Colovenous fistula complicating diverticulitis: CT and radiographic findings.

We report a case of colovenous fistula to the inferior mesenteric vein complicating diverticulitis and mimicking coloureteral fistula. This is the second reported case of venous intravasation of barium complicating diverticulitis that mimicks coloureteral fistula. Radiographic features and characteristics differentiating these two entities are presented.

Breast sonography: technique to mimic mammographic position.

Positional changes in the breast between supine sonography and mammography may cause difficulties in correlating abnormalities. The problem is easily surmounted by performing the breast sonogram with the patient in the upright position. This study is a prospective evaluation of 10 patients examined sonographically in the supine and upright positions. The nipple to lesion distance was measured and the clock position estimated on the upright and supine sonograms. These parameters were compared to the original mammograms. In all patients the mammographic clock position and the distances from the nipple correlated more closely with the upright sonogram. The mammographic clock position was the same on the upright sonogram in six of 10 (60%), and the remaining four (40%) varied from one half to two clock positions. In supine sonography the clock position was the same in two of 10 (20%) patients, and the remaining eight (80%) varied from one to three clock positions. Most lesions were between 4.5 and 11 cm from the nipple on the mammogram. The distances of the lesions from the nipple ranged from 3 to 10 cm on upright sonography and from 0 to 4.5 cm on supine sonography. The difference between clock positions and the distances from the nipple on upright versus supine sonography were statistically significant. Therefore, upright sonography is more accurate in localizing mammographically identified lesions than the standard supine sonographic technique.

The effect of acid pH and citrate on the release and exchange of iron on rat transferrin.

The effect of acid pH and citrate on the exchange of iron between binding sites of rat transferrin has been studied. In the absence of citrate, diferric transferrin shows stepwise loss of iron atoms with the first atom of iron released at approximately pH 5.2. Citrate at physiologic concentrations (1.10(-3) M) or greater allows random iron removal at pH 6.5 or less. Iron dissociation from monoferric transferrin at acid pH, with or without citrate, is a random process. At pH 7.4, randomization of iron on transferrin takes from 3 to 6 h in the presence of millimolar concentrations of citrate. We conclude that at acid pH and in the presence of citrate concentrations likely to occur in vivo in the rat there is little scrambling of iron bound to transferrin.