Human plasma lipid peroxide levels show a strong transient increase after successful revascularization operations

Circulating "Neutrophils extra-cellular traps" during the early post-renal transplant period and correlation with graft dysfunction and rejection

BACKGROUND

Neutrophil extracellular traps (NETs) have a role in infection, autoimmunity, autoinflammation, thrombosis, ischemia-reperfusion injury (IRI), epithelial-mesenchymal transition, vasculitis, and metabolic diseases. However, its role in early graft injury and graft outcome has not been elucidated till now. We evaluated the circulating NETs during early post-transplant periods and their correlation with graft outcome and IRI.

METHODS

Prospectively, thirty kidney transplants recipient (KTR) were recruited and grouped into non-dysfunction (Group-A) and dysfunction groups (Group-B). Serum levels of circulating NETs were estimated by measuring myeloperoxidase-DNA complex at three-time points: pre-transplant, 8 h post-transplant, and 18 h post-transplant; and correlated with early graft outcome. Malondialdehyde (MDA), a marker of oxidative stress or IRI, was also measured to assess its relation with NETs and early graft outcome.

RESULTS

Circulating NETs were significantly increased in both non-dysfunctional [Median OD: 0.11 (0.01-0.19) to 0.51 (0.22-0.91); p = 0.001] and dysfunctional [Median OD: 0.16 (0.12-0.27) to 0.38 (0.19-0.68); p = 0.047] KTR during first 8 h of transplant followed by fall at 18 h post-transplant [0.25 (0.18-0.72) and 0.35 (0.26-0.36) respectively]; however, no significant difference were observed between two groups at any time points. Isolated biopsy-proven graft rejection KTR also had higher circulating NETs during the early post-transplant period [Median OD: 0.16 (0.13-0.31) to 0.38 (0.28-1.5); p > 0.05] but no significant difference compared to non-dysfunctional KTR. MDA also displayed similar trends with an early significant rise [9.30 (7.74-12.56) μM to 17.37 (9.11-22.25) μM; p = 0.03 in group-A, and 8.7 (6.04-10.30) μM to 14.66 (13.39-21.63) μM; p = 0.01in group-B] followed by fall at 18 h in both groups [10.21 (7.64-13.90) μM and 11.11 (9.15-17.54) μM respectively]. Despite similar trends of both NETs and MDA, there was no significant correlation between these; however, creatinine exhibits a significant inverse correlation with NETs and MDA both.

CONCLUSION

Circulating NETs are significantly increased during the early post-transplant period in KTR irrespective of early graft outcome. Similar dynamics of MDA indicate that the early rise of NETs might be a part of IRI. However, molecular studies with large sample sizes and longer follow up are required to reach more defined conclusions.

Anesthetic Efficacy of Dexmedetomidine versus Midazolam When Combined with Remifentanil for Percutaneous Transluminal Angioplasty in Patients with Peripheral Artery Disease

Anesthesia for percutaneous transluminal angioplasty (PTA) involves a high-risk population having a broad spectrum of pain character and intensity. This study delved the anesthetic efficacy of dexmedetomidine versus midazolam, when used with remifentanil. Seventy patients scheduled for femoropopliteal PTA were randomized into two groups receiving either intermittent midazolam boluses (0.03–0.05 mg/kg) (MR group) or dexmedetomidine 0.2–0.7 μg/kg/h after a loading dose of 1.0 μg/kg for 10 min (DR group), both with remifentanil. The primary endpoint was the patients’ satisfaction (1–5, 5; extremely satisfied). Secondary endpoints included postprocedural pain scores (0–10, 10; worst imaginable pain) and adverse events. The satisfaction level of patients was significantly greater in the DR group compared with the MR group (4.0 [3.0, 5.0] versus 4.0 [2.0, 5.0] p = 0.021). The number of patients having a postprocedural pain score of at least 3 was significantly greater in the MR group compared with the DR group (10 [29%] versus 2 [6%], p = 0.013). The number of patients with hypotensive episodes was higher in the DR group (5 [14.7%] versus 0, p = 0.025), which could all be restored with ephedrine. The use of dexmedetomidine in conjunction with remifentanil may be a safe option that provides excellent patient satisfaction while potentially attenuating postprocedural pain.

Oxidative-inflammatory damage in cirrhosis: effect of vitamin E and a fermented papaya preparation

BACKGROUND AND AIM

Oxidative DNA damage occurs as an early event in hepatitis C virus (HCV) infection and is an indication of the potential for carcinogenesis. The aim of this study was to test a novel antioxidant/immunomodulator in patients with HCV-related cirrhosis.

METHODS

The study group consisted of 50 patients with HCV-related cirrhosis with transaminase values less than twofold increased (alanine aminotransferase [ALT] < 80 IU/L). Patients underwent a standardized food-vitamin composition assessment and were assessed for dietary intake, nutritional status and iron level. Patients were randomly allocated into two groups and then given either alpha-tocopherol 900 IU/day or 9 g/day of a fermented papaya preparation (FPP, Immun-Age, Osato Research Institute, Gifu, Japan) at bedtime for 6 months. Ten healthy subjects served as controls. Patients were checked monthly for: routine tests, redox status (reduced glutathione, glutathione peroxidase, oxidized glutathione, malondialdehyde), plasma alpha-tocopherol, 8-hydroxy-deoxy-guanidine (8-OHdG) level in circulating leukocyte DNA and serum levels of cytokines.

RESULTS

Patients with cirrhosis showed a significant imbalance of redox status (low antioxidants/high oxidative stress markers) (P < 0.005 vs controls). Neither treatment regimen affected transaminases as a whole. However, vitamin E supplementation almost normalized ALT only in the limited vitamin-E-deficient subgroup. A significant improvement of redox status was obtained by both regimens. However, only FPP significantly decreased 8-OHdG and the improvement of cytokine balance with FPP was significantly better than with vitamin E treatment (P < 0.05).

CONCLUSIONS

Although the present data seem to suggest a potential supportive role of antioxidants/immunomodulators as FPP in HCV patients, more studies are needed to substantiate their effect on the natural history of the disease.

Lipid peroxidation as additional marker in patients with colorectal cancer. Results of a preliminary study

BACKGROUND AND AIMS

Up to now, various tumor markers have been proposed for the detection of the onset of malignant cell transformation or the better follow-up of cancer patients. The aim of the present study is to investigate the diagnostic value of systemic lipid peroxidation as an additional evaluative tool in the follow-up of surgical patients with colorectal cancer in combination to the clinically routine tumor markers carcinoembryonic antigen (CEA) and carcinoantigen 19-9 (CA 19-9).

