E2F4 plays a key role in Burkitt lymphoma tumorigenesis.

Sporadic Burkitt lymphoma (sBL) is a rapidly growing B-cell non-Hodgkin's lymphoma whose treatment requires highly aggressive therapies that often result severely toxic. Identification of proteins whose expression or function is deregulated in sBL and play a role in its formation could facilitate development of less toxic therapies. We have previously shown that E2F1 expression is deregulated in sBL. We have now investigated the mechanisms underlying E2F1 deregulation and found that the E2F sites in its promoter fail to repress its transcriptional activity in BL cells and that the transcriptional repressor E2F4 barely interacts with these sites. We also have found that E2F4 protein levels, but not those of its mRNA, are reduced in sBL cell lines relative to immortal B-cell lines. E2F4 protein expression is also decreased in 24 of 26 sBL tumor samples from patients compared with control tissues. Our data demonstrate that enforced E2F4 expression in BL cells not only diminishes E2F1 levels, but also reduces selectively the tumorigenic properties and proliferation of BL cells, while increasing their accumulation in G(2)/M. Our results therefore point to E2F4 as a target for developing novel and less toxic treatments for sBL.

Evaluación del comportamiento de la relación reserva y el consumo de oxígeno en cirugía pulmonar / Behavioral evaluation of the oxygen reserve-consumption ratio in pulmonary surgery

La cirugía de cáncer pulmonar exhibe riesgos, pero es el único tratamiento eficaz. Se evalua el comportamiento de la relación reserva de oxígeno pulmonar/consumo de oxígeno, en la resección pulmonar parcial y total. Se determinó el tiempo de apnea que tarda la hemoglobina en desaturarse hasta 95 (por ciento) al comienzo de la intervención (apnea inicial) y por medio de una fórmula que relacionó ese valor con los segmentos funcionantes preoperatorios y los que quedarían posterior al acto quirúrgico para calcular el posible tiempo final de apnea (apnea final calculada). Al finalizar la intervención se midió el tiempo final de apnea (apnea final medida) y se comparó con el calculado. Por último se relacionó con la evolución postoperatoria, en cuanto a la separación del ventilador. Se realizaron 10 resecciones pulmonares totales y 13 parciales. La apnea final medida fue igual o superior a la final calculada en 16 de los 23 pacientes (70 (por ciento), 7 pacientes propuestos para resección parcial (53.8 (por ciento) y 9 de los que se le realizó neumectomías (90 (por ciento). Todos los pacientes se separaron del ventilador sin dificultad. La relación reserva pulmonar/consumo de oxígeno estimada por el tiempo que la hemoglobina tarda en desaturarse hasta 95 (por ciento), podría ser un buen indicador intraoperatorio de operabilidad en la cirugía del cáncer pulmonar, si durante el acto operatorio se decide practicar la neumectomía, en aquellos pacientes con resección parcial planificada(AU)

Cutaneous basal cell carcinoma of vulva.

Eleven cases of basal cell carcinoma of the vulvar skin are reported. There was fairly close correlation between the histologic type and the gross appearance of the lesion. The average age of the patients was 59 years, and the presenting complaint was usually that of a nodule with associated irritation or pruritus. All patients were treated surgically and none have had recurrent or metastatic disease; six patients have been followed for 12 to 25 years. The treatment of choice is wide local excision. One tumor was of particular interest in that it represented a carcinomatous change in a pre-existing premalignant fibroepithelial tumor. Basal cell carcinoma of the skin must be distinguished from adenoid cystic (basal cell) carcinoma of vestibular glands, which is a more aggressive neoplasm and which metastasizes by the lymphatic and blood vascular systems.