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Sample records for airway microvascular leakage

  1. Tachykinin NK(3) receptor agonists induced microvascular leakage hypersensitivity in the guinea-pig airways.

    PubMed

    Daoui, S; Ahnaou, A; Naline, E; Emonds-Alt, X; Lagente, V; Advenier, C

    2001-12-21

    Microvascular leakage hypersensitivity is a main component of neurogenic inflammation and of tachykinin effects. The aim of this study was to examine the ability of neurokinin B and of the tachykinin NK(3) receptor agonists, [MePhe(7)]neurokinin B or senktide, to potentiate when given by aerosol the microvascular leakage induced by histamine in guinea-pig airways and to compare their effects to those of tachykinin NK(1) (substance P, [Sar(9),Met(O(2))(11)]substance P) or tachykinin NK(2) (neurokinin A, [betaAla(8)]neurokinin A (4-10)) receptor agonists. Guinea-pigs were pretreated successively for 10 min with aerolized salbutamol and phosphoramidon; 15 min later, they were exposed for 30 min to an aerosolized solution of tachykinin receptor agonists; 24 h later, the animals were anaesthetized and vascular permeability was quantified by extravasation of Evans blue dye. Neurokinin B, [MePhe(7)]neurokinin B and senktide (3 x 10(-6)-3 x 10(-5)M) induced a potentiation of the effects of histamine on the vascular permeability in the trachea and main bronchi. Compared to other tachykinin NK(1) and NK(2) receptor agonists, the order of potency was: senktide>neurokinin B=[Sar(9),Met(O(2))(11)]substance P=[betaAla(8)]neurokinin A (4-10)=[MePhe(7)]neurokinin B>neurokinin A>substance P. The potentiation by [MePhe(7)]neurokinin B of histamine-induced microvascular leakage was abolished by the tachykinin NK(1) receptor antagonist SR140333 ([(S)1-(2-[3-(3,4-dichlorophenyl)-1-(3-iso-propoxyphenylacetyl)piperidin-3-yl]etyl)-4-phenyl-1-azoniabicyclo[2.2.2]octane, chloride]) or the tachykinin NK(3) receptor antagonists SR 142801 ([(R)-(N)-(1-(3-(l-benzoyl-3-(3,4-dichlorophenyl)piperidin-3-yl) propyl)-4-phenylpiperidin-4-yl)-N-methylacetamide]) and SB 223412 ([(S)-(-)-N-(alpha-ethylbenzyl)-3-hydroxy-2-phenylquinoline-4-carboxamide]). In conclusion, these results suggest that tachykinin NK(3) receptors might be involved in the potentiation of histamine-induced increase in microvascular

  2. Pharmacological modulation of inhaled sodium metabisulphite-induced airway microvascular leakage and bronchoconstriction in the guinea-pig.

    PubMed Central

    Sakamoto, T.; Elwood, W.; Barnes, P. J.; Chung, K. F.

    1992-01-01

    1. We have investigated the effects of chlorpheniramine, atropine and capsaicin pretreatment on inhaled sodium metabisulphite (MBS)-induced airway microvascular leakage and bronchoconstriction in anaesthetized guinea-pigs in order to clarify the mechanisms involved in these responses. The effects of frusemide and nedocromil sodium were also examined. 2. Lung resistance (RL) was measured for 6 min after inhalation of MBS (20, 40, 80 and 200 mM; 30 breaths), followed by measurement of extravasation of Evans blue dye into airway tissues, used as an index of airway microvascular leakage. MBS caused an increase in RL and leakage of dye at all airway levels in a dose-dependent manner. 3. Chlorpheniramine (10 mg kg-1, i.v.), atropine (1 mg kg-1, i.v.), their combination or inhaled nedocromil sodium (10 mg ml-1, 7 min) had no effect against the airway microvascular leakage induced by 80 mM MBS (30 breaths). Capsaicin pretreatment (50 mg kg-1, s.c.) caused a significant decrease in the leakage of dye in the main bronchi and inhaled frusemide (10 mg ml-1, 7 min) also in the main bronchi and proximal intrapulmonary airway. 4. Chlorpheniramine, atropine, their combination, capsaicin pretreatment and frusemide, but not nedocromil sodium, inhibited significantly the peak RL induced by 80 mM MBS (30 breaths) by approximately 50%. 5. We conclude that a cholinergic reflex and neuropeptides released from sensory nerve endings may participate in the mechanisms of MBS-induced airway responses. Frusemide but not nedocromil sodium may have an inhibitor effect on these neural mechanisms. The inhibitory effect of nedocromil sodium against lower doses of MBS is not excluded. PMID:1330180

  3. Effects and interactions of sensory neuropeptides on airway microvascular leakage in guinea-pigs.

    PubMed Central

    Rogers, D. F.; Belvisi, M. G.; Aursudkij, B.; Evans, T. W.; Barnes, P. J.

    1988-01-01

    1. We have studied the effect of the sensory neuropeptides substance P (SP), neurokinin A (NKA), neurokinin B (NKB) and calcitonin gene-related peptide (CGRP) on microvascular permeability in guinea-pig airways in vivo and investigated whether CGRP would potentiate the effect of SP. We used the extravasation of intravenously-injected Evans blue dye as an index of permeability. 2. The tachykinins SP, NKA and NKB (0.025-5.0 nmol kg-1, i.v.) significantly (P less than 0.05) increased extravasation of dye in a dose-related manner and with a similar pattern of distribution; they were most potent in the trachea and main bronchi, less potent in the larynx and intrapulmonary airways, and had little significant effect in the bladder. 3. SP was significantly more potent in causing extravasation of dye than NKA or NKB with ED50 values (nmol kg-1) in the range 0.04-0.1, depending on the airway level, compared with values in the range 0.3-0.7 for the neurokinins. 4. CGRP (0.0025-2.5 nmol kg-1, i.v.) had no significant effect on microvascular permeability and did not potentiate SP-induced extravasation of dye. 5. Each neuropeptide decreased mean arterial blood pressure, indicating vasodilatation, in a dose-related manner. Co-injection of CGRP and SP produced additive decreases in arterial pressure. 6. We conclude that, in guinea-pig airways, tachykinins increase microvascular permeability via tachykinin receptors of the NK-1 sub-type (indicated by an order of potency of SP greater than NKA = NKB) on endothelial cells. The response appears to be related to mechanisms in addition to vasodilatation. The relevance of the responses to the tachykinins in asthma is discussed. PMID:2464389

  4. Effect of subchronic in vivo exposure to nitrogen dioxide on lung tissue inflammation, airway microvascular leakage, and in vitro bronchial muscle responsiveness in rats.

    PubMed Central

    Chitano, P; Rado, V; Di Stefano, A; Papi, A; Boniotti, A; Zancuoghi, G; Boschetto, P; Romano, M; Salmona, M; Ciaccia, A; Fabbri, L M; Mapp, C E

    1996-01-01

    OBJECTIVES: In a previous study on bronchoalveolar lavage fluid from rats exposed in vivo for seven days to 10 ppm nitrogen dioxide (NO2), it has been shown that there is an influx of macrophages into the airways. The present study investigated the effect of seven day exposure to 10 ppm NO2, on: (a) lung tissue inflammation and morphology; (b) airway microvascular leakage; (c) in vitro contractile response of main bronchi. METHODS: Lung tissue was studied by light microscopy, after fixing the lungs by inflation with 4% formalin at a pressure of 20 cm H2O. Microvascular leakage was measured by extravasation of Evans blue dye in the larynx, trachea, main bronchi, and intrapulmonary airways. Smooth muscle responsiveness was evaluated by concentration-responses curves to acetylcholine (10(-9)-10(-3) M), serotonin (10(-9)-10(-4) M), and voltage-response curves (12-28 V) to electrical field stimulation. RESULTS: Histology showed an increased total inflammation at the level of respiratory bronchioles and alveoli. No influx of inflammatory cells was found in the main bronchi. A loss of cilia in the epithelium of small airways and ectasia of alveolar capillaries was also found. By contrast, no alterations to microvascular permeability or modification of bronchial smooth muscle responsiveness was found. CONCLUSIONS: Subchronic exposure to 10 ppm NO2 causes airway inflammation and structural damage, but does not cause any persistent alteration to microvascular permeability or bronchial smooth muscle responsiveness in rats. Images Figure 1 PMID:8758032

  5. Acute Alcohol Intoxication-Induced Microvascular Leakage

    PubMed Central

    Doggett, Travis M.; Breslin, Jerome W.

    2014-01-01

    Background Alcohol intoxication can increase inflammation and worsen injury, yet the mechanisms involved are not clear. We investigated whether acute alcohol intoxication elevates microvascular permeability, and investigated potential signaling mechanisms in endothelial cells that may be involved. Methods Conscious rats received a 2.5 g/kg alcohol bolus via gastric catheters to produce acute intoxication. Microvascular leakage of intravenously administered FITC-albumin from the mesenteric microcirculation was assessed by intravital microscopy. Endothelial-specific mechanisms were studied using cultured endothelial cell monolayers. Transendothelial electrical resistance (TER) served as an index of barrier function, before and after treatment with alcohol or its metabolite acetaldehyde. Pharmacologic agents were used to test the roles of alcohol metabolism, oxidative stress, p38 mitogen-activated protein (MAP) kinase, myosin light chain kinase (MLCK), rho kinase (ROCK), and exchange protein activated by cAMP (Epac). VE-cadherin localization was investigated to assess junctional integrity. Rac1 and RhoA activation were assessed by ELISA assays. Results Alcohol significantly increased FITC-albumin extravasation from the mesenteric microcirculation. Alcohol also significantly decreased TER and disrupted VE-cadherin organization at junctions. Acetaldehyde significantly decreased TER, but inhibition of ADH or application of a superoxide dismutase mimetic failed to prevent alcohol-induced decreases in TER. Inhibition of p38 MAP kinase, but not MLCK or ROCK, significantly attenuated the alcohol-induced barrier dysfunction. Alcohol rapidly decreased GTP-bound Rac1 but not RhoA during the drop in TER. Activation of Epac increased TER, but did not prevent alcohol from decreasing TER. However, activation of Epac after initiation of alcohol-induced barrier dysfunction quickly resolved TER to baseline levels. Conclusions Our results suggest that alcohol intoxication increases

  6. Microvascular remodelling in chronic airway inflammation in mice.

    PubMed

    Thurston, G; Maas, K; Labarbara, A; Mclean, J W; McDonald, D M

    2000-10-01

    1. Chronic inflammation is associated with blood vessel remodelling, including vessel proliferation and enlargement, and changes in vessel phenotype. We sought to characterize these changes in chronic airway inflammation and to determine whether corticosteroids that inhibit inflammation, such as dexamethasone, can also reduce microvascular remodelling. 2. Chronic airway inflammation was induced in C3H mice by infection with Mycoplasmapulmonis and the tracheal vessels treatment also decreased the immunoreactivity for P-selectin and the number of adherent leucocytes (595 +/- 203 vs 2,024 +/- 393 cells/ mm2 in treated and non-treated infected mice, respectively). 6. We conclude that microvascular enlargement and changes in vessel phenotype are features of some types of chronic inflammation and, furthermore, that dexamethasone reverses the microvascular enlargement, changes in vessel phenotype and leucocyte influx associated with chronic inflammatory airway disease. PMID:11022979

  7. Albumin microvascular leakage in brains with diabetes mellitus.

    PubMed

    Fujihara, Ryuji; Chiba, Yoichi; Nakagawa, Toshitaka; Nishi, Nozomu; Murakami, Ryuta; Matsumoto, Koichi; Kawauchi, Machi; Yamamoto, Tetsuji; Ueno, Masaki

    2016-09-01

    Their aim was to examine whether microvascular leakage of endogenous albumin, a representative marker for blood-brain barrier (BBB) damage, was induced in the periventricular area of diabetic db/db mice because periventricular white matter hyperintensity formation in magnetic resonance images was accelerating in elderly patients with diabetes mellitus. Using light and electron microscopes, and semi-quantitative analysis techniques, immunoreactivity of endogenous albumin, indicating vascular permeability, was examined in the periventricular area and spinal cord of db/db mice and db/+m control mice. Greater immunoreactivity of albumin was observed in the vessel wall of the periventricular area of db/db mice than in controls. Additionally, weak immunoreactivity was observed in the spinal cord of both db/db mice and controls. The number of gold particles, indicating immunoreactivity of albumin, in the perivascular area of db/db mice was significantly higher than that of control mice, but there was no significant difference in the number of particles in the spinal cord between db/db mice and controls. These findings suggest that albumin microvascular leakage, or BBB breakdown, is induced in the periventricular area of diabetic mice. Microsc. Res. Tech. 79:833-837, 2016. © 2016 Wiley Periodicals, Inc. PMID:27333535

  8. Microvascular leakage of plasma proteins after PUVA and UVA

    SciTech Connect

    Staberg, B.; Worm, A.M.; Rossing, N.; Brodthagen, H.

    1982-04-01

    The transcapillary escape rate of albumin (TERalb), is a parameter of the leakage of macromolecules from the total microvasculature. In patients with psoriasis short-term PUVA treatment induces an increase in TERalb. In this study TERalb was measured in 3 groups of normal humans treated with PUVA, UVA and 8-methoxypsoralen. Treatment with PUVA and UVA caused a statistically significant increase in TERalb, whereas treatment with 8-methoxypsoralen did not induce any measurable changes. It is concluded that the UVA irradiation causes the abnormal leakage of macromolecules, whereas psoralen is not the responsible component. Furthermore the phenomenon can be elicited in normals and is not based on a preexisting psoriasis.

  9. Neutrophils recruited by chemoattractants in vivo induce microvascular plasma protein leakage through secretion of TNF

    PubMed Central

    Finsterbusch, Michaela; Voisin, Mathieu-Benoit; Beyrau, Martina; Williams, Timothy John

    2014-01-01

    Microvascular plasma protein leakage is an essential component of the inflammatory response and serves an important function in local host defense and tissue repair. Mediators such as histamine and bradykinin act directly on venules to increase the permeability of endothelial cell (EC) junctions. Neutrophil chemoattractants also induce leakage, a response that is dependent on neutrophil adhesion to ECs, but the underlying mechanism has proved elusive. Through application of confocal intravital microscopy to the mouse cremaster muscle, we show that neutrophils responding to chemoattractants release TNF when in close proximity of EC junctions. In vitro, neutrophils adherent to ICAM-1 or ICAM-2 rapidly released TNF in response to LTB4, C5a, and KC. Further, in TNFR−/− mice, neutrophils accumulated normally in response to chemoattractants administered to the cremaster muscle or dorsal skin, but neutrophil-dependent plasma protein leakage was abolished. Similar results were obtained in chimeric mice deficient in leukocyte TNF. A locally injected TNF blocking antibody was also able to inhibit neutrophil-dependent plasma leakage, but had no effect on the response induced by bradykinin. The results suggest that TNF mediates neutrophil-dependent microvascular leakage. This mechanism may contribute to the effects of TNF inhibitors in inflammatory diseases and indicates possible applications in life-threatening acute edema. PMID:24913232

  10. Pharmacological characterization of the late phase reduction in lung functions and correlations with microvascular leakage and lung edema in allergen-challenged Brown Norway rats.

    PubMed

    Mauser, Peter J; House, Aileen; Jones, Howard; Correll, Craig; Boyce, Christopher; Chapman, Richard W

    2013-12-01

    Late phase airflow obstruction and reduction in forced vital capacity are characteristic features of human asthma. Airway microvascular leakage and lung edema are also present in the inflammatory phase of asthma, but the impact of this vascular response on lung functions has not been precisely defined. This study was designed to evaluate the role of increased lung microvascular leakage and edema on the late phase changes in forced vital capacity (FVC) and peak expiratory flow (PEF) in allergen-challenged Brown Norway rats using pharmacological inhibitors of the allergic inflammatory response. Rats were sensitized and challenged with ovalbumin aerosol and forced expiratory lung functions (FVC, PEF) and wet and dry lung weights were measured 48 h after antigen challenge. Ovalbumin challenge reduced FVC (63% reduction) and PEF (33% reduction) and increased wet (65% increase) and dry (51% increase) lung weights. The antigen-induced reduction in FVC and PEF was completely inhibited by oral treatment with betamethasone and partially attenuated by inhibitors of arachidonic acid metabolism including indomethacin (cyclooxygenase inhibitor), 7-TM and MK-7246 (CRTH2 antagonists) and montelukast (CysLT1 receptor antagonist). Antagonists of histamine H1 receptors (mepyramine) and 5-HT receptors (methysergide) had no significant effects indicating that these pre-formed mast cell mediators were not involved. There was a highly significant (P < 0.005) correlation for the inhibition of FVC reduction and increase in wet and dry lung weights by these pharmacological agents. These results strongly support the hypothesis that lung microvascular leakage and the associated lung edema contribute to the reduction in forced expiratory lung functions in antigen-challenged Brown Norway rats and identify an important role for the cyclooxygenase and lipoxygenase products of arachidonic acid metabolism in these responses. PMID:23523662

  11. Microvascular destruction identifies murine allografts that cannot be rescued from airway fibrosis

    PubMed Central

    Babu, Ashok N.; Murakawa, Tomohiro; Thurman, Joshua M.; Miller, Edmund J.; Henson, Peter M.; Zamora, Martin R.; Voelkel, Norbert F.; Nicolls, Mark R.

    2007-01-01

    Small airway fibrosis (bronchiolitis obliterans syndrome) is the primary obstacle to long-term survival following lung transplantation. Here, we show the importance of functional microvasculature in the prevention of epithelial loss and fibrosis due to rejection and for the first time, relate allograft microvascular injury and loss of tissue perfusion to immunotherapy-resistant rejection. To explore the role of alloimmune rejection and airway ischemia in the development of fibroproliferation, we used a murine orthotopic tracheal transplant model. We determined that transplants were reperfused by connection of recipient vessels to donor vessels at the surgical anastomosis site. Microcirculation through the newly formed vascular anastomoses appeared partially dependent on VEGFR2 and CXCR2 pathways. In the absence of immunosuppression, the microvasculature in rejecting allografts exhibited vascular complement deposition, diminished endothelial CD31 expression, and absent perfusion prior to the onset of fibroproliferation. Rejecting grafts with extensive endothelial cell injury were refractory to immunotherapy. After early microvascular loss, neovascularization was eventually observed in the membranous trachea, indicating a reestablishment of graft perfusion in established fibrosis. One implication of this study is that bronchial artery revascularization at the time of lung transplantation may decrease the risk of subsequent airway fibrosis. PMID:18060031

  12. Matrix metalloproteinase-2 and -9 expression increases in Mycoplasma-infected airways but is not required for microvascular remodeling.

    PubMed

    Baluk, Peter; Raymond, Wilfred W; Ator, Erin; Coussens, Lisa M; McDonald, Donald M; Caughey, George H

    2004-08-01

    Murine Mycoplasma pulmonis infection induces chronic lung and airway inflammation accompanied by profound and persistent microvascular remodeling in tracheobronchial mucosa. Because matrix metalloproteinase (MMP)-2 and -9 are important for angiogenesis associated with placental and long bone development and skin cancer, we hypothesized that they contribute to microvascular remodeling in airways infected with M. pulmonis. To test this hypothesis, we compared microvascular changes in airways after M. pulmonis infection of wild-type FVB/N mice with those of MMP-9(-/-) and MMP-2(-/-)/MMP-9(-/-) double-null mice and mice treated with the broad-spectrum MMP inhibitor AG3340 (Prinomastat). Using zymography and immunohistochemistry, we find that MMP-2 and MMP-9 rise strikingly in lungs and airways of infected wild-type FVB/N and C57BL/6 mice, with no zymographic activity or immunoreactivity in MMP-2(-/-)/MMP-9(-/-) animals. However, microvascular remodeling as assessed by Lycopersicon esculentum lectin staining of whole-mounted tracheae is as severe in infected MMP-9(-/-), MMP-2(-/-)/MMP-9(-/-) and AG3340-treated mice as in wild-type mice. Furthermore, all groups of infected mice develop similar inflammatory infiltrates and exhibit similar overall disease severity as indicated by decrease in body weight and increase in lung weight. Uninfected wild-type tracheae show negligible MMP-2 immunoreactivity, with scant MMP-9 immunoreactivity in and around growing cartilage. By contrast, MMP-2 appears in epithelial cells of infected, wild-type tracheae, and MMP-9 localizes to a large population of infiltrating leukocytes. We conclude that despite major increases in expression, MMP-2 and MMP-9 are not essential for microvascular remodeling in M. pulmonis-induced chronic airway inflammation. PMID:15075248

  13. Role of EP2 and EP4 receptors in airway microvascular leak induced by prostaglandin E2

    PubMed Central

    Jones, Victoria C; Birrell, Mark A; Maher, Sarah A; Griffiths, Mark; Grace, Megan; O'Donnell, Valerie B; Clark, Stephen R

    2016-01-01

    Background and Purpose Airway microvascular leak (MVL) involves the extravasation of proteins from post‐capillary venules into surrounding tissue. MVL is a cardinal sign of inflammation and an important feature of airway inflammatory diseases such as asthma. PGE2, a product of COX‐mediated metabolism of arachidonic acid, binds to four receptors, termed EP1–4. PGE2 has a wide variety of effects within the airway, including modulation of inflammation, sensory nerve activation and airway tone. However, the effect of PGE2 on airway MVL and the receptor/s that mediate this have not been described. Experimental Approach Evans Blue dye was used as a marker of airway MVL, and selective EP receptor agonists and antagonists were used alongside EP receptor‐deficient mice to define the receptor subtype involved. Key Results PGE2 induced significant airway MVL in mice and guinea pigs. A significant reduction in PGE2‐induced MVL was demonstrated in Ptger2 −/− and Ptger4 −/− mice and in wild‐type mice pretreated simultaneously with EP2 (PF‐04418948) and EP4 (ER‐819762) receptor antagonists. In a model of allergic asthma, an increase in airway levels of PGE2 was associated with a rise in MVL; this change was absent in Ptger2 −/− and Ptger4 −/− mice. Conclusions and Implications PGE2 is a key mediator produced by the lung and has widespread effects according to the EP receptor activated. Airway MVL represents a response to injury and under ‘disease’ conditions is a prominent feature of airway inflammation. The data presented highlight a key role for EP2 and EP4 receptors in MVL induced by PGE2. PMID:26639895

  14. Small airway epithelial cells exposure to printer-emitted engineered nanoparticles induces cellular effects on human microvascular endothelial cells in an alveolar-capillary co-culture model.

    PubMed

    Sisler, Jennifer D; Pirela, Sandra V; Friend, Sherri; Farcas, Mariana; Schwegler-Berry, Diane; Shvedova, Anna; Castranova, Vincent; Demokritou, Philip; Qian, Yong

    2015-01-01

    The printer is one of the most common office equipment. Recently, it was reported that toner formulations for printing equipment constitute nano-enabled products (NEPs) and contain engineered nanomaterials (ENMs) that become airborne during printing. To date, insufficient research has been performed to understand the potential toxicological properties of printer-emitted particles (PEPs) with several studies using bulk toner particles as test particles. These studies demonstrated the ability of toner particles to cause chronic inflammation and fibrosis in animal models. However, the toxicological implications of inhalation exposures to ENMs emitted from laser printing equipment remain largely unknown. The present study investigates the toxicological effects of PEPs using an in vitro alveolar-capillary co-culture model with Human Small Airway Epithelial Cells (SAEC) and Human Microvascular Endothelial Cells (HMVEC). Our data demonstrate that direct exposure of SAEC to low concentrations of PEPs (0.5 and 1.0 µg/mL) caused morphological changes of actin remodeling and gap formations within the endothelial monolayer. Furthermore, increased production of reactive oxygen species (ROS) and angiogenesis were observed in the HMVEC. Analysis of cytokine and chemokine levels demonstrates that interleukin (IL)-6 and MCP-1 may play a major role in the cellular communication observed between SAEC and HMVEC and the resultant responses in HMVEC. These data indicate that PEPs at low, non-cytotoxic exposure levels are bioactive and affect cellular responses in an alveolar-capillary co-culture model, which raises concerns for potential adverse health effects. PMID:25387250

  15. Tachykinin antagonists and the airways.

    PubMed

    Joos, G F; Kips, J C; Peleman, R A; Pauwels, R A

    1995-01-01

    There is now convincing evidence for the presence of substance P (SP) and neurokinin A (NKA) in human airway nerves. Studies on autopsy tissue, on bronchoalveolar lavage fluid and on sputum suggest that SP may be present in increased amounts in the asthmatic airway. Substance P and NKA are potent bronchoconstrictors of human airways, asthmatics being more sensitive than normal persons. The major enzyme responsible for the degradation of the tachykinins, the neutral endopeptidase, is present in the airways and is involved in the breakdown of exogenously administered SP and NKA, both in normal and asthmatic persons. Other, less well documented airway effects of SP and NKA include mucus secretion, vasodilation and plasma extravasation, as well as the chemoattraction and stimulation of various cells presumed to be involved in asthmatic airway inflammation. NK2 receptors and, to a lesser extent, NK1 receptors have been shown to be involved in bronchoconstriction, whereas NK1 receptors were found to be involved in mucus secretion, microvascular leakage and vasodilatation, and in most of the effects on inflammatory cells. The first clinical trial with FK224, a peptide NK1 and NK2 receptor antagonist, and CP99994, a nonpeptide NK1 receptor antagonist, are negative. However, FK224 failed to block the bronchoconstrictor effect of NKA in asthmatics and the dose of CP99994, needed to antagonize tachykinin effects in man, remains to be determined. PMID:7543746

  16. Endothelial gaps and adherent leukocytes in allergen-induced early- and late-phase plasma leakage in rat airways.

    PubMed

    Baluk, P; Bolton, P; Hirata, A; Thurston, G; McDonald, D M

    1998-06-01

    Exposure of sensitized individuals to antigen can induce allergic responses in the respiratory tract, manifested by early and late phases of vasodilatation, plasma leakage, leukocyte influx, and bronchoconstriction. Similar responses can occur in the skin, eye, and gastrointestinal tract. The early-phase response involves mast cell mediators and the late-phase response is leukocyte dependent, but the mechanism of leakage is not understood. We sought to identify the leaky blood vessels, to determine whether these vessels contained endothelial gaps, and to analyze the relationship of the gaps to adherent leukocytes, using biotinylated lectins or silver nitrate to stain the cells in situ and Monastral blue as a tracer to quantify plasma leakage. Most of the leakage occurred in postcapillary venules (< 40-microns diameter), whereas most of the leukocyte migration (predominantly neutrophils) occurred in collecting venules. Capillaries and arterioles did not leak. Endothelial gaps were found in the leaky venules, both by silver nitrate staining and by scanning electron microscopy, and 94% of the gaps were distinct from sites of leukocyte adhesion or migration. We conclude that endothelial gaps contribute to both early and late phases of plasma leakage induced by antigen, but most leakage occurs upstream to sites of leukocyte adhesion. PMID:9626051

  17. Endothelial gaps and adherent leukocytes in allergen-induced early- and late-phase plasma leakage in rat airways.

    PubMed Central

    Baluk, P.; Bolton, P.; Hirata, A.; Thurston, G.; McDonald, D. M.

    1998-01-01

    Exposure of sensitized individuals to antigen can induce allergic responses in the respiratory tract, manifested by early and late phases of vasodilatation, plasma leakage, leukocyte influx, and bronchoconstriction. Similar responses can occur in the skin, eye, and gastrointestinal tract. The early-phase response involves mast cell mediators and the late-phase response is leukocyte dependent, but the mechanism of leakage is not understood. We sought to identify the leaky blood vessels, to determine whether these vessels contained endothelial gaps, and to analyze the relationship of the gaps to adherent leukocytes, using biotinylated lectins or silver nitrate to stain the cells in situ and Monastral blue as a tracer to quantify plasma leakage. Most of the leakage occurred in postcapillary venules (< 40-microns diameter), whereas most of the leukocyte migration (predominantly neutrophils) occurred in collecting venules. Capillaries and arterioles did not leak. Endothelial gaps were found in the leaky venules, both by silver nitrate staining and by scanning electron microscopy, and 94% of the gaps were distinct from sites of leukocyte adhesion or migration. We conclude that endothelial gaps contribute to both early and late phases of plasma leakage induced by antigen, but most leakage occurs upstream to sites of leukocyte adhesion. Images Figure 3 Figure 5 Figure 6 Figure 7 PMID:9626051

  18. Comparison of diltiazem and verapamil on rat microvascular permeability.

    PubMed

    Taherzadeh, M; Warren, J B

    1997-11-01

    Calcium channel antagonists are among the most widely prescribed cardiovascular drugs. Their benefit is limited by the side effect of edema, the microvascular mechanism of which is not known. We compared the local effect on edema formation in rat skin and skeletal muscle of two calcium channel antagonists, diltiazem and verapamil, and determined if the edema effect correlated with changes in microvascular flow. An increase in microvascular flow can potentiate edema formation by increasing microvascular hydrostatic pressure and the proportion of the bed that is perfused. Diltiazem, but not verapamil or control, injected s.c. in scrotal skin caused plasma albumin leakage visualized as local bluing of tissue in rats that had been pretreated with Evans blue dye systemically. Topographic studies using Monastral blue dye showed that in the underlying cremaster muscle, diltiazem increased leakage of dye particles not from capillaries but from postcapillary venules. The postcapillary venule is associated with inflammatory edema, suggesting a direct effect of diltiazem on endothelial permeability. The local injection of diltiazem also increased significantly (P < 0.05) plasma leakage quantified as the local accumulation of systemically injected 125I-radiolabeled albumin, from 14.5 +/- 2.0 and 6.9 +/- 1.0 microliters in control sites to 30.0 +/- 7.3 and 18.0 +/- 2.5 microliters in dorsal skin and abdominal rat skin, respectively. In contrast, verapamil at similar doses did not increase plasma albumin leakage significantly. At the doses that caused local skin edema, diltiazem had less effect on microvascular skin blood flow, measured by a laser Doppler flow probe, (12.6 +/- 5.3% at 15 min and 2.8 +/- 8.4% change at 30 min) than verapamil (39.0 +/- 7.3% at 15 min 30.0 +/- 6.7% change at 30 min, P < 0.01). The microvascular effects of these two calcium channel antagonists differ in that diltiazem had a significant effect on microvascular permeability whereas verapamil had a

  19. What Causes Coronary Microvascular Disease?

    MedlinePlus

    ... Living With Clinical Trials Links Related Topics Angina Atherosclerosis Coronary Heart Disease Coronary Heart Disease Risk Factors ... Microvascular Disease? The same risk factors that cause atherosclerosis may cause coronary microvascular disease. Atherosclerosis is a ...

  20. Microvascular invasion in hepatocellular carcinoma

    PubMed Central

    Ünal, Emre; İdilman, İlkay Sedakat; Akata, Deniz; Özmen, Mustafa Nasuh; Karçaaltıncaba, Muşturay

    2016-01-01

    Microvascular invasion is a crucial histopathologic prognostic factor for hepatocellular carcinoma. We reviewed the literature and aimed to draw attention to clinicopathologic and imaging findings that may predict the presence of microvascular invasion in hepatocellular carcinoma. Imaging findings suggesting microvascular invasion are disruption of capsule, irregular tumor margin, peritumoral enhancement, multifocal tumor, increased tumor size, and increased glucose metabolism on positron emission tomography-computed tomography. In the presence of typical findings, microvascular invasion may be predicted. PMID:26782155

  1. Autologous Microvascular Breast Reconstruction

    PubMed Central

    Ramakrishnan, Venkat

    2013-01-01

    Autologous microvascular breast reconstruction is widely accepted as a key component of breast cancer treatment. There are two basic donor sites; the anterior abdominal wall and the thigh/buttock region. Each of these regions provides for a number of flaps that are successfully utilised in breast reconstruction. Refinement of surgical technique and the drive towards minimising donor site morbidity whilst maximising flap vascularity in breast reconstruction has seen an evolution towards perforator based flap reconstructions, however myocutaneous flaps are still commonly practiced. We review herein the current methods of autologous microvascular breast reconstruction. PMID:23362474

  2. Applications of microvascular surgery.

    PubMed

    Miller, C W; Fowler, J D

    1990-09-01

    The advent of microvascular surgery has radically changed the discipline of human reconstructive surgery over the last decade. The ability to anastomose vessels less than 1 mm in diameter allows the distant transfer of tissues with a known blood supply from one area of the body to another. These tissues can be detached from their local blood supply and reperfused by anastomosing vessels supplying the tissue transfer to vessels near the recipient site. This technique has been used to transfer a variety of tissues and combinations of tissues including skin, muscle, bone, and bowel to solve a variety of difficult reconstructive problems. Applications, potential applications, and problems associated with microvascular free tissue transfer will be discussed in this chapter. PMID:2134600

  3. Improving stopping construction to minimize leakage

    PubMed Central

    Grau, Roy H.; Mazzella, Andrew L.; Martikainen, Anu L.

    2015-01-01

    The proper sealing of stoppings is an important step in reducing leakage from the intake to the return airways. Leakage and the subsequent loss of ventilation resulting from improperly sealed stoppings can lead to unhealthy and unsafe working conditions. The research presented in this paper investigates the total leakage of a stopping, including air leakage through the stopping, at the stopping perimeter, and through the coalbed. The study also examines sealing considerations for stoppings that are constructed under roof control screen, the effects that wooden wedges had on inhibiting efficient application of polyurethane foam sealant, and airflow leakage through the surrounding coal. The work involved building a stopping in a dead end room of the NIOSH Safety Research Coal Mine and then pressurising the room using compressed air. Stopping leakage was evaluated by measuring air pressure loss in the enclosed room due to the air leakage. Part of the research utilises a diluted soap solution that was applied to the stopping and the surrounding coal to detect air leakage signified by bubble formations. The results show that stopping leakage can be minimised with proper sealing PMID:26379366

  4. Surgical Airway

    PubMed Central

    Patel, Sapna A; Meyer, Tanya K

    2014-01-01

    Close to 3% of all intubation attempts are considered difficult airways, for which a plan for a surgical airway should be considered. Our article provides an overview of the different types of surgical airways. This article provides a comprehensive review of the main types of surgical airways, relevant anatomy, necessary equipment, indications and contraindications, preparation and positioning, technique, complications, and tips for management. It is important to remember that the placement of a surgical airway is a lifesaving procedure and should be considered in any setting when one “cannot intubate, cannot ventilate”. PMID:24741501

  5. Microvascular decompression for intractable singultus.

    PubMed

    Saito, Atsushi; Hatayama, Toru; Kon, Hiroyuki; Nakamura, Taigen; Sasaki, Tatsuya

    2016-10-01

    Intractable singultus due to cerebrovascular disease is very rare. We report a case of intractable singultus that improved after microvascular decompression and present a literature review. The patient was a 58-year-old man with a 30-year history of persistent singultus. Its frequency and duration gradually increased and it was resistant to multiple medical treatments. Microvascular decompression to relieve pressure on the anterolateral surface of the lower medulla oblongata from the vertebral artery resulted in the resolution of singultus. Patients with intractable idiopathic singultus who fail to respond to medical therapy need to be considered for the evaluation of cerebrovascular diseases and microvascular decompression. PMID:27335312

  6. Sensory neuropeptides and airway function.

    PubMed

    Solway, J; Leff, A R

    1991-12-01

    Sensory nerves synthesize tachykinins and calcitonin-gene related peptide and package these neuropeptides together in synaptic vesicles. Stimulation of these C-fibers by a range of chemical and physical factors results in afferent neuronal conduction that elicits central parasympathetic reflexes and in antidromic conduction that results in local release of neuropeptides through the axon reflex. In the airways, sensory neuropeptides act on bronchial smooth muscle, the mucosal vasculature, and submucosal glands to promote airflow obstruction, hyperemia, microvascular hyperpermeability, and mucus hypersecretion. In addition, tachykinins potentiate cholinergic neurotransmission. Proinflammatory effects of these peptides also promote the recruitment, adherence, and activation of granulocytes that may further exacerbate neurogenic inflammation (i.e., neuropeptide-induced plasma extravasation and vasodilation). Enzymatic degradation limits the physiological effects of tachykinins but may be impaired by respiratory infection or other factors. Given their sensitivity to noxious compounds and physical stimuli and their potent effects on airway function, it is possible that neuropeptide-containing sensory nerves play an important role in mediating airway responses in human disease. Supporting this view are the striking phenomenological similarities between hyperpnea-induced bronchoconstriction (HIB) in guinea pigs and HIB in patients with exercise-induced asthma. Endogenous tachykinins released from airway sensory nerves mediate HIB in guinea pigs and also cause hyperpnea-induced bronchovascular hyperpermeability in these animals. On the basis of these observations, it is reasonable to speculate that sensory neuropeptides participate in the pathogenesis of hyperpnea-induced airflow obstruction in human asthmatic subjects as well. PMID:1663932

  7. Pathophysiological roles of microvascular alterations in pulmonary inflammatory diseases: possible implications of tumor necrosis factor-alpha and CXC chemokines

    PubMed Central

    Orihara, Kanami; Matsuda, Akio

    2008-01-01

    Chronic obstructive pulmonary disease (COPD) and bronchial asthma are common respiratory diseases that are caused by chronic inflammation of the airways. Although these diseases are mediated by substantially distinct immunological reactions, especially in mild cases, they both show increased numbers of neutrophils, increased production of tumor necrosis factor-alpha (TNF-α) and poor responses to corticosteroids, particularly in patients with severe diseases. These immunological alterations may contribute strongly to airway structural changes, commonly referred to as airway remodeling. Microvascular alterations, a component of airway remodeling and caused by chronic inflammation, are observed and appear to be clinically involved in both diseases. It has been well established that vascular endothelial growth factor (VEGF) plays important roles in the airway microvascular alterations in mild and moderate cases of both diseases, but any role that VEGF might play in severe cases of these diseases remains unclear. Here, we review recent research findings, including our own data, and discuss the possibility that TNF-α and its associated CXC chemokines play roles in microvascular alterations that are even more crucial than those of VEGF in patients with severe COPD or asthma. PMID:19281078

  8. Cardiopulmonary bypass increases pulmonary microvascular permeability through the Src kinase pathway: Involvement of caveolin-1 and vascular endothelial cadherin

    PubMed Central

    ZHANG, JUNWEN; JIANG, ZHAOLEI; BAO, CHUNRONG; MEI, JU; ZHU, JIAQUAN

    2016-01-01

    Changes in pulmonary microvascular permeability following cardiopulmonary bypass (CPB) and the underlying mechanisms have not yet been established. Therefore, the aim of the present study was to elucidate the alterations in pulmonary microvascular permeability following CPB and the underlying mechanism. The pulmonary microvascular permeability was measured using Evans Blue dye (EBD) exclusion, and the neutrophil infiltration and proinflammatory cytokine secretion was investigated. In addition, the activation of Src kinase and the phosphorylation of caveolin-1 and vascular endothelial cadherin (VE-cadherin) was examined. The results revealed that CPB increased pulmonary microvascular leakage, neutrophil count and proinflammatory cytokines in the bronchoalveolar lavage fluid, and activated Src kinase. The administration of PP2, an inhibitor of Src kinase, decreased the activation of Src kinase and attenuated the increase in pulmonary microvascular permeability observed following CPB. Two important proteins associated with vascular permeability, caveolin-1 and VE-cadherin, were significantly activated at 24 h in the lung tissues following CPB, which correlated with the alterations in pulmonary microvascular permeability and Src kinase. PP2 administration inhibited their activation, suggesting that they are downstream factors of Src kinase activation. The data indicated that the Src kinase pathway increased pulmonary microvascular permeability following CPB, and the activation of caveolin-1 and VE-cadherin may be involved. Inhibition of this pathway may provide a potential therapy for acute lung injury following cardiac surgery. PMID:26847917

  9. Land-use Leakage

    SciTech Connect

    Calvin, Katherine V.; Edmonds, James A.; Clarke, Leon E.; Bond-Lamberty, Benjamin; Kim, Son H.; Wise, Marshall A.; Thomson, Allison M.; Kyle, G. Page

    2009-12-01

    Leakage occurs whenever actions to mitigate greenhouse gas emissions in one part of the world unleash countervailing forces elsewhere in the world so that reductions in global emissions are less than emissions mitigation in the mitigating region. While many researchers have examined the concept of industrial leakage, land-use policies can also result in leakage. We show that land-use leakage is potentially as large as or larger than industrial leakage. We identify two potential land-use leakage drivers, land-use policies and bioenergy. We distinguish between these two pathways and run numerical experiments for each. We also show that the land-use policy environment exerts a powerful influence on leakage and that under some policy designs leakage can be negative. International “offsets” are a potential mechanism to communicate emissions mitigation beyond the borders of emissions mitigating regions, but in a stabilization regime designed to limit radiative forcing to 3.7 2/m2, this also implies greater emissions mitigation commitments on the part of mitigating regions.

  10. Predicting Leakage in Labyrinth Seals

    NASA Technical Reports Server (NTRS)

    Morrison, G. L.; Rhode, D. L.; Cogan, K. C.; Chi, D.; Demko, J.

    1985-01-01

    Analytical and empirical methods evaluated. 264-page report presents comprehensive information on leakage in labyrinth seals. Summarizes previous analyses of leakage, reviews leakage tests conducted by authors and evaluates various analytical and experimental methods of determining leakage and discusses leakage prediction techniques.

  11. Shroud leakage flow discouragers

    DOEpatents

    Bailey, Jeremy Clyde; Bunker, Ronald Scott

    2002-01-01

    A turbine assembly includes a plurality of rotor blades comprising a root portion, an airfoil having a pressure sidewall and a suction sidewall, and a top portion having a cap. An outer shroud is concentrically disposed about said rotor blades, said shroud in combination with said tip portions defining a clearance gap. At least one circumferential shroud leakage discourager is disposed within the shroud. The leakage discourager(s) increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the clearance gap to improve overall turbine efficiency.

  12. Emergency airway puncture

    MedlinePlus

    Emergency airway puncture is the placement of a hollow needle through the throat into the airway. It ... Emergency airway puncture is done in an emergency situation, when someone is choking and all other efforts ...

  13. Endoscopic and Microscopic Microvascular Decompression.

    PubMed

    Piazza, Matthew; Lee, John Y K

    2016-07-01

    The introduction of the endoscope into the neurosurgeon's armamentarium has revolutionized ventral and anterior skull-base surgery and, more recently, has been used in the surgical treatment of cerebellopontine angle (CPA) pathology. The utilization of the endoscope in microvascular decompression (MVD) for trigeminal neuralgia and other associated cranial nerve hyperactivity syndromes allows for unparalleled panoramic views and illumination of the neurovascular structures within the CPA and identification of vessel-nerve contact traditionally unseen using the microscope. In this article, the technical advantages and challenges of using the endoscope for MVD, operative technique, and patient outcomes of endoscopic MVD are discussed. PMID:27324997

  14. Blockage of upper airway

    MedlinePlus

    ... Airway obstruction - acute upper Images Throat anatomy Choking Respiratory system References Cukor J, Manno M. Pediatric respiratory emergencies: upper airway obstruction and infections. In: Marx ...

  15. Coronary microvascular dysfunction: an update

    PubMed Central

    Crea, Filippo; Camici, Paolo G.; Bairey Merz, Cathleen Noel

    2014-01-01

    Many patients undergoing coronary angiography because of chest pain syndromes, believed to be indicative of obstructive atherosclerosis of the epicardial coronary arteries, are found to have normal angiograms. In the past two decades, a number of studies have reported that abnormalities in the function and structure of the coronary microcirculation may occur in patients without obstructive atherosclerosis, but with risk factors or with myocardial diseases as well as in patients with obstructive atherosclerosis; furthermore, coronary microvascular dysfunction (CMD) can be iatrogenic. In some instances, CMD represents an epiphenomenon, whereas in others it is an important marker of risk or may even contribute to the pathogenesis of cardiovascular and myocardial diseases, thus becoming a therapeutic target. This review article provides an update on the clinical relevance of CMD in different clinical settings and also the implications for therapy. PMID:24366916

  16. Zero leakage sealings

    NASA Astrophysics Data System (ADS)

    Kotesovec, Bernhard; Steinrück, Herbert

    2010-11-01

    The piston rod of a reciprocating compressor is sealed with elastic cylindrical sealing elements. Across the sealings the pressure drops from the operating pressure to the ambient pressure. The lubrication gap between the elastic sealing and reciprocating piston rod is studied with the aim to find conditions of a leakage free sealing. The flow in the lubrication gap and the elastic deformation of the sealing are determined simultaneously. The net-flow during one cycle of the reciprocating piston rod is calculated. It turns out that maintaining zero leakage is very sensible. Indeed the outbound flow during out-stroke has to be equal the inbound flow during the in-stroke. By prescribing a special shape of the undeformed sealing zero leakage can be attained - at least theoretically for certain operating conditions. It turns out that temperature dependent material data and a model for cavitation is necessary. The model, its numerical implementation and results will be discussed.

  17. Coronary microvascular dysfunction, microvascular angina, and treatment strategies.

    PubMed

    Marinescu, Mark A; Löffler, Adrián I; Ouellette, Michelle; Smith, Lavone; Kramer, Christopher M; Bourque, Jamieson M

    2015-02-01

    Angina without coronary artery disease (CAD) has substantial morbidity and is present in 10% to 30% of patients undergoing angiography. Coronary microvascular dysfunction (CMD) is present in 50% to 65% of these patients. The optimal treatment of this cohort is undefined. We performed a systematic review to evaluate treatment strategies for objectively-defined CMD in the absence of CAD. We included studies assessing therapy in human subjects with angina and coronary flow reserve or myocardial perfusion reserve <2.5 by positron emission tomography, cardiac magnetic resonance imaging, dilution methods, or intracoronary Doppler in the absence of coronary artery stenosis ≥50% or structural heart disease. Only 8 papers met the strict inclusion criteria. The papers were heterogeneous, using different treatments, endpoints, and definitions of CMD. The small sample sizes severely limit the power of these studies, with an average of 11 patients per analysis. Studies evaluating sildenafil, quinapril, estrogen, and transcutaneous electrical nerve stimulation application demonstrated benefits in their respective endpoints. No benefit was found with L-arginine, doxazosin, pravastatin, and diltiazem. Our systematic review highlights that there is little data to support therapies for CMD. We assess the data meeting rigorous inclusion criteria and review the related but excluded published data. We additionally describe the next steps needed to address this research gap, including a standardized definition of CMD, routine assessment of CMD in studies of chest pain without obstructive CAD, and specific therapy assessment in the population with confirmed CMD. PMID:25677893

  18. Adenovirus-mediated HIF-1α gene transfer promotes repair of mouse airway allograft microvasculature and attenuates chronic rejection.

    PubMed

    Jiang, Xinguo; Khan, Mohammad A; Tian, Wen; Beilke, Joshua; Natarajan, Ramesh; Kosek, Jon; Yoder, Mervin C; Semenza, Gregg L; Nicolls, Mark R

    2011-06-01

    Chronic rejection, manifested as small airway fibrosis (obliterative bronchiolitis [OB]), is the main obstacle to long-term survival in lung transplantation. Recent studies demonstrate that the airways involved in a lung transplant are relatively hypoxic at baseline and that OB pathogenesis may be linked to ischemia induced by a transient loss of airway microvasculature. Here, we show that HIF-1α mediates airway microvascular repair in a model of orthotopic tracheal transplantation. Grafts with a conditional knockout of Hif1a demonstrated diminished recruitment of recipient-derived Tie2⁺ angiogenic cells to the allograft, impaired repair of damaged microvasculature, accelerated loss of microvascular perfusion, and hastened denudation of epithelial cells. In contrast, graft HIF-1α overexpression induced via an adenoviral vector prolonged airway microvascular perfusion, preserved epithelial integrity, extended the time window for the graft to be rescued from chronic rejection, and attenuated airway fibrotic remodeling. HIF-1α overexpression induced the expression of proangiogenic factors such as Sdf1, Plgf, and Vegf, and promoted the recruitment of vasoreparative Tie2⁺ cells. This study demonstrates that a therapy that enhances vascular integrity during acute rejection may promote graft health and prevent chronic rejection. PMID:21606594

  19. Flows with tip leakage

    NASA Astrophysics Data System (ADS)

    Moore, John

    The flow development within the tip gap and the flow tip leakage, applying Navier-Stokes codes, are discussed. The loss production, the turbine inefficiency and the heat transfer to the blade tip, are considered. The measurements and calculations used demonstrate features of the flow, such as separation and reattachment on the blade tip, shock formation in the tip gap, and formation and dissipation of tip gap secondary kinetic energy. A procedure for calculating turbine blade tip temperatures is included. The results for a centrifugal compressor show the interaction of the tip leakage and passage flows. The radial blackflow near the shroud wall at low off-design flow rates is considered. The calculations demonstrate the potential use of a computational fluid dynamics code for predicting a centrifugal compressor map.

  20. Upper airway test (image)

    MedlinePlus

    An upper airway biopsy is obtained by using a flexible scope called a bronchoscope. The scope is passed down through ... may be performed when an abnormality of the upper airway is suspected. It may also be performed as ...

  1. Careers in Airway Science.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC.

    The Federal Aviation Administration (FAA) has initiated the Airway Science curriculum as a method of preparing the next generation of aviation technicians and managers. This document: (1) discusses the FAA's role in the Airway Science program; (2) describes some of the career fields that FAA offers to Airway Science graduates (air traffic control…

  2. Who Is at Risk for Coronary Microvascular Disease?

    MedlinePlus

    ... Stumble. Share this page from the NHLBI on Tumblr. Share this page from the NHLBI on Twitter. Who Is at Risk for Coronary Microvascular Disease? Coronary microvascular disease can affect both men and ...

  3. Neutrophils, nitric oxide, and microvascular permeability in severe sepsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    STUDY OBJECTIVES: Alterations in microvascular permeability are prevalent in patients with sepsis; a recent study reported that patients with septic shock had increased capillary filtration coefficient (Kf), a noninvasive index of microvascular permeability. We aimed to determine whether patients wi...

  4. Coronary microvascular obstruction in acute myocardial infarction.

    PubMed

    Niccoli, Giampaolo; Scalone, Giancarla; Lerman, Amir; Crea, Filippo

    2016-04-01

    The success of a primary percutaneous intervention (PCI) in the setting of ST elevation myocardial infarction depends on the functional and structural integrity of coronary microcirculation. Coronary microvascular dysfunction and obstruction (CMVO) occurs in up to half of patients submitted to apparently successful primary PCI and is associated to a much worse outcome. The current review summarizes the complex mechanisms responsible for CMVO, including pre-existing coronary microvascular dysfunction, and highlights the current limitations in the assessment of microvascular function. More importantly, at the light of the substantial failure of trials hitherto published on the treatment of CMVO, this review proposes a novel integrated therapeutic approach, which should overcome the limitations of previous studies. PMID:26364289

  5. Electrical leakage detection circuit

    DOEpatents

    Wild, Arthur

    2006-09-05

    A method is provided for detecting electrical leakage between a power supply and a frame of a vehicle or machine. The disclosed method includes coupling a first capacitor between a frame and a first terminal of a power supply for a predetermined period of time. The current flowing between the frame and the first capacitor is limited to a predetermined current limit. It is determined whether the voltage across the first capacitor exceeds a threshold voltage. A first output signal is provided when the voltage across the capacitor exceeds the threshold voltage.

  6. The Physiologically Difficult Airway.

    PubMed

    Mosier, Jarrod M; Joshi, Raj; Hypes, Cameron; Pacheco, Garrett; Valenzuela, Terence; Sakles, John C

    2015-12-01

    Airway management in critically ill patients involves the identification and management of the potentially difficult airway in order to avoid untoward complications. This focus on difficult airway management has traditionally referred to identifying anatomic characteristics of the patient that make either visualizing the glottic opening or placement of the tracheal tube through the vocal cords difficult. This paper will describe the physiologically difficult airway, in which physiologic derangements of the patient increase the risk of cardiovascular collapse from airway management. The four physiologically difficult airways described include hypoxemia, hypotension, severe metabolic acidosis, and right ventricular failure. The emergency physician should account for these physiologic derangements with airway management in critically ill patients regardless of the predicted anatomic difficulty of the intubation. PMID:26759664

  7. The Physiologically Difficult Airway

    PubMed Central

    Mosier, Jarrod M.; Joshi, Raj; Hypes, Cameron; Pacheco, Garrett; Valenzuela, Terence; Sakles, John C.

    2015-01-01

    Airway management in critically ill patients involves the identification and management of the potentially difficult airway in order to avoid untoward complications. This focus on difficult airway management has traditionally referred to identifying anatomic characteristics of the patient that make either visualizing the glottic opening or placement of the tracheal tube through the vocal cords difficult. This paper will describe the physiologically difficult airway, in which physiologic derangements of the patient increase the risk of cardiovascular collapse from airway management. The four physiologically difficult airways described include hypoxemia, hypotension, severe metabolic acidosis, and right ventricular failure. The emergency physician should account for these physiologic derangements with airway management in critically ill patients regardless of the predicted anatomic difficulty of the intubation. PMID:26759664

  8. Effects of S-nitrosation on hemoglobin-induced microvascular damage.

    PubMed

    Burke, Tara K; Teng, Xinjun; Patel, Rakesh P; Baldwin, Ann L

    2006-01-01

    Blood substitutes, such as diaspirin cross-linked hemoglobin (Hb), cause microvascular leakiness to macromolecules. Because of the potentially stabilizing effects of nitric acid (NO) on endothelium, experiments were performed to determine whether S-nitrosohemoglobin (SNO-Hb), a potential NO-donor Hb-based blood substitute, would not cause microvascular damage. Release of NO, or its metabolites, from the SNO-Hb was facilitated by addition of glutathione, which aids in the decomposition of S-nitrosothiols. In anesthetized rats, the mesenteric microvasculature was perfused with SNO-Hb with glutathione (six rats), SNO-Hb alone (six rats), or saline (eight rats) for 10 min, followed by fluorescein isothiocyanate (FITC)-albumin for 1 min, and finally fixed for epifluorescence microscopic examination. When comparing the SNO-Hb group with saline, both the numbers and areas of leaks were significantly increased [0.019 +/- 0.003 (SEM) microm vs. 0.0030 +/- 0.0004 and 7.36 +/- 1.50 vs. 0.156 +/- 0.035 (p < 0.005)]. With the addition of glutathione, leakage was still high (0.005 +/- 0.00005 microm and 5.086 +/- 0.064 microm) but decreased compared with SNO-Hb alone (p < 0.005). In conclusion, NO, or a related vasodilator, when released from SNO-Hb, significantly reduces but does not eliminate microvascular damage. Further improvements may result by S-nitrosating a more stable form of modified hemoglobin. PMID:16910757

  9. Atrial natriuretic peptide increases microvascular blood flow and macromolecular escape during renin infusion in the hamster

    SciTech Connect

    Boric, M.P.; Albertini, R. )

    1990-02-01

    The effects of Atrial Natriuretic Peptide (ANP) on microvascular hemodynamics and macromolecular permselectivity were studied in the hamster cheek pouch under resting conditions and during intravenous renin infusion. Fluorescent intravital microscopy was used to observe arteriolar diameters and to detect escape of fluorescent dextran of 150 K-Daltons (FITC-Dx-150). Microvascular plasma flow was estimated by clearance of 51Cr-EDTA and net macromolecular transport by clearance of FITC-Dx-150. At rest, topical ANP (2-250 ng/ml) had no effect on arteriolar diameter, 51Cr-EDTA clearance, relative vascular conductance (RVC) or FITC-Dx-150 clearance. Infusion of renin (10 mU/Kg/Hr, iv) elevated systemic arterial pressure by 30% and reduced cheek pouch RVC by 26%. During renin infusion, topical ANP (50 ng/ml) produced transient arteriolar vasodilation, and increased 51Cr-EDTA clearance (+35%), RVC (+58%) and FITC-Dx-150 clearance (+54%), without affecting systemic pressure. ANP did not induce venular leakage sites under any condition, but changes in FITC-Dx-150 clearance were highly correlated with changes in 51Cr-EDTA clearance, suggesting that the larger macromolecular escape was due to increases in microvascular blood flow and capillary/post-capillary hydrostatic pressure.

  10. Dammarenediol-II Prevents VEGF-Mediated Microvascular Permeability in Diabetic Mice.

    PubMed

    Kim, Su-Hyeon; Jung, Se-Hui; Lee, Yeon-Ju; Han, Jung Yeon; Choi, Yong-Eui; Hong, Hae-Deun; Jeon, Hye-Yoon; Hwang, JongYun; Na, SungHun; Kim, Young-Myeong; Ha, Kwon-Soo

    2015-12-01

    Diabetic retinopathy is a major diabetic complication predominantly caused by vascular endothelial growth factor (VEGF)-induced vascular permeability in the retina; however, treatments targeting glycemic control have not been successful. Here, we investigated the protective effect of dammarenediol-II, a precursor of triterpenoid saponin biosynthesis, on VEGF-induced vascular leakage using human umbilical vein endothelial cells (HUVECs) and diabetic mice. We overproduced the compound in transgenic tobacco expressing Panax ginseng dammarenediol-II synthase gene and purified using column chromatography. Analysis of the purified compound using a gas chromatography-mass spectrometry system revealed identical retention time and fragmentation pattern to those of authentic standard dammarenediol-II. Dammarenediol-II inhibited VEGF-induced intracellular reactive oxygen species generation, but it had no effect on the levels of intracellular Ca(2+) in HUVECs. We also found that dammarenediol-II inhibited VEGF-induced stress fiber formation and vascular endothelial-cadherin disruption, both of which play critical roles in modulating endothelial permeability. Notably, microvascular leakage in the retina of diabetic mice was successfully inhibited by intravitreal dammarenediol-II injection. Our results suggest that the natural drug dammarenediol-II may have the ability to prevent diabetic microvascular complications, including diabetic retinopathy. PMID:26400610

  11. How to assess microvascular structure in humans.

    PubMed

    Rizzoni, Damiano; Aalkjaer, Christian; De Ciuceis, Carolina; Porteri, Enzo; Rossini, Claudia; Rosei, Claudia Agabiti; Sarkar, Annamaria; Rosei, Enrico Agabiti

    2011-12-01

    Structural alterations of subcutaneous small resistance arteries, as indicated by an increased media to lumen ratio, are frequently present in hypertensive and/or diabetic patients. However, the evaluation of microvascular structure is not an easy task. Among the methods that may be applied to humans, plethysmographic evaluation of small arteries and wire or pressure micromyography were extensively used in the last decades. Media to lumen ratio of small arteries evaluated by micromyography was demonstrated to possess a strong prognostic significance; however, its extensive evaluation is limited by the invasiveness of the assessment, since a biopsy of subcutaneous fat is needed. Non-invasive approaches were then proposed, including capillaroscopy, which provides information about microvascular rarefaction. Recently, the interest of investigators has focused on the retinal microvascular bed. In particular, a non-invasive measurement of wall thickness to internal lumen ratio of retinal arterioles using scanning laser Doppler flowmetry has been recently introduced. Preliminary data suggest a fairly good agreement between this approach and micromyographic measurements, generally considered the gold standard approach. Therefore, the evaluation of microvascular structure is progressively moving from bench to bedside, and it could represent, in the immediate future, an evaluation to be performed in all hypertensive patients, in order to obtain a better stratification of cardiovascular risk. PMID:22283671

  12. Roles of LOX-1 in microvascular dysfunction.

    PubMed

    Lubrano, Valter; Balzan, Silvana

    2016-05-01

    Studies from human and animal models with metabolic disease and hypertension highlight atrophic remodeling, reduced lumen size and thinner vascular walls of microvessels with profound density reduction. This impaired vascular response limits the perfusion of peripheral tissues inducing organ damage. These conditions are strongly associated with oxidative stress and in particular with the up-regulation of lectin-like oxidized low density lipoprotein receptor-1 (LOX-1). Several factors such as cytokines, shear stress, and advanced glycation end-products, especially oxLDL, can up-regulate LOX-1. The activation of this receptor induces the production of adhesion molecules, cytokines and the release of reactive oxygen species via NADPH oxidase. LOX-1 is considered a potent mediator of endothelial dysfunction and it is significantly associated with reduced microvascular endothelium NO-dependent vasodilation in hypercholesterolemia and hypertension. Microvascular endothelial cells increased the expression of IL-6 in association with the increased concentration of LDL and its degree of oxidation. Moreover, increased IL-6 levels are associated with up-regulation of LOX-1 in a dose-dependent manner. Another consequence of microvascular inflammation is the generation of small amounts of ROS, similar to those induced by low concentration of oxLDL (<5 μg/mL) which induces capillary tube formation of endothelial cells, through LOX-1 up-regulation. In light of its central role, LOX-1 represents an attractive therapeutic target for the treatment of human atherosclerotic diseases and microvascular disorders. PMID:26907636

  13. Engineering Airway Epithelium

    PubMed Central

    Soleas, John P.; Paz, Ana; Marcus, Paula; McGuigan, Alison; Waddell, Thomas K.

