排序方式: 共有81条查询结果,搜索用时 31 毫秒
11.
The reaction of cyanate with C-terminal carboxyl groups of peptides in aqueous solution was considered as a potential pathway for the abiotic formation of peptide bonds under the condition of the primitive Earth. The catalytic effect of dicarboxylic acids on cyanate hydrolysis was definitely attributed to intramolecular nucleophilic catalysis by the observation of the 1H-NMR signal of succinic anhydride when reacting succinic acid with KOCN in aqueous solution (pH 2.2–5.5). The formation of amide bonds was noticed when adding amino acids or amino acid derivatives into the solution. The reaction of N-acyl aspartic acid derivatives was observed to proceed similarly and the scope of the cyanate-promoted reaction was analyzed from the standpoint of prebiotic peptide formation. The role of cyanate in activating peptide C-terminus constitutes a proof of principle that intramolecular reactions of adducts of peptides C-terminal carboxyl groups with activating agents represent a pathway for peptide activation in aqueous solution, the relevance of which is discussed in connexion with the issue of the emergence of homochirality. 相似文献
12.
Zoé Uhry Laurent Remontet Marc Colonna Aurélien Belot Pascale Grosclaude Nicolas Mitton Solenne Delacour-Billon Julie Gentil Marjorie Boussac-Zarebska Nadine Bossard Arlette Danzon Michelle Altana François Frete Alain Weill Agnès Rogel 《Cancer epidemiology》2013,37(2):99-114
Background: District-level cancer incidence estimation is an important issue in countries without a national cancer registry. This study aims to both evaluate the validity of district-level estimations in France for 24 cancer sites, using health insurance data (ALD demands – Affection de Longue Durée) and to provide estimations when considered valid. Incidence is estimated at a district-level by applying the ratio between the number of first ALD demands and incident cases (ALD/I ratio), observed in those districts with cancer registries, to the number of first ALD demands available in all districts. These district-level estimations are valid if the ratio does not vary greatly across the districts or if variations remain moderate compared with variations in incidence rates. Methods: Validation was performed in the districts covered by cancer registries over the period 2000–2005. The district variability of the ALD/I ratio was studied, adjusted for age (mixed-effects Poisson model), and compared with the district variability in incidence rate. The epidemiological context is also considered in addition to statistical analyses. Results: District-level estimation using the ALD/I ratio was considered valid for eight cancer sites out of the 24 studied (lip–oral cavity–pharynx, oesophagus, stomach, colon–rectum, lung, breast, ovary and testis) and incidence maps were provided for these cancer sites. Conclusion: Estimating cancer incidence at a sub-national level remains a difficult task without a national registry and there are few studies on this topic. Our validation approach may be applied in other countries, using health insurance or hospital discharge data as correlate of incidence. 相似文献
13.
Nicolas Gaidet-Drapier Hervé Fritz Mathieu Bourgarel Pierre-Cyril Renaud Pierre Poilecot Philippe Chardonnet Craig Coid Denys Poulet Sébastien Le Bel 《Biodiversity and Conservation》2006,15(2):735-754
The comparison of precision is often advocated for the selection of an appropriate census and/or monitoring method for wildlife,
but little attention is generally paid to their cost effectiveness, a crucial criterion given budgetary and logistical constraints.
We present six direct count methods conducted in a communal area of the Zambezi Valley, Zimbabwe, and compare them in terms
of (1) effort and cost to survey an area (sampling efficiency), and (2) efficiency in data collection (detection efficiency).
Methods ranged from c.US$0.2 to over US$6.0/km2 and needed from 0.1 to 5.0 human-h/km2. The comparison of efficiencies showed the advantages of simple ground methods: foot counts and particularly bicycle counts
appear well adapted to the ecological and human context of our study. The relative benefits and constraints of the different
methods are discussed in the context of a community-based wildlife management programme. 相似文献
14.
