Browsing by Person "Vasilaki, Katerina"

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Assessment of vitamin E status in patients with systemic inflammatory response syndrome: Plasma, plasma corrected for lipids or red blood cell measurements?
(Elsevier, 2009-08-19) Vasilaki, Katerina; Leivaditi, Dimitra; Talwar, Dinesh; Kinsella, John; Duncan, Andrew; O'Reilly, Denis St J.; McMillan, Donald C.
Background: There is some evidence that the plasma vitamin E status is perturbed as part of systemic inflammatory response and correcting this with other plasma markers may not lead to reliable results. The aim of the present study was to examine the longitudinal inter-relationships between plasma and red blood cell vitamin α-tocopherol in patients with systemic inflammatory response syndrome. Methods: α-tocopherol concentrations were measured, by HPLC, in plasma and red blood cells in normal subjects (n = 67) and in critically ill patients with systemic inflammatory response syndrome (n = 82) on admission and on follow-up. Results: Plasma α-tocopherol was significantly lower in the critically ill patients compared with the controls (all p < 0.001) with 41% of patients having concentrations below the 95% confidence interval. In contrast, when corrected for cholesterol, α-tocopherol concentrations were significantly higher in the critically ill patients compared with the control group (p < 0.001, 27% above the 95% confidence interval) and when corrected for triglycerides, α-tocopherol concentrations were significantly lower in the critically ill patients compared with the control group (p < 0.001). Red blood cell α-tocopherol corrected for haemoglobin was similar (p = 0.852) in the critically ill patients compared with control subjects. The longitudinal measurements (n = 53) gave similar results. Conclusions: These results indicate that there is a discrepancy between vitamin E measurements in plasma, in plasma corrected for lipids and in red blood cells. Although the value of correcting vitamin E concentrations by lipids is well established in population studies, the present study indicates that such correction is unreliable in the presence of systemic inflammatory response syndrome and that vitamin E status should be assessed using red blood cell α-tocopherol measurement.
The effect of the systemic inflammatory response on plasma zinc and selenium adjusted for albumin
(Elsevier, 2015-02-26) Ghashut, Rawia A.; McMillan, Donald C.; Kinsella, John; Vasilaki, Katerina; Talwar, Dinesh; Duncan, Andrew
Background & aim: The magnitude of systemic inflammatory response, as evidenced by C-reactive protein (CRP), is a major factor associated with lower zinc and selenium. They may also be influenced by their binding proteins, such as albumin. The aim of the present study was to examine the relationships between plasma zinc, selenium and the systemic inflammatory response in a large cohort of patients referred for nutritional screen and also to examine these relationships in patients with critical illness. Methods: Patients referred for nutritional assessment of zinc (n ¼ 743) and selenium (n ¼ 833) and 114 patients with critical illness were examined. Intra-assay imprecision was <10% for these analytes. Results: In the nutritional screen cohort, plasma zinc was significantly associated with CRP (rs ¼ 0.404, p < 0.001) and albumin (rs ¼ 0.588, p < 0.001). For each CRP category ( 10, 11e80, >80 mg/l) the zinc/ albumin ratio x100 was similar (31, 33 and 32 respectively, p ¼ 0.029). Plasma selenium was significantly associated with CRP (rs ¼ 0.489, p < 0.001) and albumin (rs ¼ 0.600, p < 0.001). With increasing CRP category ( 10, 11e80, >80 mg/l) the selenium/albumin ratio 100 was lower (2.3, 2.1 and 1.8 respec- tively, p < 0.001). Similar relationships were also observed in the cohort of patients with critical illness. Conclusion: Plasma zinc was associated with both CRP and albumin. The impact of the systemic in- flammatory response could be largely adjusted by albumin concentrations. Plasma selenium was asso- ciated with both CRP and albumin. The impact of the systemic inflammatory response on plasma selenium concentrations could not be reasonably adjusted by albumin concentrations.
