Factors affecting medical students' satisfaction with online learning: a regression analysis of a survey.

BACKGROUND: Medical education requires the implementation of different teaching methods and strategies for future doctors to achieve broad learning objectives. This wide range of methods and strategies includes the use of Information Technologies. For a long time, there was a call for a change in medical education for blending new teaching approaches to lessen medical students' class time. The COVID-19 pandemic then sped up the transition to the new way of medical education and classroom lectures were quickly moved to a virtual environment. We expect that these changes will continue, and online learning will be one of the main teaching strategies in medical education. Therefore, educational experiences during the COVID-19 pandemic will improve our understanding of online learning and will help to develop blended medical school curricula in the future. For this reason, we aimed to determine students' overall satisfaction with their online learning experience and to define the main factors affecting students' satisfaction with their online learning program at Cerrahpasa Medical Faculty. METHODS: A cross-sectional survey study was conducted to determine medical students' overall satisfaction with online learning methods and to identify factors associated with positive and negative satisfaction levels. A questionnaire, consisting of 24 questions to collect demographic characteristics, factors associated with online education experience and overall satisfaction levels was developed and distributed to 1600 medical students. Multivariable linear regression analysis was used to determine the factors associated with positive and negative satisfaction levels. RESULTS: Regression analysis showed that being familiar with online teaching techniques (ß = 0.19, 95% CI [0.07, 0.30], faculty members' higher online teaching skill levels (ß = 0.42, 95% CI [0.32, 0.51], interactive online teaching approaches (ß = 0.54, 95% CI [0.41, 0.67], having a personal workspace (ß = 0.43, 95% CI [0.19, 0.67], and a self-reported longer attention span (ß = 0.75, 95% CI [0.57, 0.92] were associated with higher overall satisfaction with online learning. The occurrence of technical problems (ß = -0.19, 95% CI [-0.26, -0.12] was associated with lower overall satisfaction. CONCLUSIONS: Higher online teaching skills of faculty members, use of interactive approaches, students' familiarity with online teaching techniques, provision of a personal workspace, and self-reported longer attention spans positively contributed to higher levels of student satisfaction with online learning. Considering the increasing significance of online educational methods, our study identified key components that affect students' level of satisfaction. This information might contribute to the development of online educational programs in the future.

The safety of intraocular usage of aspirin.

PURPOSE: To determine the effects of intravitreally injected aspirin on normal ocular tissues. METHODS: Six eyes of 3 rabbits as a control group, 18 eyes of 9 albino rabbits which were injected aspirin intravitreally were studied. In the control group, the same volume of balanced salt solution (BSS) as in drug groups were injected. Clinical examination methods including biomicroscopy, indirect ophthalmoscopy, and Schiotz tonometry, electrophysiological test including ERG, and histopathological examination including light microscopy were used to evaluate the ocular effects after drug injections. All the study tests were performed before the injections and 1 week, 1 month, and 3 months after the injections as well. RESULTS: No significant toxicity was determined after injection in terms of the clinical examination methods in all eyes. Cataracts were observed in 27.7% (5/18) of the eyes in the study group. All cataracts in 5 eyes disappeared at the end of three months. In tonometry, no value out of the normal range of rabbits (17.5 ± 3.1 mmHg) was observed. No toxicity sign was observed at electrophysiological and histopathological evaluations. CONCLUSION: After intravitreal injection of aspirin, no significant toxicity sign was observed other than a reversible cataract. Thus, intravitreal aspirin injections may be an additional or alternative treatment option for several anterior or posterior segment ocular diseases in addition to their topical utilization.

Investigation of doxorubicin combined with ciprofloxacin-induced cardiotoxicity: from molecular mechanism to fundamental heart function.

This study was designed to investigate the impacts of Doxo alone and in combination with Cipro on the hepatic and cardiac CYP1A2, CYP2J3, and CYP3A1 mRNA levels. We also aimed to analyze the cardiac function by perfusing isolated rat hearts. Rats were given Doxo and/or Cipro in chronic (3-week) and acute (single-day) dosing schedules. Cardiac CYP2J3, CYP3A1, and CYP1A2 gene expression levels were measured by quantitative reverse transcription PCR. Cardiac functions of the isolated hearts were evaluated by using the Langendorff technique. Doxo alone (2.5 mg/kg) and Doxo + Cipro (2.5 mg + 20 mg/kg) significantly decreased hepatic CYP1A2 expression compared to saline, whereas Doxo (2.5 mg/kg) and Doxo + Cipro (2.5 mg + 20 mg/kg) showed significantly higher cardiac CYP1A2 expression in comparison to control. In the liver tissue, Doxo (2.5 mg/kg) and Doxo + Cipro (2.5 + 20 mg/kg) decreased the CYP2J3 expression than the control group. The Doxo (2.5 mg/kg) and Doxo + Cipro (2.5 + 20 mg/kg)-treated group had significantly higher cardiac CYP2J3 expression compared to control. Doxo (2.5 mg/kg; cumulative dose 15 mg/kg) and Doxo + Cipro (2.5 + 20 mg/kg) showed significantly higher cardiac CYP3A1 expressions than the control. Rate-pressure product (HR × LVDP)/1000) showed an overall decrease in cardiac functions of Doxo (2.5 mg/kg) and Doxo + Cipro (2.5 + 20 mg/kg)-treated group. We found considerable effects in chronic protocol; Doxo alone high dose and plus Cipro decreased hepatic CYP1A2 and CYP2J3 mRNA. On the other hand, these treatment groups exhibited an increase in the cardiac CYP1A2, CYP2J3, and CYP3A1 expression and likewise deteriorated the overall hemodynamic parameters.

