مجله دانشکده پزشکی اصفهان
پیاپی 408 (هفته چهارم دی 1395)

Using contrast media is very important in diagnosis and identification of organ from the surrounding tissue. Contrast media can alter radiation absorption of studied organs following by enhanced image contrast. This study aimed to assess the influence of contrast media on treatment planning and dose calculation in radiation therapy of pelvic cancers.
Six patients with pelvic area cancer with two sets of computed tomography (CT) images, one with contrast media and another without it, were studied and the effects of contrast media were studied.
Findings: After using contrast media, an increase of 2.91% in monitor unit (MU) for right lateral (RL) field and decreases of 0.59%, 0.75%, and 1.47% in monitor unit anterior-posterior (AP), posterior-anterior (PA), and left lateral (LL) fields was obtained in rectum cancer, respectively. For bladder cancer, a decrease of 0.34% in monitor unit for AP filed and increases of 1.57%, 0.46%, and 0.39% in monitor unit for PA, RL and LL fields was calculated, respectively. For cervix cancer, a decrease of 1.1% for AP field and an increase of 0.68% for PA field were obtained.
Regarding dose-volume histograms (DVHs) and calculated monitor units, the results showed that the dose differences between the plans for the CT images with and without contrast media were less than 1%. Of course to ensure the effect of contrast media on the amount of delivered dose to the target organ, study on more patients is recommended.

The main aim of this study was to compare the effect of labetalol and remifentanil on blood pressure and heart rate after laryngoscopy and intubation in comparison with the control group.
In a clinical trial study, 105 patients scheduled for surgery were randomly assigned to three groups receiving 1 mg/kg of labetalol, 1 µg/kg remifentanil, or the same amount of normal saline. Hemodynamic parameters were measured and compared.
Findings: The incidence of bradycardia in groups receiving labetalol, remifentanil and control was 28.6%, 22.9% and 5.7%, respectively, and the difference between three groups was significant (P = 0.040). In contrast, the incidence of tachycardia in the three groups was 2.9%, 5.7% and 28.6%, respectively, and significant difference was observed between the groups (P = 0.002). The prevalence of hypotension in the three groups was 22.9%, 14.3% and 2.9%, respectively, and there were significant differences among them (P = 0.047). The prevalence of hypertension in the three groups was 6.3%, 18.8% and 34.3%, respectively, and the difference between the groups was significant (P = 0.001).
Based on the results of the present study, intravenous administration of 1 mg/kg labetalol in patients under laryngoscopy tends to more favorable hemodynamic stability and less hemodynamic imparements compared to remifentanil; using this dose before the laryngoscopy is more favorable.

Distal radius fracture is a common fracture in elderly. It has well established that vitamin D deficiency and hip fractures are related. Some studies have claimed such a relation for distal radius fractures.
In this matched case-control study conducted from June 2015 to April 2016, patients aged beyond 50 years presenting to Alzahra hospital, Isfahan, Iran, with a distal radius fracture were enrolled. The serum levels of 25(OH) vitamin D, calcium and phosphorus were measured and then data were compared to control group.
Findings: During this study, 130 people including 65 cases and 65 controls in each group composed of 30 men and 35 women were studied. Mean level of serum vitamin D was significantly lower in case group; such a difference was also seen in affected men compared to control ones. There was no significant difference in vitamin D levels between case and control women. Mean serum levels of calcium and phosphorus were significantly higher in case group.
The results show a direct correlation between low serum vitamin D level and the incidence of distal radius fractures. More studies are needed to assess whether the correction of this lack of vitamin D leads to a decrease in distal radius fracture and other future fractures.

The aim of this study was assessing the response of plasma levels of atrogin-1 and insulin-like growth factor-1 to low-fat milk consumption after one session of high-intensity interval exercise in fasting state among overweight young men.
Ten overweight young men (mean age: 20.50 ± 1.71 years and body mass index: 28.08 ± 2.80 kg/m2) were randomly selected. They were participated in two exercise sessions of two non-consecutive days. The exercise program in each day included 4 sets of 30-second Wingate test with 4.5 minutes active rests between sets. The difference was that in the second session, immediately after exercise, participants drank 500 ml of low-fat milk. Blood samples were taken before exercise and 5, 90 and 180 minutes after it. Data were analyzed using analysis of variance with repeated measures and Bonferroni test (P Findings: The plasma level of atrogin-1 was not significantly different after exercise in both sessions (P > 0.05). The plasma level of insulin-like growth factor-1 significantly reduced after 90 and 180 minutes post-exercise in the sessions without milk consumption (P = 0.04 and 0.02, respectively); while milk consumption caused no significant change in this variable after exercise by prevention of reducing in insulin-like growth factor-1 levels (P > 0.05).
It seems that consumption of low-fat milk, immediately after exercise in the fasting state, can help to maintain muscle mass by avoid reducing growth factors.

Because of its radio-biological and physical advantages, proton therapy method is highly popular compared to other radiotherapy methods. Recent attempts at enhancing dose in tumors and reducing dose in adjacent tissues have been mainly relying on the use of metal nanoparticles with the aim of activating tumors. Numerous qualitative studies have been carried out on the safety and clinical use of gold nanoparticles and the results have been promising. However, some quantitative studies should be conducted to examine the factors affecting this method. With respect to the performance of Monte Carlo Method in simulation of the particles transport, the aim of this article was to obtain the dose enhancement in tumor sensitized by gold nanoparticles (GNPs) using MCNPX code.
A slab head phantom with homogenized-GNPs-aided tumor was considered to simulate proton therapy in brain tissue. Monte Carlo simulation was performed using MCNPX code to assess the dose and its enhancement in a radio-sensitized tumor by GNPs using proton therapy.
Findings: The Bragg peak calculations were conducted for proton beams with energies in the rage of 40-150 Mev. Dose and its enhancements in tumor were obtained for several concentrations. Then, Spread-out Bragg Peak (SOBP) was evaluated.
According to our calculations, if the protons energy is high enough so that they can pass the sensitized tumor; dose will be improved in Bragg peak and then, will decrease immediately. In addition, in relation to the SOBP, solid dose enhancement in sensitized tumor and decreasing the dose immediately after it, were concluded. Dose enhancement due to the presence of nanoparticles in the tumor confirms the results of previous research. But, a significant reduction in the dose immediately after the tumor was the result of this research.