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971.
Abstract Some cytological aspects of Phaseolus coccineus L. endosperm. — Cytological observations were made on the endosperm of Phaseolus coccineus, in a limited stage of development of the seed, using different dyes and labelling with 3H-thymidine and 3H-uridine. The results seem to indicate that, contrary to suspensor cells, in the endosperm of Phaseolus, at least in the considered stage, extra DNA synthesis is not present. Chromosomes in these nuclei, however, undergo several endoreduplication cycles. Nucleoli may be either one or more in a cell, and show a characteristic structure. They are often eccentric in the nucleus and extrusions of nucleolar content in the nucleoplasm or cytoplasm are seen. An apparent alternate activity of RNA synthesis in the nucleoli of the suspensor and in those of endosperm cells is discussed. 相似文献
972.
Chiesura Lorenzoni Francesca Luigino Curti Giovanni Giorgio Lorenzoni Silvano Marchior 《Plant biosystems》2013,147(4-5):259-267
Abstract Cistus clusii Dunal: a note on nomenclature and distribution with special reference to the station of Lesina (Foggia). — The recent finding of Cistus clusii Dunal at Torre del Fortore (Pietramaura) near Lesina (Puglia - Southern Italy), besides confirming its presence in the region, indicates that its diffusion is larger than it was thought. This species is in danger of disappearing because the larger part of the station is included within a lotting area. 相似文献
973.
Sabry M. Youssef Iraida Amaya José M. López-Aranda Rafael Sesmero Victoriano Valpuesta Giorgio Casadoro Rosario Blanco-Portales Fernando Pliego-Alfaro Miguel A. Quesada José A. Mercado 《Molecular breeding : new strategies in plant improvement》2013,31(2):313-322
Strawberry is a soft fruit with a short postharvest shelf-life. The loss of fruit firmness during ripening is mainly due to the disassembly of parenchyma cell walls mediated by the expression of genes encoding enzymes acting on pectins, such as pectate lyase, or hemicellulose, e.g. endo-β-1,4-glucanase. To determine if the simultaneous down-regulation of FaplC and FaEG3 genes, encoding a pectate lyase and a endo-β-1,4-glucanase, respectively, exerted an additive effect on strawberry softening, transgenic plants expressing tandem antisense sequences of both genes under the control of the constitutive promoter CaMV35S were generated. Fifteen independent transgenic lines were obtained and fruit yields and several quality parameters of transgenic ripe fruit were recorded during two consecutive years. Fruit yield was reduced in most of the lines, especially in the first evaluation period, and five out of 15 lines (33 %) did not set fruit. The expression of FaplC and FaEG3 genes was measured in ripe fruits from six selected lines showing the highest fruit yields. All selected lines showed a high level of FaplC gene silencing, ranging from 97 to 71 %; however, FaEG3 gene expression was only significantly down-regulated in two lines. Fruit colour and soluble solids contents were similar in control and transgenic ripe fruits, while fruit weight was slightly lower than control in some of the lines. In all lines, transgenic fruits were significantly firmer than control, with an increase in firmness ranging from 19 to 32 %. The reduction of fruit softening in transgenic fruits was not correlated with the suppression of FaEG3 gene expression, and lines with the highest simultaneous down-regulation of FaplC and FaEG3 showed similar fruit firmness to lines where only FaplC was suppressed. These results indicate that pectate lyase and endo-β-1,4-glucanase do not act in an additive or synergistic way during strawberry softening, and question the role of glucanases in this process. 相似文献
974.
