RESUMEN
Post-dialysis fever is commonly reported in patients undergoing hemodialysis (HD). However, it is often challenging to identify the underlying cause owing to the wide variety of potential factors that can lead to fever. In this case, a 66-year-old Japanese man experienced recurrent fever after HD treatment. Initially, antibiotics were prescribed to treat pneumonia, but it was later discovered that the pneumonia was an alveolar hemorrhage caused by cryoglobulinemic vasculitis. It is believed that cryoglobulin was sensitized by cold exposure owing to the dialysate temperature, which resulted in fever being experienced only after HD. Although treatment for vasculitis required prednisolone and rituximab, simple plasma exchange and a dialysate temperature of 37.5 °C dramatically suppressed the occurrence of post-dialysis fever. Cryoglobulinemia should be considered as a potential cause of fever, as it may be a common occurrence in patients undergoing HD and could be overlooked as a possible cause of localized fever following HD treatment.
RESUMEN
Skeletal muscle contains several progenitor/stem cells with myogenicity as well as adipogenicity such as satellite cells. Our previous study demonstrated that forced expression of PPAR gamma is sufficient to induce transdifferentiation of predetermined myoblasts in vitro. In the present study, we examined whether introduction of PPAR gamma gene could induce adipogenesis of satellite cells in vivo. A plasmid vector containing enhanced green fluorescent protein (EGFP) or PPAR gamma gene was introduced into rat tibialis anterior muscle by electroporation. Histological analyses revealed that electroporation induces degenerative/regenerative response in skeletal muscle, including activation of satellite cells. When EGFP gene was introduced, newly formed myotubes resulted from fusion of activated satellite cells, showed EGFP expression, indicating that electroporation could transfect satellite cells with exogenously introduced gene. Gene transfer of PPAR gamma resulted in an increase of PPAR gamma-positive mononucleated cells on day 3 after electroporation but failed to induce adipogenesis thereafter. These results suggested that, in addition to an expression of PPAR gamma, niches that support adipogenesis are required for satellite cells to enter adipogenesis in vivo.
Asunto(s)
Adipogénesis/fisiología , Técnicas de Transferencia de Gen , Músculo Esquelético/citología , Músculo Esquelético/fisiología , PPAR gamma/genética , Adipocitos/citología , Animales , Electroporación/métodos , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Masculino , Ratas , Ratas WistarRESUMEN
The present study was conducted to investigate whether goat fetal myoblasts with no inherent adipogenic potential can be induced to transdifferentiate into adipocytes. Goat fetal myoblasts were transiently transfected by the adipogenic transcription factors, peroxisome proliferator-activated receptor-gamma (PPARgamma) and CCAAT/enhancer-binding protein-alpha (C/EBPalpha). Both PPARgamma and C/EBPalpha were capable of inducing adipogenic transdifferentiation as indicated by the appearance of mature adipocytes when the transfected cells were cultured in adipogenic differentiation medium (ADM). Ectopic expression of PPARgamma induced endogenous C/EBPalpha expression and vice versa only when the cells were cultured in ADM. Removal of troglitazone, a PPARgamma agonist, from the ADM resulted in a dramatic decline in the number of adipocytes, indicating that PPARgamma stimulation is necessary to induce adipogenic transdifferentiation of goat fetal myoblasts. These results demonstrate for the first time that primary cultured myoblasts can be transdifferentiated into adipocytes.