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61.
J B Fishman M Cahill P Morin M McCrory N L Bucher M D Ullman 《Biochemical and biophysical research communications》1991,174(2):638-646
Rat liver gangliosides (sialic acid containing glycosphingolipids) were analyzed by HPTLC and HPLC following either partial hepatectomy or sham operation. Analysis of whole liver gangliosides by HPTLC demonstrated that within 6 h after partial (68%) hepatectomy, there was a significant increase in GM1 compared to both sham and control animals. By 48 h, GM1 was further increased and the polysialylgangliosides GD1a, GD1b and GT1b had also risen significantly, whereas changes in GM3 were negligible. Gangliosides associated with the plasma membrane were increased up to 3.5-fold in regenerating liver compared to sham-hepatectomized controls as assessed by HPLC. Although elevations in membrane gangliosides were associated with hepatocyte proliferation, they did not closely follow the growth curve. The time course of changes in ganglioside biosynthesis suggests differential upregulation of GM3 synthase and GD3 synthase in regenerating livers. 相似文献
62.
Alternaria alternata is a common fungal parasite on fruits and other plants and produces a number of mycotoxins, including alternariol (3,7,9-trihydroxy-1-methyl-6H-dibenzo [b,d]pyran-6-one), alternariol monomethyl ether (3,7-dihydroxy-9-methoxy-1-methyl-6H-dibenzo[b,d]pyran-6-one), and the mutagen altertoxin I {[1S-(1α,12aβ,12bα)] 1,2,11,12,12a, 12b-hexahydro-1,4,9,12a-tetrahydroxy-3,10-perylenedione}.
Alternariol and alternariol monomethyl ether have previously been detected in some samples of fruit beverages. Stability studies
of these toxins as well as altertoxin I added to fruit juices and wine (10–100 ng/mL) were carried out. To include altertoxin
I in the analysis, cleanup with a polymer-based Varian Abselut solid phase extraction column was used, as recoveries from
C-18 columns were low. The stabilities of alternariol and alternariol monomethyl ether in a low acid apple juice containing
no declared vitamin C were compared with those in the same juice containing added vitamin C (60 mg/175 ml); there were no
apparent losses at room temperature over 20 days or at 80°C after 20 min. in either juice. Altertoxin I was moderately stable
in pH 3 buffer (75% remaining after a two week period). Furthermore, altertoxin I was stable or moderately stable in three
brands of apple juice tested over 1–27 day periods and in a sample of red grape juice over 7 days. It is concluded that altertoxin
I is sufficiently stable to be found in fruit juices and should be included in methods for alternariol and alternariol monomethyl
ether. 相似文献
63.
64.
The claudin multigene family encodes tetraspan membrane proteins that are crucial structural and functional components of
tight junctions, which have important roles in regulating paracellular permeability and maintaining cell polarity in epithelial
and endothelial cell sheets. In mammals, the claudin family consists of 24 members, which exhibit complex tissue-specific
patterns of expression. The extracellular loops of claudins from adjacent cells interact with each other to seal the cellular
sheet and regulate paracellular transport between the luminal and basolateral spaces. The claudins interact with multiple
proteins and are intimately involved in signal transduction to and from the tight junction. Several claudin mouse knockout
models have been generated and the diversity of phenotypes observed clearly demonstrates their important roles in the maintenance
of tissue integrity in various organs. In addition, mutation of some claudin genes has been causatively associated with human
diseases and claudin genes have been found to be deregulated in various cancers. The mechanisms of claudin regulation and
their exact roles in normal physiology and disease are being elucidated, but much work remains to be done. The next several
years are likely to witness an explosion in our understanding of these proteins, which may, in turn, provide new approaches
for the targeted therapy of various diseases. 相似文献
65.
Investigation of the antifouling constituents from the brown alga Sargassum muticum (Yendo) Fensholt
Alexandra Bazes Alla Silkina Philippe Douzenel Fabienne Faÿ Nelly Kervarec Danièle Morin Jean-Pascal Berge Nathalie Bourgougnon 《Journal of applied phycology》2009,21(4):395-403
One of the most promising alternatives to toxic heavy metal-based paints is offered by the development of antifouling coatings
in which the active ingredients are compounds naturally occurring in marine organisms and operating as natural antisettlement
agents. Sessile marine macroalgae are remarkably free from settlement by fouling organisms. They produce a wide variety of
chemically active metabolites in their surroundings, potentially as an aid to protect themselves against other settling organisms.
In this study, a dichloromethane extract from the brown seaweed Sargassum muticum was tested in situ and, after 2 months of immersion, showed less fouling organisms on paints in which the extract was included,
compared to paints containing only copper after 2 months of immersion. No barnacles or mussels have been observed on the test
rack. Identification by NMR and GC/MS of the effective compound revealed the abundance of palmitic acid, a commonly found
fatty acid. Pure palmitic acid showed antibacterial activity at 44 μg mL−1, and also inhibited the growth of the diatom Cylindrotheca closterium at low concentration (EC50 = 45.5 μg mL−1), and the germination of Ulva lactuca spores at 3 μg mL−1. No cytotoxicity was highlighted, which is promising in the aim of the development of an environmentally friendly antifouling
paint. 相似文献
66.
