central

    Tonkinson, J L; Stein, C A

    1994-01-01

    We have examined the intracellular compartmentalization and trafficking of fluorescein labeled (F) phosphodiester (PO) and phosphorothioate (PS) oligodeoxynucleotides (oligos) in HL60 cells. A series of F-oligos (PO and PS) were incubated for 6 hrs. with HL60 cells and the mean intracellular fluorescence determined by flow cytometry. The F signal was normalized by the addition of the ionophore monensin. An increase in signal intensity following addition of monensin indicated that the oligo was resident in an acidic intracellular environment. F-PS, but not F-PO oligos were found to reside in an acidic environment. An exception was a PO homopolymer of 15 cytidine bases (FOdC15) which was acidified. Using two different methods, the average resident intracellular pH of F-PS oligos and F-OdC15 was shown to be approximately 1 pH unit lower than that of F-PO oligos. Acidification of F-PS oligos could be blocked by the antibiotic bafilomycin, indicating that acidification was occurring in endosomes or vacuoles. F-PO and F-PS oligos were effluxed from HL60 cells from two intracellular compartments. However, approximately 60% of internalized F-PO oligo resided in a 'shallow' compartment that was turned over rapidly (t1/2 = 5-10 min.) whereas only 20% of F-PS oligo resided in this compartment. Conversely, approximately 80% of the internalized F-PS oligo but only 40% of F-PO oligo resided in a 'deep' compartment that turned over with t1/2 = 2-5 hrs. This report is the first quantitative demonstration that PO and PS oligos, and PO oligos of different sequences are trafficked differently by HL60 cells. Images PMID:7937155

  20. Danger signals, inflammasomes, and the intricate intracellular lives of chlamydiae.

    PubMed

    Pettengill, Matthew A; Abdul-Sater, Ali; Coutinho-Silva, Robson; Ojcius, David M

    2016-10-01

    Chlamydiae are obligate intracellular bacterial pathogens, and as such are sensitive to alterations in the cellular physiology of their hosts. Chlamydial infections often cause pathologic consequences due to prolonged localized inflammation. Considerable advances have been made in the last few years regarding our understanding of how two key inflammation-associated signaling pathways influence the biology of Chlamydia infections: inflammation regulating purinergic signaling pathways significantly impact intracellular chlamydial development, and inflammasome activation modulates both chlamydial growth and infection mediated pro-inflammatory cytokine production. We review here elements of both pathways, presenting the latest developments contributing to our understanding of how chlamydial infections are influenced by inflammasomes and purinergic signaling.

  1. Stochastic Turing patterns: analysis of compartment-based approaches.

    PubMed

    Cao, Yang; Erban, Radek

    2014-12-01

    Turing patterns can be observed in reaction-diffusion systems where chemical species have different diffusion constants. In recent years, several studies investigated the effects of noise on Turing patterns and showed that the parameter regimes, for which stochastic Turing patterns are observed, can be larger than the parameter regimes predicted by deterministic models, which are written in terms of partial differential equations (PDEs) for species concentrations. A common stochastic reaction-diffusion approach is written in terms of compartment-based (lattice-based) models, where the domain of interest is divided into artificial compartments and the number of molecules in each compartment is simulated. In this paper, the dependence of stochastic Turing patterns on the compartment size is investigated. It has previously been shown (for relatively simpler systems) that a modeler should not choose compartment sizes which are too small or too large, and that the optimal compartment size depends on the diffusion constant. Taking these results into account, we propose and study a compartment-based model of Turing patterns where each chemical species is described using a different set of compartments. It is shown that the parameter regions where spatial patterns form are different from the regions obtained by classical deterministic PDE-based models, but they are also different from the results obtained for the stochastic reaction-diffusion models which use a single set of compartments for all chemical species. In particular, it is argued that some previously reported results on the effect of noise on Turing patterns in biological systems need to be reinterpreted.

  2. Treatment of Atypical Compartment Syndrome Due to Proteus Infection.

    PubMed

    Stull, Justin; Bhat, Suneel; Miller, Andrew J; Hoffman, Ryan; Wang, Mark L

    2017-01-01

    Compartment syndrome is an orthopedic emergency with a multitude of etiologies. Although it is most commonly associated with trauma to the extremity, hematoma and infection are 2 rare etiologies of insidious compartment syndrome. Proteus mirabilis is an opportunistic gram-negative species that can infect the respiratory tract, urinary tract, and open wounds. The authors present the case of a 69-year-old woman who developed tissue necrosis and compartment syndrome secondary to an untreated hematoma infected by P mirabilis. This case involves an atypical presentation caused by an untreated infected hematoma, emphasizing the need for a high index of suspicion. Current literature supports immediate surgical intervention in the clinical scenario of fulminant compartment syndrome, regardless of compartment pressure findings. The probability of compartment syndrome in the patient presenting with pain, paresthesias, paresis, and pain with passive stretch, all of which were positive findings in this patient, has been reported to be 98%. Thus, Doppler evaluation and intercompartmental pressures were considered but forgone to expedite operative treatment. Emergent 4-compartment fasciotomies, with excision and debridement of nonviable tissue, are potentially limb-saving procedures, intended to limit loss of function and obviate the need for lower extremity amputation. The decision was made to perform a dual-incision fasciotomy to avoid contamination of the uninvolved compartments with a standard single-incision approach. To date, this represents the first report in the English literature of the insidious onset of tissue necrosis secondary to a Proteus-infected hematoma, highlighting a unique etiology of atypical compartment syndrome. [Orthopedics. 2017; 40(1):e176-e178.]. Copyright 2016, SLACK Incorporated.

  3. Silent compartment syndrome in children: a report of five cases.

    PubMed

    Lee, Christopher; Lightdale-Miric, Nina; Chang, Emory; Kay, Robert

    2014-09-01

    Compartment syndrome does not always present classically in the pediatric population, making clinical diagnosis uniquely challenging. The purpose of this study was to identify signs and symptoms of compartment syndrome that may help risk-stratify pediatric patients upon presentation, as well as to report outcomes of 'silent' compartment syndrome in children. A retrospective review of cases of 'silent' compartment syndrome at a level I pediatric trauma center between 2000 and 2010 was conducted. Patient demographics and clinical data were reviewed, including complications and patient outcomes. Radiographs taken at presentation, on intraoperative fluoroscopy, and at postoperative follow-up were reviewed for fracture type, and severity and outcome analyses. Five patients were found to have compartment syndrome without the presence of significant pain at rest or on passive range of motion. The study included three male and two female patients with a median age of 7 years. Three upper-extremity and two lower-extremity fractures were involved. The mean time from presentation to surgery was 14 h. At presentation, three of five patients had muscle paralysis, whereas at diagnosis of compartment syndrome, four of five had paralysis. Of the classic five P's, a maximum of two were found at diagnosis. The mean clinical follow-up period was 11 months (2-26 months). Long-term complications from compartment syndrome were found in one of five patients, who at the most recent follow-up, continued to be debilitated. This study reviews a series of cases of 'silent' compartment syndrome and confirms its atypical presentation. It is recommended that caution be used when assessing fractures with high risk for compartment syndrome in children, especially those complicated by nerve injury, as they do not always present in the classic manner, with missed diagnosis leading to significant functional deficits. IV.

  4. Organic Pollutant Penetration through Fruit Polyester Skin: A Modified Three-compartment Diffusion Model

    PubMed Central

    Li, Yungui; Li, Qingqing; Chen, Baoliang

    2016-01-01

    The surface of plants is covered by a continuous but heterogeneous cuticular membrane (CM). Serving as the first protective barrier, the uptake and transport behavior of organic pollutants at this interface continue to engage the research efforts of environmental chemist. To date, the contributions of cuticular components as a defense against the organic pollutants penetration remain unresolved. In this study, the unsteady-state penetration characteristics of phenanthrene (PHE) through isolated fruit CM was investigated. PHE penetration was differentiated by three cuticular compartments: epicuticular waxes (EW), cuticle proper (CP) and cuticular layer (CL). The driving force for PHE penetration was ascribed to the sharp concentration gradient built up endogenously by cuticular compartments with different lipophilic affinities. A modified penetration model was established and verified in terms of its general suitability for the hydrophobic chemicals and CMs of various plant species (apple, tomato and potato). The new three-compartment model demonstrates much higher accuracy in characterizing the uptake and transport behavior of semivolatile chemicals with fewer limitations in terms of environmental conditions and complexity (e.g., coexisting contaminants and temperature). This model could contribute to a more comprehensive understanding on the role of polymeric lipids in the organic pollutant sorption and transport into plants. PMID:27009902

  5. Organic Pollutant Penetration through Fruit Polyester Skin: A Modified Three-compartment Diffusion Model

    NASA Astrophysics Data System (ADS)

    Li, Yungui; Li, Qingqing; Chen, Baoliang

    2016-03-01

    The surface of plants is covered by a continuous but heterogeneous cuticular membrane (CM). Serving as the first protective barrier, the uptake and transport behavior of organic pollutants at this interface continue to engage the research efforts of environmental chemist. To date, the contributions of cuticular components as a defense against the organic pollutants penetration remain unresolved. In this study, the unsteady-state penetration characteristics of phenanthrene (PHE) through isolated fruit CM was investigated. PHE penetration was differentiated by three cuticular compartments: epicuticular waxes (EW), cuticle proper (CP) and cuticular layer (CL). The driving force for PHE penetration was ascribed to the sharp concentration gradient built up endogenously by cuticular compartments with different lipophilic affinities. A modified penetration model was established and verified in terms of its general suitability for the hydrophobic chemicals and CMs of various plant species (apple, tomato and potato). The new three-compartment model demonstrates much higher accuracy in characterizing the uptake and transport behavior of semivolatile chemicals with fewer limitations in terms of environmental conditions and complexity (e.g., coexisting contaminants and temperature). This model could contribute to a more comprehensive understanding on the role of polymeric lipids in the organic pollutant sorption and transport into plants.

  6. Inhibition of hepatocyte apoB secretion by naringenin: enhanced rapid intracellular degradation independent of reduced microsomal cholesteryl esters.

