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Biomedical subjects

I Chanarin

Publications and source records attributed to I Chanarin.

At least 127 records · Page 7Linked to original sources
PubMed1977

Deoxyuridine suppression test: a comparison of two methods and effect of thymidine on the incorporation of 3H-deoxyuridine into DNA in human bone marrow cells.

Deoxyuridine suppression tests have been performed by two different methods of six normoblastic and eight megaloblastic marrows. A good correlation was obtained between the results by the modified and the original methods. The simplified method was found to be applicable for a clinical purpose to diagnose megaloblastosis in the marrow. Uptake of 3H-deoxyuridine into DNA and effect of various concentrations of thymidine was studied on five normoblastic and six megaloblastic marrows. In megaloblastic marrows, a greater amount of thymidine was required to obtain the same rate of suppression of 3H-deoxyuridine incorporation into DNA than in normoblastic marrows. Impairment of thymidine incorporation into DNA in megaloblastic marrows was not revealed. Therefore, lower rate of suppression of 3H-deoxyuridine by thymidine in megaloblastic marrows may be due to impairment of the incorporation of deoxyuridine before the addition of thymidine.

Anemia, Megaloblastic↗
PubMed1977

Lack of association of the development of anti-sperm antibodies and other autoantibodies as a consequence of vasectomy.

The possibility of autoantibodies--other than sperm antibodies--developing as a consequence of vasectomy has been investigated in 255 volunteers. During the first year after vasectomy no obvious increase was observed in the occurrence of any of these antibodies (rheumatoid factor, antinuclear antibodies and antibodies against smooth muscle, mitochondria, gastric parietal cell, thyroid microsomes and thyroglobulin). Ninety-nine of the patients were also examined for agglutinating and immunofluorescent antibodies to sperm to see if there was any relationship between the occurrence of anti-sperm antibodies and other autoantibodies. However, the prevalence of non-sperm autoantibodies did not differ in two nearly equal groups of patients with and without indications of autoimmune reactions to spermatozoa, respectively. Consequently the present results lend no support to the hypothesis that vasectomy could induce autoimmunity to other autoantigens than sperm-specific antigens.

Agglutinins↗
PubMed1976

Quantitation of ineffective erythropoiesis from the incorporation of [15N] delta-aminolaevulinic acid and [15N] glycine into early labelled bilirubin. I. Normal subjects.

The incorporation of [15N] glycine into early labelled bilirubin and haemoglobin haem was measured in four haematologically normal subjects, using the clearance of [14C] bilirubin to measure total bilirubin production rate. Hepatic haem turnover was calculated from the incorporation of [15N]=sigma-aminolaevulinic acid into early labelled bilirubin. From the exprimental data previously published data in normal subjects a method is derived for the quantitation of ineffective erythropoiesis which can be applied to similar studies in patients with haematological disorders.

Aged↗
PubMed1976

Quantitation of ineffective erythropoiesis from the incorporation of [15N] delta-aminolaevulinic acid and [15N] glycin into early labelled bilirubin. II. Anaemic patients.

The incorporation of [15N]delta-aminolaevulinic acid and [15N glycine into haemoglobin haem and early labelled bilirubin was measured in subjects with various haematological disorders. The clearance of [14C bilirubin was used to measure bilirubin production rate, and the magnitude of the various sources of bilirubin production and the percentage ineffective erythropoiesis were calculated. Ineffective erythropoiesis was found to be a major factor in the production of the anaemia in patients with the following disorders: megaloblastic anaemia associated with the Lesch-Nyhan syndrome, thalassaemia intermedia, sideroblastic anaemia, and the anaemia of chronic disorders. In three patients with iron-deficiency anaemia ineffective erythropoiesis was increased, but was of minor importance in the production of the anaemia, while in two patients with aplastic anaemia and one with macrocytosis of alcoholism there was no increase in ineffective erythropoiesis.

Adolescent↗
PubMed1976

Role of vitamin B12 in folate coenzyme synthesis.

Normal red cells in man were found to contain predominantly folate pentaglutamates with smaller amounts of tetra- and hexapolyglutamates. There was no change in the type of polyglutamate present in red cells from patients with vitamin B12 deficiency and primary folate deficiency. In contrast to the fall in red cell polyglutamate concentration in vitamin B12 deficiency, there was a marked fall in short-chain folates in early folate deficiency (treated non-anaemic epileptics) and a fall in both short chain and long chain polyglutamates in patients with severe folate deficiency and megaloblastic anaemia. These differences in folate distribution within cells exclude a primary failure to transport methylfolate into cells as the lesion in vitamin B12 deficiency. The failure of folate polyglutamate synthesis in ivtamin B12 deficiency arises either from a failure to provide the proper substrate for polyglutamate synthesis or to a direct requirement for vitamin B12 for polyglutamate synthesis.

Anemia, Pernicious↗
PubMed1976

HL-A groups in pernicious anaemia.

There is a significant association with HL-A3 type and pernicious anaemia. In addition there is a negative association with HL-A2. There is no association between HL-A type and the presence or absence of immunity to intrinsic factor.

