The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Per Magne Ueland - One of the best experts on this subject based on the ideXlab platform.
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redox status and protein binding of plasma homocysteine and other aminothiols in patients with early onset peripheral vascular disease homocysteine and peripheral vascular disease
Arteriosclerosis Thrombosis and Vascular Biology, 1995Co-Authors: Azam M Mansoor, Asbjorn Svardal, Claes Bergmark, Per Eystein Lonning, Per Magne UelandAbstract:Abstract Elevated total homocysteine (Hcy) in plasma is an independent risk factor for early-onset vascular disease in the coronary, cerebral, and peripheral arteries. Different forms of Hcy, and their relation to other aminothiols in plasma, have not been investigated in patients with vascular disease. We therefore investigated 65 patients (35 men and 30 women) operated on for peripheral arterial disease at <50 years of age and 65 age- and sex-matched control subjects. Total, reduced, oxidized, and protein-bound Hcy, cysteine (Cys), and Cysteinylglycine (CysGly) were measured 0 to 11 years (mean, 6 years) postoperatively, in the fasting state, and after a standard methionine loading dose that caused a transient increase in reduced, oxidized, and protein-bound Hcy. All forms of Hcy and Cys, except reduced Cys, were higher in fasting patients than fasting control subjects. A similar difference between the groups was observed after methionine loading. The levels of most Hcy forms both during fasting and aft...
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homocysteine and other thiols in plasma and urine automated determination and sample stability
Clinical Chemistry, 1993Co-Authors: Torunn Fiskerstrand, Helga Refsum, Gry Kvalheim, Per Magne UelandAbstract:We have developed a modified version of our fully automated column-switching HPLC method for determining total plasma homocysteine based on single-column (reversed-phase) separation. Homocysteine, cysteine, and Cysteinylglycine in plasma (total concentrations), acid-precipitated plasma (non-protein-bound concentrations), and urine can be determined. The derivatization and chromatography were performed automatically by a sample processor. The successful separation of all thiol species (within 15 min) was accomplished by accurate adjustment of the pH of the mobile phase to 3.65 (plasma) or 3.50 (acid-precipitated plasma, urine). Maximal fluorescence yield of cysteine, Cysteinylglycine, and, to a lesser degree, homocysteine was dependent on optimal concentrations of EDTA and dithioerythritol during reduction (with NaBH4) and derivatization (with monobromobimane). The method is sensitive (detection limit approximately 0.05 pmol) and has a high degree of precision (CV < 5%). The sample output is approximately 70 samples in 24 h. Serum and heparin plasma can also be analyzed. Hemolysis up to approximately 2.0 g/L of hemoglobin did not interfere with the analytical recovery of homocysteine or cysteine. Collection of blood, separation of plasma from whole blood, and acid precipitation must be standardized to obtain reproducible thiol results. Our modifications and the standardization of blood-sampling procedures have substantially improved the method and broadened its applications.
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determination of the in vivo redox status of cysteine Cysteinylglycine homocysteine and glutathione in human plasma
Analytical Biochemistry, 1992Co-Authors: M A Mansoor, Asbjorn Svardal, Per Magne UelandAbstract:An assay that measures the reduced, oxidized, and protein-bound forms of cysteine, Cysteinylglycine, homocysteine, and glutathione in human plasma is described. Oxidized and protein-bound thiols are converted to their reduced counterparts by the use of NaBH4, and, following derivatization with monobromobimane (mBrB), the thiol-bimane adducts are quantified by reversed-phase ion-pair liquid chromatography and fluorescence detection. The presence of 50 microM dithioerythritol provides linearity of the standard curves at very low thiol concentrations. Selective determination of the oxidized forms was accomplished by blocking free sulfhydryl groups with N-ethylmaleimide (NEM) and excess NEM is inactivated by the subsequent addition of NaBH4. The reduced forms of the thiols in plasma were trapped with minimal oxidation by derivatizing blood samples at the time of collection. This was attained by drawing blood directly into tubes containing isotonic solutions of mBrB or NEM. The assay is sufficiently sensitive (less than 2 pmol) to detect the various forms of the four thiol compounds in human plasma. The analytical recovery of cysteine, Cysteinylglycine, homocysteine, and glutathione was close to 100%, and the within-day precision corresponded to a coefficient of variation of 7, 8, 6, and 7%, respectively. The assay has been used to determine the various forms of the four thiol compounds in human plasma.
