Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0242339 (dyslipidemia)
 13,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Atherosclerosis is remarkably increased in type 2 diabetes suggesting that mechanisms causing arterial lesion are enhanced by the metabolic disturbances of insulin resistance (IR) and diabetes. Several lines of research suggest that processes taking place in the arterial intima extracellular matrix may be part of a shared pathogenic mechanism. The intima extracellular matrix is where atherogenesis takes place. This layer contains fibrilar macromolecules like collagens, proteoglycans (PGs), hyaluronate, and extracellular multi-domain proteins. Specific interaction of lysine, arginine-rich segments of the apoB-100 lipoproteins, LDL, IDL and Lp (a), with the negatively charged glycosaminoglycans (GAGs) of PGs cause retention of the lipoproteins, one of the initiation process of atherogenesis. Such interactions cause structural modifications of the lipid and protein moieties of the lipoproteins that appear to increase their susceptibility to proteases, phospholipases and free radical-mediated processes. The association of apoB-lipoproteins, specially small and dense LDL, with intima PGs increases their uptake by macrophages and human arterial smooth muscle cells (HASMC) leading to 'foam cell' formation. In vitro, elevated levels of non-esterified fatty acids (NEFA) alter the matrix of endothelial cells basement membrane making them more permeable to macromolecules. NEFA cause changes in the expression of genes controlling the PGs composition of the PGs secreted by HASMC causing formation of a matrix with high affinity for LDL. These results lead us to speculate that an important component of the dyslipidemia of IR and type 2 diabetes, chronic high NEFA, may contribute to cellular alterations that cause changes of the arterial intima extracellular matrix. Such changes may increase the atherogenicity of the retention of apoB lipoproteins in the intima and contribute to the systemic alteration of the arterial wall frequently observed in IR and type 2 diabetes.
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PMID:The extracellular matrix on atherogenesis and diabetes-associated vascular disease. 1204 79

Asymmetric dimethylarginine (ADMA) is an emerging cardiovascular risk factor. Its increased levels have been hypothesized to be a cause of endothelial dysfunction in pathological conditions such as hypertension, dyslipidemia, renal failure, hyperglycemia, and hyperhomocysteinemia. It acts as a potent competitive inhibitor of nitric oxide synthase. Methods using ortho-phthaldialdehyde (OPA) as derivatization reagent are widely performed in HPLC determination of ADMA, but they produce derivatives whose fluorescence rapidly decreases during time. Moreover, these methods do not allow a clear separation of ADMA from its stereoisomer symmetric dimethylarginine (SDMA). Our work describes a new method to determine ADMA, SDMA, and arginine that uses, as derivatizing reagent, naphthalene-2,3-dicarboxaldehyde (NDA). Chromatograms with low background, showing a complete separation of ADMA and SDMA, are obtained. NDA derivatives are considerably more stable than the OPA derivatives. The calibration curves of ADMA and SDMA are linear within the range of 0.01-16.0 microM. Coefficients of variation are less than 1.7% for within day and less then 2.3% for day to day. Absolute mean recoveries from supplemented samples are between 100 and 104%. These characteristics make this method reliable and easily manageable for large routine analyses.
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PMID:High-performance liquid chromatographic assay of asymmetric dimethylarginine, symmetric dimethylarginine, and arginine in human plasma by derivatization with naphthalene-2,3-dicarboxaldehyde. 1278 25