    2012-01-01

    Airway epithelium is constantly presented with injurious signals, yet under healthy circumstances, the epithelium maintains its innate immune barrier and mucociliary elevator function. This suggests that airway epithelium has regenerative potential (I. R. Telford and C. F. Bridgman, 1990). In practice, however, airway regeneration is problematic because of slow turnover and dedifferentiation of epithelium thereby hindering regeneration and increasing time necessary for full maturation and function. Based on the anatomy and biology of the airway epithelium, a variety of tissue engineering tools available could be utilized to overcome the barriers currently seen in airway epithelial generation. This paper describes the structure, function, and repair mechanisms in native epithelium and highlights specific and manipulatable tissue engineering signals that could be of great use in the creation of artificial airway epithelium. PMID:22523471

  14. Conquering the difficult airway.

    PubMed

    Gandy, William E

    2008-01-01

    Every medic should practice regularly for the inevitable difficult airway case. Practice should include review of the causes of difficult airways, as well as skill practice. Having a preassembled airway kit can make your response to an unexpected difficult situation easier. Of all the devices mentioned, the bougie is the airway practitioner's best friend. Using the BURP technique, if not contraindicated, together with the bougie will enable you to intubate many difficult patients with confidence. Remember, "If your patient cannot breathe, nothing else matters. PMID:18251307

  15. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  16. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  17. Multifamily Envelope Leakage Model

    SciTech Connect

    Faakye, Omari; Griffiths, Dianne

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  18. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study.

    PubMed

    Berlet, Thomas; Marchon, Mathias

    2016-01-01

    This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema. PMID:27073395

  19. Leakage Characteristics of Dual-Cannula Fenestrated Tracheostomy Tubes during Positive Pressure Ventilation: A Bench Study

    PubMed Central

    2016-01-01

    This study compared the leakage characteristics of different types of dual-cannula fenestrated tracheostomy tubes during positive pressure ventilation. Fenestrated Portex® Blue Line Ultra®, TRACOE® twist, or Rüsch® Traceofix® tracheostomy tubes equipped with nonfenestrated inner cannulas were tested in a tracheostomy-lung simulator. Transfenestration pressures and transfenestration leakage rates were measured during positive pressure ventilation. The impact of different ventilation modes, airway pressures, temperatures, and simulated static lung compliance settings on leakage characteristics was assessed. We observed substantial differences in transfenestration pressures and transfenestration leakage rates. The leakage rates of the best performing tubes were <3.5% of the delivered minute volume. At body temperature, the leakage rates of these tracheostomy tubes were <1%. The tracheal tube design was the main factor that determined the leakage characteristics. Careful tracheostomy tube selection permits the use of fenestrated tracheostomy tubes in patients receiving positive pressure ventilation immediately after stoma formation and minimises the risk of complications caused by transfenestration gas leakage, for example, subcutaneous emphysema. PMID:27073395

  20. Brachycephalic airway syndrome: management.

    PubMed

    Lodato, Dena L; Hedlund, Cheryl S

    2012-08-01

    Brachycephalic airway syndrome (BAS) is a group of primary and secondary abnormalities that result in upper airway obstruction. Several of these abnormalities can be addressed medically and/or surgically to improve quality of life. This article reviews potential complications, anesthetic considerations, recovery strategies, and outcomes associated with medical and surgical management of BAS. PMID:22935992

  1. Simvastatin Inhibits Airway Hyperreactivity

    PubMed Central

    Zeki, Amir A.; Franzi, Lisa; Last, Jerold; Kenyon, Nicholas J.

    2009-01-01

    Rationale: Statin use has been linked to improved lung health in asthma and chronic obstructive pulmonary disease. We hypothesize that statins inhibit allergic airway inflammation and reduce airway hyperreactivity via a mevalonate-dependent mechanism. Objectives: To determine whether simvastatin attenuates airway inflammation and improves lung physiology by mevalonate pathway inhibition. Methods: BALB/c mice were sensitized to ovalbumin over 4 weeks and exposed to 1% ovalbumin aerosol over 2 weeks. Simvastatin (40 mg/kg) or simvastatin plus mevalonate (20 mg/kg) was injected intraperitoneally before each ovalbumin exposure. Measurements and Main Results: Simvastatin reduced total lung lavage leukocytes, eosinophils, and macrophages (P < 0.05) in the ovalbumin-exposed mice. Cotreatment with mevalonate, in addition to simvastatin, reversed the antiinflammatory effects seen with simvastatin alone (P < 0.05). Lung lavage IL-4, IL-13, and tumor necrosis factor-α levels were all reduced by treatment with simvastatin (P < 0.05). Simvastatin treatment before methacholine bronchial challenge increased lung compliance and reduced airway hyperreactivity (P = 0.0001). Conclusions: Simvastatin attenuates allergic airway inflammation, inhibits key helper T cell type 1 and 2 chemokines, and improves lung physiology in a mouse model of asthma. The mevalonate pathway appears to modulate allergic airway inflammation, while the beneficial effects of simvastatin on lung compliance and airway hyperreactivity may be independent of the mevalonate pathway. Simvastatin and similar agents that modulate the mevalonate pathway may prove to be treatments for inflammatory airway diseases, such as asthma. PMID:19608720

  2. Controversies in Pediatric Perioperative Airways

    PubMed Central

    Klučka, Jozef; Štourač, Petr; Štoudek, Roman; Ťoukálková, Michaela; Harazim, Hana; Kosinová, Martina

    2015-01-01

    Pediatric airway management is a challenge in routine anesthesia practice. Any airway-related complication due to improper procedure can have catastrophic consequences in pediatric patients. The authors reviewed the current relevant literature using the following data bases: Google Scholar, PubMed, Medline (OVID SP), and Dynamed, and the following keywords: Airway/s, Children, Pediatric, Difficult Airways, and Controversies. From a summary of the data, we identified several controversies: difficult airway prediction, difficult airway management, cuffed versus uncuffed endotracheal tubes for securing pediatric airways, rapid sequence induction (RSI), laryngeal mask versus endotracheal tube, and extubation timing. The data show that pediatric anesthesia practice in perioperative airway management is currently lacking the strong evidence-based medicine (EBM) data that is available for adult subpopulations. A number of procedural steps in airway management are derived only from adult populations. However, the objective is the same irrespective of patient age: proper securing of the airway and oxygenation of the patient. PMID:26759809

  3. Sex-Specific Factors in Microvascular Angina

    PubMed Central

    Humphries, Karin H.; Bairey Merz, C. Noel

    2014-01-01

    Among women presenting for evaluation of suspected ischemic symptoms, a diagnosis of normal coronary arteries is five times more common, as compared to men. These women are often labeled as cardiac syndrome X (CSX), a subset of which have microvascular angina (MA) due to microvascular coronary dysfunction (MCD). MCD is not benign and is associated with an annual 2.5% cardiac event rate. Non-invasive testing for MCD remains insensitive although newer imaging modalities such as adenosine cardiac magnetic resonance imaging (CMRI) appear promising. The gold standard for diagnosis of MCD is coronary reactivity testing (CRT), an invasive technique which is not available in many countries. With regard to treatment, large scale trials are lacking. While research is ongoing, the current platform of therapy consists of anti-anginal, anti-platelet and endothelial modifying agents (primarily angiotensin converting enzyme inhibitors and statins). PMID:24582724

  4. Predictors of Microvascular Invasion in Hepatocellular Carcinoma.

    PubMed

    Yamashita, Yo-Ichi; Shirabe, Ken; Aishima, Shinichi; Maehara, Yoshihiko

    2015-09-01

    This chapter covers a range of important topics in the evaluation of the microvascular invasion (MVI) in hepatocellular carcinoma (HCC) before treatment. The malignant potential of HCC is reflected by the types of MVI such as portal venous (vp), hepatic vein (vv) or bile duct (b) infiltration. The identification of the type of MVI in HCC has a key role in decisions regarding the effective treatment of HCC. Here, we describe the possible and important predictors of MVI in HCC. PMID:26398341

  5. Neutrino Leakage and Supernova Explosion

    NASA Astrophysics Data System (ADS)

    Liao, Dao-Bing; Zhang, Miao-Jing; Li, Yan; Pan, Jiang-Hong; Chen, Xiu

    2015-04-01

    In the process of supernova explosion the leakage of neutrinos is very important. Adopting an one-dimensional spherically symmetrical model, and under the different neutrino leakage modes, the explosion processes of type II supernovae with masses of 12 M⊙, 14 M⊙, and 15 M⊙ are simulated numerically. The results indicate that all these different neutrino leakage modes have influences on the supernova collapse, shock propagation, and supernova explosion. The best values of the related parameters which are propitious for the type II supernova explosion are given. In addition, the impacts of the equation of state and the compression modulus on the simulated results are discussed.

  6. Retinal microvascular network attenuation in Alzheimer's disease

    PubMed Central

    Williams, Michael A.; McGowan, Amy J.; Cardwell, Chris R.; Cheung, Carol Y.; Craig, David; Passmore, Peter; Silvestri, Giuliana; Maxwell, Alexander P.; McKay, Gareth J.

    2015-01-01

    Introduction Cerebral small-vessel disease has been implicated in the development of Alzheimer's disease (AD). The retinal microvasculature enables the noninvasive visualization and evaluation of the systemic microcirculation. We evaluated retinal microvascular parameters in a case-control study of AD patients and cognitively normal controls. Methods Retinal images were computationally analyzed and quantitative retinal parameters (caliber, fractal dimension, tortuosity, and bifurcation) measured. Regression models were used to compute odds ratios (OR) and confidence intervals (CI) for AD with adjustment for confounders. Results Retinal images were available in 213 AD participants and 294 cognitively normal controls. Persons with lower venular fractal dimension (OR per standard deviation [SD] increase, 0.77 [CI: 0.62–0.97]) and lower arteriolar tortuosity (OR per SD increase, 0.78 [CI: 0.63–0.97]) were more likely to have AD after appropriate adjustment. Discussion Patients with AD have a sparser retinal microvascular network and retinal microvascular variation may represent similar pathophysiological events within the cerebral microvasculature of patients with AD. PMID:26634224

  7. Hypertension Management and Microvascular Insulin Resistance in Diabetes

    PubMed Central

    Ko, Seung-Hyun; Cao, Wenhong; Liu, Zhenqi

    2011-01-01

    Type 2 diabetes is in essence a vascular disease and is frequently associated with hypertension, macrovascular events, and microvascular complications. Microvascular dysfunction, including impaired recruitment and capillary rarefaction, has been implicated in the pathogenesis of diabetic complications. Microvascular insulin resistance and renin-angiotensin system upregulation are present in diabetes, and each contributes to the development of hypertension and microvascular dysfunction. In the insulin-sensitive state, insulin increases microvascular perfusion by increasing endothelial nitric oxide production, but this effect is abolished by insulin resistance. Angiotensin II, acting via the type 1 receptors, induces inflammation and oxidative stress, leading to impaired insulin signaling, reduced nitric oxide availability, and vasoconstriction. Conversely, it acts on the type 2 receptors to cause vasodilatation. Because substrate and hormonal exchanges occur in the microvasculature, antihypertensive agents targeted to improve microvascular insulin sensitivity and function may have beneficial effects beyond their capacity to lower blood pressure in patients with diabetes. PMID:20582734

  8. TWO NEW DUCT LEAKAGE TESTS

    SciTech Connect

    ANDREWS,J.W.

    1998-12-01

    Two variations on the tests for duct leakage currently embodied in ASHRAE Standard 152P (Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems) are presented. Procedures are derived for calculating supply and return duct leakage to/from outside using these new variations. Results of these tests are compared with the original ones in Standard 152P on the basis of data collected in three New York State homes.

  9. Two New Duct Leakage Tests

    SciTech Connect

    Andrews, J.W.

    1998-12-01

    Two variations on the tests for duct leakage currently embodied in ASHRAE Standard 152P (Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems) are presented. Procedures are derived for calculating supply and return duct leakage to/from outside using these new variations. Results of these tests are compared with the original ones in Standard 152P on the basis of data collected in three New York State homes.

  10. Airway dysfunction in swimmers.

    PubMed

    Bougault, Valérie; Boulet, Louis-Philippe

    2012-05-01

    Elite competitive swimmers are particularly affected by airway disorders that are probably related to regular and intense training sessions in a chlorinated environment. Upper and lower airway respiratory symptoms, rhinitis, airway hyper-responsiveness, and exercise-induced bronchoconstriction are highly prevalent in these athletes, but their influence on athletic performance is still unclear. The authors reviewed the main upper and lower respiratory ailments observed in competitive swimmers who train in indoor swimming pools, their pathophysiology, clinical significance and possible effects on performance. Issues regarding the screening of these disorders, their management and preventive measures are addressed. PMID:22247299

  11. Meteorological conditions along airways

    NASA Technical Reports Server (NTRS)

    Gregg, W R

    1927-01-01

    This report is an attempt to show the kind of meteorological information that is needed, and is in part available, for the purpose of determining operating conditions along airways. In general, the same factors affect these operating conditions along all airways though in varying degree, depending upon their topographic, geographic, and other characteristics; but in order to bring out as clearly as possible the nature of the data available, a specific example is taken, that of the Chicago-Dallas airway on which regular flying begins this year (1926).

  12. Decreased Rate of CSF Leakage Associated with Complete Reconstruction of Suboccipital Cranial Defects

    PubMed Central

    Stoker, Michael A.; Forbes, Jonathan A.; Hanif, Rimal; Cooper, Calvin; Nian, Hui; Konrad, Peter E.; Neimat, Joseph S.

    2012-01-01

    Background Cerebrospinal fluid (CSF) leakage represents a major source of morbidity following microvascular decompression (MVD) surgery. The objective of this study was to retrospectively assess whether complete versus incomplete reconstruction of the suboccipital cranial defect influences the incidence of CSF leakage following MVD. Methods We reviewed the charts of 100 patients who consecutively underwent MVD for trigeminal neuralgia by two attending neurosurgeons between July 2004 and April 2010. Operative variables including incomplete or complete calvarial reconstruction, primary dural closure or dural closure with adjunct, and use of lumbar drainage were recorded. The effect of complete calvarial reconstruction on the incidence of postoperative CSF leakage was examined using a multivariate logistic regression model. Results Of the 36 patients whose wound closure was reconstructed with a complete cranioplasty, 2 (5.6%) patients experienced a postoperative CSF leak. Of the 64 patients whose wound closure was augmented with an incomplete cranioplasty, 15 (23.4%) experienced a postoperative CSF leak. There was suggestive but inconclusive evidence that the risk of CSF leakage following MVD was smaller with complete reconstruction of calvarial defect than with incomplete reconstruction (two-sided p value = 0.059), after accounting for age, dural closure method, use of lumbar drainage, and previous MVD. Conclusion Complete reconstruction of the suboccipital cranial defect decreases the risk of CSF leakage. PMID:23905005

  13. Direct ink writing of microvascular networks

    NASA Astrophysics Data System (ADS)

    Wu, Willie

    Nature is replete with examples of embedded microvascular systems that enable efficient fluid flow and distribution for autonomic healing, cooling, and energy harvesting. The ability to incorporate microvascular networks in functional materials systems is therefore both scientifically and technologically important. In this PhD thesis, the direct-write assembly of planar and 3D biomimetic microvascular networks within polymer and hydrogel matrices is demonstrated. In addition, the influence of network design of fluid transport efficiency is characterized. Planar microvascular networks composed of periodic lattices of uniformal microchannels and hierarchical, branching architectures are constructed by direct-write assembly of a fugitive organic ink. Several advancements are required to facilitate their patterning, including pressure valving, dual ink printing, and dynamic pressure variation to allow tunable control of ink deposition. The hydraulic conductance is measured using a high pressure flow meter as a function of network design. For a constant vascular volume and areal coverage, 2- and 4-generation branched architectures that obey Murray's Law exhibited the highest hydraulic conductivity. These experimental observations are in good agreement with predictions made by analytic models. 3D microvascular networks are fabricated by omnidirectional printing a fugitive organic ink into a photopolymerizable hydrogel matrix that is capped with fluid filler of nearly identical composition. Using this approach, 3D networks of arbitrary design can be patterned. After ink deposition is complete, the matrix and fluid filler are chemically cross-linked via UV irradiation, and the ink is removed by liquefication. Aqueous solutions composed of a triblock copolymer of polyethylene oxide (PEO)-polypropylene oxide (PPO)-PEO constitute the materials system of choice due to their thermal- and concentration-dependent phase behavior. Specifically, the fugitive ink consists of a 23 w

  14. Airway management in trauma.

    PubMed

    Langeron, O; Birenbaum, A; Amour, J

    2009-05-01

    Maintenance of a patent and prevention of aspiration are essential for the management of the trauma patient, that requires experienced physicians in airway control techniques. Difficulties of the airway control in the trauma setting are increased by the vital failures, the risk of aspiration, the potential cervical spine injury, the combative patient, and the obvious risk of difficult tracheal intubation related to specific injury related to the trauma. Endotracheal intubation remains the gold standard in trauma patient airway management and should be performed via the oral route with a rapid sequence induction and a manual in-line stabilization maneuver, to decrease the risks previously mentioned. Different techniques to control the airway in trauma patients are presented: improvement of the laryngoscopic vision, lighted stylet tracheal intubation, retrograde technique for orotracheal intubation, the laryngeal mask and the intubating laryngeal mask airways, the combitube and cricothyroidotomy. Management of the airway in trauma patients requires regular training in these techniques and the knowledge of complementary techniques allowing tracheal intubation or oxygenation to overcome difficult intubation and to prevent major complications as hypoxemia and aspiration. PMID:19412149

  15. Microvascular transplantation of the rat submandibular gland.

    PubMed

    Spiegel, J H; Zhang, F; Levin, D E; Singer, M I; Buncke, H J

    2000-11-01

    Xerostomia results from salivary gland irradiation during treatment of head and neck malignancies. In addition to having difficulty with speech and swallowing, these patients experience loss of taste, dental caries, and chronic fungal infections. The paired submandibular glands provide 70 percent of the normal salivary flow and are difficult to shield during radiation therapy. Another sicca condition, xerophthalmia, may result from facial nerve injury or other medical disorders and results in pain, corneal ulceration, and possible vision loss. Treatment options for xerostomia are limited, and management of xerophthalmia usually focuses on the eyelids, rather than the fundamental problem of inadequate secretory protection. In this study, a rat model for submandibular gland microvascular transplantation was developed to assess the feasibility of salivary tissue transfer. Sixteen rats underwent submandibular gland transplantation from the neck to the groin. Fourteen of these rats underwent microvascular anastomosis of the vascular pedicle. Ten glands were assessed for viability at 4 days after transplantation, and four glands were examined after 7, 10, 14, or 21 days. By gross and histologic examination, 93 percent of transplanted glands showed expected long-term viability after at least 4 postoperative days. Microvascular techniques were shown to be applicable to the transplantation of submandibular gland salivary tissue. This has not previously been shown in a rat model. It is possible that submandibular glands could be transplanted to the eye for treatment of xerophthalmia and out of the neck during irradiation of the head and neck, with subsequent replantation after treatment as a means of preventing permanent xerostomia. PMID:11083564

  16. Cathepsin S Cleavage of Protease-Activated Receptor-2 on Endothelial Cells Promotes Microvascular Diabetes Complications.

    PubMed

    Kumar Vr, Santhosh; Darisipudi, Murthy N; Steiger, Stefanie; Devarapu, Satish Kumar; Tato, Maia; Kukarni, Onkar P; Mulay, Shrikant R; Thomasova, Dana; Popper, Bastian; Demleitner, Jana; Zuchtriegel, Gabriele; Reichel, Christoph; Cohen, Clemens D; Lindenmeyer, Maja T; Liapis, Helen; Moll, Solange; Reid, Emma; Stitt, Alan W; Schott, Brigitte; Gruner, Sabine; Haap, Wolfgang; Ebeling, Martin; Hartmann, Guido; Anders, Hans-Joachim

    2016-06-01

    Endothelial dysfunction is a central pathomechanism in diabetes-associated complications. We hypothesized a pathogenic role in this dysfunction of cathepsin S (Cat-S), a cysteine protease that degrades elastic fibers and activates the protease-activated receptor-2 (PAR2) on endothelial cells. We found that injection of mice with recombinant Cat-S induced albuminuria and glomerular endothelial cell injury in a PAR2-dependent manner. In vivo microscopy confirmed a role for intrinsic Cat-S/PAR2 in ischemia-induced microvascular permeability. In vitro transcriptome analysis and experiments using siRNA or specific Cat-S and PAR2 antagonists revealed that Cat-S specifically impaired the integrity and barrier function of glomerular endothelial cells selectively through PAR2. In human and mouse type 2 diabetic nephropathy, only CD68(+) intrarenal monocytes expressed Cat-S mRNA, whereas Cat-S protein was present along endothelial cells and inside proximal tubular epithelial cells also. In contrast, the cysteine protease inhibitor cystatin C was expressed only in tubules. Delayed treatment of type 2 diabetic db/db mice with Cat-S or PAR2 inhibitors attenuated albuminuria and glomerulosclerosis (indicators of diabetic nephropathy) and attenuated albumin leakage into the retina and other structural markers of diabetic retinopathy. These data identify Cat-S as a monocyte/macrophage-derived circulating PAR2 agonist and mediator of endothelial dysfunction-related microvascular diabetes complications. Thus, Cat-S or PAR2 inhibition might be a novel strategy to prevent microvascular disease in diabetes and other diseases. PMID:26567242

  17. Influenza Infects Lung Microvascular Endothelium Leading to Microvascular Leak: Role of Apoptosis and Claudin-5

    PubMed Central

    Armstrong, Susan M.; Wang, Changsen; Tigdi, Jayesh; Si, Xiaoe; Dumpit, Carlo; Charles, Steffany; Gamage, Asela; Moraes, Theo J.; Lee, Warren L.

    2012-01-01

    Severe influenza infections are complicated by acute lung injury, a syndrome of pulmonary microvascular leak. The pathogenesis of this complication is unclear. We hypothesized that human influenza could directly infect the lung microvascular endothelium, leading to loss of endothelial barrier function. We infected human lung microvascular endothelium with both clinical and laboratory strains of human influenza. Permeability of endothelial monolayers was assessed by spectrofluorimetry and by measurement of the transendothelial electrical resistance. We determined the molecular mechanisms of flu-induced endothelial permeability and developed a mouse model of severe influenza. We found that both clinical and laboratory strains of human influenza can infect and replicate in human pulmonary microvascular endothelium, leading to a marked increase in permeability. This was caused by apoptosis of the lung endothelium, since inhibition of caspases greatly attenuated influenza-induced endothelial leak. Remarkably, replication-deficient virus also caused a significant degree of endothelial permeability, despite displaying no cytotoxic effects to the endothelium. Instead, replication-deficient virus induced degradation of the tight junction protein claudin-5; the adherens junction protein VE-cadherin and the actin cytoskeleton were unaffected. Over-expression of claudin-5 was sufficient to prevent replication-deficient virus-induced permeability. The barrier-protective agent formoterol was able to markedly attenuate flu-induced leak in association with dose-dependent induction of claudin-5. Finally, mice infected with human influenza developed pulmonary edema that was abrogated by parenteral treatment with formoterol. Thus, we describe two distinct mechanisms by which human influenza can induce pulmonary microvascular leak. Our findings have implications for the pathogenesis and treatment of acute lung injury from severe influenza. PMID:23115643

  18. Mechanisms underlying the cerebral microvascular responses to angiotensin II-induced hypertension.

    PubMed

    Vital, Shantel A; Terao, Satoshi; Nagai, Mutsumi; Granger, D Neil

    2010-11-01

    Angiotensin II (AngII) and AngII type-1 receptors (AT1r) have been implicated in the pathogenesis of hypertension and ischemic stroke. The objectives of this study was to determine if/how chronic AngII administration affects blood-brain barrier (BBB) function and blood cell adhesion in the cerebral microvasculature. AngII-loaded osmotic pumps were implanted in wild type (WT) and mutant mice. Leukocyte and platelet adhesion were monitored in cerebral venules by intravital microscopy and BBB permeability detected by Evans blue leakage. AngII (two week) infusion increased blood pressure in WT mice. This was accompanied by an increased BBB permeability and a high density of adherent leukocytes and platelets. AT1r (on the vessel wall, but not on blood cells) was largely responsible for the microvascular responses to AngII. Immunodeficient (Rag-1(-/-) ) mice exhibited blunted blood cell recruitment responses without a change in BBB permeability. A similar protection pattern was noted in RANTES(-/-) and P-selectin(-/-) mice, with bone marrow chimeras (blood cell deficiency only) yielding responses comparable to the respective knockouts. These findings implicate AT1r in the microvascular dysfunction associated with AngII-induced hypertension and suggest that immune cells and blood cell-associated RANTES and P-selectin contribute to the blood cell recruitment, but not the BBB failure, elicited by AngII. PMID:21044218

  19. Listeriolysin O mediates cytotoxicity against human brain microvascular

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Penetration of the brain microvascular endothelial layer is one of the routes L. monocytogenes use to breach the blood-brain barrier. Because host factors in the blood severely limit direct invasion of human brain microvascular endothelial cells (HBMECs) by L. monocytogenes, alternative mechanisms m...

  20. Malvidin’s Effects on Rat Pial Microvascular Permeability Changes Due to Hypoperfusion and Reperfusion Injury

    PubMed Central

    Lapi, Dominga; Chiurazzi, Martina; Di Maro, Martina; Mastantuono, Teresa; Battiloro, Laura; Sabatino, Lina; Ricci, Serena; Di Carlo, Angelina; Starita, Noemy; Guida, Bruna; Santillo, Mariarosaria; Colantuoni, Antonio

    2016-01-01

    The present study was aimed to evaluate the malvidin’s protective effects on damage induced by 30 min bilateral common carotid artery occlusion (BCCAO) and 60 min reperfusion (RE) in rat pial microcirculation. Rat pial microcirculation was observed using fluorescence microscopy through a closed cranial window. Western blotting analysis was performed to investigate the endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS) and matrix metalloproteinase 9 (MMP-9) expression. Moreover, MMP-9 activity was evaluated by zymography. Finally, neuronal damage and radical oxygen species (ROS) formation were assessed. In all animals, pial arterioles were classified in five orders of branching according to Strahler’s method. In hypoperfused rats, 30 min BCCAO and 60 min RE caused a decrease in arteriolar diameter, an increase in microvascular leakage and leukocyte adhesion, accompanied by decreased capillary perfusion and red blood cell velocity (VRBC). Moreover, marked neuronal damage and evident ROS generation were detected. Conversely, malvidin administration induced arteriolar dilation in dose-related manner, reducing microvascular leakage as well as leukocyte adhesion. Capillary perfusion and VRBC were protected. Nitric oxide (NO) synthase inhibition significantly attenuated malvidin’s effects on arteriolar diameter. Western blotting analysis revealed an increase in eNOS and p-eNOS expression, while zymography indicated a decrease in MMP-9 activity after malvidin’s administration. Furthermore, malvidin was able to prevent neuronal damage and to decrease ROS generation. In conclusion, malvidin protects rat pial microcirculation against BCCAO/RE injury, preventing blood-brain impairment and neuronal loss. Malvidin’s effects appear to be mediated by eNOS activation and scavenger activity. PMID:27445688

  1. Current Diagnostic and Therapeutic Strategies in Microvascular Angina

    PubMed Central

    Mumma, Bryn; Flacke, Nathalie

    2014-01-01

    Microvascular angina is common among patients with signs and symptoms of acute coronary syndrome and is associated with an increased risk of cardiovascular and cerebrovascular events. Unfortunately, microvascular is often under-recognized in clinical settings. The diagnosis of microvascular angina relies on assessment of the functional status of the coronary microvasculature. Invasive strategies include acetylcholine provocation, intracoronary Doppler ultrasound, and intracoronary thermodilution; noninvasive strategies include cardiac positron emission tomography (PET), cardiac magnetic resonance, and Doppler echocardiography. Once the diagnosis of microvascular angina is established, treatment is focused on improving symptoms and reducing future risk of cardiovascular and cerebrovascular events. Pharmacologic options and lifestyle modifications for patients with microvascular angina are similar to those for patients with coronary artery disease. PMID:25685641

  2. Robust characterization of leakage errors

    NASA Astrophysics Data System (ADS)

    Wallman, Joel J.; Barnhill, Marie; Emerson, Joseph

    2016-04-01

    Leakage errors arise when the quantum state leaks out of some subspace of interest, for example, the two-level subspace of a multi-level system defining a computational ‘qubit’, the logical code space of a quantum error-correcting code, or a decoherence-free subspace. Leakage errors pose a distinct challenge to quantum control relative to the more well-studied decoherence errors and can be a limiting factor to achieving fault-tolerant quantum computation. Here we present a scalable and robust randomized benchmarking protocol for quickly estimating the leakage rate due to an arbitrary Markovian noise process on a larger system. We illustrate the reliability of the protocol through numerical simulations.

  3. Leakage currents in SOI MOSFETS

    SciTech Connect

    Annamala, N.K.; Biwer, M.C.

    1988-12-01

    Total dose response of both NMOS and PMOS FETs fabricated on SOI substrates was studied. Two types of back-channel leakage currents were identified. A back-channel leakage due to MOSFET action uses the substrate bias as the gate bias. The other component is due to soft reverse characteristics of the body-drain junction. The back-channel leakage due to MOSFET action varies with the substrate bias and hence varies with irradiation due to threshold voltage shift. The soft reverse characteristics are a function of drain-body voltage and hence vary with substrate bias and irradiation. I-V characteristics and subthreshold currents of both front and back channels as a function of total dose were obtained.

  4. Microvascular Repair: Post-Angiogenesis Vascular Dynamics

    PubMed Central

    LeBlanc, Amanda J.; Krishnan, Laxminarayanan; Sullivan, Christopher J.; Williams, Stuart K.; Hoying, James B.

    2013-01-01

    Vascular compromise and the accompanying perfusion deficits cause or complicate a large array of disease conditions and treatment failures. This has prompted the exploration of therapeutic strategies to repair or regenerate vasculatures thereby establishing more competent microcirculatory beds. Growing evidence indicates that an increase in vessel numbers within a tissue does not necessarily promote an increase in tissue perfusion. Effective regeneration of a microcirculation entails the integration of new stable microvessel segments into the network via neovascularization. Beginning with angiogenesis, neovascularization entails an integrated series of vascular activities leading to the formation of a new mature microcirculation and includes vascular guidance and inosculation, vessel maturation, pruning, arterio-venous specification, network patterning, structural adaptation, intussusception, and microvascular stabilization. While the generation of new vessel segments is necessary to expand a network, without the concomitant neovessel remodeling and adaptation processes intrinsic to microvascular network formation, these additional vessel segments give rise to a dysfunctional microcirculation. While many of the mechanisms regulating angiogenesis have been detailed, a thorough understanding of the mechanisms driving post-angiogenesis activities specific to neovascularization has yet to be fully realized, but is necessary in order to develop effective therapeutic strategies for repairing compromised microcirculations as a means to treat disease. PMID:22734666

  5. Heterogeneous ageing of skeletal muscle microvascular function.

    PubMed

    Muller-Delp, Judy M

    2016-04-15

    The distribution of blood flow to skeletal muscle during exercise is altered with advancing age. Changes in arteriolar function that are muscle specific underlie age-induced changes in blood flow distribution. With advancing age, functional adaptations that occur in resistance arterioles from oxidative muscles differ from those that occur in glycolytic muscles. Age-related adaptations of morphology, as well as changes in both endothelial and vascular smooth muscle signalling, differ in muscle of diverse fibre type. Age-induced endothelial dysfunction has been reported in most skeletal muscle arterioles; however, unique alterations in signalling contribute to the dysfunction in arterioles from oxidative muscles as compared with those from glycolytic muscles. In resistance arterioles from oxidative muscle, loss of nitric oxide signalling contributes significantly to endothelial dysfunction, whereas in resistance arterioles from glycolytic muscle, alterations in both nitric oxide and prostanoid signalling underlie endothelial dysfunction. Similarly, adaptations of the vascular smooth muscle that occur with advancing age are heterogeneous between arterioles from oxidative and glycolytic muscles. In both oxidative and glycolytic muscle, late-life exercise training reverses age-related microvascular dysfunction, and exercise training appears to be particularly effective in reversing endothelial dysfunction. Patterns of microvascular ageing that develop among muscles of diverse fibre type and function may be attributable to changing patterns of physical activity with ageing. Importantly, aerobic exercise training, initiated even at an advanced age, restores muscle blood flow distribution patterns and vascular function in old animals to those seen in their young counterparts. PMID:26575597

  6. Myocardial perfusion echocardiography and coronary microvascular dysfunction

    PubMed Central

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-01-01

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

  7. Effects of radiation therapy in microvascular anastomoses

    SciTech Connect

    Fried, M.P.

    1985-07-01

    The otolaryngologist, as a head and neck surgeon, commonly cares for patients with upper aerodigestive tract malignancies. Therapy of these neoplasms often requires wide excision. One standard reconstructive procedure utilizes pedicled regional flaps, both dermal and myodermal which have some disadvantages. The shortcomings of these pedicled regional flaps have led to the use of the vascularized free flap in certain cases. The occasional case may lead to catastrophe if microanastomoses fail when combined with radiation. Notwithstanding, many surgical series have reported success when radiation has been given. The present investigation was undertaken to assess the effects of radiation therapy on microvascular anastomoses when radiation is administered pre- or postoperatively or when nonradiated tissue is transferred to an irradiated recipient site. These effects were observed serially in an experimental rat model using a tubed superficial epigastric flap that adequately reflected tissue viability and vascular patency. The histologic changes were then noted over a three month period after completion of both radiation and surgery. This study adds credence to the observation of the lack of deleterious effects of radiation on experimental microvascular anastomotic patency whether the radiation is given before or after surgery or if radiated tissue is approximated to nonradiated vessels.

  8. Myocardial perfusion echocardiography and coronary microvascular dysfunction.

    PubMed

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-12-26

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

  9. Pulmonary particulate matter and systemic microvascular dysfunction.

    PubMed

    Nurkiewicz, Timothy R; Porter, Dale W; Hubbs, Ann F; Stone, Samuel; Moseley, Amy M; Cumpston, Jared L; Goodwill, Adam G; Frisbee, Stephanie J; Perrotta, Peter L; Brock, Robert W; Frisbee, Jefferson C; Boegehold, Matthew A; Frazer, David G; Chen, Bean T; Castranova, Vincent

    2011-12-01

    Pulmonary particulate matter (PM) exposure has been epidemiologically associated with an increased risk of cardiovascular morbidity and mortality, but the mechanistic foundations for this association are unclear. Exposure to certain types of PM causes changes in the vascular reactivity of several macrovascular segments. However, no studies have focused upon the systemic microcirculation, which is the primary site for the development of peripheral resistance and, typically, the site of origin for numerous pathologies. Ultrafine PM--also referred to as nanoparticles, which are defined as ambient and engineered particles with at least one physical dimension less than 100 nm (Oberdorster et al. 2005)--has been suggested to be more toxic than its larger counterparts by virtue of a larger surface area per unit mass. The purpose of this study was fourfold: (1) determine whether particle size affects the severity of postexposure microvascular dysfunction; (2) characterize alterations in microvascular nitric oxide (NO) production after PM exposure; (3) determine whether alterations in microvascular oxidative stress are associated with NO production, arteriolar dysfunction, or both; and (4) determine whether circulating inflammatory mediators, leukocytes, neurologic mechanisms, or a combination of these play a fundamental role in mediating pulmonary PM exposure and peripheral microvascular dysfunction. To achieve these goals, we created an inhalation chamber that generates stable titanium dioxide (TiO2) aerosols at concentrations up to 20 mg/m3. TiO2 is a well-characterized particle devoid of soluble metals. Sprague Dawley and Fischer 344 (F-344) rats were exposed to fine or nano-TiO2 PM (primary count modes of approximately 710 nm and approximately 100 nm in diameter, respectively) at concentrations of 1.5 to 16 mg/m3 for 4 to 12 hours to produce pulmonary loads of 7 to 150 microg in each rat. Twenty-four hours after pulmonary exposure, the following procedures were

  10. Cyclosporine Does Not Prevent Microvascular Loss in Transplantation but Can Synergize With a Neutrophil Elastase Inhibitor, Elafin, to Maintain Graft Perfusion During Acute Rejection.

    PubMed

    Jiang, X; Nguyen, T T; Tian, W; Sung, Y K; Yuan, K; Qian, J; Rajadas, J; Sallenave, J-M; Nickel, N P; de Jesus Perez, V; Rabinovitch, M; Nicolls, M R

    2015-07-01

    The loss of a functional microvascular bed in rejecting solid organ transplants is correlated with fibrotic remodeling and chronic rejection; in lung allografts, this pathology is predicted by bronchoalveolar fluid neutrophilia which suggests a role for polymorphonuclear cells in microcirculatory injury. In a mouse orthotopic tracheal transplant model, cyclosporine, which primarily inhibits T cells, failed as a monotherapy for preventing microvessel rejection and graft ischemia. To target neutrophil action that may be contributing to vascular injury, we examined the effect of a neutrophil elastase inhibitor, elafin, on the microvascular health of transplant tissue. We showed that elafin monotherapy prolonged microvascular perfusion and enhanced tissue oxygenation while diminishing the infiltration of neutrophils and macrophages and decreasing tissue deposition of complement C3 and the membrane attack complex, C5b-9. Elafin was also found to promote angiogenesis through activation of the extracellular signal-regulated kinase (ERK) signaling pathway but was insufficient as a single agent to completely prevent tissue ischemia during acute rejection episodes. However, when combined with cyclosporine, elafin effectively preserved airway microvascular perfusion and oxygenation. The therapeutic strategy of targeting neutrophil elastase activity alongside standard immunosuppression during acute rejection episodes may be an effective approach for preventing the development of irreversible fibrotic remodeling. PMID:25727073

  11. Cyclosporine does not prevent microvascular loss in transplantation but can synergize with a neutrophil elastase inhibitor, elafin, to maintain graft perfusion during acute rejection

    PubMed Central

    Jiang, Xinguo; Nguyen, Tom T.; Tian, Wen; Sung, Yon K.; Yuan, Ke; Qian, Jin; Rajadas, Jayakumar; Sallenave, Jean-Michel; Nickel, Nils P.; de Jesus Perez, Vinicio; Rabinovitch, Marlene; Nicolls, Mark R.

    2015-01-01

    The loss of a functional microvascular bed in rejecting solid organ transplants is correlated with fibrotic remodeling and chronic rejection; in lung allografts, this pathology is predicted by bronchoalveolar fluid neutrophilia which suggests a role for polymorphonuclear cells in microcirculatory injury. In a mouse orthotopic tracheal transplant model, cyclosporine, which primarily inhibits T cells, failed as a monotherapy for preventing microvessel rejection and graft ischemia. To target neutrophil action that may be contributing to vascular injury, we examined the effect of a neutrophil elastase inhibitor, elafin, on the microvascular health of transplant tissue. We showed that elafin monotherapy prolonged microvascular perfusion and enhanced tissue oxygenation while diminishing the infiltration of neutrophils and macrophages and decreasing tissue deposition of complement C3 and the membrane attack complex, C5b-9. Elafin was also found to promote angiogenesis through activation of the extracellular signal-regulated kinase (ERK) signaling pathway but was insufficient as a single agent to completely prevent tissue ischemia during acute rejection episodes. However, when combined with cyclosporine, elafin effectively preserved airway microvascular perfusion and oxygenation. The therapeutic strategy of targeting neutrophil elastase activity alongside standard immunosuppression during acute rejection episodes may be an effective approach for preventing the development of irreversible fibrotic remodeling. PMID:25727073

  12. Role of upper airway ultrasound in airway management.

    PubMed

    Osman, Adi; Sum, Kok Meng

    2016-01-01

    Upper airway ultrasound is a valuable, non-invasive, simple, and portable point of care ultrasound (POCUS) for evaluation of airway management even in anatomy distorted by pathology or trauma. Ultrasound enables us to identify important sonoanatomy of the upper airway such as thyroid cartilage, epiglottis, cricoid cartilage, cricothyroid membrane, tracheal cartilages, and esophagus. Understanding this applied sonoanatomy facilitates clinician to use ultrasound in assessment of airway anatomy for difficult intubation, ETT and LMA placement and depth, assessment of airway size, ultrasound-guided invasive procedures such as percutaneous needle cricothyroidotomy and tracheostomy, prediction of postextubation stridor and left double-lumen bronchial tube size, and detecting upper airway pathologies. Widespread POCUS awareness, better technological advancements, portability, and availability of ultrasound in most critical areas facilitate upper airway ultrasound to become the potential first-line non-invasive airway assessment tool in the future. PMID:27529028

  13. Angiogenesis is induced by airway smooth muscle strain.

    PubMed

    Hasaneen, Nadia A; Zucker, Stanley; Lin, Richard Z; Vaday, Gayle G; Panettieri, Reynold A; Foda, Hussein D

    2007-10-01

    Angiogenesis is an important feature of airway remodeling in both chronic asthma and chronic obstructive pulmonary disease (COPD). Airways in those conditions are exposed to excessive mechanical strain during periods of acute exacerbations. We recently reported that mechanical strain of human airway smooth muscle (HASM) led to an increase in their proliferation and migration. Sustained growth in airway smooth muscle in vivo requires an increase in the nutritional supply to these muscles, hence angiogenesis. In this study, we examined the hypothesis that cyclic mechanical strain of HASM produces factors promoting angiogenic events in the surrounding vascular endothelial cells. Our results show: 1) a significant increase in human lung microvascular endothelial cell (HMVEC-L) proliferation, migration, and tube formation following incubation in conditioned media (CM) from HASM cells exposed to mechanical strain; 2) mechanical strain of HASM cells induced VEGF expression and release; 3) VEGF neutralizing antibodies inhibited the proliferation, migration, and tube formations of HMVEC-L induced by the strained airway smooth muscle CM; 4) mechanical strain of HASM induced a significant increase in hypoxia-inducible factor-1alpha (HIF-1alpha) mRNA and protein, a transcription factor required for VEGF gene transcription; and 5) mechanical strain of HASM induced HIF-1alpha/VEGF through dual phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and ERK pathways. In conclusion, exposing HASM cells to mechanical strain induces signal transduction pathway through PI3K/Akt/mTOR and ERK pathways that lead to an increase in HIF-1alpha, a transcription factor required for VEGF expression. VEGF release by mechanical strain of HASM may contribute to the angiogenesis seen with repeated exacerbation of asthma and COPD. PMID:17693481

  14. Comparative Efficacy of the Air-Q Intubating Laryngeal Airway during General Anesthesia in Pediatric Patients: A Systematic Review and Meta-Analysis

    PubMed Central

    Ahn, Eun Jin; Choi, Geun Joo; Kang, Hyun; Baek, Chong Wha; Jung, Yong Hun; Woo, Young Cheol; Bang, Si Ra

    2016-01-01

    Air-Q® (air-Q) is a supraglottic airway device which can be used as a guidance of intubation in pediatric as well as in adult patients. We evaluated the efficacy and safety of air-Q compared to other airway devices during general anesthesia in pediatric patients by conducting a systematic review and meta-analysis. A total of 10 studies including 789 patients were included in the final analysis. Compared with other supraglottic airway devices, air-Q showed no evidence for a difference in leakage pressure and insertion time. The ease of insertion was significantly lower than other supraglottic airway devices. The success rate of intubation was significantly lower than other airway devices. However, fiberoptic view was better through the air-Q than other supraglottic airway devices. Therefore, air-Q could be a safe substitute for other airway devices and may provide better fiberoptic bronchoscopic view. PMID:27419134

  15. Targeting complement component 5a promotes vascular integrity and limits airway remodeling.

    PubMed

    Khan, Mohammad A; Maasch, Christian; Vater, Axel; Klussmann, Sven; Morser, John; Leung, Lawrence L; Atkinson, Carl; Tomlinson, Stephen; Heeger, Peter S; Nicolls, Mark R

    2013-04-01

    Increased microvascular dilatation and permeability is observed during allograft rejection. Because vascular integrity is an important indicator of transplant health, we have sought to limit injury to blood vessels by blocking complement activation. Although complement component 3 (C3) inhibition is known to be vasculoprotective in transplantation studies, we recently demonstrated the paradoxical finding that, early in rejection, C3(-/-) transplant recipients actually exhibit worse microvascular injury than controls. In the genetic absence of C3, thrombin-mediated complement component 5 (C5) convertase activity leads to the generation of C5a (anaphylatoxin), a promoter of vasodilatation and permeability. In the current study, we demonstrated that microvessel thrombin deposition is significantly increased in C3(-/-) recipients during acute rejection. Thrombin colocalization with microvessels is closely associated with remarkably elevated plasma levels of C5a, vasodilatation, and increased vascular permeability. Administration of NOX-D19, a specific C5a inhibitor, to C3(-/-) recipients of airway transplants significantly improved tissue oxygenation, limited microvascular leakiness, and prevented airway ischemia, even in the absence of conventional T-cell-directed immunosuppression. As C3 inhibitors enter the clinics, the simultaneous targeting of this thrombin-mediated complement activation pathway and/or C5a itself may confer significant clinical benefit. PMID:23530212

  16. Air-leakage control manual

    SciTech Connect

    Maloney, J.

    1991-05-01

    This manual is for builders and designers who are interested in building energy-efficient homes. The purpose of the manual is to provide the ``how and why`` of controlling air leakage by means of a system called the ``Simple Caulk and Seal`` (SIMPLE{center_dot}CS) system. This manual provides an overview of the purpose and contents of the manual; It discusses the forces that affect air leakage in homes and the benefits of controlling air leakage. Also discussed are two earlier approaches for controlling air leakage and the problems with these approaches. It describes the SIMPLE-{center_dot}CS system. It outlines the standard components of the building envelope that require sealing and provides guidelines for sealing them. It outlines a step-by-step procedure for analyzing and planning the sealing effort. The procedure includes (1) identifying areas to be sealed, (2) determining the most effective and convenient stage of construction in which to do the sealing, and (3) designating the appropriate crew member or trade to be responsible for the sealing.

  17. Air-Leakage Control Manual.

    SciTech Connect

    Maloney, Jim; Washington State Energy Office; United States. Bonneville Power Administration.

    1991-05-01

    This manual is for builders and designers who are interested in building energy-efficient homes. The purpose of the manual is to provide the how and why'' of controlling air leakage by means of a system called the Simple Caulk and Seal'' (SIMPLE{center dot}CS) system. This manual provides an overview of the purpose and contents of the manual; It discusses the forces that affect air leakage in homes and the benefits of controlling air leakage. Also discussed are two earlier approaches for controlling air leakage and the problems with these approaches. It describes the SIMPLE-{center dot}CS system. It outlines the standard components of the building envelope that require sealing and provides guidelines for sealing them. It outlines a step-by-step procedure for analyzing and planning the sealing effort. The procedure includes (1) identifying areas to be sealed, (2) determining the most effective and convenient stage of construction in which to do the sealing, and (3) designating the appropriate crew member or trade to be responsible for the sealing.

  18. Supraglottic airway devices.

    PubMed

    Ramachandran, Satya Krishna; Kumar, Anjana M

    2014-06-01

    Supraglottic airway devices (SADs) are used to keep the upper airway open to provide unobstructed ventilation. Early (first-generation) SADs rapidly replaced endotracheal intubation and face masks in > 40% of general anesthesia cases due to their versatility and ease of use. Second-generation devices have further improved efficacy and utility by incorporating design changes. Individual second-generation SADs have allowed more dependable positive-pressure ventilation, are made of disposable materials, have integrated bite blocks, are better able to act as conduits for tracheal tube placement, and have reduced risk of pulmonary aspiration of gastric contents. SADs now provide successful rescue ventilation in > 90% of patients in whom mask ventilation or tracheal intubation is found to be impossible. However, some concerns with these devices remain, including failing to adequately ventilate, causing airway damage, and increasing the likelihood of pulmonary aspiration of gastric contents. Careful patient selection and excellent technical skills are necessary for successful use of these devices. PMID:24891199

  19. Effect of Melilotus suaveolens extract on pulmonary microvascular permeability by downregulating vascular endothelial growth factor expression in rats with sepsis.

    PubMed

    Liu, Ming-Wei; Su, Mei-Xian; Zhang, Wei; Wang, Yun Hui; Qin, Lan-Fang; Liu, Xu; Tian, Mao-Li; Qian, Chuan-Yun

    2015-05-01

    A typical indicator of sepsis is the development of progressive subcutaneous and body‑cavity edema, which is caused by the breakdown of endothelial barrier function, leading to a marked increase in vascular permeability. Microvascular leakage predisposes to microvascular thrombosis, breakdown of microcirculatory flow and organ failure, which are common events preceding mortality in patients with severe sepsis. Melilotus suaveolens (M. suaveolens) is a Traditional Tibetan Medicine. Previous pharmacological studies have demonstrated that an ethanolic extract of M. suaveolens has powerful anti‑inflammatory activity and leads to an improvement in capillary permeability. However, the mechanisms underlying its pharmacological activity remain elusive. The present study aimed to assess the impact of M. suaveolens extract tablets on pulmonary vascular permeability, and their effect on regulating lung inflammation and the expression of vascular endothelial growth factor (VEGF) in the lung tissue of rats with sepsis. A cecal ligation and puncture (CLP) sepsis model was established for both the control and treatment groups. ~2 h prior to surgery, 25 mg/kg of M. suaveolens extract tablet was administered to the treatment group. Polymerase chain reaction and western blot analyses were used to assess the expression of nuclear factor (NF)‑κB and VEGF in the lung tissue, and ELISA was applied to detect changes in serum tumor necrosis factor‑α as well as interleukins (IL) ‑1, ‑4, ‑6, and ‑10. The lung permeability, wet/dry weight ratio and lung pathology were determined. The results demonstrated that in the lung tissue of CLP‑rats with sepsis, M. suaveolens extract inhibited the expression of NF‑κB, reduced the inflammatory response and blocked the expression of VEGF, and thus significantly decreased lung microvascular permeability. The effects of M. Suaveolens extract may be of potential use in the treatment of CLP‑mediated lung microvascular permeability

  20. Assessment of v-gel supraglottic airway device placement in cats performed by inexperienced veterinary students.

    PubMed

    Barletta, M; Kleine, S A; Quandt, J E

    2015-11-21

    Endotracheal intubation has been associated with several complications in cats. The v-gel supraglottic airway device (SGAD) has been developed to adapt to the unique oropharynx of the cat and to overcome these complications. Thirty-three cats were randomly assigned to receive an endotracheal tube (ETT group) or a v-gel SGAD (v-gel group) after induction of general anaesthesia. Third year veterinary students without previous clinical experience placed these devices under direct supervision of an anaesthesiologist. Amount of propofol, number of attempts, time required to secure the airway, leakage around the device, signs of upper airway discomfort and food consumption were compared between the two groups. The v-gel group required less propofol (P=0.03), less time (P<0.01) and fewer attempts (P<0.01) to secure the cats' airway. The incidence of leakage was lower for the v-gel group immediately after placement of the device (P<0.01) and 60 minutes after induction of general anaesthesia (P=0.04). Cats that received the v-gel SGAD presented a lower incidence of upper airway discomfort immediately after the device was removed (P=0.03) and recorded a higher food consumption score (P=0.03). The v-gel SGAD is a feasible way to secure the airway of healthy cats when performed by inexperienced personnel. PMID:26543177

  1. Differentiation state determines neural effects on microvascular endothelial cells

    SciTech Connect

    Muffley, Lara A.; Pan, Shin-Chen; Smith, Andria N.; Ga, Maricar; Hocking, Anne M.; Gibran, Nicole S.

    2012-10-01

    Growing evidence indicates that nerves and capillaries interact paracrinely in uninjured skin and cutaneous wounds. Although mature neurons are the predominant neural cell in the skin, neural progenitor cells have also been detected in uninjured adult skin. The aim of this study was to characterize differential paracrine effects of neural progenitor cells and mature sensory neurons on dermal microvascular endothelial cells. Our results suggest that neural progenitor cells and mature sensory neurons have unique secretory profiles and distinct effects on dermal microvascular endothelial cell proliferation, migration, and nitric oxide production. Neural progenitor cells and dorsal root ganglion neurons secrete different proteins related to angiogenesis. Specific to neural progenitor cells were dipeptidyl peptidase-4, IGFBP-2, pentraxin-3, serpin f1, TIMP-1, TIMP-4 and VEGF. In contrast, endostatin, FGF-1, MCP-1 and thrombospondin-2 were specific to dorsal root ganglion neurons. Microvascular endothelial cell proliferation was inhibited by dorsal root ganglion neurons but unaffected by neural progenitor cells. In contrast, microvascular endothelial cell migration in a scratch wound assay was inhibited by neural progenitor cells and unaffected by dorsal root ganglion neurons. In addition, nitric oxide production by microvascular endothelial cells was increased by dorsal root ganglion neurons but unaffected by neural progenitor cells. -- Highlights: Black-Right-Pointing-Pointer Dorsal root ganglion neurons, not neural progenitor cells, regulate microvascular endothelial cell proliferation. Black-Right-Pointing-Pointer Neural progenitor cells, not dorsal root ganglion neurons, regulate microvascular endothelial cell migration. Black-Right-Pointing-Pointer Neural progenitor cells and dorsal root ganglion neurons do not effect microvascular endothelial tube formation. Black-Right-Pointing-Pointer Dorsal root ganglion neurons, not neural progenitor cells, regulate

  2. Diagnosis of coronary microvascular dysfunction - Present status.

    PubMed

    Mittal, S R

    2015-01-01

    Definite clinical diagnosis of microvascular angina is not possible with the existing knowledge. Resting electrocardiogram may be normal, and exercise electrocardiogram may be unremarkable. Echocardiography usually does not show regional wall motion abnormalities. Transthoracic Doppler echocardiography can satisfactorily evaluate only left anterior descending coronary artery and that too in some patients. Radio-isotope imaging can detect only severe localized disease. Noninvasive diagnosis needs high index of suspicion. At present, definite diagnosis is based on documentation of normal epicardial coronaries, coronary flow reserve less than 2.5 on adenosine induced hyperemia, and absence of spasm of epicardial coronaries on acetylcholine provocation. Invasive evaluation is costly, needs sophisticated equipments and expertise. Therapeutic and prognostic implications of various parameters remains to be evaluated. At present invasive evaluation is recommended only for patients with intractable symptoms with unconfirmed diagnosis, requiring repeated hospitalization and evaluation with failure of empirical therapy. PMID:26702685

  3. Phase transition of the microvascular network architecture in human pathologies.

    PubMed

    Bianciardi, Giorgio; Traversi, Claudio; Cattaneo, Ruggero; De Felice, Claudia; Monaco, Annalisa; Tosi, Gianmarco; Parrini, Stefano; Latini, Giuseppe

    2012-01-01

    We have investigated the microvascular pattern in acquired or genetic diseases in humans. The lower gingival and vestibular oral mucosa, as well as the optic nerve head, was chosen to characterize the vascular pattern complexity due to the simple accessibility and visibility Local fractal dimensions, fractal dimension of the minimum path and Lempel-Ziv complexity have been used as operational numerical tools to characterize the microvascular networks. In the normal healthy subjects microvascular networks show nonlinear values corresponding to the complexity of a diffusion limited aggregation (DLA) model, while in several acquired or genetic diseases they are approaching the ones of an invasion percolation model. PMID:23193796

  4. Endoneurial Microvascular Pathology in Feline Diabetic Neuropathy

    PubMed Central

    Estrella, Jeannelyn S.; Nelson, Richard N.; Sturges, B.K.; Vernau, Karen M.; Williams, D. Collette; LeCouteur, Richard A.; Shelton, G. Diane; Mizisin, Andrew P.

    2008-01-01

    Endoneurial capillaries in nerve biopsies from 12 adult diabetic cats with varying degrees of neurological dysfunction were examined for evidence of microvascular pathology and compared to nerves obtained at autopsy from 7 adult non-diabetic cats without clinical evidence of neurological dysfunction. As reported previously (Mizisin et al., 2007), the diabetic cats had elevated glycosylated hemoglobin and serum fructosamine levels, decreased motor nerve conduction velocity and compound muscle action potentials (CMAP), and markedly decreased myelinated nerve fiber densities. Compared to non-diabetic cats, there was a non-significant 26% increase in capillary density and a significant (P<0.009) 45% increase in capillary size in diabetic cats. Capillary luminal size was also significantly (P<0.001) increased, while an index of vasoconstriction was significantly decreased (P<0.001) in diabetic cats compared to non-diabetic controls. No differences in endothelial cell size, endothelial cell number or pericyte size were detected between non-diabetic and diabetic cats. In diabetic cats, basement membrane thickening, seen as a reduplication of the basal lamina, was significantly (P<0.0002) increased by 73% compared to non-diabetic controls. Regression analysis of either myelinated nerve fiber density or CMAP amplitude against basement membrane size demonstrated a negative correlation with significant slopes (P<0.03 and P<0.04, respectively). These data demonstrate that myelinated nerve fiber injury in feline diabetic neuropathy is associated with microvascular pathology and that some of these changes parallel those documented in experimental rodent and human diabetic neuropathy. PMID:18207200

  5. Issues of critical airway management (Which anesthesia; which surgical airway?).

    PubMed

    Bonanno, Fabrizio Giuseppe

    2012-10-01

    Which anesthesia for patients with critical airway? Safe and effective analgesia and anesthesia in critical airway is a skilled task especially after severe maxillofacial injury combined with head injury and hemorrhagic shock. If on one side sedation is wanted, on the other hand it may worsen the airway and hemodynamic situation to a point where hypoventilation and decrease of blood pressure, common side-effect of many opioids, may prejudice the patient's level of consciousness and hemodynamic compensation, compounding an already critical situation. What to do when endotracheal intubation fails and blood is trickling down the airways in an unconscious patient or when a conscious patient has to sit up to breathe? Which surgical airway in critical airway? Comparative studies among the various methods of emergency surgical airway would be unethical; furthermore, operator's training and experience is relevant for indications and performance. PMID:23248494

  6. Therapeutic effect of apatinib-loaded nanoparticles on diabetes-induced retinal vascular leakage

    PubMed Central

    Jeong, Ji Hoon; Nguyen, Hong Khanh; Lee, Jung Eun; Suh, Wonhee

    2016-01-01

    Apatinib, a novel and selective inhibitor of vascular endothelial growth factor (VEGF) receptor 2, has been demonstrated recently to exhibit anticancer efficacy by inhibiting the VEGF signaling pathway. Given the importance of VEGF in retinal vascular leakage, the present study was designed to investigate whether apatinib-loaded polymeric nanoparticles inhibit VEGF-mediated retinal vascular hyperpermeability and block diabetes-induced retinal vascular leakage. For the delivery of water-insoluble apatinib, the drug was encapsulated in nanoparticles composed of human serum albumin (HSA)-conjugated polyethylene glycol (PEG). In vitro paracellular permeability and transendothelial electric resistance assays showed that apatinib-loaded HSA-PEG (Apa-HSA-PEG) nanoparticles significantly inhibited VEGF-induced endothelial hyperpermeability in human retinal microvascular endothelial cells. In addition, they substantially reduced the VEGF-induced junctional loss and internalization of vascular endothelial-cadherin, a major component of endothelial junction complexes. In vivo intravitreal injection of Apa-HSA-PEG nanoparticles in mice blocked VEGF-induced retinal vascular leakage. These in vitro and in vivo data indicated that Apa-HSA-PEG nanoparticles efficiently blocked VEGF-induced breakdown of the blood–retinal barrier. In vivo experiments with streptozotocin-induced diabetic mice showed that an intravitreal injection of Apa-HSA-PEG nanoparticles substantially inhibited diabetes-induced retinal vascular leakage. These results demonstrated, for the first time, that apatinib-loaded nanoparticles may be a promising therapeutic agent for the prevention and treatment of diabetes-induced retinal vascular disorders. PMID:27462154

  7. Therapeutic effect of apatinib-loaded nanoparticles on diabetes-induced retinal vascular leakage.

    PubMed

    Jeong, Ji Hoon; Nguyen, Hong Khanh; Lee, Jung Eun; Suh, Wonhee

    2016-01-01

    Apatinib, a novel and selective inhibitor of vascular endothelial growth factor (VEGF) receptor 2, has been demonstrated recently to exhibit anticancer efficacy by inhibiting the VEGF signaling pathway. Given the importance of VEGF in retinal vascular leakage, the present study was designed to investigate whether apatinib-loaded polymeric nanoparticles inhibit VEGF-mediated retinal vascular hyperpermeability and block diabetes-induced retinal vascular leakage. For the delivery of water-insoluble apatinib, the drug was encapsulated in nanoparticles composed of human serum albumin (HSA)-conjugated polyethylene glycol (PEG). In vitro paracellular permeability and transendothelial electric resistance assays showed that apatinib-loaded HSA-PEG (Apa-HSA-PEG) nanoparticles significantly inhibited VEGF-induced endothelial hyperpermeability in human retinal microvascular endothelial cells. In addition, they substantially reduced the VEGF-induced junctional loss and internalization of vascular endothelial-cadherin, a major component of endothelial junction complexes. In vivo intravitreal injection of Apa-HSA-PEG nanoparticles in mice blocked VEGF-induced retinal vascular leakage. These in vitro and in vivo data indicated that Apa-HSA-PEG nanoparticles efficiently blocked VEGF-induced breakdown of the blood-retinal barrier. In vivo experiments with streptozotocin-induced diabetic mice showed that an intravitreal injection of Apa-HSA-PEG nanoparticles substantially inhibited diabetes-induced retinal vascular leakage. These results demonstrated, for the first time, that apatinib-loaded nanoparticles may be a promising therapeutic agent for the prevention and treatment of diabetes-induced retinal vascular disorders. PMID:27462154

  8. 49 CFR 229.59 - Leakage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Leakage from the main air reservoir and related piping may not exceed an average of 3 pounds per square... shall remain applied at least 5 minutes. (d) Leakage from control air reservoir, related piping,...

  9. 49 CFR 229.59 - Leakage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Leakage from the main air reservoir and related piping may not exceed an average of 3 pounds per square... shall remain applied at least 5 minutes. (d) Leakage from control air reservoir, related piping,...