Ciriaco Carru - One of the best experts on this subject based on the ideXlab platform.
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clinical and biochemical correlates of serum l ergothioneine concentrations in community dwelling middle aged and older adults
PLOS ONE, 2014Co-Authors: Salvatore Sotgia, John Attia, Angelo Zinellu, Gianfranco Pintus, Ciriaco Carru, Arduino A Mangoni, Mark McevoyAbstract:Background: Despite the increasing interest towards the biological role of L-ergothioneine, little is known about the serum concentrations of this unusual aminothiol in older adults. We addressed this issue in a representative sample of communitydwelling middle-aged and older adults. Methods: Body mass index, estimated glomerular filtration rate, serum concentrations of L-ergothioneine, taurine, homocysteine, cysteine, glutathione, Cysteinylglycine, and glutamylcysteine were evaluated in 439 subjects (age 55–85 years) randomly selected from the Hunter Community Study. Results: Median L-ergothioneine concentration in the entire cohort was 1.01 IQR 0.78–1.33 mmol/L. Concentrations were not affected by gender (P = 0.41) or by presence of chronic medical conditions (P = 0.15). By considering only healthy subjects, we defined a reference interval for L-ergothioneine serum concentrations from 0.36 (90% CI 0.31–0.44) to 3.08 (90% CI 2.45–3.76) mmol/L. Using stepwise multiple linear regression analysis L-ergothioneine was negatively correlated with age (rpartial =20.15; P = 0.0018) and with glutamylcysteine concentrations (rpartial =20.13; P = 0.0063). Conclusions: A thorough analysis of serum L-ergothioneine concentrations was performed in a large group of communitydwelling middle-aged and older adults. Reference intervals were established. Age and glutamylcysteine were independently negatively associated with L-ergothioneine serum concentration.
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regular cigarette smoking influences the transsulfuration pathway endothelial function and inflammation biomarkers in a sex gender specific manner in healthy young humans
American Journal of Translational Research, 2013Co-Authors: Ilaria Campesi, Angelo Zinellu, Ciriaco Carru, Stefano Occhioni, Manuela Sanna, Mario Palermo, Giancarlo Tonolo, Giuseppe Mercuro, Flavia FranconiAbstract:Cigarette smoking (CS) is the primary cause of preventable morbidity and mortality. Abundant clinical evidence suggests that CS is more harmful to women; however, the mechanisms responsible for these differences are not yet known. CS alters endothelial function, the redox state, inflammation, and global DNA methylation, which is associated with one-carbon metabolism and the transsulfuration pathway. However, it is not known whether the previously identified alterations are sex-gender related. Healthy adult men and oral contraceptive-free women with regular menstrual cycles were enrolled; women were examined during the follicular phase. Men had higher plasma levels of uric acid, total bilirubin, homocysteine, glutamylcysteine, total glutathione, Cysteinylglycine; had more monocytes and released more TNF-alpha from human monocytes derived macrophages (hMDMs), but they had fewer platelets and lower levels of DNA methylation, and their hMDMs released less TNF-alpha after LPS stimulation. MDA, taurine, cysteine, arginine, ADMA, and SDMA were not different. CS decreased global DNA methylation more in women and increased the platelet, monocyte, and lymphocyte counts and the homocysteine, arginine, and ADMA levels only in women, whereas increased the neutrophil and eosinophil counts only in men. Additionally, CS reduced the sex-gender differences in total bilirubin, basal and LPS-induced TNF-alpha release, total glutathione, and glutamylcysteine, leaving unchanged Cysteinylglycine, taurine, SDMA, MDA, and cysteine. These data suggest that cardiovascular risk factors seem to come earlier in young healthy female smokers than in young healthy male smokers, supporting the greater alarmism regarding the effects of CS in women and providing a basis for understanding the sex-gender differences. These results also suggest that cessation programs targeting women are needed.
