Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is likely that leukemia results, at least in part, from mutations that lead to a block in the normal process of differentiation. A defined region of the cytoplasmic domain of the granulocyte colony-stimulating factor receptor (G-CSF-R) transmits signals for maturation or differentiation of myeloid progenitor cells. Mutations in this region have been found in some patients with severe congenital neutropenia (SCN) who subsequently evolved to acute myeloid leukemia (AML). To determine if mutations of the G-CSF-R are more widespread in hematological malignancies, we have investigated a total of 47 patients, including 29 patients with blast crisis of chronic myeloid leukemia (CML-BC) and 18 patients with de novo acute leukemia as well as 19 normal controls, by RT-PCR and SSCP analysis. Two point mutations were found in a single individual with secondary AML (FAB type M1). The first was heterozygous and is predicted to replace the normal glutamine at position 718 with a stop codon, leading to a truncated protein. An identical mutation has been described previously and shown to act in a dominant negative manner. The second mutation was homozygous and would substitute a lysine for the normal glutamic acid at position 785. No mutations were found in any other patient or control samples. We conclude that mutations in the cytoplasmic domain of the G-CSF-R are infrequent in CML-BC or acute leukemia but may contribute to malignant transformation in some cases.
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PMID:Rarity of dominant-negative mutations of the G-CSF receptor in patients with blast crisis of chronic myeloid leukemia or de novo acute leukemia. 920 82

Nepsilon-(Carboxymethyl)lysine (CML) is a stable chemical modification of proteins formed from both carbohydrates and lipids during autoxidation reactions. We hypothesized that carboxymethyl lipids such as (carboxymethyl)phosphatidylethanolamine (carboxymethyl-PE) would also be formed in these reactions, and we therefore developed a gas chromatography-mass spectrometry assay for quantification of carboxymethylethanolamine (CME) following hydrolysis of phospholipids. In vitro, CME was formed during glycation of dioleoyl-PE under air and from linoleoylpalmitoyl-PE, but not from dioleoyl-PE, in the absence of glucose. In vivo, CME was detected in lipid extracts of red blood cell membranes, approximately 0.14 mmol of CME/mol of ethanolamine, from control and diabetic subjects, (n = 22, p >> 0.5). Levels of CML in erythrocyte membrane proteins were approximately 0.2 mmol/mol of lysine for both control and diabetic subjects (p >> 0.5). For this group of diabetic subjects there was no indication of increased oxidative modification of either lipid or protein components of red cell membranes. CME was also detected in fasting urine at 2-3 nmol/mg of creatinine in control and diabetic subjects (p = 0.085). CME inhibited detection of advanced glycation end product (AGE)-modified protein in a competitive enzyme-linked immunosorbent assay using an anti-AGE antibody previously shown to recognize CML, suggesting that carboxymethyl-PE may be a component of AGE lipids detected in AGE low density lipoprotein. Measurement of levels of CME in blood, tissues, and urine should be useful for assessing oxidative damage to membrane lipids during aging and in disease.
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PMID:Carboxymethylethanolamine, a biomarker of phospholipid modification during the maillard reaction in vivo. 921 92

Advanced glycation end products (AGEs) such as pentosidine and N epsilon-(carboxymethyl)lysine (CML) have been traditionally quantified by HPLC or gas chromatography--mass spectrometry (GC/MS). Enzyme-linked immunosorbent assays (ELISA) have been introduced as a convenient alternative to simplify the detection and measurement of AGEs in proteins and tissues, but some of these studies are limited by the lack of information on the structure of the epitopes recognized by antibodies to AGE-proteins. In this work we demonstrate that an antibody used in a previous study, reporting increased levels of AGEs in patients with diabetes or on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD), recognizes CML as its major epitope. We also show that there is a significant correlation between the concentration of AGEs in serum measured by ELISA and a GC/MS assay for CML in serum proteins. Both analyses yielded comparable results, with patients on CAPD and HD having about threefold higher AGE- or CML-concentrations in their serum. Our data suggest that ELISA assays for CML should be useful for the clinical measurement of AGEs in serum proteins.
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PMID:Technical note. The serum concentration of the advanced glycation end-product N epsilon-(carboxymethyl)lysine is increased in uremia. 932 46

