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

Islets of Langerhans were isolated from WAGola rats and encapsulated in high mannuronic acid sodium alginate droplets. The capsules were completed in the following ways: (a) poly-l-lysine alone, (b) poly-l-lysine plus high guluronic acid alginate, (c) poly-l-lysine plus high mannuronic acid alginate. Islet viability was assessed every 3-4 days over a period of 4 weeks, by a microfluorometric assay using fluorescein diacetate and propidium iodide, and every 7 days by perifusion. The perifusion results were corrected for DNA content to take islet size differences into account. The results from the microfluorometric assay showed a generally high viability of the islets in all groups at each time interval. The perifusion experiments showed that the response time and stimulation indices of the islets was similar in all groups, but the absolute amount of insulin released was slightly lower from encapsulated islets relative to unencapsulated controls. It was concluded that the presence of a capsule, regardless of its composition, did not adversely affect the membrane integrity of the islets, their response time, nor their proportionate increase in insulin release following glucose stimulation. However, the absolute amount of insulin released from encapsulated islets was reduced during perifusion. This reduction was apparent after 1 week in culture, but remained stable thereafter.
Diabetes Res 1990 Jul
PMID:A study of the effect of capsule composition on the viability of cultured alginate/poly-l-lysine--encapsulated rat islets. 213 84

Nonenzymatic glycosylation of plasma proteins may contribute to the excess risk of developing atherosclerosis in patients with diabetes mellitus. Because high-density lipoprotein (HDL) is believed to protect against atherosclerosis and is glycosylated at increased levels in diabetic individuals, the effects of nonenzymatic glycosylation of HDL3 on binding of HDL3 to cultured fibroblasts and to the candidate HDL-receptor protein were examined. HDL3 was glycosylated in vitro with glucose alone or in combination with sodium cyanoborohydride. With this catalyst, up to 40-50% of the lysine residues could be glycosylated, resulting in a progressive drop to nearly 60% in high-affinity binding to cultured fibroblasts at 4 degrees C. Binding to the 110,000-Mr candidate HDL-receptor protein was reduced by almost 75%. At levels of HDL glycosylation equivalent to the 3-5% observed in diabetes, high-affinity binding to fibroblasts at 4 degrees C was diminished by up to 15-20%. Binding kinetic studies paradoxically suggested that glycosylated HDL3 binds with higher affinity to a reduced number of binding sites. The findings in this study suggest that nonenzymatically glycosylated HDL may be functionally abnormal and might contribute to the development of atherosclerosis in patients with diabetes mellitus.
Diabetes 1990 Oct
PMID:Nonenzymatic glycosylation of HDL resulting in inhibition of high-affinity binding to cultured human fibroblasts. 217 Feb 16

We evaluated six patients in whom a diagnosis of Sheehan's syndrome had been made. The plasma levels of the following hormones were measured: basal thyroxine (T4), estradiol and cortisol; and also follicle-stimulating hormone (FSH), luteinizing hormone (LH), growth hormone (GH), thyrotropin (TSH), prolactin (PRL) and adrenocorticotropic hormone (ACTH), basally and after acute challenge with LH releasing hormone (LHRH), GRF (1-29)NH2 or insulin hypoglycemia, TSH releasing hormone (TRH) and lysine-8-vasopressin, respectively. Two patients underwent chronic LHRH stimulation by pulsatile subcutaneous administration with infusion pump. In 4 cases, computed tomography (CT) was performed although cranial X-ray study was normal. A severe and generalized pituitary involvement was found in all patients, 3 of whom had diabetes mellitus. Probably, more insidious cases go unnoticed. The presence of asymptomatic partial empty sella (ES) in all the CTs that were carried out raises the possibility that it is another evolutive feature of SS.
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PMID:[Relations between Sheehan's syndrome and empty sella turcica. A functional study apropos of 6 cases]. 217 69

Superoxide dismutases (SOD) and their changes in diabetes, aging, ischemia and cancer were studied, Cu, Zn-SOD undergoes glycation reaction in vitro and in vivo and loses its activity by formation of Amadori compounds. Two lysine residues of Cu, Zn-SOD, Lys-122 and Lys-128 are primary glycated sites which are located on the surface of the molecule. The sites are also located on the active site liganding loop which plays a major role in the activity. The glycated Cu, Zn-SOD increased in the red cells of diabetic patients, especially those with diabetic complications. Mn-SOD appears in the serum of patients with acute myocardial infarction in a biphasic manner. The enzyme appears in sera 16 hr and 108 hr after the attack as determined by ELISA. The Mn-SOD levels are also increased in the serum of patients with epithelial ovarian cancer and it is a good marker for detecting and monitoring this cancer. Mn-SOD may play an important role in the ischemic and cancer tissues.
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PMID:[Superoxide dismutases: significances in aging, diabetes, ischemia and cancer]. 223 47

Structure elucidation of a specific fluorophore from the aging extracellular matrix revealed the presence of a protein crosslink formed through nonenzymatic glycosylation of lysine and arginine residues. The unexpected finding that a pentose instead of a hexose is involved in the crosslinking process suggested that the crosslink, named pentosidine, might provide insight into abnormalities of pentose metabolism in aging and disease. This hypothesis was investigated by quantitating pentosidine in hydrolysates of 103 human skin specimens obtained randomly at autopsy. Pentosidine level was found to increase exponentially from 5 to 75 pmol/mg collagen over lifespan (r = 0.86, P less than 0.001). A three- to tenfold increase was noted in insulin-dependent diabetic and nondiabetic subjects with severe end-stage renal disease requiring hemodialysis (P less than 0.001). Moderately elevated levels were also noted in some very old subjects, some subjects with non-insulin dependent diabetes, and two subjects with cystic fibrosis and diabetes. The cause of the abnormal pentose metabolism in these conditions is unknown but may relate to hemolysis, impaired pentose excretion, cellular stress, and accelerated breakdown of ribonucleotides. Thus, pentosidine emerges as a useful tool for assessment of previously unrecognized disorders of pentose metabolism in aging and disease. Its presence in red blood cells and plasma proteins suggests that it might be used as a measure of integrated pentosemia in analogy to glycohemoglobin for the assessment of cumulative glycemia.
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PMID:End-stage renal disease and diabetes catalyze the formation of a pentose-derived crosslink from aging human collagen. 229 12

