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141.
Contini C Seraceni S Cultrera R Incorvaia C Sebastiani A Picot S 《International journal for parasitology》2005,35(3):275-283
PCR based methods have advantages over traditional methods for the diagnosis of toxoplasmosis, especially when serology fails and clinical symptoms are not evident. However, current PCR-based assays are often labour-intensive and not readily quantifiable and have the potential for contamination due to a requirement for postamplification sample handling. Real-time PCR can address these limitations. We have developed and evaluated a highly sensitive Real-time PCR (Light-cycler, LC-PCR) to detect and quantify Toxoplasma gondii B1 and bradyzoite specific genes (SAG-4, MAG-1) in serum and peripheral blood mononuclear cells (PBMC) specimens, from five immunocompetent subjects with clinically suspected toxoplasmic retinochoroiditis (TRC) or without a suspected T. gondii infection. A standard curve for quantitation of parasitic load was generated using SYBR Green I fluorescent detection. The results were compared with those obtained with a nested PCR (n-PCR). In TRC patients, both PCR methods confirmed ophtalmoscopy and fluorangiographic findings. Among the TRC patients, the use of LC-PCR was more sensitive than n-PCR for detection and quantification of either B1 gene (P<0.001) or SAG-4/MAG-1 gene (P<0.05). LC-PCR has been shown particularly useful to accurately determine the parasite DNA load in follow-up specimens in whom the performance of either B1 or SAG-4 and MAG-1 in detecting T. gondii loads, varied with respect to specific antitoxoplasmic treatment. 相似文献
142.
143.
Alfonso-Sánchez MA Calderón R Peña JA 《Human biology; an international record of research》2004,76(3):361-381
Analysis of the interaction between mortality patterns and opportunity for natural selection could help to elucidate potential evolutionary implications of epidemic mortality. In this paper secular trends are studied in relation to Crow's index (It) and its components of mortality (Im) and fertility (If), using parish records for family reconstitution in a Basque population. A principal components analysis (91% of the variance accounted for) showed marked quantitative and qualitative variations of Im and If depending on the stage of demographic transition of the population analyzed: In pretransitional societies the opportunity for natural selection is determined mainly by differential prereproductive mortality, whereas in posttransitional societies selection resulting from differential fertility plays a key role. The highest values for the mortality component (range 0.81-1.26) and for the relative contribution of Im, to It (range 47.1-57.2%) were observed in periods with a high incidence of infectious diseases and when the most severe mortality crises were detected (1830-1859, 1860-1889, and 1890-1919). A differential incidence of epidemic mortality was also found at prereproductive ages (before 16 years) and at reproductive ages (16-45 years), which provides strong support for the idea of the long-term genetic consequences of mortality crises. 相似文献
144.
Bcl-2 and Bax exert opposing effects on Ca2+ signaling, which do not depend on their putative pore-forming region 总被引:6,自引:0,他引:6
Chami M Prandini A Campanella M Pinton P Szabadkai G Reed JC Rizzuto R 《The Journal of biological chemistry》2004,279(52):54581-54589
Recent work has shown that Bcl-2 and other anti-apoptotic proteins partially deplete the endoplasmic reticulum (ER) Ca(2+) store and that this alteration of Ca(2+) signaling reduces cellular sensitivity to apoptotic stimuli. We expressed in HeLa cells Bcl-2, Bax, and Bcl-2/Bax chimeras in which the putative pore-forming domains of the two proteins (alpha 5-alpha 6) were mutually swapped, comparing the effects on Ca(2+) signaling of the two proteins and relating them to defined molecular domains. The results showed that only Bcl-2 reduces ER Ca(2+) levels and that this effect does not depend on the alpha 5-alpha 6 helices of this oncoprotein. Soon after its expression, Bax increased ER Ca(2+) loading, with ensuing potentiation of mitochondrial Ca(2+) responses. Then the cells progressed into an apoptotic phenotype (which included drastic reductions of cytosolic and mitochondrial Ca(2+) responses and alterations of organelle morphology). These results provide a coherent scenario that high-lights a primary role of Ca(2+) signals in deciphering apoptotic stimuli. 相似文献
145.
Pinton P Leo S Wieckowski MR Di Benedetto G Rizzuto R 《The Journal of cell biology》2004,165(2):223-232
The modulation of Ca2+ signaling patterns during repetitive stimulations represents an important mechanism for integrating through time the inputs received by a cell. By either overexpressing the isoforms of protein kinase C (PKC) or inhibiting them with specific blockers, we investigated the role of this family of proteins in regulating the dynamic interplay of the intracellular Ca2+ pools. The effects of the different isoforms spanned from the reduction of ER Ca2+ release (PKCalpha) to the increase or reduction of mitochondrial Ca2+ uptake (PKCzeta and PKCbeta/PKCdelta, respectively). This PKC-dependent regulatory mechanism underlies the process of mitochondrial Ca2+ desensitization, which in turn modulates cellular responses (e.g., insulin secretion). These results demonstrate that organelle Ca2+ homeostasis (and in particular mitochondrial processing of Ca2+ signals) is tuned through the wide molecular repertoire of intracellular Ca2+ transducers. 相似文献
146.
