103 research outputs found
Direct surgery for brainstem tumours [Asportazione chirurgica diretta dei tumori del tronco cerebrale].
No full textNo abstract availabl
Transmission Electron Microscopy of Lipid Vesicles for Drug Delivery: Comparison between Positive and Negative Staining
No full textLipid-containing nanostructures, in the form of solid lipid nanoparticles or iron oxide nanoparticles (NPs) coated with a lipid shell, were used as case studies for assessing and optimizing staining for transmission electron microscopy structural and compositional characterization. These systems are of paramount importance as drug delivery systems or as bio-compatible contrast agents. In particular, we have treated the systems with a negative (phospshotungstic acid) or with a positive (osmium tetroxide) staining agent. For iron-oxide NPs coated with the lipid shell, negative staining was more efficient with respect to the positive one. Nevertheless, in particular cases the combination of the two staining procedures provided more complete morphological and compositional characterization of the particles
MOLECULAR CHARACTERIZATION OF COMMON VARIABLE IMMUNODEFICIENCY-RELATED LYMPHOMAS
No full textCommon variable immunodeficiency (CVI) patients are at high relative risk of developing non-Hodgkin lymphomas (NHL), mainly represented by B-lineage diffuse large cell lymphomas. The molecular pathogenesis and histogenesis of CVI-related NHL are poorly understood. We have thus attempted to provide a detailed molecular characterization of their histogenesis and pathogenesis. A panel of 5 CVI-related NHL was subjected to detailed analysis of histogenetic markers (mutations of immunoglobulin variable heavy chain-IgVH and of BCL-6 genes) acquired by B-cells at the time of germinal center transit. Somatic hypermutation of IgVH and BCL-6 genes occurred in 5/5 cases; in all cases, mutations were stable with no evidence of ongoing mutation processes. In 3/5 cases, the pattern of IgVH mutations was consistent with selection and stimulation of the tumor clone by antigen. To further clarify the pathogenesis, samples were tested for inactivation by promoter hypermethylation of the genes 0(6)-methylguanine-DNA-methyltransferase (MGMT) and glutathione S-transferase (GST) p1, which code for detoxifying enzymes, as well as of death-associated protein (DAP)-kinase, coding for a proapoptotic molecule. Promoter hypermethylation of MGMT, GSTp1 and DAP-kinase was detected in 2/5, 3/5 and 3/5 CVI-related NHL, respectively. Overall, these data indicate that: i) similarly to other immunodeficiency-related NHL, CVI-related NHL derive from germinal center-related B-cells, namely centrocytes or post-germinal center B-cells; ii) antigen stimulation and selection are involved in the development of at least a fraction of these cases; iii) hypermethylation of the MGMT, DAP-kinase and GSTp1 genes occurs at sustained frequencies in CVI-related NHL and may provide novel prognostic markers and therapeutic targets for the clinical management of these lymphomas
Risk factors for death in nonneutropenic patients with candidemia at a tertiary-care hospital
No full textOral methylprednisolone megadose in the treatment of recurrent gliomas and intracranial metastases. Preliminary report.
No full textL'evento e il vivente. In Jacques Derrida
No full textVi è vivente solo là dove vi è o vi può essere evento, sorpresa, imprevidibilità, singolarità. Il pensiero derridiano dell'evento si rivela un pensiero del vivente, che si colloca a una notevole distanza tanto da un vitalismo trionfante e "costruttivo" quanto da un nichilismo mortifero. La vita del vivente è pensata cioè come «sopra-vivenza» o, per usare un'ultima volta la parola, essa stessa come evento
FREQUENT MUTATION OF THE BCL-6 PROTO-ONCOGENE IN HIGH GRADE, BUT NOT LOW GRADE, MALT LYMPHOMAS OF THE GASTROINTESTINAL TRACT
No full textBACKGROUND AND OBJECTIVE:
Knowledge regarding the molecular pathogenesis and histogenesis of gastrointestinal mucosa-associated lymphoid tissue non-Hodgkin's lymphomas (MALT-NHL) is limited. Mutations of BCL-6, a zinc finger transcription factor implicated in lymphoid development, occur frequently in lymphomas and represent a histogenetic marker of B-cell transit through the germinal center. The distribution of BCL-6 mutations in gastrointestinal MALT-NHL was analyzed in this study.
DESIGN AND METHODS:
This study was based on 26 gastrointestinal MALT-NHL, including 16 cases of low grade histology and 10 cases of high grade histology. Mutations of BCL-6 were investigated by a combination of polymerase chain reaction-single strand conformation polymorphism and DNA direct sequencing analysis.
RESULTS:
Mutations of BCL-6 occurred in 6/10 high grade MALT-NHL, whereas they were absent from all low grade cases tested (n = 16; p = 0.001). MALT-NHL harboring BCL-6 mutations included 5 cases of gastric MALT-NHL and 1 case of jejunal MALT-NHL. Mutations were predominantly represented by single nucleotide substitutions which were multiple in most cases. All sequence alterations were unique to individual cases of gastrointestinal MALT-NHL.
INTERPRETATION AND CONCLUSIONS:
Mutations of BCL-6 occur frequently in high grade gastrointestinal MALT-NHL and display characteristics similar to those of BCL-6 mutations harbored by other B-cell lymphomas. The association of high grade MALT-NHL with BCL-6 mutations corroborates their histogenetic derivation from germinal center-related B-cells and may be of potential pathogenetic relevance for these disorders
Francesca Vivenza : Dive
No full textSituating Vivenza's sculptural work under the influence of the Arte Povera movement, Farrell describes the exhibition as an allegory on the immigrant experience of subjective dislocation; the author then provides short critiques of four pieces. Biographical notes. 2 bibl. ref
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