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G Ter Riet DA Korevaar M Leenaars PJ Sterk CJ Van Noorden LM Bouter R Lutter RP Elferink L Hooft 《PloS one》2012,7(9):e43404
Context
Publication bias jeopardizes evidence-based medicine, mainly through biased literature syntheses. Publication bias may also affect laboratory animal research, but evidence is scarce.Objectives
To assess the opinion of laboratory animal researchers on the magnitude, drivers, consequences and potential solutions for publication bias. And to explore the impact of size of the animals used, seniority of the respondent, working in a for-profit organization and type of research (fundamental, pre-clinical, or both) on those opinions.Design
Internet-based survey.Setting
All animal laboratories in The Netherlands.Participants
Laboratory animal researchers.Main Outcome Measure(s)
Median (interquartile ranges) strengths of beliefs on 5 and 10-point scales (1: totally unimportant to 5 or 10: extremely important).Results
Overall, 454 researchers participated. They considered publication bias a problem in animal research (7 (5 to 8)) and thought that about 50% (32–70) of animal experiments are published. Employees (n = 21) of for-profit organizations estimated that 10% (5 to 50) are published. Lack of statistical significance (4 (4 to 5)), technical problems (4 (3 to 4)), supervisors (4 (3 to 5)) and peer reviewers (4 (3 to 5)) were considered important reasons for non-publication (all on 5-point scales). Respondents thought that mandatory publication of study protocols and results, or the reasons why no results were obtained, may increase scientific progress but expected increased bureaucracy. These opinions did not depend on size of the animal used, seniority of the respondent or type of research.Conclusions
Non-publication of “negative” results appears to be prevalent in laboratory animal research. If statistical significance is indeed a main driver of publication, the collective literature on animal experimentation will be biased. This will impede the performance of valid literature syntheses. Effective, yet efficient systems should be explored to counteract selective reporting of laboratory animal research. 相似文献54.
Jordis Trischler Nick Merkel Stephanie K?nitzer Christina-Maria Müller Susanne Unverzagt Christiane Lex 《Respiratory research》2012,13(1):14
Background
Asthma is a chronic inflammatory disease of the airways but recent studies have shown that alveoli are also subject to pathophysiological changes. This study was undertaken to compare hydrogen peroxide (H2O2) concentrations in different parts of the lung using a new technique of fractioned breath condensate sampling.Methods
In 52 children (9-17 years, 32 asthmatic patients, 20 controls) measurements of exhaled nitric oxide (FENO), lung function, H2O2 in exhaled breath condensate (EBC) and the asthma control test (ACT) were performed. Exhaled breath condensate was collected in two different fractions, representing mainly either the airways or the alveoli. H2O2 was analysed in the airway and alveolar fractions and compared to clinical parameters.Results
The exhaled H2O2 concentration was significantly higher in the airway fraction than in the alveolar fraction comparing each single pair (p = 0.003, 0.032 and 0.040 for the whole study group, the asthmatic group and the control group, respectively). Asthma control, measured by the asthma control test (ACT), correlated significantly with the H2O2 concentrations in the alveolar fraction (r = 0.606, p = 0.004) but not with those in the airway fraction in the group of children above 12 years. FENO values and lung function parameters did not correlate to the H2O2 concentrations of each fraction.Conclusion
The new technique of fractionated H2O2 measurement may differentiate H2O2 concentrations in different parts of the lung in asthmatic and control children. H2O2 concentrations of the alveolar fraction may be related to the asthma control test in children. 相似文献55.
Riem Vis PW Sluijter JP Soekhradj-Soechit RS van Herwerden LA Kluin J Bouten CV 《Journal of cellular and molecular medicine》2012,16(4):730-739
For clinical application of tissue engineering strategies, the use of animal-derived serum in culture medium is not recommended, because it can evoke immune responses in patients. We previously observed that human platelet-lysate (PL) is favourable for cell expansion, but generates weaker tissue as compared to culture in foetal bovine serum (FBS). We investigated if human serum (HS) is a better human supplement to increase tissue strength. Cells were isolated from venous grafts of 10 patients and expanded in media supplemented with PL or HS, to determine proliferation rates and expression of genes related to collagen production and maturation. Zymography was used to assess protease expression. Collagen contraction assays were used as a two-dimensional (2D) model for matrix contraction. As a prove of principle, 3D tissue culture and tensile testing was performed for two patients, to determine tissue strength. Cell proliferation was lower in HS-supplemented medium than in PL medium. The HS cells produced less active matrix metallo-proteinase 2 (MMP2) and showed increased matrix contraction as indicated by gel contraction assays and 3D-tissue culture. Tensile testing showed increased strength for tissues cultured in HS when compared to PL. This effect was more pronounced if cells were sequentially cultured in PL, followed by tissue culture in HS. These data suggest that sequential use of PL and HS as substitutes for FBS in culture medium for cardiovascular tissue engineering results in improved cell proliferation and tissue mechanical properties, as compared to use of PL or HS apart. 相似文献
56.
