Konstantinos Tsarouhas

Alzheimer’s disease treated patients showed different patterns for oxidative stress and inflammation markers

Alzheimers disease (AD) is the most common type of dementia accounting for 60-80% of the reported cases. The aim of this study was to evaluate levels of certain parameters of oxidative stress and markers of endothelial dysfunction in the blood of 21 AD patients under standard treatment compared with 10 controls, in an attempt to elucidate the contribution of AD to the total oxidative stress status of the patients. Results indicate that IL-6, TNF-α, ADMA and homocysteine levels were significantly elevated in AD patients. Protein carbonyls levels were higher in AD group, while glutathione reductase and total antioxidant capacity were lower, depicting decreased defense ability against reactive oxygen species. Besides, a higher level of advanced glycation end-products was observed in AD patients. Depending on the treatment received, a distinct inflammatory and oxidative stress profile was observed: in Rivastigmine-treated group, IL6 levels were 47% lower than the average value of the remaining AD patients; homocysteine and glutathione reductase were statistically unchanged in the Rivastigmine and Donepezil-Memantine, respectively Donepezil group. Although the study is based on a limited population, the results could constitute the basis for further studies regarding the effect of medication and diet on AD patients.

Cardiotoxicity of nano-particles

Nano-particles (NPs) are used in industrial and biomedical fields such as cosmetics, food additives and biosensors. Beside their favorable properties, nanoparticles are responsible for toxic effects. Local adverse effects and/or systemic toxicity are described with nanoparticle delivery to target organs of the human body. Animal studies provide evidence for the aforementioned toxicity. Cardiac function is a specific target of nanoparticles. Thus, reviewing the current bibliography on cardiotoxicity of nanoparticles and specifically of titanium, zinc, silver, carbon, silica and iron oxide nano-materials is the aim of this study.

Medication Use by Athletes during the Athens 2004 Paralympic Games

Objective: To examine the use of food supplements and pharmaceutical preparations by elite Paralympic athletes. Design: Survey study. Setting: Athens 2004 Paralympic Games. Participants: Data obtained from two sources: (i) athletes’ declaration of intake of drugs/supplements recorded on the Doping Control Official Record during sample collection for doping control; (ii) athletes’ application forms for granting of a therapeutic use exemption. Main outcome measures: Classification of declared food supplements according to the active ingredient and medications according to therapeutic actions and active compounds. Results: 64.2% of the athletes tested for doping control declared use of medications or food supplements, and 81.3% of these athletes declared intake of fewer than four preparations. Non-invasive routes of administration dominated. Food supplements (42.1%) were popular, and drugs used to treat several pathological conditions noted. Non-steroidal anti-inflammatory agents and analgesics were commonly used (9.8% and 5.6%, respectively). The prevalence of inhaled β2-agonist use (4.8%) was higher than expected and exceeded that at the Athens Olympic Games. Conclusions: This review, the first to examine elite Paralympic athletes, shows a more rational approach to the use of medication and food supplements, but a similar consumption pattern to that of athletes at the Athens Olympic Games. Because of the dearth of such studies, consumption trends among Paralympic athletes remain unclear. The need to counsel athletes with disabilities on their nutritional needs is confirmed, and close monitoring by healthcare professionals is recommended.

Effects of walking on heart rate recovery, endothelium modulators and quality of life in patients with heart failure

Background: Few studies have addressed the impact of moderate unsupervised everyday physical activity in patients with chronic heart failure (CHF). Design: We investigated the effects of a 12-week walking programme as the sole exercise intervention on heart rate recovery (HRR), index of the autonomic system equilibrium, serum modulators of endothelial function (i.e. asymmetric dimethylarginine (ADMA) and homocysteine), markers of inflammation and oxidative stress and quality of life measures (i.e. SF-36 and the Zung depression scale) in CHF patients. Methods: Twenty-eight stabilized CHF patients of ΝYHΑ class II and III volunteered to participate either in the exercise (n = 18) or in the non-exercise (n = 10) groups. Ten age-matched healthy volunteers provided reference values. The exercise programme consisted of unsupervised 40-minute walking for five days per week. Results: Repeated measures ANOVA revealed significant improvements in HRR (p < 0.001) in the exercise patients compared to their non-exercise counterparts. ADMA levels in CHF patients at baseline were found higher than the healthy reference volunteers (p < 0.03), while a decrease in ADMA levels after walking was associated with HRR changes (r = 0.74, p = 0.007). Homocysteine levels both at baseline and at the end of the walking intervention decreased in the exercise group, but were still higher than in the healthy individuals. Average walking distance positively correlated with homocysteine decrease (p < 0.05). Total SF-36 score significantly improved (p < 0.02) mainly due to enhancements in the physical component score (p < 0.026). Conclusion: A 12-week unsupervised walking programme exhibits a pronounced HRR amelioration, possibly attenuates endothelial damage and induces a concomitant improvement in perceived quality of life in CHF patients.

