Pneumocystis carinii pneumonia in rheumatoid arthritis patients treated with methotrexate. A report of two cases

OBJECTIVE: The induction and repair of DNA single-strand breaks (SSBs) were measured in primary cultured infant rat lens epithelial cells (RLECs) following hydrogen peroxide (HP) exposure, and the influential factors were detected. METHODS: Utilizing nick translation methodology which utilizes incorporation of labeled nucleotides at the sites of DNA SSBs to sensitively quantitate the damage, we studied the effects of temperature, doses of HP and trace amount of selenium on cell survival. RESULTS: The number of DNA SSBs at 37 degrees was higher than that at 4C (P < 0.01). Significant numbers of SSBs were detected after being insulted by as low as 36.4 mumol/L hydrogen peroxide for 12 minutes 4 degrees (P < 0.05). Repair rapidly initiated and almost completed in 60 minutes after mild damage, and it was unable to repair when the DNA damage was induced by HP at toxic concentration. Trace selenium was added to the culture and incubated for 24 hours, then the number of SSBs was significantly decreased (P < 0.01). CONCLUSIONS: At 37 degrees HP may induce DNA SSBs in RLECs. HP induces the SSBs in a dose dependent manner. The DNA SSBs can not be repaired after severe damage. Trace selenium can decrease the degree of susceptibility to oxidative damage in infant RLECs.     

The species specificity of fish and mammalian gonadotropic hormones

Protein spectra of the hypophyses of fishes from various taxonomic groups obtained by disc electrophoresis in polyacrylamide gel exhibit high species specificity. By means of biological testing on the loach Misgurnus fossilis, zones of gonadotropic activity were obtained which differ in various species by the electrophoretic mobility. The mammalian gonadotropins obtained reveal lower electrophoretic mobility. The gonadotropins investigated significantly differ in their biological effect.     

The Canadian influenza decision, 1976

This paper explains the Canadian decision process following the isolation and identification of A/New Jersey/8/76 at Fort Dix, New Jersey in February 1976. The cause for concern was the emergence of a swine-like strain related to that which caused the 1918-19 pandemic, together with proved man-to-man transmission. This concern was reinforced since all new influenza A strains known to have infected the number of persons involved at Fort Dix have become strains of epidemic importance. The Fort Dix outbreak gave sufficient warning to allow implementation of a national vaccination program, to prevent and protect against influenza. In the past such an opportunity had not occurred, and vaccine use had, at best, constituted an intervention in the course of an outbreak. The National Advisory Committee on Immunizing Agents had all available information when it reached its decision to recommend vaccination with bivalent (A/Victoria and A/New Jersey) or with monovalent (A/New Jersey) vaccine for selective, high-risk groups. This was an independent, scientifically based decision.     

Infection of the urinary tract after anti-reflux surgery

Two hundred twenty-three children who underwent anti-reflux surgery were evaluated. Pyelonephritic scarring was more apt to occur with greater degrees of reflux. Postoperative infection was principally confined to the bladder and occurred primarily in females. The beneficial effect of anti-reflux surgery is discussed.