Studies on the Vitamin B12 Binding Capacity in the Hypophysectomized Rat Stomach

Abstract 1. Mature neutrophilic leukocytes show the highest Co60B12 binding capacity. 2. Less mature granulocytes, "blast" forms and eosinophils have little or no Co60B12 binding capacity. 3. Disintegrated mature leukocytes from chronic myelocytic leukemia and polycythemia vera show higher B12 binding capacity than intact cells. 4. Mature leukocytes from patients with chronic myelocytic leukemia and polycythemia vera show a two-phase B12 curve suggesting specific and nonspecific binding, similar to that observed in human serum. 5. Disintegration products from mature neutrophilic leukocytes probably contribute largely to increased B12 binding capacity of serum in chronic myelocytic leukemia and polycythemia vera.

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Vitamin B12 transport in blood. I. Congenital deficiency of transcobalamin II

Blood ◽

10.1182/blood.v45.1.71.71 ◽

1975 ◽

Vol 45 (1) ◽

pp. 71-82 ◽

Cited By ~ 18

Author(s):

E Gimpert ◽

M Jakob ◽

WH Hitzig

Keyword(s):

Vitamin B12 ◽

Binding Capacity ◽

Polyacrylamide Gel Electrophoresis ◽

Congenital Deficiency ◽

Complete Clinical Remission ◽

High Concentrations ◽

High Doses ◽

Vitamin B12 Binder ◽

Very High ◽

Transcobalamin Ii

Abstract Some characteristics of vitamin B12 binding and transport in the serum of an infant with congenital hereditary transcobalamin II (TC II) deficiency were studied using the following parameters and methods: vitamin B12 level and binding capacity; electrophoretic mobility in polyacrylamide gel electrophoresis; various immunodiffusion and absorption experiments, using a specific anti-TC II antiserum and the patient's serum as antigen. The results of these studies point to a deficient synthesis of TC II. Parenteral administration of high doses of vitamin B12 was followed by rapid and complete clinical remission and the appearance of vitamin B12 binder in the alpha 2 region which is similar to “fetal binder.” Thus, very high concentrations of vitamin B12, either carrier free or bound to this alpha 2 binder, were able to correct the disturbed physiology of TC II deficiency, presumably by normalization of DNA-thymine synthesis.

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Studies of Cyclic AMP Effect on Release of Unsaturated Vitamin B12 Binding Capacity from Human Blood Cells

Experimental Biology and Medicine ◽

10.3181/00379727-145-37885 ◽

1974 ◽

Vol 145 (2) ◽

pp. 734-736 ◽

Cited By ~ 1

Author(s):

R. Stebbins ◽

V. Herbert

Keyword(s):

Cyclic Amp ◽

Vitamin B12 ◽

Human Blood ◽

Blood Cells ◽

Binding Capacity ◽

Human Blood Cells

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Circulating antibody to transcobalamin II causing retention of vitamin B12 in the blood

Blood ◽

10.1182/blood.v49.6.987.bloodjournal496987 ◽

1977 ◽

Vol 49 (6) ◽

pp. 987-1000 ◽

Cited By ~ 2

Author(s):

R Carmel ◽

B Tatsis ◽

L Baril

Keyword(s):

Vitamin B12 ◽

Binding Capacity ◽

Megaloblastic Anemia ◽

Serum Vitamin ◽

Vitamin B12 Deficiency ◽

High Serum ◽

The Status ◽

B12 Deficiency ◽

Long Acting

A patient with recurrent pulmonary abscess, weight loss, and alcoholism was found to have extremely high serum vitamin B12 and unsaturated vitamin B12-binding capacity (UBBC) levels. While transcobalamin (TC) II was also increased, most of his UBBC was due to an abnormal binding protein which carried greater than 80% of the endogenous vitamin B12 and was not found in his saliva, granulocytes, or urine. This protein was shown to be a complex of TC II and a circulating immunoglobulin (IgGkappa and IgGlambda). Each IgG molecule appeared to bind two TC II molecules. The reacting site did not interfere with the ability of TC II to bind vitamin B12, but did interfere with its ability to transfer the vitamin to cells in vitro. The site was not identical to that reacting with anti-human TC II antibody produced in rabbits. Because of this abnormal complex, 57Co-vitamin B12 injected intravenously was cleared slowly by the patient. However, no metabolic evidence for vitamin B12 deficiency was demonstrable, although the patient initially had megaloblastic anemia apparently due to folate deficiency. The course of the vitamin B12-binding abnormalities was followed over 4 yr and appeared to fluctuate with the status of the patient's illness. The IgG-TC II complex resembled one induced in some patients with pernicious anemia by intensive treatment with long-acting vitamin B12 preparations. The mechanism of induction of the antibody formation in our patient is unknown.

