Science.gov

Sample records for airway microvascular leakage

  1. Promotion of airway anastomotic microvascular regeneration and alleviation of airway ischemia by deferoxamine nanoparticles

    PubMed Central

    Tian, Wen; Sung, Yon K.; Sun, Wenchao; Hsu, Joe L.; Manickam, Sathish; Wagh, Dhananjay; Joubert, Lydia-Marie; Semenza, Gregg L.; Rajadas, Jayakumar; Nicolls, Mark R.

    2014-01-01

    Airway tissue ischemia and hypoxia in human lung transplantation is a consequence of the sacrifice of the bronchial circulation during the surgical procedure and is a major risk factor for the development of airway anastomotic complications. Augmented expression of hypoxia-inducible factor (HIF)-1α promotes microvascular repair and alleviates allograft ischemia and hypoxia. Deferoxamine mesylate (DFO) is an FDA-approved iron chelator which has been shown to upregulate cellular HIF-1α. Here, we developed a nanoparticle formulation of DFO that can be topically applied to airway transplants at the time of surgery. In a mouse orthotopic tracheal transplant (OTT) model, the DFO nanoparticle was highly effective in enhancing airway microvascular perfusion following transplantation through the production of the angiogenic factors, placental growth factor (PLGF) and stromal cell-derived factor (SDF)-1. The endothelial cells in DFO treated airways displayed higher levels of p-eNOS and Ki67, less apoptosis, and decreased production of perivascular reactive oxygen species (ROS) compared to vehicle-treated airways. In summary, a DFO formulation topically-applied at the time of surgery successfully augmented airway anastomotic microvascular regeneration and the repair of alloimmune-injured microvasculature. This approach may be an effective topical transplant-conditioning therapy for preventing airway complications following clinical lung transplantation. PMID:24161166

  2. [Effect of sodium cromoglycate on airway vascular leakage caused by hypertonic saline in the rat trachea].

    PubMed

    Yamawaki, I; Tamaoki, J; Takeda, Y; Konno, K

    1996-09-01

    The action of the anti-asthmatic drug sodium cromoglycate (SCG) on airway inflammation remains uncertain. Using Evans blue dye as a maker of plasma leakage, we studied the effect of SCG on neurogenic vascular extravasation evoked by hypertonic saline (HTS) in the rat trachea. Inhalation of HTS (5-15%) caused a concentration-dependent increase in plasma leakage, but inhaled 0.9% NaCl had no effect. Inhalation of SCG did not affect the baseline level of vascular permeability, but it inhibited the effect of HTS in a dose-dependent manner: plasma extravasation induced by 10% NaCl was significantly reduced by 2 minutes of inhalation of SCG at concentrations of 10 and 50 mg/ml (p < 0.05 and p < 0.01, respectively). SCG (10 mg/ml), also inhibited the changes in microvascular permeability caused by aerosols of substance P (10(-4) M), whereas it did not affect the responses to aerosols of platelet-activating factor (3 x 10(-4) M). A similar dose of SCG did not significantly alter microvascular leakage caused by 5% NaCl. However, phosphoramidon, a selective inhibitor of neutral endopeptidase, potentiated the response to 5% NaCl, an effect that was inhibited by SCG (p < 0.05). These results suggest that SCG inhibits HTS-induced airway vascular permeability, presumably through a tachykinin-antagonist-like property, and that this inhibition is exaggerated when the activity of endogenous neutral endopeptidase is low.

  3. 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.

  4. Involvement of ROCK-mediated endothelial tension development in neutrophil-stimulated microvascular leakage

    PubMed Central

    Breslin, Jerome W.; Sun, Hengrui; Xu, Wenjuan; Rodarte, Charles; Moy, Alan B.; Wu, Mack H.; Yuan, Sarah Y.

    2009-01-01

    Neutrophil-induced coronary microvascular barrier dysfunction is an important pathophysiological event in heart disease. Currently, the precise cellular and molecular mechanisms of neutrophil-induced microvascular leakage are not clear. The aim of this study was to test the hypothesis that rho kinase (ROCK) increases coronary venular permeability in association with elevated endothelial tension. We assessed permeability to albumin (Pa) in isolated porcine coronary venules and in coronary venular endothelial cell (CVEC) monolayers. Endothelial barrier function was also evaluated by measuring transendothelial electrical resistance (TER) of CVEC monolayers. In parallel, we measured isometric tension of CVECs grown on collagen gels. Transference of constitutively active (ca)-ROCK protein into isolated coronary venules or CVEC monolayers caused a significant increase in Pa and decreased TER in CVECs. The ROCK inhibitor Y-27632 blocked the ca-ROCK-induced changes. C5a-activated neutrophils (106/ml) also significantly elevated venular Pa, which was dose-dependently inhibited by Y-27632 and a structurally distinct ROCK inhibitor, H-1152. In CVEC monolayers, activated neutrophils increased permeability with a concomitant elevation in isometric tension, both of which were inhibited by Y-27632 or H-1152. Treatment with ca-ROCK also significantly increased CVEC monolayer permeability and isometric tension, coupled with actin polymerization and elevated phosphorylation of myosin regulatory light chain on Thr18/Ser19. The data suggest that during neutrophil activation, ROCK promotes microvascular leakage in association with actin-myosin-mediated tension development in endothelial cells. PMID:16172166

  5. Magnetic resonance imaging of microvascular leakage induced by myocardial contrast echocardiography in rats.

    PubMed

    Swanson, Scott D; Dou, Chunyan; Miller, Douglas L

    2006-06-01

    The extent and magnitude of microvascular leakage induced by myocardial contrast echocardiography (MCE) were characterized with contrast-aided magnetic resonance imaging (MRI). Evans blue dye, Definity ultrasound contrast agent and Omniscan magnetic resonance contrast agent were injected intravenously in anesthetized rats suspended in a water bath. Diagnostic ultrasound B mode scans with 1:4 end-systolic triggering were performed at 1.5 MHz using a cardiac phased array scanhead to provide a short axis view of the left ventricle. The in situ peak rarefactional pressure amplitude (PRPA) was 2.0 MPa. Microvascular leakage was characterized by extraction of the dye from tissue samples and by imaging the distribution and concentration of Omniscan within the myocardium. The extracted Evans blue was 2.3 times greater than in shams (P<.05) for heart samples perfused with heparin saline, and 1.6 times greater than shams (not significant) for unperfused samples. The MRI showed the penetration of the ultrasound-induced capillary leakage throughout much of the scan plane. The overall gadolinium content measured by MR showed the same trends as the extracted Evans blue, but was more variable. For pooled data (perfused and unperfused), the exposed samples were significantly increased (P<.05) relative to the sham samples for both Evans blue and gadolinium content. Omniscan leakage was also discernable in two of four MRIs from intact rats (after sacrifice). These results demonstrate a potential for MR mapping of capillary leakage induced by contrast-aided ultrasound, with a possible application to spatial characterization of local drug delivery.

  6. 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.

  7. Differential effects of topically applied formalin and aromatic compounds on neurogenic-mediated microvascular leakage in rat skin.

    PubMed

    Futamura, Masaki; Goto, Shiho; Kimura, Ryoko; Kimoto, Izumi; Miyake, Mio; Ito, Komei; Sakamoto, Tatsuo

    2009-01-08

    Various volatile organic compounds (VOCs) act as a causative agent of skin inflammation. We investigated the effect of topical application of several VOCs and formalin on microvascular leakage in rat skin. We tested capsaicin, which is a reagent that specifically causes the skin response via endogenously released tachykinins. Evans blue dye extravasation served as an index of the increase in skin vascular permeability. After shaving the abdomen, we applied formalin, m-xylene, toluene, styrene, benzene, ethylbenzene, acetone, diethyl ether, hexane, heptane, cyclohexane and capsaicin to the skin. At 40min after application, skin samples were collected. Among all of the VOCs tested, all of the aromatic compounds significantly produced skin microvascular leakage that was similar to formalin and capsaicin. We also investigated the skin responses seen after the intravenous administration of CP-99,994 (1.5 or 5mg/kg), which is a tachykinin NK1 receptor antagonist, ketotifen (1 or 3mg/kg), which is a histamine H1 receptor antagonist that stabilizes the mast cells, and the topical application of capsazepine (22.5 or 50mM), which is the transient receptor potential vanilloid 1 (TRPV1) antagonist. The response induced by formalin and capsaicin was completely inhibited by CP-99,994. On the other hand, the antagonist partially reduced the response induced by m-xylene, toluene and styrene by 39%, 50% and 46%, respectively. Capsazepine and ketotifen did not alter the response induced by formalin or any of the aromatic compounds. Like capsaicin, formalin and the aromatic compounds at least partially caused skin microvascular leakage, which was due to tachykinin NK1 receptor activation related to the release of tachykinins from the sensory nerve endings. However, it is unlikely that mast cells and TRPV1 play an important role in the skin response.

  8. 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

  9. Microvascular dysfunction with increased vascular leakage response in mice systemically exposed to arsenic.

    PubMed

    Chen, Shih-Chieh; Huang, Shin-Yin; Lu, Chi-Yu; Hsu, Ya-Hung; Wang, Dean-Chuan

    2014-09-01

    The mechanisms underlying cardiovascular disease induced by arsenic exposure are not completely understood. The objectives of this study were to investigate whether arsenic-fed mice have an increased vascular leakage response to vasoactive agents and whether enhanced type-2 protein phosphatase (PP2A) activity is involved in mustard oil-induced leakage. ICR mice were fed water or sodium arsenite (20 mg/kg) for 4 or 8 weeks. The leakage response to vasoactive agents was quantified using the Evans blue (EB) technique or vascular labeling with carbon particles. Increased EB leakage and high density of carbon-labeled microvessels were detected in arsenic-fed mice treated with mustard oil. Histamine induced significantly higher vascular leakage in arsenic-fed mice than in water-fed mice. Pretreatment with the PP2A inhibitor okadaic acid or the neurokinin 1 receptor (NK1R) blocker RP67580 significantly reduced mustard oil-induced vascular leakage in arsenic-fed mice. The protein levels of PP2Ac and NK1R were similar in both groups. PP2A activity was significantly higher in the arsenic-fed mice compared with the control group. These findings indicate that microvessels generally respond to vasoactive agents, and that the increased PP2A activity is involved in mustard oil-induced vascular leakage in arsenic-fed mice. Arsenic may initiate endothelial dysfunction, resulting in vascular leakage in response to vasoactive agents.

  10. Involvement of inflammatory mediators in the airway responses to trimellitic anhydride in sensitized guinea-pigs.

    PubMed Central

    Hayes, J. P.; Lotvall, J. O.; Barnes, P. J.; Newman Taylor, A. J.; Chung, K. F.

    1992-01-01

    1. We examined the effect of various pharmacological agents on the acute bronchoconstrictor response and airway microvascular leakage in a model of guinea-pig sensitization to trimellitic anhydride (TMA) a cause of low molecular weight occupational asthma in man. 2. Guinea-pigs were given intradermal injections of 0.1 ml of 0.3% TMA in corn oil; 21-28 days later, anaesthetized guinea-pigs were challenged with TMA conjugated to guinea-pig albumin by tracheal instillation. Changes in lung resistance were measured and airway microvascular leakage was quantified by measuring the extravasation of Evans blue dye into the airway tissue. 3. Sensitized guinea-pig (n = 9 in each group) were pretreated with chlorpheniramine (2.5 mg kg-1, i.v.), WEB 2086 (10 micrograms kg-1, i.v.), BW 4AC (50 mg kg-1, i.p.), nedocromil sodium (2% aerosol for 60 s) or vehicle alone. 4. Pretreatment with chlorpheniramine inhibited both the acute bronchoconstrictor response and the increase in airway microvascular leakage. WEB 2086 and nedocromil sodium partially inhibited the bronchoconstrictor response but had no significant effect on airway microvascular leakage. BW 4AC caused a non-significant reduction of the bronchoconstrictor response and airway microvascular leakage. 5. These results indicate that both the bronchoconstrictor response and the airway microvascular response in this model of sensitization is mediated to a large extent by histamine. PAF but not 5-lipoxygenase products also partially mediates the bronchoconstrictor response but not the airway microvascular leakage. Nedocromil sodium partially inhibits the bronchoconstrictor response only. PMID:1382788

  11. Review And Insights Into The Bleeding Mechanism Incited By Antithrombotic Therapy: Mechanistic Nuances Of Dual Pro-Hemorrhagic Substrate Incorporating Drug-Induced Microvascular Leakage.

    PubMed

    Stirbys Md PhD, Petras

    2015-01-01

    In patients with atrial fibrillation antithrombotic prophylaxis for stroke is associated with an increased risk of bleeding. Cerebrovascular risk-benefit ratio for oral anticoagulation therapies continues to be debated. Macro and/or microhematomas as well as visible or cryptic ones may appear unexpectedly in any anatomic region. The diagnostic and prognostic value of subcutaneous hematomas (petechia, ecchymosis, bruise) potentially predisposing intracerebral micro- or macrobleeding might be reconsidered. Hypothetically, subcutaneous hemorrhagic events are "transparent" signs and reflect the coexistence of remote vulnerable sites that are potential bleeding sources. Obviously vigilance is needed for early signs of drug-related petechiae evaluation to determine whether it is a local/superficial subtlety or a systemic problem. Any bleeding complication, regardless of its scale and anatomical location, might be treated as a worrisome clinical symptom requiring subtle correction of antithrombotic regimen. The focus of this article is to review the current knowledge of drug-related hemorrhage with special emphasis on underlying mechanisms and links between the visible bleeding (predominantly subcutaneous) and remote (such as cerebral) hemorrhagic sources. To mitigate inappropriate therapy, we should consider new conceptual insights and more individualized approaches to achieve an optimal balance of efficacy and safety. We hypothesize that bleeding complications occur as a result of two factors - impact of antithrombotic drugs and related detrimental effect on microvascular network. Most likely the microvasculature undergoes pro-hemorrhagic medication stress leading to unfavorable vascular wall "fenestration" with ensuing consequences. If so, it suggests the presence of dual substrate responsible for hemorrhagic events.

  12. 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 ...

  13. Microvascular Autonomic Composites

    DTIC Science & Technology

    2012-01-06

    characterization of carbon nanotube yarns, 3-D braids, and their composites. SAMPE Journal 43: 6-19. Bogdanovich A and Mohamed MH. 2009. Three-Dimensional... carbon in red and bromine in yellow. The fracture surfaces were analyzed by SEM to show film was indistinguishable from the matrix, but by using the...nature, the mother of composite materials, applying microvascular technology to create skin, cartilages, tendons, bones and teeth. Cellulose fiber

  14. Monitoring in microvascular surgery.

    PubMed

    Furnas, H; Rosen, J M

    1991-03-01

    The importance of monitoring in microvascular surgery is underscored by the high reported salvage rates of failing free flaps and replants. In this overview, we begin by defining the physiology of ischemic tissue with emphasis given to the no-reflow phenomenon and the secondary critical ischemia times. Based on the physiological changes accompanying ischemia, several variables are defined that can be monitored to reflect the vascular state of a free flap or replant. Multifarious monitoring systems are then reviewed, including clinical observation, temperature, isotope clearance, ultrasonic Doppler, laser Doppler, transcutaneous oxygen tension, reflection plethysmography, dermofluorometry, pH, electromagnetic flowmetry, serial hematocrits, interstitial fluid pressure, and magnetic resonance imaging.

  15. Intracranial microvascular free flaps.

    PubMed

    Levine, Steven; Garfein, Evan S; Weiner, Howard; Yaremchuk, Michael J; Saadeh, Pierre B; Gurtner, Geoffrey; Levine, Jamie P; Warren, Stephen M

    2009-02-01

    Large acquired intracranial defects can result from trauma or surgery. When reoperation is required because of infection or tumor recurrence, management of the intracranial dead space can be challenging. By providing well-vascularized bulky tissue, intracranial microvascular free flaps offer potential solutions to these life-threatening complications. A multi-institutional retrospective chart and radiographic review was performed of all patients who underwent microvascular free-flap surgery for salvage treatment of postoperative intracranial infections between 1998 and 2006. A total of six patients were identified with large intracranial defects and postoperative intracranial infections. Four patients had parenchymal resections for tumor or seizure and two patients had posttraumatic encephalomalacia. All patients underwent operative debridement and intracranial free-flap reconstruction using the latissimus dorsi muscle (N=2), rectus abdominis muscle (N=2), or omentum (N=2). All patients had titanium (N=4) or Medpor (N=2) cranioplasties. We concluded that surgery or trauma can result in significant intracranial dead space. Treatment of postoperative intracranial infection can be challenging. Vascularized free tissue transfer not only fills the void, but also provides a delivery system for immune cells, antibodies, and systemically administered antibiotics. The early use of this technique when intracranial dead space and infection coexist is beneficial.

  16. 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.

  17. 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.

  18. The Phillips airway.

    PubMed

    Haridas, R P; Wilkinson, D J

    2012-07-01

    The Phillips airway was developed by George Ramsay Phillips. There is no known original description of the airway and the earliest known reference to it is from 1919. The airway and its modifications are described.

  19. 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 ...

  20. Triggers of airway inflammation.

    PubMed

    Kerrebijn, K F

    1986-01-01

    Most asthmatics have hyperresponsive airways. This makes them more sensitive than non-asthmatics to bronchoconstricting environmental exposures which, in their turn, may enhance responsiveness. Airway inflammation is considered to be a key determinant of airway hyperresponsiveness: the fact that chronic airway inflammation in cystic fibrosis does not lead to airway hyperresponsiveness of any importance indicates, however, that the role of airway inflammation is complex and incompletely elucidated. The main inducers of airway inflammation are viral infections, antigens, occupational stimuli and pollutants. Although exercise, airway cooling and hyper- or hypotonic aerosols are potent stimuli of bronchoconstriction, it is questionable if airway inflammation is involved in their mode of action. Each of the above-mentioned stimuli is discussed, with emphasis laid on the relation of symptoms to mechanisms.

  1. The role of the microvascular tortuosity in tumor transport phenomena.

    PubMed

    Penta, R; Ambrosi, D

    2015-01-07

    The role of the microvascular network geometry in transport phenomena in solid tumors and its interplay with the leakage and pressure drop across the vessels is qualitatively and quantitatively discussed. Our starting point is a multiscale homogenization, suggested by the sharp length scale separation that exists between the characteristic vessels and the tumor tissue spatial scales, referred to as the microscale and the macroscale, respectively. The coupling between interstitial and capillary compartment is described by a double Darcy model on the macroscale, whereas the geometric information on the microvascular structure is encoded in the effective hydraulic conductivities, which are numerically computed by solving classical differential problems on the microscale representative cell. Then, microscale information is injected into the macroscopic model, which is analytically solved in a prototypical geometry and compared with previous experimentally validated, phenomenological models. In this way, we are able to capture the role of the standard blood flow determinants in the tumor, such as tumor radius, tissue hydraulic conductivity and vessels permeability, as well as influence of the vascular tortuosity on fluid convection. The results quantitatively confirm that transport of blood (and, as a consequence, of any advected anti-cancer drug) can be dramatically impaired by increasing the geometrical complexity of the microvasculature. Hence, our quantitative analysis supports the argument that geometric regularization of the capillary network improves blood transport and drug delivery in the tumor mass.

  2. Emergency airway puncture

    MedlinePlus

    ... support for only a very short period of time. Alternative Names Needle cricothyrotomy Images Emergency airway puncture Cricoid cartilage Emergency airway puncture - series References Hebert RB, Bose S, Mace SE. Cricothyrotomy and ...

  3. Upper airway biopsy

    MedlinePlus

    ... upper airway Images Upper airway test Bronchoscopy Throat anatomy References Yung RC, Boss EF. Tracheobronchial endoscopy. In: Flint PW, Haughey BH, Lund LJ, et al, eds. Cummings Otolaryngology: Head & Neck Surgery. 5th ed. Philadelphia, PA: Elsevier Mosby; ...

  4. 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…

  5. Leakage-resistant blood vessels in mice transgenically overexpressing angiopoietin-1.

    PubMed

    Thurston, G; Suri, C; Smith, K; McClain, J; Sato, T N; Yancopoulos, G D; McDonald, D M

    1999-12-24

    Angiopoietin-1 (Ang1) and vascular endothelial growth factor (VEGF) are endothelial cell-specific growth factors. Direct comparison of transgenic mice overexpressing these factors in the skin revealed that the VEGF-induced blood vessels were leaky, whereas those induced by Ang1 were nonleaky. Moreover, vessels in Ang1-overexpressing mice were resistant to leaks caused by inflammatory agents. Coexpression of Ang1 and VEGF had an additive effect on angiogenesis but resulted in leakage-resistant vessels typical of Ang1. Ang1 therefore may be useful for reducing microvascular leakage in diseases in which the leakage results from chronic inflammation or elevated VEGF and, in combination with VEGF, for promoting growth of nonleaky vessels.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Association of Microvascular Function and Endothelial Biomarkers With Clinical Outcome in Dengue: An Observational Study

    PubMed Central

    Yacoub, Sophie; Lam, Phung Khanh; Vu, Le Hoang Mai; Le, Thi Lien; Ha, Ngo Thanh; Toan, Tran Thi; Van, Nguyen Thu; Quyen, Nguyen Than Ha; Le Duyen, Huynh Thi; Van Kinh, Nguyen; Fox, Annette; Mongkolspaya, Juthathip; Wolbers, Marcel; Simmons, Cameron Paul; Screaton, Gavin Robert; Wertheim, Heiman; Wills, Bridget

    2016-01-01

    Background. The hallmark of severe dengue is increased microvascular permeability, but alterations in the microcirculation and their evolution over the course of dengue are unknown. Methods. We conducted a prospective observational study to evaluate the sublingual microcirculation using side-stream dark-field imaging in patients presenting early (<72 hours after fever onset) and patients hospitalized with warning signs or severe dengue in Vietnam. Clinical findings, microvascular function, global hemodynamics assessed with echocardiography, and serological markers of endothelial activation were determined at 4 time points. Results. A total of 165 patients were enrolled. No difference was found between the microcirculatory parameters comparing dengue with other febrile illnesses. The proportion of perfused vessels (PPV) and the mean flow index (MFI) were lower in patients with dengue with plasma than those without leakage (PPV, 88.1% vs 90.6% [P = .01]; MFI, 2.1 vs 2.4 [P = .007]), most markedly during the critical phase. PPV and MFI were correlated with the endothelial activation markers vascular cell adhesion molecule 1 (P < .001 for both) and angiopoietin 2 (P < .001 for both), negatively correlated. Conclusions. Modest microcirculatory alterations occur in dengue, are associated with plasma leakage, and are correlate with molecules of endothelial activation, angiopoietin 2 and vascular cell adhesion molecule 1. PMID:27230099

  11. 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.

  12. Pulmonary Microvascular Blood Flow in Mild Chronic Obstructive Pulmonary Disease and Emphysema. The MESA COPD Study

    PubMed Central

    Hueper, Katja; Vogel-Claussen, Jens; Parikh, Megha A.; Austin, John H. M.; Bluemke, David A.; Carr, James; Choi, Jiwoong; Goldstein, Thomas A.; Gomes, Antoinette S.; Hoffman, Eric A.; Kawut, Steven M.; Lima, Joao; Michos, Erin D.; Post, Wendy S.; Po, Ming Jack; Prince, Martin R.; Liu, Kiang; Rabinowitz, Dan; Skrok, Jan; Smith, Ben M.; Watson, Karol; Yin, Youbing; Zambeli-Ljepovic, Alan M.

    2015-01-01

    Rationale: Smoking-related microvascular loss causes end-organ damage in the kidneys, heart, and brain. Basic research suggests a similar process in the lungs, but no large studies have assessed pulmonary microvascular blood flow (PMBF) in early chronic lung disease. Objectives: To investigate whether PMBF is reduced in mild as well as more severe chronic obstructive pulmonary disease (COPD) and emphysema. Methods: PMBF was measured using gadolinium-enhanced magnetic resonance imaging (MRI) among smokers with COPD and control subjects age 50 to 79 years without clinical cardiovascular disease. COPD severity was defined by standard criteria. Emphysema on computed tomography (CT) was defined by the percentage of lung regions below −950 Hounsfield units (−950 HU) and by radiologists using a standard protocol. We adjusted for potential confounders, including smoking, oxygenation, and left ventricular cardiac output. Measurements and Main Results: Among 144 participants, PMBF was reduced by 30% in mild COPD, by 29% in moderate COPD, and by 52% in severe COPD (all P < 0.01 vs. control subjects). PMBF was reduced with greater percentage emphysema−950HU and radiologist-defined emphysema, particularly panlobular and centrilobular emphysema (all P ≤ 0.01). Registration of MRI and CT images revealed that PMBF was reduced in mild COPD in both nonemphysematous and emphysematous lung regions. Associations for PMBF were independent of measures of small airways disease on CT and gas trapping largely because emphysema and small airways disease occurred in different smokers. Conclusions: PMBF was reduced in mild COPD, including in regions of lung without frank emphysema, and may represent a distinct pathological process from small airways disease. PMBF may provide an imaging biomarker for therapeutic strategies targeting the pulmonary microvasculature. PMID:26067761

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Treatment of hemimasticatory spasm with microvascular decompression.

    PubMed

    Wang, Yong-Nan; Dou, Ning-Ning; Zhou, Qiu-Meng; Jiao, Wei; Zhu, Jin; Zhong, Jun; Li, Shi-Ting

    2013-01-01

    Hemimasticatory spasm is a rare disorder characterized by paroxysmal involuntary contraction of the jaw-closing muscles. As the ideology and pathogenesis of the disease are still unclear, there has been no treatment that could give rise to a good outcome so far. Herein, we tried to use surgical management to cure the disease. Six patients with the disease were included in this study. These patients underwent microvascular decompression of the motor fibers of the trigeminal root. After the operation, all faces of the patients felt relaxed at varied degrees, except for 1 patient. Our study showed that microvascular decompression of the trigeminal nerve could lead to a better outcome. However, a control study with a large sample is needed before this technique is widely used.

  19. Microvascular Targets for Anti-Fibrotic Therapeutics

    PubMed Central

    Pu, Kai-Ming T.; Sava, Parid; Gonzalez, Anjelica L.

    2013-01-01

    Fibrosis is characterized by excessive extracellular matrix deposition and is the pathological outcome of repetitive tissue injury in many disorders. The accumulation of matrix disrupts the structure and function of the native tissue and can affect multiple organs including the lungs, heart, liver, and skin. Unfortunately, current therapies against the deadliest and most common fibrosis are ineffective. The pathogenesis of fibrosis is the result of aberrant wound healing, therefore, the microvasculature plays an important role, contributing through regulation of leukocyte recruitment, inflammation, and angiogenesis. Further exacerbating the condition, microvascular endothelial cells and pericytes can transdifferentiate into matrix depositing myofibroblasts. The contribution of the microvasculature to fibrotic progression makes its cellular components and acellular products attractive therapeutic targets. In this review, we examine many of the cytokine, matrix, and cellular microvascular components involved in fibrosis and discuss their potential as targets for fibrotic therapies with a particular focus on developing nanotechnologies. PMID:24348218

  20. 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

  1. 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.

  2. 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.

  3. Vitamin D and retinal microvascular damage

    PubMed Central

    Mutlu, Unal; Ikram, M Arfan; Hofman, Albert; de Jong, Paulus T V M; Uitterlinden, Andre G; Klaver, Caroline C W; Ikram, M Kamran

    2016-01-01

    Abstract Vitamin D has been linked to various cardiovascular risk factors including indices of large-vessel disease. However, it remains unclear whether vitamin D is also associated with microvascular damage. In a community-dwelling population, we studied associations between vitamin D serum levels and retinal microvascular damage defined as retinopathy signs, narrower arterioles, and wider venules. From the population-based Rotterdam Study, we included 5675 participants (age ≥45 years) with vitamin D data and gradable retinal photographs. Serum levels of vitamin D were measured using an antibody-based assay. Retinal exudates, microaneurysms, cotton wool spots, and dot/blot hemorrhages were graded on fundus photographs by experienced graders in the whole sample; retinal vascular calibers, that is, arteriolar and venular diameters, were semiautomatically measured in a subsample (n = 2973). We examined the cross-sectional association between vitamin D and retinal microvascular damage using logistic and linear regression models, adjusting for age, sex, and cardiovascular risk factors. We found that persons with lower vitamin D levels were more likely to have retinopathy (adjusted odds ratio per standard deviation (SD) decrease of vitamin D = 1.30; 95% confidence interval (CI): = 1.12–1.49). Furthermore, lower vitamin D levels were associated with wider venular calibers (adjusted mean difference per SD decrease in vitamin D = 1.35; 95% CI = 0.64–2.06). This association was strongest among men (P for interaction = 0.023). Lower levels of vitamin D are associated with retinal microvascular damage, suggesting that the link with cardiovascular risk may partly run through changes in the microvasculature. PMID:27930528

  4. Fabrication, characterization, and modeling of microvascular composites

    NASA Astrophysics Data System (ADS)

    Ryan, Thomas J.

    Composite laminates of glass fiber and epoxy pre-preg were fabricated with microvascular channels. The channels were created using polylactic acid (PLA) filament that evaporates at a temperature of 392 °F (200 °C) above the resin cure temperature of 250 °F (121 °C). After the composite is cured, the panel was removed from the oven and allowed to cool to room temperature. The panel is then reheated to 392 °F to vaporize the filament, leaving a cylindrical channel. A microvascular channel can be used for withdrawing heat, damage detection and self-healing. However, increasing the temperatures of the laminate above the cure temperature of the resin causes excess cross linking, potentially decreasing the mechanical properties. Tensile and flexural mechanical tests were performed on composite specimens and tensile tests were performed on neat resin specimens. A three-dimensional finite element model (FEM) was developed to study the progressive deformation and damage mechanics under tensile loading. The load carrying capacity of the microvascular composite was shown to decrease by 40% from a standard composite material. This paper will present the details of the fabrication, characterization and modeling techniques that were used in this study.

  5. Human airway organoid engineering as a step toward lung regeneration and disease modeling.

    PubMed

    Tan, Qi; Choi, Kyoung Moo; Sicard, Delphine; Tschumperlin, Daniel J

    2017-01-01

    Organoids represent both a potentially powerful tool for the study cell-cell interactions within tissue-like environments, and a platform for tissue regenerative approaches. The development of lung tissue-like organoids from human adult-derived cells has not previously been reported. Here we combined human adult primary bronchial epithelial cells, lung fibroblasts, and lung microvascular endothelial cells in supportive 3D culture conditions to generate airway organoids. We demonstrate that randomly-seeded mixed cell populations undergo rapid condensation and self-organization into discrete epithelial and endothelial structures that are mechanically robust and stable during long term culture. After condensation airway organoids generate invasive multicellular tubular structures that recapitulate limited aspects of branching morphogenesis, and require actomyosin-mediated force generation and YAP/TAZ activation. Despite the proximal source of primary epithelium used in the airway organoids, discrete areas of both proximal and distal epithelial markers were observed over time in culture, demonstrating remarkable epithelial plasticity within the context of organoid cultures. Airway organoids also exhibited complex multicellular responses to a prototypical fibrogenic stimulus (TGF-β1) in culture, and limited capacity to undergo continued maturation and engraftment after ectopic implantation under the murine kidney capsule. These results demonstrate that the airway organoid system developed here represents a novel tool for the study of disease-relevant cell-cell interactions, and establishes this platform as a first step toward cell-based therapy for chronic lung diseases based on de novo engineering of implantable airway tissues.

  6. Elevated expression of placental growth factor is associated with airway-wall vascular remodelling and thickening in smokers with asthma

    PubMed Central

    Wu, Dong; Lai, Tianwen; Yuan, Yalian; Chen, Min; Xia, Jun; Li, Wen; Pan, Guihai; Yuan, Binfan; Lv, Quanchao; Li, Yanyu; Li, Dongmin; Wu, Bin

    2017-01-01

    The increased expression of placental growth factor (PlGF) in chronic obstructive pulmonary disease and allergy-related asthma suggests its role in the pathogenesis of these diseases. In asthmatic smokers, airway remodelling is accompanied by an accelerated decline in lung function. However, whether PlGF contributes to the persistent airflow obstruction and vascular remodelling typically seen in asthmatic smokers is unknown. In this study we measured lung function, airway-wall thickening, and PlGF levels in serum and induced sputum in 74 asthmatic and 42 healthy smokers and never-smokers. Using human lung microvascular endothelial cells (HLMECs), we evaluated the in vitro effects of PlGF on each step of vascular remodelling, including proliferation, migration, stress-fibre expression, and tubule formation. Our data showed significantly higher serum and sputum PlGF levels in asthma patients, especially asthmatic smokers, than in healthy controls. Serum and sputum PlGF levels correlated negatively with post-bronchodilator forced expiratory volume in 1 s (FEV1) and the FEV1/forced vital capacity, but positively with airway-wall thickening. Stimulation of HLMECs with rhPlGF promoted all of the steps of airway-microvascular remodelling. These findings provide insights into the influence of cigarette smoking on the structural changes in the airways of asthmatics and the important pathogenic role played by PlGF. PMID:28220848

  7. Use of 125I-labeled human serum albumin for quantitation of microvascular permeability in rat skin: reevaluation of an old method for studies on substances with an enhancing effect on microvascular permeability

    SciTech Connect

    Gerdin, B.

    1981-11-01

    A method of determining the leakage of 125I-labeled human serum albumin in the plasma into a standardized area of rat skin to study the effects of intracutaneous application of vasoactive substances on microvascular permeability, was reevaluated. The effect is expressed as a quotient (Q) between the amount of labeled albumin in the test area and that in an area injected with buffer. This calculation is simple and as reliable as more complicated expressions of activity. Within a limited dose range, linear/log dose-response curves can be obtained after application of histamine or bradykinin. Locally injected 125I-labeled human serum albumin is eliminated very slowly from rat skin and determination of the amount of radiolabeled albumin in skin after an intravenous injection therefore represents leakage from the vascular compartments. The potentialities and advantages of this method in pharmacological studies are stressed.

  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. Upper airway radiographs in infants with upper airway insufficiency.

    PubMed Central

    Tonkin, S L; Davis, S L; Gunn, T R

    1994-01-01

    Upper airway measurements in nine infants considered to be at risk of upper airway insufficiency, six of whom presented after an apnoeic episode, were compared with measurements taken in two age groups of healthy infants. Paired, inspiratory and expiratory, lateral upper airway radiographs were obtained while the infants were awake and breathing quietly. The radiographs of all nine infants demonstrated narrowing in the oropharyngeal portion of the airway during inspiration and in six infants there was ballooning of the upper airway during expiration. Seven of the nine infants subsequently experienced recurrent apnoeic episodes which required vigorous stimulation to restore breathing. Experience suggests that respiratory phase timed radiographs are a useful adjunct to the evaluation of infants who are suspected of having upper airway dysfunction. They provide information regarding both the dimensions and compliance of the upper airway as well as the site of any restriction. Images PMID:8048825

  10. Micropuncture measurement of lung microvascular pressure profile during hypoxia in cats.

    PubMed

    Nagasaka, Y; Bhattacharya, J; Nanjo, S; Gropper, M A; Staub, N C

    1984-01-01

    To determine the lung microvascular pressure profile during hypoxia, we micropunctured the subpleural microcirculation of isolated perfused cat lungs. Our procedures involved exsanguinating a cat, then cannulating its pulmonary artery, left atrium, and trachea. Using the cat's own blood, we perfused the lungs at pulmonary artery and left atrial pressures of 18 and 9 cm water, respectively, to obtain lung blood flow of 81 +/- 29 ml/(kg body weight x min), which we held constant throughout the experiment. We stabilized the lung surface with a vacuum ring and micropunctured 30- to 50-micrometers arterioles and venules to measure microvascular pressure by the servo-null method. During micropuncture, we held the lungs at constant inflation using airway pressure of 8 cm water. We varied the oxygen concentration of the inflation gas from 30% during baseline to 2% during hypoxia. We studied groups with high (more than 7.5) or normal pH. During normoxia, 27, 44, and 29% of the pressure drop occurred in the arterial, capillary and venous segments, respectively. During hypoxia, the increase in pulmonary vascular resistance, which was marked in both groups, was significantly greater in the normal pH group. All segmental pressure drops increased significantly during hypoxia. However, the predominant increase occurred in the arteries where segmental pressure drop increased by 148% and 210%, respectively, in the high and normal pH groups. We conclude that the major site of hypoxic vasoconstriction is in the pulmonary arteries.

  11. Leakage Current Measurements in SOI Devices

    DTIC Science & Technology

    1991-12-01

    Total dose response of both NMOS and PMOS FETs fabrication on SOI substrates were studied. Back channel leakage currents were studied. Two types of...dose of the back channel and front channel of SIMOX and ZMR SOI substrates are reported. Some preliminary reports on the buried oxide leakage current are also provided. Bach channel leakage, SIMOX, ZMR, Total Dose Response .

  12. "Geyser" leakage on fluorescein angiography.

    PubMed

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

    2013-11-22

    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.

  13. Duct leakage measurement and analysis

    SciTech Connect

    Swim, W.B.; Griggs, E.I.

    1995-08-01

    Leakage measurements were made on 6-in. (150-mm) and 10-in. (250-mm) round and 14-in. by 6-in. (350-mm by 150-mm) and 22-in. by 8-in. (560-mm by 200-mm) rectangular ducts for both positive and negative internal pressures. The data were found to fit a power law model, with the leakage rate (Q) increasing with a power, n, of static pressure difference ({Delta}p), i.e., Q {proportional_to} ({Delta}p){sup n}. A convenient leakage prediction equation, Q = C ({Delta}p*){sup n}, uses a normalized pressure difference, {Delta}p* = {Delta}p/{Delta}p{sub ref}, with {Delta}p in in. wg (Pa) and a reference pressure difference, {Delta}p{sub ref}, of 1 in. wg (250 Pa). C{sub D}, the recommended design values of C for a repetitive element of a duct system--one duct section and one joint, ranged from 0.01 cfm (0.005 L/s) for a Vanstone flanged joint to 18.5 cfm (8.7 L/s) for an unsealed 22-in. by 8-in (560-mm by 200-mm) duct with a slip-and-drive joint. Most test ducts had C{sub D} values of 6 to 8 cfm (3 to 4 L/s) and had values of n close to 0.58. Joints were found to account for most of the leakage, and thus most of the value of C{sub D}, in unsealed ducts, with seams contributing only 10% to 38% of the total.

  14. 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

  15. 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

  16. Lipopolysaccharide Induces Human Pulmonary Micro-Vascular Endothelial Apoptosis via the YAP Signaling Pathway

    PubMed Central

    Yi, Lei; Huang, Xiaoqin; Guo, Feng; Zhou, Zengding; Chang, Mengling; Tang, Jiajun; Huan, Jingning

    2016-01-01

    Gram-negative bacterial lipopolysaccharide (LPS) induces a pathologic increase in lung vascular leakage under septic conditions. LPS-induced human pulmonary micro-vascular endothelial cell (HPMEC) apoptosis launches and aggravates micro-vascular hyper-permeability and acute lung injury (ALI). Previous studies show that the activation of intrinsic apoptotic pathway is vital for LPS-induced EC apoptosis. Yes-associated protein (YAP) has been reported to positively regulate intrinsic apoptotic pathway in tumor cells apoptosis. However, the potential role of YAP protein in LPS-induced HPMEC apoptosis has not been determined. In this study, we found that LPS-induced activation and nuclear accumulation of YAP accelerated HPMECs apoptosis. LPS-induced YAP translocation from cytoplasm to nucleus by the increased phosphorylation on Y357 resulted in the interaction between YAP and transcription factor P73. Furthermore, inhibition of YAP by small interfering RNA (siRNA) not only suppressed the LPS-induced HPMEC apoptosis but also regulated P73-mediated up-regulation of BAX and down-regulation of BCL-2. Taken together, our results demonstrated that activation of the YAP/P73/(BAX and BCL-2)/caspase-3 signaling pathway played a critical role in LPS-induced HPMEC apoptosis. Inhibition of the YAP might be a potential therapeutic strategy for lung injury under sepsis. PMID:27807512

  17. 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

  18. Computer-aided quantification of microvascular networks: Application to alterations due to pathological angiogenesis in the hamster.

    PubMed

    Bulant, Carlos A; Blanco, Pablo J; Müller, Lucas O; Scharfstein, Julio; Svensjö, Erik

    2017-03-12

    Angiogenesis is both a physiological and a pathological process of great complexity, which is difficult to measure objectively and automatically. The hamster cheek pouch (HCP) prepared for intravital-microscopy (IVM) has been used to characterize microvascular functions in many studies and was chosen to investigate microvascular characteristics observed in normal non-infected hamsters as compared to those HCPs parasitized by Trypanosoma cruzi. Images of HCPs captured at IVM were subjected to computer based measurements of angiogenesis and histamine-induced macromolecular (FITC-dextran) leakage with an image segmentation approach that has the capacity to discriminate between fluorescence emitted by macromolecular tracers inside the vasculature and in the extravascular space. We present such an automatic segmentation methodology using known tools from image processing field that, to our knowledge, have not been tested in IVM images. We have compared this methodology with a recently published segmentation strategy based on image intensity thresholding. Our method renders an accurate and robust segmentation of blood vessels for different microvascular scenarios, normal and pathological. Application of the proposed strategy for objective and automatic measurement of angiogenesis detection was explored in detail.

  19. 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

  20. Skin microvascular reactivity in trained adolescents.

    PubMed

    Roche, Denise M; Rowland, T W; Garrard, M; Marwood, S; Unnithan, V B

    2010-04-01

    Whilst endothelial dysfunction is associated with a sedentary lifestyle, enhanced endothelial function has been documented in the skin of trained individuals. The purpose of this study was to investigate whether highly trained adolescent males possess enhanced skin microvascular endothelial function compared to their untrained peers. Seventeen highly and predominantly soccer trained boys (V(O)(2)(peak): 55 +/- 6 mL kg(-1) min(-1)) and nine age- and maturation-matched untrained controls (V(O)(2)(peak): 43 +/- 5 mL kg(-1) min(-1)) aged 13-15 years had skin microvascular endothelial function assessed using laser Doppler flowmetry. Baseline and maximal thermally stimulated skin blood flow (SkBF) responses were higher in forearms of trained subjects compared to untrained participants [baseline SkBF: 11 +/- 4 vs. 9 +/- 3 perfusion units (PU), p < 0.05; SkBF(max): 282 +/- 120 vs. 204 +/- 68 PU, p < 0.05]. Similarly, cutaneous vascular conductance (CVC) during local heating was superior in the forearm skin of trained versus untrained individuals (CVC(max): 3 +/- 1 vs. 2 +/- 1 PU mmHg(-1), p < 0.05). Peak hyperaemia following arterial occlusion and area under the reactive hyperaemia curve were also greater in forearm skin of the trained group (peak hyperaemia: 51 +/- 21 vs. 35 +/- 15 PU, p < 0.05; area under curve: 1596 +/- 739 vs. 962 +/- 796 PUs, p < 0.05). These results suggest that chronic exercise training in adolescents is associated with enhanced microvascular endothelial vasodilation in non-glabrous skin.

  1. 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...

  2. Rapid homogeneous endothelialization of high aspect ratio microvascular networks.

    PubMed

    Naik, Nisarga; Hanjaya-Putra, Donny; Haller, Carolyn A; Allen, Mark G; Chaikof, Elliot L

    2015-08-01

    Microvascularization of an engineered tissue construct is necessary to ensure the nourishment and viability of the hosted cells. Microvascular constructs can be created by seeding the luminal surfaces of microfluidic channel arrays with endothelial cells. However, in a conventional flow-based system, the uniformity of endothelialization of such an engineered microvascular network is constrained by mass transfer of the cells through high length-to-diameter (L/D) aspect ratio microchannels. Moreover, given the inherent limitations of the initial seeding process to generate a uniform cell coating, the large surface-area-to-volume ratio of microfluidic systems demands long culture periods for the formation of confluent cellular microconduits. In this report, we describe the design of polydimethylsiloxane (PDMS) and poly(glycerol sebacate) (PGS) microvascular constructs with reentrant microchannels that facilitates rapid, spatially homogeneous endothelial cell seeding of a high L/D (2 cm/35 μm; > 550:1) aspect ratio microchannels. MEMS technology was employed for the fabrication of a monolithic, elastomeric, reentrant microvascular construct. Isotropic etching and PDMS micromolding yielded a near-cylindrical microvascular channel array. A 'stretch - seed - seal' operation was implemented for uniform incorporation of endothelial cells along the entire microvascular area of the construct yielding endothelialized microvascular networks in less than 24 h. The feasibility of this endothelialization strategy and the uniformity of cellularization were established using confocal microscope imaging.

  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. Skin microvascular reactivity in patients with hypothyroidism.

