Chloroquine and cinchonine affect rat vascular smooth muscle tonus through calcium channels - in silico and in vitro approaches.

BACKGROUND: In the present study, two structurally similar alkaloids from trees of Cinchona genus, chloroquine and cinchonine, were examined for their vasorelaxant effects in a model of phenylephrine-induced smooth muscle contractions. METHODS: Potential mechanisms of action associated with endothelial vasorelaxant compounds, voltage-gated Ca2+ channels (LTCCs), and inositol triphosphate receptors were examined in isolated rat aortic rings. Also, an in silico approach was used to predict the activity of the two test compounds. RESULTS: Experimental results revealed that both chloroquine and cinchonine significantly decrease phenylephrine-induced smooth muscle contractions, although to a different extent. Evaluated mechanisms of action indicate that endothelium is not involved in the vasorelaxant action of the two tested alkaloids. On the other hand, voltage-gated Ca2+ channels were found to be the dominant way of action associated with the vasorelaxant action of chloroquine and cinchonine. Finally, IP3R is found to have only a small impact on the observed activity of the tested compounds. CONCLUSION: Molecular docking studies predicted that chloroquine possesses a significant activity toward a suitable model of LTCCs, while cinchonine does not. The results of the present study point to the fact that great caution should be paid while administering chloroquine to vulnerable patients, especially those with cardiovascular disorders (Tab. 3, Fig. 3, Ref. 28).

Potentially inappropriate prescribing of drugs in elderly patients on chronic hemodialysis treatment
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PURPOSE: The aim of this study was to determine the prevalence of potentially inappropriate drug prescription (PIP) in older patients who were on chronic hemodialysis treatment and to explore the factors that lead to PIP. MATERIALS AND METHODS: The study was performed at the Department of Nephrology, Clinical Center Nis, Serbia. It included patients who were 65 years old and older who suffered from the end-stage of kidney failure and were treated by hemodialysis. Univariate and subsequent multivariate logistic regression was used to analyze risk factors for PIP or omission (PPO) according to the STOPP and START criteria. RESULTS: The study included 83 patients. According to the START criteria, PPO was found in 18 (22%) patients, and 32 (39%) patients experienced PIPs according to the STOPP criteria. The following factors were associated with PIP according to the START criteria: a number of comorbidities, reading the patient leaflet, and having the habit of drinking coffee. According to the STOPP criteria, polypharmacy was associated with PIP (OR = 1.287, p = 0.021): each additional drug increased the risk of potentially inadequate medications (PIM) by 28.7%. CONCLUSION: Adequate consideration of potential risk factors, as well as the implementation of valid criteria for assessment of PIP, are just some of the measures that would contribute to solving complex therapeutic problems and designing strategies for rational prescribing according to the individual characteristics of patients.
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Factors associated with potentially inappropriate prescribing in elderly patients with various degrees of chronic kidney disease.

INTRODUCTION: This study aimed to compare the prevalence of potentially inappropriately prescribed drugs in hemodialysis patients and patients with chronic kidney disease who did not require renal replacement therapy, as well as to identify risk factors associated with potentially inappropriate prescribing. METHODS: The study was designed as a cross-sectional study conducted at the Department of Nephrology, Clinical Center in Nis, Serbia. The patients were divided into two groups: (1) patients on hemodialysis treatment and (2) patients with various degrees of chronic kidney disease without renal replacement therapy. The presence or absence of potentially inappropriate prescribing was determined using the 2015 AGS Beers criteria. FINDINGS: The study included a total of 218 patients aged 65 years and over. The number of patients with potentially inappropriate prescribed drugs did not differ significantly (chi-square = 0.000, p = 1.000) between patients on hemodialysis (27 of 83, i.e., 32.5%) and patients with various degrees of chronic kidney disease without renal replacement therapy (44 of 135, i.e., 32.6%). Factors associated with potentially inappropriate prescribing in hemodialysis patients were the number of drugs (hazard ratio [HR] = 1.919, 95% confidence interval [CI]: 1.325-2.780) and number of comorbidities (HR = 1.743, 95% CI: 1.109-2.740). The number of drugs (HR = 1.438, 95% CI: 1.191-1.736) was the only independent factor associated with increased risk of potentially inappropriate prescribing in patients without renal replacement therapy. DISCUSSION: Our study showed that potentially inappropriate prescribing is a relatively frequent phenomenon present in about a third of patients in both study groups. The number of prescribed drugs was the main factor associated with the increased risk of potentially inappropriate prescribing in both groups.