Subclinical hypothyroidism (sHT) is associated with enhanced cardiovascular risk. To test the hypothesis that patients with sHT are characterized by endothelial dysfunction and impaired nitric oxide (NO) availability, in 14 patients [serum cholesterol, 218 +/- 41 mg/dl (5.6 +/- 0.9 mM)] and 28 euthyroid subjects, subdivided into groups A and B [serum cholesterol, 170 +/- 19 mg/dl (4.4 +/- 0.5 mM) and 217 +/- 21 mg/dl (5.6 +/- 0.5 mM), respectively], we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine, an endothelium-dependent vasodilator, at baseline and during infusion of N(G)-monomethyl-L-arginine (L-NMMA), a NO synthase inhibitor. Response to sodium nitroprusside and minimal forearm vascular resistances were also evaluated. In sHT patients, vasodilation to acetylcholine was reduced, compared with group B (+358 +/- 29% vs. +503 +/- 19%, P = 0.0003) and group A (663 +/- 65%, P = 0.02 vs. group B and P = 0.0002 vs. sHT). L-NMMA blunted the vasodilation to acetylcholine in groups A and B (49.1 +/- 6.3% and 42.7 +/- 5.5% maximal forearm blood flow reduction, respectively, P < 0.0001 vs. acetylcholine), whereas it was ineffective in sHT patients (12.8 +/- 2.5%). Response to sodium nitroprusside and minimal vascular resistances were similar. In sHT (n = 9) patients, 6 months of euthyroidism by levothyroxine replacement increased acetylcholine-vasodilation and restored L-NMMA inhibition. Patients with sHT are characterized by endothelial dysfunction resulting from a reduction in NO availability, an alteration partially independent of dyslipidemia and reversed by levothyroxine supplementation.
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PMID:Impaired endothelium-dependent vasodilatation in subclinical hypothyroidism: beneficial effect of levothyroxine therapy. 1291 62

In the recent HEMO study, the most common cause of death in dialyzed patients was ischemic heart disease. In Europe there are regional differences, but the mortality due to cardiovascular disease is also very high. The long-lasting controversy whether the high incidence and prevalence of atherosclerotic manifestations (particularly ischemic heart disease) may be explained by known risk factors, or non-traditional risk factors are also involved seems to be partially solved with the increasing evidence that the latter hypothesis is true. Thus, together with classic risk factors such as hypertension, dyslipidemia and diabetes, other situations such as microinflammation, increased concentration of asymmetrical dimethyl-L-arginine, disturbed phosphate metabolism and anemia may represent important risk factors for accelerated atherosclerosis in dialyzed patients.
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PMID:Atherosclerosis in dialyzed patients. 1473 9

Endothelial dysfunction is one of the earliest events in atherogenesis. A consequence of endothelial damage is a lower availability of nitric oxide (NO), the most potent endogenous vasodilator. NO inhibits platelet aggregation, smooth muscle cell proliferation and adhesion of monocytes to endothelial cells. Endothelial dysfunction is present in patients with cardiovascular disease and/or coronary risk factors, such as hypertension, dyslipidemia, diabetes, smoking or hyperhomocysteinemia. At present, soluble markers and high resolution ultrasound of the brachial artery, have provided simple tools for the study of endothelial function and the effects of several interventions. It has been demonstrated that dietary factors may induce significant changes on vascular reactivity. Nutrients, such as fish oil, antioxidants, L-arginine, folic acid and soy protein have shown an improvement in endothelial function that can mediate, at least partially, the cardioprotective effects of these substances. Attention has been focused on dietary patterns in populations with lower prevalence of cardiovascular disease. There is some evidence suggesting that Mediterranean diet characterized by high consumption of vegetables, fish, olive oil and moderate wine consumption may have a positive effect on endothelial function. These results give us evidence on the significant role of diet on endothelial function and its impact on the pathogenesis of atherosclerosis.
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PMID:Diet and endothelial function. 1545 51

