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11.
Goeminne A Berg M McNaughton M Bal G Surpateanu G Van der Veken P De Prol S Versées W Steyaert J Haemers A Augustyns K 《Bioorganic & medicinal chemistry》2008,16(14):6752-6763
A key enzyme within the purine salvage pathway of parasites, nucleoside hydrolase, is proposed as a good target for new antiparasitic drugs. We have developed N-arylmethyl-iminoribitol derivatives as a novel class of inhibitors against a purine specific nucleoside hydrolase from Trypanosoma vivax. Several of our inhibitors exhibited low nanomolar activity, with 1,4-dideoxy-1,4-imino-N-(8-quinolinyl)methyl-d-ribitol (UAMC-00115, K(i) 10.8nM), N-(9-deaza-adenin-9-yl)methyl-1,4-dideoxy-1,4-imino-d-ribitol (K(i) 4.1nM), and N-(9-deazahypoxanthin-9-yl)methyl-1,4-dideoxy-1,4-imino-d-ribitol (K(i) 4.4nM) being the three most active compounds. Docking studies of the most active inhibitors revealed several important interactions with the enzyme. Among these interactions are aromatic stacking of the nucleobase mimic with two Trp-residues, and hydrogen bonds between the hydroxyl groups of the inhibitors and amino acid residues in the active site. During the course of these docking studies we also identified a strong interaction between the Asp40 residue from the enzyme and the inhibitor. This is an interaction which has not previously been considered as being important. 相似文献
12.
Francisco H Andrade Anita P Merriam Wei Guo Georgiana Cheng Colleen A McMullen Katrin Hayess Peter F M van der ven John D Porter 《Journal of applied physiology》2003,95(2):692-699
The M lines are structural landmarks in striated muscles, necessary for sarcomeric stability and as anchoring sites for the M isoform of creatine kinase (CK-M). These structures, especially prominent in fast skeletal muscles, are missing in rodent extraocular muscle, a particularly fast and active muscle group. In this study, we tested the hypotheses that 1). myomesin and M protein (cytoskeletal components of the M lines) and CK-M are downregulated in mouse extraocular muscle compared with the leg muscles, gastrocnemius and soleus; and 2). the expression of other cytosolic and mitochondrial CK isoforms is correspondingly increased. As expected, mouse extraocular muscles expressed lower levels of myomesin, M protein, and CK-M mRNA than the leg muscles. Immunocytochemically, myomesin and M protein were not detected in the banding pattern typically seen in other skeletal muscles. Surprisingly, message abundance for the other known CK isoforms was also lower in the extraocular muscles. Moreover, total CK activity was significantly decreased compared with that in the leg muscles. Based on these data, we reject our second hypothesis and propose that other energy-buffering systems may be more important in the extraocular muscles. The downregulation of major structural and metabolic elements and relative overexpression of two adenylate kinase isoforms suggest that the extraocular muscle group copes with its functional requirements by using strategies not seen in typical skeletal muscles. 相似文献
13.
Vicentiu Bogdan Horincar Georgiana Parfene Amit Kumar Tyagi Davide Gottardi Rodica Dinică Maria Elisabetta Guerzoni Gabriela Bahrim 《Journal of applied phycology》2014,26(1):551-559
Three species of macroalgae, Ceramium virgatum (Rhodophyta), Ulva intestinalis, and Cladophora vagabunda (Chlorophyta), harvested from the Romanian Black Sea coast, were studied as sources of valuable compounds that could be used as additives and biopreservatives. Volatile compounds including hexanal (11.2 %), octane (9.8 %), nonanal (7.0 %), octanal (6.7 %), 2,5,5-trimethyl-2-hexene (4.7 %), 3-hexen-2-one (4 %), and o-cymene (3.6 %) were identified as the major components in the biomass extract of C. vagabunda. In C. virgatum, the major volatile components were 3-hexen-2-one (27.9 %), acetone (12.4 %), hexanal (3.4 %), and o-cymene (2.7 %). The major volatile compounds of U. intestinalis were hexanal (14.6 %), trichloromethane (7.3 %), nonanal (5.6 %), 3-hexen-2-one (5.3 %), and octanal (3.1 %). Some of these compounds have industrial applications as additives in the food, pharmaceutical, or cosmetics industries. The U. intestinalis extract had a greater content of mono- and polyunsaturated fatty acids around 46.0 % as compared with 42.0 % for C. vagabunda and 31.9 % for C. virgatum. The most abundant fatty acids were palmitic acid (C16:0), arachidonic acid (C20:4n-6), and oleic acid (C18:1ω-9cis). The antimicrobial effect of fatty acid extracts was tested against four pathogenic bacteria. The minimum inhibitory concentrations of C. vagabunda, C. virgatum, and U. intestinalis fatty acids extracts were 1.8, 3.8, and 3.8 mg mL?1, respectively, for all bacterial strains. This study can help the efforts of finding new, value-added uses for natural marine resources. 相似文献
14.
Many factors can affect the assembly of communities, ranging from species pools to habitat effects to interspecific interactions.
In microbial communities, the predominant focus has been on the well-touted ability of microbes to disperse and the environment
acting as a selective filter to determine which species are present. In this study, we investigated the role of biotic interactions
(e.g., competition, facilitation) in fungal endophyte community assembly by examining endophyte species co-occurrences within
communities using null models. We used recombinant inbred lines (genotypes) of maize (Zea mays) to examine community assembly at multiple habitat levels, at the individual plant and host genotype levels. Both culture-dependent
and culture-independent approaches were used to assess endophyte communities. Communities were analyzed using the complete
fungal operational taxonomic unit (OTU) dataset or only the dominant (most abundant) OTUs in order to ascertain whether species
co-occurrences were different for dominant members compared to when all members were included. In the culture-dependent approach,
we found that for both datasets, OTUs co-occurred on maize genotypes more frequently than expected under the null model of
random species co-occurrences. In the culture-independent approach, we found that OTUs negatively co-occurred at the individual
plant level but were not significantly different from random at the genotype level for either the dominant or complete datasets.