    PubMed

    Mihor, Ana; Gergar, Maša; Gaberšček, Simona; Lenasi, Helena

    2016-11-04

    Hypothyroidism is associated with impaired vascular function; however, little is known about its impact on microcirculation. We aimed to determine skin microvascular reactivity in hypothyroidism focusing on endothelial function and the sympathetic response. We measured skin laser Doppler (LD) flux (LDF) on the volar forearm and the finger pulp using LD flowmetry in hypothyroid patients (N = 13) and healthy controls (N = 15). Skin microvascular reactivity was assessed by a three-minute occlusion of the brachial artery, inducing postocclusive reactive hyperaemia (PRH), and by a four-minute local cooling of the hand. An electrocardiogram (ECG), digital artery blood pressure and skin temperature at the measuring sites were recorded. Baseline LDF, the digital artery blood pressure and the heart rate were comparable between patients and controls. On the other hand, patients exhibited significantly longer PRH duration, significantly higher blood pressure during cooling (unpaired t-test, p <0.05) and lower, albeit not significant, LDF in the ipsilateral finger pulp during cooling compared to controls. Unexpectedly, the results of the present study point to an increased vasodilator capacity of skin microcirculation and an apparent increase in sympathetic reactivity after local cooling in hypothyroid patients. Hypothyroidism induces subtle changes of some haemodynamic parameters in skin microcirculation implying altered endothelial function and altered sympathetic reactivity.

  5. 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

  6. 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.

  7. Factors affecting apical leakage assessment.

    PubMed

    Karagöz-Küçükay, I; Küçükay, S; Bayirli, G

    1993-07-01

    This study was conducted to evaluate the influence of immediate versus delayed immersion time, and passive dye immersion versus centrifuged dye on apical leakage measurements. Eighty-four extracted human teeth with single straight canals were instrumented and divided into four experimental groups of 20 teeth each plus 2 negative and 2 positive controls. Low-temperature injection thermoplasticized gutta-percha and sealer were used to obturate the root canals. In groups A and B the filling materials were allowed to set for 72 h before the teeth were placed in India ink. In groups C and D the teeth were placed in India ink immediately after obturation. Also, in groups B and D the teeth were centrifuged in India ink for 20 min at 3,000 rpm before being immersed in ink. After 72 h in India ink, the teeth were cleared, and the linear extent of ink penetration was measured with a stereomicroscope. Statistical analysis of the data revealed no significant difference in leakage among the experimental groups whether the teeth were immersed in ink immediately after obturation or after setting of the filling materials for 72 h, and whether or not the teeth were centrifuged in ink prior to immersion.

  8. 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.

  9. Energy Conservation Through Duct Leakage Reduction

    DTIC Science & Technology

    2004-02-26

    Energy Conservation Through Duct Leakage Reduction February 26, 2004 Rich Glatt – Lindab Inc. Report Documentation Page Form ApprovedOMB No. 0704...4. TITLE AND SUBTITLE Energy Conservation Through Duct Leakage Reduction 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Wall – DW that installs like SW - easiest installing DW system on the market – Eliminates the need for costly flanged connections – SMACNA Leakage

  10. 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.

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

    PubMed

    Zhou, Gang; Kamenos, George; Pendem, Suresh; Wilson, John X; Wu, Feng

    2012-02-15

    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

  12. Fractal analysis of microvascular networks in malignant brain tumors.

    PubMed

    Di Ieva, Antonio

    2012-01-01

    Brain tumors are characterized by a microvascular network which differs from normal brain vascularity. Different tumors show individual angiogenic patterns. Microvascular heterogeneity can also be observed within a neoplastic histotype. It has been shown that quantification of neoplastic microvascular patterns could be used in combination with the histological grade for tumor characterization and to refine clinical prognoses, even if no objective parameters have yet been validated. To overcome the limits of the Euclidean approach, we employ fractal geometry to analyze the geometric complexity underlying the microangioarchitectural networks in brain tumors. We have developed a computer-aided fractal-based analysis for the quantification of the microvascular patterns in histological specimens and ultra-high-field (7-Tesla) magnetic resonance images. We demonstrate that the fractal parameters are valid estimators of microvascular geometrical complexity. Furthermore, our analysis allows us to demonstrate the high geometrical variability underlying the angioarchitecture of glioblastoma multiforme and to differentiate low-grade from malignant tumors in histological specimens and radiological images. Based on the results of this study, we speculate the existence of a gradient in the geometrical complexity of microvascular networks from those in the normal brain to those in malignant brain tumors. Here, we summarize a new methodology for the application of fractal analysis to the study of the microangioarchitecture of brain tumors; we further suggest this approach as a tool for quantifying and categorizing different neoplastic microvascular patterns and as a potential morphometric biomarker for use in clinical practice.

  13. Inhibitory effects of cyclic AMP elevating agents on lipopolysaccharide (LPS)-induced microvascular permeability change in mouse skin.

    PubMed

    Irie, K; Fujii, E; Ishida, H; Wada, K; Suganuma, T; Nishikori, T; Yoshioka, T; Muraki, T

    2001-05-01

    Anti-inflammatory effects of cyclic AMP elevating agents were examined in a mouse model of lipopolysaccharide (LPS)-induced microvascular permeability change. Vascular permeability on the back skin was measured by the local accumulation of Pontamine sky blue (PSB) after subcutaneous injection of LPS (400 microg site-1) from Salmonella typhimurium. Dye leakage in the skin was significantly increased 2 h after injection of LPS. This LPS-induced dye leakage was suppressed by phosphodiesterase inhibitors, including pentoxifylline (160 mg kg-1), milrinone (5 - 10 mg kg-1), rolipram (0.5 - 10 mg kg-1) and zaprinast (5 - 10 mg kg-1). The dye leakage was also inhibited by beta-adrenoceptor agonists, including isoproterenol (0.5 - 5 mg kg-1) and salbutamol (0.05 - 5 mg kg-1), an adenylate cyclase activator, forskolin (5 mg kg-1), and a cell permeable cyclic AMP analogue, 8-bromo-cyclic AMP (8-Br-cAMP, 10 mg kg-1). LPS caused a transient increase in serum TNF-alpha level peaking at 1 h after the injection. This increase in serum TNF-alpha was completely blocked by a pretreatment with pentoxifylline (160 mg kg-1), milrinone (5 mg kg-1), rolipram (1 mg kg-1), zaprinast (10 mg kg-1), salbutamol (0.5 mg kg-1), forskolin (1 mg kg-1) and 8-Br-cAMP (10 mg kg-1). LPS caused an increase in serum IL-1alpha level peaking at 3 h after injection. This increase in serum IL-1alpha was not significantly suppressed by the cyclic AMP elevating agents. Our study suggests that cyclic AMP elevating agents attenuate LPS-induced microvascular permeability change by suppressing TNF-alpha up regulation.

  14. 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

  15. 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.

  16. Microvascular free flaps in skull base reconstruction.

    PubMed

    Herr, Marc W; Lin, Derrick T

    2013-01-01

    The anatomical challenges of skull base surgery are well known. Furthermore, ablative and traumatic defects in this region produce complex reconstructive problems with a high risk of significant postoperative morbidity and mortality. Over the past two decades, microvascular free tissue reconstruction following open resection has been shown to improve outcomes and reduce complication rates when compared to the traditional use of pedicled flaps. The increasing use of free tissue transfer has been further strengthened by improved technical expertise and high flap success rates. Since the size and type of free tissue to be utilized must be individualized to each defect, the accomplished reconstructive surgeon should be extremely versatile and, by extension, facile with a several types of free flaps. Thus, four of the most commonly used flaps--the rectus abdominis, radial forearm, latissimus dorsi and anterolateral thigh flaps--are discussed.

  17. Mandibular reconstruction with composite microvascular tissue transfer

    SciTech Connect

    Coleman, J.J. III; Wooden, W.A. )

    1990-10-01

    Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons (lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)). Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure.

  18. 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

  19. Global airway disease beyond allergy.

    PubMed

    Hellings, Peter W; Prokopakis, Emmanuel P

    2010-03-01

    Besides the anatomic continuity of the upper and lower airways, inflammation in one part of the airway influences the homeostasis of the other. The mechanisms underlying this interaction have been studied primarily in allergic disease, showing systemic immune activation, induction of inflammation at a distance, and a negative impact of nasal inflammation on bronchial homeostasis. In addition to allergy, other inflammatory conditions of the upper airways are associated with lower airway disease. Rhinosinusitis is frequently associated with asthma and chronic obstructive pulmonary disease. The impairment of purification, humidification, and warming up of the inspired air by the nose in rhinosinusitis may be responsible in part for bronchial pathology. The resolution of sinonasal inflammation via medical and/or surgical treatment is responsible for the beneficial effect of the treatment on bronchial disease. This article provides a comprehensive overview of the current knowledge of upper and lower airway communication beyond allergic disease.

  20. Recurrent airway obstruction: a review.

    PubMed

    Pirie, R S

    2014-05-01

    Recurrent airway obstruction is a widely recognised airway disorder, characterised by hypersensitivity-mediated neutrophilic airway inflammation and lower airway obstruction in a subpopulation of horses when exposed to suboptimal environments high in airborne organic dust. Over the past decade, numerous studies have further advanced our understanding of different aspects of the disease. These include clarification of the important inhaled airborne agents responsible for disease induction, improving our understanding of the underlying genetic basis of disease susceptibility and unveiling the fundamental immunological mechanisms leading to establishment of the classic disease phenotype. This review, as well as giving a clinical overview of recurrent airway obstruction, summarises much of the work in these areas that have culminated in a more thorough understanding of this debilitating disease.

  1. The airway microbiome and disease.

    PubMed

    Marsland, Benjamin J; Yadava, Koshika; Nicod, Laurent P

    2013-08-01

    Although traditionally thought to be sterile, accumulating evidence now supports the concept that our airways harbor a microbiome. Thus far, studies have focused upon characterizing the bacterial constituents of the airway microbiome in both healthy and diseased lungs, but what perhaps provides the greatest impetus for the exploration of the airway microbiome is that different bacterial phyla appear to dominate diseased as compared with healthy lungs. As yet, there is very limited evidence supporting a functional role for the airway microbiome, but continued research in this direction is likely to provide such evidence, particularly considering the progress that has been made in understanding host-microbe mutualism in the intestinal tract. In this review, we highlight the major advances that have been made discovering and describing the airway microbiome, discuss the experimental evidence that supports a functional role for the microbiome in health and disease, and propose how this emerging field is going to impact clinical practice.

  2. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Current, leakage. A stray electric current of relatively small value which flows through or across the... 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...

  3. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Current, leakage. A stray electric current of relatively small value which flows through or across the... 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...

  4. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Current, leakage. A stray electric current of relatively small value which flows through or across the... 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...

  5. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Current, leakage. A stray electric current of relatively small value which flows through or across the... 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...

  6. 49 CFR 236.735 - Current, leakage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Current, leakage. A stray electric current of relatively small value which flows through or across the... 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...

  7. 49 CFR 229.59 - Leakage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... inch per minute for 3 minutes after the pressure has been reduced to 60 percent of the maximum pressure. (b) Brake pipe leakage may not exceed 5 pounds per square inch per minute. (c) With a full service... shall remain applied at least 5 minutes. (d) Leakage from control air reservoir, related piping,...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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.

  14. 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.

  15. Radiofrequency radiation leakage from microwave ovens.

    PubMed

    Lahham, Adnan; Sharabati, Afifeh

    2013-12-01

    This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm(-2) with an average value equalling 3.64 μW cm(-2). Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm(-2). The highest radiation leakage from any tested oven was ∼16.4 μW cm(-2), and found in two cases only. In no case did the leakage exceed the limit of 1 mW cm(-2) recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age.

  16. 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.

  17. 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

  18. Airway complications after lung transplantation.

    PubMed

    Machuzak, Michael; Santacruz, Jose F; Gildea, Thomas; Murthy, Sudish C

    2015-01-01

    Airway complications after lung transplantation present a formidable challenge to the lung transplant team, ranging from mere unusual images to fatal events. The exact incidence of complications is wide-ranging depending on the type of event, and there is still evolution of a universal characterization of the airway findings. Management is also wide-ranging. Simple observation or simple balloon bronchoplasty is sufficient in many cases, but vigilance following more severe necrosis is required for late development of both anastomotic and nonanastomotic airway strictures. Furthermore, the impact of coexisting infection, rejection, and medical disease associated with high-level immunosuppression further complicates care.

  19. Gene Delivery to the Airway

    PubMed Central

    Keiser, Nicholas W.; Engelhardt, John F.

    2013-01-01

    This unit describes generation of and gene transfer to several commonly used airway models. Isolation and transduction of primary airway epithelial cells are first described. Next, the preparation of polarized airway epithelial monolayers is outlined. Transduction of these polarized cells is also described. Methods are presented for generation of tracheal xenografts as well as both ex vivo and in vivo gene transfer to these xenografts. Finally, a method for in vivo gene delivery to the lungs of rodents is included. Methods for evaluating transgene expression are given in the support protocols. PMID:23853081

  20. New methods for monitoring dynamic airway tissue oxygenation and perfusion in experimental and clinical transplantation.

    PubMed

    Khan, Mohammad A; Dhillon, Gundeep; Jiang, Xinguo; Lin, Yu-Chun; Nicolls, Mark R

    2012-11-15

    A dual circulation, supplied by bronchial and pulmonary artery-derived vessels, normally perfuses the airways from the trachea to the terminal bronchioles. This vascular system has been highly conserved through mammalian evolution and is disrupted at the time of lung transplantation. In most transplant centers, this circulation is not restored. The Papworth Hospital Autopsy study has revealed that an additional attrition of periairway vessels is associated with the development of chronic rejection, otherwise known as the bronchiolitis obliterans syndrome (BOS). Experimental studies subsequently demonstrated that airway vessels are subject to alloimmune injury and that the loss of a functional microvascular system identifies allografts that cannot be rescued with immunosuppressive therapy. Therefore, surgical and medical strategies, which preserve the functionality of the existent vasculature in lung transplant patients, may conceivably limit the incidence of BOS. Given these unique anatomic and physiological considerations, there is an emerging rationale to better understand the perfusion and oxygenation status of airways in transplanted lungs. This article describes novel methodologies, some newly developed by our group, for assessing airway tissue oxygenation and perfusion in experimental and clinical transplantation.

  1. TLR4 signalling in pulmonary stromal cells is critical for inflammation and immunity in the airways.

    PubMed

    Perros, Frederic; Lambrecht, Bart N; Hammad, Hamida

    2011-09-24

    Inflammation of the airways, which is often associated with life-threatening infection by Gram-negative bacteria or presence of endotoxin in the bioaerosol, is still a major cause of severe airway diseases. Moreover, inhaled endotoxin may play an important role in the development and progression of airway inflammation in asthma. Pathologic changes induced by endotoxin inhalation include bronchospasm, airflow obstruction, recruitment of inflammatory cells, injury of the alveolar epithelium, and disruption of pulmonary capillary integrity leading to protein rich fluid leak in the alveolar space. Mammalian Toll-like receptors (TLRs) are important signalling receptors in innate host defense. Among these receptors, TLR4 plays a critical role in the response to endotoxin. Lungs are a complex compartmentalized organ with separate barriers, namely the alveolar-capillary barrier, the microvascular endothelium, and the alveolar epithelium. An emerging theme in the field of lung immunology is that structural cells (SCs) of the airways such as epithelial cells (ECs), endothelial cells, fibroblasts and other stromal cells produce activating cytokines that determine the quantity and quality of the lung immune response. This review focuses on the role of TLR4 in the innate and adaptive immune functions of the pulmonary SCs.

  2. 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.

  3. Retinal microvascular plasticity in a premature neonate.

    PubMed

    Kandasamy, Y; Hartley, L; Smith, R

    2017-01-31

    Dilation and abnormal tortuosity of retinal vessels are the hallmarks of severe retinopathy of prematurity (ROP) in premature infants. The stages of ROP are defined by vessel appearance at the interface between the vascular and avascular retinal areas. Deregulated signaling pathways involving hypoxia-inducible factors such as vascular endothelial growth factor (VEGF) are involved in the pathogenesis of ROP. VEGF-antagonists are increasingly being used as 'off-label medication' to treat this condition, with some success. We present Baby SM (female), who was born prematurely at 24 weeks gestation in a tertiary neonatal intensive care unit, and with a birth weight of 640 g. On screening at 35 weeks postmenstrual age (PMA), she was noted to have ROP, which became severe by 37 weeks PMA. She received one dose of intravitreal VEGF antagonist (Bevacizumab), resulting in a decrease in vessel tortuosity and dilation. However, repeat imaging at 4 weeks showed a re-emergence of vessel tortuosity. We believe the observed changes demonstrate an inherent retinal microvascular plasticity in premature neonates. With improved survival of extremely premature neonates and the availability of retinal imaging technology, we are now able to observe this plasticity.

  4. [Microvascular anastomoses in cervical esophageal reconstruction].

    PubMed

    Takushima, A; Harii, K; Asato, H

    2001-09-01

    Ischemia or hemostasis in the gastric, jejunal, and colonic pedicle after esophagectomy is believed to contribute significantly to postoperative complications. With the advent of microvascular anastomoses, many surgeons have adopted vascular augmentation (supercharge) as a means of avoiding these difficulties. Microsurgical free tissue transfer represented by the free jejunum and forearm flap also plays an important role in esophageal reconstruction. In this paper, the authors introduce the technical points important for successful revascularization including the choice of recipient vessels, setting up of the reconstructive materials, and postoperative monitoring. In cases of gastric pull-up elevated via posterior mediastinum, the left gastroduodenal vessels are anastomosed to the cervical transverse or superior thyroidal vessels. In cases of duodenal or colonic pull-up elevated via the anterosternal route, the vascular pedicles are anastomosed to the internal mammary vessels which are dissected by resecting the costal cartilage. When the free jejunum flap is used, the cervical transverse or superior thyroidal vessels are most frequently used as recipients. Postoperative monitoring of free flaps is performed using Doppler ultrasound or through a small skin incision made above the transferred tissue. Although gastric or colonic pull-up is difficult to monitor, color Doppler sonography permits quantitative analysis of blood flow and may be a useful option.

  5. 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

  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. 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.

  9. Solute Leakage Resulting from Leaf Desiccation

    PubMed Central

    Leopold, A. Carl; Musgrave, Mary E.; Williams, Kathleen M.

    1981-01-01

    The leakage of solutes from foliar tissue is utilized as a dynamic measure of apparent changes in membrane integrity in response to desiccation. It is found that rehydrating leaf discs of cowpea (Vigna sinensis [L.] Endl.) show increasing leakiness in proportion to the extent of prior desiccation, whereas Selaginella lepidophylla Spring., a resurrection plant, does not. The elevated leakage rate of cowpea after desiccation recovers with time, and the passage of time in the stressed condition results in reduced subsequent leakiness. These characteristics are interpreted as suggesting that the leakage of solute reflects the condition of cellular membranes, and that desiccation stress leads to lesions in the membranes. The kinetics of solute leakage is suggested as a simple means of following changes in membrane lesions and associated features of membrane repair and hardening. PMID:16662082

  10. A new removable airway stent

    PubMed Central

    Amundsen, Tore; Sørhaug, Sveinung; Leira, Håkon Olav; Tyvold, Stig Sverre; Langø, Thomas; Hammer, Tommy; Manstad-Hulaas, Frode; Mattsson, Erney

    2016-01-01

    Background Malignant airway obstruction is a feared complication and will most probably occur more frequently in the future because of increasing cancer incidence and increased life expectancy in cancer patients. Minimal invasive treatment using airway stents represents a meaningful and life-saving palliation. We present a new removable airway stent for improved individualised treatment. Methods To our knowledge, the new airway stent is the world's first knitted and uncovered self-expanding metal stent, which can unravel and be completely removed. In an in vivo model using two anaesthetised and spontaneously breathing pigs, we deployed and subsequently removed the stents by unravelling the device. The procedures were executed by flexible bronchoscopy in an acute and a chronic setting – a ‘proof-of-principle’ study. Results The new stent was easily and accurately deployed in the central airways, and it remained fixed in its original position. It was easy to unravel and completely remove from the airways without clinically significant complications. During the presence of the stent in the chronic study, granulation tissue was induced. This tissue disappeared spontaneously with the removal. Conclusions The new removable stent functioned according to its purpose and unravelled easily, and it was completely removed without significant technical or medical complications. Induced granulation tissue disappeared spontaneously. Further studies on animals and humans are needed to define its optimal indications and future use. PMID:27608269

  11. [Bile leakage in laparoscopic cholecystectomy. Authors' experience].

    PubMed

    Sperlongano, P; Pisaniello, D; Corsale, I; Cozza, G

    1999-01-01

    The Authors report their experience of two patients with bile leakage following videocholecystectomy (VLC) among a series of 163 cases. Reviewing the Literature, they analyze possible causes and mechanisms of bile spillage occurring after VCL. They also suggest some guidelines for a safe VLC, stressing the importance of the routinary placement of the sub-hepatic drainage to remove 48 hours to early detect possible bile leakages after surgery.

  12. 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.

  13. 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.

  14. EFFECTS OF LEAKAGE NEUTRAL PARTICLES ON SHOCKS

    SciTech Connect

    Ohira, Yutaka

    2012-10-20

    In this paper, we investigate effects of neutral particles on shocks propagating into the partially ionized medium. We find that for 120 km s{sup -1} < u {sub sh} < 3000 km s{sup -1} (u {sub sh} is the shock velocity), about 10% of upstream neutral particles leak into the upstream region from the downstream region. Moreover, we investigate how the leakage neutral particles affect the upstream structure of the shock and particle accelerations. Using four-fluid approximations (upstream ions, upstream neutral particles, leakage neutral particles, and pickup ions), we provide analytical solutions of the precursor structure due to leakage neutral particles. It is shown that the upstream flow is decelerated in the precursor region and the shock compression ratio becomes smaller than without leakage neutral particles, but the total compression ratio does not change. Even if leakage of neutral particles is small (a few percent of total upstream particles), this smaller compression ratio of the shock can explain steep gamma-ray spectra from young supernova remnants. Furthermore, leakage neutral particles could amplify the magnetic field and heat the upstream region.

  15. Rat Pial Microvascular Responses to Transient Bilateral Common Carotid Artery Occlusion and Reperfusion: Quercetin’s Mechanism of Action

    PubMed Central

    Lapi, D.; Vagnani, S.; Pignataro, G.; Esposito, E.; Paterni, M.; Colantuoni, A.

    2012-01-01

    The aim of the present study was to assess quercetin’s mechanism of action in rat pial microvessels during transient bilateral common carotid artery occlusion (BCCAO) and reperfusion. Rat pial microcirculation was visualized using fluorescence microscopy through a closed cranial window. Pial arterioles were classified in five orders of branchings. In ischemic rats, 30 min BCCAO and 60 min reperfusion caused arteriolar diameter decrease, microvascular leakage, leukocyte adhesion in venules, and reduction of capillary perfusion. Quercetin highest dose determined dilation in all arteriolar orders, by 40 ± 4% of baseline in order 2 vessels, and prevented microvascular permeability [0.15 ± 0.02 normalized gray levels (NGL)], leukocyte adhesion, and capillary failure. Protein kinase C (PKC) inhibition exerted by chelerythrine prior to quercetin attenuated quercetin-induced effects: order 2 arterioles dilated by 19.0 ± 2.4% baseline, while there was an increase in permeability (0.40 ± 0.05 NGL) and leukocyte adhesion with a marked decrease in capillary perfusion. Tyrosine kinase (TK) inhibition by tyrphostin 47 prior to quercetin lessened smaller pial arterioles responses, dilating by 20.7 ± 2.5% of baseline, while leakage increased (0.39 ± 0.04 NGL) sustained by slight leukocyte adhesion and ameliorated capillary perfusion. Inhibition of endothelium nitric oxide synthase (eNOS) by NG-nitro-L-arginine-methyl ester (L-NAME) prior to PKC or TK reduced the quercetin’s effects on pial arteriolar diameter and leakage. eNOS inhibition by L-NAME reduced quercetin effects on pial arteriolar diameter and leakage. Finally, combined inhibition of PKC and TK prior to quercetin abolished quercetin-induced effects, decreasing eNOS expression, while blocking ATP-sensitive potassium (KATP) channels by glibenclamide suppressed arteriolar dilation. In conclusion, the protective effects of quercetin could be due to different mechanisms resulting in NO

  16. Cutaneous tactile allodynia associated with microvascular dysfunction in muscle

    PubMed Central

    Laferrière, Andre; Millecamps, Magali; Xanthos, Dimitris N; Xiao, Wen Hua; Siau, Chiang; de Mos, Marissa; Sachot, Christelle; Ragavendran, J Vaigunda; Huygen, Frank JPM; Bennett, Gary J; Coderre, Terence J

    2008-01-01

    Background Cutaneous tactile allodynia, or painful hypersensitivity to mechanical stimulation of the skin, is typically associated with neuropathic pain, although also present in chronic pain patients who do not have evidence of nerve injury. We examine whether deep tissue microvascular dysfunction, a feature common in chronic non-neuropathic pain, contributes to allodynia. Results Persistent cutaneous allodynia is produced in rats following a hind paw ischemia-reperfusion injury that induces microvascular dysfunction, including arterial vasospasms and capillary slow flow/no-reflow, in muscle. Microvascular dysfunction leads to persistent muscle ischemia, a reduction of intraepidermal nerve fibers, and allodynia correlated with muscle ischemia, but not with skin nerve loss. The affected hind paw muscle shows lipid peroxidation, an upregulation of nuclear factor kappa B, and enhanced pro-inflammatory cytokines, while allodynia is relieved by agents that inhibit these alterations. Allodynia is increased, along with hind paw muscle lactate, when these rats exercise, and is reduced by an acid sensing ion channel antagonist. Conclusion Our results demonstrate how microvascular dysfunction and ischemia in muscle can play a critical role in the development of cutaneous allodynia, and encourage the study of how these mechanisms contribute to chronic pain. We anticipate that focus on the pain mechanisms associated with microvascular dysfunction in muscle will provide new effective treatments for chronic pain patients with cutaneous tactile allodynia. PMID:18957097

  17. 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

  18. Airway Hydration and COPD

    PubMed Central

    Ghosh, Arunava; Boucher, R.C.; Tarran, Robert

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is one of the prevalent causes of worldwide mortality and encompasses two major clinical phenotypes, i.e., chronic bronchitis (CB) and emphysema. The most common cause of COPD is chronic tobacco inhalation. Research focused on the chronic bronchitic phenotype of COPD has identified several pathological processes that drive disease initiation and progression. For example, the lung’s mucociliary clearance (MCC) system performs the critical task of clearing inhaled pathogens and toxic materials from the lung. MCC efficiency is dependent on: (i) the ability of apical plasma membrane ion channels such as the cystic fibrosis transmembrane conductance regulator (CFTR) and the epithelial Na+ channel (ENaC) to maintain airway hydration; (ii) ciliary beating; and, (iii) appropriate rates of mucin secretion. Each of these components is impaired in CB and likely contributes to the mucus stasis/accumulation seen in CB patients. This review highlights the cellular components responsible for maintaining MCC and how this process is disrupted following tobacco exposure and with CB. We shall also discuss existing therapeutic strategies for the treatment of chronic bronchitis and how components of the MCC can be used as biomarkers for the evaluation of tobacco or tobacco-like-product exposure. PMID:26068443

  19. Brain microvascular function during cardiopulmonary bypass

    SciTech Connect

    Sorensen, H.R.; Husum, B.; Waaben, J.; Andersen, K.; Andersen, L.I.; Gefke, K.; Kaarsen, A.L.; Gjedde, A.

    1987-11-01

    Emboli in the brain microvasculature may inhibit brain activity during cardiopulmonary bypass. Such hypothetical blockade, if confirmed, may be responsible for the reduction of cerebral metabolic rate for glucose observed in animals subjected to cardiopulmonary bypass. In previous studies of cerebral blood flow during bypass, brain microcirculation was not evaluated. In the present study in animals (pigs), reduction of the number of perfused capillaries was estimated by measurements of the capillary diffusion capacity for hydrophilic tracers of low permeability. Capillary diffusion capacity, cerebral blood flow, and cerebral metabolic rate for glucose were measured simultaneously by the integral method, different tracers being used with different circulation times. In eight animals subjected to normothermic cardiopulmonary bypass, and seven subjected to hypothermic bypass, cerebral blood flow, cerebral metabolic rate for glucose, and capillary diffusion capacity decreased significantly: cerebral blood flow from 63 to 43 ml/100 gm/min in normothermia and to 34 ml/100 gm/min in hypothermia and cerebral metabolic rate for glucose from 43.0 to 23.0 mumol/100 gm/min in normothermia and to 14.1 mumol/100 gm/min in hypothermia. The capillary diffusion capacity declined markedly from 0.15 to 0.03 ml/100 gm/min in normothermia but only to 0.08 ml/100 gm/min in hypothermia. We conclude that the decrease of cerebral metabolic rate for glucose during normothermic cardiopulmonary bypass is caused by interruption of blood flow through a part of the capillary bed, possibly by microemboli, and that cerebral blood flow is an inadequate indicator of capillary blood flow. Further studies must clarify why normal microvascular function appears to be preserved during hypothermic cardiopulmonary bypass.

  20. 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

  1. Efficacy of Surgical Airway Plasty for Benign Airway Stenosis

    PubMed Central

    Takahama, Makoto; Nakajima, Ryu; Kimura, Michitaka; Inoue, Hidetoshi; Yamamoto, Ryoji

    2015-01-01

    Background: Long-term patency is required during treatment for benign airway stenosis. This study investigated the effectiveness of surgical airway plasty for benign airway stenosis. Methods: Clinical courses of 20 patients, who were treated with surgical plasty for their benign airway stenosis, were retrospectively investigated. Results: Causes of stenosis were tracheobronchial tuberculosis in 12 patients, post-intubation stenosis in five patients, malacia in two patients, and others in one patient. 28 interventional pulmonology procedures and 20 surgical plasty were performed. Five patients with post-intubation stenosis and four patients with tuberculous stenosis were treated with tracheoplasty. Eight patients with tuberculous stenosis were treated with bronchoplasty, and two patients with malacia were treated with stabilization of the membranous portion. Anastomotic stenosis was observed in four patients, and one to four additional treatments were required. Performance status, Hugh–Jones classification, and ventilatory functions were improved after surgical plasty. Outcomes were fair in patients with tuberculous stenosis and malacia. However, efficacy of surgical plasty for post-intubation stenosis was not observed. Conclusion: Surgical airway plasty may be an acceptable treatment for tuberculous stenosis. Patients with malacia recover well after surgical plasty. There may be untreated patients with malacia who have the potential to benefit from surgical plasty. PMID:26567879

  2. Airway management in emergency situations.

    PubMed

    Dörges, Volker

    2005-12-01

    Securing and monitoring the airway are among the key requirements of appropriate therapy in emergency patients. Failures to secure the airways can drastically increase morbidity and mortality of patients within a very short time. Therefore, the entire range of measures needed to secure the airway in an emergency, without intermediate ventilation and oxygenation, is limited to 30-40 seconds. Endotracheal intubation is often called the 'gold standard' for airway management in an emergency, but multiple failed intubation attempts do not result in maintaining oxygenation; instead, they endanger the patient by prolonging hypoxia and causing additional trauma to the upper airways. Thus, knowledge and availability of alternative procedures are also essential in every emergency setting. Given the great variety of techniques available, it is important to establish a well-planned, methodical protocol within the framework of an algorithm. This not only facilitates the preparation of equipment and the training of personnel, it also ensures efficient decision-making under time pressure. Most anaesthesia-related deaths are due to hypoxaemia when difficulty in securing the airway is encountered, especially in obstetrics during induction of anaesthesia for caesarean delivery. The most commonly occurring adverse respiratory events are failure to intubate, failure to recognize oesophageal intubation, and failure to ventilate. Thus, it is essential that every anaesthesiologist working on the labour and delivery ward is comfortable with the algorithm for the management of failed intubation. The algorithm for emergency airway management describing the sequence of various procedures has to be adapted to internal standards and to techniques that are available.

  3. 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.

  4. 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...

  5. 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... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak...

  6. 49 CFR 192.723 - Distribution systems: Leakage surveys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 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...

  7. 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... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak...

  8. 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...

  9. 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... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak...

  10. 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... transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak...

  11. 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...

  12. 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...

  13. 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...

  14. Therapeutic Effects of PPARα on Neuronal Death and Microvascular Impairment

    PubMed Central

    Moran, Elizabeth P.; Ma, Jian-xing

    2015-01-01

    Peroxisome-proliferator activated receptor-alpha (PPARα) is a broadly expressed nuclear hormone receptor and is a transcription factor for diverse target genes possessing a PPAR response element (PPRE) in the promoter region. The PPRE is highly conserved, and PPARs thus regulate transcription of an extensive array of target genes involved in energy metabolism, vascular function, oxidative stress, inflammation, and many other biological processes. PPARα has potent protective effects against neuronal cell death and microvascular impairment, which have been attributed in part to its antioxidant and anti-inflammatory properties. Here we discuss PPARα's effects in neurodegenerative and microvascular diseases and also recent clinical findings that identified therapeutic effects of a PPARα agonist in diabetic microvascular complications. PMID:25705219

  15. 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.

  16. 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.

  17. Effects of babassu nut oil on ischemia/reperfusion-induced leukocyte adhesion and macromolecular leakage in the microcirculation: Observation in the hamster cheek pouch

    PubMed Central

    2012-01-01

    Background The babassu palm tree is native to Brazil and is most densely distributed in the Cocais region of the state of Maranhão, in northeastern Brazil. In addition to the industrial use of refined babassu oil, the milk, the unrefined oil and the nuts in natura are used by families from several communities of African descendants as one of the principal sources of food energy. The objective of this study was to evaluate the effects of babassu oil on microvascular permeability and leukocyte-endothelial interactions induced by ischemia/reperfusion using the hamster cheek pouch microcirculation as experimental model. Methods Twice a day for 14 days, male hamsters received unrefined babassu oil (0.02 ml/dose [BO-2 group], 0.06 ml/dose [BO-6 group], 0.18 ml/dose [BO-18 group]) or mineral oil (0.18 ml/dose [MO group]). Observations were made in the cheek pouch and macromolecular permeability increase induced by ischemia/reperfusion (I/R) or topical application of histamine, as well as leukocyte-endothelial interaction after I/R were evaluated. Results The mean value of I/R-induced microvascular leakage, determined during reperfusion, was significantly lower in the BO-6 and BO-18 groups than in the MO one (P < 0.001). In addition, histamine-induced increase of microvascular permeability was significantly less pronounced in BO groups compared to MO one. No significant differences among groups in terms of leukocyte adhesion, concentrations of tumor necrosis factor alpha, interleukin 1, and interleukin 6 were found. Conclusions Our findings suggest that unrefined babassu oil reduced microvascular leakage and protected against histamine-induced effects in postcapillary venules and highlights that these almost unexploited nut and its oil might be secure sources of food energy. PMID:23158555

  18. 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

  19. 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.

  20. Sustainable management of leakage from wastewater pipelines.

    PubMed

    DeSilva, D; Burn, S; Tjandraatmadja, G; Moglia, M; Davis, P; Wolf, L; Held, I; Vollertsen, J; Williams, W; Hafskjold, L

    2005-01-01

    Wastewater pipeline leakage is an emerging concern in Europe, especially with regards to the potential effect of leaking effluent on groundwater contamination and the effects infiltration has on the management of sewer reticulation systems. This paper describes efforts by Australia, in association with several European partners, towards the development of decision support tools to prioritize proactive rehabilitation of wastewater pipe networks to account for leakage. In the fundamental models for the decision support system, leakage is viewed as a function of pipeline system deterioration. The models rely on soil type identification across the service area to determine the aggressiveness of the pipe environment and for division of the area into zones based on pipe properties and operational conditions. By understanding the interaction between pipe materials, operating conditions, and the pipe environment in the mechanisms leading to pipe deterioration, the models allow the prediction of leakage rates in different zones across a network. The decision support system utilizes these models to predict the condition of pipes in individual zones, and to optimize the utilization of rehabilitation resources by targeting the areas with the highest leakage rates.

  1. Protective Effects of Quercetin on Rat Pial Microvascular Changes during Transient Bilateral Common Carotid Artery Occlusion and Reperfusion

    PubMed Central

    Lapi, Dominga; Vagnani, S.; Pignataro, G.; Esposito, E.; Paterni, M.; Colantuoni, Antonio

    2012-01-01

    The aim of this study was to assess the in vivo effects of quercetin on pial microvascular responses during transient bilateral common carotid artery occlusion (BCCAO) and reperfusion. Rat pial microcirculation was visualized by fluorescence microscopy through a closed cranial window. Pial arterioles were classified in five orders of branchings. Capillaries were assigned order 0, the smallest arterioles order 1, and the largest ones order 5. In ischemic rats, 30 min BCCAO and 60 min reperfusion caused arteriolar diameter decrease (by 14.5 ± 3.3% of baseline in order 2), microvascular leakage [0.47 ± 0.04, normalized gray levels (NGL)], leukocyte adhesion in venules (9 ± 2/100 μm venular length, v.l./30 s), and reduction of capillary perfusion (by 40 ± 7% of baseline). Moreover, at the end of BCCAO and reperfusion there was a significant increase in reactive oxygen species (ROS) formation when compared with baseline. Quercetin highest dose determined dilation in all arteriolar orders (by 40 ± 4% of baseline in order 2) and prevented microvascular permeability (0.15 ± 0.02 NGL), leukocyte adhesion (3 ± 1/100 μm v.l./30 s) as well as ROS formation, while capillary perfusion was protected. Inhibition of endothelial nitric oxide synthase (NOS) prior to quercetin reduced arteriolar dilation (order 2 diameter increase by 10.3 ± 2.5% of baseline) and caused permeability increase (0.29 ± 0.03 NGL); inhibition of neuronal NOS or inducible NOS did not affect quercetin-induced effects. Inhibition of guanylyl cyclase prior to quercetin reversed the quercetin’s effects on pial arteriolar diameter and leakage. In conclusion, quercetin was able to protect pial microcirculation from ischemia–reperfusion damage inducing arteriolar dilation likely by nitric oxide release. Moreover, quercetin scavenger activity blunted ROS formation preserving the blood–brain barrier integrity. PMID:22403549

  2. Cystic Fibrosis Transmembrane Conductance Regulator in Sarcoplasmic Reticulum of Airway Smooth Muscle. Implications for Airway Contractility

    PubMed Central

    Cook, Daniel P.; Rector, Michael V.; Bouzek, Drake C.; Michalski, Andrew S.; Gansemer, Nicholas D.; Reznikov, Leah R.; Li, Xiaopeng; Stroik, Mallory R.; Ostedgaard, Lynda S.; Abou Alaiwa, Mahmoud H.; Thompson, Michael A.; Prakash, Y. S.; Krishnan, Ramaswamy; Meyerholz, David K.; Seow, Chun Y.

    2016-01-01

    Rationale: An asthma-like airway phenotype has been described in people with cystic fibrosis (CF). Whether these findings are directly caused by loss of CF transmembrane conductance regulator (CFTR) function or secondary to chronic airway infection and/or inflammation has been difficult to determine. Objectives: Airway contractility is primarily determined by airway smooth muscle. We tested the hypothesis that CFTR is expressed in airway smooth muscle and directly affects airway smooth muscle contractility. Methods: Newborn pigs, both wild type and with CF (before the onset of airway infection and inflammation), were used in this study. High-resolution immunofluorescence was used to identify the subcellular localization of CFTR in airway smooth muscle. Airway smooth muscle function was determined with tissue myography, intracellular calcium measurements, and regulatory myosin light chain phosphorylation status. Precision-cut lung slices were used to investigate the therapeutic potential of CFTR modulation on airway reactivity. Measurements and Main Results: We found that CFTR localizes to the sarcoplasmic reticulum compartment of airway smooth muscle and regulates airway smooth muscle tone. Loss of CFTR function led to delayed calcium reuptake following cholinergic stimulation and increased myosin light chain phosphorylation. CFTR potentiation with ivacaftor decreased airway reactivity in precision-cut lung slices following cholinergic stimulation. Conclusions: Loss of CFTR alters porcine airway smooth muscle function and may contribute to the airflow obstruction phenotype observed in human CF. Airway smooth muscle CFTR may represent a therapeutic target in CF and other diseases of airway narrowing. PMID:26488271

  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.

  4. 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.

  5. 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.

  6. Air heater leakage: worse than you think

    SciTech Connect

    Guffre, J.

    2006-04-15

    Every good engineer knows that you cannot control what you cannot measure. In the case of rotary regenerative air heaters, many plants fail to limit the negative impact of heater leakage because they use measurement procedures and/or devices that fail to take into account its indirect effects. For a 500 MW coal-fired plant the heat energy that air heaters capture and recycle amounts to about 60% of that existing in the boiler, equivalent to 1.5 Btu per hour. This article explains the importance of accurately measuring leakage levels and the need to use modern seals to make heaters air-tight. 4 figs.

  7. Comments to Role of upper airway ultrasound in airway management.

    PubMed

    Lien, Wan-Ching

    2017-01-01

    Tracheal ultrasound can be an alternative diagnostic tool in airway management, besides traditional confirmatory methods such as capnography and auscultation. The standard image is a hyperechoic air-mucosa (A-M) interface with a reverberation artifact posteriorly (comet-tail artifact). If the second A-M interface appears, which we call a "double-tract sign," esophageal intubation is considered.

  8. 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

  9. 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

  10. Thermal provocation to evaluate microvascular reactivity in human skin.

    PubMed

    Minson, Christopher T

    2010-10-01

    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.

  11. Methods to investigate coronary microvascular function in clinical practice.

    PubMed

    Lanza, Gaetano A; Camici, Paolo G; Galiuto, Leonarda; Niccoli, Giampaolo; Pizzi, Carmine; Di Monaco, Antonio; Sestito, Alfonso; Novo, Salvatore; Piscione, Federico; Tritto, Isabella; Ambrosio, Giuseppe; Bugiardini, Raffaele; Crea, Filippo; Marzilli, Mario

    2013-01-01

    A growing amount of data is increasingly showing the relevance of coronary microvascular dysfunction (CMVD) in several clinical contexts. This article reviews techniques and clinical investigations of the main noninvasive and invasive methods proposed to study coronary microcirculation and to identify CMVD in the presence of normal coronary arteries, also trying to provide indications for their application in clinical practice.

  12. Microvascular imaging: techniques and opportunities for clinical physiological measurements.

    PubMed

    Allen, John; Howell, Kevin

    2014-07-01

    The microvasculature presents a particular challenge in physiological measurement because the vessel structure is spatially inhomogeneous and perfusion can exhibit high variability over time. This review describes, with a clinical focus, the wide variety of methods now available for imaging of the microvasculature and their key applications. Laser Doppler perfusion imaging and laser speckle contrast imaging are established, commercially-available techniques for determining microvascular perfusion, with proven clinical utility for applications such as burn-depth assessment. Nailfold capillaroscopy is also commercially available, with significant published literature that supports its use for detecting microangiopathy secondary to specific connective tissue diseases in patients with Raynaud's phenomenon. Infrared thermography measures skin temperature and not perfusion directly, and it has only gained acceptance for some surgical and peripheral microvascular applications. Other emerging technologies including imaging photoplethysmography, optical coherence tomography, photoacoustic tomography, hyperspectral imaging, and tissue viability imaging are also described to show their potential as techniques that could become established tools for clinical microvascular assessment. Growing interest in the microcirculation has helped drive the rapid development in perfusion imaging of the microvessels, bringing exciting opportunities in microvascular research.

  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. The Lung Microbiome and Airway Disease.

    PubMed

    Lynch, Susan V

    2016-12-01

    A growing body of literature has demonstrated relationships between the composition of the airway microbiota (mixed-species communities of microbes that exist in the respiratory tract) and critical features of immune response and pulmonary function. These studies provide evidence that airway inflammatory status and capacity for repair are coassociated with specific taxonomic features of the airway microbiome. Although directionality has yet to be established, the fact that microbes are known drivers of inflammation and tissue damage suggests that in the context of chronic inflammatory airway disease, the composition and, more importantly, the function, of the pulmonary microbiome represent critical factors in defining airway disease outcomes.

  15. Airway nerves: in vitro electrophysiology.

    PubMed

    Fox, Alyson

    2002-06-01

    Recording the activity of single airway sensory fibres or neuronal cell bodies in vitro has allowed detailed characterisation of fibre types and membrane properties. Fibre types can be identified by their conduction velocities and further studied by the application of drugs to their receptive field. C-fibres are sensitive to mechanical stimuli and a range of irritant chemicals (bradykinin, capsaicin, low pH, platelet-activating factor), whereas Adelta-fibres are relatively insensitive to chemical stimuli and appear to correlate to the rapidly adapting receptors identified in airways in vivo. Their site of origin also differs: upper airway C-fibres arise predominantly from the jugular ganglion and Adelta-fibres from the jugular and nodose ganglia. Intracellular recording from cell bodies in the ganglia has revealed a calcium-dependent potassium current common to many putative C-fibre cell bodies. This slow after hyperpolarisation current may be inhibited by stimuli that excite and sensitise C-fibres - this could be an important mechanism underlying the sensitisation of C-fibres in airway irritability.

  16. 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…

  17. 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.

  18. 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.