  10. Total airway reconstruction.

    PubMed

    Connor, Matthew P; Barrera, Jose E; Eller, Robert; McCusker, Scott; O'Connor, Peter

    2013-02-01

    We present a case of obstructive sleep apnea (OSA) that required multilevel surgical correction of the airway and literature review and discuss the role supraglottic laryngeal collapse can have in OSA. A 34-year-old man presented to a tertiary otolaryngology clinic for treatment of OSA. He previously had nasal and palate surgeries and a Repose tongue suspension. His residual apnea hypopnea index (AHI) was 67. He had a dysphonia associated with a true vocal cord paralysis following resection of a benign neck mass in childhood. He also complained of inspiratory stridor with exercise and intolerance to continuous positive airway pressure. Physical examination revealed craniofacial hypoplasia, full base of tongue, and residual nasal airway obstruction. On laryngoscopy, the paretic aryepiglottic fold arytenoid complex prolapsed into the laryngeal inlet with each breath. This was more pronounced with greater respiratory effort. Surgical correction required a series of operations including awake tracheostomy, supraglottoplasty, midline glossectomy, genial tubercle advancement, maxillomandibular advancement, and reconstructive rhinoplasty. His final AHI was 1.9. Our patient's supraglottic laryngeal collapse constituted an area of obstruction not typically evaluated in OSA surgery. In conjunction with treating nasal, palatal, and hypopharyngeal subsites, our patient's supraglottoplasty represented a key component of his success. This case illustrates the need to evaluate the entire upper airway in a complicated case of OSA. PMID:22965285

  11. Epithelial hyperplasia, airways

    Cancer.gov

    Number of respiratory epithelial cells is increased diffusely or focally. Frequently luminal protrusions are observed, sometimes forming papillae. Mucous (goblet) cell metaplastic hyperplasia is a variant, in which the respiratory epithelium of conducting airways is replaced by mucous cells either as a single or a pseudostratified layer.

  12. MiR-221 and miR-130a Regulate Lung Airway and Vascular Development

    PubMed Central

    Mujahid, Sana

    2013-01-01

    Epithelial-mesenchymal interactions play a crucial role in branching morphogenesis, but very little is known about how endothelial cells contribute to this process. Here, we examined how anti-angiogenic miR-221 and pro-angiogenic miR-130a affect airway and vascular development in the fetal lungs. Lung-specific effects of miR-130a and miR-221 were studied in mouse E14 whole lungs cultured for 48 hours with anti-miRs or mimics to miR-130a and miR-221. Anti-miR 221 treated lungs had more distal branch generations with increased Hoxb5 and VEGFR2 around airways. Conversely, mimic 221 treated lungs had reduced airway branching, dilated airway tips and decreased Hoxb5 and VEGFR2 in mesenchyme. Anti-miR 130a treatment led to reduced airway branching with increased Hoxa5 and decreased VEGFR2 in the mesenchyme. Conversely, mimic 130a treated lungs had numerous finely arborized branches extending into central lung regions with diffusely localized Hoxa5 and increased VEGFR2 in the mesenchyme. Vascular morphology was analyzed by GSL-B4 (endothelial cell-specific lectin) immunofluorescence. Observed changes in airway morphology following miR-221 inhibition and miR-130a enhancement were mirrored by changes in vascular plexus formation around the terminal airways. Mouse fetal lung endothelial cells (MFLM-91U) were used to study microvascular cell behavior. Mimic 221 treatment resulted in reduced tube formation and cell migration, where as the reverse was observed with mimic 130a treatment. From these data, we conclude that miR-221 and miR-130a have opposing effects on airway and vascular morphogenesis of the developing lung. PMID:23409087

  13. "Geyser" leakage on fluorescein angiography.

    PubMed

    Levy, Jaime; Fagan, Xavier J; Lifshitz, Tova; Schneck, Marina

    2013-01-01

    An 82-year-old patient with diabetes was followed up due to moderate nonproliferative diabetic retinopathy with macular edema in the right eye. Visual acuity was 6/36. Focal macular laser was conducted (A). Three years later, the patient presented with blurry vision in the right eye. Visual acuity was 3/60. Vitreous hemorrhage was observed (B), and neovascularization of the disc was suspected (C). Fluorescein angiography (D, mid venous phase; E-F, recirculation phase) confirmed neovascularization of the disc and depicted a striking vertical leakage. Panretinal photocoagulation was started. Possible explanations for the "geyser" leakage may be either a partial posterior vitreous detachment allowing the fluorescein to track upwards but not elsewhere or a pocket of syneretic vitreous allowing the fluorescein passage in which to diffuse, much like the passage the blood would have taken. PMID:24548789

  14. Advances in prehospital airway management

    PubMed Central

    Jacobs, PE; Grabinsky, A

    2014-01-01

    Prehospital airway management is a key component of emergency responders and remains an important task of Emergency Medical Service (EMS) systems worldwide. The most advanced airway management techniques involving placement of oropharyngeal airways such as the Laryngeal Mask Airway or endotracheal tube. Endotracheal tube placement success is a common measure of out-of-hospital airway management quality. Regional variation in regard to training, education, and procedural exposure may be the major contributor to the findings in success and patient outcome. In studies demonstrating poor outcomes related to prehospital-attempted endotracheal intubation (ETI), both training and skill level of the provider are usually often low. Research supports a relationship between the number of intubation experiences and ETI success. National standards for certification of emergency medicine provider are in general too low to guarantee good success rate in emergency airway management by paramedics and physicians. Some paramedic training programs require more intense airway training above the national standard and some EMS systems in Europe staff their system with anesthesia providers instead. ETI remains the cornerstone of definitive prehospital airway management, However, ETI is not without risk and outcomes data remains controversial. Many systems may benefit from more input and guidance by the anesthesia department, which have higher volumes of airway management procedures and extensive training and experience not just with training of airway management but also with different airway management techniques and adjuncts. PMID:24741499

  15. Methods of airway resistance assessment.

    PubMed

    Urbankowski, Tomasz; Przybyłowski, Tadeusz

    2016-01-01

    Airway resistance is the ratio of driving pressure to the rate of the airflow in the airways. The most frequent methods used to measure airway resistance are whole-body plethysmography, the interrupter technique and the forced oscillation technique. All these methods allow to measure resistance during respiration at the level close to tidal volume, they do not require forced breathing manoeuvres or deep breathing during measurement. The most popular method for measuring airway resistance is whole-body plethysmography. The results of plethysmography include among others the following parameters: airway resistance (Raw), airway conductance (Gaw), specific airway resistance (sRaw) and specific airway conductance (sGaw). The interrupter technique is based on the assumption that at the moment of airway occlusion, air pressure in the mouth is equal to the alveolar pressure . In the forced oscillation technique (FOT), airway resistance is calculated basing on the changes in pressure and flow caused by air vibration. The methods for measurement of airway resistance that are described in the present paper seem to be a useful alternative to the most common lung function test - spirometry. The target group in which these methods may be widely used are particularly the patients who are unable to perform spirometry. PMID:27238174

  16. Supraglottic airway devices in children

    PubMed Central

    Ramesh, S; Jayanthi, R

    2011-01-01

    Modern anaesthesia practice in children was made possible by the invention of the endotracheal tube (ET), which made lengthy and complex surgical procedures feasible without the disastrous complications of airway obstruction, aspiration of gastric contents or asphyxia. For decades, endotracheal intubation or bag-and-mask ventilation were the mainstays of airway management. In 1983, this changed with the invention of the laryngeal mask airway (LMA), the first supraglottic airway device that blended features of the facemask with those of the ET, providing ease of placement and hands-free maintenance along with a relatively secure airway. The invention and development of the LMA by Dr. Archie Brain has had a significant impact on the practice of anaesthesia, management of the difficult airway and cardiopulmonary resuscitation in children and neonates. This review article will be a brief about the clinical applications of supraglottic airways in children. PMID:22174464

  17. Mechanics of airway and alveolar collapse in human breath-hold diving.

    PubMed

    Fitz-Clarke, John R

    2007-11-15

    A computational model of the human respiratory tract was developed to study airway and alveolar compression and re-expansion during deep breath-hold dives. The model incorporates the chest wall, supraglottic airway, trachea, branched airway tree, and elastic alveoli assigned time-dependent surfactant properties. Total lung collapse with degassing of all alveoli is predicted to occur around 235 m, much deeper than estimates for aquatic mammals. Hysteresis of the pressure-volume loop increases with maximum diving depth due to progressive alveolar collapse. Reopening of alveoli occurs stochastically as airway pressure overcomes adhesive and compressive forces on ascent. Surface area for gas exchange vanishes at collapse depth, implying that the risk of decompression sickness should reach a plateau beyond this depth. Pulmonary capillary transmural stresses cannot increase after local alveolar collapse. Consolidation of lung parenchyma might provide protection from capillary injury or leakage caused by vascular engorgement due to outward chest wall recoil at extreme depths. PMID:17827075

  18. Impact of hetastarch on the intestinal microvascular barrier during ECLS.

    PubMed

    Cox, C S; Brennan, M; Allen, S J

    2000-04-01

    The effects of hetastarch on microvascular fluid flux were determined in anesthetized dogs undergoing extracorporeal life support (ECLS) with a roller pump and membrane oxygenator. ECLS with a lactated Ringer priming solution resulted in a decrease in microvascular protein reflection coefficient and an increase in transvascular protein clearance. Use of a 6% hetastarch priming solution attenuated the decrease in microvascular protein reflection coefficient and blunted the increase in transvascular protein clearance. Ileal tissue water increased in the group treated with the lactated Ringer priming solution compared with the group treated with 6% hetastarch. The effective plasma-to-interstitial colloid osmotic pressure gradient was greater in the group treated with hetastarch than in the group treated with lactated Ringer solution. Hetastarch decreases the edema associated with ECLS. The reduction in edema is due to the maintenance of the plasma-to-interstitial colloid osmotic pressure gradient and the reduction in the microvascular permeability to protein. PMID:10749832

  19. Microvascular temporalis fascia transfer for penile girth enhancement.

    PubMed

    Küçükçelebi, A; Ertaş, N M; Aydin, A; Eroğlu, A; Ozmen, E; Velidedeoğlu, H

    2001-07-01

    The authors report a 44-year-old man with inadequate penile girth that caused psychological problems. Using microvascular temporalis fascia transfer, they achieved satisfactory penile girth enhancement based on reliable vascularity in a single stage. PMID:11756810

  20. Protein osmotic pressure gradients and microvascular reflection coefficients.

    PubMed

    Drake, R E; Dhother, S; Teague, R A; Gabel, J C

    1997-08-01

    Microvascular membranes are heteroporous, so the mean osmotic reflection coefficient for a microvascular membrane (sigma d) is a function of the reflection coefficient for each pore. Investigators have derived equations for sigma d based on the assumption that the protein osmotic pressure gradient across the membrane (delta II) does not vary from pore to pore. However, for most microvascular membranes, delta II probably does vary from pore to pore. In this study, we derived a new equation for sigma d. According to our equation, pore-to-pore differences in delta II increase the effect of small pores and decrease the effect of large pores on the overall membrane osmotic reflection coefficient. Thus sigma d for a heteroporous membrane may be much higher than previously derived equations indicate. Furthermore, pore-to-pore delta II differences increase the effect of plasma protein osmotic pressure to oppose microvascular fluid filtration. PMID:9277520

  1. Management of the Traumatized Airway.

    PubMed

    Jain, Uday; McCunn, Maureen; Smith, Charles E; Pittet, Jean-Francois

    2016-01-01

    There is a lack of evidence-based approach regarding the best practice for airway management in patients with a traumatized airway. General recommendations for the management of the traumatized airway are summarized in table 5. Airway trauma may not be readily apparent, and its evaluation requires a high level of suspicion for airway disruption and compression. For patients with facial trauma, control of the airway may be significantly impacted by edema, bleeding, inability to clear secretions, loss of bony support, and difficulty with face mask ventilation. With the airway compression from neck swelling or hematoma, intubation attempts can further compromise the airway due to expanding hematoma. For patients with airway disruption, the goal is to pass the tube across the injured area without disrupting it or to insert the airway distal to the injury using a surgical approach. If airway injury is extensive, a surgical airway distal to the site of injury may be the best initial approach. Alternatively, if orotracheal intubation is chosen, spontaneous ventilation may be maintained or RSI may be performed. RSI is a common approach. Thus, some of the patients intubated may subsequently require tracheostomy. A stable patient with limited injuries may not require intubation but should be watched carefully for at least several hours. Because of a paucity of evidence-based data, the choice between these approaches and the techniques utilized is a clinical decision depending on the patient's condition, clinical setting, injuries to airway and other organs, and available personnel, expertise, and equipment. Inability to obtain a definitive airway is always an absolute indication for an emergency cricothyroidotomy or surgical tracheostomy. PMID:26517857

  2. Microvascular Plasticity: Angiogenesis in Health and Disease--Preface.

    PubMed

    Secomb, Timothy W; Pries, Axel R

    2016-02-01

    This Special Topic Issue is concerned with the mechanisms that determine the structure of microvascular networks. The vast number of vessels and the highly plastic character of the microcirculation give evidence that microvascular network structures emerge as a result of responses of individual vessels and cells to the local stimuli that they experience, through a combination of angiogenesis, remodeling and pruning. The articles in this issue of Microcirculation address a range of cellular and molecular mechanisms involved in these processes. PMID:26639099

  3. Vascular tracers alter hemodynamics and airway pressure in anesthetized sheep

    SciTech Connect

    Albertine, K.H.; Staub, N.C.

    1986-11-01

    The technique of vascular labeling was developed to mark sites of increased microvascular permeability. We used the vascular labeling technique in anesthetized sheep and found that hemodynamics and airway pressure were adversely affected by intraarterial infusions of two vascular tracers. Monastral blue (nine sheep) immediately caused systemic arterial hypotension, pulmonary arterial hypertension, and bronchoconstriction. All three physiological responses were partially blocked by a cyclooxygenase inhibitor (indomethacin) but not by an H1-antihistamine (chlorpheniramine). Colloidal gold (nine sheep) caused immediate, but less dramatic, pulmonary arterial hypertension which was not attenuated by the blocking agents. We conclude that these two vascular tracers caused detrimental physiological side effects in sheep at the usual doses used to label injured microvessels in other species.

  4. [Supraglottic airway devices in emergency medicine : impact of gastric drainage].

    PubMed

    Mann, V; Mann, S T; Alejandre-Lafont, E; Röhrig, R; Weigand, M A; Müller, M

    2013-04-01

    This case report describes a life-saving use of a supraglottic airway device (LT-D™-Larynxtubus, VBM Medizintechnik, Sulz, Germany) in an out-of-hospital emergency patient suffering from severe traumatic brain injury. Mechanical ventilation with the laryngeal tube was complicated by repeated airway obstructions and pronounced gastric distension with air as a consequence of oropharyngeal leakage. In this situation pulmonary ventilation of the patient was compromised so that emergency endotracheal intubation became necessary in the resuscitation area with vital indications. In this context the status of supraglottic airway devices in emergency medicine is discussed as well as the reasons for the gastric distension. Besides the immediate drastic consequences of gastric distension with respect to pulmonary ventilation, potential deleterious non-pulmonary consequences of this complication are highlighted. The clinical relevance of the described complications as well as the associated possibility of an optimized position control necessitate the recommendation only to use second generation supraglottic airway devices with integrated gastric access in (out-of-hospital) emergency medicine. PMID:23494024

  5. Upper Airway Mechanics

    PubMed Central

    Verbraecken, Johan A.; De Backer, Wilfried A.

    2009-01-01

    This review discusses the pathophysiological aspects of sleep-disordered breathing, with focus on upper airway mechanics in obstructive and central sleep apnoea, Cheyne-Stokes respiration and obesity hypoventilation syndrome. These disorders constitute the end points of a spectrum with distinct yet interrelated mechanisms that lead to substantial pathology, i.e. increased upper airway collapsibility, control of breathing instability, increased work of breathing, disturbed ventilatory system mechanics and neurohormonal changes. Concepts are changing. Although sleep apnoea is considered more and more to be an increased loop gain disorder, the central type of apnoea is now considered as an obstructive event, because it causes pharyngeal narrowing, associated with prolonged expiration. Although a unifying concept for the pathogenesis is lacking, it seems that these patients are in a vicious circle. Knowledge of common patterns of sleep-disordered breathing may help to identify these patients and guide therapy. PMID:19478479

  6. Brachycephalic airway syndrome.

    PubMed

    Meola, Stacy D

    2013-08-01

    Brachycephalic airway syndrome is a common finding in brachycephalic breeds. A combination of primary and secondary changes can progress to life-threatening laryngeal collapse. Early recognition of primary anatomic abnormalities that include stenotic nares, elongated soft palate, and hypoplastic trachea would allow the clinician to make early recommendations for medical and surgical management, which can improve the quality of life in affected animals. PMID:24182996

  7. Microvascular pathology in late-life depression.

    PubMed

    Santos, Micaela; Xekardaki, Aikaterini; Kövari, Enikö; Gold, Gabriel; Bouras, Constantin; Giannakopoulos, Panteleimon

    2012-11-15

    Since the era of Gaupp who introduced the concept of atheroscletic depressive disorder, the concept of late-life depression has been correlated with cerebrovascular comorbidities, microvascular lesions, frontal cortical and subcortical gray and white matter hyperintensities. The predominant neuropsychological deficits concern the domains of planning, organization and abstraction, with executive dysfunction being the predominant finding. MRI studies reveal a higher prevalence of white matter lesions in elderly patients with depression. Molecular mechanisms underlying the disease still remain unclear. Hyperhomocysteinemia has been associated with depression through its toxicity to neurons and blood vessels. Endothelial dysfunction is another possible mechanism referring to the loss of vasodilatation capacity. Inflammatory phenomena, such as increased peripheral leucocytes, elevated CRP and cytokine levels, could play a role in endothelial dysfunction. In this review we will briefly combine findings from neurobiological, epidemiological, structural and post-mortem data. A more complex model in late-life depression combining different modalities could be an elucidating approach to the disease's etiopathogeny in the future. PMID:22687957

  8. Scalp reconstruction by microvascular free tissue transfer

    SciTech Connect

    Furnas, H.; Lineaweaver, W.C.; Alpert, B.S. )

    1990-05-01

    We report on a series of patients with scalp defects who have been treated with a variety of free flaps, spanning the era of microvascular free tissue transfer from its incipient stages to the present. Between 1971 and 1987, 18 patients underwent scalp reconstruction with 21 free flaps: 11 latissimus dorsi, 3 scalp transfers between identical twins, 3 groin, one combined latissimus dorsi and serratus anterior, two serratus anterior, and one omentum. These flaps were used to cover scalp defects resulting from burns, trauma, radiation, and tumors in patients ranging from 7 to 79 years of age. Follow-up has ranged from 3 weeks to 7 years. All of our flaps survived and covered complex defects, many of which had failed more conservative attempts at cover. One patient received radiation therapy to his flap without unfavorable sequelae. This experience began with a pioneering omental flap and includes cutaneous and muscle flaps. The latissimus dorsi is our first choice for free flap reconstruction of extensive, complicated scalp wounds because of its large size, predictable blood supply, ease of harvesting, and provision of excellent vascularity to compromised beds.

  9. Upper airway resistance syndrome.

    PubMed

    Hasan, N; Fletcher, E C

    1998-07-01

    Many clinicians are familiar with the clinical symptoms and signs of obstructive sleep apnea (OSA). In its most blatant form, OSA is complete airway obstruction with repetitive, prolonged pauses in breathing, arterial oxyhemoglobin desaturation; followed by arousal with resumption of breathing. Daytime symptoms of this disorder include excessive daytime somnolence, intellectual dysfunction, and cardiovascular effects such as systemic hypertension, angina, myocardial infarction, and stroke. It has been recently recognized that increased pharyngeal resistance with incomplete obstruction can lead to a constellation of symptoms identical to OSA called "upper airway resistance syndrome" (UARS). The typical findings of UARS on sleep study are: (1) repetitive arousals from EEG sleep coinciding with a (2) waxing and waning of the respiratory airflow pattern and (3) increased respiratory effort as measured by esophageal pressure monitoring. There may be few, if any, obvious apneas or hypopneas with desaturation, but snoring may be a very prominent finding. Treatment with nasal positive airway pressure (NCPAP) eliminates the symptoms and confirms the diagnosis. Herein we describe two typical cases of UARS. PMID:9676067

  10. Airway closure in microgravity.

    PubMed

    Dutrieue, Brigitte; Verbanck, Sylvia; Darquenne, Chantal; Prisk, G Kim

    2005-08-25

    Recent single breath washout (SBW) studies in microgravity and on the ground have suggested an important effect of airway closure on gas mixing in the human lung, reflected particularly in the phase III slope of vital capacity SBW and bolus tests. In order to explore this effect, we designed a SBW in which subjects inspired 2-l from residual volume (RV) starting with a 150 ml bolus of He and SF6. In an attempt to vary the pattern of airways closure configuration before the test, the experiments were conducted in 1G and in microgravity during parabolic flight allowing the pre-test expiration to RV to be either in microgravity or at 1.8 G, with the actual test gas inhalation performed entirely in microgravity. Contrary to our expectations, the measured phase III slope and phase IV height and volume obtained from seven subjects in microgravity were essentially identical irrespective of the gravity level during the pre-test expiration to RV. The results suggest that airway closure configuration at RV before the test inspiration has no apparent impact on phases III and IV generation. PMID:15979418

  11. Reevaluating the Definition of Intraretinal Microvascular Abnormalities and Neovascularization Elsewhere in Diabetic Retinopathy Using Optical Coherence Tomography and Fluorescein Angiography

    PubMed Central

    LEE, CECILIA S.; LEE, AARON Y.; SIM, DAWN A.; KEANE, PEARSE A.; MEHTA, HEMAL; ZARRANZ-VENTURA, JAVIER; FRUTTIGER, MARCUS; EGAN, CATHERINE A.; TUFAIL, ADNAN

    2016-01-01

    PURPOSE To evaluate the agreement between clinical examination, spectral-domain ocular coherence tomography (SD OCT), and fluorescein angiography (FA) in diagnosing intraretinal microvascular abnormality (IRMA) and neovascularization elsewhere (NVE) and define the SD OCT features that differentiate NVEs from IRMAs. DESIGN Retrospective study. METHODS Data were collected from 23 lesions from 8 diabetic patients, seen from July 2012 through October 2013 at Moorfields Eye Hospital, United Kingdom. Main outcomes were SD OCT features and FA leakage of IRMA and neovascular complex. The agreement between 3 evaluations was analyzed by Fleiss’ kappa. RESULTS The following 5 SD OCT features significantly differentiated IRMAs from NVEs: (1) hyperreflective dots in superficial inner retina (P = .002); (2) the outpouching of internal limiting membrane (ILM) (P = .004); (3) the breach of ILM (P =.004); (4) the breach of posterior hyaloid (P = .0005); (5) hyperreflective dots in vitreous (P = .008). The agreement was moderate between 3 evaluations (κ = 0.48, P = 7.11 × 10−5) but substantial between clinical and SD OCT evaluation (κ = 0.72, P = .00055). There was no significant agreement between OCT evaluation and FA leakage (κ = 0.249, P = .232). CONCLUSIONS SD OCT will be a valuable adjunct in evaluating IRMA and NVE, since it can verify the histopathologic correlate. SD OCT provides subtle anatomic insights and may be more accurate than clinical examination or leakage on FA, our current method of diagnosing this important endpoint, which has implications in future trial design for proliferative diabetic retinopathy prevention. PMID:25284762

  12. Essential Role of Transglutaminase 2 in Vascular Endothelial Growth Factor-Induced Vascular Leakage in the Retina of Diabetic Mice.

    PubMed

    Lee, Yeon-Ju; Jung, Se-Hui; Kim, Su-Hyeon; Kim, Min-Soo; Lee, Sungeun; Hwang, JongYun; Kim, Soo-Youl; Kim, Young-Myeong; Ha, Kwon-Soo

    2016-08-01

    Diabetic retinopathy is predominantly caused by vascular endothelial growth factor (VEGF)-induced vascular leakage; however, the underlying mechanism is unclear. Here we designed an in vivo transglutaminase (TGase) activity assay in mouse retina and demonstrated that hyperglycemia induced vascular leakage by activating TGase2 in diabetic retina. VEGF elevated TGase2 activity through sequential elevation of intracellular Ca(2+) and reactive oxygen species (ROS) concentrations in endothelial cells. The TGase inhibitors cystamine and monodansylcadaverin or TGase2 small interfering RNA (siRNA) prevented VEGF-induced stress fiber formation and vascular endothelial (VE)-cadherin disruption, which play a critical role in modulating endothelial permeability. Intravitreal injection of two TGase inhibitors or TGase2 siRNA successfully inhibited hyperglycemia-induced TGase activation and microvascular leakage in the retinas of diabetic mice. C-peptide or ROS scavengers also inhibited TGase activation in diabetic mouse retinas. The role of TGase2 in VEGF-induced vascular leakage was further supported using diabetic TGase2(-/-) mice. Thus, our findings suggest that ROS-mediated activation of TGase2 plays a key role in VEGF-induced vascular leakage by stimulating stress fiber formation and VE-cadherin disruption. PMID:27207524

  13. Intermedin/adrenomedullin-2 is a hypoxia-induced endothelial peptide that stabilizes pulmonary microvascular permeability

    PubMed Central

    Aslam, Muhammad; Paddenberg, Renate; Quanz, Karin; Chang, Chia L.; Park, Jae-Il; Gries, Barbara; Rafiq, Amir; Faulhammer, Petra; Goldenberg, Anna; Papadakis, Tamara; Noll, Thomas; Hsu, Sheau Y. T.; Weissmann, Norbert; Kummer, Wolfgang

    2009-01-01

    Accumulating evidence suggests a pivotal role of the calcitonin receptor-like receptor (CRLR) signaling pathway in preventing damage of the lung by stabilizing pulmonary barrier function. Intermedin (IMD), also termed adrenomedullin-2, is the most recently identified peptide targeting this receptor. Here we investigated the effect of hypoxia on the expression of IMD in the murine lung and cultured murine pulmonary microvascular endothelial cells (PMEC) as well as the role of IMD in regulating vascular permeability. Monoclonal IMD antibodies were generated, and transcript levels were assayed by quantitative RT-PCR. The promoter region of IMD gene was analyzed, and the effect of hypoxia-inducible factor (HIF)-1α on IMD expression was investigated in HEK293T cells. Isolated murine lungs and a human lung microvascular endothelial cell monolayer model were used to study the effect of IMD on vascular permeability. IMD was identified as a pulmonary endothelial peptide by immunohistochemistry and RT-PCR. Hypoxia caused an upregulation of IMD mRNA in the murine lung and PMEC. As shown by these results, HIF-1α enhances IMD promoter activity. Our functional studies showed that IMD abolished the increase in pressure-induced endothelial permeability. Moreover, IMD decreased basal and thrombin-induced hyperpermeability of an endothelial cell monolayer in a receptor-dependent manner and activated PKA in these cells. In conclusion, IMD is a novel hypoxia-induced gene and a potential interventional agent for the improvement of endothelial barrier function in systemic inflammatory responses and hypoxia-induced vascular leakage. PMID:19684198

  14. Management of the artificial airway.

    PubMed

    Branson, Richard D; Gomaa, Dina; Rodriquez, Dario

    2014-06-01

    Management of the artificial airway includes securing the tube to prevent dislodgement or migration as well as removal of secretions. Preventive measures include adequate humidification and appropriate airway suctioning. Monitoring airway patency and removing obstruction are potentially life-saving components of airway management. Cuff pressure management is important for preventing aspiration and mucosal damage as well as assuring adequate ventilation. A number of new monitoring techniques have been introduced, and automated cuff pressure control is becoming more common. The respiratory therapist should be adept with all these devices and understand the appropriate application and management. PMID:24891202

  15. Ascorbate protects against vascular leakage in cecal ligation and puncture-induced septic peritonitis

    PubMed Central

    Zhou, Gang; Kamenos, George; Pendem, Suresh; Wilson, John X.

    2012-01-01

    Vascular leakage in multiple organs is a characteristic pathological change in sepsis. Our recent study revealed that ascorbate protects endothelial barrier function in microvascular endothelial cell monolayers through inhibiting serine/threonine protein phosphatase 2A (PP2A) activation (Han M, Pendem S, Teh SL, Sukumaran DK, Wu F, Wilson JX. Free Radic Biol Med 48: 128–135, 2010). The present study addressed the mechanism of protection by ascorbate against vascular leakage in cecal ligation and puncture (CLP)-induced septic peritonitis in mice. CLP caused NADPH oxidase activation and endothelial nitric oxide synthase (eNOS) uncoupling to produce superoxide, increased NO production by inducible NOS (iNOS) and neuronal NOS (nNOS) activity, and elevated 3-nitrotyrosine (a product of peroxynitrite) formation and PP2A activity in the hindlimb skeletal muscles at 12 h after CLP. The increase in PP2A activity was associated with decreased levels of phosphorylated serine and threonine in occludin, which was immunoprecipitated from freshly harvested endothelial cells of the septic skeletal muscles. Moreover, CLP increased the vascular permeability to fluorescent dextran and Evans blue dye in skeletal muscles. An intravenous bolus injection of ascorbate (200 mg/kg body wt), given 30 min prior to CLP, prevented eNOS uncoupling, attenuated the increases in iNOS and nNOS activity, decreased 3-nitrotyrosine formation and PP2A activity, preserved the phosphorylation state of occludin, and completely inhibited the vascular leakage of dextran and Evans blue. A delayed ascorbate injection, given 3 h after CLP, also prevented the vascular permeability increase. We conclude that ascorbate injection protects against vascular leakage in sepsis by sequentially inhibiting excessive production of NO and superoxide, formation of peroxynitrite, PP2A activation, and occludin dephosphorylation. Our study provides a scientific basis for injection of ascorbate as an adjunct treatment for

  16. Systemic Microvascular Dysfunction and Inflammation after Pulmonary Particulate Matter Exposure

    PubMed Central

    Nurkiewicz, Timothy R.; Porter, Dale W.; Barger, Mark; Millecchia, Lyndell; Rao, K. Murali K.; Marvar, Paul J.; Hubbs, Ann F.; Castranova, Vincent; Boegehold, Matthew A.

    2006-01-01

    The epidemiologic association between pulmonary exposure to ambient particulate matter (PM) and cardiovascular dysfunction is well known, but the systemic mechanisms that drive this effect remain unclear. We have previously shown that acute pulmonary exposure to PM impairs or abolishes endothelium-dependent arteriolar dilation in the rat spinotrapezius muscle. The purpose of this study was to further characterize the effect of pulmonary PM exposure on systemic microvascular function and to identify local inflammatory events that may contribute to these effects. Rats were intratracheally instilled with residual oil fly ash (ROFA) or titanium dioxide at 0.1 or 0.25 mg/rat 24 hr before measurement of pulmonary and systemic microvascular responses. In vivo microscopy of the spinotrapezius muscle was used to study systemic arteriolar responses to intraluminal infusion of the Ca2+ ionophore A23187 or iontophoretic abluminal application of the adrenergic agonist phenylephrine (PHE). Leukocyte rolling and adhesion were quantified in venules paired with the studied arterioles. Histologic techniques were used to assess pulmonary inflammation, characterize the adherence of leukocytes to systemic venules, verify the presence of myeloperoxidase (MPO) in the systemic microvascular wall, and quantify systemic microvascular oxidative stress. In the lungs of rats exposed to ROFA or TiO2, changes in some bronchoalveolar lavage markers of inflammation were noted, but an indication of cellular damage was not found. In rats exposed to 0.1 mg ROFA, focal alveolitis was evident, particularly at sites of particle deposition. Exposure to either ROFA or TiO2 caused a dose-dependent impairment of endothelium-dependent arteriolar dilation. However, exposure to these particles did not affect microvascular constriction in response to PHE. ROFA and TiO2 exposure significantly increased leukocyte rolling and adhesion in paired venules, and these cells were positively identified as

  17. Systemic microvascular dysfunction and inflammation after pulmonary particulate matter exposure.

    PubMed

    Nurkiewicz, Timothy R; Porter, Dale W; Barger, Mark; Millecchia, Lyndell; Rao, K Murali K; Marvar, Paul J; Hubbs, Ann F; Castranova, Vincent; Boegehold, Matthew A

    2006-03-01

    The epidemiologic association between pulmonary exposure to ambient particulate matter (PM) and cardiovascular dysfunction is well known, but the systemic mechanisms that drive this effect remain unclear. We have previously shown that acute pulmonary exposure to PM impairs or abolishes endothelium-dependent arteriolar dilation in the rat spinotrapezius muscle. The purpose of this study was to further characterize the effect of pulmonary PM exposure on systemic microvascular function and to identify local inflammatory events that may contribute to these effects. Rats were intratracheally instilled with residual oil fly ash (ROFA) or titanium dioxide at 0.1 or 0.25 mg/rat 24 hr before measurement of pulmonary and systemic microvascular responses. In vivo microscopy of the spinotrapezius muscle was used to study systemic arteriolar responses to intraluminal infusion of the Ca2+ ionophore A23187 or iontophoretic abluminal application of the adrenergic agonist phenylephrine (PHE). Leukocyte rolling and adhesion were quantified in venules paired with the studied arterioles. Histologic techniques were used to assess pulmonary inflammation, characterize the adherence of leukocytes to systemic venules, verify the presence of myeloperoxidase (MPO) in the systemic microvascular wall, and quantify systemic microvascular oxidative stress. In the lungs of rats exposed to ROFA or TiO2, changes in some bronchoalveolar lavage markers of inflammation were noted, but an indication of cellular damage was not found. In rats exposed to 0.1 mg ROFA, focal alveolitis was evident, particularly at sites of particle deposition. Exposure to either ROFA or TiO2 caused a dose-dependent impairment of endothelium-dependent arteriolar dilation. However, exposure to these particles did not affect microvascular constriction in response to PHE. ROFA and TiO2 exposure significantly increased leukocyte rolling and adhesion in paired venules, and these cells were positively identified as

  18. Cell-microenvironment interactions and architectures in microvascular systems.

    PubMed

    Bersini, Simone; Yazdi, Iman K; Talò, Giuseppe; Shin, Su Ryon; Moretti, Matteo; Khademhosseini, Ali

    2016-11-01

    In the past decade, significant advances have been made in the design and optimization of novel biomaterials and microfabrication techniques to generate vascularized tissues. Novel microfluidic systems have facilitated the development and optimization of in vitro models for exploring the complex pathophysiological phenomena that occur inside a microvascular environment. To date, most of these models have focused on engineering of increasingly complex systems, rather than analyzing the molecular and cellular mechanisms that drive microvascular network morphogenesis and remodeling. In fact, mutual interactions among endothelial cells (ECs), supporting mural cells and organ-specific cells, as well as between ECs and the extracellular matrix, are key driving forces for vascularization. This review focuses on the integration of materials science, microengineering and vascular biology for the development of in vitro microvascular systems. Various approaches currently being applied to study cell-cell/cell-matrix interactions, as well as biochemical/biophysical cues promoting vascularization and their impact on microvascular network formation, will be identified and discussed. Finally, this review will explore in vitro applications of microvascular systems, in vivo integration of transplanted vascularized tissues, and the important challenges for vascularization and controlling the microcirculatory system within the engineered tissues, especially for microfabrication approaches. It is likely that existing models and more complex models will further our understanding of the key elements of vascular network growth, stabilization and remodeling to translate basic research principles into functional, vascularized tissue constructs for regenerative medicine applications, drug screening and disease models. PMID:27417066

  19. Computational design of microvascular biomimetic materials

    NASA Astrophysics Data System (ADS)

    Aragon, Alejandro Marcos

    Biomimetic microvascular materials are increasingly considered for a variety of autonomic healing, cooling and sensing applications. The microvascular material of interest in this work consists of a network of hollow microchannels, with diameters as small as 10 mum, embedded in a polymeric matrix. Recent advances in the manufacturing of this new class of materials have allowed for the creation of very complex 2D and 3D structures. The computational design of such network structures, which is the focus of this work, involves a set of particular challenges, including a large number of design variables (e.g., topology of the network, number of diameters to consider and their sizes) that define the network, and a large number of multidisciplinary objective functions and constraints that drive the optimization process. The computational design tool to be developed must be capable of capturing the trade-off between the different objective and constraint functions, as, for example, networks designed for flow efficiency are likely to have a topology that is very different from those designed for structural integrity or thermal control. In this work, we propose to design these materials using Genetic Algorithms (GAs), the most common methodology within a broader category of Evolutionary Algorithms (EAs). GAs can be combined with a Pareto-selection mechanism to create Multi-Objective Genetic Algorithms (MOGAs), which enable the optimization of an arbitrary number of objective functions. As a result, a Pareto-optimal front is obtained, where all candidates are optimal solutions to the optimization problem. Adding a procedure to deal with constraints results in a powerful tool for multi-objective constrained optimization. The method allows the use of discrete variable problems and it does not require any a priori knowledge of the optimal solution. Furthermore, GAs search the entire decision space so the optimal solutions found are likely to be global. The

  20. Bioengineering human microvascular networks in immunodeficient mice.

    PubMed

    Lin, Ruei-Zeng; Melero-Martin, Juan M

    2011-01-01

    The future of tissue engineering and cell-based therapies for tissue regeneration will likely rely on our ability to generate functional vascular networks in vivo. In this regard, the search for experimental models to build blood vessel networks in vivo is of utmost importance. The feasibility of bioengineering microvascular networks in vivo was first shown using human tissue-derived mature endothelial cells (ECs); however, such autologous endothelial cells present problems for wide clinical use, because they are difficult to obtain in sufficient quantities and require harvesting from existing vasculature. These limitations have instigated the search for other sources of ECs. The identification of endothelial colony-forming cells (ECFCs) in blood presented an opportunity to non-invasively obtain ECs (5-7). We and other authors have shown that adult and cord blood-derived ECFCs have the capacity to form functional vascular networks in vivo. Importantly, these studies have also shown that to obtain stable and durable vascular networks, ECFCs require co-implantation with perivascular cells. The assay we describe here illustrates this concept: we show how human cord blood-derived ECFCs can be combined with bone marrow-derived mesenchymal stem cells (MSCs) as a single cell suspension in a collagen/fibronectin/fibrinogen gel to form a functional human vascular network within 7 days after implantation into an immunodeficient mouse. The presence of human ECFC-lined lumens containing host erythrocytes can be seen throughout the implants indicating not only the formation (de novo) of a vascular network, but also the development of functional anastomoses with the host circulatory system. This murine model of bioengineered human vascular network is ideally suited for studies on the cellular and molecular mechanisms of human vascular network formation and for the development of strategies to vascularize engineered tissues. PMID:21775960

  1. Zero leakage separable and semipermanent ducting joints

    NASA Technical Reports Server (NTRS)

    Mischel, H. T.

    1973-01-01

    A study program has been conducted to explore new methods of achieving zero leakage, separable and semipermanent, ducting joints for space flight vehicles. The study consisted of a search of literature of existing zero leakage methods, the generation of concepts of new methods of achieving the desired zero leakage criteria and the development of detailed analysis and design of a selected concept. Other techniques of leak detection were explored with a view toward improving this area.

  2. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a... provide a patent airway. (b) Classification. Class I (general controls). The device is exempt from...

  3. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a... provide a patent airway. (b) Classification. Class I (general controls). The device is exempt from...

  4. Leakage-current properties of encapsulants

    NASA Technical Reports Server (NTRS)

    Wen, L. C.

    1986-01-01

    A theoretical modeling of leakage current in ethylene vinyl acetate (EVA) and polyvinyl butyral (PVB) modules is being developed and is described. The modeling effort derives mathematical relationships for the bulk and surface conductivites of EVA and PVB, the surface conductivities of glass and polymeric films, and the EVA and PVB pottants, all as functions of environmental parameters. Results from the modeling indicate that for glass/EVA, the glass surface controls the interfacial conductivity, although EVA bulk conductivity controls total leakage current. For PVB/glass, the interface conductivity controls leakage currents for relative humidity (RH) less than 40 to 50%, but PVB bulk conductivity controls leakage current above 50% RH.

  5. Brachycephalic airway obstructive syndrome.

    PubMed

    Wykes, P M

    1991-06-01

    This is a complex condition, recognized primarily in brachycephalic breeds, that results in varying degrees of upper airway obstruction. The signs consist of respiratory distress, stridor, reduced exercise tolerance, and in more severe cases, cyanosis and collapse. The inherent anatomy of the brachycephalic skull contributes to the development of these signs. Such anatomic features include: a shortened and distorted nasopharynx, stenotic nares, an elongated soft palate, and everted laryngeal saccules. The increased negative pressure created in the pharyngolaryngeal region, as a result of these obstructing structures, ultimately results in distortion and collapse of the arytenoid cartilages of the larynx. PMID:1802247

  6. Vascular grafts in microvascular surgery. An experimental study

    SciTech Connect

    Marrangoni, A.G.; Marcelli, G.; Culig, M.; Simone, S.T.

    1988-02-01

    The patency of microvascular grafts depends on the luminal diameter, which is determined by the amount of fibrin and platelets deposited on the intraluminal surface and the anastomotic site, and the extent of pseudointimal formation. An experimental microvascular model in rats has been developed in our laboratory using Indium-111-labeled platelets to measure the amount of deposition on grafts inserted into the infrarenal aorta. This study was designed to assess the patency rates in these grafts and the pathologic maturation as determined by light and electron microscopy. Our study suggests that substantial patency rates can be achieved in aspirin-treated rats, although there was little influence on the pathologic maturation. Indium-111 oxine-labeled platelets can be used to document platelet aggregation, and the technique can be a valuable adjunct in the study of microvascular grafts.

  7. Regional cutaneous microvascular flow responses during gravitational and LBNP stresses

    NASA Technical Reports Server (NTRS)

    Breit, Gregory A.; Watenpaugh, Donald E.; Ballard, Richard E.; Murthy, Gita; Hargens, Alan R.

    1993-01-01

    Due to the regional variability of local hydrostatic pressures, microvascular flow responses to gravitational stress probably vary along the length of the body. Although these differences in local autoregulation have been observed previously during whole-body tilting, they have not been investigated during application of artificial gravitational stresses, such as lower body negative pressure or high gravity centrifugation. Although these stresses can create equivalent G-levels at the feet, they result in distinct distributions of vascular transmural pressure along the length of the body, and should consequently elicit different magnitudes and distributions of microvascular response. In the present study, the effects of whole-body tilting and lower body negative pressure on the level and distribution of microvascular flows within skin along the length of the body were compared.

  8. Particle Deposition During Airway Closure

    NASA Astrophysics Data System (ADS)

    Tai, Cheng-Feng; Halpern, David; Grotberg, James B.

    2011-11-01

    Inhaled aerosol particles deposit in the lung and may be from environmental, toxic, or medical therapy sources. While much research focuses on inspiratory deposition, primarily at airway bifurcations due to inertial impaction, there are other mechanisms that allow the particles to reach the airway surface, such as gravitational settling and diffusion depending on particle size. We introduce a new mechanism not previously studied, i.e. aerosol deposition from airway closure. The airways are lined with a liquid layer. Due to the surface tension driven instability, a liquid plug can form from this layer which blocks the airway. This process of airway closure tends to occur toward the end of expiration. In this study, the efficiency of the impaction of the particles during airway closure will be investigated. The particles will be released from the upstream of the airway and convected by the air flow and deposited onto the closing liquid layer. We solve the governing equations using a finite volume approach in conjunction with a sharp interface method for the interfaces. Once the velocity field of the gas flow is obtained, the path of the particles will be calculated and the efficiency of the deposition can be estimated. We acknowledge support from the National Institutes of Health grant number NIH HL85156.

  9. Operative endoscopy of the airway

    PubMed Central

    Walters, Dustin M.

    2016-01-01

    Airway endoscopy has long been an important and useful tool in the management of thoracic diseases. As thoracic specialists have gained experience with both flexible and rigid bronchoscopic techniques, the technology has continued to evolve so that bronchoscopy is currently the foundation for diagnosis and treatment of many thoracic ailments. Airway endoscopy plays a significant role in the biopsy of tumors within the airways, mediastinum, and lung parenchyma. Endoscopic methods have been developed to treat benign and malignant airway stenoses and tracheomalacia. And more recently, techniques have been conceived to treat end-stage emphysema and prolonged air leaks in select patients. This review describes the abundant uses of airway endoscopy, as well as technical considerations and limitations of the current technologies. PMID:26981263

  10. Monitoring microvascular reactivity in dental subjects.

    PubMed

    Roth, G I; Matheny, J L; Gonty, A A; Paterson, R L

    1980-01-01

    In this section of a larger study, a system for monitoring changes in the microcirculation, in humans in the dental setting, is described. The technique involves clinical nailfold capillary photomicroscopy and electronic image-scan measurements. The system was tested using reactive hyperemia after vascular occlusion; it proved reliable and sufficiently sensitive for measuring vascular reactivity in humans. (In a subsequent paper, clinical findings relative to the use of this technique with patients undergoing nitrous oxide/oxygen anesthesia will be presented).The importance of the microcirculation for the integrity of the tissues cannot be overemphasized. Since the term "microcirculation" can be defined as the microscopic subdivisions of the vascular system that lie within the tissue proper and are exposed to its immediate environment,(1) it is evident that most of the exchange of nutrients and waste products occuring in the tissue will occur at this level. Furthermore, the adequacy of tissue perfusion during drug administration, or during and after anesthesia, is dependent on the adequacy and reactivity of this subdivision of the vascular system.(2)A basic prerequisite to the understanding of microcirculatory function in a given vascular bed is the precise quantitation of dimensional changes in those vessels(3). Dynamic measurements in vivo are required, since it is difficult, if not impossible, to ensure that the dimensions obtained from fixed tissue specimens are accurate measures of those occurring in the living state. This is especially true where vessel dimensions are rapidly changing in response to endogenous or exogenous influences. Unfortunately the task of in vivo measurement of microvascular dimensions is difficult in most microcirculatory beds. Since the vessels are an integral part of a threedimensional structure,(4) the tasks of visualizing, isolating and measuring the vessels are formidable. These difficulties are compounded if the particular vessels

  11. A differential geometric approach to automated segmentation of human airway tree.

    PubMed

    Pu, Jiantao; Fuhrman, Carl; Good, Walter F; Sciurba, Frank C; Gur, David

    2011-02-01

    Airway diseases are frequently associated with morphological changes that may affect the physiology of the lungs. Accurate characterization of airways may be useful for quantitatively assessing prognosis and for monitoring therapeutic efficacy. The information gained may also provide insight into the underlying mechanisms of various lung diseases. We developed a computerized scheme to automatically segment the 3-D human airway tree depicted on computed tomography (CT) images. The method takes advantage of both principal curvatures and principal directions in differentiating airways from other tissues in geometric space. A "puzzle game" procedure is used to identify false negative regions and reduce false positive regions that do not meet the shape analysis criteria. The negative impact of partial volume effects on small airway detection is partially alleviated by repeating the developed differential geometric analysis on lung anatomical structures modeled at multiple iso-values (thresholds). In addition to having advantages, such as full automation, easy implementation and relative insensitivity to image noise and/or artifacts, this scheme has virtually no leakage issues and can be easily extended to the extraction or the segmentation of other tubular type structures (e.g., vascular tree). The performance of this scheme was assessed quantitatively using 75 chest CT examinations acquired on 45 subjects with different slice thicknesses and using 20 publicly available test cases that were originally designed for evaluating the performance of different airway tree segmentation algorithms. PMID:20851792

  12. A Differential Geometric Approach to Automated Segmentation of Human Airway Tree

    PubMed Central

    Pu, Jiantao; Fuhrman, Carl; Good, Walter F; Sciurba, Frank C; Gur, David

    2012-01-01

    Airway diseases are frequently associated with morphological changes that may affect the physiology of the lungs. Accurate characterization of airways may be useful for quantitatively assessing prognosis and for monitoring therapeutic efficacy. The information gained may also provide insight into the underlying mechanisms of various lung diseases. We developed a computerized scheme to automatically segment the three-dimensional human airway tree depicted on CT images. The method takes advantage of both principal curvatures and principal directions in differentiating airways from other tissues in geometric space. A “puzzle game” procedure is used to identify false negative regions and reduce false positive regions that do not meet the shape analysis criteria. The negative impact of partial volume effects on small airway detection is partially alleviated by repeating the developed differential geometric analysis on lung anatomical structures modeled at multiple iso-values (thresholds). In addition to having advantages, such as full automation, easy implementation and relative insensitivity to image noise and/or artifacts, this scheme has virtually no leakage issues and can be easily extended to the extraction or the segmentation of other tubular type structures (e.g., vascular tree). The performance of this scheme was assessed quantitatively using 75 chest CT examinations acquired on 45 subjects with different slice thicknesses and using 20 publicly available test cases that were originally designed for evaluating the performance of different airway tree segmentation algorithms. PMID:20851792

  13. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  14. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  15. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  16. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  17. 16 CFR 1507.5 - Pyrotechnic leakage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be...

  18. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, leakage. A stray electric current of relatively small value which flows through or across...

  19. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, leakage. A stray electric current of relatively small value which flows through or across...

  20. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, leakage. A stray electric current of relatively small value which flows through or across...

  1. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, leakage. A stray electric current of relatively small value which flows through or across...

  2. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Current, leakage. 236.735 Section 236.735 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, leakage. A stray electric current of relatively small value which flows through or across...

  3. Predicting Envelope Leakage in Attached Dwellings

    SciTech Connect

    Faakye, O.; Arena, L.; Griffiths, D.

    2013-07-01

    The most common method for measuring air leakage is to use a single blower door to pressurize and/or depressurize the test unit. In detached housing, the test unit is the entire home and the single blower door measures air leakage to the outside. In attached housing, this 'single unit', 'total', or 'solo' test method measures both the air leakage between adjacent units through common surfaces as well air leakage to the outside. Measuring and minimizing this total leakage is recommended to avoid indoor air quality issues between units, reduce energy losses to the outside, reduce pressure differentials between units, and control stack effect. However, two significant limitations of the total leakage measurement in attached housing are: for retrofit work, if total leakage is assumed to be all to the outside, the energy benefits of air sealing can be significantly over predicted; for new construction, the total leakage values may result in failing to meet an energy-based house tightness program criterion. The scope of this research is to investigate an approach for developing a viable simplified algorithm that can be used by contractors to assess energy efficiency program qualification and/or compliance based upon solo test results.

  4. Bag Test Measures Leakage From Insulated Pipe

    NASA Technical Reports Server (NTRS)

    Schock, Kent D.; Easter, Barry P.

    1994-01-01

    Test quantifies leakage of gas from pipe even though pipe covered with insulation. Involves use of helium analyzer to measure concentration of helium in impermeable bag around pipe. Test administered after standard soap-solution bubble test indicates presence and general class of leakage.

  5. 49 CFR 230.78 - Leakage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Brake and Signal Equipment § 230.78 Leakage. (a) Main reservoirs and related piping. Leakage from main reservoir and related piping shall be tested at every 92 service day inspection and shall not exceed an...

  6. 49 CFR 230.78 - Leakage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Brake and Signal Equipment § 230.78 Leakage. (a) Main reservoirs and related piping. Leakage from main reservoir and related piping shall be tested at every 92 service day inspection and shall not exceed an...

  7. Putting the Squeeze on Airway Epithelia.

    PubMed

    Park, Jin-Ah; Fredberg, Jeffrey J; Drazen, Jeffrey M

    2015-07-01

    Asthma is characterized by chronic inflammation, airway hyperresponsiveness, and progressive airway remodeling. The airway epithelium is known to play a critical role in the initiation and perpetuation of these processes. Here, we review how excessive epithelial stress generated by bronchoconstriction is sufficient to induce airway remodeling, even in the absence of inflammatory cells. PMID:26136543

  8. Putting the Squeeze on Airway Epithelia

    PubMed Central

    Park, Jin-Ah; Fredberg, Jeffrey J.

    2015-01-01

    Asthma is characterized by chronic inflammation, airway hyperresponsiveness, and progressive airway remodeling. The airway epithelium is known to play a critical role in the initiation and perpetuation of these processes. Here, we review how excessive epithelial stress generated by bronchoconstriction is sufficient to induce airway remodeling, even in the absence of inflammatory cells. PMID:26136543

  9. Airway clearance in neuromuscular weakness.

    PubMed

    Gauld, Leanne Maree

    2009-05-01

    Impaired airway clearance leads to recurrent chest infections and respiratory deterioration in neuromuscular weakness. It is frequently the cause of death. Cough is the major mechanism of airway clearance. Cough has several components, and assessment tools are available to measure the different components of cough. These include measuring peak cough flow, respiratory muscle strength, and inspiratory capacity. Each is useful in assessing the ability to generate an effective cough, and can be used to guide when techniques of assisting airway clearance may be effective for the individual and which are most effective. Techniques to assist airway clearance include augmenting inspiration by air stacking, augmenting expiration by assisting the cough, and augmenting both inspiration and expiration with the mechanical insufflator-exsufflator or by direct suctioning via a tracheostomy. Physiotherapists are invaluable in assisting airway clearance, and in teaching patients and their families how to use these techniques. Use of the mechanical insufflator-exsufflator has gained popularity in recent times, but several simpler, more economical methods are available to assist airway clearance that can be used effectively alone or in combination. This review examines the literature available on the assessment and management of impaired airway clearance in neuromuscular weakness. PMID:19379290

  10. Histamine-induced airway mucosal exudation of bulk plasma and plasma-derived mediators is not inhibited by intravenous bronchodilators.

    PubMed

    Svensson, C; Alkner, U; Pipkorn, U; Persson, C G

    1994-01-01

    Experimental data suggest the possibility that common bronchodilators, such as the xanthines and beta 2-adrenoceptor agonists, may produce microvascular anti-permeability effects in the subepithelial microcirculation of the airways. In this study, we have examined the effect of bronchodilators given intravenously on exudation of different-sized plasma proteins (albumin and fibrinogen) and the generation of plasma-derived peptides (bradykinins) in human nasal airways challenged with histamine. In a double-blind, crossover, placebo-controlled and randomised trial, 12 normal volunteers were given i.v.infusions of terbutaline sulphate, theophylline and enprofylline to produce therapeutic drug levels. The effect of topical nasal provocation with histamine was closely followed by frequently nasal lavage with saline. The lavage fluid levels of albumin, fibrinogen and bradykinins increased significantly after each histamine provocation. The ratio of albumin-to-fibrinogen in plasma and the lavage fluid was 24 and 56, respectively, indicating that topical histamine provocation induced a largely non-sieved flux of macromolecules across the endothelial-epithelial barriers. The systemically administered drugs did not affect the nasal symptoms (sneezing, secretion and blockage), nor did they significantly reduce the levels of plasma proteins and plasma-derived mediators in the nasal lavage fluids. The present data suggest that systemic xanthines and beta 2-adrenoceptor agonists, at clinically employed plasma levels, may not affect the microvascular (and epithelial) exudative permeability and the bradykinin forming capacity of human airways. PMID:8005188

  11. Microvascular effects of copper deficiency in rats

    SciTech Connect

    Schuschke, D.A.; Saari, J.T.; Ackermann, D.M.; Miller, F.N. )

    1989-02-15

    We have studied the microcirculatory responses in copper deficient rats using the rat cremaster muscle preparation. Male Sprague-Dawley rats were fed either a copper supplemented diet (CuS, 5 ppm) or a copper deficient diet (CuD, O ppm) for five weeks prior to experimentation. The rats (240-300g) were anesthetized with pentobarbital and the cremaster (with intact nerve and blood supply) were spread in a tissue bath filled with krebs solution. In vivo television microscopy was used to observe the microcirculation. Fluorescein isothiocyanate tagged to bovine serum albumin (FITC-BSA) was injected i.a. 30 min prior to the start of experimentation. In the CuS animals photoactivation of the intravascular FITC-BSA caused significant platelet aggregation and reduction in red blood cell column diameter (RBCCD) by 30 min and stasis of flow by 60 min. In CuD animals there was no reduction in RBCCD and only minor platelet aggregation after 60 min of photoactivation. Topical administration of compound 48/80 (1.0 and 10.0 {mu}g/ml) induced a significantly greater macromolecular leakage (increased interstitial fluorescence of FITC-BSA) in the CuD animals than in the control, CuS animals. These results suggest that copper deficiency results in marked alterations of the regulatory mechanisms governing thrombosis and inflammation.

  12. Targeting brain microvascular endothelial cells: a therapeutic approach to neuroprotection against stroke

    PubMed Central

    Yu, Qi-jin; Tao, Hong; Wang, Xin; Li, Ming-chang

    2015-01-01

    Brain microvascular endothelial cells form the interface between nervous tissue and circulating blood, and regulate central nervous system homeostasis. Brain microvascular endothelial cells differ from peripheral endothelial cells with regards expression of specific ion transporters and receptors, and contain fewer fenestrations and pinocytotic vesicles. Brain microvascular endothelial cells also synthesize several factors that influence blood vessel function. This review describes the morphological characteristics and functions of brain microvascular endothelial cells, and summarizes current knowledge regarding changes in brain microvascular endothelial cells during stroke progression and therapies. Future studies should focus on identifying mechanisms underlying such changes and developing possible neuroprotective therapeutic interventions. PMID:26807131

  13. Xenobiotic Particle Exposure and Microvascular Endpoints: A Call to Arms

    PubMed Central

    Stapleton, Phoebe A.; Minarchick, Valerie C.; McCawley, Michael; Knuckles, Travis L.; Nurkiewicz, Timothy R.

    2011-01-01

    Xenobiotic particles can be considered in two genres: air pollution particulate matter and engineered nanoparticles. Particle exposures can occur in the greater environment, the workplace, and our homes. The majority of research in this field has, justifiably, focused on pulmonary reactions and outcomes. More recent investigations indicate that cardiovascular effects are capable of correlating with established mortality and morbidity epidemiological data following particle exposures. While the preliminary and general cardiovascular toxicology has been defined, the mechanisms behind these effects, specifically within the microcirculation, are largely unexplored. Therefore, the purpose of this review is several fold: first, a historical background on toxicological aspects of particle research is presented. Second, essential definitions, terminology, and techniques that may be unfamiliar to the microvascular scientist will be discussed. Third, the most current concepts and hypotheses driving cardiovascular research in this field will be reviewed. Lastly, potential future directions for the microvascular scientist will be suggested. Collectively speaking, microvascular research in the particle exposure field represents far more than a “niche”. The immediate demand for basic, translational, and clinical studies is high and diverse. Microvascular scientists at all career stages are strongly encouraged to expand their research interests to include investigations associated with particle exposures. PMID:21951337

  14. Thermal provocation to evaluate microvascular reactivity in human skin

    PubMed Central

    2010-01-01

    With increased interest in predictive medicine, development of a relatively noninvasive technique that can improve prediction of major clinical outcomes has gained considerable attention. Current tests that are the target of critical evaluation, such as flow-mediated vasodilation of the brachial artery and pulse-wave velocity, are specific to the larger conduit vessels. However, evidence is mounting that functional changes in the microcirculation may be an early sign of globalized microvascular dysfunction. Thus development of a test of microvascular reactivity that could be used to evaluate cardiovascular risk or response to treatment is an exciting area of innovation. This mini-review is focused on tests of microvascular reactivity to thermal stimuli in the cutaneous circulation. The skin may prove to be an ideal site for evaluation of microvascular dysfunction due to its ease of access and growing evidence that changes in skin vascular reactivity may precede overt clinical signs of disease. Evaluation of the skin blood flow response to locally applied heat has already demonstrated prognostic utility, and the response to local cooling holds promise in patients in whom cutaneous disorders are present. Whether either of these tests can be used to predict cardiovascular morbidity or mortality in a clinical setting requires further evaluation. PMID:20507974

  15. Evidence of microvascular dysfunction in patients with cystic fibrosis.

    PubMed

    Rodriguez-Miguelez, Paula; Thomas, Jeffrey; Seigler, Nichole; Crandall, Reva; McKie, Kathleen T; Forseen, Caralee; Harris, Ryan A

    2016-06-01

    Cystic fibrosis (CF) is a genetic, multisystemic disorder with broad clinical manifestations apart from the well-characterized pulmonary dysfunction. Recent findings have described impairment in conduit vessel function in patients with CF; however, whether microvascular function is affected in this population has yet to be elucidated. Using laser-Doppler imaging, we evaluated microvascular function through postocclusive reactive hyperemia (PORH), local thermal hyperemia (LTH), and iontophoresis with acetylcholine (ACh). PORH [518 ± 174% (CF) and 801 ± 125% (control), P = 0.039], LTH [1,338 ± 436% (CF) and 1,574 ± 620% (control), P = 0.045], and iontophoresis with ACh [416 ± 140% (CF) and 617 ± 143% (control), P = 0.032] were significantly lower in patients with CF than control subjects. In addition, the ratio of PORH to LTH was significantly (P = 0.043) lower in patients with CF (55.3 ± 5.1%) than control subjects (68.8 ± 3.1%). Significant positive correlations between LTH and forced expiratory volume in 1 s (%predicted) (r = 0.441, P = 0.013) and between the PORH-to-LTH ratio and exercise capacity (r = 0.350, P = 0.049) were observed. These data provide evidence of microvascular dysfunction in patients with CF compared with control subjects. In addition, our data demonstrate a complex relationship between microvascular function and classical markers of disease severity (i.e., pulmonary function and exercise capacity) in CF. PMID:27084387

  16. Irritant-induced airway disorders.

    PubMed

    Brooks, Stuart M; Bernstein, I Leonard

    2011-11-01

    Thousands of persons experience accidental high-level irritant exposures each year but most recover and few die. Irritants function differently than allergens because their actions proceed nonspecifically and by nonimmunologic mechanisms. For some individuals, the consequence of a single massive exposure to an irritant, gas, vapor or fume is persistent airway hyperresponsiveness and the clinical picture of asthma, referred to as reactive airways dysfunction syndrome (RADS). Repeated irritant exposures may lead to chronic cough and continual airway hyperresponsiveness. Cases of asthma attributed to repeated irritant-exposures may be the result of genetic and/or host factors. PMID:21978855

  17. Increased airway glucose increases airway bacterial load in hyperglycaemia

    PubMed Central

    Gill, Simren K.; Hui, Kailyn; Farne, Hugo; Garnett, James P.; Baines, Deborah L.; Moore, Luke S.P.; Holmes, Alison H.; Filloux, Alain; Tregoning, John S.