    PubMed

    Borradaile, Nica M; de Dreu, Linda E; Barrett, P Hugh R; Huff, Murray W

    2002-09-01

    The grapefruit flavonoid, naringenin, is hypocholesterolemic in vivo, and inhibits basal apolipoprotein B (apoB) secretion and the expression and activities of both ACAT and microsomal triglyceride transfer protein (MTP) in human hepatoma cells (HepG2). In this report, we examined the effects of naringenin on apoB kinetics in oleate-stimulated HepG2 cells and determined the contribution of microsomal lumen cholesteryl ester (CE) availability to apoB secretion. Pulse-chase studies of apoB secretion and intracellular degradation were analyzed by multicompartmental modeling. The model for apoB metabolism in HepG2 cells includes an intracellular compartment from which apoB can be either secreted or degraded by both rapid and slow pathways. In the presence of 0.1 mM oleic acid, naringenin (200 micro M) reduced the secretion of newly synthesized apoB by 52%, due to a 56% reduction in the rate constant for secretion. Intracellular degradation was significantly increased due to a selective increase in rapid degradation, while slow degradation was unaffected. Incubation with either N-acetyl-leucinyl-leucinyl-norleucinal (ALLN) or lactacystin showed that degradation via the rapid pathway was largely proteasomal. Although these changes in apoB metabolism were accompanied by significant reductions in CE synthesis and mass, subcellular fractionation experiments comparing naringenin to specific ACAT and HMG-CoA reductase inhibitors revealed that reduced accumulation of newly synthesized CE in the microsomal lumen is not consistently associated with reduced apoB secretion. However, naringenin, unlike the ACAT and HMG-CoA reductase inhibitors, significantly reduced lumenal TG accumulation. We conclude that naringenin inhibits apoB secretion in oleate-stimulated HepG2 cells and selectively increases intracellular degradation via a largely proteasomal, rapid kinetic pathway. Although naringenin inhibits ACAT, CE availability in the endoplasmic reticulum (ER) lumen does not appear to

  7. The Interaction between the Fiber Knob Domain and the Cellular Attachment Receptor Determines the Intracellular Trafficking Route of Adenoviruses

    PubMed Central

    Shayakhmetov, Dmitry M.; Li, Zong-Yi; Ternovoi, Vladimir; Gaggar, Anuj; Gharwan, Helen; Lieber, André

    2003-01-01

    Most of the presently used adenovirus (Ad) vectors are based on serotype 5. However, the application of these vectors is limited by the native tropism of Ad5. To address this problem, a series of fiber chimeric vectors were produced to take advantage of the different cellular receptors used by Ad of different subgroups. In this study we utilize an Ad5-based chimeric vector containing sequences encoding the Ad35 fiber knob domain instead of the Ad5 knob (Ad5/35L) to analyze factors responsible for selection of intracellular trafficking routes by Ads. By competition analysis with recombinant Ad5 and Ad35 knobs we showed that the Ad5/35L vector infected cells through a receptor different from the Ad5 receptor. Intracellular trafficking of Ad5 and Ad5/35L viruses was analyzed in HeLa cells by tracking fluorophore-conjugated Ad particles, by immunostaining for capsid hexon protein, by electron microscopy, and by Southern blotting for viral DNA. These studies showed that the interaction with the Ad35 receptor(s) predestines Ad5/35L vector to intracellular trafficking pathways different from those of Ad5. Ad5 efficiently escaped from the endosomes early after infection. In contrast, Ad5/35L remained longer in late endosomal/lysosomal compartments and used them to achieve localization to the nucleus. However, a significant portion of Ad5/35L particles appeared to be recycled back to the cell surface. This phenomenon resulted in significantly less efficient Ad5/35L-mediated gene transfer compared to that of Ad5. We also demonstrated that the selection of intracellular trafficking routes was determined by the fiber knob domain and did not depend on the length of the fiber shaft. This study contributes to a better understanding of the mechanisms that govern the infection of retargeted, capsid-modified vectors which have potential application for hematopoietic stem cell and tumor gene therapy. PMID:12610146

  8. Quantification and characterization of mucosa-associated and intracellular Escherichia coli in inflamatory bowel disease

    USDA-ARS?s Scientific Manuscript database

    Background and aims: Mucosa-associated E. coli are abundant in Crohn’s disease (CD) but whether these bacteria gain intracellular access within the mucosa is less certain. If E. coli does gain intracellular access in CD, the contribution of bacterial pathogenicity as opposed to a defect in host inna...

  9. Menin localization in cell membrane compartment

    PubMed Central

    He, Xin; Wang, Lei; Yan, Jizhou; Yuan, Chaoxing; Witze, Eric S.; Hua, Xianxin

    2016-01-01

    ABSTRACT Menin is encoded by the MEN1 gene, which is mutated in an inherited human syndrome, multiple endocrine neoplasia type 1(MEN1). Menin is primarily nuclear protein, acting as a tumor suppressor in endocrine organs, but as an oncogenic factor in the mixed lineage leukemia, in a tissue-specific manner. Recently, the crystal structures of menin with different binding partners reveal menin as a key scaffold protein that functionally interacts with various partners to regulate gene transcription in the nucleus. However, outside the nucleus, menin also regulates multiple signaling pathways that traverse the cell surface membrane. The precise nature regarding to how menin associates with the membrane fraction is poorly understood. Here we show that a small fraction of menin associates with the cell membrane fraction likely via serine palmitoylation. Moreover, the majority of the membrane-associated menin may reside inside membrane vesicles, as menin is protected from trypsin-mediated proteolysis, but disruption of the membrane fraction using detergent abolishes the detection. Consistently, cellular staining for menin also reveals the distribution of menin in the cell membrane and the punctate-like cell organelles. Our findings suggest that part of intracellular menin associates with the cell membrane peripherally as well as resides within the membrane vesicles. PMID:26560942

  10. New insights on human skeletal muscle tissue compartments revealed by in vivo t2 NMR relaxometry.

    PubMed

    Araujo, Ericky C A; Fromes, Yves; Carlier, Pierre G

    2014-05-20

    The spin-spin (T2) relaxation of (1)H-NMR signals in human skeletal muscle has been previously hypothesized to reveal information about myowater compartmentation. Although experimental support has been provided, no consensus has yet emerged concerning the attribution of specific anatomical compartments to the observed T2 components. Potential application of a noninvasive tool that might offer such information urges the quest for a definitive answer to this question. The purpose of this work was to obtain new information that might help elucidate the mechanism of T2 distribution in muscle. To do so, in vivo T2 relaxation data was acquired from the soleus of eight healthy volunteers using a localized Carr-Purcell-Meiboom-Gill technique. Each acquisition contained 1000 echoes with an interecho spacing of 1 ms. Data were acquired from each subject under different vascular filling preparations expected to change exclusively the extracellular water fraction. Two exponential components were systematically observed: an intermediate component (T2 ~ 32 ms) and a long component (100 < T2 < 210 ms). The relative fraction and T2 value characterizing the long component systematically increased after progressive augmentation of extracellular water volume. Characteristic relaxation behavior for each vascular filling condition was analyzed with a two-site exchange model and a three-site two-exchange model. We show that a two-site exchange model can only predict the observations for small exchange rates, much more representative of transendothelial than transcytolemmal exchange regimes. The three-site two-exchange model representing the intracellular, interstitial, and vascular spaces was capable of precisely predicting the observations for realistic transcytolemmal and transendothelial exchange rates. The estimated intrinsic relative fractions of each of these compartments corroborate with estimations from previous works and strongly suggest that the T2 relaxation from water within

  11. Compartment syndrome obscured by post-operative epidural analgesia

    PubMed Central

    Azam, Md. Quamar; Ali, Mir Sadat; Al Ruwaili, Majed; Al Sayed, Hassan Noori

    2012-01-01

    Compartment syndrome is an orthopedic emergency that require early recognition and urgent intervention to avoid catastrophic complications. High index of suspicion is required for early diagnosis based on a constellation of signs and symptoms that include pain out of proportion and worsened by passive stretching, altered sensorium and palpable tenseness. Any event thus, that masks pain, may lead to delay the diagnosis of compartment syndrome. We report here a case of polytrauma where post-operative analgesia was administered using epidural catheter, which obscured pain and lead to delay in recognition of compartment syndrome. Authors wish to share a lesson, learned at the expense of tragedy. PMID:24765418

  12. Compartment Syndrome of the Calf Due to Nicolau Syndrome

    PubMed Central

    Enshaei, Ali; Afshar, Ahmadreza

    2016-01-01

    We report a case of Nicolau syndrome in a 15 months old girl following an intramuscular injection of penicillin 6.3.3 in her left buttock. This case is unique because she developed compartment syndrome in her left calf far from her injection site. Her toe’s tips gangrened in the course of her ailment. We hypothesized that the compartment syndrome might be produced by a probable intra-arterial injection that had produced embolic obstruction of the small and medium size arteries in her leg or a probable perineural or periarteial injection had produced secondary sympathetic stimulation, extensive vasospasm, compromised microcirculation and the development of compartment syndrome. PMID:26894227

  13. Compartment Syndrome of the Calf Due to Nicolau Syndrome.

    PubMed

    Enshaei, Ali; Afshar, Ahmadreza

    2016-01-01

    We report a case of Nicolau syndrome in a 15 months old girl following an intramuscular injection of penicillin 6.3.3 in her left buttock. This case is unique because she developed compartment syndrome in her left calf far from her injection site. Her toe's tips gangrened in the course of her ailment. We hypothesized that the compartment syndrome might be produced by a probable intra-arterial injection that had produced embolic obstruction of the small and medium size arteries in her leg or a probable perineural or periarteial injection had produced secondary sympathetic stimulation, extensive vasospasm, compromised microcirculation and the development of compartment syndrome.

  14. Current thinking about acute compartment syndrome of the lower extremity

    PubMed Central

    Shadgan, Babak; Menon, Matthew; Sanders, David; Berry, Gregg; Martin, Claude; Duffy, Paul; Stephen, David; O’Brien, Peter J.

    2010-01-01

    Acute compartment syndrome of the lower extremity is a clinical condition that, although uncommon, is seen fairly regularly in modern orthopedic practice. The pathophysiology of the disorder has been extensively described and is well known to physicians who care for patients with musculoskeletal injuries. The diagnosis, however, is often difficult to make. In this article, we review the clinical risk factors of acute compartment syndrome of the lower extremity, identify the current concepts of diagnosis and discuss appropriate treatment plans. We also describe the Canadian medicolegal environment in regard to compartment syndrome of the lower extremity. PMID:20858378

  15. Pivotal Role for the Visceral Fat Compartment in the Release of Persistent Organic Pollutants During Weight Loss.

    PubMed

    Dirinck, E; Dirtu, A C; Jorens, P G; Malarvannan, G; Covaci, A; Van Gaal, L F

    2015-12-01

    Polychlorinated biphenyls (PCBs), are implicated as potential endocrine disruptors and obesogens. These lipophilic substances are preferentially stored in the fat compartment and released into the circulation during weight loss. The aim of this study was to examine the contribution of abdominal adiposity, and visceral adiposity in particular, to the increase of serum PCB levels during weight loss. Fourty-five obese women were prospectively recruited. Twenty individuals received dietary counseling and 25 underwent bariatric surgery. Anthropometric data were collected and intra-abdominal adiposity was assessed by measurement computed tomography scanning of the abdominal fat compartment, delineating the visceral and subcutaneous compartment. Serum levels of 27 PCBs were determined and the sum of all PCBs (ΣPCBs) calculated. Follow-up measurements of anthropometric data, computed tomography scanning, and PCB levels were performed after 6 months in all patients. In patients who lost weight, serum ΣPCB levels displayed an increase after 6 months of approximately 50%. Both correlation and regression analysis, focusing on the relative contribution of the visceral vs the subcutaneous fat compartment, suggested that the increase in ΣPCB serum levels after 6 months of weight loss was more pronounced in patients losing relatively more visceral adipose tissue. This trend could be established in the diet-treated, but not the surgery-treated subgroup. Our study suggests that the contribution of PCBs released from the visceral fat compartment might be more pronounced compared with the subcutaneous fat compartment during weight loss. These findings are present in the entire study group whereas subanalysis of the diet vs surgery groups suggested the same effect in the diet group but failed to reach statistical significance in the surgery group. This suggests a possible weight-loss method-specific effect.