Pascreau G Delcros JG Morin N Prigent C Arlot-Bonnemains Y 《Developmental biology》2008,317(2):523-530
Xenopus laevis Aurora-A is phosphorylated in vivo onto three amino acids: Ser53, Thr295 and Ser349. The activation of the kinase depends on its autophosphorylation on Thr295 within the T-loop. The phosphorylation of Ser53 by still unknown kinase(s) prevents its degradation. The present work focused on the regulation of Aurora-A function via Ser349 phosphorylation. Mutagenesis of Ser349 to alanine (S349A) had few impact in vitro on the capability of the kinase to autophosphorylate as well as on its activity. These data in addition to in gel kinase assays and site-specific proteolytic digestion experiments prove that Ser349 is clearly neither a primary autophosphorylation site, nor an autophosphorylation site depending on the priming phosphorylation of Thr295. Using specific antibodies, we also show that the phosphorylation of Aurora-A Ser349 is a physiological event during Xenopus oocyte maturation triggered by progesterone. A peak of phosphorylation paralleled the decrease of Aurora activity observed between meiosis I and II. In response to progesterone, X. laevis stage VI oocytes microinjected with the Aurora-A S349A mutant proceeded normally to germinal vesicle breakdown (GVBD), but degenerated rapidly soon after. Since phosphorylation of Ser349 is responsible for a decrease in kinase activity, our results suggest that a down-regulation of Aurora-A activity involving Ser349 phosphorylation is required in the process of maturation. 相似文献
67.
Claudio Iribarren Viviana Hermosilla Violeta Morin Marcia Puchi 《Journal of cellular biochemistry》2013,114(8):1779-1788
In amphibians, sperm histone transition post‐fertilization during male pronucleus formation is commanded by histone chaperone Nucleoplasmin (NPM). Here, we report the first studies to analyze the participation of a Nucleoplasmin‐like protein on male chromatin remodeling in sea urchins. In this report, we present the molecular characterization of a nucleoplasmin‐like protein that is present in non fertilized eggs and early zygotes in sea urchin specie Tetrapygus niger. This protein, named MP62 can interact with sperm histones in vitro. By male chromatin decondensation assays and immunodepletion experiments in vitro, we have demonstrated that this protein is responsible for sperm nucleosome disorganization. Furthermore, as amphibian nucleoplasmin MP62 is phosphorylated in vivo immediately post‐fertilization and this phosphorylation is dependent on CDK‐cyclin activities found after fertilization. As we shown, olomoucine and roscovitine inhibits male nucleosome decondensation, sperm histone replacement in vitro and MP62 phosphorylation in vivo. This is the first report of a nucleoplasmin‐like activity in sea urchins participating during male pronucleus formation post‐fecundation. J. Cell. Biochem. 114: 1779–1788, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
68.
Uxmal and Tulum are two important Mayan sites in the Yucatan peninsula. The buildings are mainly composed of limestone and grey/black discoloration is seen on exposed walls and copious greenish biofilms on inner walls. The principal microorganisms detected on interior walls at both Uxmal and Tulum were cyanobacteria; heterotrophic bacteria and filamentous fungi were also present. A dark‐pigmented mitosporic fungus and Bacillus cereus, both isolated from Uxmal, were shown to be acidogenic in laboratory cultures. Cyanobacteria belonging to rock‐degrading genera Synechocystis and Gloeocapsa were identified at both sites. Surface analysis previously showed that calcium ions were present in the biofilms on buildings at Uxmal and Tulum, suggesting the deposition of biosolubilized stone. Apart from their potential to degrade the substrate, the coccoid cyanobacteria supply organic nutrients for bacteria and fungi, which can produce organic acids, further increasing stone degradation. 相似文献
69.
Bezy V Morin P Couerbe P Leleu G Agrofoglio L 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2005,821(2):132-143
Zalcitabine (ddC), lamivudine (3TC), didanosine (ddI), stavudine (d4T), carbovir (CBV), zidovudine (AZT), tenofovir (PMPA) and its administrated form (tenofovir diisoproxyl fumarate, TDF), are nucleosides currently approved in HIV therapy. To facilitate pharmacokinetics studies, a specific reversed-phase high-performance liquid chromatography (HPLC) method was developed for their analysis in rat plasma. The method involved a quantitative recovery of these drugs from rat plasma by solid-phase extraction on Oasis HLB Waters cartridges followed by optimised HPLC separation on an Atlantis dC18 column with acetic acid-hydroxylamine buffer (ionic strength 5mM, pH 7)-acetonitrile elution gradient. Quantitation was performed by HPLC/UV at 260 nm. Linear calibration curves were obtained within a 30-10,000 ng/mL plasma concentration range. Correlation coefficients (r2) greater than 0.992 were obtained by least-squares regression and limits of quantification were in 30-90 ng/mL concentration range. Quantitative parameters (accuracy, intra-day repeatability and inter-day reproducibility) yielded satisfactory results. Finally, a new buffer, obtained with acetic acid and hydroxylamine, has been tested in HPLC/ESI-MS/MS and appears to be an efficient volatile buffer in the medium 5-7 pH range. Indeed, at pH 7 and low ionic strength (5 mM), its buffer capacity is one hundred times higher to that obtained for the usual acetic acid/ammonia buffer. 相似文献
70.
Lisa Langsetmo Tuan V. Nguyen Nguyen D. Nguyen Christopher S. Kovacs Jerilynn C. Prior Jacqueline R. Center Suzanne Morin Robert G. Josse Jonathan D. Adachi David A. Hanley John A. Eisman the Canadian Multicentre Osteoporosis Study Research Group 《CMAJ》2011,183(2):E107-E114