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781.
M De Felice H M Bond R Pizzano M C Turco G Valerio A Lamberti P Carandente Giarrusso S Venuta 《Cellular immunology》1991,138(1):55-63
Cells of the human erythroleukemia cell line K562 constitutively secrete a factor that inhibits human T lymphocyte proliferation induced via CD3/Ti. The factor, termed K-TIF (K562-derived T cell inhibitory factor) is produced in either the presence or absence of fetal calf serum in cultures of K562 cells and can be precipitated by 70% NH4SO4. Gel filtration chromatography on Superose 12 resin by FPLC showed that the inhibitory factor has a molecular weight of approximately 30-35 kDa. A protein of this size, metabolically labeled with [35S]methionine, specifically bound human peripheral blood mononuclear cells. Chromatofocusing with Mono P by FPLC (pH gradient 7.2-5) indicates that the inhibitory factor has an isoelectric point of 6.0-6.4. 相似文献
782.
Valerio Vidotto Laura Guevara Ochoa Juan Michea Cortes Massimo Bruatto 《Mycopathologia》1991,113(3):139-142
Candida albicans strain B 311-10 with and without starvation was cultivated in the minimal synthetic medium of Shepherd et al. [18], modified without biotin, aminoacids, low glucose concentration [20] and with decreasing amounts of (NH4)2SO4, to determine the optimal growth requirement for this strain. All the experiments were carried out under sterile conditions at 25 °C in a thermostat with initial O.D.s (675 nm) of 0.500 and 0.100. Cell growth was generally monitored everyday for six days with a spectrophotometer by determining the absorbance of the cultures at 675 nm. All the experiments were repeated three times and a statistical analysis of the data with a probability of 99% and 1% of error was performed to confirm the validity of the results. Best growth was obtained with starved cells at an initial O.D. of 0.100 and with a 0.1 g/L concentration of (NH4)2SO4. At this concentration, the growth of C. albicans B 311-10 was best between the first and the fourth day with the maximum at the third day. With (NH4)2SO4 concentrations of 0.05 and 0.5 g/L, cell growth was the same. 相似文献
783.
Luigi de Pasquale Donatella Cesaroni Claudio di Russo Valerio Sbordoni 《Ecography》1995,18(3):217-224
Shifts in feeding habits are expected to occur during adaptation to cave life Doltchopoda cave crickets inhabit both natural and artificial caves showing differences in population size, fecundity, phenology and age structure Compared to artificial caves, typically holding a seasonal age structure, populations from natural caves maintain a constantly heterogeneous age structure Faecal content analysis of 605 individuals from 24 natural and artificial cave populations, enabled us to characterize their trophic niche and to investigate its variation The results of multivariate analyses and measures of niche breadth and niche overlap outlined differences in trophic resource exploitation between natural and artificial cave populations Seasonal variation in diet occurred in both types of caves, and it was greater in artificial cave populations However, within any season, differences in feeding habits between individuals were much greater in natural caves resulting in a wider heterogeneity in trophic resources exploitation. Such heterogeneity appears to be mainly due to differences in diet between individuals of different developmental stages In fact, in a sample of 15 populations we found a positive, statistical significant correlation between niche breadth and heterogeneity in age structure These data are discussed in a broader evolutionary context in order to understand the role of limited resources availability in shaping and maintaining heterogeneity in age structure of Dolichopoda populations 相似文献
784.
André Aubry Valerio Del Duca Monica Pantano Fernando Formaggio Marco Crisma Claudio Toniolo Johan Kamphuis 《Letters in Peptide Science》1995,1(4):157-162
Summary An X-ray diffraction analysis of pBrBz-[d-(Me)Leu]3-OtBu revealed that in the crystal state this terminally blocked tripeptide adopts a multiple fully extended conformation (25-helix). This is the first unequivocal observation of such a structure in a homopeptide from a C-methylated chiral -amino acid. No intermolecular NH. . . O=C H- bonds are seen in the crystal packing. 相似文献
785.
Drug-induced myelosuppression is a frequent reason for curtailing chemotherapy in cancer patients. Rescue of myelosuppressed patients with autologous marrow transplants is reasonably advanced and permits an increase in the dose of anticancer drugs. Despite this improvement, patients often relapse with drug resistance disease. The human multidrug resistance (mdr1) gene might make it possible to render hemopoietic stem cells resistant to anticancer drugs after transfer of this gene. By introducing resistant stem cells into patients it might be possible to treat these patients repeatedly with otherwise ablative therapy. This review explores the feasibility ofmdr1 gene therapy.Abbreviations MDR
multidrug resistance
- ABMT
autologous bone marrow transplantation
- P-gp
P-glycoprotein
- RCR
replication-competent retrovirus 相似文献
786.
