Dengue virus-induced regulation of the host cell translational machinery

Dengue virus (DV)-induced changes in the host cell protein synthesis machinery are not well understood. We investigated the transcriptional changes related to initiation of protein synthesis. The human hepatoma cell line, HepG2, was infected with DV serotype 2 for 1 h at a multiplicity of infection of one. RNA was extracted after 6, 24 and 48 h. Microarray results showed that 36.5 percent of the translation factors related to initiation of protein synthesis had significant differential expression (Z-score ≥ ±2.0). Confirmation was obtained by quantitative real-time reverse transcription-PCR. Of the genes involved in the activation of mRNA for cap-dependent translation (eIF4 factors), eIF4A, eIF4G1 and eIF4B were up-regulated while the negative regulator of translation eIF4E-BP3 was down-regulated. This activation was transient since at 24 h post-infection levels were not significantly different from control cells. However, at 48 h post-infection, eIF4A, eIF4E, eIF4G1, eIF4G3, eIF4B, and eIF4E-BP3 were down-regulated, suggesting that cap-dependent translation could be inhibited during the progression of infection. To test this hypothesis, phosphorylation of p70S6K and 4E-BP1, which induce cap-dependent protein synthesis, was assayed. Both proteins remained phosphorylated when assayed at 6 h after infection, while infection induced dephosphorylation of p70S6K and 4E-BP1 at 24 and 48 h of infection, respectively. Taken together, these results provide biological evidence suggesting that in HepG2 cells DV sustains activation of the cap-dependent machinery at early stages of infection, but progression of infection switches protein synthesis to a cap-independent process.

Foliculitis pustubulosa eosinofila: presentación de dos casos y revisión bibliográfica / Eosinophilic pustular follicullitis: report of 2 cases and bibliographic review

Se presentan dos casos de FPE, un hombre de 46 años y una mujer de 23 años, con lesiones pápulopustulosas sobre placas eritematosas, pruriginosas, localizadas en distintas áreas del cuerpo, de evolución cíclica con escasa respuesta a las terapéuticas instituidas (DAPS, corticoides). Se comparan los hallazgos de estas dos observaciones con otros casos publicados

Fibroma de la vaina tendinosa / Fibroma of the tendon sheath

Se presenta una paciente de 36 años con fibroma de la vaina tendinosa ubicado en el dedo índice de la mano derecha, de 2 x 1 x 1,5 cm. La paciente consultaba por dificultad a la flexión y tenía una evolución de 10 años. Se efectúa tratamiento quirúrgico y se obtiene un tumor duroelástico, blanquecino, multilobulado. La histopatología mostró una formación bien circunscripta, parcialmente encapsulada y constituída por lóbulos fibrohialinos donde destacan hendiduras vasculares rodeadas por colágeno denso hipocelular y con fibroblastos fusiformes cortos. No se observó recaída después de 24 meses del tratamiento quirúrgico