Elliott R. Baker

Cobalamin (Vitamin B12) and Holotranscobalamin Changes in Plasma and Liver Tissue in Alcoholics with Liver Disease

OBJECTIVE We wanted to know if alterations in plasma cobalamin (B12) concentration and B12 carriers, e.g., holotranscobalamins (holo TC), occur in blood and liver tissue from patients with severe alcoholic liver disease. Our purpose was to test the hypothesis that liver disease may disrupt B12 distribution. METHOD Total B12, as well as B12 bound to transcobalamin I, II, III (holo TC), were measured to determine their concentration in plasma and in liver tissue; Poteriochromonas malhamensis--a protozoan reagent served to measure only metabolically active (true) B12. Total B12 as distributed in holo TC in plasma and liver tissue of healthy subjects (controls) were compared to patients with severe alcoholic liver disease. RESULTS Severe liver disease initiates highly elevated B12 levels in plasma and a lowered liver tissue total B12 concentration. The percent of B12 distributed to holo TC II is significantly depleted during liver disease. In contrast, holo TC I and III are elevated in plasma during liver disease and contain more B12 than controls. Total B12 and B12 distributed to TC are lower in diseased liver tissue. CONCLUSION Severe alcoholic liver disease involves leakage of total B12 from liver tissue into the plasma. Holo TC I and III concentration increases in plasma; this preserves the high plasma B12 from being excreted. However, plasma holo TC II B12 distribution is decreased, indicating that there is a depression of exogenous B12 entering the plasma and tissues. In severe liver disease, liver tissue B12 binding and storage by TC is disrupted and causes B12 to leak out of the liver into the circulation. Eventually liver disease could produce enough severe tissue B12 deficits to cause metabolic dysfunction despite elevated plasma total B12. Elevation of plasma B12, accompanied by a lowering of holo TC II distribution, seemed to be a useful index of liver disease severity suggesting preventive treatment.

Lack of Effect of 1 Year Intake of a High-Dose Vitamin and Mineral Supplement on Cognitive Function of Elderly Women

Objective: To determine if long-term, high-vitamin supplementation could reverse cognitive malfunction in old people. Methods: We performed a longitudinal study relating the 12-month outcome to baseline values. Twenty non-vitamin-deficient elderly females with a Folstein mini mental state examination score indicating cognitive malfunctions were recruited to ascertain if feeding a high-dose vitamin-mineral supplement for 1 year could, by mass vitamin action, reverse some existing cognitive malfunctions. Ten females were fed a high-dose vitamin-mineral supplement pill with each of three daily meals for 1 year; the other 10 did not receive this supplementation. Twelve blood vitamin analyses and a Folstein mini mental state examination were performed for each of the 20 subjects before and after 1 year; each subject served as its own control. Results: No improvement in cognitive malfunction was noted despite elevation of blood vitamins. Conclusion: Feeding of a high-dose vitamin and mineral supplement for 1 year did not improve cognitive malfunction in non-vitamin-deficient elderly in this study.

Human plasma patterns during 14 days ingestion of vitamin E, beta-carotene, ascorbic acid, and their various combinations.

OBJECTIVE We wanted to learn about plasma patterns of ascorbic acid (AA), beta carotene (BC), and vitamin E (vit E) when each or their various combinations were fed to humans. Conceivably, the combined absorption of these antioxidants could synergize maximum plasma redox potential. METHODS Vit E (800 mg/day), BC (30 mg/day), and AA (1000 mg/day) were fed individually or in various combinations with each other to 91 volunteers divided into different feeding groups for 14 days. Plasma vit E, carotenes, and AA patterns were analyzed by standardized methods; values were compared with each groups baseline value. RESULTS AA feeding did not significantly increase already saturated plasma AA concentrations above baseline. Intake of BC did not influence vitamin A (vit A) levels. Feeding of only vit E or only BC, with or without AA addition, or a combination of BC and vit E significantly increased plasma vit E and carotene levels after 2 days. A statistically (ANOVA) significant increase in plasma vit E above baseline was noted when vit E was ingested combined with AA or BC; this increase in plasma vit E was not significant when AA, BC and vit E were taken in combination. CONCLUSION Our results show that BC or AA ingestion in combination with vit E significantly increases circulating vit E above that seen when vit E is individually ingested. Vit E in combination with BC or AA seems a practical means or increasing the circulating antioxidant potential afforded by vit E. Reasons why such synergism does not exist when an AA, BC, vit E combination is ingested is not yet obvious.