Since its emergence in China in 1996, highly pathogenic avian influenza virus subtype H5N1 has spread across Asia, Africa, and Europe. Countries had to promptly implement control and prevention measures. Numerous research and capacity building initiatives were conducted in the affected regions to improve the capacity of national animal health services to support the development of risk-based mitigation strategies. This paper reviews and discusses risk assessments initiated in several South-East Asian and African countries under one of these projects. Despite important data gaps, the risk assessment results improved the ability of policy makers to design appropriate risk management policies. Disease risk was strongly influenced by various human behavioral factors. The ongoing circulation of HPAIV H5N1 in several Asian countries and in Egypt, despite major disease control efforts, supports the need for an interdisciplinary approach to development of tailored risk management policies, in accordance with the EcoHealth paradigm and the broad concept of risk governance. In particular, active stakeholders engagement and integration of economic and social studies into the policy making process are needed to optimize compliance and sustainable behavioral changes, thereby increasing the effectiveness of mitigation strategies. 相似文献
15.
Wolowczuk I Hennart B Leloire A Bessede A Soichot M Taront S Caiazzo R Raverdy V Pigeyre M;ABOS Consortium Guillemin GJ Allorge D Pattou F Froguel P Poulain-Godefroy O 《American journal of physiology. Regulatory, integrative and comparative physiology》2012,303(2):R135-R143
Human obesity is characterized by chronic low-grade inflammation in white adipose tissue and is often associated with hypertension. The potential induction of indoleamine 2,3-dioxygenase-1 (IDO1), the rate-limiting enzyme in tryptophan/kynurenine degradation pathway, by proinflammatory cytokines, could be associated with these disorders but has remained unexplored in obesity. Using immunohistochemistry, we detected IDO1 expression in white adipose tissue of obese patients, and we focused on its contribution in the regulation of vascular tone and on its immunoregulatory effects. Concentrations of tryptophan and kynurenine were measured in sera of 36 obese and 15 lean women. The expression of IDO1 in corresponding omental and subcutaneous adipose tissues and liver was evaluated. Proinflammatory markers and T-cell subsets were analyzed in adipose tissue via the expression of CD14, IL-18, CD68, TNFα, CD3ε, FOXP3 [a regulatory T-cell (Treg) marker] and RORC (a Th17 marker). In obese subjects, the ratio of kynurenine to tryptophan, which reflects IDO1 activation, is higher than in lean subjects. Furthermore, IDO1 expression in both adipose tissues and liver is increased and is inversely correlated with arterial blood pressure. Inflammation is associated with a T-cell infiltration in obese adipose tissue, with predominance of Th17 in the omental compartment and of Treg in the subcutaneous depot. The Th17/Treg balance is decreased in subcutaneous fat and correlates with IDO1 activation. In contrast, in the omental compartment, despite IDO1 activation, the Th17/Treg balance control is impaired. Taken together, our results suggest that IDO1 activation represents a local compensatory mechanism to limit obesity-induced inflammation and hypertension. 相似文献
16.
Mondésert-Deveraux Solenne Aubry Denis Allena Rachele 《Biomechanics and modeling in mechanobiology》2019,18(5):1281-1295
Biomechanics and Modeling in Mechanobiology - Considering the major role of confined cell migration in biological processes and diseases, such as embryogenesis or metastatic cancer, it has become... 相似文献
17.
G. Lizard M. C. Chignol P. Roignot C. Souchier Y. Chardonnet D. Schmitt 《Journal of molecular histology》1997,29(7):545-554
Human papillomavirus (HPV) infection with potentially oncogenic types 16 or 18 is common in genital lesions especially in
uterine carcinomas. In such lesions, in situ hybridization with non-radioactive probes is a powerful tool for the histopathologist to detect and type HPV DNA either on
cell deposits or on tissue sections. The use of an immunohistochemical method involving alkaline phosphatase and Fast Red
TR salt/naphthol AS-MX phosphate is proposed for use with conventional bright-field or fluorescence microscopy as well as
by laser scanning confocal microscopy. The alkaline phosphatase-Fast Red reaction has the advantage of producing a red precipitate
that permits the detection of in situ hybridization signals by bright-field microscopy, and of obtaining a strong red fluorescence characterized by a lack of bleaching
when excited by a green light. Therefore, the alkaline phosphatase-Fast Red reaction is well adapted for observations by fluorescence
and confocal microscopy, the latter method allowing the detection, in tissue sections of cervical intraepithelial lesions,
of small punctate and large diffuse hybridization signals, considered as integrated and episomal states of HPV DNA respectively.
