Vitamin B6 and the immunity in kidney transplant recipients.

OBJECTIVE: The study aimed to determine vitamin B6 status in elderly (age ≥ 60 years) and younger (age <60 years) recipients of allogeneic kidney graft and to investigate associations between vitamin B6 status and immunity markers. DESIGN: A retrospective observational study. SETTING: The study was conducted at the Medical University of Gdansk, Poland. SUBJECTS: We recruited 34 kidney allograft recipients (17 males and 17 females) and allocated them into 2 groups: patients aged ≥ 60 years (18 patients) and those aged <60 years (16 patients). Exclusion criteria included patients receiving vitamin B6 supplementation or drugs known to influence vitamin B6 metabolism. MAIN OUTCOME MEASURE: Plasma levels of pyridoxal 5'-phosphate (PLP), pyridoxal, pyridoxine, pyridoxamine, pyridoxamine 5'-phosphate, and 4 pyridoxic acid were determined by high-performance liquid chromatography. Measured immunity markers were serum cytokines (interleukin-6, interleukin-10, and transforming growth factor-ß), levels of T-lymphocyte subsets, and the proliferative ability of peripheral blood mononuclear cells. RESULTS: Concentrations of all vitamin B6 vitamers in plasma (PLP, pyridoxal, pyridoxamine 5'-phosphate, pyridoxamine, pyridoxine, 4 pyridoxic acid) were comparable in the 2 studied groups. There were no cases of PLP deficiency in the study population, but 29% of patients had PLP concentrations more than the upper reference limit. Vitamin B6 vitamer concentrations were not influenced by gender, estimated glomerular filtration rate, and circulating phosphate concentration. There was no difference in immunity markers according to age. However, the plasma concentrations of vitamin B6 vitamers were inversely associated with levels of CD28(+) lymphocyte subsets, as well as with the proliferative response of peripheral blood mononuclear cells in both groups. CONCLUSIONS: No cases of vitamin B6 deficiency were found among kidney allograft recipients, and we report inverse links between vitamin B6 vitamer concentrations and markers of cellular immunity, suggesting that bioactive vitamin B6 concentration in kidney allograft recipients merits further investigation.

[Smoking influence on the level of homocysteine and 5-methyltetrahydrofolic acid in active and non smokers]. / Ekspozycja na dym tytoniowy a poziom homocysteiny i kwasu 5-metylotetrahydrofoliowego u osób palacych i niepalacych.

Cigarette smoking is associated with oxidative stress and increased risk of many chronic diseased. Smoking inducts depletion of cellular antioxidant and is also known to be associated with an increased homocysteine level. Exposure to tobacco smoke has negative impact on the folic acid level. Folic acid is cofactor by demethyla-tion of homocysteine to non toxic methionine. The aim of this study was to determine the concentration of total plasma homocysteine and 5-methyltetrahydrofolic acid in active and non smokers and to evaluate the influence of the tobacco smoke exposure on urinary cotinine levels. The results indicated significant increase of total plasma homocysteine in smokers, than non smokers. We also investigated the negative influence of tobacco smoke on the level of folic acid in plasma and it suggests, that additional supplementation of folic acid in smokers is necessary.

[Smoking influence on cadmium, lead, selenium and zinc level in placenta, cord blood and maternal blood of women at delivery from Gdansk region]. / Wplyw palenia tytoniu na stezenie kadmu, olowiu, selenu oraz cynku w lozysku, krwi pepowinowej i krwi kobiet rodzacych z Gdanska.

Cadmium, lead, selenium and zinc levels were determined in placenta, maternal blood and cord blood of 53 women at delivery from Gdansk region. Non-smokers [NS], passive smokers [PS] and smokers [S] were identified by the questionnaire. Our results suggest that there is no smoking impact on the levels of determined elements in placenta. Smoking women have higher Cd and Pb blood levels than mothers who never smoked (p < 0.01). Selenium levels in maternal and cord blood were higher in non-smoking group than in smokers (maternal blood NS vs S p < 0.01; cord blood NS vs S p < 0.001), but there is no smoking impact on the zinc levels in the study tissues. We also investigated the negative influence of tobacco smoke exposure on the distribution of the micro-elements in the feto-placental unit and that the ratio of Zn/Cd and Se/ Pb is higher in all tissues of non-smoking than smoking women.

High-performance liquid chromatography method for the simultaneous determination of thiamine hydrochloride, pyridoxine hydrochloride and cyanocobalamin in pharmaceutical formulations using coulometric electrochemical and ultraviolet detection.

The method for the simultaneous determination of thiamine hydrochloride, pyridoxine hydrochloride and cyanocobalamin by high-performance liquid chromatography (HPLC) with coulometric electrochemical and UV detections is presented. The retention time of vitamins was repeatedly determined by isocratic elution using 0.05 M phosphate buffer-10% methanol and 0.018 M trimethylamine (1 ml min(-1), pH 3.55) as mobile phase with the Supelco LC 18 column 5 microm (25 cm x 4.6 mm). The specificity of the method was demonstrated by the retention characteristics, coulometric electrochemical and UV detection. The limits of detection of thiamine, pyridoxine and cyanocobalamin were: 9.2, 2.7 and 0.08 ng/ml, respectively. The method was characterized also by wide concentration range, high sensitivity and good accuracy (99.6-102.7%). The repeatability of the method was evaluated at different level of concentration of vitamins and the relative standard deviation was below 4.5%. The method was successfully applied for the quantification of Vitamins B1, B6 and B12 in pharmaceutical preparations and dietary supplements.