Barbara Millo

Elements of Mediterranean diet improve oxidative status in blood of kidney graft recipients

Patients were fully informed as to the study objectives and benefits, and provided written consent prior to enrolment. The study protocol was approved by the Committee on Human Research at the Pomeranian Medical University, Szczecin, Poland. An intensification of free-radical reactions may contribute to accelerated atherosclerosis in kidney graft recipients. We examined the effect of a Mediterranean-type diet (MD) on the oxidative status of the plasma and erythrocytes of kidney graft recipients. Two patient groups were formed: a study group consuming the MD diet and a control group with a low-fat diet. C-reactive protein levels in plasma, oleic acid C18 : 1n-9 and linoleic acid C18 : 2n-6 concentrations in triacylglycerols were determined. To determine the oxidative status, we measured the concentrations of alpha-tocopherol in plasma, the content of thiobarbituric acid-reactive species (TBARS) in plasma and erythrocytes, and the activities of superoxide dismutase, catalase and glutathione peroxidase in erythrocytes. In the MD group, the activities of erythrocyte enzymes changed significantly: those of superoxide dismutase increased (P<0.001 after 6 months), catalase decreased (P<0.001 after 6 months) and glutathione peroxidase decreased (P<0.05 after 2 months). The oleic acid content of triacylglycerols was increased (P<0.006) whereas that of linoleic acid was decreased (P<0.00005), alpha-tocopherol levels remaining unchanged. TBARS in plasma were decreased after 6 months of MD (P<0.05). No significant correlations were observed between TBARS, oleic acid, linoleic acid and alpha-tocopherol levels in plasma. MD appears to protect the erythrocytes against the action of free radicals, as reflected in the modified activities of some enzymes regulating the oxidative status of these blood cells.

MMP-9, homocysteine and CRP circulating levels are associated with intraluminal thrombus thickness of abdominal aortic aneurysms – new implication of the old biomarkers

Background: Abdominal aortic aneurysms (AAAs) are characterized by presence of high proteolytic activity, atherosclerotic lesions, extensive transmural inflammation and the presence of variably sized and shaped intraluminal thrombus (ILT). Therefore, we evaluated a possible association between plasma matrix metalloproteinase-9 (MMP-9), homocysteine (Hcy), high-sensitivity C-reactive protein (hsCRP) levels and ILT thickness in patients with AAA. Methods: Plasma concentrations of MMP-9, Hcy and hsCRP were determined and ILT thickness was measured in 71 patients with AAA. They were divided into 2 groups according to ILT thickness: 34 patients with ILT mean thickness ≥ 9 mm and 37 patients with ILT < 9 mm. Results: Plasma MMP-9 and CRP concentrations in patients with thin ILT were significantly higher than in group with thick ILT (medians 610 vs. 485 ng/mL, p = 0.00003, and 7.7 vs. 3.3 mg/L, p < 0.00001, respectively) In contrast, plasma Hcy concentrations in patients with thin ILT were significantly lower than in the group with thick ILT (medians 14.3 vs. 19.2 μmol/L, p < 0.00001). Multiple regression models adjusted for age and AAA diameter showed that thin ILT is an independent predictor of high MMP-9 and CRP concentrations, while thick ILT predicts high Hcy concentrations. Conclusions: Association of higher plasma levels of MMP-9 and CRP with thin ILT may be related to two phenomena: thin thrombi convey more elastolysis-stimulating factors from blood to the AAA wall and thin thrombi convey more factors involved in proteolysis and inflammation from AAA wall to blood. The association of thin ILT with lower plasma Hcy concentrations may be related to the role of Hcy as a prothrombotic marker and needs further research.

Does Glucose in Dialysis Fluid Protect Erythrocytes in Patients with Chronic Renal Failure

Background/Aims: The aim of this study was to assess the multifaceted influence of glucose present in dialyzing fluid on erythrocytes of patients with chronic renal failure (CRF) undergoing regular hemodialysis. Methods: A group of 44 subjects with CRF undergoing regular hemodialysis was studied. Two tests were used: osmotic fragility and resistance to the hemolytic agent saponin. The total content of isoprostane 8-iso-prostaglandin F2α type III (8-iPF2α-III) in plasma and erythrocyte’s membrane were determined by the ELISA method. Results: The presence of glucose in the dialysate is associated with lower intravascular hemolysis markers and high total 8-iPF2α-III concentrations in plasma. Conclusion: The presence of glucose in dialyzing fluid could protect erythrocytes. It limits hemolysis in patients with CRF, but, on the other hand, increases the oxidative processes. This kind of treatment along with other therapeutic intervention such as administration of antioxidants (e.g. α-tocopherol, ascorbic acid, N-acetylcysteine) could improve the condition of erythrocytes and outcome in CRF.

