مجله دانشکده پزشکی اصفهان
پیاپی 401 (هفته اول آذر 1395)

As the application of the cone beam computed tomography (CBCT) is increasing in dental radiology and the departments with this equipment are developing, it seems that the determination of absorbed dose and evaluation of ionizing radiation risk from CBCT is essential. In this study, the absorbed dose of eyes, thyroid and parotid glands were compared in both examinations of dental CBCT and panoramic with CRANEX® 3D machine.
For each patient, 5 thermoluminescence dosimeter (TLDs) were placed as a pair in the back of upper eyelids, a pair 2 cm ahead of small anterior ear cartilage and the last one in the middle of neck on a prominence. The average absorbed dose was calculated for comparison of absorbed doses of different organs in two examinations.
Findings: In panoramic examination, right eye with 0.020 ± 0.002 cGy and right parotid with 0.283 ± 0.053 cGy had the lowest and the highest mean absorbed doses, respectively. In CBCT examination, the highest and the lowest mean doses belonged to the right parotid (0.465 ± 0.078) and the left eye (0.0311 ± 0.004), respectively. Mean absorbed doses for eyes, parotid and thyroid in panoramic was 0.022 ± 0.002, 0.270 ± 0.051, 0.027 ± 0.002 and in CBCT 0.033 ± 0.005, 4.410 ± 0.740, 0.0389 ± 0.051, respectively. The absorbed doses show meaningful differences for all organs in two examinations (P 0.001 for all).
Because of the wider beam (cone beam) and higher exposure factors in CBCT, the absorbed doses in this examination are higher than those of panoramic examination (more than 10 times).

Various fluids such as saline, hypertonic saline, and serum colloid are used to compensate the body lost fluids after head trauma. The aim of this study was to determine the effects of various solutions on vital signs, serum electrolytes and acid-base status in patients with head trauma.
This cross-sectional study was done in Alzahra hospital, Isfahan University of Medical Sciences, Iran. 340 hospital records of patients with head trauma were studied and hemodynamic parameters, blood gases and electrolytes were analyzed based on the osmolarity status. The data were analyzed using chi-square and one-way and repeated-measures analysis of variance (ANOVA) tests.
Findings: During hospitalization in intensive care unit (ICU), 74 patients (21.8%) died. Need to ventilation was different based on the kind of fluid and the percent of ventilation in hyperosmolar group (48.8%) was lower significantly than the iso- (64.4%) and hypo-osmolar (56.4%) groups (P = 0.042). The mortality rate was significantly higher in iso-osmolar group (37.8%) compared to hypo- (17.9%) and hyperosmolar (15.6%) groups (P Using hyperosmolar solutions in patients with head trauma led to more favorable hemodynamic stability and electrolyte status and lower mortality rates in these patients. So, using hyperosmolar solutions, if there is no contraindication, is preferred to hypo- and iso-smolar solutions and is recommended.

Postanesthetic shivering is one of the important complications of regional anesthesia that causes discomfort for patient and increases the metabolic rate up to 400%. We compared the efficacy of two low doses of ketamine on prevention of postanesthetic shivering in Cesarean section under spinal anesthesia.
In this randomized double-blind placebo-controlled clinical trial, 135 patients with classes I-II of American Society of Anesthesiologists (ASA) grading undergoing elective Cesarean section under spinal anesthesia were involved. Patients were randomly allocated to three group: K1:0.3 mg/kg ketamine up to 4 cc normal saline, K2: 0.5mg/kg ketamine up to 4 cc normal saline, and C: 4 cc normal saline. Drugs were injected after cord clamping and vital signs and outbreak and grade of shivering were detected immediately after the anesthesia and every 15 minutes until leaving the recovery room.
Findings: Rate of the postanesthetic shivering in groups that receive medication (K1 and K2) was significantly less than control group at 45 (K1: 11.1%, K2: 0.0%, and C: 17.8%) and 60 (K1: 15.6%, K2: 8.9%, and C: 51.1%) minutes after initiation of the surgery and the 15th minutes in recovery (K1: 42.2%, K2: 24.4%, C: 68.9%) (P = 0.015, P Using ketamine with the dosage of 0.5 mg/kg is more effective than 0.3 mg/kg in prevention of postanesthetic shivering in Cesarean section under spinal anesthesia.

Some studies showed that strabismus surgery is associated with possible damage to macula. This study aimed to determine the changes in macular thickness in patients undergone strabismus surgery for inferior oblique muscle weakening associated with its overactivity.
In a prospective study, 35 eyes undergone strabismus surgery with recession or myectomy were selected and thickness and volume of macula were measured before and one day, one week and one month after the surgery and compared between the two groups.
Findings: The changes of mean macular volume over the course of follow-up were not significant difference between the myectomia and recession groups. In addition, macular thickness in the fovea was not significantly different between the groups in any of the study period. But in parafovea part, macular thickness was significantly lower in group of myectomy one week after the surgery (P = 0.04); whereas for other segments and the rest of the time, there was no significant difference between the two groups.
Both myectomy and recession have not considerable effect on macular thickness and volume. However, our study had limitations including the lack of samples in recession group. Further studies with larger sample sizes are recommended to determine the merits of each of the two methods of myectomy and recession of the inferior oblique muscle.

Mammalian sperm DNA is the most compacted eukaryotic DNA and this compacted DNA can resist against different environmental and chemical factors. The aim of this study was to assess the effects of keeping washed semen sample in refrigerator (4-6 ˚C) on sperm viability, total motility and DNA integrity in normozoospermic men.
In this experimental study, 13 semen samples of normozoospermic men were washed twice in modified Ham's F10 medium. These samples were kept in refrigerator (4-6 ˚C) up to 12 days. On the 0 (immediately after sampling), 1st, 2nd, 5th, 7th and 12th days, the proportion of viable, motile, double stranded DNA spermatozoa were examined. Viability and DNA integrity of sperm cells were examined consecutively using eosin-nigrosin and acridine orange staining.
Findings: The viability and total motility of sperm cells significantly decreased (P This study suggests that sperm DNA integrity is preserved even after 12 days of keeping semen sample in refrigerator.