Pediatric urography: comparison of metrizamide and methylglucamine diatrizoate.

A non-ionic contrast medium (metrizamide) was compared to an ionic agent (methylglucamine diatrizoate) for pediatric urography. Fifty children were divided into two age groups: under 5, and 5 to 10. In younger children, metrizamide gave more excellent images (19% vs. 0%) and fewer inadequate images (0% vs. 18%) than methylglucamine diatrizoate (p = 0.06). In older children, metrizamide likewise gave more excellent images (44% vs. 14%) and fewer inadequate images (0% vs. 7%). The same pattern was seen when the two groups were combined (excellent, 28% vs. 8%; inadequate, 0% vs. 12%) (p = 0.05). Differences with respect to changes in hematocrit, serum osmolality, serum sodium, and SGOT were statistically significant, but not adverse reactions. In terms of both efficacy and safety, the authors conclude that metrizamide is preferred for pediatric urography.

Extragonadal endodermal sinus tumors in children: a review of 24 cases.

Endodermal sinus tumors (EST) are highly malignant lesions with a tendency to recur locally and with a high incidence of metastatic disease at the time of diagnosis. The clinical and radiographic spectra of 24 patients with extragonadal EST are reported. There were 17 females and seven males and the mean age of presentation was 21 months. The primary lesion occurred in the sacrococcygeal region in 16 patients; in the vagina in two patients; in the anterior mediastinum in two patients; and in the bladder, liver, nasopharynx and posterior cranial fossa in one patient each. Computed tomography (CT) is the most accurate study in delineating the extent of primary lesions particularly in the pelvis and head and neck and also for demonstrating metastatic disease in the lungs. Significant improvement in survival rates is obtained with a combination of surgery, chemotherapy and radiotherapy.

Pancreatic carcinoma in a neonate.

The clinical and radiographic findings in a neonate with adenocarcinoma of the head of the pancreas are presented. CT revealed the mass to be well defined, with an inhomogeneous density before and after intravenous contrast enhancement. Ultrasound revealed the mass to be mainly densely echogenic with small, irregular echo-free areas. The portal vein was intimately applied to the posterior aspect of the mass. The literature concerning adenocarcinoma of the pancreas in the pediatric age group is reviewed.

Terbium as a solid-state probe for RNA.

This paper continues previous work on the analysis of nucleic acid-terbium complexes in the solid state. The fluorescence excitation and emission spectra of the RNA-terbium(III) complex is reported. The fluorescence excitation and emission spectra of both the RNA-terbium(III) and DNA-terbium(III) complexes as trapped on millipore filters is reported. One hundred percent of the DNA combined with terbium was trapped on millipore filters. Deoxyribonucleic acid was recovered from DNA-terbium(III) complexes trapped on millipore filters using SDS-extraction. Energy transfer was shown to occur from the bases in nucleic acids to the terbium ion, whereas the actual binding of terbium to nucleic acids was due to phosphate groups. The relative fluorescence of homopolyribonucleotide-terbium complexes showed that the guanine moiety was responsible for most of the observed fluorescence. Binding studies showed an equal affinity of radioactive terbium for all the homopolyribonucleotides. The fluorescence of solid-state DNA and RNA terbium complexes was used to measure picomole quantities of DNA or RNA.

Measurement of binding of terbium to DNA.

This communication demonstrates further that terbium(III) can be used as a probe for DNA. The stoichiometry of terbium binding to DNA was measured by two new methods. In the first method, calf-thymus DNA was titrated with radioactive terbium-160, which is an isotope of the common terbium-159. The resulting DNA-terbium complex was trapped and measured on millipore filters. In the second method, a peak of UV absorption of terbium was found at 219 nm and was used to measure stocichiometry. By both methods, the stoichiometry of binding was one Tb(III) for each three available phosphate groups in DNA. Finally, a rapid method was developed using terbrium-160 to measure the amount of nucleic acid in a solution.

Isolation and characterization of a thymic factor.

A protein was isolated from bovine thymus that was shown to accelerate the appearance of hemolysin to sheep erythrocytes in neonatal mice. The isolation procedure consisted of saline homogenization, ammonium sulfate precipitation, and methanol precipitation, followed by chromatography on diethylaminoethyl-cellulose and two chromatographies on Sephadex G-150. The protein was shown to be homogeneous by polyacrylamide gel electrophoresis and by sedimentation velocity and sedimentation equilibrium analytical ultracentrifugation. The molecular weight was determined to be 79,950. Additional physical and chemical characteristics were also determined.