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排序方式: 共有704条查询结果,搜索用时 15 毫秒
1.
Liliana Gianfreda Anna Maria Livolsi Maria Rosaria Scarfì Guido Greco 《Enzyme and microbial technology》1982,4(5):322-326
Cellobiose hydrolysis by β-d-glucosidase (β-d-glucoside glucohydrolase EC 3.2.1.21) can become the rate-limiting step in the hydrolysis of cellulosic wastes because of inhibition phenomena involving other enzymes of the cellulase complex. Enhancement of the overall rate can therefore be obtained by increasing the amount of β-d-glucosidase present in the reactor. Unfortunately, the thermal stability of β-d-glucosidase is rather poor compared to and cellobiohydrolase. A novel stabilization method is proposed that exploits the polarization phenomena that take place in an unstirred ultrafiltration membrane enzymatic reactor. As much as a 20-fold increase in half-life compared to the native enzyme is obtained by injecting small amounts of hydroxyethyl cellulose into the system. No reduction in enzyme activity levels is observed. 相似文献
2.
Maurizio Grimaldi Rosaria Arcone †Gennaro Ciliberto Gennaro Schettini 《Journal of neurochemistry》1995,64(5):1945-1953
Abstract: The involvement of protein kinase C and its interaction with interleukin 1β in the control of interleukin 6 release by cortical astrocytes was studied. The blockade of protein kinase C catalytic domain, by staurosporine, as well as the desensitization of protein kinase C by short-term phorbol 12-myristate 13-acetate pretreatment, increased the basal release of interleukin 6 by rat cortical astrocytes, whereas calphostin C, an antagonist of phorbol ester binding on protein kinase C regulatory domain, did not affect the basal release of the cytokine. The activation of protein kinase C by phorbol 12-myristate 13-acetate enhanced concentration- and time-dependently interleukin 6 release. This stimulatory action of phorbol 12-myristate 13-acetate was significantly reduced by staurosporine, by calphostin C, and by the desensitization of protein kinase C. Interleukin 1β increased interleukin 6 release in a concentration-related manner. Protein kinase C inhibition, by staurosporine or desensitization, potentiated severalfold, whereas calphostin C reduced interleukin 1β stimulation of interleukin 6 release. The treatment of cortical astrocytes with both interleukin 1β (3 ng/ml) and phorbol 12-myristate 13-acetate (10 nM) caused a synergistic stimulation of interleukin 6 release and its gene expression, an effect that was not relieved by either 20 nM staurosporine or by calphostin C but was slightly affected by protein kinase C desensitization. In conclusion, our data show that in rat cortical astrocytes the basal release of interleukin 6 is under a tonic inhibition exerted by a protein kinase C isoform or isoforms sensitive to blockade by staurosporine and desensitization but insensitive to calphostin C. Interleukin 1β stimulated interleukin 6 secretion via a mechanism that is also negatively modulated by a protein kinase C isoform or isoforms sensitive to staurosporine and desensitization. Finally, we showed that interleukin 1β and phorbol 12-myristate 13-acetate synergistically stimulated interleukin 6 release and its gene expression, operating in a manner insensitive to protein kinase C blockers and slightly reduced by protein kinase C desensitization. 相似文献
3.
Mario Venza Maria Visalli Teresa Catalano Cinzia Fortunato Rosaria Oteri Diana Teti Isabella Venza 《Biochemical and biophysical research communications》2013
Aberrant promoter methylation and resultant silencing of TRAIL decoy receptors were reported in a variety of cancers, but to date little is known about the relevance of this epigenetic modification in melanoma. In this study, we examined the methylation and the expression status of TRAIL receptor genes in cutaneous and uveal melanoma cell lines and specimens and their interaction with DNA methyltransferases (DNMTs) DNMT1, DNMT3a, and DNMT3b. DR4 and DR5 methylation was not frequent in cutaneous melanoma but on the contrary it was very frequent in uveal melanoma. No correlation between methylation status of DR4 and DR5 and gene expression was found. DcR1 and DcR2 were hypermethylated with very high frequency in both cutaneous and uveal melanoma. The concordance between methylation and loss of gene expression ranged from 91% to 97%. Here we showed that DNMT1 was crucial for DcR2 hypermethylation and that DNMT1 and DNMT3a coregulate the methylation status of DcR1. Our work also revealed the critical relevance of DcR1 and DcR2 expression in cell growth and apoptosis either in cutaneous or uveal melanoma. In conclusion, the results presented here claim for a relevant impact of aberrant methylation of decoy receptors in melanoma and allow to understand how the silencing of DcR1 and DcR2 is related to melanomagenesis. 相似文献
4.
