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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The paper is devoted to a study of the role of serum glycoprotein fructosamine and serum albumin in the pathogenesis of a severe course of insulin dependent diabetes mellitus (IDDM) in children. Fructosamine was determined in 43 pediatric patients with IDDM by direct spectrophotometry using Hoffman-La-Roche kits; albumin, C-peptide and malonic aldehyde were also determined. Disorder of the mechanism of regulation of homeostasis by albumin was shown to play an important role in the pathogenesis of a severe course of IDDM in children. It could be caused by its enhanced glycosylation and a decrease in liver synthesis in some cases as a result of considerable reduction of insulin secretion. A prognostically unfavorable sign was a raised ratio of fructosamine to albumin and enhanced lipid peroxidation against a background of low insulin secretion. The determination of serum levels of fructosamine and albumin can be a valuable diagnostic criterion in examination of children with diabetes mellitus.
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PMID:[Clinical significance of the determination of serum fructosamine and albumin in children with diabetes mellitus]. 271 69

Since evidence suggests that ascorbic acid deficits may provoke certain diabetic complications, it becomes necessary to develop a diabetic animal model which, like man, is unable to synthesize this vitamin. To this end, the present study monitored the diabetogenic effects of streptozotocin (STZ, 150 mg/kg) in the male guinea pig, a species rarely used in diabetes research. Over a 3-week period, body weight and relative food intake were lower in the STZ group compared to controls. The mean daily water intake and urine volume of the STZ group after 1 week were 175 and 270% of their initial pretreatment values, respectively, while control values were unchanged. The STZ group also exhibited a persistent glycosuria throughout the study. At the end of 3 weeks, aldehyde fuchsin staining of pancreatic beta cell granules (an index of stored insulin) was 58% lower in the STZ group compared to controls. Plasma C-peptide (indicator of insulin secretion) was expressed in human equivalents (mean +/- SEM). C-peptide was reduced in the STZ group (103 +/- 65 pg/ml) compared to controls (549 +/- 96 pg/ml); however, no change in plasma glucose was observed. Plasma ascorbic acid levels also were lower for STZ animals (150 +/- 26 micrograms%) versus controls (410 +/- 28 micrograms%). This study 1) demonstrates a diabetic syndrome in the STZ-treated guinea pig based on a reduced growth rate, beta cell dysfunction, polydipsia, polyuria and glycosuria, and 2) suggests the usefulness of this diabetic model in studies of pathologic mechanisms influenced by ascorbic acid.
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PMID:Selected physical and biochemical parameters in the streptozotocin-treated guinea pig: insights into the diabetic guinea pig model. 295 57

The metabolism of 13C-labeled substrates was followed by 13C and 31P NMR in perfused liver from the streptozotocin-treated rat model of insulin-dependent diabetes. Comparison was made with perfused liver from untreated littermates, fasted either 24 or 12 h. The major routes of pyruvate metabolism were followed by a 13C NMR approach that provided for the determination of the metabolic fate of several substances simultaneously. The rate of gluconeogenesis was 2-4-fold greater and beta-hydroxybutyrate production was 50% greater in liver from the chronically diabetic rats as compared with the control groups. Large differences in the distribution of 13C label in hepatic alanine were measured between diabetic and control groups. The biosyntheses of 13C-labeled glutathione and N-carbamoylaspartate were monitored in time-resolved 13C NMR spectra of perfused liver. Assignments for the resonances of glutathione and N-carbamoylaspartate were made with the aid of 13C NMR studies of perchloric acid extracts of the freeze-clamped livers. 13C NMR spectroscopy of the perfusates provided a convenient, rapid assay of the rate of oxidation of [2-13C]ethanol, the hepatic output of [2-13C]acetaldehyde, and the accumulation of [2-13C]acetate in the perfusate. By 31P NMR spectroscopy, carbamoyl phosphate was measured in all diabetic livers and an unusual P,P'-diesterified pyrophosphate was observed in one-fourth of the diabetic livers examined. Neither of these phosphorylated metabolites was detected in control liver. Both 13C and 31P NMR were useful in defining changes in hepatic metabolism in experimental diabetes.
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PMID:13C and 31P NMR study of gluconeogenesis: utilization of 13C-labeled substrates by perfused liver from streptozotocin-diabetic and untreated rats. 303 Apr 11

