The relationship between aerobic capacity and cognitive/academic performance in medical students.

The positive relationship between aerobic capacity and cognitive performance is well known, but there is little information regarding young adults. Therefore, we aimed to test the hypothesis that aerobic capacity (VO2max) correlates with cognitive and academic performance in medical students who have higher academic achievement with academic performance. We included 65 volunteer medical students who were in term 2/6 in this descriptive, cross-sectional study. Body composition and the International Physical Activity Questionnaire and cardiopulmonary exercise test results of all participants were analyzed. Lumosity application with 6 categories of cognitive tests was applied to evaluate cognitive performance. The university entrance exam scores of the students were taken into consideration to assess their academic performance. We observed a significant "positive" relationship between aerobic capacity and some domains of cognitive performance, especially problem solving (p < 0.05), but we did not find a significant relationship between aerobic capacity and academic performance. Consequently, although we confirmed the existence of a positive effect of high aerobic capacity on cognitive performance stated in the literature, we couldn't confirm this for all cognitive domains or academic performance. These results suggest that more comprehensive studies on this subject are needed.

Assessment of the dissimilarities of totally 186 countries and regions according to COVID-19 indicators at the end of March 2020.

Background: This study is aimed at evaluating the relationship between the number of days elapsed since a country's first case(s) of coronavirus disease 2019 (COVID-19), the total number of tests conducted, and outbreak indicators such as the total numbers of cases, deaths, and patients who recovered. The study compares COVID-19 indicators among countries and clusters them according to similarities in the indicators. Methods: Descriptive statistics of the indicators were computed and the results were presented in figures and tables. A fuzzy c-means clustering algorithm was used to cluster/group the countries according to the similarities in the total numbers of patients who recovered, deaths, and active cases. Results: The highest numbers of COVID-19 cases were found in Gibraltar, Spain, Switzerland, Liechtenstein and Italy were also of that order with about 1500 cases per million population. Spain and Italy had the highest total number of deaths, which were about 140 and 165 per million population, respectively. In Japan, where exposure to the causative virus was longer than in most other countries, the total number of deaths per million population was less than 0.5. According to cluster analysis, the total numbers of deaths, patients who recovered, and active cases were higher in Western countries, especially in central and southern European countries, which had the highest numbers when compared with other countries. Conclusion: There may be various reasons for the differences between the clusters obtained by fuzzy c-means clustering. These include quarantine measures, climatic conditions, economic levels, health policies, and the duration of the fight against the outbreak.

The effects of certain TRP channels and voltage-gated KCNQ/Kv7 channel opener retigabine on calcitonin gene-related peptide release in the trigeminovascular system.

BACKGROUND: Calcitonin gene-related peptide release in trigeminovascular system is a pivotal component of neurogenic inflammation underlying migraine pathophysiology. Transient receptor potential channels and voltage-gated KCNQ/Kv7 potassium channels expressed throughout trigeminovascular system are important targets for modulation of calcitonin gene-related peptide release. We investigated the effects of certain transient receptor potential (TRP) channels the vanilloid 1 and 4 (TRPV1 and TRPV4), the ankyrin 1 (TRPA1), and metastatin type 8 (TRPM8), and voltage-gated potassium channel (Kv7) opener retigabine on calcitonin gene-related peptide release from peripheral (dura mater and trigeminal ganglion) and central (trigeminal nucleus caudalis) trigeminal components of rats. METHODS: The experiments were carried out using well-established in-vitro preparations (hemiskull, trigeminal ganglion and trigeminal nucleus caudalis) from male Wistar rats. Agonists and antagonists of TRPV1, TRPV4, TRPA1 and TRPM8 channels, and also retigabine were tested on the in-vitro release of calcitonin gene-related peptide. Calcitonin gene-related peptide concentrations were measured using enzyme-linked immunosorbent assay. RESULTS: Agonists of these transient receptor potential channels induced calcitonin gene-related peptide release from hemiskull, trigeminal ganglion and trigeminal nucleus caudalis, respectively. The transient receptor potential channels-induced calcitonin gene-related peptide releases were blocked by their specific antagonists and reduced by retigabine. Retigabine also decreased basal calcitonin gene-related peptide releases in all preparations. CONCLUSION: Our findings suggest that favorable antagonists of these transient receptor potential channels, or Kv7 channel opener retigabine may be effective in migraine therapy by inhibiting neurogenic inflammation that requires calcitonin gene-related peptide release.

Receptor mechanisms mediating the anti-neuroinflammatory effects of endocannabinoid system modulation in a rat model of migraine.

