956 resultados para Respiratory Physiologic Phenomena


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The phosphorylation status of the small hydrophobic (SH) protein of respiratory syncytial virus (RSV) was examined in virus-infected Vero cells. The SH protein v.,as isolated from [S-35]methionine- and [P-33]orthophosphate-labelled IRSV-infected cells and analysed by SDS-PAGE. In each case, a protein product of the expected size for the SH protein was observed. Phosphoamino acid analysis and reactivity with the phosphotyrosine specific antibody PY20 showed that the SH protein was modified by tyrosine phosphorylation. The role or tyrosine kinase activity in SH protein phosphorylation was confirmed by the use of genistein, a broad-spectrum tyrosine kinase inhibitor, to inhibit SH protein phosphorylation. Further analysis showed that the different glycosylated forms of the SH protein were phosphorylated, as was the oligomeric form of the protein. Phosphorylation of the SH protein was specifically inhibited by the mitogen-activated protein kinase (MAPK) p38 inhibitor SB203580, suggesting that SH protein phosphorylation occurs via a MAPK p38-dependent pathway. Analysis of virus-infected cells using fluorescence microscopy showed that, although the SH protein was distributed throughout the cytoplasm, it appeared to accumulate, at low levels, in the endoplasmic reticulum/Golgi complex, confirming recent observations. However, in the presence of SB203580. an increased accumulation of the SH protein in the Golgi complex was observed, although other virus structures, such as virus filaments and inclusion bodies, remained largely unaffected. These results showed that during RSV infection, the SH protein is modified by an MAPK p38-dependant tyrosine kinase activity and that this modification influences its cellular distribution.

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We report calculations of double ionization energy spectra and momentum distributions of laser-driven helium due to few-cycle pulses of wavelength 195 nm. The results are obtained from full-dimensional numerical integration of the two electron time-dependent Schr¨odinger equation. A momentum-space analysis of doubly ionizing wavepackets shows that the concentric-ring structure of above-threshold double ionization, together with the associated structure of peaks in the total kinetic energy spectrum, may be attributed to wavepacket interference effects, where at least two doubly-ionizing wavepackets from different recollision events populate the same spatial hemisphere.

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Introduction: The most effective treatment for high altitude sickness is prompt descent. However, rapid descent is sometimes impossible and alternative solutions are desirable. Supplemental oxygen at ambient pressure and hyperbaric oxygen in a hyperbaric tent have both been demonstrated to improve symptoms and increase arterial oxygenation (SaO(2)) in those with high altitude sickness; however, their use in combination has not previously been described in a controlled study. Methods and Results: In this feasibility study, the SaO(2) of six healthy, well-acclimatized participants rose from 76.5 to 97.5% at 4900 m and 72.5 to 96.0% at 5700 m following the administration of oxygen via a nasal demand circuit (33 ml of oxygen per pulse) inside a hyperbaric tent (107 mmHg above ambient barometric pressure) (p

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Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury. It is a response to various diseases of variable etiology, including SARS-CoV infection. To date, a comprehensive study of the genomic physiopathology of ARDS (and SARS) is lacking, primarily due to the difficulty of finding suitable materials to study the disease process at a tissue level (instead of blood, sputa or swaps). Hereby we attempt to provide such study by analyzing autopsy lung samples from patient who died of SARS and showed different degrees of severity of the pulmonary involvement. We performed real-time quantitative PCR analysis of 107 genes with functional roles in inflammation, coagulation, fibrosis and apoptosis: some key genes were confirmed at a protein expression level by immunohistochemistry and correlated to the degree of morphological severity present in the individual samples analyzed. Significant expression levels were identified for ANPEP (a receptor for CoV), as well as inhibition of the STAT1 pathway, IFNs production and CXCL10 (a T-cell recruiter). Other genes unassociated to date with ARDS/SARS include C1Qb, C5R1, CASP3, CASP9, CD14, CD68, FGF7, HLA-DRA, ICF1, IRF3, MALAT-1, MSR1, NFIL3, SLPI, USP33, CLC, GBP1 and TACI. As a result, we proposed to therapeutically target some of these genes with compounds such as ANPEP inhibitors, SLPI and dexamethasone. Ultimately, this study may serve as a model for future, tissue-based analyses of fibroinflammatory conditions affecting the lung. (C) 2009 Elsevier B.V. All rights reserved.

