Koomesh
Year:2001 | Volume:2 | Issue:3-4|Papers Count:11

This paper is a summary of our recent findings about the role of hippocampus and basolateral amygdale (BLA) glucocorticoid receptors (GRs) in modulating of memory processes in rats. In all experiments, injections of specific glucocorticoid agonist (dexamethasone) and antagonist (RU 38486) were performed into BLA and hippocampus. The animals were trained and tested in  Passive and Place Avoidance learning and Morris Water Maze models. Results indicated that pre- or post-training injections of specific glucocorticoid receptor agonist or antagonist enhancer impair memory storage, respectively. Retrieval test was not affected by glucocorticoid receptor agonist or antagonist injection in BLA or hippocampus. These finding indicate that glucocorticoid effects on memory consolidation are mediated in part by activation of GRs in the BLA and hippocampus and are in agreement with this general hypothesis that BLA and hippocampus integrate hormonal and neuromodulatory influences on memory consolidation.

Introduction.Previous studies  indicated that if regenerational rate in injured peripheral nerves is speeded, a new neuromuscular junction is performed before atrophy in denervated organs. The aim of this study was to examine the effect of fetal brain extract on regeneration of the injured nerve in rat's tongue. Materials and Methods.12 male wistar rats  at the age of 2 months were used in this study. The animals were anesthetized and their right hypoglossal nerves  transected near the tongue. Rats divided into the experimental and control groups (n=6 in each group). The first group was treated with fetal brain extract (FBE, 0.1 ml) for 20 days (every other day). In the similar condition, the second group was received physiological serum. In the days of 20 and 40 after operation, the animals were anesthetized and  perfused and their tongues were removed. Then tongues were processed and microscopic specimens were studied in both experimental and control groups. Results.The data  show a significant low atrophy (P<0.05) in denervated side of tongue in experimental group in comparison with control group. Conclusion.FBE can enhance  regenerational rate in the injured peripheral nerves and prevent the atrophy in denervated organ.

Introduction.Intraocular pressure (IOP) produced by the aqueous humor secretion, choroidal volume changes and tonocity of extraocular muscles. This pressure is 15 mmHg. Many factors such as age, sex and anesthetic drugs affect on IOP. Elevation of IOP during the eye operation restrics the operation and sometimes causes a serious complication of expulsive hemmorhage. In this study, the effects of two muscle relaxants Atracuriom and Succinyl-Choline drugs usually used in general anesthesia on IOP were compared. Materials and Methods. 70 candidates for operation; at the age of 50Y/O or less were selected. They were divided in two groups. The first group received Atracurium and the second ones Succinyl-Choline. IOP was measured three times; before, during and after the operation by Schiotz tonometer. Results. IOP changes in the Atracuriom group from the first to the second stage (P=0.71), the second to the third stage (P= 0.44) and the first to the third stage (P=0.58) were not significant. IOP change in the Succinyl-Choline group from the first to the second stage (P=0.002) and the second to the third stage (P= 0.001) were significant, but from the first to the third stage (P= 0.77) were not. Conclusion. Succinyl-Choline, the depolarizing muscle relaxant, causes more IOP changes in comparison with Atracuriom, the non-depolarizing muscle relaxant, during the operation.

Introduction. Athermanous lesions of carotid artery have a role in pathophysiology of ischemic stroke by reducing the distal perfusion and sending emboli from atherom. As there area lot of collaterals there, especially willis ring, this stenosis may be silent or asymptomatic. On the other hand, there are some theories said that the prevalence of extracranial and intracranial stenosis of internal carotid artery differs in eastern and western population. The aim of this study was to determine the prevalence of extracranial carotid artery stenosis in ischemic stroke patients.Materials and Methods. This study was performed on 100 patients with ischemic stroke referring to neurology ward of shafa hospital in Kerman. The diagnosis was based on the history physical examination, brain CT scan and confirmation of the masters of the ward. Carotid artery stenosis was investigated by doppler sonography.Results. The results showed that 12% of the patients have  50% stenosis or more in the extra cranial part of carotid artery, 5%  with mild, 4% moderate and 3% with severe stenosis. Diabetes and smoking were significant risk factors, but age, sex and history of hypertension had no significant relation with stenosis.Conclusion. we concluded that the prevalence of extra cranial carotid artery stenosis is lower in our society. This can confirm this theory; saying: "intracranial carotid artery stenosis is more common among eastern population than western".

