Sonography of ruptured appendicitis

Three girls and 4 boys with the final diagnosis of ruptured appendicitis underwent 19 sonographic studies, 5 before any therapy was instituted and 14 follow-up studies. Four abscesses identified before treatment and 2 seen postoperatively were ovoid, irregularly marginated, and contained lowamplitude echoes. Gastrointestinal ileus with gas- and fluid-filled loops of bowel made the studies technically difficult. Follow-up studies also showed fluid collections distant from the original abscesses. The complete resolution of the abscess was followed sonographically in 1 patient treated with antibiotics. Ultrasound can be useful in confirming or suggesting the diagnosis of ruptured appendicitis in the child with abdominal pain, but careful attention to detail is necessary in these technically difficult studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48131/1/261_2005_Article_BF02035110.pd

Five Nuclear Loci Resolve the Polyploid History of Switchgrass (Panicum virgatum L.) and Relatives

Polyploidy poses challenges for phylogenetic reconstruction because of the need to identify and distinguish between homoeologous loci. This can be addressed by use of low copy nuclear markers. Panicum s.s. is a genus of about 100 species in the grass tribe Paniceae, subfamily Panicoideae, and is divided into five sections. Many of the species are known to be polyploids. The most well-known of the Panicum polyploids are switchgrass (Panicum virgatum) and common or Proso millet (P. miliaceum). Switchgrass is in section Virgata, along with P. tricholaenoides, P. amarum, and P. amarulum, whereas P. miliaceum is in sect. Panicum. We have generated sequence data from five low copy nuclear loci and two chloroplast loci and have clarified the origin of P. virgatum. We find that all members of sects. Virgata and Urvilleana are the result of diversification after a single allopolyploidy event. The closest diploid relatives of switchgrass are in sect. Rudgeana, native to Central and South America. Within sections Virgata and Urvilleana, P. tricholaenoides is sister to the remaining species. Panicum racemosum and P. urvilleanum form a clade, which may be sister to P. chloroleucum. Panicum amarum, P. amarulum, and the lowland and upland ecotypes of P. virgatum together form a clade, within which relationships are complex. Hexaploid and octoploid plants are likely allopolyploids, with P. amarum and P. amarulum sharing genomes with P. virgatum. Octoploid P. virgatum plants are formed via hybridization between disparate tetraploids. We show that polyploidy precedes diversification in a complex set of polyploids; our data thus suggest that polyploidy could provide the raw material for diversification. In addition, we show two rounds of allopolyploidization in the ancestry of switchgrass, and identify additional species that may be part of its broader gene pool. This may be relevant for development of the crop for biofuels