PATIENTS AND METHODS

36 patients with a colorectal carcinoma were included in this study. Blood samples were collected 1 day prior to the operation, 10 days and 1 year after the operation. Oxygen free radical mediated lipid peroxidation was determined by measurement of thiobarbituric acid-reactive substances in the same serum that were used for the determination of tumor markers.

RESULTS

Compared to control values, a highly significant increase of lipid peroxidation was found in the serum of all colorectal carcinoma patients up to the first 10 postoperative days. Differentiation of the patients, according to the T-stage, showed a marked and more obvious tendency towards higher serum lipid peroxides with increased tumor stage when compared to the conventional tumor markers. One year postoperatively the serum levels of lipid peroxidation returned to nearly normal values. Also the conventional tumor markers CEA and CA 19-9 showed a relative rise in the levels with the respective tumor stage, but differences were only statistically significant in the highest T-categories.

CONCLUSION

After curative resection of the tumor, the level of systemic lipid peroxides decreases to normal values. We conclude from these results that the tumor is the primary cause of the increased systemic lipid peroxides.

Alterations of thrombogenesis, endothelial damage and oxidative stress with reperfusion during femoral artery bypass surgery for peripheral vascular disease

Peripheral vascular disease (PVD) is a significant cause of cardiovascular morbidity. We hypothesised that there would be significant alterations of thrombogenesis, platelet activation and endothelial damage, which could be associated with abnormal oxidative stress during femoral artery bypass surgery for PVD, where the femoral artery is cross-clamped (causing acute ischaemia) and reperfused (following revascularisation). To test this hypothesis, we measured sequential changes in von Willebrand factor (vWF, and index of endothelial damage/dysfunction), tissue factor (TF, an index of thrombogenesis) and soluble P-selectin (sP-sel, an index of platelet activation) as well as lipid hydroperoxides (LPO, an index of oxidative stress) in 28 consecutive patients undergoing elective peripheral artery bypass surgery. Mean baseline vWF and sP-sel levels in PVD patients (before clamping) were significantly higher compared with age- and sex-matched controls (unpaired t test, both p < 0.05), but there were no significant differences in TF and LPO levels. There was a correlation between TF and vWF (Spearman's, r = 0.374, p = 0.05), as well as between sP-sel and vWF at the start of surgery (r = 0.467, p = 0.012). The patients undergoing peripheral artery bypass surgery had a mean femoral artery clamp time of 28 min (standard deviation 14 min; range 11-65 min). There were no significant overall changes in sP-sel, vWF, TF and LPO with femoral artery cross-clamping and reperfusion (repeated measures ANOVA, p = NS). In conclusion, we found that during ischaemia-reperfusion during peripheral arterial bypass surgery, thrombogenesis (as measured by plasma TF) and oxidative damage (as measured by LPO) within the affected leg does not increase in the immediate perioperative period. Further studies are required to assess the mechanism(s) of ischaemia-reperfusion injury in PVD, and the contributory role(s) of the endothelium and platelets.

Multi-antioxidant supplementation does not prevent an increase in gut permeability after lower torso ischemia and reperfusion in humans

BACKGROUND

An increase in gut permeability can have serious consequences leading to sepsis and multiple organ failure. After lower torso ischemia an increase in gut permeability is seen in both animals and humans. There is proof that this can be modified by antioxidant supplementation.

METHODS

In this prospective, randomized study we have looked at the influence of a multiantioxidant supplementation regime, using allopurinol, vitamins E and C, mannitol and N-acetylcysteine, perioperatively. Twenty-two patients received standard treatment and 20 patients received supplementation. Gut permeability was determined using a double sugar test with lactulose and rhamnose.

RESULTS

A significant increase in gut permeability was found neither in the non-treatment group (p = 0.012) nor in the treatment group (p = 0.006) after 6 and 24 h. No difference was found between the group receiving antioxidants and the standard treatment group. p = 0.93 6 h post clamp; p = 0.97 24 h post clamp.

CONCLUSION

In this study we have not found an influence of multiantioxidant supplementation on gut permeability after lower torso ischemia. Possible explanations for this negative result are being discussed.

NADH/NADPH oxidase p22 phox C242T polymorphism and lipid peroxidation in coronary artery disease

The nicotinamide adenine dinucleotide (NADH)/nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system is a major source of superoxide anion (.O2-) production in the human vasculature and may therefore influence lipid peroxidation and severity of atherosclerosis. This study aimed to investigate a hypothetical influence of the p22 phox C242T polymorphism on the generation of malondialdehyde (MDA), extent and clinical onset of coronary artery disease (CAD) in patients. We studied 108 male Caucasians with angiographically documented CAD and 45 controls free of vascular disease under 60 years of age. p22 phox C242T genotypes and MDA levels were determined. Additional information was obtained from each subject on classic risk factors and clinical events of CAD. Genotype distribution in CAD-patients and controls was thymine-thymine (TT): 13.8% (13.3%), cytosine-thymine (CT): 46.3% (53.3%) and cytosine-cytosine (CC): 39.8% (33.3%), respectively. No significant influence was seen of the p22 phox C242T polymorphism on corresponding mean MDA levels in both groups. Furthermore, age at onset of first time angina pectoris (AP) and myocardial infarction (MCI) was not significantly different between genotype groups. It is concluded that the C242T polymorphism of the p22 phox gene is not associated with lipid peroxidation as measured by MDA, and is not a genetic risk marker for CAD Caucasians.

Cytoprotective effect of trimetazidine on 75 min warm renal ischemia-reperfusion injury in rats

In this experimental study, we evaluated the effect of trimetazidine (TMZ) on renal ischemia-reperfusion (IR) injury in Sprague-Dawley rats. Renal IR was achieved by a 75-min clamping of the left renal pedicle and subsequent 24 h reperfusion, after right nephrectomy was performed. The rats were randomly divided into three groups: group 1 (sham-operated: no IR injury), group 2 (ischemic control: saline treatment), and group 3 (3 mg/kg TMZ before ischemia). After 24 h of reperfusion, blood samples and renal tissue samples were taken to measure the levels of creatinine, tissue malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) activity. Histopathological changes were evaluated. In addition, the 7-day survival rates in each group were evaluated. We found significant increases in the levels of creatinine and tissue MDA, severe acute tubular necrosis, and a significant decrease in the activity of the GSH-Px in group 2. There were significant decreases in the levels of creatinine and tissue MDA, mild acute tubular necrosis, and a significant increase in activity of the GSH-Px in group 3 when compared with the control group (p <0.05). Statistically significant differences (p <0.05) in survival were noted between the ischemic control and sham-operated and TMZ groups. We have concluded that TMZ is able to protect the kidney from warm IR injury.

