[Jejunum perforation following blunt abdominal trauma--a case report]. / Jejunumperforation nach stumpfem Bauchtrauma--ein Fallbericht.

We describe an intestinal perforation in a football player who had been hit with the knee in the abdomen. Perforation of the small bowel, following blunt abdominal trauma, is relatively rare. Its most frequent cause is a deceleration trauma, usually from a traffic accident. Clinical signs are frequently discrete and nonspecific. The most frequent symptom is abdominal pain. Lack of bowel sounds is reported in 64% oft the cases. Enteric lesions should be suspected in the presence of a corresponding history (deceleration trauma) and of other pathologies (fractures of vertebrae and/or pelvis). Sonography and computed tomography are rarely helpful. Delayed perforations have been described, necessitating prolonged observation for 48 to 72 h. after painful abdominal trauma. Repeated examinations are essential to rule out enteric perforation. Initially, less than 50% of the cases show free air, thus limiting the usefulness of thoracic and abdominal radiography. Mortality reaches 30%. This rate is adversely affected by concomitant lesions in other organs and by delay (more than 10 h.) in diagnosis. When laparotomy has been delayed and peritonitis is present, antibiotic treatment should be started immediately during surgical intervention (cephalosporin, aminoglycoside, metronidazole). Postoperative complications include septicaemia, wound infection and, rarely, enterocutaneous fistulae.

The precursor of mitochondrial aspartate aminotransferase is imported into mitochondria faster than the homologous cytosolic isoenzyme with the same presequence attached.

Mitochondrial and cytosolic aspartate aminotransferase (AspAT) are homologous proteins with identically folded polypeptide chains. The cDNAs of the two isoenzymes of chicken were used to express the following proteins in yeast: the precursor of mitochondrial AspAT, mature mitochondrial AspAT, and two chimeric proteins in one of which (pc) the presequence of the precursor was attached to the entire cytosolic isoenzyme and in the other one (pmc) the N-terminal segment (amino acid residues -22 to 23) of the precursor was linked to the slightly truncated cytosolic isoenzyme (residues 34 to 412). All presequence containing proteins were imported into the mitochondria and processed to the mature form whereas mature mitochondrial AspAT remained in the cytosol. The rate of import of the authentic precursor was four times faster than that of the chimeric proteins pc and pmc, t1/2 for importation at 29 degrees C being 3, 13 and 14 min, respectively. Apparently, the mature moiety of the precursor of mitochondrial AspAT promotes importation.

Structure of cDNA of cytosolic aspartate aminotransferase of chicken and its expression in E. coli.

The structure of the mRNA of chicken cytosolic aspartate aminotransferase has been determined by analysis of cDNA and genomic clones. Two transcripts of different length were found that appear to arise from the alternate use of 2 polyadenylation signals in the 3' untranslated region. The expression product of the full-length construct in E. coli proved to be catalytically active and possessed the expected molecular weight.