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Background Human respiratory syncytial virus (RSV) causes severe respiratory disease in infants. Airway epithelial cells are the principle targets of RSV infection. However, the mechanisms by which it causes disease are poorly understood. Most RSV pathogenesis data are derived using laboratory-adapted prototypic strains. We hypothesized that such strains may be poorly representative of recent clinical isolates in terms of virus/host interactions in primary human bronchial epithelial cells (PBECs). Methods To address this hypothesis, we isolated three RSV strains from infants hospitalized with bronchiolitis and compared them with the prototypic RSV A2 in terms of cytopathology, virus growth kinetics and chemokine secretion in infected PBEC monolayers. Results RSV A2 rapidly obliterated the PBECs, whereas the clinical isolates caused much less cytopathology. Concomitantly, RSV A2 also grew faster and to higher titers in PBECs. Furthermore, dramatically increased secretion of IP-10 and RANTES was evident following A2 infection compared with the clinical isolates. Conclusions The prototypic RSV strain A2 is poorly representative of recent clinical isolates in terms of cytopathogenicity, viral growth kinetics and pro-inflammatory responses induced following infection of PBEC monolayers. Thus, the choice of RSV strain may have important implications for future RSV pathogenesis studies.

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Early meningococcal disease (MD) diagnosis is difficult. We assessed rapid molecular testing of respiratory specimens. We performed genotyping of respiratory swabs, blood, and cerebrospinal fluid from children with suspected disease and nasal swabs (NSs) from matched controls. Thirty-nine of 104 suspected cases had confirmed disease. Four controls were carriers. Throat swab ctrA and porA testing for detection of disease gave a sensitivity of 81% (17/21), specificity of 100% (44/44), positive predictive value (PPV) of 100% (17/17), negative predictive value (NPV) of 92% (44/48), and relative risk of 12. NS ctrA and porA testing gave a sensitivity of 51% (20/39), specificity of 95% (62/65), PPV of 87% (20/23), NPV of 77% (62/81), and relative risk of 4. Including only the 86 NSs taken within 48 h of presentation, the results were sensitivity of 60% (18/30), specificity of 96% (54/56), PPV of 90% (18/20), NPV of 82% (54/66), and relative risk of 5. Swab type agreement was excellent (kappa 0.80, P

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Background: The purpose of this systematic literature review was to examine current empirical research on general and respiratory health outcomes in adult survivors of bronchopulmonary dysplasia (BPD).

Methods: We searched seven databases up to the end of November 2010 (MEDLINE, PubMed, EMBASE, PsycINFO, Maternity and Infant Care, Cumulative Index of Nursing and Allied Health Literature, and Web of Knowledge). We independently screened and included only those studies concerning the assessment of outcome measures in adult survivors of BPD. Data on methodologic design and findings were extracted from each included study; in addition, the methodologic quality of each study was assessed using the Critical Appraisal Skills Programme checklist.

Results: Fourteen cohort studies met the review criteria. Of those, a total of eight studies were considered to be of high quality (score 9-12), five of moderate quality (score 5-8), and only one was of low quality (score 0-4). In all studies of adult survivors of BPD, differences were found between the index and control groups, suggesting that many adults survivors of BPD who were born preterm or with very low birth weight had more respiratory symptoms and pulmonary function abnormalities compared with their peers. Five studies concerning radiologic findings reported structural changes persisting into adulthood. Findings from three studies suggested impairment in exercise capacity, although firm conclusions were limited by the small sample size in the studies reviewed.

Conclusions: Compared with adults born at term, adult survivors of BPD have more impairment in general and respiratory health, which does not seem to diminish over time.

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Heart activity of Pecten maximus (L.) has been recorded during various forms of experimentally induced respiratory stress. There was considerable variation in the responses of individual scallops but bradycardia generally occurred in response to all forms of respiratory stress, with the rate of fall in heart rate dependent upon the severity of hypoxia. When oxygen tension declined slowly in a closed respirometer there was regulation of both heart rate and oxygen consumption. The critical tension, Pc, for oxygen consumption lay between 70 and 80 mm Hg, and corresponded with a slight regulatory upswing of the heart rate, whereas the Pc for heart rate was much lower at 20–30 mm Hg. Sudden transfer to deoxygenated water for 3 h resulted in very rapid bradycardia and there was a rapid recovery and initial overshoot of the normal rate on return to well-oxygenated sea water. Aerial exposure for 3 h produced more gradual bradycardia followed by gradual recovery on return to sea water. The results of this work are compared in some detail with previous work on other species of bivalve from different geographical areas and habitats, and the mechanisms controlling cardiac and respiratory regulation are discussed. It is concluded that there are few clear-cut general differences between littoral and sublittoral species in their behavioural and physiological adaptations to hypoxia; the main distinguishing feature of littoral-adapted species is their ability to control air-gaping. Changes in heart activity generally indicate variations in metabolic rate, the speed at which the metabolic rate may be altered reflecting the degree of adaptation to the littoral environment.