مجله دانشکده پزشکی اصفهان
پیاپی 404 (هفته چهارم آذر 1395)

When two eyes are faced with two completely different sights, corresponding areas of the two eyes retina triggered with entirely two different stimulus and instead of receiving a fixed and stable image of two stimulus, brain perceive the alternation of the two images. This phenomenon is known as an intelligent tool to study cognitive processes.
Taking a network of excitatory and inhibitory Hodgkin-Huxley type neuron in network architecture of visual cortex, the behavior of coupled spiking neuron in cortical brain that have a direct effect on the emergence of this phenomenon was modeled. To evaluate the performance of this model, direction lines as the two stimuli were applied to the eyes.
Findings: Rebuilding the predominance time of each eye, and independence between the two successive dominance times were reported by this model. In addition, the effect of changes in the stimulus applied to each of the two eyes was studied and it was figured out that applied changing stimulus strength to one eye was affected only on dominance time of the other eye. Besides, increasing stimulus strength of both eyes decreased mean dominance time.
Obtained results of this model were consistent with known experimental result for this phenomenon and many of dynamics features of this phenomenon reconstructed. Discussed theories in this field were also confirmed.

Hydatid cyst almost is caused by Echinococcus granulosus. Due to probable differences in fibrous layer of cyst, our main objectives were to investigate any difference of fibrous layer of hydatid cyst in camel, cattle and sheep, using histopathological methods.
For each kind of animal, 22 samples including hydatid-cyst-infected livers and/or lungs were collected from Isfahan City abattoirs (Iran) during April to June 2016. A specimen of about 1 cm2 of fibrous layer was taken, and underwent usual pathologic processing and analyzing.
Findings: Overall, 138 pathological sections were examined. The diameter size range of the cysts was 1.5-6.0 cm in camel and cattle and 0.5-2.0 cm in sheep. Cattle have maximum sterile cyst. The average age was 9, 6 and 3 years for camels, cows and sheep, respectively. The fibrous capsule presented in all 66 studied animals (100%). The necrosis was seen in 20 animals (30.3%), 12 cases in camels’ lung, 6 cases in cattle’s lung and only 2 cases in sheep (1 case in lung and 1 case in liver). There was only one 1case of granuloma (1.52%) in cattle’s liver.
There were some differences in fibrous layer of hydatid cyst in camel, cattle and sheep. The severity of pathologic changes led to necrosis and granuloma were different in these animals and the relative frequencies as well. It may be due to hosts’ types, parasites’ strains and average age of host. More investigation is required.

The present study aimed to compare the quality changes of medical students’ thesis before and after implementation of new thesis regulations.
In a cross-sectional study, 100 theses that were written during 2006-2010 and 100 theses from 2011 till 2015 were selected and the quality and quantity of them were assessed based on the university regulations. All data were collected using special questionnaire and then were analyzed using SPSS software.
Findings: Type of study, inclusion and exclusion criteria, sample size and adjustment of tables and figures with text content were the most completed parts during the both periods. In contrast, results and discussions were the most incomplete ones during 2006-2010; these parts had improved significantly during the period 2011-2016.
According to the present study, the medical students’ theses had no acceptable quality and were not adjusted with new university regulations. They had poor quality in content and were not up-to-date; however, we saw some improvements since 2011-2016 in different aspects of thesis. Still, it is necessary to qualify the studies by precise assessment and introducing better consultation to students, especially in scientific and statistics fields.

B1 (AFB1) is hepatocarcinogen, teratogen and mutagen. Aflatoxin M1 (AFM1) is the hydroxylated metabolite of AFB1. The liver protects the body by lowering the toxicity of AFB1 to form different hydroxylates like AFM1. According to the synergistic effect of hepatitis and also AFB1 as the parent molecule of AFM1, the main purpose of this study was to assess the relationship between the mean levels of AFM1, in the hepatitis-C-virus (HCV)-positive patients compared to healthy individuals.
After the tests of liver function enzymes, the level of AFM1 was measured and compared in the urine sample of 71 patients with HCV and 71 healthy individuals. The AFM1 of urine samples were tested using enzyme-linked immunosorbent assay (ELISA) method. Besides, the levels of serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic-pyruvic transaminase (SGPT), alkaline phosphatase, total bilirubin and direct bilirubin were assessed in the blood samples.
Findings: The urine of 29.7% of HCV-positive patients and 19.71% of healthy individuals consisted of some amount of AFM1. The mean level of AFM1 was 2.45 and 1.66 pg/ml in patients and controls, respectively; which was significantly different (P = 0.005). The mean levels of SGPT and alkaline phosphatase were significantly more among HCV-positive patients with AFM1 compared to those without AFM1 (P = 0.012). But, there was not any significant difference between the mean levels of SGOT and total and direct bilirubin between the HCV-positive patients with and without AFM1.
The mean levels of SGPT and Alkaline phosphatase, which are more exclusive to survey of liver function, were significantly different between HCV-positive patients with and without AFM1. Consequently, progression of the chronic liver disease is caused by the existence of AFB1 in HCV-positive patients; therefore, the reduction of AFM1 via improving the food consumption pattern can prevent this progression.

Constipation and functional constipation are of the prevalent functional gastrointestinal disorders with negative effects on health-related quality of life and have high socioeconomic burden. In this study, the prevalence of these disorder and their related factors were evaluated.
This study was a part of a great study with 4763 participants that evaluated constipation and functional constipation using Rome III questionnaire and demographic questionnaire.
Findings: The prevalence of constipation and functional constipation were 33.4% and 15.2%, respectively and both were more common in women than men. Sensation of incomplete defecation was the most prevalent symptom. Using manual maneuver was the less prevalent and most severe symptom. Having hard stool was the mildest symptom among participants. All Symptoms was more prevalent in women.
Constipation and functional constipation are prevalent disorders around the world. These conditions need more attention and attempts to prevent and treat.