Introduction. There is a risk of high exposure to waste anesthetic gasses for the staff working in unscranged rooms. The aim of this study is to investigate the mutagenic effect of anesthetic gasses.Materials and Methods. The study in a group of 45 (anesthetic and support staff) was planned to ascertain the cytogenetic risk in a group of  personnel who worked in various hospitals. Their exposure, in terms of employment duration divided into three groups (0-5 years, 5-10 years and more than 10 years). The control groups (n=30) consisted of people with different occupation matched for possible confounding variable. Cytogenetic risk was in terms of chromosome and chromatic aberration in 72 hours lymphocyte culture.Results. A significant increase in the percentage of chromosome and chromatic aberration was observed. The chromosome gap seems to be stood out. Thus, the finding does not have any relation between duration of service and cytogenetic damage.Conclusion. These findings indicate the possible risk of cytogenetic damage for staff working in unscreened rooms.

Introduction. Self rating or "internal evaluation" is a fundamental determinant for quality development in teaching departments and faculties. The purpose of this study was an internal evaluation of the Department of Pediatrics of Semnan University of Medical Sciences (SUMS) with quality development of the department.Materials and Methods. This study was performed in the pediatric ward of Amir-al-Momenin hospital of SUMS, during Jan. to Mar. 2000; utilizing an accreditation model. The assessment covered 6 areas, namely: "educational objectives", "therapeutic goals", "research activity", "organizational ranking", "teaching achievements" and "logistic parameters". Educational objectives and teaching achievement were evaluated at the level of clinical clerkship, internship and the first and third years of resident ship. Therapeutic goals comprised the diagnostic  and therapeutic facilities. Research activities consisted of the number of thesis's supervised, contributions made to seminars and congresses and the number of papers compiled and published in medical periodicals by the teaching staff. Organizational ranking included the head of department, the members of the organizing body, and the teaching staff of the department. Logistic parameters encompassed the manpower and personnel of different sub sectors of the department; as well as the available space and facilities of each. Data collection involved the use of 35 questionnaires with 460 criteria. The final score was obtained as the average of all scores and interpreted according to Gourman classification.Results. Educational objectives ranked as "more than satisfactory" with 3.45 pts, with those pertaining to first year residents and clerkship students being the highest and lowest respectively. Therapeutic goals and sanitary objectives ranked as "more than satisfactory" and "area of strength" with  3.2 and 4.16 pts, respectively. Appraisal of research objectives and teaching achievement placed the department in the "more than satisfactory" category with 3.2  & 3.52 pts., respectively. Organizational ranking and logistic parameters earned 3.07 and  3.6 pts., respectively and were appraised as "more than satisfactory".Conclusion. Analysis of the  results placed the SUMS Department  of  Pediatrics in the "more than satisfactory" class of the  Gourman  classification; indicating an over ally desirable modus operandi for the department. Three areas including the organizing body, para clinical (particularly imaging) facilities and research activity of the department were found to be suboptimal, and to require further improvement.

Introduction. Nitric oxide (NO) is a neuromodulator and an intercellular messenger that mediate several functions in the CNS. Possible involvement of  NO  in anxiety like behavior induced by ovarian hormones was studied in ovarectomized female rats.Materials and Methods.12 groups of rats were ovarectomized bilateraly and 14 days after surgery they received estradiol benzoate (10µg/kg, sc) and or progesterone (25 mg/kg, sc) or corn oil (0.2 ml/rat, sc) and L-Name (60 mg/kg, i.p) or L-Aarginine (100 mg/kg, i.p) or normal saline (0.5 ml/rat, i.p). The behavioral tests began 6 hours after progesterone  and  3 hours after estradiol administeration. Behavioural test consisted measurment of exploratory activities on elevated plus maze test.Results. There was increased exploration of open arms under progesterone administeration alone or with L-Name, and decreased under estradiol administeration alone or with L-Arginine. The anxiolytic-like effect of progesterone abolished when L-Arginine administerated, and anxiogenic-like effect of estradiol was inhibited  when L-Name injected.Conclusion. These data indicate involvement of NO in the mediation of the effects of ovarian steroid hormones on anxiety process.

