Assessment of a simple electrophoretic method for measuring HbA1

Read, Ann; Tibi, Laila; Smith, A. F.

doi:10.1016/0009-8981(80)90359-9

Cited by 33 publications

(9 citation statements)

References 5 publications

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“…Menard et al 98 found a very high correlation (r = 0·98) with a standardised minicolumn system. These good results were confirmed by several other studies.…”

Section: Electrophoresismentioning

confidence: 94%

Glycosylated Haemoglobins: Biochemical Evaluation and Clinical Utility

Miedema¹,

Casparie²

1984

Ann Clin Biochem

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SUMMARY. A review is given of the biochemical background of the glycosylated haemoglobins, their methods of determination, and their clinical significance. Special attention is paid to the sample preparation. For all methods except the colorimetric TBA-method, the removal of the labile pre-HbA1c fraction is essential. Under proper conditions, high-performance liquid chromatography, agar-gel electrophoresis and affinity chromatography are suitable methods for use in the clinical laboratory for the estimation of HbA 1c and HbA 1. However, the colorimetric TBA-method must be considered to be the method of choice. The clinical utility of the test is stressed with special respect to the management of diabetic pregnancies, the control of home-monitoring of blood glucose, and the objective measurement of the effect of changing diabetic therapy.Despite increasing understanding of the pathogenesis and therapy of diabetes mellitus, the most important question concerning the relationship between the degree of metabolic control and the occurrence of long-term complications of diabetes is still not answered. The lack of satisfactory methods for the quantitative assessment of diabetic control was one of the main reasons for the difficulty in resolving this problem.Nowadays, the measurement of glycosylated haemoglobin (HbA 1c, HbA 1 ) is becoming widely accepted as an objective and quantitative index of blood glucose levels during the preceding six to ten weeks. This review discusses the structure and biosynthesis of glycosylated haemoglobins, the methods available for their measurement, and the clinical usefulness of measuring glycosylated haemoglobin.Structure and biosynthesis HISTORY Heterogeneity of human haemoglobins has been reported by several investigators. Schroeder and his colleagues,1-3 using column chromatography on weak-cation exchange resins, isolated several minor fractions from adult red cell haemolysates. These minor fractions elute before the main component HbA o (nomenclature according to Huisman and Dozy") and are therefore called 'fast' haemoglobins, At least three different fractions, HbA 1a, HbA l b and 2 HbA1c, were identified. These findings were confirmed by Huisman et al.,45 who already in 1962 reported an increase in the fast-moving Hb in four diabetic patients who had been treated with tolbutamide. This increase was attributed to the reaction of tolbutamide to HbAo.The finding of the 'diabetic haemoglobin components' was reported by Rahbar," who found in both agar and cellulose acetate electrophoresis a , negatively charged haemoglobin band in blood samples of several patients with diabetes mellitus. Soon it was demonstrated that the diabetic component had a chromatographic characteristic similar to that of HbA\c, theminor Hbcomponent previously described by Schnek and Schroeder." Structural studies later established that the diabetic haemoglobin was indeed identical with HbA\c. 7 BIOCHEMISTRYIn human adults, more than 90 % of haemoglobin is HbAo, a tetrameric molecule, composed of two pairs ...

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“…Menard et al 98 found a very high correlation (r = 0·98) with a standardised minicolumn system. These good results were confirmed by several other studies.…”

Section: Electrophoresismentioning

confidence: 94%

Glycosylated Haemoglobins: Biochemical Evaluation and Clinical Utility

Miedema¹,

Casparie²

1984

Ann Clin Biochem

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“…The band intensity of immunoblot was determined four times by the method of Goochee et al (14) using a densitometer, Photoscan system P-1000 HS (Optronics International, Inc., Chelmsford, MA), combined with Image software for densitometry running on a Macintosh II computer. Levels of HgA x in diabetic children were measured according to a previously reported method (15). The reagents not listed in the text were the highest grades commercially available.…”

Section: Immunoblot Analysis and Other Methodsmentioning

confidence: 99%

Cytochrome P450IIE1 Is Elevated in Lymphocytes from Poorly Controlled Insulin-Dependent Diabetics^*

Song

Veech²,

Saenger³

1990

The Journal of Clinical Endocrinology & Metabolism

114

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Cytochrome P450IIE1, a member of the cytochrome P450 supergene family, was measured in peripheral lymphocytes of 14 patients with insulin-dependent diabetes mellitus who were in poor metabolic control, as evidenced by elevated hemoglobin A1 levels (mean, 11.9 +/- 2.8%; normal, less than 7.8). Only one major form (mol wt, 48,000 daltons) of cytochrome P450IIE1 was detected with a specific polyclonal antibody against P450IIE1. Levels of cytochrome P450IIE1 were very low to undetectable in human lymphocytes from seven normal subjects. However, levels of P450IIE1 were elevated in lymphocytes from patients with insulin-dependent diabetes mellitus. Elevated levels of cytochrome P450IIE1 determined by immunoblot analysis correlate positively with the levels of hemoglobin A1 (r = 0.8), a metabolic indicator in diabetic subjects. In one study subject in whom diabetic control was improved, the drop in hemoglobin A1C levels was accompanied by normalization of P450IIE1 levels.

