Genetic variants of folate metabolism and the risk of multiple sclerosis.

BACKGROUND AND AIMS: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) of unknown cause. Alterations in one-carbon metabolism have impact in the pathophysiology by genetic susceptibility to MS and increased the risk of MS. The aim of this study was to investigate the contribution of the gene polymorphism on Methylenetetrahydrofolate Reductase (MTHFR), Methionine Synthase Reductase (MTRR), Methionine Synthase (MTR) enzymes and of the essential factors (homocysteine, Hcy; cysteine, Cys; and vitamin B12, VitB12) in folate metabolism. METHODS: Eligible MS patients (n = 147) and health controls (n = 127) were participated. The gene polymorphisms were analyzed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and the levels of plasma Hcy, Cys and VitB12 were measured by Enzyme Linked Immunuabsorbent Assay (ELISA). RESULTS AND CONCLUSION: Our results showed that the levels of Hcy and VitB12 were lower and the levels of Cys were higher in MS compared to controls. The observation of high Cys values in all 3 gene polymorphisms suggests that the transsulfiration pathway of Hcy is directed towards Cys formation since the methionine synthesis pathway does not work. We could not find any association with all gene polymorphisms with the risk of MS. The T allele of MTHFR C677T and G allele of MTR A2756G are risk factors for serum Cys level on MS. As for MTR A2756G, serum vitB12 was observed in MS patients with G allele.

Toxic effects of Aroclor 1254 on rat liver and modifying roles of selenium.

Polychlorinated biphenyls (PCBs) were used in different industrial areas and banned due to their high toxicity. Aroclor 1254 (A1254), commercial PCB congener, accumulates in environment leading to high human exposure. A1254 may cause hepatotoxicity, metabolic and endocrine disorders. In our study, 3-week-old male rats were separated into 6 groups: C (0.15 mg/kg Se in diet); SeS (1 mg/kg Se in diet); SeD (0.05 mg/kg Se in diet); A1254 receiving groups (A; ASeS; ASeD) were given 10 mg/kg/day A1254 orally for last 15 days of feeding period with control, SeD or SeS diet, respectively, for 5 weeks. Histopathology, oxidant/antioxidant balance, apoptosis and cell cycle proteins (p53, p21) in liver were evaluated. Our results suggest that A1254 leads to changes in histology, oxidative stress and apoptosis. Selenium deficiency augments oxidative stress and apoptosis while selenium supplementation is partially protective. More mechanistic in vivo experiments are necessary for evaluation of hepatotoxicity of PCBs.

Determination of neopterin in urine of industrial workers by HPLC.

This study aimed to determine neopterin levels in the urine of industrial workers by the high-performance liquid chromatography method. Intra- and inter-day precision values for neopterin in urine were less than 3.14, and accuracy (relative error) was better than 3.00%. The limits of detection and quantification of neopterin were 0.3 and 1.0 ng/mL, respectively. Also, the developed method was applied to real samples to determine the neopterin levels in the urines of industrial workers, who have been exposed to various chemicals such as formaldehyde, heavy metals and thinners. Urine neopterin levels of industrial workers including auto painters, bodywork and furniture workers were statistically compared with healthy volunteers. The highest and lowest values of urinary neopterin for industrial workers were obtained 908.96 and 119.86 µmol/mol, respectively. Our investigation demonstrates that there is a meaningful difference in urinary neopterin levels between the workers and the control groups (P<0.05). Workers in the auto paint, body and furniture business may have been exposed to a toxic environmental exposure in their occupation. As a result, an increase in the concentration of neopterin in the urine may be important in the diagnosis and treatment of various diseases.

Renal changes and apoptosis caused by subacute exposure to Aroclor 1254 in selenium-deficient and selenium-supplemented rats.

