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Biomedical subjects

D L Mollin

Publications and source records attributed to D L Mollin.

At least 37 records · Page 2Linked to original sources
PubMed1976

The serum vitamin B12 level: its assay and significance.

1. Low serum B12 levels can be measured with considerable precision by microbiological assay with the Euglena gracilis assay and B12 deficiency can be recognised with a high level of consistency by either the Euglena or L. leichmannii assays. Either method is ideally suited for the assay of large numbers of specimens. The Lactobacillus leichmanii technique requires preliminary extraction of protein and it has been suggested that this may be a source of inaccuracy. 2. The radioisotope dilution assay should be the ideal method of measuring B12 levels in small or moderate numbers of specimens for it is a simple method that can be carried out in any laboratory with suitable counting equipment. After many false starts the conditions required for accurate assay are now understood. Each of 40 to 50 radioisotopic dilution techniques that have been introduced claims to be capable of differentiating B12 deficiency from control subjects but the reported correlations between the actual levels found in the two different assays are variable and the levels may be much higher with some radioisotopic methods. 3. The subnormal serum levels which are found in pernicious anaemia with all these techniques indicate severe reduction of the liver B12 level. A low serum B12 level in other conditions has, in the absence of associated folate or iron deficiency, the same significance. If the fall in the serum B12 level is associated with folate or iron deficiency, the tissue B12 levels are usually reduced but not to the low levels found in B12 deficiency states. 4. In practice, a subnormal B12 level is a valuable pointer not only to unsuspected pernicious anaemia but also to other gastrointestinal or nutritional disorders. The significance of a fall in the B12 level can only be understood if its cause is defined by a full clinical and gastroenterological investigation. 5. Falsely low serum B12 levels are found under certain iatrogenic conditions and B12 levels may be normal in spite of cellular deficiency of B12 under the rare circumstances of pernicious anaemia being associated with chronic myeloid leukaemia or when there is deficiency of TC 2.

Anemia, Megaloblastic↗
PubMed1973

The diagnosis of iron deficiency in patients with Crohn's disease.

Red cell indices were determined and bone marrow was examined in a selected group of 21 patients with Crohn's disease who had a routine peripheral blood picture suggestive of iron deficiency. Only nine (43%) of these patients had no stainable iron stores in the marrow fragments and could be considered as being definitely iron deficient. All indirect measurements in the diagnosis of iron deficiency, except the total iron-binding capacity (TIBC), appeared likely to result in over-diagnosis. Iron-deficient erythropoiesis, without true deficiency, may be due to the inflammatory disease process and this study indicates that the examination of bone marrow aspirate is necessary for the certain diagnosis of iron deficiency in Crohn's disease.

Adolescent↗
PubMed1971

Small intestinal bacterial flora and folate status in gastrointestinal disease.

Serumfolate folate levels and the bacteriology of the small intestine were studied in 13 patients with jejunal diverticulosis, 29 patients with partial gastrectomy, and five patients with ileal disease. The mean serum folate level in the patients with partial gastrectomy (7.2 mmug/ml) was similar to that of control subjects but the mean level in the patients with jejunal diverticulosis (14.6 mmug/ml) was significantly higher than the mean level of the control group (8.0 mmug/ml). Five of the 13 patients with jejunal diverticulosis and two of the patients with partial gastrectomy had levels above the upper limit of the control group (> 16.6 mmug/ml), and five of six patients with jejunal diverticulosis studied excreted raised amounts of folate in the urine (> 13.2 mug in 24 hours). Serum folate in one of these patients with jejunal diverticulosis was identified chromatographically as 5-methyltetrahydrofolic acid. The mean serum folate level (9.0 mmug/ml) in the patients with partial gastrectomy who had Esch. coli in the jejunal aspirates was significantly higher than in those without Esch. coli present (mean 4.2 mmug/ml). It is suggested that in gastrointestinal disease jejunal bacteria may contribute to the serum folate level even though this remains in an accepted normal range. Some patients had low serum folate levels despite having a large number of Esch. coli in the jejunum. No evidence of malabsorption of folic acid was found in three such patients even though one had lactobacilli capable of consuming folate in the jejunum. No relationship was found between serum folate level and ileal bacteriology.

Adult↗
PubMed1967

Incidence and pathogenesis of megaloblastic erythropoiesis in multiple myeloma.

Intermediate megaloblastic changes occurred in six (19%) of 32 patients with multiple myeloma and trivial megaloblastic changes in a further ten (31%). Folate deficiency was the predominant cause of these changes and in at least two patients was sufficiently severe to contribute to anaemia. Folate deficiency appeared to be due to exćess folate utilization by the tumour and was related to the amount of paraprotein produced daily. Five of the 32 patients had subnormal serum B(12) levels. Reduction in the serum B(12) level was related to the reduction in the normal circulating immunoglobulins and occurred despite normal B(12) absorption. Possible explanations for this finding are discussed.

Adult↗