Investigations into the Euglena method for the assay of the vitamin B12 in serum

Chromosomal studies were performed in phytohaemagglutinin-stimulated cultures of lymphocytes and in bone marrow cells without culture from 115 patients with megaloblastic anaemia resulting from nutritional deficiency of folate and vitamin B₁₂ Essentially similar chromosomal abnormalities were observed in the two cell lines. These were characterized by striking morphological aberrations such as elongation and despiralization (uncoiling or incomplete contraction), increased frequency of chromosome breakage and centromere spreading. Numerical abnormalities, chromatid exchanges and translocations were virtually absent. Autoradiographic studies of chromosomes after pulse-labelling with ³H-thymidine during the terminal 6 h of phytohaemagglutinin-stimulated lymphocyte cultures revealed a differential pattern of distribution of the radionucleotide in the chromosomes of megaloblastic lymphocytes as compared to those from normal lymphocytes. Repeated chromosomal studies were done in 65 of these patients at various intervals after starting therapy with the deficient vitamins. After 48 h of therapy, chromosomal abnormalities were remarkably reduced in the bone marrow; but many of these morphological chromosomal changes (i.e. despiralization and breaks) persisted in the lymphocytes of a significant proportion of patients for variable periods up to 6–12 months after haematological remission resulting from therapy with the deficient vitamins. These abnormalities did not, however, persist after remission in those patients who had repeated episodes of infections.

Section: Methodsmentioning

confidence: 99%

Cytogenetics in Nutritional Megaloblastic Anaemia: Prolonged Persistence of Chromosomal Abnormalities in Lymphocytes after Remission

Das¹,

Mohanty²,

Garewal³

1986

“…Serum vitamin Bts levels were determined in a microbiological assay system using Euglena gracilis [1]. By the use of this technique the serum levels were di vided into a deficient range (less than 120 pg/ml), an intermediate range (120-180 pg/ml) and a normal range (over 180 pg/ml).…”

Section: Methodsmentioning

confidence: 99%

‘Latent’ Pernicious Anaemia in Delhi (India)

Singh¹,

Sood²

1973

Parietal cell antibody, vitamin B₁₂ andpepsinogen in serum were measured for the investigation of prevalence of pernicious anaemia amongst Indians in the Delhi area in India. Low levels of serum pepsinogen were observed in age groups 11–20and 41–50 years, and low levels of serum pepsinogen appear to occur with greater frequency in vitamin B₁₂ deficient subjects. The significance of these findings in relation to the prevalence of pernicious anaemia is discussed.

“…Haemoglobin was estimated by the cyanmethaemoglobin method using a photoe lectric colorimeter [9]. Serum vitamin B12 using Euglena gracilis Z strain [10] and UBBC using 57Co B12 (specific activity 1 /xCilfig) [11] were estimated. TBBC was calculated therefrom.…”

Section: Methodsmentioning

confidence: 99%

Serum B<sub>12</sub> Binders in Vitamin B<sub>12</sub> Deficiency

Saraya¹,

Chopra²

1973

In 74 adults with serum B₁₂ Z. 140 pg/ml with or without anaemia, unsaturated B₁₂-binding capacity (UBBC), total B₁₂-binding capacity and transcobalamin I and II (TC I, TC II) were determined using ⁵⁷Co B₁₂. The results were statistically analysed in relatíon to severity of anaemia and vitamin B₁₂ deficiency. In severe vitamin B₁₂ deficiency, TC II was reduced and contributed to the reduction of UBBC. Greater unsaturation and moderate increase in total TC I were also seen. It is suggested that anaemia is a contributory factor in the moderate increase of TCI. On the basis of limited evidence presently available, it is argued that abnormal intestinal structure and function associ; ciency may result in impaired synthesis of TC II.