Relationship between classic risk factors, plasma antioxidants and indicators of oxidant stress in angina pectoris (AP) in Tehran

Cardiovascular disease (CVD) in general seems to be the leading cause of death in the Eastern Mediterranean Region (EMR) including Iran. This may be due to classic risk factors such as high triglyceride (TG), high total cholesterol (TC), and low levels of high density lipoprotein cholesterol (HDL-C). The impact of antioxidants as potentially protective risk factors against early coronary heart disease (CHD) is unknown in Iran. Therefore, relationships between angina and plasma antioxidants and indicators of lipid peroxidation were investigated in a case-control study. In this study, 82 cases of previously undiagnosed angina pectoris (AP), identified by a modified WHO Rose chest pain questionnaire and verified by electrocardiography during treadmill exercise testing, were compared with 146 controls selected from the same population of over 4000 male civil servants aged 40-60 years. Subjects with AP declared significantly less physical activity and had higher serum TG [means (S.E.M.) 2.32 (0.18) versus 1.61 (0.07) mmol/l] but lower HDL-C [1.01 (0.04) versus 1.18 (0.03) mmol/l] than age-matched controls. Levels of total serum cholesterol, low-density lipoprotein cholesterol (LDL-C) and lipoprotein(a) [Lp(a)] were not significantly different between the two groups, while the ratio of LDL-C/HDL-C was significantly higher [4.51 (0.23) versus 3.54 (0. 11)] for subjects with AP than for the controls. There was no significant difference in plasma levels of alpha-tocopherol, vitamin C, alpha- and beta-carotene. However, retinol [1.90 (0.06) versus 2. 09 (0.05)] and beta-cryptoxanthin [0.398 (0.04) versus 0.467 (0.03)] were significantly lower in AP. Furthermore, angina cases exhibited a higher index of lipid peroxidation than controls (e.g. malondialdehyde, MDA; 0.376 (0.010) versus 0.337 (0.009) micromol/l). On multiple logistic regression analysis, retinol with odds ratio (OR) of 0.644 [95% confidence interval (CI; 0.425-0.978)], beta-cryptoxanthin, with an OR of 0.675 (CI; 0.487-0.940), oxidation indices, MDA with OR of 1.612 (95% CI; 1.119-2.322) and LDL-C/HDL-C ratio with OR of 2.006 (95% CI; 1.416-2.849) showed the most significant independent associations with AP in this group of Iranians. In conclusion, the state of lipid peroxidation as well as the status of special antioxidants may be co-determinants of AP in Iran, in parallel with the influence of classical risk factors for cardiovascular disease.

Low density lipoprotein immunoapheresis does not increase plasma lipid peroxidation products in vivo

Extracorporeal elimination of low density lipoprotein (LDL) is frequently used in drug-resistant hypercholesterolemia. LDL-immunoapheresis selectively removes LDL and lipoprotein(a) [Lp(a)] from plasma. Lipid peroxidation is one unwanted side effect, that occurs during extracorporeal plasma treatment. The purpose of this study was to investigate the effect of LDL immunoapheresis on lipid peroxidation. Before and after a single LDL-immunoapheresis treatment, plasma concentrations of lipid hydroperoxides, determined with two different spectophotometric assays, thiobarbituric acid-reacting substances (TBARS), determined spectrophotometrically and malondialdehyde (MDA), determined by an MDA-TBA/HPLC method, were measured in 13 hypercholesterolemic patients. In addition MDA was also determined in the eluate of the apheresis column. Before treatment, plasma cholesterol and LDL cholesterol concentrations were significantly higher in patients than in healthy control subjects, as were the lipid peroxidation products. LDL-immunoapheresis treatment of the patients led to significant decreases in total cholesterol (69+/-8%), LDL-cholesterol (79+/-7%), HDL-cholesterol (35+/-17%), triglycerides (38+/-21%), apolipoprotein-B (77+/-6%), apolipoprotein-A1 (25+/-5%) and Lp(a) concentrations (76+/-10%). Changes in plasma lipid peroxide concentrations (17+/-8 nmol/l before vs. 14+/-5 nmol/l after treatment) were not significant, neither were those in TBARS (3. 0+/-2.6 micromol/l vs. 2.3+/-1.3 micromol/l) or MDA concentrations (1.03+/-0.17 micromol/l vs. 1.0+/-0.20 micromol/l). Patients with high baseline values showed a decrease, whereas others did not. MDA was present (0.57+/-0.13 micromol/l) in the eluate of the apheresis column, suggesting that, along with LDL, lipid peroxidation products are also removed. From these results we conclude that a single LDL-immunoapheresis treatment effectively reduces LDL and Lp(a) in the absence of increases in plasma lipid peroxidation products.

Normothermic liver ischemia and antioxidant treatment during hepatic resections

The purpose of our study was to evaluate the clinical impact of reperfusion injury after normothermic ischemia during major liver resections and the effect of an intraoperative antioxidant infusion. This prospective randomized study comprised 50 patients; half of them (treatment group) were given an antioxidant infusion containing tocopherol and ascorbate immediately prior to reperfusion onset. Venous blood samples for the determination of MDA-TBARS (malondialdehyde-thiobarbituric acid reactive substances) by a HPLC-based test as a marker of lipid peroxidation were taken prior to ischemia, 30 min after reperfusion onset and at the end of the operation. In the control group there was a significant increase of MDA-TBARS (p = 0.001) at 30 min after reperfusion onset. At the end of the operation the values had returned to the initial level. The treatment group showed only a marginal increase (p-value for the difference between the two groups: 0.007). After exclusion of the patients with histologically proven advanced cirrhosis the increase in the control group (p < 0.001) and the difference between the increase in the two groups (p = 0.001) became more significant. Prothrombin time was also significantly better in the treatment group (p = 0.003). Postoperative complications such as prolonged liver failure, bleeding disorders and infections were seen more often in the control group. In our study MDA-TBARS was increased after liver ischemia, but in patients with advanced cirrhosis the effect was smaller or even absent. This increase and possible clinical consequences of reperfusion injury could be reduced by intraoperative administration of an antioxidant infusion.