Aerobic capacity as an indicator in different kinds of sports.

Physical capacity of athletes is an important element of success in sports achievements. Aerobic capacity has been accepted as its major component. Maximal oxygen uptake (VO2max) has been regarded by majority of authors as the best indicator of aerobic capacity of an organism, and at the same time, the best indicator of an athlete's physical capacity. The aim of the investigation was to analyze the aerobic capacity as an indicator of physical capacity of athletes, differences in their aerobic capacity with regard to the kind of sport they are practicing, as well as the differences obtained when compared to physically inactive subjects. The investigation included the determination of absolute and relative VO2max in the total of 66 male examinees. The examinees were divided into two groups of active athletes (football players (n=22) and volleyball players (n=18) of different profiles, while the third group of non-athletes served as control group. Maximal oxygen uptake was determined by performing the Astrand 6 minute cycle test. Peak values of VO2 max were recorded in the group of football players (4,25+/-0,27 l/min), and they were statistically significantly higher (p<0,001) compared to other examined groups. In the group of volleyball players the oxygen uptake was 3,95+/-0,18 l/min, while statistically significantly lower values were reported in the group of non-athletes compared to the groups of athletes (p<0,01). A similar ratio of VO2 max values was also shown by the analysis of values expressed in relative units. Our results showed that peak values of VO2 max were obtained in football players, and that football as a sport requires higher degree of endurance compared to volleyball. Having considered the morphological and functional changes which are the consequence of the training process, it can be concluded that VO2 max values are statistically significantly higher in the groups of athletes compared to the group of non-athletes.

Modulatory effect of curcumin on ketamine-induced toxicity in rat thymocytes: Involvement of reactive oxygen species (ROS) and the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway.

Ketamine is a widely used anesthetic in pediatric clinical practice. Previous studies have demonstrated that ketamine induces neurotoxicity and has a modulatory effect on the cells of the immune system. Here, we evaluated the potential protective effect and underlying mechanisms of natural phenolic compound curcumin against ketamine-induced toxicity in rat thymocytes. Rat thymocytes were exposed to 100 µM ketamine alone or combined with increasing concentrations of curcumin (0.3, 1, and 3 µM) for 24 hours. Cell viability was analyzed with CCK-8 assay kit. Apoptosis was analyzed using flow cytometry and propidium iodide as well as Z-VAD-FMK and Z-LEHD-FMK inhibitors. Reactive oxygen species (ROS) production and mitochondrial membrane potential [MMP] were measured by flow cytometry. Colorimetric assay with DEVD-pNA substrate was used for assessing caspase-3 activity. Involvement of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was tested with Wortmannin inhibitor. Ketamine induced toxicity in cells, increased the number of hypodiploid cells, caspase-3 activity and ROS production, and inhibited the MMP. Co-incubation of higher concentrations of curcumin (1 and 3 µM) with ketamine markedly decreased cytotoxicity, apoptosis rate, caspase-3 activity, and ROS production in rat thymocytes, and increased the MMP. Application of Z-VAD-FMK (a pan caspase inhibitor) or Z-LEHD-FMK (caspase-9 inhibitor) with ketamine effectively attenuated the ketamine-induced apoptosis in rat thymocytes. Administration of Wortmannin (a PI3K inhibitor) with curcumin and ketamine significantly decreased the protective effect of curcumin on rat thymocytes. Our results indicate that ketamine-induced toxicity in rat thymocytes mainly occurs through the mitochondria-mediated apoptotic pathway and that the PI3K/Akt signaling pathway is involved in the anti-apoptotic effect of curcumin.