Young adult rats were immunized with either in vitro glucosylated or unmodified rat serum albumin (RSA) followed by induction of the diabetic state. At various times after streptozotocin administration, sera were evaluated for specific antibody response using the enzyme-linked immunosorbent assay while urine was monitored for the presence of albumin by radial immunodiffusion. The data indicate that glucosylated RSA is capable of eliciting the production of antibodies, but unmodified RSA is not. The specificity of the generated antibodies appears to be directed toward the glucitol-lysine residues of the modified albumin. Preimmunization of rats with glucosylated RSA followed by induction of diabetes causes a rapid decline in specific antibody titers and greatly enhances the rate of progression to albuminuria. These results demonstrate that in vitro and in vivo glucosylation of an endogenous protein provide products with identical antigenicity. They also suggest an animal model for the study of diabetic autoimmunity involving glucosylated endogenous proteins.
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PMID:Accelerated onset of albuminuria in diabetic rats preimmunized with glucosylated rat serum albumin. 241 26

Fifty human fetal pancreases of 4-6 months gestation obtained from legal abortions were microencapsulated with alginate, poly-lysine after culture for 4-7 days. The microcapsules were studied morphologically and functionally. Immunocytochemical staining for insulin indicated B-cells were morphologically intact at 48 days. Insulin and C-peptide of the culture medium measured with radioimmuno-assay (RIA) showed that the microcapsules still retained the function of insulin secretion after culture for 25 days. There was no statistical difference when compared with noncapsulated tissues. No exocrine function was detected as evidenced by the amylase determination. We conclude that microencapsulated human fetal pancreatic tissues retain viability in culture for more than 25 days and can be used as transplants in the treatment of diabetes mellitus.
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PMID:Morphological and functional studies on microencapsulated human fetal pancreatic tissue. 248 42

Many insulin-dependent diabetic patients with albuminuria in the "not at risk range" for diabetic nephropathy present high urinary excretion rates of glycosaminoglycans. A lysine provocative test in these subjects disclosed abnormal urinary excretion of albumin, unlike findings obtained in insulin-dependent diabetic patients with normal urinary excretion rates of glycosaminoglycans. These data support the hypothesis that high urinary excretion of glycosaminoglycans is a marker of glomerular involvement in diabetes mellitus.
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PMID:High urinary excretion of glycosaminoglycans: a possible marker of glomerular involvement in diabetes. 249 11

The extent of glycation in pieces of human aorta was estimated by determining the content of furosine, which is derived from fructose-lysine through acid hydrolysis. Glycation of human aorta was found to increase with advancing age. A significant positive correlation was found between the degree of atherosclerosis and the furosine level in the aorta in subjects over 60 years of age. Furthermore, the furosine level in the aortae of diabetic patients was significantly higher than that in normal subjects of the same age. These results suggest not only that glycation in the aorta may increase with aging and with the development of arteriosclerosis, but also that diabetes may be related as well to premature aging as to arteriosclerosis.
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PMID:Age- and diabetes-accelerated glycation in the human aorta. 250 75

A radioimmunoassay for glycated serum protein (GSP) was developed using monoclonal antibody to glucitollysine and polystyrene beads coated with Coomassie-Brilliant-Blue (CBB) as adsorbent for serum protein. The monoclonal antibody was raised by immunizing BALB/c mice with reduced glycated LDL and fusing their spleen cells with mouse myeloma cells. CBB-coated polystyrene beads were introduced to absorb a constant amount of serum protein. The protein adsorbed on the CBB-coated beads was reduced by NaHB4, and after treatment with radiolabeled antibody, the radioactivity of each bead was counted with an automatic gamma-counter. The standard glycated protein used was reduced glycated human serum albumin, in which 8 of 59 lysine residues were glycated. The intra- and interassay coefficients of variation of GSP were 4.8-6.5% and 1.6-6.0%, respectively. The GSP level of diabetic patients was significantly higher than that of normal controls (1.97 +/- 1.23 vs. 0.47 +/- 0.21 nmol/mg-protein; mean +/- SD, p less than 0.001). The GSP levels of patients with insulin-dependent and non-insulin-dependent diabetes mellitus were 3.03 +/- 1.05 and 1.51 +/- 1.00 nmol/mg-protein, respectively. A good correlation was found between the levels of GSP and hemoglobin A1c (HbA1c) (r = 0.85, p less than 0.001). In patients admitted to the hospital for diabetes education and glycemic control, the GSP level decreased 43 +/- 12% with the decrease in the fasting plasma glucose level (39 +/- 13%) and the mean daily plasma glucose level (MPG, 47 +/- 15%) in a four week period after admission, whereas the HbA1c level decreased only 13 +/- 6% during this period.(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes Res 1989 May
PMID:Radioimmunoassay of glycated serum protein using monoclonal antibody to glucitollysine and coomassie-brilliant-blue-coated polystyrene beads. 251 33


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