Lower limb oedema following distal arterial bypass grafting

Lower-limb oedema following arterial bypass surgery for ischemia is a common sequela which can complicate wound healing or delay resumption of mobility. Its exact pathogenesis remains uncertain but many theories have been proposed. Lymphatic disruption during arterial exposure, and endothelial damage from atrophy of the media and oxygen-derived free radical release are currently favoured hypotheses. Infrequently, deep vein thrombosis follows surgery and may exacerbate the condition. Efforts aimed at reducing the oedema, such as the use of lymphatic preserving incisional approaches or the use of antioxidants, have given conflicting results. The use of compression hosiery and leg elevation appear to be the most effective measures in reducing postoperative lower limb oedema.

Ischemia/reperfusion injury in human kidney transplantation: an immunohistochemical analysis of changes after reperfusion

Organs used for transplantation undergo varying degrees of cold ischemia and reperfusion injury after transplantation. In renal transplantation, prolonged cold ischemia is strongly associated with delayed graft function, an event that contributes to inferior graft survival. At present, the pathophysiological changes associated with ischemia/reperfusion injury in clinical renal transplantation are poorly understood. We have performed an immunohistochemical analysis of pre- and postreperfusion biopsies obtained from cadaver (n = 55) and living/related donor (LRD) (n = 11) renal allografts using antibodies to adhesion molecules and leukocyte markers to investigate the intragraft changes after cold preservation and reperfusion. Neutrophil infiltration and P-selectin expression were detected after reperfusion in 29 of 55 (53%) and 24 of 55 (44%) cadaver renal allografts, respectively. In marked contrast, neutrophil infiltration was not observed in LRD allografts, and only 1 of 11 (9%) had an increased level of P-selectin after reperfusion. Immunofluorescent double-staining demonstrated that P-selectin expression resulted from platelet deposition and not from endothelial activation. No statistically significant association was observed between neutrophil infiltration and P-selectin expression in the glomeruli or intertubular capillaries despite the large number of cadaver renal allografts with postreperfusion changes. Neutrophil infiltration into the glomeruli was significantly associated with long cold ischemia times and delayed graft function. Elevated serum creatinine levels at 3 and 6 months after transplantation were also associated with the presence of neutrophils and platelets after reperfusion. Our results suggest that graft function may be influenced by early inflammatory events after reperfusion, which can be targeted for future therapeutic intervention.

Lead-induced hypertension: interplay of nitric oxide and reactive oxygen species

An elevation of mean blood pressure was found in rats treated with low lead (0.01% lead acetate) for 3 months, as contrasted to paired Sprague-Dawley control rats. In these rats, measurement of plasma and urine endothelins-1 and -3 revealed that plasma concentration and urinary excretion of endothelin-3 increased significantly after 3 months (plasma: lead group, 31.8+/-2.2, versus controls, 23.0+1.7 pg/mL, P<.001; urinary excretion: lead group, 46.6+11.7, versus controls, 35.6+6.7 pg/24 h, P<.05), whereas endothelin-1 was unaffected. Plasma and urinary nitric oxide (NO) and cyclic GMP concentrations were not significantly changed. However, assay of plasma and kidney cortex malondialdehyde by high-pressure liquid chromatography, as a measure of reactive oxygen species, was elevated in lead-treated rats compared with that in control rats (plasma: lead group, 4.74+1.27, versus controls, 2.14+.49 micromol/L, P<.001; kidney cortex: lead group, 28.75+3.46, versus controls, 16.38+2.37 nmol/g wet weight, P<.001). There was increased NO synthase activity in lead-treated rat brain cortex and cerebellum. In lead-treated rat kidney cortex, the endothelial constitutive NO synthase protein mass was unaffected, whereas the inducible NO synthase protein mass was increased. These data suggest a balance between increased NO synthesis and degradation (by reactive oxygen species) in lead-treated rats, which results in normal levels of NO. Thus, the hypertension may be related to an increase in the pressure substances, endothelin-3 and reactive oxygen species, rather than to an absolute decrease in nitric NO.

Changes in the polymorphonuclear leukocyte function of blood samples induced by storage time, temperature and agitation

We have investigated changes in polymorphonuclear leukocyte (PMN) functions of blood samples caused by such typical elements of laboratory handling as storage time, temperature and agitation. The blood of five healthy subjects was stored upright in test tubes at 4, 22 and 37 degrees C over periods of 20 min, one, two, six and 24 h. Controlled agitation was performed on a shaker. The following PMN functional parameters were measured: the white blood cell count (WBC), migration, elastase (EL) release, reactive oxygen species (ROS) production and lipid peroxidation. Migration was determined in a whole-blood membrane filter assay; ROS production by latex-stimulated, luminol-enhanced chemiluminescence (CL) in a whole-blood assay; EL as EL alpha 1-antitrypsin complex; and lipid peroxidation by malondialdehyde (MDA) generation. The reactions after handling were compared with the values measured immediately after blood withdrawal which served as reference values of 'genuine' PMN reactivity. The outstanding result was the marked scatter between the individual reactions. Overall, the proportion of migrating PMNs in the blood total decreased, while CL, correlating positively with MDA, increased with the time of storage. EL increased considerably in some of the samples. Agitation raised CL and MDA. The effect of temperature was apparent only after 24 h at 37 degrees C. There was evidence that inhomogeneities in the blood samples were another interfering factor, since resuspension of sedimented blood after storage can be incomplete. In order to obtain reliable results from PMN functional tests, whole-blood assays and processing of blood samples within 20 min after blood withdrawal are recommended.

Vitamin E protects human skeletal muscle from damage during surgical ischemia-reperfusion

PURPOSE

The biochemical and morphological alterations induced in lower limb skeletal muscle by ischemia-reperfusion (I-R) during aortic surgery and the effect of vitamin E pretreatment were investigated.

METHODS

Two groups of patients undergoing aortic aneurysm resection, one untreated and one treated with vitamin E, were examined. Quadricep muscle biopsies were taken after induction of anesthesia, at the end of ischemia, and after reperfusion. The malondialdehyde (MDA) content and morphology of biopsies were examined to assess peroxidative processes.