  19. Airway malacia in children with achondroplasia.

    PubMed

    Dessoffy, Kimberly E; Modaff, Peggy; Pauli, Richard M

    2014-02-01

    This study was undertaken to assess the frequency of airway malacia in infants and young children with achondroplasia, a population well known to be at risk for a variety of respiratory problems. We also wished to evaluate what, if any, contribution airway malacia makes to the complex respiratory issues that may be present in those with achondroplasia. Retrospective chart review of all infants and young children with achondroplasia who were assessed through the Midwest Regional Bone Dysplasia Clinics from 1985 through 2012 (n = 236) was completed. Records of comprehensive clinical examinations, polysomnographic assessments, and airway visualization were reviewed and abstracted using a data collection form. Analyses were completed comparing the group with and those without evidence for airway malacia. Thirteen of 236 patients (5.5%) were found to have airway malacia. Most of those affected had lower airway involvement (9/13). The presence of airway malacia was correlated with an increased occurrence of obstructive sleep apnea as well as need for oxygen supplementation, airway surgeries and tracheostomy placement. Although estimates of the frequency of airway malacia in the general population are limited, its frequency in children with achondroplasia appears to be much higher than any published general population estimate. The presence of airway malacia appears to confound other breathing abnormalities in this population and results in the need for more invasive airway treatments.

  20. Native Small Airways Secrete Bicarbonate

    PubMed Central

    Quinton, Paul M.

    2014-01-01

    Since the discovery of Cl− impermeability in cystic fibrosis (CF) and the cloning of the responsible channel, CF pathology has been widely attributed to a defect in epithelial Cl− transport. However, loss of bicarbonate (HCO3−) transport also plays a major, possibly more critical role in CF pathogenesis. Even though HCO3− transport is severely affected in the native pancreas, liver, and intestines in CF, we know very little about HCO3− secretion in small airways, the principle site of morbidity in CF. We used a novel, mini-Ussing chamber system to investigate the properties of HCO3− transport in native porcine small airways (∼ 1 mm φ). We assayed HCO3− transport across small airway epithelia as reflected by the transepithelial voltage, conductance, and equivalent short-circuit current with bilateral 25-mM HCO3− plus 125-mM NaGlu Ringer’s solution in the presence of luminal amiloride (10 μM). Under these conditions, because no major transportable anions other than HCO3− were present, we took the equivalent short-circuit current to be a direct measure of active HCO3− secretion. Applying selective agonists and inhibitors, we show constitutive HCO3− secretion in small airways, which can be stimulated significantly by β-adrenergic– (cAMP) and purinergic (Ca2+) -mediated agonists, independently. These results indicate that two separate components for HCO3− secretion, likely via CFTR- and calcium-activated chloride channel–dependent processes, are physiologically regulated for likely roles in mucus clearance and antimicrobial innate defenses of small airways. PMID:24224935

  1. 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.

  2. Airway remodeling in asthma: what really matters.

    PubMed

    Fehrenbach, Heinz; Wagner, Christina; Wegmann, Michael

    2017-03-01

    Airway remodeling is generally quite broadly defined as any change in composition, distribution, thickness, mass or volume and/or number of structural components observed in the airway wall of patients relative to healthy individuals. However, two types of airway remodeling should be distinguished more clearly: (1) physiological airway remodeling, which encompasses structural changes that occur regularly during normal lung development and growth leading to a normal mature airway wall or as an acute and transient response to injury and/or inflammation, which ultimately results in restoration of a normal airway structures; and (2) pathological airway remodeling, which comprises those structural alterations that occur as a result of either disturbed lung development or as a response to chronic injury and/or inflammation leading to persistently altered airway wall structures and function. This review will address a few major aspects: (1) what are reliable quantitative approaches to assess airway remodeling? (2) Are there any indications supporting the notion that airway remodeling can occur as a primary event, i.e., before any inflammatory process was initiated? (3) What is known about airway remodeling being a secondary event to inflammation? And (4), what can we learn from the different animal models ranging from invertebrate to primate models in the study of airway remodeling? Future studies are required addressing particularly pheno-/endotype-specific aspects of airway remodeling using both endotype-specific animal models and "endotyped" human asthmatics. Hopefully, novel in vivo imaging techniques will be further advanced to allow monitoring development, growth and inflammation of the airways already at a very early stage in life.

  3. Cuff leakage, not paravalvular leakage, in the Carpentier Edwards PERIMOUNT Magna Ease aortic bioprosthesis.

    PubMed

    Tokunaga, Shigehiko; Cho, Tomoki; Izubuchi, Ryo; Masuda, Munetaka

    2015-12-01

    Though the Carpentier Edwards PERIMOUNT Magna Ease valve is a bioprosthesis with documented excellent haemodynamics and easy implantability, this valve has a gap between the cobalt-chromium-nickel alloy stent and silicone sewing ring. This gap, which is widest just below each of the three commissural struts, lacks silicone and leaves the two-layer polytetrafluoroethylene fabric unsupported and unprotected. If the needle of a valve suture is placed in this structurally weak area of the sewing ring, the resultant fabric tear may result in a true cuff leakage, not the usual paravalvular leakage. We describe this pitfall in the context of a recent operation to alert surgeons everywhere that suture placement too close to the stent (missing the silicone sewing ring) can result in postoperative cuff leakage. We need to be very careful to include the silicone ring in each stitch to prevent injury to the valve cuff of this prosthesis and to avoid cuff leakage.

  4. 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

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. Nonlinear Acoustics Used To Reduce Leakage Flow

    NASA Technical Reports Server (NTRS)

    Daniels, Christopher C.; Steinetz, Bruce M.

    2004-01-01

    Leakage and wear are two fundamental problems in all traditional turbine seals that contribute to an engine's inefficiency. The solutions to seal leakage and wear conflict in the conventional design space. Reducing the clearance between the seal and rotating shaft reduces leakage but increases wear because of increased contact incidents. Increasing the clearance to reduce the contact between parts reduces wear but increases parasitic leakage. The goal of this effort is to develop a seal that restricts leakage flow using acoustic pressure while operating in a noncontacting manner, thereby increasing life. In 1996, Dr. Timothy Lucas announced his discovery of a method to produce shock-free high-amplitude pressure waves. For the first time, the formation of large acoustic pressures was possible using dissonant resonators. A pre-prototype acoustic seal developed at the NASA Glenn Research Center exploits this fundamental acoustic discovery: a specially shaped cavity oscillated at the contained fluid's resonant frequency produces high-amplitude acoustic pressure waves of a magnitude approaching those required of today's seals. While the original researchers are continuing their development of acoustic pumps, refrigeration compressors, and electronic thermal management systems using this technology, the goal of researchers at Glenn is to apply these acoustic principles to a revolutionary sealing device. When the acoustic resonator shape is optimized for the sealing device, the flow from a high-pressure cavity to a low-pressure cavity will be restricted by a series of high-amplitude standing pressure waves of higher pressure than the pressure to be sealed. Since the sealing resonator cavity will not touch the adjacent sealing structures, seal wear will be eliminated, improving system life. Under a cooperative agreement between Glenn and the Ohio Aerospace Institute (OAI), an acoustic-based pre-prototype seal was demonstrated for the first time. A pressurized cavity was

  11. 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).

  12. Scintigraphic detection of urinary leakage after kidney transplantation.

    PubMed

    DeLange, E E; Pauwels, E K; Lobatto, S; Tjon Pian Gi-van Loon, C E; van Hooff, J P

    1982-01-01

    Urinary leakage after kidney transplantation is a serious complication. In a retrospective study we analyzed 8 relevant cases of 14 patients with urinary leakage. In these eight patients kidney scintigraphy indicated the presence of urinary extravasation. Compared with other imaging modalities such as IV urography, cystography and ultrasound, scintigraphy seems to be an easy and safe method to detect urinary leakage. Moreover scintigraphic examination may suggest leakage, while this may not be clinically evident or suspected.

  13. 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.

  14. Generation of Pig Airways using Rules Developed from the Measurements of Physical Airways

    PubMed Central

    Azad, Md Khurshidul; Mansy, Hansen A.

    2017-01-01

    Background A method for generating bronchial tree would be helpful when constructing models of the tree for benchtop experiments as well as for numerical modeling of flow or sound propagation in the airways. Early studies documented the geometric details of the human airways that were used to develop methods for generating human airway tree. However, methods for generating animal airway tree are scarcer. Earlier studies suggested that the morphology of animal airways can be significantly different from that of humans. Hence, using algorithms for the human airways may not be accurate in generating models of animal airway geometry. Objective The objective of this study is to develop an algorithm for generating pig airway tree based on the geometric details extracted from the physical measurements. Methods In the current study, measured values of branch diameters, lengths and bifurcation angles and rotation of bifurcating planes were used to develop an algorithm that is capable of generating a realistic pig airway tree. Results The generation relations between parent and daughter branches were found to follow certain trends. The diameters and the length of different branches were dependent on airway generations while the bifurcation angles were primarily dependent on bifurcation plane rotations. These relations were sufficient to develop rules for generating a model of the pig large airways. Conclusion The results suggested that the airway tree generated from the algorithm can provide an approximate geometric model of pig airways for computational and benchtop studies. PMID:28255517

  15. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    SciTech Connect

    Hult, Erin L.; Dickerhoff, Darryl J.; Price, Phillip N.

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  16. 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...

  17. Recent trends in airway management

    PubMed Central

    Karlik, Joelle; Aziz, Michael

    2017-01-01

    Tracheal intubation remains a life-saving procedure that is typically not difficult for experienced providers in routine conditions. Unfortunately, difficult intubation remains challenging to predict and intubation conditions may make the event life threatening. Recent technological advances aim to further improve the ease, speed, safety, and success of intubation but have not been fully investigated. Video laryngoscopy, though proven effective in the difficult airway, may result in different intubation success rates in various settings and in different providers’ hands. The rescue surgical airway remains a rarely used but critical skill, and research continues to investigate optimal techniques. This review highlights some of the new thoughts and research on these important topics. PMID:28299194

  18. 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.

  19. Treatment of Angina Pectoris Associated with Coronary Microvascular Dysfunction.

    PubMed

    Ong, Peter; Athanasiadis, Anastasios; Sechtem, Udo

    2016-08-01

    Treatment of angina pectoris associated with coronary microvascular dysfunction is challenging as the underlying mechanisms are often diverse and overlapping. Patients with type 1 coronary microvascular dysfunction (i.e. absence of epicardial coronary artery disease and myocardial disease) should receive strict control of their cardiovascular risk factors and thus receive statins and ACE-inhibitors in most cases. Antianginal medication consists of ß-blockers and/or calcium channel blockers. Second line drugs are ranolazine and nicorandil with limited evidence. Despite individually titrated combinations of these drugs up to 30 % of patients have refractory angina. Rho-kinase inhibitors and endothelin-receptor antagonists represent potential drugs that may prove useful in these patients in the future.

  20. Efficient quantum dialogue without information leakage

    NASA Astrophysics Data System (ADS)

    Yin, Ai-Han; Tang, Zhi-Hui; Chen, Dong

    2015-02-01

    A two-step quantum dialogue scheme is put forward with a class of three-qubit W state and quantum dense coding. Each W state can carry three bits of secret information and the measurement result is encrypted without information leakage. Furthermore, we utilize the entangle properties of W state and decoy photon checking technique to realize three-time channel detection, which can improve the efficiency and security of the scheme.

  1. A microvascular system for chemical reactions using surface waste heat.

    PubMed

    Nguyen, Du Thai; Esser-Kahn, Aaron P

    2013-12-16

    Coffee-powered chemistry: Low-grade waste heat on surfaces can be used to drive chemical reactions, including the regeneration of a CO2 capture solution. Flowing two-phase heat transfer has been implemented within microvascular systems. This stripping system can be adapted to pre-fabricated surfaces, as demonstrated by a coffee mug containing a 1.2 m long microchannel. MEA=monoethanolamine.

  2. Microvascular Perfusion Changes following Transarterial Hepatic Tumor Embolization

    PubMed Central

    Johnson, Carmen Gacchina; Sharma, Karun V.; Levy, Elliot B.; Woods, David L.; Morris, Aaron H.; Bacher, John D.; Lewis, Andrew L.; Wood, Bradford J.; Dreher, Matthew R.

    2015-01-01

    Purpose To quantify changes in tumor microvascular (< 1 mm) perfusion relative to commonly used angiographic endpoints. Materials and Methods Rabbit Vx2 liver tumors were embolized with 100–300-µm LC Bead particles to endpoints of substasis or complete stasis (controls were not embolized). Microvascular perfusion was evaluated by delivering two different fluorophore-conjugated perfusion markers (ie, lectins) through the catheter before embolization and 5 min after reaching the desired angiographic endpoint. Tumor microvasculature was labeled with an anti-CD31 antibody and analyzed with fluorescence microscopy for perfusion marker overlap/mismatch. Data were analyzed by analysis of variance and post hoc test (n = 3–5 per group; 18 total). Results Mean microvascular density was 70 vessels/mm2 ± 17 (standard error of the mean), and 81% ± 1 of microvasculature (ie, CD31+ structures) was functionally perfused within viable Vx2 tumor regions. Embolization to the extent of substasis eliminated perfusion in 37% ± 9 of perfused microvessels (P > .05 vs baseline), whereas embolization to the extent of angiographic stasis eliminated perfusion in 56% ± 8 of perfused microvessels. Persistent microvascular perfusion following embolization was predominantly found in the tumor periphery, adjacent to normal tissue. Newly perfused microvasculature was evident following embolization to substasis but not when embolization was performed to complete angiographic stasis. Conclusions Nearly half of tumor microvasculature remained patent despite embolization to complete angiographic stasis. The observed preservation of tumor microvasculature perfusion with angiographic endpoints of substasis and stasis may have implications for tumor response to embolotherapy. PMID:26321051

  3. 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

  4. Hemimasticatory spasm treated with microvascular decompression of the trigeminal nerve.

    PubMed

    Chon, Kyu-Hyon; Lee, Jong-Myong; Koh, Eun-Jeong; Choi, Ha-Young

    2012-09-01

    Hemimasticatory spasm is a very rare disorder of the trigeminal nerve characterized by paroxysmal involuntary contraction of the jaw-closing muscles. The mechanisms leading to hemimasticatory spasm are still unclear. Recently, injection of botulinum toxin has become the treatment of choice due to its excellent results. We report a case of a successful treatment of hemimasticatory spasm via microvascular decompression of the motor branch of the trigeminal nerve.

  5. 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.

  6. 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.

  7. 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

  8. Pulmonary microvascular cytology in the diagnosis of lymphangitic carcinomatosis.

    PubMed

    Masson, R G; Krikorian, J; Lukl, P; Evans, G L; McGrath, J

    1989-07-13

    The diagnosis of lymphangitic spread of carcinoma in the lungs is sometimes difficult. We studied the cytologic characteristics of blood drawn through a wedged pulmonary-artery catheter from eight patients in whom lymphangitic carcinomatosis was confirmed by subsequent autopsy, lung biopsy, or clinical evaluation. The sites of the primary tumors were the prostate, breast, esophagus, and lung. Malignant cells were found in seven of the eight patients. Cytologic findings were normal in 16 of 17 patients with cancer but without pulmonary metastases and in 22 of 23 patients with nonmalignant pulmonary disorders. In a patient with cancer with tumor embolism to the lungs, the findings were positive, probably because of extensive intravascular tumor in large hepatic veins. One false positive finding occurred in a patient with extensive pulmonary infarction. Megakaryocytes, which are present in large numbers in the pulmonary capillary bed, are the hallmark of a satisfactory pulmonary vascular blood sample for pulmonary microvascular cytologic study. Familiarity with the cytologic characteristics of these cells in Papanicolaou preparations is essential to avoid mistakenly identifying them as malignant. Although transbronchial lung biopsy remains the diagnostic procedure of choice in this disorder, our findings suggest that the presence of malignant cells in pulmonary microvascular-cytology preparations in patients with cancer and unexplained dyspnea constitutes presumptive evidence of lymphangitic carcinomatosis. Pulmonary microvascular cytology may be particularly valuable when lung biopsy is refused or is thought to be too hazardous.

  9. Delayed, bilateral, non-microvascular ear replantation after violent amputation.

    PubMed

    García-Murray, E; Adán-Rivas, O; Salcido-Calzadilla, H

    2009-06-01

    Amputation of any body part is undoubtedly a traumatic experience leaving a terrible deformity, especially when the part or parts involved are visible and constitute an essential component of someone's facial whole. Bilateral ear amputation and successful subsequent replantation has been reported historically, but not in the modern surgical literature. We report the case of a 27-year-old female who was abducted and suffered a bilateral ear amputation at the hands of one of her captors to speed delivery of ransom money; the severed parts were sent to the parents approximately 2 hours after the amputation had taken place, and the girl was released some 48 hours after the ears were delivered. Microvascular replantation was attempted immediately after admission to the hospital some 2 hours after her release, but failed, and so a non-microvascular replantation was performed and was successful, after approximately 54 hours of ischaemia time. We consider this the first report of a complete bilateral, delayed, non-microvascular, successful ear replantation in a human being in the modern literature.

  10. Early Experiences with Microvascular Free Tissue Transfer in Lagos, Nigeria

    PubMed Central

    Mofikoya, Bolaji O; Ugburo, Andrew O

    2014-01-01

    Objectives: Microvascular free tissue transfer within our subregion is fraught with considerable challenges. We aim to highlight our experiences gained with our first fifteen cases of microvascular free tissue transfer at the Lagos University Teaching Hospital. We believe our report will be useful to colleagues embarking on such reconstructions in similar settings. Materials and Methods: The clinical records of the first 15 cases of free flaps done at our center were reviewed. The indications for surgery, choice of flap, recipient vessels, duration of surgery and complications were noted. Results: Fifteen cases were done, 10 flaps survived, ten defects occurred following trauma while remaining five followed cancer resections. Anterolateral thigh and radial forearm flaps were the most common flap used. The mean duration of surgeries was 7.1 hours SD ± 1.10 hours. Our take back rate was 13.3%, with a salvage rate of 50%. Three flaps failed on account venous congestion while remaining two failed due to arterial occlusion. Conclusion: 66.67% free flap success rate recorded reflect our early experiences in our institution. We believe meticulous planning, careful vessel selection, close flap monitoring as well as improved infrastructural support can lead to much better success rates in microvascular reconstruction in our country. PMID:24665201

  11. [Microvascular anastomoses in reconstructive head and neck surgery].

    PubMed

    Remmert, S

    1995-04-01

    At the ENT Department of the University of Lübeck, 57 microvascular tissue transplants with 129 anastomoses (61 arterial and 68 venous) have been performed in the last three years. Arteries have always been anastomosed end to end. The venous anastomoses have primarily been performed as end-to-side unions with the jugular vein. In nine patients, great distances between the donor and recipient vessel had to be connected with venous interponates. In two cases in which veins were lacking in the neck after radical neck dissection or radiation fibrosis, we used the cephalic vein or veins of the capsule of the thyroid gland as recipient vessels. The jejunal or osteomyocutaneous transplants were first fitted into the defect before performing the anastomosis. The jejunal peristalsis and the required freedom of movement in shaping the bone necessitated this technique. Microvascular anastomosis was first performed on the transplant of the radialis flap and the neurovascular infrahyoid muscular flap, and then they were integrated into the defect. We lost two transplants postoperatively because of venous thrombosis. In this article wie describe our anastomosis technique, the frequency distribution of recipient vessels, and the rules and characteristics of microvascular anastomosis after radiation and neck dissection.

  12. Tight junctional abnormality in multiple sclerosis white matter affects all calibres of vessel and is associated with blood-brain barrier leakage and active demyelination.

    PubMed

    Kirk, John; Plumb, Jonnie; Mirakhur, Meenakshi; McQuaid, Stephen

    2003-10-01

    Blood-brain barrier (BBB) hyperpermeability in multiple sclerosis (MS) is associated with lesion pathogenesis and has been linked to pathology in microvascular tight junctions (TJs). This study quantifies the uneven distribution of TJ pathology and its association with BBB leakage. Frozen sections from plaque and normal-appearing white matter (NAWM) in 14 cases were studied together with white matter from six neurological and five normal controls. Using single and double immunofluorescence and confocal microscopy, the TJ-associated protein zonula occludens-1 (ZO-1) was examined across lesion types and tissue categories, and in relation to fibrinogen leakage. Confocal image data sets were analysed for 2198 MS and 1062 control vessels. Significant differences in the incidence of TJ abnormalities were detected between the different lesion types in MS and between MS and control white matter. These were frequent in oil-red O (ORO)(+) active plaques, affecting 42% of vessel segments, but less frequent in ORO(-) inactive plaques (23%), NAWM (13%), and normal (3.7%) and neurological controls (8%). A similar pattern was found irrespective of the vessel size, supporting a causal role for diffusible inflammatory mediators. In both NAWM and inactive lesions, dual labelling showed that vessels with the most TJ abnormality also showed most fibrinogen leakage. This was even more pronounced in active lesions, where 41% of vessels in the highest grade for TJ alteration showed severe leakage. It is concluded that disruption of TJs in MS, affecting both paracellular and transcellular paths, contributes to BBB leakage. TJ abnormality and BBB leakage in inactive lesions suggests either failure of TJ repair or a continuing pathological process. In NAWM, it suggests either pre-lesional change or secondary damage. Clinically inapparent TJ pathology has prognostic implications and should be considered when planning disease-modifying therapy.

  13. Gas pipeline leakage detection based on PZT sensors

    NASA Astrophysics Data System (ADS)

    Zhu, Junxiao; Ren, Liang; Ho, Siu-Chun; Jia, Ziguang; Song, Gangbing

    2017-02-01

    In this paper, an innovative method for rapid detection and location determination of pipeline leakage utilizing lead zirconate titanate (PZT) sensors is proposed. The negative pressure wave (NPW) is a stress wave generated by leakage in the pipeline, and propagates along the pipeline from the leakage point to both ends. Thus the NPW is associated with hoop strain variation along the pipe wall. PZT sensors mounted on the pipeline were used to measure the strain variation and allowed accurate (within 2% error) and repeatable location (within 4% variance) of five manually controlled leakage points. Experimental results have verified the effectiveness and the location accuracy for leakage in a 55 meter long model pipeline.

  14. Observation of anomalous leakage increase of narrow and short BCPMOS

    NASA Astrophysics Data System (ADS)

    Xu, Y. Z.; Pohland, O.; Cai, C.; Puchner, H.

    2004-07-01

    Leakage performance of BCPMOS (Buried channel PMOS) is investigated by experimentally varying the LDD implant conditions. An anomalous leakage increase with Boron LDD implant is observed for a small geometry (narrow and short) PMOS. Experimental results indicate that the increase of leakage current for narrow and short channel PMOS can be explained by boron piling up at the edge of STI isolation and from source/drain towards the middle of channel. Further confirmation of boron piling up is proven by the surface channel NMOS threshold voltage. Based on the leakage sensitivity, BCPMOS LDD is optimized to reduce leakage current for the small geometry transistors.

  15. Alopecia associated with unexpected leakage from electron cone

    SciTech Connect

    Wen, B.C.; Pennington, E.C.; Hussey, D.H.; Jani, S.K.

    1989-06-01

    Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region.

  16. Measuring and Suppressing Quantum State Leakage in a Superconducting Qubit

    NASA Astrophysics Data System (ADS)

    Chen, Zijun; Kelly, Julian; Quintana, Chris; Barends, R.; Campbell, B.; Chen, Yu; Chiaro, B.; Dunsworth, A.; Fowler, A. G.; Lucero, E.; Jeffrey, E.; Megrant, A.; Mutus, J.; Neeley, M.; Neill, C.; O'Malley, P. J. J.; Roushan, P.; Sank, D.; Vainsencher, A.; Wenner, J.; White, T. C.; Korotkov, A. N.; Martinis, John M.

    2016-01-01

    Leakage errors occur when a quantum system leaves the two-level qubit subspace. Reducing these errors is critically important for quantum error correction to be viable. To quantify leakage errors, we use randomized benchmarking in conjunction with measurement of the leakage population. We characterize single qubit gates in a superconducting qubit, and by refining our use of derivative reduction by adiabatic gate pulse shaping along with detuning of the pulses, we obtain gate errors consistently below 1 0-3 and leakage rates at the 1 0-5 level. With the control optimized, we find that a significant portion of the remaining leakage is due to incoherent heating of the qubit.

  17. 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

  18. 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.

  19. Method for 3D Airway Topology Extraction

    PubMed Central

    Grothausmann, Roman; Kellner, Manuela; Heidrich, Marko; Lorbeer, Raoul-Amadeus; Ripken, Tammo; Meyer, Heiko; Kuehnel, Mark P.; Ochs, Matthias; Rosenhahn, Bodo

    2015-01-01

    In lungs the number of conducting airway generations as well as bifurcation patterns varies across species and shows specific characteristics relating to illnesses or gene variations. A method to characterize the topology of the mouse airway tree using scanning laser optical tomography (SLOT) tomograms is presented in this paper. It is used to test discrimination between two types of mice based on detected differences in their conducting airway pattern. Based on segmentations of the airways in these tomograms, the main spanning tree of the volume skeleton is computed. The resulting graph structure is used to distinguish between wild type and surfactant protein (SP-D) deficient knock-out mice. PMID:25767561

  20. Automated Lobe-Based Airway Labeling

    PubMed Central

    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

  1. 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.

  2. Rationale for Measuring Duct Leakage Flows in Large Commercial Buildings

    SciTech Connect

    Wray, Craig P.; Diamond, Richard C.; Sherman, Max H.

    2005-07-01

    Industry-wide methods of assessing duct leakage are based on duct pressurization tests, and focus on ''high pressure'' ducts. Even though ''low pressure'' ducts can be a large fraction of the system and tend to be leaky, few guidelines or construction specifications require testing these ducts. We report here on the measured leakage flows from ten large commercial duct systems at operating conditions: three had low leakage (less than 5% of duct inlet flow), and seven had substantial leakage (9 to 26%). By comparing these flows with leakage flows estimated using the industry method, we show that the latter method by itself is not a reliable indicator of whole-system leakage flow, and that leakage flows need to be measured.

  3. 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

  4. 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.

  5. Methodological issues in the assessment of skin microvascular endothelial function in humans.

    PubMed

    Cracowski, Jean-Luc; Minson, Christopher T; Salvat-Melis, Muriel; Halliwill, John R

    2006-09-01

    The study of microvascular function can be performed in humans using laser Doppler flowmetry of the skin. This technology lends itself to a wide range of applications for studying the endothelial function of skin blood vessels. We review the advantages and limitations of postocclusive hyperemia, local thermal hyperemia, acetylcholine iontophoresis, flowmotion and association with microdialysis as tools with which to investigate skin microvascular endothelial function in humans. Postocclusive hyperemia, thermal hyperemia and acetylcholine iontophoresis provide integrated indexes of microvascular function rather than specific endothelial markers. However, they are valuable tools and can be used as surrogate endpoints in clinical trials in which the assessment of microvascular function in humans is required.

  6. The comparison of ProSeal and I-gel laryngeal mask airways in anesthetized adult patients under controlled ventilation

    PubMed Central

    Ekinci, Osman; Abitagaoglu, Süheyla; Turan, Güldem; Sivrikaya, Zübeyir; Bosna, Gülşen; Özgultekin, Asu

    2015-01-01

    Objectives: To compare the insertion time, ease of device insertion, ease of gastric tube insertion, airway leakage pressure, and complications between the laryngeal mask airway (LMA) ProSeal (P-LMA) and I-gel (I-gel) groups. Methods: Eighty patients with age range 18-65 years who underwent elective surgery were included in the study. The study took place in the operation rooms of Haydarpaşa Numune Hospital, Istanbul, Turkey from November 2013 to April 2014. Patients were equally randomized into 2 groups; the I-gel group, and the P-LMA group. In both groups, the same specialist inserted the supraglottic airway devices. The insertion time of the devices, difficulty during insertion, difficulty during gastric tube insertion, coverage of airway pressure, and complications were recorded. Results: The mean insertion time in the I-gel group was significantly lower than that of the P-LMA group (I-gel: 8±3; P-LMA: 13±5 s). The insertion success rate was higher in the I-gel group (100%, first attempt) than in the P-LMA group (82.5%, first attempt). The gastric tube placement success rate was higher in the I-gel group (92.5%, first attempt) than in the P-LMA group (72.5%, first attempt). The airway leakage pressures were similar. Conclusion: Insertion was easier, insertion time was lower, and nasogastric tube insertion success was higher with the I-gel application, and is, therefore, the preferred LMA. PMID:25828279

  7. 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.

  8. Detecting margin leakage of dental composite restorations

    SciTech Connect

    Wu, W.; Cobb, E.; Dermann, K.; Rupp, N.W.

    1983-01-01

    The degree of microleakage between a restoration and the cavity wall is difficult to quantify objectively. A silver-staining method is used and compared to the radioisotope method with results that indicate a superior definition and more accurate evaluation of microleakage. In addition to the accuracy, two advantages are presented: (1) scoring of the leakage can be refined and divided into more precise numbers, and (2) teeth can be observed directly in a microscope without resorting to the indirect interpretation of film or photograph.

  9. Airway management: induced tension pneumoperitoneum

    PubMed Central

    Ahmed, Khedher; Amine, El Ghali Mohamed; Abdelbaki, Azouzi; Jihene, Ayachi; Khaoula, Meddeb; Yamina, Hamdaoui; Mohamed, Boussarsar

    2016-01-01

    Pneumoperitoneum is not always associated with hollow viscus perforation. Such condition is called non-surgical or spontaneous pneumoperitoneum. Intrathoracic causes remain the most frequently reported mechanism inducing this potentially life threatening complication. This clinical condition is associated with therapeutic dilemma. We report a case of a massive isolated pneumoperitoneum causing acute abdominal hypertension syndrome, in a 75 year female, which occurred after difficult airway management and mechanical ventilation. Emergent laparotomy yielded to full recovery. The recognition of such cases for whom surgical management can be avoided is primordial to avoid unnecessary laparotomy and its associated morbidity particularly in the critically ill.

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

    PubMed

    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

    2007-05-01

    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.

  11. Analysis of U.S. residential air leakage database

    SciTech Connect

    Chan, Wanyu R.; Price, Phillip N.; Sohn, Michael D.; Gadgil, Ashok J.

    2003-07-01

    The air leakage of a building envelope can be determined from fan pressurization measurements with a blower door. More than 70,000 air leakage measurements have been compiled into a database. In addition to air leakage, the database includes other important characteristics of the dwellings tested, such as floor area, year built, and location. There are also data for some houses on the presence of heating ducts, and floor/basement construction type. The purpose of this work is to identify house characteristics that can be used to predict air leakage. We found that the distribution of leakage normalized with floor area of the house is roughly lognormal. Year built and floor area are the two most significant factors to consider when predicting air leakage: older and smaller houses tend to have higher normalized leakage areas compared to newer and larger ones. Results from multiple linear regression of normalized leakage with respect to these two factors are presented for three types of houses: low-income, energy-efficient, and conventional. We demonstrate a method of using the regression model in conjunction with housing characteristics published by the US Census Bureau to derive a distribution that describes the air leakage of the single-family detached housing stock. Comparison of our estimates with published datasets of air exchange rates suggests that the regression model generates accurate estimates of air leakage distribution.

  12. 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.

  13. Mechanisms of inflammation-mediated airway smooth muscle plasticity and airways remodeling in asthma.

    PubMed

    Halayko, Andrew J; Amrani, Yassine

    2003-09-16

    Recent evidence points to progressive structural change in the airway wall, driven by chronic local inflammation, as a fundamental component for development of irreversible airway hyperresponsiveness. Acute and chronic inflammation is orchestrated by cytokines from recruited inflammatory cells, airway myofibroblasts and myocytes. Airway myocytes exhibit functional plasticity in their capacity for contraction, proliferation, and synthesis of matrix protein and cytokines. This confers a principal role in driving different components of the airway remodeling process, and mediating constrictor hyperresponsiveness. Functional plasticity of airway smooth muscle (ASM) is regulated by an array of environmental cues, including cytokines, which mediate their effects through receptors and a number of intracellular signaling pathways. Despite numerous studies of the cellular effects of cytokines on cultured airway myocytes, few have identified how intracellular signaling pathways modulate or induce these cellular responses. This review summarizes current understanding of these concepts and presents a model for the effects of inflammatory mediators on functional plasticity of ASM in asthma.

  14. 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.

  15. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 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....

  16. 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....

  17. 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 ...

  18. Upper airway resistance: species-related differences.

    PubMed

    Kirschvink, N; Reinhold, P

    2010-07-01

    In veterinary medicine, upper airway resistance deserves a particular attention in equines athletes and brachycephalic dogs. Due to the anatomical peculiarities of the upper airway and/or pathological conditions, significant alterations of performance and/or well being might occur in horses and dogs. Physiological specificities and pathological changes of the lower respiratory tract deserve a major attention in other species.

  19. 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

  20. Immunoglobulin M-enriched human intravenous immunoglobulins reduce leukocyte-endothelial cell interactions and attenuate microvascular perfusion failure in normotensive endotoxemia.

    PubMed

    Hoffman, Johannes N; Fertmann, Jan M; Vollmar, Brigitte; Laschke, Matthias W; Jauch, Karl W; Menger, Michael D

    2008-01-01

    Clinical studies indicate potential differences in the efficacy of immunoglobulin (Ig) preparations in patients with sepsis. A recent meta-analysis showed improved survival rates with IgM-enriched Igs. It was the objective of the present study to characterize microcirculatory actions of different clinically used Ig preparations in a rodent endotoxin model by intravital microscopy. Male Syrian golden hamsters 6 to 8 weeks old with a body weight of 60 to 80 g were investigated by intravital fluorescence microscopy. Endotoxemia was induced by administration of 2 mg/kg (i.v.) endotoxin (LPS, Escherichia coli). Two different Ig preparations containing IgM, IgA, and IgG (intravenous IgM group; n = 6; 5 mL Pentaglobin/kg body weight, i.v.) or exclusively IgG (intravenous IgG group; n = 5; 5 mL Flebogamma/kg body weight, i.v.) were applied 5 min before LPS. Saline-treated endotoxemic animals served as controls (control; n = 8). In controls, LPS induced massive leukocyte-endothelial cell interactions, pronounced microvascular leakage, a decrease of systemic platelet count, and distinct capillary perfusion failure (P < 0.05). Both intravenous IgM and IgG reduced venular leakage (P< 0.05) and ameliorated the decrease in platelet count (P < 0.05). Of interest, intravenous IgM was capable of significantly (P< 0.05) reducing leukocyte adhesion in venules. This was associated with normalization of capillary perfusion at 24 h of endotoxemia, whereas intravenous IgG could not prevent LPS-mediated microvascular perfusion failure. We demonstrate that IgM-enriched Igs are superior to IgG alone in attenuating LPS-induced leukocytic inflammation and microcirculatory dysfunction. Our findings can explain better efficacy of IgM-enriched Igs in patients with severe sepsis.

  1. LPS causes pericyte loss and microvascular dysfunction via disruption of Sirt3/angiopoietins/Tie-2 and HIF-2α/Notch3 pathways

    PubMed Central

    Zeng, Heng; He, Xiaochen; Tuo, Qin-hui; Liao, Duan-fang; Zhang, Guo-qiang; Chen, Jian-xiong

    2016-01-01

    Recent studies reveal a crucial role of pericyte loss in sepsis-associated microvascular dysfunction. Sirtuin 3 (SIRT3) mediates histone protein post-translational modification related to aging and ischemic disease. This study investigated the involvement of SIRT3 in LPS-induced pericyte loss and microvascular dysfunction. Mice were exposed to LPS, expression of Sirt3, HIF-2α, Notch3 and angiopoietins/Tie-2, pericyte/endothelial (EC) coverage and vascular permeability were assessed. Mice treated with LPS significantly reduced the expression of SIRT3, HIF-2α and Notch3 in the lung. Furthermore, exposure to LPS increased Ang-2 while inhibited Ang-1/Tie-2 expression with a reduced pericyte/EC coverage. Intriguingly, knockout of Sirt3 upregulated Ang-2, but downregulated Tie-2 and HIF-2α/Notch3 expression which resulted in a dramatic reduction of pericyte/EC coverage and exacerbation of LPS-induced vascular leakage. Conversely, overexpression of Sirt3 reduced Ang-2 expression and increased Ang-1/Tie-2 and HIF-2α/Notch3 expression in the LPS treated mice. Overexpression of Sirt3 further prevented LPS-induced pericyte loss and vascular leakage. This was accompanied by a significant reduction of the mortality rate. Specific knockout of prolyl hydroxylase-2 (PHD2) increased HIF-2α/Notch3 expression, improved pericyte/EC coverage and reduced the mortality rate in the LPS-treated mice. Our study demonstrates the importance of SIRT3 in preserving vascular integrity by targeting pericytes in the setting of LPS-induced sepsis. PMID:26868537

  2. 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

  3. The critical airway in adults: The facts

    PubMed Central

    Bonanno, Fabrizio Giuseppe

    2012-01-01

    An algorithm on the indications and timing for a surgical airway in emergency as such cannot be drawn due to the multiplicity of variables and the inapplicability in the context of life-threatening critical emergency, where human brain elaborates decisions better in cluster rather than in binary fashion. In particular, in emergency or urgent scenarios, there is no clear or established consensus as to specifically who should receive a tracheostomy as a life-saving procedure; and more importantly, when. The two classical indications for emergency tracheostomy (laryngeal injury and failure to secure airway with endotracheal intubation or cricothyroidotomy) are too generic and encompass a broad spectrum of possibilities. In literature, specific indications for emergency tracheostomy are scattered and are biased, partially comprehensive, not clearly described or not homogeneously gathered. The review highlights the indications and timing for an emergency surgical airway and gives recommendations on which surgical airway method to use in critical airway. PMID:22787346

  4. Modeling of the double leakage and leakage spillage flows in axial flow compressors

    NASA Astrophysics Data System (ADS)

    Du, Hui; Yu, Xianjun; Liu, Baojie

    2014-04-01

    A model to predict the double leakage and tip leakage leading edge spillage flows was developed. This model was combined by a TLV trajectory model and a TLV diameter model and formed as a function of compressor one-dimensional design parameters, i.e. the compressor massflow coefficient, ϕ and compressor loading coefficient, Ψ, and some critical blade geometrical parameters, i.e. blade solidity, σ, stagger angle, β S , blade chord length, C, and blade pitch length, S. By using this model, the double leakage and tip leakage leading edge spillage flow could be predicted even at the compressor preliminary design process. Considering the leading edge spillage flow usually indicates the inception of spike-type stall, i.e. the compressor is a tip critical design, this model could also be used as a tool to choose the critical design parameters for designers. At last, some experimental data from literature was used to validate the model and the results proved that the model was reliable.

  5. 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.

  6. 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

  7. Microvascular transplantation of epiphyseal plates: studies utilizing allograft donor material.

    PubMed

    Boyer, Martin I; Bowen, C Vaughan A

    2007-01-01

    Compromised function of an epiphyseal plate caused by trauma, tumor, infection, or congenital malformation can result in significant musculoskeletal deformity. Techniques used to correct or minimize the extent of these deformities include autogenous or allogeneic cancellous bone grafts, nonvascularized cortical allografts, vascularized bone and composite tissue transfers, and distraction osteogenesis. These solutions are not ideal for children because they do not adequately address the actively growing nature of the extremity. Microvascular techniques have enabled the experimental transplantation of vascularized epiphyseal plates with high levels of postoperative viability and subsequent growth and offer a potential advantage over conventional treatments.

  8. Autonomic neurosurgery: from microvascular decompression to image guided stimulation

    PubMed Central

    Pereira, EAC; Green, AL

    2007-01-01

    The paper reviews mechanisms underlying autonomic disorders, with a focus on cardiovascular dysfunction. Neurosurgical approaches are described for medically refractory hypertension and orthostatic hypotension. After review of microvascular decompression of the rostral ventrolateral medulla, stereotactic CT and MRI guided deep brain stimulation of the periaqueductal grey matter (PAG) is evaluated. Results are presented from patient studies showing reductions in blood pressure with ventral PAG stimulation and increases in blood pressure with dorsal PAG stimulation. A rationale for the treatment of autonomic disorders by neurosurgical intervention is discussed. PMID:21614256

  9. 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.

  10. 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

  11. 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.

  12. Tasman leakage in a fine-resolution ocean model

    NASA Astrophysics Data System (ADS)

    van Sebille, Erik; England, Matthew H.; Zika, Jan D.; Sloyan, Bernadette M.

    2012-03-01

    Tasman leakage, the westward flow of thermocline waters south of Australia from the Pacific to the Indian Ocean, is one of the lesser-studied of the inter-ocean exchanges. Here, some of the properties of the Tasman leakage are inferred from Lagrangian particles integrated using the three-dimensional velocity fields of the 1/10 degree resolution OFES model. The mean Tasman leakage in this model is 4.2 Sv, with a standard deviation of 4.3 Sv. The heat flux associated with this leakage lies in the range 0.08-0.18 PW. There is large variability in the Tasman leakage on both sub-weekly and inter-annual scales, but no trend over the 1983-1997 period. Despite the large weekly variability, with peaks of more than 20 Sv, it appears that less than half of the Tasman leakage is carried within eddies.

  13. Sleep quality and duration are related to microvascular function: the Amsterdam Growth and Health Longitudinal Study.

    PubMed

    Bonsen, Thomas; Wijnstok, Nienke J; Hoekstra, Trynke; Eringa, Etto C; Serné, Erik H; Smulders, Yvo M; Twisk, Jos W R

    2015-04-01

    Sleep and sleep disorders are related to cardiovascular disease, and microvascular function is an early cardiovascular disease marker. Therefore, the relationship of sleep (measured in sleep quality and duration) with microvascular function was examined in healthy adults. Sleep quality was assessed with the validated Sleep Wake Experience List (SWEL) questionnaire. Duration of sleep was self-reported in an additional question. Microvascular function was measured using nailfold capillaroscopy. Linear regression analyses were used to examine the relationship between sleep and microvascular function. Potential confounders included physical activity, smoking, blood pressure, body mass index and several biochemical parameters. Analyses were performed in 259 participants (116 men). For women reporting insufficient (<7 h) sleep duration, microvascular function (post-ischaemic capillary recruitment) was significantly lower (b = -11.17; P = 0.04) compared to women reporting sufficient sleep duration. There was no relationship between sleep quality and microvascular function in females. In males, a trend towards lower capillary recruitment was found in those reporting a combination of poor sleep quality and insufficient duration (b = -7.54; P = 0.09), compared to those reporting good sleep quality as well as sufficient duration. This study suggests an association between sleep and microvascular function. Which aspects of sleep exactly affect microvascular function, and if indeed the association is different between males and females in other samples, needs further research.

  14. Glutathione redox regulates airway hyperresponsiveness and airway inflammation in mice.

    PubMed

    Koike, Yoko; Hisada, Takeshi; Utsugi, Mitsuyoshi; Ishizuka, Tamotsu; Shimizu, Yasuo; Ono, Akihiro; Murata, Yukie; Hamuro, Junji; Mori, Masatomo; Dobashi, Kunio

    2007-09-01

    Glutathione is the major intracellular redox buffer. We have shown that glutathione redox status, which is the balance between intracellular reduced (GSH) and oxidized (GSSG) glutathione, in antigen-presenting cells (APC) regulates the helper T cell type 1 (Th1)/Th2 balance due to the production of IL-12. Bronchial asthma is a typical Th2 disease. Th2 cells and Th2 cytokines are characteristic of asthma and trigger off an inflammation. Accordingly, we studied the effects of the intracellular glutathione redox status on airway hyperresponsiveness (AHR) and allergen-induced airway inflammation in a mouse model of asthma. We used gamma-Glutamylcysteinylethyl ester (gamma-GCE), which is a membrane-permeating GSH precursor, to elevate the intracellular GSH level and GSH/GSSG ratio of mice. In vitro, gamma-GCE pretreatment of human monocytic THP-1 cells elevated the GSH/GSSG ratio and enhanced IL-12(p70) production induced by LPS. In the mouse asthma model, intraperitoneal injection of gamma-GCE elevated the GSH/GSSG ratio of lung tissue and reduced AHR. gamma-GCE reduced levels of IL-4, IL-5, IL-10, and the chemokines eotaxin and RANTES (regulated on activation, normal T cell expressed and secreted) in bronchoalveolar lavage fluid, whereas it enhanced the production of IL-12 and IFN-gamma. Histologically, gamma-GCE suppressed eosinophils infiltration. Interestingly, we also found that gamma-GCE directly inhibited chemokine-induced eosinophil chemotaxis without affecting eotaxin receptor chemokine receptor 3 (CCR3) expressions. Taken together, these findings suggest that changing glutathione redox balance, increase in GSH level, and the GSH/GSSG ratio by gamma-GCE, ameliorate bronchial asthma by altering the Th1/Th2 imbalance through IL-12 production from APC and suppressing chemokine production and eosinophil migration itself.

  15. The role of intrinsic apoptotic signaling in hemorrhagic shock-induced microvascular endothelial cell barrier dysfunction.

