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排序方式: 共有334条查询结果,搜索用时 265 毫秒
121.
Biagi G Bianucci AM Coi A Costa B Fabbrini L Giorgi I Livi O Micco I Pacchini F Santini E Leonardi M Nofal FA Salerni OL Scartoni V 《Bioorganic & medicinal chemistry》2005,13(15):4679-4693
A number of N6-(N-arylcarbamoyl)-2-substituted-9-benzyl-8-azaadenines, obtained by a modification of the synthetic scheme used to prepare selective A1 ligands, by only three or two steps, are described. At first we prepared a series of 2-phenyl-9-benzyl-8-azaadenines having as N6 substituent a variously substituted N-phenylcarbamoyl group. Some of these derivatives demonstrated good affinity towards the A3 subtype but low selectivity. Compounds having p-CF3, p-F and p-OCH3, as substituents on the phenylcarbamoyl group were selected as lead compounds for the second part of this study. Without modifying the N6 substituent, which would assure A3 affinity, we varied the 9 and 2 positions on these molecules to enhance selectivity. Some compounds having a p-methyl group on the 2-phenyl substituent showed a very good affinity and selectivity for the A3 subtype, revealing the first class of A3 adenosine receptor selective antagonists with a bicyclic structure strictly correlated to the adenine nucleus. The molecular modelling work, carried out using the DOCK program, supplied two models which may be useful for a better understanding of the binding modes. Both models highlighted the preferred interacting tautomeric forms of the antagonists for human A1 and A3 receptors. 相似文献
122.
Mancuso M Pasquali E Giardullo P Leonardi S Tanori M Di Majo V Pazzaglia S Saran A 《Current molecular medicine》2012,12(5):613-624
A long-held dogma in radiation biology has been that the biological effects of exposure to ionizing radiation occur as a result of damage in directly irradiated cells and that no effect would occur in neighboring unirradiated cells. This paradigm has been frequently challenged by reports of radiation effects in unirradiated or 'bystander' cells receiving signals from directly irradiated cells, an issue that may have substantial impact on radiation risk assessment and development of radiation-based therapies. Radiation-induced bystander effects have been shown in single-cell systems in vitro for an array of cancer relevant endpoints, and may trigger damage in more complex 3-D tissue systems. They may be mediated by soluble factors released by irradiated cells into the extracellular environment and/or by the passage of mediator molecules through gap-junction intercellular communication. To date, evidence that radiation-associated bystander or abscopal responses are effectual in vivo has been limited, but new data suggest that they may significantly affect tumor development in susceptible mouse models. Further understanding of how the signal/s is transmitted to unirradiated cells and tissues and how it provokes long-range and significant responses is crucial. By summarizing the existing evidence of radiation induced bystander-like effects in various systems with emphasis on in vivo findings, we will discuss the potential mechanisms involved in these observations and how effects in bystander cells contribute to uncertainties in assessing cancer risks associated with radiation exposure. 相似文献
123.
José M. Estevez Patricia I. Leonardi Josefina S. Alberghina 《Journal of phycology》2008,44(5):1257-1268
Cell wall changes in vegetative and suffultory cells (SCs) and in oogonial structures from Oedogonium bharuchae N. D. Kamat f. minor Vélez were characterized using monoclonal antibodies against several carbohydrate epitopes. Vegetative cells and SCs develop only a primary cell wall (PCW), whereas mature oogonial cells secrete a second wall, the oogonium cell wall (OCW). Based on histochemical and immunolabeling results, (1→4)‐β‐glucans in the form of crystalline cellulose together with a variable degree of Me‐esterified homogalacturonans (HGs) and hydroxyproline‐rich glycoprotein (HRGP) epitopes were detected in the PCW. The OCW showed arabinosides of the extensin type and low levels of arabinogalactan‐protein (AGP) glycans but lacked cellulose, at least in its crystalline form. Surprisingly, strong colabeling in the cytoplasm of mature oogonia cells with three different antibodies (LM‐5, LM‐6, and CCRC‐M2) was found, suggesting the presence of rhamnogalacturonan I (RG‐I)–like structures. Our results are discussed relating the possible functions of these cell wall epitopes with polysaccharides and O‐glycoproteins during oogonium differentiation. This study represents the first attempt to characterize these two types of cell walls in O. bharuchae, comparing their similarities and differences with those from other green algae and land plants. This work represents a contribution to the understanding of how cell walls have evolved from simple few‐celled to complex multicelled organisms. 相似文献
124.
Salgueiro J Leonardi N Segal M Shapira N Shafran N Carasso Y Zubillaga M Goldman C Barrado A Janjetic M Boccio J 《Biological trace element research》2006,109(1):91-96
In this research, we measure the iron bioavailability of micronized ferric orthophosphate when it is used to fortify low-fat
fluid milk enriched with calcium and petit suisse cheese using the prophylactic-preventive method in rats. Four groups of
male weaned rats received a basal diet (control diet; 6.5 ppm Fe), a reference standard diet (SO4Fe; 18.2 ppm Fe), a basal diet using iron-fortified fluid milk as the iron source (milk diet; Fe ppm 17.9), and a basal diet
using iron-fortified petit suisse cheese as the iron source (cheese diet; 18.0 ppm Fe) for 22 d. The iron bioavailability
of the different sources was calculated as the ratio between the mass of iron incorporated into hemoglobin during the experiment
and the total iron intake per animal. The relative biological values with regard to the reference standard (RBV%) were 61%
and 69% for the milk and cheese diet, respectively. These results show that according to this method, the iron bioavailability
in both fortified foods can be considered as medium bioavailability rates. 相似文献
125.
