Effect of isoleucine on toxin production by Clostridium difficile in a defined medium.

Supplementation of a carbohydrate-free minimal medium with a high level (100 mM) of histidine, methionine, valine, isoleucine, proline and leucine, in particular isoleucine, markedly increased toxin production by Clostridium difficile VPI 10463. The effect of isoleucine was further examined. Increasing the concentration of isoleucine from 20 to 100 mM remarkably increased toxin production, while bacterial growth decreased gradually. Amino acid analysis of the culture revealed that, at 100 mM isoleucine, consumption of isoleucine was remarkably increased. During the incubation period when toxin titers increased markedly but bacterial growth was declining, isoleucine, leucine and cysteine were taken up preferentially and alanine and cystathionine, which were not found at 1 mM isoleucine, were produced in large quantities. These findings suggest that isoleucine may play an important role in toxin production by C. difficile and that alanine and cystathionine production may be co-regulated with the toxin production in the absence of fermentable carbohydrates.

Colovesical fistula due to sigmoid colon diverticulitis: a case report.

We present a case of colovesical fistula due to sigmoid colon diverticulitis. A 63-year-old woman was referred to our department with the complaints of dysuria, turbid and foul smelling urine. She was treated twice for acute cystitis at the referral hospitals. A diagnosis of colovesical fistula was confirmed on barium enema. She underwent partial resection of sigmoid colon with primary anastomosis and partial cystectomy with repair of bladder wall and covered with omentum. Retrograde cytography taken on the 20th post-operative day revealed no leakage of contrast medium. She was asymptomatic at 3 months of follow-up.

Localization and needle aspiration of breast lesions: complications in 370 cases.

A prospective study of the immediate complications of 370 consecutive breast-imaging procedures (203 wire localizations and 167 radiographically or sonographically guided fine-needle aspirations) is reported. Vasovagal reactions occurred in 27 (7%) of 370 cases, ranging in severity from syncope (four of 370, 1%) to mild light-headedness. These vasovagal reactions were independent of procedure type or use of local anesthesia, but were more common in younger patients. Other complications included prolonged (5 min or longer) bleeding (three of 370, 1%) and extreme pain (two of 370, 1%). One patient was found to have malignant hypertension. We conclude that wire localizations and imaging-guided aspirations are generally well tolerated procedures. However, vasovagal reactions are frequent enough to warrant close observation of patients. Radiologists and breast-imaging personnel should be able to recognize and treat vasovagal reactions.