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981.
Dominik Herzog Alexander Poellinger Felix Doellinger Dirk Schuermann Bettina Temmesfeld-Wollbrueck Vera Froeling Nils F. Schreiter Konrad Neumann Stefan Hippenstiel Norbert Suttorp Ralf-Harto Hubner 《PloS one》2015,10(5)
ObjectiveEndoscopic lung volume reduction (ELVR) with valves has been shown to improve COPD patients with severe emphysema. However, a major complication is pneumothoraces, occurring typically soon after valve implantation, with severe consequences if not managed promptly. Based on the knowledge that strain activity is related to a higher risk of pneumothoraces, we asked whether modifying post-operative medical care with the inclusion of strict short-term limitation of strain activity is associated with a lower incidence of pneumothorax.MethodsSeventy-two (72) emphysematous patients without collateral ventilation were treated with bronchial valves and included in the study. Thirty-two (32) patients received standard post-implantation medical management (Standard Medical Care (SMC)), and 40 patients received a modified medical care that included an additional bed rest for 48 hours and cough suppression, as needed (Modified Medical Care (MMC)).ResultsThe baseline characteristics were similar for the two groups, except there were more males in the SMC cohort. Overall, ten pneumothoraces occurred up to four days after ELVR, eight pneumothoraces in the SMC, and only two in the MMC cohorts (p=0.02). Complicated pneumothoraces and pneumothoraces after upper lobe treatment were significantly lower in MMC (p=0.02). Major clinical outcomes showed no significant differences between the two cohorts.ConclusionsIn conclusion, modifying post-operative medical care to include bed rest for 48 hours after ELVR and cough suppression, if needed, might reduce the incidence of pneumothoraces. Prospective randomized studies with larger numbers of well-matched patients are needed to confirm the data. 相似文献
982.
Hong-Wen Deng Vera Haynatzka Ken Spitze Gleb Haynatzki 《Evolution; international journal of organic evolution》1999,53(5):1592-1599
There is much interest in measuring selection, quantifying evolutionary constraints, and predicting evolutionary trajectories in natural populations. For these studies, genetic (co)variances among fitness traits play a central role. We explore the conditions that determine the sign of genetic covariances and demonstrate a critical role of selection in shaping genetic covariances. In addition, we show that genetic covariance matrices rather than genetic correlation matrices should be characterized and studied in order to infer genetic basis of population differentiation and/or to predict evolutionary trajectories. 相似文献
983.
Hydrochory was investigated in the seeds of the Amazonian floodplain tree, Swartzia polyphylla, in which pods open on the tree to release one large seed. Seeds collected from beach drift along the Rio Negro showed a high percentage of floaters (82%). Yet most seeds sank following collection from: adult trees (89%), unflooded ground under adults (96%), and flooded ground under adults (86%). The specific gravity of the seeds was near that of water, 1.04 ± 0.03 for sinkers and 0.98 ± 0.02 for floaters. The ability to float was correlated directly with the volume of the air pocket between the two cotyledons, which varied from 5.6 to 20.5 percent of the total seed volume. In a long-term floatation test lasting 81 days, 45 percent of the seeds never floated, 33 percent always floated, and 22 percent first sank for one week and then floated for at least one month. Seeds that never floated eventually rotted, but not until days 63-73. Seeds that were floating at day 81, regardless of how long they had been floating, were placed on moistened filter paper for 18 days during which time 36 percent germinated, 45 percent rotted, and 19 percent did neither but remained viable. These results suggest that S. polyphylla achieves dimorphism in flotation of its seeds, some sinking and some floating, by producing seeds of continuous variation in specific gravity around a mean close to 1.00. Seeds that float can be dispersed long distances along river margins, while those that sink may be moved only marginally from the parent tree. 相似文献
984.
