Vitamin B<sub>12</sub>Assay in Body Fluids using<i>Euglena gracilis</i>

Ross, G. I. M.

doi:10.1136/jcp.5.3.250

Cited by 210 publications

(56 citation statements)

References 12 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Euglena cells require cobalamin (Cbl) for growth and have the ability to take up and accumulate exogenous Cbl (Ross, 1952;Varma et al, 1961). The kinetics of Cbl uptake in Euglena are biphasic, as in Escherichia coli (DiGirolamo & Bradbeer, 1971 ;Bradbeer & Woodrow, 1976) and the protozoan Ochromonas malhamensis (Bradbeer,197 1).…”

Section: Introductionmentioning

confidence: 99%

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Watanabe¹,

Nakano

Stupperich

1992

Journal of General Microbiology

View full text Add to dashboard Cite

A variety of cobalamin analogues synthesized chemically or microbiologically were used to study the corrinoid specificities of cell growth and the cobalamin uptake system in Euglena gracilis z. Although Euglena could not utilize most of the analogues for cell growth, benzimidazolyl cobamide, cyanocobalamin-@'-phosphate, and cyanocobalamin-6-, -d-and -e-monocarboxylates had effects similar to that of cyanocobalamin on cell growth. It is suggested that Euglena cells have the ability to synthesize 'complete cobalamin' from the acid derivatives (amidation reaction) and/or the phosphate derivative (dephosphorylation reaction). Inhibition of uptake of radiolabelled cyanocobalamin caused by addition of various analogues indicates that both the d o w e r axial ligand (the cobalt-coordinated nucleotide) and the (6)-propionamide side-chain of the cobalamin molecule are essential for the cobalamin uptake system in Euglena. These results indicate that there are different corrinoid specificities for cell growth and the cobalamin uptake system in E. gradis z.

show abstract

Section: Introductionmentioning

confidence: 99%

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Watanabe¹,

Nakano

Stupperich

1992

Journal of General Microbiology

View full text Add to dashboard Cite

show abstract

“…Normal rats excrete about 50 per cent of this dose of Co'°-Bl, Human gastric juice was collected by Histalog® 1 stimulation of normal donors after gastric intubation. The juice was filtered through cheesecloth, allowed to stand at pH 10 for 20 minutes in order to destroy pepsin (21) (24).…”

Section: Materials and General Methodsmentioning

confidence: 99%

Sequential Mechanisms in the Enhanced Absorption of Vitamin B12 by Intrinsic Factor in the Rat*

Cooper¹,

Castle²

1960

J. Clin. Invest.

111

View full text Add to dashboard Cite

“…"Total" vitamin B,2 concentration of the serum was determined by the modification of Lear, Harris, Castle, and Fleming (5) of the Euglena gracilis method of Ross (6). "Free" vitamin B,2, measured on occasional serum samples from normal subjects and patients with chronic myelogenous leukemia, constituted 15 per cent or less of the total serum vitamin B12.…”

Section: B Analytical Proceduresmentioning

confidence: 99%

The in Vitro Binding of Cobalt60 Labeled Vitamin B1 by Normal and Leukemic Sera

Miller¹

1958

J. Clin. Invest.

View full text Add to dashboard Cite

In chronic myelogenous leukemia both the serum concentration of vitamin B12 and the capacity of the serum to bind added vitamin B12 are markedly increased (1-3), suggesting an abnormality of the serum proteins in this disease. In vitro measurements of vitamin B12 binding capacity employing a microbiological assay method have not demonstrated a qualitative difference between normal and leukemic sera in respect to the binding of added vitamin B12 by the various serum protein fractions (1,4 of radioactivity in each sample determined by means of a plastic scintillation well counter. After one hour incubation at 220 C., the bags were dialyzed against 250 ml. of 1/15 M phosphate buffer, pH 7.3. Initially, the dialysis was carried on for 24 hours at 22°C. with constant agitation but subsequently this was performed for 48 hours at 40 C. without agitation. Equilibrium was attained in both situations, and similar values for vitamin B12 binding were obtained under both experimental conditions. At the conclusion of dialysis each bag was rinsed externally in running water for one-half to one minute after which its radioactivity was determined in the plastic scintillation well counter. The bags were then slit in two, emptied of their contents, washed for one-half to one minute in running water and recounted for the measurement of the residual radioactivity bound to the bag. The unsaturated vitamin B. binding capacity of the serum (UBBC) was determined from the following calculations:1. Fraction of added Co°B12 bound per ml. = (a) Co60B12 in bag postdialysis (cpm) -Co°B12 bound to bag (cpm) CoO°B12 added predialysis (cpm) X ml. serum -mean Co6B12 in blank calculated as in (a) 2. UBBC, m/Ag./ml. = Co°Big added predialysis (miAg.) X calculation 1.

show abstract

Vitamin B₁₂Assay in Body Fluids usingEuglena gracilis

Cited by 210 publications

References 12 publications

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Sequential Mechanisms in the Enhanced Absorption of Vitamin B12 by Intrinsic Factor in the Rat*

The in Vitro Binding of Cobalt60 Labeled Vitamin B1 by Normal and Leukemic Sera

Contact Info

Product

Resources

About

Vitamin B12Assay in Body Fluids usingEuglena gracilis

Cited by 210 publications

References 12 publications

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Different corrinoid specificities for cell growth and the cobalamin uptake system in Euglena gracilis z

Sequential Mechanisms in the Enhanced Absorption of Vitamin B12 by Intrinsic Factor in the Rat*

The in Vitro Binding of Cobalt60 Labeled Vitamin B1 by Normal and Leukemic Sera

Contact Info

Product

Resources

About

Vitamin B₁₂Assay in Body Fluids usingEuglena gracilis