Cobalamin metabolism and its clinical aspects.

@article{Linnell1984CobalaminMA,
  title={Cobalamin metabolism and its clinical aspects.},
  author={J. Linnell and D. Matthews},
  journal={Clinical science},
  year={1984},
  volume={66 2},
  pages={
          113-21
        }
}
In 1970 we wrote: “The first major phase in the clinical investigation of vitamin B,? metabolism and its derangements began with the development and application of methods for the estimation of total Bl2 in tissues and body fluids and the assay of total serum vitamin Bl2 has been a routine diagnostic procedure for many years. Most of the information obtainable by such methods has been gained and it is now clear that we are in the early stages of a second phase, in which the further development… Expand
Human serum vitamin B12 assay methods--a review.
TLDR
Various methods of quantitation of B12 reviewed in this communication include: microbiological, radioisotopic, high-performance liquid chromatography (HPLC), and the most recent radioimmunoassay (RIA) techniques are reviewed to provide awareness of the limitations of these methods. Expand
Trends in analysis of vitamin B12.
TLDR
Vitamin B12 is an essential nutrient for the maintenance of myelin sheath surrounding nerve cells in humans that promotes growth, cell development, and fat and carbohydrate metabolism and is essential for the rapid synthesis of DNA during cell division. Expand
Inherited errors of cobalamin metabolism and their management.
TLDR
If urine and light-protected blood samples are collected and sent to an appropriate metabolic unit, an inborn error of cobalamin metabolism, including TCII deficiency in which the serum B12 may be normal, can quickly be diagnosed. Expand
Unsaturated Vitamin B12Binding Capacity in Human and Ruminant Blood Serum - A Comparison of Techniques Including a New Technique by High Performance Liquid Chromatography
A new technique by High Performance Liquid Chromatography (HPLC-gel permeation) shows promise as a tool to separate and quantitate the Unsaturated Vitamin B(12) Binding Capacity (UBSC) of theExpand
Hypervitaminosis B12 in Maintenance Hemodialysis Patients Receiving Massive Supplementation of Vitamin B12
TLDR
It is found that these patients had very high levels of serum vitamin B12 which returned to original values only after a period of three years after stopping the vitamin, and the use of such megadose vitamin compounds in dialysis patients should be re-evaluated. Expand
Vitamin B12 absorption and metabolism in milk-fed lambs
TLDR
Lambs with concentrations of vitamin B12 in plasma and liver in the marginal reference range were able to metabolise propionate and maintain normal concentrations of MMA at a rate of intake of propionatesuccinate close to that which would depress appetite. Expand
The inactivation of Cobalamin by nitrous oxide : application in experimental chemotherapy of leukemia
textabstractThe subject of this thesis is the investigation of the role of cobalamin in leukemic cell proliferation. This has been studied by the application of the nitrous oxide-inducedExpand
Iron Deficiency and Megaloblastic Anemias
TLDR
Recognition of iron deficiency, determination of its cause, and effective iron replacement are particularly important because iron metabolism is a complex process which is still not completely understood. Expand
Determination of metabolically active B12 and inactive B12 analog titers in human blood using several microbial reagents and a radiodilution assay.
TLDR
RIDA B12 determinations for active B12 in plasma showed that 44% of the B12 measured was still due to inactive analogs when compared to O malhamensis B12 activity. Expand
Effect of lacto-ovo-vegetarian diet on serum vitamin B12 concentrations - five-year prospective study
TLDR
Five-year lacto-ovo-vegetarian diet did not result in a risk of vitamin B12 deficiency in healthy subjects, however, the levels of serum vitamin B 12 concentrations in a subgroup consuming natural diet tend to be significantly lower as compared with the group consuming fortified food. Expand
...
1
2
...

References

SHOWING 1-10 OF 39 REFERENCES
Chromatographic and bioautographic estimation of plasma cobalamins in various disturbances of vitamin B12 metabolism.
TLDR
A survey of values for individual plasma cobalamins in normal subjects, hospital controls, and patients with vitamin B 12 deficiency and diseases in which there are disturbances of B 12 metabolism is reported. Expand
Plasma and hepatic cobalamins in tropical ataxic neuropathy.
1. Chromato-bioautographic analysis of cobalamins in Nigerian subjects showed that in patients with tropical ataxic neuropathy as in normal control subjects methylcobalamin was the major form ofExpand
A derangement in B12 metabolism associated with homocystinemia, cystathioninemia, hypomethioninemia and methylmalonic aciduria.
TLDR
According to autopsy, this infant could not adequately metabolize B, and as a result failed to accumulate coenzymatically-active derivatives of vitamin B, in normal amounts, and it is suggested that therapeutic benefit may derive from the administration of forms of 6, that could circumvent the metabolic block, by giving substances that could stimulate the non-B, -dependent methionine-synthesizing system or by the Administration of methamphetamineionine in large doses. Expand
The effects of nitrous oxide on cobalamins, folates, and on related events.
  • I. Chanarin
  • Chemistry, Medicine
  • Critical reviews in toxicology
  • 1982
TLDR
The anaesthetic gas nitrous oxide (N2O), when inhaled for longer than 6 hr, produces megaloblastic anemia in man, and long term exposure to low concentrations results in an increased abortion rate and neuropathy, particularly in dental personnel. Expand
Effects of low cobalamin diet and chronic cyanide toxicity in baboons.
TLDR
The results support the suggestions that cyanide affects bodily handling of Cbl and that hydroxo-cobalamin plays a part in detoxication of cyanide and suggest an inverse relationship between MMA excretion and plasma total Cbl. Expand
The metabolic basis of inherited disease
TLDR
With this sixth edition, the publishers have faced a number of challenges and it seems that all have wisely approached their tasks with a blend of freshness and due regard for a classic that soon enters its fourth decade of reliable service. Expand
Mental retardation, megaloblastic anaemia, methylmalonic aciduria and abnormal homocysteine metabolism due to an error in vitamin B12 metabolism.
TLDR
A child with retarded physical and mental development, recurrent megaloblastic anaemia, methylmalonic aciduria and abnormal homocysteine metabolism resulting from an inborn error in the metabolism of cobalamins died at the age of 7 years. Expand
Cobalamins in human pregnancy and lactation
TLDR
The findings suggest that methylcobalamin may be a more labile plasma form of the vitamin than 5-deoxyadenosyl cobalamin, and their bearing on problems of cobalamins transport is discussed. Expand
Distribution of endogenous cobalamin between the transcobalamins in various mammals.
TLDR
Unlike the situation in man, the bulk of the endogenous plasma cobalamin was found attached to a transcobalamin II-like protein in all ten animals, and this proportion appeared to be inversely related to the plasma total cobalamina. Expand
Tissue distribution of endogenous cobalamins and other corrins in the rat, cat and guinea pig.
TLDR
In the rat, cat and guinea pig, levels of methylcobalamin and hydroxobalamin were higher in erythrocytes than in plasma, a pattern almost the complete reverse of that in man. Expand
...
1
2
3
4
...