Anticancer and apoptosis‑inducing effects of quercetin in vitro and in vivo

The present study focused on the elucidation of the putative anticancer potential of quercetin. The anticancer activity of quercetin at 10, 20, 40, 80 and 120 µM was assessed in vitro by MMT assay in 9 tumor cell lines (colon carcinoma CT-26 cells, prostate adenocarcinoma LNCaP cells, human prostate PC3 cells, pheocromocytoma PC12 cells, estrogen receptor-positive breast cancer MCF-7 cells, acute lymphoblastic leukemia MOLT-4 T-cells, human myeloma U266B1 cells, human lymphoid Raji cells and ovarian cancer CHO cells). Quercetin was found to induce the apoptosis of all the tested cancer cell lines at the utilized concentrations. Moreover, quercetin significantly induced the apoptosis of the CT-26, LNCaP, MOLT-4 and Raji cell lines, as compared to control group (P<0.001), as demonstrated by Annexin V/PI staining. In in vivo experiments, mice bearing MCF-7 and CT-26 tumors exhibited a significant reduction in tumor volume in the quercetin-treated group as compared to the control group (P<0.001). Taken together, quercetin, a naturally occurring compound, exhibits anticancer properties both in vivo and in vitro.

Contrast-induced nephropathy: Basic concepts, pathophysiological implications and prevention strategies☆

&NA; Contrast‐induced nephropathy (CIN) is reversible acute renal failure observed following administration of iodinated contrast media (CM) during angiographic or other medical procedures such as urography. There are various mechanisms through which CM develop their nephrotoxic effects, including oxidative stress and apoptosis. CIN is a real‐life, albeit not very rare, entity. Exact pathophysiology remains obscure and no standard diagnostic criteria apply. The Acute Kidney Injury Network criteria was recently employed but its incidence/clinical significance warrants further clarification based on recent methodological advancements, because most published studies to date were contaminated by bias. The current study is a comprehensive review conducted to provide an overview of the basic concepts of CIN and summarize recent knowledge on its pathophysiology and the evidence supporting potential prevention strategies. CIN is expected to increase morbidity, hospital stay and mortality, while all patients scheduled to receive CM should undergo risk assessment for CIN and high‐risk patients may be considered candidates for prevention strategies. The value of using compounds with antioxidant properties other than sodium bicarbonate, remains controversial, warranting further clinical investigation.

Oxidative stress and myocardial dysfunction in young rabbits after short term anabolic steroids administration.

The present study focuses on the short term effects of repeated low level administration of turinabol and methanabol on cardiac function in young rabbits (4 months-old). The experimental scheme consisted of two oral administration periods, lasting 1 month each, interrupted by 1-month wash-out period. Serial echocardiographic evaluation at the end of all three experimental periods was performed in all animals. Oxidative stress markers have also been monitored at the end of each administration period. Treated animals originally showed significantly increased myocardial mass and systolic cardiac output, which normalized at the end of the wash out period. Re-administration led to increased cardiac output, at the cost though of a progressive myocardial mass reduction. A dose-dependent trend towards impaired longitudinal systolic, diastolic and global myocardial function was also observed. The adverse effects were more pronounced in the methanabol group. For both anabolic steroids studied, the low dose had no significant effects on oxidative stress markers monitored, while the high dose created a hostile oxidative environment. In conclusion, anabolic administration has been found to create a possible deleterious long term effect on the growth of the immature heart and should be strongly discouraged especially in young human subjects.