Maria Rosa Buemi Laura De Luca Alba Chimirri Stefania Ferro Rosaria Gitto Julio Alvarez-Builla Ramon Alajarin 《Bioorganic & medicinal chemistry》2013,21(15):4575-4580
Several indole derivatives, that were highly potent ligands of GluN2B-subunit-containing N-methyl-d-aspartate (NMDA) receptor, also demonstrated antioxidant properties in ABTS method. In particular, the 2-(4-benzylpiperidin-1-yl)-1-(5-hydroxy-1H-indol-3-yl)ethanone (1) proved to be a dual-effective neuroprotective agent. With the aim to increase the antioxidant properties we added a catechol moiety onto piperidine moiety. The designed hybrid derivative 3,4-dihydroxy-N-[1-[2-(5-hydroxy-1H-indol-3-yl)-2-oxoethyl]piperidin-4-yl]benzamide (10) was the most effective antioxidant agent (>94.1 ± 0.1% of inhibition at 17 μM) and showed GluN2B/NMDA receptor affinity at low micromolar concentration (IC50 0.66 μM). By means of computational studies we explored the effect of the presence of this antioxidant fragment during the recognition process to binding pocket. 相似文献
5.
Alberto Martire Rita Pepponi Maria Rosaria Domenici Antonella Ferrante Valentina Chiodi Patrizia Popoli 《Journal of neurochemistry》2013,125(2):225-235
NMDA receptor‐mediated excitotoxicity is thought to play a pivotal role in the pathogenesis of Huntington's disease (HD). The neurotrophin brain‐derived neurotrophic factor (BDNF), which is also highly involved in HD and whose effects are modulated by adenosine A2ARs, influences the activity and expression of striatal NMDA receptors. In electrophysiology experiments, we investigated the role of BDNF toward NMDA‐induced effects in HD models, and the possible involvement of A2ARs. In corticostriatal slices from wild‐type mice and age‐matched symptomatic R6/2 mice (a model of HD), NMDA application (75 μM) induced a transient or a permanent (i.e., toxic) reduction of field potential amplitude, respectively. BDNF (10 ng/mL) potentiated NMDA effects in wild‐type, while it protected from NMDA toxicity in R6/2 mice. Both effects of BDNF were prevented by A2AR blockade. The protective effect of BDNF against NMDA‐induced toxicity was reproduced in a cellular model of HD. These findings may have very important implications for the neuroprotective potential of BDNF and A2AR ligands in HD. 相似文献
6.
Nenad Bukvic Carla CesaranoCaterina Ceccarini Marianna BrunoMaria Rosaria Lipsi Maria Grazia GallicchioMaria Assunta Carboni Lucia ValenteGiulia Cotoia Raffaele Antonetti 《Gene》2013
Herein, we describe a case of an infertile man detected in postnatal diagnosis with FISH characterization and array-CGH used for genome-wide screening which allowed the identification of a complex rearrangement involving sex chromosomes, apparently without severe phenotypic consequences. The deletion detected in our patient has been compared with previously reported cases leading us to propose a hypothetical diagnostic algorithm that would be useful in similar clinical situations, with imperative multi disciplinary approach integrated with genetic counseling. Our patient, uniquely of reproductive age, is one of six reported cases of duplication of Xp22.3 (~ 8.4 Mb) segment and contemporary deletion of Yq (~ 42.9 Mb) with final karyotype as follows:
- 46,X,der(Y),t(X;Y)(Ypter → Yq11.221::Xp22.33 → Xpter).ish der(Y) (Yptel+,Ycen+,RP11-529I21+,RP11-506M9-Yqtel −,Xptel +). arrXp22.33p22.31(702–8,395,963, 8,408,289x1), Yq11.221q12 (14,569,317x1, 14,587,321–57,440,839x0) 相似文献
7.
Giulia Andrighetto Jordi Brandts Rosaria Conte Jordi Sabater-Mir Hector Solaz Daniel Villatoro 《PloS one》2013,8(6)
Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices. 相似文献
8.