Giacomina Brunetti Angela Oranger Claudia Carbone Giorgio Mori Francesca Rita Sardone Claudio Mori Monica Celi Maria Felicia Faienza Umberto Tarantino Alberta Zallone Maria Grano Silvia Colucci 《Cell biochemistry and biophysics》2013,67(3):1127-1136
Apoptosis can occur throughout the life span of osteoblasts (OBs), beginning from the early stages of differentiation and continuing throughout all stages of their working life. Here, we investigated the effects of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) on normal human OBs showing for the first time that the expression of TRAIL receptors is modulated during OB differentiation. In particular, the TRAIL receptor ratio was in favor of the deaths because of the low expression of DcR2 in undifferentiated OBs, differently it was shifted toward the decoys in differentiated ones. Undifferentiated OBs treated with TRAIL showed reduced cell viability, whereas differentiated OBs displayed TRAIL resistance. The OB sensitiveness to TRAIL was due to the up-regulation of DR5 and the down-regulation of DcR2. The main death receptor involved in TRAIL-reduced OB viability was DR5 as demonstrated by the rescue of cell viability observed in the presence of anti-DR5 neutralizing antibody. Besides the ratio of TRAIL receptors, the sensitivity of undifferentiated OBs to TRAIL-cytotoxic effect was also associated with low mRNA levels of intracellular anti-apoptotic proteins, such as cFLIP, the activation of caspase-8 and -3, as well as the DNA fragmentation. This study suggests that apoptotic effect exerted by TRAIL/TRAIL-receptor system on normal human OB is strictly dependent upon cell differentiation status. 相似文献
975.
Antinori A Marcotullio S Ammassari A Andreoni M Angarano G Carosi G Cinque P d'Arminio Monforte A Di Perri G Ensoli B Ferrazzi E Galli M Mastroianni C Matteelli A Mazzotta F Moroni M Palù G Puoti M Puro V Rizzardini G Sagnelli E Suter F Vella S Lazzarin A;Italian HIV Guidelines Working Group 《The new microbiologica》2011,34(2):109-146
976.
Tafuri S Martinelli D Grimaldi A Lopatriello A Giorgio V Prato R 《The new microbiologica》2011,34(4):417-420
We report a clinical failure of a pneumococcal vaccine in a patient who developed pneumococcal pneumonia. In 2008, an 85-year-old Italian woman was admitted to the Respiratory Disease Unit of a hospital in Southern Italy. The 23-valent pneumococcal vaccine had been administered to the patient 50 days earlier. The chest x-ray disclosed a right basal bronchopneumonic focus. Streptococcus Pneumoniae serotype 19A, a strain included in the 23-valent pneumococcal vaccine, was isolated from the sputum. There is a need for more efficacious conjugated vaccines covering the majority of the pneumococcal serotypes that cause serious illness in older children and adults worldwide. 相似文献
977.
Yu SS Koblin RL Zachman AL Perrien DS Hofmeister LH Giorgio TD Sung HJ 《Biomacromolecules》2011,12(12):4357-4366
Chronic inflammation-mediated oxidative stress is a common mechanism of implant rejection and failure. Therefore, polymer scaffolds that can degrade slowly in response to this environment may provide a viable platform for implant site-specific, sustained release of immunomodulatory agents over a long time period. In this work, proline oligomers of varying lengths (P(n)) were synthesized and exposed to oxidative environments, and their accelerated degradation under oxidative conditions was verified via high performance liquid chromatography and gel permeation chromatography. Next, diblock copolymers of poly(ethylene glycol) (PEG) and poly(ε-caprolactone) (PCL) were carboxylated to form 100 kDa terpolymers of 4%PEG-86%PCL-10%cPCL (cPCL = poly(carboxyl-ε-caprolactone); i% indicates molar ratio). The polymers were then cross-linked with biaminated PEG-P(n)-PEG chains, where P(n) indicates the length of the proline oligomer flanked by PEG chains. Salt-leaching of the polymeric matrices created scaffolds of macroporous and microporous architecture, as observed by scanning electron microscopy. The degradation of scaffolds was accelerated under oxidative conditions, as evidenced by mass loss and differential scanning calorimetry measurements. Immortalized murine bone-marrow-derived macrophages were then seeded on the scaffolds and activated through the addition of γ-interferon and lipopolysaccharide throughout the 9-day study period. This treatment promoted the release of H(2)O(2) by the macrophages and the degradation of proline-containing scaffolds compared to the control scaffolds. The accelerated degradation was evidenced by increased scaffold porosity, as visualized through scanning electron microscopy and X-ray microtomography imaging. The current study provides insight into the development of scaffolds that respond to oxidative environments through gradual degradation for the controlled release of therapeutics targeted to diseases that feature chronic inflammation and oxidative stress. 相似文献
978.
