Ultrasonic evaluation of intracranial pathology in infants: a new technique.

A prospective study had demonstrated the clinical usefulness of water-delay ultrasound as a means of routinely imaging the intracranial contents in infants younger than one year of age. Correlation between ultrasound and CT images was excellent, showing both normal and pathological anatomy. This technique is most helpful in the detection of hydrocephalus and other "fluid lesions" (subdural hygroma or hematoma, Dandy-Walker cyst, porencephalic cyst) and in evaluation of response to therapy.

Do eukaryotic mRNA 5' noncoding sequences base-pair with the 18 S ribosomal RNA 3' terminus?

Protein synthesis initiation on prokaryotic mRNAs involves base-pairing of a site preceding the initiation codon with the 3' terminal sequence of 16 S rRNA. It has been suggested that a similar situation may prevail in eukaryotic mRNAs. This suggestion is not based on experiments, but on observation of complementarities between mRNA 5' noncoding sequences and a conserved sequence near the 18 S rRNA 3' terminus.

Enhancement of the immunogenicity of phase I antigen of Coxiella burnetii.

The immunogenicity of the soluble phase I antigen of Coxiella burnetii for guinea pigs was enhanced by a nuclease-resistant complex of polyriboinosinic-polyribocytidylic acid, poly-L-lysine, and carboxymethyl cellulose.

The reactions of mercurated pyrimidine nucleotides with thiols and with hydrogen sulfide.

In the presence of thiols, 5-mercuripyrimidine nucleotides are quantitatively converted to 5-thiomercuri derivatives, but these compounds are unstable and decompose at a rate dependent on the nature of the thiol. The decomposition involves three different reactions and proceeds via a symmetrical mercury derivative of the nucleotide. The end product is the unmodified nucleotide.

Differences in buoyant-density properties of Coxiella burnetii and Rickettsia rickettsii.

The pronounced change in the buoyant density of Coxiella burnetii in CsCl gradients that was caused by treatment with formalin or ultraviolet radiation was not observed with Rickettsia rickettsii.

Changes in buoyant density relationships of two cell types of Coxiella burneti phase I.

Coxiella burneti phase I, purified from a formalin-inactivated yolk-sac vaccine, was separated into two bands of morphologically distinct cell types when subjected to sucrose gradient centrifugation. Recycling of the less dense, rod-shaped cells in unbuffered sucrose gradients (pH 5.5 to 6.

Effects of poly-L-lysine on infectious viral nucleic acid.

Infectious ribonucleic acids (IRNA) of Venezuelan equine encephalitis and Eastern equine encephalitis viruses were observed to form noninfectious complexes with a basic polyamino acid, poly-l-lysine. Original infectivity was recovered from the complexes by digestion of the polylysine with Pronase, and partial recovery was effected by treatment with sodium dodecyl sulfate. Infectivity could not be recovered from the complexes containing polylysine of 100,000 molecular weight by changes in ionic strength, pH, or by treatment with phenol, deoxycholate, or digitonin.

Phospholipid composition of Venezuelan equine encephalitis virus.

Phospholipid analyses of Venezuelan equine encephalitis virus showed that virus propagated in L-cell monolayers had a higher sphingomyelin content and a lower phosphatidylcholine content than virus grown in chick fibroblast monolayers. Virus of L-cell origin also was found to possess greater thermal stability than virus derived from the chick fibroblast cell.

The leader sequence from the 5'-terminus to the A-protein initiation codon in MS2-virus RNA.

RNA fragments of different chain length, each containing the 5'-terminal guanosine tetraphosphate (pppGp) of bacteriophage-MS2 RNA, have been isolated from partial ribonuclease digests of the viral RNA. The longest fragment overlaps with the ribosomalbinding site of the A-protein cistron. The base sequence has been established for the major part.