[Enhancement of in-vitro and in-vivo human T lymphocyte activation via cell painting with recombinant chimeric co-stimulatory B7-1:Fc gamma 1 Protein]

T cells express co-stimulatory molecules on their surfaces in both normal and pathologic settings; however, the possibility that expression of these co-stimulators may enable individual T cells to co-stimulate themselves has not been investigated. This study aims at assessing the possible potentiation of T cells activation and proliferation both in vitro and in vivo via enforced B7-1 expression on T lymphocytes using a non-genetic approach, i.e. cell painting, that comprises binding of recombinant B7-1 to plasma membrane-anchored palmitoylated protein A. A recombinant chimeric human co-stimulatory B7-1 protein that encompasses the extracellular domain of CD80 [B7-1] fused to the crystal fragment Fc gamma of human IgG antibody was engineered and produced in human kidney cell line 293. Recombinant protein A was chemically palmitoylated and inserted into cell membranes of T lymphocytes highly purified using negative selection. Subsequently, B7-1 Fc gamma 1 was added to protein A-decorated cells allowing its binding via the Fc portion. Quantitative transfer of B7-1 was assessed using flow cytometry, and in vitro proliferation and IL-2 production were measured. Moreover, in vivo engraftment of painted cells was evaluated using the immune deficient mouse model NOD/SCID/B2M K/O. Results from this study demonstrate the feasibility of "cell painting" using a two-step approach to quantitatively transfer palmitoylated protein A and B7-1 Fc gamma to T cells. B7-1 painted T lymphocytes exhibited augmented in vitroproliferation, enhanced IL-2 production, and superior in vivo engraftment. Cell painting technique enables arming T lymphocytes with co-stimulatory proteins that provide second signal inevitable for activation, proliferation, and production of IL-2. These results may pave the way for future applications that include but is not limited to cancer targeted immunotherapy and congenital and/or acquired immunodeficiency. This study was conducted in the laboratories of The School of Medicine, University of Pennsylvania, USA, and The National Commission for Biotechnology, Damascus between 2010 and 2012

Significacion del bloqueo AV tipo Wenckebach en atletas. / Significance of atrioventricular block type Wenckebach in athletes

Se presenta el caso de un joven remero, seleccionado nacional, que participo en los ultimos Juegos Olimpicos, y que durante su preparacion desarrollo un bloqueo AV de segundo grado tipo Wenckebach. La arritmia guardo estrecha relacion con el grado de entrenamiento fisico, y desaparecio con el ejercicio, sugeriendo su etiologia funcional. Se revisa la literatura a proposito del caso

Tratamiento de la taquicardia paroxistica, del recien nacido con reflejo de la sumersion. / Treatment of paroxysmal tachycardia of the newborn infant with submersion reflex

Se presenta el caso de un recien nacido de 25 dias de edad con una taquicardia paroxistica supraventricular (TPSV), convertida a ritmo sinusal con el llamado "reflejo de sumersion". Este es el primer recien nacido con TPSV convertido con este eficaz y sencillo procedimiento que se comunica en nuestro medio

Malformaciones congenitas de la tricuspide y anomalia de Ebstein con estenosis pulmonar valvular. / Congenital malformation of tricuspid valve and Ebstein anomaly with pulmonary valvular stenosis

Informamos de um caso con anomalia de Ebstein tricuspidea y de otro con doble lesion tricuspidea congenita, ambos asociados a estenosis valvular pulmonar y con hemodinamica y fisiopatologia similares. Dado que existen pocos casos informados en la literatura, analizamos los hallazgos clinicos y electrocardiograficos de ambos; se discute la utilidad del ecocardiograma en el diagnostico de tales anormalidades y comentamos sus datos hemodinamicos y angiograficos. Se enfatiza que la hipertension ventricular derecha: de 105 mm Hg en uno y de 98 mm Hg en el otro, modifica la hemodinamica de la cardiopatia y su historia natural y que esta se ve favorablemente modificada por la cirugia correctiva aislada de la obstruccion pulmonar. El gradiente transvalvular en el postoperatorio se midio en 27 y 11 mm Hg respectivamente. Despues de hecha la revision bibliografica pertinente se comentan los factores de los que depende la elevada mortalidad de la cirugia del Ebstein y las anomalias congenitas con las que mas frecuentemente se asocia