Aroclor 1254 (A1254), a mixture of polychlorinated biphenyls, exerts hepatic, renal, and reproductive toxicity in rodents. This study aimed to determine a protective role of selenium on histopathological changes, oxidative stress, and apoptosis caused by A1254 in rat kidney. It included a control group, which received regular diet containing 0.15 mg/kg Se (C), a Se-supplemented group (SeS) receiving 1 mg/kg Se, a Se-deficient group (SeD) receiving Se-deficient diet of ≤0.05 mg/kg Se, an A1254-treated group (A) receiving 10 mg/kg of Aroclor 1254 and regular diet, an A1254-treated group receiving Se-supplementation (ASeS), and an A1254-treated group receiving Se-deficient diet (ASeD). Treatments lasted 15 days. After 24 h of the last dose of A1254, the animals were decapitated under anaesthesia and their renal antioxidant enzyme activities, lipid peroxidation (LP), glutathione, protein oxidation, and total antioxidant capacity levels measured. Histopathological changes were evaluated by light and electron microscopy. Apoptosis was detected with the TUNEL assay. Kidney weights, CAT activities, and GSH levels decreased significantly in all A1254-treated groups. Renal atrophic changes and higher apoptotic cell counts were observed in the A and ASeD groups. Both groups also showed a significant drop in GPx1 activities (A - 34.92 % and ASeD - 86.46 %) and rise in LP (A - 30.45 % and ASeD - 20.44 %) vs control. In contrast, LP levels and apoptotic cell counts were significantly lower in the ASeS group vs the A group. Histopathological changes and renal apoptosis were particularly visible in the ASeD group. Our findings suggest that selenium supplementation provides partial protection against renal toxicity of Aroclor 1254.

Oxidative Stress Parameters, Selenium Levels, DNA Damage, and Phthalate Levels in Plastic Workers.

Di(2-ethylhexyl)phthalate (DEHP) is the most widely used phthalate. DEHP is highly used in PVC floorings and PVC windows and carpeting. The objective of this study was to determine sex hormone levels, oxidative stress parameters, selenium levels, DNA damage, and phthalate levels in plastics workers (n = 24, age = 20-58 years) working in the production of rubber mechanical goods and exposed to DEHP in workplace. The control group (n = 29, age = 25-54, all male) was selected from age-matched healthy adults. Antioxidant parameters and DNA damage were determined by spectrophotometry. Selenium levels were determined by atomic absorption spectroscopy. Plasma hormone levels were measured by chemiluminescence microparticle immunoassay. Plasma phthalate levels were determined by high-pressure liquid chromatography. Plastic workers had lower serum testosterone and free T4 levels and higher follicle-stimulating hormone levels vs. controls. Liver enzyme activities were markedly higher in workers vs. controls. There were also increases in plasma glutathione peroxidase levels and marked decreases in plasma selenium and erythrocyte total glutathione levels in plastics workers (P < 0.05 vs. control). Plasma 8-hydroxy-2'-deoxyguanosine levels were 14-fold higher in plastics workers than in controls. Plasma DEHP and mono(2-ethylhexyl)phthalate were also markedly higher in workers vs. controls. The results of this study show that occupational exposure to DEHP may lead to disturbances in sex hormones, increased liver problems, higher oxidative stress and DNA damage levels, and lower trace element concentrations in workers. More comprehensive and mechanistic studies with higher numbers of subjects are needed to show the unwanted effects of occupational exposure to DEHP.

Lead and Mercury Levels in Preterm Infants Before and After Blood Transfusions.

Very low birth weight (VLBW) infants usually receive packed red blood cell unit (pRBC) transfusions. Heavy metal transfer via pRBCs is not widely discussed before. This study aimed to determine pre-/post-transfusion erythrocyte lead and mercury levels in infants and to correlate these levels to heavy metal concentrations in pRBCs. VLBW infants (n = 80), needing pRBC transfusion for the first time, were enrolled. Erythrocyte heavy metal levels were determined in pre-/post-transfusion blood samples and also in pRBC units. Mean lead and mercury levels in the pRBCs were found to be 16.3 ± 10.8 and 3.75 ± 3.23 µg/L, respectively. Of the infants, 69.7% received lead above reference dose. Erythrocyte lead levels increased significantly after transfusions (10.6 ± 10.3 vs. 13 ± 8.5, p < 0.05) with significant correlated to amount of lead within pRBCs (r = 0.28). Mean pre-/post-transfusion erythrocyte mercury levels were 3.28 ± 3.08 and 3.5 ± 2.83 µg/L, respectively (p > 0.05). There was a significant correlation between mean difference of mercury levels after transfusion and amount of mercury delivered by pRBCs (r = 0.28). Infants can be subject to high levels of lead and mercury through pRBC transfusions.

