Late-onset vital complication after the Nuss procedure for pectus excavatum.

The Nuss procedure is the most popular technique for correction of pectus excavatum recently. Life-threatening complications associated with the procedure are very rare. We report a 13-year-old boy who developed late-onset bilateral hemothorax with hypovolemic shock 5 months after the Nuss procedure. In literature review, this is the first case of the late-onset life-threatening bilateral hemothorax with hypovolemic shock ever reported.

The zebrafish homeobox gene irxl1 is required for brain and pharyngeal arch morphogenesis.

Iroquois homeobox-like 1 (irxl1) is a novel member of the TALE superfamily of homeobox genes that is most closely related to the Iroquois class. We have identified the zebrafish irxl1 gene and characterized its structure. The protein contains a homeodomain that shares 100% sequence identity with other vertebrate orthologs. During embryogenesis, irxl1 is expressed from 18 hours postfertilization onward and prominent expression is detected in the pharyngeal arches. Knockdown of irxl1 by morpholinos results in malformed brain and arch structures, which can be partially rescued by cRNA injection. The heads of the morphants become small and flat, and extensions along the anterior-posterior/dorso-ventral axes are reduced without affecting regional specification. Loss of irxl1 function also causes deficit in neural crest cells which consequently results in partial loss of craniofacial muscles and severe deformation of arch cartilages. These observations suggest that irxl1 may regulate factors involved in brain and pharyngeal arch development.

Zebrafish muscleblind-like genes: identification, structural features and expression.

Muscleblind-like (MBNL) proteins are a family of RNA-binding proteins that participate in the regulation of tissue-specific alternative splicing. Misregulation of MBNL activity in humans leads to pathogenesis. Here, we report upon the identification and characterization of three muscleblind-like genes in zebrafish (zmbnl1, zmbnl2 and zmbnl3). Alternative splicing of the three zmbnl primary transcripts gives rise to at least four protein isoforms for zmbnl1, four for zmbnl2 and five for zmbnl3, respectively. All of the zmbnl proteins contain the characteristic CCCH zinc fingers required for RNA binding. In addition, several structural motifs, including a C-terminal Ser/Thr-rich region, are conserved among Mbnl orthologs in vertebrates, but not invertebrates. These genes are broadly expressed in most adult tissues. However, the relative expression levels of specific spliceforms vary across different tissues. During embryogenesis, zmbnl1 and zmbnl2 are both maternally and zygotically expressed. In contrast, zmbnl3 transcripts are not detected until the late pharyngula stage. Our results reveal the expression pattern of various mbnl spliceforms for the first time and suggest that they may play specific roles during fish development.