RESULTS

Ischemia did not induce an increase in MDA content but did increase neutrophil infiltration in muscle fibers of untreated patients. Reperfusion led to a significant increase in MDA content and to intermyofibrillar edema and mitochondrial swelling. The MDA content was not increased during ischemia and neutrophil infiltration was minimal in vitamin E treated patients. At reperfusion, the MDA content, the ultrastructural injuries and neutrophil infiltration were significantly reduced by the treatment.

CONCLUSIONS

Vitamin E is effective in reducing the oxidative muscle damage occurring after a period of I-R.

Modified low density lipoprotein is a potent stimulus for smooth muscle cell outgrowth from rat aortic explant in vitro

Outgrowth of vascular wall cells from rat aortic tissue explant was studied. In addition to fresh rat serum (3%), the complete culture medium contained either low density lipoprotein (LDL) separated from rat plasma (n-LDL, 100 microg/ml) or rat LDL modified either by activated rat polymorphonuclear leucocytes (pmn-LDL) or by exposure to UV light (uv-LDL). Compared to n-LDL, pmn-LDL significantly increased the start of cell outgrowth and the further rate of growth. High concentration of uv-LDL (500 microg/ml) was cytotoxic. Cells which grew out from aortic tissue in the presence of n-LDL were characterised as endothelial cells by staining with lectin Ulex europaeus, with monoclonal antibody to Factor VIII or with monoclonal antibody to endothelial cells (CD31). However, cells which grew out in the presence either of pmn-LDL or uv-LDL did not stain with any of these endothelial cell markers, instead they showed intense staining with monoclonal anti-alpha-smooth muscle actin, indicating that they were smooth muscle cells. Growth rate of subcultured rat aortic smooth muscles cells was increased (P < 0.05) by the presence of uv-LDL (100 microg/ml). It is concluded that LDL modified either by activated leucocytes or by UV light prevents the normal outgrowth of endothelial cells from aortic explant and at the same time greatly promotes outgrowth of smooth muscle cells. Stimulation of both outgrowth of smooth muscle cells from vascular tissue and their proliferation by modified (oxidised) LDL may have important pathological significance in atherogenesis and restenosis.

Renoprotective effects of the 21-aminosteroid U74389G in ischemia-reperfusion injury and cold storage preservation

Free radical mediated lipid peroxidation (LPO) has been implicated in the pathogenesis of ischemic-reperfusion injury (IRI). To address the renoprotective effect(s) of LPO inhibition, the efficacy of the 21 aminosteroid U74389G was evaluated in three IRI models. In Model 1 51 unilateral nephrectomized rats that underwent 60 min of warm ischemia followed by a 72-hr reperfusion interval were treated with the test vehicle only, or 3, 6, or 12 mg/kg of U74389G intravenously, 5 min pre- or postischemia. In Model 2 Sprague-Dawley rats underwent sham operation (n=9), or 45 min of warm ischemia and 10 min of reperfusion with U74389G (6 mg/kg; n=10) or test vehicle only (n=10) administered intravenously over 10 min beginning 5 min prior to clamp release. After reperfusion, LPO was determined by assay of snap frozen tissue for thiobarbituric acid (TBA) concentrations (nmol/g tissue weight). In Model 3 domestic lean maid pigs (14-18 kg) underwent left nephrectomy with 30 min of warm ischemia, Collins C-4 flush, and 24 hr of cold storage preservation. Heterotopic autotransplantation and immediate contralateral nephrectomy was then performed in Group A-nonischemic controls (n=4), Group B-ischemic controls (n=5), and Group C-U74389G (6 mg/kg) administered preischemia and at autotransplantation (n=5). In Model 1 maximal renoprotection was demonstrated with the 6 mg/kg dose of U74389G administered after ischemia (ischemic control 72-hr serum creatinine (Cr) = 8.01+/-1.1 mg% vs. 3.32+/-0.96 mg%; ischemic control creatinine clearance = 0.069+/-0.03 ml/min vs. 0.206+/-0.04 ml/min; P<0.05). In Model 2 TBA levels were significantly lower in U74389G treated animals (88.5+/-10.0 vs. ischemic controls = 296.8+/-81.4; P=0.02). In Model 3 graft survivals were 100%, 0%, and 60% respectively. Peak Cr and BUN (mg%) were significantly greater in Group C vs. Group A, (Group A Cr = 8.59+/-0.63 vs. Group C = 12.8+/-1.01; Group A BUN = 64.1+/-2.73 vs. Group C = 104.9+/-12.21)--however, by day 10, thee were no significant differences in renal function: (Group A Cr = 2.15+/-0.3 vs. Group C = 2.10+/-0.06; Group A BUN = 27.0+/-6.0 vs. Group C = 31.1+/-6.4). These results support the beneficial effects of LPO inhibitors in models of ischemia-reperfusion, as well as preservation/transplantation, and suggest that this renoprotection correlates with decreased membrane lipid peroxidation.

Lipid peroxidation-associated oxidative stress during percutaneous transluminal coronary angioplasty in humans

Animal studies suggest that myocardial ischemia/reperfusion causes oxidative stress. We, therefore, examined whether routinely performed percutaneous transluminal coronary angioplasty (PTCA) might be a human ischemia/reperfusion model for oxidative stress-induced lipid peroxidation. Fasting antecubital venous blood was sampled from 13 patients on the morning of PTCA, and 2 d after PTCA. Venous and coronary arterial blood were sampled just before and 10 min after the first balloon inflation. Samples were analyzed for plasma and LDL lipid hydroperoxide levels, in vitro oxidation of LDL, and LDL antioxidant levels. Lipid hydroperoxide levels in plasma and LDL remained unchanged throughout the study. During the first 10 min of PTCA, the lag time during oxidation of LDL in vitro did not change, but the maximum rate of oxidation decreased in venous and arterial samples (Wilcoxon signed rank test: p < .002). At the same time, total tocopherol levels in LDL significantly increased by 6.3% (p = .048) in arterial, but not in venous samples. Total carotenoid levels increased by 3.8% (p = .127) in arterial samples and decreased by 2.9% (p = .040) in venous samples. Forty hours after PTCA, LDL oxidation parameters and LDL antioxidant levels were similar to baseline, except for about 17% lower levels of delta-tocopherol (p = .037) and gamma-tocopherol (p = .014). Our results, therefore, do not support that PTCA in humans is associated with oxidative stress-induced lipid peroxidation.