Calcitonin gene-related peptide (CGRP), substance P and dural mast cells are main contributors in neurogenic inflammation underlying migraine pathophysiology. Modulation of endocannabinoid system attenuates migraine pain, but its mechanisms of action remain unclear. We investigated receptor mechanisms mediating anti-neuroinflammatory effects of endocannabinoid system modulation in in vivo migraine model and ex vivo hemiskull preparations in rats. To induce acute model of migraine, a single dose of nitroglycerin was intraperitoneally administered to male rats. Moreover, isolated ex vivo rat hemiskulls were prepared to study CGRP and substance P release from meningeal trigeminal afferents. We used methanandamide (cannabinoid agonist), rimonabant (cannabinoid receptor-1 CB1 antagonist), SR144528 (CB2 antagonist) and capsazepine (transient receptor potential vanilloid-1 TRPV1 antagonist) to explore effects of endocannabinoid system modulation on the neurogenic inflammation, and possible involvement of CB1, CB2 and TRPV1 receptors during endocannabinoid effects. Methanandamide attenuated nitroglycerin-induced CGRP increments in in vivo plasma, trigeminal ganglia and brainstem and also in ex vivo hemiskull preparations. Methanandamide also alleviated enhanced number and degranulation of dural mast cells induced by nitroglycerin. Rimonabant, but not capsazepine or SR144528, reversed the attenuating effects of methanandamide on CGRP release in both in vivo and ex vivo experiments. Additionally, SR144528, but not rimonabant or capsazepine, reversed the attenuating effects of methanandamide on dural mast cells. However, neither nitroglycerin nor methanandamide changed substance P levels in both in vivo and ex vivo experiments. Methanandamide modulates CGRP release in migraine-related structures via CB1 receptors and inhibits the degranulation of dural mast cells through CB2 receptors. Selective ligands targeting CB1 and CB2 receptors may provide novel and effective treatment strategies against migraine.

Global evaluation of coronavirus disease 2019 cases and clustering of similar countries.

OBJECTIVE: It was aimed to be obtained descriptive values with respect to the outbreak time course, demographic structure, and symptom distribution by the help of case-based data, and to be compared countries by being grouped according to their similarities of outbreak indicators. METHODS: The data were obtained from open-access database. Univariate tests and cluster analysis were used to analyze the data. RESULTS: After the symptoms onset, the prolonged admission to the hospital significantly increases the risk of death. The average age and percentage of the male gender of the deceased cases were found to be significantly higher. In addition, the symptoms including fever, throat complaints, and dyspnea were determined in 70%. Countries were divided into four clusters according to their similarities in terms of three outbreak indicators. The differences among the clusters with regard to mean age, urban rate, and average of the outbreak indicators were found significant. CONCLUSION: Delaying treatment from the moment the symptoms appear will increase the risk of death and the average time to recovery or death was 2.5 weeks. It can be stated that the most important measure is to focus on methods that can detect the cases before symptoms. The indicators that have a very important role in defining the pandemic are also related to each other. Therefore, multivariate methods, which take these relationships into account, are able to produce more accurate information in determining the similarities of countries.

Protective effects of long-term probiotic mixture supplementation against pentylenetetrazole-induced seizures, inflammation and oxidative stress in rats.

Emerging evidence indicates that dysbiosis of gut microbiota plays an important role in epilepsy, although the underlying mechanisms remain unclear due to the complex nature of both microbial composition and pathophysiology of epilepsy. We investigated effects of long-term probiotics supplementation on epileptic seizures, and inflammatory and oxidant/antioxidant biomarkers in a pentylenetetrazole(PTZ)-induced seizure model in rats. Male Wistar weaner-rats were divided into four groups. The first two groups received 1 ml/day saline solution, while the other groups received 0.05 mg/1ml/day vehicle or 109cfu/1ml/day probiotic-mixture, respectively, for 60 days by gavage. Seizure was induced by a single convulsive dose of PTZ. Seizures were evaluated using Racine's scale. Concentrations of pro-inflammatory cytokines in plasma and brain tissue were determined using ELISA, while oxidant/antioxidant biomarkers were measured using an automated-colorimetric method. Probiotics supplementation exhibited anticonvulsant effects against PTZ-induced seizures by retarding onset-times of both myoclonic-jerk and generalized tonic-clonic seizure, and by shortening duration of generalized tonic-clonic seizure. Additionally, it alleviated PTZ-induced increases in levels of pro-inflammatory cytokines IL-1ß, IL-6, and IL-17A, but not of IFNγ, in plasma and brain tissue. Moreover, it restored PTZinduced fluctuations in levels of oxidants TOS and disulfide, and of antioxidants native thiol and total thiol. Our findings suggest that long-term probiotics supplementation exhibits protective effects against epileptic seizures, and alleviates (neuro)inflammation and oxidative stress related to pathophysiology of epilepsy. A probiotic-rich diet provided from childhood may provide prophylaxis against epileptic seizures, especially in susceptible individuals, as the neonate diet represents a fundamental extrinsic factor in establishing gut microbiota.

