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

Basement membrane thickening and mesangial expansion characterize the renal involvement in diabetes mellitus and precede any symptoms of renal dysfunction, e.g., albuminuria and changes in glomerular filtration rate. Since the morphological changes can only be diagnosed by biopsy, this study was designed to investigate whether the urinary excretion of renal extracellular matrix proteins might reflect the morphological alterations. To specify the extent of renal involvement in diabetes, the patients, type I as well as type II diabetics, were classified according to their urinary albumin excretion: normal albumin excretion below 30 micrograms/min, microalbuminuria from 30 to 300 micrograms/min, and overt albuminuria above 200 micrograms/min. Laminin, collagen IV, and fibronectin, all intrinsic components of the renal extracellular matrix, were determined in serum and urine by radioimmunoassay or enzyme-linked-immunosorbent-assay, respectively. The results are given as median values (mean). Additionally, the urinary fragment pattern of fibronectin was analysed qualitatively by immunoblotting. Laminin concentrations in serum and in urine did not change in diabetics. Collagen IV decreased in serum of patients with increased albumin excretion (controls: mean = 255 micrograms/l, normoalbuminuric patients: mean = 56 micrograms/l, microalbuminuric patients: mean = 52 micrograms/l, and patients with overt albuminuria: mean = 70 micrograms/l; alpha < 0.01) and increased in urine (controls, normoalbuminuric and microalbuminuric patients: not detectable, patients with overt albuminuria: mean = 5 ng/12 h; apha < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Extracellular matrix proteins as early markers in diabetic nephropathy. 762 93

Many people with diabetes mellitus have foot lesions that can lead to amputation if they do not receive excellent care. Coordinating patient care with other specialists, using new treatment technology, educating the patient, and including the patient as a significant part of the team are all required for effective patient care. The use of a new, technologically advanced product, Kollagen, is illustrated in two case studies. Collagen plays a significant part in almost every function of the body. Previously, the broad use of collagen was stifled because of cost. Recent advances have made it possible to develop cost-effective gels, powders, pouches, and thin dressings.
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PMID:Tracking the diabetic foot: adjunctive treatment with collagen material. 779 64

Collagen is one of the major components of the extracellular matrices of the kidney. Basement membrane collagen, type IV collagen, is the major component in normal glomeruli. Fibril and interstitial collagen such as type III collagen, type V collagen, and type VI collagen are minor components of glomerular extracellular matrices and are localized mainly in the interstitium. Diabetic glomerulosclerosis is characterized by the expansion of the glomerular mesangial matrix as well as by thickening of the glomerular basement membrane. In order to clarify the roles of these various types of collagen in the development of diabetic glomerulosclerosis, immunohistochemical studies were performed in kidney specimens from patients with Type 2 diabetes. Early glomerulosclerosis is characterized by expansion of mesangial matrix with basement membrane collagen. However, in later stages glomerulosclerosis is characterized by an increase in the minor collagen components, such as type V and type VI collagen or collagens not normally present, such as type III collagen. Mesangial cells are known to synthesize all these types of collagen. In diabetes, phenotypic change in mesangial cells might produce excess amounts of fibril and interstitial collagen such as type III, type V, and type VI collagen, thus, leading to glomerulosclerosis.
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PMID:Localization of fibril/microfibril and basement membrane collagens in diabetic glomerulosclerosis in type 2 diabetes. 803 31

Nonenzymatic collagen cross-linking occurs in a variety of connective tissues as a result of formation of advanced glycosylation end products. Diabetes and aging significantly increase levels of nonenzymatic collagen cross-linking in connective tissues. This study was undertaken to determine whether nonenzymatic collagen cross-linking occurs in rat cortical bone and if these levels are increased in diabetic and aged rats. Collagen-linked fluorescence, a measurement of nonenzymatic collagen cross-linking, was significantly increased in rat cortical bone with diabetes and age. In addition, incubation of bone powder with glucose resulted in a similar increase in collagen-linked fluorescence. These changes in bone collagen may contribute to alterations observed in bone with diabetes and age by influencing bone cell function and the ability of the matrix to be responsive to bone cells.
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PMID:Diabetic and age-related enhancement of collagen-linked fluorescence in cortical bones of rats. 807 86

