Lynn D. Abbott

Erythrocyte Destruction in Sickle-Cell Anemia Simultaneous N15-Hemin and N15-Stercobilin Studies.

Summary 1. Study of erythrocyte destruction in sickle-cell anemia by analysis of hemin N15 disappearance and fecal stercobilin N15 appearance after a 1 g dose of N15-glycine indicates a completely random destruction of circulating red cells. 2. This individuals cells had a half-life of 11 days indicating a turnover rate of 6.3% per day with a mean survival time of approximately 16 days. 3. There was no evidence of more than one population of cells. 4. Comparison with a similar study by London and coworkers shows a similar clinical condition but a physiological state twice as active, and further suggests still unknown factors involved in the destruction of circulating red cells in this type of hemolytic anemia.

Effectiveness of Thiocyanate Analog of Vitamin B12 in Pernicious Anemia.

Summary The thiocyanate analog of vit. B12 (thiocyanato—cobalamin) has been shown to be fully active hematologically in pernicious anemia. In two patients the early biochemical and hematologic responses were the same as observed with same dosages of vit. B12. Further evaluation of the neurological response to this analog is necessary.

Natural abundance of N15 in hemin and plasma protein from normal blood.

Summary Hemin and plasma protein isolated from normal blood were found to have a slightly increased abundance of N15 over tank nitrogen or ammonium chloride. The mean values for normal hemin, 0.0046, and for normal plasma protein, 0.0039 atom % excess N15, were similar to the N15 concentration found in urinary urea. These results lend further support to the idea that minute fractionation of the nitrogen isotopes might occur through normal biological processes.

ALCAPTONURIA IN A NEGRO FAMILY

A report of the occurrence of alcaptonuria in two children of a Negro family is presented. Other members of the family were investigated and found to be unaffected. This is the first evidence that this inborn error of metabolism exists in the American Negro.

Effect of 5-Nitro and 5-Chloro Benzimidazole Derivatives on Heme Synthesis in vitro∗

Summary 5-Nitro-, 2-methyl-5-nitro-, and 2-ethyl-5-nitrobenzimidazole; 5-chloro-, 2-methyl-5-chloro-, and 2-ethyl-5-chlorobenzimidazole were prepared and their effects on incorporation of N15 from N15-glycine into heme by chicken erythrocytes incubated in vitro were studied. Similar to the 5-methyl-benzimidazole series studied previously, the 2-ethyl-5-nitro- was considerably more inhibitory than the 5-nitro- or 2-methyl-5-nitro-benzimidazole. Likewise in the 5-chloro series, 2-ethyl-5-chloro- was considerably more inhibitory than the 5-chloro- or 2-methyl-5-chlorobenzimidazole. 5-Chloro derivatives appeared to be more inhibitory than the corresponding 5-nitro analogues; 2-ethyl-5-chlorobenzimidazole was as effective as 2-ethyl - 5 - methylbenzimidazole, whereas 2-ethyl-5-nitrobenzimidazole was not. All were more effective than benzimidazole itself. Although methyl, chloro or nitro groups in the 5 position gave compounds having inhibitory activity greater than that of unsubstituted benzimidazole, 5-hydroxybenzimidazole was comparatively ineffective.

Inhibition of in vitro Heme Synthesis from N15-Glycine by 2-Ethyl-5-methylbenzimidazole.

Summary 2-Ethyl-5-methylbenzimidazole was found to be considerably more inhibitory than 2,5-dimethylbenzimidazole, or benzimi-dazole, for the synthesis of heme by chicken erythrocytes incubated in vitro. This was in the same relative order of inhibitory activities as was noted for multiplication of influenza A or B virus, and is considered to add further support to the concept that the same basic mechanism, possibly involving a fundamental role of nucleic acid in biosynthesis, underlies both processes.

Antibacterial Activity of Gentisyl Alcohol and Homogentisic Acid

Summary Gentisyl alcohol in our experiments was found to have only slight antibacterial activity over a broad pH range. Our results with this compound are at variance with those of Brack 1 but are in agreement with the original report of Raistrick and coworkers. 5 Homogentisic acid was found to have a definite but slight antibacterial activity. The effect of pH of the medium on the antibacterial activity of these compounds against S. aureus was studied.

Chemiluminescence of Alcaptonuric Urines.

Summary Alcaptonuric urines, as well as solutions of homo-gentisic acid or lead homogentisate, give off light when made alkaline and shaken with air.