Comparing the long-term retention of a physiology course for medical students with the traditional and problem-based learning

The rapid improvements in medical sciences and the ever-increasing related data, however, require novel methods of instruction. One such method, which has been given less than due attention in Iran, is problem-based learning (PBL). In this study, we aimed to evaluate the impact of study skills and the PBL methods on short and long-term retention of information provided for medical students in the course of respiratory physiology and compare it with traditional learning method. In this study, 39 medical students from Medical School of Kerman University of Medical Sciences, Kerman, Iran (2006–2010) were enrolled in the study and allocated randomly in three equal groups (13 in each group). All groups underwent a pre-test to be assessed for their basic information regarding respiratory physiology. Two groups were instructed using the traditional method, and one group used PBL. Among the two groups of the traditional method, one was instructed about study skills and the other was not. Once the PBL group took the study skill workshop, they were aided by tutors for their education. In the final term test, those students who had learned study skills and were instructed with the traditional method scored higher compared to other groups (p\0.05). However, in the 1 year (p\0.05) and 4 year (p\0.01) interval examinations, the PBL group achieved significantly higher scores. Despite the fact that PBL had no positive effect on the final term exam of our students, it yielded a more profound and retained understanding of the subject course. Moreover, considering the positive effect of study skills on long-term student scores, we recommend students to receive instructions regarding the appropriate study skills when initiated into universities

Ascorbic acid decreases morphine self-administration and withdrawal symptoms in rats

Recent studies have indicated that the glutamatergic system is involved in the motivational aspects during the initiation of drug selfadministration. Ascorbic acid (AA), an antioxidant vitamin, is released from glutamatergic neurons, and it modulates the synaptic action of dopamine and glutamate. In this study the AA effects on the self-administration of morphine and on the morphine withdrawal syndrome have been investigated. Wistar rats were allowed to self-administer morphine (1 mg/infusion) during 10 consecutive days for 2 h/session. The number of lever pressings was recorded. An intrapritoneal AA injection (500 mg/kg, i.p.), 30 min before morphine self-administration produced a significant decrease in the initiation of morphine self administration during all sessions. After the last test session morphine withdrawal symptom signs (MWS) were recorded after naloxone precipitation. Most of MWS (but not all) were decreased by AA application. In conclusion, AA may change the motivational processes underlying the morphine self-administration

Involvement of β-adrenergic receptor of nucleus tractus solitarius in changing of baroreflex sensitivity by estrogen in female rats

Background: Arterial baroreflex (ABR) is an important factor in preventing of blood pressure fluctuations that determined by baroreflex sensitivity (BRS). Estrogen is an ovarian hormone that has influence on ABR. The mechanism of this effect of estrogen unknown and may be mediated by β-adrenergic receptor of nucleus tractus solitarius (NTS), an important area in regulation of baroreflex. Therefore, in this study changing of BRS by estrogen after blockade β-adrenergic receptor of NTS in ovariectomized rats (Ovx) and Ovx treated with estrogen (Est) was examined. Materials and Methods: After ovariectomy, all female rats divided to Ovx and Ovx + Est groups and two series of experiments were performed. In the first experiment, phenylephrine was [intravenously, IV] injected in both the Ovx and Ovx + Est groups, and mean arterial pressure (MAP), heart rate (HR), and BRS were evaluated (n = 8 for each group). In the second experiment, each of Ovx and Ovx + Est groups divided into saline and propranolol (pro) groups, saline and pro stereotaxically were microinjected into NTS, respectively. Further, phenylephrine (IV) was injected in all groups and BRS was evaluated. Results: BRS significantly increased in estrogen-treated groups (Ovx + Est) compared to Ovx groups (P < 0.01). The blockade β-adrenergic receptor of NTS by pro did not significantly changed BRS in both Ovx and Ovx + Est groups. Conclusion: We concluded that there aren′t any intraction between estrogen and β-adrenergic receptor of NTS in BRS

Effect of Various Concentrations of Inhibitors on the Expression of Chemokine Ip-10/Mob-1

Introduction: Chemokines are low molecular weight proteins (8-17kDa) with the main role of immune cells recruitment to injured tissues. IP-10/Mob-1 is a CXC chemokine and different cell systems in response to external stimulation produce this chemokine. Various signaling pathways are used by cell and tissue systems to regulate production of proteins e.g. chemokines. Therefore we have investigated some of these pathways leading to production of IP-10/Mob-1 by primary cultured hepatocytes. Methods: In the present study, hepatocyts were isolated from male Sprague Dawley rats and cultured on Waymouth medium in presence and absence of different inhibitors such as SB203580, MG132, KN62 and Staurosporine for indicated time points. Supernatant medium of culture was centrifuged and proteins were isolated by SDS-PAGE and transferred to nitrocellulose membranes, then membranes were incubated with IP-10/Mob-1 antibody overnight and followed by incubation with secondary antibody and then IP-10/Mob-1 was detected by ECL. Results: We showed that the expression of IP-10/Mob-1 has been decreased in presence of Staurosporine (10 and 50μM), SB203580(50μM) MG132 (20μM) and KN62 (10 and 20μM) but did not change in absence or lower concentrations of these inhibitors. Conclusion: Hence, these in vitro data may aid to a better understanding of the pathways in chronic liver injuries and identify clinical studies that may aid in treatment or prevention of these conditions. Furthermore, there may be further potential to prevent changes to hepatocyte phenotype and allow isolation of hepatocytes with a greater physiological phenotype. Therefore it could be concluded that all of these pathways are used by hepatocytes regarding expression of IP-10/Mob-1

Active Learning Methods and Strategies to Improve Student Conceptual Understanding: Some Considerations from Physics Education Research

Active learning methods and strategies are credited to be important means for development of student cognitive skills This paper describes some forms of active learning common in Physics Education and briefly introduces some of the pedagogical and psychological theories at the basis of active learning. Then, some evidence for active learning effectiveness in developing student critical cognitive skills and improving their conceptual understanding are examined. An example study regarding the effectiveness of an Inquiry-Based learning approach in helping students to build mechanisms of functioning and explicative models, and to identify common aspects in apparently different phenomena, is briefly discussed