Effects of resveratrol on carbon monoxide-induced cardiotoxicity in rats

Carbon monoxide (CO) poisoning leads to tissue hypoxia resulting in cardiovascular disturbances. Resveratrol (RES) is considered a natural cardioprotective agent especially in the setting of ischemia/reperfusion injury. In the present study, the cardioprotective potential of RES against CO-induced cardiotoxicity was evaluated. 45 male Wistar rats, animals were randomly assigned to 5 experimental groups. The first group served as negative control and was not exposed to CO. All remaining rats were exposed to CO 3000ppm for 60min. The second group received normal saline following CO exposure, while groups 3, 4 and 5 were injected intraperitoneally with different doses of RES (1, 5 and 10mg/kg, respectively). Histopathological examination showed that RES administration reduced myocardial lesions compared to control groups. Myocardial Akt expression was significantly increased in rats treated with the highest dose of RES (p<0.05) compared to CO-exposed non-treated animals. Caspase-3 activity in rat cardiomyocytes of RES-treated animals was significantly decreased in a dose-dependent manner. ECG findings did not differ significantly among CO-exposed groups. In conclusion, the present study offers evidence of a protective effect of RES administration on CO-induced cardiotoxicity via Akt up-regulation and attenuation of caspase-3 activity in rat hearts.

Homocysteine and metalloprotease-3 and −9 in patients with ascending Aorta Aneurysms

INTRODUCTION Matrix metalloprotease (MMP) activity is increased in ascending and abdominal aortic aneurysms. Elevated plasma homocysteine (Hc) levels have been reported in patients with abdominal aneurysms. However, there are no published reports correlating, Hc and MMP levels in patients with ascending aortic aneurysms (AAAs). MATERIALS AND METHODS This study attempts to determine whether serum or tissue Hc in patients undergoing surgery for AAAs is associated with aneurysm diameter, circulating and tissue levels of MMP-3 and MMP-9 assessed by Enzyme-linked immunosorbent assay (ELISA) and their mRNA tissue expression assessed by real-time PCR. Twenty-seven patients were recruited in the study. RESULTS Forty-three percent of the patients had abnormal Hc serum levels (>35.9 μmol/L). Circulating MMP-3 (6.44±4.20 ng/mL) and MMP-9 levels (134±11.4 ng/mL) were elevated compared to healthy controls (p<0.001). Positive correlations were observed between circulating MMP-9, tissue MMP-3 and MMP-9 concentrations with serum Hc (r=0.773, p=0.011; r=0.461, p=0.014; r=0.526, p=0.024, respectively). MMP-9 mRNA was expressed in 21% of the aneurysms. No MMP-3 mRNA expression was detected in the studied specimens. A negative correlation between tissue Hc and aneurysm diameter was detected. No associations of serum Hc, MMP-3 and MMP-9 levels in both serum and tissue with aneurysm diameter were noted. CONCLUSION Our results suggest that Hc, even in patients with mild hyperhomocysteinaemia, is involved in the pathophysiology of AAA, through the regulation of MMP-3 and MMP-9 activity.

Cardiotoxicity in rabbits after long-term nandrolone decanoate administration

Abuse of anabolic androgenic steroids is linked to a variety of cardiovascular complications. The aim of our study was to investigate the possible cardiovascular effects of nandrolone decanoate on young rabbits using echocardiography, histology and monitoring of telomerase activity, oxidative stress and biochemical markers. Fourteen rabbits were divided into three administration groups and the control group. Doses of 4mg/kg and 10mg/kg of nandrolone decanoate, given intramuscularly and subcutaneously, two days per week for six months were applied. A 4-months wash-out period followed. Focal fibrosis and inflammatory infiltrations of cardiac tissue were observed in the high dose groups. Thiobarbituric acid-reactive species (TBARS) levels were significantly increased in the high dose groups, while catalase activity decreased. Myocardial Performance Index (MPI) is the main echocardiographic index primarily affected by nandrolone administration in rabbits. Despite the preserved systolic performance, histological lesions observed associated with distorted MPI values, point to diastolic impairment of the thickened myocardium due to nandrolone treatment. Oxidative stress accumulates and telomerase activity in cardiac tissue rises. Subcutaneous administration seems to be more deleterious to the cardiovascular system, as oxidative stress, telomerase activity and biochemical markers do not appear to return into normal values in the wash-out period.