Risk factors affecting seizure recurrence in childhood epilepsy during short-term follow-up.

PURPOSE: The aim of this study is to examine the factors affecting seizure recurrence in pediatric patients diagnosed with epilepsy. METHODS: Three hundred patients presenting to the pediatric neurology clinic between 2015 and 2018 and diagnosed with epilepsy and treated with single antiseizure drug were included in the study. Medical histories and clinical and laboratory findings were retrieved retrospectively from the hospital data system. The combined and adjusted effects of risk factors on seizure recurrence were evaluated using multivariate binary logistic regression analysis. RESULTS: Boys had a higher rate of seizure recurrence than girls. Seizure recurrence was also higher in patients with abnormal neurological examinations at the time of diagnosis compared to those with normal neurological examinations. Seizure recurrence was significantly higher in patients with global growth retardation. Epilepsy patients with abnormal MRI findings also had a higher rate of seizure recurrence than patients with normal neuroimaging findings. In addition, seizure recurrence was significantly higher in epilepsy patients with comorbidities such as cerebral palsy and autism spectrum disorders compared to patients without comorbidities. No significant association was observed between seizure recurrence and the first drug, perinatal asphyxia history, localization of epileptiform discharges on EEG, family history of epilepsy, family history of febrile seizures, history of stay in the neonatal intensive care unit during the perinatal period, or preterm delivery. CONCLUSION: Abnormal neurological examination, abnormal neuroimaging and accompanying comorbidities, and global growth retardation at the time of diagnosis are important factors affecting seizure recurrence in pediatric patients with epilepsy.

A Statistical Modeling of the Course of COVID-19 (SARS-CoV-2) Outbreak: A Comparative Analysis.

This study aims to provide both a model by using cumulative cases and cumulative death toll for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) outbreak in four countries, China, Italy, South Korea, and Turkey, starting from the first diagnosis and to compare associated indicators. The most successful estimation was obtained from the cubic model with natural logarithm for China, Italy, South Korea, and Turkey. The success of the models was around 99%. However, differences began to emerge in China, Italy, and South Korea after the second week. Although the highest number of new cases per 1 million people in China was 9.8 on February 28, 2020; it was 108.4 on March 21, 2020, in Italy; and this was 16.6 on March 5, 2020, in South Korea. On the other hand, the number of new cases was 24.6 per 1 million people on March 27, 2020, in Turkey. The log-cubic model proposed in this study has been set forth to obtain successful results for aforementioned countries, as well as to estimate the course of the COVID-19 outbreak. Other factors such as climacteric factors and genetic differences, which may have an impact on viral spreading and transmission, would also have strengthened the model prediction capacity.

The use of neodymium magnets in healthcare and their effects on health.

The strong magnetic field properties of magnets have led to their use in many modern technologies, as well as in the fields of medicine and dentistry. Neodymium magnets are a powerful type of magnet that has been the subject of recent research. This review provides a brief explanation of the definition, history, and characteristics of rare earth magnets. In addition, a broad overview of results obtained in studies performed to date on the effects of magnets, and neodymium magnets in particular, on body systems, tissues, organs, diseases, and treatment is provided. Though they are used in the health sector in various diagnostic devices and as therapeutic tools, there is some potential for harmful effects, as well as the risk of accident. The research is still insufficient; however, neodymium magnets appear to hold great promise for both diagnostic and therapeutic purposes.

A New SEYHAN's Approach in Case of Heterogeneity of Regression Slopes in ANCOVA.

In this study, when the assumptions of linearity and homogeneity of regression slopes of conventional ANCOVA are not met, a new approach named as SEYHAN has been suggested to use conventional ANCOVA instead of robust or nonlinear ANCOVA. The proposed SEYHAN's approach involves transformation of continuous covariate into categorical structure when the relationship between covariate and dependent variable is nonlinear and the regression slopes are not homogenous. A simulated data set was used to explain SEYHAN's approach. In this approach, we performed conventional ANCOVA in each subgroup which is constituted according to knot values and analysis of variance with two-factor model after MARS method was used for categorization of covariate. The first model is a simpler model than the second model that includes interaction term. Since the model with interaction effect has more subjects, the power of test also increases and the existing significant difference is revealed better. We can say that linearity and homogeneity of regression slopes are not problem for data analysis by conventional linear ANCOVA model by helping this approach. It can be used fast and efficiently for the presence of one or more covariates.