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decreased plasma Cysteinylglycine and taurine levels in branch retinal vein occlusion
Ophthalmic Research, 2010Co-Authors: Antonio Daniele Pinna, Angelo Zinellu, Flavia Franconi, G Solinas, Ciriaco CarruAbstract:Purpose: Our aim was to determine the plasma levels of the sulfur-containing amino acids homocysteine, cysteine, Cysteinylglycine, glutamylcysteine, glutathione and taurine in patie
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high throughput capillary electrophoresis method for plasma Cysteinylglycine measurement evidences for a clinical application
Amino Acids, 2008Co-Authors: Angelo Zinellu, Salvatore Sotgia, Antonio Daniele Pinna, Elisabetta Zinellu, Luca Deiana, Ciriaco CarruAbstract:Increased levels in plasma homocysteine and cysteine, and more recently, decreased levels in Cysteinylglycine have been indicated as a risk factor for vascular diseases. Most assays focused their attention only on homocysteine determination and when also other thiols were measured, analytical times drastically increased. By modifying our previous method for thiols detection, we set up a rapid capillary electrophoresis method for the selective quantification of plasma Cysteinylglycine, cutting the analysis time of about 50%. Samples were treated with tri-n-butylphosphine as reducing agent, proteins were precipitated with trichloroacetic acid and released thiols were successively derivatized by the selective thiol laser-induced fluorescence-labeling agent 5-iodoacetamidofluorescein and separated by capillary electrophoresis. A baseline separation between peaks was obtained in about 2 min using 3 mmol/L sodium phosphate/2.5 mmol/L boric acid as electrolyte solution with 75 mmol/L N-methyl-D-glucamine at pH 11.25 in a 47 cm long capillary with a cartridge temperature of 45 °C. The method application was checked by measuring plasma Cys-Gly levels in a group of patients affected by retinal vein occlusion (RVO), an important cause of visual loss in the elderly. The low levels of Cys-Gly found in the RVO patients suggest that these small thiols may have importance in the disease development.
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n methyl d glucamine improves the laser induced fluorescence capillary electrophoresis performance in the total plasma thiols measurement
Electrophoresis, 2003Co-Authors: Angelo Zinellu, Ciriaco Carru, Giorgio Federici, Franca Galistu, Maria Franca Usai, Giovanni Mario Pes, Giovannella Baggio, Luca DeianaAbstract:We describe an ultrarapid capillary electrophoresis with laser-induced fluorescence (CE-LIF) method for total plasma thiols measurement. Reduced thiols by 10% tri-n-butylphosphine (TBP) were derivatized in 10 min at room temperature with 5-iodoacetamidofluorescein (5-IAF) as fluorescent reagent. We show that CE-LIF allows a baseline separation of total plasma Cysteinylglycine, homocysteine, cysteine, and glutathione in less than 5 min when N-methyl-D-glucamine in run buffer was added. CE was compared with high-performance liquid chromatography (HPLC) with fluorescence detection. The Bland-Altman test and Passing-Bablok regression demonstrates that the results obtained by CE-LIF and by HPLC are highly comparable. The simplified procedure of sample preparation, the short incubation and fast separation times, the high specificity, sensitivity and reproducibility, and the lower cost of analysis suggest that our proposed method can be considered valuable for the automation analysis in a routine laboratory.
Giorgio Federici - One of the best experts on this subject based on the ideXlab platform.
