mean radioactivity in the serum was lower in both patients with pernicious anaemia and in control subjects, and the results in the patients with pernicious anaemia were more definitive. There was no significant difference between the results obtained with an Ekco scaler and those with an I.D.L. scaler. This is the simplest and most convenient method of measuring vitamin B12 absorption. It is su...

In pregnancy the level of serum vitamin B(12) is lower in women who smoke than in non-smokers. This finding occurs independently of social class, parity, or level of haemoglobin. In addition, the mean serum B(12) level tends to be less in women who are anaemic and is less in those women who have smaller babies. These findings may be an effect of the cyanide content of tobacco smoke, since cyani...

In this paper the term vitamin B,, is used to signify vitamin B,, activity measured by microbiological assay with Lactobacillus leichmannii as test organism. The concentration of vitamin B,, in the serum of the rabbit is remarkably high compared with that of some other species. In man and the rat the highest normal values found in this laboratory have been 0.001 and 0-00088 pg/ml respectively (...

Certain diets essentially identical with those previously reported as causing an elevation of the blood pressure of rats have failed to produce any elevation. Examination of micro sections from the kidneys of these rats, with the aid of special stains, has failed to demonstrate any vascular lesions similar to those previously described by Calder. Evidence of tubular atrophy was present to a min...

The important role of the vitamin B12 coenzyme (FIGURE 1) in biochemiStryl and the discovery of a relatively easy method of conversion of the cobalamins to the coenzymes as well as a wide variety of cobalt-alkyl and cobalt-acyl analogues2 • .s,4.1i has stimulated a thorough examination of the structure, properties, and reactions of these unique compounds, which are the first examples of stable ...

Absorption of radioactive vitamin B(12) was measured by the Schilling procedure in 14 patients who had had a partial gastrectomy. Injection of carbachol (250 mug) before the administration of the test dose increased absorption to a much smaller degree than the ingestion of a light meal containing a minimal quantity of the natural vitamin. The results support the belief that food may improve abs...

Megalin has previously been shown to bind and mediate endocytosis of transcobalamin (TC)-B(12). However, the physiological significance of this has not been established, and other TC-B(12) binding proteins have been suggested to mediate renal uptake of this vitamin complex. The present study demonstrates by the use of megalin-deficient mice that megalin is, in fact, essential for the normal ren...

The present study was performed to investigate the effects of long-term intraperitoneal (IP) injection of vitamin B12 and diclofenac in separate and combined treatments on cold and mechanical allodynia in a neuropathic pain model in rats. Neuropathic pain was induced by crush injury in right tibial nerve. Acetone spray and von Frey tests were used to obtain cold and mechanical allody...

Samples of milk were taken at intervals during lactation from 35 mothers of term and 26 mothers of preterm infants and assayed for 8 B complex vitamins. Both term and preterm milks varied widely in vitamin content between mothers. Mean concentrations of thiamin, vitamin B6, nicotinic acid, pantothenic acid, biotin, and folic acid increased progressively over several weeks after parturition but ...

BACKGROUND Haptocorrin (HC) carries the major part of circulating cobalamin, but whether HC is altered on treatment with vitamin B12 remains unknown. METHODS Our study included 3 populations: a population of vegan men (n = 174; vegan population), of whom 63 were treated daily with 5 mg of oral vitamin B12 for 3 months; a group of patients with a previous methylmalonic acid (MMA) concentration...