Rafael Noal Moresco

A simple and inexpensive automated technique for measurement of serum nitrite/nitrate

OBJECTIVE We described an automated technique for measurement of serum nitrite/nitrate (NO(x)) using the Cobas Mira clinical chemistry analyzer. DESIGN AND METHODS NO(x) was measured by the modified Griess method. Precision, accuracy, linearity, instrument carry-over and lower limit of quantitation (LLOQ) were assessed. RESULTS The automated technique for measurement of serum NO(x) was linear, precise, and accurate. It has a LLOQ of 2.0 μmol/L. CONCLUSION Serum NO(x) measured by the modified Griess method can be applied easily to the Cobas Mira clinical chemistry analyzer.

Association between ischemia-modified albumin, lipids and inflammation biomarkers in patients with hypercholesterolemia.

OBJECTIVES The aim of this study was to evaluate the association between ischemia-modified albumin (IMA), lipids and inflammation biomarkers in patients with hypercholesterolemia, and the possible involvement of IMA in atheromatous plaque development and oxidative stress. DESIGN AND METHODS Glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, oxidized LDL (ox-LDL), ox-LDL autoantibodies, high-sensitivity C reactive protein (hs-CRP), and IMA were measured in 37 subjects with hypercholesterolemia and 37 controls. RESULTS Total cholesterol, LDL cholesterol, triglycerides, ox-LDL, ox-LDL autoantibodies, hs-CRP, and IMA were higher in the hypercholesterolemia group, and HDL cholesterol levels were lower in this group. We observed significant correlations between IMA and total cholesterol, LDL cholesterol, ox-LDL antibodies, and hs-CRP levels. Significant correlations were also observed between hs-CRP and total cholesterol, HDL cholesterol, LDL cholesterol, ox-LDL, ox-LDL autoantibodies, and triglycerides. CONCLUSIONS Hypercholesterolemia is associated with an increase in inflammatory and oxidative stress biomarkers, and it also reduces the capacity of albumin to bind cobalt owing to ischemia, resulting in an increased IMA. IMA formation appears to be associated with oxidative stress and atheromatous plaque development.

Associations among Metabolic Syndrome, Ischemia, Inflammatory, Oxidatives, and Lipids Biomarkers

CONTEXT Metabolic syndrome (MS) is described as a cluster of cardiometabolic risk factors. Studies suggest that ischemia-modified albumin (IMA) is a biomarker of cardiovascular diseases. IMA levels could be associated with cardiometabolic risks and represent a possible indication of microvascular dysfunction in MS patients. OBJECTIVE To confirm this possible association, we evaluated the association between IMA levels and MS. DESIGN We performed a case-control study (32 healthy individuals and 74 subjects with MS) to evaluate the association between MS, IMA, and other biomarkers [high-sensitivity C-reactive protein (hs-CRP), oxidized low-density lipoprotein (OxLDL), oxidized low-density lipoprotein autoantibodies (anti-OxLDL), IL-6, lipid profile, and glucose]. RESULTS The MS group showed higher levels of IMA (0.618 +/- 0.1355) as well as higher levels of hs-CRP, OxLDL, anti-OxLDL, and IL-6 than did control subjects (IMA = 0.338 +/- 0.0486) (P < 0.01). Multivariate analysis showed that IMA and MS association was independent of sex, age, diabetes mellitus 2, and hypercholesterolemia. CONCLUSION We found an association between IMA and MS. Additional studies including prospective genetic variation approaches need to be performed to help elucidate this association between IMA and MS and its potential clinical role.

