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  • 1
    Online Resource
    Online Resource
    Wiley ; 1993
    In:  physica status solidi (b) Vol. 179, No. 1 ( 1993-09-01), p. K41-K46
    In: physica status solidi (b), Wiley, Vol. 179, No. 1 ( 1993-09-01), p. K41-K46
    Type of Medium: Online Resource
    ISSN: 0370-1972 , 1521-3951
    URL: Issue
    Language: German
    Publisher: Wiley
    Publication Date: 1993
    detail.hit.zdb_id: 208851-4
    detail.hit.zdb_id: 1481096-7
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  • 2
    Online Resource
    Online Resource
    Elsevier BV ; 1994
    In:  Computers & Chemistry Vol. 18, No. 1 ( 1994-3), p. 1-4
    In: Computers & Chemistry, Elsevier BV, Vol. 18, No. 1 ( 1994-3), p. 1-4
    Type of Medium: Online Resource
    ISSN: 0097-8485
    Language: English
    Publisher: Elsevier BV
    Publication Date: 1994
    detail.hit.zdb_id: 1497012-0
    SSG: 12
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  • 3
    In: Nuclear Physics A, Elsevier BV, Vol. 553 ( 1993-03), p. 757-762
    Type of Medium: Online Resource
    ISSN: 0375-9474
    Language: English
    Publisher: Elsevier BV
    Publication Date: 1993
    detail.hit.zdb_id: 1466542-6
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  • 4
    Online Resource
    Online Resource
    Optica Publishing Group ; 1990
    In:  Applied Optics Vol. 29, No. 12 ( 1990-04-20), p. 1718-
    In: Applied Optics, Optica Publishing Group, Vol. 29, No. 12 ( 1990-04-20), p. 1718-
    Type of Medium: Online Resource
    ISSN: 0003-6935 , 1539-4522
    Language: English
    Publisher: Optica Publishing Group
    Publication Date: 1990
    detail.hit.zdb_id: 207387-0
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  • 5
    Online Resource
    Online Resource
    American Physiological Society ; 1991
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 261, No. 4 ( 1991-10-01), p. 97-104
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 261, No. 4 ( 1991-10-01), p. 97-104
    Abstract: Newborn animals develop more severe hypoxic pulmonary hypertension than do adults, their vascular changes are greater, and both the hypertension and vascular changes occur more rapidly. We hypothesize that this differential developmentally controlled response may arise from either a difference in the type or quantity of endogenously secreted mediators in response to a given injury or a difference in the replicative and/or matrix-producing response of the vascular cells to physical or chemical stimuli. We investigated the effect of chronic hypoxia (14 days) on the proliferative and matrix-producing phenotype of the neonatal (14-day-old) pulmonary artery smooth muscle cell (SMC) and examined the heterogeneity and potential mechanisms responsible for this response. In situ hybridization studies demonstrated a remarkable change in the distribution of cells hybridizing with a tropoelastin cRNA probe after 14 days of hypoxia. Studies also demonstrated a population of SMC that did not hybridize with the elastin or collagen probes, indicating that the pulmonary artery contains SMC of multiple phenotypes and that the response to hypoxic and hemodynamic stress is not uniform for the various types. Bromodeoxyuridine labeling experiments indicated a large increase in DNA synthesis in hypertensive vessels, which, again, was not uniform either across or along the arterial wall. In vitro experiments with neonatal SMC suggested that hypoxia alone could not be responsible for the proliferative or matrix changes. These observations were supported by in vivo experiments in which coarctation of the left pulmonary artery, which markedly decreased pressure and flow to the left lung in hypoxic animals (14 days), resulted in significant decreases in collagen and elastin message levels in the left pulmonary artery distal to the coarctation compared with location-matched vessels from the right lung. Finally, we noted marked decreases in B-receptor density and adenyl cyclase activity in right atrial and pulmonary artery tissue from the chronically hypoxic animals. Decreases in the ability of the cell to produce adenosine 3',5'-cyclic monophosphate could significantly affect both the proliferative and matrix-producing potential of the SMC. We conclude that in vivo adaptation of the pulmonary artery SMC to chronic hypoxia includes changes in protein synthesis, cell proliferation, receptor expression, and enzyme activity. Further, there is a marked heterogeneity of these responses both across and along the arterial wall., hypoxia; phenotype; signal transductions; smooth muscle cells
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 1991
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 6
    Online Resource
    Online Resource
    American Physiological Society ; 1990
    In:  American Journal of Physiology-Lung Cellular and Molecular Physiology Vol. 259, No. 6 ( 1990-12-01), p. L451-L458
    In: American Journal of Physiology-Lung Cellular and Molecular Physiology, American Physiological Society, Vol. 259, No. 6 ( 1990-12-01), p. L451-L458
    Abstract: The Fischer rat is known for its susceptibility to develop liver necrosis when challenged with paraquat (Smith et al., J. Pharmacol. Exp. Ther. 235: 172-177, 1985). We postulated that other organs, specifically the lung, may also be more susceptible to injury and examined whether lungs from Fischer (F) rats were injured more easily when challenged with active oxygen species than Sprague-Dawley (SD) rat lungs. We aimed to investigate whether increased susceptibility to oxidant injury was related to differences in lung antioxidant defenses. Perfused lungs from both rat strains were challenged by addition of H2O2 to the perfusate or by short-term hyperoxic ventilation. To assess nonoxidant modes of lung injury, we examined lung responses after exposure to protamine sulfate or neutrophil elastase. Intravascular H2O2 or 3 h in vitro hyperoxia caused lung edema in F but not SD rats, and elastase injured F rat lungs more than the lungs from SD rats. Protamine, however, injured the lungs from both strains to a similar degree. Catalase, but not superoxide dismutase or allopurinol, protected F rat lungs against edema, resulting from 3 h in vitro hyperoxia. The lung homogenate levels for reduced glutathione or conjugated dienes and the activities of lung tissue catalase, glutathione peroxidase, and cytochrome P-450 were not different between the two strains. Lung tissue ATP levels, however, were lower in F than in SD rats. Although the F rat strain appears to have an altered oxidant-antioxidant defense balance, the exact cause of the greater susceptibility to oxidant stress of the F rat strain remains elusive.