    2016-01-01

    Diabetes is associated with increased frequency of hospitalization due to bacterial lung infection. We hypothesize that increased airway glucose caused by hyperglycaemia leads to increased bacterial loads. In critical care patients, we observed that respiratory tract bacterial colonisation is significantly more likely when blood glucose is high. We engineered mutants in genes affecting glucose uptake and metabolism (oprB, gltK, gtrS and glk) in Pseudomonas aeruginosa, strain PAO1. These mutants displayed attenuated growth in minimal medium supplemented with glucose as the sole carbon source. The effect of glucose on growth in vivo was tested using streptozocin-induced, hyperglycaemic mice, which have significantly greater airway glucose. Bacterial burden in hyperglycaemic animals was greater than control animals when infected with wild type but not mutant PAO1. Metformin pre-treatment of hyperglycaemic animals reduced both airway glucose and bacterial load. These data support airway glucose as a critical determinant of increased bacterial load during diabetes. PMID:27273266

  18. Increased airway glucose increases airway bacterial load in hyperglycaemia.

    PubMed

    Gill, Simren K; Hui, Kailyn; Farne, Hugo; Garnett, James P; Baines, Deborah L; Moore, Luke S P; Holmes, Alison H; Filloux, Alain; Tregoning, John S

    2016-01-01

    Diabetes is associated with increased frequency of hospitalization due to bacterial lung infection. We hypothesize that increased airway glucose caused by hyperglycaemia leads to increased bacterial loads. In critical care patients, we observed that respiratory tract bacterial colonisation is significantly more likely when blood glucose is high. We engineered mutants in genes affecting glucose uptake and metabolism (oprB, gltK, gtrS and glk) in Pseudomonas aeruginosa, strain PAO1. These mutants displayed attenuated growth in minimal medium supplemented with glucose as the sole carbon source. The effect of glucose on growth in vivo was tested using streptozocin-induced, hyperglycaemic mice, which have significantly greater airway glucose. Bacterial burden in hyperglycaemic animals was greater than control animals when infected with wild type but not mutant PAO1. Metformin pre-treatment of hyperglycaemic animals reduced both airway glucose and bacterial load. These data support airway glucose as a critical determinant of increased bacterial load during diabetes. PMID:27273266

  19. Rare Upper Airway Anomalies.

    PubMed

    Windsor, Alanna; Clemmens, Clarice; Jacobs, Ian N

    2016-01-01

    A broad spectrum of congenital upper airway anomalies can occur as a result of errors during embryologic development. In this review, we will describe the clinical presentation, diagnosis, and management strategies for a few select, rare congenital malformations of this system. The diagnostic tools used in workup of these disorders range from prenatal tests to radiological imaging, swallowing evaluations, indirect or direct laryngoscopy, and rigid bronchoscopy. While these congenital defects can occur in isolation, they are often associated with disorders of other organ systems or may present as part of a syndrome. Therefore workup and treatment planning for patients with these disorders often involves a team of multiple specialists, including paediatricians, otolaryngologists, pulmonologists, speech pathologists, gastroenterologists, and geneticists. PMID:26277452

  20. [Reactive airways dysfunction syndrome].

    PubMed

    Costa, R; Orriols, R

    2005-01-01

    Reactive airways dysfunction syndrome, better known as RADS, was described as a clinical entity consisting in the appearance of bronchial asthma due to massive toxic inhalation. The term was coined and recognised for the first time in 1985. Since then different publications have verified new cases as well as different causal agents. It usually arises from an accident at the work place and in closed or poorly ventilated spaces, where high concentrations of irritant products are inhaled in the form of gas, smoke or vapour. In the following minutes or hours symptoms of bronchial obstruction appear in an acute form, with bronchial hyperresponsiveness persisting for months or years. The affected patients do not show a recurrence of symptoms following exposure to non-toxic doses of the same agent that started the symptoms. This is why diagnosis is based on clinical manifestations as it is not reproducible through a provocation test. PMID:15915173

  1. Air leakage of newly instaled residential windows

    SciTech Connect

    Weidt, J.; Weidt, J.

    1980-06-01

    The air-leakage characteristics of five major window designs were measured in a field survey conducted in Twin Cities, Minnesota. A total of 192 windows (16 manufacturers) were tested at 58 sites representing a cross-section of single-family homes, townhouses, low- and high-rise apartments, and condominiums. Air-leakage measurements of the installed windows were compared with the current standard used by industry and government of 0.50 ft/sup 3//min/linear ft of crack. Other parameters studied were: effect of sash and frame material, effect of leakage between window frame and wall, differences among the product lines of a single manufacturer and between manufacturers, effect of installation practices, effect of cold weather on performance, change in performance over time for older windows, and performance of fixed glazing. Based on industry and government standards, 40% of all windows tested showed air-leakage characteristics higher than the 0.50 cfm/lfc standard, and 60% exceeded manufacturers' specifications for performance which in some cases were lower than the general industry standard. Analysis of the impact of various parameters on air-leakage performance showed that the operational design of the window was the most critical determinant although the ranking changes if performance is expressed in cfm/unit area or cfm/opening area. Air leakage was measured using a portable pressurization chamber. Smoke pencils, thermographic techniques and extensive photographic documentation provided additional data as to the location and cause of air leakage problems.

  2. Choroid Sprouting Assay: An Ex Vivo Model of Microvascular Angiogenesis

    PubMed Central

    Shao, Zhuo; Friedlander, Mollie; Hurst, Christian G.; Cui, Zhenghao; Pei, Dorothy T.; Evans, Lucy P.; Juan, Aimee M.; Tahir, Houda; Duhamel, François; Chen, Jing; Sapieha, Przemyslaw; Chemtob, Sylvain; Joyal, Jean-Sébastien; Smith, Lois E. H.

    2013-01-01

    Angiogenesis of the microvasculature is central to the etiology of many diseases including proliferative retinopathy, age-related macular degeneration and cancer. A mouse model of microvascular angiogenesis would be very valuable and enable access to a wide range of genetically manipulated tissues that closely approximate small blood vessel growth in vivo. Vascular endothelial cells cultured in vitro are widely used, however, isolating pure vascular murine endothelial cells is technically challenging. A microvascular mouse explant model that is robust, quantitative and can be reproduced without difficulty would overcome these limitations. Here we characterized and optimized for reproducibility an organotypic microvascular angiogenesis mouse and rat model from the choroid, a microvascular bed in the posterior of eye. The choroidal tissues from C57BL/6J and 129S6/SvEvTac mice and Sprague Dawley rats were isolated and incubated in Matrigel. Vascular sprouting was comparable between choroid samples obtained from different animals of the same genetic background. The sprouting area, normalized to controls, was highly reproducible between independent experiments. We developed a semi-automated macro in ImageJ software to allow for more efficient quantification of sprouting area. Isolated choroid explants responded to manipulation of the external environment while maintaining the local interactions of endothelial cells with neighboring cells, including pericytes and macrophages as evidenced by immunohistochemistry and fluorescence-activated cell sorting (FACS) analysis. This reproducible ex vivo angiogenesis assay can be used to evaluate angiogenic potential of pharmacologic compounds on microvessels and can take advantage of genetically manipulated mouse tissue for microvascular disease research. PMID:23922736

  3. Endothelialized Microfluidics for Studying Microvascular Interactions in Hematologic Diseases

    PubMed Central

    Tran, Reginald; Ahn, Byungwook; Hardy, Elaissa Trybus; Mannino, Robert; Kita, Ashley; Tsai, Michelle; Lam, Wilbur A.

    2012-01-01

    Advances in microfabrication techniques have enabled the production of inexpensive and reproducible microfluidic systems for conducting biological and biochemical experiments at the micro- and nanoscales 1,2. In addition, microfluidics have also been specifically used to quantitatively analyze hematologic and microvascular processes, because of their ability to easily control the dynamic fluidic environment and biological conditions3-6. As such, researchers have more recently used microfluidic systems to study blood cell deformability, blood cell aggregation, microvascular blood flow, and blood cell-endothelial cell interactions6-13.However, these microfluidic systems either did not include cultured endothelial cells or were larger than the sizescale relevant to microvascular pathologic processes. A microfluidic platform with cultured endothelial cells that accurately recapitulates the cellular, physical, and hemodynamic environment of the microcirculation is needed to further our understanding of the underlying biophysical pathophysiology of hematologic diseases that involve the microvasculature. Here, we report a method to create an "endothelialized" in vitro model of the microvasculature, using a simple, single mask microfabrication process in conjunction with standard endothelial cell culture techniques, to study pathologic biophysical microvascular interactions that occur in hematologic disease. This "microvasculature-on-a-chip" provides the researcher with a robust assay that tightly controls biological as well as biophysical conditions and is operated using a standard syringe pump and brightfield/fluorescence microscopy. Parameters such as microcirculatory hemodynamic conditions, endothelial cell type, blood cell type(s) and concentration(s), drug/inhibitory concentration etc., can all be easily controlled. As such, our microsystem provides a method to quantitatively investigate disease processes in which microvascular flow is impaired due to alterations in

  4. Endothelial Dysfunction and Microvascular Complications in Type 1 Diabetes Mellitus

    PubMed Central

    Jin, Seon Mi; Yang, Sei Won; Bae, Eun Jung; Shin, Choong Ho; Chung, Hae Rim; Kim, You Yeh; Yun, Yong Soo

    2008-01-01

    We examined whether alterations in vascular endothelial function and early structural changes in atherosclerosis are associated with microvascular complications in patients with type 1 diabetes mellitus (DM). Flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (IMT) measurement were performed in 70 young adults (aged 19 to 35 yr), 48 with type 1 DM, and 22 normal controls. Patients with diabetes had a lower peak FMD response (7.8±3.9 vs. 11.1±1.9%, p<0.001) and increased IMT (0.51±0.10 vs. 0.42±0.07 mm, p<0.001) compared with controls. Twenty (41.7%) of the patients had microvascular complications including neuropathy, nephropathy, or retinopathy. In these complicated diabetic patients, we found a lower FMD response (6.1±2.5 vs. 9.9±3.5%, p=0.001) compared with diabetics without microvascular complications. The presence of microvascular complications was also associated with older age and longer duration of the disease. However, no differences were observed in IMT, body size, blood pressure, HbA1c, C-reactive protein, low-density lipoprotein or high-density lipoprotein cholesterol levels between complicated and non-complicated patients. Endothelial dysfunction and early structural atherosclerotic changes are common manifestations in type 1 DM, and endothelial dysfunction is thought to be an early event in the atherosclerotic process and important in the pathogenesis of microvascular complications. PMID:18303203

  5. Sublingual microvascular perfusion is altered during normobaric and hyperbaric hyperoxia.

    PubMed

    Milstein, Dan M J; Helmers, Renée; Hackmann, Sanne; Belterman, Charly N W; van Hulst, Robert A; de Lange, Jan

    2016-05-01

    Hyperoxia and hyperbaric oxygen therapy can restore oxygen tensions in tissues distressed by ischemic injury and poor vascularization and is believed to also yield angiogenesis and regulate tissue perfusion. The aim of this study was to develop a model in which hyperoxia-driven microvascular changes could be quantified and to test the hypothesis that microcirculatory responses to both normobaric (NB) and hyperbaric (HB) hyperoxic maneuvers are reversible. Sublingual mucosa microcirculation vessel density, proportion of perfused vessels, vessel diameters, microvascular flow index, macrohemodynamic, and blood gas parameters were examined in male rabbits breathing sequential O2/air mixtures of 21%, 55%, 100%, and return to 21% during NB (1.0bar) and HB (2.5bar) conditions. The results indicate that NB hyperoxia (55% and 100%) produced significant decreases in microvascular density and vascular diameters (p<0.01 and p<0.05, respectively) accompanied by significant increases in systolic and mean arterial blood pressure (p<0.05, respectively) with no changes in blood flow indices when compared to NB normoxia. HB normoxia/hyperoxia resulted in significant decreases in microvascular density (p<0.05), a transient rise in systolic blood pressure at 55% (p<0.01), and no changes in blood vessel diameter and blood flow indices when compared to NB hyperoxia. All microcirculation parameters reverted back to normal values upon return to NB normoxia. We conclude that NB/HB hyperoxia-driven changes elicit reversible physiological control of sublingual mucosa blood perfusion in the presence of steady cardiovascular function and that the absence of microvascular vasoconstriction during HB conditions suggests a beneficial mechanism associated with maintaining peak tissue perfusion states. PMID:26851620

  6. Apoptosis and the Airway Epithelium

    PubMed Central

    White, Steven R.

    2011-01-01

    The airway epithelium functions as a barrier and front line of host defense in the lung. Apoptosis or programmed cell death can be elicited in the epithelium as a response to viral infection, exposure to allergen or to environmental toxins, or to drugs. While apoptosis can be induced via activation of death receptors on the cell surface or by disruption of mitochondrial polarity, epithelial cells compared to inflammatory cells are more resistant to apoptotic stimuli. This paper focuses on the response of airway epithelium to apoptosis in the normal state, apoptosis as a potential regulator of the number and types of epithelial cells in the airway, and the contribution of epithelial cell apoptosis in important airways diseases. PMID:22203854

  7. Extraglottic airway devices: A review

    PubMed Central

    Ramaiah, Ramesh; Das, Debasmita; Bhananker, Sanjay M; Joffe, Aaron M

    2014-01-01

    Extraglottic airway devices (EAD) have become an integral part of anesthetic care since their introduction into clinical practice 25 years ago and have been used safely hundreds of millions of times, worldwide. They are an important first option for difficult ventilation during both in-hospital and out-of-hospital difficult airway management and can be utilized as a conduit for tracheal intubation either blindly or assisted by another technology (fiberoptic endoscopy, lightwand). Thus, the EAD may be the most versatile single airway technique in the airway management toolbox. However, despite their utility, knowledge regarding specific devices and the supporting data for their use is of paramount importance to patient's safety. In this review, number of commercially available EADs are discussed and the reported benefits and potential pitfalls are highlighted. PMID:24741502

  8. United airway disease: current perspectives

    PubMed Central

    Giavina-Bianchi, Pedro; Aun, Marcelo Vivolo; Takejima, Priscila; Kalil, Jorge; Agondi, Rosana Câmara

    2016-01-01

    Upper and lower airways are considered a unified morphological and functional unit, and the connection existing between them has been observed for many years, both in health and in disease. There is strong epidemiologic, pathophysiologic, and clinical evidence supporting an integrated view of rhinitis and asthma: united airway disease in the present review. The term “united airway disease” is opportune, because rhinitis and asthma are chronic inflammatory diseases of the upper and lower airways, which can be induced by allergic or nonallergic reproducible mechanisms, and present several phenotypes. Management of rhinitis and asthma must be jointly carried out, leading to better control of both diseases, and the lessons of the Allergic Rhinitis and Its Impact on Asthma initiative cannot be forgotten. PMID:27257389

  9. Tachykinin receptors and airway pathophysiology.

    PubMed

    Maggi, C A

    1993-05-01

    The mammalian tachykinins (TKs), substance P and neurokinin A, are present in sensory nerve fibres in the upper and lower airways of various mammalian species, including humans. TKs are released from these afferent nerves in an "efferent" mode at peripheral level, especially in response to irritant stimuli. TKs exert a variety of biological effects (bronchoconstriction, plasma protein extravasation, stimulation of mucus secretion), collectively known as "neurogenic inflammation", and this process is thought to be of potential pathogenic relevance for various airway diseases. The recent development of potent and selective TK receptor antagonists on the one hand provides important new tools for the understanding of basic airway physiology and pathophysiology and, on the other, opens new possibilities for therapy of airway diseases. PMID:8390944

  10. Eosinophilic phenotypes of airway disease.

    PubMed

    Pavord, Ian D

    2013-12-01

    Our understanding of the clinical implications of eosinophilic airway inflammation has increased significantly over the last 20 years, aided by the development of noninvasive means to assess it. This pattern of airway inflammation can occur in a diverse range of airway diseases. It is associated with a positive response to corticosteroids and a high risk of preventable exacerbations. Our new understanding of the role of eosinophilic airway inflammation has paved the way for the clinical development of a number of more specific inhibitors that may become new treatment options. Different definitions, ideas of disease, and adoption of biomarkers that are not well known are necessary to fully realize the potential of these treatments. PMID:24313765

  11. Imaging of the Distal Airways

    PubMed Central

    Tashkin, Donald P.; de Lange, Eduard E.

    2009-01-01

    Imaging techniques of the lung continues to advance with improving ability to image the more distal airways. Two imaging techniques are reviewed, computerized tomography and magnetic resonance with hyperpolarized helium-3. PMID:19962040

  12. The Virtual Pediatric Airways Workbench.

    PubMed

    Quammen, Cory W; Taylor Ii, Russell M; Krajcevski, Pavel; Mitran, Sorin; Enquobahrie, Andinet; Superfine, Richard; Davis, Brad; Davis, Stephanie; Zdanski, Carlton

    2016-01-01

    The Virtual Pediatric Airways Workbench (VPAW) is a patient-centered surgical planning software system targeted to pediatric patients with airway obstruction. VPAW provides an intuitive surgical planning interface for clinicians and supports quantitative analysis regarding prospective surgeries to aid clinicians deciding on potential surgical intervention. VPAW enables a full surgical planning pipeline, including importing DICOM images, segmenting the airway, interactive 3D editing of airway geometries to express potential surgical treatment planning options, and creating input files for offline geometric analysis and computational fluid dynamics simulations for evaluation of surgical outcomes. In this paper, we describe the VPAW system and its use in one case study with a clinician to successfully describe an intended surgery outcome. PMID:27046595

  13. Airway Surface Mycosis in Chronic Th2-Associated Airway Disease

    PubMed Central

    Porter, Paul; Lim, Dae Jun; Maskatia, Zahida Khan; Mak, Garbo; Tsai, Chu-Lin; Citardi, Martin J; Fakhri, Samer; Shaw, Joanne L.; Fothergil, Annette; Kheradmand, Farrah; Corry, David B; Luong, Amber

    2014-01-01

    Background Environmental fungi have been linked to T helper type 2 (Th2) cell-related airway inflammation and the Th2-associated chronic airway diseases asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and allergic fungal rhinosinusitis (AFRS), but whether these organisms participate directly or indirectly in disease pathology remains unknown. Objective To determine the frequency of fungus isolation and fungus-specific immunity in Th2-associated and non-associated airway disease patients. Methods Sinus lavage fluid and blood were collected from sinus surgery patients (n=118) including CRS patients with and without nasal polyps and AFRS and non-CRS/non-asthmatic control patients. Asthma status was deteremined from medical history. Sinus lavage fluids were cultured and directly examined for evidence of viable fungi. Peripheral blood mononuclear cells were restimulated with fungal antigens in an enzyme linked immunocell spot (ELISpot) assay to determine total memory fungus-specific IL-4-secreting cells. These data were compared to fungus-specific IgE levels measured from plasma by ELISA. Results Filamentous fungi were significantly more commonly cultured from Th2-associated airway disease subjects (asthma, CRSwNP, or AFRS: n=68) compared to non-Th2-associated control patients (n=31); 74% vs 16% respectively, p<0.001. Both fungus-specific IL-4 ELISpot (n=48) and specific IgE (n=70) data correlated with Th2-associated diseases (sensitivity 73% and specificity 100% vs. 50% and 77%, respectively). Conclusions The frequent isolation of fungi growing directly within the airways accompanied by specific immunity to these organisms only in patients with Th2-associated chronic airway diseases suggests that fungi participate directly in the pathogenesis of these conditions. Efforts to eradicate airway fungi from the airways should be considered in selected patients. Clinical Implications Airway fungi may contribute to the expression of sinusitis with nasal polyps and

  14. Airway obstruction with cricoid pressure.

    PubMed

    Hartsilver, E L; Vanner, R G

    2000-03-01

    Cricoid pressure may cause airway obstruction. We investigated whether this is related to the force applied and to the technique of application. We recorded expired tidal volumes and inflation pressures during ventilation via a face-mask and oral airway in 52 female patients who were anaesthetised and about to undergo elective surgery. An inspired tidal volume of 900 ml was delivered using a ventilator. Ventilation was assessed under five different conditions: no cricoid pressure, backwards cricoid pressure applied with a force of 30 N, cricoid pressure applied in an upward and backward direction with a force of 30 N, backwards cricoid pressure with a force of 44 N and through a tracheal tube. An expired tidal volume of < 200 ml was taken to indicate airway obstruction. Airway obstruction did not occur without cricoid pressure, but did occur in one patient (2%) with cricoid pressure at 30 N, in 29 patients (56%) with 30 N applied in an upward and backward direction and in 18 (35%) patients with cricoid pressure at 44 N. Cricoid pressure applied with a force of 44 N can cause airway obstruction but if cricoid pressure is applied with a force of 30 N, airway obstruction occurs less frequently (p = 0.0001) unless the force is applied in an upward and backward direction. PMID:10671836

  15. Surfactant and allergic airway inflammation.

    PubMed

    Winkler, Carla; Hohlfeld, Jens M

    2013-01-01

    Pulmonary surfactant is a complex mixture of unique proteins and lipids that covers the airway lumen. Surfactant prevents alveolar collapse and maintains airway patency by reducing surface tension at the air-liquid interface. Furthermore, it provides a defence against antigen uptake by binding foreign particles and enhancing cellular immune responses. Allergic asthma is associated with chronic airway inflammation and presents with episodes of airway narrowing. The pulmonary inflammation and bronchoconstriction can be triggered by exposure to allergens or pathogens present in the inhaled air. Pulmonary surfactant has the potential to interact with various immune cells which orchestrate allergen- or pathogen-driven episodes of airway inflammation. The complex nature of surfactant allows multiple sites of interaction, but also makes it susceptible to external alterations, which potentially impair its function. This duality of modulating airway physiology and immunology during inflammatory conditions, while at the same time being prone to alterations accompanied by restricted function, has stimulated numerous studies in recent decades, which are reviewed in this article. PMID:23896983

  16. Coronary Microvascular Dysfunction and Microvascular Angina: A Systematic Review of Therapies

    PubMed Central

    Marinescu, Mark A; Löffler, Adrián I.; Ouellette, Michelle; Smith, Lavone; Kramer, Christopher M.; Bourque, Jamieson

    2015-01-01

    Angina without coronary artery disease (CAD) has substantial morbidity and is present in 10–30% of patients undergoing angiography. Coronary microvascular dysfunction (CMD) is present in 50–65% of these patients. The optimal treatment of this cohort is undefined. We performed a systematic review to evaluate treatment strategies for objectively defined CMD in the absence of CAD. We included studies assessing therapy in human subjects with angina and coronary flow reserve (CFR) or myocardial perfusion reserve (MPR) <2.5 by positron emission tomography (PET), cardiac magnetic resonance imaging (CMR), dilution methods, or intracoronary Doppler in the absence of coronary artery stenosis ≥50% or structural heart disease. Only 8 articles met strict inclusion criteria. The articles were heterogeneous, using different treatments, end-points, and definitions of CMD. Small sample sizes severely limit the power of these studies, with an average of 11 patients per analysis. Studies evaluating, sildenafil, quinapril, estrogen, and transcutaneous electrical nerve stimulation (TENS) application demonstrated benefits in their respective endpoints. No benefit was found with L-arginine, doxazosin, pravastatin, and diltiazem. Our systematic review highlights that there is little data to support therapies for CMD. We assess the data meeting rigorous inclusion criteria and review the related but excluded literature. We additionally describe the next steps needed to address this research gap, including a standardized definition of CMD, routine assessment of CMD in studies of chest pain without obstructive CAD, and specific therapy assessment in the population with confirmed CMD. PMID:25677893

  17. Early Alzheimer's Linked to Brain 'Leakage'

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_159116.html Early Alzheimer's Linked to Brain 'Leakage' Normally, blood-brain barrier ... HealthDay News) -- People in the early stages of Alzheimer's disease may have more "leaks" in the barrier ...

  18. Composite seal reduces alkaline battery leakage

    NASA Technical Reports Server (NTRS)

    Clatterbuck, C. H.; Plitt, K. F.

    1965-01-01

    Composite seal consisting of rubber or plastic washers and a metal washer reduces alkaline battery leakage. Adhesive is applied to each washer interface, and the washers are held together mechanically.

  19. Early Alzheimer's Linked to Brain 'Leakage'

    MedlinePlus

    ... news/fullstory_159116.html Early Alzheimer's Linked to Brain 'Leakage' Normally, blood-brain barrier prevents this from happening To use the ... more "leaks" in the barrier that separates the brain from the bloodstream, a small study suggests. Known ...

  20. Apparatus for detecting leakage of liquid sodium

    DOEpatents

    Himeno, Yoshiaki

    1978-01-01

    An apparatus for detecting the leakage of liquid sodium includes a cable-like sensor adapted to be secured to a wall of piping or other equipment having sodium on the opposite side of the wall, and the sensor includes a core wire electrically connected to the wall through a leak current detector and a power source. An accidental leakage of the liquid sodium causes the corrosion of a metallic layer and an insulative layer of the sensor by products resulted from a reaction of sodium with water or oxygen in the atmospheric air so as to decrease the resistance between the core wire and the wall. Thus, the leakage is detected as an increase in the leaking electrical current. The apparatus is especially adapted for use in detecting the leakage of liquid sodium from sodium-conveying pipes or equipment in a fast breeder reactor.

  1. Measuring Heat-Exchanger Water Leakage

    NASA Technical Reports Server (NTRS)

    Zampiceni, J.

    1986-01-01

    Water leakage in heat exchanger measured directly with help of electroytic hygrometer. In new technique, flow of nitrogen gas set up in one loop of heat exchanger. Other loop filled with water under pressure. Water concentration produced by leakage of water into nitrogen flow measured by hygrometer. New measurement method determines water concentrations up to 2,000 parts per million with accuracy of +/- 5 percent.

  2. Technology evaluation for space station atmospheric leakage

    SciTech Connect

    Lemon, D.K.; Friesel, M.A.; Griffin, J.W.; Skorpik, J.R.; Shepard, C.L.; Antoniak, Z.I.; Kurtz, R.J.

    1990-02-01

    A concern in operation of a space station is leakage of atmosphere through seal points and through the walls as a result of damage from particle (space debris and micrometeoroid) impacts. This report describes a concept for a monitoring system to detect atmosphere leakage and locate the leak point. The concept is based on analysis and testing of two basic methods selected from an initial technology survey of potential approaches. 18 refs., 58 figs., 5 tabs.

  3. Leakage Suppression in the Toric Code

    NASA Astrophysics Data System (ADS)

    Suchara, Martin; Cross, Andrew; Gambetta, Jay

    2015-03-01

    Quantum codes excel at correcting local noise but fail to correct leakage faults that excite qubits to states outside the computational space. Aliferis and Terhal have shown that an accuracy threshold exists for leakage faults using gadgets called leakage reduction units (LRUs). However, these gadgets reduce the threshold and increase experimental complexity, and the costs have not been thoroughly understood. We explore a variety of techniques for leakage resilience in topological codes. Our contributions are threefold. First, we develop a leakage model that differs in critical details from earlier models. Second, we use Monte-Carlo simulations to survey several syndrome extraction circuits. Third, given the capability to perform 3-outcome measurements, we present a dramatically improved syndrome processing algorithm. Our simulations show that simple circuits with one extra CNOT per qubit reduce the accuracy threshold by less than a factor of 4 when leakage and depolarizing noise rates are comparable. This becomes a factor of 2 when the decoder uses 3-outcome measurements. Finally, when the physical error rate is less than 2 ×10-4 , placing LRUs after every gate may achieve the lowest logical error rate. We expect that the ideas may generalize to other topological codes.

  4. Comparing the Laryngeal Mask Airway, Cobra Perilaryngeal Airway and Face Mask in Children Airway Management

    PubMed Central

    Tekin, Beyza; Hatipoğlu, Zehra; Türktan, Mediha; Özcengiz, Dilek

    2016-01-01

    Objective We compared the effects of the laryngeal mask airway (LMA), face mask and Cobra perilaryngeal airway (PLA) in the airway management of spontaneously breathing paediatric patients undergoing elective inguinal surgery. Methods In this study, 90 cases of 1–14-year-old children undergoing elective inguinal surgery were scheduled. The patients were randomly divided into three groups. Anaesthesia was provided with sevoflurane and 50%–50% nitrous oxide and oxygen. After providing an adequate depth of anaesthesia, supraglottic airway devices were inserted in the group I and II patients. The duration and number of insertion, haemodynamic parameters, plateau and peak inspiratory pressure and positive end-expiratory pressure of the patients were recorded preoperatively, after induction and at 5, 10, 15 and 30 min peroperatively. Results There were no statistical differences between the groups in terms of haemodynamic parameters (p>0.05). In group II, instrumentation success was higher and instrumentation time was shorter than group II. The positive end-expiratory pressure and plateau and peak inspiratory pressure values were statistically lower in group II (p<0.05). Conclusion We concluded that for airway safety and to avoid possible complications, LMA and Cobra PLA could be alternatives to face mask and that the Cobra PLA provided lower airway pressure and had a faster and more easy placement than LMA. PMID:27366563

  5. Human airway ciliary dynamics

    PubMed Central

    Thompson, Kristin; Knowles, Michael R.; Davis, C. William

    2013-01-01

    Airway cilia depend on precise changes in shape to transport the mucus gel overlying mucosal surfaces. The ciliary motion can be recorded in several planes using video microscopy. However, cilia are densely packed, and automated computerized systems are not available to convert these ciliary shape changes into forms that are useful for testing theoretical models of ciliary function. We developed a system for converting planar ciliary motions recorded by video microscopy into an empirical quantitative model, which is easy to use in validating mathematical models, or in examining ciliary function, e.g., in primary ciliary dyskinesia (PCD). The system we developed allows the manipulation of a model cilium superimposed over a video of beating cilia. Data were analyzed to determine shear angles and velocity vectors of points along the cilium. Extracted waveforms were used to construct a composite waveform, which could be used as a standard. Variability was measured as the mean difference in position of points on individual waveforms and the standard. The shapes analyzed were the end-recovery, end-effective, and fastest moving effective and recovery with mean (± SE) differences of 0.31(0.04), 0.25(0.06), 0.50(0.12), 0.50(0.10), μm, respectively. In contrast, the same measures for three different PCD waveforms had values far outside this range. PMID:23144323

  6. Role of Small Airways in Asthma.

    PubMed

    Finkas, Lindsay K; Martin, Richard

    2016-08-01

    Asthma is an inflammatory condition of both the small and large airways. Recently the small airways have gained attention as studies have shown significant inflammation in the small airways in all severities of asthma. This inflammation has correlated with peripheral airway resistance and as a result, noninvasive methods to reliably measure small airways have been pursued. In addition, recent changes in asthma inhalers have led to alterations in drug formulations and the development of extrafine particle inhalers that improve delivery to the distal airways. PMID:27401620

  7. Accurate airway segmentation based on intensity structure analysis and graph-cut

    NASA Astrophysics Data System (ADS)

    Meng, Qier; Kitsaka, Takayuki; Nimura, Yukitaka; Oda, Masahiro; Mori, Kensaku

    2016-03-01

    This paper presents a novel airway segmentation method based on intensity structure analysis and graph-cut. Airway segmentation is an important step in analyzing chest CT volumes for computerized lung cancer detection, emphysema diagnosis, asthma diagnosis, and pre- and intra-operative bronchoscope navigation. However, obtaining a complete 3-D airway tree structure from a CT volume is quite challenging. Several researchers have proposed automated algorithms basically based on region growing and machine learning techniques. However these methods failed to detect the peripheral bronchi branches. They caused a large amount of leakage. This paper presents a novel approach that permits more accurate extraction of complex bronchial airway region. Our method are composed of three steps. First, the Hessian analysis is utilized for enhancing the line-like structure in CT volumes, then a multiscale cavity-enhancement filter is employed to detect the cavity-like structure from the previous enhanced result. In the second step, we utilize the support vector machine (SVM) to construct a classifier for removing the FP regions generated. Finally, the graph-cut algorithm is utilized to connect all of the candidate voxels to form an integrated airway tree. We applied this method to sixteen cases of 3D chest CT volumes. The results showed that the branch detection rate of this method can reach about 77.7% without leaking into the lung parenchyma areas.

  8. Key Molecular Mechanisms of Chaiqinchengqi Decoction in Alleviating the Pulmonary Albumin Leakage Caused by Endotoxemia in Severe Acute Pancreatitis Rats.

    PubMed

    Wu, Wei; Luo, Ruijie; Lin, Ziqi; Xia, Qing; Xue, Ping

    2016-01-01

    To reveal the key molecular mechanisms of Chaiqinchengqi decoction (CQCQD) in alleviating the pulmonary albumin leakage caused by endotoxemia in severe acute pancreatitis (SAP) rats. Rats models of SAP endotoxemia-induced acute lung injury were established, the studies in vivo provided the important evidences that the therapy of CQCQD significantly ameliorated the increases in plasma levels of lipopolysaccharide (LPS), sCd14, and Lbp, the elevation of serum amylase level, the enhancements of systemic and pulmonary albumin leakage, and the depravation of airways indicators, thus improving respiratory dysfunction and also pancreatic and pulmonary histopathological changes. According to the analyses of rats pulmonary tissue microarray and protein-protein interaction network, c-Fos, c-Src, and p85α were predicted as the target proteins for CQCQD in alleviating pulmonary albumin leakage. To confirm these predictions, human umbilical vein endothelial cells were employed in in vitro studies, which provide the evidences that (1) LPS-induced paracellular leakage and proinflammatory cytokines release were suppressed by pretreatment with inhibitors of c-Src (PP1) or PI3K (LY294002) or by transfection with siRNAs of c-Fos; (2) fortunately, CQCQD imitated the actions of these selective inhibitions agents to inhibit LPS-induced high expressions of p-Src, p-p85α, and c-Fos, therefore attenuating paracellular leakage and proinflammatory cytokines release. PMID:27413385

  9. Key Molecular Mechanisms of Chaiqinchengqi Decoction in Alleviating the Pulmonary Albumin Leakage Caused by Endotoxemia in Severe Acute Pancreatitis Rats

    PubMed Central

    Wu, Wei; Luo, Ruijie; Lin, Ziqi; Xia, Qing

    2016-01-01

    To reveal the key molecular mechanisms of Chaiqinchengqi decoction (CQCQD) in alleviating the pulmonary albumin leakage caused by endotoxemia in severe acute pancreatitis (SAP) rats. Rats models of SAP endotoxemia-induced acute lung injury were established, the studies in vivo provided the important evidences that the therapy of CQCQD significantly ameliorated the increases in plasma levels of lipopolysaccharide (LPS), sCd14, and Lbp, the elevation of serum amylase level, the enhancements of systemic and pulmonary albumin leakage, and the depravation of airways indicators, thus improving respiratory dysfunction and also pancreatic and pulmonary histopathological changes. According to the analyses of rats pulmonary tissue microarray and protein-protein interaction network, c-Fos, c-Src, and p85α were predicted as the target proteins for CQCQD in alleviating pulmonary albumin leakage. To confirm these predictions, human umbilical vein endothelial cells were employed in in vitro studies, which provide the evidences that (1) LPS-induced paracellular leakage and proinflammatory cytokines release were suppressed by pretreatment with inhibitors of c-Src (PP1) or PI3K (LY294002) or by transfection with siRNAs of c-Fos; (2) fortunately, CQCQD imitated the actions of these selective inhibitions agents to inhibit LPS-induced high expressions of p-Src, p-p85α, and c-Fos, therefore attenuating paracellular leakage and proinflammatory cytokines release. PMID:27413385

  10. Photoacoustic microscopy of microvascular responses to cortical electrical stimulation

    NASA Astrophysics Data System (ADS)

    Tsytsarev, Vassiliy; Hu, Song; Yao, Junjie; Maslov, Konstantin; Barbour, Dennis L.; Wang, Lihong V.

    2011-07-01

    Advances in the functional imaging of cortical hemodynamics have greatly facilitated the understanding of neurovascular coupling. In this study, label-free optical-resolution photoacoustic microscopy (OR-PAM) was used to monitor microvascular responses to direct electrical stimulations of the mouse somatosensory cortex through a cranial opening. The responses appeared in two forms: vasoconstriction and vasodilatation. The transition between these two forms of response was observed in single vessels by varying the stimulation intensity. Marked correlation was found between the current-dependent responses of two daughter vessels bifurcating from the same parent vessel. Statistical analysis of twenty-seven vessels from three different animals further characterized the spatial-temporal features and the current dependence of the microvascular response. Our results demonstrate that OR-PAM is a valuable tool to study neurovascular coupling at the microscopic level.

  11. Coronary microvascular dysfunction in chronic inflammatory rheumatoid diseases.

    PubMed

    Faccini, Alessia; Kaski, Juan Carlos; Camici, Paolo G

    2016-06-14

    Chronic inflammatory rheumatoid diseases (CIRD) such as rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis are an important risk factor for the development of ischaemic heart disease and a source of high cardiovascular morbidity and mortality. In patients affected by CIRD, inflammation can affect coronary microvascular function and contribute to the development of myocardial ischemia and cardiovascular events, even in the absence of obstructive epicardial coronary artery disease. Understanding the molecular aspects that underlie the development of coronary microvascular dysfunction (CMD) in CIRD is of fundamental importance to identify specific therapeutic targets. In this article, we review the pathogenic mechanisms leading to CMD in CIRD, including the controversial results obtained with the use of different therapeutic strategies. We also propose that a practical diagnostic algorithm as the identification of CMD in patients with CIRD may lead to effective measures to prevent the development of angina pectoris and reduce the risk of rapid disease progression. PMID:26912605

  12. Microvascular complications of diabetes mellitus: renal protection accompanies cardiovascular protection.

    PubMed

    Brown, W Virgil

    2008-12-22

    The microvascular complications of diabetes mellitus confer substantial morbidity and impair patient quality of life. Dyslipidemia and prolonged hyperglycemia promote an increase in oxidative stress, inflammation, and vascular damage, which together promote endothelial dysfunction and are associated with macrovascular and microvascular complications. Microalbuminuria is an early marker of diabetic nephropathy and an independent risk factor for cardiovascular disease. Diabetic nephropathy is the most common cause of end-stage renal disease in developed countries, and its prevalence is increasing. Preventing or limiting the progression of diabetic nephropathy, as demonstrated in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial, may prevent or delay renal complications, as well as convey important cardioprotective benefits in patients with type 2 diabetes. PMID:19084084

  13. Impact of simulated microgravity on microvascular endothelial cell apoptosis.

    PubMed

    Kang, Chun-Yan; Zou, Lin; Yuan, Ming; Wang, Yang; Li, Tian-Zhi; Zhang, Ye; Wang, Jun-Feng; Li, Yan; Deng, Xiao-Wei; Liu, Chang-Ting

    2011-09-01

    Cardiovascular deconditioning is known to occur in astronauts exposed to microgravity. Endothelial dysfunction at microcirculatory sites might contribute to cardiovascular deconditioning induced by weightlessness. Recent studies have reported changes in the morphology and gene expression of endothelial cells exposed to conditions of simulated microgravity. The present study was aimed at examining the effects of microgravity on the apoptosis of microvascular endothelial cells and the mechanism underlying these effects. We simulated a microgravity environment and found that microgravity induced microvascular endothelial cell apoptosis and that this effect was correlated with the downregulation of the PI3K/Akt pathway, increased expression of NF-κB, and depolymerization of F-actin. These findings may provide important insights into the origin of the adverse physiological changes occurring due to exposure to microgravity conditions. PMID:21287193

  14. Non-invasive assessment of microvascular and endothelial function.

    PubMed

    Cheng, Cynthia; Daskalakis, Constantine; Falkner, Bonita

    2013-01-01

    The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of cardiovascular disease. Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. Percent capillary recruitment is assessed by dividing the increase in capillary density induced by postocclusive reactive hyperemia (postocclusive reactive hyperemia capillary density minus baseline capillary density), by the maximal capillary density (observed during passive venous occlusion). Percent perfused capillaries represents the proportion of all capillaries present that are perfused (functionally active), and is calculated by dividing postocclusive reactive hyperemia capillary density by the maximal capillary density. Both percent capillary recruitment and percent perfused capillaries reflect the number of functional capillaries. The forearm blood flow (FBF) technique provides accepted non-invasive measures of endothelial function: The ratio FBF(max)/FBF(base) is computed as an estimate of vasodilation, by dividing the mean of the four FBF(max) values by the mean of the four FBFbase values. Forearm vascular resistance at maximal vasodilation (FVR(max)) is calculated as the mean arterial pressure (MAP) divided by FBF(max). Both the capillaroscopy and forearm techniques are readily acceptable to patients and can be learned quickly. The microvascular and endothelial function measures obtained using the methodologies described in this paper may have future utility in clinical patient cardiovascular risk-reduction strategies. As we have published reports demonstrating that microvascular and endothelial dysfunction are found in initial stages of hypertension including prehypertension, microvascular and endothelial function measures may eventually aid in early identification, risk-stratification and prevention of end-stage vascular pathology, with its potentially fatal

  15. Endothelial nitric oxide synthase regulates microvascular hyperpermeability in vivo

    PubMed Central

    Hatakeyama, Takuya; Pappas, Peter J; Hobson, Robert W; Boric, Mauricio P; Sessa, William C; Durán, Walter N

    2006-01-01

    Nitric oxide (NO) is an important regulator of blood flow, but its role in permeability is still challenged. We tested in vivo the hypotheses that: (a) endothelial nitric oxide synthase (eNOS) is not essential for regulation of baseline permeability; (b) eNOS is essential for hyperpermeability responses in inflammation; and (c) molecular inhibition of eNOS with caveolin-1 scaffolding domain (AP-Cav) reduces eNOS-regulated hyperpermeability. We used eNOS-deficient (eNOS−/−) mice and their wild-type control as experimental animals, platelet-activating factor (PAF) at 10−7 m as the test pro-inflammatory agent, and integrated optical intensity (IOI) as an index of microvascular permeability. PAF increased permeability in wild-type cremaster muscle from a baseline of 2.4 ± 2.2 to a peak net value of 84.4 ± 2.7 units, while the corresponding values in cremaster muscle of eNOS−/− mice were 1.0 ± 0.3 and 15.6 ± 7.7 units (P < 0.05). Similarly, PAF increased IOI in the mesentery of wild-type mice but much less in the mesentery of eNOS−/− mice. PAF increased IOI to comparable values in the mesenteries of wild-type mice and those lacking the gene for inducible NOS (iNOS). Administration of AP-Cav blocked the microvascular hyperpermeability responses to 10−7 m PAF. We conclude that: (1) baseline permeability does not depend on eNOS; (2) eNOS and NO are integral elements of the signalling pathway for the hyperpermeability response to PAF; (3) iNOS does not affect either baseline permeability or hyperpermeability responses to PAF; and (4) caveolin-1 inhibits eNOS regulation of microvascular permeability in vivo. Our results establish eNOS as an important regulator of microvascular permeability in inflammation. PMID:16675496

  16. Preventing microvascular complications in type 1 diabetes mellitus.

    PubMed

    Viswanathan, Vijay

    2015-04-01

    Patients with complications of diabetes such as retinopathy, nephropathy, and cardiovascular complications have increased hospital stay with greater economic burden. Prevention of complications should be started before the onset of type 1 diabetes mellitus (T1DM) by working on risk factors and thereafter by intervention upon confirmatory diagnosis which can prevent further damage to β-cells. The actual risk of getting microvascular complications like microalbuminuria and retinopathy progression starts at glycated hemoglobin (HbA1c) level of 7%. As per the American Diabetes Association, a new pediatric glycemic control target of HbA1c <7.5% across all ages replaces previous guidelines that had called for different targets by age. Evidence shows that prevalence of microvascular complications is greater in patients with age >20 years as compared to patients <10 years of age. Screening of these complications should be done regularly, and appropriate preventive strategies should be followed. Angiotensin converting enzyme inhibitors and angiotensin II receptor blocker reduce progression from microalbuminuria to macroalbuminuria and increase the regression rate to normoalbuminuria. Diabetic microvascular complications can be controlled with tight glycemic therapy, dyslipidemia management and blood pressure control along with renal function monitoring, lifestyle changes, including smoking cessation and low-protein diet. An integrated and personalized care would reduce the risk of development of microvascular complications in T1DM patients. The child with diabetes who receives limited care is more likely to develop long-term complications at an earlier age. Screening for subclinical complications and early interventions with intensive therapy is the need of the hour. PMID:25941647

  17. Osseointegrated implants in microvascular fibula free flap reconstructed mandibles.

    PubMed

    Huryn, J M; Zlotolow, I M; Piro, J D; Lenchewski, E

    1993-11-01

    In the past, prosthodontic rehabilitation of patients who underwent segmental mandibular resection relied on removable prostheses, which were less than ideal. The advent of the microvascular free flap has provided improved appearance and function through reconstruction of the skeletal integrity of the mandible. In select patients osseointegrated implants strategically placed in the reconstructed mandible can be used to restore masticatory function. Patient selection criteria and techniques are discussed. PMID:8254548

  18. Patterns and Variations in Microvascular Decompression for Trigeminal Neuralgia

    PubMed Central

    TODA, Hiroki; GOTO, Masanori; IWASAKI, Koichi

    2015-01-01

    Microvascular decompression (MVD) is a highly effective surgical treatment for trigeminal neuralgia (TN). Although there is little prospective clinical evidence, accumulated observational studies have demonstrated the benefits of MVD for refractory TN. In the current surgical practice of MVD for TN, there have been recognized patterns and variations in surgical anatomy and various decompression techniques. Here we provide a stepwise description of surgical procedures and relevant anatomical characteristics, as well as procedural options. PMID:25925756

  19. Microvascular Transport and Tumor Cell Adhesion in the Microcirculation

    PubMed Central

    Fu, Bingmei M.; Liu, Yang

    2016-01-01

    One critical step in tumor metastasis is tumor cell adhesion to the endothelium forming the microvessel wall. Understanding this step may lead to new therapeutic concepts for tumor metastasis. Vascular endothelium forming the microvessel wall and the glycocalyx layer at its surface are the principal barriers to, and regulators of the material exchange between circulating blood and body tissues. The cleft between adjacent ECs (interendothelial cleft) is the principal pathway for water and solutes transport through the microvessel wall in health. It is also suggested to be the pathway for high molecular weight plasma proteins, leukocytes and tumor cells across microvessel walls in disease. Thus the first part of the review introduced the mathematical models for water and solutes transport through the interendothelial cleft. These models, combined with the experimental results from in vivo animal studies and electron microscopic observations, are used to evaluate the role of the endothelial surface glycocalyx, the junction strand geometry in the interendothelial cleft, and the surrounding extracellular matrix and tissue cells, as the determinants of microvascular transport. The second part of the review demonstrated how the microvascular permeability, hydrodynamic factors, microvascular geometry and cell adhesion molecules affect tumor cell adhesion in the microcirculation. PMID:22476895

  20. Clinical Outcomes of Metabolic Surgery: Microvascular and Macrovascular Complications.

    PubMed

    Adams, Ted D; Arterburn, David E; Nathan, David M; Eckel, Robert H

    2016-06-01

    Understanding of the long-term clinical outcomes associated with bariatric surgery has recently been advanced. Research related to the sequelae of diabetes-in particular, long-term microvascular and macrovascular complications-in patients who undergo weight-loss surgery is imperative to this pursuit. While numerous randomized control trials have assessed glucose control with bariatric surgery compared with intensive medical therapy, bariatric surgery outcome data relating to microvascular and macrovascular complications have been limited to observational studies and nonrandomized clinical trials. As a result, whether bariatric surgery is associated with a long-term reduction in microvascular and macrovascular complications when compared with current intensive glycemic control therapy cannot be determined because the evidence is insufficient. However, the consistent salutary effects of bariatric surgery on diabetes remission and glycemic improvement support the opportunity (and need) to conduct high-quality studies of bariatric surgery versus intensive glucose control. This review provides relevant background information related to the treatment of diabetes, hyperglycemia, and long-term complications; reports clinical findings (to date) with bariatric surgery; and identifies ongoing research focusing on long-term vascular outcomes associated with bariatric surgery. PMID:27222549

  1. Evaluation of gravimetric techniques to estimate the microvascular filtration coefficient.

    PubMed

    Dongaonkar, R M; Laine, G A; Stewart, R H; Quick, C M

    2011-06-01

    Microvascular permeability to water is characterized by the microvascular filtration coefficient (K(f)). Conventional gravimetric techniques to estimate K(f) rely on data obtained from either transient or steady-state increases in organ weight in response to increases in microvascular pressure. Both techniques result in considerably different estimates and neither account for interstitial fluid storage and lymphatic return. We therefore developed a theoretical framework to evaluate K(f) estimation techniques by 1) comparing conventional techniques to a novel technique that includes effects of interstitial fluid storage and lymphatic return, 2) evaluating the ability of conventional techniques to reproduce K(f) from simulated gravimetric data generated by a realistic interstitial fluid balance model, 3) analyzing new data collected from rat intestine, and 4) analyzing previously reported data. These approaches revealed that the steady-state gravimetric technique yields estimates that are not directly related to K(f) and are in some cases directly proportional to interstitial compliance. However, the transient gravimetric technique yields accurate estimates in some organs, because the typical experimental duration minimizes the effects of interstitial fluid storage and lymphatic return. Furthermore, our analytical framework reveals that the supposed requirement of tying off all draining lymphatic vessels for the transient technique is unnecessary. Finally, our numerical simulations indicate that our comprehensive technique accurately reproduces the value of K(f) in all organs, is not confounded by interstitial storage and lymphatic return, and provides corroboration of the estimate from the transient technique. PMID:21346245

  2. Obesity Related Coronary Microvascular Dysfunction: From Basic to Clinical Practice

    PubMed Central

    Selthofer-Relatić, K.; Bošnjak, I.; Kibel, A.

    2016-01-01

    Obesity related coronary microvascular disease is a medical entity which is not yet fully elucidated. The pathophysiological basis of coronary microcirculatory dysfunction consists of a heterogeneous group of disorders with individual morphologic/functional/clinical presentation and prognosis. Coronary microcirculatory changes include mechanisms connected with vascular dysfunction, as well as extravascular and vasostructural changes in responses to neural, mechanical, and metabolic factors. Cardiometabolic changes that include obesity, dyslipidemia, diabetes mellitus type II, and hypertension are associated with atherosclerosis of epicardial coronary arteries and/or microvascular coronary dysfunction, with incompletely understood underlying mechanisms. In obesity, microvascular disease is mediated via adipokines/cytokines causing chronic, subclinical inflammation with (a) reduced NO-mediated dilatation, (b) changed endothelial- and smooth muscle-dependent vasoregulating mechanisms, (c) altered vasomotor control with increased sympathetic activity, and (d) obesity related hypertension with cardiomyocytes hypertrophy and impaired cardiac vascular adaptation to metabolic needs. From a clinical point of view it can present itself in acute or chronic form with different prognosis, as a practice problem for real-life diagnosis and treatment. PMID:27092288

  3. Endothelial Progenitor Cells in Diabetic Microvascular Complications: Friends or Foes?

    PubMed Central

    Yu, Cai-Guo; Zhang, Ning; Yuan, Sha-Sha; Ma, Yan; Yang, Long-Yan; Feng, Ying-Mei; Zhao, Dong

    2016-01-01

    Despite being featured as metabolic disorder, diabetic patients are largely affected by hyperglycemia-induced vascular abnormality. Accumulated evidence has confirmed the beneficial effect of endothelial progenitor cells (EPCs) in coronary heart disease. However, antivascular endothelial growth factor (anti-VEGF) treatment is the main therapy for diabetic retinopathy and nephropathy, indicating the uncertain role of EPCs in the pathogenesis of diabetic microvascular disease. In this review, we first illustrate how hyperglycemia induces metabolic and epigenetic changes in EPCs, which exerts deleterious impact on their number and function. We then discuss how abnormal angiogenesis develops in eyes and kidneys under diabetes condition, focusing on “VEGF uncoupling with nitric oxide” and “competitive angiopoietin 1/angiopoietin 2” mechanisms that are shared in both organs. Next, we dissect the nature of EPCs in diabetic microvascular complications. After we overview the current EPCs-related strategies, we point out new EPCs-associated options for future exploration. Ultimately, we hope that this review would uncover the mysterious nature of EPCs in diabetic microvascular disease for therapeutics. PMID:27313624

  4. Microvascular Abnormality in Schizophrenia as Shown by Retinal Imaging

    PubMed Central

    Meier, Madeline H.; Shalev, Idan; Moffitt, Terrie E.; Kapur, Shitij; Keefe, Richard S.E.; Wong, Tien; Belsky, Daniel W.; Harrington, HonaLee; Hogan, Sean; Houts, Renate; Caspi, Avshalom; Poulton, Richie

    2013-01-01

    Objective Retinal and cerebral microvessels are structurally and functionally homologous, but, unlike cerebral microvessels, retinal microvessels can be noninvasively measured in vivo via retinal imaging. Here we test the hypothesis that individuals with schizophrenia show microvascular abnormality and evaluate the utility of retinal imaging as a tool for future schizophrenia research. Methods Participants were members of the Dunedin Study, a population-representative cohort followed from birth with 95% retention. Study members underwent retinal imaging at age 38 years. We assessed retinal arteriolar and venular caliber for all members of the cohort, including individuals who developed schizophrenia. Results Study members who developed schizophrenia were distinguished by wider retinal venules, suggesting microvascular abnormality reflective of insufficient brain oxygen supply. Analyses that controlled for confounding health conditions suggested that wider retinal venules are not simply an artifact of co-occurring health problems in schizophrenia patients. Wider venules were also associated with a dimensional measure of adult psychosis symptoms and with psychosis symptoms reported in childhood. Conclusions Findings provide initial support for the hypothesis that individuals with schizophrenia show microvascular abnormality. Moreover, results suggest that the same vascular mechanisms underlie subthreshold symptoms and clinical disorder and that these associations may begin early in life. These findings highlight the promise of retinal imaging as a tool for understanding the pathogenesis of schizophrenia. PMID:24030514

  5. 4D microvascular imaging based on ultrafast Doppler tomography.

    PubMed

    Demené, Charlie; Tiran, Elodie; Sieu, Lim-Anna; Bergel, Antoine; Gennisson, Jean Luc; Pernot, Mathieu; Deffieux, Thomas; Cohen, Ivan; Tanter, Mickael

    2016-02-15

    4D ultrasound microvascular imaging was demonstrated by applying ultrafast Doppler tomography (UFD-T) to the imaging of brain hemodynamics in rodents. In vivo real-time imaging of the rat brain was performed using ultrasonic plane wave transmissions at very high frame rates (18,000 frames per second). Such ultrafast frame rates allow for highly sensitive and wide-field-of-view 2D Doppler imaging of blood vessels far beyond conventional ultrasonography. Voxel anisotropy (100 μm × 100 μm × 500 μm) was corrected for by using a tomographic approach, which consisted of ultrafast acquisitions repeated for different imaging plane orientations over multiple cardiac cycles. UFT-D allows for 4D dynamic microvascular imaging of deep-seated vasculature (up to 20 mm) with a very high 4D resolution (respectively 100 μm × 100 μm × 100 μm and 10 ms) and high sensitivity to flow in small vessels (>1 mm/s) for a whole-brain imaging technique without requiring any contrast agent. 4D ultrasound microvascular imaging in vivo could become a valuable tool for the study of brain hemodynamics, such as cerebral flow autoregulation or vascular remodeling after ischemic stroke recovery, and, more generally, tumor vasculature response to therapeutic treatment. PMID:26555279

  6. Endothelial Progenitor Cells in Diabetic Microvascular Complications: Friends or Foes?

    PubMed

    Yu, Cai-Guo; Zhang, Ning; Yuan, Sha-Sha; Ma, Yan; Yang, Long-Yan; Feng, Ying-Mei; Zhao, Dong

    2016-01-01

    Despite being featured as metabolic disorder, diabetic patients are largely affected by hyperglycemia-induced vascular abnormality. Accumulated evidence has confirmed the beneficial effect of endothelial progenitor cells (EPCs) in coronary heart disease. However, antivascular endothelial growth factor (anti-VEGF) treatment is the main therapy for diabetic retinopathy and nephropathy, indicating the uncertain role of EPCs in the pathogenesis of diabetic microvascular disease. In this review, we first illustrate how hyperglycemia induces metabolic and epigenetic changes in EPCs, which exerts deleterious impact on their number and function. We then discuss how abnormal angiogenesis develops in eyes and kidneys under diabetes condition, focusing on "VEGF uncoupling with nitric oxide" and "competitive angiopoietin 1/angiopoietin 2" mechanisms that are shared in both organs. Next, we dissect the nature of EPCs in diabetic microvascular complications. After we overview the current EPCs-related strategies, we point out new EPCs-associated options for future exploration. Ultimately, we hope that this review would uncover the mysterious nature of EPCs in diabetic microvascular disease for therapeutics. PMID:27313624

  7. Noninvasive assessment of alveolar microvascular recruitment in conscious nonsedated rats

    PubMed Central

    Yilmaz, Cuneyt; Dane, Dan M.; Ravikumar, Priya; Unger, Roger H.; Hsia, Connie C.W.