Urinary phthalate metabolite concentrations in girls with premature thelarche.

In girls, breast development before eight years of age is called "premature thelarche (PT)". There are few studies in literature that show the interaction between PT and phthalate exposure. The aim of this study was to determine the urinary levels of di-(2-ethylhexyl) phthalate (DEHP) metabolites and other phthalate metabolites in girls with PT. PT group consisted of 29 newly diagnosed subjects. Control group comprised of healthy age-matched girls (n = 25). Urinary phthalate metabolite concentrations were measured by liquid chromatography/tandem mass spectroscopy (LC-MS/MS). The urinary concentrations of mono-(2-ethyl-hexyl)phthalate (MEHP) in the PT group (33.96 ±â€¯6.88 µg/g creatinine) were found to be significantly higher compared to control group (11.54 ±â€¯1.39 µg/g creatinine, p = 0.002). In PT group, %MEHP was also markedly higher vs. control (17.84 ±â€¯3.31 vs. 6.44 ±â€¯1.13, p = 0.001). Our results suggest that DEHP is more efficiently converted to MEHP in girls with PT, the importance of which needs to be further elucidated.

The evaluation of possible role of endocrine disruptors in central and peripheral precocious puberty.

Exposure to environmental chemicals can affect genetic and epigenetic molecular pathways and may cause altered growth and development. Among those exposures, endocrine-disrupting chemicals (EDCs) are of particular concern as humans are abundantly exposed to these chemicals by various means in every period of life. Several well-known environmental chemicals, including phthalates and bisphenol A (BPA), are classified as EDCs. These EDCs are suggested to play roles in early onset of puberty in girls. The aim of this study is to determine plasma phthalate (di(2-ethylhexyl)phthalate [DEHP] and its main metabolite mono(2-ethylhexyl)phthalate [MEHP]) and urinary BPA levels in girls with idiopathic central precocious puberty (CPP) and peripheral precocious puberty (PPP). This study was performed on newly diagnosed idiopathic central precocious puberty (CPP) patients (n = 42) and peripheral precocious puberty (PPP) (n = 42) patients, who were admitted to Keçiören Training and Research Hospital, Clinic of Pediatric Endocrinology between August 2012 and -July 2013. Nonobese healthy girls (n = 50) were used as the control group. Urinary BPA levels were not statistically different in control, PPP and CPP groups (medians 10.91, 10.63 and 10.15 µg/g creatinine, respectively; p > 0.05). Plasma DEHP levels were significantly higher in PPP group when compared to control. Plasma MEHP levels were not significantly different in control and PPP groups (p > 0.05). However, in CPP group, both plasma DEHP and MEHP levels were significantly higher than control and PPP groups. This study showed that phthalates might play a role in the occurence of CPP in girls.

Copper, zinc and iron levels in premature infants following red blood cell transfusion.

This study aimed to investigate effect of erythrocyte suspension (ES) transfusion on Cu, Zn, and Fe levels. It was conducted on 53 premature infants who were admitted to Hacettepe Hospital and received EST for first time. Blood samples were drawn before and 96h after ES transfusion to determine Cu, Zn, and Fe levels in plasma and/or erythrocytes. The mean plasma Cu levels were 99±3µg/dl and 113±3µg/dl; Zn levels were 105±2µg/dl and 115±23µg/dl; mean plasma Fe level was 58.1±19.4 and 75.2±25.4µg/dl and mean erythrocyte Fe level was 4182±2314µg/ml and 7009±5228µg/ml, before and after ES transfusion. The differences between before and after ES transfusion in Cu, Zn and Fe levels were significant. Correlation between plasma and erythrocyte Fe levels was significant both before and after ES transfusion. Though Fe overload is a major cause of morbidity/mortality after ES transfusion, alterations in trace elements should also be considered when transfusing blood to infants and children.