    PubMed

    Sawant, Devendra A; Tharakan, Binu; Hunter, Felicia A; Childs, Ed W

    2014-11-01

    Hemorrhagic shock leads to endothelial cell barrier dysfunction resulting in microvascular hyperpermeability. Hemorrhagic shock-induced microvascular hyperpermeability is associated with worse clinical outcomes in patients with traumatic injuries. The results from our laboratory have illustrated a possible pathophysiological mechanism showing involvement of mitochondria-mediated "intrinsic" apoptotic signaling in regulating hemorrhagic shock-induced microvascular hyperpermeability. Hemorrhagic shock results in overexpression of Bcl-2 family of pro-apoptotic protein, BAK, in the microvascular endothelial cells. The increase in BAK initiates "intrinsic" apoptotic signaling cascade with the release of mitochondrial cytochrome c in the cytoplasm and activation of downstream effector caspase-3, leading to loss of endothelial cell barrier integrity. Thus, this review article offers a brief overview of important findings from our past and present research work along with new leads for future research. The summary of our research work will provide information leading to different avenues in developing novel strategies against microvascular hyperpermeability following hemorrhagic shock.

  16. 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…

  17. Airway adequacy, head posture, and craniofacial morphology.

    PubMed

    Solow, B; Siersbaek-Nielsen, S; Greve, E

    1984-09-01

    Previous studies of different samples have demonstrated associations between craniocervical angulation and craniofacial morphology, between airway obstruction by adenoids and craniofacial morphology, and between airway obstruction and craniocervical angulation. A hypothesis to account for the different sets of associations was suggested by Solow and Kreiborg in 1977. In the present study, the three sets of associations were examined in a single group of nonpathologic subjects with no history of airway obstruction. Cephalometric radiographs taken in the natural head position and rhinomanometric recordings were obtained from twenty-four children 7 to 9 years of age. Correlations were calculated between twenty-seven morphologic, eight postural, and two airway variables. A large craniocervical angle was, on the average, seen in connection with small mandibular dimensions, mandibular retrognathism, and a large mandibular inclination. Obstructed nasopharyngeal airways (defined as a small pm-ad 2 radiographic distance and a large nasal respiratory resistance, NRR, determined rhinomanometrically) were, on the average, seen in connection with a large craniocervical angle and with small mandibular dimensions, mandibular retrognathism, a large mandibular inclination, and retroclination of the upper incisors. The observed correlations were in agreement with the predicted pattern of associations between craniofacial morphology, craniocervical angulation, and airway resistance, thus suggesting the simultaneous presence of such associations in the sample of nonpathologic subjects with no history of airway obstruction.

  18. 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.

  19. Bosentan fosters microvascular de-remodelling in systemic sclerosis.

    PubMed

    Guiducci, S; Bellando Randone, S; Bruni, C; Carnesecchi, G; Maresta, A; Iannone, F; Lapadula, G; Matucci Cerinic, M

    2012-12-01

    Bosentan, a dual endothelin receptor antagonist, may reduce blood pressure by blocking the vasoconstrictor effect of endothelin-1. In systemic sclerosis (SSc) nailfold videocapillaroscopy (NVC); allows diagnostic and follow-up of microvascular damage. Distinct NVC patterns have been identified for the evaluation of severity of SSc microvascular damage. The objective of this study is to evaluate the modification of the microvasculature under Bosentan therapy in SSc patients with pulmonary arterial hypertension (PAH). Nine patients with PAH related to SSc in New York Heart Association classes III-IV were treated with Bosentan 125 mg twice a day. NVC optical probe videocapillaroscopy equipped with 100× and 200× contact lenses and connected to image analyse software was performed before and after 12 months of Bosentan therapy to evaluate the modification of microvasculature. Nine PAH SSc patients treated with Iloprost were used as controls. Before Bosentan therapy, seven patients showed at NVC severe loss of capillaries with large avascular areas and vascular architectural disorganisation which are typically "late" SSc pattern. After 12 months of Bosentan, NVC pattern changed in seven patients from "late" into "active" SSc pattern. The disappearance of avascular areas and capillary haemorrhages was the most striking result. Two patients had an "active" SSc pattern, not modified by Bosentan treatment. These data show that Bosentan may improve NVC pattern in SSC and the presence of new capillaries suggests that it may favour angiogenesis. Bosentan may improve and stabilise the microvasculature in long-term treatment modulating the structural modifications detected by NVC.

  20. Microvascular flow estimation by microbubble-assisted Nakagami imaging.

    PubMed

    Tsui, Po-Hsiang; Yeh, Chih-Kuang; Chang, Chien-Cheng

    2009-04-01

    The destruction and replenishment of microbubbles has been previously applied to estimating blood flow in the microcirculation. The rate of increase of the time-intensity curve (TIC) due to microbubbles flowing into the region-of-interest (ROI) as measured from the conventional B-mode images reflects the flow velocity. In this study, we monitored microbubble replenishment using a new proposed approach called the time-Nakagami-parameter curve (TNC) obtained from the parametric image based on the Nakagami statistical parameter for quantifying the microvascular flow velocity. The Nakagami parameter is estimated from signal envelope to reflect the backscattered statistics. The feasibility of using the TNC to estimate the microvascular flow was explored by carrying out phantom measurements and in vivo animal experiments. The rates of increase of the TIC and TNC were quantified as the rate constants beta(I) and beta(N) of monoexponential fitted curves, respectively. The experimental results showed that beta(N) behaves similarly to the conventional beta(I) in quantifying the flow velocity. Moreover, the tolerance to the effects of clutter is greater for the TNC than for the TIC, which makes it possible to use beta(N) to differentiate various flow velocities even when the ROI contains nonperfused areas. This finding suggests that the TNC-based technique can be used as a complementary tool for the conventional TIC to improve measurement of blood flow in the microcirculation.

  1. Assessment of Conjunctival Microvascular Hemodynamics in Stages of Diabetic Microvasculopathy

    PubMed Central

    Khansari, Maziyar M.; Wanek, Justin; Tan, Michael; Joslin, Charlotte E.; Kresovich, Jacob K.; Camardo, Nicole; Blair, Norman P.; Shahidi, Mahnaz

    2017-01-01

    Diabetes impairs the microcirculation and function of various vital tissues throughout the body. The conjunctival microcirculation can be non-invasively imaged and thus enables assessment of microvascular hemodynamics. In this study, alterations in conjunctival microvascular hemodynamics were quantitatively assessed at stages of increasing diabetic microvasculopathy based on diabetic retinopathy (DR). Subjects were categorized into non-diabetic control (C, N = 34), no clinically visible DR (NDR, N = 47), non-proliferative DR (NPDR, N = 45), and proliferative DR (PDR, N = 35). Conjunctival hemodynamic descriptors, namely vessel diameter (D), blood velocity (V), blood flow (Q), wall shear rate (WSR), and wall shear stress (WSS) were measured in arterioles and venules, and compared between DR and C subjects using generalized linear mixed models. In arterioles, V, WSR, and WSS were lower in NDR (P ≤ 0.01). V was lower in NDR than NPDR and PDR subjects (P ≤ 0.02). In venules, D was higher in NDR and NPDR (P ≤ 0.03), while V was lower in PDR (P = 0.04). Venular V and Q were higher in NPDR than PDR subjects (P ≤ 0.04). WSR and WSS were lower in all stages of DR (P ≤ 0.05), suggestive of the potential of WSS as a marker of diabetic microvasculopathy. Quantitative assessment of conjunctival hemodynamics can potentially be useful for evaluation of diabetic microvasculopathy. PMID:28387229

  2. Effects of hyperoxia on microvascular cells in vitro

    SciTech Connect

    D'Amore, P.A.; Sweet, E.

    1987-02-01

    Microvascular cells are most vulnerable to direct oxygen damage. Using an in vitro model system we have investigated the effect of elevated oxygen on the proliferation, morphology, and integrity of microvascular endothelial cells (EC) and pericytes. Cultivation of these cells at oxygen concentrations of 40% for 1 wk resulted in the inhibition of EC proliferation but had no effect on the growth of the pericytes. Similarly, hyperoxia induced a dramatic change in the shape of the EC, increasing their spread area by close to six-fold. Under the same conditions, the spread area of the pericytes was unaffected. To understand the effect of the hyperoxic treatment on the cells, the integrity of various membrane systems was assessed. /sup 51/Cr release was used to monitor plasma membrane integrity. There was no difference in chromium release by EC and pericytes over the 7 d of growth under normoxic and hyperoxic conditions. Mitochondrial integrity was examined by staining the cells with Rhodamine 123, which is selectively accumulated by the mitochondria. The staining pattern of the mitochondria of both EC and pericytes was altered by growth in the elevated oxygen. Finally, the lysosomes were visualized using acridine orange. The acridine orange staining pattern revealed enlarged and perinuclear lysosomes in the EC but no change in the pericyte lysosomal staining pattern. Thus, the cells of the microvasculature seem to be differentially affected by hyperoxia, a fact that may be significant in the etiology of reperfusion injury, ischemic disease, and pathologies associated with prematurity.

  3. Informational dynamics of vasomotion in microvascular networks: a review.

    PubMed

    Pradhan, R K; Chakravarthy, V S

    2011-02-01

    Vasomotion refers to spontaneous oscillation of small vessels observed in many microvascular beds. It is an intrinsic phenomenon unrelated to cardiac rhythm or neural and hormonal regulation. Vasomotion is found to be particularly prominent under conditions of metabolic stress. In spite of a significant existent literature on vasomotion, its physiological and pathophysiological roles are not clear. It is thought that modulation of vasomotion by vasoactive substances released by metabolizing tissue plays a role in ensuring optimal delivery of nutrients to the tissue. Vasomotion rhythms exhibit a great variety of temporal patterns from regular oscillations to chaos. The nature of vasomotion rhythm is believed to be significant to its function, with chaotic vasomotion offering several physiological advantages over regular, periodic vasomotion. In this article, we emphasize that vasomotion is best understood as a network phenomenon. When there is a local metabolic demand in tissue, an ideal vascular response should extend beyond local microvasculature, with coordinated changes over multiple vascular segments. Mechanisms of information transfer over a vessel network have been discussed in the literature. The microvascular system may be regarded as a network of dynamic elements, interacting, either over the vascular anatomical network via gap junctions, or physiologically by exchange of vasoactive substances. Drawing analogies with spatiotemporal patterns in neuronal networks of central nervous system, we ask if properties like synchronization/desynchronization of vasomotors have special significance to microcirculation. Thus the contemporary literature throws up a novel view of microcirculation as a network that exhibits complex, spatiotemporal and informational dynamics.

  4. 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.

  5. [The problem of information value in microvascular networks].

    PubMed

    Krupatkin, A I

    2011-01-01

    The methodology of quantitative estimation of information value in microvascular networks is proposed for the first time with the use of wavelet analysis of skin blood flow oscillations registrated by laser Doppler flowmetry at 30 healthy persons and 56 patients after hand injuries and diseases. It includes calculation of relative indices for the information preservation, the predomination of preserved information and the efficacy of information. The most deviation from multistable information regimen happened after formation of resonance oscillations: the general quantity of information decreased but the preservation of predominated information increased. The preservation of trophic myogenic information predominated after reduction of sympathetic influences. With the increase in the number of information channels the quantity of information increased but its preservation varied. Sensory peptidergic nerve fibres were activated during local heating to 34 degrees C at dorsal forearm skin. This information was the most effective at the beginning of heating during the growth of blood flow to the plateau level. Blood flow oscillations represented in wavelet spectrum serve as operators build on the basis of effective information. These oscillations play not only hemodynamic role but are the bearers of information in microvascular networks.

  6. Angina pectoris in women: focus on microvascular disease.

    PubMed

    Zuchi, Cinzia; Tritto, Isabella; Ambrosio, Giuseppe

    2013-02-20

    Ischemic heart disease (IHD) is the leading cause of death among women in Western countries, and it is associated with higher morbidity and mortality than in men. Nevertheless, IHD in women remains underdiagnosed and undertreated, and the misperception that females are "protected" against cardiovascular disease leads to underestimation of their cardiovascular risk; instead, women with chest pain have a high risk of cardiovascular events. Women suffering from angina pectoris tend to have different characteristics compared to men, with a high prevalence of non-significant coronary artery disease. Angina in women is more commonly microvascular in origin than in men, and therefore standard diagnostic algorithms may be suboptimal for women. This different pathophysiology impacts clinical management of IHD in women. While response to medical therapy may differ in women, they are scarcely represented in clinical trials. Therefore, solid data in terms of gender efficacy of antianginal drugs are lacking, and particularly when angina is microvascular in origin women often continue to be symptomatic despite maximal therapy with classical antianginal drugs. Recently, new molecules have shown promising results in women. In conclusion, women with angina are a group of patients in whom it seems appropriate to concentrate efforts aimed at reducing morbidity and improving quality of life.

  7. 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.

  8. Microvascular protection is essential for successful neuroprotection in stroke.

    PubMed

    Gursoy-Ozdemir, Yasemin; Yemisci, Muge; Dalkara, Turgay

    2012-11-01

    Currently, the best way of neuroprotection for acute ischemic stroke appears to be restoration of blood flow to the ischemic area by thrombolysis. Unfortunately, a short therapeutic time window as well as thrombolysis-induced bleeding and edema limit the use of recanalization therapies. Here, we review the evidence suggesting that ischemia/reperfusion-induced microvascular injury plays a critical role in determining tissue survival after recanalization in focal cerebral ischemia by disrupting the blood-brain barrier integrity and promoting microcirculatory clogging. Among many complex mechanisms of the ischemia-reperfusion injury, overproduction of oxygen and nitrogen radicals on the microvascular wall appears to significantly contribute to these pathological processes. These developments bring about the exciting possibility that effective suppression of oxidative/nitrative stress during pharmacological or interventional re-opening of the occluded artery may significantly improve the outcome of recanalization therapies in stroke patients by improving microcirculatory reflow as well as by preventing hemorrhagic conversion and vasogenic edema. They also point to the critical (but partly neglected) importance of the microcirculation in neuroprotection.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Airway smooth muscle growth in asthma: proliferation, hypertrophy, and migration.

    PubMed

    Bentley, J Kelley; Hershenson, Marc B

    2008-01-01

    Increased airway smooth muscle mass is present in fatal and non-fatal asthma. However, little information is available regarding the cellular mechanism (i.e., hyperplasia vs. hypertrophy). Even less information exists regarding the functional consequences of airway smooth muscle remodeling. It would appear that increased airway smooth muscle mass would tend to increase airway narrowing and airflow obstruction. However, the precise effects of increased airway smooth muscle mass on airway narrowing are not known. This review will consider the evidence for airway smooth muscle cell proliferation and hypertrophy in asthma, potential functional effects, and biochemical mechanisms.

  15. Myeloid sarcoma causing airway obstruction

    PubMed Central

    Krause, John R.

    2017-01-01

    Myeloid sarcoma is an extramedullary collection of blasts of the myeloid series that partially or totally effaces the architecture of the tissue in which it is found. These tumors have been described in many sites of the body, but the skin, lymph nodes, gastrointestinal tract, bone, soft tissue, and testes are most common. They can arise in a patient following the diagnosis of acute myeloid leukemia, but they may also be precursors of leukemia and should be considered diagnostic for acute myeloid leukemia. The differential diagnosis of this neoplasm includes malignant lymphoma, with which it is often mistaken, leading to diagnostic and therapeutic delays. We present the case of an 84-year-old African American man with a history of renal disease secondary to hypertension and coronary artery disease without any prior history of malignancies who presented with airway obstruction. He was diagnosed with a myeloid sarcoma of the mediastinum compressing his trachea.

  16. The Development and Application of Airway Devices in China

    PubMed Central

    Chen, Xiangdong; Ma, Wuhua; Liu, Renyu; Yao, Shanglong

    2017-01-01

    Airway management is one of the most important tasks for anesthesiologists. Anesthesiologists are experts in airway management and have made tremendous contribution to the development of the airway devices. Chinese anesthesiologists have made significant contribution in introducing advanced airway management and developing innovative techniques and devices for airway management in China. This article overviews the development and application of airway devices in China as well as the dedication and contribution of Chinese experts in the development of novel airway devices. With the development of science and technology accompanied by the advanced knowledge in airway management, more effective and safe artificial airways will be developed for clinical practice. The authors believe that Chinese experts will continue their outstanding contribution to the development of innovative airway devices, systems and knowledge. PMID:28191485

  17. Pharmacology of airway afferent nerve activity

    PubMed Central

    Undem, Bradley J; Carr, Michael J

    2001-01-01

    Afferent nerves in the airways serve to regulate breathing pattern, cough, and airway autonomic neural tone. Pharmacologic agents that influence afferent nerve activity can be subclassified into compounds that modulate activity by indirect means (e.g. bronchial smooth muscle spasmogens) and those that act directly on the nerves. Directly acting agents affect afferent nerve activity by interacting with various ion channels and receptors within the membrane of the afferent terminals. Whether by direct or indirect means, most compounds that enter the airspace will modify afferent nerve activity, and through this action alter airway physiology. PMID:11686889

  18. Firefighting acutely increases airway responsiveness.

    PubMed

    Sherman, C B; Barnhart, S; Miller, M F; Segal, M R; Aitken, M; Schoene, R; Daniell, W; Rosenstock, L

    1989-07-01

    The acute effects of the products of combustion and pyrolysis on airway responsiveness among firefighters are poorly documented. To study this relationship, spirometry and methacholine challenge testing (MCT) were performed on 18 active Seattle firefighters before and 5 to 24 h after firefighting. Body plethysmography was used to measure changes in specific airway conductance (SGaw), and results of MCT were analyzed using PD35-SGaw, the cumulative dose causing a 35% decrease in SGaw. Subjects who did not react by the end of the protocol were assigned a value of 640 inhalational units, the largest cumulative dose. Fire exposure was defined as the total time (hours) spent without a self-contained breathing apparatus at the firesite and was categorized as mild (less than 1 h, n = 7), moderate (1 to 2 h, n = 5), or severe (greater than 2 h, n = 6). Mean age of the 18 firefighters was 36.7 +/- 6.7 yr (range, 25 to 51), with a mean of 9.1 +/- 7.9 active years in the trade (range, zero to 22). None was known to be asthmatic. After firefighting, FEV1 % predicted (%pred) and FEF25-75 %pred significantly decreased by means of 3.4 +/- 1.1% and 5.6 +/- 2.6%, respectively. The mean decline in PD35-SGaw after firefighting was 184.5 +/- 53.2 units (p = 0.003). This observed decline in PD35-SGaw could not be explained by decrements in prechallenge SGaw, FEV1, or FVC.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Microvascular effects of selective prostaglandin analogues in the eye with special reference to latanoprost and glaucoma treatment.

    PubMed

    Stjernschantz, J; Selén, G; Astin, M; Resul, B

    2000-07-01

    Prostaglandin F(2alpha) analogues have recently been introduced on the market for glaucoma treatment. While these drugs have a well-documented intraocular pressure reducing effect only a limited number of studies have been published regarding their effects on the microvasculature in the eye. Since many naturally occurring prostaglandins have marked effects on the cardiovascular system it is conceivable that synthetic prostaglandins used as glaucoma drugs may exert microvascular effects in the eye, even if they exhibit receptor selectivity. Latanoprost, the active principle of Xalatan((R)) eye drops, is a selective FP prostanoid receptor agonist, and much of the paper is focused on the microvascular effects of latanoprost and some closely related prostaglandin analogues. The purpose of the paper is to review the literature on the microvascular effects of prostaglandins in the eye, and to present some unpublished data on the effects of selective prostaglandin analogues. Most of the prostaglandin analogues studied exhibit selectivity for the FP prostanoid receptor. Results from studies with the following prostaglandin analogues are presented in the paper: PGF(2alpha)-isopropyl ester (PGF(2alpha)-IE), 17-phenyl-18,19,20-trinor-PGF(2alpha)-isopropyl ester (17-phenyl-PGF(2a)-IE), 15-keto-17-phenyl-18,19, 20-trinor-PGF(2alpha)-isopropyl ester (15-keto-17-phenyl-PGF(2a)-IE), 13,14-dihydro-17-phenyl-18,19,20-trinor-PGF(2alpha)-isopropy l ester (latanoprost), 13,14-dihydro-15R,S-17-phenyl-18,19, 20-trinor-PGF(2alpha)-isopropyl ester (PhXA34), 17-phenyl-18,19, 20-trinor-PGE(2)-isopropyl ester (17-phenyl-PGE(2)-IE), and 19R-hydroxy-PGE(2) (19R-OH-PGE(2)). The regional blood flow has been determined with radioactively labelled microspheres, the blood volume with (51)Cr labelled erythrocytes and the capillary permeability to albumin with (125)I and (131)I labelled albumin. PGF(2alpha)-IE has been shown to exert marked microvascular effects in the rabbit anterior segment

  20. 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)...

  1. 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)...

  2. 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)...

  3. 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)...

  4. A review of leakage flow in centrifugal blood pumps.

    PubMed

    Chan, Weng-Kong; Wong, Yew-Wah

    2006-05-01

    This article presents a new approach in determining the functional relationship between the leakage flow in a centrifugal blood pump and various parameters that affect it. While high leakage flow in a blood pump is essential for good washout and can help prevent thrombus formation, excessive leakage flow will result in higher fluid shear stress that may lead to hemolysis. Dimensional analysis is employed to provide a functional relationship between leakage flow rate and other important parameters governing the operation of a centrifugal blood pump. Results showed that pump performance with a smaller gap clearance is clearly superior compared to those of two other similar pumps with larger gap clearances. It was also observed that the nondimensional leakage flow rate varies almost linearly with dimensionless pump head. It also decreases with increasing volume flow rate. A smaller gap clearance will also increase the flow resistance and hence, decrease the nondimensional leakage flow rate. Increasing surface roughness, length of the gap clearance passage, or loss coefficient of the gap geometry will increase losses and hence, decrease the leakage flow rate. It is also interesting to note that for a given pump and gap clearance geometry, the nondimensional leakage flow rate is almost independent of the Reynolds number when specific speed is constant.

  5. 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....

  6. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Pressure and leakage tests. 178.346-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.346-5 Pressure and leakage tests. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  7. 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)...

  8. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Pressure and leakage tests. 178.346-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.346-5 Pressure and leakage tests. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  9. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Pressure and leakage tests. 178.346-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.346-5 Pressure and leakage tests. (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, 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)...

  11. 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....

  12. 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....

  13. 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....

  14. 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....

  15. 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....

  16. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Pressure and leakage tests. 178.346-5 Section 178... Specifications for Containers for Motor Vehicle Transportation § 178.346-5 Pressure and leakage tests. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b) Pressure test....

  17. 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....

  18. 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....

  19. 49 CFR 178.346-5 - Pressure and leakage tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Pressure and leakage tests. 178.346-5 Section 178... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.346-5 Pressure and leakage tests. (a) Each cargo tank must be tested in accordance with § 178.345-13 and this section. (b)...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 40 CFR 265.222 - Action leakage rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... to § 265.221(a). The action leakage rate is the maximum design flow rate that the leak detection... proposed response actions (e.g., the action leakage rate must consider decreases in the flow capacity of... exceeded, the owner or operator must convert the weekly or monthly flow rate from the monitoring...

  8. 40 CFR 264.302 - Action leakage rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... landfill units subject to § 264.301(c) or (d). The action leakage rate is the maximum design flow rate that... action leakage rate has been exceeded, the owner or operator must convert the weekly or monthly flow rate from the monitoring data obtained under § 264.303(c) to an average daily flow rate (gallons per...

  9. Galangin attenuates airway remodelling by inhibiting TGF-β1-mediated ROS generation and MAPK/Akt phosphorylation in asthma.

    PubMed

    Liu, Ya-Nan; Zha, Wang-Jian; Ma, Yuan; Chen, Fei-Fei; Zhu, Wen; Ge, Ai; Zeng, Xiao-Ning; Huang, Mao

    2015-07-09

    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.

  10. 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 ...

  11. 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.

  12. 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

  13. 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

  14. 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

  15. Taste Receptors in Upper Airway Immunity.

    PubMed

    Carey, Ryan M; Lee, Robert J; Cohen, Noam A

    2016-01-01

    Taste receptors are well known for their role in communicating information from the tongue to the brain about nutritional value or potential toxicity of ingested substances. More recently, it has been shown that taste receptors are expressed in other locations throughout the body, including the airway, gastrointestinal tract, brain and pancreas. The roles of some 'extraoral' taste receptors are largely unknown, but emerging research suggests that bitter and sweet taste receptors in the airway are capable of sensing bacteria and modulating innate immunity. This chapter focuses on the role of bitter and sweet taste receptors in human airway innate immunity and their clinical relevance to rhinosinusitis. The bitter taste receptor T2R38 expressed in sinonasal cilia detects bitter bacterial quorum-sensing molecules and activates a nitric oxide-dependent innate immune response; moreover, there are polymorphisms in T2R38 that underlie susceptibility to chronic rhinosinusitis (CRS). Bitter and sweet receptors in sinonasal solitary chemosensory cells control secretion of antimicrobial peptides in the upper airway and may have a profound impact on airway infections in patients with CRS and diabetes. Future research on taste receptors in the airway has enormous potential to expand our understanding of host-pathogen immune interactions and provide novel therapeutic targets.

  16. Sensory nerves in lung and airways.

    PubMed

    Lee, Lu-Yuan; Yu, Jerry

    2014-01-01

    Sensory nerves innervating the lung and airways play an important role in regulating various cardiopulmonary functions and maintaining homeostasis under both healthy and disease conditions. Their activities conducted by both vagal and sympathetic afferents are also responsible for eliciting important defense reflexes that protect the lung and body from potential health-hazardous effects of airborne particulates and chemical irritants. This article reviews the morphology, transduction properties, reflex functions, and respiratory sensations of these receptors, focusing primarily on recent findings derived from using new technologies such as neural immunochemistry, isolated airway-nerve preparation, cultured airway neurons, patch-clamp electrophysiology, transgenic mice, and other cellular and molecular approaches. Studies of the signal transduction of mechanosensitive afferents have revealed a new concept of sensory unit and cellular mechanism of activation, and identified additional types of sensory receptors in the lung. Chemosensitive properties of these lung afferents are further characterized by the expression of specific ligand-gated ion channels on nerve terminals, ganglion origin, and responses to the action of various inflammatory cells, mediators, and cytokines during acute and chronic airway inflammation and injuries. Increasing interest and extensive investigations have been focused on uncovering the mechanisms underlying hypersensitivity of these airway afferents, and their role in the manifestation of various symptoms under pathophysiological conditions. Several important and challenging questions regarding these sensory nerves are discussed. Searching for these answers will be a critical step in developing the translational research and effective treatments of airway diseases.

  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. Nitrogen Dioxide Exposure and Airway Responsiveness in ...

    EPA Pesticide Factsheets

    Controlled human exposure studies evaluating the effect of inhaled NO2 on the inherent responsiveness of the airways to challenge by bronchoconstricting agents have had mixed results. In general, existing meta-analyses show statistically significant effects of NO2 on the airway responsiveness of individuals with asthma. However, no meta-analysis has provided a comprehensive assessment of clinical relevance of changes in airway responsiveness, the potential for methodological biases in the original papers, and the distribution of responses. This paper provides analyses showing that a statistically significant fraction, 70% of individuals with asthma exposed to NO2 at rest, experience increases in airway responsiveness following 30-minute exposures to NO2 in the range of 200 to 300 ppb and following 60-minute exposures to 100 ppb. The distribution of changes in airway responsiveness is log-normally distributed with a median change of 0.75 (provocative dose following NO2 divided by provocative dose following filtered air exposure) and geometric standard deviation of 1.88. About a quarter of the exposed individuals experience a clinically relevant reduction in their provocative dose due to NO2 relative to air exposure. The fraction experiencing an increase in responsiveness was statistically significant and robust to exclusion of individual studies. Results showed minimal change in airway responsiveness for individuals exposed to NO2 during exercise. A variety of fa

  19. Mechanical Properties of the Upper Airway

    PubMed Central

    Strohl, Kingman P.; Butler, James P.; Malhotra, Atul

    2013-01-01

    The importance of the upper airway (nose, pharynx, and larynx) in health and in the pathogenesis of sleep apnea, asthma, and other airway diseases, discussed elsewhere in the Comprehensive Physiology series, prompts this review of the biomechanical properties and functional aspects of the upper airway. There is a literature based on anatomic or structural descriptions in static circumstances, albeit studied in limited numbers of individuals in both health and disease. As for dynamic features, the literature is limited to studies of pressure and flow through all or parts of the upper airway and to the effects of muscle activation on such features; however, the links between structure and function through airway size, shape, and compliance remain a topic that is completely open for investigation, particularly through analyses using concepts of fluid and structural mechanics. Throughout are included both historically seminal references, as well as those serving as signposts or updated reviews. This article should be considered a resource for concepts needed for the application of biomechanical models of upper airway physiology, applicable to understanding the pathophysiology of disease and anticipated results of treatment interventions. PMID:23723026

  20. Slowly Adapting Sensory Units Have More Receptors in Large Airways than in Small Airways in Rabbits

    PubMed Central

    Liu, Jun; Song, Nana; Guardiola, Juan; Roman, Jesse; Yu, Jerry

    2016-01-01

    Sensory units of pulmonary slowly adapting receptors (SARs) are more active in large airways than in small airways. However, there is no explanation for this phenomenon. Although sensory structures in large airways resemble those in small airways, they are bigger and more complex. Possibly, a larger receptor provides greater surface area for depolarization, and thus has a lower activating threshold and/or a higher sensitivity to stretch, leading to more nerve electrical activities. Recently, a single sensory unit has been reported to contain multiple receptors. Therefore, sensory units in large airways may contain more SARs, which may contribute to high activities. To test this hypothesis, we used a double staining technique to identify sensory receptor sizes. We labeled the sensory structure with Na+/K+-ATPase antibodies and the myelin sheath with myelin basic protein (MBP) antibodies. A SAR can be defined as the end formation beyond MBP labeling. Thus, we are able to compare sizes of sensory structures and SARs in large (trachea and bronchi) vs. small (bronchioles <500 μm in diameter) airways in the rabbit. We found that even though the sensory structure was bigger in large airways than in small airways (3340 ± 223 vs. 1168 ± 103 μm2; P < 0.0001), there was no difference in receptor sizes (349 ± 14 vs. 326 ± 16 μm2; > 0.05). However, the sensory structure contains more SARs in large airways than in small airways (9.6 ± 0.6 vs. 3.6 ± 0.3; P < 0.0001). Thus, our data support the hypothesis that greater numbers of SARs in sensory units of large airways may contribute to higher activities. PMID:28018231

  1. Slowly Adapting Sensory Units Have More Receptors in Large Airways than in Small Airways in Rabbits.

    PubMed

    Liu, Jun; Song, Nana; Guardiola, Juan; Roman, Jesse; Yu, Jerry

    2016-01-01

    Sensory units of pulmonary slowly adapting receptors (SARs) are more active in large airways than in small airways. However, there is no explanation for this phenomenon. Although sensory structures in large airways resemble those in small airways, they are bigger and more complex. Possibly, a larger receptor provides greater surface area for depolarization, and thus has a lower activating threshold and/or a higher sensitivity to stretch, leading to more nerve electrical activities. Recently, a single sensory unit has been reported to contain multiple receptors. Therefore, sensory units in large airways may contain more SARs, which may contribute to high activities. To test this hypothesis, we used a double staining technique to identify sensory receptor sizes. We labeled the sensory structure with Na(+)/K(+)-ATPase antibodies and the myelin sheath with myelin basic protein (MBP) antibodies. A SAR can be defined as the end formation beyond MBP labeling. Thus, we are able to compare sizes of sensory structures and SARs in large (trachea and bronchi) vs. small (bronchioles <500 μm in diameter) airways in the rabbit. We found that even though the sensory structure was bigger in large airways than in small airways (3340 ± 223 vs. 1168 ± 103 μm(2); P < 0.0001), there was no difference in receptor sizes (349 ± 14 vs. 326 ± 16 μm(2); > 0.05). However, the sensory structure contains more SARs in large airways than in small airways (9.6 ± 0.6 vs. 3.6 ± 0.3; P < 0.0001). Thus, our data support the hypothesis that greater numbers of SARs in sensory units of large airways may contribute to higher activities.

  2. 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

  3. 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

  4. Microvascular Function in Aging Among Women Living with HIV.

    PubMed

    Monsuez, Jean-Jacques; Belin, Catherine; Bouchaud, Olivier

    2016-12-01

    Combined antiretroviral therapy (CART) has turned HIV-infection to a treatable chronic disease during which many patients survive to middle and older age. However, they prematurely develop non-AIDS comorbidities such as cardiovascular disease, metabolic syndrome, diabetes, and HIV-associated neurocognitive disorders (HAND). Microcirculatory changes and endothelial dysfunction occur early both in HIV-infected and in aging patients, in whom they usually precede cardiovascular and neurocognitive impairments. Also, mild cognitive involvement has been reported in women during the menopausal transition. Disruption of the blood-brain barrier, as well as microvascular and cerebral blood flow changes, has been reported in HIV patients with HAND, including postmenopausal women. However, most studies addressing this issue included women aged less than 50 years. Whether HIV-infected women growing older with CART would be subsequently exposed to an increased progression of cognitive impairment overtime remains unknown.

  5. Inflammation in the pathogenesis of microvascular complications in diabetes

    PubMed Central

    Nguyen, Dung V.; Shaw, Lynn C.; Grant, Maria B.

    2012-01-01

    Diabetes and hyperglycemia create a proinflammatory microenvironment that progresses to microvascular complications such as nephropathy, retinopathy, and neuropathy. Diet-induced insulin resistance is a potential initiator of this change in type 2 diabetes which can increase adipokines and generate a chronic low-grade inflammatory state. Advanced glycation end-products and its receptor, glycation end-products AGE receptor axis, reactive oxygen species, and hypoxia can also interact to worsen complications. Numerous efforts have gained way to understanding the mechanisms of these modulators and attenuation of the inflammatory response, however, effective treatments have still not emerged. The complexity of inflammatory signaling may suggest a need for multi-targeted therapy. This review presents recent findings aimed at new treatment strategies. PMID:23267348

  6. Vasoregression: A Shared Vascular Pathology Underlying Macrovascular And Microvascular Pathologies?

    PubMed Central

    Gupta, Akanksha

    2015-01-01

    Abstract Vasoregression is a common phenomenon underlying physiological vessel development as well as pathological microvascular diseases leading to peripheral neuropathy, nephropathy, and vascular oculopathies. In this review, we describe the hallmarks and pathways of vasoregression. We argue here that there is a parallel between characteristic features of vasoregression in the ocular microvessels and atherosclerosis in the larger vessels. Shared molecular pathways and molecular effectors in the two conditions are outlined, thus highlighting the possible systemic causes of local vascular diseases. Our review gives us a system-wide insight into factors leading to multiple synchronous vascular diseases. Because shared molecular pathways might usefully address the diagnostic and therapeutic needs of multiple common complex diseases, the literature analysis presented here is of broad interest to readership in integrative biology, rational drug development and systems medicine. PMID:26669709

  7. Intra-operative neurophysiology during microvascular decompression for hemifacial spasm.

    PubMed

    Fernández-Conejero, I; Ulkatan, S; Sen, C; Deletis, V

    2012-01-01

    There is evidence that primary hemifacial spasm (HFS) in the majority of patients is related to a vascular compression of the facial nerve at its root exit zone (REZ). As a consequence, the hyperexcitability of facial nerve generates spasms of the facial muscles. Microvascular decompression (MVD) of the facial nerve near its REZ has been established as an effective treatment of HFS. Intra-operative disappearance of abnormal muscle responses (lateral spread) elicited by stimulating one of the facial nerve branches has been used as a method to predict MVD effectiveness. Other neurophysiologic techniques, such as facial F-wave, blink reflex and facial corticobulbar motor evoked potentials (FCoMEP), are feasible to intra-operatively study changes in excitability of the facial nerve and its nucleus during MVDs. Intra-operative neuromonitoring with the mentioned techniques allows a better understanding of HFS pathophysiology and helps to optimise the MVD.

  8. Novel Genetic Loci Associated with Retinal Microvascular Diameter

    PubMed Central

    Jensen, Richard A.; Sim, Xueling; Smith, Albert Vernon; Li, Xiaohui; Jakobsdóttir, Jóhanna; Cheng, Ching-Yu; Brody, Jennifer A.; Cotch, Mary Frances; Mcknight, Barbara; Klein, Ronald; Wang, Jie Jin; Kifley, Annette; Harris, Tamara B.; Launer, Lenore J.; Taylor, Kent D.; Klein, Barbara E.K.; Raffel, Leslie J.; Li, Xiang; Ikram, M. Arfan; Klaver, Caroline C.; van der Lee, Sven J.; Mutlu, Unal; Hofman, Albert; Uitterlinden, Andre G.; Liu, Chunyu; Kraja, Aldi T.; Mitchell, Paul; Gudnason, Vilmundur; Rotter, Jerome I.; Boerwinkle, Eric; van Duijn, Cornelia M.; Psaty, Bruce M.; Wong, Tien Y.

    2015-01-01

    Background There is increasing evidence that retinal microvascular diameters are associated with cardio- and cerebrovascular conditions. The shared genetic effects of these associations are currently unknown. The aim of this study was to increase our understanding of the genetic factors that mediate retinal vessel size. Methods and Results This study extends previous genome-wide association study results using 24,000+ multi-ethnic participants from 7 discovery and 5,000+ subjects of European ancestry from 2 replication cohorts. Using the Illumina HumanExome BeadChip, we investigate the association of single nucleotide polymorphisms (SNPs) and variants collectively across genes with summary measures of retinal vessel diameters, referred to as the central retinal venule equivalent (CRVE) and the central retinal arteriole equivalent (CRAE). We report 4 new loci associated with CRVE, one of which is also associated with CRAE. The 4 SNPs are rs7926971 in TEAD1 (p=3.1×10−11, minor allele frequency (MAF)=0.43), rs201259422 in TSPAN10 (p=4.4×10−9, MAF=0.27), rs5442 in GNB3 (p=7.0×10−10, MAF=0.05) and rs1800407 in OCA2 (p=3.4×10−8, MAF=0.05). The latter SNP, rs1800407, was also associated with CRAE (p=6.5×10−12). Results from the gene-based burden tests were null. In phenotype look-ups, SNP rs201255422 was associated with both systolic (p=0.001) and diastolic blood pressure (p=8.3×10−04). Conclusions Our study expands the understanding of genetic factors influencing the size of the retinal microvasculature. These findings may also provide insight into the relationship between retinal and systemic microvascular disease. PMID:26567291

  9. 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.

  10. Isolation of primary murine brain microvascular endothelial cells.

    PubMed

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

    2014-11-14

    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.

  11. Serum factors involved in human microvascular endothelial cell morphogenesis.

    PubMed

    Harvey, Kevin; Siddiqui, Rafat A; Sliva, Daniel; Garcia, Joe G N; English, Denis

    2002-09-01

    Our previous studies have demonstrated that lipid and protein angiogenic factors operate in tandem to induce optimal angiogenic responses in vivo. This study was undertaken to clarify the nature of the substances in human serum that are responsible for its remarkable ability to promote capillary morphogenesis in vitro. The ability of dilute (2%) human serum to promote the morphogenic differentiation of human dermal microvascular endothelial cells on Matrigel supports was depleted by more than 50% by treatment of the serum with activated charcoal, a procedure that effectively removes biologically active lipid growth factors. The remainder of the activity within serum was lost on heating to 60 degrees C for 60 minutes, indicating the involvement of a protein in the response. The ability of charcoal-treated serum to promote capillary morphogenesis was completely restored by the addition of sphingosine 1-phosphate (SPP, 500 nmol/L), but other lipids thought to be released into serum during clotting were ineffective. In addition, basic fibroblast growth factor (bFGF) effectively restored the ability of heat-treated serum to promote endothelial cell morphogenesis, but other protein growth factors, including vascular endothelial growth factor and platelet-derived growth factor, were ineffective. Together, SPP and bFGF were as effective as whole serum in promoting capillary morphogenesis. Responses to purified SPP were entirely sensitive to the effects of preexposure of the cells to pertussis toxin, whereas responses to bFGF were entirely pertussis toxin-resistant. Consistent with our hypothesis that two distinct factors in serum play a role in promoting capillary morphogenesis, responses induced by serum were inhibited approximately 50% by preexposure of endothelial cells to pertussis toxin. We conclude that platelet-released SPP acts in conjunction with circulating bFGF to promote capillary formation by microvascular endothelial cells. Lipid and protein growth factors

  12. Alteration of the sublingual microvascular glycocalyx in critically ill patients.

    PubMed

    Donati, Abele; Damiani, Elisa; Domizi, Roberta; Romano, Rocco; Adrario, Erica; Pelaia, Paolo; Ince, Can; Singer, Mervyn

    2013-11-01

    Glycocalyx degradation may contribute to microvascular dysfunction and tissue hypoperfusion during systemic inflammation and sepsis. In this observational study we evaluated the alteration of the sublingual microvascular glycocalyx in 16 healthy volunteers and 50 critically ill patients. Sidestream Dark Field images of the sublingual microcirculation were automatically analyzed by dedicated software. The Perfused Boundary Region (PBR) was calculated as the dimensions of the permeable part of the glycocalyx allowing the penetration of circulating red blood cells, providing an index of glycocalyx damage. The PBR was increased in ICU patients compared to healthy controls (2.7 [2.59-2.88] vs. 2.46 [2.37-2.59]μm, p<0.0001) and tended to be higher in the 32 septic patients compared to non-septics (2.77 [2.62-2.93] vs. 2.67 [2.55-2.75]μm, p=0.05), suggesting more severe glycocalyx alterations. A PBR of 2.76 showed the best discriminative ability towards the presence of sepsis (sensitivity: 50%, specificity: 83%; area under the receiver operating characteristic curve: 0.67, 95% CI 0.52-0.82, p=0.05). A weak positive correlation was found between PBR and heart rate (r=0.3, p=0.03). In 17 septic patients, a correlation was found between PBR and number of rolling leukocytes in post-capillary venules (RL/venule) (r=0.55, p=0.02), confirming that glycocalyx shedding enhances leukocyte-endothelium interaction.

  13. Comprehensive Analysis of Chicken Vessels as Microvascular Anastomosis Training Model

    PubMed Central

    Kang, Bo Young; Jeon, Byung-Joon; Lee, Kyeong-Tae

    2017-01-01

    Background Nonliving chickens are commonly used as a microvascular anastomosis training model. However, previous studies have investigated only a few types of vessel, and no study has compared the characteristics of the various vessels. The present study evaluated the anatomic characteristics of various chicken vessels as a training model. Methods Eight vessels—the brachial artery, basilic vein, radial artery, ulnar artery, ischiatic artery and vein, cranial tibial artery, and common dorsal metatarsal artery—were evaluated in 26 fresh chickens and 30 chicken feet for external diameter (ED) and thicknesses of the tunica adventitia and media. The dissection time from skin incision to application of vessel clamps was also measured. Results The EDs of the vessels varied. The ischiatic vein had the largest ED of 2.69±0.33 mm, followed by the basilic vein (1.88±0.36 mm), ischiatic artery (1.68±0.24 mm), common dorsal metatarsal artery (1.23±0.23 mm), cranial tibial artery (1.18±0.19 mm), brachial artery (1.08±0.15 mm), ulnar artery (0.82±0.13 mm), and radial artery (0.56±0.12 mm), and the order of size was consistent across all subjects. Thicknesses of the tunica adventitia and media were also diverse, ranging from 74.09±19.91 µm to 158.66±40.25 µm (adventitia) and from 31.2±7.13 µm to 154.15±46.48 µm (media), respectively. Mean dissection time was <3 minutes for all vessels. Conclusions Our results suggest that nonliving chickens can provide various vessels with different anatomic characteristics, which can allow trainees the choice of an appropriate microvascular anastomosis training model depending on their purpose and skillfulness. PMID:28194342

  14. 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

  15. Microvascular response to red blood cell transfusion in trauma patients.

    PubMed

    Weinberg, Jordan A; MacLennan, Paul A; Vandromme-Cusick, Marianne J; Angotti, Jonathan M; Magnotti, Louis J; Kerby, Jeffrey D; Rue, Loring W; Barnum, Scott R; Patel, Rakesh P

    2012-03-01

    Trauma patients are often transfused allogeneic red blood cells (RBCs) in an effort to augment tissue oxygen delivery. However, the effect of RBC transfusion on microvascular perfusion in this patient population is not well understood. To this end, we investigated the effect of RBC transfusion on sublingual microvascular perfusion in trauma patients. Sublingual microcirculation was imaged at bedside with a sidestream dark-field illumination microscope before and after transfusion of one RBC unit in hemodynamically stable, anemic trauma patients. The perfused proportion of capillaries (PPC) before and after transfusion was determined, and the percent change in capillary perfusion following transfusion (ΔPPC) calculated. Sublingual microcirculation was observed in 30 patients. Mean age was 47 (SD, 21) years, mean Injury Severity Score was 29 (SD, 16), and mean pretransfusion hemoglobin was 7.5 (SD, 0.9) g/dL. No patients had a mean arterial pressure of less than 65 mmHg (mean, 89 [SD, 17] mmHg) or lactate of greater than 2.5 mmol/L (mean, 1.1 [SD, 0.3] mmol/L). Following transfusion, ΔPPC ranged from +68% to -36% and was found to inversely correlate significantly with pretransfusion PPC (Spearman r = -0.63, P = 0.0002). Pretransfusion PPC may be selectively deranged in otherwise stable trauma patients. Patients with relatively altered baseline PPC tend to demonstrate improvement in perfusion following transfusion, whereas those with relatively normal perfusion at baseline tend to demonstrate either no change or, in fact, a decline in PPC. Bedside sublingual imaging may have the potential to detect subtle perfusion defects and ultimately inform clinical decision making with respect to transfusion.