The Maillard or browning reaction between sugar and protein contributes to the increased chemical modification and cross-linking of long-lived tissue proteins in diabetes. To evaluate the role of glycation and oxidation in these reactions, we have studied the effects of oxidative and antioxidative conditions and various types of inhibitors on the reaction of glucose with rat tail tendon collagen in phosphate buffer at physiological pH and temperature. The chemical modifications of collagen that were measured included fructoselysine, the glycoxidation products N epsilon-(carboxymethyl)lysine and pentosidine and fluorescence. Collagen cross-linking was evaluated by analysis of cyanogen bromide peptides using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by changes in collagen solubilization on treatment with pepsin or sodium dodecylsulfate. Although glycation was unaffected, formation of glycoxidation products and cross-linking of collagen were inhibited by antioxidative conditions. The kinetics of formation of glycoxidation products proceeded with a short lag phase and were independent of the amount of Amadori adduct on the protein, suggesting that autoxidative degradation of glucose was a major contributor to glycoxidation and cross-linking reactions. Chelators, sulfhydryl compounds, antioxidants, and aminoguanidine also inhibited formation of glycoxidation products, generation of fluorescence, and cross-linking of collagen without significant effect on the extent of glycation of the protein. We conclude that autoxidation of glucose or Amadori compounds on protein plays a major role in the formation of glycoxidation products and cross-liking of collagen by glucose in vitro and that chelators, sulfhydryl compounds, antioxidants, and aminoguanidine act as uncouplers of glycation from subsequent glycoxidation and cross-linking reactions.
Diabetes 1994 May
PMID:Glycation, glycoxidation, and cross-linking of collagen by glucose. Kinetics, mechanisms, and inhibition of late stages of the Maillard reaction. 816 45

An ultrastructural study of a typical case of acquired perforating dermatosis in a patient with renal failure and diabetes mellitus is reported. Crystal-like microdeposits of an electron-lucid material were detected in the upper dermis, close to the transepidermal channel. Compact macrophage conglomerations surrounded the deposits, and a strong histiocytic response was present. Mononuclear inflammatory cells of "activated" type penetrated the acanthotic epidermis provoking basement membrane dissolution and widening of interkeratinocyte spaces. Collagen fibers were seen in the keratotic plug, indicating the process of transepidermal elimination. Our observation supports the hypothesis suggesting that some kind of storage phenomenon may be at the origin of perforating skin lesions in renal failure patients.
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PMID:Acquired perforating dermatosis of diabetes mellitus and renal failure: further ultrastructural clues to its pathogenesis. 822 11

To investigate the contribution of glycation and oxidation reactions to the modification of insoluble collagen in aging and diabetes, Maillard reaction products were measured in skin collagen from 39 type 1 diabetic patients and 52 nondiabetic control subjects. Compounds studied included fructoselysine (FL), the initial glycation product, and the glycoxidation products, N epsilon-(carboxymethyl) lysine (CML) and pentosidine, formed during later Maillard reactions. Collagen-linked fluorescence was also studied. In nondiabetic subjects, glycation of collagen (FL content) increased only 33% between 20 and 85 yr of age. In contrast, CML, pentosidine and fluorescence increased five-fold, correlating strongly with age. In diabetic patients, collagen FL was increased threefold compared with nondiabetic subjects, correlating strongly with glycated hemoglobin but not with age. Collagen CML, pentosidine and fluorescence were increased up to twofold in diabetic compared with control patients: this could be explained by the increase in glycation alone, without invoking increased oxidative stress. There were strong correlations among CML, pentosidine and fluorescence in both groups, providing evidence for age-dependent chemical modification of collagen via the Maillard reaction, and acceleration of this process in diabetes. These results support the description of diabetes as a disease characterized by accelerated chemical aging of long-lived tissue proteins.
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PMID:Accumulation of Maillard reaction products in skin collagen in diabetes and aging. 851 58

