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61.
Romani A Menichetti S Arapitsas P Nativi C Turchetti B Buzzini P 《Bioorganic & medicinal chemistry letters》2005,15(18):4000-4003
The two anomers of O-methyl gluco-2,3-digalloyl esters were synthesized and their antimycotic activity toward yeasts of biomedical importance was evaluated. When used at subinhibitory concentration and regardless of stereochemistry at the anomeric carbon, these compounds enhance the antimycotic activity of Amphotericin B. 相似文献
62.
Lorenzen JA Bonacci BB Palmer RE Wells C Zhang J Haber DA Goldstein AM Mayer AN 《Gene expression patterns : GEP》2005,6(1):45-56
Intestinal development and homeostasis rely on the coordination of proliferation and differentiation of the epithelium. To better understand this process, we are studying Rbm19, a gene expressed in the gut epithelium that is essential for intestinal morphogenesis and differentiation in the zebrafish (Development 130, 3917). Here we analyzed the expression of Rbm19 in several biological contexts that feature proliferation/differentiation cell fate decisions. In the undifferentiated embryonic gut tube, Rbm19 is expressed throughout the epithelium, but then becomes localized to the crypts of Lieberkühn of the adult intestine. Consistent with its expression in adult crypt/progenitor cells, expression is widespread in human colorectal carcinomas and dividing Caco-2 cells. Its expression in Caco-2 cells recapitulates the in vivo pattern, declining when the cells undergo confluence-induced arrest and differentiation. Rbm19 protein localizes to the nucleolus during interphase and to the perichromosomal sheath during mitosis, in accordance with the pattern described for other nucleolar proteins implicated in ribosome biogenesis. Interestingly, the loss of nucleolar rbm19, nucleolin/C23, and nucleophosmin/B23 in confluent Caco-2 cells did not signify loss of nucleoli as detected by electron microscopy. Taken together, these data point to the nucleolus as a possible locus for regulating the proliferation/differentiation cell fate decision in the intestinal epithelium. 相似文献
63.
Marchionni I Paffi A Pellegrino M Liberti M Apollonio F Abeti R Fontana F D'Inzeo G Mazzanti M 《Biochimica et biophysica acta》2006,1758(5):597-605
Alteration of membrane surface charges represents one of the most interesting effects of the electromagnetic exposure on biological structures. Some evidence exists in the case of extremely low frequency whereas the same effect in the radiofrequency range has not been detected. Changes in transmembrane voltages are probably responsible for the mobilization of intracellular calcium described in some previous studies but not confirmed in others. These controversial results may be due to the cell type under examination and/or to the permeability properties of the membranes. According to such a hypothesis, calcium oscillations would be a secondary effect due to the induced change in the membrane voltage and thus dependent on the characteristics of ionic channels present in a particular preparation. Calcium increases could suggest more than one mechanism to explain the biological effects of exposure due to the fact that all the cellular pathways using calcium ions as a second messenger could be, in theory, disturbed by the electromagnetic field exposure. In the present work, we investigate the early phase of the signal transmission in the peripheral nervous system. We present evidence that the firing rate of rat sensory neurons can be modified by 50/60 Hz magnetic field but not by low level 900 MHz fields. The action of the 50/60 Hz magnetic field is biphasic. At first, the number of action potentials increases in time. Following this early phase, the firing rate decreases more rapidly than in control conditions. The explanation can be found at the single-channel level. Dynamic action current recordings in dorsal root ganglion neurons acutely exposed to the electromagnetic field show increased functionality of calcium channels. In parallel, a calcium-activated potassium channel is able to increase its mean open time. 相似文献
64.
Galzio R Cristiano L Fidoamore A Cifone MG Benedetti E Cinque B Menghini P Raysi Dehcordi S Ippoliti R Giordano A Cimini A 《Journal of cellular biochemistry》2012,113(11):3342-3352
Gliobastoma (GB), the most common adult brain tumor, infiltrates normal brain area rendering impossible the complete surgical resection, resulting in a poor median survival (14–15 months), despite the aggressive multimodality treatments post‐surgery, such as radiation and chemo‐therapy. GB is characterized by hypoxic and necrotic regions due to a poorly organized tumor vascularization, leading to inadequate blood supply and consequently to hypoxic and necrotic areas. We have previously shown that, under hypoxia GB primary cells increased the expression of stemness markers as well as the expression of the nuclear receptor peroxisome proliferator‐activated receptor α (PPARα) and also the crucial role played by PPARs in mouse neural stem cells maintenance and differentiation. Due to the importance of lipid signaling in cell proliferation and differentiation, in this work, we analyzed the expression of PPARs in GB neurospheres both in normoxic and hypoxic conditions. The results obtained suggest a differential regulation of the three PPARs by hypoxia, thus indicating a possible therapeutic strategy to counteract GB recurrencies. J. Cell. Biochem. 113: 3342–3352, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
65.