Effects of thymoquinone, the major constituent of Nigella sativa seeds, on penicillin-induced epileptiform activity in rats.

OBJECTIVE: To investigate the effects of thymoquinone (TQ) in a penicillin-induced epilepsy model in rats. METHODS: This experimental study included 56 adult male Wistar rats. Experiments were performed in the Research Laboratory of the Department of Physiology, Medical School, Duzce University, Duzce, Turkey, between October 2013 and December 2014. Animals were divided into the following 7 groups: sham, control, only thymoquinone, vehicle (Dimethylsulfoxide), and doses of 10, 50, and 100 mg/kg of TQ. After rats were anesthetized, the left part of the skull was removed. A pair of silver/silver chloride electrodes was placed on the somatomotor area, and electrocorticographic recording was started. After 5 minutes basal activity was recorded, and TQ was applied intraperitoneally. At the thirtieth minute after TQ, epileptiform activity was induced by intracortical penicillin. The first spike latency, spike frequency, and the amplitude of epileptiform activity were analyzed statistically. RESULTS: The different doses of TQ significantly increased the latency time to onset of first spike wave, and decreased the frequency, and amplitude of epileptiform activity in the first 20 minutes compared with the control group. CONCLUSION: Thymoquinone shows potential as an antiepileptic drug resulting from its effects of prolonged latency time, and reduced spike wave frequency and amplitude of epileptiform activity.

The hemostatic effect of calcium alginate in experimental splenic injury model.

BACKGROUND: We evaluated the effect of calcium alginate as a hemostatic agent in a splenic injury model. METHODS: Experimental rats (Wistar albino) were divided into four groups. Group I: Laparotomy was not performed. Group II: After laparotomy, the abdomen was closed without any splenic injury. Group III: After laparotomy, splenic injury about 0.5 cm in depth and 0.3 cm in length was created by standard Rochester pean forceps. Physiological serum treated gauze dressing, about 2x2 cm in size, was applied to the injured splenic tissue for 3 minutes. Group IV: After laparotomy, standard splenic injury about 0.5 cm in length and 0.3 cm in depth was created. Calcium alginate wound dressing, 1x1 cm in size, was applied to the splenic wound. In all groups, blood samples for bleeding time and hemogram were taken. Peroperative blood loss, pre- and post-operative hemoglobin and hematocrit values were calculated. RESULTS: Comparing hematocrit values and peroperative bleeding in Groups III and IV, Group IV had a lower decline in hematocrit values and lower peroperative bleeding. CONCLUSION: Calcium alginate has hemostatic capacity. It may be used in splenic injuries, especially for Grades I and II.

In vivo comparison of the effects of bupivacaine and levobupivacaine on the pregnant rat myometrium using electrohysterogram.

BACKGROUND AND AIMS: The effect of local anesthetics on myometrial contractility during labor analgesia is debatable. We aimed to compare the effects of bupivacaine and levobupivacaine on rat uterine contractility in an in vivo setting. METHODS: Electrical activities of 40 pregnant rat uteruses were recorded on electrohysterogram after dividing the rats into bupivacaine and levobupivacaine groups. Uterine contraction frequencies were recorded at each 5-min interval. The first 5-min recording was considered the control, which was immediately followed by intramyometrial administration of either bupivacaine or levobupivacaine. The recordings were continued for 30 min. The changes in frequencies at each time interval of the groups were compared with each other and the control recording. RESULTS: The frequencies from both groups at each interval were lower than the control values, but not different between the groups. The frequencies of the bupivacaine group during the 5-10 min and 10-15 min intervals were lower than the control time interval, but no significant differences were present between the control and the other time intervals. However, no significant differences were found at any time interval for the levobupivacaine group. CONCLUSION: Levobupivacaine led to less muscle relaxation compared to bupivacaine and may be a better option for labor analgesia and anesthesia considering uterine contractility.

The interactions of nitric oxide and adenosine on penicillin-induced epileptiform activity in rats.