The effects of ethanol, acetaldehyde, and the two novel metabolites of ethanol 2,3-butanediol and 1,2-propanediol on basal and insulin-stimulated adipocyte lipogenesis and glucose oxidation in vitro were investigated. Whereas ethanol and acetaldehyde inhibited both processes at concentrations far greater than those found in alcoholic subjects, the two diols were extremely potent inhibitors of basal and insulin-stimulated adipocyte metabolism at concentrations far below those observed in alcoholic subjects. The incorporation of labeled glucose into the fatty acid moiety and glucose oxidation were inhibited at lower concentrations (0.25 microM) than those required to inhibit the incorporation of the labeled glucose into glycerol. The diols are therefore potent inhibitors of basal and insulin-stimulated adipocyte metabolism. This effect may be relevant to the pathogenesis of insulin resistance in alcoholic subjects.
Diabetes 1988 Jul
PMID:Ethanol and its novel metabolites inhibit insulin action on adipocytes. 313 60

We have recently reported that type II diabetic subjects with macroangiopathy have a higher activity of aldehyde dehydrogenase (ALDH) in blood than those without clinical vascular disease. ALDH activity was measured as the elimination of acetaldehyde added to a blood homogenate in vitro. We have re-examined our clinical material with another assay of ALDH which uses indole-3-acetaldehyde as substrate and measures the formation of indole-3-acetic acid. A negative correlation between the half-life of acetaldehyde and the formation of indole-3-acetic acid was found in the group of subjects free from vascular disease (r = -0.55, p less than 0.01). Thus, a rapid elimination of acetaldehyde corresponded to a rapid formation of indole-3-acetic acid. No such correlation was found in subjects with macroangiopathy. These results suggest that the 2 groups, with and without clinical vascular disease, have differences in isoenzyme composition, in the kinetic properties of the enzyme, or in the non-enzymatic binding of acetaldehyde.
Diabetes Res 1987 Oct
PMID:Aldehyde dehydrogenase activity and vascular disease in type II diabetes--a comparison between 2 different assays for activity. 342 70

Human platelet membrane proteins (PMP), incubated in vitro in the presence of various concentrations of glucose, undergo nonenzymatic glycation, as evidenced by incorporation of [3-3H]glucose radioactivity into the acid-precipitable fraction. The time course of the reaction is linear for the first hours, and the rate of glycation depends on the glucose concentration in the medium: at a glucose concentration of 80 mmol/L, up to 60 nmol of glucose is bound per milligram of PMP. The ketoaminic nature of the glucose/protein linkages was demonstrated by the finding of 5-hydroxymethylfurfuraldehyde by liquid-chromatographic analysis of acid hydrolysates of PMP. We analyzed PMP from 13 subjects with type I poorly controlled diabetes and from 10 nondiabetics. Nonenzymatic glycation, evaluated as nanomoles of the aldehyde per milligram of protein, was much greater in diabetic patients than in nondiabetics: 1.58 +/- 0.70 vs 0.37 +/- 0.18 (mean +/- SD).
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PMID:Nonenzymatic glycation of human platelet membrane proteins in vitro and in vivo. 371 41

The stabilities of 14C-acetaldehyde with various hemoglobin fractions (HbA1a + b, HbA1a, and HbA0) were examined by determining amounts of adducts remaining after dialysis at 4 degrees C for various time intervals. Significant differences were found in the stabilities of adducts formed with various hemoglobin fractions. Acetaldehyde adducts formed with HbA1a + b were more stable to dialysis than adducts formed with HbA0 or HbA1c (7-8% of total adducts formed with HbA1a + b were stable to dialysis, compared with 4-5% stable adducts formed with either HbA0 or HbA1c). While only 37-57% of the trichloroacetic acid (TCA) precipitable adducts from HbA0 or HbA1c samples were stable to dialysis, 72-75% of TCA precipitable adducts from HbA1a + b were retained after dialysis. Posttranslational modification of hemoglobin by phosphorylated glycolytic intermediates appears to alter the physical properties of hemoglobin following further modification with acetaldehyde. In view of the increased amounts of glycosylated proteins found in patients with diabetes, these observations may be relevant to the pathogenesis of the sequelae of diabetes and/or alcoholism and the influence of one chronic illness on the other.
Diabetes Res 1986 Jun
PMID:Stability of acetaldehyde fractions with various hemoglobin fractions. 374 46

