Use of ribonucleosides as protecting groups in synthesis of polynucleotides with phosphorylated terminals.

Two new protected 5'-ribonucleotides, 2'3'-O-bis(4,4'-dimethoxytrityl)uridine 5'-(4-chlorophenyl phosphate) and 2',3'-O-(methoxymethylene)uridine 5'-(4-chlorophenyl phosphate), form the basis of a chemical procedure for phosphorylating the 5'-ends of DNA fragments synthesized by the phosphotriester approach. Condensation of either of these mononucleotide units with the free 5'-hydroxyl of an otherwise fully protected oligomer results in high-yield formation of a 5'-5' triester linkage. Subsequently, the terminal ribonucleotide of the deprotected product rU5'-5'd(N-Nn-N) can be cleaved by periodate oxidation of its 2',3'-cis-hydroxyl system followed by beta-elimination, leaving its phosphate attached to the 5'-hydroxyl group of the oligodeoxyribonucleotide. This procedure together with a tactic employing a 2',3'-O-acylribonucleotide residue at the 3'-terminus of the chain allows the synthesis of oligomers possessing monophosphate groups at either end or both ends. Furthermore, oligonucleotide intermediates possessing a 5'-5'-linked uridine terminal are shown to have a special application as acceptors in RNA ligase reactions, where the presence of the ribonucleoside cap on the 5'-phosphate limits ligation specifically to the 3'-ends of the oligomers. Removal of the uridine residues to expose free 5'-phosphates would then enable the products to participate as donors in further elongation reactions.

Planning health services for a city jail: impact of contractual services on men's sick call.

A nonviolent protest by prisoners began a 2-year planning process leading to the implementation of contractual medical services at Baltimore City Jail. This study was conducted in order to assess the impact of contractual services on the process of men's sick call. The contractual program was associated with a decrease in utilization of men's sick call: 62.9 patient visits per day per 1,000 prisoners in 1975 versus 27.4 patient visits per day per 1,000 prisoners in 1978; an increased duration of encounter; 2.8 minutes in 1975 versus 10.9 minutes in 1978; and with changes in prescribing patterns and in categories of patients' complaints. Baltimore City Jail spent about $588 per prisoner-year during fiscal year 1977, and about $670 per prisoner-year during fiscal year 1978, the first year of contractual services. We conclude that a system of health services for a large, urban jail can allow time for humane and professional encounters between providers and patients.