    2013-01-01

    Recruitment of alveolar microvascular reserves, assessed from the relationship between pulmonary diffusing capacity (DLCO) and perfusion (Q̇c), is critical to maintenance of arterial blood oxygenation. Leptin-resistant ZDF fatty diabetic (fa/fa) rats exhibit restricted cardiopulmonary physiology under anesthesia. To assess alveolar microvascular function in conscious, non-sedated, non-instrumented, and minimally restrained animals, we adapted a rebreathing technique to fa/fa and control non-diabetic (+/+) rats (4-5 and 7-11 mo old) at rest and mild spontaneous activity. Measurements included O2 uptake, lung volume, Q̇c, DLCO, membrane diffusing capacity (DMCO), capillary blood volume (Vc) and septal tissue-blood volume. In older fa/fa than +/+ animals, DLCO and DMCO at a given Q̇c were lower; Vc was reduced in proportion to Q̇c. Results demonstrate the consequences of alveolar microangiopathy in metabolic syndrome: lung volume restriction, reduced Q̇c, and elevated membrane resistance to diffusion. At a given Q̇c, DLCO is lower in rats and guinea pigs than dogs or humans, consistent with limited alveolar microvascular reserves in small animals. PMID:24100202

  8. A Novel Three-Dimensional Human Peritubular Microvascular System.

    PubMed

    Ligresti, Giovanni; Nagao, Ryan J; Xue, Jun; Choi, Yoon Jung; Xu, Jin; Ren, Shuyu; Aburatani, Takahide; Anderson, Susan K; MacDonald, James W; Bammler, Theo K; Schwartz, Stephen M; Muczynski, Kimberly A; Duffield, Jeremy S; Himmelfarb, Jonathan; Zheng, Ying

    2016-08-01

    Human kidney peritubular capillaries are particularly susceptible to injury, resulting in dysregulated angiogenesis, capillary rarefaction and regression, and progressive loss of kidney function. However, little is known about the structure and function of human kidney microvasculature. Here, we isolated, purified, and characterized human kidney peritubular microvascular endothelial cells (HKMECs) and reconstituted a three-dimensional human kidney microvasculature in a flow-directed microphysiologic system. By combining epithelial cell depletion and cell culture in media with high concentrations of vascular endothelial growth factor, we obtained HKMECs of high purity in large quantity. Unlike other endothelial cells, isolated HKMECs depended on high vascular endothelial growth factor concentration for survival and growth and exhibited high tubulogenic but low angiogenic potential. Furthermore, HKMECs had a different transcriptional profile. Under flow, HKMECs formed a thin fenestrated endothelium with a functional permeability barrier. In conclusion, this three-dimensional HKMEC-specific microphysiologic system recapitulates human kidney microvascular structure and function and shows phenotypic characteristics different from those of other microvascular endothelial cells. PMID:26657868

  9. Airway Gland Structure and Function.

    PubMed

    Widdicombe, Jonathan H; Wine, Jeffrey J

    2015-10-01

    Submucosal glands contribute to airway surface liquid (ASL), a film that protects all airway surfaces. Glandular mucus comprises electrolytes, water, the gel-forming mucin MUC5B, and hundreds of different proteins with diverse protective functions. Gland volume per unit area of mucosal surface correlates positively with impaction rate of inhaled particles. In human main bronchi, the volume of the glands is ∼ 50 times that of surface goblet cells, but the glands diminish in size and frequency distally. ASL and its trapped particles are removed from the airways by mucociliary transport. Airway glands have a tubuloacinar structure, with a single terminal duct, a nonciliated collecting duct, then branching secretory tubules lined with mucous cells and ending in serous acini. They allow for a massive increase in numbers of mucus-producing cells without replacing surface ciliated cells. Active secretion of Cl(-) and HCO3 (-) by serous cells produces most of the fluid of gland secretions. Glands are densely innervated by tonically active, mutually excitatory airway intrinsic neurons. Most gland mucus is secreted constitutively in vivo, with large, transient increases produced by emergency reflex drive from the vagus. Elevations of [cAMP]i and [Ca(2+)]i coordinate electrolyte and macromolecular secretion and probably occur together for baseline activity in vivo, with cholinergic elevation of [Ca(2+)]i being mainly responsive for transient increases in secretion. Altered submucosal gland function contributes to the pathology of all obstructive diseases, but is an early stage of pathogenesis only in cystic fibrosis. PMID:26336032

  10. The Airway Microbiome at Birth

    PubMed Central

    Lal, Charitharth Vivek; Travers, Colm; Aghai, Zubair H.; Eipers, Peter; Jilling, Tamas; Halloran, Brian; Carlo, Waldemar A.; Keeley, Jordan; Rezonzew, Gabriel; Kumar, Ranjit; Morrow, Casey; Bhandari, Vineet; Ambalavanan, Namasivayam

    2016-01-01

    Alterations of pulmonary microbiome have been recognized in multiple respiratory disorders. It is critically important to ascertain if an airway microbiome exists at birth and if so, whether it is associated with subsequent lung disease. We found an established diverse and similar airway microbiome at birth in both preterm and term infants, which was more diverse and different from that of older preterm infants with established chronic lung disease (bronchopulmonary dysplasia). Consistent temporal dysbiotic changes in the airway microbiome were seen from birth to the development of bronchopulmonary dysplasia in extremely preterm infants. Genus Lactobacillus was decreased at birth in infants with chorioamnionitis and in preterm infants who subsequently went on to develop lung disease. Our results, taken together with previous literature indicating a placental and amniotic fluid microbiome, suggest fetal acquisition of an airway microbiome. We speculate that the early airway microbiome may prime the developing pulmonary immune system, and dysbiosis in its development may set the stage for subsequent lung disease. PMID:27488092

  11. Allergen-induced airway responses.

    PubMed

    Gauvreau, Gail M; El-Gammal, Amani I; O'Byrne, Paul M

    2015-09-01

    Environmental allergens are an important cause of asthma and can contribute to loss of asthma control and exacerbations. Allergen inhalation challenge has been a useful clinical model to examine the mechanisms of allergen-induced airway responses and inflammation. Allergen bronchoconstrictor responses are the early response, which reaches a maximum within 30 min and resolves by 1-3 h, and late responses, when bronchoconstriction recurs after 3-4 h and reaches a maximum over 6-12 h. Late responses are followed by an increase in airway hyperresponsiveness. These responses occur when IgE on mast cells is cross-linked by an allergen, causing degranulation and the release of histamine, neutral proteases and chemotactic factors, and the production of newly formed mediators, such as cysteinyl leukotrienes and prostaglandin D2. Allergen-induced airway inflammation consists of an increase in airway eosinophils, basophils and, less consistently, neutrophils. These responses are mediated by the trafficking and activation of myeloid dendritic cells into the airways, probably as a result of the release of epithelial cell-derived thymic stromal lymphopoietin, and the release of pro-inflammatory cytokines from type 2 helper T-cells. Allergen inhalation challenge has also been a widely used model to study potential new therapies for asthma and has an excellent negative predictive value for this purpose. PMID:26206871

  12. The Airway Microbiome at Birth.

    PubMed

    Lal, Charitharth Vivek; Travers, Colm; Aghai, Zubair H; Eipers, Peter; Jilling, Tamas; Halloran, Brian; Carlo, Waldemar A; Keeley, Jordan; Rezonzew, Gabriel; Kumar, Ranjit; Morrow, Casey; Bhandari, Vineet; Ambalavanan, Namasivayam

    2016-01-01

    Alterations of pulmonary microbiome have been recognized in multiple respiratory disorders. It is critically important to ascertain if an airway microbiome exists at birth and if so, whether it is associated with subsequent lung disease. We found an established diverse and similar airway microbiome at birth in both preterm and term infants, which was more diverse and different from that of older preterm infants with established chronic lung disease (bronchopulmonary dysplasia). Consistent temporal dysbiotic changes in the airway microbiome were seen from birth to the development of bronchopulmonary dysplasia in extremely preterm infants. Genus Lactobacillus was decreased at birth in infants with chorioamnionitis and in preterm infants who subsequently went on to develop lung disease. Our results, taken together with previous literature indicating a placental and amniotic fluid microbiome, suggest fetal acquisition of an airway microbiome. We speculate that the early airway microbiome may prime the developing pulmonary immune system, and dysbiosis in its development may set the stage for subsequent lung disease. PMID:27488092

  13. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  14. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  15. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  16. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Distribution systems: Leakage surveys. 192.723... Distribution systems: Leakage surveys. (a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. (b) The type and scope of the leakage control...

  17. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Portable leakage current alarm. 870.2640 Section... leakage current alarm. (a) Identification. A portable leakage current alarm is a device used to measure the electrical leakage current between any two points of an electrical system and to sound an alarm...

  18. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Portable leakage current alarm. 870.2640 Section... leakage current alarm. (a) Identification. A portable leakage current alarm is a device used to measure the electrical leakage current between any two points of an electrical system and to sound an alarm...

  19. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Portable leakage current alarm. 870.2640 Section... leakage current alarm. (a) Identification. A portable leakage current alarm is a device used to measure the electrical leakage current between any two points of an electrical system and to sound an alarm...

  20. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Portable leakage current alarm. 870.2640 Section... leakage current alarm. (a) Identification. A portable leakage current alarm is a device used to measure the electrical leakage current between any two points of an electrical system and to sound an alarm...

  1. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Portable leakage current alarm. 870.2640 Section... leakage current alarm. (a) Identification. A portable leakage current alarm is a device used to measure the electrical leakage current between any two points of an electrical system and to sound an alarm...

  2. Determination of leakage areas in nuclear piping

    SciTech Connect

    Keim, E.

    1997-04-01

    For the design and operation of nuclear power plants the Leak-Before-Break (LBB) behavior of a piping component has to be shown. This means that the length of a crack resulting in a leak is smaller than the critical crack length and that the leak is safely detectable by a suitable monitoring system. The LBB-concept of Siemens/KWU is based on computer codes for the evaluation of critical crack lengths, crack openings, leakage areas and leakage rates, developed by Siemens/KWU. In the experience with the leak rate program is described while this paper deals with the computation of crack openings and leakage areas of longitudinal and circumferential cracks by means of fracture mechanics. The leakage areas are determined by the integration of the crack openings along the crack front, considering plasticity and geometrical effects. They are evaluated with respect to minimum values for the design of leak detection systems, and maximum values for controlling jet and reaction forces. By means of fracture mechanics LBB for subcritical cracks has to be shown and the calculation of leakage areas is the basis for quantitatively determining the discharge rate of leaking subcritical through-wall cracks. The analytical approach and its validation will be presented for two examples of complex structures. The first one is a pipe branch containing a circumferential crack and the second one is a pipe bend with a longitudinal crack.

  3. [Orthodontics and the upper airway].

    PubMed

    Cobo Plana, J; de Carlos Villafranca, F; Macías Escalada, E

    2004-03-01

    One of the general aims of orthodontic treatment and of the combination of orthodontics and orthognathic surgery is to achieve good occlusion and aesthetic improvement, especially in cases of severe dentoskeletal deformities. However, on many occasions, the parameters of the upper airways are not taken into account when the aims of conventional treatment are fulfilled. Patients with obstructive alterations during sleep represent for the orthodontist a type of patient who differs from the normal; for them, treatment should include the objective of improving oxygen saturation. Here, functional considerations should outweigh purely aesthetic ones. It is important, when making an orthodontic, surgical or combined diagnosis for a patient, to bear in mind the impact that treatment may have on the upper airways. Good aesthetics should never be achieved for some of our patients at the expense of diminishing the capacity of their upper airways. PMID:15301356

  4. Topical Combinations to Treat Microvascular Dysfunction of Chronic Postischemia Pain

    PubMed Central

    Laferrière, André; Abaji, Rachid; Tsai, Cheng-Yu Mark; Ragavendran, J. Vaigunda; Coderre, Terence J.

    2015-01-01

    Background Growing evidence indicates that patients with complex regional pain syndrome (CRPS) exhibit tissue abnormalities caused by microvascular dysfunction in the blood vessels of skin, muscle and nerve. We tested whether topical combinations aimed at improving microvascular function would relieve allodynia in an animal model of CRPS. We hypothesized that topical administration of either α2-adrenergic (α2A) receptor agonists or nitric oxide (NO) donors given to increase arterial blood flow, combined with either phosphatidic acid (PA) or phosphodiesterase (PDE) inhibitors to increase capillary blood flow, would effectively reduce allodynia and signs of microvascular dysfunction in the animal model of chronic pain. Methods Mechanical allodynia was induced in the hind paws of rats with chronic postischemia pain (CPIP). Allodynia was assessed before and after topical application of vehicle, single drugs or combinations of an α2A receptor agonist (apraclonidine) or an NO donor (linsidomine), with PA or PDE inhibitors (lisofylline, pentoxifylline). A topical combination of apraclonidine + lisofylline was also evaluated for its effects on a measure of microvascular function (post-occlusive reactive hyperemia) and tissue oxidative capacity (formazan production by tetrazolium reduction) in CPIP rats. Results Each of the single topical drugs produced significant dose-dependent antiallodynic effects compared to vehicle in CPIP rats (n = 30), and the antiallodynic dose-response curves of either PA or PDE inhibitors were shifted 5 to 10 fold to the left when combined with nonanalgesic doses of α2A receptor agonists or NO donors (n = 28). The potent antiallodynic effects of ipsilateral treatment with combinations of α2A receptor agonists or NO donors with PA or PDE inhibitors, were not reproduced by the same treatment of the contralateral hindpaw (n = 28). Topical combinations produced antiallodynic effects lasting up to 6 h (n = 15), and were significantly enhanced by

  5. 21 CFR 868.5810 - Airway connector.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Airway connector. 868.5810 Section 868.5810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5810 Airway connector. (a) Identification. An airway connector is a device intended to...

  6. Chronic effects of mechanical force on airways.

    PubMed

    Tschumperlin, Daniel J; Drazen, Jeffrey M

    2006-01-01

    Airways are embedded in the mechanically dynamic environment of the lung. In utero, this mechanical environment is defined largely by fluid secretion into the developing airway lumen. Clinical, whole lung, and cellular studies demonstrate pivotal roles for mechanical distention in airway morphogenesis and cellular behavior during lung development. In the adult lung, the mechanical environment is defined by a dynamic balance of surface, tissue, and muscle forces. Diseases of the airways modulate both the mechanical stresses to which the airways are exposed as well as the structure and mechanical behavior of the airways. For instance, in asthma, activation of airway smooth muscle abruptly changes the airway size and stress state within the airway wall; asthma also results in profound remodeling of the airway wall. Data now demonstrate that airway epithelial cells, smooth muscle cells, and fibroblasts respond to their mechanical environment. A prominent role has been identified for the epithelium in transducing mechanical stresses, and in both the fetal and mature airways, epithelial cells interact with mesenchymal cells to coordinate remodeling of tissue architecture in response to the mechanical environment. PMID:16460284

  7. Site of Fluid Secretion in Small Airways.

    PubMed

    Flores-Delgado, Guillermo; Lytle, Christian; Quinton, Paul M

    2016-03-01

    The secretion and management of readily transportable airway surface liquid (ASL) along the respiratory tract is crucial for the clearance of debris and pathogens from the lungs. In proximal large airways, submucosal glands (SMGs) can produce ASL. However, in distal small airways, SMGs are absent, although the lumens of these airways are, uniquely, highly plicated. Little is known about the production and maintenance of ASL in small airways, but using electrophysiology, we recently found that native porcine small airways simultaneously secrete and absorb. How these airways can concurrently transport ASL in opposite directions is puzzling. Using high expression of the Na-K-2Cl cotransport (NKCC) 1 protein (SLC12a2) as a phenotypic marker for fluid secretory cells, immunofluorescence microscopy of porcine small airways revealed two morphologically separated sets of luminal epithelial cells. NKCC1 was abundantly expressed by most cells in the contraluminal regions of the pleats but highly expressed very infrequently by cells in the luminal folds of the epithelial plications. In larger proximal airways, the acini of SMGs expressed NKCC1 prominently, but cells expressing NKCC1 in the surface epithelium were sparse. Our findings indicate that, in the small airway, cells in the pleats of the epithelium secrete ASL, whereas, in the larger proximal airways, SMGs mainly secrete ASL. We propose a mechanism in which the locations of secretory cells in the base of pleats and of absorptive cells in luminal folds physically help maintain a constant volume of ASL in small airways. PMID:26562629

  8. Component external leakage and rupture frequency estimates

    SciTech Connect

    Eide, S.A.; Khericha, S.T.; Calley, M.B.; Johnson, D.A.; Marteeny, M.L.

    1991-11-01

    In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results.

  9. Air leakage in residential solar heating systems

    NASA Astrophysics Data System (ADS)

    Shingleton, J. G.; Cassel, D. E.; Overton, R. L.

    1981-02-01

    A series of computer simulations was performed to evaluate the effects of component air leakage on system thermal performance for a typical residential solar heating system, located in Madison, Wisconsin. Auxiliary energy required to supplement solar energy for space heating was determined using the TRNSYS computer program, for a range of air leakage rates at the solar collector and pebble bed storage unit. The effects of heat transfer and mass transfer between the solar equipment room and the heated building were investigated. The effect of reduced air infiltration into the building due to pressurized by the solar air heating system were determined. A simple method of estimating the effect of collector array air leakage on system thermal performance was evaluated, using the f CHART method.

  10. Laryngeal mask airway: an alternative for the difficult airway.

    PubMed

    Jones, J R

    1995-10-01

    The laryngeal mask airway (LMA) was invented by Dr. Archie Brain at the London Hospital, Whitechapel, in 1981. Dr. Brain's main objective for the LMA was that it would provide a better method of maintaining a patient's airway than by face mask. Also, the LMA would be less hemodynamically stressful than with insertion of an endotracheal tube. The LMA consists of a silicone rubber tube connected to a miniature silicone mask. The perimeter of the mask consists of an inflatable elliptical cuff, which forms a tip at the distal aspect of the LMA. The aperture bars in the dome of the mask lift the epiglottis away, so the lumen remains unobstructive. The LMA forms a low pressure seal around the larynx. The LMA is contraindicated in any situation where the patient is at risk for pulmonary aspiration. The LMA is not a substitute for a properly placed endotracheal tube in this situation. The American Society of Anesthesiologists' difficult airway algorithm recommends the insertion of an LMA when ventilation and/or intubation are difficult. The distal aperture of the LMA is in close approximation to the vocal cords, so a 6.0-mm internal diameter endotracheal tube can be passed over an intubating stylet or a pediatric fiberoptic bronchoscope to secure a patient's airway. PMID:7502644

  11. ID3 Contributes to the Acquisition of Molecular Stem Cell-Like Signature in Microvascular Endothelial Cells: Its implication for understanding microvascular diseases

    PubMed Central

    Das, Jayanta K.; Voelkel, Norbert F.; Felty, Quentin

    2015-01-01

    While significant progress has been made to advance our knowledge of microvascular lesion formation, yet the investigation of how stem-like cells may contribute to the pathogenesis of microvascular diseases is still in its infancy. We assessed whether the inhibitor of DNA binding and differentiation 3 (ID3) contributes to the acquisition of a molecular stem cell-like signature in microvascular endothelial cells. The effects of stable ID3 overexpression and SU5416 treatment — a chemical inducer of microvascular lesions, had on the stemness signature was determined by flow cytometry, immunoblot, and immunohistochemistry. Continuous ID3 expression produced a molecular stemness signature consisting of CD133+ VEGFR3+ CD34+ cells. Cells exposed to SU5416 showed positive protein expression of ID3, VEGFR3, CD34 and increased expression of pluripotent transcription factors Oct-4 and Sox-2. ID3 overexpressing cells supported the formation of a 3-D microvascular lesion co-cultured with smooth muscle cells. In addition, in vivo microvascular lesions from SuHx rodent model showed an increased expression of ID3, VEGFR3, and Pyk2 similar to SU5416 treated human endothelial cells. Further investigations into how normal and stem-like cells utilize ID3 may open up new avenues for a better understanding of the molecular mechanisms which are underlying the pathological development of microvascular diseases. PMID:25665868

  12. Leakage Sign for Primary Intracerebral Hemorrhage

    PubMed Central

    Hirohata, Masaru; Nakamura, Yukihiko; Takeshige, Nobuyuki; Aoki, Takachika; Hattori, Gousuke; Sakata, Kiyohiko; Abe, Toshi; Uchiyama, Yuusuke; Sakamoto, Teruo; Morioka, Motohiro

    2016-01-01

    Background and Purpose— Recent studies of intracerebral hemorrhage treatments have highlighted the need to identify reliable predictors of hematoma expansion. Several studies have suggested that the spot sign on computed tomographic angiography (CTA) is a sensitive radiological predictor of hematoma expansion in the acute phase. However, the spot sign has low sensitivity for hematoma expansion. In this study, we evaluated the usefulness of a novel predictive method, called the leakage sign. Methods— We performed CTA for 80 consecutive patients presenting with spontaneous intracerebral hemorrhage. Two scans were completed: CTA phase and delayed phase (5 minutes after the CTA phase). By comparing the CTA phase images, we set a region of interest with a 10-mm diameter and calculated the Hounsfield units. We defined a positive leakage sign as a >10% increase in Hounsfield units in the region of interest. Additionally, hematoma expansion was determined on plain computed tomography at 24 hours in patients who did not undergo emergent surgery. Results— Positive spot signs and leakage signs were present in 18 (22%) patients and 35 (43%) patients, respectively. The leakage sign had higher sensitivity (93.3%) and specificity (88.9%) for hematoma expansion than the spot sign. The leakage sign, but not the spot sign, was significantly related with poor outcomes (severely disabled, vegetative state, and death) in all of the patients (P=0.03) and in patients with a hemorrhage in the putamen (P=0.0016). Conclusions— The results indicate that the leakage sign is a useful and sensitive method to predict hematoma expansion. PMID:26931155

  13. Inward leakage in tight-fitting PAPRs.

    PubMed

    Koh, Frank C; Johnson, Arthur T; Rehak, Timothy E

    2011-01-01

    A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves. In both cases, the leakage was not enough for fog to appear at the mouth of the head form. PMID:21647352

  14. Inward Leakage in Tight-Fitting PAPRs

    PubMed Central

    Koh, Frank C.; Johnson, Arthur T.; Rehak, Timothy E.

    2011-01-01

    A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves. In both cases, the leakage was not enough for fog to appear at the mouth of the head form. PMID:21647352

  15. [Airway equipment and its maintenance for a non difficult adult airway management (endotracheal intubation and its alternative: face mask, laryngeal mask airway, laryngeal tube)].

    PubMed

    Francon, D; Estèbe, J P; Ecoffey, C

    2003-08-01

    The airway equipment for a non difficult adult airway management are described: endotracheal tubes with a specific discussion on how to inflate the balloon, laryngoscopes and blades, stylets and intubation guides, oral airways, face masks, laryngeal mask airways and laryngeal tubes. Cleaning and disinfections with the maintenance are also discussed for each type of airway management. PMID:12943860

  16. Effect of Qi-regulating,Phlegm-resolving,and Blood-promoting Prescription on Rat Coronary Microvascular Thrombosis and Coronary Microvascular Occlusion.

    PubMed

    2016-06-10

    Objective To explore the effect of qi-regulating,phlegm-resolving,and blood-promoting prescription on coronary microvascular thrombosis and coronary microvascular occlusion in rat models. Methods Totally 125 healthy clean-grade male SD rats weighing (300±25) g were sequentially numbered and then randomly divided into treatment group (n=60),control group (n=60) and blank group (n=5).Rats in the treatment group and control group received apical left ventricular injection of sodium laurate to establish rat models of coronary microvascular thrombosis. Then,rats in the control group were given distilled water by gavage one day before operation and after surgery. In contrast,rats in the treatment group were given qi-regulating,phlegm-resolving,and blood-promoting prescription by gavage one day before operation and after surgery. Five rats from both treatment group and control group were killed at each of six time points (1 hour,24th hour,7th day,14th day,21th day,and 28th day),and the myocardium specimens were harvested. The 5 rats in the blank group did not receive any special treatment and were given normal feeding;in the 28th day,they were sacrificed to obtain the myocardial specimens. Pathological sections of rat myocardial tissues were made to observe and compare the degrees of coronary microvascular thrombosis and coronary microvascular obstruction. Results In the treatment group and the control group,coronary microvascular thrombosis occurred 1 hour after apical sodium laurate injection and reached the peak at the 24th hour. Compared with the blank group,the treatment group and the control group showed different degree of coronary microvascular obstruction. Comparison between the treatment group and the control group at each time point showed that the coronary microvascular thrombosis in the treatment group was significantly lower than that in the control group (P<0.05 or P<0.01).The severity of coronary

  17. Jaw thrust can deteriorate upper airway patency.

    PubMed

    von Ungern-Sternberg, B S; Erb, T O; Frei, F J

    2005-04-01

    Upper airway obstruction is a frequent problem in spontaneously breathing children undergoing anesthesia or sedation procedures. Failure to maintain a patent airway can rapidly result in severe hypoxemia, bradycardia, or asystole, as the oxygen demand of children is high and oxygen reserve is low. We present two children with cervical masses in whom upper airway obstruction exaggerated while the jaw thrust maneuver was applied during induction of anesthesia. This deterioration in airway patency was probably caused by medial displacement of the lateral tumorous tissues which narrowed the pharyngeal airway. PMID:15777312

  18. Systems-level airway models of bronchoconstriction.

    PubMed

    Donovan, Graham M

    2016-09-01

    Understanding lung and airway behavior presents a number of challenges, both experimental and theoretical, but the potential rewards are great in terms of both potential treatments for disease and interesting biophysical phenomena. This presents an opportunity for modeling to contribute to greater understanding, and here, we focus on modeling efforts that work toward understanding the behavior of airways in vivo, with an emphasis on asthma. We look particularly at those models that address not just isolated airways but many of the important ways in which airways are coupled both with each other and with other structures. This includes both interesting phenomena involving the airways and the layer of airway smooth muscle that surrounds them, and also the emergence of spatial ventilation patterns via dynamic airway interaction. WIREs Syst Biol Med 2016, 8:459-467. doi: 10.1002/wsbm.1349 For further resources related to this article, please visit the WIREs website. PMID:27348217

  19. The Importance of Airway Management in Trauma

    PubMed Central

    Jacobs, Lenworth M.

    1988-01-01

    The airway is the most important priority in the management of the severely injured patient. It is essential to open and clear the airway to allow free access of air to the distal endobronchial tree. Manual methods of opening the airway are described. Numerous methods for establishing definitive control of the airway as well as the associated devices currently available to maintain control are described. Once the airway is maintained, it is important to ensure adequate oxygenation and ventilation through the airway. Modern portable devices that monitor the carbon dioxide in the expired air at the end of each breath are currently available. These devices allow the physician to verify the position of the tube in the airway as well as to continuously monitor the efficacy of ventilation. PMID:3073226

  20. Sarcoidosis of the upper and lower airways.

    PubMed

    Morgenthau, Adam S; Teirstein, Alvin S

    2011-12-01

    Sarcoidosis is a systemic granulomatous disease of undetermined etiology characterized by a variable clinical presentation and disease course. Although clinical granulomatous inflammation may occur within any organ system, more than 90% of sarcoidosis patients have lung disease. Sarcoidosis is considered an interstitial lung disease that is frequently characterized by restrictive physiologic dysfunction on pulmonary function tests. However, sarcoidosis also involves the airways (large and small), causing obstructive airways disease. It is one of a few interstitial lung diseases that affects the entire length of the respiratory tract - from the nose to the terminal bronchioles - and causes a broad spectrum of airways dysfunction. This article examines airway dysfunction in sarcoidosis. The anatomical structure of the airways is the organizational framework for our discussion. We discuss sarcoidosis involving the nose, sinuses, nasal passages, larynx, trachea, bronchi and small airways. Common complications of airways disease, such as, atelectasis, fibrosis, bullous leions, bronchiectasis, cavitary lesions and mycetomas, are also reviewed. PMID:22082167

  1. Vacuum test fixture improves leakage rate measurements

    NASA Technical Reports Server (NTRS)

    Maier, H.; Marx, H.

    1966-01-01

    Cylindrical chamber, consisting of two matching halves, forms a vacuum test fixture for measuring leakage rates of individual connections, brazed joints, and entrance ports used in closed fluid flow line systems. Once the chamber has been sufficiently evacuated, atmospheric pressure holds the two halves together.

  2. Imaging inflammatory plasma leakage in vivo.

    PubMed

    Kenne, E; Lindbom, L

    2011-05-01

    Increased vascular permeability and consequent plasma leakage from postcapillary venules is a cardinal sign of inflammation. Although the movement of plasma constituents from the vasculature to the affected tissue aids in clearing the inflammatory stimulus, excessive plasma extravasation can lead to hospitalisation or death in cases such as influenza-induced pneumonia, burns or brain injury. The use of intravital imaging has significantly contributed to the understanding of the mechanisms controlling the vascular permeability alterations that occur during inflammation. Today, intravital imaging can be performed using optical and non-optical techniques. Optical techniques, which are generally used in experimental settings, include traditional intravital fluorescence microscopy and near-infrared fluorescence imaging. Magnetic resonance (MRI) and radioisotopic imaging are used mainly in the clinical setting, but are increasingly used in experimental work, and can detect plasma leakage without optics. Although these methods are all able to visualise inflammatory plasma leakage in vivo, the spatial and temporal resolution differs between the techniques. In addition, they vary with regards to invasiveness and availability. This overview discusses the use of imaging techniques in the visualisation of inflammatory plasma leakage. PMID:21437352

  3. Measurements of the atmospheric neutron leakage rate

    NASA Technical Reports Server (NTRS)

    Lockwood, J. A.; Ifedili, S. O.; Jenkins, R. W.

    1973-01-01

    The atmospheric neutron leakage rate in the energy range from 0.01 to 10,000,000 eV has been measured as a function of latitude, altitude, and time with a neutron detector on board the Ogo 6 satellite. The latitude dependence of the neutron leakage is in reasonable agreement with that predicted by Lingenfelter (1963) and Light et al. (1973) if the neutron energy spectrum has the shape calculated by Newkirk (1963). The change in the neutron latitude dependence with the cosmic ray modulation agrees with the predictions of Lingenfelter and Light et al. For several solar proton events enhancements were observed in the neutron counting rates at lambda greater than or equal to 70 deg. Such events, however, provide an insignificant injection of protons at E less than or equal to 20 MeV into the radiation belts. An isotropic angular distribution of the neutron leakage in the energy range from 0.1 keV to 10 MeV best fits the observed altitude dependence of the neutron leakage flux.

  4. 49 CFR 230.78 - Leakage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of 3 psi per minute in a test of 3 minutes duration that is made after the pressure has been reduced to 60 percent of the maximum operating pressure. (b) Brake cylinders. Leakage from brake cylinders... pipe pressure, and with communication to the brake cylinders closed, the brakes on the steam...

  5. 49 CFR 230.78 - Leakage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... of 3 psi per minute in a test of 3 minutes duration that is made after the pressure has been reduced to 60 percent of the maximum operating pressure. (b) Brake cylinders. Leakage from brake cylinders... pipe pressure, and with communication to the brake cylinders closed, the brakes on the steam...

  6. The concept of leakage in threat assessment.

    PubMed

    Meloy, J Reid; O'Toole, Mary Ellen

    2011-01-01

    Leakage in the context of threat assessment is the communication to a third party of an intent to do harm to a target. Third parties are usually other people, but the means of communication vary, and include letters, diaries, journals, blogs, videos on the internet, emails, voice mails, and other social media forms of transmission. Leakage is a type of warning behavior that typically infers a preoccupation with the target, and may signal the research, planning, and implementation of an attack. Nomothetic data suggest that leakage occurs in a majority of cases of attacks on and assassinations of public figures, adult mass murders, adolescent mass murders, and school or campus shootings: very low-frequency, but catastrophic acts of intended and targeted violence. Idiographic or case data illustrate the various permutations of leakage. We discuss the operational importance of the concept, place it in the context of other warning behaviors, emphasize the need for further research, and outline risk management strategies for the mitigation of such acts of violence in both law enforcement and clinical mental health settings. PMID:21710573

  7. Control of Air Leakage in Buildings.

    ERIC Educational Resources Information Center

    Wilson, A. Grant

    This discussion of air leakage emphasizes cause and provides suggestions for elimination of undesirable effects. Cause parameters described are--(1) pressure differential, (2) building shape, (3) temperature differential, (4) opening sizes, (5) mechanical system pressures, and (6) climatic factors. Effects discussed are--(1) increased mechanical…

  8. Microvascular Reconstructions of Full-Thickness Oncological Chest Wall Defects

    PubMed Central

    Tukiainen, Erkki; Popov, Pentscho; Asko-Seljavaara, Sirpa

    2003-01-01

    Objective: To evaluate the suitability of microvascular flaps for the reconstruction of extensive full-thickness defects of the chest wall. Summary Background Data: Chest wall defects are conventionally reconstructed with pedicular musculocutaneous flaps or the omentum. Sometimes, however, these flaps have already been used, are not reliable due to previous operations or radiotherapy, or are of inadequate size. In such cases, microvascular flaps offer the only option for reconstruction. Methods: From 1988 to 2001, 26 patients with full-thickness resections of the chest wall underwent reconstruction with microvascular flaps. There were 8 soft tissue sarcomas, 8 recurrent breast cancers, 5 chondrosarcomas, 2 desmoid tumors, 1 large cell pulmonary cancer metastasis, 1 renal cancer metastasis, and 1 bronchopleural fistula. The surgery comprised 5 extended forequarter amputations, 5 lateral resections, 8 thoracoabdominal resections, and 8 sternal resections. The mean diameter of a resection was 28 cm. The soft tissue defect was reconstructed with 16 tensor fasciae latae, 5 tensor fascia latae combined with rectus femoris, and 3 transversus rectus abdominis myocutaneous flaps. In 2 patients with a forequarter amputation, the remnant forearm was used as the osteomusculocutaneous free flap. Results: There were no flap losses or perioperative mortality. Four patients needed tracheostomy owing to prolonged respiratory difficulties. The mean survival time for patients with sarcomas was 39 months and for those with recurrent breast cancer 18 months. Conclusions: Extensive chest wall resections are possible with acceptable results. In patients with breast cancer, the surgery may offer valuable palliation and in those with sarcomas it can be curative. PMID:14631216

  9. Cerebral microvascular pericytes and neurogliovascular signaling in health and disease.

    PubMed

    Dalkara, Turgay; Alarcon-Martinez, Luis

    2015-10-14

    Increases in neuronal activity cause an enhanced blood flow to the active brain area. This neurovascular coupling is regulated by multiple mechanisms: Adenosine and lactate produced as metabolic end-products couple activity with flow by inducing vasodilation. As a specific mechanism to the brain, synaptic activity-induced Ca(2+) increases in astrocytes, interneurons and neurons translate neuronal activity to vasoactive signals such as arachidonic acid metabolites and NO. K(+) released onto smooth muscle cells through Ca(2+)-activated K(+) channels on end-feet can also induce vasodilation during neuronal activity. An intense communication between the endothelia, pericytes and astrocytes is required for development and functioning of the neurovascular unit as well as the BBB. The ratio of pericytes to endothelial cells is higher in the cerebral microcirculation than other tissues. Pericytes play a role in distribution of microvascular blood flow in response to the local demand as a final regulatory step after arterioles, which feed a larger cohort of cells. Pericyte-endothelial communication is essential for vasculogenesis. Pericyte also take part in leukocyte infiltration and immune responses. The microvascular injury induced by ischemia/reperfusion plays a critical role in tissue survival after recanalization by inducing sustained pericyte contraction and microcirculatory clogging (no-reflow) and by disrupting BBB integrity. Suppression of oxidative/nitrative stress or sustained adenosine delivery during re-opening of an occluded artery improves the outcome of recanalization by promoting microcirculatory reflow. Pericyte dysfunction in retinal microvessels is the main cause of diabetic retinopathy. Recent findings suggest that the age-related microvascular dysfunction may initiate the neurodegenerative changes seen Alzheimer׳s dementia. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke. PMID:25862573

  10. Pipeline leakage detection using distributed fibre optical temperature sensing

    NASA Astrophysics Data System (ADS)

    Grosswig, S.; Hurtig, E.; Luebbecke, S.; Vogel, B.

    2005-05-01

    The leakage detection system based on the distributed fibre optical temperature measurement method is an analysing method for continuous detection and localization of leakages at pipelines in the steady and unsteady operation states according to the German rules for pipelines TRbF 301/TRFL which is valid in Germany since April 2003. The leakage detection system is useable under the precondition that there is a sufficient large temperature gradient between the leakage area and the unaffected environment. This can be caused by the medium itself or through a physical effect due to the leakage, e.g. gas expansion, evaporation. It's a very sensitive method, so also creeping leakages can be detected.

  11. Quantifying Therapeutic and Diagnostic Efficacy in 2D Microvascular Images

    NASA Technical Reports Server (NTRS)

    Parsons-Wingerter, Patricia; Vickerman, Mary B.; Keith, Patricia A.

    2009-01-01

    VESGEN is a newly automated, user-interactive program that maps and quantifies the effects of vascular therapeutics and regulators on microvascular form and function. VESGEN analyzes two-dimensional, black and white vascular images by measuring important vessel morphology parameters. This software guides the user through each required step of the analysis process via a concise graphical user interface (GUI). Primary applications of the VESGEN code are 2D vascular images acquired as clinical diagnostic images of the human retina and as experimental studies of the effects of vascular regulators and therapeutics on vessel remodeling.

  12. Microvascular alterations and the role of complement in dermatomyositis.

    PubMed

    Lahoria, Rajat; Selcen, Duygu; Engel, Andrew G

    2016-07-01

    Different mechanisms have been proposed to explain the pathological basis of perifascicular muscle fibre atrophy in dermatomyositis. These include ischaemia due to immune-mediated microvascular injury, enhanced expression of type 1 interferon-induced gene transcripts in perifascicular capillaries and muscle fibres, and occlusion of larger perimysial blood vessels. Microvascular complement deposition is a feature of dermatomyositis pathology but the trigger for complement activation, the predominant complement pathway involved, or its role in the pathogenesis of the disease, has not been clearly defined. In the first step of this study we examined the density of capillaries and transverse vessels and searched for occlusion or depletion of larger perimysial blood vessels in 10 patients with dermatomyositis. This revealed an invariable association of perifascicular atrophy with capillary and transverse vessel depletion. The capillary and transverse vessel densities in non-atrophic fibre regions were not significantly different from those in muscle specimens of 10 age-matched controls. Next, in the same 10, as well as in 40 additional dermatomyositis patients, we searched for vascular deposits of IgG, IgM, and the C5b-9 complement membrane attack complex. Thirty-one of 50 dermatomyositis specimens contained C5b-9 reactive endomysial microvessels but none of these or other vessels reacted for IgG. Ten of 50 specimens harboured IgM-positive capillaries but only a few of these reacted for C5b-9. Finally, we analysed and compared different pathways of complement activation in dermatomyositis, lupus nephritis, and necrotic muscle fibres in Duchenne dystrophy. In lupus nephritis, C5-b9 deposits co-localized with IgG, IgM, C1q, and C4d, consistent with immune complex dependent activation of the classical complement pathway. In both dermatomyositis and Duchenne dystrophy, C5-b9 deposits co-localized with C1q and C4d and rarely with IgM indicating activation of the classical

  13. Antiproliferative effect of elevated glucose in human microvascular endothelial cells

    NASA Technical Reports Server (NTRS)

    Kamal, K.; Du, W.; Mills, I.; Sumpio, B. E.

    1998-01-01

    Diabetic microangiopathy has been implicated as a fundamental feature of the pathological complications of diabetes including retinopathy, neuropathy, and diabetic foot ulceration. However, previous studies devoted to examining the deleterious effects of elevated glucose on the endothelium have been performed largely in primary cultured cells of macrovessel origin. Difficulty in the harvesting and maintenance of microvascular endothelial cells in culture have hindered the study of this relevant population. Therefore, the objective of this study was to characterize the effect of elevated glucose on the proliferation and involved signaling pathways of an immortalized human dermal microvascular endothelial cell line (HMEC-1) that possess similar characteristics to their in vivo counterparts. Human dermal microvascular endothelial cells (HMEC-1) were grown in the presence of normal (5 mM) or high D-glucose (20 mM) for 14 days. The proliferative response of HMEC-1 was compared under these conditions as well as the cAMP and PKC pathways by in vitro assays. Elevated glucose significantly inhibited (P < 0.05) HMEC-1 proliferation after 7, 10, and 14 days. This effect was not mimicked by 20 mM mannitol. The antiproliferative effect was more pronounced with longer exposure (1-14 days) to elevated glucose and was irreversible 4 days after a 10-day exposure. The antiproliferative effect was partially reversed in the presence of a PKA inhibitor, Rp-cAMP (10-50 microM), and/or a PKC inhibitor, Calphostin C (10 nM). HMEC-1 exposed to elevated glucose (20 mM) for 14 days caused an increase in cyclic AMP accumulation, PKA, and PKC activity but was not associated with the activation of downstream events such as CRE and AP-1 binding activity. These data support the hypothesis that HMEC-1 is a suitable model to study the deleterious effects of elevated glucose on microvascular endothelial cells. Continued studies with HMEC-1 may prove advantageous in delineation of the molecular

  14. Globular Adiponectin Enhances Muscle Insulin Action via Microvascular Recruitment and Increased Insulin Delivery

    PubMed Central

    Zhao, Lina; Chai, Weidong; Fu, Zhuo; Dong, Zhenhua; Aylor, Kevin W.; Barrett, Eugene J.; Cao, Wenhong; Liu, Zhenqi

    2014-01-01

    Rationale Adiponectin enhances insulin action and induces nitric oxide–dependent vasodilatation. Insulin delivery to muscle microcirculation and transendothelial transport are 2 discrete steps that limit insulin's action. We have shown that expansion of muscle microvascular surface area increases muscle insulin delivery and action. Objective To examine whether adiponectin modulates muscle microvascular recruitment thus insulin delivery and action in vivo. Methods and Results Overnight fasted adult male rats were studied. We determined the effects of adiponectin on muscle microvascular recruitment, using contrast-enhanced ultrasound, on insulin-mediated microvascular recruitment and whole-body glucose disposal, using contrast-enhanced ultrasound and insulin clamp, and on muscle insulin clearance and uptake with 125I-insulin. Globular adiponectin potently increased muscle microvascular blood volume without altering microvascular blood flow velocity, leading to a significantly increased microvascular blood flow. This was paralleled by a ≈30% to 40% increase in muscle insulin uptake and clearance, and ≈30% increase in insulin-stimulated whole-body glucose disposal. Inhibition of endothelial nitric oxide synthase abolished globular adiponectin-mediated muscle microvascular recruitment and insulin uptake. In cultured endothelial cells, globular adiponectin dose-dependently increased endothelial nitric oxide synthase phosphorylation but had no effect on endothelial cell internalization of insulin. Conclusions Globular adiponectin increases muscle insulin uptake by recruiting muscle microvasculature, which contributes to its insulin-sensitizing action. PMID:23459195

  15. Sudomotor function assessment as a screening tool for microvascular complications in type 2 diabetes.

    PubMed

    Eranki, V G; Santosh, R; Rajitha, K; Pillai, A; Sowmya, P; Dupin, J; Calvet, J H

    2013-09-01

    Sudoscan, a non invasive, quick, and simple method to measure sweat function, was evaluated as a screening tool for microvascular complications in type 2 diabetes. AUC of the ROC curve for detection of microvascular complication was 0.75 for an autonomic risk score, with a sensitivity of 82% and a specificity of 61%. PMID:23880037

  16. Noninvasive clearance of airway secretions.

    PubMed

    Hardy, K A; Anderson, B D

    1996-06-01

    Airway clearance techniques are indicated for specific diseases that have known clearance abnormalities (Table 2). Murray and others have commented that such techniques are required only for patients with a daily sputum production of greater than 30 mL. The authors have observed that patients with diseases known to cause clearance abnormalities can have sputum clearance with some techniques, such as positive expiratory pressure, autogenic drainage, and active cycle of breathing techniques, when PDPV has not been effective. Hasani et al has shown that use of the forced exhalatory technique in patients with nonproductive cough still resulted in movement of secretions proximally from all regions of the lung in patients with airway obstruction. It is therefore reasonable to consider airway clearance techniques for any patient who has a disease known to alter mucous clearance, including CF, dyskinetic cilia syndromes, and bronchiectasis from any cause. Patients with atelectasis from mucous plugs and hypersecretory states, such as asthma and chronic bronchitis, patients with pain secondary to surgical procedures, and patients with neuromuscular disease, weak cough, and abnormal patency of the airway may also benefit from the application of airway clearance techniques. Infants and children up to 3 years of age with airway clearance problems need to be treated with PDPV. Manual percussion with hands alone or a flexible face mask or cup and small mechanical vibrator/percussors, such as the ultrasonic devices, can be used. The intrapulmonary percussive ventilator shows growing promise in this area. The high-frequency oscillator is not supplied with vests of appropriate sizes for tiny babies and has not been studied in this group. Young patients with neuromuscular disease may require assisted ventilation and airway oscillations can be applied. CPAP alone has been shown to improve achievable flow rates that will increase air-liquid interactions for patients with these diseases

  17. Integrated care pathways for airway diseases (AIRWAYS-ICPs).

    PubMed

    Bousquet, J; Addis, A; Adcock, I; Agache, I; Agusti, A; Alonso, A; Annesi-Maesano, I; Anto, J M; Bachert, C; Baena-Cagnani, C E; Bai, C; Baigenzhin, A; Barbara, C; Barnes, P J; Bateman, E D; Beck, L; Bedbrook, A; Bel, E H; Benezet, O; Bennoor, K S; Benson, M; Bernabeu-Wittel, M; Bewick, M; Bindslev-Jensen, C; Blain, H; Blasi, F; Bonini, M; Bonini, S; Boulet, L P; Bourdin, A; Bourret, R; Bousquet, P J; Brightling, C E; Briggs, A; Brozek, J; Buhl, R; Bush, A; Caimmi, D; Calderon, M; Calverley, P; Camargos, P A; Camuzat, T; Canonica, G W; Carlsen, K H; Casale, T B; Cazzola, M; Cepeda Sarabia, A M; Cesario, A; Chen, Y Z; Chkhartishvili, E; Chavannes, N H; Chiron, R; Chuchalin, A; Chung, K F; Cox, L; Crooks, G; Crooks, M G; Cruz, A A; Custovic, A; Dahl, R; Dahlen, S E; De Blay, F; Dedeu, T; Deleanu, D; Demoly, P; Devillier, P; Didier, A; Dinh-Xuan, A T; Djukanovic, R; Dokic, D; Douagui, H; Dubakiene, R; Eglin, S; Elliot, F; Emuzyte, R; Fabbri, L; Fink Wagner, A; Fletcher, M; Fokkens, W J; Fonseca, J; Franco, A; Frith, P; Furber, A; Gaga, M; Garcés, J; Garcia-Aymerich, J; Gamkrelidze, A; Gonzales-Diaz, S; Gouzi, F; Guzmán, M A; Haahtela, T; Harrison, D; Hayot, M; Heaney, L G; Heinrich, J; Hellings, P W; Hooper, J; Humbert, M; Hyland, M; Iaccarino, G; Jakovenko, D; Jardim, J R; Jeandel, C; Jenkins, C; Johnston, S L; Jonquet, O; Joos, G; Jung, K S; Kalayci, O; Karunanithi, S; Keil, T; Khaltaev, N; Kolek, V; Kowalski, M L; Kull, I; Kuna, P; Kvedariene, V; Le, L T; Lodrup Carlsen, K C; Louis, R; MacNee, W; Mair, A; Majer, I; Manning, P; de Manuel Keenoy, E; Masjedi, M R; Melen, E; Melo-Gomes, E; Menzies-Gow, A; Mercier, G; Mercier, J; Michel, J P; Miculinic, N; Mihaltan, F; Milenkovic, B; Molimard, M; Momas, I; Montilla-Santana, A; Morais-Almeida, M; Morgan, M; N'Diaye, M; Nafti, S; Nekam, K; Neou, A; Nicod, L; O'Hehir, R; Ohta, K; Paggiaro, P; Palkonen, S; Palmer, S; Papadopoulos, N G; Papi, A; Passalacqua, G; Pavord, I; Pigearias, B; Plavec, D; Postma, D S; Price, D; Rabe, K F; Radier Pontal, F; Redon, J; Rennard, S; Roberts, J; Robine, J M; Roca, J; Roche, N; Rodenas, F; Roggeri, A; Rolland, C; Rosado-Pinto, J; Ryan, D; Samolinski, B; Sanchez-Borges, M; Schünemann, H J; Sheikh, A; Shields, M; Siafakas, N; Sibille, Y; Similowski, T; Small, I; Sola-Morales, O; Sooronbaev, T; Stelmach, R; Sterk, P J; Stiris, T; Sud, P; Tellier, V; To, T; Todo-Bom, A; Triggiani, M; Valenta, R; Valero, A L; Valiulis, A; Valovirta, E; Van Ganse, E; Vandenplas, O; Vasankari, T; Vestbo, J; Vezzani, G; Viegi, G; Visier, L; Vogelmeier, C; Vontetsianos, T; Wagstaff, R; Wahn, U; Wallaert, B; Whalley, B; Wickman, M; Williams, D M; Wilson, N; Yawn, B P; Yiallouros, P K; Yorgancioglu, A; Yusuf, O M; Zar, H J; Zhong, N; Zidarn, M; Zuberbier, T

    2014-08-01

    The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers). PMID:24925919

  18. Airway oedema and obstruction in guinea pigs exposed to inhaled endotoxin.

    PubMed Central

    Gordon, T; Balmes, J; Fine, J; Sheppard, D

    1991-01-01

    Protein extravasation and airway conductance (SGaw) were examined in awake guinea pigs exposed to inhaled endotoxin or saline for three hours. A significant increase in protein extravasation (as estimated by the leakage of protein bound Evans blue dye) was seen in the conducting airways of endotoxin exposed animals compared with saline exposed animals. Mean dye extravasation was significantly increased by one to threefold in the mainstem and hilar bronchi of endotoxin exposed animals. These changes in extravasation were accompanied by decrements in pulmonary function and by an influx of polymorphonuclear leucocytes into the airway wall. The SGaw decreased significantly by 60-90 minutes into exposure to endotoxin and had decreased by 22% and 34% at the end of exposure in the low and high dose endotoxin groups, respectively. Similar findings were obtained in animals exposed to cotton dust. Contrary to studies suggesting that platelet activating factor (PAF) is involved in the systemic and peripheral lung effects of endotoxin, pretreatment with the PAF antagonist WEB2086 did not prevent the conducting airway injury produced by inhaled endotoxin. PMID:1911406

  19. Plasma exudation. Correlation between Evans blue dye and radiolabeled albumin in guinea pig airways in vivo

    SciTech Connect

    Rogers, D.F.; Boschetto, P.; Barnes, P.J. )

    1989-07-01

    We quantified the tissue exudation and luminal transudation of two plasma markers, Evans blue (EB) dye and ({sup 125}I)-human serum albumin (HSA), into the airways of the anesthetized guinea pig in response to platelet activating factor (PAF). There was a highly significant correlation between the tissue content of EB and ({sup 125}I)-HSA in all airways studied. Significant correlation for transudation of the two markers was limited to high rates of plasma leakage. ({sup 125}I)-HSA was the more sensitive marker for the association between exudation and transudation and the effect of PAF on transudation. EB was the better marker for assessing the relationship between the dose of PAF and plasma exudation.

  20. Interaction between haemopoietic regulation and airway inflammation.

    PubMed

    O'Byrne, P M; Gauvreau, G M; Wood, L J

    1999-06-01

    Asthma is characterized by reversible airway narrowing, by airway hyperresponsiveness, and by airway inflammation. Inhaled allergens are the most important of the stimuli known to cause asthma. Methods for studying inhaled allergen in the laboratory have been well standardized and extensively used for the investigation of the pathophysiology and the pharmacological modulation of allergen-induced airway responses. Allergen inhalation by a sensitized subject results in an early asthmatic response, and, in the majority of subjects, a late asthmatic response and airway hyperresponsiveness. The late response and airway hyperresponsiveness are associated with increases in airway eosinophils and metachromatic cells. Allergen-induced airway inflammation in dogs (predominantly neutrophilic) is associated with increased granulocyte-macrophage progenitors in bone marrow, which is dependent on the effects of a circulating serum factor stimulating the bone marrow. The newly formed cells traffic to the airways. These increases in granulocyte-macrophage progenitors are blocked by inhaled corticosteroids. In human subjects, allergen-induced eosinophilic inflammation is associated with increases in Eo/B progenitors, mediated through up-regulation if the IL-5 receptor on progenitors and increases responsiveness to IL-5. Inhaled corticosteroids also attenuate all allergen-induced physiological responses and airway inflammation, an effect possibly mediated, in part, through inhibition of eosinophil and basophil maturation or release from the bone marrow. PMID:10421819

  1. Paediatric airway management: What is new?

    PubMed Central

    Ramesh, S; Jayanthi, R; Archana, SR

    2012-01-01

    Airway management plays a pivotal role in Paediatric Anaesthesia. Over the last two decades many improvements in this area have helped us to overcome this final frontier. From an era where intubation with a conventional laryngoscope or blind nasal intubation was the only tool for airway management, we have come a long way. Today supraglottic airway devices have pride of place in the Operating Room and are becoming important airway devices used in routine procedures. Direct and indirect fibreoptic laryngoscopes and transtracheal devices help us overcome difficult and previously impossible airway situations. These developments mean that we need to update our knowledge on these devices. Also much of our basic understanding of the physiology and anatomy of the paediatric airway has changed. This article attempts to shed light on some of the most important advances/opinions in paediatric airway management like, cuffed endotracheal tubes, supraglottic airway devices, video laryngoscopes, rapid sequence intubation, the newly proposed algorithm for difficult airway management and the role of Ex Utero Intrapartum Treatment (EXIT) procedure in the management of the neonatal airway. PMID:23293383

  2. Salvianolic Acid B Ameliorates Lipopolysaccharide-Induced Albumin Leakage from Rat Mesenteric Venules through Src-Regulated Transcelluar Pathway and Paracellular Pathway.

    PubMed

    Pan, Chun-Shui; Liu, Ying-Hua; Liu, Yu-Ying; Zhang, Yu; He, Ke; Yang, Xiao-Yuan; Hu, Bai-He; Chang, Xin; Wang, Ming-Xia; Wei, Xiao-Hong; Fan, Jing-Yu; Wu, Xin-Min; Han, Jing-Yan

    2015-01-01

    Lipopolysaccharide (LPS) causes microvascular barrier disruption, leading to albumin leakage from microvessels resulting in a range of disastrous sequels. Salvianolic acid B (SalB) is a major water-soluble component derived from Salvia miltiorrhiza. Previous studies showed its potential to attenuate microvascular barrier dysfunction, but the underlying mechanism is not fully understood. The present study was intended to investigate the impact of SalB on endothelial cell barrier in vivo in rat mesenteric venules as well as in vitro in human umbilical vein endothelial cells (HUVECs), aiming at disclosing the mechanism thereof, particularly the role of Src in its action. Male Wistar rats were challenged by infusion of LPS (2 mg/kg/h) through left femoral vein for 90 min. SalB (5 mg/kg/h) was administrated either simultaneously with LPS or 30 min after LPS infusion through the left jugular vein. Vesicles in venular walls were observed by electron microscopy. HUVECs were incubated with LPS with or without SalB. The expression of Zonula occluden-1 (ZO-1), VE-cadherin, caveolin-1 and Src in HUVECs was assessed by Western blot and confocal microscopy, binding of SalB to Src was measured using Surface Plasmon Resonance and BioLayer Interferometry. Treatment with SalB inhibited albumin leakage from rat mesenteric venules and inhibited the increase of vesicle number in venular endothelial cells induced by LPS. In addition, SalB inhibited the degradation of ZO-1, the phosphorylation and redistribution of VE-cadherin, the expression and phosphorylation of caveolin-1, and phosphoirylation of Src in HUVECs exposed to LPS. Furthermore, SalB was found able to bind to Src. This study demonstrates that protection of SalB against microvascular barrier disruption is a process involving both para- and trans-endothelial cell pathway, and highly suggests Src as the key enzyme for SalB to work. PMID:25992563

  3. Salvianolic Acid B Ameliorates Lipopolysaccharide-Induced Albumin Leakage from Rat Mesenteric Venules through Src-Regulated Transcelluar Pathway and Paracellular Pathway

    PubMed Central

    Liu, Yu-Ying; Zhang, Yu; He, Ke; Yang, Xiao-Yuan; Hu, Bai-He; Chang, Xin; Wang, Ming-Xia; Wei, Xiao-Hong; Fan, Jing-Yu; Wu, Xin-Min; Han, Jing-Yan

    2015-01-01

    Lipopolysaccharide (LPS) causes microvascular barrier disruption, leading to albumin leakage from microvessels resulting in a range of disastrous sequels. Salvianolic acid B (SalB) is a major water-soluble component derived from Salvia miltiorrhiza. Previous studies showed its potential to attenuate microvascular barrier dysfunction, but the underlying mechanism is not fully understood. The present study was intended to investigate the impact of SalB on endothelial cell barrier in vivo in rat mesenteric venules as well as in vitro in human umbilical vein endothelial cells (HUVECs), aiming at disclosing the mechanism thereof, particularly the role of Src in its action. Male Wistar rats were challenged by infusion of LPS (2 mg/kg/h) through left femoral vein for 90 min. SalB (5 mg/kg/h) was administrated either simultaneously with LPS or 30 min after LPS infusion through the left jugular vein. Vesicles in venular walls were observed by electron microscopy. HUVECs were incubated with LPS with or without SalB. The expression of Zonula occluden-1 (ZO-1), VE-cadherin, caveolin-1 and Src in HUVECs was assessed by Western blot and confocal microscopy, binding of SalB to Src was measured using Surface Plasmon Resonance and BioLayer Interferometry. Treatment with SalB inhibited albumin leakage from rat mesenteric venules and inhibited the increase of vesicle number in venular endothelial cells induced by LPS. In addition, SalB inhibited the degradation of ZO-1, the phosphorylation and redistribution of VE-cadherin, the expression and phosphorylation of caveolin-1, and phosphoirylation of Src in HUVECs exposed to LPS. Furthermore, SalB was found able to bind to Src. This study demonstrates that protection of SalB against microvascular barrier disruption is a process involving both para- and trans-endothelial cell pathway, and highly suggests Src as the key enzyme for SalB to work. PMID:25992563

  4. Microvascular oxygen consumption during sickle cell pain crisis.

    PubMed

    Rowley, Carol A; Ikeda, Allison K; Seidel, Miles; Anaebere, Tiffany C; Antalek, Matthew D; Seamon, Catherine; Conrey, Anna K; Mendelsohn, Laurel; Nichols, James; Gorbach, Alexander M; Kato, Gregory J; Ackerman, Hans

    2014-05-15

    Sickle cell disease is an inherited blood disorder characterized by chronic hemolytic anemia and episodic vaso-occlusive pain crises. Vaso-occlusion occurs when deoxygenated hemoglobin S polymerizes and erythrocytes sickle and adhere in the microvasculature, a process dependent on the concentration of hemoglobin S and the rate of deoxygenation, among other factors. We measured oxygen consumption in the thenar eminence during brachial artery occlusion in sickle cell patients and healthy individuals. Microvascular oxygen consumption was greater in sickle cell patients than in healthy individuals (median [interquartile range]; sickle cell: 0.91 [0.75-1.07] vs healthy: 0.75 [0.62-0.94] -ΔHbO2/min, P < .05) and was elevated further during acute pain crisis (crisis: 1.10 [0.78-1.30] vs recovered: 0.88 [0.76-1.03] -ΔHbO2/min, P < .05). Increased microvascular oxygen consumption during pain crisis could affect the local oxygen saturation of hemoglobin when oxygen delivery is limiting. Identifying the mechanisms of elevated oxygen consumption during pain crisis might lead to the development of new therapeutic interventions. This trial was registered at www.clinicaltrials.gov as #NCT01568710. PMID:24665133

  5. Microvascular oxygen consumption during sickle cell pain crisis

    PubMed Central

    Rowley, Carol A.; Ikeda, Allison K.; Seidel, Miles; Anaebere, Tiffany C.; Antalek, Matthew D.; Seamon, Catherine; Conrey, Anna K.; Mendelsohn, Laurel; Nichols, James; Gorbach, Alexander M.; Kato, Gregory J.

    2014-01-01

    Sickle cell disease is an inherited blood disorder characterized by chronic hemolytic anemia and episodic vaso-occlusive pain crises. Vaso-occlusion occurs when deoxygenated hemoglobin S polymerizes and erythrocytes sickle and adhere in the microvasculature, a process dependent on the concentration of hemoglobin S and the rate of deoxygenation, among other factors. We measured oxygen consumption in the thenar eminence during brachial artery occlusion in sickle cell patients and healthy individuals. Microvascular oxygen consumption was greater in sickle cell patients than in healthy individuals (median [interquartile range]; sickle cell: 0.91 [0.75-1.07] vs healthy: 0.75 [0.62-0.94] −ΔHbO2/min, P < .05) and was elevated further during acute pain crisis (crisis: 1.10 [0.78-1.30] vs recovered: 0.88 [0.76-1.03] −ΔHbO2/min, P < .05). Increased microvascular oxygen consumption during pain crisis could affect the local oxygen saturation of hemoglobin when oxygen delivery is limiting. Identifying the mechanisms of elevated oxygen consumption during pain crisis might lead to the development of new therapeutic interventions. This trial was registered at www.clinicaltrials.gov as #NCT01568710. PMID:24665133

  6. Microvascular supply of the lateral epicondyle and common extensor origin.

    PubMed

    Bales, Chris P; Placzek, Jeffrey D; Malone, Kevin J; Vaupel, Zachary; Arnoczky, Steven P

    2007-01-01

    Lateral epicondylitis is a common condition affecting 1% to 3% of the population. Although the exact cause is still unknown, numerous theories have been put forth. One theory suggests a hypovascular zone at the origin of the common extensor mass. This study examines the microvascular supply of the lateral epicondyle and the common extensor mass, with the use of India ink injection and the Spalteholz tissue-clearing technique. Six fresh-frozen cadaveric arms underwent serial sectioning (coronal plane in five and axial plane in one) after vascular injection with India ink. Sections were cleared via a modified Spalteholz technique. Photographs were taken before and after the clearing procedure, and the microvascular pattern of the common extensor mass and lateral epicondyle was described. Two hypovascular zones were identified in the region of the lateral epicondyle. The first was noted at the proximal lateral epicondyle just distal to the supracondylar ridge and the second 2 to 3 cm distal to the lateral epicondyle on the deep surface of the common extensor tendon. Two regions of hypovascularity were noted at the lateral epicondyle and within the common extensor origin. These hypovascular regions may preclude the normal inflammatory cascade and healing response to microtearing in this region. Thus, these zones may play a role in the etiology of lateral epicondylitis. PMID:17254813

  7. Determinants of Microvascular Network Topologies in Implanted Neovasculatures

    PubMed Central

    Chang, Carlos C.; Krishnan, Laxminarayanan; Nunes, Sara S.; Church, Kenneth H.; Edgar, Lowell T.; Boland, Eugene D.; Weiss, Jeffery A.; Williams, Stuart K.; Hoying, James B.

