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51.
Giuseppe Fossati Andrea Balsari Donatella Taramelli Maria Luisa Sensi Giuseppe Pellegris Maurizio Nava Giorgio Parmiani 《Cancer immunology, immunotherapy : CII》1982,14(2):99-104
Summary Peripheral blood lymphocytes (PBL) of melanoma patients were sensitized in vitro with lymphocytes of a single donor or with a pool of lymphocytes of 5–20 different donors. After 6–7 days, the cytotoxic activity of the sensitized PBL was tested against cultured autologous tumor cells and lymphocytes in a 51Cr-release assay. Tumor lysis was observed in 13 of 16 cases in which patients' PBL (Pt-PBL) were stimulated by a pool of allogeneic lymphocytes and in five out of seven cases when single sensitization was performed. In no case was lysis of autologous normal lymphocytes or blasts seen. Cultivation of Pt-PBL with irradiated autologous tumor cells never led to the induction of lymphocytes cytotoxic to melanoma cells. Lysability by pool-activated autologous Pt-PBL of fresh cryopreserved tumor cells was compared to that of short-term cultured tumor cells, and no significant differences were observed. Cold-target inhibition experiments indicated that the cytotoxicity of Pt-PBL was tumor-restricted since only autologous melanoma cells but not lymphocytes were able to inhibit the reaction. These results indicate that activation of Pt-PBL is necessary in order to elicit or amplify their antitumor activity. 相似文献
52.
George W. Arana Ross J. Baldessarini Michael Herschel Maurizio Fava 《Life sciences》1981,29(2):121-133
The binding of low concentrations of [3H](?)apomorphine to preparations of calf and rat forebrain tissue was evaluated. Fractionation of crude homogenates to prepare a membrane fraction (P4) of striatal or caudate homogenates increased the proportion of saturable to total binding from 33% to over 80%, and increased the apparent density of binding sites from 94 to 681 fmol/mg protein. Binding in calf caudate P4 tissue was protein-dependent and optimal at pH = 7.0 to 7.5, and T = 20 to 25°C; at higher temperatures tissue binding sites appeared to degrade. The half-time of association and dissociation at 22°C were, respectively, 14.0 and 18.5 min; equilibration was complete in 60 min. Kinetic characteristics of high-affinity binding obtained from association and dissociation constants and from saturation isotherms were similar (Kd = 2.1 to 3.4 nM). The pharmacology of competition for 3H-APO suggests selectivity for dopamine-agonist interactions. These results indicate that the P4 membrane preparation may be useful for the evaluation of dopamine-agonist binding sites or “receptors.” 相似文献
53.
Andreas Gescher Maurizio DIncalci Roberto Fanelli Pierluigi Farina 《Life sciences》1980,26(2):147-154
N-Hydroxymethylpentamethylmelamine (HMPMM) was identified by HPLC and by GLC-MS after derivatization, as a metabolite of the anticancer drug hexamethylmelamine (HMM) in incubation mixtures with fortified mouse liver 9000 × g and microsomal preparations. HMPMM formation was dependent on the presence of NADPH and oxygen. N-demethylated metabolites were also found. HMPMM displays appreciable chemical stability and 29% was recovered after 60 min incubation in buffer. HMPMM constituted more than 50% of total HMM metabolites in 30 min incubations. The known chemical reactivity of carbinolamines means that HMPMM could be involved in the pharmacological or toxic effects of HMM. 相似文献
54.
The carrier-mediated transport of GABA in rat brain synaptosomes was strongly and permanently inhibited byl-2,4-diaminobutyric acid (DAB). In order to discriminate between carrier-mediated and non-carrier-mediated release of [3H]GABA, synaptosomes prelabeled with 0.5 M [3H]GABA in the presence of 100 M DAB, or with 0.2 M [3H]GABA without DAB, were superfused in conditions stimulating the release of [3H]GABA. Only the release elicited by unlabeled GABA or DAB (by homo- and heteroexchange, respectively) was strongly inhibited in DAB-pretreated synaptosomes. The spontaneous release and the release induced by 56 mM KCl in the presence of CaCl2, by the ionophore A23187, by ouabain, by lack of K+, or by purified black widow spider toxin were unaffected or only barely decreased in DAB-treated synaptosomes, and therefore do not seem to be mediated by the DAB-blocked GABA carrier. 相似文献
55.
The effects of the ionophore A23187 and of ouabain on the release of [3H]GABA and [3H]norepinephrine were studied in superfused rat brain synaptosomes. Each of the two drugs moderately stimulated the spontaneous release of [3H]GABA, but greatly potentiated the release of [3H]GABA induced by unlabeled GABA. In contrast, the ionophore and norepinephrine showed an additive, but not a supraadditive, releasing effect on synaptosomal [3H]norepinephrine. Ouabain modestly and transiently potentiated the norepinephrine-induced [3H]norepinephrine release, which, however, was inhibited by the drug after a few minutes. It is suggested that in the new intrasynaptosomal ionic conditions determined by the two drugs, the stoichiometry of the basal homoexchange of GABA is changed in a direction favoring net outward transport. 相似文献
56.