Advanced glycation end products (AGEs) include a variety of protein adducts whose accumulation alters the structure and function of tissue proteins and stimulates cellular responses. They have been implicated in tissue damage associated with diabetic complications. To assess the possible link between AGE accumulation and the development of diabetic nephropathy (DN), we have examined the immunohistochemical localization of various AGE structures postulated to date, i.e., pentosidine, Nepsilon-(carboxymethyl)lysine (CML), and pyrraline, in diabetic and control kidneys. CML and pentosidine accumulate in the expanded mesangial matrix and thickened glomerular capillary walls of early DN and in nodular lesions and arterial walls of advanced DN, but were absent in control kidneys. By contrast, pyrraline was not found within diabetic glomeruli but was detected in the interstitial connective tissue of both normal and diabetic kidneys. Although the distribution of pyrraline was topographically identical to type III collagen, distribution of pentosidine and CML was not specific for collagen type, suggesting that difference in matrix protein composition per se could not explain heterogeneous AGE localization. Since oxidation is linked closely to the formation of pentosidine and CML, we also immunostained malondialdehyde (MDA), a lipid peroxidation product whose formation is accelerated by oxidative stress, assuming that local oxidative stress may serve as a mechanism of pentosidine and CML accumulation. Consistent with our assumption, diabetic nodular lesions were stained positive for MDA. These findings show that AGE localization in DN varies according to AGE structure, and suggest that the colocalization of markers of glycoxidation (pentosidine and CML) with a marker of lipid peroxidation reflects a local oxidative stress in association with the pathogenesis of diabetic glomerular lesions. Thus, glycoxidation markers may serve as useful biomarkers of oxidative damage in DN.
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PMID:Immunohistochemical colocalization of glycoxidation products and lipid peroxidation products in diabetic renal glomerular lesions. Implication for glycoxidative stress in the pathogenesis of diabetic nephropathy. 939 45

Glycation and subsequent Maillard or browning reactions of glycated proteins, leading to the formation of advanced glycation end products (AGEs), are involved in the chemical modification of proteins during normal aging and have been implicated in the pathogenesis of diabetic complications. Oxidative conditions accelerate the browning of proteins by glucose, and AGE proteins also induce oxidative stress responses in cells bearing AGE receptors. These observations have led to the hypothesis that glycation-induced pathology results from a cycle of oxidative stress, increased chemical modification of proteins via the Maillard reaction, and further AGE-dependent oxidative stress. Here we show that the preparation of AGE-collagen by incubation with glucose under oxidative conditions in vitro leads not only to glycation and formation of the glycoxidation product Nepsilon-(carboxymethyl)lysine (CML), but also to the formation of amino acid oxidation products on protein, including m-tyrosine, dityrosine, dopa, and valine and leucine hydroperoxides. The formation of both CML and amino acid oxidation products was prevented by anaerobic, anti-oxidative conditions. Amino acid oxidation products were also formed when glycated collagen, prepared under anti-oxidative conditions, was allowed to incubate under aerobic conditions that led to the formation of CML. These experiments demonstrate that amino acid oxidation products are formed in proteins during glycoxidation reactions and suggest that reactive oxygen species formed by redox cycling of dopa or by the metal-catalysed decomposition of amino acid hydroperoxides, rather than by redox activity or reactive oxygen production by AGEs on protein, might contribute to the induction of oxidative stress by AGE proteins.
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PMID:Presence of dopa and amino acid hydroperoxides in proteins modified with advanced glycation end products (AGEs): amino acid oxidation products as a possible source of oxidative stress induced by AGE proteins. 946 15

Nepsilon-(carboxymethyl)lysine (CML) is known to be formed by oxidative cleavage of Amadori products between C-2 and C-3 of the carbohydrate chain. We report here that CML formation from Amadori compounds is highly accelerated under alkaline conditions. Incubation of glycated human serum albumin (HSA) in 0.1 N NaOH led to the formation of CML whereas glycated HSA reduced by NaCNBH3 or non-glycated HSA did not generate CML. Nalpha-t-butyloxycarbonyl-Nepsilon-fructoselysine (Boc-FL), a model compound of Amadori product, was converted to CML under alkaline conditions. CML level of human sera (n=224) preincubated with 0.1 N NaOH correlated well with glycated albumin value (r=0.912) and hemoglobin A1c (r=0.797).
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PMID:Conversion of Amadori product of Maillard reaction to Nepsilon-(carboxymethyl)lysine in alkaline condition. 955 79

