Faculty Bibliography

The formation and identification of DNA-protein crosslinks are usually detected by filter binding assays such as alkaline elution. We describe a modified blotting method to selectively identify DNA-protein complexes (DPCs) formed in vitro by either Cr3+ ion or formaldehyde. This protocol allows DPC formation in vitro to be assayed with various chemical agents, requires minimal usage of radioactivity, and is performed in a shorter time frame than that commonly used to resolve DPCs from free proteins and unbound DNA

One hundred thirty-nine children with neoplasms were studied using magnetic resonance imaging (MRI). This procedure was as accurate as computed tomography in predicting tumor histology, except that MRI was unable to detect small areas of tumor calcification. Magnetic resonance imaging could accurately identify the organ of origin of tumor masses and differentiate soft tissue from fat, fluid, or hemorrhage. In addition, MRI was helpful in planning surgery in many cases: It was better than computed tomography in defining the size and extent of soft-tissue tumor masses. It was accurate in defining the extent of the spread of bone sarcomas in the bone marrow. Without requiring the injection of intravenous contrast agents, it accurately defined displacement, encasement, or invasion of major abdominal blood vessels by Wilms' tumors and neuroblastomas. As a means of evaluating pediatric neoplasms, MRI is noninvasive, painless, and well tolerated by children, and it uses no radiation.

Although the diagnosis of bowel perforation is frequently straightforward, it may be difficult in the neonate. Clinical signs may be limited to abdominal distension. If the patient is on assisted ventilation, pneumoperitoneum may be due to air tracking down from the chest rather than perforation. The authors report 6 cases of bowel perforation in infants in whom the diagnosis could not readily be made from the clinical findings and plain radiographs but was apparent when oral metrizamide was employed. This suggests that metrizamide can be a valuable adjunct in some cases of neonatal bowel perforation.