979.
Leo L Gherardini L Barone V De Fusco M Pietrobon D Pizzorusso T Casari G 《PLoS genetics》2011,7(6):e1002129
Familial hemiplegic migraine type 2 (FHM2) is an autosomal dominant form of migraine with aura that is caused by mutations of the α2-subunit of the Na,K-ATPase, an isoform almost exclusively expressed in astrocytes in the adult brain. We generated the first FHM2 knock-in mouse model carrying the human W887R mutation in the Atp1a2 orthologous gene. Homozygous Atp1a2(R887/R887) mutants died just after birth, while heterozygous Atp1a2(+/R887) mice showed no apparent clinical phenotype. The mutant α2 Na,K-ATPase protein was barely detectable in the brain of homozygous mutants and strongly reduced in the brain of heterozygous mutants, likely as a consequence of endoplasmic reticulum retention and subsequent proteasomal degradation, as we demonstrate in transfected cells. In vivo analysis of cortical spreading depression (CSD), the phenomenon underlying migraine aura, revealed a decreased induction threshold and an increased velocity of propagation in the heterozygous FHM2 mouse. Since several lines of evidence involve a specific role of the glial α2 Na,K pump in active reuptake of glutamate from the synaptic cleft, we hypothesize that CSD facilitation in the FHM2 mouse model is sustained by inefficient glutamate clearance by astrocytes and consequent increased cortical excitatory neurotransmission. The demonstration that FHM2 and FHM1 mutations share the ability to facilitate induction and propagation of CSD in mouse models further support the role of CSD as a key migraine trigger. 相似文献
980.
Sonia Fabris Valentina Bollati Luca Agnelli Fortunato Morabito Valeria Motta Giovanna Cutrona Serena Matis Anna Grazia Recchia Vincenzo Gigliotti Massimo Gentile Giorgio Lambertenghi Deliliers Pier Alberto Bertazzi Manlio Ferrarini Antonino Neri Andrea Baccarelli 《Epigenetics》2011,6(2):188-194
Global DNA hypomethylation affecting repeat sequences has been reported in different cancer types. Herein, we investigated the methylation levels of repetitive DNA elements in chronic lymphocytic leukemia (CLL), their correlation with the major cytogenetic and molecular features, and clinical relevance in predicting therapy-free survival (TFS). A quantitative bisulfite-PCR Pyrosequencing method was used to evaluate methylation of Alu, long interspersed nuclear elements-1 (LINE-1) and satellite-α (SAT-α) sequences in 77 untreated early-stage (Binet A) CLL patients. Peripheral B-cells from 7 healthy donors were used as controls. Methylation levels (median %5mC) were lower in B-CLLs compared with controls (21.4 vs. 25.9; 66.8 vs. 85.7; 84.0, vs. 88.2 for Alu, LINE-1 and SAT-α, respectively) (p < 0.001). Among CLL patients, a significant association was observed with 17p13.1 deletion (16.8 vs. 22.4; 51.2 vs. 68.5; 52.6 vs. 85.0, for Alu, LINE-1 and SAT-α) but not with other major genetic lesions, IgVH mutation status, CD38 or ZAP-70 expression. Follow-up analyses showed that lower SAT-α methylation levels appeared to be an independent prognostic marker significantly associated with shorter TFS. Our study extended previous limited evidences in methylation of repetitive sequences in CLL suggesting an important biological and clinical relevance in the disease. 相似文献