Simple high-performance liquid chromatography method for formaldehyde determination in human tissue through derivatization with 2,4-dinitrophenylhydrazine.

A simple high-performance liquid chromatography method has been developed for the determination of formaldehyde in human tissue. FA Formaldehyde was derivatized with 2,4-dinitrophenylhydrazine. It was extracted from human tissue with ethyl acetate by liquid-liquid extraction and analyzed by high-performance liquid chromatography. The calibration curve was linear in the concentration range of 5.0-200 µg/mL. Intra- and interday precision values for formaldehyde in tissue were <6.9%, and accuracy (relative error) was better than 6.5%. The extraction recoveries of formaldehyde from human tissue were between 88 and 98%. The limits of detection and quantification of formaldehyde were 1.5 and 5.0 µg/mL, respectively. Also, this assay was applied to liver samples taken from a biopsy material.

Plasma phthalate and bisphenol a levels and oxidant-antioxidant status in autistic children.

Phthalates and bisphenol A (BPA) are endocrine disruting chemicals (EDCs) that are suggested to exert neurotoxic effects. This study aimed to determine plasma phthalates and BPA levels along with oxidant/antioxidant status in autistic children [n=51; including 12 children were diagnosed with "Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS)]. Plasma levels of BPA, di (2-ethylhexyl)-phthalate (DEHP) and its main metabolite mono (2-ethylhexyl)-phthalate (MEHP); thiobarbituric acid reactive substance (TBARS) and carbonyl groups; erythrocyte glutathione peroxidase (GPx1), thioredoxin reductase (TrxR), catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR) activities and glutathione (GSH) and selenium levels were measured. Plasma BPA levels of children with PDD-NOS were significantly higher than both classic autistic children and controls (n=50). Carbonyl, selenium concentrations and GPx1, SOD and GR activities were higher (p<0.05); CAT activity was markedly lower in study group. BPA exposure might be associated with PDD-NOS. Intracellular imbalance between oxidant and antioxidant status might facilitate its neurotoxicity.

Oxidant and antioxidant status in neonatal proven and clinical sepsis according to selenium status.

BACKGROUND: Selenium is a trace element required for the functioning of the immune system. Neonatal sepsis is a serious condition leading to morbidity and mortality in neonates worldwide. The purpose of this study was to measure selenium and plasma selenoprotein P (SePP), selenoenzyme activity, and alterations in oxidant/antioxidant status with immune biomarkers in neonates with clinical (n = 27) and proven neonatal sepsis (n = 25). METHODS: Erythrocyte selenium and SePP; plasma lipid peroxidation (LP), protein oxidation and total antioxidant capacity and erythrocyte total glutathione (GSH) concentration; erythrocyte glutathione peroxidase (GPx), thioredoxin reductase (TrxR), catalase (CAT) and total superoxide dismutase (SOD) activity were measured spectrophotometrically/spectrofluorometrically. Plasma interleukin 2 and 6 were also measured. RESULTS: Erythrocyte selenium and SePP were markedly lower both in the clinical and proven sepsis groups versus control. Erythrocyte GPx activity was higher only in the clinical sepsis group. TrxR activity was markedly lower in proven sepsis. SOD activity and GSH were markedly higher both in clinical sepsis and in proven sepsis. CAT activity was significantly higher both in clinical sepsis and in proven sepsis. LP and protein oxidation were significantly higher in both of the sepsis groups. CONCLUSIONS: Both selenium-dependent and selenium-independent blood redox systems were altered in sepsis, suggesting that sepsis causes an imbalance between cellular antioxidant and oxidant states.

Urinary bisphenol a levels in girls with idiopathic central precocious puberty.