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, and until recently prophylactic cranial radiotherapy (CRT) was important for achieving long-term survival. Hypothalamic-pituitary hormone insufficiency is a well-recognized consequence of CRT for childhood cancer. Another problem is increased cardiovascular risk, which has been shown in long-term survivors of other childhood cancers. In the only previously reported study on cardiovascular risk after childhood ALL, obesity and dyslipidemia were recorded in a small subgroup treated with CRT, compared with patients treated with chemotherapy. The mechanisms behind the increase in cardiovascular risk in survivors of childhood cancer are not clarified. The aim of the present study was to elucidate mechanisms of increased cardiovascular risk in former childhood ALL patients. A group of 44 ALL survivors (23 males, median age 25 yr, range 19-32 yr at the time of study) treated with CRT (median 24 Gy, 18-30 Gy) at a median age of 5 yr (1-18 yr) and chemotherapy were investigated for prevalence of GH deficiency and cardiovascular risk factors. Comparison was made with controls randomly selected from the general population and individually matched for sex, age, smoking habits, and residence. All patients and controls underwent a GHRH-arginine test, and patients with a peak GH 3.9 microg/liter or greater were further investigated with an additional insulin tolerance test. Significantly higher plasma levels of insulin (P = 0.002), blood glucose (P = 0.01), and serum levels of low-density lipoprotein cholesterol, apolipoprotein (Apo) B, triglycerides, fibrinogen, and leptin (all P <or= 0.05) were recorded among the ALL patients, compared with controls. Furthermore, the serum levels of high-density lipoprotein cholesterol (P = 0.03) and Apo A1 (P = 0.005) were significantly lower among the patients. Compared with controls, the patients had higher body mass index and waist to hip ratio, and body composition measured with dual-energy x-ray absorptiometry showed significantly higher fat mass and lower lean mass (P < 0.001). Forty of 44 ALL patients (91%) were considered GH deficient according to the insulin tolerance test and/or the GHRH-arginine test, and the rest were considered GH insufficient. In patients, peak GH during GHRH-arginine was significantly negatively correlated to total body fat mass measured with dual-energy x-ray absorptiometry (r = -0.48, P = 0.001), waist to hip ratio (r = -0.32, P = 0.03), plasma insulin (r = -0.49, P = 0.001), and leptin (r = -0.46, P = 0.002). Moreover, a significantly positive correlation was recorded with high-density lipoprotein cholesterol (r = 0.38, P = 0.012). Using Doppler echocardiography, a marked reduction in cardiac dimensions and performance (ejection fraction P < 0.001 and fractional shortening P = 0.01), compared with controls, was recorded. In conclusion, at a median 17 yr after treatment with CRT and chemotherapy in former childhood ALL patients, a significant increase in cardiovascular risk factors was recorded. We suggest that GH deficiency, induced by CRT, is a primary cause for this because strong correlations between the stimulated GH peak and several of the cardiovascular risk factors were observed.
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PMID:Growth hormone deficiency predicts cardiovascular risk in young adults treated for acute lymphoblastic leukemia in childhood. 1547 98

Experimentally, we demonstrated the beneficial effects of L-arginine on regulation of hyperglycemia and dyslipidemia in experimental diabetes, in addition to a positive anti-aggregating effect in platelets in animals and humans. Here, the effect of L-arginine on foot ulcers from diabetic patients was studied. Three groups of diabetic patients were included: 11 patients without ulcer received neither treatment and served as controls. Eleven patients with diabetic ulcer received the standard treatment, this group served as diabetic control with diabetic ulcer. Eleven remain patients with diabetic ulcer received 10 mM L-arginine subcutaneously on the site of the wound. Biopsy with punch number 5 on wound site comprising both ulcerative and contiguous undamaged skin were performed in all patients with ulcerative lesions before any treatment. Patients with intact skin had biopsy performed with punch number 5 on external malleolar region of right lower limb. Biopsies were examined by light and confocal microscopy utilizing histochemical and immunohistochemical methods. Initial and final blood samples were collected to determine glucose, triglycerides, total cholesterol, glycated hemoglobin (HbA(1c)), low (LDL), and high density lipoproteins (HDL). Significant differences (P < 0.05) were observed between initial and final serum glucose levels for treated patients, and initial serum glucose levels between treated and control patients without diabetic ulcer. Glycated hemoglobin, triglycerides, cholesterol, and lipoprotein levels showed no significant changes. Eight patients treated with L-arginine reached total wound healing and the remaining three who abandoned the study because of change of residence showed relevant improvement. Histochemistry and immunohistochemistry methods have shown vascular impairment in both patients with diabetic ulcer (prior to treatment) and control patients without diabetic ulcer. Our observations strongly support efficacy of L-arginine for successful wound healing of diabetic ulcers.
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PMID:Healing of diabetic foot ulcers in L-arginine-treated patients. 1558 68

