The glycation of proteins alters both their structure and function. These changes have been linked to diabetic disorders and aging. The glycation of hemoglobin is also used as a diagnostic tool; the extent of glycation being a reflection of blood glucose averaged over a two to three month period. Accurate ...

Glycation, a deleterious form of post-translational modification of macromolecules has been linked to diseases such as diabetes, cataract, Alzheimer's, dialysis related amyloidosis (DRA), atherosclerosis and Parkinson's as well as physiological aging. This review attempts to summarize the data on glycation in relation to its chemistry, role in macromolecular damage and ...

The relationship of glucose in the blood with colorectal adenoma or cancer is not clear. Fructosamine, equivalent to total serum glycated proteins, is a marker of blood glucose levels in the previous 3 weeks. We evaluated in a case-control study the association between fructosamine and colorectal adenoma, a precursor of ...

The factors responsible for variable susceptibility to diabetic nephropathy are not clear. According to the non-enzymatic glycation hypothesis, diabetes-related tissue damage occurs due to a complex mixture of toxic products, including alpha-oxoaldehydes, which are inherently toxic as well as serving as precursors for advanced glycation end-products. Protective mechanisms exist to ...

One hundred and fifty type 2 diabetes mellitus patients were investigated to determine extent of haemoglobin glycation and factors that might influence it. Factors so considered were age, sex, disease duration, and body mass index. The mean HbA(1c) was 8.0%. Ninety-six (about 64%) of the subjects had HbA(1c) > 7.2%. ...

Following the discovery of FN3K (fructosamine 3-kinase), and more recently of FN3KRP (FN3K-related protein), research in our laboratory has been focused on testing the enzymatic deglycation hypothesis and investigating the roles of FN3K and FN3KRP. Thus far, using human erythrocytes as a model system, we have obtained the following evidence ...

Studies on relationships between aspects of physique and glucose physiology generally focus on clinical glucose tolerance or on fasting glucose or insulin assays showing glycemic status at the time of testing. Little work has examined the associations between body variables and glycemic control, or average past glucose levels in regular ...

Modification of proteins by nonenzymatic glycation is one of the underlying factors contributory to the development of complications of diabetes. In general, the nature of this structural modification falls into two broad categories: nonenzymatic glycation per se, which refers to the attachment of free carbohydrate to proteins in the Amadori ...

Glycation of proteins forms fructosamines and advanced glycation endproducts. Glycation adducts may be risk markers and risk factors of disease development. We measured the concentrations of the early glycation adduct fructosyl-lysine and 12 advanced glycation endproducts by liquid chromatography with tandem mass spectrometric detection. Underivatized analytes were detected free in ...

1. The level of glycated haemoglobin (GHb) in diabetic rats was measured using a newly developed automatic high-performance liquid chromatography (HPLC) with a boronate affinity column that requires only 2.5 min per sample for analysis. 2. Levels of GHb were 2.7% in normal 7-week-old Sprague-Dawley rats. These levels increased gradually ...

Introduction: Diabetes is one of the most common endocrine diseases spreading rapidly in the world. Diabetes complications are classified to acute and chronic. Non-enzymatic glycosylation of all body proteins, such as hemoglobin, albumin is the main cause of pathogenesis in chronic complications of diabetes. As glycosylation reaction of proteins is ...

The measurement of glycated haemoglobin has become centrally important in the monitoring of glycaemic control in the patient with diabetes. A number of analytical techniques have been described to measure this important haemoglobin fraction, and the fraction measured depends on the technique used; this has resulted in laboratories reporting different ...

BACKGROUND: Glucose, an osmotic agent generally used in continuous ambulatory peritoneal dialysis (CAPD) dialysate, has a critical characteristic of forming advanced glycation endproducts (AGEs). We undertook this study to investigate whether a possible osmotic agent, trehalose, formed fewer AGEs than glucose. METHODS: Hemoglobin (Hb), a counter-protein of AGE, was incubated ...