The evolution of spinnable cotton fiber entailed prolonged development and a novel metabolism
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A central question in evolutionary biology concerns the developmental processes by which new phenotypes arise. An exceptional example of evolutionary innovation is the single-celled seed trichome in Gossypium (“cotton fiber”). We have used fiber development in Gossypium as a system to understand how morphology can rapidly evolve. Fiber has undergone considerable morphological changes between the short, tightly adherent fibers of G. longicalyx and the derived long, spinnable fibers of its closest relative, G. herbaceum, which facilitated cotton domestication. We conducted comparative gene expression profiling across a developmental time-course of fibers from G. longicalyx and G. herbaceum using microarrays with ~22,000 genes. Expression changes between stages were temporally protracted in G. herbaceum relative to G. longicalyx, reflecting a prolongation of the ancestral developmental program. Gene expression and GO analyses showed that many genes involved with stress responses were upregulated early in G. longicalyx fiber development. Several candidate genes upregulated in G. herbaceum have been implicated in regulating redox levels and cell elongation processes. Three genes previously shown to modulate hydrogen peroxide levels were consistently expressed in domesticated and wild cotton species with long fibers, but expression was not detected by quantitative real time-PCR in wild species with short fibers. Hydrogen peroxide is important for cell elongation, but at high concentrations it becomes toxic, activating stress processes that may lead to early onset of secondary cell wall synthesis and the end of cell elongation. These observations suggest that the evolution of long spinnable fibers in cotton was accompanied by novel expression of genes assisting in the regulation of reactive oxygen species levels. Our data suggest a model for the evolutionary origin of a novel morphology through differential gene regulation causing prolongation of an ancestral developmental program. 相似文献
57.
Annette AM Gerritsen Rob JPM Scholten Willem JJ Assendelft Herman Kuiper Henrica CW de Vet Lex M Bouter 《BMC neurology》2001,1(1):8-7
Background
Carpal tunnel syndrome is a common disorder, which can be treated with surgery or conservative options. However, there is insufficient evidence and no consensus among physicians with regard to the preferred treatment for carpal tunnel syndrome. Therefore, a randomized controlled trial is conducted to compare the short- and long-term efficacy of surgery and splinting in patients with carpal tunnel syndrome. An attempt is also made to avoid the (methodological) limitations encountered in earlier trials on the efficacy of various treatment options for carpal tunnel syndrome. 相似文献58.
The purpose of the present investigation was to compare similarities and differences in immune response among Echinacea species,
which are commonly used to treat upper respiratory infections. The investigation involved two components: acquisition of immunomodulatory
data reported here for the first time, and combined phenetic analysis of these data along with previous reports. Experimental
data were obtained by stimulating human PBMC in vitro with extracts from Echinacea spp. and assaying production of three cytokines
(interleukin-1β [IL-1β] interleukin-2 [IL-2], and tumor necrosis factor α [TNF-α]). Phenetic analyses were employed to compare
responses across the entire data set, including UPGMA (Unweighted Pair Group Method with Arithmetic Mean) and neighbor-joining
methods. In the immune experiments conducted for this investigation, E. angustifolia,E. paradoxa, E. purpurea, E. simulata, andE. tennesseensis extracts significantly augmented IL-1 β and TNF-α production, whereas no extracts significantly modulated IL-2. All phenetic
methods produced similar dendrograms, revealing two species pairs (E. angustifolia + E. simulata and E. pallida + E.sanguinea) where both species cluster tightly and have similar immune-response profiles. These two species-pairs are maximally dissimilar
from each other. The remaining species (E. paradoxa, E. purpurea, and E. tennesseensis) occupy intermediate positions in the dendrogram. Our results suggest that Echinacea spp. act heterogeneously on immune function.
The utility of these data for science and industry is discussed. 相似文献
59.
Efficient soybean transformation using hygromycin B selection in the cotyledonary-node method 总被引:49,自引:0,他引:49
The efficiency of soybean [Glycine max (L.) Merrill] transformation was significantly increased from an average of 0.7% to 16.4% by combining strategies to enhance Agrobacterium tumefaciens-mediated T-DNA delivery into cotyledonary-node cells with the development of a rapid, efficient selection protocol based on hygromycin B. Wounded cotyledonary-node explants were inoculated with A. tumefaciens carrying either a standard-binary or super-binary plasmid and co-cultivated in the presence of mixtures of the thiol compounds, L-cysteine, dithiothreitol, and sodium thiosulfate. Transformed shoots began elongating only 8 weeks after co-cultivation. Southern analysis confirmed integration of the T-DNA into genomic DNA and revealed no correlation between the complexity of the integration pattern and thiol treatment applied at co-cultivation. All T(0) plants were fertile and the majority of the lines transmitted the beta-glucuronidase (GUS) phenotype in 3:1 or 15:1 ratios to their progenies. 相似文献
60.