The vascular endothelium achieved a critical place in the understanding of vascular physiology and pathophysiology, after the discovery of the production of prostacyclin by endothelial cells, followed by the recognition that substances like acetylcholine, assumed to be direct vasodilators, could only trigger dilation in the presence of an intact endothelium. The endothelium-derived relaxing factor (EDRF) behaves as an endogenous nitrovasodilator and causes vasodilatation through stimulation of guanylyl cyclase and cellular accumulation of cyclic GMP. Subsequently, it was demonstrated that the EDRF is nitric oxide (NO), produced through the metabolism of the aminoacid L-arginine by the nitric oxide synthases (NOS). Three isoforms of this enzyme were discovered and cloned: a constitutive neuronal isoform (nNOS); an inducible isoform (iNOS), ubiquitous in cells stimulated by certain cytokines; and an endothelial isoform (eNOS). The importance of the different isoforms is well demonstrated in animal models; more recently, human studies unveiled the importance of these enzymes. The endothelium produces other vasodilators besides NO and prostacyclin; furthermore, it produces several vasoconstrictors. There is a delicate balance between these factors, which can be disturbed: several well known cardiovascular aggressors, like arterial hypertension, diabetes, smoking, dyslipidemia or renal insufficiency, can alter several invasive or non-invasive tests of endothelial function. The fact that an intervention on these factors may reverse endothelial dysfunction as measured by these tests, raises hope that they may be surrogate markers of global cardiovascular risk. If correlation of these tests with clinical outcomes proves to be robust, they may become extensively used in clinical practise.
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PMID:[Vascular endothelium: the history of a recent revolution in angiology]. 1607 83

To differentiate between the effects that antiretroviral drugs have on the endothelium and the secondary effects that they have on immune function, viral load, and dyslipidemia, 6 non-human immunodeficiency virus-infected human subjects were treated with lopinavir-ritonavir for 1 month and, on the basis of forearm blood flow, the treatment's effects on endothelial cell function were measured. Surprisingly, after exposure to lopinavir-ritonavir, absolute forearm blood-flow responses to the endothelium-dependent vasodilator, acetylcholine, increased significantly (P=.03), and forearm blood flow decreased to a greater extent during specific inhibition of NO synthase by N(G)-monomethyl-L-arginine. Thus, in this small cohort of subjects, short-term treatment with lopinavir-ritonavir does not appear to directly promote endothelial cell dysfunction.
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PMID:Lopinavir-ritonavir: effects on endothelial cell function in healthy subjects. 1665 79

In recent years, increasing evidence has been provided that even minor renal dysfunction is a powerful cardiovascular risk factor that induces typical cardiovascular alterations and thus predisposes to coronary heart disease as well as to noncoronary cardiovascular problems. This first had been noted in patients with diabetes but now has been confirmed amply in patients without diabetes as well. Numerous heterogeneous abnormalities have been described in patients with early renal dysfunction (e.g., microalbuminuria, reduced estimated GFR). One final common pathway seems to be endothelial cell dysfunction. The link between albuminuria and generalized endothelial cell dysfunction (as indicated by diminished flow-mediated vasodilation, markers of endothelial cell dysfunction, sloughed off endothelial cells, and high transcapillary albumin escape rate) is unclear. In patients with early renal dysfunction, a long list of classical and nonclassical cardiovascular risk factors have been identified: Elevated asymmetric dimethyl-l-arginine concentrations, markers of microinflammation, oxidative stress, features of metabolic syndrome, abnormal adipokine concentrations, dyslipidemia, inappropriate activation of the renin-angiotensin system, and sympathetic overactivity. The mechanisms that link dysfunction of the kidney and the cardiovascular system are being sought. The most interesting unifying concept, however, is deranged fetal programming linking nephron underdosing to the increased cardiovascular risk.
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PMID:Cross-talk between the kidney and the cardiovascular system. 1682 29


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