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91.
92.
Thomas Waldow Konstantin Alexiou Wolfgang Witt Florian M. Wagner Utz Kappert Michael Knaut Klaus Matschke 《Nitric oxide》2004,10(4):195-201
Topical administration of nitric oxide (NO) by inhalation is currently used as therapy in various pulmonary diseases, but preconditioning with NO to ameliorate lung ischemia/reperfusion (I/R) injury has not been fully evaluated. In this study, we investigated the effects of NO inhalation on functional pulmonary parameters using an in situ porcine model of normothermic pulmonary ischemia. After left lateral thoracotomy, left lung ischemia was maintained for 90 min, followed by a 5h reperfusion period (group I, n = 7). In group II (n = 6), I/R was preceded by inhalation of NO (10 min, 15 ppm). Animals in group III (n = 7) underwent sham surgery without NO inhalation or ischemia. In order to evaluate the effects of NO preconditioning, lung functional and hemodynamic parameters were measured, and the zymosan-stimulated release of reactive oxygen species in arterial blood was determined. Animals in group I developed significant pulmonary I/R injury, including pulmonary hypertension, a decreased pO(2) level in pulmonary venous blood of the ischemic lung, and a significant increase of the stimulated release of reactive oxygen species. All these effects were prevented, or the onset (release of reactive oxygen species) was delayed, by NO inhalation. These results indicate that preconditioning by NO inhalation before lung ischemia is protective against I/R injury in the porcine lung. 相似文献
93.
G. Oettler F. Wehmann H. F. Utz 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,81(3):401-405
Summary Thirty-five hexaploid and twenty octoploid primary triticales (xTriticosecale Wittmack) derived from homozygous wheat and rye inbred lines were used (1) to investigate the parental wheat, rye, and interaction effects and (2) to estimate quantitative genetic parameters for agronomic traits. The winter triticales were tested in four environments in a three-replicate split-plot design with drilled 1 m2 plots. Superior performance of hexaploid triticales as compared to the octoploids was revealed. Substantial genetic variation and high heritability estimates were found for nearly all of the characters investigated. Estimates of wheat, rye, and wheat×rye interaction variance components disclosed parental main effects to be the most important source of genetic variation in primary triticales. The rye parent was dominant for all characters affecting fertility, and the wheat parent was more important for vegetative development. Character correlations were very similar for triticales of both ploidy levels. The lack of association between grain yield and tillering and the positive correlation between kernels per spike and thousand kernel weight indicated physiological disorders specific for primary triticales. 相似文献
94.
Identification of a neutralizing epitope on glycoprotein gp58 of human cytomegalovirus. 总被引:16,自引:12,他引:4
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Human cytomegalovirus contains an envelope glycoprotein of 58 kilodaltons (gp58). The protein, which is derived from a glycosylated precursor molecule of 160 kilodaltons via proteolytic cleavage, is capable of inducing neutralizing antibodies. We have mapped the epitopes recognized by the neutralizing monoclonal antibody 7-17 and a second antibody (27-287) which is not neutralizing. Overlapping fragments of the carboxy-terminal part of the open reading frame coding for gp58 were expressed in Escherichia coli as beta-galactosidase fusion proteins. The reactivities of antibodies 7-17 and 27-287 were determined by Western blot (immunoblot) analysis. Both antibodies recognized sequences between amino acids 608 and 625 of the primary gp58 translation product. The antibodies almost completely inhibited one another in a competitive binding assay with intact virus as antigen. Moreover, antibody 27-287 was able to inhibit the complement-independent neutralizing activity of antibody 7-17. 相似文献
95.
Jörg Schmidt Kathrin Heermeier Utz Linzner Arne Luz Michael Silbermann Erella Livne Volker Erfle 《Radiation and environmental biophysics》1994,33(1):69-79
Cartilage tissue from embryonic mice which undergoes osteogenic differentiation during in vitro cultivation was used to study the effect of osteosarcomagenic doses of -irradiation and bone-tumor-inducing retroviruses on proliferation and phenotypic differentiation of skeletal cells in a defined tissue culture model. Irradiated mandibular condyles showed dose-dependent enhancement of cell proliferation at day 7 of the culture and increased osteogenic differentiation at day 14. Maximal effects were found with 7.4 Bq/ml of224Ra-labeled medium. Doses of 740 and 7400 Bq/ml of224Ra-labeled medium induced increasing cell death. Retrovirus infection enhanced osteogenic differentiation and extended the viability of irradiated cells. After transplantation none of the treated tissues developed tumors in syngeneic mice. 相似文献
96.