Our results showed that interspecific interactions can affect endophyte community assembly, but the effects can be complex
and depend on host habitat level. To our knowledge, this is the first study to examine endophyte community assembly in the
same host species at multiple habitat levels. Understanding the processes and mechanisms that shape microbial communities
will provide important insights into microbial community structure and the maintenance of microbial biodiversity. 相似文献
15.
16.
Catalina Petrareanu Alina Macovei Izabela Sokolowska Alisa G. Woods Catalin Lazar Gabriel L. Radu Costel C. Darie Norica Branza-Nichita 《PloS one》2013,8(8)
Hepatitis B virus (HBV) is a human pathogen causing severe liver disease and eventually death. Despite important progress in deciphering HBV internalization, the early virus-cell interactions leading to infection are not known. HepaRG is a human bipotent liver cell line bearing the unique ability to differentiate towards a mixture of hepatocyte- and biliary-like cells. In addition to expressing metabolic functions normally found in liver, differentiated HepaRG cells support HBV infection in vitro, thus resembling cultured primary hepatocytes more than other hepatoma cells. Therefore, extensive characterization of the plasma membrane proteome from HepaRG cells would allow the identification of new cellular factors potentially involved in infection. Here we analyzed the plasma membranes of non-differentiated and differentiated HepaRG cells using nanoliquid chromatography-tandem mass spectrometry to identify the differences between the proteomes and the changes that lead to differentiation of these cells. We followed up on differentially-regulated proteins in hepatocytes- and biliary-like cells, focusing on Cathepsins D and K, Cyclophilin A, Annexin 1/A1, PDI and PDI A4/ERp72. Major differences between the two proteomes were found, including differentially regulated proteins, protein-protein interactions and intracellular localizations following differentiation. The results advance our current understanding of HepaRG differentiation and the unique properties of these cells. 相似文献
17.
Collagen regulates the ability of endothelial progenitor cells to protect hypoxic myocardium through a mechanism involving miR‐377/VE‐PTP axis
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Ana‐Maria Rosca Daniel Nicolae Mitroi Valeriu Cismasiu Rodica Badea Georgiana Necula‐Petrareanu Mihai Bogdan Preda Cristina Niculite Raluca Tutuianu Stefan Szedlacsek Alexandrina Burlacu 《Journal of cellular and molecular medicine》2018,22(10):4700-4708
The possibility to employ stem/progenitor cells in the cardiovascular remodelling after myocardial infarction is one of the main queries of regenerative medicine. To investigate whether endothelial progenitor cells (EPCs) participate in the restoration of hypoxia‐affected myocardium, we used a co‐culture model that allowed the intimate interaction between EPCs and myocardial slices, mimicking stem cell transplantation into the ischaemic heart. On this model, we showed that EPCs engrafted to some extent and only transiently survived into the host tissue, yet produced visible protective effects, in terms of angiogenesis and protection against apoptosis and identified miR‐377‐VE‐PTP axis as being involved in the protective effects of EPCs in hypoxic myocardium. We also showed that collagen, the main component of the myocardial scar, was important for these protective effects by preserving VE‐PTP levels, which were otherwise diminished by miR‐377. By this, a good face of the scar is revealed, which was so far perceived as having only detrimental impact on the exogenously delivered stem/progenitor cells by affecting not only the engraftment, but also the general protective effects of stem cells. 相似文献
18.
Georgiana M. Jagiello James Dennis Masamichi Hiura Mercedes B. Ducayen 《Molecular reproduction and development》1983,7(2):155-160
The concept of Byskov which hypothesizes a glycoprotein inducer of meiosis for the mammalian fetal ovary has been tested by examining the incorporation of the specific precursor 3H-fucose into the rete ovarii of day 14 mouse ovaries. Semiquantitation of grains in autoradiographs has documented a concentration over the rete ovarii which exceeded that over the oogonia, ovarian fibroblasts, or surface epithelia. These data support the concept that the cytoplasm of mouse rete ovarii is capable of synthesizing a glycoprotein that may be the meiosis-inducing substance. 相似文献
19.
Georgiana Jagiello Mercedes Ducayen J. S. Lin 《Molecular & general genetics : MGG》1972,118(3):209-214
Summary The effects of caffeine on meiosis of mouse ova in vitro and in vivo have been studied. Concentrations of 200 g/cc or more suppressed entry of ova into in vitro meiosis without production of any numerical or structural abnormalities at dose levels above or below that. Acute superovulation by the standard technique was prevented at a dose of 0.25 mg/g/body weight and examination of the intrafollicular ova revealed presistence of the germinal vesicle stage. Chronic administration of the same dose (0.25 mg/g/bw) throughout the period from weaning to puberty did not induce any cytologically detectable meiotic abnormalities in ova studied in vitro at the end of that period. It is suggested that the reduced fertility seen by some previous authors may have been due to the suppression of entry into meiosis of the ova with diminished numbers of ova being ovulated.Aided by a grant from The National Foundation — March of Dimes. 相似文献
20.
Unilateral fixation of the middle ear ossicles and possible delayed pubescence were associated with a short-arm deletion of one of the G-group chromosomes in a 15-year-old Negro girl. A similar chromosomal abnormality was found in the mother and three of six siblings without any clinical evidence of middle ear disease. The association of G-group deletions with other hereditary disease of bone suggests, however, that a pathogenic relationship may exist between them. 相似文献