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981.
Fabio Ponticelli Antoaneta Trendafilova Massimo Valoti Simona Saponara GianPietro Sgaragli 《Carbohydrate research》2001,330(4)
We describe the synthesis of some 3-tert-butyl-4-hydroxyphenyl
-glycopyranosides by reaction of tert-butylhydroquinone with β-
-pentaacetyl-glucose, β-
-pentaacetyl-galactose, 2-acetamido- and 3,4,6-tri-O-acetyl-2-butanamido-2-deoxy-β-
-glucopyranosyl chlorides as well as the formation of anomeric 3-tert-butyl-4-hydroxyphenyl 4,6-di-O-acetyl-2,3-dideoxy-
-erythro-hex-2-eno-pyranosides by reaction between tert-butylhydroquinone and 3,4,6-tri-O-acetyl-
-glucal. All compounds, except 3-tert-butyl-4-hydroxyphenyl α- and β-
-glucopyranosides, inhibited lipid peroxidation with a degree of potency comparable to that of tert-butyl hydroxyanisole. 相似文献
982.
983.
Sergio Esposito Graziella Massaro Vincenza Vona Vittoria Di Martino Rigano Simona Carfagna Carmelo Rigano 《Physiologia plantarum》2001,113(4):469-476
The effects of ammonium and glutamine supply on amino acid levels and the activity of glucose-6P dehydrogenase (G6PDH EC 1.1.1.49), the main regulated enzyme of the oxidative pentose phosphate pathway, were investigated in barley roots ( Hordeum vulgare cv. Alfeo). Feeding ammonium to barley plants increased the contents of glutamine, asparagine and G6PDH in roots. These effects were abolished by using inhibitors of glutamine synthetase. Glutamine-fed barley roots showed a similar increase in G6PDH activities to ammonium-fed plants. Two G6PDH enzymes (G6PDH 1 and 2) were partially purified and characterized from ammonium-fed and glutamine-fed roots. The isozymes had different pH optima and apparent Km values for glucose-6P. G6PDH 2 showed similar kinetic parameters to the G6PDH present in root extracts of barley grown without any nitrogen source, while G6PDH 1 exhibited different kinetic parameters, suggesting the appearance of a second G6PDH isoform in response to ammonium. Western blot analysis demonstrated the existence of two G6PDH subunits of different molecular mass in barley roots grown in the presence of ammonium or glutamine, while only one isoform could be detected in roots grown without any nitrogen source. The results suggest a primary role of ammonium and/or glutamine in the appearance of a novel G6PDH isoform; this enzyme (G6PDH 1) shows kinetic parameters similar to those measured previously for chloroplastic and plastidic isoforms and seems to be induced by changes in glutamine content or a related compound(s) in the roots. 相似文献
984.
Mihaela ChivuEconomescu Coralia Bleotu Camelia Grancea Daniela Chiriac Anca Botezatu Iulia V. Iancu Ioana Pitica Laura G. Necula Ana Neagu Lilia Matei Denisa Dragu Camelia Sultana Elena L. Radu Alina Nastasie Oana Voicu Marius Ataman Saviana Nedeianu Cristina Mambet Carmen C. Diaconu Simona Maria Ruta 《Journal of cellular and molecular medicine》2022,26(4):1293
SARS‐CoV‐2 vaccines are highly efficient against severe forms of the disease, hospitalization and death. Nevertheless, insufficient protection against several circulating viral variants might suggest waning immunity and the need for an additional vaccine dose. We conducted a longitudinal study on the kinetics and persistence of immune responses in healthcare workers vaccinated with two doses of BNT162b2 mRNA vaccine with or without prior SARS‐CoV‐2 infection. No new infections were diagnosed during follow‐up. At 6 months, post‐vaccination or post‐infection, despite a downward trend in the level of anti‐S IgG antibodies, the neutralizing activity does not decrease significantly, remaining higher than 75% (85.14% for subjects with natural infection, 88.82% for vaccinated after prior infection and 78.37% for vaccinated only). In a live‐virus neutralization assay, the highest neutralization titres were present at baseline and at 6 months follow‐up in persons vaccinated after prior infection. Anti‐S IgA levels showed a significant descending trend in vaccinated subjects (p < 0.05) after 14 weeks. Cellular immune responses are present even in vaccinated participants with declining antibody levels (index ratio 1.1–3) or low neutralizing activity (30%–40%) at 6 months, although with lower T‐cell stimulation index (p = 0.046) and IFN‐γ secretion (p = 0.0007) compared to those with preserved humoral responses. 相似文献
985.
986.
987.