OBJECTIVE: Bisphenol A (BPA) is an industrial chemical, particularly used to harden plastics. BPA is thought to have negative health effects on both laboratory animals and humans. Consider ing the decline in age of onset of puberty noted in recent years, particularly among girls, the importance of BPA as an estrogenic endocrine disruptor has increased. In this study, we aimed to determine urinary BPA levels in girls with idiopathic central precocious puberty (ICPP). METHODS: Non-obese girls newly diagnosed with ICPP (n=28, age 4-8 years) constituted the study group. The control group consisted of 25 healthy age-matched girls with no history of ICPP or any other endocrine disorder. Urinary BPA levels were measured by using high-performance liquid chromatography. RESULTS: In the ICPP group, urinary BPA levels were significantly higher compared to the control group [median 8.34 (0.84-67.35) µg/g creatinine and 1.62 (0.3-25.79) µg/g creatinine, respectively (OR=8.68, 95% CI:2.03-32.72, p=0.001)]. There was no marked correlation between urinary BPA levels and body mass index in either group. In the ICPP group, no significant correlations were found between urinary BPA levels and serum luteinizing hormone, follicle-stimulating hormone and estradiol levels. CONCLUSIONS: To our knowledge, this is the first study evaluating the urinary BPA levels in Turkish girls with ICPP. Our results indicate that the estrogenic effects of BPA may be an etiologic factor in ICPP.

HPLC method for naproxen determination in human plasma and its application to a pharmacokinetic study in Turkey.

A simple high-performance liquid chromatography method has been developed for the determination of naproxen in human plasma. The method was validated on an Ace C18 column using ultraviolet detection. The mobile phase consisted of 20 mM phosphate buffer (pH 7) containing 0.1% trifluoroacetic acid-acetonitrile (65:35, v/v). The calibration curve was linear between the concentration ranges of 0.10 and 5.0 µg/mL. Intra-day and inter-day precision values for naproxen in plasma were less than 4.84, and accuracy (relative error) was better than 3.67%. The extraction recovery values of naproxen from human plasma were between 91.0 and 98.9%. The limits of detection and quantification of naproxen were 0.03 and 0.10 µg/mL, respectively. Also, this assay was applied to determine the pharmacokinetic parameters of naproxen in six healthy Turkish volunteers who had been given 220 mg of naproxen.

Selenium levels, selenoenzyme activities and oxidant/antioxidant parameters in H1N1-infected children.

Selenium (Se) is an essential trace element, and it shows its biological functions within low molecular Se compounds and Se-containing proteins, known as "selenoproteins". Glutathione peroxidases (GPxs) and thioredoxin reductases (TrxRs) are the most important selenoproteins functioning as antioxidant enzymes. These enzymes protect the body from the endogenous products of cellular metabolism that have been implicated in DNA damage, mutagenesis, and carcinogenesis. H1N1 virus is a subtype of the influenza A virus and was an endemic in humans in 2009 and 2010. Taking into account the high incidence of Se deficiency and the high mortality and morbidity rates in H1N1 infection, this study was designed to investigate the plasma and erythrocyte Se levels, selenoenzyme activities and other oxidant/antioxidant parameters in H1N1-infected children during the 2009-2010 pandemic. We observed a significant increase in C-reactive protein levels (245%) and marked decreases in both plasma and erythrocyte Se levels (11%, both) and in GPx1 (45%), GPx3 (16%) and TrxR (30%) activities in H1N1-infected children compared to the control group. In addition, significant decreases were observed in erythrocyte catalase (CAT) (38%), total superoxide dismutase (SOD) (42%) and glutathione S-transferase (GST) (19%) activities and in erythrocyte total glutathione (GSH) (18%) and plasma GSH (10%) concentrations, while marked increases were observed in plasma lipid peroxidation levels (27%). However, we did not find a significant difference in selenoprotein P (SePP) levels between the groups. Our findings show that Se-dependent and -independent blood redox systems are down-regulated in H1N1 influenza. These findings emphasized the critical role of Se as an effective redox regulator and the importance of Se status in infections, particularly in H1N1 influenza.

HPLC method for determination of atenolol in human plasma and application to a pharmacokinetic study in Turkey.