  16. Intracellular Signalling in Retinal Ischemia

    DTIC Science & Technology

    1990-07-01

    36) However, vascularization of the RPE is not known to occur in human diseases of photoreceptor degeneration, such as retinitis pigmentosa ...A.C. (1986) Retinitis pigmentosa and retinal neovascularization. Ophthalmology 91, 1599- 1603. Figure la: Control rat retina, 8 weeks of age, central...TITLE (Include Security Classification) Intracellular Signalling in Retinal Ischemia 12. PERSONAL AUTHOR(S) Burns, Margaret Sue; Bellhorn, Roy William

  17. Direct Measurement of Intracellular Pressure

    PubMed Central

    Petrie, Ryan J.; Koo, Hyun

    2014-01-01

    A method to directly measure the intracellular pressure of adherent, migrating cells is described in the Basic Protocol. This approach is based on the servo-null method where a microelectrode is introduced into the cell to directly measure the physical pressure of the cytoplasm. We also describe the initial calibration of the microelectrode as well as the application of the method to cells migrating inside three-dimensional (3D) extracellular matrix (ECM). PMID:24894836

  18. Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis

    PubMed Central

    Natale, Gianfranco; Lenzi, Paola; Lazzeri, Gloria; Falleni, Alessandra; Biagioni, Francesca; Ryskalin, Larisa; Fornai, Francesco

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article each motor neuron compartment (cell body, central, and peripheral axons) of G93A SOD-1 mice was studied concerning mitochondrial alterations as well as other intracellular structures. We could confirm the occurrence of ALS-related mitochondrial damage encompassing total swelling, matrix dilution and cristae derangement along with non-pathological variations of mitochondrial size and number. However, these alterations occur to a different extent depending on motor neuron compartment. Lithium, a well-known autophagy inducer, prevents most pathological changes. However, the efficacy of lithium varies depending on which motor neuron compartment is considered. Remarkably, some effects of lithium are also evident in wild type mice. Lithium is effective also in vitro, both in cell lines and primary cell cultures from the ventral spinal cord. In these latter cells autophagy inhibition within motor neurons in vitro reproduced ALS pathology which was reversed by lithium. Muscle and glial cells were analyzed as well. Cell pathology was mostly severe within peripheral axons and muscles of ALS mice. Remarkably, when analyzing motor axons of ALS mice a subtotal clogging of axoplasm was described for the first time, which was modified under the effects of lithium. The effects induced by lithium depend on several mechanisms such as direct mitochondrial protection, induction of mitophagy and mitochondriogenesis. In this study, mitochondriogenesis induced by lithium was confirmed in situ by a

  19. Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis.

    PubMed

    Natale, Gianfranco; Lenzi, Paola; Lazzeri, Gloria; Falleni, Alessandra; Biagioni, Francesca; Ryskalin, Larisa; Fornai, Francesco

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article each motor neuron compartment (cell body, central, and peripheral axons) of G93A SOD-1 mice was studied concerning mitochondrial alterations as well as other intracellular structures. We could confirm the occurrence of ALS-related mitochondrial damage encompassing total swelling, matrix dilution and cristae derangement along with non-pathological variations of mitochondrial size and number. However, these alterations occur to a different extent depending on motor neuron compartment. Lithium, a well-known autophagy inducer, prevents most pathological changes. However, the efficacy of lithium varies depending on which motor neuron compartment is considered. Remarkably, some effects of lithium are also evident in wild type mice. Lithium is effective also in vitro, both in cell lines and primary cell cultures from the ventral spinal cord. In these latter cells autophagy inhibition within motor neurons in vitro reproduced ALS pathology which was reversed by lithium. Muscle and glial cells were analyzed as well. Cell pathology was mostly severe within peripheral axons and muscles of ALS mice. Remarkably, when analyzing motor axons of ALS mice a subtotal clogging of axoplasm was described for the first time, which was modified under the effects of lithium. The effects induced by lithium depend on several mechanisms such as direct mitochondrial protection, induction of mitophagy and mitochondriogenesis. In this study, mitochondriogenesis induced by lithium was confirmed in situ by a

  20. Dynamics of HIV-Containing Compartments in Macrophages Reveal Sequestration of Virions and Transient Surface Connections

    PubMed Central

    Gaudin, Raphaël; Berre, Stefano; Cunha de Alencar, Bruna; Decalf, Jérémie; Schindler, Michael; Gobert, François-Xavier; Jouve, Mabel; Benaroch, Philippe

    2013-01-01

    During HIV pathogenesis, infected macrophages behave as “viral reservoirs” that accumulate and retain virions within dedicated internal Virus-Containing Compartments (VCCs). The nature of VCCs remains ill characterized and controversial. Using wild-type HIV-1 and a replication-competent HIV-1 carrying GFP internal to the Gag precursor, we analyzed the biogenesis and evolution of VCCs in primary human macrophages. VCCs appear roughly 14 hours after viral protein synthesis is detected, initially contain few motile viral particles, and then mature to fill up with virions that become packed and immobile. The amount of intracellular Gag, the proportion of dense VCCs, and the density of viral particles in their lumen increased with time post-infection. In contrast, the secretion of virions, their infectivity and their transmission to T cells decreased overtime, suggesting that HIV-infected macrophages tend to pack and retain newly formed virions into dense compartments. A minor proportion of VCCs remains connected to the plasma membrane overtime. Surprisingly, live cell imaging combined with correlative light and electron microscopy revealed that such connections can be transient, highlighting their dynamic nature. Together, our results shed light on the late phases of the HIV-1 cycle and reveal some of its macrophage specific features. PMID:23922713

  1. Revisiting intracellular calcium signaling semantics.

    PubMed

    Haiech, Jacques; Audran, Emilie; Fève, Marie; Ranjeva, Raoul; Kilhoffer, Marie-Claude

    2011-12-01

    Cells use intracellular free calcium concentration changes for signaling. Signal encoding occurs through both spatial and temporal modulation of the free calcium concentration. The encoded message is detected by an ensemble of intracellular sensors forming the family of calcium-binding proteins (CaBPs) which must faithfully translate the message using a new syntax that is recognized by the cell. The cell is home to a significant although limited number of genes coding for proteins involved in the signal encoding and decoding processes. In a cell, only a subset of this ensemble of genes is expressed, leading to a genetic regulation of the calcium signal pathways. Calmodulin (CaM), the most ubiquitous expressed intracellular calcium-binding protein, plays a major role in calcium signal translation. Similar to a hub, it is central to a large and finely tuned network, receiving information, integrating it and dispatching the cognate response. In this review, we examine the different steps starting with an external stimulus up to a cellular response, with special emphasis on CaM and the mechanism by which it decodes calcium signals and translates it into exquisitely coordinated cellular events. By this means, we will revisit the calcium signaling semantics, hoping that we will ease communication between scientists dealing with calcium signals in different biological systems and different domains.

  2. Stochastic models of intracellular transport

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.; Newby, Jay M.

    2013-01-01

    The interior of a living cell is a crowded, heterogenuous, fluctuating environment. Hence, a major challenge in modeling intracellular transport is to analyze stochastic processes within complex environments. Broadly speaking, there are two basic mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually in the form of adenosine triphosphate hydrolysis, and can be direction specific, allowing biomolecules to be transported long distances; this is particularly important in neurons due to their complex geometry. In this review a wide range of analytical methods and models of intracellular transport is presented. In the case of diffusive transport, narrow escape problems, diffusion to a small target, confined and single-file diffusion, homogenization theory, and fractional diffusion are considered. In the case of active transport, Brownian ratchets, random walk models, exclusion processes, random intermittent search processes, quasi-steady-state reduction methods, and mean-field approximations are considered. Applications include receptor trafficking, axonal transport, membrane diffusion, nuclear transport, protein-DNA interactions, virus trafficking, and the self-organization of subcellular structures.

  3. Temporal and compartment-specific signals coordinate mitotic exit with spindle position.

    PubMed

    Caydasi, Ayse Koca; Khmelinskii, Anton; Duenas-Sanchez, Rafael; Kurtulmus, Bahtiyar; Knop, Michael; Pereira, Gislene

    2017-01-24

    The spatiotemporal control of mitotic exit is crucial for faithful chromosome segregation during mitosis. In budding yeast, the mitotic exit network (MEN) drives cells out of mitosis, whereas the spindle position checkpoint (SPOC) blocks MEN activity when the anaphase spindle is mispositioned. How the SPOC operates at a molecular level remains unclear. Here, we report novel insights into how mitotic signalling pathways orchestrate chromosome segregation in time and space. We establish that the key function of the central SPOC kinase, Kin4, is to counterbalance MEN activation by the cdc fourteen early anaphase release (FEAR) network in the mother cell compartment. Remarkably, Kin4 becomes dispensable for SPOC function in the absence of FEAR. Cells lacking both FEAR and Kin4 show that FEAR contributes to mitotic exit through regulation of the SPOC component Bfa1 and the MEN kinase Cdc15. Furthermore, we uncover controls that specifically promote mitotic exit in the daughter cell compartment.