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“…Total glycosylated haemoglobin was determined by an electrophoretic method [9] and serum fructosamine was measured by the method of Johnson et al [10] adapted for use on the Cobas Fara cen-trifugal analyser (Roche Products Ltd., Welwyn Garden City, UK). Values for the normal control subjects were: glycosylated haemoglobin 5.7-8.2%, fructosamine 1.1-1.6 mmol/1 and plasma glucose 3.2-5.3 mmol/1.…”

Section: Measurement Of Plasma Glucose Glycosylated Haemoglobin and mentioning

confidence: 99%

Impairment of monocyte ?lectin-like? receptor activity in Type 1 (insulin-dependent) diabetic patients

et al. 1987

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Summary. In order to investigate whether the ability of peripheral blood monocytes to bind bacteria is impaired in diabetes, we studied carbohydrate-binding ("lectin-like") receptors and the receptor for the Fc portion of immunoglobulin on monocytes from 25 male Type 1 (insulin-dependent) diabetic patients and 10 age-matched healthy control subjects. Peripheral blood monocytes from the diabetic patients expressed lower levels of "lectin-like" receptors compared to the control subjects, whereas the expression of the receptor for the Fc portion of immunoglobulin was similar in both populations. There was no correlation between the degree of "lectin-like" binding activity and plasma glucose concentration or glycaemic control. Recognition of unopsonized bacteria by the "lectin-like" receptor is impaired in Type I diabetes; this may affect the efficient elimination of potential pathogens.Key words: Diabetes, monocytes, "lectin-like" receptors, bacterial recognition.The mechanisms responsible for the immune dysfunction and increased susceptibility to infection [1, 2] seen in patients with diabetes mellitus are not yet understood. Studies with alloxan-induced diabetes in mice suggest that macrophage cell-surface receptors and function are altered in the diabetic state [3]. These cells perform critical and diverse functions in the induction, regulation and amplification of the immune response [4]. Their activity is controlled by recognition events at the cell surface. Identified receptor sites on macrophage cell membranes include receptors for the Fc portion of immunoglobulin (Fc), complement components, carbohydrates and various lymphokines. The alteration in the expression of these cell surface molecules may drastically affect cellular activity and function.A carbohydrate binding receptor that recognises various bacterial species by their cell wall sugars has been described [5]. This "lectin-like" receptor is blocked by simple sugars such as D-glucose and D-galactose [6], and is associated with the major histocompatibility antigens that are involved in the inductive phase of the immune response [7].In this study we report on the expression of "lectinlike" and Fc receptors on monocytes from Type i diabetic patients, and relate this to the level of plasma glucose, fructosamine and glycosylated haemoglobin. Materials and methods Preparations of monocyte monolayersPeripheral blood was obtained from 25 male Type 1 diabetic patients, age 30.2_ 1.0 years (mean + SEM), mean duration of diabetes 10.8+1.5 years, and from 10 non-diabetic male volunteers, age 27.6 + 1.5 years. The diabetic patients received no medication other than insulin, and had no other underlying illnesses, particularly infections. Mononuclear cells were purified on Ficoll/Hypaque (density 1.077 g/ml) by the method of Boyum [8], and were resuspended in Eagle's minimum essential medium without serum to give a final concentration of 2 • 105 monocytes/ml. One millilitre of the cell suspension was layered onto 13 mm diameter (no. 1) glass coverslips in tissue cu...

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Assessment of a simple electrophoretic method for measuring HbA1

Cited by 33 publications

References 5 publications

Glycosylated Haemoglobins: Biochemical Evaluation and Clinical Utility

Glycosylated Haemoglobins: Biochemical Evaluation and Clinical Utility

Cytochrome P450IIE1 Is Elevated in Lymphocytes from Poorly Controlled Insulin-Dependent Diabetics^*

Impairment of monocyte ?lectin-like? receptor activity in Type 1 (insulin-dependent) diabetic patients

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Assessment of a simple electrophoretic method for measuring HbA1

Cited by 33 publications

References 5 publications

Glycosylated Haemoglobins: Biochemical Evaluation and Clinical Utility

Glycosylated Haemoglobins: Biochemical Evaluation and Clinical Utility

Cytochrome P450IIE1 Is Elevated in Lymphocytes from Poorly Controlled Insulin-Dependent Diabetics*

Impairment of monocyte ?lectin-like? receptor activity in Type 1 (insulin-dependent) diabetic patients

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Cytochrome P450IIE1 Is Elevated in Lymphocytes from Poorly Controlled Insulin-Dependent Diabetics^*