Cardiovascular disease is one of the most common complications of dialysis and renal transplant patients, and high levels of AGE are present in end-stage renal failure. To address the potential involvement of AGE and growth factors in the pathophysiology of cardiovascular complications, we performed immunostaining using cardiac tissues from autopsy cases of patients on maintenance dialysis (10 cases), long-term surviving renal transplant patients with functioning grafts (8 cases), control subjects with normal renal function (7 cases) and non diabetic subjects with mild renal insufficiency (8 cases). We used two types of AGE-antibodies, 6D12 [monoclonal anti-AGE antibody, recognizing N epsilon-(carboxymethyl) lysine(CML)-modified AGE] (oxidative AGE) and non-CML-PA [polyclonal, not recognizing CML], and antibodies against PDGFs, PDGF receptors and TGF beta. Positive 6D12 staining was observed in the coronary arterial walls and in macrophages. The accumulation of 6D12-reactive AGE in the coronary arterial walls of maintenance dialysis patients was significantly greater than that of control subjects (p < 0.05). Renal transplantation significantly reduced this accumulation (p < 0.05). On the other hand non-CML-PA mainly detected AGE in intracardiac arterioles and neural tissues. There was little difference in the accumulation of non-CML-AGE among the four groups. PDGFs and PDGF receptors were mainly detected in vascular endothelial cells and infiltrating cells of cardiac tissues of renal transplant patients, but not of maintenance dialysis patients. TGF beta was not detected in cardiovascular tissue of transplant patients. Our results indicated that the accumulation of oxidative AGE (CML-AGE) in the cardiac vascular tissue is one of the factors for cardiovascular complications of maintenance dialysis patients, and also that renal transplantation has a reducing effect on CML-AGE accumulation. PDGFs may be involved in the cardiovascular complications after renal transplantation.
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PMID:Immunohistochemical study of human advanced glycation end-products (AGE) and growth factors in cardiac tissues of patients on maintenance dialysis and with kidney transplantation. 961 88

The formation of advanced glycation end products (AGEs) is associated with pathophysiological changes with aging and disease processes. In the neurodegeneration in Alzheimer's disease and other neurodegenerative diseases. AGEs are speculated to play a role in their pathogenesis. We provide the first evidence for the induction of AGEs in cultured neuronal cells. Glyoxal and 3-deoxyglucosone (3-DG), AGE precursors, induced N epsilon-(carboxymethyl) lysine (CML), a well characterized and major AGE structure, in cultured rat sensory neurons in a time- and dose-dependent manner. CML formation was prevented by addition of aminoguanidine, an inhibitor of AGE formation. This culture system provides a useful model to analyze the role of the glycoxidation reaction in neuronal aging and neurodegenerative disorder.
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PMID:Accelerated formation of N epsilon-(carboxymethyl) lysine, an advanced glycation end product, by glyoxal and 3-deoxyglucosone in cultured rat sensory neurons. 967 92

Increases in extracellular matrix (ECM) and changes in its components have been documented in the glomeruli of diabetic nephropathy. Advanced glycation end products formed by glycoxidation have been shown to induce the synthesis of ECM components and transforming growth factor beta (TGF-beta), suggesting that advanced glycation end products may be involved in the etiology of imbalance of ECM components in diabetic glomerulosclerosis. The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an inbred strain that spontaneously develops non-insulin-dependent diabetes mellitus which progresses to diabetic glomerulosclerosis. Nepsilon-(carboxymethyl)lysine (CML) is known to be formed by glycoxidation. To clarify the involvement of glycoxidation in diabetic nephropathy, we examined the localization of CML, ECM components, and TGF-beta1 in the glomeruli of OLETF rats. The amounts of alpha3(IV) collagen, type VI collagen, and fibronectin were significantly increased in the glomeruli of OLETF rats, whereas the heparan sulfate proteoglycan levels were decreased. After 6 months of age, CML levels were significantly increased in the mesangial area of the glomeruli in these animals. The overexpression of TGF-beta1 preceded the increase in glomerular ECM components. The present study demonstrated that the accumulation of CML precedes the changes of glomerular ECM components in the glomeruli during the course of diabetic nephropathy, suggesting that glycoxidation may be one of the major causes of diabetic glomerulosclerosis.
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PMID:Accumulation of Nsigma-(carboxy-methyl)lysine and changes in glomerular extracellular matrix components in Otsuka Long-Evans Tokushima fatty rat: a model of spontaneous NIDDM. 968 63

The recent identification of age-related accumulation of advanced glycation end-products (AGE) of the Maillard reaction in neurons and vessels of the human brain suggests the involvement of AGE in the aging process. A variety of inclusions such as lipofuscin granules, corpora amylacea, Hirano bodies, granulovacuolar degenerations and ubiquitin-positive granular structures are found in the aged human brain. These age-related inclusions contain insoluble and non-degradable proteins. Advanced glycation end-product-modified proteins are also known to be insoluble and protease resistant. The similarity between proteins in such inclusions and AGE-modified proteins suggests the presence of AGE in inclusions. To investigate this possibility, the presence of two known AGE structures, N epsilon(carboxymethyl)lysine (CML) and pentosidine, was examined in age-related inclusions. Immunohistochemical examination of the medial temporal area of brain tissues obtained at autopsy from seven non-demented elderly individuals demonstrated positive reactions in lipofuscin granules and corpora amylacea but not in other inclusions for anti-CML and anti-pentosidine antibodies. As CML and pentosidine are glycoxidation products among AGE, the results suggest that glycation and/or oxidation may be involved in the formation of lipofuscin granules and corpora amylacea.
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PMID:Localization of identified advanced glycation end-product structures, N epsilon(carboxymethyl)lysine and pentosidine, in age-related inclusions in human brains. 973 3


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