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n methyl d glucamine improves the laser induced fluorescence capillary electrophoresis performance in the total plasma thiols measurement
Electrophoresis, 2003Co-Authors: Angelo Zinellu, Ciriaco Carru, Giorgio Federici, Franca Galistu, Maria Franca Usai, Giovanni Mario Pes, Giovannella Baggio, Luca DeianaAbstract:We describe an ultrarapid capillary electrophoresis with laser-induced fluorescence (CE-LIF) method for total plasma thiols measurement. Reduced thiols by 10% tri-n-butylphosphine (TBP) were derivatized in 10 min at room temperature with 5-iodoacetamidofluorescein (5-IAF) as fluorescent reagent. We show that CE-LIF allows a baseline separation of total plasma Cysteinylglycine, homocysteine, cysteine, and glutathione in less than 5 min when N-methyl-D-glucamine in run buffer was added. CE was compared with high-performance liquid chromatography (HPLC) with fluorescence detection. The Bland-Altman test and Passing-Bablok regression demonstrates that the results obtained by CE-LIF and by HPLC are highly comparable. The simplified procedure of sample preparation, the short incubation and fast separation times, the high specificity, sensitivity and reproducibility, and the lower cost of analysis suggest that our proposed method can be considered valuable for the automation analysis in a routine laboratory.
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fully automated assay for total homocysteine cysteine Cysteinylglycine glutathione cysteamine and 2 mercaptopropionylglycine in plasma and urine
Clinical Chemistry, 1998Co-Authors: Anna Pastore, Renato Massoud, C Motti, Anna Lo Russo, Giorgio Fucci, Claudio Cortese, Giorgio FedericiAbstract:We describe a 6-min HPLC method to measure the total concentrations of the most important thiols in plasma and urine--cysteine, homocysteine, Cysteinylglycine, and glutathione--as well as the concentrations in plasma and urine, respectively, of cysteamine and 2-mercaptopropionylglycine, two compounds used to treat disorders of cysteine metabolism. Precolumn derivatization with bromobimane and reversed-phase HPLC were performed automatically by a sample processor. Throughput was up to 100 samples in 24 h. The within-run CV ranged from 0.9% to 3.4% and the between-run CV ranged from 1.5% to 6.1%. Analytical recovery was 97-107%, with little difference between plasma and urine samples. The detection limit was approximately 50 nmol/L for all the analytes studied. Thiol concentrations were determined in the plasma of 206 healthy donors and in the urine of 318 healthy donors distributed for age and sex. Mean values of plasma cysteine and homocysteine were significantly lower in infants (ages, <1 y) compared with other age groups (P <0.005). In adults, mean plasma homocysteine values were higher in males than in females (9.2 vs 6.7 micromol/L, P <0.0001) and in the 6- to 10-year-old group (P <0.05). Mean values for glutathione and Cysteinylglycine were not sex- and age-dependent. In urine, both cysteine and homocysteine showed a wide range of variation.
Angelo Zinellu - One of the best experts on this subject based on the ideXlab platform.
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clinical and biochemical correlates of serum l ergothioneine concentrations in community dwelling middle aged and older adults
PLOS ONE, 2014Co-Authors: Salvatore Sotgia, John Attia, Angelo Zinellu, Gianfranco Pintus, Ciriaco Carru, Arduino A Mangoni, Mark McevoyAbstract:Background: Despite the increasing interest towards the biological role of L-ergothioneine, little is known about the serum concentrations of this unusual aminothiol in older adults. We addressed this issue in a representative sample of communitydwelling middle-aged and older adults. Methods: Body mass index, estimated glomerular filtration rate, serum concentrations of L-ergothioneine, taurine, homocysteine, cysteine, glutathione, Cysteinylglycine, and glutamylcysteine were evaluated in 439 subjects (age 55–85 years) randomly selected from the Hunter Community Study. Results: Median L-ergothioneine concentration in the entire cohort was 1.01 IQR 0.78–1.33 mmol/L. Concentrations were not affected by gender (P = 0.41) or by presence of chronic medical conditions (P = 0.15). By considering only healthy subjects, we defined a reference interval for L-ergothioneine serum concentrations from 0.36 (90% CI 0.31–0.44) to 3.08 (90% CI 2.45–3.76) mmol/L. Using stepwise multiple linear regression analysis L-ergothioneine was negatively correlated with age (rpartial =20.15; P = 0.0018) and with glutamylcysteine concentrations (rpartial =20.13; P = 0.0063). Conclusions: A thorough analysis of serum L-ergothioneine concentrations was performed in a large group of communitydwelling middle-aged and older adults. Reference intervals were established. Age and glutamylcysteine were independently negatively associated with L-ergothioneine serum concentration.