  4. Temporal and compartment-specific signals coordinate mitotic exit with spindle position

    PubMed Central

    Caydasi, Ayse Koca; Khmelinskii, Anton; Duenas-Sanchez, Rafael; Kurtulmus, Bahtiyar; Knop, Michael; Pereira, Gislene

    2017-01-01

    The spatiotemporal control of mitotic exit is crucial for faithful chromosome segregation during mitosis. In budding yeast, the mitotic exit network (MEN) drives cells out of mitosis, whereas the spindle position checkpoint (SPOC) blocks MEN activity when the anaphase spindle is mispositioned. How the SPOC operates at a molecular level remains unclear. Here, we report novel insights into how mitotic signalling pathways orchestrate chromosome segregation in time and space. We establish that the key function of the central SPOC kinase, Kin4, is to counterbalance MEN activation by the cdc fourteen early anaphase release (FEAR) network in the mother cell compartment. Remarkably, Kin4 becomes dispensable for SPOC function in the absence of FEAR. Cells lacking both FEAR and Kin4 show that FEAR contributes to mitotic exit through regulation of the SPOC component Bfa1 and the MEN kinase Cdc15. Furthermore, we uncover controls that specifically promote mitotic exit in the daughter cell compartment. PMID:28117323

  5. Toward intracellular targeted delivery of cancer therapeutics: progress and clinical outlook for brain tumor therapy.

    PubMed

    Pandya, Hetal; Debinski, Waldemar

    2012-08-01

    A number of anti-cancer drugs have their targets localized to particular intracellular compartments. These drugs reach the targets mainly through diffusion, dependent on biophysical and biochemical forces that allow cell penetration. This means that both cancer cells and normal cells will be subjected to such diffusion; hence many of these drugs, like chemotherapeutics, are potentially toxic and the concentration achieved at the site of their action is often suboptimal. The same relates to radiation that indiscriminately affects normal and diseased cells. However, nature-designed systems enable compounds present in the extracellular environment to end up inside the cell and even travel to more specific intracellular compartments. For example, viruses and bacterial toxins can more or less specifically recognize eukaryotic cells, enter these cells, and direct some protein portions to designated intracellular areas. These phenomena have led to creative thinking, such as employing viruses or bacterial toxins for cargo delivery to cells and, more specifically, to cancer cells. Proteins can be genetically engineered in order to not only mimic what viruses and bacterial toxins can do, but also to add new functions, extending or changing the intracellular routes. It is possible to make conjugates or, more preferably, single-chain proteins that recognize cancer cells and deliver cargo inside the cells, even to the desired subcellular compartment. These findings offer new opportunities to deliver drugs/labels only to cancer cells and only to their site of action within the cells. The development of such dual-specificity vectors for targeting cancer cells is an attractive and potentially safer and more efficacious way of delivering drugs. We provide examples of this approach for delivering brain cancer therapeutics, using a specific biomarker on glioblastoma tumor cells.

  6. Glycosaminoglycans: Sorting determinants in intracellular protein traffic.

    PubMed

    Mihov, Deyan; Spiess, Martin

    2015-11-01

    Intracellular transport of proteins to their appropriate destinations is crucial for the maintenance of cellular integrity and function. Sorting information is contained either directly in the amino acid sequence or in a protein's post-translational modifications. Glycosaminoglycans (GAGs) are characteristic modifications of proteoglycans. GAGs are long unbranched polysaccharide chains with unique structural and functional properties also contributing to protein sorting in various ways. By deletion or insertion of GAG attachment sites it has been shown that GAGs affect polarized sorting in epithelial cells, targeting to and storage in secretory granules, and endocytosis. Most recently, the role of GAGs as signals for rapid trans-Golgi-to-cell surface transport, dominant over the cytosolic sorting motifs in the core protein, was demonstrated. Here, we provide an overview on existing data on the roles of GAGs on protein and proteoglycan trafficking.

  7. An earthquake instability model based on faults containing high fluid-pressure compartments

    USGS Publications Warehouse

    Lockner, D.A.; Byerlee, J.D.

    1995-01-01

    It has been proposed that large strike-slip faults such as the San Andreas contain water in seal-bounded compartments. Arguments based on heat flow and stress orientation suggest that in most of the compartments, the water pressure is so high that the average shear strength of the fault is less than 20 MPa. We propose a variation of this basic model in which most of the shear stress on the fault is supported by a small number of compartments where the pore pressure is relatively low. As a result, the fault gouge in these compartments is compacted and lithified and has a high undisturbed strength. When one of these locked regions fails, the system made up of the neighboring high and low pressure compartments can become unstable. Material in the high fluid pressure compartments is initially underconsolidated since the low effective confining pressure has retarded compaction. As these compartments are deformed, fluid pressure remains nearly unchanged so that they offer little resistance to shear. The low pore pressure compartments, however, are overconsolidated and dilate as they are sheared. Decompression of the pore fluid in these compartments lowers fluid pressure, increasing effective normal stress and shear strength. While this effect tends to stabilize the fault, it can be shown that this dilatancy hardening can be more than offset by displacement weakening of the fault (i.e., the drop from peak to residual strength). If the surrounding rock mass is sufficiently compliant to produce an instability, slip will propagate along the fault until the shear fracture runs into a low-stress region. Frictional heating and the accompanying increase in fluid pressure that are suggested to occur during shearing of the fault zone will act as additional destabilizers. However, significant heating occurs only after a finite amount of slip and therefore is more likely to contribute to the energetics of rupture propagation than to the initiation of the instability. We present

  8. Botulinum neurotoxin A and an engineered derivate targeted secretion inhibitor (TSI) A enter cells via different vesicular compartments.

    PubMed

    Fonfria, Elena; Donald, Sarah; Cadd, Verity A

    2016-01-01

    Botulinum neurotoxins (BoNTs) are highly potent multi-domain proteins, responsible for botulism in animals and humans. The modular structural organization of BoNTs has led to the development of novel engineered bio-therapeutic proteins called targeted secretion inhibitors (TSIs). We report here that botulinum neurotoxin A (BoNT/A) and a TSI/A in which the neuronal binding domain of BoNT/A has been substituted by an epidermal growth factor (EGF) ligand, named EGFR-targeted TSI/A, exploit different routes to gain entry in the same in vitro neuroblastoma cell system, SiMa cells. We found that the EGF ligand conferred the affinity to the EGFR-targeted TSI/A at the EGF receptor when compared to an untargeted TSI/A and also the ability to internalize into the cells and cleave its cytosolic target protein SNAP-25. Using high content analysis we found that both BoNT/A and the EGFR-targeted TSI/A enter the cell in a concentration-dependent manner and in compartments which are able to translocate the proteins into the cytosol within 4 h. The EGFR-targeted TSI/A internalized into a compartment which gave a punctate staining pattern by immunofluorescence and partially overlapped with structures positive for the early endosomal marker EAA1; whereas BoNT/A did not internalize into a punctate compartment but did so in an acidifying compartment consistent with local synaptic vesicle recycling. These findings show that the BoNT/A translocation domain, common to both BoNT/A and the EGFR-targeted TSI/A, is a versatile tool for cytosolic delivery from distinct intracellular vesicular compartments.

  9. Intracellular Ca2+ storage in acidocalcisomes of Trypanosoma cruzi.

    PubMed Central

    Docampo, R; Scott, D A; Vercesi, A E; Moreno, S N

    1995-01-01

    The use of digitonin to permeabilize the plasma membrane of Trypanosoma cruzi allowed the identification of a non-mitochondrial nigericin- or bafilomycin A1-sensitive Ca(2+)-uptake mechanism. Proton uptake, as detected by ATP-dependent Acridine Orange accumulation, was also demonstrated in these permeabilized cells. Under these conditions Acridine Orange was concentrated in abundant cytoplasmic round vacuoles. This latter process was inhibited (and reversed) by bafilomycin A1, nigericin and NH4Cl in different stages of T. cruzi. Ca2+ released Acridine Orange from permeabilized cells, suggesting that the dye and Ca2+ were being accumulated in the same acidic compartment and that Ca2+ was taken up in exchange for protons. Addition of bafilomycin A1 (5 microM), nigericin (1 microM) or carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP; 1 microM) to fura 2-loaded epimastigotes increased their intracellular Ca2+ concentration ([Ca2+]i). Although this effect was more noticeable in the presence of extracellular Ca2+, it was also observed in its absence. Addition of NH4Cl (10-40 mM) to different stages of T. cruzi, in the nominal absence of extracellular Ca2+ to preclude Ca2+ entry, increased both [Ca2+]i in fura 2-loaded cells, and intracellular pH (pHi) in 2',7'-bis-(2-carboxyethyl)-5-(and -6)-carboxyfluorescein acetoxymethyl ester (BCECF)-loaded cells. Treatment of the cells with the Ca2+ ionophore ionomycin under similar conditions (nominal absence of extracellular Ca2+) resulted in an increase in [Ca2+]i and a significantly higher increase in [Ca2+]i after addition of NH4Cl, nigericin or bafilomycin A1, all agents which increase the pH of acidic compartments and make ionomycin more effective as a Ca(2+)-releasing ionophore. Similar results were obtained when the order of additions was reversed. Taking into account the relative importance of the ionomycin-releasable and the ionomycin plus NH4Cl-releasable Ca2+ pools, it is apparent that most of the Ca2+ stored in

  10. Acute Exertional Rhabdomyolysis and Triceps Compartment Syndrome During a High School Football Camp

    PubMed Central

    Oh, John Y.; Laidler, Matthew; Fiala, Steven C.; Hedberg, Katrina

    2012-01-01

    Background: Acute exertional rhabdomyolysis has been infrequently reported among adolescents. In August 2010, several high school football players from one team developed rhabdomyolysis and triceps compartment syndrome following an upper arm exercise held in a non-air-conditioned wrestling room. Purpose: To confirm the diagnoses, characterize the spectrum of illnesses, and determine the factors contributing to rhabdomyolysis and triceps compartment syndromes. Study Design: Descriptive epidemiology study. Methods: The authors reviewed hospital medical records and interviewed players, coaches, school administrators, and hospital staff, using a standardized questionnaire that assessed symptoms, exposures, and activities. Results: Among 43 players, 22 (51%) experienced rhabdomyolysis (peak creatine kinase range, 2434-42 000 U/L): 22 patients had upper arm myalgia; 12 were hospitalized; 3 experienced triceps compartment syndrome; none experienced renal failure. Illnesses started 1 to 3 days after the triceps exercise. Forty players (93%) completed questionnaires. Among 19 players receiving at least 1 vote from a teammate as 1 of the 3 hardest working players, 13 (68%) experienced rhabdomyolysis versus 7 (33%) of 21 not considered hardest working (relative risk, 2.1; 95% confidence interval, 1.04-4.0). Of 40 players, 10 (25%) reported creatine supplement use, which was not associated with rhabdomyolysis. No player acknowledged use of alcohol, illicit drugs, or performance-enhancing drugs; results of performance-enhancing drug tests on the 4 players tested were negative. Environmental investigation did not identify additional factors contributing to illness. Conclusions: The upper arm exercise, possibly exacerbated by heat, led to rhabdomyolysis and compartment syndrome. Greater awareness of specific exercise hazards and prevention strategies can minimize risk for clinically significant muscle injury. PMID:23016070

  11. Acute exertional rhabdomyolysis and triceps compartment syndrome during a high school football cAMP.

    PubMed

    Oh, John Y; Laidler, Matthew; Fiala, Steven C; Hedberg, Katrina

    2012-01-01

    Acute exertional rhabdomyolysis has been infrequently reported among adolescents. In August 2010, several high school football players from one team developed rhabdomyolysis and triceps compartment syndrome following an upper arm exercise held in a non-air-conditioned wrestling room. To confirm the diagnoses, characterize the spectrum of illnesses, and determine the factors contributing to rhabdomyolysis and triceps compartment syndromes. Descriptive epidemiology study. The authors reviewed hospital medical records and interviewed players, coaches, school administrators, and hospital staff, using a standardized questionnaire that assessed symptoms, exposures, and activities. Among 43 players, 22 (51%) experienced rhabdomyolysis (peak creatine kinase range, 2434-42 000 U/L): 22 patients had upper arm myalgia; 12 were hospitalized; 3 experienced triceps compartment syndrome; none experienced renal failure. Illnesses started 1 to 3 days after the triceps exercise. Forty players (93%) completed questionnaires. Among 19 players receiving at least 1 vote from a teammate as 1 of the 3 hardest working players, 13 (68%) experienced rhabdomyolysis versus 7 (33%) of 21 not considered hardest working (relative risk, 2.1; 95% confidence interval, 1.04-4.0). Of 40 players, 10 (25%) reported creatine supplement use, which was not associated with rhabdomyolysis. No player acknowledged use of alcohol, illicit drugs, or performance-enhancing drugs; results of performance-enhancing drug tests on the 4 players tested were negative. Environmental investigation did not identify additional factors contributing to illness. The upper arm exercise, possibly exacerbated by heat, led to rhabdomyolysis and compartment syndrome. Greater awareness of specific exercise hazards and prevention strategies can minimize risk for clinically significant muscle injury.

