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81.
Pascale Varlet Fabrice Chretien Felipe Andreiuolo Mélanie Pages Ali Ibrahim Johan Pallud Edouard Dezamis Georges Abi‐Lahoud François Nataf Baris Turak Bertrand Devaux Darine Abi‐Haidar 《Journal of biophotonics》2017,10(2):253-263
Meningioma is the most frequent primary central nervous system tumor. The risk of recurrence and the prognosis are correlated with the extent of the resection that ideally encompasses the infiltrated dura mater and, if required, the infiltrated bone. No device can deliver real‐time intraoperative histopathological information on the tumor environment to help the neurosurgeon to achieve a gross total removal. This study assessed the abilities of nonlinear microscopy to provide relevant and real‐time data to help resection of meningiomas. Nine human meningioma samples (four World Health Organization Grade I, five Grade II) were analyzed using different optical modalities: spectral analysis and imaging, lifetime measurements, fluorescence lifetime imaging microscopy, fluorescence emitted under one‐ and two‐photon excitation and the second‐harmonic generation signal imaging using a multimodal setup. Nonlinear microscopy produced images close to histopathology as a gold standard. The second‐harmonic generation signal delineated the collagen background and two‐photon fluorescence underlined cell cytoplasm. The matching between fluorescence images and Hematoxylin and Eosin staining was possible in all cases. Grade I meningioma emitted less autofluorescence than Grade II meningioma and Grade II meningioma exhibited a distinct lifetime value. Autofluorescence was correlated with the proliferation rates and seemed to explain the observed differences between Grade I and II meningiomas. This preliminary multimodal study focused on human meningioma samples confirms the potential of tissue autofluorescence analysis and nonlinear microscopy in helping intraoperatively neurosurgeons to reach the actual boundaries of the tumor infiltration.
82.
Drop-size soda lakes: transient microbial habitats on a salt-secreting desert tree 总被引:1,自引:0,他引:1 下载免费PDF全文
We describe a hitherto unrecognized bacterial community, inhabiting the leaf surfaces of the salt-excreting desert tree Tamarix. High temperatures, strong radiation, and very low humidity dictate a daytime existence in complete desiccation, but damp nights allow the microbial population to proliferate in a sugar-rich, alkaline, and hypersaline solution, before drying up again after sunrise. The exclusively bacterial population contains many undescribed species and genera, but nevertheless appears to be characterized by relatively limited species diversity. Sequences of 16S rRNA genes from either isolates or total community DNA place the identified members of the community in five bacterial groups (Actinobacteria, Bacteroidetes, Firmicutes, alpha-, and gamma-Proteobacteria); in each of these, they concentrate in a very narrow branch that in most cases harbors organisms isolated from unrelated halophilic environments. 相似文献
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85.
Gwena?l Kaminski Slimane Dridi Christian Graff Edouard Gentaz 《Proceedings. Biological sciences / The Royal Society》2009,276(1670):3193-3200
The resemblance between human faces has been shown to be a possible cue in recognizing the relatedness between parents and children, and more recently, between siblings. However, the general inclusive fitness theory proposes that kin-selective behaviours are also relevant to more distant relatives, which requires the detection of larger kinship bonds. We conducted an experiment to explore the use of facial clues by ‘strangers’, i.e. evaluators from a different family, to associate humans of varying degrees of relatedness. We hypothesized that the visual capacity to detect relatedness should be weaker with lower degrees of relatedness. We showed that human adults are capable of (although not very efficient at) assessing the relatedness of unrelated individuals from photographs and that visible facial cues vary according to the degree of relatedness. This sensitivity exists even for kin pair members that are more than a generation apart and have never lived together. Collectively, our findings are in agreement with emerging knowledge on the role played by facial resemblance as a kinship cue. But we have progressed further to show how the capacity to distinguish between related and non-related pairs applies to situations relevant to indirect fitness. 相似文献
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Sébastien Van de Velde Edouard Delaive Marc Dieu Stéphane Carryn Françoise Van Bambeke Bart Devreese Martine Raes Paul M. Tulkens 《Proteomics》2009,9(24):5484-5496
The pathogenicity of Listeria monocytogenes is related to its ability of invading and multiplying in eukaryotic cells. Its main virulence factors are now well characterized, but limited proteomic data is available concerning its adaptation to the intracellular environment. In this study, L. monocytogenes EGD (serotype 1/2a) grown in human THP‐1 monocytes (24 h) were successfully separated from host organelles and cytosolic proteins by differential and isopycnic centrifugation. For control, we used cell homogenates spiked with bacteria grown in broth. Proteomes from both forms of bacteria were compared using a 2‐D‐DIGE approach followed by MALDI‐TOF analysis to identify proteins. From 1684 distinct spots, 448 were identified corresponding to 245 distinct proteins with no apparent contamination of host proteins. Amongst them, 61 show underexpression (stress defense; transport systems, carbon metabolism, pyrimidines synthesis, D ‐Ala‐D ‐Ala ligase) and 22 an overexpression (enzymes involved in the synthesis of cell envelope lipids, glyceraldehyde‐3‐phosphate, pyruvate and fatty acids). Our proteomic analysis of intracellular L. monocytogenes (i) suggests that bacteria thrive in a more favorable environment than extracellularly, (ii) supports the concept of metabolic adaptation of bacteria to intracellular environment and (iii) may be at the basis of improved anti‐Listeria therapy. 相似文献
88.