Effect of oral coenzyme Q10 supplementation on the oxidation resistance of human VLDL+LDL fraction: absorption and antioxidative properties of oil and granule-based preparations

Coenzyme Q10 (Q10) is supposed to be an important endogenous lipid-soluble antioxidant. We studied 60 healthy 46 +/- 7 (mean +/- SD)-year-old smoking men. They were randomized into three groups to receive oil-based or granular Q10 (90 mg/d) or placebo for 2 months. Oil-based capsule elevated Q10 in plasma by 178% and in VLDL+LDL fraction by 160%. The granular preparation increased Q10 in plasma by 168% and in VLDL+LDL by 127%. However, the 2-month Q10 supplementation did not increase the oxidation resistance of VLDL+LDL fraction, as assessed by copper induced VLDL+LDL oxidation, haemin+H(2)O(2)-induced VLDL+LDL oxidation, total antioxidative capacity of LDL, and plasma malondialdehyde measurements. The first and the last dose was used to carry out a 12 h pharmacokinetic study (five subjects per group), which indicated that only a small part of supplemented Q10 was absorbed to the circulation in 12 h and that the absorption varied extensively between subjects. Our results suggest that at least among smoking men, 90 mg of orally supplemented Q10 daily does not increase the oxidation resistance of VLDL+LDL. Bioavailability of both the granular and the oil-based Q10 preparation was similar during the long-term supplementation, but one dose of 30 mg had only a marginal effect on the plasma levels of Q10.

Influence of the 21-aminosteroid U74389F on ischemia-reperfusion injury in the rat

We examined the effects of the administration of 21-[4-(2,6-di-1-pyrrolidinyl-4-pyrimidinyl)-1-piperazinyl]-pregna-1,4,9( 11)-triene-3,20-dione, monomethansulfonate (U74389F), a 21-aminosteroid and so-called lazaroid, that is characterized by an inhibitory activity against iron-dependent lipid peroxidation, on ischemia-reperfusion renal injury in a rat model. After either 60 or 90 min of ischemia, plus 2 or 24 h of reperfusion, kidneys were assayed for glutathione, adenine nucleotides and lipid peroxidation products. 60 min of ischemia produced too little oxidative stress and/or too much spontaneous recovery to allow visualization of the protective effect of the drug. 90 min of ischemia followed by reperfusion induced significant glutathione oxidation, the free oxidized glutathione to total glutathione redox ratio (%) being enhanced from 4.6 +/- 0.7% before kidney clamping to 11 +/- 1 and 8.6 +/- 1.4% at 2 and 24 h reperfusion, respectively. Treatment with the lazaroid provided significant protection against this oxidation (4.9 +/- 1.05% at 24 h reperfusion). Results of lipid peroxidation confirmed the antioxidant effect of the lazaroid. In conclusion this study provides evidence for a protective role of the tested lazaroid against ischemia-reperfusion renal injury in the rat.

Evidence that continuous normothermic blood cardioplegia offers better myocardial protection than intermittent hypothermic cardioplegia

OBJECTIVES

To compare transmyocardial ischaemia and oxidative stress, as well as non-infarction myocardial injury, in patients randomised to intermittent hypothermic cardioplegia or continuous normothermic blood-potassium cardioplegia.

DESIGN

Prospective randomised trial.

SETTING

Tertiary cardiac referral centre.

METHODS

24 patients undergoing elective coronary artery bypass surgery were randomised to hypothermic (13 patients, mean (SEM) age 59.5 (2.6) years) or normothermic (11 patients, mean (SEM) age 59.7 (3.3) years) cardioplegia. Transmyocardial oxidative stress and ischaemia were assessed by the difference in plasma concentrations of oxidised glutathione and lactate respectively, from samples taken simultaneously from the coronary sinus and aortic root. Blood samples were taken just before cross clamp application and at intervals up to 15 min after cross clamp release. Non-infarction myocardial injury was assessed by measurement of creatine kinase MB isoenzyme activity from peripheral venous blood taken 2 and 18 h after surgery.

RESULTS

Intermittent hypothermic cardioplegia resulted in a significant increase in transmyocardial ischaemia (P < 0.001) and oxidative stress (P < 0.001). Evidence of significantly increased myocyte damage was also present (P < 0.01). No significant corresponding changes were present with normothermic cardioplegia.

CONCLUSIONS

Normothermic blood cardioplegia seems to avoid significant changes in myocardial ischaemic status and consequent oxidative stress. This study provides direct evidence that normothermic cardioplegia offers enhanced myocardial protection compared with that of hypothermic cardioplegia. Certain subsets of patients may derive more benefit from normothermic cardioplegia, although it is unclear whether this would be the case for all patients.

Analytical technologies for lipid oxidation products analysis

Productive investigation of the contribution of oxidative stress to human disease is facilitated by the design and application of suitable analytical technologies for oxidation product analysis. Lipid oxidation, including polyunsaturated fatty acid and cholesterol oxidation, produces a variety of products that can function as indexes of the extent of oxidation. These products include fatty acid hydroperoxides and hydroxides, aldehydes, prostanoids, hydrocarbons, and cholesterol hydroperoxides and hydroxides, epoxides, and carbonyls. Some of these oxidation products have biological activities that can contribute to tissue damage in unique ways. This paper reviews the state-of-the-art for chromatographic analysis of these products through a discussion of advances that have taken place since 1990.

Antioxidative vitamin treatment: effect on lipid peroxidation and limb swelling after revascularization operations

The objective of this study was to evaluate the antioxidative properties of the multivitamin cocktail Omnibionta (alpha-tocopherol, ascorbic acid, retinol, vitamin B complex) in terms of diminishing lipid peroxidation with improvement of leg edema performance after limb revascularization operations in humans. Fifty-one subjects were selected; the control group contained 27 patients and the treatment group 24 patients, who received the vitamin cocktail intravenously before the start of reperfusion. All patients suffered from acute or chronic arterial occlusive disease, except two subjects with arterial trauma. MDA-TBARS in plasma, quantified by HPLC, taken as a measure of lipid peroxidation was significantly increased (p < 0.001) in the control group 1 hour after reperfusion onset and decreased to its baseline value within the following 2 hours (0.73 +/- 0.26, 1.21 +/- 0.48, 0.99 +/- 0.48, 0.73 +/- 0.33 nmol/ml). In contrast, in the treatment group MDA-TBARS did not exceed the baseline value during the reperfusion period (0.93 +/- 0.30, 0.70 +/- 0.29, 0.65 +/- 0.23, 0.70 +/- 0.37 nmol/ml). Leg edema, expressed by extremity circumference, was significantly (p < 0.008) elevated in the control group (30.7 +/- 4.04 cm versus 35.35 +/- 4.12 cm) compared to a lack of increase in the treatment group (29.25 +/- 5.13 cm versus 29.76 +/- 5.70 cm). These results suggest that antioxidative vitamin treatment might be valuable in preventing lipid peroxidation and decreasing extremity edema.