Syzygium cumini inhibits adenosine deaminase activity and reduces glucose levels in hyperglycemic patients

Syzigium cumini (L.) Skeels from the Myrtaceae family is among the most common medicinal plants used to treat diabetes in Brazil. Leaves, fruits, and barks of S. cumini have been used for their hypoglycemic activity. Adenosine deaminase (ADA) is an important enzyme that plays a relevant role in purine and DNA metabolism, immune responses, and peptidase activity. ADA is suggested to be an important enzyme for modulating the bioactivity of insulin, but its clinical significance in diabetes mellitus (DM) has not yet been proven. In this study, we examined the effect of aqueous leaf extracts of S. cumini (L.) (ASC) on ADA activity of hyperglycemic subjects and the activity of total ADA, and its isoenzymes in serum and erythrocytes. The present study indicates that: (i) the ADA activity in hyperglycemic serum was higher than normoglycemic serum and ADA activity was higher when the blood glucose level was more elevated; (ii) ASC (60–1000 μg/mL) in vitro caused a concentration‐dependent inhibition of total ADA activity and a decrease in the blood glucose level in serum; (iii) ADA1 and 2 were reduced both in erythrocytes and in hyperglycemic serum. These results suggest that the decrease of ADA activity provoked by ASC may contribute to control adenosine levels and the antioxidant defense system of red cells and could be related to the complex ADA/DPP‐IV‐CD26 and the properties of dipeptidyl peptidase IV (DPP‐IV) inhibitors which serve as important regulators of blood glucose.

Diabetic nephropathy: Traditional to proteomic markers

Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes and it is defined as a rise in the urinary albumin excretion (UAE) rate and abnormal renal function. Currently, changes in albuminuria are considered a hallmark of onset or progression of DN. However, some patients with diabetes have advanced renal pathological changes and progressive kidney function decline even if urinary albumin levels are in the normal range, indicating that albuminuria is not the perfect marker for the early detection of DN. The present article provides an overview of the literature reporting some relevant biomarkers that have been found to be associated with DN and that potentially may be used to predict the onset and/or monitor the progression of nephropathy. In particular, biomarkers of renal damage, inflammation, and oxidative stress may be useful tools for detection at an early stage or prediction of DN. Proteomic-based biomarker discovery represents a novel strategy to improve diagnosis, prognosis and treatment of DN; however, proteomics-based approaches are not yet available in most of the clinical chemistry laboratories. The use of a panel with a combination of biomarkers instead of urinary albumin alone seems to be an interesting approach for early detection of DN, including markers of glomerular damage (e.g., albumin), tubular damage (e.g., NAG and KIM-1), inflammation (e.g., TNF-α) and oxidative stress (e.g., 8-OHdG) because these mechanisms contribute to the development and outcomes of this disease.

Evaluation of ischemia‐modified albumin in anemia associated to chronic kidney disease

Chronic kidney disease (CKD) is highly prevalent, with increasing numbers of patients affected by the disease world‐wide, and anemia is a common finding in patients with CKD. Anemia impacts negatively on cardiovascular disease, exercise capacity, and quality of life, resulting in significant mortality and morbidity. The aim of this study was to evaluate the levels of ischemia‐modified albumin and lactate in patients with established anemia associated with CKD and its correlations with hemoglobin levels. Hematocrit, hemoglobin, iron, ferritin, albumin, creatinine, lactate, and ischemia‐modified albumin (IMA) were measured in 17 patients with established anemia associated to CKD and 19 controls by standard methods. The results of hematocrit, hemoglobin, iron, and albumin were lower in the anemia group than in the control group. Ferritin, creatinine, and lactate levels were higher in anemia of the CKD group than the control group. IMA increase in the anemia group (0.8115±0.1304 absorbance units [ABSU]) compared to control (0.4951±0.0393 ABSU). Significant correlations between IMA and lactate, IMA and hemoglobin, IMA and creatinine, and hemoglobin and lactate were observed. IMA and lactate increase during anemia and this elevation could be associated to hypoxia due to low hemoglobin levels. However, our data suggest that lactate is more sensitive to anemia compared to IMA. J. Clin. Lab. Anal. 22:1–5, 2008.