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Vitamin B12 Deficiency Is Prevalent Among Czech Vegans Who Do Not Use Vitamin B12 Supplements

Nutrients ◽

10.3390/nu11123019 ◽

2019 ◽

Vol 11 (12) ◽

pp. 3019 ◽

Cited By ~ 1

Author(s):

Eliška Selinger ◽

Tilman Kühn ◽

Magdalena Procházková ◽

Michal Anděl ◽

Jan Gojda

Keyword(s):

Czech Republic ◽

Vitamin B12 ◽

Binding Capacity ◽

Iron Status ◽

Clinical Care ◽

Vegan Diet ◽

Cobalamin Deficiency ◽

Nutritional Deficiencies ◽

The Czech Republic ◽

Supplement Use

As not much is known about the prevalence and predictors of nutritional deficiencies among vegans in the Czech Republic, we evaluated whether supplement use and duration of adherence to the vegan diet are associated with the risk of cobalamin and iron deficiencies. Associations between self-reported supplementation and duration of vegan diet with biomarkers of cobalamin (serum cobalamin, holotranscobalamin, homocysteine, folate) and iron status (serum ferritin, iron binding capacity, transferrin and saturation of transferrin) were assessed by cross-sectional analyses of medical data from a clinical nutrition center. Data from 151 (72 females) adult vegans (age 18–67 years), who were free of major chronic diseases and 85 (40 females) healthy non-vegans (age 21–47 years) were analyzed. Overall, vegans had significantly lower cobalamin, hemoglobin and ferritin levels, but higher folate and MCV values compared to non-vegans. Vegans not using cobalamin supplements were at higher risk of low plasma cobalamin than regularly supplementing vegans (OR: 4.41, 95% CI 1.2–16.16 for cobalamin, OR: 19.18, 95% CI 1.02–359.42 for holotranscobalamin), whereas no significant differences in cobalamin status related to duration of the vegan diet were observed. Regularly supplementing vegans had similar levels of cobalamin/holotranscobalamin as non-vegans. Despite lower ferritin and hemoglobin levels, there was no indication of a higher risk of iron-deficiency among vegans. To conclude cobalamin deficiency risk depends on supplementation status and not on the duration of an exclusive vegan diet, which underlines the need to integrate cobalamin status monitoring and counselling on supplement use in routine clinical care in the Czech Republic.

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Serum Vitamin B12-Binding Capacity and Muramidase Changes With Cyclic Neutropenia Induced by Cytosine Arabinoside

Blood ◽

10.1182/blood.v37.1.31.31 ◽

1971 ◽

Vol 37 (1) ◽

pp. 31-39 ◽

Cited By ~ 14

Author(s):

RALPH CARMEL ◽

CHARLES A. COLTMAN

Keyword(s):

Complete Remission ◽

Acute Leukemia ◽

Vitamin B12 ◽

Cytosine Arabinoside ◽

Binding Capacity ◽

Serum Vitamin ◽

Maintenance Chemotherapy ◽

Cyclic Neutropenia ◽

Data Support ◽

Periodic Maintenance

Abstract A patient with acute leukemia in sustained complete remission was studied for 8 months. Periodic maintenance chemotherapy with cytosine arabinoside regularly induced granulocytopenia, with granulocytosis upon marrow recovery. Changes in serum unbound B12-binding capacity (UBBC) occurred simultaneously with peripheral granulocyte fluctuations. Both α- and β-globulin UBBC were affected. Serum muramidase rose and fell out of phase with the granulocyte and UBBC fluctuations, preceding them by several days. These data support the concept that serum UBBC and serum muramidase reflect different aspects of granulocyte activity.

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