A novel SDS-stable dimer of a heterogeneous nuclear ribonucleoprotein at presynaptic terminals of squid neurons.

The presence of mRNAs in synaptic terminals and their regulated translation are important factors in neuronal communication and plasticity. Heterogeneous nuclear ribonucleoprotein (hnRNP) complexes are involved in the translocation, stability, and subcellular localization of mRNA and the regulation of its translation. Defects in these processes and mutations in components of the hnRNP complexes have been related to the formation of cytoplasmic inclusion bodies and neurodegenerative diseases. Despite much data on mRNA localization and evidence for protein synthesis, as well as the presence of translation machinery, in axons and presynaptic terminals, the identity of RNA-binding proteins involved in RNA transport and function in presynaptic regions is lacking. We previously characterized a strongly basic RNA-binding protein (p65), member of the hnRNPA/B subfamily, in squid presynaptic terminals. Intriguingly, in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), p65 migrated as a 65-kDa protein, whereas members of the hnRNPA/B family typically have molecular masses ranging from 35 to 42kDa. In this report we present further biochemical and molecular characterization that shows endogenous p65 to be an SDS-stable dimer composed of ∼37-kDa hnRNPA/B-like subunits. We cloned and expressed a recombinant protein corresponding to squid hnRNPA/B-like protein and showed its propensity to aggregate and form SDS-stable dimers in vitro. Our data suggest that this unique hnRNPA/B-like protein co-localizes with synaptic vesicle protein 2 and RNA-binding protein ELAV and thus may serve as a link between local mRNA processing and presynaptic function and regulation.

[Idiopathic myelofibrosis with extramedullary hematopoiesis foci in the skin and testicles. Report of a case]. / Mielofibrosis idiopática con focos de hematopoyesis extramedular en piel y testículo. Presentación de un caso.

Idiopathic myelofibrosis (IMF) is a clonal chronic myeloproliferative syndrome characterized by the proliferation of the three haemopoietic series and the marrow connective tissue and by the development of extramedullary haemopoiesis in the liver, spleen and lymph nodes. Cutaneous extramedullary haemopoiesis is an uncommon event and we could not find any reported cases of testicular involvement in this disease. We report the case of a 28 year-old male with diagnosis of idiopathic myelofibrosis in November 1988. During the course of the disease, three years later, he developed a tumor on his right testis. Histologic examination showed extramedullary haemopoiesis with cells of the myeloid, erythroid and megakaryocyte series, in the interstice. Eight months later, numerous red-purple papules and nodules developed on the patients's trunk. The biopsy of a skin lesion revealed an infiltration of the dermis by myeloid, erythroid cells and few megakaryocytes. The patient's clinical condition worsened, and he died in February 1993 following progressive deterioration of the general condition. We describe a case of IFM with extramedullary hemopoiesis involving the skin and the testis pointing out the rarity of these localization.

Gangrena de lengua: modo de presentación de la arteritis temporal / Gangrene of the tongue: form of presentation of temporal arteritis

Se presenta el caso clínico de un varón de 85 años, con odinogafia, los moniliasis bucal y deterioro del estado general, síntomas y signos que precederon la aparición de gangrena de lengua. Se postula como causa de la misma el compromiso de las arterias linguales por arteritis, lo cual fue confirmado por biopsia de la arteria temporal izquierda. El enfermo debió sufrir amputación de los tercios anteriores de la lengua, mejorando su cuadro general con la cirugía y la administración de corticosteroides

Epidermodisplasia verruciforme y agammaglobulinemia. / Epidermodisplasia verruciformis and agammglobulinemia

Se presenta el caso de un paciente de raza amarilla, de 28 anos de edad, con verrugas planas diseminadas, cronicas de 15 anos de evolucion y maculas pitiriasiformes, ambas asintomaticas; con una hitoria de infecciones respiratorias a repeticion e inmunidad humoral y celular deprimidas. El diagnostico clinico e histologico fue de EV. Se efectua una actualizacion de esta enfermedad, destacando la poca frecuencia de la misma, su caracter de enfermedad preneoplasica y la asociacion con trastornos inmunologicos

Leiomiosarcoma de escroto: presentación de un caso / Leiomyosarcoma of scrotum: case report

El leiomiosarcoma de escroto es un tumor infrecuente. Solo existen 21 casos informados en la literatura. Se realiza el informe de un nuevo caso

Receptores H1 y H2 en piel. / H1 and H2 receptors in skin

Se registraron los cambios termicos e histologicos producidos en siete pacientes por la inyeccion intradermica de solucion fisiologica y de agentes bloqueantes de receptores histaminergicos. Se observo marcado aumento de la temperatura local con bloqueantes de los receptores H2 y escasa variacion con bloqueantes H1, en relacion al grupo testigo. La histologia mostro una luz capilar conservada en el primer caso y muy congestiva en el segundo

Enfermedad de Kaposi. / Kaposi's disease

Se presenta um caso clinico-patologico de un paciente con enfermedad de Kaposi, diagnosticada en nuestro Servicio y tratado con radioterapia sin resultado. Vuelve a la consulta 8 anos despues con mal estado general, falleciendo a los 2 meses de su internacion. El temprano comienzo de la enfermedad (a los 17 anos de edad), su procedencia (oriundo de zona rural de Santiago del Estero) y el severo compromiso cutaneo visceral, infrecuentes en nuestro medio motivan esta presentacion