This paper describes a high-performance liquid chromatography method for the determination of atenolol in human plasma. Atenolol and the internal standard, metoprolol, were extracted from plasma by using a liquid-liquid extraction method. The method was developed on an Ace C18 reverse-phase column using a mobile phase of methanol-water (50:50, v/v) containing 0.1% trifluoroacetic acid. The calibration curve was linear within the concentration range of 5-150 ng/mL. Intra-day and inter-day precision values for atenolol in plasma were less than 6.1, and accuracy (relative error) was better than 5.5%. The mean recovery of atenolol was 98.4% for plasma. The limits of detection and quantification of atenolol were 1.5 and 5 ng/mL, respectively. Also, this assay was successfully applied to six patients with hypertension who had been given an oral tablet of 50 mg atenolol.

HPLC method for determination of diclofenac in human plasma and its application to a pharmacokinetic study in Turkey.

A simple high-performance liquid chromatography (HPLC) method has been developed for determination of diclofenac in human plasma. The method was validated on Ace C(18) column using UV detection. The mobile phase consisted of 20 mM phosphate buffer (pH 7) containing 0.1% trifluoroacetic acid-acetonitrile (65:35, v/v). Calibration curve was linear between the concentration range of 75-4000 ng/mL. Intra- and inter-day precision values for diclofenac in plasma were less than 3.6, and accuracy (relative error) was better than 5.3%. The limits of detection and quantification of diclofenac were 25 and 75 ng/mL, respectively. Also, this assay was applied to determine the pharmacokinetic parameters of diclofenac in healthy Turkish volunteers who had been given 50 mg diclofenac.

Determination of metoprolol in human plasma and urine by high-performance liquid chromatography with fluorescence detection.

A simple, specific and sensitive HPLC method has been developed for the determination of metoprolol in human plasma and urine. Separation of metoprolol and atenolol (internal standard) was achieved on an Ace C(18) column (5 microm, 250 mm x 4.6 mm id) using fluorescence detection with lambda(ex)=276 nm and lambda(em)=296 nm. The mobile phase consists of methanol-water (50:50, v/v) containing 0.1% TFA. The analysis was performed in less than 10 min with a flow rate of 1 mL/min. The assay was linear over the concentration range of 3-200 and 5-300 ng/mL for plasma and urine, respectively. The LOD were 1.0 and 1.5 ng/mL for plasma and urine, respectively. The LOQ were 3.0 and 5.0 ng/mL for plasma and urine, respectively. The extraction recoveries were found to be 95.6 +/- 1.53 and 96.4 +/- 1.75% for plasma and urine, respectively. Also, the method was successfully applied to three patients with hypertension who had been given an oral tablet of 100 mg metoprolol.

Evaluation of neopterin levels in patients undergoing hemodialysis.

Neopterin is a diagnostic or a prognostic biomarker for several pathologies including renal diseases. However, the association between neopterin status and causative main reasons such as diabetes and hypertension for renal disease remains unclear. The aim of the study was to evaluate neopterin levels in diabetes and hypertension patients treated with/without hemodialysis. According to primary renal disorders, the patients undergoing hemodialysis were classified into 4 groups as diabetic nephropathy, hypertensive nephropathy, reflux nephropathy or interstitial nephritis, and others. The controls consisted of healthy subjects, hypertensive subjects, and diabetic individuals without any renal disorder. In the study, both urinary and serum neopterin levels were measured using high performance liquid chromatography and enzyme-linked immunosorbant assay in patients undergoing regular hemodialysis therapy (n=71). The effects of the duration of hemodialysis and treatment of erythropoietin and/or iron on neopterin levels were also evaluated. Neopterin levels were found to be higher in hemodialysis patients than in the healthy controls (P<0.05). A significant difference in neopterin levels was also found between diabetic control patients and diabetic nephropathy patients (P<0.05). A similar significant difference was detected in neopterin levels between hypertensive patients with/without nephropathy (P<0.05). Neopterin may be an early critical marker for progression of nephropathy in diabetic and hypertensive patients in early stages.