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 Cerrahpaşa 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 ( β = 0.19, 95% CI [0.07, 0.30], faculty members’ higher online teaching skill levels ( β = 0.42, 95% CI [0.32, 0.51], interactive online teaching approaches ( β = 0.54, 95% CI [0.41, 0.67], having a personal workspace ( β = 0.43, 95% CI [0.19, 0.67], and a self-reported longer attention span ( β = 0.75, 95% CI [0.57, 0.92] were associated with higher overall satisfaction with online learning. The occurrence of technical problems ( β = - 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.
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.
Amaç: Kolon anastomozu (CA) sonrası gelişen anastomoz kaçağı morbidite ve mortaliteyi artırır.Kalsiyum dobesilate (CaD) anjiyoprotektif, antioksidan, lenfatik kan akımını artırıcı ve nöroprotektif etkilere sahiptir.Bu kapiller ve hücresel sahadaki etkilerine rağmen CaD'nin
Abstract 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.
Lapatinib is an oral receptor tyrosine kinase inhibitor which has shown activity in the treatment of metastatic breast cancer. There is no data regarding the side effects of combination of radiotherapy and Lapatinib. 40 female Wistar-albino rats (WAR) were divided into 4 groups; G1 did not receive any treatment, G2 received radiotherapy to whole thoracic region, G3 received Lapatinib without radiotherapy, G4 received Lapatinib with radiotherapy. A total dose of 30 Gy in 10 fractions was given to both lungs. Lapatinib equivalent to 1500 mg/day were calculated according to the mean weight of rats, orally administrated. A comparative analysis was performed by scoring the pulmonary injury between 0 and 3 according to the infiltration of inflammatory cells into the alveolar spaces, alveolar wall thickening and architectural deformation across the entire lung section. In G2 inflammatory cell infiltration, fibrosis with damage to lung structure andformation of small fibrous masses were observed. Alveolar septa were significantly thicker than G1 (p <= 0.001), which revealed totally normal pulmonary structure. G3 showed minimal alveolar septal thickening and infiltration of inflammatory cells into the alveolar spaces which was not significantly different than G1. Histopathological findings in G4 were similar to those in G2 and statistically different when compared with the G1 and G3 (p <= 0.001). In this experimental study it has been shown that addition of Lapatinib to radiation did not increase RIPF in rats.
PURPOSE:To assess the efficacy and of iloprost in the treatment of Buerger's disease.METHODS:In this prospective study, 158 patients with rest pain and/or ischemic ulcers from 17 clinics were administered 1 ng/kg/min intravenous iloprost for 28-days. The primary endpoint was complete healing without pain or major amputation at 24 weeks. The secondary endpoints were pain assessment, reduction in ulcer area, 50% reduction of the ulcer size, shift in the modified SVS/ISCVS clinical status grading scale, global assessment by the investigator and an independent observer at 4 and 24 weeks. The comparisons were carried out with the initial values. The final evaluation was carried out in 150 patients.RESULTS:Complete healing rate was significantly better with iloprost treatment in comparison to the initial values at 24 weeks (<0.001). The secondary endpoints; complete healing rate, pain, the size of the ulcer, 50% reduction of the ulcer size, SVS/ISCVS grading scale, assessment by investigator, assessment by observer parameters were significantly better at 4 and 24 weeks (<0.001). The reduction of the ulcer size was significantly better when comparing 4th and 24th week values (<0.05).CONCLUSION:The results of this independent study indicate that intravenous iloprost relieves ischemic symptoms efficiently in the acute phase Buerger's disease patients. Considering unsatisfactory results following surgical revascularisation and sympathectomy in Buerger's disease, prostacyclin analogues might be the first line treatment as long as complete abstinence from smoking is achieved.
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.