Anemia, Pernicious↗
PubMed1976

Autoimmune implications of vasectomy in man.

The frequent development of sperm antibodies following vasectomy does not appear to be related to the formation of other autoantibodies. We have examined serum taken from 346 men before and 6 months after vasectomy for seven different autoantibodies. The occurrence of positive results is comparable to any normal population.

Antibody Formation↗
PubMed1975

Folate and monoamine metabolism in epilepsy.

In 27 drug-treated epileptics there was a significant fall in serum, red cell and CSF folate levels compared with 15 untreated epileptics and 22 neurological controls. The 3 folate parameters were positively correlated with each other and negatively correlated with serum phenobarbitone, diphenylhydantoin and primidone. There was also a significant elevation of CSF 5-hydroxyindoleacetic acid (5HIAA) in the drug-treated epileptics; but this was not seen until "therapeutic" serum levels of phenobarbitone and diphenylhydantoin had been achieved and was most marked in clinically intoxicated patients. Similar trends were observed in CSF homovanillic acid (HVA). CSF 5HIAA and HVA were positively correlated with each other, especially in the drug-treated patients, in whom both amine metabolites were also negatively correlated with CSF folate. A possible relationship between folate and monoamine metabolism is discussed with particular reference to the antiepileptic and toxic effects of phenobarbitone, diphenylhydantoin and primidone.

Adolescent↗
PubMed1975

Potassium changes in megaloblastic anaemia.

1. Serial measurements of serum potasssium and total-body potassium were made on eighteen patients with megaloblastic anaemia before the start of therapy and during the period of recovery. 2. In those patients who presented with an initial packed cell volume of less than 25%, a mean decrease in serum potassium of 0.4 mmol/1 occurred on average with 2.5 days of the start of therapy. This was followed by a significant increase in serum potassium during the period of recovery. There was a significant increase in total-body potassium in these patients, but this could be explained by increases in erythrocyte mass, erythrocyte potassium concentration and lean body mass.

Adolescent↗
PubMed1975

Restoration of normal red cell size after treatment in megaloblastic anaemia.

The return of the MCV to normal after treatment in megaloblastic anaemia follows a biphasic pattern. The initial more rapid decline in MCV is due to disappearance of pretreatment macrocytes from the circulation and the rate of fall is determined by their mean cell life. The second slower component is probably due to a mixture of pretreatment macrocytes and new macrocytes, the result of a young red cell population. The MCV often returned to normal most rapidly in the most severely megaloblastic patients due to a very short mean red cell life span. However, there was no significant correlation between either initial MCV or red cell count and the time after treatment for a return of a normal MCV.

Anemia, Macrocytic↗
PubMed1975

Erythraemia due to haemoglobin San Diego.

A 63-year-old man with erythraemia was found to have a high affinity haemoglobin which was subsequently identified as Hb San Diego beta 109 (G11) Val leads to Met, recently described in a Filipino family (Nute et al, 1974). The oxygen affinity of the haemolysates was increased approximately two-fold at pH values between 6.04 and 7.90. The n value was nearly normal (2.5-2.9) in the upper range of saturation (70-95% oxygenation) but was somewhat diminished (1.9-2.1) below this range. In vitro biosynthesis of globin by reticulocytes showed that there was balanced synthesis of alpha and beta chains (alpha:beta ratio = 1).

California↗
PubMed1975

Folate deficiency in the alcoholic--its relationship to clinical and haematological abnormalities, liver disease and folate stores.

Clinical and laboratory observations were made on 84 patients regularly taking more than 80 g of alcohol daily. Macrocytosis was present in 84.5%, but only 13% were anaemic. Twenty-seven of the 57 bone marrows sampled were abnormal, 20 showing megaloblastic changes, mostly mild in degree. Serum, red cell, and liver folate levels were reduced in 28%, 35% and 31% of patients respectively. Liver folate concentration showed good correlation with serum and red cell folates. The folate deficiency was more severe in those patients, more often female, who had inadequate diets or drank wine and spirits rather than beer. The amount of alcohol consumption and extent of liver damage did not affect folate status. The findings suggest that folate deficiency is common among alcoholics in this country. More frequently, however, patients had macrocytosis, sometimes with megaloblastosis, in the absence of folate deficiency emphasizing the direct toxic effect of alcohol on the developing erythroblast.

Adult↗
PubMed1975

Morphological features in a neutral lipid storage disease.

The morphological changes in a patient with a generalized storage disease characterized by the intracellular deposition of neutral lipid are described. There is widespread accumulation of lipid in the cytoplasm of many cells and in occasional nuclei. Diagnosis may be facilitated by the recognition of clear vacuoles in the cytoplasm of granulocytes in blood films. In jejunal biopsies vacuolation of the epithelial cells may simulate the appearances of a-betalipoproteinaemia. The lipid inclusions consist largely of normal triglycerides and are free in the cytoplasm, unassociated with any organelle. The biochemical basis of the lesions is uncertain. Although there are lipoprotein abnormalities the primary defect appears to be intrinsic to the cell and may involve either a defective cytoplasmic lipase or an impaired uptake and utilization of fatty acids by mitochondria.

Adult↗