  16. Microvascular Response to Red Blood Cell Transfusion in Trauma Patients

    PubMed Central

    Weinberg, Jordan A.; MacLennan, Paul A.; Vandromme–Cusick, Marianne J.; Angotti, Jonathan M.; Magnotti, Louis J.; Kerby, Jeffrey D.; Rue, Loring W.; Barnum, Scott R.; Patel, Rakesh P.

    2014-01-01

    Background Trauma patients are often transfused allogeneic red blood cells (RBCs) in an effort to augment tissue oxygen delivery. However, the effect of RBC transfusion on microvascular perfusion in this patient population is not well understood. To this end, we investigated the effect of RBC transfusion on sublingual microvascular perfusion in trauma patients. Methods Sublingual microcirculation was imaged at bedside with a sidestream dark field illumination microscope before and after transfusion of one RBC unit in hemodynamically stable, anemic trauma patients. The proportion of perfused capillaries (PPC) pre- and post-transfusion was determined, and the percent change in capillary perfusion following transfusion (ΔPPC) calculated. Results Sublingual microcirculation was observed in 30 patients. Mean age was 47 (SD=21), mean ISS was 29 (SD=16), and mean pre-transfusion hemoglobin was 7.5 g/dL (SD=0.9). No patients had MAP < 65 mm Hg (mean 89 mm Hg, SD 17) or lactate > 2.5 mmol/L (mean 1.1 mmol/L, SD 0.3). Following transfusion, ΔPPC ranged from +68% to -36% and was found to inversely correlate significantly with pre-transfusion PPC (Spearman r= -0.63, p=0.0002). Conclusions Pre-transfusion PPC may be selectively deranged in otherwise stable trauma patients. Patients with relatively altered baseline PPC tend to demonstrate improvement in perfusion following transfusion, while those with relatively normal perfusion at baseline tend to demonstrate either no change or, in fact, a decline in PPC. Bedside sublingual imaging may have the potential to detect subtle perfusion defects and ultimately inform clinical decision making with respect to transfusion. PMID:22344313

  17. Quantum Speed Limits for Leakage and Decoherence

    NASA Astrophysics Data System (ADS)

    Marvian, Iman; Lidar, Daniel A.

    2015-11-01

    We introduce state-independent, nonperturbative Hamiltonian quantum speed limits for population leakage and fidelity loss, for a gapped open system interacting with a reservoir. These results hold in the presence of initial correlations between the system and the reservoir, under the sole assumption that their interaction and its commutator with the reservoir Hamiltonian are norm bounded. The reservoir need not be thermal and can be time dependent. We study the significance of energy mismatch between the system and the local degrees of freedom of the reservoir that directly interact with the system. We demonstrate that, in general, by increasing the system gap we may reduce this energy mismatch, and, consequently, drive the system and the reservoir into resonance; this can accelerate fidelity loss, irrespective of the thermal properties or state of the reservoir. This implies that quantum error suppression strategies based on increasing the gap are not uniformly beneficial. Our speed limits also yield an elementary lower bound on the relaxation time of spin systems.

  18. Airway smooth muscle in airway reactivity and remodeling: what have we learned?

    PubMed Central

    2013-01-01

    It is now established that airway smooth muscle (ASM) has roles in determining airway structure and function, well beyond that as the major contractile element. Indeed, changes in ASM function are central to the manifestation of allergic, inflammatory, and fibrotic airway diseases in both children and adults, as well as to airway responses to local and environmental exposures. Emerging evidence points to novel signaling mechanisms within ASM cells of different species that serve to control diverse features, including 1) [Ca2+]i contractility and relaxation, 2) cell proliferation and apoptosis, 3) production and modulation of extracellular components, and 4) release of pro- vs. anti-inflammatory mediators and factors that regulate immunity as well as the function of other airway cell types, such as epithelium, fibroblasts, and nerves. These diverse effects of ASM “activity” result in modulation of bronchoconstriction vs. bronchodilation relevant to airway hyperresponsiveness, airway thickening, and fibrosis that influence compliance. This perspective highlights recent discoveries that reveal the central role of ASM in this regard and helps set the stage for future research toward understanding the pathways regulating ASM and, in turn, the influence of ASM on airway structure and function. Such exploration is key to development of novel therapeutic strategies that influence the pathophysiology of diseases such as asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. PMID:24142517

  19. Two-dimensional airway analysis using probabilistic neural networks

    NASA Astrophysics Data System (ADS)

    Tan, Jun; Zheng, Bin; Park, Sang Cheol; Pu, Jiantao; Sciurba, Frank C.; Leader, Joseph K.

    2010-03-01

    Although 3-D airway tree segmentation permits analysis of airway tree paths of practical lengths and facilitates visual inspection, our group developed and tested an automated computer scheme that was operated on individual 2-D CT images to detect airway sections and measure their morphometry and/or dimensions. The algorithm computes a set of airway features including airway lumen area (Ai), airway cross-sectional area (Aw), the ratio (Ra) of Ai to Aw, and the airway wall thickness (Tw) for each detected airway section depicted on the CT image slice. Thus, this 2-D based algorithm does not depend on the accuracy of 3-D airway tree segmentation and does not require that CT examination encompasses the entire lung or reconstructs contiguous images. However, one disadvantage of the 2-D image based schemes is the lack of the ability to identify the airway generation (Gb) of the detected airway section. In this study, we developed and tested a new approach that uses 2-D airway features to assign a generation number to an airway. We developed and tested two probabilistic neural networks (PNN) based on different sets of airway features computed by our 2-D based scheme. The PNNs were trained and tested on 12 lung CT examinations (8 training and 4 testing). The accuracy for the PNN that utilized Ai and Ra for identifying the generation of airway sections varies from 55.4% - 100%. The overall accuracy of the PNN for all detected airway sections that are spread over all generations is 76.7%. Interestingly, adding wall thickness feature (Tw) to PNN did not improve identification accuracy. This preliminary study demonstrates that a set of 2-D airway features may be used to identify the generation number of an airway with reasonable accuracy.

  20. The relation of airway size to lung function

    NASA Astrophysics Data System (ADS)

    Leader, J. Ken; Zheng, Bin; Sciurba, Frank C.; Fuhrman, Carl R.; Bon, Jessica M.; Park, Sang C.; Pu, Jiantao; Gur, David

    2008-03-01

    Chronic obstructive pulmonary disease may cause airway remodeling, and small airways are the mostly likely site of associated airway flow obstruction. Detecting and quantifying airways depicted on a typical computed tomography (CT) images is limited by spatial resolution. In this study, we examined the association between lung function and airway size. CT examinations and spirometry measurement of forced expiratory volume in one second as a percent predicted (FEV I%) from 240 subjects were used in this study. Airway sections depicted in axial CT section were automatically detected and quantified. Pearson correlation coefficients (PCC) were computed to compare lung function across three size categories: (1) all detected airways, (2) the smallest 50% of detected airways, and (3) the largest 50% of detected airways using the CORANOVA test. The mean number of all airways detected per subject was 117.4 (+/- 40.1) with mean size ranging from 20.2 to 50.0 mm2. The correlation between lung function (i.e., FEV I) and airway morphometry associated with airway remodeling and airflow obstruction (i.e., lumen perimeter and wall area as a percent of total airway area) was significantly stronger for smaller compared to larger airways (p < 0.05). The PCCs between FEV I and all airways, the smallest 50%, and the largest 50% were 0.583, 0.617, 0.523, respectively, for lumen perimeter and -0.560, -0.584, and -0.514, respectively, for wall area percent. In conclusion, analyzing a set of smaller airways compared to larger airways may improve detection of an association between lung function and airway morphology change.

  1. Leakage assessment and identification of fluid leakage scenarios at CO2 storage sites (Invited)

    NASA Astrophysics Data System (ADS)

    Bunz, S.

    2013-12-01

    One of the major objectives of the ECO2 project (EU FP7) is to assess the risks associated with the storage of CO2 below the seabed. Within this frame, work package (WP) 1 investigates the sedimentary cover at currently active and potential storage sites using novel geophysical baseline studies, monitoring and modeling techniques in order to better understand CO2 migration mechanisms and its spatial and temporal evolution. A proper risk assessment of CO2 storage hinges on a thorough understanding of the geological evolution of an area and a sound comprehension of subsurface anomalies associated with the flow of fluids and their governing geological controls. To this end, WP 1 has analyzed a wealth of seafloor imaging and seismic data from the industrial storage sites at Sleipner and Snøhvit on the Norwegian Margin. In addition to conventional seafloor and seismic data, several novel high-resolution acquisition technologies have been used during offshore expeditions in 2011 and 2012, and their data integrated into this study. A solid background on the geological development and the stratigraphic framework has been developed including an interpretation of subsurface structure and structures related to the presence of fluids and possible fluid pathways on the basis of conventional 3D seismic data and by integrating several additional high-resolution data sets. The data revealed a number of fluid-flow features, as for example gas chimneys, pipes, shallow gas accumulations, leaking faults, fractures along the seafloor as well as gas hydrates. Each of these structures or set of structures has been evaluated with respect to their occurrence, distribution, origin and as a means for providing a potential pathway for CO2 if it would leak out of the storage formation. On the basis of this evaluation and the assumptions that paleo fluid-flow structures may be reactivated by CO2 injection and that the caprock of the storage formation may breach, a number of potential leakage

  2. Airway pressure with chest compressions versus Heimlich manoeuvre in recently dead adults with complete airway obstruction.

    PubMed

    Langhelle, A; Sunde, K; Wik, L; Steen, P A

    2000-04-01

    In a previous case report a standard chest compression successfully removed a foreign body from the airway after the Heimlich manoeuvre had failed. Based on this case, standard chest compressions and Heimlich manoeuvres were performed by emergency physicians on 12 unselected cadavers with a simulated complete airway obstruction in a randomised crossover design. The mean peak airway pressure was significantly lower with abdominal thrusts compared to chest compressions, 26.4+/-19.8 cmH(2)O versus 40.8+/-16.4 cmH(2)O, respectively (P=0.005, 95% confidence interval for the mean difference 5.3-23.4 cmH(2)O). Standard chest compressions therefore have the potential of being more effective than the Heimlich manoeuvre for the management of complete airway obstruction by a foreign body in an unconscious patient. Removal of the Heimlich manoeuvre from the resuscitation algorithm for unconscious patients with suspected airway obstruction will also simplify training.

  3. Atlantic multi-decadal oscillation covaries with Agulhas leakage

    PubMed Central

    Biastoch, Arne; Durgadoo, Jonathan V.; Morrison, Adele K.; van Sebille, Erik; Weijer, Wilbert; Griffies, Stephen M.

    2015-01-01

    The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, ‘Agulhas leakage', forms a choke point for the overturning circulation in the global ocean. Here, by combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870–2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. This is relevant for climate in the North Atlantic. PMID:26656850

  4. Atlantic multi-decadal oscillation covaries with Agulhas leakage.

    PubMed

    Biastoch, Arne; Durgadoo, Jonathan V; Morrison, Adele K; van Sebille, Erik; Weijer, Wilbert; Griffies, Stephen M

    2015-12-10

    The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, 'Agulhas leakage', forms a choke point for the overturning circulation in the global ocean. Here, by combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870-2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. This is relevant for climate in the North Atlantic.

  5. Theory and Application of Magnetic Flux Leakage Pipeline Detection.

    PubMed

    Shi, Yan; Zhang, Chao; Li, Rui; Cai, Maolin; Jia, Guanwei

    2015-12-10

    Magnetic flux leakage (MFL) detection is one of the most popular methods of pipeline inspection. It is a nondestructive testing technique which uses magnetic sensitive sensors to detect the magnetic leakage field of defects on both the internal and external surfaces of pipelines. This paper introduces the main principles, measurement and processing of MFL data. As the key point of a quantitative analysis of MFL detection, the identification of the leakage magnetic signal is also discussed. In addition, the advantages and disadvantages of different identification methods are analyzed. Then the paper briefly introduces the expert systems used. At the end of this paper, future developments in pipeline MFL detection are predicted.

  6. Theory and Application of Magnetic Flux Leakage Pipeline Detection

    PubMed Central

    Shi, Yan; Zhang, Chao; Li, Rui; Cai, Maolin; Jia, Guanwei

    2015-01-01

    Magnetic flux leakage (MFL) detection is one of the most popular methods of pipeline inspection. It is a nondestructive testing technique which uses magnetic sensitive sensors to detect the magnetic leakage field of defects on both the internal and external surfaces of pipelines. This paper introduces the main principles, measurement and processing of MFL data. As the key point of a quantitative analysis of MFL detection, the identification of the leakage magnetic signal is also discussed. In addition, the advantages and disadvantages of different identification methods are analyzed. Then the paper briefly introduces the expert systems used. At the end of this paper, future developments in pipeline MFL detection are predicted. PMID:26690435

  7. The clinical effectiveness of the streamlined liner of pharyngeal airway (SLIPA™) compared with the laryngeal mask airway ProSeal™ during general anesthesia

    PubMed Central

    Choi, Yun Mi; Cha, Su Man; Baek, Chong Wha; Jung, Yong Hun; Woo, Young Cheol; Kim, Jin Yun; Koo, Gill Hoi; Park, Sun Gyoo

    2010-01-01

    Background The aim of this study was to compare the streamlined liner of the pharynx airway (SLIPA), a new supraglottic airway device (SGA), with the laryngeal mask airway ProSeal™ (PLMA) during general anesthesia. Methods Sixty patients were randomly allocated to two groups; a PLMA group (n = 30) or a SLIPA group (n = 30). Ease of use, first insertion success rate, hemodynamic responses to insertion, ventilatory efficiency and positioning confirmed by fiberoptic bronchoscopy were assessed. Lung mechanics data were collected with side stream spirometry at 10 minutes after insertion. We also compared the incidence of blood stain, incidence and severity of postoperative sore throat and other complications. Results First attempt success rates were 93.3% and 73.3%, and mean insertion time was 7.3 sec and 10.5 sec in PLMA and SLIPA. There was a significant rise in all of hemodynamic response from the pre-insertion value at one minute following insertion of SLIPA. But, insertion of PLMA was no significant rise in hemodynamic response. There was no statistically significant difference in the mean maximum sealing pressure, gas leakage, lung mechanics data, gastric distension, postoperative sore throat and other complication between the two groups. Blood stain were noted on the surface of the device in 40% (n = 12) in the SLIPA vs. 6.7% (n = 2) in the PLMA. Conclusions The SLIPA is a useful alternative to the PLMA and have comparable efficacy and complication rates. If we acquire the skill to use, SLIPA may be considered as primary SGA devices during surgery under general anesthesia. PMID:20532053

  8. Deletion of airway cilia results in noninflammatory bronchiectasis and hyperreactive airways

    PubMed Central

    Gilley, Sandra K.; Stenbit, Antine E.; Pasek, Raymond C.; Sas, Kelli M.; Steele, Stacy L.; Amria, May; Bunni, Marlene A.; Estell, Kimberly P.; Schwiebert, Lisa M.; Flume, Patrick; Gooz, Monika; Haycraft, Courtney J.; Yoder, Bradley K.; Miller, Caroline; Pavlik, Jacqueline A.; Turner, Grant A.; Sisson, Joseph H.

    2013-01-01

    The mechanisms for the development of bronchiectasis and airway hyperreactivity have not been fully elucidated. Although genetic, acquired diseases and environmental influences may play a role, it is also possible that motile cilia can influence this disease process. We hypothesized that deletion of a key intraflagellar transport molecule, IFT88, in mature mice causes loss of cilia, resulting in airway remodeling. Airway cilia were deleted by knockout of IFT88, and airway remodeling and pulmonary function were evaluated. In IFT88− mice there was a substantial loss of airway cilia on respiratory epithelium. Three months after the deletion of cilia, there was clear evidence for bronchial remodeling that was not associated with inflammation or apparent defects in mucus clearance. There was evidence for airway epithelial cell hypertrophy and hyperplasia. IFT88− mice exhibited increased airway reactivity to a methacholine challenge and decreased ciliary beat frequency in the few remaining cells that possessed cilia. With deletion of respiratory cilia there was a marked increase in the number of club cells as seen by scanning electron microscopy. We suggest that airway remodeling may be exacerbated by the presence of club cells, since these cells are involved in airway repair. Club cells may be prevented from differentiating into respiratory epithelial cells because of a lack of IFT88 protein that is necessary to form a single nonmotile cilium. This monocilium is a prerequisite for these progenitor cells to transition into respiratory epithelial cells. In conclusion, motile cilia may play an important role in controlling airway structure and function. PMID:24213915

  9. SPONTANEOUSLY HYPERTENSIVE RATS ARE SUSCEPTIBLE TO MICROVASCULAR THROMBOSIS IN RESPONSE TO PARTICULATE MATTER EXPOSURE

    EPA Science Inventory

    SPONTANEOUSLY HYPERTENSIVE RATS ARE SUSCEPTIBLE TO MICROVASCULAR THROMBOSIS IN RESPONSE TO PARTICULATE MATTER EXPOSURE.
    PS Gilmour, MC Schladweiler, AD Ledbetter, and UP Kodavanti. US EPA, ORD, NHEERL, ETD, PTB, Research Triangle Park, NC USA.
    Environmental particles (PM...

  10. Differential expression of PDGFRB and EGFR in microvascular proliferation in glioblastoma.

    PubMed

    Xu, Guiyan; Li, Jian Yi

    2016-08-01

    Glioblastoma (GBM) is the highly malignant glioma and exhibits microvascular proliferation. PCR mRNA arrays and immunohistochemical stains on tissue microarray demonstrated that the expression level of PDGFRB in GBM microvascular proliferation was significantly higher than that in GBM tumor cells while the expression level of EGFR was lower in microvascular proliferation than in GBM tumor cells. PDGFRB protein was selectively expressed in pericytes in GBM microvascular proliferation. By analyzing The Cancer Genome Atlas (TCGA) datasets for GBM, it was found that genomic DNA alterations were the main reason for the high expression of EGFR in GBM tumor cells. Our miRNA microarray data showed that microRNAs (miRNAs) (miR-193b-3p, miR-518b, miR-520f-3p, and miR-506-5p) targeting PDGFRB were downregulated in microvascular proliferation, which might be the most likely reason for the high expression of PDGFRB in GBM microvascular proliferation. The increase of several miRNAs (miR-133b, miR-30b-3p, miR-145-5p, and miR-146a-5p) targeting EGFR in GBM microvascular proliferation was one of the reasons for the lack of expression of EGFR in GBM microvascular proliferation. These findings implicated that miRNAs, such as miR-506, miR-133b, miR-145, and miR-146a, that target PDGFRB or EGFR, might be potential therapeutic agents for GBM. A new generation of targeted therapeutic agents against both EGFR and PDGFRB might be developed in the future.

  11. Preparation of the patient and the airway for awake intubation

    PubMed Central

    Ramkumar, Venkateswaran

    2011-01-01

    Awake intubation is usually performed electively in the presence of a difficult airway. A detailed airway examination is time-consuming and often not feasible in an emergency. A simple 1-2-3 rule for airway examination allows one to identify potential airway difficulty within a minute. A more detailed airway examination can give a better idea about the exact nature of difficulty and the course of action to be taken to overcome it. When faced with an anticipated difficult airway, the anaesthesiologist needs to consider securing the airway in an awake state without the use of anaesthetic agents or muscle relaxants. As this can be highly discomforting to the patient, time and effort must be spent to prepare such patients both psychologically and pharmacologically for awake intubation. Psychological preparation is best initiated by an anaesthesiologist who explains the procedure in simple language. Sedative medications can be titrated to achieve patient comfort without compromising airway patency. Additional pharmacological preparation includes anaesthetising the airway through topical application of local anaesthetics and appropriate nerve blocks. When faced with a difficult airway, one should call for the difficult airway cart as well as for help from colleagues who have interest and expertise in airway management. Preoxygenation and monitoring during awake intubation is important. Anxious patients with a difficult airway may need to be intubated under general anaesthesia without muscle relaxants. Proper psychological and pharmacological preparation of the patient by an empathetic anaesthesiologist can go a long way in making awake intubation acceptable for all concerned. PMID:22174458

  12. Macrophage adaptation in airway inflammatory resolution.

    PubMed

    Kaur, Manminder; Bell, Thomas; Salek-Ardakani, Samira; Hussell, Tracy

    2015-09-01

    Bacterial and viral infections (exacerbations) are particularly problematic in those with underlying respiratory disease, including post-viral infection, asthma, chronic obstructive pulmonary disease and pulmonary fibrosis. Patients experiencing exacerbations tend to be at the more severe end of the disease spectrum and are often difficult to treat. Most of the unmet medical need remains in this patient group. Airway macrophages are one of the first cell populations to encounter airborne pathogens and, in health, exist in a state of reduced responsiveness due to interactions with the respiratory epithelium and specific factors found in the airway lumen. Granulocyte-macrophage colony-stimulating factor, interleukin-10, transforming growth factor-β, surfactant proteins and signalling via the CD200 receptor, for example, all raise the threshold above which airway macrophages can be activated. We highlight that following severe respiratory inflammation, the airspace microenvironment does not automatically re-set to baseline and may leave airway macrophages more restrained than they were at the outset. This excessive restraint is mediated in part by the clearance of apoptotic cells and components of extracellular matrix. This implies that one strategy to combat respiratory exacerbations would be to retune airway macrophage responsiveness to allow earlier bacterial recognition.

  13. Acoustic simulation of a patient's obstructed airway.

    PubMed

    van der Velden, W C P; van Zuijlen, A H; de Jong, A T; Lynch, C T; Hoeve, L J; Bijl, H

    2016-01-01

    This research focuses on the numerical simulation of stridor; a high pitched, abnormal noise, resulting from turbulent airflow and vibrating tissue through a partially obstructed airway. Characteristics of stridor noise are used by medical doctors as indication for location and size of the obstruction. The relation between type of stridor and the various diseases associated with airway obstruction is unclear; therefore, simply listening to stridor is an unreliable diagnostic tool. The overall aim of the study is to better understand the relationship between characteristics of stridor noise and localization and size of the obstruction. Acoustic analysis of stridor may then in future simplify the diagnostic process, and reduce the need for more invasive procedures such as laryngoscopy under general anesthesia. In this paper, the feasibility of a coupled flow, acoustic and structural model is investigated to predict the noise generated by the obstruction as well as the propagation of the noise through the airways, taking into account a one-way coupled fluid, structure, and acoustic interaction components. The flow and acoustic solver are validated on a diaphragm and a simplified airway model. A realistic airway model of a patient suffering from a subglottic stenosis, derived from a real computed tomography scan, is further analyzed. Near the mouth, the broadband noise levels at higher frequencies increased with approximately 15-20 dB comparing the stridorous model with the healthy model, indicating stridorous sound.

  14. Silibinin attenuates allergic airway inflammation in mice

    SciTech Connect

    Choi, Yun Ho; Jin, Guang Yu; Guo, Hui Shu; Piao, Hong Mei; Li, Liang chang; Li, Guang Zhao; Lin, Zhen Hua; Yan, Guang Hai

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer Silibinin diminishes ovalbumin-induced inflammatory reactions in the mouse lung. Black-Right-Pointing-Pointer Silibinin reduces the levels of various cytokines into the lung of allergic mice. Black-Right-Pointing-Pointer Silibinin prevents the development of airway hyperresponsiveness in allergic mice. Black-Right-Pointing-Pointer Silibinin suppresses NF-{kappa}B transcriptional activity. -- Abstract: Allergic asthma is a chronic inflammatory disease regulated by coordination of T-helper2 (Th2) type cytokines and inflammatory signal molecules. Silibinin is one of the main flavonoids produced by milk thistle, which is reported to inhibit the inflammatory response by suppressing the nuclear factor-kappa B (NF-{kappa}B) pathway. Because NF-{kappa}B activation plays a pivotal role in the pathogenesis of allergic inflammation, we have investigated the effect of silibinin on a mouse ovalbumin (OVA)-induced asthma model. Airway hyperresponsiveness, cytokines levels, and eosinophilic infiltration were analyzed in bronchoalveolar lavage fluid and lung tissue. Pretreatment of silibinin significantly inhibited airway inflammatory cell recruitment and peribronchiolar inflammation and reduced the production of various cytokines in bronchoalveolar fluid. In addition, silibinin prevented the development of airway hyperresponsiveness and attenuated the OVA challenge-induced NF-{kappa}B activation. These findings indicate that silibinin protects against OVA-induced airway inflammation, at least in part via downregulation of NF-{kappa}B activity. Our data support the utility of silibinin as a potential medicine for the treatment of asthma.

  15. Added Qualifications in Microsurgery: Consideration for Subspecialty Certification in Microvascular Surgery in Europe.

    PubMed

    Heidekrueger, Paul I; Tanna, Neil; Weichman, Katie E; Szpalski, Caroline; Tos, Pierluigi; Ninkovic, Milomir; Broer, P Niclas

    2016-07-01

    Background While implementation of subspecializations may increase expertise in a certain area of treatment, there also exist downsides. Aim of this study was, across several disciplines, to find out if the technique of microsurgery warrants the introduction of a "Certificate of Added Qualifications (CAQ) in microsurgery." Methods An anonymous, web-based survey was administered to directors of microsurgical departments in Europe (n = 205). Respondents were asked, among other questions, whether they had completed a 12-month microvascular surgery fellowship and whether they believed a CAQ in microvascular surgery should be instituted. Results The response rate was 57%, and 33% of the respondents had completed a 12-month microvascular surgery fellowship.A total of 61% of all surgeons supported a CAQ in microsurgery. Answers ranged from 47% of support to 100% of support, depending on the countries surveyed. Discussion This is one of the few reports to evaluate the potential role of subspecialty certification of microvascular surgery across several European countries. The data demonstrate that the majority of directors of microsurgical departments support such a certificate. There was significantly greater support for a CAQ in microsurgery among those who have completed a formal microvascular surgery fellowship themselves. Conclusion This study supports the notion that further discussion and consideration of subspecialty certification in microvascular surgery appears necessary. There are multiple concerns surrounding this issue. Similar to the evolution of hand surgery certification, an exploratory committee of executive members of the respective medical boards and official societies may be warranted.

  16. DRAG REDUCING POLYMER ENCHANCES MICROVASCULAR PERFUSION IN THE TRAUMATIZED BRAIN WITH INTRACRANIAL HYPERTENSION

    PubMed Central

    Bragin, Denis E.; Thomson, Susan; Bragina, Olga; Statom, Gloria; Kameneva, Marina V.; Nemoto, Edwin M.

    2016-01-01

    SUMMARY Current treatments for traumatic brain injury (TBI) have not focused on improving microvascular perfusion. Drag-reducing polymers (DRP), linear, long-chain, blood soluble non-toxic macromolecules, may offer a new approach to improving cerebral perfusion by primary alteration of the fluid dynamic properties of blood. Nanomolar concentrations of DRP have been shown to improve hemodynamics in animal models of ischemic myocardium and limb, but have not yet been studied in the brain. Recently, we demonstrated that that DRP improved microvascular perfusion and tissue oxygenation in a normal rat brain. We hypothesized that DRP could restore microvascular perfusion in hypertensive brain after TBI. Using the in-vivo 2-photon laser scanning microscopy we examined the effect of DRP on microvascular blood flow and tissue oxygenation in hypertensive rat brains with and without TBI. DRP enhanced and restored capillary flow, decreased microvascular shunt flow and, as a result, reduced tissue hypoxia in both un-traumatized and traumatized rat brains at high ICP. Our study suggests that DRP could be an effective treatment for improving microvascular flow in brain ischemia caused by high ICP after TBI. PMID:27165871

  17. 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

  18. Classification of microvascular patterns via cluster analysis reveals their prognostic significance in glioblastoma.

    PubMed

    Chen, Long; Lin, Zhi-Xiong; Lin, Guo-Shi; Zhou, Chang-Fu; Chen, Yu-Peng; Wang, Xing-Fu; Zheng, Zong-Qing

    2015-01-01

    There are limited researches focusing on microvascular patterns (MVPs) in human glioblastoma and their prognostic impact. We evaluated MVPs of 78 glioblastomas by CD34/periodic acid-Schiff dual staining and by cluster analysis of the percentage of microvascular area for distinct microvascular formations. The distribution of 5 types of basic microvascular formations, that is, microvascular sprouting (MS), vascular cluster (VC), vascular garland (VG), glomeruloid vascular proliferation (GVP), and vasculogenic mimicry (VM), was variable. Accordingly, cluster analysis classified MVPs into 2 types: type I MVP displayed prominent MSs and VCs, whereas type II MVP had numerous VGs, GVPs, and VMs. By analyzing the proportion of microvascular area for each type of formation, we determined that glioblastomas with few MSs and VCs had many GVPs and VMs, and vice versa. VG seemed to be a transitional type of formation. In case of type I MVP, expression of Ki-67 and p53 but not MGMT was significantly higher as compared with those of type II MVP (P < .05). Survival analysis showed that the type of MVPs presented as an independent prognostic factor of progression-free survival (PFS) and overall survival (OS) (both P < .001). Type II MVP had a more negative influence on PFS and OS than did type I MVP. We conclude that the heterogeneous MVPs in glioblastoma can be categorized properly by certain histopathologic and statistical analyses and may influence clinical outcome.

  19. Results of microwave oven radiation leakage surveys at Fermilab

    SciTech Connect

    Miller, T.M.

    1987-01-01

    This report describes the results of routine microwave oven leakage surveys which were conducted at Fermi National Accelerator Laboratory (Fermilab) between 1974 and 1985. A total of 80 ovens representing 250 oven-years of operation were examined. The mean maximum leakage at any point 5 cm from the surface was 0.20 x/ 3.1 mW/cm/sup 2/. Although there was a great deal of scatter in sequential measurements for individual ovens, it appears that leakage tends to increase with oven age. The mean logarithmic rate of increase for the 55 ovens with usable data was 0.21 per year. Case histories of ovens leaking in excess of the standard were examined, and improvements in leakage monitoring programs are suggested.

  20. Cement Leakage into Adjacent Vertebral Body Following Percutaneous Vertebroplasty.

    PubMed

    Park, Jae Hoo; Kim, Hyeun Sung; Kim, Seok Won

    2016-06-01

    Percutaneous vertebroplasty (PV) is a minimally invasive procedure for osteoporotic vertebral compression fractures that fail to respond to conventional conservative treatment. It significantly improves intolerable back pain within hours, and has a low complication rate. Although rare, PV is not free of complications, most of which are directly related to cement leakage. Because of its association with new adjacent fracture, the importance of cement leakage into the adjacent disc space is paramount. Here, we report an interesting case of cement leakage into the adjacent upper vertebral body as well as disc space following PV. To the best of our knowledge, there has been no report of cement leakage into the adjacent vertebral body following PV. This rare case is presented along with a review of the literature.

  1. [A serious complication in colorectal surgery: anastomotic leakage. Our experience].

    PubMed

    Petitti, T; Lippolis, G; Ferrozzi, L

    2005-10-01

    Anastomotic leakage is a severe complication in colorectal surgery with a lot of generic and specific risk factors. There are still controversies about the possibility to prevent it or to limit its severity with the use of faecal diversions. We report our experience on 189 patients operated in five years on colon-rectum, in election and emergency, with manual or mechanical anastomoses in the last 20 cm from the anal verge. We have had 21 anastomotic leakages (11%), symptomatic in 10 cases (5.5%), and 5 deaths (2.6%), 3 directly correlated to the leakage. In the patients (n 98) with loop-ileostomy there wasn't anastomotic leakages reduction, but only of clinical impact. We prefer loop-ileostomy in cases of extraperitoneal anastomoses, always in emergency and in anastomoses at risk.

  2. The human brain intracerebral microvascular system: development and structure

    PubMed Central

    Marín-Padilla, Miguel

    2012-01-01

    The capillary from the meningeal inner pial lamella play a crucial role in the development and structural organization of the cerebral cortex extrinsic and intrinsic microvascular compartments. Only pial capillaries are capable of perforating through the cortex external glial limiting membrane (EGLM) to enter into the nervous tissue, although incapable of perforating the membrane to exit the brain. Circulatory dynamics and functional demands determine which capillaries become arterial and which capillaries become venous. The perforation of the cortex EGLM by pial capillaries is a complex process characterized by three fundamental stages: (1) pial capillary contact with the EGLM with fusion of vascular and glial basal laminae at the contact site, (2) endothelial cell filopodium penetration through the fussed laminae with the formation of a funnel between them that accompanies it into the nervous tissue while remaining open to the meningeal interstitium and, (3) penetration of the whole capillary carrying the open funnel with it and establishing an extravascular Virchow-Robin Compartment (V-RC) that maintains the perforating vessel extrinsic (outside) the nervous tissue through its entire length. The V-RC is walled internally by the vascular basal lamina and externally by the basal lamina of joined glial cells endfeet. The VRC outer glial wall appear as an extension of the cortex superficial EGLM. All the perforating vessels within the V-RCs constitute the cerebral cortex extrinsic microvascular compartment. These perforating vessels are the only one capable of responding to inflammatory insults. The V-RC remains open (for life) to the meningeal interstitium permitting the exchanges of fluid and of cells between brain and meninges. The V-RC function as the brain sole drainage (prelymphatic) system in both physiological as well as pathological situations. During cortical development, capillaries emerge from the perforating vessels, by endothelial cells growing sprouts

  3. Expedient methods of respiratory protection. II. Leakage tests. Final report

    SciTech Connect

    Cooper, D.W.; Hinds, W.C.; Price, J.M.; Weker, R.; Yee, H.S.

    1983-07-01

    The following readily-available materials were tested on a manikin connected to a breathing simulator to determine the fraction of an approximately 2-..mu..m-diameter aerosol that would leak around the seal of the materials to the manikin's face: cotton/polyester shirt material, cotton handkerchief material, toweling (a wash cloth), a surgical mask (Johnson and Johnson Co., model HRI 8137), and a NIOSH-approved disposable face mask (3M, model number 8710). The leakage tests were performed to supplement the measurements of penetration through the materials, conducted as the first phase of this investigation. The leakage tests were performed with the materials held on to the face by three methods, leakage fractions being determined from comparisons with the penetration of the same aerosol for the materials fully taped to the face. At a breathing rate of 37 liters per minute, mean leakages ranged from 0.0 percent to 63 percent. Mean penetrations exclusive of leakage ranged from 0.6 percent to 39 percent. Use of nylon hosiery material (panty hose) to hold the handkerchief material or the disposable face mask to the face was found to be very effective in preventing leakage. Such a combination could be expected to reduce leakage around the handkerchief to about ten percent or less in practice, and around the mask to less than one percent, offering substantial protection from accidentally generated aerosols. The reduction in leakage around the mask provided by the hosiery material suggests the adaptation and use of such an approach in regular industrial hygiene practice. The third and final phase of this investigation is underway, in which the penetration of the materials by particles with diameters between 0.05 and 0.5 ..mu..m is being measured and the effectiveness of the methods for dose reduction in the presence of radioactive aerosols is being modeled.

  4. Microvascular protective activity of flavonoid glucuronides fraction from Tulipa gesneriana.

    PubMed

    Budzianowski, J; Korzeniowska, K; Chmara, E; Mrozikiewicz, A

    1999-03-01

    A mixture of flavonoid glucuronides, consisting of 7-O-glucuronides of kaempferol and quercetin 3-O-rutinosides, 3-O-gentiobiosides and 3-O-glucosides, was isolated from the perianths of Tulipa gesneriana L. var. 'Paradae'. It showed protective activity against the increased (both chloroform and histamine) skin vascular permeability in rabbits. The protective effect, measured as the reduction in leakage of Evans blue, was 59.8% after peritoneal treatment at a dose of 25 mg/kg, while that of troxerutin was 45.5%.

  5. SPONTANEOUS AIRWAY HYPERRESPONSIVENESS IN ESTROGEN RECEPTOR-A DEFICIENT MICE

    EPA Science Inventory

    Rationale: Airway hyperresponsiveness is a critical feature of asthma. Substantial epidemiologic evidence supports a role for female sex hormones in modulating lung function and airway hyperresponsiveness in humans. Objectives: To examine the role of estrogen receptors in modulat...

  6. The Three A’s in Asthma – Airway Smooth Muscle, Airway Remodeling & Angiogenesis

    PubMed Central

    Keglowich, L.F; Borger, P

    2015-01-01

    Asthma affects more than 300 million people worldwide and its prevalence is still rising. Acute asthma attacks are characterized by severe symptoms such as breathlessness, wheezing, tightness of the chest, and coughing, which may lead to hospitalization or death. Besides the acute symptoms, asthma is characterized by persistent airway inflammation and airway wall remodeling. The term airway wall remodeling summarizes the structural changes in the airway wall: epithelial cell shedding, goblet cell hyperplasia, hyperplasia and hypertrophy of the airway smooth muscle (ASM) bundles, basement membrane thickening and increased vascular density. Airway wall remodeling starts early in the pathogenesis of asthma and today it is suggested that remodeling is a prerequisite for other asthma pathologies. The beneficial effect of bronchial thermoplasty in reducing asthma symptoms, together with the increased potential of ASM cells of asthmatics to produce inflammatory and angiogenic factors, indicate that the ASM cell is a major effector cell in the pathology of asthma. In the present review we discuss the ASM cell and its role in airway wall remodeling and angiogenesis. PMID:26106455

  7. Host-microbe interactions in distal airways: relevance to chronic airway diseases.

    PubMed

    Martin, Clémence; Burgel, Pierre-Régis; Lepage, Patricia; Andréjak, Claire; de Blic, Jacques; Bourdin, Arnaud; Brouard, Jacques; Chanez, Pascal; Dalphin, Jean-Charles; Deslée, Gaetan; Deschildre, Antoine; Gosset, Philippe; Touqui, Lhousseine; Dusser, Daniel

    2015-03-01

    This article is the summary of a workshop, which took place in November 2013, on the roles of microorganisms in chronic respiratory diseases. Until recently, it was assumed that lower airways were sterile in healthy individuals. However, it has long been acknowledged that microorganisms could be identified in distal airway secretions from patients with various respiratory diseases, including cystic fibrosis (CF) and non-CF bronchiectasis, chronic obstructive pulmonary disease, asthma and other chronic airway diseases (e.g. post-transplantation bronchiolitis obliterans). These microorganisms were sometimes considered as infectious agents that triggered host immune responses and contributed to disease onset and/or progression; alternatively, microorganisms were often considered as colonisers, which were considered unlikely to play roles in disease pathophysiology. These concepts were developed at a time when the identification of microorganisms relied on culture-based methods. Importantly, the majority of microorganisms cannot be cultured using conventional methods, and the use of novel culture-independent methods that rely on the identification of microorganism genomes has revealed that healthy distal airways display a complex flora called the airway microbiota. The present article reviews some aspects of current literature on host-microbe (mostly bacteria and viruses) interactions in healthy and diseased airways, with a special focus on distal airways.

  8. 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

  9. Energy Efficient High-Pressure Turbine Leakage Technology Report

    NASA Technical Reports Server (NTRS)

    Gardner, W. B.

    1980-01-01

    The leakage test program was one of such supporting technology programs structured to provide guidance to the Energy Efficient Engine High Pressure Turbine Component Design Effort. Leakage reduction techniques were identified and evaluated. Test models were used to simulate component leak paths and to evaluate leakage reduction techniques. These models simulated the blade/disk attachment, the vane inner platform attachment, and the vane outer platform attachment combined with the blade outer airseal. Disk blade attachment testing indicated that leakage in this area could be reduced to very low levels by paying careful attention to the tolerances along the contact surface between the blade vibration damper and the blade platform contact surface. The aim of feather seal testing was to achieve a goal for an effective leakage gap of one mil (.001 inch) per inch of feather seal length. Results indicated that effective gaps even below the goal level were achievable by (1) maintaining close tolerances between feather seals and their slots to minimize end gaps and limit seal rotation, (2) avoiding feather seal overlap, and (3) minimizing feather seal intersections. W seals were shown to be effective leakage control devices. Wire rope, in its present state of development, was shown not to be an effective sealing concept for application to the component design.

  10. Subtotal petrosectomy and cerebrospinal fluid leakage in unilateral anacusis.

    PubMed

    Magliulo, Giuseppe; Iannella, Giannicola; Ciniglio Appiani, Mario; Re, Massimo

    2014-12-01

    Objective This study presents a group of patients experiencing recurrent cerebrospinal fluid (CSF) leakage associated with ipsilateral anacusis who underwent subtotal petrosectomies with the goal of stopping the CSF leak and preventing meningitis. Materials and Methods Eight patients with CSF leakage were enrolled: three patients with giant vestibular schwannomas had CSF leakage after gamma knife failure and subsequent removal via a retrosigmoid approach; two patients had malformations at the level of the inner ear with consequent translabyrinthine fistulas; two had posttraumatic CSF leakages; and one had a CSF leakage coexisting with an encephalocele. Two patients developed meningitis that resolved with antibiotic therapy. Each patient had preoperative anacusis and vestibular nerve areflexia on the affected side. Results The patients with congenital or posttraumatic CSF leaks had undergone at least one unsuccessful endaural approach to treat the fistula. All eight patients were treated successfully with a subtotal petrosectomy. The symptoms disappeared within 2 months postoperatively. No meningitis, signs of fistula, or other symptoms occurred during the follow-up. Conclusion A subtotal petrosectomy should be the first choice of treatment in patients with recurrent CSF leakage whenever there is associated unilateral anacusis.

  11. Subtotal Petrosectomy and Cerebrospinal Fluid Leakage in Unilateral Anacusis

    PubMed Central

    Magliulo, Giuseppe; Iannella, Giannicola; Appiani, Mario Ciniglio; Re, Massimo

    2014-01-01

    Objective This study presents a group of patients experiencing recurrent cerebrospinal fluid (CSF) leakage associated with ipsilateral anacusis who underwent subtotal petrosectomies with the goal of stopping the CSF leak and preventing meningitis. Materials and Methods Eight patients with CSF leakage were enrolled: three patients with giant vestibular schwannomas had CSF leakage after gamma knife failure and subsequent removal via a retrosigmoid approach; two patients had malformations at the level of the inner ear with consequent translabyrinthine fistulas; two had posttraumatic CSF leakages; and one had a CSF leakage coexisting with an encephalocele. Two patients developed meningitis that resolved with antibiotic therapy. Each patient had preoperative anacusis and vestibular nerve areflexia on the affected side. Results The patients with congenital or posttraumatic CSF leaks had undergone at least one unsuccessful endaural approach to treat the fistula. All eight patients were treated successfully with a subtotal petrosectomy. The symptoms disappeared within 2 months postoperatively. No meningitis, signs of fistula, or other symptoms occurred during the follow-up. Conclusion A subtotal petrosectomy should be the first choice of treatment in patients with recurrent CSF leakage whenever there is associated unilateral anacusis. PMID:25452896

  12. Prediction of leakage flow in a shrouded centrifugal blood pump.

    PubMed

    Teo, Ji-Bin; Chan, Weng-Kong; Wong, Yew-Wah

    2010-09-01

    This article proposes a phenomenological model to predict the leakage flow in the clearance gap of shrouded centrifugal blood pumps. A good washout in the gap clearance between the rotating impeller surfaces and volute casing is essential to avoid thrombosis. However, excessive leakage flow will result in higher fluid shear stress that may lead to hemolysis. Computational fluid dynamics (CFD) analysis was performed to investigate the leakage flow in a miniaturized shrouded centrifugal blood pump operating at a speed of 2000 rpm. Based on an analytical model derived earlier, a phenomenological model is proposed to predict the leakage flow. The leakage flow rate is found to be proportional to h(α) , where h is the gap size and the exponent α ranges from 2.955 to 3.15 for corresponding gap sizes of 0.2-0.5 mm. In addition, it is observed that α is a linear function of the gap size h. The exponent α compensates for the variation of pressure difference along the circumferential direction as well as inertia effects that are dominant for larger gap clearances. The proposed model displays good agreement with computational results. The CFD analysis also showed that for larger gap sizes, the total leakage flow rate is of the same order of magnitude as the operating flow rate, thus suggesting low volumetric efficiency.

