Isolated congenital megacystis without intestinal obstruction: a mild variant of chronic intestinal pseudoobstruction syndrome?

Megacystis is frequently involved with chronic intestinal pseudoobstruction syndrome; however, isolated megacystis without intestinal obstruction is extremely rare. We present the case of a female patient with isolated congenital megacystis without severe intestinal obstruction. In this case, barium enema did not reveal any significant findings; however, histologic evaluation of her rectum showed hypoganglionosis of the submucous and myenteric plexuses.

Oligoclonal expansion of circulating and tissue-infiltrating CD8+ T cells with killer/effector phenotypes in juvenile dermatomyositis syndrome.

Although triggering by infectious agents and abnormal immune responses may play some role in the pathogenesis of juvenile dermatomyositis syndrome (JDMS), the precise mechanism of muscle destruction and vascular damage is largely unknown. In this study, we tried to elucidate the role of cytotoxic T cells in two patients with JDMS, who were diagnosed based on the characteristic symptoms, laboratory data, MRI findings and electromyographic patterns. Peripheral blood T cell phenotypes were determined by flow cytometry, using mAbs against specific T cell receptor (TCR) Vbetas.

CD8alpha alpha memory effector T cells descend directly from clonally expanded CD8alpha +beta high TCRalpha beta T cells in vivo.

Whereas most peripheral CD8(+) alphabeta T cells highly express CD8alphabeta heterodimer in healthy individuals, there is an increase of CD8alpha(+)beta(low) or CD8alphaalpha alphabeta T cells in HIV infection or Wiskott-Aldrich syndrome and after bone marrow transplantation. The significance of these uncommon cell populations is not well understood. There has been some question as to whether these subsets and CD8alpha(+)beta(high) cells belong to different ontogenic lineages or whether a fraction of CD8alpha(+)beta(high) cells have down-regulated CD8beta chain.