The combination of in situ hybridization with the alkaline phosphatase-Fast Red reaction and confocal microscopy is particularly convincing when hybridization
signals are of small size and/or of low fluorescence intensity, especially if they are present in various focal planes; in
such conditions, infected cells are easily detected by three-dimensional reconstruction. Therefore, this combination is a
suitable method for identifying and characterizing HPV DNA in cells and tissue sections
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
18.
We compared three techniques, the MTT tetrazolium assay, cell counting, and tritiated thymidine ([3H]TdR) incorporation assay to measure the antiproliferative effect of cyclosporin A (CsA) and interferon-γ (IFN-γ) on normal human skin keratinocyte cultures (NHK) used at the second passage and human papillomavirus type 16- and 18-transformed cell lines (EK16 and EK18) exposed continuously to the drugs for 3 days. The three techniques showed that under CsA (0.5 and 8 μ/ml) and IFN-γ (5 and 160 U/ml) treatments the cells remained viable and that the growth of keratinocytes was inhibited. For IFN-γ, the MTT colorimetric assay consistently underestimated its growth inhibitory activity as compared to cell counting or [3H]TdR incorporation, whatever the cells used. For high doses of CsA, MTT and cell counting gave similar percentages of inhibitory activity whatever the cells; MTT underestimated this activity as compared to [3H]TdR incorporation only in NHK and EK18 cells, whereas similar results were obtained with EK16 cells. In conclusion, this investigation shows that MTT sensitivity differed with the drug and also according to the keratinocyte cultures. The MTT test is clearly not appropriate for study of IFN-γ treatment whatever the keratinocytes used. Such discrepancies indicate that the MTT test should be done with care on cultures to measure the effects of drugs on cell growth; the growth inhibition should be carefully considered and it would be best if two different methods were used. 相似文献
19.
Dp71Δ78‐79 dystrophin mutant stimulates neurite outgrowth in PC12 cells via upregulation and phosphorylation of HspB1
下载免费PDF全文
![点击此处可从《Proteomics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Candelaria Merino‐Jiménez Jorge Aragón Víctor Ceja Griselda Rodríguez‐Martínez Febe E. Cázares‐Raga Solenne Chardonnet Cédric Pionneau Alvaro Rendon Cecilia Montañez 《Proteomics》2016,16(9):1331-1340
PC12 cells acquire a neuronal phenotype in response to nerve growth factor (NGF). However, this phenotype is more efficiently achieved when the Dp71Δ78‐79 dystrophin mutant is stably expressed in PC12‐C11 cells. To investigate the effect of Dp71Δ78‐79 overexpression on the protein profile of PC12‐C11 cells, we compared the expression profiles of undifferentiated and NGF‐differentiated PC12‐C11 and PC12 cells by 2DE. In undifferentiated cultures, one protein was downregulated, and five were upregulated. Dp71Δ78‐79 overexpression had a greater effect on differentiated cultures, with ten proteins downregulated and seven upregulated. The protein with the highest upregulation was HspB1. Changes in HspB1 expression were validated by Western blot and immunofluorescence analyses. Interestingly, the neurite outgrowth in PC12‐C11 cells was affected by a polyclonal antibody against HspB1, and the level of HspB1 and HspB1Ser86 decreased, suggesting an important role for this protein in this cellular process. Our results show that Dp71Δ78‐79 affects the expression level of some proteins and that the stimulated neurite outgrowth produced by this mutant is mainly through upregulation and phosphorylation of HspB1. 相似文献
20.
T. Gallagher Y. Chardonnet J. Viac J. Patet A. Lefèvre 《Virchows Archiv. B, Cell pathology including molecular pathology》1989,57(1):339-347
Somatic cell hybrids were obtained with electric pulse by fusion of human epithelial HeLa cells derived from a carcinoma of
the uterine cervix and mouse fibroblasts 3T3.4E, deficient in thymidine kinase. Hybrids were selected and propagated in HAT
media; some experiments were carried out in medium with delipidized serum.
The hybrid cells were characterized by indirect immunofluorescence with a biotin-streptavidin system using a panel of nine
monoclonal antibodies specific for membrane and cytoplasmic antigens of parental cells: intermediate filaments (keratins and
vimentin), HLA class 1 (β2-microglobulin), cell activation (EGF and transferrin receptors) and cellular adhesion (fibronectin and laminin). 相似文献