Genomic complexities of murine leukemia and sarcoma, reticuloendotheliosis, and visna viruses.

The genetic complexities of several ribodeoxyviruses were measured by quantitative analysis of unique RNase T1-resistant oligonucleotides from 60-70S viral RNAs. Moloney murine leukemia virus was found to have an RNA complexity of 3.5 x 10(6) daltons, whereas Moloney murine sarcoma virus had a significantly smaller genome size of 2.3 x 10(6). Reticuleondotheliosis and visna virus RNAs had complexities of 3.9 x 10(6), respectively. Analysis of RNase A-resistant oligonucleotides of Rous sarcoma virus RNA gave a complexity of 3.6 x 10(6), similar to that previously obtained with RNase T1-resistant oligonucleotides. Since each of these viruses was found to have a unique sequence genomic complexity near the molecular weight of a single 30-40S viral RNA subunit, it was concluded that ribodeoxyvirus genomes are at least largely polyploid.

A view of Danish pediatric care.

The Danish social system provides competent, accessible, continuous, and coordinated medical care to the pediatric population. The pediatrician does not deal with the routine aspects of well-infant and child care but is rather hospital based and acts on consultant to the generalists in his district. The generalist has the primary role in providing health care to the population in a program where everyone is obliged to participate and no one is excluded or ineligible for any reason. The American obsession with frequent, periodic examinations for infants, children, and young adults does not exist under the Danish pediatric health system. Hospital emergency rooms are used for truly emergent circumstances and not for episodic care.