    2011-01-01

    Objectives During neovascularization, the end result is a new functional microcirculation comprised of a network of mature microvessels with specific topologies. While much is known concerning the mechanisms underlying the initiation of angiogenesis, it remains unclear how the final architecture of microcirculatory beds is regulated. To begin to address this, we determined the impact of angiogenic neovessel pre-patterning on the final microvascular network topology using an implant model of implant neovascularization. Methods and Results To test this, we used 3-D direct-write bioprinting or physical constraints in a manner permitting post-angiogenesis vascular remodeling and adaptation to pattern angiogenic microvascular precursors (neovessels formed from isolated microvessel segments) in 3-dimensional collagen gels prior to implantation and subsequent network formation. Neovasculatures pre-patterned into parallel arrays formed functional networks following 4 weeks post-implantation, but lost the pre-patterned architecture. However, maintenance of uniaxial physical constraints during post-angiogenesis remodeling of the implanted neovasculatures produced networks with aligned microvessels as well as an altered proportional distribution of arterioles, capillaries and venules. Conclusions Here we show that network topology resulting from implanted microvessel precursors is independent from pre-patterning of precursors but can be influenced by a patterning stimulus involving tissue deformation during post-angiogenesis remodeling and maturation. PMID:22053070

  8. The use of prefabrication technique in microvascular reconstructive surgery

    PubMed Central

    Maciejewski, Adam; Szymczyk, Cezary; Wierzgoń, Janusz; Szumniak, Ryszard; Jędrzejewski, Piotr; Grajek, Maciej; Dobrut, Mirosław; Ulczok, Rafał; Półtorak, Stanisław

    2013-01-01

    Aim of the study The aim of the study was to develop standards for the prefabrication of free microvascular flaps in an animal model, followed by their application in clinical practice, and quantitative/qualitative microscopic assessment of the extent of development of a new microvascular network. Material and methods The study was carried out in 10 experimental pigs. As the first stage, a total of 20 prefabricated flaps were created using polytetrafluoroethylene (PTFE) as a support material, placed horizontally over an isolated and distally closed vascular pedicle based on superficial abdominal vessels. After completing the animal model study, one patient was selected for the grafting of the prefabricated free flap. Results All 20 free flaps prefabricated in the animal model were analyzed microscopically, exhibiting connective tissue rich in fibroblasts and small blood vessels in the porous areas across the entire thickness of the PTFE element. Conclusions Flap prefabrication is a new and fast developing reconstruction technique. The usefulness of prefabrication techniques and their status in reconstructive surgery still needs to be investigated experimentally and clinically. The method based on prefabricated free flaps is the first step towards anatomical bioengineering that will make it possible to replace missing organs with their anatomically perfect equivalents. PMID:23788942

  9. Optically measured microvascular blood flow contrast of malignant breast tumors.

    PubMed

    Choe, Regine; Putt, Mary E; Carlile, Peter M; Durduran, Turgut; Giammarco, Joseph M; Busch, David R; Jung, Ki Won; Czerniecki, Brian J; Tchou, Julia; Feldman, Michael D; Mies, Carolyn; Rosen, Mark A; Schnall, Mitchell D; DeMichele, Angela; Yodh, Arjun G

    2014-01-01

    Microvascular blood flow contrast is an important hemodynamic and metabolic parameter with potential to enhance in vivo breast cancer detection and therapy monitoring. Here we report on non-invasive line-scan measurements of malignant breast tumors with a hand-held optical probe in the remission geometry. The probe employs diffuse correlation spectroscopy (DCS), a near-infrared optical method that quantifies deep tissue microvascular blood flow. Tumor-to-normal perfusion ratios are derived from thirty-two human subjects. Mean (95% confidence interval) tumor-to-normal ratio using surrounding normal tissue was 2.25 (1.92-2.63); tumor-to-normal ratio using normal tissues at the corresponding tumor location in the contralateral breast was 2.27 (1.94-2.66), and using normal tissue in the contralateral breast was 2.27 (1.90-2.70). Thus, the mean tumor-to-normal ratios were significantly different from unity irrespective of the normal tissue chosen, implying that tumors have significantly higher blood flow than normal tissues. Therefore, the study demonstrates existence of breast cancer contrast in blood flow measured by DCS. The new, optically accessible cancer contrast holds potential for cancer detection and therapy monitoring applications, and it is likely to be especially useful when combined with diffuse optical spectroscopy/tomography. PMID:24967878

  10. Mechanisms for microvascular damage induced by ultrasound-activated microbubbles

    SciTech Connect

    Chen Hong; Brayman, Andrew A.; Evan, Andrew P.; Matula, Thomas J.

    2012-10-03

    To provide insight into the mechanisms of microvascular damage induced by ultrasound-activated microbubbles, experimental studies were performed to correlate microvascular damage to the dynamics of bubble-vessel interactions. High-speed photomicrography was used to record single microbubbles interacting with microvessels in ex vivo tissue, under the exposure of short ultrasound pulses with a center frequency of 1 MHz and peak negative pressures (PNP) ranging from 0.8-4 MPa. Vascular damage associated with observed bubble-vessel interactions was either indicated directly by microbubble extravasation or examined by transmission electron microscopy (TEM) analyses. As observed previously, the high-speed images revealed that ultrasound-activated microbubbles could cause distention and invagination of adjacent vessel walls, and could form liquid jets in microvessels. Vessel distention, invagination, and liquid jets were associated with the damage of microvessels whose diameters were smaller than those of maximally expanded microbubbles. However, vessel invagination appeared to be the dominant mechanism for the damage of relative large microvessels.

  11. Monitoring microvascular free flaps with tissue oxygen measurement and PET.

    PubMed

    Schrey, Aleksi R; Kinnunen, Ilpo A J; Grénman, Reidar A; Minn, Heikki R I; Aitasalo, Kalle M J

    2008-07-01

    Tissue oxygen measurement and positron emission tomography (PET) were evaluated as methods for predicting ischemia in microvascular free flaps of the head and neck. Ten patients with head and neck squamous cell cancer underwent resection of the tumour followed by microvascular reconstruction with a free flap. Tissue oxygenation of the flap (P(ti)O(2)) was continuously monitored for three postoperative (POP) days and the blood flow of the flap was assessed using oxygen-15 labelled water and PET. In three free flaps a perfusion problem was suspected due to a remarkable drop in P(ti)O(2)-values, due to two anastomosis problems and due to POP turgor. No flap losses occurred. During the blood flow measurements with PET [mean 8.5 mL 100 g(-1) min(-1 )(SD 2.5)], the mean P(ti)O(2) of the flaps [46.8 mmHg (SD 17.0)] appeared to correlate with each other in each patient (p<0.05, n=10). Tissue oxygenation measurement is a feasible monitoring system of free flaps. The perfusion-study with PET correlates with P(ti)O(2)-measurement. PMID:18231800

  12. Tissue viability imaging for assessment of microvascular events

    NASA Astrophysics Data System (ADS)

    O'Doherty, Jim; Nilsson, Gert E.; Henricson, Joakim; Sjoberg, Folke; Leahy, Martin J.

    2005-08-01

    A new technique for the investigation of microvascular tissue blood concentration is presented, based on the method of polarisation spectroscopy of blood in superficial skin tissue. Linearly polarised light incident on the skin is partly reflected by the surface layers, and partly backscattered from the dermal tissue. Use of orthogonal polarisation filters over both a light source and a CCD suppresses the reflections from the surface, and only the depolarised light backscattered from the dermal matrix reaches the CCD array. By separating the colour planes of an image acquired in this manner and applying a dedicated image processing algorithm, spectroscopic information about the amount of red blood cells (RBCs) in the underlying area of tissue can be discovered. The algorithm incorporates theory that utilises the differences in light absorption of RBCs and dermal tissue in the red and green wavelength regions. In vitro fluid models compare well to computer simulations in describing a linear relationship between output signal (called TiViindex) and RBC concentration in the physiological range of 0%-4%. In vivo evaluation of the technique via transepidermal application of acetylcholine by iontophoresis displayed a heterogeneity pattern of vasodilation, which is typical of the vasoactive agent. Extension of the technique to capture and process continuous real-time data creates a new possibility of online real-time image processing. Application of tissue viability (TiVi) imaging include skin care products and drug development, as well as investigations of microvascular angiogenesis.

  13. Assessing microvascular changes in systemic sclerosis diagnosis and management.

    PubMed

    Cutolo, Maurizio; Sulli, Alberto; Smith, Vanessa

    2010-10-01

    Microvascular damage and dysfunction represent the earliest morphological and functional markers of systemic sclerosis (SSc), a progressive connective tissue disease characterized by vascular abnormalities and diffuse fibrosis in the skin and internal organs. These early microvascular changes are clinically mirrored by Raynaud phenomenon, which can be primary (idiopathic) or secondary to several different conditions including SSc. Morphological and functional assessment of the cutaneous microvasculature have crucial implications for diagnosis, prognosis and therapy in SSc and secondary Raynaud phenomenon. Most importantly, imaging with nailfold videocapillaroscopy (NVC) enables the early differentiation between primary and secondary Raynaud phenomenon by identifying morphological patterns specific to various stages of SSc ('early', 'active' and 'late' patterns); the inclusion of these NVC patterns could increase the sensitivity of classification criteria for SSc. Findings on NVC are also markers of SSc severity and progression, as reduced capillary density has been associated with a high risk of developing digital skin ulcers and pulmonary arterial hypertension. Laser Doppler imaging and thermal imaging demonstrate the dysfunctional cutaneous blood flow in response to cold stimuli. Therapies targeting underlying vascular disease in SSc have been successfully designed to improve the symptoms of Raynaud phenomenon and to reduce ischemic injury to involved organs, and NVC patterns have been found to improve following targeted therapy; however, treatment of later fibrosis remains a challenge. PMID:20703220

  14. Microvascular fluid exchange and the revised Starling principle.

    PubMed

    Levick, J Rodney; Michel, C Charles

    2010-07-15

    Microvascular fluid exchange (flow J(v)) underlies plasma/interstitial fluid (ISF) balance and oedematous swelling. The traditional form of Starling's principle has to be modified in light of insights into the role of ISF pressures and the recognition of the glycocalyx as the semipermeable layer of endothelium. Sum-of-forces evidence and direct observations show that microvascular absorption is transient in most tissues; slight filtration prevails in the steady state, even in venules. This is due in part to the inverse relation between filtration rate and ISF plasma protein concentration; ISF colloid osmotic pressure (COP) rises as J(v) falls. In some specialized regions (e.g. kidney, intestinal mucosa), fluid absorption is sustained by local epithelial secretions, which flush interstitial plasma proteins into the lymphatic system. The low rate of filtration and lymph formation in most tissues can be explained by standing plasma protein gradients within the intercellular cleft of continuous capillaries (glycocalyx model) and around fenestrations. Narrow breaks in the junctional strands of the cleft create high local outward fluid velocities, which cause a disequilibrium between the subglycocalyx space COP and ISF COP. Recent experiments confirm that the effect of ISF COP on J(v) is much less than predicted by the conventional Starling principle, in agreement with modern models. Using a two-pore system model, we also explore how relatively small increases in large pore numbers dramatically increase J(v) during acute inflammation. PMID:20200043

  15. The expression of ADAMTS13 in human microvascular endothelial cells.

    PubMed

    Wang, Anyou; Duan, Qiaohong; Wu, Jingsheng; Liu, Xin; Sun, Zimin

    2016-06-01

    ADAMTS13, as a specific von Willebrand factor (VWF)-cleaving protease, prevents microvascular thrombosis of VWF/platelet thrombi. It has been reported that human vascular endothelial cells could also synthesize and secrete ADAMTS13, and these reports were focused in human umbilical vascular endothelial cells. Considering the particularity of its huge quantity and structure of human microvascular endothelial cells (HMECs) in the body, whether ADAMTS13 is expressed in HMECs also needs to be confirmed. To investigate whether ADAMTS13 is expressed in HMECs. Real-time PCR (RT-PCR) amplification detected ADAMTS13 mRNA in HMEC-1 cell line. The expression and distribution of ADAMTS13 protein and VWF were detected by fluorescence immunoassay and western blot. We observed the expression and distribution of ADAMTS13 in HMECs. We confirmed the expression of ADAMTS13 mRNA in HMEC-1, and found that there were some partly common distributions of ADAMTS13 protein and VWF. This study provides the evidence that HMECs also express ADAMTS13. HMECs might also be a primary source for human plasma ADAMTS13. The overlap region for the distribution of ADAMTS13 and VWF suggests that ADAMTS13 might have a potential regulation role for VWF inside cells. PMID:26366828

  16. Mechanisms for microvascular damage induced by ultrasound-activated microbubbles

    NASA Astrophysics Data System (ADS)

    Chen, Hong; Brayman, Andrew A.; Evan, Andrew P.; Matula, Thomas J.

    2012-10-01

    To provide insight into the mechanisms of microvascular damage induced by ultrasound-activated microbubbles, experimental studies were performed to correlate microvascular damage to the dynamics of bubble-vessel interactions. High-speed photomicrography was used to record single microbubbles interacting with microvessels in ex vivo tissue, under the exposure of short ultrasound pulses with a center frequency of 1 MHz and peak negative pressures (PNP) ranging from 0.8-4 MPa. Vascular damage associated with observed bubble-vessel interactions was either indicated directly by microbubble extravasation or examined by transmission electron microscopy (TEM) analyses. As observed previously, the high-speed images revealed that ultrasound-activated microbubbles could cause distention and invagination of adjacent vessel walls, and could form liquid jets in microvessels. Vessel distention, invagination, and liquid jets were associated with the damage of microvessels whose diameters were smaller than those of maximally expanded microbubbles. However, vessel invagination appeared to be the dominant mechanism for the damage of relative large microvessels.

  17. 40 CFR 91.324 - Analyzer leakage check.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the...

  18. 40 CFR 91.324 - Analyzer leakage check.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the...

  19. 40 CFR 91.324 - Analyzer leakage check.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the...

  20. 40 CFR 91.324 - Analyzer leakage check.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the...

  1. 40 CFR 91.324 - Analyzer leakage check.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the...

  2. Airway anastomosis for lung transplantation

    PubMed Central

    Diso, Daniele; Rendina, Erino Angelo; Venuta, Federico

    2016-01-01

    Lung transplantation (LT) is the only viable option for a selected group of patients with end stage pulmonary diseases. During the recent years satisfactory results in terms of long-term survival and quality of life have been achieved with improvements in surgical technique, immunosuppression and perioperative management. Since the beginning, the airway anastomosis has been considered crucial and significant efforts have been made to understand the healing process. A number of experimental studies allowed improving the surgical technique by modifying the technique of suturing, the anastomotic protection and type and dose of immunosuppression, reducing the risk of airway complications. Furthermore, a huge progress has been made in the management of such complications. Early diagnosis of bronchial complications and their prompt and correct management are crucial to achieve long-term survival. PMID:26981271

  3. Trending of Overboard Leakage of ISS Cabin Atmosphere

    NASA Technical Reports Server (NTRS)

    Schaezler, Ryan N.; Cook, Anthony J.; Leonard, Daniel J.; Ghariani, Ahmed

    2011-01-01

    The International Space Station (ISS) overboard leakage of cabin atmosphere is continually tracked to identify new or aggravated leaks and to provide information for planning of nitrogen supply to the ISS. The overboard leakage is difficult to trend with various atmosphere constituents being added and removed. Changes to nitrogen partial pressure is the nominal means of trending the overboard leakage. This paper summarizes the method of the overboard leakage trending and presents findings from the trending.

  4. Upper Airway Injury in Dogs Secondary to Trauma: 10 Dogs (2000-2011).

    PubMed

    Basdani, Eleni; Papazoglou, Lysimachos G; Patsikas, Michail N; Kazakos, Georgios M; Adamama-Moraitou, Katerina K; Tsokataridis, Ioannis

    2016-01-01

    Ten dogs that presented with trauma-induced upper airway rupture or stenosis were reviewed. Tracheal rupture was seen in seven dogs, tracheal stenosis in one dog, and laryngeal rupture in two dogs. Clinical abnormalities included respiratory distress in five dogs, subcutaneous emphysema in eight, air leakage through the cervical wound in seven, stridor in three dogs, pneumomediastinum in four and pneumothorax in one dog. Reconstruction with simple interrupted sutures was performed in four dogs, tracheal resection and end-to-end anastomosis in five dogs, and one dog was euthanized intraoperatively. Complications were seen in three dogs including aspiration pneumonia in one and vocalization alterations in two dogs. PMID:27487354

  5. Radiation induced inter-device leakage degradation

    NASA Astrophysics Data System (ADS)

    Hu, Zhi-Yuan; Liu, Zhang-Li; Shao, Hua; Zhang, Zheng-Xuan; Ning, Bing-Xu; Chen, Ming; Bi, Da-Wei; Zou, Shi-Chang

    2011-08-01

    The evolution of inter-device leakage current with total ionizing dose in transistors in 180 nm generation technologies is studied with an N-type poly-gate field device (PFD) that uses the shallow trench isolation as an effective gate oxide. The overall radiation response of these structures is determined by the trapped charge in the oxide. The impacts of different bias conditions during irradiation on the inter-device leakage current are studied for the first time in this work, which demonstrates that the worst condition is the same as traditional NMOS transistors. Moreover, the two-dimensional technology computer-aided design simulation is used to understand the bias dependence.

  6. Partial airway obstruction following manufacturing defect in laryngeal mask airway (Laryngeal Mask Silken™).

    PubMed

    Jangra, Kiran; Malhotra, Surender Kumar; Saini, Vikas

    2014-10-01

    Laryngeal mask (LM) airway is commonly used for securing airway in day-care surgeries. Various problems have been described while using LM airway. Out of those, mechanical obstruction causing airway compromise is most common. Here, we describe a case report of 4-year-old child who had partial upper airway obstruction due to LM manufacturer's defect. There was a silicon band in upper one-third of shaft of LM airway. This band was made up of the same material as that of LM airway so it was not identifiable on external inspection of transparent shaft. We suggest that such as non-transparent laryngeal mask, a transparent LM airway should also be inspected looking inside the lumen with naked eyes or by using a probe to rule out any manufacturing defect before its insertion. PMID:25422617

  7. 42 CFR 84.92 - Exhalation valve leakage test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Exhalation valve leakage test. 84.92 Section 84.92... Breathing Apparatus § 84.92 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be...) Leakage between the valve and the valve seat shall not exceed 30 milliliters per minute....

  8. 42 CFR 84.92 - Exhalation valve leakage test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Exhalation valve leakage test. 84.92 Section 84.92... Breathing Apparatus § 84.92 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be...) Leakage between the valve and the valve seat shall not exceed 30 milliliters per minute....

  9. 42 CFR 84.92 - Exhalation valve leakage test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Exhalation valve leakage test. 84.92 Section 84.92... Breathing Apparatus § 84.92 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be...) Leakage between the valve and the valve seat shall not exceed 30 milliliters per minute....

  10. 42 CFR 84.92 - Exhalation valve leakage test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Exhalation valve leakage test. 84.92 Section 84.92... Breathing Apparatus § 84.92 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be...) Leakage between the valve and the valve seat shall not exceed 30 milliliters per minute....

  11. 42 CFR 84.92 - Exhalation valve leakage test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Exhalation valve leakage test. 84.92 Section 84.92... Breathing Apparatus § 84.92 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be...) Leakage between the valve and the valve seat shall not exceed 30 milliliters per minute....

  12. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line...

  13. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line...

  14. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line...

  15. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line...

  16. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line...

  17. 3DHZETRN: Neutron leakage in finite objects

    NASA Astrophysics Data System (ADS)

    Wilson, John W.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-11-01

    The 3DHZETRN formalism was recently developed as an extension to HZETRN with an emphasis on 3D corrections for neutrons and light ions. Comparisons to Monte Carlo (MC) simulations were used to verify the 3DHZETRN methodology in slab and spherical geometry, and it was shown that 3DHZETRN agrees with MC codes to the degree that various MC codes agree among themselves. One limitation of such comparisons is that all of the codes (3DHZETRN and three MC codes) utilize different nuclear models/databases; additionally, using a common nuclear model is impractical due to the complexity of the software. It is therefore difficult to ascertain if observed discrepancies are caused by transport code approximations or nuclear model differences. In particular, an important simplification in the 3DHZETRN formalism assumes that neutron production cross sections can be represented as the sum of forward and isotropic components, where the forward component is subsequently solved within the straight-ahead approximation. In the present report, previous transport model results in specific geometries are combined with additional results in related geometries to study neutron leakage using the Webber 1956 solar particle event as a source boundary condition. A ratio is defined to quantify the fractional neutron leakage at a point in a finite object relative to a semi-infinite slab geometry. Using the leakage ratio removes some of the dependence on the magnitude of the neutron production and clarifies the effects of angular scattering and absorption with regard to differences between the models. Discussion is given regarding observed differences between the MC codes and conclusions drawn about the need for further code development. Although the current version of 3DHZETRN is reasonably accurate compared to MC simulations, this study shows that improved leakage estimates can be obtained by replacing the isotropic/straight-ahead approximation with more detailed descriptions.

  18. 3DHZETRN: Neutron leakage in finite objects.

    PubMed

    Wilson, John W; Slaba, Tony C; Badavi, Francis F; Reddell, Brandon D; Bahadori, Amir A

    2015-11-01

    The 3DHZETRN formalism was recently developed as an extension to HZETRN with an emphasis on 3D corrections for neutrons and light ions. Comparisons to Monte Carlo (MC) simulations were used to verify the 3DHZETRN methodology in slab and spherical geometry, and it was shown that 3DHZETRN agrees with MC codes to the degree that various MC codes agree among themselves. One limitation of such comparisons is that all of the codes (3DHZETRN and three MC codes) utilize different nuclear models/databases; additionally, using a common nuclear model is impractical due to the complexity of the software. It is therefore difficult to ascertain if observed discrepancies are caused by transport code approximations or nuclear model differences. In particular, an important simplification in the 3DHZETRN formalism assumes that neutron production cross sections can be represented as the sum of forward and isotropic components, where the forward component is subsequently solved within the straight-ahead approximation. In the present report, previous transport model results in specific geometries are combined with additional results in related geometries to study neutron leakage using the Webber 1956 solar particle event as a source boundary condition. A ratio is defined to quantify the fractional neutron leakage at a point in a finite object relative to a semi-infinite slab geometry. Using the leakage ratio removes some of the dependence on the magnitude of the neutron production and clarifies the effects of angular scattering and absorption with regard to differences between the models. Discussion is given regarding observed differences between the MC codes and conclusions drawn about the need for further code development. Although the current version of 3DHZETRN is reasonably accurate compared to MC simulations, this study shows that improved leakage estimates can be obtained by replacing the isotropic/straight-ahead approximation with more detailed descriptions. PMID:26553635

  19. Remote Sensing And Surface Hydrocarbon Leakage

    NASA Astrophysics Data System (ADS)

    Matthews, M. D.; Jones, V. T.; Richers, D. M.

    1984-08-01

    The Geosat oil and gas test site program stimulated interest in the interaction between surface hydrocarbon concentrations and interpretation of remote sensing data. The test case results suggested that lineaments correspond to avenues of preferential hydrocarbon seepage and that this seepage affects vegetation health and populations at Patrick Draw field in Wyoming and potentially at Lost River field, West Virginia. These two areas were selected for additional surface hydrocarbon surveys in order to test these hypotheses. The Patrick Draw study shows that a zone of stressed vegetation, visible on thematic mapper data, definitely coincides with an area of marked leakage of hydrocarbons and that the composition of these gases would predict an intermediate type oil and gas reservoir such as exists in the area. The study further indicates that the leakage is in large part controlled by the presence of fractures/faults recognized as lineaments on the remote sensing images. The Lost River study specifically investigated the possible existence of hydrocarbon leakage causing anomalous populations of maple trees in a climax oak forest. These maples were first recognized by study of thematic mapper simulator data. The soil gas hydrocarbon concentrations are above average in several of the maple anomalies over the field. This supports the inference that the maples are present because they are more tolerant of soil conditions where hydrocarbon seepage is active. The crest of the field has low soil gas magnitudes, but high values occur to the updip eastern edge of the field along a fault/fracture that was detected in the seismic data. The conclusion that preferential pathways of hydrocarbon leakage are recognized in spectral and textural analysis of remote sensing data is supported by other studies and integrated into a suggested exploration/hydrocarbon migration model.

  20. Airway management in cervical spine injury

    PubMed Central

    Austin, Naola; Krishnamoorthy, Vijay; Dagal, Arman

    2014-01-01

    To minimize risk of spinal cord injury, airway management providers must understand the anatomic and functional relationship between the airway, cervical column, and spinal cord. Patients with known or suspected cervical spine injury may require emergent intubation for airway protection and ventilatory support or elective intubation for surgery with or without rigid neck stabilization (i.e., halo). To provide safe and efficient care in these patients, practitioners must identify high-risk patients, be comfortable with available methods of airway adjuncts, and know how airway maneuvers, neck stabilization, and positioning affect the cervical spine. This review discusses the risks and benefits of various airway management strategies as well as specific concerns that affect patients with known or suspected cervical spine injury. PMID:24741498

  1. Airway injury during high-level exercise.

    PubMed

    Kippelen, Pascale; Anderson, Sandra D

    2012-05-01

    Airway epithelial cells act as a physical barrier against environmental toxins and injury, and modulate inflammation and the immune response. As such, maintenance of their integrity is critical. Evidence is accumulating to suggest that exercise can cause injury to the airway epithelium. This seems the case particularly for competitive athletes performing high-level exercise, or when exercise takes place in extreme environmental conditions such as in cold dry air or in polluted air. Dehydration of the small airways and increased forces exerted on to the airway surface during severe hyperpnoea are thought to be key factors in determining the occurrence of injury of the airway epithelium. The injury-repair process of the airway epithelium may contribute to the development of the bronchial hyper-responsiveness that is documented in many elite athletes. PMID:22247295

  2. Atomic Oxygen Effects on Seal Leakage

    NASA Technical Reports Server (NTRS)

    Christensen, John R.; Underwood, Steve D.; Kamenetzky, Rachel R.; Vaughn, Jason A.

    1999-01-01

    Common Berthing Mechanism (CBM provides the structural interface between separate International Space Station (ISS) elements, such as the Laboratory and Node modules. The CBM consists of an active and a passive half that join together with structural bolts. The seal at this interface is the CBM-to-CBM molded seal. The CBM-to-CBM interface is assembled on orbit, thus the seals can be exposed to the space environment for up to 65 hours. Atomic Oxygen/Vacuum Ultraviolet radiation (AO/VUV) in space is a potential hazard to the seals. Testing was conducted to determine the effect on leakage of the CBM-to-CBM seal material exposed to AO/VUV. The sealing materials were S383 silicone and V835 fluorocarbon material. Control samples, which were not exposed to the AO/VUV environment, were used to ensure that ff any changes in leakage occurred, they could be attributed to the AO/VUV exposure. After exposure to the AO/VUV environment the leakage increase was dramatic for the fluorocarbon. This testing was a major contributing factor in selecting silicone as the CBM-to-CBM seal material.

  3. Time reversal technique for gas leakage detection.

    PubMed

    Maksimov, A O; Polovinka, Yu A

    2015-04-01

    The acoustic remote sensing of subsea gas leakage traditionally uses sonars as active acoustic sensors and hydrophones picking up the sound generated by a leak as passive sensors. When gas leaks occur underwater, bubbles are produced and emit sound at frequencies intimately related to their sizes. The experimental implementation of an acoustic time-reversal mirror (TRM) is now well established in underwater acoustics. In the basic TRM experiment, a probe source emits a pulse that is received on an array of sensors, time reversed, and re-emitted. After time reversal, the resulting field focuses back at the probe position. In this study, a method for enhancing operation of the passive receiving system has been proposed by using it in the regime of TRM. Two factors, the local character of the acoustic emission signal caused by the leakage and a resonant nature of the bubble radiation at their birth, make particularly effective scattering with the conjugate wave (CW). Analytical calculations are performed for the scattering of CW wave on a single bubble when CW is formed by bubble birthing wail received on an array, time reversed, and re-emitted. The quality of leakage detection depends on the spatio-temporal distribution of ambient noise. PMID:25920866

  4. Gaseous hydrogen leakage optical fibre detection system

    NASA Astrophysics Data System (ADS)

    Trouillet, Alain; Veillas, Colette; Sigronde, E.; Gagnaire, Henri; Clement, Michel

    2004-06-01

    Liquid hydrogen has been intensively used in aerospace applications during the past forty years and is of great interest for fuel cells technologies and future automotive applications. Following upon major explosive risks due to the use of hydrogen in air, previous studies were carried out in our laboratory in order to develop optical fiber sensors for the detection of hydrogen leakage. This communication is aimed towards a prototype optical fiber system designed for the detection of gaseous hydrogen leakage near the conecting flanges of the liquid hydrogen pipes on the test bench of the engine Vulcain of the rocket ARIANE V. Depending on the configuration, the prototype sensor provides a two-level alarm signal and the detection of gaseous hydrogen leakage is possible for concentrations lower than the lower explosive limit in air (between 0.1 and 4%) with alarm response times lower than 10 seconds in a wide range of temperatures between -35°C and 300°C. The sensing principle based on palladium-hydrogen interaction is presented as well as the detection system composed of an optical fiber probe and an optoelectronic device.

  5. Atomic Oxygen Effects on Seal Leakage

    NASA Technical Reports Server (NTRS)

    Christensen, John R.; Underwood, Steve D.; Kamenetzky, Rachel R.; Vaughn, Jason A.

    1998-01-01

    Common Berthing Mechanism (CBM) provides the structural interface between separate International Space Station (ISS) elements, such as the Laboratory and Node modules. The CBM consists of an active and a passive half that join together with structural bolts. The seal at this interface is the CBM-to-CBM molded seal. The CBM-to-CBM interface is assembled on orbit, thus the seals can be exposed to the space environment for up to 65 hours. Atomic Oxygen/Vacuum Ultraviolet radiation (AO/VUV) in space is a potential hazard to the seals. Testing was conducted to determine the effect on leakage of the CBM-to-CBM seal material exposed to AO/VUV. The sealing materials were S383 silicone and V835 fluorocarbon material. Control samples, which were not exposed to the AO/VUV environment, were used to ensure that if any changes in leakage occurred, they could be attributed to the AO/VUV exposure. After exposure to the AO/VUV environment the leakage increase was dramatic for the fluorocarbon. This testing was a major contributing factor in selecting silicone as the CBM-to-CBM seal material.

  6. Airway Assessment for Office Sedation/Anesthesia.

    PubMed

    Rosenberg, Morton B; Phero, James C

    2015-01-01

    Whenever a patient is about to receive sedation or general anesthesia, no matter what the technique, the preoperative assessment of the airway is one of the most important steps in ensuring patient safety and positive outcomes. This article, Part III in the series on airway management, is directed at the ambulatory office practice and focuses on predicting the success of advanced airway rescue techniques. PMID:26061578

  7. A bug's view of allergic airways disease.

    PubMed

    Hsu, Peter S; Campbell, Dianne E

    2016-06-01

    The increase in allergic airways disease has been linked to modern urbanization and lifestyle. Recent evidence suggests that the associated reduction in microbial exposure, reduction in dietary fibre intake and increased antibiotic use may cause early dysbiosis in infancy, which predisposes to immune dysregulation and allergic airways disease later in life. This implies that there may be a window of opportunity for primary prevention strategies aimed to protect or restore the microbiome early in life and thereby decrease the risk of developing allergic airways disease. Alternatively, strategies that correct dysbiosis may aid in the treatment of established allergic airways disease. PMID:27012478

  8. Airway vascular damage in elite swimmers.

    PubMed

    Moreira, André; Palmares, Carmo; Lopes, Cristina; Delgado, Luís

    2011-11-01

    We postulated that high level swimming can promote airway inflammation and thus asthma by enhancing local vascular permeability. We aimed to test this hypothesis by a cross-sectional study comparing swimmers (n = 13, 17 ± 3 years, competing 7 ± 4 years, training 18 ± 3 h per week), asthmatic-swimmers (n = 6, 17 ± 2 years, competing 8 ± 3 years, training 16 ± 4 h per week), and asthmatics (n = 19, 14 ± 3 years). Subjects performed induced sputum and had exhaled nitric oxide, lung volumes, and airway responsiveness determined. Airway vascular permeability index was defined as the ratio of albumin in sputum and serum. Results from the multiple linear regression showed each unit change in airway vascular permeability index was associated with an increase of 0.97% (95%CI: 0.02 to 1.92; p = 0.047) in sputum eosinophilis, and of 2.64% (95%CI:0.96 to 4.31; p = 0.006) in sputum neutrophils after adjustment for confounders. In a general linear model no significant differences between airway vascular permeability between index study groups existed, after controlling for sputum eosinophilis and neutrophils. In conclusion, competitive swimmers training in chlorine-rich pools have similar levels of airway vascular permeability than asthmatics. Although competitive swimming has been associated with asthma, airway inflammation and airway hyperesponsiveness do not seem to be dependent on increased airway vascular permeability. PMID:21669516

  9. Automated lobe-based airway labeling.

    PubMed

    Gu, Suicheng; Wang, Zhimin; Siegfried, Jill M; Wilson, David; Bigbee, William L; Pu, Jiantao

    2012-01-01

    Regional quantitative analysis of airway morphological abnormalities is of great interest in lung disease investigation. Considering that pulmonary lobes are relatively independent functional unit, we develop and test a novel and efficient computerized scheme in this study to automatically and robustly classify the airways into different categories in terms of pulmonary lobe. Given an airway tree, which could be obtained using any available airway segmentation scheme, the developed approach consists of four basic steps: (1) airway skeletonization or centerline extraction, (2) individual airway branch identification, (3) initial rule-based airway classification/labeling, and (4) self-correction of labeling errors. In order to assess the performance of this approach, we applied it to a dataset consisting of 300 chest CT examinations in a batch manner and asked an image analyst to subjectively examine the labeled results. Our preliminary experiment showed that the labeling accuracy for the right upper lobe, the right middle lobe, the right lower lobe, the left upper lobe, and the left lower lobe is 100%, 99.3%, 99.3%, 100%, and 100%, respectively. Among these, only two cases are incorrectly labeled due to the failures in airway detection. It takes around 2 minutes to label an airway tree using this algorithm. PMID:23093951

  10. Airway sonography in live models and cadavers.

    PubMed

    Tsui, Ban; Ip, Vivian; Walji, Anil

    2013-06-01

    Sonography using cadavers is beneficial in teaching and learning sonoanatomy, which is particularly important because imaging of the airway can be challenging due to the cartilaginous landmarks and air artifacts. In this exploratory study, we have attempted to compare the airway sonoanatomy of cadavers and live models. Our observations support the use of cadavers as teaching tools for learning airway sonoanatomy and practicing procedures involving airway structures, such as superior laryngeal nerve blocks, transtracheal injections, and needle cricothyroidotomy, before performance on patients in clinical situations. We believe this process will improve patient safety and enhance the competency of trainees and practitioners in rare procedures such as needle cricothyroidotomy. PMID:23716527

  11. Anatomic Optical Coherence Tomography of Upper Airways

    NASA Astrophysics Data System (ADS)

    Chin Loy, Anthony; Jing, Joseph; Zhang, Jun; Wang, Yong; Elghobashi, Said; Chen, Zhongping; Wong, Brian J. F.

    The upper airway is a complex and intricate system responsible for respiration, phonation, and deglutition. Obstruction of the upper airways afflicts an estimated 12-18 million Americans. Pharyngeal size and shape are important factors in the pathogenesis of airway obstructions. In addition, nocturnal loss in pharyngeal muscular tone combined with high pharyngeal resistance can lead to collapse of the airway and periodic partial or complete upper airway obstruction. Anatomical optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images of the airway lumen without the use of ionizing radiation. In this chapter we describe the methods behind endoscopic OCT imaging and processing to generate full three dimensional anatomical models of the human airway which can be used in conjunction with numerical simulation methods to assess areas of airway obstruction. Combining this structural information with flow dynamic simulations, we can better estimate the site and causes of airway obstruction and better select and design surgery for patients with obstructive sleep apnea.

  12. Physical principle of airway design in human lungs

    NASA Astrophysics Data System (ADS)

    Park, Keunhwan; Son, Taeho; Kim, Wonjung; Kim, Ho-Young

    2014-11-01

    From an engineering perspective, lungs are natural microfluidic devices that extract oxygen from air. In the bronchial tree, airways branch by dichotomy with a systematic reduction of their diameters. It is generally accepted that in conducting airways, which air passes on the way to the acinar airways from the atmosphere, the reduction ratio of diameter is closely related to the minimization of viscous dissipation. Such a principle is formulated as the Hess-Murray law. However, in acinar airways, where oxygen transfer to alveolae occurs, the diameter reduction with progressive generations is more moderate than in conducting airways. Noting that the dominant transfer mechanism in acinar airways is diffusion rather than advection, unlike conducting airways, we construct a mathematical model for oxygen transfer through a series of acinar airways. Our model allows us to predict the optimal airway reduction ratio that maximizes the oxygen transfer in a finite airway volume, thereby rationalizing the observed airway reduction ratio in acinar airways.

  13. Microvascular Injury in Ketamine-Induced Bladder Dysfunction.

    PubMed

    Lin, Chih-Chieh; Lin, Alex Tong-Long; Yang, An-Hang; Chen, Kuang-Kuo

    2016-01-01

    The pathogenesis of ketamine-induced cystitis (KC) remains unclear. In this study, bladder microvascular injury was investigated as a possible contributing mechanism. A total of 36 KC patients with exposure to ketamine for more than 6 months, and 9 control subjects, were prospectively recruited. All participants completed questionnaires, including the O'Leary-Sant interstitial cystitis symptom index (ICSI) and the interstitial cystitis problem index (ICPI). All KC patients received a urodynamic study and radiological exams. Bladder tissues were obtained from cystoscopic biopsies in the control group and after hydrodistention in the KC group. Double-immunofluorescence staining of N-methyl-d-aspartate receptor subunit 1 (NMDAR1) and the endothelial marker, cluster of differentiation 31 (CD31), was performed to reveal the existence of NMDAR1 on the endothelium. Electron microscopy (EM) was applied to assess the microvascular change in the urinary bladder and to measure the thickening of the basement membrane (BM). A proximity ligation assay (PLA) was used to quantify the co-localization of the endothelial CD31 receptor and the mesenchymal marker [fibroblast-specific protein 1 (FSP-1)]. The Mann-Whitney U test and Spearman's correlation coefficient were used for statistical analysis. The mean ICSI [14.38 (± 4.16)] and ICPI [12.67 (± 3.54)] scores of the KC group were significantly higher than those (0 and 0, respectively) of the control group (both p < 0.001). The KC patients had decreasing cystometric bladder capacity (CBC) with a mean volume of 65.38 (± 48.67) mL. NMDAR1 was expressed on endothelial cells in both groups under immunofluorescence staining. Moreover, KC patients had significant BM duplication of microvessels in the mucosa of the urinary bladder under EM. The co-expression of the endothelial marker CD31 and mesenchymal marker FSP1 was significantly stained and calculated under PLA. In conclusion, microvascular injury and mesenchymal phenotypic

  14. Microvascular Injury in Ketamine-Induced Bladder Dysfunction

    PubMed Central

    Lin, Chih-Chieh; Lin, Alex Tong-Long; Yang, An-Hang; Chen, Kuang-Kuo

    2016-01-01

    The pathogenesis of ketamine-induced cystitis (KC) remains unclear. In this study, bladder microvascular injury was investigated as a possible contributing mechanism. A total of 36 KC patients with exposure to ketamine for more than 6 months, and 9 control subjects, were prospectively recruited. All participants completed questionnaires, including the O’Leary–Sant interstitial cystitis symptom index (ICSI) and the interstitial cystitis problem index (ICPI). All KC patients received a urodynamic study and radiological exams. Bladder tissues were obtained from cystoscopic biopsies in the control group and after hydrodistention in the KC group. Double-immunofluorescence staining of N-methyl-d-aspartate receptor subunit 1 (NMDAR1) and the endothelial marker, cluster of differentiation 31 (CD31), was performed to reveal the existence of NMDAR1 on the endothelium. Electron microscopy (EM) was applied to assess the microvascular change in the urinary bladder and to measure the thickening of the basement membrane (BM). A proximity ligation assay (PLA) was used to quantify the co-localization of the endothelial CD31 receptor and the mesenchymal marker [fibroblast-specific protein 1 (FSP-1)]. The Mann–Whitney U test and Spearman’s correlation coefficient were used for statistical analysis. The mean ICSI [14.38 (± 4.16)] and ICPI [12.67 (± 3.54)] scores of the KC group were significantly higher than those (0 and 0, respectively) of the control group (both p < 0.001). The KC patients had decreasing cystometric bladder capacity (CBC) with a mean volume of 65.38 (± 48.67) mL. NMDAR1 was expressed on endothelial cells in both groups under immunofluorescence staining. Moreover, KC patients had significant BM duplication of microvessels in the mucosa of the urinary bladder under EM. The co-expression of the endothelial marker CD31 and mesenchymal marker FSP1 was significantly stained and calculated under PLA. In conclusion, microvascular injury and mesenchymal phenotypic

  15. Directed assembly of three-dimensional microvascular networks

    NASA Astrophysics Data System (ADS)

    Therriault, Daniel

    Three-dimensional (3-D) microvascular networks with pervasive, interconnected channels less than 300 mum in diameter may find widespread application in microfluidic devices, biotechnology, sensors, and autonomic healing materials. Although microchannel arrays are readily constructed in two-dimensions by photolithographic or soft lithographic techniques, their construction in three-dimensions remains a challenging problem. The development of a microfabrication method to build 3-D microvascular networks based on direct-write assembly is described is this thesis. The method is based on the robotic deposition of a fugitive organic ink to form a free-standing scaffold structure. Secondary infiltration of a structural resin followed by setting of the matrix and removal of the scaffold yields an embedded pervasive network of smooth cylindrical channels (˜10--500 mum) with defined connectivity. Rheological and other material properties studies of fugitive organic ink were performed in order to identify the critical characteristics required for successful deposition of 3-D scaffolds by direct-write assembly. Guided by the results of these studies, several new ink formulations were screened for improved deposition performance. The most successful of these inks (40wt% microcrystalline wax, 60wt% petroleum jelly) showed excellent deposition and had an equilibrium modulus at room temperature (G 'eq ˜ 7.70 kPa 1 Hz) nearly two orders of magnitude higher than the original ink. The optimized ink was used to successfully build thick (i.e., ˜100 layers) scaffold structures at room temperature with negligible time-dependent deformation post-deposition. Secondary infiltration of the resin was accomplished at room temperature while maintaining the scaffold architecture. The optimized ink was also successfully extruded through small micronozzles (1 mum). The construction of 3-D microvascular networks enables microfluidic devices with unparallel geometric complexity. In one example, a

  16. Diagnostic Ultrasound High Mechanical Index Impulses Restore Microvascular Flow in Peripheral Arterial Thromboembolism.

    PubMed

    Porter, Thomas R; Radio, Stanley; Lof, John; Everbach, Carr; Powers, Jeffry E; Vignon, Francois; Shi, William T; Xie, Feng

    2016-07-01

    We sought to explore mechanistically how intermittent high-mechanical-index (MI) diagnostic ultrasound impulses restore microvascular flow. Thrombotic microvascular obstruction was created in the rat hindlimb muscle of 36 rats. A diagnostic transducer confirmed occlusion with low-MI imaging during an intravenous microbubble infusion. This same transducer was used to intermittently apply ultrasound with an MI that produced stable or inertial cavitation (IC) for 10 min through a tissue-mimicking phantom. A nitric oxide inhibitor, L-Nω-nitroarginine methyl ester (L-NAME), was pre-administered to six rats. Plateau microvascular contrast intensity quantified skeletal microvascular blood volume, and postmortem staining was used to detect perivascular hemorrhage. Intermittent IC impulses produced the greatest recovery of microvascular blood volume (p < 0.0001, analysis of variance). Nitric oxide inhibition did not affect the skeletal microvascular blood volume improvement, but did result in more perivascular hemorrhage. IC inducing pulses from a diagnostic transducer can reverse microvascular obstruction after acute arterial thromboembolism. Nitric oxide may prevent unwanted bio-effects of these IC pulses. PMID:27083977

  17. Relationship Between Serum Zinc Level and Microvascular Complications in Patients with Type 2 Diabetes

    PubMed Central

    Luo, Ying-Ying; Zhao, Jie; Han, Xue-Yao; Zhou, Xiang-Hai; Wu, Jing; Ji, Li-Nong

    2015-01-01

    Background: Previous studies suggested that zinc level was related to a certain diabetic microvascular complication. However, the relationship between zinc level and all the microvascular complications in type 2 diabetic patients remains unknown. The purpose of this study was to analyze the relationship between zinc level and each diabetic microvascular complication and identify the features related to low serum zinc level. Methods: We included the hospitalized patients with type 2 diabetes (T2D) at our department from May 30, 2013 to March 31, 2014. We initially compared the serum zinc levels between patients with specific microvascular complications and those without. We then analyzed the association between zinc level and each microvascular complication. Furthermore, we identified the unique features of patients with high and low serum zinc levels and analyzed the risk factors related to low zinc level. Results: The 412 patients included 271 with microvascular complications and 141 without any microvascular complications. Serum zinc level was significantly lower in patients with diabetic retinopathy (P < 0.001), diabetic nephropathy (DN, P < 0.001), or diabetic peripheral neuropathy (P = 0.002) compared with patients without that specific complication. Lower zinc level was an independent risk factor for DN (odds ratio = 0.869, 95% confidence interval = 0.765–0.987, P < 0.05). The subjects with lower serum zinc level had manifested a longer duration of diabetes, higher level of hemoglobin A1c, higher prevalence of hypertension and microvascular complications, and lower fasting and 2-h C-peptide levels. Conclusions: Lower serum zinc level in T2D patients was related to higher prevalence of diabetic microvascular complications, and represented as an independent risk factor for DN. Patients with lower zinc level were more likely to have a longer duration of diabetes, poorer glucose control, and worse β-cell function. PMID:26668140

  18. Videomicroscopy of methacholine-induced contraction of individual airways in precision-cut lung slices.

    PubMed

    Martin, C; Uhlig, S; Ullrich, V

    1996-12-01

    Contraction of airways of different size can be studied in viable lung slices by videomicroscopy. However, at present, application of this technique is limited by the heterogeneous responses obtained. We investigated the use of precision-cut lung slices to examine contraction of individual airways. Lung slices of 250 +/- 20 microns were prepared from Wistar rats and cultured in a roller incubator in serum-free minimum essential medium (MEM). Under these conditions, the slices were viable for at least 70 h, as indicated by leakage of lactate dehydrogenase into the supernatant, thymidine incorporation and ciliary beating. The slices were placed in a newly developed incubation chamber and mounted by a nylon thread that was fixed to a platinum wire. The whole chamber was positioned on a microscope stage, and contraction of single airways was followed under a microscope that was coupled to a CCD-camera. Reduction in airway area was taken as an index of bronchoconstriction and was determined by a computer program. Addition of methacholine resulted in a concentration-dependent (concentration producing half the maximal effect (EC50) = 0.64 +/- 0.08 (mean +/- SD) microM; n = 64) contraction of single airways. In the presence of hydrocortisone, the EC50 was about six times greater, i.e. 3.7 +/- 0.9 microM (n = 7), and the effect of the steroid was largely abolished by propanolol (EC50 = 1.1 +/- 0.1 microM; n = 7). Airways with an area smaller than 35,000 microns2 were nearly nine times more sensitive to methacholine (EC50 = 0.1 +/- 0.03 microM; n = 20) than larger ones (EC50 = 87 +/- 0.27 microM; n = 22). We conclude that cultured precision-cut lung slices are a useful model for routine study of contraction of individual airways of various sizes. The measurements were precise and reproducible and showed that smaller airways are more sensitive to methacholine than larger ones. PMID:8980957

  19. Reserves in Context: Planning for Leakage from Protected Areas

    PubMed Central

    Renwick, Anna R.; Bode, Michael; Venter, Oscar

    2015-01-01

    When protected areas reduce threats within their boundaries, they often displace a portion of these threats into adjacent areas through a process known as ‘leakage’, undermining conservation objectives. Using theoretical models and a case study of terrestrial mammals in Indonesia, we develop the first theoretical explanation of how leakage impacts conservation actions, and highlight conservation strategies that mitigate these impacts. Although leakage is a socio-economic process, we demonstrate that its negative impacts are also affected by the distribution of species, with leakage having larger impacts in landscapes with homogeneous distribution of species richness. Moreover, leakage has a greater negative effect when conservation strategies are implemented opportunistically, even creating the potential for perversely negative consequences from protected area establishment. Leakage thereby increases the relative benefits of systematic conservation planning over opportunism, especially in areas with high leakage and heterogeneously distributed species. Although leakage has the potential to undermine conservation actions, conservation planning can minimize this risk. PMID:26053163

  20. FELERION: a new approach for leakage power reduction

    NASA Astrophysics Data System (ADS)

    R, Anjana; Somkuwar, Ajay

    2014-12-01

    The circuit proposed in this paper simultaneously reduces the sub threshold leakage power and saves the state of art aspect of the logic circuits. Sleep transistors and PMOS-only logic are used to further reduce the leakage power. Sleep transistors are used as the keepers to reduce the sub threshold leakage current providing the low resistance path to the output. PMOS-only logic is used between the pull up and pull down devices to mitigate the leakage power further. Our proposed fast efficient leakage reduction circuit not only reduces the leakage current but also reduces the power dissipation. Power and delay are analyzed at the 32 nm BSIM4 model for a chain of four inverters, NAND, NOR and ISCAS-85 c17 benchmark circuits using DSCH3 and the Microwind tool. The simulation results reveal that our proposed approach mitigates leakage power by 90%-94% as compared to the conventional approach.

  1. Closing microvascular lesions with fibrin sealant-attached muscle pads.

    PubMed

    Fehm, Nando Percy; Vatankhah, Bijan; Dittmar, Michael S; Tevetoglu, Yesim; Retzl, Gerald; Horn, Markus

    2005-01-01

    Fibrin sealants are used in a variety of surgical procedures, mainly for purposes of hemostasis and assisted wound healing. The combined use of fibrin sealant and autologous muscle pads for hemostasis was not reported previously. Arterial incisions in the common carotid artery in rats were closed by the combined application of fibrin sealant and an autologous muscle pad. Postsurgical vessel patency and degree of stenosis were evaluated by color duplex sonography, computed tomography angiography, and postmortem histology. The combined application of muscle pad and fibrin sealant and achievement of hemostasis was feasible in all animals. Seventy-eight percent of animals showed no or only slight postsurgical vessel stenosis. Our method is simple and quick to perform, showing a high potential for hemostasis in microvascular lesions. Therefore, it might be used in future experimental studies for conservation of vessel patency after arterial catheterization and in experimental or clinical vascular surgery. PMID:16184526

  2. Diabetic microvascular complications: possible targets for improved macrovascular outcomes

    PubMed Central

    D’Elia, John A; Bayliss, George; Roshan, Bijan; Maski, Manish; Gleason, Ray E; Weinrauch, Larry A

    2011-01-01

    The results of recent outcome trials challenge hypotheses that tight control of both glycohemoglobin and blood pressure diminishes macrovascular events and survival among type 2 diabetic patients. Relevant questions exist regarding the adequacy of glycohemoglobin alone as a measure of diabetes control. Are we ignoring mechanisms of vasculotoxicity (profibrosis, altered angiogenesis, hypertrophy, hyperplasia, and endothelial injury) inherent in current antihyperglycemic medications? Is the polypharmacy for lowering cholesterol, triglyceride, glucose, and systolic blood pressure producing drug interactions that are too complex to be clinically identified? We review angiotensin–aldosterone mechanisms of tissue injury that magnify microvascular damage caused by hyperglycemia and hypertension. Many studies describe interruption of these mechanisms, without hemodynamic consequence, in the preservation of function in type 1 diabetes. Possible interactions between the renin–angiotensin–aldosterone system and physiologic glycemic control (through pulsatile insulin release) suggest opportunities for further clinical investigation. PMID:21694944

  3. Free microvascular transplantation of the trapezius musculocutaneous flap in dogs.

    PubMed

    Philibert, D; Fowler, J D; Clapson, J B

    1992-01-01

    A musculocutaneous flap based on the prescapular branch of the superficial cervical artery and including the cervical part of the trapezius muscle and overlying skin was transplanted over a defect created on the medial side of the contralateral tibia in four dogs by using microvascular technique. The donor and recipient sites in three dogs were examined clinically for 21 days, after which they were examined angiographically and histologically. All dogs were free of lameness by hour 48. Seromas formed at the donor site between days 7 and 15. One vascular pedicle was traumatized at hour 40, and the dog was euthanatized. Three flaps survived with minimal necrosis. Edema of the flaps was severe from days 5 to 11. Angiograms showed complete perfusion of the flaps, and survival was confirmed histologically. Esthetic appearance and function were good in one dog at month 7. PMID:1455645

  4. Unlocking the Biology of RAGE in Diabetic Microvascular Complications

    PubMed Central

    Manigrasso, Michaele B.; Juranek, Judyta; Ramasamy, Ravichandran; Schmidt, Ann Marie

    2013-01-01

    The discovery of the receptor for advanced glycation endproducts (RAGE) set the stage for the elucidation of important mechanisms underpinning diabetic complications. RAGE transduces the signals of advanced glycation endproducts, pro-inflammatory S100/calgranulins and high mobility group box 1 (HMGB1), and is a one of a family of receptors for lysophosphatidic acid (LPA). These ligand tales weave a theme of vascular perturbation and inflammation linked to the pathogenesis of the chronic complications of diabetes. Once deemed implausible, this concept of inflammatory cues participating in diabetic complications is now supported by a plethora of experimental evidence in the macro- and microvasculature. We review the biology of ligand-RAGE signal transduction and its roles in diabetic microvascular complications, from animal models to human subjects. PMID:24011512

  5. Blood flow in microvascular networks: A study in nonlinear biology

    PubMed Central

    Geddes, John B.; Carr, Russell T.; Wu, Fan; Lao, Yingyi; Maher, Meaghan

    2010-01-01

    Plasma skimming and the Fahraeus–Lindqvist effect are well-known phenomena in blood rheology. By combining these peculiarities of blood flow in the microcirculation with simple topological models of microvascular networks, we have uncovered interesting nonlinear behavior regarding blood flow in networks. Nonlinearity manifests itself in the existence of multiple steady states. This is due to the nonlinear dependence of viscosity on blood cell concentration. Nonlinearity also appears in the form of spontaneous oscillations in limit cycles. These limit cycles arise from the fact that the physics of blood flow can be modeled in terms of state dependent delay equations with multiple interacting delay times. In this paper we extend our previous work on blood flow in a simple two node network and begin to explore how topological complexity influences the dynamics of network blood flow. In addition we present initial evidence that the nonlinear phenomena predicted by our model are observed experimentally. PMID:21198135

  6. Microvascular filtration in subjects with connective tissue disorders.

    PubMed Central

    Edwards, J C; Snaith, M L

    1984-01-01

    A simple non-invasive method for studying microvascular filtration in the non-articular tissues of the forearm is described. Rates of filtration under a standard hydrostatic pressure were measured in 20 normal female subjects and 44 female subjects with connective tissue disorders. An increased mean filtration rate was found in 14 subjects with rheumatoid arthritis. In 20 subjects with systemic lupus erythematosus and 10 subjects with scleroderma no such generalised increase in filtration rates was seen, but isolated cases had very high filtration rates, suggesting a more heterogeneous physiological disturbance. Increased filtration was not associated with the presence of oedema. This confirms doubts raised by other workers about the importance of filtration in the genesis of clinical oedema. Images PMID:6476914

  7. Surgical variation of microvascular decompression for trigeminal neuralgia: A technical note and anatomical study

    PubMed Central

    da Silva, Otávio T.; de Almeida, César C.; Iglesio, Ricardo F.; de Navarro, Jessie M.; Teixeira, Manoel J.; Duarte, Kleber P.

    2016-01-01

    Background: In this article, the authors described their experience in microvascular decompression for trigeminal neuralgia. Methods: The microvascular decompression technique used in the authors’ institution is described in a step by step manner with some illustrative cases as well as a cadaver dissection to highlight the differences with other previously described techniques. Results: Since 2013, 107 patients were operated in the Neurosurgery Division of the University of São Paulo using the described technique, with a shorter operative time and avoiding cerebellar retractor compared with classic techniques. Conclusion: Our modified microvascular decompression technique for trigeminal neuralgia can be used with safety and efficiency for treating trigeminal neuralgia. PMID:27625893

  8. Peroxynitrite mediates testosterone-induced vasodilation of microvascular resistance vessels.

    PubMed

    Puttabyatappa, Yashoda; Stallone, John N; Ergul, Adviye; El-Remessy, Azza B; Kumar, Sanjiv; Black, Stephen; Johnson, Maribeth; Owen, Mary P; White, Richard E

    2013-04-01

    Our knowledge of how androgens influence the cardiovascular system is far from complete, and this lack of understanding is especially true of how androgens affect resistance vessels. Our aim was to identify the signaling mechanisms stimulated by testosterone (TES) in microvascular arteries and to understand how these mechanisms mediate TES-induced vasodilation. Mesenteric microvessels were isolated from male Sprague-Dawley rats. Tension studies demonstrated a rapid, concentration-dependent, vasodilatory response to TES that did not involve protein synthesis or aromatization to 17β-estradiol. Dichlorofluorescein fluorescence and nitrotyrosine immunoblot experiments indicated that TES stimulated peroxynitrite formation in microvessels, and functional studies demonstrated that TES-induced vasodilation was inhibited by scavenging peroxynitrite. As predicted, TES enhanced the production of both peroxynitrite precursors (i.e., superoxide and nitic oxide), and xanthine oxidase was identified as the likely source of TES-stimulated superoxide production. Functional and biochemical studies indicated that TES signaling involved activity of the phosphoinositide 3 (PI3) kinase-protein kinase B (Akt) cascade initiated by activation of the androgen receptor and culminated in enhanced production of cGMP and microvascular vasodilation. These findings, derived from a variety of analytical and functional approaches, provide evidence for a novel nongenomic signaling mechanism for androgen action in the microvasculature: TES-stimulated vasodilation mediated primarily by peroxynitrite formed from xanthine oxidase-generated superoxide and NO. This response was associated with activation of the PI3 kinase-Akt signaling cascade initiated by activation of the androgen receptor. We propose this mechanism could account for TES-stimulated cGMP production in microvessels and, ultimately, vasodilation. PMID:23318471

  9. Peroxynitrite Mediates Testosterone-Induced Vasodilation of Microvascular Resistance Vessels

    PubMed Central

    Puttabyatappa, Yashoda; Stallone, John N.; Ergul, Adviye; El-Remessy, Azza B.; Kumar, Sanjiv; Black, Stephen; Johnson, Maribeth; Owen, Mary P.