  13. Field size dependent mapping of medical linear accelerator radiation leakage

    NASA Astrophysics Data System (ADS)

    Vũ Bezin, Jérémi; Veres, Attila; Lefkopoulos, Dimitri; Chavaudra, Jean; Deutsch, Eric; de Vathaire, Florent; Diallo, Ibrahima

    2015-03-01

    The purpose of this study was to investigate the suitability of a graphics library based model for the assessment of linear accelerator radiation leakage. Transmission through the shielding elements was evaluated using the build-up factor corrected exponential attenuation law and the contribution from the electron guide was estimated using the approximation of a linear isotropic radioactive source. Model parameters were estimated by a fitting series of thermoluminescent dosimeter leakage measurements, achieved up to 100 cm from the beam central axis along three directions. The distribution of leakage data at the patient plane reflected the architecture of the shielding elements. Thus, the maximum leakage dose was found under the collimator when only one jaw shielded the primary beam and was about 0.08% of the dose at isocentre. Overall, we observe that the main contributor to leakage dose according to our model was the electron beam guide. Concerning the discrepancies between the measurements used to calibrate the model and the calculations from the model, the average difference was about 7%. Finally, graphics library modelling is a readily and suitable way to estimate leakage dose distribution on a personal computer. Such data could be useful for dosimetric evaluations in late effect studies.

  14. MicroRNA in United Airway Diseases

    PubMed Central

    Liu, Zheng; Zhang, Xin-Hao; Callejas-Díaz, Borja; Mullol, Joaquim

    2016-01-01

    The concept of united airway diseases (UAD) has received increasing attention in recent years. Sustained and increased inflammation is a common feature of UAD, which is inevitably accompanied with marked gene modification and tight gene regulation. However, gene regulation in the common inflammatory processes in UAD remains unclear. MicroRNA (miRNA), a novel regulator of gene expression, has been considered to be involved in many inflammatory diseases. Although there are an increasing number of studies of miRNAs in inflammatory upper and lower airway diseases, few miRNAs have been identified that directly link the upper and lower airways. In this article, therefore, we reviewed the relevant studies available in order to improve the understanding of the roles of miRNAs in the interaction and pathogenesis of UAD. PMID:27187364

  15. Electrical stimulation of upper airway musculature.

    PubMed

    Smith, P L; Eisele, D W; Podszus, T; Penzel, T; Grote, L; Peter, J H; Schwartz, A R

    1996-12-01

    Investigators have postulated that pharyngeal collapse during sleep in patients with obstructive sleep apnea (OSA) may be alleviated by stimulating the genioglossus. The effect of electrical stimulation (ES) of the genioglossus on pharyngeal patency was examined in an isolated feline upper airway preparation and in apneic humans during sleep. We found that stimulation of the genioglossus (n = 8) and of the hypoglossal nerve (n = 1) increased maximum airflow through the isolated feline upper airway in humans during sleep. Additional findings in the isolated feline upper airway suggest that such increases in airflow were due to decreases in pharyngeal collapsibility. The evidence suggests that improvements in airflow dynamics with electrical stimulation are due to selective recruitment of the genioglossus, rather than due to nonspecific activation of the pharyngeal musculature or arousal from sleep. The implications of these results for future therapy with ES are discussed.

  16. Laser applications in pediatric airway surgery

    NASA Astrophysics Data System (ADS)

    Karamzadeh, Amir M.; Ahuja, Gurpreet S.; Nguyen, John D.; Crumley, Roger

    2003-06-01

    The smaller anatomy and limited access to instrumentation pose a challenge to the pediatric airway surgeon. The enhanced precision and ability to photocoagulate tissue while operating with the laser enhances the surgeon"s ability to successfully treat unique pediatric conditions such subglottic hemangiomas, congenital cysts, respiratory papillomatosis, and laryngeal or tracheal stenosis. Due to its shallow tissue penetration and thermal effect, the carbon dioxide (CO2) laser is generally considered the laser of choice for pediatric airway applications. The potential for increased scarring and damage to underlying tissue caused by the greater penetration depth and thermal effect of the Nd:YAG and KTP lasers preclude their use in this population. In this review, we will describe the specific advantages of using lasers in airway surgery, the current technology and where the current technology is deficient.

  17. Cold weather exercise and airway cytokine expression.

    PubMed

    Davis, Michael S; Malayer, Jerry R; Vandeventer, Lori; Royer, Christopher M; McKenzie, Erica C; Williamson, Katherine K

    2005-06-01

    Athletes who perform repeated exercise while breathing cold air have a high prevalence of asthmalike chronic airway disease, but the mechanism linking such activity to airway inflammation is unknown. We used a novel animal model (exercising horses) to test the hypothesis that exercise-induced chronic airway disease is caused by exposure of intrapulmonary airways to unconditioned air, resulting in the upregulation of cytokine expression. Bronchoalveolar lavage fluid (BALF) was obtained from eight horses 5 h after submaximal exercise while they breathed room temperature or subfreezing air in a random crossover design. BALF total and differential nucleated cell counts were determined, and relative cytokine mRNA expression in BALF nucleated cells was quantified by real-time RT-PCR using primer and probe sequences specific for equine targets. There were no significant changes in total or differential cell concentrations between BALF recovered after warm and cold air exercise, although there was a strong trend toward increased concentrations of airway epithelial cells after cold air exercise (P = 0.0625). T(H)2 cytokines IL-4, IL-5, and IL-10 were preferentially upregulated after cold air exercise 12-, 9-, and 10-fold, respectively, compared with warm air exercise. Other cytokines (IL-2 and IL-6) were upregulated to a lesser extent (6- and 3-fold, respectively) or not at all (IL-1, IL-8, IFN-gamma, and TNF-alpha). These results suggest that cold weather exercise can lead to asthmalike airway disease through the local induction of cytokines typical of the T(H)2 phenotype.

  18. Airway epithelium stimulates smooth muscle proliferation.

    PubMed

    Malavia, Nikita K; Raub, Christopher B; Mahon, Sari B; Brenner, Matthew; Panettieri, Reynold A; George, Steven C

    2009-09-01

    Communication between the airway epithelium and stroma is evident during embryogenesis, and both epithelial shedding and increased smooth muscle proliferation are features of airway remodeling. Hence, we hypothesized that after injury the airway epithelium could modulate airway smooth muscle proliferation. Fully differentiated primary normal human bronchial epithelial (NHBE) cells at an air-liquid interface were co-cultured with serum-deprived normal primary human airway smooth muscle cells (HASM) using commercially available Transwells. In some co-cultures, the NHBE were repeatedly (x4) scrape-injured. An in vivo model of tracheal injury consisted of gently denuding the tracheal epithelium (x3) of a rabbit over 5 days and then examining the trachea by histology 3 days after the last injury. Our results show that HASM cell number increases 2.5-fold in the presence of NHBE, and 4.3-fold in the presence of injured NHBE compared with HASM alone after 8 days of in vitro co-culture. In addition, IL-6, IL-8, monocyte chemotactic protein (MCP)-1 and, more markedly, matrix metalloproteinase (MMP)-9 concentration increased in co-culture correlating with enhanced HASM growth. Inhibiting MMP-9 release significantly attenuated the NHBE-dependent HASM proliferation in co-culture. In vivo, the injured rabbit trachea demonstrated proliferation in the smooth muscle (trachealis) region and significant MMP-9 staining, which was absent in the uninjured control. The airway epithelium modulates smooth muscle cell proliferation via a mechanism that involves secretion of soluble mediators including potential smooth muscle mitogens such as IL-6, IL-8, and MCP-1, but also through a novel MMP-9-dependent mechanism.

  19. Benign Nodular Goiter Causing Upper Airway Obstruction

    PubMed Central

    Başoğlu, Mahmut; Öztürk, Gürkan; Aydınlı, Bülent; Yıldırgan, M. İlhan; Atamanalp, S. Selçuk; Celebi, Fehmi

    2009-01-01

    Objective Benign nodular goiter (BNG) can cause narrowing of the upper airway. In some rare cases, obstruction of the upper airway also occurs. The following paper reports our experiences with regard to BNG patients who experienced obstruction of the upper airway. Materials and Methods. We retrospectively investigated the records of 13 patients with acute airway obstruction due to BNG who were admitted to the General Surgery Department of Ataturk University Medical School between January 2000 and December 2007. Results Thirteen patients with airway obstruction secondary to BNG were hospitalized during this period. There were two males and 11 females, and the mean age was 58.5 years (range 37–74 years). For all patients, the primary symptom upon admission was defined as respiratory distress; all patients had varying degrees of respiratory distress upon admission. Three of the patients underwent emergent endotracheal intubation in the emergency room. A preoperative radiological evaluation was performed with thyroid ultrasonography (US) and computed tomography (CT). There were retrosternal or substernal components of the BNG in nine patients. Twelve patients underwent operations, while one patient with mild respiratory distress elected not to be operated on. Ten patients underwent total thyroidectomies, while two patients underwent near-total thyroidectomies. One patient with retrosternal goiter also underwent a median sternotomy. Three patients received a tracheostomy after the operation. Suction drains were utilized in all operations. During the post-operative period, two patients suffered from voice impairment, and seven patients experienced hypocalcemia. Two patients died. Pathological examination of the thyroidectomy tissue revealed BNG in all cases. In addition, two patients had micropapillary carcinomas. Conclusion Although BNG causing upper airway obstruction is rare, it is an important clinical entity because of the need for emergent operation, the

  20. Cine CT technique for dynamic airway studies

    SciTech Connect

    Ell, S.R.; Jolles, H.; Keyes, W.D.; Galvin, J.R.

    1985-07-01

    The advent of cine CT scanning with its 50-msec data acquisition time promises a much wider range of dynamic CT studies. The authors describe a method for dynamic evaluation of the extrathoracic airway, which they believe has considerable potential application in nonfixed upper-airway disease, such as sleep apnea and stridor of unknown cause. Conventional CT is limited in such studies by long data acquisition time and can be used to study only prolonged maneuvers such as phonation. Fluoroscopy and digital subtraction studies are limited by relatively high radiation dose and inability to image all wall motions simultaneously.

  1. 21 CFR 868.5090 - Emergency airway needle.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emergency airway needle. 868.5090 Section 868.5090 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... provide an emergency airway during upper airway obstruction. (b) Classification. Class II...

  2. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper...

  3. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  4. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper...

  5. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper...

  6. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  7. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper...

  8. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper...

  9. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  10. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  11. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  12. A New Era in Diagnostic Ultrasound, Superb Microvascular Imaging: Preliminary Results in Pediatric Hepato-Gastrointestinal Disorders.

    PubMed

    Ohno, Yasuharu; Fujimoto, Tamotsu; Shibata, Yukari

    2017-02-01

    Introduction Superb microvascular imaging is a new ultrasound image processing technique that uses advanced clutter suppression to extract flow signals from vessels and which helps us visualize very small vascular structures that were not previously visible without the use of a contrast agent. We herein analyzed the usefulness of superb microvascular imaging in the diagnosis of hepato-gastrointestinal disorders in pediatric patients. Materials and Methods Fifty-six pediatric patients who underwent a total of 81 superb microvascular imaging examinations with an Aplio 300 ultrasound system (Toshiba Medical Systems, Tokyo, Japan) were enrolled in this study. The subjects underwent conventional ultrasound examinations, including Doppler imaging followed by superb microvascular imaging. The superb microvascular imaging findings and standard imaging were compared. All of the examinations were performed without sedation. Results The average age of the patients (male, n = 38; female, n = 18) was 4 years. The clinical diagnoses included hepatobiliary disorders (n = 29), acute appendicitis (n = 10), and other intestinal disorders (n = 17). The target organs for superb microvascular imaging were the liver, appendix, rectum, intestine, gallbladder, and lymph node. In most of the patients, superb microvascular imaging achieved the excellent visualization of microvascular structures, revealing abnormal vasculature in 21 out of 46 (45.7%) examinations of the liver, 9/9 (100%) examinations of the appendix, 0/11 (0%) examinations of the rectum, 9/11 (81.8%) examinations of the intestine, 0/1 (0%) examinations of the gallbladder, and 3/3 (100%) examinations of the lymph nodes. Superb microvascular imaging was superior to Doppler imaging for depicting the microvascular structures. Conclusions Superb microvascular imaging is especially useful for depicting the microvascular flow and can aid in the diagnosis and treatment planning for pediatric patients with

  13. THERMAL REGAIN FROM DISPLACEMENT OF DUCT LEAKAGE WITHIN INSULATION.

    SciTech Connect

    ANDREWS,J.W.

    2002-05-01

    In one type of duct efficiency retrofit, additional insulation is added to a duct system that is already insulated. For example, a layer of R-4 insulation might be: added to a duct system that already has R-4 installed. It is possible that--either by chance or by design--the add-on layer, while not stopping duct leaks, might cause the leakage air to flow longitudinally for a distance, parallel to the duct, before it finds a way out of the newly added outer layer. This could happen by chance if the outer and inner layers of insulation have seams at different locations. Perhaps more usefully, if such longitudinal displacement of the leakage air turned out to be useful, it might be designed into the makeup of the outer insulation layer intended to be used in the retrofit. It is plausible that this leakage air might serve a useful function in keeping the insulation layer warmer (or, in the air-conditioning mode, cooler) than it would be in the absence of the leakage. By being held close to the ducts for a while, it might establish an artificially warmer (or cooler, in air conditioning) zone around the ducts. To the extent that this effect would reduce the heat losses from the ducts, the leakage should be credited with a ''thermal regain'' in the same way that leakage into buffer zones is credited with thermal regain when the leakage air warms (or cools) the buffer zone relative to the temperature it would have in the absence of such duct leakage. The purpose of this report is to investigate whether and to what extent such thermal regain exists. The model developed below applies to a situation where there are two distinct layers of insulation around the duct, with leakage air moving between them in a longitudinal direction for a distance before it finds its way out from the outer insulation layer. It may also apply approximately where there is a single insulation layer with an air barrier on the outside. Leakage air may pass into the insulation itself and thence

  14. Microvascular decompression for elderly patients with trigeminal neuralgia.

    PubMed

    Phan, Kevin; Rao, Prashanth J; Dexter, Mark

    2016-07-01

    Microvascular decompression (MVD) has been demonstrated to be an excellent surgical treatment approach in younger patients with trigeminal neuralgia (TN). However, it is not clear whether there are additional morbidity and mortality risks for MVD in the elderly population. We performed a systematic literature review using six electronic databases for studies that compared outcomes for MVD for TN in elderly (cut-off ⩾60, 65, 70years) versus younger populations. Outcomes examined included success rate, deaths, strokes, thromboembolism, meningitis, cranial nerve deficits and cerebrospinal fluid leaks. There were 1524 patients in the elderly cohort and 3488 patients in the younger cohort. There was no significant difference in success rates in elderly versus younger patients (87.5% versus 84.8%; P=0.47). However, recurrence rates were lower in the elderly (11.9% versus 15.6%; P=0.03). The number of deaths in the elderly cohort was higher (0.9% versus 0.1%; P=0.003). Rates of stroke (2.5% versus 1%) and thromboembolism (1.1% versus 0%) were also higher for elderly TN patients. No differences were found for rates of meningitis, cranial nerve deficits or cerebrospinal fluid leak. MVD remains an effective and reasonable strategy in the elderly population. There is evidence to suggest that rates of complications such as death, stroke, and thromboembolism may be significantly higher in the elderly population. The presented results may be useful in the decision-making process for MVD in elderly patients with TN.

  15. 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.

  16. 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.

  17. 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.

  18. Evidence of Microvascular Changes in the Retina following Kawasaki Disease

    PubMed Central

    Chen, Katherine Y. H.; Burgner, David P.; Wong, Tien Y.; Saw, Seang Mei; Quek, Swee Chye; Pang, Audrey Y. C.; Leo, Seo Wei; Wong, Inez B.; Zannino, Diana; Curtis, Nigel; Cheung, Michael; Cheung, Carol Y.; Lim, Terence C. W.

    2017-01-01

    It is unclear whether all children with Kawasaki disease (KD) have increased later cardiovascular risk. The retinal microvasculature reflects changes in the microcirculation and is associated with traditional cardiovascular risk factors and events. The aim of this study was to investigate retinal microvascular parameters in two populations of patients with previous KD and control participants. We performed case-control studies of 116 (57 patients and 59 control participants) Australian and 156 (78 patients and 78 control participants) Singaporean individuals, at least two years since their acute illness. Standardised retinal photographs were graded by trained technicians using a semi-automated software, which quantifies the retinal microvasculature (calibre, branching angle, fractal dimensions, and tortuosity). Retinal venules of Singaporean KD patients were 9.67 μm (95% CI 4.87 to 14.51, p < 0.001) larger than control participants following correction for traditional cardiovascular risk factors. An incremental increase in the size of retinal venules in those with coronary artery abnormalities was observed. There was limited evidence that retinal venules were larger in Australian KD patients with coronary artery abnormalities compared to control participants (7.34 μm, 95% CI 1.30 to 15.99, p = 0.10). Differences in retinal microvasculature were particularly evident in Singaporean KD patients. Larger retinal venules may reflect chronic inflammation and endothelial dysfunction, and are associated with coronary artery disease in adults. PMID:28094311

  19. NAP reduces murine microvascular endothelial cells proliferation induced by hyperglycemia.

    PubMed

    D'Amico, Agata Grazia; Scuderi, Soraya; Maugeri, Grazia; Cavallaro, Sebastiano; Drago, Filippo; D'Agata, Velia

    2014-11-01

    Hyperglycemia has been identified as a risk factor responsible for micro- and macrovascular complications in diabetes. NAP (Davunetide) is a peptide whose neuroprotective actions are widely demonstrated, although its biological role on endothelial dysfunctions induced by hyperglycemia remains uninvestigated. In the present study we hypothesized that NAP could play a protective role on hyperglycemia-induced endothelial cell proliferation. To this end we investigated the effects of NAP on an in vitro model of murine microvascular endothelial cells grown in high glucose for 7 days. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and cyclin D1 protein expression analysis revealed that NAP treatment significantly reduces viability and proliferation of the cells. Hyperglycemia induced the activation of mitogen-activated protein kinase/extracellular signal-regulated protein kinase and/or phosphatidylinositol-3 kinase/Akt pathways in a time-dependent manner. NAP treatment reduced the phosphorylation levels of ERK and AKT in cells grown in high glucose. These evidences suggest that NAP might be effective in the regulation of endothelial dysfunction induced by hyperglycemia.

  20. Microvascular network topology of the human retinal vessels.

    PubMed

    Schröder, S; Brab, M; Schmid-Schönbein, G W; Reim, M; Schmid-Schönbein, H

    1990-01-01

    A quantitative analysis of blood flow in the human retinal vessels requires a detailed picture of the microvascular network topology. In order to lay the foundation for a quantitative microcirculatory network analysis of the human retina, a novel technique for tissue preparation and network characterization was developed. After injection of hydrogen peroxide into the human bulb, the microvasculature was filled with oxygen produced by endothelial catalase and visualized after embedding in a mixture of cedar oil and gum damar. The vessel topology was documented in the form of photomicrographs, which permitted complete reconstruction of the microvasculature on transparent overlays. By considering the complete capillary system it was possible to divide the retinal network into dichotomous, asymmetric arteriolar and venular trees. The Strahler ordering method, which considers both dichotomous and side branching configurations, was selected and applied to analyze the retinal vascular trees, using the capillaries as the zero order reference vessels. The number of vessel segments was found to be an approximate logarithmic function of the order number, in accordance with Horton's law. Vessel lengths within each order were found to be log-normal distributed, and median lengths for different orders could be approximated by a 2nd degree polynomial curve. Diameters within each order could be approximated by a Gaussian distribution, and the mean values for different orders could be expressed by an exponential curve. These data provide the basis for conductance, pressure and flow computations within the retinal microvessels.

  1. The photosensitizer talaporfinum caused microvascular embolization for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Li, Liming; Aizawa, Katsuo

    2005-07-01

    Photodynamic therapy (PDT) has been evolving rapidly in the recent years. A second-generation Photosensitizer mono-1-aspartyl chlorine 6 (Talaporfin / Npe6 / ME2906, Japan Meiji Seika, Ltd.) has been sanctified for the lung cancer clinical PDT by the Japan Ministry of Health, Labor and Welfare. In this paper, Talaporfin was injected to the implant cancer of a mouse a Talaporfin dose of 5mg/kg through intravenous. After 6 hours, the fluorescence images of the mouse were observed with a microscope and a 664 nm diode laser. Effects of therapy were clarified using the different irradiation energies of the laser (50, 100, 200 J/cm2). Both in plasma and in cancer, the concentrations of Talaporfin were analyzed using High Performance Liquid Chromatography (HPLC). Authors find that the higher concentrations of Talaporfin in plasma, the better PDD effect. It is experimentally verified that local microvascular embolisms in the cancer are formed for photodynamic therapy after the Talaporfin injection and the laser irradiation.

  2. A method for evaluating aerosol leakage through the interface between protective suits and full-face respirators.

    PubMed

    Arnoldsson, Kristina; Danielsson, Signar; Thunéll, Marianne

    2016-01-01

    Military personnel and first responders use a range of personal equipment including protective suits, gloves, boots, and respirators to prevent exposure of their skin and airways to hazardous chemical, biological, radiological, and/or nuclear substances. Although each individual item of personal protective equipment is well tested against existing standards, it is also necessary to consider the performance of the interfaces between items in terms of prevention from exposure, and the protection system as a whole. This article presents an aerosol challenge method for assessing the performance of the interface between a respirator and the hood of a protective suit. The interface is formed between the sealing strip of the hood and the surface of the respirator's outer sealing area and is affected by how well the sealing strip can cover and adapt to the sealing area. The method evaluates the leakage of particles of different sizes into the hood via the interface by particle counting at sampling points around the respirator's perimeter. Three different respirators were tested together with a single hood having a tight-fitting seal. The method variation between measurements was low but increased appreciably when the protective ensemble was re-dressed between measurements. This demonstrates the difficulty of achieving a reliable and reproducible seal between respirator and hood under normal conditions. Different leakage patterns were observed for the three respirators and were linked to some specific design features, namely the respirator's sealing area at the chin and its width at cheek level. Induced leak experiments showed that to detect substantial particle leakage, channels at the hood-respirator interface must be quite large. The method outlined herein provides a straightforward way of evaluating hood-respirator interfaces and could be useful in the further development of personal protective equipment.

  3. Automated airway evaluation system for multi-slice computed tomography using airway lumen diameter, airway wall thickness and broncho-arterial ratio

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

    2006-03-01

    Pulmonary diseases such as bronchiectasis, asthma, and emphysema are characterized by abnormalities in airway dimensions. Multi-slice computed tomography (MSCT) has become one of the primary means to depict these abnormalities, as the availability of high-resolution near-isotropic data makes it possible to evaluate airways at oblique angles to the scanner plane. However, currently, clinical evaluation of airways is typically limited to subjective visual inspection only: systematic evaluation of the airways to take advantage of high-resolution data has not proved practical without automation. We present an automated method to quantitatively evaluate airway lumen diameter, wall thickness and broncho-arterial ratios. In addition, our method provides 3D visualization of these values, graphically illustrating the location and extent of disease. Our algorithm begins by automatic airway segmentation to extract paths to the distal airways, and to create a map of airway diameters. Normally, airway diameters decrease as paths progress distally; failure to taper indicates abnormal dilatation. Our approach monitors airway lumen diameters along each airway path in order to detect abnormal profiles, allowing even subtle degrees of pathologic dilatation to be identified. Our method also systematically computes the broncho-arterial ratio at every terminal branch of the tree model, as a ratio above 1 indicates potentially abnormal bronchial dilatation. Finally, the airway wall thickness is computed at corresponding locations. These measurements are used to highlight abnormal branches for closer inspection, and can be summed to compute a quantitative global score for the entire airway tree, allowing reproducible longitudinal assessment of disease severity. Preliminary tests on patients diagnosed with bronchiectasis demonstrated rapid identification of lack of tapering, which also was confirmed by corresponding demonstration of elevated broncho-arterial ratios.

  4. 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

  5. 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

  6. Sodium cromoglycate on plasma protein exudation to topically-applied substance P in the tracheal airways of rats or guinea-pigs in vivo.

    PubMed

    O'Donnell, S R; Coulson, F R; Bigg, C S

    2000-01-01

    Sodium cromoglycate (SCG) was examined against substance P(SP)-induced plasma protein exudation in the trachea of anaesthetized rats and guinea-pigs in vivo to determine whether SCG is a tachykinin receptor antagonist in the airways. A segment of trachea was prepared in situ for continuous perfusion with normal saline. Plasma-derived protein in the perfusion fluid (airway lumen) was increased after topical application of SP (1 microM, 5 min contact). In rats, the SP response was not attenuated by iv SCG but was inhibited (29%) by topical SCG under certain experimental conditions and using a high concentration of SCG (500 microM, 5 min contact, 30 min before SP and with SP). The NK(1)receptor antagonist, RP 67 580 (67 microM) abolished the SP response in rats. Sodium cromoglycate did not inhibit the SP response in guinea-pigs (same protocol as in rats). Thus, SCG attenuates plasma protein exudation (and presumably microvascular leak) induced by SP in rat tracheal airways but, if SCG is a tachykinin receptor (NK(1)) antagonist, it not only lacks potency but is species-selective, i.e. more effective in rats than in guinea-pigs.

  7. Air-leakage effects on stone cladding panels

    NASA Astrophysics Data System (ADS)

    Colantonio, Antonio

    1995-03-01

    This paper looks at the effects of air leakage on insulated stone clad precast panels used in present day construction of large commercial buildings. The building investigated was a newly built twenty story office building in a high density urban setting. Air leakage was suspected as a possible cause for thermal comfort complaints at isolated locations within the perimeter zones of the building. During the warrantee period the building owner asked for a quality control inspection of the air barrier assembly of the building envelope. Infrared thermography was used to locate areas of suspected air leakage within the building envelope. In order to differentiate thermal patterns produced by air leakage, conduction and convection as well as radiation from external sources, the building was inspected from the exterior; (1) after being pressurized for three hours, (2) one hour after the building was depressurized and (3) two and a half hours after total building depressurization was maintained by the building mechanical systems. Thermal images from similar locations were correlated for each time and pressure setting to verify air leakage locations within the building envelope. Areas exhibiting air leakage were identified and contractors were requested to carry out the necessary repairs. The pressure differential across the building envelope needs to be known in order to properly carry out an inspection to identify all locations of air leakage within a building envelope. As well the direction of the air movement and the density of the cladding material need to be accounted for in the proper inspection of these types of wall assemblies.

  8. Prehospital endotracheal tube airway or esophageal gastric tube airway: a critical comparison.

    PubMed

    Shea, S R; MacDonald, J R; Gruzinski, G

    1985-02-01

    This study compares two similar groups of patients in cardiopulmonary arrest with ventricular fibrillation (VF). In the survival study group of 296 patients, 148 patients received an endotracheal tube airway (ETA) and 148 patients received an esophageal gastric tube airway (EGTA), the improved version of the esophageal obturator airway (EOA). Survival rates, both short term (ETA = 35.8%, EGTA = 39.1%) and long term (ETA = 11.5%, EGTA = 16.2%), and neurological sequelae of survivors showed no statistically significant difference between the two groups (P greater than .05). In addition, we found that success and complication rates of intubation were similar. Training time was longer for the ETA. We conclude that both airways have a place in the prehospital setting.

  9. Expression of ligands for Siglec-8 and Siglec-9 in human airways and airway cells

    PubMed Central

    Jia, Yi; Yu, Huifeng; Fernandes, Steve M.; Wei, Yadong; Gonzalez-Gil, Anabel; Motari, Mary G.; Vajn, Katarina; Stevens, Whitney W.; Peters, Anju T.; Bochner, Bruce S.; Kern, Robert C.; Schleimer, Robert P.; Schnaar, Ronald L.

    2015-01-01

    Background Balanced activation and inhibition of the immune system ensures pathogen clearance while avoiding hyperinflammation. Siglecs, sialic acid binding proteins found on subsets of immune cells, often inhibit inflammation: Siglec-8 on eosinophils and Siglec-9 on neutrophils engage sialoglycan ligands on airways to diminish ongoing inflammation. The identities of human siglec ligands and their expression during inflammation are largely unknown. Objective The histological distribution, expression and molecular characteristics of siglec ligands were explored in healthy and inflamed human upper airways and in a cellular model of airway inflammation. Methods Normal and chronically inflamed upper airway tissues were stained for siglec ligands. The ligands were extracted from normal and inflamed tissues and from human Calu-3 cells for quantitative analysis by siglec blotting and isolation by siglec capture. Results Siglec-8 ligands were expressed on a subpopulation of submucosal gland cells of human inferior turbinate, whereas Siglec-9 ligands were expressed more broadly (submucosal glands, epithelium, connective tissue); both were significantly upregulated in chronic rhinosinusitis patients. Human airway (Calu-3) cells expressed Siglec-9 ligands on mucin 5B under inflammatory control via the NF-κB pathway, and mucin 5B carried sialoglycan ligands of Siglec-9 on human upper airway tissue. Conclusion Inflammation results in upregulation of immune inhibitory Siglec-8 and Siglec-9 sialoglycan ligands on human airways. Siglec-9 ligands were upregulated via the NF-κB pathway resulting in their enhanced expression on mucin 5B. Siglec sialoglycan ligand expression in inflamed cells and tissues may contribute to the control of airway inflammation. PMID:25747723

  10. Complications of upper airway surgery in companion animals.

    PubMed

    Mercurio, Andrew

    2011-09-01

    Surgery of the upper airway is performed in dogs for the correction of brachycephalic airway syndrome and laryngeal paralysis and for temporary or permanent tracheostomy. Although technically simple to perform, upper airway surgeries can lead to the development of significant postoperative complications. This article reviews complications associated with common surgical conditions of the upper airway. It involves a discussion of brachycephalic airway syndrome and associated respiratory and gastrointestinal complications. It also covers laryngeal paralysis with a focus on unilateral arytenoid lateralization and the complication of aspiration pneumonia. The condition of acquired laryngeal webbing/stenosis and potential treatment options is also discussed. Finally, tracheostomies and associated complications in dogs and cats are reviewed.

  11. Techniques of assessing small airways dysfunction

    PubMed Central

    McNulty, William; Usmani, Omar S.

    2014-01-01

    The small airways are defined as those less than 2 mm in diameter. They are a major site of pathology in many lung diseases, not least chronic obstructive pulmonary disease (COPD) and asthma. The small airways are frequently involved early in the course of these diseases, with significant pathology demonstrable often before the onset of symptoms or changes in spirometry and imaging. Despite their importance, they have proven relatively difficult to study. This is in part due to their relative inaccessibility to biopsy and their small size which makes their imaging difficult. Traditional lung function tests may only become abnormal once there is a significant burden of disease within them. This has led to the term ‘the quiet zone’ of the lung. In recent years, more specialised tests have been developed which may detect these changes earlier, perhaps offering the possibility of earlier diagnosis and intervention. These tests are now moving from the realms of clinical research laboratories into routine clinical practice and are increasingly useful in the diagnosis and monitoring of respiratory diseases. This article gives an overview of small airways physiology and some of the routine and more advanced tests of airway function. PMID:26557240

  12. Reproducibility of airway wall thickness measurements

    NASA Astrophysics Data System (ADS)

    Schmidt, Michael; Kuhnigk, Jan-Martin; Krass, Stefan; Owsijewitsch, Michael; de Hoop, Bartjan; Peitgen, Heinz-Otto

    2010-03-01

    Airway remodeling and accompanying changes in wall thickness are known to be a major symptom of chronic obstructive pulmonary disease (COPD), associated with reduced lung function in diseased individuals. Further investigation of this disease as well as monitoring of disease progression and treatment effect demand for accurate and reproducible assessment of airway wall thickness in CT datasets. With wall thicknesses in the sub-millimeter range, this task remains challenging even with today's high resolution CT datasets. To provide accurate measurements, taking partial volume effects into account is mandatory. The Full-Width-at-Half-Maximum (FWHM) method has been shown to be inappropriate for small airways1,2 and several improved algorithms for objective quantification of airway wall thickness have been proposed.1-8 In this paper, we describe an algorithm based on a closed form solution proposed by Weinheimer et al.7 We locally estimate the lung density parameter required for the closed form solution to account for possible variations of parenchyma density between different lung regions, inspiration states and contrast agent concentrations. The general accuracy of the algorithm is evaluated using basic tubular software and hardware phantoms. Furthermore, we present results on the reproducibility of the algorithm with respect to clinical CT scans, varying reconstruction kernels, and repeated acquisitions, which is crucial for longitudinal observations.

  13. Airway-parenchyma uncoupling in nocturnal asthma.

    PubMed

    Irvin, C G; Pak, J; Martin, R J

    2000-01-01

    Airway flow resistance is well known to be dependent upon lung volume. The rise in lung volume that occurs in asthma is therefore thought to be an important mechanism that defends airway patency. The purpose of the current study was to investigate the interdependence or mechanical coupling between airways and lung parenchyma during the inflammatory processes that occur in the patient with nocturnal asthma. Five patients with documented nocturnal asthma were studied in both a vertical and a horizontal body plethysmograph. Lung volume was altered with continuous negative pressure as applied to the chest wall with a poncho cuirass in different postures and during sleep. We found during the awake phase that an increase in lung volume decreased lower pulmonary resistance (Rlp); however, within 30 min of sleep onset, functional residual capacity (FRC) fell and Rlp rose more than would be expected for the fall in FRC. Restoring FRC to presleep values either at an early (half-hour) or a late (3-h) time point did not cause Rlp to significantly fall. A second phase of the study showed that the loss of Rlp dependence on lung volume was not due to the assumption of the supine posture. Indirect measurements of lung compliance were consistent with a stiffening of the lung. We conclude that with sleep there is an immediate uncoupling of the parenchyma to the airway, resulting in a loss of interdependence that persists throughout sleep and may contribute to the morbidity and mortality associated with nocturnal asthma.

  14. Quercetin Blocks Airway Epithelial Cell Chemokine Expression

    PubMed Central

    Nanua, Suparna; Zick, Suzanna M.; Andrade, Juan E.; Sajjan, Umadevi S.; Burgess, John R.; Lukacs, Nicholas W.; Hershenson, Marc B.

    2006-01-01

    Quercetin (3,3′,4′,5,7-pentahydroxyflavone), a dietary flavonoid, is an inhibitor of phosphatidylinositol (PI) 3-kinase and potent antioxidant. We hypothesized that quercetin blocks airway epithelial cell chemokine expression via PI 3-kinase–dependent mechanisms. Pretreatment with quercetin and the PI 3–kinase inhibitor LY294002 each reduced TNF-α–induced IL-8 and monocyte chemoattractant protein (MCP)-1 (also called CCL2) expression in cultured human airway epithelial cells. Quercetin also inhibited TNF-α–induced PI 3-kinase activity, Akt phosphorylation, intracellular H2O2 production, NF-κB transactivation, IL-8 promoter activity, and steady-state mRNA levels, consistent with the notion that quercetin inhibits chemokine expression by attenuating NF-κB transactivation via a PI 3-kinase/Akt-dependent pathway. Quercetin also reduced TNF-α–induced chemokine secretion in the presence of the transcriptional inhibitor actinomycin D, while inducing phosphorylation of eukaryotic translation initiation factor (eIF)-2α, suggesting that quercetin attenuates chemokine expression by post-transcriptional as well as transcriptional mechanisms. Finally, we tested the effects of quercetin in cockroach antigen–sensitized and –challenged mice. These mice show MCP-1–dependent airways hyperresponsiveness and inflammation. Quercetin significantly reduced lung MCP-1 and methacholine responsiveness. We conclude that quercetin blocks airway cell chemokine expression via transcriptional and post-transcriptional pathways. PMID:16794257

  15. COLCHICINE DECREASES AIRWAY HYPERACTIVITY AFTER PHOSGENE EXPOSURE

    EPA Science Inventory

    Phosgene (COCl(2)) exposure affects an influx of inflammatory cells into the lung, which can be reduced in an animal model by pretreatment with colchicine. Inflammation in the respiratory tract can be associated with an increase in airway hyperreactivity. We tested the hypotheses...

  16. Osmotic regulation of airway reactivity by epithelium.

    PubMed

    Fedan, J S; Yuan, L X; Chang, V C; Viola, J O; Cutler, D; Pettit, L L

    1999-05-01

    Inhalation of nonisotonic solutions can elicit pulmonary obstruction in asthmatic airways. We evaluated the hypothesis that the respiratory epithelium is involved in responses of the airways to nonisotonic solutions using the guinea pig isolated, perfused trachea preparation to restrict applied agents to the mucosal (intraluminal) or serosal (extraluminal) surface of the airway. In methacholine-contracted tracheae, intraluminally applied NaCl or KCl equipotently caused relaxation that was unaffected by the cyclo-oxygenase inhibitor, indomethacin, but was attenuated by removal of the epithelium and Na+ and Cl- channel blockers. Na+-K+-2Cl- cotransporter and nitric oxide synthase blockers caused a slight inhibition of relaxation, whereas Na+,K+-pump inhibition produced a small potentiation. Intraluminal hyperosmolar KCl and NaCl inhibited contractions in response to intra- or extraluminally applied methacholine, as well as neurogenic cholinergic contractions elicited with electric field stimulation (+/- indomethacin). Extraluminally applied NaCl and KCl elicited epithelium-dependent relaxation (which for KCl was followed by contraction). In contrast to the effects of hyperosmolarity, intraluminal hypo-osmolarity caused papaverine-inhibitable contractions (+/- epithelium). These findings suggest that the epithelium is an osmotic sensor which, through the release of epithelium-derived relaxing factor, can regulate airway diameter by modulating smooth muscle responsiveness and excitatory neurotransmission.

  17. Quantitative analysis of airway abnormalities in CT

    NASA Astrophysics Data System (ADS)

    Petersen, Jens; Lo, Pechin; Nielsen, Mads; Edula, Goutham; Ashraf, Haseem; Dirksen, Asger; de Bruijne, Marleen

    2010-03-01

    A coupled surface graph cut algorithm for airway wall segmentation from Computed Tomography (CT) images is presented. Using cost functions that highlight both inner and outer wall borders, the method combines the search for both borders into one graph cut. The proposed method is evaluated on 173 manually segmented images extracted from 15 different subjects and shown to give accurate results, with 37% less errors than the Full Width at Half Maximum (FWHM) algorithm and 62% less than a similar graph cut method without coupled surfaces. Common measures of airway wall thickness such as the Interior Area (IA) and Wall Area percentage (WA%) was measured by the proposed method on a total of 723 CT scans from a lung cancer screening study. These measures were significantly different for participants with Chronic Obstructive Pulmonary Disease (COPD) compared to asymptomatic participants. Furthermore, reproducibility was good as confirmed by repeat scans and the measures correlated well with the outcomes of pulmonary function tests, demonstrating the use of the algorithm as a COPD diagnostic tool. Additionally, a new measure of airway wall thickness is proposed, Normalized Wall Intensity Sum (NWIS). NWIS is shown to correlate better with lung function test values and to be more reproducible than previous measures IA, WA% and airway wall thickness at a lumen perimeter of 10 mm (PI10).

  18. Access to the Airways: Rationale and Applications.

    ERIC Educational Resources Information Center

    Hanks, William; Longini, Peter

    Current movements toward greater public access to the airways are discussed. Traditional practices have limited access to journalists employed by stations and to those who purchase time and have allowed only limited responses to station-initiated editorials. Legal arguments that support citizen demands for more access arise from the First…

  19. Upper Airway Variation and Frequent Alcohol Consumption Can Affect Compliance With Continuous Positive Airway Pressure

    PubMed Central

    Jeong, Jong In; Kim, Hyo Yeol; Hong, Sang Duk; Ryu, Gwanghui; Kim, Su Jin; Lee, Kyung Eun; Dhong, Hun-Jong; Chung, Seung-Kyu

    2016-01-01

    Objectives Compliance with continuous positive airway pressure (CPAP) treatment remains a primary concern for improving treatment outcomes of obstructive sleep apnea. There are few studies that have considered the role of upper airway anatomy on the compliance with CPAP. We hypothesized that upper airway anatomy would influence the compliance with CPAP. Methods One hundred out of 161 consecutive patients were enrolled in this study. The following possible determinants were tested against CPAP use: demographic and anthropometric data, minimal cross-sectional area on acoustic rhinometry, cephalometric and polysomnographic data, questionnaires of Epworth sleepiness scale and Beck depression index, and histories of previous upper airway surgery, degree of nasal obstruction, daily cigarette consumption, and weekly frequency of alcohol intake. Results Univariate analysis showed that histories of previous upper airway surgery and less frequent alcohol consumption, and longer mandibular plane-hyoid length (MP-H) on cephalometry were associated with longer average daily CPAP use. After adjustment for the confounding factors with multiple linear regression analysis, alcohol consumption and MP-H were still associated with the compliance with CPAP significantly. Conclusion To improve compliance with CPAP, careful evaluations of upper airway problems and life style are important before initiating CPAP. PMID:27334512

  20. Instantaneous Leakage Evaluation of Metal Cask at Drop Impact

    SciTech Connect

    Hirofumi Takeda; Norihiro Kageyama; Masumi Wataru; Ryoji Sonobe; Koji Shirai; Toshiari Saegusa

    2006-07-01

    There have been a lot of tests and analyses reported for evaluation of drop tests of metal casks. However, no quantitative measurement has ever been made for any instantaneous leakage through metal gaskets during the drop tests due to loosening of the bolts in the containments and lateral sliding of the lids. In order to determine a source term for radiation exposure dose assessment, it is necessary to obtain fundamental data of instantaneous leakage. In this study, leak tests were performed by using scale models of the lid structure and a full scale cask without impact limiters simulating drop accidents in a storage facility, with aim of measuring and evaluating any instantaneous leakage at drop impact. Prior to drop tests of a full scale metal cask, a series of leakage tests using scale models were carried out to establish the measurement method and to examine a relationship between the amount of the lateral sliding of the lid and the leak rate. It was determined that the leak rate did not depend on the lateral sliding speeds. Drop tests of a full scale metal cask without impact limiters were carried out by simulating drop accidents during handling in a storage facility. The target was designed to simulate a reinforced concrete floor in the facility. The first test was a horizontal drop from a height of 1 m. The second test simulated a rotational impact around an axis of a lower trunnion of the cask from the horizontal status at a height of 1 m. In the horizontal drop test, the amount of helium gas leakage was calculated by integrating the leak rate with time. The total amount of helium gas leakage from the primary and secondary lids was 1.99 x 10{sup -6} Pa.m{sup 3}. This value is 9.61 x 10{sup -9}% of the initially installed helium gas. The amount of leakage was insignificant. In the rotational drop test, the total amount of leakage from the primary and secondary lids was 1.74 x 10{sup -5} Pa.m{sup 3}. This value is 8.45 x 10{sup -8}% of the initially installed

  1. Gas-path leakage seal for a gas turbine

    DOEpatents

    Wolfe, Christopher E.; Dinc, Osman S.; Bagepalli, Bharat S.; Correia, Victor H.; Aksit, Mahmut F.

    1996-01-01

    A gas-path leakage seal for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the "plane" of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member.

  2. Gas-path leakage seal for a gas turbine

    DOEpatents

    Wolfe, C.E.; Dinc, O.S.; Bagepalli, B.S.; Correia, V.H.; Aksit, M.F.

    1996-04-23

    A gas-path leakage seal is described for generally sealing a gas-path leakage-gap between spaced-apart first and second members of a gas turbine (such as combustor casing segments). The seal includes a generally imperforate foil-layer assemblage which is generally impervious to gas and is located in the leakage-gap. The seal also includes a cloth-layer assemblage generally enclosingly contacting the foil-layer assemblage. In one seal, the first edge of the foil-layer assemblage is left exposed, and the foil-layer assemblage resiliently contacts the first member near the first edge to reduce leakage in the ``plane`` of the cloth-layer assemblage under conditions which include differential thermal growth of the two members. In another seal, such leakage is reduced by having a first weld-bead which permeates the cloth-layer assemblage, is attached to the metal-foil-layer assemblage near the first edge, and unattachedly contacts the first member. 4 figs.

  3. Suppression and control of leakage field in electromagnetic helical microwiggler

    SciTech Connect

    Ohigashi, N.; Tsunawaki, Y.; Imasaki, K.

    1995-12-31

    Shortening the period of electromagnetic wiggler introduces both the radical increase of the leakage field and the decrease of the field in the gap region. The leakage field is severer problem in planar electromagnetic wiggler than in helical wiggler. Hence, in order to develop a short period electromagnetic wiggler, we have adopted {open_quotes}three poles per period{close_quotes} type electromagnetic helical microwiggler. In this work, we inserted the permanent magnet (PM) blocks with specific magnetized directions in the space between magnetic poles, for suppressing the leakage field flowing out from a pole face to the neighboring pole face. These PM-blocks must have higher intrinsic coersive force than saturation field of pole material. The gap field due to each pole is adjustable by controlling the leakage fields, that is, controlling the position of each iron screw set in each retainer fixing the PM-blocks. At present time, a test wiggler with period 7.8mm, periodical number 10 and gap length 4.6mm has been manufactured. Because the ratio of PM-block aperture to gap length is important parameter to suppress the leakage field, the parameter has been surveyed experimentally for PM-blocks with several dimensions of aperture. The field strength of 3-5kG (K=0.2-0.4) would be expected in the wiggler.