Cardioprotective effects of zofenopril, enalapril and valsartan against ischaemia/reperfusion injury as well as doxorubicin cardiotoxicity.

OBJECTIVE: The aim of this study is to compare possible protective effects of zofenopril, enalapril and valsartan against both ischaemia/reperfusion injury as well as acute doxorubicin cardiotoxicity. All three agents have never been compared in this setting before. METHODS AND RESULTS: Sixty-four male rats were divided into eight groups by computer-generated random numbers and each group included 8 rats. Groups 1, 2, 3 and 4, respectively, received 0.5 ml distilled water, 15 mg/kg/day zofenopril, 2 mg/kg/day enalapril, and 30 mg/kg/day valsartan intragastrically for 7 days. Groups 5, 6, 7, and 8 underwent the same procedures as groups 1, 2, 3 and 4. On the 7th day, groups 1-4 and groups 5-8, respectively, were injected with serum saline or 20 mg/kg doxorubicin intraperitoneally. On the 9th day, isolated rat hearts were perfused in the Langendorff perfusion system. At the end of each Langendorff experiment, the rat hearts were kept for histological analysis. Left ventricular systolic pressures were negatively affected by doxorubicin with ischaemia (group 5 initially: 61.4 +/- 13.6 mmHg--post-ischaemic (PI): 20.7 +/- 17.5 mmHg (P = 0.0002), group 6 initially: 63 +/- 18.2 mmHg--PI: 24.2 +/- 24.3 mmHg (P = 0.0135), group 7:82 +/- 26 mmHg--PI: 14.3 +/- 12.1 mmHg (P < 0.0001), group 8:73.1 +/- 27.8 mmHg--PI: 20.4 +/- 27.3 mmHg (P < 0.0001). The lowest troponin I levels (group 2: 0.3 +/- 0.2 ng/ml, group 6:0.2 +/- 0.1 ng/ml (P = 0.003) versus the groups' baseline value) were recorded in the groups of zofenopril in the coronary perfusate during post-ischaemic period. Light microscopic evaluation revealed marked cardiac damage with doxorubicin, since zofenopril treatment prevented a doxorubicin induced increase in the histopathological scores. CONCLUSIONS: In respect of our results zofenopril could be considered more effective than enalapril and valsartan in protecting against both ischaemia/reperfusion injury as well as doxorubicin induced-cardiotoxicity.

Donor heart preservation with iloprost supplemented St. Thomas Hospital cardioplegic solution in isolated rat hearts.

This study was designed to assess the influence of St. Thomas Hospital cardioplegic solution (St. Th.) on heart preservation in rat hearts subjected to 6h ischemia when supplemented with iloprost. In the control group (n=8), nothing was added to St. Th., whereas 10 or 1000 nmol L(-1) iloprost was added in the second (n=7) and third (n=8) groups, respectively. Mechanical contraction parameters, cardiac tissue damage and oxidative stress markers were evaluated. The 10 nmol/L iloprost group peak systolic pressure (71.0+/-30.9 versus 41.0+/-9.4 mm Hg) and -dp/dtmax (1103.8+/-94.3 versus 678.6+/-156.8 mm Hg s(-1)) were significantly higher than control group at 30 min of reperfusion (p<0.05). Iloprost supplemented groups had higher GSH and catalase levels of coronary perfusate at reperfusion, in comparison with initial values (p<0.05). AST, CK, CK-MB values increased at 0 min of reperfusion and cTnI values at 45 min of reperfusion (p<0.05) in all groups with no difference between groups. According to our results, iloprost supplementation had mild but significant improvement in postischemic values in mechanical and oxidative stress parameters, resulting in better heart preservation.

Hypotensive effects of intravenously administered uridine and cytidine in conscious rats: involvement of adenosine receptors.

