1,720,976 research outputs found
Le prove di valutazione nella formazione iniziale degli insegnanti: la prospettiva del cambiamento concettuale
No full textQuesto contributo riflette sul ruolo che l’analisi critica delle prove assume nella formazione iniziale degli insegnanti, per promuovere la “conoscenza dei contenuti disciplinari dal punto di vista pedagogico” (“Pe- dagogical Content Knowledge - PCK”). Per favorire la transizione da una concezione strumentale a una strut- turale dei compiti di valutazione, si ritiene che l’insegnamento vada considerato come un processo socio-culturale che implica l’organizzazione del setting, la scelta dei materiali e la strutturazione delle attività e delle modalità di partecipazione degli studenti; si propone l’uso di modalità analitiche “Scenario-based” (Skilling and Stylianides 2017), per ricostruire le concezioni implicite dei futuri insegnanti e favorire la concezione della valutazione per l’apprendimento
DNA damage promotes mistyping in the allele specific oligonucleotide probing analysis of forensic samples
No full textUsing archaeal histones for precise DNA fragmentation
No full textThe fragmentation of DNA is a useful procedure for many molecular biology procedures. However, most methods used to fragment DNA are poorly controllable, and cannot be used to create small fragments. We describe a method to generate random DNA fragments of a predictable size to be cloned in expression vectors for the construction of display libraries. The DNA is allowed to form complexes with archaeal histones from Methanothermus fervidus (HMf) and the HMf/DNA core complex is naturally protected from nuclease DNaseI activity, giving rise to DNA fragments of approximately 60 bp and multiples thereof. We found that by varying the wt/wt ratio between DNA and HMf, the concentration of DNA and the incubation time with DNaseI, DNA fragments of desired size can be obtained. This approach should be applicable to the efficient fragmentation of DNA for the construction of phage display polypeptide libraries, as well as any other molecular biology procedures in which small DNA fragments of defined size are required
Population genetics of the crayfish Austropotamobius pallipes complex in Friuli Venezia Giulia (Italy)
No full textIdentification of novel non-myelin biomarkers in multiple sclerosis using an improved phage-display approach
Full text linkAlthough the etiology of multiple sclerosis is not yet understood, it is accepted that its pathogenesis involves both autoimmune and neurodegenerative processes, in which the role of autoreactive T-cells has been elucidated. Instead, the contribution of humoral response is still unclear, even if the presence of intrathecal antibodies and B-cells follicle-like structures in meninges of patients has been demonstrated. Several myelin and non-myelin antigens have been identified, but none has been validated as humoral biomarker. In particular autoantibodies against myelin proteins have been found also in healthy individuals, whereas non-myelin antigens have been implicated in neurodegenerative phase of the disease. To provide further putative autoantigens of multiple sclerosis, we investigated the antigen specificity of immunoglobulins present both in sera and in cerebrospinal fluid of patients using phage display technology in a new improved format. A human brain cDNA phage display library was constructed and enriched for open-read-frame fragments. This library was selected against pooled and purified immunoglobulins from cerebrospinal fluid and sera of multiple sclerosis patients. The antigen library was also screened against an antibody scFv library obtained from RNA of B cells purified from the cerebrospinal fluid of two relapsing remitting patients. From all biopanning a complex of 14 antigens were identified; in particular, one of these antigens, corresponding to DDX24 protein, was present in all selections. The ability of more frequently isolated antigens to discriminate between sera from patients with multiple sclerosis or other neurological diseases was investigated. The more promising novel candidate autoantigens were DDX24 and TCERG1. Both are implicated in RNA modification and regulation which can be altered in neurodegenerative processes. Therefore, we propose that they could be a marker of a particular disease activity state
Alteration in the Arf6-regulated plasma membrane endosomal recycling pathway in cells overexpressing the tetraspan protein Gas3/PMP22
No full textAlterations in the Arf6-regulated plasma membrane endosomal recycling pathway in cells overexpressing the tetraspan protein Gas3/PMP22
No full textApoptotic phenotype induced by overexpression of wild-type gas3/PMP22: its relation to the demyelinating peripheral neuropathy CMT1A
No full textAlthough the Gas3/PMP22 protein is expressed at highest levels in differentiated Schwann cells, its presence, albeit at lower levels, in non-neuronal tissues and in NIH-3T3 growth-arrested fibroblasts argues for a more general function of this protein that is uncoupled to myelin structure. We show that gas3/PMP22 overexpression in NIH-3T3 growing cells leads to an apoptotic-like phenotype, which is suppressed by antioxidants and characterized by typical membrane blebbing, rounding up, and chromatin condensation, but with no evidence of DNA fragmentation. REF-52 fibroblasts seem to be completely refractive to gas3/PMP22 overexpression. Recently, several point mutations of the human gas3/PMP22 gene have been associated with Charcot-Marie-Tooth type 1A (CMT1A), a common hereditary demyelinating neuropathy. When gas3/PMP22 point mutations (L16P, S79C, T118M, and G150D) are similarly overexpressed in NIH-3T3 cells, the induced apoptotic-like phenotype as compared to the wild-type is significantly reduced. Both of the dominant mutations (L16P, S79C) for CMT1A behave as dominant negatives with respect to the wild type, whereas T118M, the only recessive mutant described, behaves as recessive under the same coexpression experiments. These data suggest a role for altered Schwann cell apoptosis in the pathogenesis of CMT1A
A method for rapid and high-yield production of the tick-borne encephalitis virus E and DIII recombinant proteins in E. coli with preservation of the antigenic properties
Full text linkTick-borne encephalitis virus (TBEV) is a member of the Flavivirus genus and is the main pathogenic arbovirus circulating in Europe, Russia and China. The envelope (E) protein is exposed on the viral surface and is the main antigen that is employed in diagnostic tests based on the detection of protein-specific antibodies from serum samples of infected individuals. The high degree of similarity among the E proteins of flaviviruses can, in some cases, lead to cross-reactivity and false-positive results in serological tests. Increased specificity in the detection of positive sera for different Flavivirus infections is often obtained by using a portion of the E protein, namely, the DIII domain. Different strategies and expression systems have been described for E and DIII protein production. Here, we present the optimization of an easy and fast method for TBEV E and DIII antigen production and partial purification from E. coli inclusion bodies. The antigenic properties of the produced antigens are retained, as validated by ELISAs with anti-TBEV murine sera as well as sera from infected human patients. The potential applications of both proteins as diagnostic reagents were confirmed
- …