    Type of Medium: Online Resource
    ISSN: 1040-0605 , 1522-1504
    Language: English
    Publisher: American Physiological Society
    Publication Date: 1990
    detail.hit.zdb_id: 1477300-4
    SSG: 12
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  • 7
    Online Resource
    Online Resource
    American Physiological Society ; 1991
    In:  Journal of Applied Physiology Vol. 71, No. 6 ( 1991-12-01), p. 2483-2492
    In: Journal of Applied Physiology, American Physiological Society, Vol. 71, No. 6 ( 1991-12-01), p. 2483-2492
    Abstract: Lung platelet-activating factor (PAF) levels increased in some rats at 1–3 wk after subcutaneous injection of monocrotaline (MCT). We tested the effect of specific PAF antagonists, WEB 2086 and WEB 2170, on MCT-induced lung injury and subsequent pulmonary hypertension and right ventricular hypertrophy. Treatment with either agent decreased MCT-induced pulmonary hypertension and right ventricular hypertrophy at 3 wk after injection. Treatment with WEB 2170 reduced MCT-induced pulmonary vascular leak at 1 wk after injection, and WEB 2086-treatment exclusively during the early leak phase also decreased MCT-induced right ventricular hypertrophy at 3 wk. Treatment with WEB 2170 between the 3rd and 4th wk after MCT injection inhibited the progression of right ventricular hypertrophy at 4 wk. These results suggest that PAF contributes to the early pulmonary vascular leak, and this leak phase is important for the development of pulmonary hypertension and right ventricular hypertrophy in MCT-treated rats. Furthermore, it appears that PAF action contributes to the maintenance of a chronic inflammatory process that involves the synthesis of other lipid mediators (prostaglandins and leukotrienes) and leads to pulmonary hypertension. We conclude that PAF has a role in the MCT-induced inflammatory lung injury and pulmonary hypertension.
    Type of Medium: Online Resource
    ISSN: 8750-7587 , 1522-1601
    RVK:
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 1991
    detail.hit.zdb_id: 1404365-8
    SSG: 12
    SSG: 31
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  • 8
    Online Resource
    Online Resource
    American Physiological Society ; 1990
    In:  American Journal of Physiology-Heart and Circulatory Physiology Vol. 258, No. 1 ( 1990-01-01), p. H153-H158
    In: American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 258, No. 1 ( 1990-01-01), p. H153-H158
    Abstract: We tested the hypothesis that platelet-activating factor plays an important role in promoting endotoxin-induced lung injury by studying the effect of WEB 2086, a specific platelet-activating factor receptor antagonist, on lung vascular leak in endotoxin-treated rats. Intraperitoneal injection of Salmonella enteritidis endotoxin (2 mg/kg) increased the extravascular leakage of 125I-labeled albumin in perfused lungs at 30 min, 2 h, 6 h, and 48 h. Treatment with WEB 2086 (10 mg/kg ip) either 20 min before or 30 min after endotoxin injection significantly reduced lung injury at 2 h after endotoxin (leak index: control 0.74 +/- 0.03, endotoxin 1.79 +/- 0.14, endotoxin + pretreated WEB 1.23 +/- 0.09, endotoxin + posttreated WEB 1.21 +/- 0.13). In addition, posttreatment with WEB 2086 starting at 90 min after endotoxin injection markedly reduced lung leak at 6 h (control 0.74 +/- 0.03, endotoxin 1.29 +/- 0.14, endotoxin + WEB 0.71 +/- 0.06). The protective effect of WEB 2086 was not the result of cyclooxygenase blockade because the release of thromboxane B2 by endotoxin-treated lungs was not affected by WEB 2086. Furthermore, neither pretreatment nor posttreatment with WEB 2086 significantly reduced the endotoxin-induced increase in plasma glutathione disulfide, a marker of in vivo oxidative stress. In rats given a lethal dose of endotoxin (20 mg/kg ip), posttreatment with WEB 2086, starting at 2 h after endotoxin, significantly improved survival compared with vehicle treatment. We conclude that WEB 2086 ameliorated endotoxin-induced lung injury without reducing oxidative stress in the rat and suggest that blockade of platelet-activating factor receptor may be an important therapeutic consideration in sepsis-induced acute lung vascular injury.