AIMS: Glycation of insulin has been demonstrated within pancreatic beta-cells and the resulting impaired bioactivity may contribute to insulin resistance in diabetes. We used a novel radioimmunoassay to evaluate the effect of nateglinide on plasma concentrations of glycated insulin and glucose tolerance in type 2 diabetes. METHODS: Ten patients (5 ...

Determination of glyoxal and methylglyoxal levels in plasma is of great interest, since it allows us to evaluate oxidation processes occurring in glycated proteins. A method based on a simple derivatization procedure followed by gas chromatography/mass spectrometry (GC/MS) analysis has been developed. Ten diabetic patients were evaluated before and after ...

Glucose modifies the amino groups of proteins by a process of non-enzymatic glycation, leading to potentially deleterious effects on structure and function that have been implicated in the pathogenesis of diabetic complications. These changes are extremely complex and occur very slowly. We demonstrate here that hemoglobin and myoglobin are extremely ...

Advanced glycation and lipoxidation end-products (AGE/ALE) increase in tissue proteins with age and at an accelerated rate in diabetes. This Review focuses on the nature and source of AGEs/ALEs and the factors affecting their formation in tissue and plasma proteins. Lipids are identified as an important source of chemical modification ...

The Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) demonstrated conclusively that risks for complications in patients with diabetes are directly related to glycemic control, as measured by glycated hemoglobin (GHb). Many diabetes organizations worldwide now recommend GHb targets in terms of DCCT/ UKPDS ...

The course of glycation of calf skin fibrous type I collagen was monitored in vitro under physiological conditions during an 8-week incubation period in order to take into account the long half-life of this protein. The formation of glycated compounds was measured by determining fructosamine, pentosidine, and carboxymethyllysine content. The ...

It is well recognized that haemoglobin variants can be detected during the measurement of HbA1c by high-performance liquid chromatography (HPLC). A number of variants have been reported as compromising the quantification of HbA1c, a marker used in the assessment of glycaemic control in diabetes. We describe a case of haemoglobin ...

Persistent differences in blood glucose and serum glycosylated hemoglobin (HbA1C) measurements were observed in 4 human immunodeficiency virus-positive patients with diabetes mellitus, all of whom were taking drugs associated with hemolysis, which interferes with the reliability of HbA1C levels. Determination of fructosamine levels was a more accurate alternative for measuring ...

In the present study, we examined the efficacy of a dithiocarbamate-based compound, denoted as NOX-700, on diabetes-induced endothelial dysfunction and glycosylation of hemoglobin (Hb). Streptozotocin-induced diabetic rats received 3 mg/ml NOX-700 in drinking water beginning at 72 h or 4 weeks and continued to 8 weeks. Oxidative and glycooxidative stress ...

In the Maillard reaction, nonenzymatic glycation reaction reversibly produces Amadori rearrangement products which subsequently lead to the formation of irreversible advanced glycation end-product (AGE). These reactions are important in the pathogenesis of complications associated with diabetes. This study examined the antioxidant activity of rutin and related efficacy to inhibit glycation ...

BACKGROUND: Diabetic keratopathy manifests as persistent and recurrent erosions and delayed wound healing. To investigate the role of non-enzymatic glycation of proteins in the pathogenesis of diabetic keratopathy, we studied the presence of advanced glycation end products in corneas normal and diabetic donors, and the ability of human comeal epithelial ...

Decrease in cardiac contractility is a hallmark of chronic diabetes. Previously we showed that this defect results, at least in part, from a dysfunction of the type 2 ryanodine receptor calcium-release channel (RyR2). The mechanism(s) underlying RyR2 dysfunction is not fully understood. The present study was designed to determine whether ...

Quantification of the extent of glycation of human serum albumin (HSA) and of haemoglobin provides a record of average mid- and long-term blood-sugar concentrations, respectively; this is very useful for the management of diabetes. The reaction of D-glucose with propylamine affords the corresponding Schiff base, N-propylamino-D-glucoside, in the cyclic form. ...