  12. 14 CFR 29.853 - Compartment interiors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and acoustical insulation and insulation covering, air ducting, joint and edge covering, cargo... ducting joints, and trim strips (decorative and chafing) that are constructed of materials not covered in... contribute significantly to the propagation of a fire, materials in items not specified in paragraphs...

  13. 14 CFR 29.853 - Compartment interiors.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... and acoustical insulation and insulation covering, air ducting, joint and edge covering, cargo... ducting joints, and trim strips (decorative and chafing) that are constructed of materials not covered in... contribute significantly to the propagation of a fire, materials in items not specified in paragraphs...

  14. 14 CFR 29.853 - Compartment interiors.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... and acoustical insulation and insulation covering, air ducting, joint and edge covering, cargo... ducting joints, and trim strips (decorative and chafing) that are constructed of materials not covered in... contribute significantly to the propagation of a fire, materials in items not specified in paragraphs...

  15. 14 CFR 29.853 - Compartment interiors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and acoustical insulation and insulation covering, air ducting, joint and edge covering, cargo... ducting joints, and trim strips (decorative and chafing) that are constructed of materials not covered in... contribute significantly to the propagation of a fire, materials in items not specified in paragraphs...

  16. Regulation of intracellular pH values in higher plant cells. Carbon-13 and phosphorus-31 nuclear magnetic resonance studies.

    PubMed

    Gout, E; Bligny, R; Douce, R

    1992-07-15

    The regulation of the cytoplasmic and vacuolar pH values (pHc and pHv) in sycamore (Acer pseudoplatanus L.) cells was analyzed using 31P and 13C nuclear magnetic resonance spectroscopy. Suspension-cultured cells were compressed in the NMR tube and perfused with the help of an original arrangement enabling a tight control of the pH (external pH, pHe) of the carefully oxygenated circulating nutrient medium. Intracellular pH values were measured from the chemical shifts of: CH2-linked carboxyl groups of citric acid below pH 5.7; orthophosphate between pH 5.7 and 8.0; 13C-enriched bicarbonate over pH 8.0. pHc and pHv were independent of pHe over the range 4.5-7.5. In contrast intracellular pH values decreased rapidly below pHe 4.5 and increased progressively at pHe over 7.5. There was an acceleration in the rate of O2 consumption accompanied with a decrease in cytoplasmic ATP concentration as pHe decreased. When the rate of O2 consumption was approaching the uncoupled O2 uptake rate, a loss of pHc control was observed. It is concluded that as pHe decreased, the plasma membrane ATPase consumed more and more ATP to reject the invading H+ ions in order to maintain pHc at a constant value. Below pHe 4.5 the efficiency of the H+ pump to react to back leakage of H+ ions became insufficient, leading to an acidification of pHc and to an alkalinization of pHe. On the other hand, over pHe 7.5 a passive influx of OH- ions was observed, and pHc increased proportionally to the increase of pHe. Simultaneously appreciable amounts of organic acids (malate and citrate) were synthesized by cells during the course of the alkalinization of the cytoplasmic compartment. The synthesis of organic acids which partially counteract the alkalinization of the cytoplasmic compartment may result from a marked activation of the cytoplasmic phosphoenolpyruvate carboxylase induced by an increase in cytoplasmic bicarbonate concentration. The fluctuations of pHv followed a similar course to that of p

  17. Compartment pressure monitoring during anterior cruciate ligament reconstruction.

    PubMed

    Amendola, A; Faber, K; Willits, K; Miniaci, A; Labib, S; Fowler, P

    1999-09-01

    A prospective double blind randomized study was carried out using 20 healthy males with anterior cruciate ligament (ACL) insufficiency undergoing bone-patellar tendon-bone ACL reconstruction. The subjects were randomized into either water or saline irrigation and then underwent identical reconstructive procedures using an arthroscopic pump. Continuous preoperative, intraoperative, and postoperative pressures were monitored using the slit catheter technique. Blood pressure and compartment pressure measurements were continuously recorded and noted at all stages of the procedure. Mean preoperative anterior and posterior compartment pressures were similar in both groups. No significant differences were noted between the anterior and posterior compartments of each group. No difference between water and saline irrigation was identified throughout the procedure. In both groups, postoperative pressures were slightly lower in the anterior and posterior compartments compared with preoperative pressures, but not significantly.

  18. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  19. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  20. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  1. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  2. 14 CFR 23.787 - Baggage and cargo compartments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... inertial load factor is 9g and assuming the maximum allowed baggage or cargo weight for the compartment. (b... means to protect the occupants from injury when the baggage or cargo is subjected to the inertial...

  3. 10. Interior view of communications compartment. View toward front of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Interior view of communications compartment. View toward front of aircraft. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  4. 11. Interior view of communications compartment. View toward rear of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Interior view of communications compartment. View toward rear of aircraft. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  5. 19 CFR 123.24 - Sealing of conveyances or compartments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or Mexico § 123.24 Sealing of conveyances or compartments. (a) Sealing required. Merchandise in transit...

  6. The pathophysiology, diagnosis and current management of acute compartment syndrome.

    PubMed

    Donaldson, James; Haddad, Behrooz; Khan, Wasim S

    2014-01-01

    Acute compartment syndrome (ACS) is a surgical emergency warranting prompt evaluation and treatment. It can occur with any elevation in interstitial pressure in a closed osseo-fascial compartment. Resultant ischaemic damage may be irreversible within six hours and can result in long-term morbidity and even death. The diagnosis is largely clinical with the classical description of 'pain out of proportion to the injury'. Compartment pressure monitors can be a helpful adjunct where the diagnosis is in doubt. Initial treatment is with the removal of any constricting dressings or casts, avoiding hypotension and optimizing tissue perfusion by keeping the limb at heart level. If symptoms persist, definitive treatment is necessary with timely surgical decompression of all the involved compartments. This article reviews the pathophysiology, diagnosis and current management of ACS.

  7. FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FEATURE 3, LARGE GUN POSITION, SHOWING MULTIPLE COMPARTMENTS, VIEW FACING SOUTH. - Naval Air Station Barbers Point, Anti-Aircraft Battery Complex-Large Gun Position, East of Coral Sea Road, northwest of Hamilton Road, Ewa, Honolulu County, HI

  8. Condensation on crew compartment aft flight deck window W10

    NASA Image and Video Library

    1982-03-30

    STS003-24-211 (22-30 March 1982) --- Crew compartment aft flight deck viewing window W10 fogged with condensation. The condensation is a result of the spacecraft's position in relation to the sun. Photo credit: NASA

  9. Kononenko uses laptop computer in the SM Transfer Compartment

    NASA Image and Video Library

    2012-03-21

    ISS030-E-161167 (21 March 2012) --- Russian cosmonaut Oleg Kononenko, Expedition 30 flight engineer, uses a computer in the transfer compartment of the International Space Station?s Zvezda Service Module. Russia's Zarya module is visible in the background.

  10. 14 CFR 27.1193 - Cowling and engine compartment covering.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... part of the cowling or engine compartment in the normal ground and flight attitudes. (c) No drain may... covering must be provided to preclude hazardous damage to rotors or critical control components in the...

  11. Kononenko uses laptop computer in the SM Transfer Compartment

    NASA Image and Video Library

    2012-03-21

    ISS030-E-161169 (21 March 2012) --- Russian cosmonaut Oleg Kononenko, Expedition 30 flight engineer, works in the transfer compartment of the International Space Station?s Zvezda Service Module. Russia's Zarya module is visible in the background.

  12. 2. INTERIOR, SOUTHWEST VIEW (STORAGE COMPARTMENTS). Vanadium Corporation of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. INTERIOR, SOUTHWEST VIEW (STORAGE COMPARTMENTS). - Vanadium Corporation of America (VCA) Naturita Mill, Mine Warehouse, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  13. Abdominal compartment syndrome successfully treated with neuromuscular blockade

    PubMed Central

    Chiles, Kris T; Feeney, Colin M

    2011-01-01

    A 48 year old male admitted to the intensive care unit after a cardiac arrest complicated by a stroke intra-operatively during automatic implantable cardioverter defibrillator placement. He post-operatively developed a rigid abdomen, elevated peak and plateau pressures, hypoxia and renal insufficiency. He was diagnosed with abdominal compartment syndrome with an intra-abdominal compartment pressure of 40mmHg. The patient was administered 10 mg of intravenous cisatracuriumbesylate in preparation for bedside surgical abdominal decompression. Cisatracurium eliminated the patients need for surgical intervention by reducing his abdominal compartment pressures to normal and improving his hypoxia and renal function. This case illustrates that neuromuscular blockade should be attempted in patients with abdominal compartment syndrome prior to surgical intervention. PMID:22013257

  14. A Case of Acute Atraumatic Compartment Syndrome of the Thigh.

    PubMed

    Gutfraynd, Alexander; Philpott, Sheila

    2016-09-01

    In the absence of trauma, compartment syndrome of the thigh is rare. Several case reports have described compartment syndrome in the presence of trauma, comorbid medical conditions, and acute muscle overuse. Very few reports have demonstrated an acute onset of atraumatic thigh compartment syndrome. A 24-year-old man presented to the Emergency Department (ED) with a painful and swollen left thigh immediately after a night of dancing at a concert. He was found to have an elevated intracompartmental quadriceps pressure of 45 mm Hg in the ED, which led to his transfer to the operating room for an emergent fasciotomy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although acute, atraumatic compartment syndrome of the thigh is a rare entity, failure to diagnose it promptly can lead to muscle necrosis, permanent neurologic deficits, and amputation. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Diagnosis of compartment syndrome using a microwave-based detector

    NASA Astrophysics Data System (ADS)

    Ling, Geoffrey S. F.; Riechers, Ronald G., Sr.; Pasala, Krishna M.; Blanchard, Jeremy; Rosner, Michael; Jarell, Abel; Yun, Catherine; Garcia-Pinto, Patricia; Song, Ki-Il; Day, Keith; Riechers, Ronald G., Jr.; Zeidman, Seth M.; Rhee, Peter; Ecklund, James M.; Fitzpatrick, Thomas; Lockhart, Stephen

    2002-07-01

    A novel method for identifying compartment syndrome is presented. This method is based on a novel device that uses electromagnetic waves in the microwave radio frequency (RF) region and a modified algorithm previously used for the estimation of the angle of arrival of radar signals. In this study, we employ this radio frequency triage tool (RAFT) to the clinical condition of compartment syndrome, which is a clinical condition where blood or edema in the muscle compartment of the leg leads to critical sichemia of that exptremity. In anesthetized pigs, RAFT, can detect changes in the RF signature from a leg is due to 2cc or greater of either blood or slaine (a surrogate of edema). These results are compared to clinical examination. RAFT is superior to clinical examination in its ability to detect compartment syndrome in pgis.