Anastomotic leakage remains the most important cause of morbidity and mortality in digestive surgery. Despite the development of new surgical techniques and devices, intestinal anastomose continue to be complicated by leakage even in the best and most experienced of hands. One may explain the persistence of anastomotic leakage in spite of these technical advances on the basis of the dynamic effect that multiple factors (shock, peritoneal sepsis, inadequate intestinal preparation, advanced age, malignancy, malnutrition, coagulopathy, steroid dependence, uremia, radiation therapy, diabetes, perforation, anemia, fecal soiling and deficiency of vitamin C, iron and zinc) have on the healing of an anastomosis. Awareness of these factors and proper precautions by the surgeon can make a high-risk anastomosis less prone to leakage. Collagen is the essential material for composing an anastomosis and the basis of a good surgical suture. Recognition an correction of factors that compromise collagen synthesis, should be the goal of the surgeon. Over the years, numerous anastomotic techniques have been proposed, but the search for the ideal technical anastomosis goes on. Traditional inverting methods ignore the basic principle of accurately opposing clean-cut tissues, and temporary clamping of the gut and crushing of mucosal tissue by intraluminal sutures may damage the microcirculation. Submucosa should always be included in the formation of an anastomosis because it is the strongest intestinal layer and because the collagen has its origin and its synthesis just in submucosa. Monofilament sutures may be more desirable for anastomosis. Staple sutures have minimum tissue reaction. Single layer extramucosal technique has many of the attributes of an ideal intestinal anastomosis. Single interrupted and continuous sutures are not opposite and both give satisfactory results.
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PMID:[Sutures in digestive surgery]. 869 52

Growth hormone stimulates collagen type I synthesis. Collagen type I is a common matrix compound in a large number of connective tissues. The aim of our study was to prove whether a stimulation of collagen type I synthesis might be accompanied by a deposition of collagen type I in the skin (cutis). Twenty growth hormone-deficient hypopituitary patients were included in a randomised, double-blind, placebo controlled, prospective, twelve-month study (eighteen patients assessable at the end of the study). The patients were treated with recombinant human growth hormone 0.25 U/kg/week subdivided in daily subcutaneous injections beginning with half the dosage during the first four weeks. During the first six months half of the patients were treated with placebo. PICP, the indicator of collagen type I synthesis, was increased after six months of therapy when compared to placebo. Skin thickness measured by ultrasound at the forearm and mechanically at the dorsum of the hand with strong compression of the skin both increased significantly following growth hormone substitution. Our data indicate that the stimulation of collagen type I synthesis by growth hormone substitution is followed by a deposition of collagen type I in the skin.
Exp Clin Endocrinol Diabetes 1996
PMID:Growth hormone substitution in growth hormone-deficient adults: effects on collagen type I synthesis and skin thickness. 888 50

Two cases of acquired reactive perforating collagenosis with poorly controlled diabetes mellitus were studied by histochemistry and by electron microscopy. In excoriated wound the necrotic mass on the bottom of the ulcer contained the collagen bundles which were continuous with the collagen bundles in the reticular layer. In the developing stage, the epidermis regenerated between the necrotic mass and the reticular dermis, and the collagen bundles in the reticular dermis were in continuity with those in the necrotic mass through the epithelial tunnels. The collagen in the epidermal channels did not degenerate ultrastructurally. In the mature lesion, collagen bundles being eliminated through the epidermis were surrounded by the fibroblasts at the basal cell layer. Collagen fibers were seen in the cytoplasm of these fibroblasts. From these findings, the mechanisms of the formation of the eruption in acquired reactive perforating collagenosis might be as follow: 1) In the developing stage, the regeneration of epidermis progresses between the necrotic mass and the reticular dermis, and among the collagen bundles. As a result, the collagen bundles remain in the channels of the epidermis. And then, 2) the regenerated epidermis makes the thick horny layer. As a result, the necrotic masses are lifted up and the collagen bundles are pulled up from the dermis through the epidermal channels.
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PMID:The pathogenesis of the transepithelial elimination of the collagen bundles in acquired reactive perforating collagenosis. A light and electron microscopical study. 891 48


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