Evaluation of the addition of organic acids in the feed and/or water for broilers and the subsequent recovery of Salmonella Typhimurium from litter and ceca.

Three separate broiler Salmonella Typhimurium challenge experiments were conducted evaluating efficacy of formic and propionic acid feed supplements to suppress environmental and cecal Salmonella Typhimurium prevalence. In experiment 1, broilers were provided feed with 1 kg/ton formic acid or 5 kg/ton propionic acid feed additives or a basal control diet. At the day of placement, half of the pens were inoculated with seeder chicks orally challenged with a marker strain of Salmonella Typhimurium and to yield challenged and adjacent nonchallenged pens. No differences in weekly litter samples or cecal Salmonella prevalence at 3 or 6 wk among feeding treatments were detected. In experiment 2, treatments were: 2 kg/ton propionic acid in feed, 1.0 mL/L formic acid in water, both propionic acid in feed and formic acid in water, and a basal control. Every pen was challenged with seeder chicks inoculated with Salmonella Typhimurium. By 6 wk all pens maintained detectable litter Salmonella, and broilers provided both propionic acid in feed and formic acid in water had the lowest cecal recovery (35%), compared to the control (60%). In experiment 3, treatments were: formic acid at 4 or 6 kg/ton from wk 0 to 6 or for only the last wk, propionic acid at 5 or 10 kg/ton for only the last wk, and a basal control. Each pen was challenged with Salmonella Typhimurium inoculated seeder chicks. By 6 wk, broilers fed formic acid (4 kg/ton) for the entire growout had no Salmonella-positive ceca (0/30). All treatments that provided acid supplemented feed for only the last wk had 3-13% Salmonella-positive ceca. These experiments indicate that adding formic acid to broiler feed appears to prevent Salmonella colonization from challenge pens entering into the adjacent nonchallenge pens. Feeding formic acid (4 kg/ton) for 6 wk resulted in no recovery of Salmonella from ceca compared to the control prevalence of 17%.

CT of neuroblastomas and ganglioneuromas in children.

Computed tomography (CT) has made a profound impact on the diagnosis and treatment of neuroblastomas and ganglioneuromas. The size, location, calcification, composition, and contiguous spread of the tumors has been well demonstrated by CT. CT is essential for their staging, subsequent treatment, and follow-up. Seventy-seven children were reviewed, 67 with neuroblastoma and 10 with ganglioneuroma seen between 1976 and 1980. Fifty-eight had one or more body CT scans, 22 had metrizamide myelography and/or CT metrizamide myelography, and three patients had cranial CT. Intraspinal extension of tumor occurred in 11 instances, several requiring decompressive surgery. A workup plan for optimal use of CT and CT metrizamide myelography was developed from this experience.