Oxidative stress in hypercholesterolemia and its association with Ala16Val superoxide dismutase gene polymorphism

OBJECTIVES To investigate the role of the oxidative stress and the antioxidant system as well as the influence of the manganese superoxide dismutase (Ala16Val) polymorphism on hypercholesterolemia. DESIGN AND METHODS Levels of glucose, lipid, high-sensitivity C reactive protein (hs-CRP), thiobarbituric acid reactive substances (TBARS), carbonyl protein, thiols, reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and vitamin C, vitamin E, as well as the presence of the manganese superoxide dismutase (Ala16Val) polymorphism were determined in 40 subjects with hypercholesterolemia and 40 controls. RESULTS Lipid profile, hs-CRP, glucose, TBARS, carbonyl protein, CAT, and vitamin E were significantly higher in subjects with hypercholesterolemia. In contrast, GSH and SOD were lower. TBARS, carbonyl protein, thiols, CAT, and vitamin E were significantly higher in hypercholesterolemic subjects with VV genotype for MnSOD, while GSH, SOD, and vitamin C were lower in these subjects. CONCLUSIONS We suggest an association between the genotypes of MnSOD, hypercholesterolemia, and oxidative stress biomarkers.

Ischemia-modified albumin as an oxidative stress biomarker in obesity.

OBJECTIVE We evaluated the levels of ischemia-modified albumin (IMA) and its association with body mass index (BMI) in patients who are obese. DESIGN AND METHODS Fasting glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, malondialdehyde, and IMA levels were assessed in 148 subjects. RESULTS IMA, malondialdehyde, and fasting glucose levels were significantly higher while the HDL cholesterol levels were lower in obese population. CONCLUSIONS IMA levels increase in overweight and obese subjects.

Association between thyroid hormones, lipids and oxidative stress biomarkers in overt hypothyroidism

Abstract Background: The aim of this study was to investigate the effect of hypothyroidism on lipid peroxidation and the antioxidant profile, as well as to evaluate the interaction between thyroid hormones and biomarkers of oxidative stress in patients with overt hypothyroidism. We also evaluated the influence of cholesterol concentrations on biomarkers of oxidative stress in these same patients. Methods: Total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and vitamin E were measured in 20 subjects with overt hypothyroidism (OH) and 20 controls. Results: TC, LDL cholesterol, triglycerides, TBARS, SOD, CAT, and vitamin E were significantly higher in the OH group. Significant correlation was observed for TSH and SOD, CAT, vitamin E and TBARS. Correlation was observed for triiodothyronine (T3) and SOD, CAT, vitamin E and TBARS. Significant correlation was also observed for free thyroxine and vitamin E and TBARS. However, correlation between T3 and CAT remained significant after controlling for TC concentrations. Conclusions: Overt hypothyroidism is associated with an increase in oxidative stress, and hypercholesterolemia has a stronger influence on development of oxidative stress in hypothyroid conditions compared with thyroid hormones. Clin Chem Lab Med 2010;48:1635–9.

Habitual Intake of Guaraná and Metabolic Morbidities: An Epidemiological Study of an Elderly Amazonian Population

The aim of the present study was to evaluate the associations of metabolic disorders and anthropometric and biochemical biomarkers of lipid, glucose and oxidative metabolism and the habitual ingestion of guaraná (Paullinia cupana, Mart. Var. sorbilis) by an elderly population residing in the Amazon Riverine region of the Maués municipality (Brazil). A case‐controlled study was performed that included 637 elderly (≥60 years of age) patients classified as either those who habitually drank guaraná (GI, n = 421) or those who never drank guaraná (NG, n = 239) based upon their self‐reported intake of guaraná. Indeed, the prevalence of various metabolic disorders was associated with guaraná ingestion. The prevalence of hypertension, obesity and metabolic syndrome in the GI group was lower than the prevalence found in the NG group. The NG group exhibited lower systolic and diastolic blood pressure values. The males in the GI group exhibited a lower waist circumference, on average, than the circumference found in the NG group, whereas the females in the GI group had lower cholesterol (total and LDL‐c) levels than the control cohort. Additionally, a significant association was found between lower levels of advanced oxidative protein product (AOPP) and habitual guaraná consumption. The results constitute the first epidemiological study to suggest a potentially protective effect of habitual guaraná ingestion against metabolic disorders in elderly subjects. Copyright