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91.
Failure of therapy with 2,3-dihydroxybenzoic acid to modify the course of sepsis-induced lung injury
Sharpe M. D.; Mustard R. A.; Finley R. R.; Rutledge F. S.; Sibbald W. J. 《Journal of applied physiology》1990,69(5):1893-1902
Oxidant-induced injury of the pulmonary microvasculature reportedly contributes to an increase in microvascular permeability and pulmonary hypertension, both of which are principal features of acute lung injury (ALI). We tested the hypothesis that antioxidant therapy with 2,3-dihydroxybenzoic acid (DHB), initiated in awake sheep after the development of sepsis-induced ALI, would ameliorate the progression of these lesions. DHB has many actions that suggested to us the potential for demonstrating benefit in ALI complicating sepsis; it is a nontoxic hydroxyl-radical scavenger that also inhibits the cyclooxygenase pathway and acts as a weak iron chelator. In preliminary experiments, we demonstrated that pretreatment with DHB prevented an increase in mean pulmonary arterial pressure, plasma thromboxane A2, measured as its metabolite thromboxane B2, and lymph total protein clearance that otherwise followed an infusion of zymosan-activated plasma (ZAP) in sheep. In subsequent experiments, 12 additional sheep were rendered septic by cecal ligation and perforation. Twenty-four to 36 h after cecal ligation and perforation, an increase in lung microvascular permeability was confirmed, because pulmonary lymph flow had increased by 82% while the mean lymph-to-plasma total protein ratio was unchanged from baseline. At this point, six sheep were then treated with parenteral DHB and six with DHB vehicle for the subsequent 24 h. In contrast to the demonstrated benefit of DHB pretreatment in preventing ALI secondary to an infusion of ZAP, the progressive increase in lymph total protein clearance that complicated septic lung injury in the DHB vehicle group throughout this 24-h study period was not ameliorated in the DHB treatment group. However, DHB did prevent a modest increase in mean pulmonary arterial pressures that was demonstrated in the DHB vehicle group throughout this 24-h treatment period. Although pretreatment prevented ALI after a ZAP infusion, we conclude that DHB only incompletely modified disease progression when administered after the onset of sepsis-induced ALI because it ameliorated the pulmonary hypertensive response without concurrently modifying an increase in lung microvascular fluid flux. 相似文献
92.
Satellite deoxyribonucleic acid in Pseudomonas aeruginosa 总被引:1,自引:0,他引:1
93.
Pim van Hooft Herbert HT Prins Wayne M Getz Anna E Jolles Sipke E van Wieren Barend J Greyling Paul D van Helden Armanda DS Bastos 《BMC evolutionary biology》2010,10(1):106
Background
The Y-chromosomal diversity in the African buffalo (Syncerus caffer) population of Kruger National Park (KNP) is characterized by rainfall-driven haplotype frequency shifts between year cohorts. Stable Y-chromosomal polymorphism is difficult to reconcile with haplotype frequency variations without assuming frequency-dependent selection or specific interactions in the population dynamics of X- and Y-chromosomal genes, since otherwise the fittest haplotype would inevitably sweep to fixation. Stable Y-chromosomal polymorphism due one of these factors only seems possible when there are Y-chromosomal distorters of an equal sex ratio, which act by negatively affecting X-gametes, or Y-chromosomal suppressors of a female-biased sex ratio. These sex-ratio (SR) genes modify (suppress) gamete transmission in their own favour at a fitness cost, allowing for stable polymorphism. 相似文献94.
J T Snow J W Finley M Friedman 《International journal of peptide and protein research》1976,8(1):57-64
The reaction rates in aqueous solutions of aminothiols, thiols, and other compounds with N-acetyl dehydroalanine and its methyl ester (2-acetamindoacrylic acid and methyl 2-acetamidoacrylate) were studied as a function of the structure of the thiol compound in aqueous solutions. Correction of the observed second-order rate constants to identical thiol anion concentration gave a series of computed rate constants whose logarithms showed a linear dependence on the pK's of the thiol group in similar steric environments. Comparison of the addition rates of penicillamine to N-acetyl dehydroalanine and its methyl ester showed the methyl ester to react approximately 11,400 times faster than the acid. Addition rates for thiol acids and aromatic and heterocyclic thiols were also compared; each showed sluggish reactivity with dehydroalanine, but each reacted readily with methyl dehydroalanine. The kinetic data were applied in developing a method for preparing lanthionine in high yield. 相似文献
95.
