Selenium in the prevention and subsidiary therapy of cancer of soft tissues.

Selenium as an antioxidant has attracted attention because of its anticancer activity. This review presents a view on selenium and its compounds exerting influence against cancer in the soft tissues. The results reveal a significant strong association between a low selenium level in blood and a cancer risk. Seleno-supplementation is important in the prevention of metastatic cancer. These results help to elucidate the anticancer effect of selenium providing further evidence to exploit novel anticancer agents targeting selenium-containing organic compounds. Key words: selenium • cancer prevention • cancer treatment • soft tissues.

Long-term Treatment with Hesperidin Improves Endothelium-dependent Vasodilation in Femoral Artery of Spontaneously Hypertensive Rats: The Involvement of NO-synthase and Kv Channels.

Hesperidin is the most common flavonoid found in citrus fruits and is expected to exert vasodilation action relevant to its health benefits. The present study aimed to explore the effect of hesperidin on the vascular responses in normotensive and hypertensive rats and the involvement of NO-synthase and Kv channels. The 15-week-old Wistar and spontaneously hypertensive rats (SHR) were randomized to orally receive either hesperidin (50 mg/kg/day) or a corresponding volume of the water for 4 weeks. Vascular responses of isolated femoral arteries were studied with myograph in control conditions and during inhibition of NO-synthase with l-NNA and Kv channels with 4-AP. Hesperidin had no effect on blood pressure. Endothelium-dependent vasodilation in Wistar and SHR was significantly improved by the treatment with hesperidin. The contraction responses after l-NNA were increased in all groups of rats to similar extent, but relaxatory responses were significantly attenuated only in SHR. The inhibition of Kv channels significantly reduced endothelium-dependent vasodilatory responses in only in SHR administered with hesperidin. The results of our experiment indicate that hesperidin might improve the endothelium-dependent vasodilation during hypertension, possibly through the enhancement of Kv channels function. Copyright © 2016 John Wiley & Sons, Ltd.

Naproxen and Diclofenac Attenuate Atorvastatin-induced Preconditioning of the Myocardium.

Statins reduce infarct size (IS) in ischemia-reperfusion injury of the myocardium. Inhibition of cyclooxygenase-2 (COX-2) attenuates this benefit. We investigated the effect of two widely used non-selective non-steroidal anti-inflammatory drugs (NSAIDs) with different degree of anti-COX-2 activity on atorvastatin-mediated preconditioning. Wistar rats received oral atorvastatin (10 mg∙kg-1∙day-1), naproxen (10 mg∙kg-1∙day-1), diclofenac (8 mg∙kg-1∙day-1), atorvastatin+naproxen, atorvastatin+diclofenac or water for three days. Hearts were then excised and perfused in the Langendorff system. Area at risk (AR) and IS were determined after 30 min of regional ischemia and 120 min of reperfusion. Atorvastatin reduced IS by 51.3% compared with controls (14.7 ± 3.9% vs. 30.2 ± 4.6% of the AR; P < 0.001). Naproxen and diclofenac alone did not alter IS compared to control. Diclofenac completely abrogated atorvastatin-mediated protection of the myocardium. Naproxen significantly attenuated but did not eliminate the IS reducing the effect of atorvastatin when compared with controls (P = 0.038). The difference in IS between the atorvastatin+naproxen group and the atorvastatin+diclofenac group showed a strong trend in reaching statistical significance (P = 0.058), but was not found to be significant. Our results suggest relatively small, but noticeable differences among non-selective NSAIDs in their potential to attenuate statin-mediated preconditioning.

Participation of reactive oxygen species in diabetes-induced endothelial dysfunction.

OBJECTIVES: In the present study, the relationship between diabetes-induced hyperglycemia, reactive oxygen species production and endothelium-mediated arterial function was examined. The effect of antioxidant on the reactive oxygen species induced damage was tested. METHODS: Diabetes was induced by streptozotocin (STZ), 3 x 30 mg/kg i.p., administered on three consecutive days. After 10 weeks of diabetes, the functional state of the endothelium of the aorta was tested, endothelemia evaluation was performed and systolic blood pressure was measured. Reactive oxygen species (ROS) formation in blood and the aorta was measured using luminol-enhanced chemiluminescence (CL). Levels of reduced glutathione (GSH) were determined in the aorta, kidney, and plasma. To study the involvement of hyperglycemia in functional impairment of the endothelium, aortal rings incubated in solution with high glucose concentration were tested in in vitro experiments. RESULTS: After 10 weeks of diabetes, endothelial injury was observed, exhibited by diminished endothelium-dependent relaxation of the aorta, increased endothelemia and by elevated systolic blood pressure. Using luminol-enhanced CL, a significant increase of ROS production was found in arterial tissue and blood. GSH levels were significantly increased in the kidney, while there were no GSH changes in plasma and the aorta. Incubation of aortic rings in solution with high glucose concentration led to impairment of endothelium-dependent relaxation. The synthetic antioxidant SMe1EC2 was able to restore reduced endothelium-mediated relaxation. CONCLUSIONS: Our results suggest an important role of hyperglycemia-induced ROS production in mediating endothelial dysfunction in experimental diabetes, confirmed by CL and the protective effect of the antioxidant SMe1EC2.