Harald Jungnickel Hayo H. W. Velthuis†‡ Vera L. Imperatriz Fonseca¶ E. David Morgan 《Physiological Entomology》2001,26(4):300-305
Abstract. Queen-laid eggs of Melipona bees stand upright on their larval food, in part because the upper part of the egg is covered with a water-repellent layer of fatty acids and C21 to C29 hydrocarbons. The lower, wettable portion does not have these materials. Trophic eggs laid by workers are essentially devoid of this coating and tend to sink in the food, when not detected and consumed by the queen. Reproductive workers' eggs, which have about 50% of the water-repellent coating in comparison with the queen's eggs, are usually laid in the cell after oviposition by the queen, and therefore there are two eggs in the cell. Surface tension forces cause the two eggs to float towards each other so they become attached. When alone inside the cell, the reproductive worker egg often floats at an angle to the surface, reflecting the instability of this kind of egg. Attachment to a queen's egg therefore compensates this instability and enhances the reproductive worker egg's chances to develop. Such reproductive worker eggs have about 50% of the water-repellent coating in comparison with the queen's eggs. The surface of an 'undetermined' egg laid by a worker was much closer in composition to that of a queen's egg, from which it is deduced that this was the rarer type of reproductive worker egg, namely those that are laid before queen oviposition has taken place. The layer of hydrophobic material on a queen's egg is about one molecule thick, and probably orientated with the carboxyl groups toward the chorion of the egg and the hydrocarbon chains perpendicular to the surface. 相似文献
985.
Acosta M Beard S Ponce J Vera M Mobarec JC Jerez CA 《Omics : a journal of integrative biology》2005,9(1):13-29
Eight nucleotide sequences containing a single rhodanese domain were found in the Acidithiobacillus ferrooxidans ATCC 23270 genome: p11, p14, p14.3, p15, p16, p16.2, p21, and p28. Amino acids sequence comparisons allowed us to identify the potentially catalytic Cys residues and other highly conserved rhodanese family features in all eight proteins. The genomic contexts of some of the rhodanese-like genes and the determination of their expression at the mRNA level by using macroarrays suggested their implication in sulfur oxidation and metabolism, formation of Fe-S clusters or detoxification mechanisms. Several of the putative rhodanese genes were successfully isolated, cloned and overexpressed in E. coli and their thiosulfate:cyanide sulfurtransferase (TST) and 3-mercaptopyruvate/cyanide sulfurtransferase (MST) activities were determined. Based on their sulfurtransferase activities and on structural comparisons of catalytic sites and electrostatic potentials between homology- modeled A. ferrooxidans rhodaneses and the reported crystal structures of E. coli GlpE (TST) and SseA (MST) proteins, two of the rhodanese-like proteins (P15 and P16.2) could clearly be defined as TSTs, and P14 and P16 could possibly correspond to MSTs. Nevertheless, several of the eight A. ferrooxidans rhodanese-like proteins may have some different functional activities yet to be discovered. 相似文献
986.
The yeast Debaryomyces hansenii is usually found in salty environments such as the sea and salted food. It is capable of accumulating sodium without being intoxicated even when potassium is present at low concentration in the environment. In addition, sodium improves growth and protects D. hansenii in the presence of additional stress factors such as high temperature and extreme pH. An array of advantageous factors, as compared with Saccharomyces cerevisiae, is putatively involved in the increased halotolerance of D. hansenii: glycerol, the main compatible solute, is kept inside the cell by an active glycerol-Na+ symporter; potassium uptake is not inhibited by sodium; sodium protein targets in D. hansenii seem to be more resistant. The whole genome of D. hansenii has been sequenced and is now available at http://cbi.labri.fr/Genolevures/ and, so far, no genes specifically responsible for the halotolerant behaviour of D. hansenii have been found. 相似文献
987.