Effect of irreversible inhibitors on transport ATPase 总被引:1,自引:0,他引:1
G Sachs E Z Finley T Tsuji B I Hirschowitz 《Archives of biochemistry and biophysics》1969,134(2):497-499
96.
Costimulation in Tetrahymena. II. A nonspecific response to heterotypic cell--cell interactions 总被引:2,自引:0,他引:2
Costimulation, a developmental interaction requiring cell-to-cell contact, is the second stage in a linear sequence of events leading from vegetative growth to mating pairs in the ciliate Tetrahymena thermophila. This paper uses the kinetics of appearance of genetically marked progeny to measure accurately the duration of normal costimulation and then to examine the role of mating type in costimulation. Although diverse mating types are required for costimulation to occur, the costimulated cell's response is not specific to the mating type of the cell contacting it; costimulation by one mating type appears to prepare a cell for mating with any complementary mating type. 相似文献
97.
Cutaneous silica granuloma 总被引:1,自引:0,他引:1
Cutaneous silica granuloma is a rare and fascinating cause of delayed scarring. Symptoms may arise many years after minor wounding if glass, sand, or other silica-containing particles have been embedded. Such granulomatous lesions are often nodular, indurated, and erythematous. They may respond to surgical excision or medical treatment, and in rare cases, they may spontaneously regress. We present one case in which three separate areas of cutaneous silica granulomas developed after a latent period of about 20 years and then involuted without intervention. The etiology and therapeutic options are discussed. 相似文献
98.
99.
Eric P. Burkhart Michael G. Jacobson James Finley 《Biodiversity and Conservation》2012,21(14):3657-3679
Following its inclusion in Appendix II of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the harvest, sale and trade of wild ginseng (Panax quinquefolius) for international commerce has been restricted by law in Pennsylvania since the late 1980s. Since then, exports from the state have declined driving the need to better understand the impact of CITES listing and related state and federal laws. Between 2004 and 2010, we conducted a mixed-methods study in Pennsylvania of stakeholder perspectives on state and federal government conservation efforts and experiences relating to enforcement of harvest and trade restrictions. Results from a survey, key informant interviews, and facilitated group discussions indicate widespread support for ginseng conservation efforts but, not with the CITES driven, top-down regulatory approach. It was widely asserted that ginseng stewardship has been, and will continue to be, governed by personal experience, family teachings, and industry norms and not CITES driven restrictions per se. Moreover, study participants were unable to cite instances where prosecution for ginseng-related “crimes” had occurred within their networks and most believed laws are an ineffective deterrent to “bad behavior.” This emic is externally validated by the fact that agency enforcement is constrained by limited personnel and jurisdictional boundaries, not least of which is an inability to enforce on private lands in the state. These findings suggest that a CITES driven regulatory approach has limitations in actually conserving wild ginseng in Pennsylvania, and suggests that this approach should be complemented by stakeholder supported “bottom-up” partnerships involving greater stakeholder participation, such as government-sponsored or supported ginseng planting programs to counter over-exploitation by collectors and/or extirpation resulting from habitat loss. 相似文献
100.
Gao Y Ravert HT Valentine H Scheffel U Finley P Wong DF Dannals RF Horti AG 《Bioorganic & medicinal chemistry》2012,20(12):3698-3702
The radiosynthesis and in vivo evaluation of 5-(5-(6-[(11)C]methyl-3,6-diazabicyclo[3.2.0]heptan-3-yl)pyridin-2-yl)-1H-indole [(11)C]rac-(1), a potential PET tracer for α7 nicotinic acetylcholine receptors (α7-nAChR), are described. Syntheses of the nonradioactive standard rac-1 and corresponding desmethyl precursor 7 were achieved in several reaction steps. Radiomethylation of 7 with [(11)C]CH(3)I afforded [(11)C]rac-1 in an average radiochemical yield of 30 ± 5% (n=5) with high radiochemical purity and an average specific radioactivity of 444 ± 74 GBq/μmol (n=5). The total synthesis time was 30 min from end-of-bombardment. Biodistribution studies in mice showed that [(11)C]rac-1 penetrates the blood-brain barrier and specifically labels neuronal α7-nAChRs. 相似文献