A chromatographic method for determining glycated hemoglobin (Hb A1c) by use of a new monodisperse cation-exchanger has been investigated. Hb A1c was separated from other "minor hemoglobins": Hb F, Hb A3 (the glutathione adduct), and the acetaldehyde adduct in alcoholics. The method was fully automated and a single column could be used for more than 1000 runs. The normal reference interval was 4.0-5.2%; the interval for diabetic outpatients was 5.6-12.4%. Within-run and the between-run CVs were less than 0.9% and 1.7%, respectively. Carbamylation in uremic patients who were undergoing hemodialysis increased the proportion of Hb A1c to 1%. Hb A1c results were compared with results from glucose tolerance tests. In our study, Hb A1c less than 5.5% excluded diabetes: subjects with Hb A1c greater than 6.2% showed diabetes. If blood sampled during fasting had been screened with determinations of glucose and Hb A1c, only 20% of referred subjects would have needed an oral glucose tolerance test for diagnosis of diabetes.
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PMID:Measurement of hemoglobin A1c by a new liquid-chromatographic assay: methodology, clinical utility, and relation to glucose tolerance evaluated. 375 6

Aldehyde dehydrogenase (ALDH) activity is increased in Type 2 diabetics with macrovascular disease, and is a critical factor determining the chlorpropamide-alcohol flush (CPAF), a phenomenon possibly related to diabetic complications. To evaluate the possible effects of chlorpropamide (CP) on ALDH activity we studied 8 Type 1 and 20 Type 2 diabetics. Blood acetaldehyde concentration after intake of CP and alcohol was higher in patients with CPAF than in those without CPAF (p less than 0.005), and in those with low basal erythrocyte ALDH activity than in those with high basal enzyme activity (p less than 0.05). Administration of CP reduced ALDH activity in 20 of 26 patients (p less than 0.05). Alcohol intake was observed to have an additional inhibitory effect on ALDH activity. Accordingly, a combination of CP and alcohol decreases the activity of erythrocyte ALDH which might explain the CPAF phenomenon. Absent correlation between CP level and reduction of ALDH activity indicates a major role for alcohol in CPAF. A therapeutic dose of CP or a small amount of alcohol might be used when a reduction of ALDH activity is considered.
Diabetes Res 1986 Sep
PMID:Effects of chlorpropamide and alcohol on aldehyde dehydrogenase activity and blood acetaldehyde concentration. 378 Jan 35

Type II diabetic subjects, 26 with symptoms and/or signs of large vessel disease (LVD group) and 26 free from clinical vascular disease (FVD group), matched for sex, age, body weight, and duration of diabetes after diagnosis, together with 28 healthy controls participated in a preliminary study on new potential risk factors of large vessel disease. The activity of erythrocyte aldehyde dehydrogenase (ALDH) was significantly higher (P less than 0.005) in the LVD than in the FVD group and in the controls, as indicated by a shorter half-life of acetaldehyde in homogenates of erythrocytes and plasma (100 +/- 11, 203 +/- 28, and 180 +/- 21 min, respectively). The results were unaffected by antidiabetes therapy, blood glucose control, alcohol consumption, or by recognized risk factors of angiopathy, such as blood pressure, hyperlipidemia, or smoking. Whether ALDH activity is a primary factor in large vessel disease or is merely a secondary phenomenon is unknown. However, ALDH activity is a critical factor determining chlorpropamide alcohol flush (CPAF), which has been suggested to be an inherited trait in some type II diabetic subjects. In conclusion, high ALDH activity was shown to be associated with an increased risk of large vessel disease in diabetes.
Diabetes 1986 Mar
PMID:Aldehyde dehydrogenase activity and large vessel disease in diabetes mellitus. A preliminary study. 394 78


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