A highly sensitive LC-MS-MS assay for analysis of midazolam and its major metabolite in human plasma: applications to drug metabolism 总被引:2,自引:0,他引:2
Jabor VA Coelho EB Dos Santos NA Bonato PS Lanchote VL 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,828(1-2):27-32
Betamethasone is a synthetic corticosteroid designed to exert a marked glucocorticoid activity. As the free alcohol, betamethasone finds widespread clinical applications related to its anti-inflammatory and immunosuppressant activity. In the present study, a fast, sensitive, robust method was developed for the determination and quantification of betamethasone in human plasma by liquid chromatography coupled with tandem mass spectrometry, using photospray ionization in negative mode. Betamethasone was extracted from 0.5 ml human plasma by liquid-liquid extraction (LLE) using chloramphenicol as internal standard. The method has a chromatographic run of 2.5 min using a C(18) analytical column (100 mm x 2.1 mm i.d.) and the linear calibration curve over the range was linear from 0.05 to 50 ng ml(-1) (r(2)>0.993). The between-run precision, based on the relative standard deviation replicate quality controls was 94.1% (0.15 ng ml(-1)), 90.7% (4.0 ng ml(-1)) and 97.2% (40 ng ml(-1)). The between-run accuracy for the above-mentioned concentrations was 11.9, 9.0 and 9.8%, respectively. The method herein described was employed in a bioequivalence study of two formulations of dexchlorpheniramine/betamethasone 2 mg/0.25 mg tablets. 相似文献
988.
Ribeiro-Gomes FL Otero AC Gomes NA Moniz-De-Souza MC Cysne-Finkelstein L Arnholdt AC Calich VL Coutinho SG Lopes MF DosReis GA 《Journal of immunology (Baltimore, Md. : 1950)》2004,172(7):4454-4462
Macrophages are host cells for the pathogenic parasite Leishmania major. Neutrophils die and are ingested by macrophages in the tissues. We investigated the role of macrophage interactions with inflammatory neutrophils in control of L. major infection. Coculture of dead exudate neutrophils exacerbated parasite growth in infected macrophages from susceptible BALB, but killed intracellular L. major in resistant B6 mice. Coinjection of dead neutrophils amplified L. major replication in vivo in BALB, but prevented parasite growth in B6 mice. Neutrophil depletion reduced parasite load in infected BALB, but exacerbated infection in B6 mice. Exacerbated growth of L. major required PGE(2) and TGF-beta production by macrophages, while parasite killing depended on neutrophil elastase and TNF-alpha production. These results indicate that macrophage interactions with dead neutrophils play a previously unrecognized role in host responses to L. major infection. 相似文献
989.
Korachi M Pravica V Barson AJ Hutchinson IV Drucker DB 《FEMS immunology and medical microbiology》2004,42(1):125-129
In a previous study an association was shown between SIDS and an interleukin-10 (IL-10) genotype. That study was carried out on frozen, unfixed tissue samples, but these are difficult to obtain. Fixed samples used for pathological examination are available. The purpose of this study was to extend the previous work by establishing methods to extract and genotype DNA from fixed, wax-embedded tissues specimens and to use the results to seek confirmation of the association between IL-10 genotype and SIDS in a larger collection of SIDS babies. Using an amplification refractory mutation system-polymerase chain reaction method, a total of 38 infants were genotyped for IL-10 alleles and compared with controls. There was a significant association between the IL-10 -592*A allele and SIDS, consistent with the earlier findings. This study lends support to the hypothesis that IL-10 genotype is related to the susceptibility of babies to SIDS. 相似文献
990.
In order to develop an efficient large-scale extraction of secologanin from Symphoricarpos albus, different methods have been compared. Ultrasonication with organic solvents and water, microwave-assisted extraction and hot water extraction methods were evaluated for their efficiencies. Among the methods tested, ultrasonication with methanol showed the highest yield of secologanin (3.35 +/- 0.24 mg/g fresh weight). For reliable quantification of secologanin a 1H-NMR method was developed. The experiment was performed by the analysis of the integral of the signal of H-9, which was well separated in the range delta 7.4-7.5 in the 1H-NMR spectrum. The quantity of the compound was calculated from the relative ratio of intensity of the target peak to the known amount of internal standard, 200 microg of gallic acid. This method allows rapid and simple quantification of secologanin in 5 min without any pre-purification steps. 相似文献