  16. The Pathophysiology, Diagnosis and Current Management of Acute Compartment Syndrome

    PubMed Central

    Donaldson, James; Haddad, Behrooz; Khan, Wasim S

    2014-01-01

    Acute compartment syndrome (ACS) is a surgical emergency warranting prompt evaluation and treatment. It can occur with any elevation in interstitial pressure in a closed osseo-fascial compartment. Resultant ischaemic damage may be irreversible within six hours and can result in long-term morbidity and even death. The diagnosis is largely clinical with the classical description of ‘pain out of proportion to the injury’. Compartment pressure monitors can be a helpful adjunct where the diagnosis is in doubt. Initial treatment is with the removal of any constricting dressings or casts, avoiding hypotension and optimizing tissue perfusion by keeping the limb at heart level. If symptoms persist, definitive treatment is necessary with timely surgical decompression of all the involved compartments. This article reviews the pathophysiology, diagnosis and current management of ACS. PMID:25067973

  17. 9. Interior view of electronics compartment. View toward rear of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Interior view of electronics compartment. View toward rear of aircraft. - Offutt Air Force Base, Looking Glass Airborne Command Post, Looking Glass Aircraft, On Operational Apron covering northeast half of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  18. Four open mammillary and catenary compartment models for pharmacokinetics studies.

    PubMed

    de Biasi, J

    1989-11-01

    A mathematical method is proposed to solve a fourth degree equation which gives the eigenvalues of the matrix connected with a four open compartment model used in pharmacokinetic studies. As examples, the method is applied to mammillary and catenary models.

  19. Fire spread and percolation in polydisperse compartment structures

    NASA Astrophysics Data System (ADS)

    Zekri, N.; Zekri, L.; Lallemand, C.; Pizzo, Y.; Kaiss, A.; Clerc, J.-P.; Porterie, B.

    2012-11-01

    In this paper, we employ a cellular automata and percolation analysis to model fire spread in polydisperse amorphous massively multi-compartmented structures (e.g. naval vessels, high-rise buildings, warehouses, or nuclear plants). Various shapes and sizes of compartments are considered. Each compartment is composed of nc equal-size cells. It is found that increasing nc increases fingering and lacunarities of fire patterns, and subsequently front roughness. However, this also increases the probability of fire propagation throughout the system as the percolation threshold presents a power-law decrease with nc -1 for small values of nc. For large polydisperse compartments, the propagation/non propagation transition seems to be size-independent. A special emphasis is put on the dynamics of fire propagation. Further study is needed to evaluate network properties that should help in developing better strategies to reduce fire consequences.

  20. Dynamics of the Establishment of Multinucleate Compartments in Fusarium oxysporum

    PubMed Central

    Shahi, Shermineh; Beerens, Bas; Manders, Erik M. M.

    2014-01-01

    Nuclear dynamics can vary widely between fungal species and between stages of development of fungal colonies. Here we compared nuclear dynamics and mitotic patterns between germlings and mature hyphae in Fusarium oxysporum. Using fluorescently labeled nuclei and live-cell imaging, we show that F. oxysporum is subject to a developmental transition from a uninucleate to a multinucleate state after completion of colony initiation. We observed a special type of hypha that exhibits a higher growth rate, possibly acting as a nutrient scout. The higher growth rate is associated with a higher nuclear count and mitotic waves involving 2 to 6 nuclei in the apical compartment. Further, we found that dormant nuclei of intercalary compartments can reenter the mitotic cycle, resulting in multinucleate compartments with up to 18 nuclei in a single compartment. PMID:25398376

  1. Fire safety arrangement of inhabited pressurized compartments of manned spacecraft

    NASA Astrophysics Data System (ADS)

    Bolodian, Ivan; Melikhov, Anatoliy; Tanklevskiy, Leonid

    2017-06-01

    The article deals with innovative technical solutions that provide fire safety in inhabited pressurized compartments of manned spacecraft by means of a fireproof device of inhabited pressurized compartments via application of engineering means of fire prevention and fire spreading prevention by lowering fire load in an inhabited pressurized module up to the point when the maximum possible levels of fire factors in an inhabited pressurized compartment of a manned spacecraft are prevented. Represented technical solutions are used at the present time according to stated recommendations during provision of fire safety of equipment created by a number of Russian organizations for equipage of inhabited pressurized compartments of spacecraft of the Russian segment of International space station.

  2. Methods to follow intracellular trafficking of cell-penetrating peptides.

    PubMed

    Pärnaste, Ly; Arukuusk, Piret; Zagato, Elisa; Braeckmans, Kevin; Langel, Ülo

    2016-01-01

    Cell-penetrating peptides (CPPs) are efficient vehicles to transport bioactive molecules into the cells. Despite numerous studies the exact mechanism by which CPPs facilitate delivery of cargo to its intracellular target is still debated. The current work presents methods that can be used for tracking CPP/pDNA complexes through endosomal transport and show the role of endosomal transport in the delivery of cargo. Separation of endosomal vesicles by differential centrifugation enables to pinpoint the localization of delivered cargo without labeling it and gives important quantitative information about pDNA trafficing in certain endosomal compartments. Single particle tracking (SPT) allows following individual CPP/cargo complex through endosomal path in live cells, using fluoresently labled cargo and green fluoresent protein expressing cells. These two different methods show similar results about tested NickFect/pDNA complexes intracellular trafficing. NF51 facilitates rapid internalization of complexes into the cells, prolongs their stay in early endosomes and promotes release to cytosol. NF1 is less capable to induce endosomal release and higher amount of complexes are routed to lysosomes for degradation. Our findings offer potential delivery vector for in vivo applications, NF51, where endosomal entrapment has been allayed. Furthermore, these methods are valuable tools to study other CPP-based delivery systems.

  3. Mechanisms of Obligatory Intracellular Infection with Anaplasma phagocytophilum

    PubMed Central

    Rikihisa, Yasuko

    2011-01-01

    Summary: Anaplasma phagocytophilum persists in nature by cycling between mammals and ticks. Human infection by the bite of an infected tick leads to a potentially fatal emerging disease called human granulocytic anaplasmosis. A. phagocytophilum is an obligatory intracellular bacterium that replicates inside mammalian granulocytes and the salivary gland and midgut cells of ticks. A. phagocytophilum evolved the remarkable ability to hijack the regulatory system of host cells. A. phagocytophilum alters vesicular traffic to create an intracellular membrane-bound compartment that allows replication in seclusion from lysosomes. The bacterium downregulates or actively inhibits a number of innate immune responses of mammalian host cells, and it upregulates cellular cholesterol uptake to acquire cholesterol for survival. It also upregulates several genes critical for the infection of ticks, and it prolongs tick survival at freezing temperatures. Several host factors that exacerbate infection have been identified, including interleukin-8 (IL-8) and cholesterol. Host factors that overcome infection include IL-12 and gamma interferon (IFN-γ). Two bacterial type IV secretion effectors and several bacterial proteins that associate with inclusion membranes have been identified. An understanding of the molecular mechanisms underlying A. phagocytophilum infection will foster the development of creative ideas to prevent or treat this emerging tick-borne disease. PMID:21734244

  4. Intracellular fates of cell-penetrating block copolypeptide vesicles.

    PubMed

    Sun, Victor Z; Li, Zhibo; Deming, Timothy J; Kamei, Daniel T

    2011-01-10

    The block copolypeptide poly(l-homoarginine)(60)-b-poly(l-leucine)(20) (R(60)L(20)) was previously found to self-assemble into versatile vesicles with controllable size and encapsulate hydrophilic cargo. These R(60)L(20) vesicles also demonstrated the ability to cross the cell membrane and transport encapsulated cargo into different cell lines. To assess the potential for using the R(60)L(20) vesicles as drug delivery vehicles further, we have investigated their endocytosis and intracellular trafficking behavior. Using drugs that inhibit different endocytosis pathways, we identified macropinocytosis to be a major process by which the R(60)L(20) vesicles enter HeLa cells. Subsequent immunostaining experiments demonstrated that the vesicles entered the early endosomes but not the lysosomes, suggesting that they recycle back to the cell surface. Overall, our studies indicate that the R(60)L(20) vesicles are able to enter cells intact with their cargos, and although some manage to escape from early endosomes, most are trapped within these intracellular compartments.

  5. Role of cholesterol in SNARE-mediated trafficking on intracellular membranes.

    PubMed

    Enrich, Carlos; Rentero, Carles; Hierro, Aitor; Grewal, Thomas

    2015-03-15

    The cell surface delivery of extracellular matrix (ECM) and integrins is fundamental for cell migration in wound healing and during cancer cell metastasis. This process is not only driven by several soluble NSF attachment protein (SNAP) receptor (SNARE) proteins, which are key players in vesicle transport at the cell surface and intracellular compartments, but is also tightly modulated by cholesterol. Cholesterol-sensitive SNAREs at the cell surface are relatively well characterized, but it is less well understood how altered cholesterol levels in intracellular compartments impact on SNARE localization and function. Recent insights from structural biology, protein chemistry and cell microscopy have suggested that a subset of the SNAREs engaged in exocytic and retrograde pathways dynamically 'sense' cholesterol levels in the Golgi and endosomal membranes. Hence, the transport routes that modulate cellular cholesterol distribution appear to trigger not only a change in the location and functioning of SNAREs at the cell surface but also in endomembranes. In this Commentary, we will discuss how disrupted cholesterol transport through the Golgi and endosomal compartments ultimately controls SNARE-mediated delivery of ECM and integrins to the cell surface and, consequently, cell migration.