Background: We aimed to investigate the effects of calcium dobesilate (DOBE) and micronized purified flavonoid fractions (MPFF) on the functions of rat hearts following ischemia and reperfusion.Methods: Eighteen male Wistar albino rats were randomly divided into three groups: the DOBE group (100 mg/kg/day), the MPFF group (100 mg/kg/day), and the control group. The hearts were perfused twice for 25 minutes before and after 15 minutes of ischemia. Creatine kinase, lactate dehydrogenase, troponin I and myoglobin levels in the coronary perfusates, and malondialdehyde and glutathione levels in the myocardial tissue samples were analyzed. Mean P (mean pressure perfusing coronary arteries), PP (peak systolic pressure), (+)dp/dtmax (contraction strength change over time), (-)dp/dtmax (relaxation strength change over time), time to reach PP, ejection time, and contraction time were calculated.Results: The mean 'p' values of the DOBE group were significantly lower than those of the control group at the first and fifth minutes of reperfusion; moreover, PP, (+)dp/dtmax, and (-)dp/dtmax values were found to be significantly higher than the measurements made at the 15(th), 20(th) and 25(th) minutes in the control group. In the MPFF group, the (-)dp/dtmax value was significantly higher than that of the control group at the fifth minute of reperfusion.Conclusion: DOBE is helpful in improving myocardial functions following ischemia and reperfusion.
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.
AIM:Calcium dobesilate is an angio-protective agent that has positive effects on hemorheological parameters. It decreases blood and plasma viscosity, thrombocyte aggregation, and microvascular hyperpermeability. It is an antioxidant that increases endothelial-derived vasodilator substance secretion. In this experimental study, the effects of calcium dobesilate on myocardial ischemia reperfusion injury were investigated.METHODS:Using the Langendorff setup, 24 adult Wistar albino rat hearts were perfused. MeanP (mean pressure perfusing the coronary arteries), PSP (maximum left ventricle pressure), +dp/dt(max) (change in contraction power over time), -dp/dt(max) (change in relaxing power over time), PP (peak systolic pressure-minimum balloon pressure) and bpm (number of heart beats per minute) were evaluated. The control group (N.=6) was perfused with Tyrode solution alone. The other three groups (N.=6 for each group) were perfused with the Tyrode solution and calcium dobesilate either before ischemia, during the ischemia reperfusion period, or during the reperfusion-only period.RESULTS:The meanP values were significantly higher in groups perfused by calcium dobesilate. For other parameters, calcium dobesilate did not demonstrate a positive effect.CONCLUSIONS:This study showed that calcium dobesilate may have cardio-protective effects in isolated, perfused rat hearts. In hearts perfused by calcium dobesilate, the increase in mean P may be explained by the increase in endothelium-derived vasodilator substances. Further studies are needed to better characterize the myocardial protective effects of calcium dobesilate.
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.
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) (I mg/kg), nonselective adenosine receptor antagonists, or 8-p-sulfophenyltheophyl line (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 mu g) or 8-SPT (50 lug) 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, 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 uridnme 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. (c) 2008 Elsevier B.V. All rights reserved.
Improved preservation of the harvested heart with attenuation of the reperfusion injury is important for successful outcomes of cardiac transplantations. The most commonly used cardioplegic solution, to prevent ischemic changes has been St Thomas' Hospital cardioplegic solution (STHCS). However, it is neither ideal nor sufficient to prevent myocardial ischemia and reperfusion injury. Phosphodiesterase inhibitors can attenuate the damage due to the injuries of ischemia and reperfusion. In this study we sought to enrich STHCS with a phosphodiesterase inhibitor to improve preservation of cardiac functions. The harvested hearts of 24 rats were divided into four groups. All hearts were mounted on a Langendorff perfusion system. After a stabilization period, cardiac arrest was maintained by STHCS. The hearts were stored in STHCS alone or with milrinone, amrinone, or enoximone for 6 hours. The reperfusion was maintained using a modified Tyrode's solution. All hearts were compared for their preischemic and postischemic left ventricular developed pressure, +dp/dtmax, −dp/dtmax, duration