In this study, the influence of nitric oxide (NO) and adenosine systems on penicillin-induced epileptiform activity was examined in rats. NO donor, sodium nitroprusside (SNP, 50 micrograms per rat, i.c.v.) reduced the frequency but not the amplitude of epileptiform discharges. Non-selective NOS inhibitor, N-omega-nitro-L-arginine methyl ester (L-NAME, 100 micrograms per rat, i.c.v.) practically did not exert any effect on the spike frequency and amplitude. Adenosine (100 micrograms per rat, i.c.) reduced spike frequency but not the amplitude, whereas theophylline (100 micrograms per rat, i.c.v.) increased the mean spike frequency and amplitude of penicillin-induced epileptiform discharges. Co-injection of theophylline and L-NAME did not cause a further increase in the epileptiform activity compared with theophylline. When NO production was blocked with L-NAME, the inhibitory effects of adenosine were lost. The obtained results suggest that NO and adenosine may decrease penicillin-induced epileptiform activity in rats and that NO, at least in part, may mediate the anticonvulsant effect of adenosine.

The effect of intra-arterial papaverine on ECoG activity in the ketamine anesthetized rat.

The opium alkaloid papaverine (PPV) causes vasodilatation of the cerebral arteries through direct action on smooth muscle that reduces the constriction of smooth muscle. Intra-arterial papaverine (IAP) has been used widely to increase the regional cerebral blood flow in order to reverse the cerebral vasospasm that occurs during endovascular procedures. IAP-induced seizures have been reported, although PPV has anticonvulsive effects. This study determined the effects of IAP on electrocorticography (ECoG) in the ketamine anesthetized rats. We used 24 Sprague-Dawley male rats weighing 200-250 g. The animals were divided randomly into four groups: three treatment groups (groups 1-3) and a control (group 4). Groups 1, 2, and 3 were given 1, 7, and 14 mg/kg IAP, respectively. The ECoG was compared across groups. Our results indicated that IAP did not cause seizures and that it decreased the frequency of ketamine-induced epileptiform activity in the 14 mg/kg group.

Detailed spectral profile analysis of penicillin-induced epileptiform activity in anesthetized rats.

Penicillin model is a widely used experimental model for epilepsy research. In the present study we aimed to portray a detailed spectral analysis of penicillin-induced epileptiform activity in comparison with basal brain activity in anesthetized Wistar rats. Male Wistar rats were anesthetized with i.p. urethane and connected to an electrocorticogram setup. After a short period of basal activity recording, epileptic focus was induced by injecting 400IU/2 microl penicillin-G potassium into the left lateral ventricle while the cortical activity was continuously recorded. Basal activity, latent period and the penicillin-induced epileptiform activity periods were then analyzed using both conventional methods and spectral analysis. Spectral analyses were conducted by dividing the whole spectrum into different frequency bands including delta, theta (slow and fast), alpha-sigma, beta (1 and 2) and gamma (1 and 2) bands. Our results show that the most affected frequency bands were delta, theta, beta-2 and gamma-2 bands during the epileptiform activity and there were marked differences in terms of spectral densities between three investigated episodes (basal activity, latent period and epileptiform activity). Our results may help to analyze novel data obtained using similar experimental models and the simple analysis method described here can be used in similar studies to investigate the basic neuronal mechanism of this or other types of experimental epilepsies.

Further evidence for enhancing effects of NO on monosynaptic and polysynaptic spinal reflexes in cats.

There are a number of studies on the effects of different NO donors and inhibitors on spinal cord with quite contradictory results. The aim of this study was to investigate the effects of sodium nitroprusside (SNP), a NO donor, and N(G)-nitro-L-arginine methyl ester (L-NAME), a nonselective NOS inhibitor, on monosynaptic and polysynaptic spinal reflexes in anesthetized and spinalized cats. After a dorsal laminectomy between L5 and S1, monosynaptic and polysynaptic spinal reflexes were evoked by stimulation of gastrocnemius nerves. Following control recordings, administration of L-NAME in 100, 200, 500 microM (local) and 10, 20, 50 mg/kg (i.v.) doses decreased significantly the monosynaptic and polysynaptic reflex amplitudes in a dose-dependent manner. Administration of SNP in 100, 200, 500 microM (local) and 100, 200, 500 microg/kg (i.v.) doses enhanced significantly the both reflex amplitudes in a dose-dependent manner. In another series of experiments it has been observed that the maximal decrease in reflex amplitudes caused by 500 microM local L-NAME administration in the 15th minute was reversed by locally administered SNP (500 microM). Our results support the hypothesis stating that NO may play a role in the modulation of mono- and polysynaptic spinal reflexes and the NO appears to have an enhancing role on these responses.