Cyanide toxicity following nitroprusside induced hypotension

Several recently reported deaths following the use of sodium nitroprusside have been attributed to the accumulation of the nitroprusside metabolite, cyanide. In this study, brief nitroprusside infusions (mean = 36 minutes) were administered in currently recommended doses during intracranial surgery. The peak blood cyanide following the infusions was 65.2 +/- 17.5 microgram per cent (mean +/- SE) (n = 13). It occurred within 45 minutes after infusion. The highest cyanide level detected was 205 microgram per cent, which is within the range of reported lethal blood cyanide levels. Metabolic acidosis developed in the four patients with the highest blood cyanide levels (range 90-205 microgram per cent). This occurred between 45 and 180 minutes following the cyanide peak. Blood ATP levels were depressed in the same patients. These findings are indicative of disturbed aerobic metabolism. We conclude that there is evidence of cyanide toxicity when nitroprusside is infused into patients using currently recommended doses. We recommend that for short infusions the dose of sodium nitroprusside should not exceed 0.5 mg/kg.

Epidemiology of cancer of the testis in upstate New York

We collected data on the 434 individuals reported with cancer of the testis to the New York State Tumor Registry, 1960-64, from upstate New York. We compared these with the 410 members of a random sample of the upstate population interviewed from 1959 to 1962. A high risk of developing cancer of the testis was associated with professional occupations, native-born parentage, rural residence, and having been married, especially while young. These findings paralleled some other studies, as well as our earlier inquiry. Each of these factors carried a higher risk even when considered in the context of the other traits, and risk increased with an increase in the number of characteristics possessed.

Isolation and characterization of Caulobacter crecentus bacteriophage phi Cd1

A DNA-containing bacteriophage, phiCd1, was isolated from sewage and shown to infect both stalked and swarmer cells of Caulobacter crescentus strain CB13B1a. phiCd1 is a small, icosohedral bacteriophage, 60 nm in diameter, which possesses a short, noncontractile tail, 10 to 12 nm in length. The bacteriophage particle is composed of at least eight structural proteins. phiCd1 nucleic acid exists as a linear duplex of DNA as judged by: (i) thermal denaturation (Tm), (ii) CsCl density gradient centrifugation, and (iii) chemical analysis of its base composition. The DNA is 61% guanosine plus cytosine, has a buoyant density in CsCl of 1.721 +/- 0.001 g/cm3, and denatures sharply at 78.5 C in 0.1 SSC (standard saline citrate) buffer. The S20, w value for the DNA is 34.3 +/- 0.1S as compared with T7 DNA, indicating a molecular weight of about 29 x 10(6).

Complete separation of lipid classes on a single thin-layer plate

A double-development procedure employing first a polar and then a nonpolar solvent system is described for the complete separation by thin-layer chromatography of the main lipid classes encountered in natural lipids. For better quantification, long plates (34 cm) are employed. Diglycerides were separated from cholesterol, 1,2- from 1,3-diglycerides, and monoglycerides from phospholipids.