Effects of anabolic steroids and antioxidant vitamins on ethanol-induced tissue injury.

Various mechanisms are involved in the process of ethanol-induced tissue impairment. Oxidative stress and its effects are among the most important. We compared the effects of antioxidant vitamins (vitamin C and E in combination) and steroids (testosterone and nandrolone separately) on the toxicity of ethanol in rats. Animals (male Wistar rats, n = 48) were randomised into following groups-Control, Ethanol, Testosterone, Ethanol + Testosterone, Ethanol + Nandrolone, Ethanol + Vitamins. Alcohol was given daily by gavage in a dose of 5 g/kg of body weight. On the 27th day of the study the animals were sacrificed by decapitation and tissue samples were taken. Metabolic status, parameters of the hepatic metabolism, hormone levels (testosterone, ACTH, corticosterone), lipoperoxidation markers (malondialdehyde and conjugated diens in forebrain cortex and in cerebellum) and advanced glycation end-products were analysed. Tissue samples underwent histological examination. Histological outcomes showed a protective effect of antioxidants on hepatic and cerebellar injury caused by chronic ethanol intake. Anabolic steroids protected especially the central nervous tissue against the toxicity of alcohol. Both, antioxidant vitamins and anabolic steroids protect against the ethanol-induced toxicity, however, this effect is tissue specific.

Analysis of non-steroidal anti-inflammatory drug use in hospitalized patients and perception of their risk.

Non-steroidal anti-inflammatory drugs (NSAIDs) belong to the most widely prescribed and used pharmacological agents worldwide. Data gathered in the last decade show increased incidence of thrombotic events during NSAID administration. Analysis of NSAID usage and assessment of risk for development of cardiovascular adverse effects is needed for improving patient safety. For limiting the impact of adverse effects on the health of patients, NSAID users should be informed about the possible adverse effects and their symptoms to ensure early detection and treatment discontinuation. In the presented study, we retrospectively analyzed the administration of NSAIDs in a group of patients (n=428) in need of analgesic treatment hospitalized at a department of internal medicine. Factors increasing the risk for cardiovascular adverse effects were also investigated. A separate questionnaire study was conducted to gather information concerning the knowledge of hospitalized NSAID users (n=251) about adverse effects of the medication used. For purpose of comparison, we conducted a similar study in a group of 234 random respondents from a shopping center. Data were evaluated using descriptive statistics, Student's t-test and chi-squared test. Our results suggest that the majority of patients treated with NSAIDs have factors indicating increased risk of development of adverse effects, most commonly arterial hypertension (58.2% of patients). The results of our questionnaire study show limited knowledge of NSAID users about the risk of the therapy. Nearly half of the respondents were unaware of any adverse effects. We consider as alarming that only a limited number of respondents were informed by their physician or pharmacist about the possible risks of treatment. In conclusion, we found that hospitalized NSAID users often have a history of diseases predisposing to the development of cardiovascular adverse effects of NSAIDs. Despite this, their knowledge about the risk of treatment is insufficient.

Trends in vascular pharmacology research in the Department of Pharmacology and Clinical Pharmacology, Faculty of Medicine, Comenius University, Bratislava.

Research in the Department of Pharmacology started to focus intensively on fetal circulation in the 60s. Results of experiments contributed to clarification of the conversion of fetal circulation type to the adult type: the mechanism of the ductus arteriosus closure, examination of fetal and neonatal pulmonary vessel responses. In the early 80s, increased attention was dedicated to fetal vascular endothelium, later on to vascular reactivity in relation to the endothelium in adult animals. We developed original models of vascular endothelial damage using the perfusion method (repeated vasoconstrictive stimuli, deendothelization by air bubbles). We developed a new technique for in vitro endothelial loss quantification on Millipore filters. Under in vitro conditions, the protective effects of sulodexide and pentoxifylline on vascular endothelium were evaluated. In recent years were studied protective effects of selected substances in vivo in models of endothelial damage (e.g. stress, toxic tissue damage, diabetes mellitus, hypertension). The role of potassium channels in the hypertension model was studied in cooperation with the Czech Academy of Sciences. Assessment of vascular reactivity in the diabetic model was significantly improved by computer. In addition to experimental work, the department is solving problems of clinical pharmacology - especially drug risk evaluation (non-steroidal anti-inflammatory drugs). Recently, we have dealt with pharmacoepidemiological studies in geriatric patients and with cardiovascular risk of NSAIDs in relation to pharmacotherapy. The results of these studies may be an impulse for targeted problem solving in our experiments.

Protection of the vascular endothelium in experimental situations.