Francesca Rossi Antonio Giorgio Marco Battaglini Maria Laura Stromillo Emilio Portaccio Benedetta Goretti Antonio Federico Bahia Hakiki Maria Pia Amato Nicola De Stefano 《PloS one》2012,7(11)
Objective
To assess the relationship between cognition and brain white matter (WM) lesion distribution and frequency in patients with relapsing-remitting multiple sclerosis (RR MS).Methods
MRI-based T2 lesion probability map (LPM) was used to assess the relevance of brain lesion location for cognitive impairment in a group of 142 consecutive patients with RRMS. Significance of voxelwise analyses was p<0.05, cluster-corrected for multiple comparisons. The Rao Brief Repeatable Battery was administered at the time of brain MRI to categorize the MS population into cognitively preserved (CP) and cognitively impaired (CI).Results
Out of 142 RRMS, 106 were classified as CP and 36 as CI. Although the CI group had greater WM lesion volume than the CP group (p = 0.001), T2 lesions tended to be less widespread across the WM. The peak of lesion frequency was almost twice higher in CI (61% in the forceps major) than in CP patients (37% in the posterior corona radiata). The voxelwise analysis confirmed that lesion frequency was higher in CI than in CP patients with significant bilateral clusters in the forceps major and in the splenium of the corpus callosum (p<0.05, corrected). Low scores of the Symbol Digit Modalities Test correlated with higher lesion frequency in these WM regions.Conclusions
Overall these results suggest that in MS patients, areas relevant for cognition lie mostly in the commissural fiber tracts. This supports the notion of a functional (multiple) disconnection between grey matter structures, secondary to damage located in specific WM areas, as one of the most important mechanisms leading to cognitive impairment in MS. 相似文献66.
67.
Male spacing behaviour of roe deer Capreolus capreolus (Linnaeus, 1758) was studied in a wooded mountainous habitat in the Casentinesi Forest National Park, Italy. Data were collected using radio-tracking techniques from March 1997 to February 1998. Annual, seasonal, and bimonthly home ranges were analysed. Different factors may influence male spacing behaviour throughout the year. Winter home range sizes may be dependent on environmental conditions, while social factors could determine a high level of individual variability during the territorial and reproductive period. Prime age males showed great spatial stability, in contrast to the ranging movements of yearlings. 相似文献
68.
Helicobacter pylori is a gram-negative bacterium that causes gastric and duodenal diseases in humans. Despite a robust antibody and cellular immune response, H. pylori infection persists chronically. To understand if and how H. pylori could modulate T cell activation, in the present study we investigated in vitro the interaction between H. pylori and human T lymphocytes freshly isolated from peripheral blood of H. pylori-negative donors. A direct interaction of live, but not killed bacteria with purified CD3+ T lymphocytes was observed by microscopy and confirmed by flow cytometry. Live H. pylori activated CD3+ T lymphocytes and predominantly γδ+ T cells bearing the TCR chain Vδ2. Upon interaction with H. pylori, these cells up-regulated the activation molecule CD69 and produced cytokines (such as TNFα, IFNγ) and chemokines (such as MIP-1β, RANTES) in a non-antigen-specific manner. This activation required viable H. pylori and was not exhibited by other gram-negative bacteria. The cytotoxin-associated antigen-A (CagA), was at least partially responsible of this activation. Our results suggest that H. pylori can directly interact with T cells and modulate the response of γδ+ T cells, thereby favouring an inflammatory environment which can contribute to the chronic persistence of the bacteria and eventually to the gastric pathology. 相似文献
69.
Pablo?González-Melendi María?Antonietta?Germanà Nathalie?Levy?Guarda Benedetta?Chiancone María?Carmen?Risue?oEmail author 《Acta Physiologiae Plantarum》2005,27(4):687-694
Before approaching anther culture as a tool to trigger an androgenic response in a new species, it is advisable to characterize
and correlate flower and male gametophyte development to enable reproducible identification of the appropriate starting material.
Buds and flowers of Opuntia ficus-indica cv. Gialla were classified in eight stages according to their total length at the earlier stages and the length of the corolla
in flowers with emerging sepals. Due to the low condensation of chromatin in the microspore nucleus as well as in the vegetative
nucleus of the bi- and tricellular pollen along with the high autofluorescence of the intricate exine, DAPI staining turned
out not to be feasible in this species. Therefore an approach based on light-microscopy observation of semithin sections was
used. These sections were stained with toluidine blue for general structure recognition and I2KI to study starch deposition. Correlations were made between the sequential floral and male gametophyte development. Using
this approach we determined the timing of pollen formation and observed that pollen development is impaired in plants producing
seedless fruits. Furthermore, anther culture was carried out with anthers collected from flower buds at stages 2 and 3. Most
of the anthers produced callus, however no regeneration was obtained. 相似文献
70.