Increased oxidative damage is one of the most common complications in patients suffering from chronic renal failure (CRF), undergoing hemodialysis, which leads to various abnormalities including anemia. The study was designed in order to evaluate the changes in activities of two intracellular antioxidant enzymes; superoxide dismutase (SOD) and Glutathione peroxidase (GPX); in patients with CRF under regular hemodialysis and renal transplant recipients. Relationship between the enzymes activities and altered osmotic fragility of red blood cells, one of the minor causes of anemia, was also determined in these subjects.
The activities of SOD and GPX were measured by spectrophotometric methods in red blood cells of 40 hemodialyzed patients and 26 renal transplant recipients with mean age of 42.5 ± 14 years and 38.6 ± 10 years respectively. The results were compared with those obtained from 39 age and sex matched apparently healthy individuals with mean age of 39.9 ± 15.5 years as controls. Median osmotic fragility (MOF) of red blood cells was also determined colourimeterically in each group and its relationship to the enzyme activites was evaluated.
The activity of SOD in hemodialyzed patients (1080.5 ± 700.2 U/g Hb) was markedly lower than those of renal transplant recipients (1303.5 ± 442.2 U/g Hb) and the control group (1307.8 ± 452 U/g Hb) (p<0.05). The activity of GPX in hemodialyzed patients (23.9 ± 9.5 U/g Hb) was significantly lower than those of renal transplant recipient (28.1 ± 16.8 U/g Hb) and control group (34.6 ± 7.5 U/g Hb) (p<0.05). Although the activities of the both enzymes in the renal transplant recipients were higher than that of hemodialyzed patients but they were still lower than that of the control. Calculated values for MOF in hemodialyzed patients (0.46 ± 0.03) were significantly higher than those of renal recipients (0.42 ± 0.02) and control (0.41 ± 0.01) (p<0.05). In patients under hemodialysis significant correlations between SOD and MOF were observed (r = -0.3, p = 0.02).
As antioxidant measurement may help to delineate susceptibility to free radical attack, decreased activities of GPX and SOD in red blood cells of patients under hemodialysis may thus contribute to increased oxidative stress in hemodialyzed patients. Elevation of MOF in hemodialyzed patients and no correlation between MOF and the activity of GPX suggests that deficiency of SOD may be one of causes of elevated MOF. It seems that measurement of total antioxidant capacity will provide useful information in these patients.

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Left ventricular volume indices (LVVI) were measured in fifty patients with chronic mitral and/or aortic regurgitation. Their age ranged from 12 to 71 (mean ± SD, 38 ± 15) years. End-diastole (ED) and end-systole (ES) frames were selected from video replay of two dimensional echocardiograph (TDE) recorded from apical long axis view. LVVI were calculated using the ellipsoid formula. The data compared LVVI measured from left ventricular angiography (LVA) done within one week of TDE study. The mean end-diastolic volume index (EDVI) for all 50 patients was 215 ± 111 ml ( mean ± SD) was not different from the single plane angiographic value of 221 ± 68 m1 (r = 0.94). The mean end-systolic volume index (ESVI) of 111 ± 77 ml was also not significantly different from the angiographic value of 118 ± 77 ml (r = 0.94). The average TDE and angiographic ejection fraction (EF) values of 51 ± 11 and 52 ± 12 were not different (r = 0.904). The excellent correlation between the two techniques is due to better endocardial delineation and smoothening of the trabeculae in dilated ventricles. LVVI and EF estimated by TDE are adequate for follow up and surgical decision making in patients with mitral and/or aortic regurgitation.

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Medical education is, for the last two decades, undergoing a steady process of restructuring to become more student-centered rather than tutor-centered system/computer aided learning. Such a move started in the 1970s, as a result of introducing problem-based learning (PBL) as a student-centered educational strategy. Considerable curricular changes were made by many medical institutes to implement PBL. This approach, however, necessitated the training of tutors and the creation of a learning environment, which is not adequately attained yet. The advancing information technology (IT) is anticipated to provide the necessary tools to achieve that objective. The students may be granted the opportunity to have more freedom in selecting their learning material and to enjoy a degree of distance-learning. The consequence of applying IT in medical institutes would, probably, enforce the trend towards moving to a student-centered learning environment, inducing hesitant tutors to become more compliant with the change. The future medical curriculum is anticipated to be more student-centered, more modular, more integrated, more PBL-oriented and more inter-institutionalized, with less memorizing and with more learning about learning. In addition, medical education as a whole at least in part, would be, performed at distance. The future medical tutor may have to be more PBL-oriented, more qualified in learning strategies, competent in small group (probably single-student) learning, more of a 'mentor' or a 'facilitator' than of a 'teacher', able to train students at higher cognitive levels rather than being an 'authority' in its field, fluent in IT, and interactive with learning via other learning-collaborating institutions.

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Abstract | Full Text PDF

Abstract | Full Text PDF