One of the factors proposed as mediators of vascular dysfunction observed in diabetes is the increased generation of reactive oxygen species (ROS). This provides support for the use of antioxidants as early and appropriate pharmacological intervention in the development of late diabetic complications. In streptozotocin (STZ)-induced diabetes in rats we observed endothelial dysfuction manifested by reduced endothelium-dependent response to acetylcholine of the superior mesenteric artery (SMA) and aorta, as well as by increased endothelaemia. Changes in endothelium-dependent relaxation of SMA were induced by injury of the nitric oxide radical (·NO)-signalling pathway since the endothelium-derived hyperpolarising factor (EDHF)-component of relaxation was not impaired by diabetes. The endothelial dysfunction was accompanied by decreased ·NO bioavailabity as a consequence of reduced activity of eNOS rather than its reduced expression. The results obtained using the chemiluminiscence method (CL) argue for increased oxidative stress and increased ROS production. The enzyme NAD(P)H-oxidase problably participates in ROS production in the later phases of diabetes. Oxidative stress was also connected with decreased levels of reduced glutathione (GSH) in the early phase of diabetes. After 10 weeks of diabetes, adaptational mechanisms probably took place because GSH levels were not changed compared to controls. Antioxidant properties of SMe1EC2 found in vitro were partly confirmed in vivo. Administration of SMe1EC2 protected endothelial function. It significantly decreased endothelaemia of diabetic rats and improved endothelium-dependent relaxation of arteries, slightly decreased ROS-production and increased bioavailability of ·NO in the aorta. Further studies with higher doses of SMe1EC2 may clarify the mechanism of its endothelium-protective effect in vivo.

Adverse drug reactions related to hospital admission in Slovak elderly patients.

The aims of the present study were: to evaluate the prevalence of adverse drug reactions (ADRs) leading to hospitalization in elderly patients; to analyze the drugs which have been identified as having causal relationship with ADRs and to identify risk factors which predispose the patient to such ADRs. The study has been performed in 600 patients aged> or =65 years, hospitalized in a general hospital between 1 December 2003 and 31 March 2005. The ADRs recorded in patient's documentation as one of the reasons for hospital admission were evaluated. ADRs leading to hospital admission were recorded in 47 (7.8%) patients. ADRs in 43 patients represented A-type ADRs which are preventable. The most frequent ADRs were cardiovascular disorders. According to the results of multivariate analysis ischemic heart disease (odds ratio (OR)=4.50; 95% confidence interval (CI)=1.36-14.88), depression (OR, 2.49; 95% CI, 1.08-5.77) and heart failure (OR, 2.08; 95% CI, 1.13-3.81) were the most important patient-related characteristics predicting ADRs leading to hospitalization. The majority of ADRs in elderly patients could be avoided. Regular re-evaluation of the medication as well as taking into account the specific features of elderly patients represent the most important tools for ADR prevention.

Polypharmacy in elderly hospitalised patients in Slovakia.

OBJECTIVE: The aims of the present study were to: analyse the prevalence of polypharmacy in a group of older patients; evaluate the influence of hospital stay on the number of drugs taken; assess the most frequently prescribed pharmacological classes; identify risk factors that predisposed the patient to polypharmacy. Setting The study was carried out in the Department of Internal Medicine of a non-university general hospital. METHOD: In the retrospective study, 600 patients aged 65 years or more were enrolled. They were hospitalised in the period from 1st December 2003 to 31st March 2005. Each person taking six or more medications per day was considered to be a patient with polypharmacy. Particular sociodemographic and clinical characteristics, as well as comorbid conditions, were evaluated as factors potentially influencing the prevalence of polypharmacy. MAIN OUTCOME MEASURE: The number and type of medications taken at the time of hospital admission and discharge were recorded and compared for each patient. RESULTS: Polypharmacy on admission and at discharge was observed in 362 (60.3%) and 374 (62.3%) patients, respectively. Hospitalisation led to a significant increase in the number of medications. The spectrum of medications used corresponded to the proportions of diagnoses in the evaluated group, in which cardiovascular diseases were most prevalent. According to the multivariate analysis using a logistic regression model, diabetes mellitus (odds ratio (OR) 2.40; 95% confidence interval (CI): 1.64-3.50), heart failure (OR 2.14; 95% CI: 1.46-3.14), dementia (OR 2.12; 95% CI: 1.26-3.57), living alone (OR 2.00; 95% CI: 1.28-3.10), arterial hypertension (OR 1.63; 95% CI: 1.08-2.44) and cerebrovascular disease (OR 1.58; 95% CI: 1.03-2.44) significantly increased the risk of the presence of polypharmacy. CONCLUSION: Our study confirmed a relatively high prevalence of polypharmacy in Slovak elderly patients. Polypharmacy risk rose especially with the increased prevalence of diseases of advancing age (diabetes mellitus, heart failure, arterial hypertension, dementia and cerebrovascular diseases). The increasing numbers of medications in inpatients indicate the need for the careful re-evaluation of pharmacotherapy during the stay in hospital.