  4. Estimation of airway obstruction using oximeter plethysmograph waveform data

    PubMed Central

    Arnold, Donald H; Spiro, David M; Desmond, Renee' A; Hagood, James S

    2005-01-01

    Background Validated measures to assess the severity of airway obstruction in patients with obstructive airway disease are limited. Changes in the pulse oximeter plethysmograph waveform represent fluctuations in arterial flow. Analysis of these fluctuations might be useful clinically if they represent physiologic perturbations resulting from airway obstruction. We tested the hypothesis that the severity of airway obstruction could be estimated using plethysmograph waveform data. Methods Using a closed airway circuit with adjustable inspiratory and expiratory pressure relief valves, airway obstruction was induced in a prospective convenience sample of 31 healthy adult subjects. Maximal change in airway pressure at the mouthpiece was used as a surrogate measure of the degree of obstruction applied. Plethysmograph waveform data and mouthpiece airway pressure were acquired for 60 seconds at increasing levels of inspiratory and expiratory obstruction. At each level of applied obstruction, mean values for maximal change in waveform area under the curve and height as well as maximal change in mouth pressure were calculated for sequential 7.5 second intervals. Correlations of these waveform variables with mouth pressure values were then performed to determine if the magnitude of changes in these variables indicates the severity of airway obstruction. Results There were significant relationships between maximal change in area under the curve (P < .0001) or height (P < 0.0001) and mouth pressure. Conclusion The findings suggest that mathematic interpretation of plethysmograph waveform data may estimate the severity of airway obstruction and be of clinical utility in objective assessment of patients with obstructive airway diseases. PMID:15985171

  5. Deposition of Graphene Nanoparticles in Human Upper Airways

    PubMed Central

    Su, Wei-Chung; Ku, Bon-Ki; Kulkarni, Pramod; Cheng, Yung Sung

    2016-01-01

    Graphene nanomaterials have attracted wide attention in recent years on their application to state-of-the-art technology due to their outstanding physical properties. On the other hand, the nanotoxicity of graphene materials also has rapidly become a serious concern especially in occupational health. Graphene materials inevitably could become airborne in the workplace during manufacturing processes. The inhalation and subsequent deposition of graphene nanoparticles in the human respiratory tract could potentially result in adverse health effects to exposed workers. Therefore, investigating the deposition of graphene nanoparticles in the human airways is considered essential for an integral graphene occupational health study. For this reason, this study carried out a series of airway replica deposition experiments to obtain original data of graphene nanoparticle airway deposition. In this study, size classified graphene nanoparticles were delivered into human airway replicas (both nasal and oral-to-lung airways). The deposition fraction and efficiency of graphene nanoparticle in the airway were obtained by a novel experimental approach. The experimental results acquired showed that the fractional deposition of graphene nanoparticles in airway sections studied were all less than 4%, and the deposition efficiencies in each airway section were generally lower than 0.03. These results implies that the majority of the graphene nanoparticles inhaled into the human respiratory tract could easily penetrate through the head airways as well as the upper part of the tracheobronchial airways and then transit down to the lower lung airways, where undesired biological responses might be induced. PMID:26317666

  6. Protective effects of anisodamine on cigarette smoke extract-induced airway smooth muscle cell proliferation and tracheal contractility

    SciTech Connect

    Xu, Guang-Ni; Yang, Kai; Xu, Zu-Peng; Zhu, Liang; Hou, Li-Na; Qi, Hong; Chen, Hong-Zhuan Cui, Yong-Yao

    2012-07-01

    Anisodamine, an antagonist of muscarinic acetylcholine receptors (mAChRs), has been used therapeutically to improve smooth muscle function, including microvascular, intestinal and airway spasms. Our previous studies have revealed that airway hyper-reactivity could be prevented by anisodamine. However, whether anisodamine prevents smoking-induced airway smooth muscle (ASM) cell proliferation remained unclear. In this study, a primary culture of rat ASM cells was used to evaluate an ASM phenotype through the ability of the cells to proliferate and express contractile proteins in response to cigarette smoke extract (CSE) and intervention of anisodamine. Our results showed that CSE resulted in an increase in cyclin D1 expression concomitant with the G0/G1-to-S phase transition, and high expression of M2 and M3. Functional studies showed that tracheal hyper-contractility accompanied contractile marker α-SMA high-expression. These changes, which occur only after CSE stimulation, were prevented and reversed by anisodamine, and CSE-induced cyclin D1 expression was significantly inhibited by anisodamine and the specific inhibitor U0126, BAY11-7082 and LY294002. Thus, we concluded that the protective and reversal effects and mechanism of anisodamine on CSE-induced events might involve, at least partially, the ERK, Akt and NF-κB signaling pathways associated with cyclin D1 via mAChRs. Our study validated that anisodamine intervention on ASM cells may contribute to anti-remodeling properties other than bronchodilation. -- Highlights: ► CSE induces tracheal cell proliferation, hyper-contractility and α-SMA expression. ► Anisodamine reverses CSE-induced tracheal hyper-contractility and cell proliferation. ► ERK, PI3K, and NF-κB pathways and cyclin D1 contribute to the reversal effect.

  7. Airway evaluation in obstructive sleep apnea.

    PubMed

    Stuck, Boris A; Maurer, Joachim T

    2008-12-01

    As the interest in sleep-disordered breathing has increased, various attempts have been made to assess upper airway anatomy in patients with this relatively frequent disorder. The aim is not only to reveal potential differences in upper airway anatomy to better understand origin and pathophysiology of the disease but also to improve patient management and treatment success. The present review is based on a systematic literature search with regard to upper airway evaluation in sleep-disordered breathing; the articles were selected and discussed in light of our clinical experiences. Based on clinical assessment including endoscopy during wakefulness, the value of the Mueller Maneuver, static radiologic imaging techniques (X-ray cephalometry, computed tomography (CT) scanning and magnetic resonance imaging (MRI)), dynamic scanning protocols (e.g. ultrafast CT or cine MRI), upper airway endoscopy during sleep and sedated sleep, pressure measurements and the assessment of the critical closing pressure are discussed. Each technique itself and its history in the field of sleep medicine are briefly reviewed and problems of standardization and interpretation are discussed when appropriate. Insights into the pathophysiology of the disease gained with the help of the investigational techniques are presented and the impact of the techniques on patient management is reported. Although all these additional techniques for upper airway assessment have substantially improved our understanding of sleep-disordered breathing, their significance in daily practice is limited. In contrast to the widespread use of the Mueller maneuver and sedated endoscopy, convincing data supporting their use in terms of treatment outcome are lacking. So far, there is only very limited evidence that selected techniques improve treatment outcome for selected indications. In general, there is not enough evidence that these techniques are superior to the routine clinical assessment.

  8. The Diagnosis and Management of Airway Complications Following Lung Transplantation.

    PubMed

    Mahajan, Amit K; Folch, Erik; Khandhar, Sandeep J; Channick, Colleen L; Santacruz, Jose F; Mehta, Atul C; Nathan, Steven D

    2017-03-05

    Airway complications following lung transplantation result in considerable morbidity and are associated with a mortality of 2-4 percent. The incidence of lethal and non-lethal airway complications has decreased since the early experiences with double- and single-lung transplantation. The most common risk factor associated with post-lung transplant airway complications is anastomotic ischemia. Airway complications include development of exophytic granulation tissue, bronchial stenosis, bronchomalacia, airway fistula, endobronchial infection, and anastomotic dehiscence. The broadening array of bronchoscopic therapies has enhanced treatment options for lung transplant recipients with airway complications. This article reviews the risk factors, clinical manifestations, and treatments of airway complications following lung transplantation, and provides our expert opinion where evidence is lacking.

  9. BLUNTING AIRWAYS EOSINOPHILIC INFLAMMATION RESULTS IN A DECREASED AIRWAY NEUTROPHIL RESPONSE TO INHALED LPS IN ATOPIC ASTHMATICS A ROLE FOR CD-14

    EPA Science Inventory

    Recent data demonstrate that atopic inflammation might enhance airway responses to inhaled LPS in individuals with atopic asthma by increasing CD14 expression on airway macrophages. We sought to determine whether blunting airway eosinophilic inflammation decreases CD14 expressio...

  10. Effect of acetylsalicylic acid on microvascular thrombosis in autologous breast reconstruction.

    PubMed

    Enajat, Morteza; Aziz Mohammadi, Mujzgan; Debeij, Jan; van der Hulst, Rene R W J; Mureau, Marc A M

    2014-01-01

    Although advances in microsurgery have increased success rates of autologous breast reconstruction, microvascular thrombosis still remains a major concern as a cause of flap failure. At present, no evidence-based guidelines on pharmacological prevention of microvascular thrombosis exist. This study investigates the effect of acetylsalicylic acid on the incidence of microvascular complications in patients undergoing autologous breast reconstruction. Patients undergoing deep inferior epigastric artery perforator or free transverse rectus abdominis myocutaneous flap breast reconstruction at two academic centers in the Netherlands between 2005 and 2011 were included. Patients at one center received once daily 0.6 mL of nadroparine and 40 mg acetylsalicylic acid, while patients at the other center received 0.6 mL nadroparine only. A total of 430 consecutive patients underwent 592 breast reconstructions. No statistically significant differences were found between the two groups in the incidence of flap failure (2.8 and 2.5%), microvascular thromboembolic complications (2.6 and 3.8%), venous congestion (3.4 and 2.8%), or overall complications (28.0 and 32.3%). Hematoma tended to occur more often in the group receiving acetylsalicylic acid (9.2 and 4.7%).It was found that no protective effect of acetylsalicylic acid on microvascular complications was present. Given its known risks and the somewhat increased occurrence of hematoma in the present study, we stopped to routinely administer acetylsalicylic acid after autologous breast reconstruction.

  11. Host defenses to Rickettsia rickettsii infection contribute to increased microvascular permeability in human cerebral endothelial cells.

    PubMed

    Woods, Michael E; Olano, Juan P

    2008-03-01

    Rickettsiae are arthropod-borne intracellular bacterial pathogens that primarily infect the microvascular endothelium leading to systemic spread of the organisms and the major pathophysiological effect, increased microvascular permeability, and edema in vital organs such as the lung and brain. Much work has been done on mechanisms of immunity to rickettsiae, as well as the responses of endothelial cells to rickettsial invasion. However, to date, no one has described the mechanisms of increased microvascular permeability during acute rickettsiosis. We sought to establish an in vitro model of human endothelial-target rickettsial infection using the etiological agent of Rocky Mountain spotted fever, Rickettsia rickettsii, and human cerebral microvascular endothelial cells. Endothelial cells infected with R. rickettsii exhibited a dose-dependent decrease in trans-endothelial electrical resistance, which translates into increased monolayer permeability. Additionally, we showed that the addition of pro-inflammatory stimuli essential to rickettsial immunity dramatically enhanced this effect. This increase in permeability correlates with dissociation of adherens junctions between endothelial cells and is not dependent on the presence of nitric oxide. Taken together, these results demonstrate for the first time that increased microvascular permeability associated with rickettsial infection is partly attributable to intracellular rickettsiae and partly attributable to the immune defenses that have evolved to protect the host from rickettsial spread.

  12. Conditioned Media from Microvascular Endothelial Cells Cultured in Simulated Microgravity Inhibit Osteoblast Activity

    PubMed Central

    Cazzaniga, Alessandra; Castiglioni, Sara; Maier, Jeanette A. M.

    2014-01-01

    Background and Aims. Gravity contributes to the maintenance of bone integrity. Accordingly, weightlessness conditions during space flight accelerate bone loss and experimental models in real and simulated microgravity show decreased osteoblastic and increased osteoclastic activities. It is well known that the endothelium and bone cells cross-talk and this intercellular communication is vital to regulate bone homeostasis. Because microgravity promotes microvascular endothelial dysfunction, we anticipated that the molecular cross-talk between endothelial cells exposed to simulated microgravity and osteoblasts might be altered. Results. We cultured human microvascular endothelial cells in simulated microgravity using the rotating wall vessel device developed by NASA. Endothelial cells in microgravity show growth inhibition and release higher amounts of matrix metalloproteases type 2 and interleukin-6 than controls. Conditioned media collected from microvascular endothelial cells in simulated microgravity were used to culture human osteoblasts and were shown to retard osteoblast proliferation and inhibit their activity. Discussion. Microvascular endothelial cells in microgravity are growth retarded and release high amounts of matrix metalloproteases type 2 and interleukin-6, which might play a role in retarding the growth of osteoblasts and impairing their osteogenic activity. Conclusions. We demonstrate that since simulated microgravity modulates microvascular endothelial cell function, it indirectly impairs osteoblastic function. PMID:25210716

  13. Mst1 inhibits CMECs autophagy and participates in the development of diabetic coronary microvascular dysfunction

    PubMed Central

    Lin, Jie; Zhang, Lei; Zhang, Mingming; Hu, Jianqiang; Wang, Tingting; Duan, Yu; Man, Wanrong; Wu, Bin; Feng, Jiaxu; Sun, Lei; Li, Congye; Zhang, Rongqing; Wang, Haichang; Sun, Dongdong

    2016-01-01

    Cardiovascular complications account for a substantial proportion of morbidity and mortality in diabetic patients. Abnormalities of cardiac microvascular endothelial cells (CMECs) lead to impaired cardiac microvascular vessel integrity and subsequent cardiac dysfunction, underlining the importance of coronary microvascular dysfunction. In this study, experimental diabetes models were constructed using Mst1 transgenic, Mst1 knockout and sirt1 knockout mice. Diabetic Mst1 transgenic mice exhibited impaired cardiac microvessel integrity and decreased cardiac function. Mst1 overexpression deceased CMECs autophagy as evidenced by decreased LC3 expression and enhanced protein aggregation when subjected to high glucose culture. Mst1 knockout improved cardiac microvessel integrity and enhanced cardiac functions in diabetic mice. Mst1 knockdown up-regulated autophagy as indicated by more typical autophagosomes and increased LC3 expression in CMECs subjected to high glucose cultures. Mst1 knockdown also promoted autophagic flux in the presence of bafilomycin A1. Mst1 overexpression increased CMECs apoptosis, whereas Mst1 knockout decreased CMECs apoptosis. Sirt1 knockout abolished the effects of Mst1 overexpression in cardiac microvascular injury and cardiac dysfunction. In conclusion, Mst1 knockout preserved cardiac microvessel integrity and improved cardiac functions in diabetic mice. Mst1 decreased sirt1 activity, inhibited autophagy and enhanced apoptosis in CMECs, thus participating in the pathogenesis of diabetic coronary microvascular dysfunction. PMID:27680548

  14. Methylene blue solder re-absorption in microvascular anastomoses

    NASA Astrophysics Data System (ADS)

    Birch, Jeremy F.; Hepplewhite, J.; Frier, Malcolm; Bell, Peter R. F.

    2003-06-01

    Soldered vascular anastomoses have been reported using several chromophores but little is known of the optimal conditions for microvascular anastomosis. There are some indications of the optimal protein contents of a solder, and the effects of methylene blue on anastomotic strength. The effects of varying laser power density in vivo have also been described, showing a high rate of thrombosis with laser power over 22.9Wcm-2. However no evidence exists to describe how long the solder remains at the site of the anastomosis. Oz et al reported that the fibrin used in their study had been almost completely removed by 90 days but without objective evidence of solder removal. In order to address the issue of solder re-absorption from the site of an anastomosis we used radio-labelled albumin (I-125) incorporated into methylene blue based solder. This was investigated in both the situation of the patent and thrombosed anastomosis with anastomoses formed at high and low power. Iodine-125 (half life: 60.2 days) was covalently bonded to porcine albumin and mixed with the solder solution. Radio-iodine has been used over many years to determine protein turnover using either I-125 or I-131. Iodine-125 labelled human albumin is regularly used as a radiopharmaceutical tool for the determination of plasma volume. Radio-iodine has the advantages of not affecting protein metabolism and the label is rapidly excreted after metabolic breakdown. Labelling with chromium (Cr-51) causes protein denaturation and is lost from the protein with time. Labelled albumin has been reported in human studies over a 21-day period, with similar results reported by Matthews. Most significantly McFarlane reported a different rate of catabolism of I-131 and I-125 over a 22-day period. The conclusion from this is that the rate of iodine clearance is a good indicator of protein catabolism. In parallel with the surgery a series of blank standards were prepared with a known mass of solder to correct for isotope

  15. Novel Biomarkers of Arterial and Venous Ischemia in Microvascular Flaps

    PubMed Central

    Nguyen, Gerard K.; Monahan, John F. W.; Davis, Gabrielle B.; Lee, Yong Suk; Ragina, Neli P.; Wang, Charles; Zhou, Zhao Y.; Hong, Young Kwon; Spivak, Ryan M.; Wong, Alex K.

    2013-01-01

    both diagnose and successfully treat microvascular complications before irreversible tissue damage and flap loss occurs. PMID:23977093

  16. Microvascular Fragment Transplantation Improves Rat Dorsal Skin Flap Survival

    PubMed Central

    Rathbone, Christopher R.

    2016-01-01

    Background: The development of flap necrosis distally remains a concern during microsurgical flap transfers because, at least in part, of decreased perfusion. Microvascular fragments (MVFs) are microvessels isolated from adipose tissue that are capable of improving tissue perfusion in a variety of tissue defects. The aim of this study was to determine whether the transplantation of MVFs in a dorsal rat skin flap model can improve flap survival. Methods: A 10 × 3 cm flap was raised in a cranial to caudal fashion on the dorsal side of 16 Lewis rats, with the caudal side remaining intact. The rats were equally divided into a treatment group (MVFs) and a control group (sterile saline). At the time of surgery, sterile saline with or without MVFs was injected directly into the flap. Microvessel density was determined after harvesting flap tissue by counting vessels that positively stained for Griffonia simplicifolia lectin I-isolectin B4. Laser Doppler was used to measure blood flow before and after surgery and 7 and 14 days later. Flap survival was evaluated 7 and 14 days after surgery by evaluating the percentage of viable tissue of the flap with photodigital planimetry. Results: Despite the lack of a significant difference in microvessel density and tissue perfusion, flap survival increased 6.4% (P < 0.05) in MVF-treated animals compared with controls. Conclusions: The use of MVFs may be a means to improve flap survival. Future studies are required to delineate mechanisms whereby this occurs and to further optimize their application. PMID:28293502

  17. Detection of Upper Airway Status and Respiratory Events by a Current Generation Positive Airway Pressure Device

    PubMed Central

    Li, Qing Yun; Berry, Richard B.; Goetting, Mark G.; Staley, Bethany; Soto-Calderon, Haideliza; Tsai, Sheila C.; Jasko, Jeffrey G.; Pack, Allan I.; Kuna, Samuel T.

    2015-01-01

    Study Objectives: To compare a positive airway pressure (PAP) device's detection of respiratory events and airway status during device-detected apneas with events scored on simultaneous polysomnography (PSG). Design: Prospective PSGs of patients with sleep apnea using a new-generation PAP device. Settings: Four clinical and academic sleep centers. Patients: Forty-five patients with obstructive sleep apnea (OSA) and complex sleep apnea (Comp SA) performed a PSG on PAP levels adjusted to induce respiratory events. Interventions: None. Measurements and Results: PAP device data identifying the type of respiratory event and whether the airway during a device-detected apnea was open or obstructed were compared to time-synced, manually scored respiratory events on simultaneous PSG recording. Intraclass correlation coefficients between device-detected and PSG scored events were 0.854 for apnea-hypopnea index (AHI), 0.783 for apnea index, 0.252 for hypopnea index, and 0.098 for respiratory event-related arousals index. At a device AHI (AHIFlow) of 10 events/h, area under the receiver operating characteristic curve was 0.98, with sensitivity 0.92 and specificity 0.84. AHIFlow tended to overestimate AHI on PSG at values less than 10 events/h. The device detected that the airway was obstructed in 87.4% of manually scored obstructive apneas. Of the device-detected apneas with clear airway, a minority (15.8%) were manually scored as obstructive apneas. Conclusions: A device-detected apnea-hypopnea index (AHIFlow) < 10 events/h on a positive airway pressure device is strong evidence of good treatment efficacy. Device-detected airway status agrees closely with the presumed airway status during polysomnography scored events, but should not be equated with a specific type of respiratory event. Citation: Li QY, Berry RB, Goetting MG, Staley B, Soto-Calderon H, Tsai SC, Jasko JG, Pack AI, Kuna ST. Detection of upper airway status and respiratory events by a current generation positive

  18. Identifying and Managing Gas Leakage from Subsurface Sources

    NASA Astrophysics Data System (ADS)

    Benson, S. M.

    2015-12-01

    Subsurface gas accumulations exist from both natural sources such as hydrocarbon reservoirs, as well as, man-made sources such as natural gas storage, gas pipelines, CO2 storage, or even H2 storage. Both natural and manmade sources of subsurface gases have the potential to leak to the surface. Leakage can cause safety hazards and detrimental impacts associated with the release of greenhouse gases into the atmosphere. Leak management, which involves identifying, characterizing, assessing, and remediating leakage requires a coordinated and systematic approach to effectively deal with these occurrences. Here an overall workflow for leak management is presented, along with technological options and challenges for successful implementation. Many tools and approaches for leak management are available and in use today. However, the increased attention to leakage from a larger variety of sources, particularly associated with legacy facilities and infrastructure, raises new issues and challenges that are highlighted here.

  19. Dynamic sealing principles. [design configurations for fluid leakage control

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    The fundamental principles governing dynamic sealing operation are discussed. Different seals are described in terms of these principles. Despite the large variety of detailed construction, there appear to be some basic principles, or combinations of basic principles, by which all seals function. They are: (1) selection and control of seal geometry, (2) control of leakage fluid properties, and (3) control of forces acting on leakage fluids. Theoretical and practical considerations in the application of these principles are discussed. Advantages, disadvantages, limitations, and application examples of various conventional and special seals are presented. Fundamental equations governing liquid and gas flows in thin-film seals, which enable leakage calculations to be made, are also presented.

  20. Crack detection and leakage monitoring on reinforced concrete pipe

    NASA Astrophysics Data System (ADS)

    Feng, Qian; Kong, Qingzhao; Huo, Linsheng; Song, Gangbing

    2015-11-01

    Reinforced concrete underground pipelines are some of the most widely used types of structures in water transportation systems. Cracks and leakage are the leading causes of pipeline structural failures which directly results in economic losses and environmental hazards. In this paper, the authors propose a piezoceramic based active sensing approach to detect the cracks and the further leakage of concrete pipelines. Due to the piezoelectric properties, piezoceramic material can be utilized as both the actuator and the sensor in the active sensing approach. The piezoceramic patch, which is sandwiched between protective materials called ‘smart aggregates,’ can be safely embedded into concrete structures. Circumferential and axial cracks were investigated. A wavelet packet-based energy analysis was developed to distinguish the type of crack and determine the further leakage based on different stress wave energy attenuation propagated through the cracks.

  1. Air Leakage Rates in Typical Air Barrier Assemblies

    SciTech Connect

    Hun, Diana E.; Atchley, Jerald Allen; Childs, Phillip W.

    2016-11-01

    Estimates for 2010 indicate that infiltration in residential buildings was responsible for 2.85 quads of energy (DOE 2014), which is about 3% of the total energy consumed in the US. One of the mechanisms being implemented to reduce this energy penalty is the use of air barriers as part of the building envelope. These technologies decrease airflow through major leakage sites such as oriented strand board (OSB) joints, and gaps around penetrations (e.g., windows, doors, pipes, electrical outlets) as indicated by Hun et al. (2014). However, most air barrier materials do not properly address leakage spots such as wall-to-roof joints and wall-to-foundation joints because these are difficult to seal, and because air barrier manufacturers usually do not provide adequate instructions for these locations. The present study focuses on characterizing typical air leakage sites in wall assemblies with air barrier materials.

  2. Leakage radiation microscope for observation of non-transparent samples.

    PubMed

    Merlo, Juan M; Ye, Fan; Burns, Michael J; Naughton, Michael J

    2014-09-22

    We describe a leakage radiation microscope technique that can be used to extend the leakage radiation microscopy to optically non-transparent samples. In particular, two experiments are presented, first to demonstrate that acquired images with our configuration correspond to the leakage radiation phenomenon and second, to show possible applications by directly imaging a plasmonic structure that previously could only be imaged with a near-field scanning optical microscope. It is shown that the measured surface plasmon wavelength and propagation length agree with theoretically-calculated values. This configuration opens the possibility to study important effects where samples are optically non-transparent, as in plasmonic cavities and single hole plasmonic excitation, without the use of time-consuming near-field scanning optical microscopy.

  3. An Investigation of Tendon Corrosion-Inhibitor Leakage into Concrete

    SciTech Connect

    Costello, J.F.; Naus, D.J.; Oland, C.B.

    1999-07-05

    During inspections performed at US nuclear power plants several years ago, some of the prestressed concrete containment had experienced leakage of the tendon sheathing filler. A study was conducted to indicate the extent of the leakage into the concrete and its potential effects on concrete properties. Concrete core samples were obtained from the Trojan Nuclear Plant. Examination and testing of the core samples indicated that the appearance of tendon sheathing filler on the surface was due to leakage of the filler from the conduits and its subsequent migration to the concrete surface through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks with no perceptible movement into the concrete. Results of compressive strength tests indicated that the concrete quality was consistent in the containment and that the strength had increased relative to the strength at 28 days age.

  4. Air Leakage of U.S. Homes: Model Prediction

    SciTech Connect

    Sherman, Max H.; McWilliams, Jennifer A.

    2007-01-01

    Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. The Lawrence Berkeley National Laboratory has been gathering residential air leakage data from many sources and now has a database of more than 100,000 raw measurements. This paper uses a model developed from that database in conjunction with US Census Bureau data for estimating air leakage as a function of location throughout the US.

  5. Albumin leakage in online hemodiafiltration, more convective transport, more losses?

    PubMed

    Vega, Almudena; Quiroga, Borja; Abad, Soraya; Aragoncillo, Inés; Arroyo, David; Panizo, Nayara; López-Gómez, Juan M

    2015-06-01

    Online hemodiafiltration (OL-HDF) has now demonstrated some benefits in reducing mortality. It seems that rising convective volumes improve the outcomes, but the risks of it, such as albumin leakage, are not well defined yet. The aim of the present study was to evaluate the albumin leakage using two different filters with 20 and 30 L of post-dilution OL-HDF. In this cross-sectional study, 20 prevalent patients receiving post-dilution OL-HDL were included. We analyzed two dialyzers: FX1000, FMC and Polyflux 210H, Gambro. During four consecutive dialysis sessions, monitors were programmed using control-volume to obtain 20 or 30 L with both dialyzers. We collected albumin samples of the effluent at 5, 15, 30, 45 and 60 min and performed area under the curve (AUC) determinations for evaluating the losses. Mean patient age was 60 ± 9 years, and 70% were men. Albumin leakage was significant higher with Polyflux 210H when compared to FX 1000 FMC. A convective volume of 30 L produced greater albumin leakage than 20 L with both filters, though only with the FX 1000 FMC was it significant (minimum albumin leakage during first hour with FX 1000 FMC 20 L: 79.2 [0.0-175.7] mg; 30 liters: 403.3 [63.5-960.7] mg; with PF 210 Gambro 20 L: 869.1 [420.0-3214.7] mg; 30 L: 1841.7 [443.8-3417.5] mg). During OL-HDF, convective transport causes albumin leakage at least during the first hour. The albumin concentration in the effluent differs according to the type of filter used and the convective volume.

  6. Atlantic multi-decadal oscillation covaries with Agulhas leakage

    SciTech Connect

    Biastoch, Arne; Durgadoo, Jonathan V.; Morrison, Adele K.; van Sebille, Erik; Weijer, Wilbert; Griffies, Stephen M.

    2015-12-10

    The interoceanic transfer of seawater between the Indian Ocean and the Atlantic, ‘Agulhas leakage’, forms a choke point for the overturning circulation in the global ocean. Here, by combining output from a series of high-resolution ocean and climate models with in situ and satellite observations, we construct a time series of Agulhas leakage for the period 1870–2014. The time series demonstrates the impact of Southern Hemisphere westerlies on decadal timescales. Agulhas leakage shows a correlation with the Atlantic Multi-decadal Oscillation on multi-decadal timescales; the former leading by 15 years. Lastly, this is relevant for climate in the North Atlantic.

  7. Leakage estimation using Kalman filtering in noninvasive mechanical ventilation.

    PubMed

    Rodrigues, G G; Freitas, U S; Bounoiare, D; Aguirre, L A; Letellier, C

    2013-05-01

    Noninvasive mechanical ventilation is today often used to assist patient with chronic respiratory failure. One of the main reasons evoked to explain asynchrony events, discomfort, unwillingness to be treated, etc., is the occurrence of nonintentional leaks in the ventilation circuit, which are difficult to account for because they are not measured. This paper describes a solution to the problem of variable leakage estimation based on a Kalman filter driven by airflow and the pressure signals, both of which are available in the ventilation circuit. The filter was validated by showing that based on the attained leakage estimates, practically all the untriggered cycles can be explained.

  8. Leakage Current and Floating Gate Capacitor Matching Test

    NASA Astrophysics Data System (ADS)

    Tian, Weidong; Trogolo, Joe R.; Todd, Bob

    Capacitor mismatch is an important device parameter for precision analog applications. In the last ten years, the floating gate measurement technique has been widely used for its characterization. In this paper we describe the impact of leakage current on the technique. The leakage can come from, for example, thin gate oxide MOSFETs or high dielectric constant capacitors in advanced technologies. SPICE simulation, bench measurement, analytical model and numerical analyses are presented to illustrate the problem and key contributing factors. Criteria for accurate capacitor systematic and random mismatch characterization are developed, and practical methods of increasing measurement accuracy are discussed.

  9. Microvascular Branching as a Determinant of Blood Flow by Intravital Particle Imaging Velocimetry

    NASA Technical Reports Server (NTRS)

    Parsons-Wingerter, Patricia; McKay, Terri L.; Vickerman, Mary B.; Wernet, Mark P.; Myers, Jerry G.; Radhakrishnan, Krishnan

    2007-01-01

    The effects of microvascular branching on blood flow were investigated in vivo by microscopic particle imaging velocimetry (micro-PIV). We use micro-PIV to measure blood flow by tracking red blood cells (RBC) as the moving particles. Velocity flow fields, including flow pulsatility, were analyzed for the first four branching orders of capillaries, postcapillary venules and small veins of the microvascular network within the developing avian yolksac at embryonic day 5 (E5). Increasing volumetric flowrates were obtained from parabolic laminar flow profiles as a function of increasing vessel diameter and branching order. Maximum flow velocities increased approximately twenty-fold as the function of increasing vessel diameter and branching order compared to flow velocities of 100 - 150 micron/sec in the capillaries. Results from our study will be useful for the increased understanding of blood flow within anastomotic, heterogeneous microvascular networks.

  10. Gene expression microarray data from human microvascular endothelial cells supplemented with a low concentration of niacin

    PubMed Central

    Hughes-Large, Jennifer M.; Borradaile, Nica M.

    2016-01-01

    The systemic lipid modifying drug, niacin, can directly improve human microvascular endothelial cell angiogenic function under lipotoxic conditions, possibly through activation of niacin receptors “Niacin receptor activation improves human microvascular endothelial cell angiogenic function during lipotoxicity” (Hughes-Large et al. 2014). Here we provide accompanying data collected using Affymetrix GeneChip microarrays to identify changes in gene expression in human microvascular endothelial cells treated with 10 μM niacin. Statistical analyses of robust multi-array average (RMA) values revealed that only 16 genes exhibited greater than 1.3-fold differential expression. Of these 16, only 5 were identified protein coding genes, while 3 of the remaining 11 genes appeared to be small nuclear/nucleolar RNAs. Altered expression of EFCAB4B, NAP1L2, and OR13C8 was confirmed by real time quantitative PCR. PMID:26937468

  11. Gene expression microarray data from human microvascular endothelial cells supplemented with a low concentration of niacin.

    PubMed

    Hughes-Large, Jennifer M; Borradaile, Nica M

    2016-03-01

    The systemic lipid modifying drug, niacin, can directly improve human microvascular endothelial cell angiogenic function under lipotoxic conditions, possibly through activation of niacin receptors "Niacin receptor activation improves human microvascular endothelial cell angiogenic function during lipotoxicity" (Hughes-Large et al. 2014). Here we provide accompanying data collected using Affymetrix GeneChip microarrays to identify changes in gene expression in human microvascular endothelial cells treated with 10 μM niacin. Statistical analyses of robust multi-array average (RMA) values revealed that only 16 genes exhibited greater than 1.3-fold differential expression. Of these 16, only 5 were identified protein coding genes, while 3 of the remaining 11 genes appeared to be small nuclear/nucleolar RNAs. Altered expression of EFCAB4B, NAP1L2, and OR13C8 was confirmed by real time quantitative PCR.

  12. Syk Regulates Neutrophilic Airway Hyper-Responsiveness in a Chronic Mouse Model of Allergic Airways Inflammation

    PubMed Central

    Juvet, Stephen; Scott, Jeremy A.; Chow, Chung-Wai

    2017-01-01

    Background Asthma is a chronic inflammatory disease characterized by airways hyper-responsiveness (AHR), reversible airway obstruction, and airway inflammation and remodeling. We previously showed that Syk modulates methacholine-induced airways contractility in naïve mice and in mice with allergic airways inflammation. We hypothesize that Syk plays a role in the pathogenesis of AHR; this was evaluated in a chronic 8-week mouse model of house dust mite (HDM)-induced allergic airways inflammation. Methods We used the Sykflox/flox//rosa26CreERT2 conditional Syk knock-out mice to assess the role of Syk prior to HDM exposure, and treated HDM-sensitized mice with the Syk inhibitor, GSK143, to evaluate its role in established allergic airways inflammation. Respiratory mechanics and methacholine (MCh)-responsiveness were assessed using the flexiVent® system. Lungs underwent bronchoalveolar lavage to isolate inflammatory cells or were frozen for determination of gene expression in tissues. Results MCh-induced AHR was observed following HDM sensitization in the Syk-intact (Sykflox/flox) and vehicle-treated BALB/c mice. MCh responsiveness was reduced to control levels in HDM-sensitized Sykdel/del mice and in BALB/c and Sykflox/flox mice treated with GSK143. Both Sykdel/del and GSK143-treated mice mounted appropriate immune responses to HDM, with HDM-specific IgE levels that were comparable to Sykflox/flox and vehicle-treated BALB/c mice. HDM-induced increases in bronchoalveolar lavage cell counts were attenuated in both Sykdel/del and GSK143-treated mice, due primarily to decreased neutrophil recruitment. Gene expression analysis of lung tissues revealed that HDM-induced expression of IL-17 and CXCL-1 was significantly attenuated in both Sykdel/del and GSK143-treated mice. Conclusion Syk inhibitors may play a role in the management of neutrophilic asthma. PMID:28107345

  13. Does the length dependency of airway smooth muscle force contribute to airway hyperresponsiveness?

    PubMed

    Lee-Gosselin, Audrey; Pascoe, Chris D; Couture, Christian; Paré, Peter D; Bossé, Ynuk

    2013-11-01

    Airway wall remodeling and lung hyperinflation are two typical features of asthma that may alter the contractility of airway smooth muscle (ASM) by affecting its operating length. The aims of this study were as follows: 1) to describe in detail the "length dependency of ASM force" in response to different spasmogens; and 2) to predict, based on morphological data and a computational model, the consequence of this length dependency of ASM force on airway responsiveness in asthmatic subjects who have both remodeled airway walls and hyperinflated lungs. Ovine tracheal ASM strips and human bronchial rings were isolated and stimulated to contract in response to increasing concentrations of spasmogens at three different lengths. Ovine tracheal strips were more sensitive and generated greater force at longer lengths in response to acetylcholine (ACh) and K(+). Equipotent concentrations of ACh were approximately a log less for ASM stretched by 30% and approximately a log more for ASM shortened by 30%. Similar results were observed in human bronchi in response to methacholine. Morphometric and computational analyses predicted that the ASM of asthmatic subjects may be elongated by 6.6-10.4% (depending on airway generation) due to remodeling and/or hyperinflation, which could increase ACh-induced force by 1.8-117.8% (depending on ASM length and ACh concentration) and enhance the increased resistance to airflow by 0.4-4,432.8%. In conclusion, elongation of ASM imposed by airway wall remodeling and/or hyperinflation may allow ASM to operate at a longer length and to consequently generate more force and respond to lower concentration of spasmogens. This phenomenon could contribute to airway hyperresponsiveness.

  14. Yellow nail syndrome: does protein leakage play a role?

    PubMed

    D'Alessandro, A; Muzi, G; Monaco, A; Filiberto, S; Barboni, A; Abbritti, G

    2001-01-01

    Yellow nail syndrome is characterized by primary lymphoedema, recurrent pleural effusion and yellow discoloration of the nails. Although mechanical lymphatic obstruction is assumed to be the underlying pathology, it cannot explain the common finding of high albumin concentration in the pleural space. This paper describes a case of yellow nail syndrome presenting with the classical triad of lymphoedema, recurrent pleural effusion and yellow discoloration of the nails, associated with persistent hypoalbuminaemia and increased enteric loss of albumin. Based on the findings in this case and those in the literature, it is speculated that increased microvascular permeability may contribute to the pathogenesis of this syndrome.

  15. Effect of phentolamine on the hyperemic response to adenosine in patients with microvascular disease.

    PubMed

    Aarnoudse, Wilbert; Geven, Maartje; Barbato, Emanuele; Botman, Kees-joost; De Bruyne, Bernard; Pijls, Nico H J

    2005-12-15

    For accurate measurement of the fractional flow reserve (FFR) of the myocardium, the presence of maximum hyperemia is of paramount importance. It has been suggested that the hyperemic effect of the conventionally used hyperemic stimulus, adenosine, could be submaximal in patients who have microvascular dysfunction and that adding alpha-blocking agents could augment the hyperemic response in these patients. We studied the effect of the nonselective alpha-blocking agent phentolamine, which was administered in addition to adenosine after achieving hyperemia, in patients who had microvascular disease and those who did not. Thirty patients who were referred for percutaneous coronary intervention were selected. Of these 30 patients, 15 had strong indications for microvascular disease and 15 did not. FFR was measured using intracoronary adenosine, intravenous adenosine, and intracoronary papaverine before and after intracoronary administration of the nonselective alpha blocker phentolamine. In patients who did not have microvascular disease, no differences in hyperemic response to adenosine were noted, whether or not alpha blockade was given before adenosine administration; FFR levels before and after phentolamine were 0.76 and 0.75, respectively, using intracoronary adenosine (p = 0.10) and 0.75 and 0.74, respectively, using intravenous adenosine (p = 0.20). In contrast, in patients who had microvascular disease, some increase in hyperemic response was observed after administration of phentolamine; FFR levels decreased from 0.74 to 0.70 using intracoronary adenosine (p = 0.003) and from 0.75 to 0.72 using intravenous adenosine (p = 0.04). Although statistically significant, the observed further decrease in microvascular resistance after addition of phentolamine was small and did not affect clinical decision making in any patient. In conclusion, when measuring FFR, routinely adding an alpha-blocking agent to adenosine does not affect clinical decision making.

  16. Effect of high altitude and exercise on microvascular parameters in acclimatized subjects.

    PubMed

    Bauer, Andreas; Demetz, Florian; Bruegger, Dirk; Schmoelz, Martin; Schroepfer, Sebastian; Martignoni, André; Baschnegger, Heiko; Hoelzl, Josef; Thiel, Manfred; Choukér, Alexander; Peter, Klaus; Gamble, John; Christ, Frank

    2006-02-01

    The role of microvascular fluid shifts in the adaptation to hypobaric hypoxia and its contribution to the pathophysiology of AMS (acute mountain sickness) is unresolved. In a systematic prospective study, we investigated the effects of hypobaric hypoxia and physical exercise alone, and in combination, on microvascular fluid exchange and related factors. We used computer-assisted VCP (venous congestion plethysmography) on the calves of ten altitude-acclimatized volunteers. We investigated the effects of: (i) actively climbing to an altitude of 3196 m, (ii) airlifting these subjects to the same altitude, and (iii) exercise at low altitude. CFC (capillary filtration capacity), Pvi (isovolumetric venous pressure) and Qa (calf blood flow) were assessed before and after each procedure and then repeated after an overnight rest. Measurements of CFC showed no evidence of increased microvascular permeability after any of the procedures. Pvi was significantly decreased (P<0.001) from 20.3+/-4.4 to 8.9+/-4.3 mmHg after active ascent, and was still significantly lower (P=0.009) after overnight rest at high altitude (13.6+/-5.9 mmHg). No such changes were observed after the passive ascent (16.7+/-4.0 mmHg at baseline; 17.3+/-4.5 mmHg after passive ascent; and 19.9+/-5.3 mmHg after overnight rest) or after exercise at low altitude. After the active ascent, Qa was significantly increased. We also found a significant correlation between Qa, Pvi and the number of circulating white blood cells. In conclusion, we found evidence to support the hypothesis that increased microvascular permeability associated with AMS does not occur in acclimatized subjects. We also observed that the microvascular equilibrium pressure (Pvi) fell in inverse relation to the increase in Qa, especially in hypoxic exercise. We hypothesize that this inverse relationship reflects the haemodynamic changes at the microvascular interface, possibly attributable to the flow-induced increases in endothelial surface

  17. Long-term high-fat diet induces hippocampal microvascular insulin resistance and cognitive dysfunction.

    PubMed

    Fu, Zhuo; Wu, Jing; Nesil, Tanseli; Li, Ming D; Aylor, Kevin W; Liu, Zhenqi

    2017-02-01

    Insulin action on hippocampus improves cognitive function, and obesity and type 2 diabetes are associated with decreased cognitive function. Cerebral microvasculature plays a critical role in maintaining cerebral vitality and function by supplying nutrients, oxygen, and hormones such as insulin to cerebral parenchyma, including hippocampus. In skeletal muscle, insulin actively regulates microvascular opening and closure, and this action is impaired in the insulin-resistant states. To examine insulin's action on hippocampal microvasculature and parenchyma and the impact of diet-induced obesity, we determined cognitive function and microvascular insulin responses, parenchyma insulin responses, and capillary density in the hippocampus in 2- and 8-mo-old rats on chow diet and 8-mo-old rats on a long-term high-fat diet (6 mo). Insulin infusion increased hippocampal microvascular perfusion in rats on chow diet by ~80-90%. High-fat diet feeding completely abolished insulin-mediated microvascular responses and protein kinase B phosphorylation but did not alter the capillary density in the hippocampus. This was associated with a significantly decreased cognitive function assessed using both the two-trial spontaneous alternation behavior test and the novel object recognition test. As the microvasculature provides the needed endothelial surface area for delivery of nutrients, oxygen, and insulin to hippocampal parenchyma, we conclude that hippocampal microvascular insulin resistance may play a critical role in the development of cognitive impairment seen in obesity and diabetes. Our results suggest that improvement in hippocampal microvascular insulin sensitivity might help improve or reverse cognitive function in the insulin-resistant states.

  18. Airway acidification initiates host defense abnormalities in cystic fibrosis mice

    PubMed Central

    Shah, Viral S.; Meyerholz, David K.; Tang, Xiao Xiao; Reznikov, Leah; Alaiwa, Mahmoud Abou; Ernst, Sarah E.; Karp, Philip H.; Wohlford-Lenane, Christine L.; Heilmann, Kristopher P.; Leidinger, Mariah R.; Allen, Patrick D.; Zabner, Joseph; McCray, Paul B.; Ostedgaard, Lynda S.; Stoltz, David A.; Randak, Christoph O.; Welsh, Michael J.

    2016-01-01

    Cystic fibrosis (CF) is caused by mutations in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel. In humans and pigs, the loss of CFTR impairs respiratory host defenses, causing airway infection. But CF mice are spared. We found that in all three species, CFTR secreted bicarbonate into airway surface liquid. In humans and pigs lacking CFTR, unchecked H+ secretion by the nongastric H+/K+ adenosine triphosphatase (ATP12A) acidified airway surface liquid, which impaired airway host defenses. In contrast, mouse airways expressed little ATP12A and secreted minimal H+; consequently, airway surface liquid in CF and non-CF mice had similar pH. Inhibiting ATP12A reversed host defense abnormalities in human and pig airways. Conversely, expressing ATP12A in CF mouse airways acidified airway surface liquid, impaired defenses, and increased airway bacteria. These findings help explain why CF mice are protected from infection and nominate ATP12A as a potential therapeutic target for CF. PMID:26823428

  19. Dynamics of Surfactant Liquid Plugs at Bifurcating Lung Airway Models

    NASA Astrophysics Data System (ADS)

    Tavana, Hossein

    2013-11-01

    A surfactant liquid plug forms in the trachea during surfactant replacement therapy (SRT) of premature babies. Under air pressure, the plug propagates downstream and continuously divides into smaller daughter plugs at continuously branching lung airways. Propagating plugs deposit a thin film on airway walls to reduce surface tension and facilitate breathing. The effectiveness of SRT greatly depends on the final distribution of instilled surfactant within airways. To understand this process, we investigate dynamics of splitting of surfactant plugs in engineered bifurcating airway models. A liquid plug is instilled in the parent tube to propagate and split at the bifurcation. A split ratio, R, is defined as the ratio of daughter plug lengths in the top and bottom daughter airway tubes and studied as a function of the 3D orientation of airways and different flow conditions. For a given Capillary number (Ca), orienting airways farther away from a horizontal position reduced R due to the flow of a larger volume into the gravitationally favored daughter airway. At each orientation, R increased with 0.0005 < Ca < 0.05. This effect diminished by decrease in airways diameter. This approach will help elucidate surfactant distribution in airways and develop effective SRT strategies.