A major function of haptoglobin (Hp) is to bind hemoglobin (Hb) to form a stable Hp-Hb complex and thereby prevent Hb-induced oxidative tissue damage. Clearance of the Hp-Hb complex can be mediated by the monocyte/macrophage scavenger receptor CD163. We recently demonstrated that diabetic individuals homozygous for the Hp 2 allele ...

This report describes a case of artifactually low glycated haemoglobin (Hb) in a patient with type II diabetes and severe hypertriglyceridaemia. The effect of hypertriglyceridaemia on glycated Hb determination using the Abbott Vision method was investigated in a series of patients with diabetes. The interference of triglycerides in glycated Hb ...

BACKGROUND: Measuring HbA1c blood levels allows us to assess average glycaemia in individuals during the preceding 6-8 weeks. There is a clear association between increasing risk of complications with higher HbA1c values and a significant risk reduction of the complications with lower HbA1c values. METHODS: The performance of South African ...

BACKGROUND: Although gastrointestinal symptoms occur frequently, there is no validated measure of gastrointestinal symptoms in patients with diabetes mellitus. AIM: To develop the Diabetes Bowel Symptom Questionnaire. METHODS: A questionnaire derived from previously validated symptom measures was compiled to assess all relevant gastrointestinal and diabetes items. Face and content validity ...

PURPOSE: To investigate the occurrence of advanced glycation end products (AGEs) formed oxidatively (pentosidine and N(epsilon)-carboxymethyl lysine [CML]) or nonoxidatively (imidazolone) in human lenses and the relation of AGEs to lens coloration, cataract type, and patients' diabetic state. SETTING: Departments of Ophthalmology and Internal Medicine III, University of Jena, Jena, ...

Increasing evidence supports a role for glycated insulin in the insulin-resistant state of type 2 diabetes. We measured 24-hour profiles of plasma glycated insulin, using a novel radioimmunoassay (RIA), to evaluate the effects of meal stimulation and intermittent fasting on circulating concentrations of plasma glycated insulin in type 2 diabetes. ...

OBJECTIVE: To identify a technique for measurement of glycated hemoglobin percentage in blood samples obtained from various species of nonhuman primates (NHPs), to determine whether these percentages varied with respect to glycemic control, and to assess whether this physiologic variable provided a suitable test for diagnosing diabetes mellitus in NHPs. ...

Nonenzymatic glycosylation (glycation) has been recognized as an important posttranslational modification underlying alterations of structure and function of extracellular proteins during aging and diabetes. Intracellular proteins may also be affected by this modification, and glycation has been suggested to contribute to aging-related impairment in skeletal muscle function. Glycation is the ...

BACKGROUND: Advanced glycation endproduct (AGE) formation is thought to contribute to aging and cataract formation in the lens. In this study, we evaluated AGE immunoreactivity in human diabetic (n=14) and nondiabetic (n=31) cataractous lenses in relation to high-molecular-weight (HMW) protein content, which is believed to contribute to the onset of ...

We investigated the possible relations of hemoglobin A1c (HbA1c) level, a parameter of blood glucose control with scores on anxiety, depression, and self-efficacy for 113 outpatients (55 men and 58 women) with type II diabetes mellitus. The relation between the HbA1c level and the self-efficacy scores as well as with ...

Current methods for measuring long-term glycemia in patients with diabetes are HbA(1c) and advanced glycation end products (AGEs), which are estimated by phenyl boronate affinity chromatography and competitive enzyme-linked immunosorbent assay, respectively. In this study, we hypothesize that the intrinsic fluorescence property of hemoglobin-AGE (Hb-AGE) may be a simple, accurate, ...

AIMS/HYPOTHESIS: Glycation of insulin, resulting in impaired bioactivity, has been shown within pancreatic beta cells. We have used a novel and specific radioimmunoassay to detect glycated insulin in plasma of Type 2 diabetic subjects. METHODS: Blood samples were collected from 102 Type 2 diabetic patients in three main categories: those ...