Claudia Menichelli Franco Casamassima Cynthia Aristei Gianluca Ingrosso Simona Borghesi Fabio Arcidiacono Valentina Lancellotta Ciro Franzese Stefano Arcangeli 《Reports of Practical Oncology and Radiotherapy》2022,27(1):32
The liver is the first metastatic site in 15–25% of colorectal cancer patients and one of the first metastatic sites for lung and breast cancer patients.A computed tomography (CT ) scan with contrast medium is a standard procedure for assessing liver lesions but magnetic resonance imaging (MRI) characterizes small lesions better thanks to its high soft-tissue contrast. Positron emission tomography with computed tomography (PET-CT ) plays a complementary role in the diagnosis of liver metastases. Triphasic (arterial, venous and time-delayed) acquisition of contrast-medium CT images is the first step in treatment planning. Since the liver exhibits a relatively wide mobility due to respiratory movements and bowel filling, appropriate techniques are needed for target identification and motion management. Contouring requires precise recognition of target lesion edges. Information from contrast MRI and/or PET-CT is crucial as they best visualize metastatic disease in the parenchyma. Even though different fractionation schedules were reported, doses and fractionation schedules for liver stereotactic radiotherapy (SRT ) have not yet been established. The best local control rates were obtained with BED10 values over 100 Gy. Local control rates from most retrospective studies, which were limited by short follow-ups and included different primary tumors with intrinsic heterogeneity, ranged from 60% to 90% at 1 and 2 years. The most common SRT-related toxicities are increases in liver enzymes, hyperbilirubinemia and hypoalbuminemia. Overall, late toxicity is mild even in long-term follow-ups. 相似文献
988.
Trupti Joshi Susana Rodriguez Vladimir Perovic Ian A. Cockburn Simona St?ger 《PLoS pathogens》2009,5(5)
Experimental visceral leishmaniasis (VL) represents an exquisite model to study CD8+ T cell responses in a context of chronic inflammation and antigen persistence, since it is characterized by chronic infection in the spleen and CD8+ T cells are required for the development of protective immunity. However, antigen-specific CD8+ T cell responses in VL have so far not been studied, due to the absence of any defined Leishmania-specific CD8+ T cell epitopes. In this study, transgenic Leishmania donovani parasites expressing ovalbumin were used to characterize the development, function, and fate of Leishmania-specific CD8+ T cell responses. Here we show that L. donovani parasites evade CD8+ T cell responses by limiting their expansion and inducing functional exhaustion and cell death. Dysfunctional CD8+ T cells could be partially rescued by in vivo B7-H1 blockade, which increased CD8+ T cell survival but failed to restore cytokine production. Nevertheless, B7-H1 blockade significantly reduced the splenic parasite burden. These findings could be exploited for the design of new strategies for immunotherapeutic interventions against VL. 相似文献
989.
Soil-Atmosphere Methane Exchange in Undisturbed and Burned Mediterranean Shrubland of Southern Italy
Soils represent the primary biotic sink for atmospheric methane (CH4). Uncertainty is associated, however, with global soil CH4 consumption because of the few data available from many areas and, in particular, from Mediterranean-type ecosystems. In this study, soil-atmosphere CH4 exchange was measured for one year in a coastal Italian shrubland (maquis), from both undisturbed areas and areas treated with experimental fire. Although fire represents one of the most frequent disturbance factors in seasonally dry environments, very few studies in these ecosystems have focused on its effect on soil CH4 fluxes. Significant differences in soil ammonium content, water content, and temperature were measured between burned and unburned plots, however, no statistical differences were observed for CH4 fluxes. CH4 fluxes varied between −0.39 and −16.1 mg CH4 m−2 day−1 and temporal variations were mainly driven by variations in soil water content and temperature. The highest CH4 oxidation rates were measured during the driest and warmest period. Low gravimetric soil water content in the top 10 cm, as well as high NH4+ concentration, did not seem to reduce methanotrophic activity, suggesting that maximal CH4 oxidation activity might take place deeper in the soil profile, at least during part of the year. 相似文献
990.
Estrogen receptor alpha (ERalpha)-negative breast cancer cells display an aggressive phenotype. We previously showed that adenoviral expression of ERalpha in ER-negative breast cancer cells leads to an estrogen-dependent down-regulation of the proliferation, which could be of interest to control the growth of such cells. In this study, we observed an increase in protein levels of p21 and p27 cyclin-dependent kinase inhibitors, whereas pRb phosphorylation is strongly decreased. Flow cytometry experiments showed a slower transit of cells in G1 (hormone-independent), a hormone-induced accelerated transit through S phase and a possible arrest in G2/M phase. In addition, ERalpha-expressing cells were undergoing apoptosis. By using cDNA macroarrays, we identified a novel collection of genes regulated by liganded ERalpha potentially regulating cell cycle, apoptosis, cell signalling, stress response and DNA repair. 相似文献