Alvarado-Ramírez E Torres-Rodríguez JM Sellart M Vidotto V 《Revista iberoamericana de micología》2008,25(3):150-153
Cryptococcosis is a life-threatening infection in humans and animals caused by encapsulated yeasts of the genus Cryptococcus. Cryptococcus neoformans and Cryptococcus gattii are the main agents of this mycosis. Until 2002 C. gattii was classified as a variety of C. neoformans but now is accepted as an independent species. The laccase (phenoloxydase) enzyme produced by these yeasts is considered one of the main pathogenic factors for its ability to induce melanin from dihydroxyphenolic compounds. The vast majority of the studies in laccase and melanin synthesis have been developed using isolates of C. neoformans. The main objective of this study was to evaluate laccase activity in strains of C. gattii, serotype B isolated from immunocompetent goats that died of lung and disseminated cryptococcosis, in several outbreaks occurring in Spain. The laccase activities of these isolates were compared with those of other strains of C. gattii and C. neoformans. After fungal cell rupture, the supernatant of each isolate was analyzed for its laccase activity using as substrate an L-dopa 20 mM solution. The degree of enzymatic activity was assessed according to its absorbance at 450 nm and scored using Enzymatic Units (EU). The maximum values were observed in three strains of C. gattii from goats (EU > 12). The smallest values were observed in one environmental isolate of C. gattii serotype C (EU = 0.7). The highest recorded value for C. neoformans was 6.3 EU in a serotype A isolate from one human case of meningitis. C. gattii serotype B obtained from goats showed different degrees of laccase activity, being the highest in those isolated from severe outbreaks of cryptococcosis. This enzyme appears to represent a major, though nonexclusive, pathogenic factor for Cryptococcus gattii. 相似文献
787.
Tatiana Gianni Valerio Leoni Gabriella Campadelli-Fiume 《Journal of virology》2013,87(24):13911-13916
αvβ3 integrin represents a novel sensing system which detects herpes simplex virus (HSV) and bacterial constituents. In cooperation with Toll-like receptor 2 (TLR2), it elicits an innate response that leads to activation of type I interferon (IFN), NF-κB, and a specific set of cytokines. We report that this defensive branch is functional in cells which represent experimental models of epithelial, including keratinocytic, and neuronal cells. These are the major targets of HSV in vivo. HSV entered the three cell lines via distinct routes. Hence, the defensive response was independent of the route of virus entry. Soluble gH/gL sufficed to elicit type I IFN and NF-κB activation and represents the viral pathogen-associated molecular pattern (PAMP) of this defense system. 相似文献
788.
Glucocorticoid-induced Leucine Zipper (GILZ) and Long GILZ Inhibit Myogenic Differentiation and Mediate Anti-myogenic Effects of Glucocorticoids 总被引:1,自引:0,他引:1
789.
Daniela Giustarini Elena Perrino Valerio Tazzari Ranieri Rossi 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(3-4):340-346
A panel of new drugs obtained by grafting a sulfurated moiety, i.e. 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADTOH) onto existing drugs have been synthesized and their in vivo action is under preclinical evaluation. In the present paper we describe rapid HPLC methods to detect ADTOH derivatives of valproic acid (ACS2), sildenafil (ACS6), aspirin (ACS14) and diclofenac (ACS15) in plasma. These methods allow the simultaneous detection of the potential drugs and of ADTOH moiety. In the case of ACS14 the de-acetylated metabolite (ACS21) can also be concomitantly measured. The chromatographic separation was performed on a C18 column, applying a mobile phase consisting of a mixture of trifluoroacetic acid and acetonitrile. ADTOH, ACS6, ACS14, ACS21 were separated isocratically whereas ACS2 and ACS15 were separated applying gradient elution. The methods are precise and accurate, with a low quantification limit of 200 nM for ACS2, ACS15 and ACS21 or 100 nM for ADTOH, ACS6 and ACS14. The mean absolute recovery for all tested molecules was always found to be close to 100%. The methods are shown to be selective and linear in the range 0.2–50 μM and thus appear suitable for pharmacokinetic studies with ADTOH containing compounds, as indicated by exemplificative experiments performed with intravenous administration of the drugs to rats. 相似文献
790.
We propose a new generalization of the Drude model for describing the conductors in nanostructured form. The new feature that appeared is the assumption of a collective mode at a finite frequency. This leads to the occurrence of anomalous charge transport. With appropriate scattering times it is possible to mimic the infrared properties of oxides and poor conductors in the form of nanoparticles and nanowires. The electron current in these cases reverses its direction before decaying to zero. Specific examples considered are ZnO, TiO2, GaAs, Si, SWCN. The model also predicts that the current will have a damped oscillation in time, a possible new effect detectable with femtosecond time resolved techniques. Results are presented for the velocity correlation functions, the mean square deviation of position and the diffusion coefficient. 相似文献