Abdominal Aortic Aneurysm: Association Between Haptoglobin Phenotypes, Elastase Activity, and Neutrophil Count in the Peripheral Blood

To investigate the role of genetic factors on susceptibility to atherosclerotic arterial disease, the influence of haptoglobin phenotypes (Hp) on serum elastase activity, neutrophil count, and elastin concentration in the aorta was measured in patients with abdominal aortic aneurysm (AAA; n=52) and aortoiliac atherosclerotic occlusive disease (AOD; n=37). Findings (serum elastase activity, peripheral blood neutrophil count) were compared to a control group (CG) of 37 subjects without atherosclerosis. Hp phenotyping performed by starch-gel electrophoresis produced a haptoglobin-hemoglobin complex of three phenotypes: Hp1-1, Hp2-2, and Hp2-1. Distribution of Hp phenotypes was similar in the three study groups (AAA, AOD, CG). Significant increases in serum elastase activity and neutrophil count was measured in Hp2-1 phenotype of AAA patients. Although the aorta wall of aneurysm patients contained less (p<0.001) elastin than that of AOD patients, no significant difference of aorta elastin concentration between the three Hp phenotypes, including Hp2-1, was measured. The postulated association of AAA susceptibility with Hp2-1 phenotype was supported by the study data that demonstrated an increase in serum elastase activity in patients undergoing AAA repair.

The effect of L-ascorbic acid and/or tocopherol supplementation on electrophysiological parameters of the colon of rats chronically exposed to lead

Summary Background The aim of this study was to assess the effect of diet supplementation with L-ascorbic acid (500 mg/L), tocopherol (3 mg/kg b.w.), and/or a water soluble analog of tocopherol (Trolox) (48 mg/L) on ion transport in the colon of rats subjected to a chronic exposure (9 months) to 0.1% lead acetate in drinking water. Material/Methods The electrophysiological parameters of the colon wall were measured with Ussing methods. Lead content in the whole blood was analyzed by graphite furnace atomic absorption spectrometry (GFAAS) using Zeeman correction. L-ascorbic acid and tocopherol in plasma was measured by high performance liquid chromatography. Immunohistochemical reaction was carried out for visualization of occludin, the intracellular tight junction protein. Results We showed a strong inhibitory effect of lead on the electrophysiological parameters, changes in intestinal permeability, disappearance of junctional occludin, decreased amount of mucus covering the colon surface, and the accumulation of PAS-positive substance in the apical region of the cytoplasm in the absorptive cells. Conclusions Supplementation with tocopherol or Trolox did not exert a beneficial influence on the studied parameters. L-ascorbic acid positively influenced the examined electrophysiological parameters, as it cancelled the inhibitory influence of lead on ion transport in the rat colon. L-ascorbic acid also protected against tight junction disruption of epithelial cells in the colon of the lead-treated rats. A similar effect was observed in the group of rats receiving lead and supplemented with L-ascorbic acid plus Trolox.

Characterisation of rat and human tissue alkaline phosphatase isoforms by high-performance liquid chromatography and agarose gel electrophoresis

Alkaline phosphatase (ALP) exists as several isoenzymes and many isoforms present in tissues and serum. The objective of this study was to separate tissue ALP forms in rats and humans and characterise their properties. The materials for the investigation were intestinal, bone, and liver tissue of rats and commercially available human preparations of tissue ALP. Two methods of separation were used: high-performance liquid chromatography (HPLC) and agarose gel electrophoresis. Using HPLC in the rat tissues, two ALP isoforms in the intestine, one in the bone, and three in the liver were identified. In humans three intestinal, two bone, and one liver isoform were resolved. Electrophoresis showed two ALP activity bands in rat intestine, one wide band in the bone, and three bands in the liver. ALP of human tissues was visualised as a single wide band, with a different mobility observed for each organ. In both species the presence of a form with properties characteristic of the bone isoform of the tissue-nonspecific isoenzyme was observed in the intestine. HPLC offers a higher resolution than electrophoresis with respect to tissue ALP fractions in rats and in humans, but electrophoresis visualises high-molecular-mass insoluble enzyme forms.