Transient reduction of autoantibodies against oxidized LDL in patients with acute myocardial infarction

Fifteen consecutive patients (mean age 66 +/- 14, range 31-82) with an acute myocardial infarction (MI) suitable for thrombolytic therapy were included in this study. Autoantibodies against oxidized low-density lipoprotein (LDL) were determined by enzyme-linked immunosorbent assay (ELISA). Patients (n = 10) with marked elevation of the MB isoenzyme of creatinine kinase (CK-MB)-mass had significant decreases of oLDL-Ab during the acute phase, with a minimum after 8 h following the onset of thrombolytic therapy (within-group significance: p < .001; between groups: p = .01). Patients (n = 5) with CK-MB-mass values less than 70 ng/ml did not show this phenomenon. Furthermore, significant correlations existed between CK-MB-mass and oLDL-Ab after 6 and 8 h (n = 15; r = .72; p = .003) and the time of the highest CK-MB-mass values (after 12 h) and the time of the maximal decrease of oLDL-Ab (after 8 h) (r = .74; p = .003). Our observations provide further evidence for the release of free radicals and for increased lipid peroxidation during reperfusion after prolonged ischemia. The decrease of oLDL-Ab appears to be a marker for the severity of MI.

Enhanced resistance to oxidation of low density lipoproteins and decreased lipid peroxide formation during beta-carotene supplementation in cystic fibrosis

We investigated the effect of correcting beta-carotene deficiency in cystic fibrosis (CF) patients on two parameters of lipid peroxidation. The resistance to oxidation of low density lipoprotein (LDL) was measured by the lag time preceding the onset of conjugated diene formation during exposure to copper(II) ions, and lipid peroxide formation was quantitated by malondialdehyde concentrations in plasma (TBA/HPLC method). Simultaneously, alpha-tocopherol and beta-carotene concentrations were determined in LDL and in plasma. Thirty-four CF patients were investigated before and after 3 months of oral beta-carotene supplementation. Beta-carotene concentrations increased (p < 0.0001) in plasma (mean +/- SD) (0.09 +/- 0.06 vs. 1.07 +/- 0.86 mumol/l) and in LDL (0.02 +/- 0.02 vs. 0.31 +/- 0.28 mol/mol), without significant changes in alpha-tocopherol, either in plasma (24.7 +/- 5.9 vs. 25.4 +/- 7.6) or in LDL (8.47 +/- 2.95 vs. 9.05 +/- 4.13). Lag times, being shorter (p < 0.05) in patients than in controls, increased from 48.5 +/- 21.3 to 69.1 +/- 27.9 min (p < 0.001) and plasma MDA concentrations, being greater (p < 0.0001) in patients than in controls, decreased from 0.95 +/- 0.32 to 0.61 +/- 0.15 mumol/l (p < 0.0001). At 3 months, lag times and MDA concentrations did not any longer differ between patients and controls. These data suggest that excess lipid peroxidation occurring in beta-carotene deficiency can be limited and normalized during efficient beta-carotene supplementation in CF patients.

Postanoxic formation of aldehydic lipid peroxidation products in human renal tubular cells

The levels of the aldehydic lipid peroxidation products 4-hydroxynonenal and malondialdehyde and the levels of adenine nucleotides were measured during anoxia/reoxygenation studies with isolated human renal tubular cells in vitro. Energy depletion of renal cells was demonstrated by the decrease of ATP level. ATP could be restored completely and rapidly during postanoxic reoxygenation. 4-Hydroxynonenal and malondialdehyde levels increased during reoxygenation. In parallel, the breakdown of physiological 4-hydroxynonenal levels was estimated. The 4-hydroxynonenal formation rate was estimated from accumulation and metabolic breakdown rates of this compound.

Activation of the phagocytic system increases intimal proliferation in hypercholesterolemic rabbits

The effect of in vivo stimulation of the phagocytic system (neutrophils, monocytes and hepatic Kupffer-cells) by inducing phagocytosis of intravenously administered latex particles on lipid peroxidation and aortic intimal proliferation was tested in cholesterol-fed rabbits. Three weeks after starting the diet, aortic intimal proliferation was measured by the intimal to medial ratios and by the incorporation of [3H]thymidine, infused into the circulation for the preceding 14 days. Intimal to medial ratios were increased (0.473 +/- 0.023 vs. 0.282 +/- 0.011, P < 0.01) and aortic [3H]thymidine contents were higher (66.8 +/- 3.5 vs. 27.8 +/- 49 counts/min per mg, P = 0.0001) in latex bead-treated than in control animals. Injection of beads transiently increased plasma lipid peroxide levels. At the end of the 3 week experiment, plasma lipid peroxide levels were still elevated and lipid peroxide contents of the aortic walls were higher in the latex-treated rabbits (82.8 +/- 5.8 vs. 46.4 +/- 4.9 nmol/mg cholesterol, latex-treated vs. controls, P = 0.004). These data suggest a significant acceleration of atherogenesis by the stimulated phagocytic system, the mechanism of which may involve lipid peroxidation.

Lipid peroxidation in open-heart surgery

Production of oxygen free radicals and subsequent lipid peroxidation are thought to occur during cardiopulmonary bypass (CPB) and myocardial ischaemia-reperfusion injury. Malondialdehyde (MDA), a lipid peroxidation product, was measured simultaneously in arterial and coronary sinus blood before CPB and after release of the aortic crossclamp. Additional arterial samples were drawn pre-, per-, and postoperatively. Thirteen patients scheduled for coronary artery and/or valvular surgery were studied. Cold, crystalloid, cardioplegic arrest (54 [35-120] minutes, median [range]) was induced retrogradely. Preoperatively, arterial MDA was 0.78 +/- 0.4 (mean +/- SD) mumol/l, and increased during CPB (highest level 3.66 +/- 1.08 mumol/l, p < 0.002, 30 minutes after the start of reperfusion). Arterial MDA was still increased four hours after the end of CPB (3.17 +/- 0.88 mumol/l, p < 0.003), but had returned to normal the first postoperative day. No difference was found between arterial and coronary sinus samples at any time. In conclusion, MDA increased in arterial blood during CPB, indicating that lipid peroxidation occurred. There was no intracoronary release of MDA during reperfusion of the ischaemic heart.