Michelangela Barbieri Antonietta Esposito Edith Angellotti Maria Rosaria Rizzo Raffaele Marfella Giuseppe Paolisso 《PloS one》2013,8(8)
The importance of genetics and epigenetic changes in the pathogenesis of non alcoholic fatty liver disease (NAFLD) has been increasingly recognized. Adiponectin has a central role in regulating glucose and lipid metabolism and controlling inflammation in insulin-sensitive tissues and low adiponectin levels have been linked to NAFLD. APPL1 and APPL2 are adaptor proteins that interact with the intracellular region of adiponectin receptors and mediate adiponectin signaling and its effects on metabolism. The aim of our study was the evaluation of a potential association between variants at APPL1 and APPL2 loci and NAFLD occurrence. The impact on liver damage and hepatic steatosis severity has been also evaluated. To this aim allele frequency and genotype distribution of APPL1- rs3806622 and -rs4640525 and APPL2-rs 11112412 variants were evaluated in 223 subjects with clinical diagnosis of NAFLD and compared with 231 healthy subjects. The impact of APPL1 and APPL2 SNPs on liver damage and hepatic steatosis severity has been also evaluated. The minor-allele combination APPL1-C/APPL2-A was associated with an increased risk of NAFLD (OR = 2.50 95% CI 1.45–4.32; p<0.001) even after adjustment for age, sex, body mass index, insulin resistance (HOMA-IR), triglycerides and adiponectin levels. This allele combination carrier had higher plasma alanine aminotransferase levels (Diff = 15.08 [7.60–22.57] p = 0.001) and an increased frequency of severe steatosis compared to the reference allele combination (OR = 3.88; 95% CI 1.582–9.531; p<0.001). In conclusion, C-APPL1/A-APPL2 allele combination is associated with NAFLD occurrence, with a more severe hepatic steatosis grade and with a reduced adiponectin cytoprotective effect on liver. 相似文献
9.
Maria Rosaria Faraone-Mennella Anna Petrella Francesco Manguso Rosario Peluso Benedetta Farina 《Biomarkers》2013,18(6):381-387
The clinical usefulness of an immunotest was evaluated by using purified poly(adenosine diphosphate (ADP)-ribose) polymerase from Sulfolobus solfataricus (PARPSso) as an antigen to detect the presence of abnormal anti-PARP antibodies in the sera of patients with systemic lupus erythematosus (SLE) at different clinical stages. Sera from 44 patients with SLE, subgrouped on the basis of disease activity (16 with inactive disease, 28 with active disease) were analysed with a new immunotest to detect anti-PARP antibodies, and with an immunofluorescent (IIF) assay for antinuclear antibodies (ANA) detection. ANA detection by IIF revealed that sera of healthy subjects were negative, whereas sera from patients with SLE were positive in all cases (13 positive at 1:80, 15 at 1:160, 15 at 1:320, 1 at 1:640, v/v). Anti-PARP activity was higher in ANA-positive patients than in controls (p?=?0.005). Within the group of SLE sera, disease and anti-PARP activity was increased more significantly in patients with active than in those with inactive disease (p?0.001 and p?=?0.001, respectively). Correlation between anti-PARP and disease activity in SLE patients was statistically significant (p?0.001). PARPSso seems to be suitable for detecting anti-PARP antibodies and could play a role as a serological marker of disease activity in patients with SLE. 相似文献
10.
Michela Buccioni Diego Dal Ben Catia Lambertucci Aleix Martí Navia Massimo Ricciutelli Andrea Spinaci Rosaria Volpini Gabriella Marucci 《Bioorganic & medicinal chemistry》2019,27(15):3328-3333
In recent years, special attention has been paid to the A3 adenosine receptor (A3AR) as a possible pharmacological target to treat intestinal inflammation. In this work, it was set up a novel method to quantify the concentration of a promising anti-inflammatory agent inside and outside of intestinal barrier using the everted gut sac technique. The compound chosen for the present study is one of the most potent and selective A3AR agonist reported so far, named AR 170 (N6-methyl-2-phenylethynyl-5′-N-methylcarboxamidoadenosine). In order to evaluate the intestinal absorption of AR 170 the radioligand binding assay in comparison with HPLC-DAD was used. Results showed that the compound is absorbed via passive diffusion by paracellular pathway. The concentrations determined in the serosal (inside the sac) fluid by radioligand binding assay are in good agreement with those obtained through the widely used HPLC/MS protocol, demonstrating the reliability of the method. It is worthwhile to note that the radioligand binding assay allows detecting very low concentrations of analyte, thus offering an excellent tool to measure the intestinal absorption of receptor ligands. Moreover, the AR 170 quantity outside the gut sac and the interaction with A3AR could presuppose good topical anti-inflammatory effects of this compound. 相似文献