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58.
Rosa Angela Raccuglia Gabriella Bellone Kristina Loziene Franco Piozzi Sergio Rosselli Antonella Maggio Maurizio Bruno Monique S.J. Simmonds 《Phytochemistry》2010,71(17-18):2087-2091
From the aerial parts of Scutellaria hastifolia, family Lamiaceae (Labiatae), seven neo-clerodane diterpenoids (hastifolins A–G) were isolated. The products are similar to the known scuteparvin and are characterized by being trans-cinnamoyl derivatives. Structures and stereochemistry were determined by intensive NMR investigation. Six of the products form three pairs of epimers at C-13. Hastifolins A–C showed significant antifeedant activity. 相似文献
59.
Hui Yang Philippe Ciais Maurizio Santoro Yuanyuan Huang Wei Li Yilong Wang Ana Bastos Daniel Goll Almut Arneth Peter Anthoni Vivek K. Arora Pierre Friedlingstein Vanessa Harverd Emilie Joetzjer Markus Kautz Sebastian Lienert Julia E. M. S. Nabel Michael O'Sullivan Stephen Sitch Nicolas Vuichard Andy Wiltshire Dan Zhu 《Global Change Biology》2020,26(7):3997-4012
Gaps in our current understanding and quantification of biomass carbon stocks, particularly in tropics, lead to large uncertainty in future projections of the terrestrial carbon balance. We use the recently published GlobBiomass data set of forest above‐ground biomass (AGB) density for the year 2010, obtained from multiple remote sensing and in situ observations at 100 m spatial resolution to evaluate AGB estimated by nine dynamic global vegetation models (DGVMs). The global total forest AGB of the nine DGVMs is 365 ± 66 Pg C, the spread corresponding to the standard deviation between models, compared to 275 Pg C with an uncertainty of ~13.5% from GlobBiomass. Model‐data discrepancy in total forest AGB can be attributed to their discrepancies in the AGB density and/or forest area. While DGVMs represent the global spatial gradients of AGB density reasonably well, they only have modest ability to reproduce the regional spatial gradients of AGB density at scales below 1000 km. The 95th percentile of AGB density (AGB95) in tropics can be considered as the potential maximum of AGB density which can be reached for a given annual precipitation. GlobBiomass data show local deficits of AGB density compared to the AGB95, particularly in transitional and/or wet regions in tropics. We hypothesize that local human disturbances cause more AGB density deficits from GlobBiomass than from DGVMs, which rarely represent human disturbances. We then analyse empirical relationships between AGB density deficits and forest cover changes, population density, burned areas and livestock density. Regression analysis indicated that more than 40% of the spatial variance of AGB density deficits in South America and Africa can be explained; in Southeast Asia, these factors explain only ~25%. This result suggests TRENDY v6 DGVMs tend to underestimate biomass loss from diverse and widespread anthropogenic disturbances, and as a result overestimate turnover time in AGB. 相似文献
60.
Paulo R. L. Bittencourt Rafael S. Oliveira Antonio C. L. da Costa Andre L. Giles Ingrid Coughlin Patricia B. Costa David C. Bartholomew Leandro V. Ferreira Steel S. Vasconcelos Fernanda V. Barros Joao A. S. Junior Alex A. R. Oliveira Maurizio Mencuccini Patrick Meir Lucy Rowland 《Global Change Biology》2020,26(6):3569-3584
The fate of tropical forests under future climate change is dependent on the capacity of their trees to adjust to drier conditions. The capacity of trees to withstand drought is likely to be determined by traits associated with their hydraulic systems. However, data on whether tropical trees can adjust hydraulic traits when experiencing drought remain rare. We measured plant hydraulic traits (e.g. hydraulic conductivity and embolism resistance) and plant hydraulic system status (e.g. leaf water potential, native embolism and safety margin) on >150 trees from 12 genera (36 species) and spanning a stem size range from 14 to 68 cm diameter at breast height at the world's only long‐running tropical forest drought experiment. Hydraulic traits showed no adjustment following 15 years of experimentally imposed moisture deficit. This failure to adjust resulted in these drought‐stressed trees experiencing significantly lower leaf water potentials, and higher, but variable, levels of native embolism in the branches. This result suggests that hydraulic damage caused by elevated levels of embolism is likely to be one of the key drivers of drought‐induced mortality following long‐term soil moisture deficit. We demonstrate that some hydraulic traits changed with tree size, however, the direction and magnitude of the change was controlled by taxonomic identity. Our results suggest that Amazonian trees, both small and large, have limited capacity to acclimate their hydraulic systems to future droughts, potentially making them more at risk of drought‐induced mortality. 相似文献