Harmonic US imaging of appendicitis in children.

BACKGROUND: Harmonic imaging (HI), a relatively new ultrasound modality, was initially reported to be of use only in obese adult patients. HI increases the contrast and spatial resolution resulting in artefact-free images, and has been shown in adults to significantly improve abdominal sonography. Regarding its application in paediatric patients, just a handful reports exist and these do not encompass its use in intestinal sonography. OBJECTIVE: To compare the sonomorphological image quality of HI and fundamental imaging (FI, conventional grey-scale imaging) in the diagnosis of histologically confirmed appendicitis in children. MATERIALS AND METHODS: For this prospective comparative study, 50 children (male/female 25/25; mean age 9.9 years) suspected of having appendicitis were recruited. In all patients US examination of the appendix and periappendiceal region was performed preoperatively and appendectomy carried out. The final diagnosis was based on histological examination of the appendix. Both FI and HI were used in the US examination (tissue harmonic imaging, THI; Sonoline Elegra, Siemens; 7.5 MHz linear transducer). A detailed comparison of the images from FI and HI was performed using a scoring system. The parameters compared included delineation of the appendiceal contour, wall, mucosa, contents of the appendix and surrounding tissues. Furthermore, periappendiceal findings such as mesenteric echogenicity, free fluid, lymph nodes and adjacent bowel wall thickening were compared. RESULTS: In 43 children (86%) acute appendicitis was histologically confirmed. The inflamed appendix could be depicted in the HI and FI modes in 93% and 86%, respectively. HI was found to be significantly better for the depiction of the outer contour, wall, mucosa and contents of the appendix (P<0.01). This was also true for the demonstration of free fluid, mesenteric lymph nodes, adjacent bowel walls and mesenteric echogenicity. CONCLUSION: HI should be the preferred modality for scanning the right lower abdomen in suspected acute appendicitis. The diagnosis of acute appendicitis can then be more definitely ascertained.

Missense mutations in N-acetylglucosamine-1-phosphotransferase alpha/beta subunit gene in a patient with mucolipidosis III and a mild clinical phenotype.

Mucolipidosis type III (ML III, pseudo-Hurler polydystrophy), an autosomal recessive inherited disorder of lysosomal enzyme targeting is due to a defective N-acetylglucosamine 1-phosphotransferase (phosphotransferase) activity and leads to the impaired formation of mannose 6-phosphate markers in soluble lysosomal enzymes followed by their increased excretion into the serum. Mutations in the phosphotransferase gamma subunit gene (GNPTAG) have been reported to be responsible for ML III. Here we report on a 14-year-old adolescent with a mild clinical phenotype of ML III. He presented with progressive joint stiffness and swelling. Urinary oligosaccharide and mucopolysaccharide excretion was normal. Lysosomal enzyme activities were significantly elevated in the serum and decreased in cultured fibroblasts. Impaired trafficking of the lysosomal protease cathepsin D (CtsD) was confirmed by metabolic labeling of the patient's fibroblasts. Neither mutations in the GNPTAG gene nor alterations in the GNPTAG mRNA level were detected whereas the steady state concentration of the 97 kDa GNPTAG dimer was reduced. Most importantly, the patient is homozygous for a pathogenic nucleotide substitution and a polymorphism in the phosphotransferase alpha/beta subunit gene (GNPTA). The data indicate that defects in genes other than GNPTAG can be linked to ML III contributing to the variability of the phenotype.