  6. Intracellular calcium signals regulate growth of hepatic stellate cells via specific effects on cell cycle progression.

    PubMed

    Soliman, Elwy M; Rodrigues, Michele Angela; Gomes, Dawidson Assis; Sheung, Nina; Yu, Jin; Amaya, Maria Jimina; Nathanson, Michael H; Dranoff, Jonathan A

    2009-03-01

    Hepatic stellate cells (HSC) are important mediators of liver fibrosis. Hormones linked to downstream intracellular Ca(2+) signals upregulate HSC proliferation, but the mechanisms by which this occurs are unknown. Nuclear and cytosolic Ca(2+) signals may have distinct effects on cell proliferation, so we expressed plasmid and adenoviral constructs containing the Ca(2+) chelator parvalbumin (PV) linked to either a nuclear localization sequence (NLS) or a nuclear export sequence (NES) to block Ca(2+) signals in distinct compartments within LX-2 immortalized human HSC and primary rat HSC. PV-NLS and PV-NES constructs each targeted to the appropriate intracellular compartment and blocked Ca(2+) signals only within that compartment. PV-NLS and PV-NES constructs inhibited HSC growth. Furthermore, blockade of nuclear or cytosolic Ca(2+) signals arrested growth at the G2/mitosis (G2/M) cell-cycle interface and prevented the onset of mitosis. Blockade of nuclear or cytosolic Ca(2+) signals downregulated phosphorylation of the G2/M checkpoint phosphatase Cdc25C. Inhibition of calmodulin kinase II (CaMK II) had identical effects on LX-2 growth and Cdc25C phosphorylation. We propose that nuclear and cytosolic Ca(2+) are critical signals that regulate HSC growth at the G2/M checkpoint via CaMK II-mediated regulation of Cdc25C phosphorylation. These data provide a new logical target for pharmacological therapy directed against progression of liver fibrosis.

  7. Comparison of tissue oxygenation and compartment pressure following tibia fracture.

    PubMed

    Hansen, Erik N; Manzano, Givenchy; Kandemir, Utku; Mok, James M

    2013-08-01

    We investigated the ability of direct continuous measurement of intramuscular tissue oxygenation (PmO(2)) to detect acute ischaemia in the leg in patients at risk for acute extremity compartment syndrome. Following tibia fracture treated by intramedullary nailing, we compared the proportions of PmO(2) and compartment pressure (CP) measurements that met the warning criteria for compartment syndrome. Participants included 10 patients sustaining acute isolated closed tibia shaft fractures treated by intramedullary nailing. A tissue oxygenation probe and a CP probe were percutaneously placed into the anterior compartment of the leg. PmO(2) and CP in the anterior compartment were measured in the injured leg for 48 h postoperatively. Measurements meeting the warning criteria were defined as PmO(2) < 10 mmHg, CP > 30 mmHg and perfusion pressure ΔP < 30 mmHg. None of the patients developed compartment syndrome. Comparison of CP and PmO(2) showed a CP > 30 mmHg in 50.39% of CP measurements in all patients and a PmO(2) < 10 mmHg in 0.75% of PmO(2) measurements in two patients (P = 0.005). Comparison of ΔP and PmO(2) showed a ΔP < 30 mmHg in 31.01% of ΔP measurements in nine patients and a PmO(2) < 10 mmHg in 0.76% of PmO(2) measurements in one patient (P = 0.01). In the absence of compartment syndrome, pressure measurements following tibia fracture treated with intramedullary nailing often met the warning criteria, whereas PmO(2) did not, suggesting that measurement of intramuscular tissue oxygenation may represent a potential method for the identification of acute compartment syndrome that deserves continued investigation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Acute pediatric leg compartment syndrome in chronic myeloid leukemia.

    PubMed

    Cohen, Eric; Truntzer, Jeremy; Trunzter, Jeremy; Klinge, Steve; Schwartz, Kevin; Schiller, Jonathan

    2014-11-01

    Acute compartment syndrome is an orthopedic surgical emergency and may result in devastating complications in the setting of delayed or missed diagnosis. Compartment syndrome has a variety of causes, including posttraumatic or postoperative swelling, external compression, burns, bleeding disorders, and ischemia-reperfusion injury. Rare cases of pediatric acute compartment syndrome in the setting of acute myeloid leukemia and, even less commonly, chronic myeloid leukemia have been reported. The authors report the first known case of pediatric acute compartment syndrome in a patient without a previously known diagnosis of chronic myeloid leukemia. On initial examination, an 11-year-old boy presented with a 2-week history of progressive left calf pain and swelling after playing soccer. Magnetic resonance imaging scan showed a hematoma in the left superficial posterior compartment. The patient had unrelenting pain, intermittent lateral foot parethesias, and inability to bear weight. Subsequently, he was diagnosed with acute compartment syndrome and underwent fasciotomy and evacuation of a hematoma. Laboratory results showed an abnormal white blood cell count of 440×10(9)/L (normal, 4.4-11×10(9)) and international normalized ratio of 1.3 (normal, 0.8-1.2). Further testing included the BCR-ABL1 fusion gene located on the Philadelphia chromosome, leading to a diagnosis of chronic myeloid leukemia. Monotherapy with imatinib mesylate (Gleevec) was initiated. This report adds another unique case to the growing literature on compartment syndrome in the pediatric population and reinforces the need to consider compartment syndrome, even in unlikely clinical scenarios. Copyright 2014, SLACK Incorporated.

  9. Contralateral compartment syndrome inoculated by invasive group A streptococcus

    PubMed Central

    Chen, Huiwen; Mcphillips, Sean Thomas; Chundi, Vishnu

    2016-01-01

    Compartment syndrome is a rare but a well-documented complication in patients with trauma-induced group A streptococcus infection. Here, we present a case of a male who developed compartment syndrome on the left lower extremity after an injury inoculated by group A streptococcus on the right lower extremity. The patient was resuscitated with antibiotics, urgent fasciotomy, and immunoglobulin. The patient was eventually transferred to a burn center for further care. PMID:27802865

  10. Differential gene expression in anatomical compartments of the human eye

    PubMed Central

    Diehn, Jennifer J; Diehn, Maximilian; Marmor, Michael F; Brown, Patrick O

    2005-01-01

    Background The human eye is composed of multiple compartments, diverse in form, function, and embryologic origin, that work in concert to provide us with our sense of sight. We set out to systematically characterize the global gene expression patterns that specify the distinctive characteristics of the various eye compartments. Results We used DNA microarrays representing approximately 30,000 human genes to analyze gene expression in the cornea, lens, iris, ciliary body, retina, and optic nerve. The distinctive patterns of expression in each compartment could be interpreted in relation to the physiology and cellular composition of each tissue. Notably, the sets of genes selectively expressed in the retina and in the lens were particularly large and diverse. Genes with roles in immune defense, particularly complement components, were expressed at especially high levels in the anterior segment tissues. We also found consistent differences between the gene expression patterns of the macula and peripheral retina, paralleling the differences in cell layer densities between these regions. Based on the hypothesis that genes responsible for diseases that affect a particular eye compartment are likely to be selectively expressed in that compartment, we compared our gene expression signatures with genetic mapping studies to identify candidate genes for diseases affecting the cornea, lens, and retina. Conclusion Through genome-scale gene expression profiling, we were able to discover distinct gene expression 'signatures' for each eye compartment and identified candidate disease genes that can serve as a reference database for investigating the physiology and pathophysiology of the eye. PMID:16168081

  11. Modulatory compartments in cortex and local regulation of cholinergic tone.

    PubMed

    Coppola, Jennifer J; Ward, Nicholas J; Jadi, Monika P; Disney, Anita A

    2016-09-01

    Neuromodulatory signaling is generally considered broad in its impact across cortex. However, variations in the characteristics of cortical circuits may introduce regionally-specific responses to diffuse modulatory signals. Features such as patterns of axonal innervation, tissue tortuosity and molecular diffusion, effectiveness of degradation pathways, subcellular receptor localization, and patterns of receptor expression can lead to local modification of modulatory inputs. We propose that modulatory compartments exist in cortex and can be defined by variation in structural features of local circuits. Further, we argue that these compartments are responsible for local regulation of neuromodulatory tone. For the cholinergic system, these modulatory compartments are regions of cortical tissue within which signaling conditions for acetylcholine are relatively uniform, but between which signaling can vary profoundly. In the visual system, evidence for the existence of compartments indicates that cholinergic modulation likely differs across the visual pathway. We argue that the existence of these compartments calls for thinking about cholinergic modulation in terms of finer-grained control of local cortical circuits than is implied by the traditional view of this system as a diffuse modulator. Further, an understanding of modulatory compartments provides an opportunity to better understand and perhaps correct signal modifications that lead to pathological states.

  12. Intracellular insulin processing is altered in monocytes from patients with type II diabetes mellitus

    SciTech Connect

    Trischitta, V.; Benzi, L.; Brunetti, A.; Cecchetti, P.; Marchetti, P.; Vigneri, R.; Navalesi, R.

    1987-05-01

    We studied total cell-associated A14-(/sup 125/I)insulin radioactivity (including surface-bound and internalized radioactivity), insulin internalization, and its intracellular degradation at 37 C in monocytes from nonobese type II untreated diabetic patients (n = 9) and normal subjects (n = 7). Total cell-associated radioactivity was decreased in diabetic patients (2.65 +/- 1.21% (+/- SD) vs. 4.47 +/- 1.04% of total radioactivity. Insulin internalization was also reduced in diabetic patients (34.0 +/- 6.8% vs. 59.0 +/- 11.3% of cell-associated radioactivity. Using high performance liquid chromatography six intracellular forms of radioactivity derived from A14-(/sup 125/I) insulin were identified; 10-20% of intracellular radioactivity had approximately 300,000 mol wt and was identified as radioactivity bound to the insulin receptor, and the remaining intracellular radioactivity included intact A14-(/sup 125/I)insulin, (/sup 125/I)iodide, or (/sup 125/I)tyrosine, and three intermediate compounds. A progressive reduction of intact insulin and a corresponding increase in iodine were found when the incubation time was prolonged. Intracellular insulin degradation was reduced in monocytes from diabetic patients; intracellular intact insulin was 65.6 +/- 18.1% vs. 37.4 +/- 18.0% of intracellular radioactivity after 2 min and 23.6 +/- 22.3% vs. 3.9 +/- 2.3% after 60 min in diabetic patients vs. normal subjects, respectively. In conclusion, 1) human monocytes internalize and degrade insulin in the intracellular compartment in a stepwise time-dependent manner; and 2) in monocytes from type II diabetic patients total cell-associated radioactivity, insulin internalization, and insulin degradation are significantly reduced. These defects may be related to the cellular insulin resistance present in these patients.