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regular cigarette smoking influences the transsulfuration pathway endothelial function and inflammation biomarkers in a sex gender specific manner in healthy young humans
American Journal of Translational Research, 2013Co-Authors: Ilaria Campesi, Angelo Zinellu, Ciriaco Carru, Stefano Occhioni, Manuela Sanna, Mario Palermo, Giancarlo Tonolo, Giuseppe Mercuro, Flavia FranconiAbstract:Cigarette smoking (CS) is the primary cause of preventable morbidity and mortality. Abundant clinical evidence suggests that CS is more harmful to women; however, the mechanisms responsible for these differences are not yet known. CS alters endothelial function, the redox state, inflammation, and global DNA methylation, which is associated with one-carbon metabolism and the transsulfuration pathway. However, it is not known whether the previously identified alterations are sex-gender related. Healthy adult men and oral contraceptive-free women with regular menstrual cycles were enrolled; women were examined during the follicular phase. Men had higher plasma levels of uric acid, total bilirubin, homocysteine, glutamylcysteine, total glutathione, Cysteinylglycine; had more monocytes and released more TNF-alpha from human monocytes derived macrophages (hMDMs), but they had fewer platelets and lower levels of DNA methylation, and their hMDMs released less TNF-alpha after LPS stimulation. MDA, taurine, cysteine, arginine, ADMA, and SDMA were not different. CS decreased global DNA methylation more in women and increased the platelet, monocyte, and lymphocyte counts and the homocysteine, arginine, and ADMA levels only in women, whereas increased the neutrophil and eosinophil counts only in men. Additionally, CS reduced the sex-gender differences in total bilirubin, basal and LPS-induced TNF-alpha release, total glutathione, and glutamylcysteine, leaving unchanged Cysteinylglycine, taurine, SDMA, MDA, and cysteine. These data suggest that cardiovascular risk factors seem to come earlier in young healthy female smokers than in young healthy male smokers, supporting the greater alarmism regarding the effects of CS in women and providing a basis for understanding the sex-gender differences. These results also suggest that cessation programs targeting women are needed.
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decreased plasma Cysteinylglycine and taurine levels in branch retinal vein occlusion
Ophthalmic Research, 2010Co-Authors: Antonio Daniele Pinna, Angelo Zinellu, Flavia Franconi, G Solinas, Ciriaco CarruAbstract:Purpose: Our aim was to determine the plasma levels of the sulfur-containing amino acids homocysteine, cysteine, Cysteinylglycine, glutamylcysteine, glutathione and taurine in patie
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high throughput capillary electrophoresis method for plasma Cysteinylglycine measurement evidences for a clinical application
Amino Acids, 2008Co-Authors: Angelo Zinellu, Salvatore Sotgia, Antonio Daniele Pinna, Elisabetta Zinellu, Luca Deiana, Ciriaco CarruAbstract:Increased levels in plasma homocysteine and cysteine, and more recently, decreased levels in Cysteinylglycine have been indicated as a risk factor for vascular diseases. Most assays focused their attention only on homocysteine determination and when also other thiols were measured, analytical times drastically increased. By modifying our previous method for thiols detection, we set up a rapid capillary electrophoresis method for the selective quantification of plasma Cysteinylglycine, cutting the analysis time of about 50%. Samples were treated with tri-n-butylphosphine as reducing agent, proteins were precipitated with trichloroacetic acid and released thiols were successively derivatized by the selective thiol laser-induced fluorescence-labeling agent 5-iodoacetamidofluorescein and separated by capillary electrophoresis. A baseline separation between peaks was obtained in about 2 min using 3 mmol/L sodium phosphate/2.5 mmol/L boric acid as electrolyte solution with 75 mmol/L N-methyl-D-glucamine at pH 11.25 in a 47 cm long capillary with a cartridge temperature of 45 °C. The method application was checked by measuring plasma Cys-Gly levels in a group of patients affected by retinal vein occlusion (RVO), an important cause of visual loss in the elderly. The low levels of Cys-Gly found in the RVO patients suggest that these small thiols may have importance in the disease development.