Elevated vitamin levels in colon adenocarcinoma as compared with metastatic liver adenocarcinoma from colon primary and normal adjacent tissue

Twenty‐four samples of colon adenocarcinoma removed at surgery and autopsy together with adjacent uninvaded normal colon from the same subjects were analyzed for vitamin B12 and B6, biopterin, nicotinate, riboflavin, pantothenate, thiamin, biotin, and folates. Nine specimens of metastatic liver adenocarcinoma from colon primary together with adjacent uninvaded normal liver were also analyzed for these same vitamins. Primary colon adenocarcinoma contains significantly (p < 0.001) more of the above vitamins than normal colon; 1.8‐ to 3.5‐fold higher concentrations of vitamins were found in this tumor. In contrast, vitamin B12 levels were almost two‐fold lower. Unlike colon tumor, metastatic liver adenocarcinoma from colon primary contained from 1.2‐ to 28‐fold lower vitamin concentration than normal liver tissue. The present findings suggest that those types of primary tumors with conspicuously high vitamin content needed for the enhanced growth and catalysis of tumor metabolism may be arrested with antivitamins targeted at metabolic sites other than those involved with nucleic acid synthesis.

Antioxidant survey to assess antagonism to redox stress using a prokaryotic and an eukaryotic system

Using a prokaryote (Escherichia coli) and a metazoa-resembling eukaryote (Ochromonas danica), we surveyed antioxidants which might overcome redox stress imposed by menadione sodium bisulphite (MD) and buthionine sulphoximine (BSO). BSO oxidant stress was evident only inO. danica; MD oxidant stress was evident in both organisms. Glutathione, its precursors, e.g. cysteine, homocysteine, and 2-oxo-4-thiazolidine carboxylic acid, and red blood cells, emerged as prime antioxidants for relieving BSO and MD oxidant stress. BSO and MD oxidant activity and antioxidant-annulling effect inO. danica were judged comparable to those found in animal cells whereas the resultsE. coli were not entirely equivalent. TheO. danica system emerged as a practical, rapid, and useful system for pinpointing oxidant stressors and antioxidants, and shows promise for studies with mammalian systems.

Routine microbiological assay for carnitine activity in biological fluids and tissues

Abstract A practical method for measuring acid-soluble and total (acid- and alkaline-soluble) carnitine growth activity for a carnitine-specific mutant of the enteric yeast Torulopsis bovina in biological fluids and tissues is described. It grows at 37°C in a simple, cheap, chemically defined medium; its response threshold to carnitine is 100 pg ml −1 . Growth is measured as absorbance units with any turbidometer. Carnitine contents in human and rat fluids and tissues so measured accord with those obtained after multi-step extraction methods, enzyme procedures or radiochemical procedures.

HOLOTRANSCOBALAMINS IN B12 AND NON B12 REQUIRING PROKARYOTES AND EUKARYOTES

Transcobalamins, vitamin B12 binding proteins, deliver B12 to cell surface receptors which then permit B12 to cross cell membranes for metabolic use. There is little documentation concerning B12 binding proteins in bacteria and protists. We found that prokaryotes and eukaryotes requiring B12, as well as those protists synthesizing B12, also produce several transcobalamins for functionally transporting B12 similar to humans.

Protozoological method for assaying lipoate in human biologic fluids and tissue.

Publisher Summary This chapter discusses the protozoological method for assaying lipoate in human biologic fluids and tissue. A procedure for assaying lipoic acid concentration in biologic fluids and tissues is described using a eukaryotic protozoan Tetrahymena thermophila. This protozoan has a specific and sensitive (30 pg/ml) requirement for lipoic acid. Unlike humans and other microorganisms, T. thermophila cannot synthesize lipoic acid and therefore its requirement for exogenous lipoic acid is specific. The lipoic acid supplied to T. thermophila by processing biologic fluids and tissues during the assay procedure permits the derivation of a practical assay by turbidimetrically assessing its growth response to various lipoate concentrations. The chapter presents various procedures for extracting, measuring, assaying, and calculating lipoate in biologic fluids and tissues.