Tonachini L Monticone M Puri C Tacchetti C Pinton P Rizzuto R Cancedda R Tavella S Castagnola P 《Journal of cellular physiology》2004,201(3):470-482
We have recently identified a chondrocyte protein with a poly-proline region, referred to as CHPPR, and showed that this protein is expressed intracellularly in chick embryo chondrocytes. Conventional fluorescence and confocal localization of CHPPR shows that CHPPR is sorted to mitochondria. Furthermore, immunoelectron microscopy of CHPPR transfected cells demonstrates that this protein is mostly associated with the mitochondrial inner membranes. Careful analysis of CHPPR expressing cells reveals, instead of the regular mitochondrial tubular network, the presence of a number of small spheroid mitochondria. Here we show that the domain responsible for network-spheroid transition spans amino acid residues 182-309 including the poly-proline region. Functional analyses of mitochondrial activity rule out the possibility of mitochondrial damage in CHPPR transfected cells. Since cartilage expresses high levels of CHPPR mRNA when compared to other tissues and because CHPPR is associated with late stages of chondrocyte differentiation, we have investigated mitochondrial morphology in hypertrophic chondrocytes by MitoTracker Orange labeling. Confocal microscopy shows that these cells have spheroid mitochondria. Our data demonstrate that CHPPR is able to promote mitochondrial fission with a sequence specific mechanism suggesting that this event may be relevant to late stage of chondrocyte differentiation. 相似文献
147.
Preparation and characterization of Eudragit Retard nanosuspensions for the ocular delivery of cloricromene 总被引:1,自引:0,他引:1
Pignatello R Ricupero N Bucolo C Maugeri F Maltese A Puglisi G 《AAPS PharmSciTech》2006,7(1):E192-E198
The purpose of this study was to improve the stability of cloricromene (AD6) in ophthalmic formulations and its drug availability
at the ocular level. To this end, AD6-loaded polymeric nanoparticle suspensions were made using inert polymer resins (Eudragit
RS100 and RL100). We modified the quasi-emulsion solvent diffusion technique by varying some formulation parameters (the drug-to-polymer
ratio, the total drug and polymer amount, and the stirring speed). The chemical stability of AD6 in the nanosuspensions was
assessed by preparing some formulations using (unbuffered) isotonic saline or a pH 7 phosphate buffer solution as the dispersing
medium. The formulations were stored at 4°C, and the rate of degradation of AD6 was followed by high performance liquid chromatography
(HPLC). The obtained nanosuspensions showed mean sizes and a positive surface charge (ζ-potential) that make them suitable
for an ophthalmic application; these properties were maintained upon storage at 4°C for several months. In vitro dissolution
tests confirmed a modified release of the drug from the polymer matrixes. Nanosuspensions prepared with saline solution and
no or lower amounts of surfactant (Tween 80) showed an enhanced stability of the ester drug for several months, with respect
to an AD6 aqueous solution. Based on the tecnological results, AD6-loaded Eudragit Retard nanoparticle suspensions appear
to, offer promise as a means to improving the shelf life and bioavailability of this drug after ophthalmic application.
Published: March 24, 2006 相似文献
148.
Rodríguez Patino JM Fernandez MC Rodríguez Niño MR Sanchez CC 《Biomacromolecules》2006,7(9):2661-2670
In this work, we have analyzed the structural, topographical, and surface dilatational characteristics of pure beta-lactoglobulin adsorbed films and the effect of the self-assembly of monoglycerides (monopalmitin or monoolein) in beta-lactoglobulin films at the air-water interface. Measurements were performed in a single device that incorporates a Wilhelmy-type film balance, Brewster angle microscopy, and interfacial dilatational rheology. The structural and topographical characteristics of beta-lactoglobulin adsorbed and spread films are similar. However, the surface dilatational modulus of beta-lactoglobulin films shows a complex behavior depending on film formation. The self-assembly of monoglyceride in a beta-lactoglobulin adsorbed film has an effect on the structural, topographical, and dilatational properties of the mixed films, depending on the interfacial composition and the surface pressure (pi). At low pi, a mixed film of monoglyceride and beta-lactoglobulin may exist. At high pi (after the collapse of beta-lactoglobulin), the mixed films are dominated by monoglyceride molecules. However, the small amounts of collapsed beta-lactoglobulin have a significant effect on the surface dilatational properties of the mixed films. Protein displacement by monoglyceride is higher for monopalmitin than for monoolein. However, some degree of interaction exists between proteins and monoglycerides, and these interactions are more evident in adsorbed films than in spread films. 相似文献
149.
150.
Anna Aiello Ernesto Fattorusso Paolo Luciano Marialuisa Menna Marco A. Calzado Eduardo Muñoz Francesco Bonadies Marcella Guiso Maria Filomena Sanasi Gianfranco Cocco Rosario Nicoletti 《Bioorganic & medicinal chemistry》2010,18(2):719-727
The synthesis of analogues of aplidinone A (7), a prenylated quinone isolated from the Mediterranean ascidian Aplidium conicum, has been performed. This work not only allowed confirming the structural assignment of aplidinone A, previously made with the support of GIAO shielding calculations, but, above all, made a series of structurally related quinone derivatives (compounds 8–13 and the natural metabolite) available for a screening in vitro for cytotoxic and pro-apoptotic activity and for SAR studies. The study evidenced one of the synthetic analogues (11) as a potent cytotoxic and pro-apoptotic agent against several tumor cell lines which also inhibits the TNFα-induced NF-κB activation in a human leukemia T cell line. This exemplifies the potential of a natural product to qualify as lead structure for medicinal chemistry campaigns, affording simplified analogues with better bioactivity and easier to synthesize. 相似文献