    2013-01-01

    Our knowledge of how androgens influence the cardiovascular system is far from complete, and this lack of understanding is especially true of how androgens affect resistance vessels. Our aim was to identify the signaling mechanisms stimulated by testosterone (TES) in microvascular arteries and to understand how these mechanisms mediate TES-induced vasodilation. Mesenteric microvessels were isolated from male Sprague-Dawley rats. Tension studies demonstrated a rapid, concentration-dependent, vasodilatory response to TES that did not involve protein synthesis or aromatization to 17β-estradiol. Dichlorofluorescein fluorescence and nitrotyrosine immunoblot experiments indicated that TES stimulated peroxynitrite formation in microvessels, and functional studies demonstrated that TES-induced vasodilation was inhibited by scavenging peroxynitrite. As predicted, TES enhanced the production of both peroxynitrite precursors (i.e., superoxide and nitic oxide), and xanthine oxidase was identified as the likely source of TES-stimulated superoxide production. Functional and biochemical studies indicated that TES signaling involved activity of the phosphoinositide 3 (PI3) kinase-protein kinase B (Akt) cascade initiated by activation of the androgen receptor and culminated in enhanced production of cGMP and microvascular vasodilation. These findings, derived from a variety of analytical and functional approaches, provide evidence for a novel nongenomic signaling mechanism for androgen action in the microvasculature: TES-stimulated vasodilation mediated primarily by peroxynitrite formed from xanthine oxidase-generated superoxide and NO. This response was associated with activation of the PI3 kinase-Akt signaling cascade initiated by activation of the androgen receptor. We propose this mechanism could account for TES-stimulated cGMP production in microvessels and, ultimately, vasodilation. PMID:23318471

  10. Changes in retinal microvascular diameter in patients with diabetes

    PubMed Central

    da Silva, Andréa Vasconcellos Batista; Gouvea, Sonia Alves; da Silva, Aurélio Paulo Batista; Bortolon, Saulo; Rodrigues, Anabel Nunes; Abreu, Glaucia Rodrigues; Herkenhoff, Fernando Luiz

    2015-01-01

    Background and objectives Diabetic retinopathy is the main microvascular complication in diabetes mellitus and needs to be diagnosed early to prevent severe sight-threatening retinopathy. The purpose of this study was to quantify the retinal microvasculature pattern and analyze the influence of blood glucose level and the duration of diabetes mellitus on the retinal microvasculature. Methods Two groups were analyzed: patients with diabetes (N=26) and patients without diabetes, ie, controls (N=26). A quantitative semiautomated method analyzed retinal microvasculature. The diameters of arterioles and venules were measured. The total numbers of arterioles and venules were counted. The ratio of arteriole diameter to venule diameter was calculated. The retinal microvasculature pattern was related to clinical and biochemical parameters. Results Patients with diabetes exhibited larger venule diameters in the upper temporal quadrant of the retina compared to the lower temporal quadrant (124.85±38.03 µm vs 102.92±15.69 µm; P<0.01). Patients with diabetes for 5 or more years had larger venule diameters in the upper temporal quadrant than patients without diabetes (141.62±44.44 vs 112.58±32.11 µm; P<0.05). The degree of venodilation in the upper temporal quadrant was positively correlated with blood glucose level and the estimated duration of diabetes mellitus. Interpretation and conclusion The employed quantitative method demonstrated that patients with diabetes exhibited venule dilation in the upper temporal quadrant, and the duration of diabetes mellitus was positively correlated with blood glucose level. Therefore, the early assessment of retinal microvascular changes is possible prior to the onset of diabetic retinopathy. PMID:26345217

  11. Evaluation of Microvascular Perfusion and Resuscitation after Severe Injury.

    PubMed

    Lee, Yann-Leei L; Simmons, Jon D; Gillespie, Mark N; Alvarez, Diego F; Gonzalez, Richard P; Brevard, Sidney B; Frotan, Mohammad A; Schneider, Andrew M; Richards, William O

    2015-12-01

    Achieving adequate perfusion is a key goal of treatment in severe trauma; however, tissue perfusion has classically been measured by indirect means. Direct visualization of capillary flow has been applied in sepsis, but application of this technology to the trauma population has been limited. The purpose of this investigation was to compare the efficacy of standard indirect measures of perfusion to direct imaging of the sublingual microcirculatory flow during trauma resuscitation. Patients with injury severity scores >15 were serially examined using a handheld sidestream dark-field video microscope. In addition, measurements were also made from healthy volunteers. The De Backer score, a morphometric capillary density score, and total vessel density (TVD) as cumulative vessel area within the image, were calculated using Automated Vascular Analysis (AVA3.0) software. These indices were compared against clinical and laboratory parameters of organ function and systemic metabolic status as well as mortality. Twenty severely injured patients had lower TVD (X = 14.6 ± 0.22 vs 17.66 ± 0.51) and De Backer scores (X = 9.62 ± 0.16 vs 11.55 ± 0.37) compared with healthy controls. These scores best correlated with serum lactate (TVD R(2) = 0.525, De Backer R(2) = 0.576, P < 0.05). Mean arterial pressure, heart rate, oxygen saturation, pH, bicarbonate, base deficit, hematocrit, and coagulation parameters correlated poorly with both TVD and De Backer score. Direct measurement of sublingual microvascular perfusion is technically feasible in trauma patients, and seems to provide real-time assessment of microcirculatory perfusion. This study suggests that in severe trauma, many indirect measurements of perfusion do not correlate with microvascular perfusion. However, visualized perfusion deficiencies do reflect a shift toward anaerobic metabolism. PMID:26736167

  12. Microvascular dysfunction in schizophrenia: a case–control study

    PubMed Central

    Vetter, Martin W; Martin, Billie-Jean; Fung, Marinda; Pajevic, Milada; Anderson, Todd J; Raedler, Thomas J

    2015-01-01

    Background: Schizophrenia is a mental illness associated with cardiovascular disease at a younger age than in the general population. Endothelial dysfunction has predictive value for future cardiovascular events; however, the impact of a diagnosis of schizophrenia on this marker is unknown. Aims: We tested the hypothesis that subjects with schizophrenia have impaired endothelial function. Methods: A total of 102 subjects (34.5±7.5 years) participated in this study. This sample consisted of 51 subjects with a diagnosis of schizophrenia and 51 healthy subjects, who were matched for age (P=0.442), sex (P>0.999), and smoking status (P=0.842). Peripheral artery microvascular and conduit vessel endothelial function was measured using hyperemic velocity time integral (VTI), pulse arterial tonometry (PAT), and flow-mediated dilation (FMD). Results: Significantly lower values of VTI were noted in subjects with schizophrenia (104.9±33.0 vs. 129.1±33.8 cm, P<0.001), whereas FMD (P=0.933) and PAT (P=0.862) did not differ between the two groups. A multivariable-linear-regression analysis, built on data from univariate and partial correlations, showed that only schizophrenia, sex, lipid-lowering medications, antihypertensive medications, and low-density lipoprotein (LDL)-cholesterol were predictive of attenuated VTI, whereas age, ethnicity, family history of cardiovascular disease, smoking status, systolic blood pressure, waist circumference, HDL-cholesterol, triglycerides, C-reactive protein, and homeostatic model assessment-insulin resistance (HOMA-IR), antidiabetic medications, antidepressant medications, mood stabilizers, benzodiazepines, and anticholinergic medications did not predict VTI in this model (adjusted R 2=0.248). Conclusions: Our findings suggest that a diagnosis of schizophrenia is associated with impaired microvascular function as indicated by lower values of VTI, irrespective of many other clinical characteristics. It might be an early indicator of

  13. Oxidative stress modulates nucleobase transport in microvascular endothelial cells.

    PubMed

    Bone, Derek B J; Antic, Milica; Vilas, Gonzalo; Hammond, James R

    2014-09-01

    Purine nucleosides and nucleobases play key roles in the physiological response to vascular ischemia/reperfusion events. The intra- and extracellular concentrations of these compounds are controlled, in part, by equilibrative nucleoside transporter subtype 1 (ENT1; SLC29A1) and by equilibrative nucleobase transporter subtype 1 (ENBT1). These transporters are expressed at the membranes of numerous cell types including microvascular endothelial cells. We studied the impact of reactive oxygen species on the function of ENT1 and ENBT1 in primary (CMVEC) and immortalized (HMEC-1) human microvascular endothelial cells. Both cell types displayed similar transporter expression profiles, with the majority (>90%) of 2-chloro[(3)H]adenosine (nucleoside) uptake mediated by ENT1 and [(3)H]hypoxanthine (nucleobase) uptake mediated by ENBT1. An in vitro mineral oil-overlay model of ischemia/reperfusion had no effect on ENT1 function, but significantly reduced ENBT1 Vmax in both cell types. This decrease in transport function was mimicked by the intracellular superoxide generator menadione and could be reversed by the superoxide dismutase mimetic MnTMPyP. In contrast, neither the extracellular peroxide donor TBHP nor the extracellular peroxynitrite donor 3-morpholinosydnonimine (SIN-1) affected ENBT1-mediated [(3)H]hypoxanthine uptake. SIN-1 did, however, enhance ENT1-mediated 2-chloro[(3)H]adenosine uptake. Our data establish HMEC-1 as an appropriate model for study of purine transport in CMVEC. Additionally, these data suggest that the generation of intracellular superoxide in ischemia/reperfusion leads to the down-regulation of ENBT1 function. Modification of purine transport by oxidant stress may contribute to ischemia/reperfusion induced vascular damage and should be considered in the development of therapeutic strategies. PMID:24976360

  14. Isolation of Primary Murine Brain Microvascular Endothelial Cells

    PubMed Central

    Ruck, Tobias; Bittner, Stefan; Epping, Lisa; Herrmann, Alexander M.; Meuth, Sven G.

    2014-01-01

    The blood-brain-barrier is ultrastructurally assembled by a monolayer of brain microvascular endothelial cells (BMEC) interconnected by a junctional complex of tight and adherens junctions. Together with other cell-types such as astrocytes or pericytes, they form the neurovascular unit (NVU), which specifically regulates the interchange of fluids, molecules and cells between the peripheral blood and the CNS. Through this complex and dynamic system BMECs are involved in various processes maintaining the homeostasis of the CNS. A dysfunction of the BBB is observed as an essential step in the pathogenesis of many severe CNS diseases. However, specific and targeted therapies are very limited, as the underlying mechanisms are still far from being understood. Animal and in vitro models have been extensively used to gain in-depth understanding of complex physiological and pathophysiological processes. By reduction and simplification it is possible to focus the investigation on the subject of interest and to exclude a variety of confounding factors. However, comparability and transferability are also reduced in model systems, which have to be taken into account for evaluation. The most common animal models are based on mice, among other reasons, mainly due to the constantly increasing possibilities of methodology. In vitro studies of isolated murine BMECs might enable an in-depth analysis of their properties and of the blood-brain-barrier under physiological and pathophysiological conditions. Further insights into the complex mechanisms at the BBB potentially provide the basis for new therapeutic strategies. This protocol describes a method to isolate primary murine microvascular endothelial cells by a sequence of physical and chemical purification steps. Special considerations for purity and cultivation of MBMECs as well as quality control, potential applications and limitations are discussed. PMID:25489873

  15. Effects of tracheal airway occlusion on hyoid muscle length and upper airway volume.

    PubMed

    van Lunteren, E; Haxhiu, M A; Cherniack, N S

    1989-12-01

    Complex relationships exist among electromyograms (EMGs) of the upper airway muscles, respective changes in muscle length, and upper airway volume. To test the effects of preventing lung inflation on these relationships, recordings were made of EMGs and length changes of the geniohyoid (GH) and sternohyoid (SH) muscles as well as of tidal changes in upper airway volume in eight anesthetized cats. During resting breathing, tracheal airway occlusion tended to increase the inspiratory lengthening of GH and SH. In response to progressive hypercapnia, the GH eventually shortened during inspiration in all animals; the extent of muscle shortening was minimally augmented by airway occlusion despite substantial increases in EMGs. SH lengthened during inspiration in six of eight animals under hypercapnic conditions, and in these cats lengthening was greater during airway occlusion even though EMGs increased. Despite the above effects on SH and GH length, upper airway tidal volume was increased significantly by tracheal occlusion under hypercapnic conditions. These data suggest that the thoracic and upper airway muscle reflex effects of preventing lung inflation during inspiration act antagonistically on hyoid muscle length, but, because of the mechanical arrangement of the hyoid muscles relative to the airway and thorax, they act agonistically to augment tidal changes in upper airway volume. The augmentation of upper airway tidal volume may occur in part as a result of the effects of thoracic movements being passively transmitted through the hyoid muscles. PMID:2606835

  16. Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma

    PubMed Central

    An, S.S.; Bai, T.R.; Bates, J.H.T.; Black, J.L.; Brown, R.H.; Brusasco, V.; Chitano, P.; Deng, L.; Dowell, M.; Eidelman, D.H.; Fabry, B.; Fairbank, N.J.; Ford, L.E.; Fredberg, J.J.; Gerthoffer, W.T.; Gilbert, S.H.; Gosens, R.; Gunst, S.J.; Halayko, A.J.; Ingram, R.H.; Irvin, C.G.; James, A.L.; Janssen, L.J.; King, G.G.; Knight, D.A.; Lauzon, A.M.; Lakser, O.J.; Ludwig, M.S.; Lutchen, K.R.; Maksym, G.N.; Martin, J.G.; Mauad, T.; McParland, B.E.; Mijailovich, S.M.; Mitchell, H.W.; Mitchell, R.W.; Mitzner, W.; Murphy, T.M.; Paré, P.D.; Pellegrino, R.; Sanderson, M.J.; Schellenberg, R.R.; Seow, C.Y.; Silveira, P.S.P.; Smith, P.G.; Solway, J.; Stephens, N.L.; Sterk, P.J.; Stewart, A.G.; Tang, D.D.; Tepper, R.S.; Tran, T.; Wang, L.

    2008-01-01

    Excessive airway obstruction is the cause of symptoms and abnormal lung function in asthma. As airway smooth muscle (ASM) is the effecter controlling airway calibre, it is suspected that dysfunction of ASM contributes to the pathophysiology of asthma. However, the precise role of ASM in the series of events leading to asthmatic symptoms is not clear. It is not certain whether, in asthma, there is a change in the intrinsic properties of ASM, a change in the structure and mechanical properties of the noncontractile components of the airway wall, or a change in the interdependence of the airway wall with the surrounding lung parenchyma. All these potential changes could result from acute or chronic airway inflammation and associated tissue repair and remodelling. Anti-inflammatory therapy, however, does not “cure” asthma, and airway hyperresponsiveness can persist in asthmatics, even in the absence of airway inflammation. This is perhaps because the therapy does not directly address a fundamental abnormality of asthma, that of exaggerated airway narrowing due to excessive shortening of ASM. In the present study, a central role for airway smooth muscle in the pathogenesis of airway hyperresponsiveness in asthma is explored. PMID:17470619

  17. EVA Suit Microbial Leakage Investigation Project

    NASA Technical Reports Server (NTRS)

    Falker, Jay; Baker, Christopher; Clayton, Ronald; Rucker, Michelle

    2016-01-01

    The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during simulated planetary exploration activities. Data will be released to the planetary protection and science communities, and advanced EVA system designers. In the best case scenario, we will discover that very little microbial contamination leaks from our current or prototype suit designs, in the worst case scenario, we will identify leak paths, learn more about what affects leakage--and we'll have a new, flight-certified swab tool for our EVA toolbox.

  18. Athletic Trainers' Knowledge Regarding Airway Adjuncts

    ERIC Educational Resources Information Center

    Edler, Jessica R.; Eberman, Lindsey E.; Kahanov, Leamor; Roman, Christopher; Mata, Heather Lynne

    2015-01-01

    Context: Research suggests that knowledge gaps regarding the appropriate use of airway adjuncts exist among various health care practitioners, and that knowledge is especially limited within athletic training. Objective: To determine the relationship between perceived knowledge (PK) and actual knowledge (AK) of airway adjunct use and the…

  19. SUBCHRONIC ENDOTOXIN INHALATION CAUSES PERSISTENT AIRWAY DISEASE

    EPA Science Inventory

    ABSTRACT

    The endotoxin component of organic dusts causes acute reversible airflow obstruction and airway inflammation. To test the hypothesis that endotoxin alone causes airway remodeling, we have compared the response of two inbred mouse strains to subchronic endotoxin ...

  20. Airway and Extracellular Matrix Mechanics in COPD

    PubMed Central

    Bidan, Cécile M.; Veldsink, Annemiek C.; Meurs, Herman; Gosens, Reinoud

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases worldwide, and is characterized by airflow obstruction that is not fully reversible with treatment. Even though airflow obstruction is caused by airway smooth muscle contraction, the extent of airway narrowing depends on a range of other structural and functional determinants that impact on active and passive tissue mechanics. Cells and extracellular matrix in the airway and parenchymal compartments respond both passively and actively to the mechanical stimulation induced by smooth muscle contraction. In this review, we summarize the factors that regulate airway narrowing and provide insight into the relative contributions of different constituents of the extracellular matrix and their biomechanical impact on airway obstruction. We then review the changes in extracellular matrix composition in the airway and parenchymal compartments at different stages of COPD, and finally discuss how these changes impact airway narrowing and the development of airway hyperresponsiveness. Finally, we position these data in the context of therapeutic research focused on defective tissue repair. As a conclusion, we propose that future works should primarily target mild or early COPD, prior to the widespread structural changes in the alveolar compartment that are more characteristic of severe COPD. PMID:26696894

  1. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  2. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway....

  3. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  4. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway....

  5. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  6. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  7. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway....

  8. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  9. Trefoil factor-2 reverses airway remodeling changes in allergic airways disease.

    PubMed

    Royce, Simon G; Lim, Clarice; Muljadi, Ruth C; Samuel, Chrishan S; Ververis, Katherine; Karagiannis, Tom C; Giraud, Andrew S; Tang, Mimi L K

    2013-01-01

    Trefoil factor 2 (TFF2) is a small peptide with an important role in mucosal repair. TFF2 is up-regulated in asthma, suggesting a role in asthma pathogenesis. Given its known biological role in promoting epithelial repair, TFF2 might be expected to exert a protective function in limiting the progression of airway remodeling in asthma. The contribution of TFF2 to airway remodeling in asthma was investigated by examining the expression of TFF2 in the airway and lung, and evaluating the effects of recombinant TFF2 treatment on established airway remodeling in a murine model of chronic allergic airways disease (AAD). BALB/c mice were sensitized and challenged with ovalbumin (OVA) or saline for 9 weeks, whereas mice with established OVA-induced AAD were treated with TFF2 or vehicle control (intranasally for 14 d). Effects on airway remodeling, airway inflammation, and airway hyperresponsiveness were then assessed, whereas TFF2 expression was determined by immunohistochemistry. TFF2 expression was significantly increased in the airways of mice with AAD, compared with expression levels in control mice. TFF2 treatment resulted in reduced epithelial thickening, subepithelial collagen deposition, goblet-cell metaplasia, bronchial epithelium apoptosis, and airway hyperresponsiveness (all P < 0.05, versus vehicle control), but TFF2 treatment did not influence airway inflammation. The increased expression of endogenous TFF2 in response to chronic allergic inflammation is insufficient to prevent the progression of airway inflammation and remodeling in a murine model of chronic AAD. However, exogenous TFF2 treatment is effective in reversing aspects of established airway remodeling. TFF2 has potential as a novel treatment for airway remodeling in asthma. PMID:22652198

  10. Difficult Airway Response Team: A Novel Quality Improvement Program for Managing Hospital-Wide Airway Emergencies

    PubMed Central

    Mark, Lynette J.; Herzer, Kurt R.; Cover, Renee; Pandian, Vinciya; Bhatti, Nasir I.; Berkow, Lauren C.; Haut, Elliott R.; Hillel, Alexander T.; Miller, Christina R.; Feller-Kopman, David J.; Schiavi, Adam J.; Xie, Yanjun J.; Lim, Christine; Holzmueller, Christine; Ahmad, Mueen; Thomas, Pradeep; Flint, Paul W.; Mirski, Marek A.

    2015-01-01

    Background Difficult airway cases can quickly become emergencies, increasing the risk of life-threatening complications or death. Emergency airway management outside the operating room is particularly challenging. Methods We developed a quality improvement program—the Difficult Airway Response Team (DART)—to improve emergency airway management outside the operating room. DART was implemented by a team of anesthesiologists, otolaryngologists, trauma surgeons, emergency medicine physicians, and risk managers in 2005 at The Johns Hopkins Hospital in Baltimore, Maryland. The DART program had three core components: operations, safety, and education. The operations component focused on developing a multidisciplinary difficult airway response team, standardizing the emergency response process, and deploying difficult airway equipment carts throughout the hospital. The safety component focused on real-time monitoring of DART activations and learning from past DART events to continuously improve system-level performance. This objective entailed monitoring the paging system, reporting difficult airway events and DART activations to a web-based registry, and using in situ simulations to identify and mitigate defects in the emergency airway management process. The educational component included development of a multispecialty difficult airway curriculum encompassing case-based lectures, simulation, and team building/communication to ensure consistency of care. Educational materials were also developed for non-DART staff and patients to inform them about the needs of patients with difficult airways and ensure continuity of care with other providers after discharge. Results Between July 2008 and June 2013, DART managed 360 adult difficult airway events comprising 8% of all code activations. Predisposing patient factors included body mass index > 40, history of head and neck tumor, prior difficult intubation, cervical spine injury, airway edema, airway bleeding, and previous

  11. Airway tissue engineering for congenital laryngotracheal disease.

    PubMed

    Maughan, Elizabeth; Lesage, Flore; Butler, Colin R; Hynds, Robert E; Hewitt, Richard; Janes, Sam M; Deprest, Jan A; Coppi, Paolo De

    2016-06-01

    Regenerative medicine offers hope of a sustainable solution for severe airway disease by the creation of functional, immunocompatible organ replacements. When considering fetuses and newborns, there is a specific spectrum of airway pathologies that could benefit from cell therapy and tissue engineering applications. While hypoplastic lungs associated with congenital diaphragmatic hernia (CDH) could benefit from cellular based treatments aimed at ameliorating lung function, patients with upper airway obstruction could take advantage from a de novo tissue engineering approach. Moreover, the international acceptance of the EXIT procedure as a means of securing the precarious neonatal airway, together with the advent of fetal surgery as a method of heading off postnatal co-morbidities, offers the revolutionary possibility of extending the clinical indication for tissue-engineered airway transplantation to infants affected by diverse severe congenital laryngotracheal malformations. This article outlines the necessary basic components for regenerative medicine solutions in this potential clinical niche. PMID:27301606

  12. Regulation of human airway surface liquid.

    PubMed

    Widdicombe, J H; Widdicombe, J G

    1995-01-01

    Human airways are lined with a film of liquid from 5-100 microns in depth, consisting of a periciliary sol around and a mucous gel above the cilia. Microscopical studies have shown the sol to be invariably the same depth as the length of the cilia, and we discuss possible reasons for this. The composition and sources of the airway surface liquid are also described. In addition the forces regulating its volume are analyzed. Several airway diseases are characterised by dramatic changes in the volume and composition of airway liquid. We review recent research suggesting that the accumulation of airway mucous secretions in cystic fibrosis is caused by alterations in active transport of ions and water across both the surface and gland epithelia. PMID:7740210

  13. Awake Craniotomy: A New Airway Approach.

    PubMed

    Sivasankar, Chitra; Schlichter, Rolf A; Baranov, Dimitry; Kofke, W Andrew

    2016-02-01

    Awake craniotomies have been performed regularly at the University of Pennsylvania since 2004. Varying approaches to airway management are described for this procedure, including intubation with an endotracheal tube and use of a laryngeal mask airway, simple facemask, or nasal cannula. In this case series, we describe the successful use (i.e., no need for endotracheal intubation related to inadequate gas exchange) of bilateral nasopharyngeal airways in 90 patients undergoing awake craniotomies. The use of nasopharyngeal airways can ease the transition between the asleep and awake phases of the craniotomy without the need to stimulate the airway. Our purpose was to describe our experience and report adverse events related to this technique. PMID:26579845

  14. Airway fires during surgery: Management and prevention

    PubMed Central

    Akhtar, Navaid; Ansar, Farrukh; Baig, Mirza Shahzad; Abbas, Akbar

    2016-01-01

    Airway fires pose a serious risk to surgical patients. Fires during surgery have been reported for many years with flammable anesthetic agents being the main culprits in the past. Association of airway fires with laser surgery is well-recognized, but there are reports of endotracheal tube fires ignited by electrocautery during pharyngeal surgery or tracheostomy or both. This uncommon complication has potentially grave consequences. While airway fires are relatively uncommon occurrences, they are very serious and can often be fatal. Success in preventing such events requires a thorough understanding of the components leading to a fire (fuel, oxidizer, and ignition source), as well as good communication between all members present to appropriately manage the fire and ensure patient safety. We present a case of fire in the airway during routine adenotonsillectomy. We will review the causes, preventive measures, and brief management for airway fires. PMID:27006554

  15. Anaesthetic management of acute airway obstruction

    PubMed Central

    Wong, Patrick; Wong, Jolin; Mok, May Un Sam

    2016-01-01

    The acutely obstructed airway is a medical emergency that can potentially result in serious morbidity and mortality. Apart from the latest advancements in anaesthetic techniques, equipment and drugs, publications relevant to our topic, including the United Kingdom’s 4th National Audit Project on major airway complications in 2011 and the updated American Society of Anesthesiologists’ difficult airway algorithm of 2013, have recently been published. The former contained many reports of adverse events associated with the management of acute airway obstruction. By analysing the data and concepts from these two publications, this review article provides an update on management techniques for the acutely obstructed airway. We discuss the principles and factors relevant to the decision-making process in formulating a logical management plan. PMID:26996162

  16. Anaesthetic management of acute airway obstruction.

    PubMed

    Wong, Patrick; Wong, Jolin; Mok, May Un Sam

    2016-03-01

    The acutely obstructed airway is a medical emergency that can potentially result in serious morbidity and mortality. Apart from the latest advancements in anaesthetic techniques, equipment and drugs, publications relevant to our topic, including the United Kingdom's 4th National Audit Project on major airway complications in 2011 and the updated American Society of Anesthesiologists' difficult airway algorithm of 2013, have recently been published. The former contained many reports of adverse events associated with the management of acute airway obstruction. By analysing the data and concepts from these two publications, this review article provides an update on management techniques for the acutely obstructed airway. We discuss the principles and factors relevant to the decision-making process in formulating a logical management plan. PMID:26996162

  17. Predicting Envelope Leakage in Attached Dwellings (Fact Sheet)

    SciTech Connect

    Not Available

    2013-11-01

    The most common method of measuring air leakage is to perform single (or solo) blower door pressurization and/or depressurization test. In detached housing, the single blower door test measures leakage to the outside. In attached housing, however, this "solo" test method measures both air leakage to the outside and air leakage between adjacent units through common surfaces. Although minimizing leakage to neighboring units is highly recommended to avoid indoor air quality issues between units, reduce pressure differentials between units, and control stack effect, the energy benefits of air sealing can be significantly overpredicted if the solo air leakage number is used in the energy analysis. Guarded blower door testing is more appropriate for isolating and measuring leakage to the outside in attached housing. This method uses multiple blower doors to depressurize adjacent spaces to the same level as the unit being tested. Maintaining a neutral pressure across common walls, ceilings, and floors acts as a "guard" against air leakage between units. The resulting measured air leakage in the test unit is only air leakage to the outside. Although preferred for assessing energy impacts, the challenges of performing guarded testing can be daunting.

  18. Geologic Carbon Sequestration: Leakage Potential and Policy Implications

    NASA Astrophysics Data System (ADS)

    Bielicki, J. M.; Peters, C. A.; Fitts, J. P.; Wilson, E. J.

    2014-12-01

    The geologic reservoirs that could be used for long-term sequestration of carbon dioxide (CO2) may have natural or manmade pathways that allow injected CO2, or the brine it displaces, to leak into overlying formations. Using a basin-scale leakage estimation model, we investigated the geophysical parameters that govern this leakage, and the resulting accumulations of leaked fluids in overlying formations. The results are discussed in the context of two polices aimed at governing long-term sequestration and protecting groundwater: the U.S. DOE guideline for storage permanence and the U.S. EPA UIC Program Class VI Rule. For a case study of CO2 injection into the Mt. Simon sandstone in the Michigan sedimentary basin, we showed that (1) the U.S. DOE guideline would allow for more leakage from larger injection projects than for smaller ones; (2) leakage amounts are determined mostly by well leakage permeability rather than by variation in formation permeabilities; (3) numerous leaking wells with anomalously high leakage permeabilities are necessary in order to achieve substantial leakage rates; (4) leakage can reach potable groundwater but intervening stratigraphic traps reduce the amount to be multiple orders of magnitude less than the leakage out of the reservoir, and (5) this leakage can reduce the Area of Review that is defined by the U.S. EPA as the area within which leakage can threaten groundwater. In summary, leakage that exceeds the U.S. DOE storage permanence goal would occur only under extreme conditions, the amount that reaches shallow potable groundwater may be inconsequential from a pollution standpoint, and leakage may be beneficial. Future federal policies should be harmonized to achieve the dual goals of protecting groundwater while allowing for adaptive management that incorporates uncertainties and imperfections inherent in geologic reservoirs.

  19. Genetic Studies on Diabetic Microvascular Complications: Focusing on Genome-Wide Association Studies

    PubMed Central

    Kwak, Soo Heon

    2015-01-01

    Diabetes is a common metabolic disorder with a worldwide prevalence of 8.3% and is the leading cause of visual loss, end-stage renal disease and amputation. Recently, genome-wide association studies (GWASs) have identified genetic risk factors for diabetic microvascular complications of retinopathy, nephropathy, and neuropathy. We summarized the recent findings of GWASs on diabetic microvascular complications and highlighted the challenges and our opinion on future directives. Five GWASs were conducted on diabetic retinopathy, nine on nephropathy, and one on neuropathic pain. The majority of recent GWASs were underpowered and heterogeneous in terms of study design, inclusion criteria and phenotype definition. Therefore, few reached the genome-wide significance threshold and the findings were inconsistent across the studies. Recent GWASs provided novel information on genetic risk factors and the possible pathophysiology of diabetic microvascular complications. However, further collaborative efforts to standardize phenotype definition and increase sample size are necessary for successful genetic studies on diabetic microvascular complications. PMID:26194074

  20. Adipose tissue-derived microvascular fragments: natural vascularization units for regenerative medicine.

    PubMed

    Laschke, Matthias W; Menger, Michael D

    2015-08-01

    The establishment of effective vascularization is a key challenge in regenerative medicine. To achieve this, the transplantation of native microvascular fragments has emerged as a promising novel concept. Microvascular fragments can be isolated in large amounts from fat tissue, exhibit a high angiogenic activity, and represent a rich source of mesenchymal stem cells. Originally, microvascular fragments have been used in angiogenesis research for the isolation of capillary endothelium and for functional sprouting assays. More recent studies have demonstrated that they rapidly develop into microvascular networks after transfer into tissue defects. Moreover, they are suitable for the generation of prevascularized tissue constructs. Hence, a wide range of future medical applications may benefit from the use of these natural vascularization units. PMID:26137863

  1. Investigating the geometry of pig airways using computed tomography

    NASA Astrophysics Data System (ADS)

    Mansy, Hansen A.; Azad, Md Khurshidul; McMurray, Brandon; Henry, Brian; Royston, Thomas J.; Sandler, Richard H.

    2015-03-01

    Numerical modeling of sound propagation in the airways requires accurate knowledge of the airway geometry. These models are often validated using human and animal experiments. While many studies documented the geometric details of the human airways, information about the geometry of pig airways is scarcer. In addition, the morphology of animal airways can be significantly different from that of humans. The objective of this study is to measure the airway diameter, length and bifurcation angles in domestic pigs using computed tomography. After imaging the lungs of 3 pigs, segmentation software tools were used to extract the geometry of the airway lumen. The airway dimensions were then measured from the resulting 3 D models for the first 10 airway generations. Results showed that the size and morphology of the airways of different animals were similar. The measured airway dimensions were compared with those of the human airways. While the trachea diameter was found to be comparable to the adult human, the diameter, length and branching angles of other airways were noticeably different from that of humans. For example, pigs consistently had an early airway branching from the trachea that feeds the superior (top) right lung lobe proximal to the carina. This branch is absent in the human airways. These results suggested that the human geometry may not be a good approximation of the pig airways and may contribute to increasing the errors when the human airway geometric values are used in computational models of the pig chest.

  2. Puberty and Upper Airway Dynamics During Sleep

    PubMed Central

    Bandla, Preetam; Huang, Jingtao; Karamessinis, Laurie; Kelly, Andrea; Pepe, Michelle; Samuel, John; Brooks, Lee; Mason, Thornton. A.; Gallagher, Paul R.; Marcus, Carole L.

    2008-01-01

    Study Objectives: The upper airway compensatory response to subatmospheric pressure loading declines with age. The epidemiology of obstructive sleep apnea suggests that sex hormones play a role in modulating upper airway function. Sex hormones increase gradually during puberty, from minimally detectable to adult levels. We hypothesized that the upper airway response to subatmospheric pressure loading decreased with increasing pubertal Tanner stage in males but remained stable during puberty in females. Design: Upper airway dynamic function during sleep was measured over the course of puberty. Participants: Normal subjects of Tanner stages 1 to 5. Measurements: During sleep, maximal inspiratory airflow was measured while varying the level of nasal pressure. The slope of the upstream pressure-flow relationship (SPF) was measured. Results: The SPF correlated with age and Tanner stage. However, the relationship with Tanner stage became nonsignificant when the correlation due to the mutual association with age was removed. Females had a lower SPF than males. Conclusions: In both sexes, the upper airway compensatory response to subatmospheric pressure loading decreased with age rather than degree of pubertal development. Thus, changes in sex hormones are unlikely to be a primary modulator of upper airway function during the transition from childhood to adulthood. Although further studies of upper airway structural changes during puberty are needed, we speculate that the changes in upper airway function with age are due to the depressant effect of age on ventilatory drive, leading to a decrease in upper airway neuromotor tone. Citation: Bandla P; Huang J; Karamessinis L; Kelly A; Pepe M; Samuel J; Brooks L; Mason TA; Gallagher PR; Marcus CL. Puberty and Upper Airway Dynamics During Sleep. SLEEP 2008;31(4):534-541. PMID:18457241

  3. Intrathoracic airway measurement: ex-vivo validation

    NASA Astrophysics Data System (ADS)

    Reinhardt, Joseph M.; Raab, Stephen A.; D'Souza, Neil D.; Hoffman, Eric A.

    1997-05-01

    High-resolution x-ray CT (HRCT) provides detailed images of the lungs and bronchial tree. HRCT-based imaging and quantitation of peripheral bronchial airway geometry provides a valuable tool for assessing regional airway physiology. Such measurements have been sued to address physiological questions related to the mechanics of airway collapse in sleep apnea, the measurement of airway response to broncho-constriction agents, and to evaluate and track the progression of disease affecting the airways, such as asthma and cystic fibrosis. Significant attention has been paid to the measurements of extra- and intra-thoracic airways in 2D sections from volumetric x-ray CT. A variety of manual and semi-automatic techniques have been proposed for airway geometry measurement, including the use of standardized display window and level settings for caliper measurements, methods based on manual or semi-automatic border tracing, and more objective, quantitative approaches such as the use of the 'half-max' criteria. A recently proposed measurements technique uses a model-based deconvolution to estimate the location of the inner and outer airway walls. Validation using a plexiglass phantom indicates that the model-based method is more accurate than the half-max approach for thin-walled structures. In vivo validation of these airway measurement techniques is difficult because of the problems in identifying a reliable measurement 'gold standard.' In this paper we report on ex vivo validation of the half-max and model-based methods using an excised pig lung. The lung is sliced into thin sections of tissue and scanned using an electron beam CT scanner. Airways of interest are measured from the CT images, and also measured with using a microscope and micrometer to obtain a measurement gold standard. The result show no significant difference between the model-based measurements and the gold standard; while the half-max estimates exhibited a measurement bias and were significantly

  4. EM information leakage from display unit and visual inspection for its leakage source

    NASA Astrophysics Data System (ADS)

    Watanabe, Takashi; Sako, Hiroshi

    2013-05-01

    Display unit emits a small amount of electromagnetic wave. Although it is weak enough to prevent interference with human body, information leaks through it. This paper presents an experiment on exploring the leakage source by visually inspecting the screen images reconstructed from captured electromagnetic waves. Additionally, some countermeasures are investigated to avoid the problem.

  5. Apical leakage of four endodontic sealers.

    PubMed

    Pommel, Ludovic; About, Imad; Pashley, David; Camps, Jean

    2003-03-01

    The purpose of this study was to evaluate the sealing properties of four root canal sealers. Forty-eight maxillary central incisors were instrumented with Profile rotary instruments. They were randomly divided into four groups (n = 12) and filled using lateral condensation with one of the four sealers: Sealapex, Pulp Canal Sealer, AH 26, and Ketac-Endo. The apical leakage was measured with a fluid filtration method and expressed as L s(-1) KPa(-1). The teeth filled with Sealapex displayed a higher apical leakage (8.42 +/- 4.2 10(-11) L s(-1) KPa(-1)) than those filled with AH 26 (2.10 +/- 1.39 10(-11) L s(-1) KPa(-1)), Pulp Canal Sealer (0.17 +/- 0.09 10(-11) L s(-1) KPa(-1)) or Ketac-Endo (0.32 +/- 0.24 10(-1) L s(-1) KPa(-1)) (p < 0.01). No statistically significant difference was found among AH 26, Pulp Canal Sealer, and Ketac-Endo. No correlation was found between the sealing efficiency of the four sealers and their adhesive properties recorded in a previous study. PMID:12669883

  6. Improved myocardial perfusion after transmyocardial laser revascularization in a patient with microvascular coronary artery disease

    PubMed Central

    Mayeda, Guy S; Burstein, Steven; Gheissari, Ali; French, William J; Thomas, Joseph; Kloner, Robert A

    2014-01-01

    We report the case of a 59-year-old woman who presented with symptoms of angina that was refractory to medical management. Although her cardiac catheterization revealed microvascular coronary artery disease, her symptoms were refractory to optimal medical management that included ranolazine. After undergoing transmyocardial revascularization, her myocardial ischemia completely resolved and her symptoms dramatically improved. This case suggests that combination of ranolazine and transmyocardial revascularization can be applied to patients with microvascular coronary artery disease. PMID:27489642

  7. Interactions of the Gasotransmitters Contribute to Microvascular Tone (Dys)regulation in the Preterm Neonate

    PubMed Central

    Dyson, Rebecca M.; Palliser, Hannah K.; Latter, Joanna L.; Kelly, Megan A.; Chwatko, Grazyna; Glowacki, Rafal; Wright, Ian M. R.

    2015-01-01

    Background & Aims Hydrogen sulphide (H2S), nitric oxide (NO), and carbon monoxide (CO) are involved in transitional microvascular tone dysregulation in the preterm infant; however there is conflicting evidence on the interaction of these gasotransmitters, and their overall contribution to the microcirculation in newborns is not known. The aim of this study was to measure the levels of all 3 gasotransmitters, characterise their interrelationships and elucidate their combined effects on microvascular blood flow. Methods 90 preterm neonates were studied at 24h postnatal age. Microvascular studies were performed by laser Doppler. Arterial COHb levels (a measure of CO) were determined through co-oximetry. NO was measured as nitrate and nitrite in urine. H2S was measured as thiosulphate by liquid chromatography. Relationships between levels of the gasotransmitters and microvascular blood flow were assessed through partial correlation controlling for the influence of gestational age. Structural equation modelling was used to examine the combination of these effects on microvascular blood flow and derive a theoretical model of their interactions. Results No relationship was observed between NO and CO (p = 0.18, r = 0.18). A positive relationship between NO and H2S (p = 0.008, r = 0.28) and an inverse relationship between CO and H2S (p = 0.01, r = -0.33) exists. Structural equation modelling was used to examine the combination of these effects on microvascular blood flow. The model with the best fit is presented. Conclusions The relationships between NO and H2S, and CO and H2S may be of importance in the preterm newborn, particularly as NO levels in males are associated with higher H2S levels and higher microvascular blood flow and CO in females appears to convey protection against vascular dysregulation. Here we present a theoretical model of these interactions and their overall effects on microvascular flow in the preterm newborn, upon which future mechanistic studies may

  8. Microvascular anastomoses for bone grafts in the treatment of massive defects in bone.

    PubMed

    Weiland, A J; Daniel, R K

    1979-01-01

    Six patients with large defects in bone are described in whom we performed microvascular anastomoses of grafted fibular vessels (arteries and veins) to vessels in the recipient site. Two other patients, with massive loss of bone and skin, were treated by grafting of osteocutaneous composites also using microvascular anastomoses. All but one defect healed successfully. There is a wide potential for applications of these two techniques in the treatment of large segmental bone defects secondary to trauma or following tumor resection. PMID:365868

  9. [Protective effect of combined administration of active ingredients of Danhong on cerebral micro-vascular endothelial cell injured by hypoxia].

    PubMed

    Zhou, Hui-fen; He, Yu; Zhang, Yu-yan; Yang, Jie-hong; Zhao, Tao; Fu, Wei; Zhou, Peng; Wan, Hai-tong

    2014-11-01

    To study the protective effect of combined administration of active ingredients of Danhong on cultured primary mice's brain microvascular endothelial cells (rBMECs) injured by hypoxia. Primary mice's brain micro-vascular endothelial cells were cultured to establish the 4 h hypoxia model. Meanwhile, active ingredients (protocatechuic aldehyde, salvianolic acid B, hydroxysafflor yellow A and tanshinol) of Danhong were administered in rBMECs. The non-toxic dosage was determined by MTT. The leakage of lactate dehydrogenase(LDH), cell superoxide dismutase (SOD) activity and MDA level were detected by the colorimetric method. The expressions of ICAM-1, MMP-9, P53 mRNA were detected by RT-PCR method. Changes in rBMECs cell cycle and early apoptosis were detected by flow cytometry. Danhong's active ingredients and prescriptions 1, 2, 3, 7, 8, 9 could be combined to significantly restrain LDH in hypoxic cells supernatant. Prescriptions 1, 2, 3, 7, 8, 9 could significantly enhance SOD activity in anoxic cells; Prescriptions 1, 2, 3, 8, 9 could significantly decrease the MDA level; Prescriptions 1, 2, 6, 7, 9 could significantly inhibit the early rB-MECs apoptosis induced by hypoxia. After hypoxia, the up-regulated P53 mRNA expression could cause retardation in G, phase and promote cell apoptosis. This proved that the regulatory function of P53 gene lay in monitoring of calibration points in G, phase. Prescriptions 1, 2, 5, 6, 7, 8, 9 could significantly down-regulate the P53 mRNA expression; Prescriptions 1, 4, 7, 8, 9 could significantly down-regulate the ICAM-1 mRNA expression; Prescriptions 1, 3, 6, 9 could significantly down-regulate the MMP-9 mRNA expression. The combined administration of Danhong's active ingredients showed a significant protective effect on primary cultured rBMECs injury induced by hypoxia Its mechanism may be related to the enhancement of cellular antioxidant capacity and the inhibition of inflammatory response and cell apoptosis. This study could

  10. Microvascular lesions by estrogen-induced ID3: its implications in cerebral & cardiorenal vascular disease

    PubMed Central

    Das, Jayanta K.; Felty, Quentin

    2014-01-01

    Severe symptoms of cerebral and cardiorenal vascular diseases can be triggered when cerebral, coronary, or glomerular arterioles grow inappropriately as a result of abnormal cell proliferation. The risk factor(s) and molecular mechanisms responsible for microvascular lesion formation are largely unknown. Although controversial, both animal and epidemiological studies have shown that estrogen increases the risk of stroke which may be due to microvascular lesions. Since microvascular diseases are characterized by excessive vessel growth, it is plausible that estrogen-induced neovascularization contributes to the growth of microvascular lesions. We present evidence for how ID3 overexpression in endothelial cells contributes to the development of an estrogen-induced neovascular phenotype with an additional focus on Pyk2 kinase. Our data showed that ID3 overexpression increased neovascularization, cell migration, and spheroid growth of human cerebral microvascular endothelial cells, hCMEC/D3. ID3 overexpressing cells showed significant estrogen-induced G2/M phase transition. Estrogen treatment increased both ID3 phosphorylation and total protein that was inhibited by tamoxifen; and Pyk2 mediated estrogen-induced ID3 mRNA expression. These findings suggest that Pyk2 signals ID3 expression and ID3 is necessary for estrogen-induced neovascularization in hCMEC/D3 cells. A better understanding of how microvascular lesions depend on ID3 may open new avenues for prevention and treatment of neurological diseases. PMID:25129100

  11. Acetaminophen-induced microvascular injury in the rat liver: protection with misoprostol.

    PubMed

    Lim, S P; Andrews, F J; O'Brien, P E

    1995-12-01

    Studies into the mechanism of acetaminophen (APAP)-induced hepatotoxicity have focused mainly at the hepatocellular level. This study aimed to investigate the effect of acetaminophen on the hepatic microvasculature using a vascular casting technique. Acetaminophen was administered at a dose of 650 mg/kg body weight (intraperitoneally) to fasted male Long Evans rats. Microvascular casting was performed at various points after drug administration. Liver casts from control rats showed good patency with normal hepatic microvasculature. Thirty-six hours after overdose with acetaminophen, liver casts showed rounded centrilobular cavities of various sizes, representing regions in which cast-filled sinusoids were absent with relatively normal microvasculature within periportal regions. Evidence of microvascular injury occurred as early as 5 hours after acetaminophen overdose. This injury consisted of changes to centrilobular sinusoids including areas of incomplete filling and dilated centrilobular sinusoids. Misoprostol (a prostaglandin E1 analog) treatment (6 x 25 micrograms/kg) given before and after acetaminophen administration markedly reduced the extent of microvascular injury with only small focal unfilled areas in the casts and a generally intact microvasculature. In conclusion, this study shows that overdosage with APAP resulted in an extensive, characteristic pattern of hepatic microvascular injury in the centrilobular region. The results also suggest that microvascular injury is an early event in the pathogenesis of acetaminophen hepatotoxicity. Misoprostol was found to protect against injury occurring at the microvascular level. PMID:7489988

  12. Deeper Penetration of Erythrocytes into the Endothelial Glycocalyx Is Associated with Impaired Microvascular Perfusion

    PubMed Central

    Lee, Dae Hyun; Dane, Martijn J. C.; van den Berg, Bernard M.; Boels, Margien G. S.; van Teeffelen, Jurgen W.; de Mutsert, Renée; den Heijer, Martin; Rosendaal, Frits R.; van der Vlag, Johan; van Zonneveld, Anton Jan; Vink, Hans; Rabelink, Ton J.

    2014-01-01

    Changes in endothelial glycocalyx are one of the earliest changes in development of cardiovascular disease. The endothelial glycocalyx is both an important biological modifier of interactions between flowing blood and the vessel wall, and a determinant of organ perfusion. We hypothesize that deeper penetration of erythrocytes into the glycocalyx is associated with reduced microvascular perfusion. The population-based prospective cohort study (the Netherlands Epidemiology of Obesity [NEO] study) includes 6,673 middle-aged individuals (oversampling of overweight and obese individuals). Within this cohort, we have imaged the sublingual microvasculature of 915 participants using sidestream darkfield (SDF) imaging together with a recently developed automated acquisition and analysis approach. Presence of RBC (as a marker of microvascular perfusion) and perfused boundary region (PBR), a marker for endothelial glycocalyx barrier properties for RBC accessibility, were assessed in vessels between 5 and 25 µm RBC column width. A wide range of variability in PBR measurements, with a mean PBR of 2.14 µm (range: 1.43–2.86 µm), was observed. Linear regression analysis showed a marked association between PBR and microvascular perfusion, reflected by RBC filling percentage (regression coefficient β: −0.034; 95% confidence interval: −0.037 to −0.031). We conclude that microvascular beds with a thick (“healthy”) glycocalyx (low PBR), reflects efficient perfusion of the microvascular bed. In contrast, a thin (“risk”) glycocalyx (high PBR) is associated with a less efficient and defective microvascular perfusion. PMID:24816787

  13. Allergic airways disease develops after an increase in allergen capture and processing in the airway mucosa.

    PubMed

    von Garnier, Christophe; Wikstrom, Matthew E; Zosky, Graeme; Turner, Debra J; Sly, Peter D; Smith, Miranda; Thomas, Jennifer A; Judd, Samantha R; Strickland, Deborah H; Holt, Patrick G; Stumbles, Philip A

    2007-11-01

    Airway mucosal dendritic cells (AMDC) and other airway APCs continuously sample inhaled Ags and regulate the nature of any resulting T cell-mediated immune response. Although immunity develops to harmful pathogens, tolerance arises to nonpathogenic Ags in healthy individuals. This homeostasis is thought to be disrupted in allergic respiratory disorders such as allergic asthma, such that a potentially damaging Th2-biased, CD4(+) T cell-mediated inflammatory response develops against intrinsically nonpathogenic allergens. Using a mouse model of experimental allergic airways disease (EAAD), we have investigated the functional changes occurring in AMDC and other airway APC populations during disease onset. Onset of EAAD was characterized by early and transient activation of airway CD4(+) T cells coinciding with up-regulation of CD40 expression exclusively on CD11b(-) AMDC. Concurrent enhanced allergen uptake and processing occurred within all airway APC populations, including B cells, macrophages, and both CD11b(+) and CD11b(-) AMDC subsets. Immune serum transfer into naive animals recapitulated the enhanced allergen uptake observed in airway APC populations and mediated activation of naive allergen-specific, airway CD4(+) T cells following inhaled allergen challenge. These data suggest that the onset of EAAD is initiated by enhanced allergen capture and processing by a number of airway APC populations and that allergen-specific Igs play a role in the conversion of normally quiescent AMDC subsets into those capable of inducing airway CD4(+) T cell activation. PMID:17947647

  14. Optical imaging to map blood-brain barrier leakage

    NASA Astrophysics Data System (ADS)

    Jaffer, Hayder; Adjei, Isaac M.; Labhasetwar, Vinod

    2013-11-01

    Vascular leakage in the brain is a major complication associated with brain injuries and certain pathological conditions due to disruption of the blood-brain barrier (BBB). We have developed an optical imaging method, based on excitation and emission spectra of Evans Blue dye, that is >1000-fold more sensitive than conventional ultraviolet spectrophotometry. We used a rat thromboembolic stroke model to validate the usefulness of our method for vascular leakage. Optical imaging data show that vascular leakage varies in different areas of the post-stroke brain and that administering tissue plasminogen activator causes further leakage. The new method is quantitative, simple to use, requires no tissue processing, and can map the degree of vascular leakage in different brain locations. The high sensitivity of our method could potentially provide new opportunities to study BBB leakage in different pathological conditions and to test the efficacy of various therapeutic strategies to protect the BBB.

  15. Residential Forced Air System Cabinet Leakage and Blower Performance

    SciTech Connect

    Walker, Iain S.; Dickerhoff, Darryl J.; Delp, William W.

    2010-03-01

    This project evaluated the air leakage and electric power consumption of Residential HVAC components, with a particular focus on air leakage of furnace cabinets. Laboratory testing of HVAC components indicated that air leakage can be significant and highly variable from unit to unit ? indicating the need for a standard test method and specifying maximum allowable air leakage in California State energy codes. To further this effort, this project provided technical assistance for the development of a national standard for Residential HVAC equipment air leakage. This standard is being developed by ASHRAE and is called"ASHRAE Standard 193P - Method of test for Determining the Air Leakage Rate of HVAC Equipment". The final part of this project evaluated techniques for measurement of furnace blower power consumption. A draft test procedure for power consumption was developed in collaboration with the Canadian General Standards Board: CSA 823"Performance Standard for air handlers in residential space conditioning systems".

  16. Microvascular system of anterior cruciate ligament in dogs.

    PubMed

    Kobayashi, Shigeru; Baba, Hisatoshi; Uchida, Kenzo; Negoro, Kohei; Sato, Mituhiko; Miyazaki, Tsuyoshi; Nomura, Eiki; Murakami, Kaname; Shimizubata, Matsuyuki; Meir, Adam

    2006-07-01

    This study was done to investigate the microvascular system of anterior cruciate ligament (ACL) using dogs. The objective was to study the microvascular architecture and the status of the barrier function of the capillary wall in the ACL by using microangiogram, scanning (SEM), and transmission electron microscopy (TEM). The vascular system in the ACL has been intensively studied by a number of researchers, using several microangiographic techniques in dogs, rabbits, and humans. However, most of these microangiographic studies had significant shortcomings, including the lack of three-dimensional observations and function of the blood-joint barrier in the ACL. In this study, the microstructure of the ACL was examined using microangiogram, SEM, and TEM. We investigated the vasculature of the ACL with SEM of vascular corrosion casts. In addition, we examined the status of the barrier function of the capillary wall in the ACL using the protein tracer horseradish peroxidase (HRP). Feeding vessels of the ligament were predominantly coming from the synovial-derived vessels originating from the synovium attached to the ligament near the tibial and femoral bone insertions of the ACL. The anterior cruciate ligament was surrounded by synovium, which had abundant vessels. The branches of these synovial vessels were penetrating into the ligament and making the intrinsic vascular network. It was also ascertained under SEM that the perivascular space around the intrinsic vessels were communicating through the intrinsic ligament fiber bundles and the mesh-like synovial membrane. The capillaries in the ACL were all of the continuous type under TEM. The protein tracer that was injected into the joint space passed through the synovial membrane and entered into the capillary lumen in the ACL, but the tracer that was injected intravenously did not appear in the perivascular space. The existence of a blood-ACL barrier does not necessarily imply the existence of an ACL-blood barrier. We

  17. Educating the Educator: Teaching Airway Adjunct Techniques in Athletic Training

    ERIC Educational Resources Information Center

    Berry, David C.; Seitz, S. Robert

    2011-01-01

    The 5th edition of the "Athletic Training Education Competencies" ("Competencies") now requires athletic training educators (ATEs) to introduce into the curriculum various types of airway adjuncts including: (1) oropharyngeal airways (OPA), (2) nasopharyngeal airways (NPA), (3) supraglottic airways (SGA), and (4) suction. The addition of these…

  18. Small particles disrupt postnatal airway development

    PubMed Central

    Lee, DongYoub; Wallis, Chris; Schelegle, Edward S.; Van Winkle, Laura S.; Plopper, Charles G.; Fanucchi, Michelle V.; Kumfer, Ben; Kennedy, Ian M.; Chan, Jackie K. W.

    2010-01-01

    Increasing numbers of epidemiologic studies associate air pollution exposure in children with decreased lung function development. The objective of this study was to examine the effects of exposure to combustion-generated fine [230 and 212 nm number mean aerodynamic particle diameter (NMAD)] to ultrafine (73 nm NMAD) particles differing in elemental (EC) and organic (OC) carbon content on postnatal airway development in rats. Neonatal Sprague-Dawley rats were exposed from postnatal day 7 through 25, and lung function and airway architecture were evaluated 81 days of age. In a separate group of rats, cell proliferation was examined after a single particle exposure at 7 days of age. Early life exposure to 73 nm high OC/EC particles altered distal airway architecture and resulted in subtle changes in lung mechanics. Early life exposure to 212 nm high OC/EC particles did not alter lung architecture but did alter lung mechanics in a manner suggestive of central airway changes. In contrast, early life exposure to 230 nm low OC/EC particles did not alter lung architecture or mechanics. A single 6-h exposure to 73 nm high OC/EC particle decreased airway cell proliferation, whereas 212 nm high OC/EC particles increased it and 230 nm low OC/EC particles did not. The early life exposure to ultrafine, high OC/EC particles results in persistent alterations in distal airway architecture that is characterized by an initial decrease in airway cell proliferation. PMID:20634362

  19. Lung Transplantation: The State of the Airways.

    PubMed

    Husain, Aliya N; Garrity, Edward R

    2016-03-01

    Context .- Lung transplantation has become a viable option for definitive treatment of several end-stage lung diseases for which there are no other options available. However, long-term survival continues to be limited by chronic lung allograft dysfunction, which primarily affects the airways. Objective . -To highlight the complications occurring mainly in the airways of the lung transplant recipient from the early to late posttransplant periods. Data Sources .- Review literature focusing on the airways in patients with lung transplants and clinical experience of the authors. Conclusions .- Postsurgical complications and infections of the airways have decreased because of better techniques and management. Acute cellular rejection of the airways can be distinguished from infection pathologically and on cultures. Separating small from large airways need not be an issue because both are risk factors for bronchiolitis obliterans. Grading of airway rejection needs to be standardized. Chronic lung allograft dysfunction consists of both bronchiolitis obliterans and restrictive allograft syndrome, neither of which can be treated very effectively at present. PMID:26927718

  20. Comparison of analysis methods for airway quantification

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.

    2012-03-01

    Diseased airways have been known for several years as a possible contributing factor to airflow limitation in Chronic Obstructive Pulmonary Diseases (COPD). Quantification of disease severity through the evaluation of airway dimensions - wall thickness and lumen diameter - has gained increased attention, thanks to the availability of multi-slice computed tomography (CT). Novel approaches have focused on automated methods of measurement as a faster and more objective means that the visual assessment routinely employed in the clinic. Since the Full-Width Half-Maximum (FWHM) method of airway measurement was introduced two decades ago [1], several new techniques for quantifying airways have been detailed in the literature, but no approach has truly become a standard for such analysis. Our own research group has presented two alternative approaches for determining airway dimensions, one involving a minimum path and the other active contours [2, 3]. With an increasing number of techniques dedicated to the same goal, we decided to take a step back and analyze the differences of these methods. We consequently put to the test our two methods of analysis and the FWHM approach. We first measured a set of 5 airways from a phantom of known dimensions. Then we compared measurements from the three methods to those of two independent readers, performed on 35 airways in 5 patients. We elaborate on the differences of each approach and suggest conclusions on which could be defined as the best one.

  1. Breath tests and airway gas exchange.

    PubMed

    Anderson, Joseph C; Hlastala, Michael P

    2007-01-01

    Measuring soluble gas in the exhaled breath is a non-invasive technique used to estimate levels of respiratory, solvent, and metabolic gases. The interpretation of these measurements is based on the assumption that the measured gases exchange in the alveoli. While the respiratory gases have a low blood-solubility and exchange in the alveoli, high blood-soluble gases exchange in the airways. The effect of airway gas exchange on the interpretation of these exhaled breath measurements can be significant. We describe airway gas exchange in relation to exhaled measurements of soluble gases that exchange in the alveoli. The mechanisms of airway gas exchange are reviewed and criteria for determining if a gas exchanges in the airways are provided. The effects of diffusion, perfusion, temperature and breathing maneuver on airway gas exchange and on measurement of exhaled soluble gas are discussed. A method for estimating the impact of airway gas exchange on exhaled breath measurements is presented. We recommend that investigators should carefully control the inspired air conditions and type of exhalation maneuver used in a breath test. Additionally, care should be taken when interpreting breath tests from subjects with pulmonary disease. PMID:16413216

  2. Postoperative Cerebrospinal Fluid Leakage Associated With Total En Bloc Spondylectomy.

    PubMed

    Yokogawa, Noriaki; Murakami, Hideki; Demura, Satoru; Kato, Satoshi; Yoshioka, Katsuhito; Hayashi, Hiroyuki; Ishii, Takayoshi; Igarashi, Takashi; Fang, Xiang; Tsuchiya, Hiroyuki

    2015-07-01

    Cerebrospinal fluid (CSF) leakage is a serious postoperative complication associated with total en bloc spondylectomy. The authors examined the risk factors for CSF leakage after this procedure. A total of 72 patients underwent total en bloc spondylectomy at the authors' institution between May 2010 and April 2013. Postoperative CSF leakage was observed in 17 of the 72 patients (23.6%). The results of univariate analysis suggested that age 54 years or older, preoperative surgical site irradiation, resection of 3 or more vertebral bodies, and dural injury were significant risk factors for postoperative CSF leakage after total en bloc spondylectomy. Multivariate analysis showed that preoperative surgical site irradiation was the only significant risk factor for postoperative CSF leakage (adjusted odds ratio, 5.22; 95% confidence interval, 1.03-26.45, P=.046). The authors also assessed the course of treatment for postoperative CSF leakage in each patient. Of 17 patients with postoperative CSF leakage, 13 recovered without further complications, but 4 required reoperation (2 for wound dehiscence, 1 for surgical site infection, and 1 for severe intracranial hypotension). All 4 patients who required reoperation had a history of surgical site irradiation. Thus, this study suggests that careful consideration should be given to postoperative CSF leakage in patients with a history of surgical site irradiation. These findings may contribute to the management of postoperative CSF leakage associated with total en bloc spondylectomy and supplement the information given to the patient in the process of obtaining informed consent. PMID:26186316

  3. Estimation of leakage rates through flexible membrane liners

    SciTech Connect

    Murray, G.B.; McBean, E.A.; Sykes, J.F.

    1995-12-31

    Leakage rate calculations for both low-permeability soil liners and composite liners using flexible membrane liners (FMLs) overlying low-permeability soil are developed. Latin-Hypercube simulations with uncertainty assigned to the soil liner hydraulic conductivity value and the spatial frequency of FML holes are used to examine the variability in the liner leakage rats. The low-permeability soil hydraulic conductivity is the parameter with the greatest effect on landfill liner leakages rates. Composite liners have a significant impact on reducing leakage rates through the landfill liner.

  4. Replication-deficient adenoviral vector for gene transfer potentiates airway neurogenic inflammation.

    PubMed

    Piedimonte, G; Pickles, R J; Lehmann, J R; McCarty, D; Costa, D L; Boucher, R C

    1997-03-01

    Human trials for the treatment of cystic fibrosis lung disease with adenoviral vectors have been complicated by acute inflammatory reactions of unknown etiology. Because replicating respiratory viruses can potentiate tachykinin-mediated neurogenic inflammatory responses in airways, we studied whether the endotracheal administration of a replication-deficient adenoviral vector potentiated this response. The vector Ad5CMVLacZ was administered endotracheally to rats and the leakage of Evans blue dye was used to measure the capsaicin-induced neurogenic albumin extravasation. These studies show that neurogenic albumin extravasation is significantly potentiated in the airways of rats after administration of Ad5CMVLacZ. This inflammatory response can be blocked by selective antagonists of the substance P receptor or by glucocorticoids. Therefore, (1) the acute airway inflammation observed in patients after exposure to adenoviral vectors may exhibit a neurogenic component, which can be blocked pharmacologically, and (2) preclinical adenoviral vector safety studies of other organs innervated by the tachykinin system, e.g., coronary arteries and gastrointestinal tract, should include assessment of neurogenic inflammation. PMID:9070609

  5. Human airway measurement from CT images

    NASA Astrophysics Data System (ADS)

    Lee, Jaesung; Reeves, Anthony P.; Fotin, Sergei; Apanasovich, Tatiyana; Yankelevitz, David

    2008-03-01

    A wide range of pulmonary diseases, including common ones such as COPD, affect the airways. If the dimensions of airway can be measured with high confidence, the clinicians will be able to better diagnose diseases as well as monitor progression and response to treatment. In this paper, we introduce a method to assess the airway dimensions from CT scans, including the airway segments that are not oriented axially. First, the airway lumen is segmented and skeletonized, and subsequently each airway segment is identified. We then represent each airway segment using a segment-centric generalized cylinder model and assess airway lumen diameter (LD) and wall thickness (WT) for each segment by determining inner and outer wall boundaries. The method was evaluated on 14 healthy patients from a Weill Cornell database who had two scans within a 2 month interval. The corresponding airway segments were located in two scans and measured using the automated method. The total number of segments identified in both scans was 131. When 131 segments were considered altogether, the average absolute change over two scans was 0.31 mm for LD and 0.12 mm for WT, with 95% limits of agreement of [-0.85, 0.83] for LD and [-0.32, 0.26] for WT. The results were also analyzed on per-patient basis, and the average absolute change was 0.19 mm for LD and 0.05 mm for WT. 95% limits of agreement for per-patient changes were [-0.57, 0.47] for LD and [-0.16, 0.10] for WT.

  6. Estimating sewer leakage from continuous tracer experiments.

    PubMed

    Rieckermann, Jörg; Bares, Vojtech; Kracht, Oliver; Braun, Daniel; Gujer, Willi

    2007-05-01

    Direct measurements of sewer leakage with continuous dosing of tracers are often considered too imprecise for practical applications. However, no mathematical framework for data analysis is reported in literature. In this paper, we present an improved experimental design and data analysis procedure together with a comprehensive framework for uncertainty assessment. Test runs in a 700 m-long watertight sewer showed no significant bias and a very high precision of the methodology. The standard error in the results was assessed to 2.6% of the labeled flow with a simplified model. It could be reduced to 1.2% when a dynamic data analysis procedure was applied. The major error contribution was caused by transient transport phenomena, which suggests that careful choosing of the experimental time is more important than the choice of a very specific tracer substance. Although the method is not intended to replace traditional CCTV inspections, it can provide complementary information for rational rehabilitation planning. PMID:17363025

  7. Torque Transmission Device at Zero Leakage

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Mullen, R. L.

    2005-01-01

    In a few critical applications, mechanical transmission of power by rotation at low speed is required without leakage at an interface. Herein we examine a device that enables torque to be transmitted across a sealed environmental barrier. The barrier represents the restraint membrane through which the torque is transmitted. The power is transferred through elastic deformation of a circular tube into an elliptical cross-section. Rotation of the principle axis of the ellipse at one end results in a commensurate rotation of an elliptical cross section at the other end of the tube. This transfer requires no rigid body rotation of the tube allowing a membrane to seal one end from the other. Both computational and experimental models of the device are presented.

  8. Fluid leakage near the percolation threshold

    PubMed Central

    Dapp, Wolf B.; Müser, Martin H.