  20. Airway Inflammation and Hypersensitivity Induced by Chronic Smoking

    PubMed Central

    Kou, Yu Ru; Kwong, Kevin; Lee, Lu-Yuan

    2011-01-01

    Airway hypersensitivity, characterized by enhanced excitability of airway sensory nerves, is a prominent pathophysiological feature in patients with airway inflammatory diseases. Although the underlying pathogenic mechanism is not fully understood, chronic airway inflammation is believed to be primarily responsible. Cigarette smoking is known to cause chronic airway inflammation, accompanied by airway hyperresponsiveness. Experimental evidence indicates that enhanced excitability of vagal bronchopulmonary sensory nerves and increased tachykinin synthesis in these nerves resulting from chronic inflammation are important contributing factors to the airway hyperresponsiveness. Multiple inflammatory mediators released from various types of structural and inflammatory cells are involved in the smoking-induced airway inflammation, which is mainly regulated by redox-sensitive signaling pathways and transcription factors. Furthermore, recent studies have reported potent sensitizing and stimulatory effects of these inflammatory mediators such as prostanoids and reactive oxygen species on these sensory nerves. In summary, these studies using cigarette smoking as an experimental approach have identified certain potentially important cell signaling pathways and underlying mechanisms of the airway hypersensitivity induced by chronic airway inflammation. PMID:21397052

  1. Effects of local anaesthesia on subdermal needle insertion pain and subsequent tests of microvascular function in human.

    PubMed

    Cracowski, Jean-Luc; Lorenzo, Santiago; Minson, Christopher T

    2007-03-22

    Post-occlusive and local thermal hyperemia are currently used as integrated tests to study microvascular function in microvascular diseases. However, further pathophysiological insight would require its association with microdialysis. The major limitation remains the microinvasive approach as local anaesthesia prior to fiber insertion could lead to confounding effects. The objective of our study was to determine whether EMLA cream treatment, applied for 20 min, 40 or 60 min, significantly decreases the pain related to intradermal needle insertions, while not decreasing the microvascular response to post-occlusive and thermal hyperemia 2 h after cream removal. EMLA cream, when applied during 40 min, induces a significant 75% decrease in the pain following intradermal needle insertion, while not modifying skin post-occlusive and thermal hyperemia 2 h after cream removal. Therefore, we recommend its use in such conditions before performing microdialysis coupled with laser Doppler flowmetry in cohort studies aimed at studying microvascular dysfunction in patients with microvascular diseases.

  2. The Diacetyl-exposed Human Airway Epithelial Secretome: New Insights Into Flavoring Induced Airways Disease.

    PubMed

    Brass, David M; Gwinn, William M; Valente, Ashlee M; Kelly, Francine L; Brinkley, Christie D; Nagler, Andrew E; Moseley, M Arthur; Morgan, Daniel L; Palmer, Scott M; Foster, Matthew W

    2017-03-01

    Bronchiolitis obliterans (BO) is an increasingly important lung disease characterized by fibroproliferative airway lesions and decrements in lung function. Occupational exposure to the artificial food flavoring ingredient diacetyl, commonly used to impart a buttery flavor to microwave popcorn, has been associated with BO development. In the occupational setting, diacetyl vapor is first encountered by the airway epithelium. To better understand the effects of diacetyl vapor on the airway epithelium we used an unbiased proteomic approach to characterize both the apical and basolateral secretomes of air liquid interface cultures of primary human airway epithelial cells from four unique donors after exposure to an occupationally relevant ~1100 ppm of diacetyl vapor or PBS as a control on alternating days. Basolateral and apical supernatants collected 48 hours after the third exposure were analyzed using one-dimensional liquid chromatography tandem mass spectrometry. Paired t-tests adjusted for multiple comparisons were used to assess differential expression between diacetyl and PBS exposure. Of the significantly differentially expressed proteins identified, 61 were unique to the apical secretome, 81 were unique to the basolateral secretome and there were an additional 11 present in both. Pathway enrichment analysis using publicly available databases reveals that proteins associated with matrix remodeling including degradation, assembly and new matrix organization were over-represented in the data sets. Similarly, protein modifiers of epidermal growth factor receptor signaling were significantly altered. The ordered changes in protein expression suggest that the airway epithelial response to diacetyl may contribute to BO pathogenesis.

  3. Comparison of laryngeal mask airway vs tracheal intubation: a systematic review on airway complications.

    PubMed

    van Esch, Babette F; Stegeman, Inge; Smit, Adriana L

    2017-02-01

    To determine whether the laryngeal mask airway (LMA) has advantages over the tracheal tube (TT) in terms of incidence of cough, sore throat, laryngospasm, dysphagia, dysphonia, and blood staining. This is a systematic literature review performed at the Universtity Medical Center of Utrecht. The online databases PubMed, Embase, and the Cochrane Library were searched for relevant randomized controlled trials. Two independent reviewers selected relevant articles after title, abstract, and full text screening. Articles were assessed on risk of bias in accordance with the Cochrane risk of bias tool. Study results of the LMA and the TT were related to the method of selection of the device size and the method for cuff inflation. Of the 1718 unique articles, we included 19 studies which used the LMA Classic, the LMA Proseal, the Flexible Reinforced LMA, and the LMA Supreme compared with TT. After methodological inspection, data could not be pooled due to heterogeneity among the selected studies. Overall, no clear advantage of the LMA over the TT was found but the LMA Supreme was related to the lowest incidence of airway complications. In this review, no clear difference in incidence of postoperative airway complications could be demonstrated between LMA and TT. The LMA Supreme may reduce the incidence of airway complication in comparison to the TT but high quality randomized trials are recommended to further objectify if use of the LMA decreases the risk on postoperative airway complications.

  4. Advances in upper airway cough syndrome.

    PubMed

    Yu, Li; Xu, Xianghuai; Lv, Hanjing; Qiu, Zhongmin

    2015-05-01

    Upper airway cough syndrome (UACS), previously referred to as postnasal drip syndrome, is one of the most common causes of chronic cough. However, the pathogenesis of UACS/postnasal drip syndrome remains unclear, and physicians in countries throughout the world have different definitions and ways of treating this disease. The various proposed pathogeneses of UACS include the early postnasal drip theory, subsequent chronic airway inflammation theory, and a recent sensory neural hypersensitivity theory. Additionally, some researchers suggest that UACS is a clinical phenotype of cough hypersensitivity syndrome. While the general principles involved in treating UACS are similar throughout the world, the specific details of treatment differ. This review summarizes the various definitions, pathogenic mechanisms, treatments, and other aspects of UACS, to aid clinicians in expanding their knowledge of how to diagnose and treat this syndrome.

  5. When continuous positive airway pressure (CPAP) fails

    PubMed Central

    Virk, Jagdeep S.

    2016-01-01

    Obstructive sleep apnoea (OSA) is increasingly prevalent, particularly in the context of the obesity epidemic, and is associated with a significant social, health and economic impact. The gold standard of treatment for moderate to severe OSA is continuous positive airway pressure (CPAP). However compliance rates can be low. Methodology to improve patient tolerance to CPAP alongside with alternative, non-surgical and surgical, management strategies are discussed. All patients that fail CPAP therapy would benefit from formal upper airway evaluation by the otolaryngologist to identify any obvious causes and consider site-specific surgical therapies. Patient selection is integral to ensuring successful outcomes. A multidisciplinary team is needed to manage these patients. PMID:27867577

  6. Silencing nociceptor neurons reduces allergic airway inflammation

    PubMed Central

    Talbot, Sébastien; Abdulnour, Raja-Elie E.; Burkett, Patrick R.; Lee, Seungkyu; Cronin, Shane J.F.; Pascal, Maud A.; Laedermann, Cedric; Foster, Simmie L.; Tran, Johnathan V.; Lai, Nicole; Chiu, Isaac M.; Ghasemlou, Nader; DiBiase, Matthew; Roberson, David; Von Hehn, Christian; Agac, Busranour; Haworth, Oliver; Seki, Hiroyuki; Penninger, Josef M.; Kuchroo, Vijay K.; Bean, Bruce P.; Levy, Bruce D.; Woolf, Clifford J.

    2015-01-01

    Summary Lung nociceptors initiate cough and bronchoconstriction. To elucidate if these fibers also contribute to allergic airway inflammation we stimulated lung nociceptors with capsaicin and observed increased neuropeptide release and immune cell infiltration. In contrast, ablating Nav1.8+ sensory neurons or silencing them with QX-314, a charged sodium channel inhibitor that enters via large pore ion channels to specifically block nociceptors, substantially reduced ovalbumin or house dust mite-induced airway inflammation and bronchial hyperresponsiveness. We also discovered that IL-5, a cytokine produced by activated immune cells, acts directly on nociceptors to induce release of vasoactive intestinal peptide (VIP). VIP then stimulates CD4+ and resident innate lymphoid type 2 cells, creating an inflammatory signaling loop that promotes allergic inflammation. Our results indicate that nociceptors amplify pathological adaptive immune responses and that silencing these neurons with QX-314 interrupts this neuro-immune interplay, revealing a potential new therapeutic strategy for asthma. PMID:26119026

  7. Mechanically patterning the embryonic airway epithelium.

    PubMed

    Varner, Victor D; Gleghorn, Jason P; Miller, Erin; Radisky, Derek C; Nelson, Celeste M

    2015-07-28

    Collections of cells must be patterned spatially during embryonic development to generate the intricate architectures of mature tissues. In several cases, including the formation of the branched airways of the lung, reciprocal signaling between an epithelium and its surrounding mesenchyme helps generate these spatial patterns. Several molecular signals are thought to interact via reaction-diffusion kinetics to create distinct biochemical patterns, which act as molecular precursors to actual, physical patterns of biological structure and function. Here, however, we show that purely physical mechanisms can drive spatial patterning within embryonic epithelia. Specifically, we find that a growth-induced physical instability defines the relative locations of branches within the developing murine airway epithelium in the absence of mesenchyme. The dominant wavelength of this instability determines the branching pattern and is controlled by epithelial growth rates. These data suggest that physical mechanisms can create the biological patterns that underlie tissue morphogenesis in the embryo.

  8. Endoscopic low coherence interferometry in upper airways

    NASA Astrophysics Data System (ADS)

    Delacrétaz, Yves; Boss, Daniel; Lang, Florian; Depeursinge, Christian

    2009-07-01

    We introduce Endoscopic Low Coherence Interferometry to obtain topology of upper airways through commonly used rigid endoscopes. Quantitative dimensioning of upper airways pathologies is crucial to provide maximum health recovery chances, for example in order to choose the correct stent to treat endoluminal obstructing pathologies. Our device is fully compatible with procedures used in day-to-day examinations and can potentially be brought to bedside. Besides this, the approach described here can be almost straightforwardly adapted to other endoscopy-related field of interest, such as gastroscopy and arthroscopy. The principle of the method is first exposed, then filtering procedure used to extract the depth information is described. Finally, demonstration of the method ability to operate on biological samples is assessed through measurements on ex-vivo pork bronchi.

  9. Mechanically patterning the embryonic airway epithelium

    PubMed Central

    Varner, Victor D.; Gleghorn, Jason P.; Miller, Erin; Radisky, Derek C.; Nelson, Celeste M.

    2015-01-01

    Collections of cells must be patterned spatially during embryonic development to generate the intricate architectures of mature tissues. In several cases, including the formation of the branched airways of the lung, reciprocal signaling between an epithelium and its surrounding mesenchyme helps generate these spatial patterns. Several molecular signals are thought to interact via reaction-diffusion kinetics to create distinct biochemical patterns, which act as molecular precursors to actual, physical patterns of biological structure and function. Here, however, we show that purely physical mechanisms can drive spatial patterning within embryonic epithelia. Specifically, we find that a growth-induced physical instability defines the relative locations of branches within the developing murine airway epithelium in the absence of mesenchyme. The dominant wavelength of this instability determines the branching pattern and is controlled by epithelial growth rates. These data suggest that physical mechanisms can create the biological patterns that underlie tissue morphogenesis in the embryo. PMID:26170292

  10. Liquid secretion properties of airway submucosal glands

    PubMed Central

    Ballard, Stephen T; Inglis, Sarah K

    2004-01-01

    The tracheobronchial submucosal glands secrete liquid that is important for hydrating airway surfaces, supporting mucociliary transport, and serving as a fluid matrix for numerous secreted macromolecules including the gel-forming mucins. This review details the essential structural elements of airway glands and summarizes what is currently known regarding the ion transport processes responsible for producing the liquid component of gland secretion. Liquid secretion most likely arises from serous cells and is principally under neural control with muscarinic agonists, substance P, and vasoactive intestinal peptide (VIP) functioning as effective secretogogues. Liquid secretion is driven by the active transepithelial secretion of both Cl− and HCO3− and at least a portion of this process is mediated by the cystic fibrosis transmembrane conductance regulator (CFTR), which is highly expressed in glands. The potential role of submucosal glands in cystic fibrosis lung disease is discussed. PMID:14660706

  11. Microvascular Decompression for Hemifacial Spasm Associated with Vertebrobasilar Artery

    PubMed Central

    Kim, Joo Pyung; Choi, Seok Keun; Rhee, Bong Arm; Lim, Young Jin

    2008-01-01

    Objective Hemifacial spasm (HFS) is considered as a reversible pathophysiological condition mainly induced by continuous vascular compression of the facial nerve root exit zone (REZ) at the cerebellopontine angle. As an offending vessel, vertebrobasilar artery tends to compress much more heavily than others. The authors analyzed HFS caused by vertebrobasilar artery and described the relationships between microsurgical findings and clinical courses. Methods Out of 1,798 cases treated with microvascular decompression (MVD) from Jan. 1980 to Dec. 2004, the causative vessels were either vertebral artery or basilar artery in 87 patients. Seventy-nine patients were enrolled in this study. Preoperatively, computed tomography (CT) or brain magnetic resonance (MR) imaging with 3-dimentional short range MR technique was performed and CT was checked immediately or 2-3 days after anesthetic recovery. The authors retrospectively analyzed the clinical features, the compression patterns of the vessels at the time of surgery and treatment outcomes. Results There were 47 were male and 32 female patients. HFS developed on the left side in 52 cases and on the right side in 27. The mean age of onset was 52.3 years (range 19-60) and the mean duration of symptoms was 10.7 years. Many patients (39 cases; 49.1%) had past history of hypertension. HFS caused only by the vertebral artery was 8 cases although most of the other cases were caused by vertebral artery (VA) in combination with its branching arteries. Most frequently, the VA and the posterior inferior cerebellar artery (PICA) were the simultaneous causative blood vessels comprising 32 cases (40.5%), and in 27 cases (34.2%) the VA and the anterior inferior cerebellar artery (AICA) were the offenders. Facial symptoms disappeared in 61 cases (77.2%) immediately after the operation and 68 cases (86.1%) showed good outcome after 6 months. Surgical outcome just after the operation was poor in whom the perforators arose from the offending

  12. N-n-butyl haloperidol iodide ameliorates hypoxia/reoxygenation injury through modulating the LKB1/AMPK/ROS pathway in cardiac microvascular endothelial cells

    PubMed Central

    Lu, Binger; Wang, Bin; Zhong, Shuping; Zhang, Yanmei; Gao, Fenfei; Chen, Yicun; Zheng, Fuchun; Shi, Ganggang

    2016-01-01

    Endothelial cells are highly sensitive to hypoxia and contribute to myocardial ischemia/reperfusion injury. We have reported that N-n-butyl haloperidol iodide (F2) can attenuate hypoxia/reoxygenation (H/R) injury in cardiac microvascular endothelial cells (CMECs). However, the molecular mechanisms remain unclear. Neonatal rat CMECs were isolated and subjected to H/R. Pretreatment of F2 leads to a reduction in H/R injury, as evidenced by increased cell viability, decreased lactate dehydrogenase (LDH) leakage and apoptosis, together with enhanced AMP-activated protein kinase (AMPK) and liver kinase B1 (LKB1) phosphorylation in H/R ECs. Blockade of AMPK with compound C reversed F2-induced inhibition of H/R injury, as evidenced by decreased cell viability, increased LDH release and apoptosis. Moreover, compound C also blocked the ability of F2 to reduce H/R-induced reactive oxygen species (ROS) generation. Supplementation with the ROS scavenger N-acetyl-L-cysteine (NAC) reduced ROS levels, increased cell survival rate, and decreased both LDH release and apoptosis after H/R. In conclusion, our data indicate that F2 may mitigate H/R injury by stimulating LKB1/AMPK signaling pathway and subsequent suppression of ROS production in CMECs. PMID:27166184

  13. Airway inflammation in aluminium potroom asthma

    PubMed Central

    Sjaheim, T; Halstensen, T; Lund, M; Bjortuft, O; Drablos, P; Malterud, D; Kongerud, J

    2004-01-01

    Aims: To examine whether asthma induced by exposure to aluminium potroom emissions (potroom asthma) is associated with inflammatory changes in the airways. Methods: Bronchial biopsy specimens from 20 asthmatic workers (8 non-smokers and 12 smokers), 15 healthy workers (8 non-smokers and 7 smokers), and 10 non-exposed controls (all non-smokers) were analysed. Immunohistofluorescent staining was performed to identify mucosal total leucocytes (CD45+ leucocytes), neutrophils, and mast cells. Results: Median RBM thickness was significantly increased in both asthmatic workers (8.2 µm) and healthy workers (7.4 µm) compared to non-exposed controls (6.7 µm). Non-smoking asthmatic workers had significantly increased median density of lamina propria CD45+ leucocytes (1519 cells/mm2v 660 and 887 cells/mm2) and eosinophils (27 cells/mm2v 10 and 3 cells/mm2) and significantly increased concentrations of exhaled NO (18.1 ppb v 6.5 and 5.1 ppb) compared to non-smoking healthy workers and non-exposed controls. Leucocyte counts and exhaled NO concentrations varied with smoking habits and fewer leucocytes were observed in asthmatic smokers than in non-smokers Asthmatic smokers had significantly increased numbers of eosinophils in lamina propria compared to non-exposed controls (10 v 3 cells/mm2). Both eosinophilic and non-eosinophilic phenotypes of asthma were recognised in the potroom workers and signs of airway inflammation were also observed in healthy workers. Conclusions: Airway inflammation is a central feature of potroom asthma and exposure to potroom emissions induces pathological alterations similar to those described in other types of asthma. Cigarette smoking seems to affect the underlying mechanisms involved in asthma, as the cellular composition of airway mucosa appears different in asthmatic smokers and non-smokers. PMID:15317920

  14. Visual Inspection of Water Leakage from Ground Penetrating Radar Radargram

    NASA Astrophysics Data System (ADS)

    Halimshah, N. N.; Yusup, A.; Mat Amin, Z.; Ghazalli, M. D.

    2015-10-01

    Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR) as a non-destructive method to correctly and efficiently detect mains water leaks has been examined. Several experiments were designed and conducted to prove that GPR can be used as tool for water leakage detection. These include instrument validation test and soil compaction test to clarify the maximum dry density (MDD) of soil and simulation studies on water leakage at a test bed consisting of PVC pipe burying in sand to a depth of 40 cm. Data from GPR detection are processed using the Reflex 2D software. Identification of water leakage was visually inspected from the anomalies in the radargram based on GPR reflection coefficients. The results have ascertained the capability and effectiveness of the GPR in detecting water leakage which could help avoiding difficulties with other leak detection methods.

  15. Blower-door techniques for measuring interzonal leakage

    SciTech Connect

    Hult, Erin L.; Sherman, Max H.; Walker, Iain

    2013-01-01

    Abstract The standard blower door test methods, such as ASTM E779, describe how to use a single blower door to determine the total leakage of a single-zone structure such as a detached single-family home. There are no standard test methods for measuring interzonal leakage in a two-zone or multi-zone building envelope such as might be encountered in with an attached garage or in a multifamily building. Some practitioners have been using techniques that involve making multiple measurements with a single blower door as well as combined measurements using multiple blower doors. Even for just two zones there are dozens of combinations of one-door and two-door test protocols that could conceivably be used to determine the interzonal air tightness. We examined many of these two-zone configurations using both simulation and measured data to estimate the accuracy and precision of each technique for realistic measurement scenarios. We also considered the impact of taking measurements at a single pressure versus over multiple pressures. We compared the various techniques and evaluated them for specific uses. Some techniques work better in one leakage regime; some are more sensitive to wind and other noise; some are more suited to determining only a subset of the leakage values. This paper makes recommendations on which techniques to use or not use for various cases and provides data that could be used to develop future test methods.

  16. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2640 Portable... the electrical leakage current between any two points of an electrical system and to sound an alarm if... exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to...

  17. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2640 Portable... the electrical leakage current between any two points of an electrical system and to sound an alarm if... exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to...

  18. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2640 Portable... the electrical leakage current between any two points of an electrical system and to sound an alarm if... exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to...

  19. 21 CFR 870.2640 - Portable leakage current alarm.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2640 Portable... the electrical leakage current between any two points of an electrical system and to sound an alarm if... exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to...

  20. 75 FR 20546 - Total Inward Leakage Requirements for Respirators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-20

    ... (CDC) is reopening the comment period for the notice of proposed rulemaking by the National Institute for Occupational Safety and Health (NIOSH) of CDC, entitled ``Total Inward Leakage Requirements for...://www.regulations.gov . Follow the instructions for submitting comments. E-mail:...

  1. Leakage Currents and Gas Generation in Advanced Wet Tantalum Capacitors

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2015-01-01

    Currently, military grade, established reliability wet tantalum capacitors are among the most reliable parts used for space applications. This has been achieved over the years by extensive testing and improvements in design and materials. However, a rapid insertion of new types of advanced, high volumetric efficiency capacitors in space systems without proper testing and analysis of degradation mechanisms might increase risks of failures. The specifics of leakage currents in wet electrolytic capacitors is that the conduction process is associated with electrolysis of electrolyte and gas generation resulting in building up of internal gas pressure in the parts. The risk associated with excessive leakage currents and increased pressure is greater for high value advanced wet tantalum capacitors, but it has not been properly evaluated yet. In this work, in Part I, leakages currents in various types of tantalum capacitors have been analyzed in a wide range of voltages, temperatures, and time under bias. Gas generation and the level of internal pressure have been calculated in Part II for different case sizes and different hermeticity leak rates to assess maximal allowable leakage currents. Effects related to electrolyte penetration to the glass seal area have been studied and the possibility of failures analyzed in Part III. Recommendations for screening and qualification to reduce risks of failures have been suggested.

  2. 49 CFR 178.345-13 - Pressure and leakage tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... be tested with the adjacent cargo tanks empty and at atmospheric pressure. Each closure, except... 49 Transportation 2 2010-10-01 2010-10-01 false Pressure and leakage tests. 178.345-13 Section 178... PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.345-13 Pressure and...

  3. Plutonium Finishing Plant assessment of confinement system bypass leakage

    SciTech Connect

    Dick, J.D.

    1996-09-30

    The purpose of this report is to document walk-through`s of the safety class confinement systems at the Plutonium Finishing Plant (PFP). In addition this document outlines the actions taken to assess the confinement system for bypass leakage as well as establishing disposition for discovered deficiencies at the PFP.

  4. Closure of cerebrospinal fluid leakage after transsphenoidal surgery: technical note.

    PubMed

    Freidberg, S R; Hybels, R L; Bohigian, R K

    1994-07-01

    It is necessary to pack the sella turcica to prevent the leakage of cerebrospinal fluid after transsphenoidal surgery if the arachnoid has been torn. The packing is usually supported by nasal cartilage. If this is not available, we recommend the Synthes minifragment plate to support the intradural pack.

  5. 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 AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks §...

  6. Thresholds of information leakage for speech security outside meeting rooms.

    PubMed

    Robinson, Matthew; Hopkins, Carl; Worrall, Ken; Jackson, Tim

    2014-09-01

    This paper describes an approach to provide speech security outside meeting rooms where a covert listener might attempt to extract confidential information. Decision-based experiments are used to establish a relationship between an objective measurement of the Speech Transmission Index (STI) and a subjective assessment relating to the threshold of information leakage. This threshold is defined for a specific percentage of English words that are identifiable with a maximum safe vocal effort (e.g., "normal" speech) used by the meeting participants. The results demonstrate that it is possible to quantify an offset that links STI with a specific threshold of information leakage which describes the percentage of words identified. The offsets for male talkers are shown to be approximately 10 dB larger than for female talkers. Hence for speech security it is possible to determine offsets for the threshold of information leakage using male talkers as the "worst case scenario." To define a suitable threshold of information leakage, the results show that a robust definition can be based upon 1%, 2%, or 5% of words identified. For these percentages, results are presented for offset values corresponding to different STI values in a range from 0.1 to 0.3.

  7. Detectivity of gas leakage based on electromagnetic radiation transfer

    NASA Astrophysics Data System (ADS)

    Long, Yunting; Wang, Lingxue; Li, Jiakun; Zhang, Changxing; Zhang, Bei

    2011-05-01

    Standoff detection of gas leakage is a fundamental need in petrochemical and power industries. The passive gas imaging system using thermal imager has been proven to be efficient to visualize leaking gas which is not visible to the naked eye. The detection probability of gas leakage is the basis for designing a gas imaging system. Supposing the performance parameters of the thermal imager are known, the detectivity based on electromagnetic radiation transfer model to image gas leakage is analyzed. This model takes into consideration a physical analysis of the gas plume spread in the atmosphere-the interaction processes between the gas and its surrounding environment, the temperature of the gas and the background, the background surface emissivity, and also gas concentration, etc. Under a certain environmental conditions, through calculating the radiation reaching to the detector from the camera's optical field of view, we obtain an entity "Gas Equivalent Blackbody Temperature Difference (GEBTD)" which is the radiation difference between the on-plume and off-plume regions. Comparing the GEBTD with the Noise Equivalent Temperature Difference (NETD) of the thermal imager, we can know whether the system can image the gas leakage. At last, an example of detecting CO2 gas by JADE MWIR thermal imager with a narrow band-pass filter is presented.

  8. Osmotic Stressing, Membrane Leakage, and Fluorescence: An Introductory Biochemistry Demonstration

    ERIC Educational Resources Information Center

    Seu, Kalani J.

    2015-01-01

    A fluorescence demonstration is described that incorporates several fundamental aspects of an introductory biochemistry course. A variation of a known leakage assay is utilized to prepare vesicles containing a quenched fluorophore. The vesicles are exposed to several osmotic environments ranging from isotonic to hypotonic. The degree of vesicle…

  9. 40 CFR 265.222 - Action leakage rate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... system (LDS) can remove without the fluid head on the bottom liner exceeding 1 foot. The action leakage..., hydraulic conductivity, thickness of drainage material), construction, operation, and location of the LDS... the system over time resulting from siltation and clogging, rib layover and creep of...

  10. Leakage diffusion of underwater crude oil in wind fields.

    PubMed

    Chen, Liqiong; Liu, Qi; Li, Yunyun; Lu, Rui; Wu, Shijuan; Li, Xin; Hou, Tao

    2016-01-01

    Leakage of underwater crude oil pipes causes severe pollution to soil and water, and results in great economic loss. To predict the diffusion area of spilled oil before it reaches the water's surface and to reduce the time required for emergency response, numerical simulations were conducted on underwater spilled oil diffusion of bare crude oil pipes using FLUENT software. The influences of water-surface wind speed, leakage hole diameter, water velocity, and initial leakage velocity on oil diffusion were analyzed. The results revealed the following: (1) with wind blowing on the surface of the water, the vertical displacement of spilled oil jet-flow was affected by the combined action of water flow and wind, making it difficult for a high-speed jet-flow to form. A horizontal oil flow mostly moved in the direction of the bottom water, and frontier oil droplets dispersed quickly; (2) during the diffusion of spilled oil in water, the maximum horizontal displacement mostly increased linearly, while the maximum vertical displacement initially increased quickly and then slowed; (3) the greater the initial velocity and leakage hole diameter, the higher the oil jet-flow and the wider the diffusion area; the higher the water flow rate and water-surface wind speed, the smaller the vertical displacement of spilled oil. The existence of water-surface wind had no obvious influence on the horizontal displacement of underwater spilled oil.

  11. Minimum permissible leakage resistance established for instrumentation systems

    NASA Technical Reports Server (NTRS)

    Perrin, J. L.

    1966-01-01

    Mathematical formulas are used to determine if, and to what extent, an instrumentation system that has been exposed to the elements should be dried out to restore minimum permissible leakage resistance to ground. Formulas are also derived and used for an intermediate number of systems that are exposed to moisture penetration.

  12. 42 CFR 84.123 - 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. 84.123 Section 84.123 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks §...

  13. 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 AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks §...

  14. 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 AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks §...

  15. 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 AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks §...

  16. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....316 Section 89.316 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) 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 checked. The analyzer flows and bypass flows may be used to estimate the...

  17. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....316 Section 89.316 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) 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 checked. The analyzer flows and bypass flows may be used to estimate the...

  18. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....316 Section 89.316 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) 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 checked. The analyzer flows and bypass flows may be used to estimate the...

  19. 40 CFR 89.316 - Analyzer leakage and response time.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....316 Section 89.316 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) 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 checked. The analyzer flows and bypass flows may be used to estimate the...

  20. Exploitation of Unintentional Information Leakage from Integrated Circuits

    ERIC Educational Resources Information Center

    Cobb, William E.

    2011-01-01

    The information leakage of electronic devices, especially those used in cryptographic or other vital applications, represents a serious practical threat to secure systems. While physical implementation attacks have evolved rapidly over the last decade, relatively little work has been done to allow system designers to effectively counter the…

  1. THE CARBON DIOXIDE LEAKAGE FROM CHAMBERS MEASURED USING SULFUR HEXAFLUORIDE

    EPA Science Inventory

    In plant chamber studies, if Co2 leaking from a chamber is not quantified, it can lead to an overestimate of assimilation rates and an underestimate of respiration rates: consequently, it is critical that Co2 leakage be determined. Sulfur Hexafluoride (SF6) was introduced into t...

  2. Can paternal leakage maintain sexually antagonistic polymorphism in the cytoplasm?

    PubMed Central

    Kuijper, B; Lane, N; Pomiankowski, A

    2015-01-01

    A growing number of studies in multicellular organisms highlight low or moderate frequencies of paternal transmission of cytoplasmic organelles, including both mitochondria and chloroplasts. It is well established that strict maternal inheritance is selectively blind to cytoplasmic elements that are deleterious to males – ’mother's curse’. But it is not known how sensitive this conclusion is to slight levels of paternal cytoplasmic leakage. We assess the scope for polymorphism when individuals bear multiple cytoplasmic alleles in the presence of paternal leakage, bottlenecks and recurrent mutation. When fitness interactions among cytoplasmic elements within an individual are additive, we find that sexually antagonistic polymorphism is restricted to cases of strong selection on males. However, when fitness interactions among cytoplasmic elements are nonlinear, much more extensive polymorphism can be supported in the cytoplasm. In particular, mitochondrial mutants that have strong beneficial fitness effects in males and weak deleterious fitness effects in females when rare (i.e. ’reverse dominance’) are strongly favoured under paternal leakage. We discuss how such epistasis could arise through preferential segregation of mitochondria in sex-specific somatic tissues. Our analysis shows how paternal leakage can dampen the evolution of deleterious male effects associated with predominant maternal inheritance of cytoplasm, potentially explaining why ’mother's curse’ is less pervasive than predicted by earlier work. PMID:25653025

  3. 40 CFR 265.255 - Action leakage rates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... maximum design flow rate that the leak detection system (LDS) can remove without the fluid head on the... the action leakage rate has been exceeded, the owner or operator must convert the weekly flow rate from the monitoring data obtained under § 265.260, to an average daily flow rate (gallons per acre...

  4. 40 CFR 264.252 - Action leakage rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... flow rate that the leak detection system (LDS) can remove without the fluid head on the bottom liner... action leakage rate has been exceeded, the owner or operator must convert the weekly flow rate from the monitoring data obtained under § 264.254(c) to an average daily flow rate (gallons per acre per day) for...

  5. 40 CFR 264.222 - Action leakage rate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... design flow rate that the leak detection system (LDS) can remove without the fluid head on the bottom... action leakage rate has been exceeded, the owner or operator must convert the weekly or monthly flow rate from the monitoring data obtained under § 264.226(d) to an average daily flow rate (gallons per...

  6. 40 CFR 264.302 - Action leakage rate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... landfill units subject to § 264.301(c) or (d). The action leakage rate is the maximum design flow rate that...) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Landfills... design (e.g., slope, hydraulic conductivity, thickness of drainage material), construction,...

  7. 40 CFR 265.302 - Action leakage rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... FACILITIES Landfills § 265.302 Action leakage rate. (a) The owner or operator of landfill units subject to... maximum design flow rate that the leak detection system (LDS) can remove without the fluid head on the... for uncertainties in the design (e.g., slope, hydraulic conductivity, thickness of drainage...

  8. 40 CFR 264.302 - Action leakage rate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... landfill units subject to § 264.301(c) or (d). The action leakage rate is the maximum design flow rate that...) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Landfills... design (e.g., slope, hydraulic conductivity, thickness of drainage material), construction,...

  9. 40 CFR 264.302 - Action leakage rate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... landfill units subject to § 264.301(c) or (d). The action leakage rate is the maximum design flow rate that...) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Landfills... design (e.g., slope, hydraulic conductivity, thickness of drainage material), construction,...

  10. 40 CFR 265.302 - Action leakage rate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FACILITIES Landfills § 265.302 Action leakage rate. (a) The owner or operator of landfill units subject to... maximum design flow rate that the leak detection system (LDS) can remove without the fluid head on the... for uncertainties in the design (e.g., slope, hydraulic conductivity, thickness of drainage...

  11. 40 CFR 265.302 - Action leakage rate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... FACILITIES Landfills § 265.302 Action leakage rate. (a) The owner or operator of landfill units subject to... maximum design flow rate that the leak detection system (LDS) can remove without the fluid head on the... for uncertainties in the design (e.g., slope, hydraulic conductivity, thickness of drainage...

  12. Airway wall stiffening increases peak wall shear stress: a fluid-structure interaction study in rigid and compliant airways.

    PubMed

    Xia, Guohua; Tawhai, Merryn H; Hoffman, Eric A; Lin, Ching-Long

    2010-05-01

    The airflow characteristics in a computed tomography (CT) based human airway bifurcation model with rigid and compliant walls are investigated numerically. An in-house three-dimensional (3D) fluid-structure interaction (FSI) method is applied to simulate the flow at different Reynolds numbers and airway wall stiffness. As the Reynolds number increases, the airway wall deformation increases and the secondary flow becomes more prominent. It is found that the peak wall shear stress on the rigid airway wall can be five times stronger than that on the compliant airway wall. When adding tethering forces to the model, we find that these forces, which produce larger airway deformation than without tethering, lead to more skewed velocity profiles in the lower branches and further reduced wall shear stresses via a larger airway lumen. This implies that pathologic changes in the lung such as fibrosis or remodeling of the airway wall-both of which can serve to restrain airway wall motion-have the potential to increase wall shear stress and thus can form a positive feed-back loop for the development of altered flow profiles and airway remodeling. These observations are particularly interesting as we try to understand flow and structural changes seen in, for instance, asthma, emphysema, cystic fibrosis, and interstitial lung disease.

  13. Catheter-Based Sensing In The Airways

    NASA Astrophysics Data System (ADS)

    Fouke, J. M.; Saunders, K. G.

    1988-04-01

    Studies attempting to define the role of the respiratory tract in heating and humidifying inspired air point to the need for sensing many variables including airway wall and airstream temperatures, humidity, and surface fluid pH and osmolarity. In order to make such measurements in vivo in human volunteers, catheter based technologies must be exploited both to assure subject safety and subject comfort. Miniturization of the electrodes or sensors becomes a top priority. This paper describes the use of thin-film microelectronic technology to fabricate a miniature, flexible sensor which can be placed directly onto the surface of the airway to measure the electrical conductance of the fluids present. From this information the osmolarity of the surface fluid was calculated. Physiologic evaluation of the device and corroboration of the calculations was performed in mongrel dogs. We also describe the successful application of current thermistor technology for the thermal mapping of the airways in humans in order to characterize the dynamic intrathoracic events that occur during breathing. The thermal probe consisted of a flexible polyvinyl tube that contained fourteen small thermistors fixed into the catheter. Data have been obtained in dozens of people, both normal subjects and asthmatic patients, under a variety of interventions. These data have substantively advanced the study of asthma, a particularly troublesome chronic obstructive pulmonary disorder.

  14. Techniques of endoscopic airway tumor treatment

    PubMed Central

    Mhanna, Laurent; Droneau, Sylvain; Plat, Gavin; Didier, Alain; Mazieres, Julien; Hermant, Christophe

    2016-01-01

    Interventional bronchoscopy has a predominant role in the management of both early and advanced-stage airway tumors. Given the very poor prognosis of lung cancer, there is a need for new tools to improve early detection and bronchoscopic treatment of endo-bronchial precancerous lesions. In more advanced stages, interventional bronchoscopy plays an important role, as nearly a third of lung cancers lead to proximal airway obstruction. This will cause great discomfort or even life-threatening symptoms related to local extension, such as dyspnea, post-obstructive pneumonia, and hemoptysis. Surgery for very locally advanced disease is only effective for a limited number of patients and the effects of conventional antitumor therapies, like radiation therapy or chemotherapy, are inconstant and are too delayed in a palliative context. In this review, we aim to provide pulmonologists with an exhaustive technical overview of (I) the bronchoscopic management of benign endobronchial lesions; (II) the bronchoscopic management of malignant tumors, including the curative treatment of localized lesions and palliative management of malignant proximal airway stenosis; and (III) descriptions of the emerging endoscopic techniques used to treat peripheral lung tumors. PMID:28066616

  15. Resting calcium influx in airway smooth muscle.

    PubMed

    Montaño, Luis M; Bazán-Perkins, Blanca

    2005-01-01

    Plasma membrane Ca2+ leak remains the most uncertain of the cellular Ca2+ regulation pathways. During passive Ca2+ influx in non-stimulated smooth muscle cells, basal activity of constitutive Ca2+ channels seems to be involved. In vascular smooth muscle, the 3 following Ca2+ entry pathways contribute to this phenomenon: (i) via voltage-dependent Ca2+ channels, (ii) receptor gated Ca2+ channels, and (iii) store operated Ca2+ channels, although, in airway smooth muscle it seems only 2 passive Ca2+ influx pathways are implicated, one sensitive to SKF 96365 (receptor gated Ca2+ channels) and the other to Ni2+ (store operated Ca2+ channels). Resting Ca2+ entry could provide a sufficient amount of Ca2+ and contribute to resting intracellular Ca2+ concentration ([Ca2+]i), maintenance of the resting membrane potential, myogenic tone, and sarcoplasmic reticulum-Ca2+ refilling. However, further research, especially in airway smooth muscle, is required to better explore the physiological role of this passive Ca2+ influx pathway as it could be involved in airway hyperresponsiveness.

  16. Surgery of the airway: historic notes

    PubMed Central

    2016-01-01

    Prior to the 20th century, the need for surgical procedures on the airway was infrequent and consisted mainly of tracheostomy to relieve airway obstruction or repair of tracheal injuries such as lacerations. Even the ability of tracheal suture lines to heal primarily was viewed with concern due to the rigidity of the tracheal wall, its precarious blood supply and uncertainty as to whether the cartilage components could heal without complications. In the 20th century the evolution of tracheal procedures on major airways evolved to meet the challenges provided by the expanding fields of thoracic surgery and advent of mechanical respiratory support with its associated complications. In the first half of the century lobar and lung resections done for tuberculosis and lung cancer required methods for safe closure of the resulting bronchial stumps and end-to-end bronchial anastomosis in the case of sleeve resections of the lung. Beginning in mid-century the advent of respiratory care units for the treatment of polio and for the expanding fields of thoracic and cardiac surgery resulted in a significant number of post-intubation tracheal stenosis requiring resection and primary repair. In the last 20 years of the century the development of lung transplantation with its requirement for successful bronchial anastomoses between the donor and recipient bronchi, created unique challenges including ischemia of the donor bronchus the adverse effects of immunosuppression, donor lung preservation and diagnosis and management of post-transplant infection and rejection. PMID:26981261

  17. Voxel classification based airway tree segmentation

    NASA Astrophysics Data System (ADS)

    Lo, Pechin; de Bruijne, Marleen

    2008-03-01

    This paper presents a voxel classification based method for segmenting the human airway tree in volumetric computed tomography (CT) images. In contrast to standard methods that use only voxel intensities, our method uses a more complex appearance model based on a set of local image appearance features and Kth nearest neighbor (KNN) classification. The optimal set of features for classification is selected automatically from a large set of features describing the local image structure at several scales. The use of multiple features enables the appearance model to differentiate between airway tree voxels and other voxels of similar intensities in the lung, thus making the segmentation robust to pathologies such as emphysema. The classifier is trained on imperfect segmentations that can easily be obtained using region growing with a manual threshold selection. Experiments show that the proposed method results in a more robust segmentation that can grow into the smaller airway branches without leaking into emphysematous areas, and is able to segment many branches that are not present in the training set.

  18. Airway mucus: From production to secretion.

    PubMed

    Williams, Olatunji W; Sharafkhaneh, Amir; Kim, Victor; Dickey, Burton F; Evans, Christopher M

    2006-05-01

    Mucus hypersecretion is a phenotype associated with multiple obstructive lung diseases. However, in spite of its nefarious reputation under pathologic conditions, there are significant benefits to having low levels of mucus present in the airways at baseline, such as the ability to trap and eliminate inhaled particles and to prevent desiccation of airway surfaces. Mucins are high-molecular-weight glycoproteins that are the chief components that render viscoelastic and gel-forming properties to mucus. Recent advances in animal models and in vitro systems have provided a wealth of information regarding the identification of the mucin genes that are expressed in the lungs, the signal transduction pathways that regulate the expression of these mucins, and the secretory pathways that mediate their release into the airways. In addition, the clinical and pathologic literature has corroborated many of the basic laboratory findings. As a result, mucin overproduction and hypersecretion are moving away from being markers of disease and toward being testable as functional components of lung disease processes.

  19. Exercise and airway injury in athletes.

    PubMed

    Couto, Mariana; Silva, Diana; Delgado, Luis; Moreira, André

    2013-01-01

    Olympic level athletes present an increased risk for asthma and allergy, especially those who take part in endurance sports, such as swimming or running, and in winter sports. Classical postulated mechanisms behind EIA include the osmotic, or airway-drying, hypothesis. Hyperventilation leads to evaporation of water and the airway surface liquid becomes hyperosmolar, providing a stimulus for water to move from any cell nearby, which results in the shrinkage of cells and the consequent release of inflammatory mediators that cause airway smooth muscle contraction. But the exercise-induced asthma/bronchoconstriction explanatory model in athletes probably comprises the interaction between environmental training factors, including allergens and ambient conditions such as temperature, humidity and air quality; and athlete's personal risk factors, such as genetic and neuroimmuneendocrine determinants. After the stress of training and competitions athletes experience higher rate of upper respiratory tract infections (URTI), compared with lesser active individuals. Increasing physical activity in non-athletes is associated with a decreased risk of URTI. Heavy exercise induces marked immunodepression which is multifactorial in origin. Prolonged, high intensity exercise temporarily impairs the immune competence while moderate activity may enhance immune function. The relationship between URTI and exercise is affected by poorly known individual determinants such genetic susceptibility, neurogenic mediated immune inflammation and epithelial barrier dysfunction. Further studies should better define the aetiologic factors and mechanisms involved in the development of asthma in athletes, and propose relevant preventive and therapeutic measures.

  20. Oral airway flow dynamics in healthy humans.

    PubMed

    Amis, T C; O'Neill, N; Wheatley, J R

    1999-02-15

    1. Oral airway resistance (RO) is an important determinant of oro-nasal partitioning of airflow (e.g. during exercise and sleep); however, little is known of factors influencing its magnitude and measurement. 2. We developed a non-invasive standardized technique for measuring RO (based on a modification of posterior rhinomanometry) and examined inspiratory RO in 17 healthy male subjects (age, 36 +/- 2 years (mean +/- s.e.m.); height, 177 +/- 2 cm; weight, 83 +/- 3 kg). 3. Inspiratory RO (at 0.4 l s-1) was 0.86 +/- 0.23 cmH2O l-1 s-1 during resting mouthpiece breathing in the upright posture. RO was unaffected by assumption of the supine posture, tended to decrease with head and neck extension and increased to 1.22 +/- 0.19 cmH2O l-1 s-1 (n = 10 subjects, P < 0.01) with 40-45 deg of head and neck flexion. When breathing via a mouth-mask RO was 2.98 +/- 0.42 cmH2O l-1 s-1 (n = 7) and not significantly different from nasal airway resistance. 4. Thus, in awake healthy male subjects with constant jaw position, RO is unaffected by body posture but increases with modest degrees of head and neck flexion. This influence on upper airway patency may be important when oral route breathing is associated with alterations in head and neck position, e.g. during sleep.