Janis Dingel Pavol Hanus Niccolò Leonardi Joachim Hagenauer Jürgen Zech Jakob C Mueller 《BMC bioinformatics》2008,9(1):190
Background
Comparative genomics aims to detect signals of evolutionary conservation as an indicator of functional constraint. Surprisingly, results of the ENCODE project revealed that about half of the experimentally verified functional elements found in non-coding DNA were classified as unconstrained by computational predictions. Following this observation, it has been hypothesized that this may be partly explained by biased estimates on neutral evolutionary rates used by existing sequence conservation metrics. All methods we are aware of rely on a comparison with the neutral rate and conservation is estimated by measuring the deviation of a particular genomic region from this rate. Consequently, it is a reasonable assumption that inaccurate neutral rate estimates may lead to biased conservation and constraint estimates. 相似文献126.
Halassy B Habjanec L Brgles M Balija ML Leonardi A Kovacic L Prijatelj P Tomasić J Krizaj I 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2008,148(2):178-183
The contribution of antibodies directed against the two main toxic groups of proteins in the Vipera ammodytes ammodytes venom, haemorrhagic metalloproteinases (H) and neurotoxic sPLA2s (Atxs), to the overall protective efficacy of the whole venom antisera was investigated. Using ELISA assays we established a high correlation between the protective efficacy of the whole venom antisera in mice and their anti-Atxs antibody content. As the haemorrhage is the prevailing toxic effect of the venom in human, the lack of correlation also with anti-H IgG content exposed that the mouse model might not be optimal to evaluate the neutralizing potential of the venom-specific antisera for human therapy. We further revealed that Atxs and structurally very similar but non-toxic AtnI2 from the venom are not immuno cross-reactive. 相似文献
127.
Adrenocorticotropic hormone and cortisol plasma levels directly correlate with childhood neglect and depression measures in addicted patients. 总被引:1,自引:0,他引:1
Gilberto Gerra Claudio Leonardi Elena Cortese Amir Zaimovic Grazia Dell'Agnello Matteo Manfredini Lorenzo Somaini Francesca Petracca Vincenzo Caretti Cristina Baroni Claudio Donnini 《Addiction biology》2008,13(1):95-104
Hypothalamic-pituitary-adrenal (HPA) axis dysfunction has been reported to be involved in vulnerability to alcohol and drug dependence in humans, possibly underlying both addictive behaviour and depression susceptibility. The aim of the present study was to investigate the possible interactions between childhood adverse experiences, depressive symptoms and HPA axis function in addicted patients, in comparison with healthy control. Eighty-two abstinent heroin or cocaine dependent patients and 44 normal controls, matched for age and sex, completed the symptoms Check List-90 (SCL-90), measuring depressive symptoms, and the Childhood Experience of Care and Abuse Questionnaire. Blood samples were collected to determine adrenocorticotropic hormone (ACTH) and cortisol basal plasma levels at 8:00 and 8:30 a.m. Addicted individuals showed significantly higher neglect and depression scores and ACTH-cortisol plasma levels respect to control subjects. Depression scores at SCL-90 in addicted patients positively correlated with plasma ACTH and cortisol values. In turn, plasma ACTH levels were directly associated with childhood neglect measures, reaching statistical significance with 'mother-neglect' scores. Plasma cortisol levels were related to 'father antipathy' among cocaine addicts. These findings suggest the possibility that childhood experience of neglect and poor parent-child attachment may have a persistent effect on HPA axis function as an adult, partially contributing, together with genetic factors and other environmental conditions, to both depressive traits and substance abuse neurobiological vulnerability. 相似文献
128.
129.
Genetics of proteome variation for QTL characterization: application to drought-stress responses in maize 总被引:11,自引:1,他引:10
The proteome is emerging as an important concept of the post-genome era.
Powerful nucleic acid approaches (EST, DNA chips, etc.) are still limited
because DNA sequences and mRNA levels are not sufficient to predict the
structure, function, amount, and activity of the proteins in the cell. The
proteome can now be subjected to large-scale analysis, owing to spectacular
progress in the techniques of identification of proteins excised from
two-dimensional (2-D) gels. In addition, computer-based analysis of 2-D
gels makes it possible to quantify the protein spot intensities, which are
commonly genetically variable. The loci controlling these variations may be
mapped on the genome (PQLs, Protein Quantity Loci). Beyond the interest for
regulatory genetics and molecular biology, the PQL methodology can provide
an additional tool for the difficult task of identifying QTLs (Quantitative
Trait Loci), in the context of the candidate gene approach. The PQL
methodology is presented with the example of the phosphoglycerate mutase
variations in maize, and the candidate gene/protein approach is illustrated
for traits responsive to drought stress. 相似文献
130.
Camilla Ugolini Logan Mulroney Adrien Leger Matteo Castelli Elena Criscuolo Maia Kavanagh Williamson Andrew D Davidson Abdulaziz Almuqrin Roberto Giambruno Miten Jain Gianmaria Frig Hugh Olsen George Tzertzinis Ira Schildkraut Madalee G Wulf Ivan R Corrêa Jr Laurence Ettwiller Nicola Clementi Massimo Clementi Nicasio Mancini Ewan Birney Mark Akeson Francesco Nicassio David
A Matthews Tommaso Leonardi 《Nucleic acids research》2022,50(6):3475