    2016-01-01

    Percolation is a concept widely used in many fields of research and refers to the propagation of substances through porous media (e.g., coffee filtering), or the behaviour of complex networks (e.g., spreading of diseases). Percolation theory asserts that most percolative processes are universal, that is, the emergent powerlaws only depend on the general, statistical features of the macroscopic system, but not on specific details of the random realisation. In contrast, our computer simulations of the leakage through a seal—applying common assumptions of elasticity, contact mechanics, and fluid dynamics—show that the critical behaviour (how the flow ceases near the sealing point) solely depends on the microscopic details of the last constriction. It appears fundamentally impossible to accurately predict from statistical properties of the surfaces alone how strongly we have to tighten a water tap to make it stop dripping and also how it starts dripping once we loosen it again. PMID:26839261

  9. Fluid leakage near the percolation threshold

    NASA Astrophysics Data System (ADS)

    Dapp, Wolf B.; Müser, Martin H.

    2016-02-01

    Percolation is a concept widely used in many fields of research and refers to the propagation of substances through porous media (e.g., coffee filtering), or the behaviour of complex networks (e.g., spreading of diseases). Percolation theory asserts that most percolative processes are universal, that is, the emergent powerlaws only depend on the general, statistical features of the macroscopic system, but not on specific details of the random realisation. In contrast, our computer simulations of the leakage through a seal—applying common assumptions of elasticity, contact mechanics, and fluid dynamics—show that the critical behaviour (how the flow ceases near the sealing point) solely depends on the microscopic details of the last constriction. It appears fundamentally impossible to accurately predict from statistical properties of the surfaces alone how strongly we have to tighten a water tap to make it stop dripping and also how it starts dripping once we loosen it again.

  10. Information Leakage Analysis by Abstract Interpretation

    NASA Astrophysics Data System (ADS)

    Zanioli, Matteo; Cortesi, Agostino

    Protecting the confidentiality of information stored in a computer system or transmitted over a public network is a relevant problem in computer security. The approach of information flow analysis involves performing a static analysis of the program with the aim of proving that there will not be leaks of sensitive information. In this paper we propose a new domain that combines variable dependency analysis, based on propositional formulas, and variables' value analysis, based on polyhedra. The resulting analysis is strictly more accurate than the state of the art abstract interpretation based analyses for information leakage detection. Its modular construction allows to deal with the tradeoff between efficiency and accuracy by tuning the granularity of the abstraction and the complexity of the abstract operators.

  11. Fluid leakage near the percolation threshold.

    PubMed

    Dapp, Wolf B; Müser, Martin H

    2016-01-01

    Percolation is a concept widely used in many fields of research and refers to the propagation of substances through porous media (e.g., coffee filtering), or the behaviour of complex networks (e.g., spreading of diseases). Percolation theory asserts that most percolative processes are universal, that is, the emergent powerlaws only depend on the general, statistical features of the macroscopic system, but not on specific details of the random realisation. In contrast, our computer simulations of the leakage through a seal--applying common assumptions of elasticity, contact mechanics, and fluid dynamics--show that the critical behaviour (how the flow ceases near the sealing point) solely depends on the microscopic details of the last constriction. It appears fundamentally impossible to accurately predict from statistical properties of the surfaces alone how strongly we have to tighten a water tap to make it stop dripping and also how it starts dripping once we loosen it again. PMID:26839261

  12. Secondary Reverse Slide Tracheoplasty for Airway Rescue.

    PubMed

    Kopelovich, Jonathan C; Wine, Todd M; Rutter, Michael J; Mitchell, Max B; Prager, Jeremy D

    2016-03-01

    Slide tracheoplasty is used in cases of tracheal stenosis or injury. With expanding indications for its use at tertiary centers, salvage techniques for dehiscence or restenosis after slide tracheoplasty are increasingly relevant. We present a case in which slide tracheoplasty was augmented with an anterior costochondral graft that stenosed again and ultimately failed. We salvaged this airway emergency by performing a secondary reverse slide tracheoplasty. Using this technique, we were able to establish a safe and durable airway using only native airway tissue. PMID:26897214

  13. Airways disorders and the swimming pool.

    PubMed

    Bougault, Valérie; Boulet, Louis-Philippe

    2013-08-01

    Concerns have been expressed about the possible detrimental effects of chlorine derivatives in indoor swimming pool environments. Indeed, a controversy has arisen regarding the possibility that chlorine commonly used worldwide as a disinfectant favors the development of asthma and allergic diseases. The effects of swimming in indoor chlorinated pools on the airways in recreational and elite swimmers are presented. Recent studies on the influence of swimming on airway inflammation and remodeling in competitive swimmers, and the phenotypic characteristics of asthma in this population are reviewed. Preventative measures that could potentially reduce the untoward effects of pool environment on airways of swimmers are discussed. PMID:23830132

  14. Brachycephalic airway syndrome: pathophysiology and diagnosis.

    PubMed

    Lodato, Dena L; Hedlund, Cheryl S

    2012-07-01

    Brachycephalic airway syndrome (BAS) is a group of abnormalities that result in upper airway obstruction. Primary malformations include stenotic nares, elongated soft palate, and hypoplastic trachea, which cause an increase in negative pressure within the upper airways that can eventually lead to secondary abnormalities such as everted laryngeal saccules, everted tonsils, and laryngeal and tracheal collapse. Abnormal nasopharyngeal turbinates are also encountered, but have not been classified as primary or secondary. BAS is readily diagnosed, and quality of life is improved with appropriate medical and/or surgical management. PMID:22847322

  15. Airway nitric oxide in microgravity

    NASA Astrophysics Data System (ADS)

    Linnarsson, D.; Gustafsson, L.; Hemmingsson, Tryggve; Frostell, C.; Paiva, M.

    2005-10-01

    Nitric Oxide (NO), a molecule with a wide range of biological effects, is found in exhaled gas. Elevation of expired NO is an early sign of airway inflammation in asthma and dust inhalation. Animal experiments have demonstrated a marked increase of expired NO after venous gas emboli (bubbles, VGE), which may occur after decompression in conjunction with extravehicular activity (EVA). For this MAP project, astronauts will perform a simple inhalation-exhalation procedure weekly during their flights, and before and after EVA. Furthermore, the microgravity environment offers a possibility to gain new insights into how and where NO is formed in the lungs and what local effects NO may have there. The planned experiments have been made possible by recent developments of new techniques by the team's industrial partners; Aerocrine has developed a highly compact and accurate NO analyser, and Linde Gas Theapeutics has developed a highly compact device for NO administration in the inhaled air.

  16. Normal Muscle Oxygen Consumption and Fatigability in Sickle Cell Patients Despite Reduced Microvascular Oxygenation and Hemorheological Abnormalities

    PubMed Central

    Waltz, Xavier; Pichon, Aurélien; Lemonne, Nathalie; Mougenel, Danièle; Lalanne-Mistrih, Marie-Laure; Lamarre, Yann; Tarer, Vanessa; Tressières, Benoit; Etienne-Julan, Maryse; Hardy-Dessources, Marie-Dominique; Hue, Olivier; Connes, Philippe

    2012-01-01

    Background/Aim Although it has been hypothesized that muscle metabolism and fatigability could be impaired in sickle cell patients, no study has addressed this issue. Methods We compared muscle metabolism and function (muscle microvascular oxygenation, microvascular blood flow, muscle oxygen consumption and muscle microvascular oxygenation variability, which reflects vasomotion activity, maximal muscle force and local muscle fatigability) and the hemorheological profile at rest between 16 healthy subjects (AA), 20 sickle cell-hemoglobin C disease (SC) patients and 16 sickle cell anemia (SS) patients. Results Muscle microvascular oxygenation was reduced in SS patients compared to the SC and AA groups and this reduction was not related to hemorhelogical abnormalities. No difference was observed between the three groups for oxygen consumption and vasomotion activity. Muscle microvascular blood flow was higher in SS patients compared to the AA group, and tended to be higher compared to the SC group. Multivariate analysis revealed that muscle oxygen consumption was independently associated with muscle microvascular blood flow in the two sickle cell groups (SC and SS). Finally, despite reduced muscle force in sickle cell patients, their local muscle fatigability was similar to that of the healthy subjects. Conclusions Sickle cell patients have normal resting muscle oxygen consumption and fatigability despite hemorheological alterations and, for SS patients only, reduced muscle microvascular oxygenation and increased microvascular blood flow. Two alternative mechanisms can be proposed for SS patients: 1) the increased muscle microvascular blood flow is a way to compensate for the lower muscle microvascular oxygenation to maintain muscle oxygen consumption to normal values or 2) the reduced microvascular oxygenation coupled with a normal resting muscle oxygen consumption could indicate that there is slight hypoxia within the muscle which is not sufficient to limit

  17. Specific albumin binding to microvascular endothelium in culture

    SciTech Connect

    Schnitzer, J.E.; Carley, W.W.; Palade, G.E. )

    1988-03-01

    The specific binding of rat serum albumin (RSA) to confluent microvascular endothelial cells in culture derived from the vasculature of the rat epididymal fat pad was studied at 4{degree}C by radioassay and immunocytochemistry. Radioiodinated RSA ({sup 125}I-RSA) binding to the cells reached equilibrium at {approximately} 20 min incubation. Albumin binding was a slowly saturating function over concentrations ranging from 0.01 to 50 mg/ml. Specific RSA binding with a moderate apparent affinity constant of 1.0 mg/ml and with a maximum binding concentration of 90 ng/cm{sup 2} was immunolocalized with anti-RSA antibody to the outer (free) side of the enothelium. Scatchard analysis of the binding yielded a nonlinear binding curve with a concave-upward shape. Dissociation rate analysis supports negative cooperativity of albumin binding, but multiple binding sites may also be present. Albumin binding fulfilled many requirements for ligand specificity including saturability, reversibility, competibility, and dependence on both cell type and cell number. The results are discussed in terms of past in situ investigations on the localization of albumin binding to vascular endothelium and its effect on transendothelial molecular transport.

  18. Microvascular Coronary Dysfunction in Women- Pathophysiology, Diagnosis, and Management

    PubMed Central

    Kothawade, Kamlesh; Merz, C. Noel Bairey

    2011-01-01

    Women exhibit a greater symptom burden, more functional disability, and a higher prevalence of no obstructive coronary artery disease (CAD) compared to men when evaluated for signs and symptoms of myocardial ischemia. Microvascular Coronary Dysfunction (MCD) defined as limited coronary flow reserve (CFR) and/or coronary endothelial dysfunction is the predominant etiological mechanism of ischemia in women with the triad of persistent chest pain, no obstructive CAD, and ischemia evidenced by stress testing. Evidence shows that approximately 50% of these patients have physiologic evidence of MCD. MCD is associated with a 2.5% annual major adverse event rate that includes death, nonfatal MI, nonfatal stroke and congestive heart failure. Although tests such as adenosine stress cardiac magnetic resonance imaging (CMRI) may be a useful non-invasive method to predict subendocardial ischemia, the gold standard test to diagnose MCD is an invasive Coronary Reactivity Testing (CRT). Early identification of MCD by CRT may be beneficial in prognostication and stratifying these patients for optimal medical therapy. Currently, understanding of MCD pathophysiology can be used to guide diagnosis and therapy. Continued research in MCD is needed to further advance our understanding. PMID:21723447

  19. Review: Cerebral microvascular pathology in aging and neurodegeneration

    PubMed Central

    Brown, William R.; Thore, Clara R.

    2010-01-01

    This review of age-related brain microvascular pathologies focuses on topics studied by this laboratory, including anatomy of the blood supply, tortuous vessels, venous collagenosis, capillary remnants, vascular density, and microembolic brain injury. Our studies feature thick sections, large blocks embedded in celloidin, and vascular staining by alkaline phosphatase (AP). This permits study of the vascular network in three dimensions, and the differentiation of afferent from efferent vessels. Current evidence suggests that there is decreased vascular density in aging, Alzheimer’s disease (AD), and leukoaraiosis (LA), and cerebrovascular dysfunction precedes and accompanies cognitive dysfunction and neurodegeneration. A decline in cerebrovascular angiogenesis may inhibit recovery from hypoxia-induced capillary loss. Cerebral blood flow (CBF) is inhibited by tortuous arterioles and deposition of excessive collagen in veins and venules. Misery perfusion due to capillary loss appears to occur before cell loss in LA, and CBF is also reduced in the normal-appearing white matter. Hypoperfusion occurs early in AD, inducing white matter lesions and correlating with dementia. In vascular dementia, cholinergic reductions are correlated with cognitive impairment, and cholinesterase inhibitors have some benefit. Most lipid microemboli from cardiac surgery pass through the brain in a few days, but some remain for weeks. They can cause what appears to be a type of vascular dementia years after surgery. Donepezil has shown some benefit. Emboli, such as clots, cholesterol crystals, and microspheres can be extruded through the walls of cerebral vessels, but there is no evidence yet that lipid emboli undergo such extravasation. PMID:20946471

  20. Brain microvascular endothelial cell transplantation ameliorates ischemic white matter damage.

    PubMed

    Puentes, Sandra; Kurachi, Masashi; Shibasaki, Koji; Naruse, Masae; Yoshimoto, Yuhei; Mikuni, Masahiko; Imai, Hideaki; Ishizaki, Yasuki

    2012-08-21

    Ischemic insults affecting the internal capsule result in sensory-motor disabilities which adversely affect the patient's life. Cerebral endothelial cells have been reported to exert a protective effect against brain damage, so the transplantation of healthy endothelial cells might have a beneficial effect on the outcome of ischemic brain damage. In this study, endothelin-1 (ET-1) was injected into the rat internal capsule to induce lacunar infarction. Seven days after ET-1 injection, microvascular endothelial cells (MVECs) were transplanted into the internal capsule. Meningeal cells or 0.2% bovine serum albumin-Hank's balanced salt solution were injected as controls. Two weeks later, the footprint test and histochemical analysis were performed. We found that MVEC transplantation improved the behavioral outcome based on recovery of hind-limb rotation angle (P<0.01) and induced remyelination (P<0.01) compared with the control groups. Also the inflammatory response was repressed by MVEC transplantation, judging from fewer ED-1-positive activated microglial cells in the MVEC-transplanted group than in the other groups. Elucidation of the mechanisms by which MVECs ameliorate ischemic damage of the white matter may provide important information for the development of effective therapies for white matter ischemia. PMID:22771710

  1. Colored microspheres reveal interarterial microvascular anastomoses in canine myocardium.

    PubMed

    Cicutti, N; Rakusan, K; Downey, H F

    1992-01-01

    While the presence of microvascular intercommunication within an individual myocardial arterial bed is well documented, there is a paucity of data to support the existence of anastomoses emanating from independent arterial beds. Simultaneous in-vivo infusion of two different colored microsphere suspensions into the left anterior descending (LAD) and left circumflex (LCx) coronary arteries identified a specific interface region of canine myocardium that was perfused by both arterial branches. Subsequent microscopic/morphometric analysis of 40 microns serial sections in eight hearts revealed clustering of microspheres in their respective perfusion territories (red microspheres in the LAD region away from the interface, blue microspheres in the LCx field away from the interface), along with a mutually perfused borderzone. In each tissue section, two regions within this zone were identified and their maximum widths measured. One region was defined as the Interface Transition Zone (ITZ) (mean width = 5251 +/- 770 microns; mean +/- SD). This region was formed by an intermingling of microvessels supplied by the parent arteries of the adjacent perfusion territories; it separated tissue containing only one or the other colored microspheres. The second region was defined as the Boundary Watershed Zone (BWZ) (mean zone width = 3151 +/- 611 microns; mean +/- SD). This region was formed by capillaries containing sphere aggregates of both colors; it was located exclusively within the ITZ. In addition, the ITZ and BWZ were significantly wider in subepicardial than in subendocardial regions (p less than 0.001). PMID:1417709

  2. Effects of nonsteroidal anti-inflammatory drugs on microvascular dynamics.

    PubMed

    Slater, C; House, S D

    1993-03-01

    Techniques of intravital microscopy were used to assess the effect of the nonsteroidal anti-inflammatory drugs (NSAIDs), indomethacin and ibuprofen, on the microcirculation. Hemodynamics in venules of the rat mesentery were studied in terms of vessel diameter, red blood cell velocity, and leukocyte-endothelium interactions: leukocyte-endothelium adhesion (LEA), white blood cell (WBC) marginating flux, and WBC velocity. Measurements were made during (1) control conditions (topical suffusion with ringer-gelatin drip), (2) topically suffused indomethacin or ibuprofen, (3) an induced inflammatory response (suffusion with the chemoattractant N-Formyl-Methionyl-Leucyl-Phenylalanine (FMLP)), and (4) concomitant suffusion with FMLP and NSAID. Short term topical suffusion (90 sec) with indomethacin and ibuprofen had little or no effect on control hemodynamics. Five-minute suffusions with indomethacin (5 x 10(-5) to 5 x 10(-4) M) significantly increased LEA while ibuprofen (5 x 10(-3) M) significantly decreased LEA. Topical suffusion with the chemotactic agent FMLP induced inflammation and significantly increased LEA in venules. Treatment with indomethacin during induced inflammation had no effect on the inflammatory reaction in terms of the microvascular hemodynamics measured in this study. Treatment with ibuprofen during induced inflammation significantly reduced LEA and increased red blood cell velocity. In conclusion, although both of the NSAIDs studied here are known to block the cyclooxygenase pathway of arachidonic acid metabolism, the actions of indomethacin and ibuprofen on the inflammatory process are very different with an important effect of ibuprofen being to decrease LEA. PMID:8361400

  3. The importance of endothelin-1 for microvascular dysfunction in diabetes

    PubMed Central

    Kalani, Majid

    2008-01-01

    Most of the late diabetic complications such as retinopathy, nephropathy, and neuropathy, have their basis in disturbed microvascular function. Structural and functional changes in the micro-circulation are present in diabetes mellitus irrespective of the organ studied, and the pathogenesis is complex. Endothelial dysfunction, characterized by an imbalance between endothelium-derived vasodilator and vasoconstrictor substances, plays an important role in the pathogenesis of diabetic microangiopathy. Increased circulating levels of endothelin-1 (ET-1), a potent vasoconstrictor peptide, has been found in patients with diabetes, and a positive correlation between plasma ET-1 levels and microangiopathy in patients with type 2 diabetes has been demonstrated. In addition to its direct vasoconstrictor effects, enhanced levels of ET-1 may contribute to endothelial dysfunction through inhibitory effects on nitric oxide (NO) production. Vascular endothelial dysfunction may precede insulin resistance, although the feature of insulin resistance syndrome includes factors that have negative effects on endothelial function. Furthermore, ET-1 induces a reduction in insulin sensitivity and may take part in the development of the metabolic syndrome. In the following, the mechanisms by which ET-1 contributes to the development of diabetic microangiopathy and the potentially beneficial effect of selective ETA receptor antagonists are discussed. PMID:19183753

  4. Intussusceptive Angiogenesis: Expansion and Remodeling of Microvascular Networks

    PubMed Central

    Mentzer, Steven J.; Konerding, Moritz A.

    2014-01-01

    Intussusceptive angiogenesis is a dynamic intravascular process capable of dramatically modifying the structure of the microcirculation. The distinctive structural feature of intussusceptive angiogenesis is the intussusceptive pillar—a cylindrical microstructure that spans the lumen of small vessels and capillaries. The extension of the intussusceptive pillar appears to be a mechanism for pruning redundant or inefficient vessels, modifying the branch angle of bifurcating vessels and duplicating existing vessels. Despite the biological importance and therapeutic potential, intussusceptive angiogenesis remains a mystery, in part, because it is an intravascular process that is unseen by conventional light microscopy. Here, we review several fundamental questions in the context of our current understanding of both intussusceptive and sprouting angiogenesis. 1) What are the physiologic signals that trigger pillar formation? 2) What endothelial and blood flow conditions specify pillar location? 3) How do pillars respond to the mechanical influence of blood flow? 4) What biological influences contribute to pillar extension? The answers to these questions are likely to provide important insights into the structure and function of microvascular networks. PMID:24668225

  5. Syndecan-2 downregulation impairs angiogenesis in human microvascular endothelial cells

    SciTech Connect

    Noguer, Oriol Villena, Joan; Lorita, Jordi; Vilaro, Senen; Reina, Manuel

    2009-03-10

    The formation of new blood vessels, or angiogenesis, is a necessary process during development but also for tumour growth and other pathologies. It is promoted by different growth factors that stimulate endothelial cells to proliferate, migrate, and generate new tubular structures. Syndecans, transmembrane heparan sulphate proteoglycans, bind such growth factors through their glycosaminoglycan chains and could transduce the signal to the cytoskeleton, thus regulating cell behaviour. We demonstrated that syndecan-2, the major syndecan expressed by human microvascular endothelial cells, is regulated by growth factors and extracellular matrix proteins, in both bidimensional and tridimensional culture conditions. The role of syndecan-2 in 'in vitro' tumour angiogenesis was also examined by inhibiting its core protein expression with antisense phosphorothioate oligonucleotides. Downregulation of syndecan-2 reduces spreading and adhesion of endothelial cells, enhances their migration, but also impairs the formation of capillary-like structures. These results suggest that syndecan-2 has an important function in some of the necessary steps that make up the angiogenic process. We therefore propose a pivotal role of this heparan sulphate proteoglycan in the formation of new blood vessels.

  6. Multifractal and Lacunarity Analysis of Microvascular Morphology and Remodeling

    PubMed Central

    Gould, Daniel J.; Vadakkan, Tegy J.; Poché, Ross A.; Dickinson, Mary E.

    2011-01-01

    Purpose Classical measures of vessel morphology including diameter and density are employed to study microvasculature in endothelial membrane labeled mice. These measurements prove sufficient for some studies; however they are less well suited for quantifying changes in microcirculatory networks lacking hierarchical structure. We demonstrate automated multifractal analysis and lacunarity may be used with classical methods to quantify microvascular morphology. Methods We present an automated extraction tool with a processing pipeline to characterize 2D representations of 3D microvasculature, using multifractal analysis and lacunarity. We apply our analysis on four tissues and the hyaloid vasculature during remodeling. Results We found that the vessel networks analyzed have multifractal geometries and that kidney microvasculature has the largest fractal dimension and the lowest lacunarity compared to microvasculature networks in the cortex, skin, and thigh muscle. Also, we found that during hyaloid remodeling, there were differences in multifractal spectra reflecting the functional transition from a space filling vasculature which nurtures the lens to a less dense vasculature as it regresses, permitting unobstructed vision. Conclusion Multifractal analysis and lacunarity are valuable additions to classical measures of vascular morphology and will have utility in future studies of normal, developing and pathological tissues. PMID:21166933

  7. Comprehensive Airway Management of Patients with Maxillofacial Trauma

    PubMed Central

    Kellman, Robert M.; Losquadro, William D.

    2008-01-01

    Airway management in patients with maxillofacial trauma is complicated by injuries to routes of intubation, and the surgeon is frequently asked to secure the airway. Airway obstruction from hemorrhage, tissue prolapse, or edema may require emergent intervention for which multiple intubation techniques exist. Competing needs for both airway and surgical access create intraoperative conflicts during repair of maxillofacial fractures. Postoperatively, edema and maxillomandibular fixation place the patient at risk for further airway compromise. PMID:22110788

  8. Mechanisms Linking Advanced Airway Management and Cardiac Arrest Outcomes

    PubMed Central

    Benoit, Justin L.; Prince, David K.; Wang, Henry E.

    2015-01-01

    Advanced airway management – such as endotracheal intubation (ETI) or supraglottic airway (SGA) insertion – is one of the most prominent interventions in out-of-hospital cardiac arrest (OHCA) resuscitation. While randomized controlled trials are currently in progress to identify the best advanced airway technique in OHCA, the mechanisms by which airway management may influence OHCA outcomes remain unknown. We provide a conceptual model describing potential mechanisms linking advanced airway management with OHCA outcomes. PMID:26073275

  9. Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study.

    PubMed

    White, David E; Bartley, Jim; Shakeel, Muhammad; Nates, Roy J; Hankin, Robin K S

    2016-06-14

    The nasal cycle, through variation in nasal airflow partitioning, allows the upper airway to accommodate the contrasting demands of air conditioning and removal of entrapped air contaminants. The purpose of this study was to investigate the influence of nasal continuous positive airway pressure (nCPAP) breathing has on both nasal airflow partitioning and nasal geometry. Using a custom-made nasal mask, twenty healthy participants had the airflow in each naris measured during normal nasal breathing followed by nCPAP breathing. Eight participants also underwent magnetic resonance imaging (MRI) of the nasal region during spontaneous nasal breathing, and then nCPAP breathing over a range of air pressures. During nCPAP breathing, a simultaneous reduction in airflow through the patent airway together with a corresponding increase in airway flow within the congested nasal airway were observed in sixteen of the twenty participants. Nasal airflow resistance is inversely proportional to airway cross-sectional area. MRI data analysis during nCPAP breathing confirmed airway cross-sectional area reduced along the patent airway while the congested airway experienced an increase in this parameter. During awake breathing, nCPAP disturbs the normal inter-nasal airflow partitioning. This could partially explain the adverse nasal drying symptoms frequently reported by many users of this therapy. PMID:27173595

  10. Airway registry: a performance improvement surveillance project of emergency department airway management.

    PubMed

    Phelan, Michael P; Glauser, Jonathan; Yuen, Ho-Wang A; Sturges-Smith, Elizabeth; Schrump, Stefanie E

    2010-01-01

    The aim of this study was to determine if use of a standardized airway data collection sheet can survey airway management practices in an emergency department. Success rates and trends from the authors' facility have been benchmarked against the National Emergency Airway Registry (NEAR). This study included all patients requiring invasive airway management during a 21-month period (July 1, 2005, through March 31, 2007). An audit form was developed and implemented to collect data on intubations. During the study period, 224 patients required invasive airway control. Of all airways managed by emergency medicine residents, the intubation success rate was 99% (200/203; 95% confidence interval [CI] = 96%-100%), with 3% of those (6/203; 95% CI = 1%-6%) requiring more than 3 attempts; 3 patients (1%; 95% CI = 0%-4%) could not be intubated and required a surgical airway. Use of an airway registry based on the NEAR registry as a benchmark of rates and types of successful intubation allows comparison of airway practices. PMID:20505111

  11. Peripheral microvascular vasodilatory response to estradiol and genistein in women with insulin resistance

    PubMed Central

    Wenner, Megan M.; Taylor, Hugh S.; Stachenfeld, Nina S.

    2015-01-01

    Objective Estradiol enhances vasodilation in healthy women, but vascular effects of the phytoestrogen genistein are still under investigation. Insulin resistance (IR) compromises microvascular function. We therefore examined the interaction of estradiol, genistein, and IR on microvascular vasodilatory responsiveness. Methods We hypothesized that estradiol and genistein increase microvascular vasodilation in healthy women (control, n=8, 23±2 yr, BMI 25.9±2.9 kg/m2) but not in women with IR (n=7, 20±1 yr, BMI 27.3±3.0 kg/m2). We used the cutaneous circulation as a model of microvascular vasodilatory function. We determined cutaneous vascular conductance (CVC) with laser Doppler flowmetry and beat-to-beat blood pressure during local cutaneous heating (42°C) with estradiol or genistein microdialysis perfusions. Because heat induced vasodilation is primarily an NO mediated response, we examined microvascular vasodilation with and without L-NMMA. Results In control women, estradiol enhanced CVC (94.4±2.6 % vs. saline 81.6±4.2 % CVCmax, P<0.05), which was reversed with L-NMMA (80.9±7.8 % CVCmax, P<0.05), but genistein did not affect vasodilation. Neither estradiol nor genistein altered CVC in IR, although L-NMMA attenuated CVC during genistein. Conclusions Our study does not support improved microvascular responsiveness during genistein exposure in healthy young women, and demonstrates that neither estradiol nor genistein improve microvascular vasodilatory responsiveness in women with IR. PMID:25996650

  12. Endurance, interval sprint, and resistance exercise training: impact on microvascular dysfunction in type 2 diabetes.

    PubMed

    Olver, T Dylan; Laughlin, M Harold

    2016-02-01

    Type 2 diabetes (T2D) alters capillary hemodynamics, causes capillary rarefaction in skeletal muscle, and alters endothelial and vascular smooth muscle cell phenotype, resulting in impaired vasodilatory responses. These changes contribute to altered blood flow responses to physiological stimuli, such as exercise and insulin secretion. T2D-induced microvascular dysfunction impairs glucose and insulin delivery to skeletal muscle (and other tissues such as skin and nervous), thereby reducing glucose uptake and perpetuating hyperglycemia and hyperinsulinemia. In patients with T2D, exercise training (EX) improves microvascular vasodilator and insulin signaling and attenuates capillary rarefaction in skeletal muscle. EX-induced changes subsequently augment glucose and insulin delivery as well as glucose uptake. If these adaptions occur in a sufficient amount of tissue, and skeletal muscle in particular, chronic exposure to hyperglycemia and hyperinsulinemia and the risk of microvascular complications in all vascular beds will decrease. We postulate that EX programs that engage as much skeletal muscle mass as possible and recruit as many muscle fibers within each muscle as possible will generate the greatest improvements in microvascular function, providing that the duration of the stimulus is sufficient. Primary improvements in microvascular function occur in tissues (skeletal muscle primarily) engaged during exercise, and secondary improvements in microvascular function throughout the body may result from improved blood glucose control. We propose that the added benefit of combined resistance and aerobic EX programs and of vigorous intensity EX programs is not simply "more is better." Rather, we believe the additional benefit is the result of EX-induced adaptations in and around more muscle fibers, resulting in more muscle mass and the associated microvasculature being changed. Thus, to acquire primary and secondary improvements in microvascular function and improved

  13. Therapeutic bronchoscopic interventions for malignant airway obstruction

    PubMed Central

    Dalar, Levent; Özdemir, Cengiz; Abul, Yasin; Karasulu, Levent; Sökücü, Sinem Nedime; Akbaş, Ayşegül; Altın, Sedat

    2016-01-01

    Abstract There is no definitive consensus about the factors affecting the choice of interventional bronchoscopy in the management of malignant airway obstruction. The present study defines the choice of the interventional bronchoscopic modality and analyzes the factors influencing survival in patients with malignant central airway obstruction. Totally, over 7 years, 802 interventional rigid bronchoscopic procedures were applied in 547 patients having malignant airway obstruction. There was a significant association between the type of stent and the site of the lesion in the present study. Patients with tracheal involvement and/or involvement of the main bronchi had the worst prognosis. The sites of the lesion and endobronchial treatment modality were independent predictors of survival in the present study. The selection of different types of airway stents can be considered on the base of site of the lesion. Survival can be estimated based on the site of the lesion and endobronchial brochoscopic modality used. PMID:27281104

  14. BEHAVIOR OF CIGARETTE SMOKE IN HUMAN AIRWAYS

    EPA Science Inventory

    Experimental deposition patterns of cigarette smoke in surrogate human airway systems are very heterogeneous. article deposits are enhanced at predictable, well-defined morphological regions; most specifically, carinal ridges within bifurcation zones, and along posterior sections...

  15. 21 CFR 868.5810 - Airway connector.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... airway connector is a device intended to connect a breathing gas source to a tracheal tube, tracheostomy tube, or mask. (b) Classification. Class I (general controls). The device is exempt from the...

  16. 21 CFR 868.5810 - Airway connector.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... airway connector is a device intended to connect a breathing gas source to a tracheal tube, tracheostomy tube, or mask. (b) Classification. Class I (general controls). The device is exempt from the...

  17. 21 CFR 868.5810 - Airway connector.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... airway connector is a device intended to connect a breathing gas source to a tracheal tube, tracheostomy tube, or mask. (b) Classification. Class I (general controls). The device is exempt from the...

  18. 21 CFR 868.5810 - Airway connector.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... airway connector is a device intended to connect a breathing gas source to a tracheal tube, tracheostomy tube, or mask. (b) Classification. Class I (general controls). The device is exempt from the...

  19. Diesel exhaust particles and airway inflammation

    EPA Science Inventory

    Purpose of review. Epidemiologic investigation has associated traffic-related air pollution with adverse human health outcomes. The capacity ofdiesel exhaust particles (DEP), a major emission source air pollution particle, to initiate an airway inflammation has subsequently been ...

  20. Role of platelets in allergic airway inflammation.

    PubMed

    Idzko, Marco; Pitchford, Simon; Page, Clive

    2015-06-01

    Increasing evidence suggests an important role for platelets and their products (e.g., platelet factor 4, β-thromboglobulin, RANTES, thromboxane, or serotonin) in the pathogenesis of allergic diseases. A variety of changes in platelet function have been observed in patients with asthma, such as alterations in platelet secretion, expression of surface molecules, aggregation, and adhesion. Moreover, platelets have been found to actively contribute to most of the characteristic features of asthma, including bronchial hyperresponsiveness, bronchoconstriction, airway inflammation, and airway remodeling. This review brings together the current available data from both experimental and clinical studies that have investigated the role of platelets in allergic airway inflammation and asthma. It is anticipated that a better understanding of the role of platelets in the pathogenesis of asthma might lead to novel promising therapeutic approaches in the treatment of allergic airway diseases. PMID:26051948

  1. Virtual Airway Skills Trainer (VAST) Simulator.

    PubMed

    Demirel, Doga; Yu, Alexander; Halic, Tansel; Sankaranarayanan, Ganesh; Ryason, Adam; Spindler, David; Butler, Kathryn L; Cao, Caroline; Petrusa, Emil; Molina, Marcos; Jones, Dan; De, Suvranu; Demoya, Marc; Jones, Stephanie

    2016-01-01

    This paper presents a simulation of Virtual Airway Skill Trainer (VAST) tasks. The simulated tasks are a part of two main airway management techniques; Endotracheal Intubation (ETI) and Cricothyroidotomy (CCT). ETI is a simple nonsurgical airway management technique, while CCT is the extreme surgical alternative to secure the airway of a patient. We developed identification of Mallampati class, finding the optimal angle for positioning pharyngeal/mouth axes tasks for ETI and identification of anatomical landmarks and incision tasks for CCT. Both ETI and CCT simulators were used to get physicians' feedback at Society for Education in Anesthesiology and Association for Surgical Education spring meetings. In this preliminary validation study, total 38 participants for ETI and 48 for CCT performed each simulation task and completed pre and post questionnaires. In this work, we present the details of the simulation for the tasks and also the analysis of the collected data from the validation study. PMID:27046559

  2. Airway management for cervical spine surgery.

    PubMed

    Farag, Ehab

    2016-03-01

    Cervical spine surgery is one of the most commonly performed spine surgeries in the United States, and 90% of the cases are related to degenerative cervical spine disease (the rest to cervical spine trauma and/or instability). The airway management for cervical spine surgery represents a crucial step in the anesthetic management to avoid injury to the cervical cord. The crux for upper airway management for cervical spine surgery is maintaining the neck in a neutral position with minimal neck movement during endotracheal intubation. Therefore, the conventional direct laryngoscopy (DL) can be unsuitable for securing the upper airway in cervical spine surgery, especially in cases of cervical spine instability and myelopathy. This review discusses the most recent evidence-based facts of the main advantages and limitations of different techniques available for upper airway management for cervical spine surgery. PMID:27036600

  3. Galangin attenuates airway remodelling by inhibiting TGF-β1-mediated ROS generation and MAPK/Akt phosphorylation in asthma

    PubMed Central

    Liu, Ya-Nan; Zha, Wang-Jian; Ma, Yuan; Chen, Fei-Fei; Zhu, Wen; Ge, Ai; Zeng, Xiao-Ning; Huang, Mao

    2015-01-01

    Galangin, a natural flavonol, has attracted much attention for its potential anti-inflammatory properties. However, its role in the regulation of airway remodelling in asthma has not been explored. The present study aimed to elucidate the effects of galangin on chronic inflammation and airway remodelling and to investigate the underlying mechanisms both in vivo and in vitro. Ovalbumin (OVA)-sensitised mice were administered with galangin 30 min before challenge. Our results showed that severe inflammatory responses and airway remodelling occurred in OVA-induced mice. Treatment with galangin markedly attenuated the leakage of inflammatory cells into bronchoalveolar lavage fluid (BALF) and decreased the level of OVA-specific IgE in serum. Galangin significantly inhibited goblet cell hyperplasia, collagen deposition and α-SMA expression. Lowered level of TGF-β1 and suppressed expression of VEGF and MMP-9 were observed in BALF or lung tissue, implying that galangin has an optimal anti-remodelling effect in vivo. Consistently, the TGF-β1-induced proliferation of airway smooth muscle cells was reduced by galangin in vitro, which might be due to the alleviation of ROS levels and inhibition of MAPK pathway. Taken together, the present findings highlight a novel role for galangin as a promising anti-remodelling agent in asthma, which likely involves the TGF-β1-ROS-MAPK pathway. PMID:26156213

  4. 49 CFR 178.345-13 - Pressure and leakage tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... adjacent cargo tanks empty and at atmospheric pressure. Each closure, except pressure relief devices and... 49 Transportation 3 2012-10-01 2012-10-01 false Pressure and leakage tests. 178.345-13 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a)...

  5. 49 CFR 178.345-13 - Pressure and leakage tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... adjacent cargo tanks empty and at atmospheric pressure. Each closure, except pressure relief devices and... 49 Transportation 3 2011-10-01 2011-10-01 false Pressure and leakage tests. 178.345-13 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a)...

  6. 49 CFR 178.345-13 - Pressure and leakage tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... adjacent cargo tanks empty and at atmospheric pressure. Each closure, except pressure relief devices and... 49 Transportation 3 2013-10-01 2013-10-01 false Pressure and leakage tests. 178.345-13 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a)...

  7. 49 CFR 178.345-13 - Pressure and leakage tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... adjacent cargo tanks empty and at atmospheric pressure. Each closure, except pressure relief devices and... 49 Transportation 3 2014-10-01 2014-10-01 false Pressure and leakage tests. 178.345-13 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and leakage tests. (a)...

  8. A CONCEPTUAL UNDERSTANDING OF LEAKAGE DURING SOIL-GAS SAMPLING

    EPA Science Inventory

    A heuristic model is developed to develop a conceptual understanding of leakage during soil-gas sampling. Leakage is shown to be simply a function of the permeability contrast between the formation and borehole and geometric factors. As the ratio of formation to borehole permea...

  9. 49 CFR 178.348-5 - Pressure and leakage test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Pressure and leakage test. 178.348-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.348-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  10. 49 CFR 178.347-5 - Pressure and leakage test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Pressure and leakage test. 178.347-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.347-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  11. 49 CFR 178.347-5 - Pressure and leakage test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Pressure and leakage test. 178.347-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.347-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  12. 49 CFR 178.348-5 - Pressure and leakage test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Pressure and leakage test. 178.348-5 Section 178... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.348-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b)...

  13. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... is equipped with vapor recovery equipment may be leakage tested in accordance with 40 CFR 63.425(e). To satisfy the leakage test requirements of this paragraph, the test specified in 40 CFR 63.425(e)(1) must be conducted using air. The hydrostatic test alternative permitted under Appendix A to 40 CFR...

  14. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... is equipped with vapor recovery equipment may be leakage tested in accordance with 40 CFR 63.425(e). To satisfy the leakage test requirements of this paragraph, the test specified in 40 CFR 63.425(e)(1) must be conducted using air. The hydrostatic test alternative permitted under Appendix A to 40 CFR...

  15. 49 CFR 178.347-5 - Pressure and leakage test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Pressure and leakage test. 178.347-5 Section 178... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.347-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b)...

  16. 49 CFR 178.347-5 - Pressure and leakage test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Pressure and leakage test. 178.347-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.347-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  17. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... is equipped with vapor recovery equipment may be leakage tested in accordance with 40 CFR 63.425(e). To satisfy the leakage test requirements of this paragraph, the test specified in 40 CFR 63.425(e)(1) must be conducted using air. The hydrostatic test alternative permitted under Appendix A to 40 CFR...

  18. 49 CFR 178.348-5 - Pressure and leakage test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Pressure and leakage test. 178.348-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.348-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  19. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... is equipped with vapor recovery equipment may be leakage tested in accordance with 40 CFR 63.425(e). To satisfy the leakage test requirements of this paragraph, the test specified in 40 CFR 63.425(e)(1) must be conducted using air. The hydrostatic test alternative permitted under Appendix A to 40 CFR...

  20. 49 CFR 178.348-5 - Pressure and leakage test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Pressure and leakage test. 178.348-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.348-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  1. 49 CFR 178.348-5 - Pressure and leakage test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Pressure and leakage test. 178.348-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.348-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  2. 49 CFR 178.347-5 - Pressure and leakage test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Pressure and leakage test. 178.347-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.347-5 Pressure and leakage test. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  3. 40 CFR 264.252 - Action leakage rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Action leakage rate. 264.252 Section 264.252 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Waste Piles § 264.252 Action leakage rate. (a)...

  4. 40 CFR 264.222 - Action leakage rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Action leakage rate. 264.222 Section 264.222 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Surface Impoundments § 264.222 Action leakage...

  5. 40 CFR 265.222 - Action leakage rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Surface Impoundments § 265.222 Action leakage rate. (a) The owner or operator of surface...) The Regional Administrator shall approve an action leakage rate for surface impoundment units...

  6. 40 CFR 265.222 - Action leakage rate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Surface Impoundments § 265.222 Action leakage rate. (a) The owner or operator of surface...) The Regional Administrator shall approve an action leakage rate for surface impoundment units...

  7. 42 CFR 84.158 - Exhalation valve leakage test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Exhalation valve leakage test. 84.158 Section 84... Respirators § 84.158 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be... between the valve and valve seat shall not exceed 30 milliliters per minute....

  8. 42 CFR 84.158 - Exhalation valve leakage test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Exhalation valve leakage test. 84.158 Section 84... Respirators § 84.158 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be... between the valve and valve seat shall not exceed 30 milliliters per minute....

  9. 42 CFR 84.158 - Exhalation valve leakage test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Exhalation valve leakage test. 84.158 Section 84... Respirators § 84.158 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be... between the valve and valve seat shall not exceed 30 milliliters per minute....

  10. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Equipment Provisions § 89.316 Analyzer leakage and response time. (a) Vacuum side leak check. (1) Any location within the analysis system where a vacuum leak could affect the test results must be checked. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for...

  11. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Equipment Provisions § 89.316 Analyzer leakage and response time. (a) Vacuum side leak check. (1) Any location within the analysis system where a vacuum leak could affect the test results must be checked. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for...

  12. 40 CFR 90.324 - Analyzer leakage check.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Provisions § 90.324 Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for the portion of the system being...

  13. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Equipment Provisions § 89.316 Analyzer leakage and response time. (a) Vacuum side leak check. (1) Any location within the analysis system where a vacuum leak could affect the test results must be checked. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for...

  14. 40 CFR 90.324 - Analyzer leakage check.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Provisions § 90.324 Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for the portion of the system being...

  15. 40 CFR 90.324 - Analyzer leakage check.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Provisions § 90.324 Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for the portion of the system being...

  16. 40 CFR 90.324 - Analyzer leakage check.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Provisions § 90.324 Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for the portion of the system being...

  17. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Equipment Provisions § 89.316 Analyzer leakage and response time. (a) Vacuum side leak check. (1) Any location within the analysis system where a vacuum leak could affect the test results must be checked. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for...

  18. 40 CFR 90.324 - Analyzer leakage check.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Provisions § 90.324 Analyzer leakage check. (a) Vacuum side leak check. (1) Check any location within the analysis system where a vacuum leak could affect the test results. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for the portion of the system being...

  19. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Equipment Provisions § 89.316 Analyzer leakage and response time. (a) Vacuum side leak check. (1) Any location within the analysis system where a vacuum leak could affect the test results must be checked. (2) The maximum allowable leakage rate on the vacuum side is 0.5 percent of the in-use flow rate for...

  20. 42 CFR 84.158 - Exhalation valve leakage test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Exhalation valve leakage test. 84.158 Section 84.158 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.158 Exhalation valve leakage...

  1. 42 CFR 84.158 - Exhalation valve leakage test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Exhalation valve leakage test. 84.158 Section 84... Respirators § 84.158 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be subjected to a suction of 25 mm. water-column height while in a normal operating position. (b)...

  2. 75 FR 29699 - Total Inward Leakage Requirements for Respirators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... Inward Leakage Requirements for Respirators on Friday, October 30, 2009 (74 FR 56141). NIOSH held a... Federal Register on Friday, October 30, 2009 (74 FR 56141). The purpose of the meeting is to allow... process in the area of filtering facepiece or other half-mask respirator inward leakage measurement,...

  3. 42 CFR 84.123 - Exhalation valve leakage test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Exhalation valve leakage test. 84.123 Section 84.123 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY....123 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be subjected to...

  4. 42 CFR 84.123 - Exhalation valve leakage test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Exhalation valve leakage test. 84.123 Section 84.123 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY....123 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be subjected to...

  5. 42 CFR 84.123 - Exhalation valve leakage test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Exhalation valve leakage test. 84.123 Section 84.123 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY....123 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be subjected to...

  6. 42 CFR 84.123 - Exhalation valve leakage test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Exhalation valve leakage test. 84.123 Section 84.123 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY....123 Exhalation valve leakage test. (a) Dry exhalation valves and valve seats will be subjected to...

  7. Endotracheal Tube Management and Obstructed Airway.

    PubMed

    Sancheti, Manu; Force, Seth

    2015-08-01

    Thoracic surgery encompasses a wide array of surgical techniques, most of which require lung isolation for surgical exposure in the pleural cavity; this, in turn, demands an extensive knowledge of respiratory mechanics and modalities of airway control. Likewise, effective treatment of an acute central airway obstruction calls for a systematic approach using clear communication between teams and a comprehensive knowledge of available therapeutic modalities by the surgeon. PMID:26210924

  8. Medical management considerations for upper airway disease.

    PubMed

    Spaulding, G L

    1992-06-01

    The conducting airways, also commonly referred to as the upper airways, provide for the passage of air to and from the atmosphere and lungs. Anatomical components include the nasal passages, pharynx, larynx, trachea, and mainstem bronchi. Clinical problems involving the conducting airways can be manifested by relatively mild clinical signs of stertorous breathing, by life-threatening dyspnea, or by chronic bouts of inspiratory stridor and cough. Concurrent disease of the lower respiratory system (ie, chronic bronchitis) as well as other organ systems (ie, cardiovascular, nervous, endocrine) may significantly contribute to the etiology and pathophysiology of upper airway disease. Diagnosis of the diseases of the conducting airways is primarily based on history and physical examination. The dynamic nature of some conditions, related to the phases of respiration, can make diagnosis more difficult. In addition to direct visualization, radiographic and endoscopic evaluation are often useful. Many upper airway problems, especially congenital conditions, lend themselves to surgical palliation that should be performed as early in life as possible. Medical management is often directed at treating underlying diseases and the relief of clinical signs. Historically, the use of variety of drugs have been advocated and frequently include decongestants, cough suppressants, bronchodilators, glucocorticoids, and antibiotics. However, their use may be detrimental and contraindicated. In addition, therapy for some conditions (ie, laryngeal paralysis and intrathoracic tracheal collapse) may be better directed at increasing airway muscle tone in order to stabilized airway patency. Therapeutic agents that may be useful include aspirin and digitalis. The overall objective to medical management must be to balance potential therapeutic benefit against untoward effects in order to minimize clinical signs and to improve the animal's quality of life. PMID:1643322

  9. Tracheal and airway collapse in dogs.

    PubMed

    Maggiore, Ann Della

    2014-01-01

    Tracheal and airway collapse (bronchomalacia) are common causes of chronic cough in middle-aged to older dogs where weakening of cartilage within the respiratory system leads to narrowing of airways, coughing, wheezing, and other secondary effects. Successful treatment involves correct identification of the problem, recognition of concurrent problems, and appropriate medical therapy. Surgical and noninvasive treatment options are becoming readily available, and it is important to understand indications for such procedures. PMID:24268337

  10. Basolateral chloride current in human airway epithelia.

    PubMed

    Itani, Omar A; Lamb, Fred S; Melvin, James E; Welsh, Michael J

    2007-10-01

    Electrolyte transport by airway epithelia regulates the quantity and composition of liquid covering the airways. Previous data indicate that airway epithelia can absorb NaCl. At the apical membrane, cystic fibrosis transmembrane conductance regulator (CFTR) provides a pathway for Cl(-) absorption. However, the pathways for basolateral Cl(-) exit are not well understood. Earlier studies, predominantly in cell lines, have reported that the basolateral membrane contains a Cl(-) conductance. However, the properties have varied substantially in different epithelia. To better understand the basolateral Cl(-) conductance in airway epithelia, we studied primary cultures of well-differentiated human airway epithelia. The basolateral membrane contained a Cl(-) current that was inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The current-voltage relationship was nearly linear, and the halide selectivity was Cl(-) > Br(-) > I(-). Several signaling pathways increased the current, including elevation of cellular levels of cAMP, activation of protein kinase C (PKC), and reduction of pH. In contrast, increasing cell Ca(2+) and inducing cell swelling had no effect. The basolateral Cl(-) current was present in both cystic fibrosis (CF) and non-CF airway epithelia. Likewise, airway epithelia from wild-type mice and mice with disrupted genes for ClC-2 or ClC-3 all showed similar Cl(-) currents. These data suggest that the basolateral membrane of airway epithelia possesses a Cl(-) conductance that is not due to CFTR, ClC-2, or ClC-3. Its regulation by cAMP and PKC signaling pathways suggests that coordinated regulation of Cl(-) conductance in both apical and basolateral membranes may be important in controlling transepithelial Cl(-) movement. PMID:17660331

  11. Suppressing leakage by localized doping in Si nanotransistor channels.

    PubMed

    Maassen, Jesse; Guo, Hong

    2012-12-28

    By first principles atomistic analysis we demonstrate how controlled localized doping distributions in nanoscale Si transistors can suppress leakage currents. We consider dopants (B and P atoms) to be randomly confined to a ≈1  nm width doping region in the channel. If this region is located away from the electrodes, roughly 20% of the channel length L, the tunneling leakage is reduced 2× compared to the case of uniform doping and shows little variation. Oppositely, we find the leakage current increases by orders of magnitude and may result in large device variability. We calculate the maximum and minimum conductance ratio that characterizes the tunnel leakage for various values of L. We conclude that doping engineering provides a possible approach to resolve the critical issue of leakage current in nanotransistors. PMID:23368599

  12. Endoscopic Treatment of Stump Leakage Related to the Ileal Conduit

    PubMed Central

    Odemis, Bulent; Oztas, Erkin; Akpinar, Muhammet Yener; Olcucuoglu, Erkan; Kayacetin, Ertugrul

    2016-01-01

    Abstract Background: Ileal conduit with leakage from either the anastomotic site or the stump is associated with high morbidity and mortality rates. The standard treatment of stump leakage is surgery. Case Presentation: A 60-year-old male patient was admitted to our hospital with complaint of hematuria and bladder carcinoma was diagnosed. After performing radical cystectomy and ileal conduit, he developed fever with abdominal pain within the first week of surgery. Stump leakage was diagnosed by endoscopic examination performed through a gastroscope. After two over-the-scope clips (OTSCs) were applied to the stump, vinyl mesh was inserted into the space between the OTSCs. Later, cyanoacrylat and lipiodol were repelled on the OTSCs and vinyl mesh. Subsequently, stump leakage was resolved. Conclusion: This is the first case of stump leakage related to ileal conduit that has been treated endoscopically, according to the current literature. PMID:27579432

  13. Technology Solutions Case Study: Predicting Envelope Leakage in Attached Dwellings

    SciTech Connect

    2013-11-01

    The most common method of measuring air leakage is to perform single (or solo) blower door pressurization and/or depressurization test. In detached housing, the single blower door test measures leakage to the outside. In attached housing, however, this “solo” test method measures both air leakage to the outside and air leakage between adjacent units through common surfaces. In an attempt to create a simplified tool for predicting leakage to the outside, Building America team Consortium for Advanced Residential Buildings (CARB) performed a preliminary statistical analysis on blower door test results from 112 attached dwelling units in four apartment complexes. Although the subject data set is limited in size and variety, the preliminary analyses suggest significant predictors are present and support the development of a predictive model. Further data collection is underway to create a more robust prediction tool for use across different construction types, climate zones, and unit configurations.

  14. Trichobezoar Causing Airway Compromise during Esophagogastroduodenoscopy.

    PubMed

    Kao, Erica Y; Scalzitti, Nicholas J; Dion, Gregory R; Bowe, Sarah N

    2015-01-01

    Objectives. (1) Report the case of a 5-year-old female with trichotillomania and trichophagia that suffered airway compromise during esophagogastroduodenoscopy for removal of a trichobezoar. (2) Provide management recommendations for an unusual foreign body causing extubation and partial airway obstruction. Methods. Case report of a rare situation of airway compromise caused by a trichobezoar. Results. A 5-year-old patient underwent endoscopic retrieval of a gastric trichobezoar (hairball) by the gastroenterology service under general endotracheal anesthesia in a sedation unit. During removal, the hairball, due to its large size, dislodged the endotracheal tube, effectively extubating the patient. The bezoar became lodged at the cricopharyngeus muscle. Attempts to remove the bezoar or reintubation were unsuccessful. The child was able to be mask ventilated while the otolaryngology service was called. Direct laryngoscopy revealed a hairball partially obstructing the view of the glottis from its position in the postcricoid area. The hairball, still entrapped in the snare from the esophagoscope, was grasped with Magill forceps and slowly extracted. The patient was then reintubated and the airway and esophagus were reevaluated. Conclusions. Trichobezoar is an uncommon cause of airway foreign body. Careful attention to airway management during these and similar foreign body extractions can prevent inadvertent extubations. PMID:26457086

  15. Acid-sensing by airway afferent nerves

    PubMed Central

    Lee, Lu-Yuan; Gu, Qihai; Xu, Fadi; Hong, Ju-Lun

    2013-01-01

    Inhalation of acid aerosol or aspiration of acid solution evokes a stimulatory effect on airway C-fiber and Aδ afferents, which in turn causes airway irritation and triggers an array of defense reflex responses (e.g., cough, reflex bronchoconstriction, etc.). Tissue acidosis can also occur locally in the respiratory tract as a result of ischemia or inflammation, such as in the airways of asthmatic patients during exacerbation. The action of proton on the airway sensory neurons is generated by activation of two different current species: a transient (rapidly activating and inactivating) current mediated through the acid-sensing ion channels, and a slowly activating and sustained current mediated through the transient receptor potential vanilloid type 1 (TRPV1) receptor. In view of the recent findings that the expression and/or sensitivity of TRPV1 are up-regulated in the airway sensory nerves during chronic inflammatory reaction, the proton-evoked irritant effects on these nerves may play an important part in the manifestation of various symptoms associated with airway inflammatory diseases. PMID:23524016

  16. Interleukin-20 promotes airway remodeling in asthma.

    PubMed

    Gong, Wenbin; Wang, Xin; Zhang, Yuguo; Hao, Junqing; Xing, Chunyan; Chu, Qi; Wang, Guicheng; Zhao, Jiping; Wang, Junfei; Dong, Qian; Liu, Tian; Zhang, Yuanyuan; Dong, Liang

    2014-12-01

    Previous studies have demonstrated that interleukin-20 (IL-20) is a pro-inflammatory cytokine, and it has been implicated in psoriasis, lupus nephritis, rheumatoid arthritis, atherosclerosis, and ulcerative colitis. Little is known about the effects of IL-20 in airway remodeling in asthma. The aim of our study was to demonstrate the function of IL-20 in airway remodeling in asthma. To identify the expression of IL-20 and its receptor, IL-20R1/IL-20R2, in the airway epithelium in bronchial tissues, bronchial biopsy specimens were collected from patients and mice with asthma and healthy subjects and stained with specific antibodies. To characterize the effects of IL-20 in asthmatic airway remodeling, we silenced and stimulated IL-20 in cell lines isolated from mice by shRNA and recombinant protein approaches, respectively, and detected the expression of α-SMA and FN-1 by Western blot analysis. First, overexpression of IL-20 and its receptor, IL-20R1/IL-20R2, was detected in the airway epithelium collected from patients and mice with asthma. Second, IL-20 increased the expression of fibronectin-1 and α-SMA, and silencing of IL-20 in mouse lung epithelial (MLE)-12 cells decreased the expression of fibronectin-1 and α-SMA. IL-20 may be a critical cytokine in airway remodeling in asthma. This study indicates that targeting IL-20 and/or its receptors may be a new therapeutic strategy for asthma. PMID:25028099

  17. Regulation of Airway Mucin Gene Expression

    PubMed Central

    Thai, Philip; Loukoianov, Artem; Wachi, Shinichiro; Wu, Reen

    2015-01-01

    Mucins are important components that exert a variety of functions in cell-cell interaction, epidermal growth factor receptor signaling, and airways protection. In the conducting airways of the lungs, mucins are the major contributor to the viscoelastic property of mucous secretion, which is the major barrier to trapping inhaled microbial organism, particulates, and oxidative pollutants. The homeostasis of mucin production is an important feature in conducting airways for the maintenance of mucociliary function. Aberrant mucin secretion and accumulation in airway lumen are clinical hallmarks associated with various lung diseases, such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, emphysema, and lung cancer. Among 20 known mucin genes identified, 11 of them have been verified at either the mRNA and/or protein level in airways. The regulation of mucin genes is complicated, as are the mediators and signaling pathways. This review summarizes the current view on the mediators, the signaling pathways, and the transcriptional units that are involved in the regulation of airway mucin gene expression. In addition, we also point out essential features of epigenetic mechanisms for the regulation of these genes. PMID:17961085

  18. Trichobezoar Causing Airway Compromise during Esophagogastroduodenoscopy

    PubMed Central

    Kao, Erica Y.; Scalzitti, Nicholas J.; Dion, Gregory R.; Bowe, Sarah N.

    2015-01-01

    Objectives. (1) Report the case of a 5-year-old female with trichotillomania and trichophagia that suffered airway compromise during esophagogastroduodenoscopy for removal of a trichobezoar. (2) Provide management recommendations for an unusual foreign body causing extubation and partial airway obstruction. Methods. Case report of a rare situation of airway compromise caused by a trichobezoar. Results. A 5-year-old patient underwent endoscopic retrieval of a gastric trichobezoar (hairball) by the gastroenterology service under general endotracheal anesthesia in a sedation unit. During removal, the hairball, due to its large size, dislodged the endotracheal tube, effectively extubating the patient. The bezoar became lodged at the cricopharyngeus muscle. Attempts to remove the bezoar or reintubation were unsuccessful. The child was able to be mask ventilated while the otolaryngology service was called. Direct laryngoscopy revealed a hairball partially obstructing the view of the glottis from its position in the postcricoid area. The hairball, still entrapped in the snare from the esophagoscope, was grasped with Magill forceps and slowly extracted. The patient was then reintubated and the airway and esophagus were reevaluated. Conclusions. Trichobezoar is an uncommon cause of airway foreign body. Careful attention to airway management during these and similar foreign body extractions can prevent inadvertent extubations. PMID:26457086

  19. Small Airway Dysfunction and Abnormal Exercise Responses

    PubMed Central

    Petsonk, Edward L.; Stansbury, Robert C.; Beeckman-Wagner, Lu-Ann; Long, Joshua L.; Wang, Mei Lin

    2016-01-01

    Rationale Coal mine dust exposure can cause symptoms and loss of lung function from multiple mechanisms, but the roles of each disease process are not fully understood. Objectives We investigated the implications of small airway dysfunction for exercise physiology among a group of workers exposed to coal mine dust. Methods Twenty coal miners performed spirometry, first breathing air and then helium-oxygen, single-breath diffusing capacity, and computerized chest tomography, and then completed cardiopulmonary exercise testing. Measurements and Main Results Six participants meeting criteria for small airway dysfunction were compared with 14 coal miners who did not. At submaximal workload, miners with small airway dysfunction used a higher proportion of their maximum voluntary ventilation and had higher ventilatory equivalents for both O2 and CO2. Regression modeling indicated that inefficient ventilation was significantly related to small airway dysfunction but not to FEV1 or diffusing capacity. At the end of exercise, miners with small airway dysfunction had 27% lower O2 consumption. Conclusions Small airway abnormalities may be associated with important inefficiency of exercise ventilation. In dust-exposed individuals with only mild abnormalities on resting lung function tests or chest radiographs, cardiopulmonary exercise testing may be important in defining causes of exercise intolerance. PMID:27073987

  20. Exercise-induced airways constriction 1

    PubMed Central

    Simonsson, Bo G.; Skoogh, B-E.; Ekström-Jodal, B.

    1972-01-01

    Airway conductance was measured in a body plethysmograph at different lung volumes before and after graded exercise. In 14 out of 19 patients, mostly asthmatics, airway conductance fell significantly after exercise. These subjects also showed other signs of an increased bronchial reactivity to different stimuli, including forced breathing, hyperventilation, and cold air, but they had no exogenous allergy. The exercise-induced bronchoconstriction could be blocked by atropine in six of the nine patients tested. Exercise-induced bronchoconstriction in patients with clinical and physiological evidence of increased airway reactivity thus seems to be primarily mediated via a vagal reflex, probably from hyperresponsive airway mechanoreceptors reacting to increased ventilatory flow or lung distension. No relation was found between PaCO2 or pH and the severity of airways constriction. Cromoglycic acid failed to block the exercise reaction in five of the six hyperreactive patients tested. In addition to or following the vagal reflex a disturbed relation between beta and alpha receptors in bronchial muscles or a release of humoral spasmogens may contribute to the progression of post-exercise airways constriction. PMID:4624586