Relation between pyridoxal and pyridoxal phosphate concentrations in plasma, red cells, and white cells in patients with critical illness
(Oxford University Press, 2008-07-01) Vasilaki, Katerina; McMillan, Donald C.; Kinsella, John; Duncan, Andrew; O'Reilly, Denis St J.; Talwar, Dinesh
Background: Evidence suggests that the relation between plasma and red cell vitamin B-6 concentrations is perturbed as part of the systemic inflammatory response in critically ill patients. Objective: The aim was to examine the cross-sectional and longitudinal interrelations between pyridoxal (PL) and pyridoxal phosphate (PLP) concentrations in plasma and red and white cells in patients with critical illness. Design: PLP and PL concentrations were measured by HPLC in plasma and red and white cells in normal subjects (n 126) and critically ill patients (n 96) on admission and on follow-up. Results: On admission, compared with the controls, median plasma PLP and PL (P 0.001 and 0.01, respectively) and red cell PLP and PL (P0.001 and0.05, respectively) andtheir ratio (PLP:PL) in plasma and red cells (P 0.001 and 0.01, respectively) were significantly lower in the critically ill. In critically ill patients, plasma PLP:PL was significantly lower than red cell PLP:PL (P 0.001) and white cell PLP:PL (P 0.008). Plasma PL concentration was directly associated with both red cell PL (rs 0.73, P 0.001) and white cell PL (rs 0.68, P 0.001). Red cell PL and white cell PL were directly associated with red cell PLP (rs 0.82, P 0.001) and white cell PLP (rs 0.68, P 0.001), respectively. Longitudinal measurements (n 48) were similar. Conclusions: The relation between plasma PLP and PL was significantly perturbed in critical illness. This effect was less pronounced in red and white cells. Therefore, these results confirm the hypothesis that intracellular PLP concentrations are more likely to be a reliable measure of status than are plasma measurements in the critically ill patient.
Relation between riboflavin, flavin mononucleotide and flavin adenine dinucleotide concentrations in plasma and red cells in patients with critical illness
(Elsevier, 2010-07-24) Vasilaki, Katerina; McMillan, Donald C.; Kinsella, John; Duncan, Andrew; O'Reilly, Denis St J.; Talwar, Dinesh
Background: There is some evidence that the relationship between plasma and red cell vitamin B2 concentrations is perturbed in the critically ill patient. The aim of the present study was to examine the longitudinal interrelationships between riboflavin, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) in plasma and red cells in patients with critical illness. Methods: Riboflavin, FMN and FAD concentrations were measured, by HPLC, in plasma and red cells in healthy subjects (n = 119) and in critically ill patients (n = 125) on admission and on follow-up. Results: On admission, compared with the controls, critically ill patients had significantly higher plasma riboflavin and FMN concentrations (p b 0.001) and lower median plasma FAD concentrations (p b 0.001). In the red cell, FAD concentrations were significantly lower in critically ill patients (p b 0.001). In healthy subjects, plasma riboflavin was directly associated with both plasma FMN (rs = 0.55, p b 0.001) and plasma FAD (rs = 0.49, p b 0.001). Red cell riboflavin was directly associated with red cell FMN (rs = 0.52, p b 0.001) but not red cell FAD. In the critically ill patients, plasma riboflavin was not significantly associated with either plasma FMN or FAD. Red cell riboflavin was directly associated with red cell FMN (rs = 0.79, p b 0.001) and red cell FAD (rs = 0.72, p b 0.001). Longitudinal measurements (n = 60) were similar. Conclusions: The relationship between plasma riboflavin, FMN and FAD was significantly perturbed in critical illness. This effect was less pronounced in red cells. Therefore, red cell FAD concentrations are more likely to be a reliable measure of status in the critically ill patient.
The relationship between plasma and red cell B-vitamin concentrations in critically-ill patients
(Elsevier, 2005-07-28) Quasim, Tara; McMillan, Donald C.; Talwar, Dinesh; Vasilaki, Katerina; O'Reilly, Denis St J.; Kinsella, John
Background and aims: Low vitamin B-complex status has been associated with poorer outcome in critically-ill patients. However, these findings have been based on indirect methods. Using direct methods for assessing vitamin status, we examined the effect of B-complex vitamin supplementation by measuring plasma and red blood cell B1, B2 and B6-vitamin concentrations in critically-ill patients. Methods: Thiamine diphosphate (TDP), flavin adenine dinucleotide (FAD) and pyridoxal phosphate (PLP) concentrations were measured in plasma and red cells of normal subjects (n ¼ 49) and ITU patients (n ¼ 41). Results: Compared with the normal subjects, critically-ill patients had higher C- reactive protein and lower albumin concentrations (Po0:001). Also, plasma FAD and PLP were lower (Po0:001) and red cell concentrations of both were higher (Po0:01) in critically-ill patients. Critically-ill patients were grouped according to whether (n ¼ 23) or not (n ¼ 18) they had been supplemented with B-complex vitamins. Compared with non-supplemented group, the supplemented group had significantly higher red cell TDP and PLP concentrations (Po0:01). Plasma FAD and PLP concentrations did not differ significantly between the groups. Conclusions: The results of the present study suggest that direct measurements of red cell FAD and PLP are more responsive to supplementation than plasma measurements in the critically-ill patient.