1,721,065 research outputs found
La medicina predittiva e il dibattito etico sui test genetici
No full textLa “rivoluzione genetica” che sta caratterizzando il terzo millennio fa sì che sempre più aspetti dell’esistenza umana possano essere soggetti al controllo scientifico e tecnologico. Ciò crea grandi aspettative in merito alle potenzialità diagnostiche e terapeutiche della genetica; allo stesso tempo, però, alle aumentate capacità di controllo si accompagna un numero crescente di situazioni che pongono seri dilemmi morali per ricercatori, medici e pazienti.
Nelle riflessioni che seguono concentreremo la nostra attenzione sulle questioni bioetiche legate alla gestione delle potenzialità diagnostiche espresse dai test genetici.
La prima parte sarà dedicata a una breve panoramica sullo stato dell’arte dei test genetici dal punto di vista scientifico; la seconda parte si occuperà del dibattito etico intorno ai loro impieghi. L’obiettivo che ci proponiamo, integrando le nostre competenze, rispettivamente quella biologica e quella bioetica, è di permettere di acquisire una visione d’insieme sui principali orientamenti che si confrontano nell’attuale dibattito bioetico in ordine all’elaborazione nel nostro contesto pluralistico di un adeguato quadro etico-normativo
Functionally antagonistic groups of macrophages can be incorporated with human pluripotent stem-cell derived cardiomyocytes to engineer a novel human myocardial infarction model in vitro.
No full textThe innate immune response upon myocardial infarction (MI), a leading cause of congestive heart failure, results in fibrosis and cardiac remodeling. Two functionally antagonistic groups of macrophages are involved in MI: CD80+CD86+ pro-inflammatory macrophages (M1) in the initial response and CD163+CD206+ anti-inflammatory macrophages (M2) in the late response. However, their precise interactions with cardiomyocytes (CMs) during MI remain elusive. To address this, we can generate M1 and M2 from human blood CMs and CMs from human pluripotent stem cells (hPSCs), and modulate their interactions, creating a novel high-throughput human MI model in vitro.
Method: We derived hPSC-CMs from NKX2.5-GFP- PSCs. Macrophages differentiated from human CD14+ monocytes were polarized towards M1 by LPS and IFNγ, and M2 by IL-4. The apoptotic response of hPSC-CMs was quantified by measuring NKX2.5+ethidium homodimer-1 (EthD-1)+ populations with M1 or M2 cytokines.
Results: We differentiated OCT4+NKX2.5- PSCs into OCT4-NKX2.5+CMs. qRT-PCR confirmed high expressions of IL-6 and TNFα in M1, and MSR-1 and MRC-1 in M2 (p<0.05). Luminex analysis showed distinct cytokine secretion levels: higher levels of MIP-1β and TNFα in M1, and IL-4 in M2, and VEGF from both, cognate receptors were expressed on the human CMs. Both M1 and M2 cytokine activities increased NKX2.5+ EthD-1+ populations over time than controls, and M2 higher than M1 (4h, 8h, 12h, 18h, p<0.05).
In our study, M1 and M2 activities induced CM injury, mimicking MI via cytokine-receptor interactions. Our novel model will further elucidate macrophage-mediated mechanisms in MI
Transfection of cultured myoblasts in high serum concentration with DODAC: DOPE liposomes
No full textThe inhibitory effect of serum is one of the main obstacles to the in vivo use of cationic liposomes as a DNA delivery system. We have found that a novel liposome formulation, DODAC:DOPE (1:1) is totally resistant to the inhibitory effects of serum for transfection of cultured myoblasts and myotubes. Transfection with a lacZ reporter gene in the presence of 95% fetal bovine serum gave up to 25% β-gal-positive cells in C2C12 myoblasts and about six-fold less in primary human myoblasts. The lower transgene expression in primary cells does not appear to be a result of less DNA uptake but might result from differences in intracellular trafficking of the complexes. DODAC-based liposomes are unique in their resistance to serum inhibition and may therefore be valuable for the systemic delivery of genetic information to muscle and other tissues
Corrigenda: DXS997 localized to intron 48 of dystrophin (Human Molecular Genetics (1993) 2 (2199))
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Genomic organization of the human dystrophin gene across the major deletion hot spot & the 3' region
No full textThe genomic organization of most of the human dystrophin gene has not been defined at single-exon level, owing to its enormous size (2300 kb). By taking advantage of a YAC-based restriction map of the gene previously constructed, we have localized individual dystrophin exons from 42 to 79 along the central and 3' regions of the gene. These data elucidate the general organization of this large portion of the gene (1250 kb) and, in particular, characterize the genomic region most frequently involved in deletion mutations responsible for Duchenne and Becker muscular dystrophies
Gene therapy for muscular dystrophy - Early experiments with liposome-mediated gene transfer
No full textDuchenne muscular dystrophy is a lethal X-linked disorder in which muscle degeneration results in confinement to a wheelchair by age 12 years and death from respiratory failure by age 20 years. Gene therapy for this disorder poses unique challenges, related to the enormous size of the gene, and to the difficulty ofdelivering a functional gene to the millions of muscle fibers through-out the body. Adenoviral vectors are limited in their DNA capacity precluding their use to deliver an intact dystrophin gene cDNA, and the vectors themselves elicit an immune response that will further limit their use. Cationic liposomes provide a means to transfect cells bothex viva and in vivo. In this study we evaluated the use of a polycationic liposome formulation in delivering areporter gene in cultured muscle cells and designed a new procedure to enhance transfection efficiency of cationic liposomes, based on the precondensation of plasmid DNA with polylysine
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