    Type of Medium: Online Resource
    ISSN: 0363-6135 , 1522-1539
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 1990
    detail.hit.zdb_id: 1477308-9
    SSG: 12
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  • 9
    Online Resource
    Online Resource
    American Physiological Society ; 1990
    In:  Journal of Applied Physiology Vol. 68, No. 3 ( 1990-03-01), p. 1059-1068
    In: Journal of Applied Physiology, American Physiological Society, Vol. 68, No. 3 ( 1990-03-01), p. 1059-1068
    Abstract: We studied the synergistic interaction between platelet-activating factor (PAF) and protamine sulfate, a cationic protein that causes pulmonary endothelial injury, in isolated rat lungs perfused with a physiological salt solution. A low dose of protamine (50 micrograms/ml) increased pulmonary artery perfusion pressure (Ppa) but did not increase wet lung-to-body weight ratio after 20 min. Pretreatment of the lungs with a noninjurious dose of PAF (1.6 nM) 10 min before protamine markedly potentiated protamine-induced pulmonary vasoconstriction and resulted in severe lung edema and increased lung tissue content of 6-keto-prostaglandin F1 alpha, thromboxane B2, and leukotriene C4. Pulmonary microvascular pressure (Pmv), measured by double occlusion, was markedly increased in lungs given PAF and protamine. These potentiating effects of PAF were blocked by WEB 2086 (10(-5) M), a specific PAF receptor antagonist. Pretreatment of the lungs with a high dose of histamine (10(-4) M) failed to enhance the effect of protamine on Ppa, Pmv, or wet lung-to-body weight ratio. Furthermore, PAF pretreatment enhanced elastase-, but not H2O2-, induced lung edema. To assess the role of hydrostatic pressure in edema formation, we compared lung permeability-surface area products (PS) in papaverine-treated lungs given either protamine alone or PAF + protamine and tested the effect of mechanical elevation of Pmv on protamine-induced lung edema. In the absence of vasoconstriction, PAF did not potentiate protamine-induced increase in lung PS. On the other hand, mechanically raising Pmv in protamine-treated lungs to a level similar to that measured in lungs given PAF + protamine did not result in a comparable degree of lung edema. We conclude that PAF potentiates protamine-induced lung edema predominantly by enhanced pulmonary venoconstriction. However, a pressure-independent effect of PAF on lung vasculature cannot be entirely excluded.
    Type of Medium: Online Resource
    ISSN: 8750-7587 , 1522-1601
    RVK:
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 1990
    detail.hit.zdb_id: 1404365-8
    SSG: 12
    SSG: 31
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  • 10
    Online Resource
    Online Resource
    American Physiological Society ; 1990
    In:  Journal of Applied Physiology Vol. 68, No. 6 ( 1990-06-01), p. 2640-2648
    In: Journal of Applied Physiology, American Physiological Society, Vol. 68, No. 6 ( 1990-06-01), p. 2640-2648
    Abstract: Samples of human bronchoalveolar lavage fluid (BALF) and urine were utilized to demonstrate methods for quantitation and validation of leukotrienes (LTs). These methods utilize an enzyme immunoassay (EIA) that uses commercially available reagents, the antibody recognizing LTC4, LTD4, LTE4, and N-acetyl LTE4. BALF containing epithelial lining fluid was collected from atopic asthmatics both before and 5 min after the subjects had been challenged with a local instillation of allergen into the airways. BALF samples collected without allergen challenge had low levels of immunoreactive LTs, whereas samples collected after allergen were markedly elevated. After high-performance liquid chromatography (HPLC) separation of LTs, EIA revealed the presence of LTC4. The identity was validated by incubating LTC4 with a bovine gamma-glutamyl transpeptidase with dipeptidase activity that converted added [3H]-LTC4 as well as LTC4 immunoreactivity to LTE4. Urine samples collected from six healthy volunteers, one patient with adult respiratory distress syndrome (ARDS), and three patients in status asthmaticus were also analyzed for LTs. After HPLC separation of LTs and quantitation by EIA, urine samples from healthy subjects were found to have low but measurable LTE4. In contrast, the urine samples from the patients in status asthmaticus and from the ARDS patient had large elevations of LTE4 levels compared with healthy subjects. When the HPLC fractions containing [3H] LTE4 and LT immunoreactivity in the ARDS sample were treated with acetic anhydride, HPLC analysis indicated that both radiolabel and immunoreactivity now eluted at the retention time of N-acetyl LTE4, the derivatized product of LTE4. The methods described are relatively easy and can be used to measure and validate the existence of peptidoleukotrienes in biological samples.
    Type of Medium: Online Resource
    ISSN: 8750-7587 , 1522-1601
    RVK:
    RVK:
    Language: English
    Publisher: American Physiological Society
    Publication Date: 1990
    detail.hit.zdb_id: 1404365-8
    SSG: 12
    SSG: 31
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