of systole, ejection time, and time to reach peak systolic pressure. Coronary effluent was collected for lactate dehydrogenase (LDH) measurements. The initial values for all metrics were comparable between the groups. During the postreperfusion period, all hearts showed lower peak systolic pressures than the initial values. Although the amrinone group seemed to have higher values, the 25-minute result was at the border of significance and the 30-minute value, significantly higher. All hearts showed far lower results of maximum changes in contractility during the time period (+dp/dtmax) versus the initial values; comparisons between groups were not significant. For the parameter of maximum changes in relaxation during the time period (−dp/dtmax), while other hearts showed lower results, the amrinone group displayed values comparable to the initial ones after 20 minutes. Comparisons between groups were insignificant. While other hearts had comparable values for time of systole, the hearts applied with milrinone reached these values after 15 minutes. Group comparison for time of ejection revealed that the results at 5-minute postreperfusion were higher in the enoximone and the amrinone groups than the milrinone group. Postreperfusion 5-minute results were higher in the enoximone and the amrinone groups than the milrinone group for time to reach peak systolic pressure. LDH levels were lowest in the amrinone group. In conclusion, our study revealed that adding phosphodiesterase inhibitors to STHCS improved peak systolic pressure and maximum changes in relaxation during the time period (−dp/dtmax, mm Hg/s). It also decreased the LDH leakage, which corresponded to the degree of ischemic tissue damage. Amrinone seemed to result in more favorable results, which may be attributed to its additional effects on inflammation, including those on cytokines and leukocyte aggregation.
Background and objective: The effects of sevoflurane on bupivacaine cardiotoxicity are mainly attributed to systemic effects. The purpose of this study was to investigate the direct myocardial effects of sevoflurane on bupivacaine toxicity. Methods: Hearts of 30 Wistar albino rats were isolated and mounted on a Langendorff apparatus perfused by modified Tyrode solution. Experimental groups were: a sevoflurane group (Group S, n = 10) - following baseline and 20 min (Stage 1) recordings, sevoflurane was added in doses of 1.4% (1 MAC) and 2.8% (2 MAC). In the two bupivacaine groups, bupivacaine 5 μmol (Group B5, n = 10) and bupivacaine 10 μmol (Group B10, n = 10) was added to the solution at Stage 1, and sevoflurane was added to the system as in Group S. Haemodynamic variables, i.e. heart rate, PR interval, QRS duration, left ventricular systolic pressure, contractility (+dp/dtmax), relaxation, time to reach peak systolic pressure, change in left ventricular diastolic pressure from baseline, and rate-pressure product were recorded. Results: In Group S, there was no change in cardiac rhythm. In bupivacaine groups, severe rhythm disturbances occurred and both the PR intervals and QRS complexes were prolonged significantly. All contractility variables deteriorated and the rate-pressure product decreased by 67-90% with the addition of bupivacaine. In all groups, 2 MAC sevoflurane lowered +dp/dtmax further. Conclusions: Sevoflurane does not have any untoward effect on bupivacaine-induced cardiotoxicity in clinically relevant doses in the isolated rat heart.
BACKGROUND:We investigated three antioxidants, inositol hexaphosphate (IP6), superoxide dismutase (SOD), and catalase (CAT), using a Langendorf model of heart transplantation.METHODS:Rat hearts were mounted on a Langendorf perfusion apparatus with addition of IP6, SOD+CAT, IP6+SOD+CAT to St. Thomas Hospital solution (n=6 for each) versus a control group (n=6), not containing supplementation. Global ischemia was achieved for 6 hours.RESULTS:The worst peak-to-peak (PP) and +dp/dt maximum values were observed in the IP6+SOD+CAT group, the values being significantly lower than those in the SOD+CAT group. The lowest plasma creatine kinase (CK), CK-muscle-band (CK-MB), and lactate dehydrogenase levels were measured from the SOD+CAT group. The highest values for CK were in the control group, and those for CK-MB were in the IP6 group. The lowest myocardial malondialdehyde and adenosine triphosphate values were observed in the SOD+CAT group.CONCLUSIONS:Supplementing St. Thomas Hospital solution with IP6 did not ameliorate myocardial damage following global ischemia. The contractility deteriorated further when IP6+SOD+CAT were used together; however, SOD+CAT improved cardiac mechanical functions, and significantly reduced myocardial damage.