  13. Preparation of Reactive Oligo(p-Phenylene Vinylene) Materials for Spatial Profiling of the Chemical Reactivity of Intracellular Compartments.

    PubMed

    Nie, Chenyao; Li, Shengliang; Wang, Bing; Liu, Libing; Hu, Rong; Chen, Hui; Lv, Fengting; Dai, Zhihui; Wang, Shu

    2016-05-01

    An oligo(p-phenylene vinylene) derivative (OPV-pfp) functionalized with pentafluorophenol active ester is designed and synthesized. The high reactivity of OPV-pfp with biological small molecules or macromolecules containing amino groups under physiological conditions leads to spectral changes of OPV-pfp; thus, spatial reactivity discrimination for different subcellular structures inside cells is realized by triggering and imaging the fluorescence signal change of the OPV-pfp.

  14. Inter- and intra-patient clonal and subclonal heterogeneity of chronic lymphocytic leukaemia: evidence from circulating and lymph nodal compartments

    PubMed Central

    Bonina, Silvia; Messina, Monica; Chiaretti, Sabina; Ilari, Caterina; Cafforio, Luciana; Raponi, Sara; Mauro, Francesca Romana; Di Maio, Valeria; De Propris, Maria Stefania; Nanni, Mauro; Ciardullo, Carmela; Rossi, Davide; Gaidano, Gianluca; Guarini, Anna; Rabadan, Raul; Foà, Robin

    2015-01-01

    Summary Whole exome sequencing and copy number aberration (CNA) analysis was performed on cells taken from peripheral blood (PB) and lymph nodes (LN) of patients with chronic lymphocytic leukaemia (CLL). Of 64 non-silent somatic mutations, 54 (84.4%) were clonal in both compartments, 3 (4.7%) were PB-specific and 7 (10.9%) were LN-specific. Most of the LN- or PB-specific mutations were subclonal in the other corresponding compartment (variant frequency 0.5-5.3%). Of 41 CNAs, 27 (65.8%) were shared by both compartments and 7 (17.1%) were LN- or PB-specific. Overall, 6 of 9 cases (66.7%) showed genomic differences between the compartments. At subsequent relapse, Case 10, with 6 LN-specific lesions, and Case 100, with 6 LN-specific and 8 PB-specific lesions, showed, in the PB, the clonal expansion of LN-derived lesions with an adverse impact: SF3B1 mutation, BIRC3 deletion, del8(p23.3-p11.1), del9(p24.3-p13.1) and gain 2(p25.3-p14). CLL shows an intra-patient clonal heterogeneity according to the disease compartment, with both LN and PB-specific mutations/CNAs. The LN microenvironment might contribute to the clonal selection of unfavourable lesions, as LN-derived mutations/CNAs can appear in the PB at relapse. PMID:26597680

  15. Modelling the extra and intracellular uptake and discharge of heavy metals in Fontinalis antipyretica transplanted along a heavy metal and pH contamination gradient.

    PubMed

    Fernández, J A; Vázquez, M D; López, J; Carballeira, A

    2006-01-01

    Samples of the aquatic bryophyte Fontinalis antipyretica Hedw. were transplanted to different sites with the aim of characterizing the kinetics of the uptake and discharge of heavy metals in the extra and intracellular compartments. The accumulation of metals in extracellular compartments, characterized by an initial rapid accumulation, then a gradual slowing down over time, fitted perfectly to a Michaelis-Menten model. The discharge of metals from the same compartment followed an inverse linear model or an inverse Michaelis-Menten model, depending on the metal. In intracellular sites both uptake and discharge occurred more slowly and progressively, following a linear model. We also observed that the acidity of the environment greatly affected metal accumulation in extracellular sites, even when the metals were present at relatively high concentrations, whereas the uptake of metals within cells was much less affected by pH.

  16. Compartment Syndrome of the Gluteus Medius Occurred without Bleeding or Trauma: A Case Report.

    PubMed

    Kong, Gyu-Min; Kwon, Yong-Uk; Park, Jun-Ho

    2015-12-01

    Compartment syndrome is an ischemic change resulting from an increase in compartment pressure. Initially, patients present with direct tenderness and swelling, and the weak circulation secondary to compartment syndrome can eventually lead to motor and sensory impairment. If the increase in pressure results in neurological impairment, emergency intervention is required to decompress the compartment. Typically, compartment syndrome develops on forearms or lower legs. The gluteal compartment is rarely the location of compartment syndrome and only a few cases have been presented in the literature with trauma or hematoma. We have treated a patient with gluteal compartment syndrome who presented with no history of trauma or hemorrhage and present that case report here.

  17. Reorganization of the Endosomal System in Salmonella-Infected Cells: The Ultrastructure of Salmonella-Induced Tubular Compartments

    PubMed Central

    Krieger, Viktoria; Liebl, David; Zhang, Yuying; Rajashekar, Roopa; Chlanda, Petr; Giesker, Katrin; Chikkaballi, Deepak; Hensel, Michael

    2014-01-01

    During the intracellular life of Salmonella enterica, a unique membrane-bound compartment termed Salmonella-containing vacuole, or SCV, is formed. By means of translocated effector proteins, intracellular Salmonella also induce the formation of extensive, highly dynamic membrane tubules termed Salmonella-induced filaments or SIF. Here we report the first detailed ultrastructural analyses of the SCV and SIF by electron microscopy (EM), EM tomography and live cell correlative light and electron microscopy (CLEM). We found that a subset of SIF is composed of double membranes that enclose portions of host cell cytosol and cytoskeletal filaments within its inner lumen. Despite some morphological similarities, we found that the formation of SIF double membranes is independent from autophagy and requires the function of the effector proteins SseF and SseG. The lumen of SIF network is accessible to various types of endocytosed material and our CLEM analysis of double membrane SIF demonstrated that fluid phase markers accumulate only between the inner and outer membrane of these structures, a space continual with endosomal lumen. Our work reveals how manipulation of the endosomal membrane system by an intracellular pathogen results in a unique tubular membrane compartmentalization of the host cell, generating a shielded niche permissive for intracellular proliferation of Salmonella. PMID:25254663

  18. Intracellular targeting with engineered proteins

    PubMed Central

    Miersch, Shane; Sidhu, Sachdev S.

    2016-01-01

    If the isolation, production, and clinical use of insulin marked the inception of the age of biologics as therapeutics, the convergence of molecular biology and combinatorial engineering techniques marked its coming of age. The first wave of recombinant protein-based drugs in the 1980s demonstrated emphatically that proteins could be engineered, formulated, and employed for clinical advantage. Yet despite the successes of protein-based drugs such as antibodies, enzymes, and cytokines, the druggable target space for biologics is currently restricted to targets outside the cell. Insofar as estimates place the number of proteins either secreted or with extracellular domains in the range of 8000 to 9000, this represents only one-third of the proteome and circumscribes the pathways that can be targeted for therapeutic intervention. Clearly, a major objective for this field to reach maturity is to access, interrogate, and modulate the majority of proteins found inside the cell. However, owing to the large size, complex architecture, and general cellular impermeability of existing protein-based drugs, this poses a daunting challenge. In recent years, though, advances on the two related fronts of protein engineering and drug delivery are beginning to bring this goal within reach. First, prompted by the restrictions that limit the applicability of antibodies, intense efforts have been applied to identifying and engineering smaller alternative protein scaffolds for the modulation of intracellular targets. In parallel, innovative solutions for delivering proteins to the intracellular space while maintaining their stability and functional activity have begun to yield successes. This review provides an overview of bioactive intrabodies and alternative protein scaffolds amenable to engineering for intracellular targeting and also outlines advances in protein engineering and formulation for delivery of functional proteins to the interior of the cell to achieve therapeutic action

  19. High-Content Imaging Reveals Expansion of the Endosomal Compartment during Coxiella burnetii Parasitophorous Vacuole Maturation

    PubMed Central

    Larson, Charles L.; Heinzen, Robert A.

    2017-01-01

    Coxiella burnetii is an obligate intracellular pathogen and the causative agent of human Q fever. Replication of the bacterium within a large parasitophorous vacuole (PV) resembling a host phagolysosome is required for pathogenesis. PV biogenesis is a pathogen driven process that requires engagement of several host cell vesicular trafficking pathways to acquire vacuole components. The goal of this study was to determine if infection by C. burnetii modulates endolysosomal flux to potentially benefit PV formation. HeLa cells, infected with C. burnetii or left uninfected, were incubated with fluorescent transferrin (Tf) for 0–30 min, and the amount of Tf internalized by cells quantitated by high-content imaging. At 3 and 5 days, but not 1 day post-infection, the maximal amounts of fluorescent Tf internalized by infected cells were significantly greater than uninfected cells. The rates of Tf uptake and recycling were the same for infected and uninfected cells; however, residual Tf persisted in EEA.1 positive compartments adjacent to large PV after 30 min of recycling in the absence of labeled Tf. On average, C. burnetii-infected cells contained significantly more CD63-positive endosomes than uninfected cells. In contrast, cells containing large vacuoles generated by Chlamydia trachomatis exhibited increased rates of Tf internalization without increased CD63 expression. Our results suggest that C. burnetii infection expands the endosomal system to increase capacity for endocytic material. Furthermore, this study demonstrates the power of high-content imaging for measurement of cellular responses to infection by intracellular pathogens. PMID:28293541

  20. Evidence for an acidic compartment in sea urchin eggs (Paracentrotus lividus): role at fertilization.

    PubMed

    Payan, P; Girard, J P; Viglietti, F

    1987-04-01

    The characteristics of [14C]methylamine accumulation by isolated cortices were measured in eggs from three species of sea urchins: Paracentrotus lividus, Arbacia lixula and Sphaerechinus granularis. In all cases, the results pointed to the existence of an acidic compartment in the cortical zone. In P. lividus eggs, cortical granules did not participate in proton storage which likely took place in pigment granules. [14C]Methylamine accumulation was dramatically reduced by monovalent cation ionophores (monensin and nigericin) and by NH4Cl, but not by valinomycin. ATP depletion only partially affected the isotope uptake. Simultaneous measurements of intracellular pH and of external titratable acidity during ammonia treatment of eggs, indicate that after fertilization, eggs increased their capacity to concentrate hydrogen ions in an intracellular store. Following insemination, cortices from P. lividus eggs exhibited a 3-fold increase in [14C]methylamine accumulation. It is concluded that the egg cortical area contains acidic organelles sequestering hydrogen ions by means of an electrogenic H+ pump, and that this mechanism, enhanced at fertilization, participates in a local alkalinization. The role of such a mechanism is discussed.