In the present study, we investigated the cardiovascular effects of intravenously injected uridine or cytidine, and the role of adenosine receptors in mediating these effects, in conscious normotensive rats. Intravenous (i.v.) administration of uridine (124, 250, 500 mg/kg) dose-dependently decreased arterial pressure and heart rate. Cytidine (124, 250, 500 mg/kg; i.v.) produced slight dose-related hypotension without changing heart rate. Plasma uridine and cytidine concentrations increased time- and dose-dependently while plasma adenosine levels did not change after injection of the respective nucleosides. Pretreatment with intravenous caffeine (20 mg/kg), 8-phenyltheophylline (8-PT) (1 mg/kg), nonselective adenosine receptor antagonists, or 8-p-sulfophenyltheophylline (8-SPT) (20 mg/kg), a nonselective adenosine receptor antagonist which does not cross the blood-brain barrier, abolished the cardiovascular effects of uridine (250 mg/kg; i.v.) or cytidine (250 mg/kg; i.v.). Intracerebroventricular (i.c.v.) caffeine (200 microg) or 8-SPT (50 microg) pretreatment did not change the magnitude of the cardiovascular responses induced by nucleosides. Intravenous 8-cyclopenthyl-1,3-dipropylxanthine (DPCPX) (5 mg/kg), a selective adenosine A(1) receptor antagonist, greatly attenuated the cardiovascular responses to uridine and cytidine. Pretreatment with 3,7,-dimethyl-1-propargylxanthine (DMPX) (2 mg/kg), an adenosine A(1)/A(2) receptor antagonist, attenuated hypotension induced by uridine and blocked the arterial pressure decrease in response to cytidine. Uridine-induced bradycardia was blocked by DMPX. 4-(2-[7-amino-2-(2-furyl[1,2,4]-triazolo[2,3-a[1,3,5]triazin-5-yl-aminoethyl)phenol (ZM241385) (1 mg/kg; i.v.), a selective adenosine A(2A) receptor antagonist, pretreatment produced an only very small blockade in the first minute of the hypotensive effects of uridine without affecting the bradycardia. ZM241385 pretreatment completely blocked cytidine's hypotensive effect. In Langendorff-perfused rat heart preparation, uridine (10(-3) M), but not cytidine, decreased the heart rate. Our results show that intravenously injected uridine or cytidine is able to decrease arterial pressure by activating peripheral adenosine receptors. The data also implicates that the mainly adenosine A(1) receptor activation is involved in the uridine-induced cardiovascular effects, while both adenosine A(1) and A(2A) receptor activations mediate the cytidine's effects.

Comparison of enoximone, amrinone, or levosimendan enriched St. Thomas' hospital cardioplegic solutions used for myocardial preservation in isolated guinea pig hearts.

Myocardial contractile function after cardioplegic arrest is often depressed and an ideal cardioplegic solution has not been developed yet. The aim of this study was to assess the efficacy of phosphodiesterase III inhibitors, amrinone and enoximone, and levosimendan, a novel Ca2+ sensitizing agent, on recovery of hearts after normothermic cardioplegic arrest when added to the St. Thomas' hospital cardioplegic solution. In the control group, isolated guinea pig hearts were perfused in Langendorff apparatus and arrested with standard St. Thomas' solution. In other groups, amrinone (10(-5) mol.L-1), levosimendan (10(-5) mol.L-1), or enoximone (10(-4) mol.L-1) were added to the cardioplegic solution. In all hearts, intraventricular pressure, +dp/dtmax, -dp/dtmax, area under pressure-time curve, heart rate, coronary flow, lactate dehydrogenase and creatine kinase enzyme leakage, and oxygen consumption were measured. In the enoximone group, contractility force and +dp/dtmax, were found to be significantly high in the reperfusion and inotropic periods in comparison with other groups (p < 0.05). -dp/dtmax and area under contractility-time curve values were significantly high in inotropic period in enoximone group (p < 0.05). No statistically significant difference was noted in other groups. Cardioplegic solution enrichment with enoximone augmented mechanic functions in reperfusion period. No positive effect of amrinone or levosimendan was observed in this study.

Effects of erucic acid supplemented feeding on chronic doxorubucin toxicity in rats.

One of the undesired complications of the chemotherapy with doxorubicin is cardiotoxicity. Cardiac effect of erucic acid, which is a member of omega-9 fatty acid, is investigated on doxorubicin treatment in this study. Forty-eight rats were divided into eight groups and each group contained six rats. First group rats were fed with milk. In the third and fifth groups we fed rats with milk supplemented 0.5% and 5% erucic acid respectively. The groups 2, 4, 6 were fed as the groups 1, 3, 5 respectively; we injected 2 mg/kg twice weekly intraperitoneal doxorubicin to these groups whereas we injected isovolumous normal saline to the groups 1, 3, 5. Two other groups (groups 7 and 8) were fed with standard pellet. Group 8 received 2 mg/kg doxorubicin twice weekly; group 7 received normal saline. After 4 weeks hearts were isolated and mounted on a Langendorff apparatus perfused by modified Tyrode solution. Surviving rats were significantly less in erucic acid + doxorubicin groups at the end of the treatment period (p<0.05). No significant difference was found between groups for malondialdehyde, catalase, cytochrome c oxidase and isolated heart measurements. Concomitant application of erucic acid and doxorubicin showed profound toxicity.