Inez Pasher

A new assay method for biotin in blood, serum, urine, and tissues

Abstract A new microbiological assay of biotin in blood, serum, urine, liver and brain tissue, using the protozoan Ochromonas danica , is described. Results are given for 12 normal subjects and 10 histological normal liver and brain specimens obtained at post mortem.

Study of Folic Acid and Vit. B12 in Blood and Urine During Normal Pregnancy.

Summary A comparison of PGA and vit. B12 levels in blood and urine during pregnancy shows that levels of PGA are high, and those of B12 are low. Possible explanations for these findings are discussed.

Vit. B12 in thyrotoxicosis and myxedema.

Summary The whole-blood B12 values in 10 hyperthyroid subjects before and after a load dose of B12 were lower than for a normal and a myxedematous group. The mean 8-hour urinary excretion after B12 administration in hyperthyroid subjects was considerably lower than in the normal and myxedematous groups. These data suggest that B12 turnover and demand is appreciably greater in hyperthyroidism and appreciably lower in myxedema.

Comparative study of vitamin B12 assay in urine.

Summary The response of Ochromonas malhamensis, Euglena gracilis, and Lactobacillus leichmannii to vit. B12 in normal urine and in urine of patients, given an intramuscular dose of 50 μg of vit. B12 was studied. The “true” vit. B12 values presumably are given by the Ochromonas malhamensis assay. The response of E. gracilis and L, leichmannii to other members of the B12 group and to other metabolites is discussed from the standpoint of how to estimate responses other than O. malhamensis-active B12. Calculations are given for the estimation of interfering metabolites.

Pantothenic acid, thiamine and folic acid levels at parturition.

Summary A comparison of pantothenic acid, thiamine, and PGA serum levels of mothers and infants at parturition shows an approximately 5-fold increase of these vitamins in the fetal circulation. The significance of these findings is discussed.

Mono-Substituted Vit. B12 Amides. I. A Microbiological Study.

Summary The methylamide, ethylamide, and anilide of the monocarboxylic acid of Vit. B12 were inactive as B12-antagonists despite their previous designation as “anti-Vit. B12substances. They satisfied the B12 requirement of E. gracilis and L. leichmannii, but not that of E. coli and O. malhamensis. Combinations of sub-optimal levels of methionine plus methylamide, or ethylamide, gave greater growth of E. coli than this level of methionine alone. Addition of amide to Vit. B12 neither inhibited nor enhanced growth over that with B12 alone.

Mono-substituted vit. B12 amides. II. Further inhibition study.

Summary The anilide, ethylamide, ethylamide monoacid, and di-(ethylamide) derivative of B12 inhibit cobalamin utilization by O. malhamensis and E. coli. The monobasic acid inhibits B12 utilization by E. coli, but not by O. malhamensis: the reverse is true for the dibasic acid. Methylamide and carbanilide derivatives are utilized as well as true B12; all compounds are as active as true B12 for E. gracilis and L. leichmannii. In E. coli, suboptimal levels of methionine in presence of B12 amides and acids give increasing growth with increasing concentrations of B12 derivatives; neither methionine nor B12 acid and amide, when added alone, permit growth.

Growth inhibition of microorganisms by thyroid hormones.

Summary The growth inhibition induced by thyroactive compounds on vit. B12 and non B12-requiring microorganisms was studied. Thyroactive compounds were inactive for the B12-requiring mutant Escherichia coli 113-3, Lactobacillus leichmannii, and Euglena gracilis, and for their non B12-requiring counterparts. Only Ochromonas malhamensis, a B12-requirer, and Ochromonas danica, a non B12-requirer, were inhibited. Vit. B12 overcame the antagonistic action of the thyroid hormones for O. malhamensis, but not for O. danica where reduced glutathione and Tween 85 overcame the growth inhibition.

Study of the roles of folic acid and vitamin B12 in pregnancy. II

Abstract 1.1. A preliminary study of the simultaneous estimation of the serum and urine levels of folic acid and vitamin B 12 in three aspects of pregnancy is presented. 2.2. The first part consists of the comparison of serum and urine levels of B 12 and folic acid ante partum and one week post partum in 13 normal pregnant patients. There is a relative decrease in the levels of folic acid and B 12 in the first week post partum; this does not provide enough time for the B 12 levels to rise. 3.3. The second part consists of the comparison of hemoglobin levels with B 12 and folic acid blood levels in 14 of the pregnant patients, who showed a hemoglobin of less than 10 Gm. at some time in their pregnancy. There seems to be no relation between the levels of hemoglobin and the levels of folic acid and vitamin B 12 , marked variety being present in all three factors. 4.4. The third part concerns the estimations of folic acid and vitamin B 12 serum and urine levels in 10 bleeding pregnant patients. There were 7 abortions and stillbirths and 3 healthy babies. The levels of folic acid in blood and urine show either high, or low normal, values. B 12 urine and serum levels fluctuate widely.