A woman was screened for diabetes using glycated haemoglobin (HbA1c). Vastly different results were obtained by high performance liquid chromatography (45%), immunoassay (2.9%), and affinity chromatography (4.2%) compared with the non-diabetic range of less than 6.4%. Mass spectral studies confirmed the presence a haemoglobin variant, haemoglobin Marseille-Long Island which had ...

Advanced glycation end products (AGE) are produced by a nonenzymatic reaction between glucose and proteins in the plasma of diabetic patients. Recently, AGE have been reported to promote and accelerate diabetic complications and atherosclerosis. The activity of aldose reductase (AR) is increased in diabetic patients. AGE are reported also to ...

Glycation, one of the post-translational modifications of proteins, is a nonenzymatic reaction initiated by the primary addition of a sugar aldehyde or ketone to the amino groups of proteins. In the early stage of glycation, the synthesis of intermediates leading to the formation of Amadori compounds occurs. In the late ...

The use of glycosylated haemoglobin in the assessment of diabetic control is ubiquitous. Hereditary spherocytosis is a haemolytic anaemia with shortened red blood cell lifespan, which can interfere with the methods of glycosylated haemoglobin measurement. We report a case of hereditary spherocytosis in a young man with type 1 diabetes, ...

OBJECTIVE: Discordances between HbA1c and other measures of glycemic control are common in clinical practice and remain unexplained. We developed a measure of discordance between HbA1c and fructosamine (FA) (glycosylated serum proteins) to conduct a systematic evaluation. We termed this the glycosylation gap (GG) and sought to determine its relationship ...

1. In experimental diabetes, enzymes of glucose and fatty acid metabolism are markedly altered. Persistent hyperglycaemia is a major contributor to such metabolic alterations, which lead to the pathogenesis of diabetic complications. To our knowledge, there are no available reports on the enzymes of hepatic glucose metabolism of Cassia auriculata ...

The authors used a relative new method of long term retrospective evaluation of metabolic balance in type 2 diabetes. This method was based on the variations of the glucose in the hair with the variations of HbA1c (r=+0.96; p<0.001). In this way the authors could follow up the diabetic's metabolic ...

The aim of the study was to monitor the erythrocyte deformability as one of important factors securing the appropriate tissues perfusion in healthy subjects and diabetic patients with insulin dependent diabetes mellitus. Erythrocyte deformability was determined by the method of filtration and centrifugation, and the erythrocyte filtrability was calculated as ...

OBJECTIVE: To examine the effectiveness of a diabetes centre in restoring metabolic control in patients with poorly controlled diabetes. DESIGN: Retrospective review of medical records. SETTING: Diabetes centre of a district hospital, Hong Kong. PARTICIPANTS: Patients with poorly controlled diabetes referred to a diabetes centre. MAIN OUTCOME MEASURES: Primary endpoints ...

Measurement of glycosylated proteins such as fructosamine and haemoglobin A1c (HbA1c) can be used to assess glycaemic control in canine diabetic patients. Two point-of-care analysers, designed for human diabetics, were evaluated for use in dogs. Blood samples were collected from 50 normoglycaemic dogs, 100 diabetic patients and five dogs with ...

AIMS: To establish the status of diabetes control in Asia, the Diabcare-Asia 198 study collected data from 230 diabetes centres in Bangladesh, People's Republic of China, India, Indonesia, Malaysia, Philippines, Singapore, South Korea, Sri Lanka, Taiwan, Thailand and Vietnam from March to December 1998. METHODS: Data were obtained either by ...

The intrinsic fluorescence from the human lens on excitation in the UV region, referred to as blue lens autofluorescence, increases with age or in the presence of diabetes. The present study reveals that the relative contribution of compounds responsible for the blue autofluorescence appears to be a constant with age. ...