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n methyl d glucamine improves the laser induced fluorescence capillary electrophoresis performance in the total plasma thiols measurement
Electrophoresis, 2003Co-Authors: Angelo Zinellu, Ciriaco Carru, Giorgio Federici, Franca Galistu, Maria Franca Usai, Giovanni Mario Pes, Giovannella Baggio, Luca DeianaAbstract:We describe an ultrarapid capillary electrophoresis with laser-induced fluorescence (CE-LIF) method for total plasma thiols measurement. Reduced thiols by 10% tri-n-butylphosphine (TBP) were derivatized in 10 min at room temperature with 5-iodoacetamidofluorescein (5-IAF) as fluorescent reagent. We show that CE-LIF allows a baseline separation of total plasma Cysteinylglycine, homocysteine, cysteine, and glutathione in less than 5 min when N-methyl-D-glucamine in run buffer was added. CE was compared with high-performance liquid chromatography (HPLC) with fluorescence detection. The Bland-Altman test and Passing-Bablok regression demonstrates that the results obtained by CE-LIF and by HPLC are highly comparable. The simplified procedure of sample preparation, the short incubation and fast separation times, the high specificity, sensitivity and reproducibility, and the lower cost of analysis suggest that our proposed method can be considered valuable for the automation analysis in a routine laboratory.
Lloyd M Taylor - One of the best experts on this subject based on the ideXlab platform.
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rapid hplc determination of total homocysteine and other thiols in serum and plasma sex differences and correlation with cobalamin and folate concentrations in healthy subjects
Clinical Chemistry, 1994Co-Authors: Donald W Jacobsen, Vytenis J Gatautis, Ralph Green, Killian Robinson, Susan R Savon, Michelle Secic, Joanne M Otto, Lloyd M TaylorAbstract:High-performance liquid chromatography with fluorescence detection has been utilized for the rapid determination of total homocysteine, cysteine, and Cysteinylglycine in human serum and plasma. Our earlier procedure (Anal Biochem 1989;178:208), which used monobromobimane to specifically derivatize thiols, has been extensively modified to allow for rapid processing of samples. As a result, > 80 samples a day can be assayed for total homocysteine, cysteine, and Cysteinylglycine. The method is sensitive (lower limit of detection < or = 4 pmol in the assay) and precise (intra- and interassay CV for homocysteine, 3.31% and 4.85%, respectively). Mean total homocysteine concentrations in plasma and serum were significantly different, both from healthy male donors (9.26 and 12.30 mumol/L, respectively; P < 0.001) and healthy female donors (7.85 and 10.34 mumol/L, respectively; P < 0.001). The differences in total homocysteine between sexes were also significant (P = 0.002 for both plasma and serum). Similar differences were found for cysteine and Cysteinylglycine. We found a significant inverse correlation between serum cobalamin and total homocysteine in men (P = 0.0102) and women (P = 0.0174). Serum folate also inversely correlated with total homocysteine in both sexes.