Sibylle Gerstl Gédeon Kiwila Mehul Dhorda Sylvaine Lonlas Mark Myatt Beno?t Kebela Ilunga Denis Lemasson Elisabeth Szumilin Philippe J. Guerin Laurent Ferradini 《PloS one》2009,4(7)
Background
Until the 1970s the prevalence of non-venereal trepanomatosis, including yaws, was greatly reduced after worldwide mass treatment. In 2005, cases were again reported in the Democratic Republic of the Congo. We carried out a survey to estimate the village-level prevalence of yaws in the region of Equator in the north of the country in order to define appropriate strategies to effectively treat the affected population.Methodology/Principal Findings
We designed a community-based survey using the Lot Quality Assurance Sampling method to classify the prevalence of active yaws in 14 groups of villages (lots). The classification into high, moderate, or low yaws prevalence corresponded to World Health Organization prevalence thresholds for identifying appropriate operational treatment strategies. Active yaws cases were defined by suggestive clinical signs and positive rapid plasma reagin and Treponema pallidum hemagglutination serological tests. The overall prevalence in the study area was 4.7% (95% confidence interval: 3.4–6.0). Two of 14 lots had high prevalence (>10%), three moderate prevalence (5–10%) and nine low prevalence (<5%.).Conclusions/Significance
Although yaws is no longer a World Health Organization priority disease, the presence of yaws in a region where it was supposed to be eradicated demonstrates the importance of continued surveillance and control efforts. Yaws should remain a public health priority in countries where previously it was known to be endemic. The integration of sensitive surveillance systems together with free access to effective treatment is recommended. As a consequence of our study results, more than 16,000 people received free treatment against yaws. 相似文献89.
Erwan Plouguerné Efstathia Ioannou Panagiota Georgantea Constantinos Vagias Vassilios Roussis Claire Hellio Edouard Kraffe Valérie Stiger-Pouvreau 《Marine biotechnology (New York, N.Y.)》2010,12(1):52-61
The purification of the chloroform extract from the brown invasive macroalga Sargassum muticum, through a series of chromatographic separations, yielded 12 fractions that were tested against strains of bacteria, microalgae,
and fungi involved in marine biofilm formation. The chemical composition of four (a, c, g, and k) out of the six fractions
that exhibited anti-microfouling activity was investigated. Fraction a contained saturated and unsaturated linear hydrocarbons
(C12–C27). Arachidonic acid was identified as the major metabolite in fraction c whereas fraction g contained mainly palmitic, linolenic,
and palmitoleic acids. Fraction k was submitted to further purification yielding the fraction kAcaF1e that was composed of
galactoglycerolipids, active against the growth of two of the four bacterial strains (Shewanella putrefaciens and Polaribacter irgensii) and all tested fungi. These promising results, in particular the isolation and the activity of galactoglycerolipids, attest
the potential of the huge biomass of S. muticum as a source of new environmentally friendly antifouling compounds. 相似文献
90.
Philip Heraud Elizabeth S. Ng Sally Caine Qing C. Yu Claire Hirst Robyn Mayberry Amanda Bruce Bayden R. Wood Don McNaughton Edouard G. Stanley Andrew G. Elefanty 《Stem cell research》2010,4(2):140-147
Human ESCs (hESCs) are a valuable tool for the study of early human development and represent a source of normal differentiated cells for pharmaceutical and biotechnology applications and ultimately for cell replacement therapies. For all applications, it will be necessary to develop assays to validate the efficacy of hESC differentiation. We explored the capacity for FTIR spectroscopy, a technique that rapidly characterises cellular macromolecular composition, to discriminate mesendoderm or ectoderm committed cells from undifferentiated hESCs. Distinct infrared spectroscopic “signatures” readily distinguished hESCs from these early differentiated progeny, with bioinformatic models able to correctly classify over 97% of spectra. These data identify a role for FTIR spectroscopy as a new modality to complement conventional analyses of hESCs and their derivatives. FTIR spectroscopy has the potential to provide low-cost, automatable measurements for the quality control of stem and differentiated cells to be used in industry and regenerative medicine. 相似文献