Clinical Significance of Spontaneous Pneumomediastinum.

Background: Spontaneous pneumomediastinum (SPM) is classified as free air in the mediastinum in the absence of any precipitating cause. It is relatively uncommon, and the clinical significance and risk associated with SPM is not well understood and has not been widely documented in the literature. Our goals were to determine the outcomes of patients who presented with SPM and to determine predictors of severe pathology associated with SPM.

Cellular context-dependent effects of H2ax and p53 deletion on the development of thymic lymphoma.

H2AX and Artemis each cooperate with p53 to suppress lymphoma. Germline H2ax(-/-)p53(-/-) mice die of T-cell receptor-β(-) (TCR-β(-)) thymic lymphomas with translocations and other lesions characteristic of human T-cell acute lymphoblastic leukemia. Here, we demonstrate that mice with inactivation of H2ax and p53 in thymocytes die at later ages to TCR-β(-) or TCR-β(+) thymic lymphomas containing a similar pattern of translocations as H2ax(-/-)p53(-/-) tumors.

Assembled DJ beta complexes influence TCR beta chain selection and peripheral V beta repertoire.

TCRbeta chain repertoire of peripheral alphabeta T cells is generated through the stepwise assembly and subsequent selection of TCRbeta V region exons during thymocyte development. To evaluate the influence of a two-step recombination process on Vbeta rearrangement and selection, we generated mice with a preassembled Dbeta1Jbeta1.1 complex on the Jbeta1(omega) allele, an endogenous TCRbeta allele that lacks the Dbeta2-Jbeta2 cluster, creating the Jbeta1(DJbeta) allele.