Evidence for the involvement of oxygen-derived free radicals in ischaemia-reperfusion injury

Six patients undergoing vascular reconstructive surgery were examined for evidence of oxygen-derived free radical (ORF) damage to the protein, immunoglobulin G (IgG). OFR damage was determined as an increase in the fluorescence (ex 360 nm em 454 nm) to ultraviolet absorption (280 nm) ratio of IgG, representing N-Formyl kynurenine and other as yet unidentified fluorophores. The IgG ratio was found to increase slightly during ischaemia and to undergo marked elevation upon reperfusion (275 +/- 405% baseline value at 40 min post-clamp; mean +/- sd). A high ratio was maintained post-reperfusion, even after 60 min reperfusion. Determination of thromboxane B2, (TXB2), leukotriene B4, (LTB4) and 6-keto prostaglandin F1 alpha, (PGF1a), revealed a decrease in their concentrations during ischaemia and a transient, marked increase on reperfusion. Only TXB2 concentrations were found to correlate with the IgG ratio (negative correlation, p < 0.05). No correlation was observed between von Willebrand antigen factor, a marker of endothelial cell damage and fluorescent IgG ratio. However, levels of the factor increased slightly during ischaemia and more sharply upon reperfusion. These preliminary results therefore suggest that a more likely source of the OFRs responsible for IgG damage is endothelial cell xanthine oxidase, rather than cyclo-oxygenase or lipoxygenase.

Nifedipine does not affect free radical induced lipid peroxidation following renal allograft reperfusion

We prospectively measured lipid peroxidation following reperfusion during 44 renal allograft transplant operations. Twenty-four (55%) recipients were taking nifedipine pre- and then postoperatively, and 20 (45%) were not. There were no differences between the groups in terms of recipient or donor status. Plasma malondialdehyde (MDA), mean 2.2 (0.2) mumol/L (SEM) vs. 1.73 (0.1) was greater in the group not prescribed nifedipine, p < .05, as were cholesterol; 5.89 (0.3) mmol/L vs. 5.58 (0.3) and triglycerides; 2.19 (0.2) mmol/L vs. 1.82 (0.2). Following allograft reperfusion there was a significant increase in the ratio of MDA/cholesterol (x 10(3)) (MDA corrected for changes in plasma volume) from 0.33 (0.03) in the nifedipine group to 0.38 (0.02) at 30 min after reperfusion and 0.38 (0.03) at 60 min, p < .01, and similarly from 0.4 (0.04) to 0.48 (0.03) at 30 min and 0.47 (0.05) after 60 min in the other group, p < .01. There was no difference in the percentage change in MDA/cholesterol ratio between the groups; 27 (5)% vs. 19 (6) at 30 min and 20 (8) vs. 15 (8) at 60 min for the nifedipine and no-nifedipine groups, respectively. There was no difference in postoperative renal function between the groups. This study suggests that the oral administration of nifedipine may not prevent the production of lipid peroxides, as measured by changes in plasma malondialdehyde, following renal allograft reperfusion and that it does not affect renal function in the early postoperative period.

Evidence for free radical formation during human kidney transplantation

Fourteen patients undergoing kidney transplantation were studied for evidence of the production of free radicals as assessed by the measurement of vitamin E (an index of lipid peroxidation) and of myeloperoxidase (a marker of neutrophil activation) in the systemic blood. Early (2 min) and late revascularization (30 min) of the kidney were respectively associated with a significant decrease of 35.5 and 40% of the initial level of plasma vitamin E. This consumption paralleled to the decrease of the vitamin E/total lipids ratio, a better indicator of vitamin E status. Heparin administration preceding renal artery clamping resulted in a twofold significant increase of baseline plasma myeloperoxidase (MPO) level (523 +/- 214 ng/ml). At kidney reperfusion, MPO concentration rose again and reached a maximum value of 1,653 +/- 882 ng/ml, indicating the presence of considerable neutrophil activation. A return to the baseline value was observed after 30 min of reperfusion. A short discussion about the possible origin of this MPO increase is given. Taken together, these data strongly suggest that free radical production, leading to lipid peroxidation phenomena, can occur within the early phase of kidney revascularization. Preliminary data using electron spin resonance with the spin-trapping technique strengthen this hypothesis.

A multivitamin infusion prevents lipid peroxidation and improves transplantation performance

The objective of this study was to test the hypothesis that ischemia reperfusion damage in kidney transplantation is associated with lipid peroxidation and that inhibition of lipid peroxidation by antioxidants improves the function of the transplanted kidney. Lipid peroxidation was assessed by measuring the plasma malonaldehyde content (as thiobarbituric acid reaction product) with high-performance liquid chromatography. Kidney function was assessed by plasma creatinine and creatinine clearance. Thirty patients of an ongoing series were randomly selected into two groups, with 14 controls and 16 patients in the antioxidant therapy group. Therapy consisted of two ampoules of Omnibionta (which contains vitamins C, E, A and B complex) diluted in 500 ml physiological sodium chloride, which was infused intravenously prior to reperfusion onset. No significant differences existed for the age of the patients in the control (43.00 +/- 9.86 years) and the therapy group (41.56 +/- 14.14 years) nor in the kidney preservation time, which was 24.12 +/- 8.73 and 18.43 +/- 9.97 hours in the control and therapy group, respectively. The controls showed a transient increase of plasma lipid peroxides as measured by malonaldehyde with a peak one hour after onset of reperfusion. Compared to the baseline value of 0.74 +/- 0.26 (mean +/- SD) the one hour malonaldehyde value increased to 1.46 +/- 0.22 nmol/ml (P < 0.001). In the therapy group the plasma malonaldehyde level did not increase, but slightly decreased by about 20% compared to the baseline value. The difference of plasma malonaldehyde between the two groups one hour after reperfusion onset was highly significant (P > 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)