Smith Shadomy Giles M. Robertson Jr. H. Jean Shadomy John P. Utz Elaine Gamble 《Journal of bacteriology》1969,97(2):481-487
Clinical responses of patients with blastomycosis to treatment with hamycin have been variable. An explanation for this was sought in a series of studies in which in vitro and in vivo susceptibilities to hamycin of five strains of Blastomyces dermatitidis were compared. Minimal inhibitory concentrations of hamycin for the five strains indicated uniformly high levels of in vitro susceptibility (0.008 to 0.016 μg/ml). In vivo activity was measured in infected mice treated intraperitoneally for a period of 28 days with doses of the drug ranging from 0.001 to 0.030 mg per mouse. Significant differences in response to treatment among the five strains were noted (P < 0.001), and protective doses were found to vary from 0.001 to >0.030 mg per mouse per day. Further observations of infected mice after treatment revealed marked rates of relapsing infection, and several strains caused death. Persistent inapparent infections were also detected on culture of selected organs. Toxicity due to hamycin alone was not observed. These results suggest that variations in clinical responses to hamycin therapy in treatment of blastomycosis reflect differences in pathogenesis and host response in vivo to the infecting organism rather than differences in susceptibility of B. dermatitidis to hamycin. 相似文献
97.
Cooperation between two periplasmic copper chaperones is required for full activity of the cbb3‐type cytochrome c oxidase and copper homeostasis in Rhodobacter capsulatus
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Petru‐Iulian Trasnea Marcel Utz Bahia Khalfaoui‐Hassani Simon Lagies Fevzi Daldal Hans‐Georg Koch 《Molecular microbiology》2016,100(2):345-361
Copper (Cu) is an essential micronutrient that functions as a cofactor in several important enzymes, such as respiratory heme‐copper oxygen reductases. Yet, Cu is also toxic and therefore cells engage a highly coordinated Cu uptake and delivery system to prevent the accumulation of toxic Cu concentrations. In this study, we analyzed Cu delivery to the cbb3‐type cytochrome c oxidase (cbb3‐Cox) of Rhodobacter capsulatus. We identified the PCuAC‐like periplasmic chaperone PccA and analyzed its contribution to cbb3‐Cox assembly. Our data demonstrate that PccA is a Cu‐binding protein with a preference for Cu(I), which is required for efficient cbb3‐Cox assembly, in particular, at low Cu concentrations. By using in vivo and in vitro cross‐linking, we show that PccA forms a complex with the Sco1‐homologue SenC. This complex is stabilized in the absence of the cbb3‐Cox‐specific assembly factors CcoGHIS. In cells lacking SenC, the cytoplasmic Cu content is significantly increased, but the simultaneous absence of PccA prevents this Cu accumulation. These data demonstrate that the interplay between PccA and SenC not only is required for Cu delivery during cbb3‐Cox assembly but also regulates Cu homeostasis in R. capsulatus. 相似文献
98.
99.
The replicometer is broken: telomeres activate cellular senescence in response to genotoxic stresses
Telomeres, the ends of our linear chromosomes, can function as ‘replicometers’, capable of counting cell division cycles as they progressively erode with every round of DNA replication. Once they are critically short, telomeres become dysfunctional and consequently activate a proliferative arrest called replicative senescence. For many years, telomeres were thought to be autonomous structures, largely isolated from cell intrinsic and extrinsic signals, whose function is to prevent limitless cellular proliferation, a characteristic of most cancer cells. It is becoming increasingly evident, however, that telomeres not only count cell divisions, but also function as sensors of genotoxic stresses to stop cell cycle progression prematurely and long before cells would have entered replicative senescence. This stable growth arrest, triggered by dysfunctional telomeres that are not necessarily critically short, likely evolved as a tumor‐suppressing mechanism as it prevents proliferation of cells that are at risk for acquiring potentially hazardous and transforming mutations both in vitro and in vivo. Here, we review studies supporting the concept that telomeres are important cellular structures whose function not only is to count cell divisions, but also to act as molecular switches that can rapidly stop cell cycle progression permanently in response to a variety of stresses, including oncogenic signals. 相似文献
100.
Adalgisa F. Cabral Roberto Júnio P. Dias Laura R. P. Utz Roberto G. Alves Marta D’Agosto 《Hydrobiologia》2010,644(1):351-359
In order to show how environmental factors could influence the spatial and temporal distribution of epibiosis, we investigated
the occurrence of the ciliate Rhabdostyla cf. chironomi (Ciliophora, Peritrichia) attached to Chironomidae larvae in an urban stream in southeast Brazil. Samples were collected
monthly for 1-year period at five sampling stations along the stream. Among the 24 genera analyzed, the genus Chironomus was the most abundant, with 16.84% carrying R. cf. chironomi. This epibiotic relationship was only recorded in sample stations located in a heavily populated urban area of the stream.
Statistical analyses demonstrated significant correlations between infestation prevalence and environmental parameters such
as rainfall, bacterial density, and host abundance. The occurrence of epibionts on the larvae was spatially and temporally
heterogeneous. The results are discussed in terms of possible factors related to the heterogeneous spatial and temporal occurrence.
Greater understanding of the ecological factors governing the occurrence of the epibiont–host relationship is essential to
establish future use of this relationship as water quality indicator in lotic systems. 相似文献