Introduction. Techniques developed in computer and automated pattern recognition can be applied to assist radiologists in reading mammograms. With the introduction of direct digital mammography, this will become a feasible approach. A radiologist in breast cancer screening can use findings of computer as a second opinion, or as a pointer to suspicious regions. This may increase the sensitivity and specificity of  screening programs and it may avoid the need for double reading.Materials and Methods. A program for detecting micro calcification clusters has performed, which discriminates clusters from normal breast tissue. First, we eliminated amorphous "clouds" or "blobs" in mammograms produced by normal parenchyma tissue of varying density using local average subtraction. Then we identified and removed the normal breast tissue. We have applied opening morphology operator and then, closing morphology in residual image. Any micro calcification that may exist in mammogram is therefore enhanced in the residual image, which makes the decision regarding the micro calcification of mammogram be much easier. The digital images were presented to radiologists before appling algorithm and after it.Results. Results of study show that sensitivity of this method in diagnosis is 100% against conventional mammogram (85.4%).Conclusion. Our results have demonstrated that this algorithm can be an effective aid to radiologists in the detection of a range of types of micro calcification in mammograms in an environment that is similar to routine clinical screening.

Introduction. Color is considered as one of the major water resource  pollutants and other parts of the environment. In tannery industries the application of trivalent chromium salts in tanning of leather produces a hazardous color which being disposed directly to environment and it is likely to change to hazardous hexavalent form in the oxidation conditions of the receiving environments. During the last few years, studies have shown the potential of fungi in removing the color of waste waters in appropriate conditions. The aim of this research was to study decolonization of tanning house effluent by Aspergillums niger in tannery industries for biological removal of chromium.Materials and Methods. The first, quality of tanning house effluent was studied. After adjusting of carbon to nitrogen ration in the effluent, A. nigar was inoculated in the different size into the effluent with different dilutions. The samples for 24 h. put in the shaker incubator. Then, the absorbance rate in the wave length of 565 nm and biomass growth was estimated.Results. In this research Aspergillums niger was selected as the species of fungi for removing color from tanning house effluent. Results showed that Aspergillums niger is able to grow effectively in the tanning house effluent with dillution percentages of 10% and 20% (or chromium concentration 122.5 and 245 mg/l), with C/N ratio of 10 and pH=3; and can reduce the color, 94.5% and 93.4%, respectively. According to the experiments in this study, the best size of inoculums was determined as 10 ml. The percentage of decolonization was increased due to the increase of dry weight of fungal mass to the concentration of chromium (1.7-23.7 mg dry weight of mass/mg trivalent chromium). The highest chromium removal percentage, 94.5%, was obtained  in the 23.7 mg/mg ratio. The meaningful relationship of these parameters is confirmed according to the multiple regression coefficient of 0.8836.Conclusion. This study showed that Aspergillums niger can grow in tanning effluent and remove about 95% of color caused by trivalent chromium. Therefore, can be removed efficiently during the decolonization process.

Introduction. Many factors can produce chronic low back pain. The purpose of this study was determined correlation between flexibility of pelvic and thigh muscles and chronic low back pain. By means of comparison with control group. Also, sex as an affecting factor was studied.Materials and Methods. A total of 160 subjects (81 males and 76 females) with mean age 41.3 y/o included case group (n=56) with chronic low back pain and 104 healthy subjects as control group. Data collection was performed by a questionnaire and, measuring of flexibility of 15 muscles in both sides of pelvic and hip region. Statistical analysis was done by t-student and levins-test.Results. The results showed that flexibility of  all muscles in patients with chronic low back pain were less than healthy ones, but only three muscles (erector spinae, piriformis, rectus femoris) were significant differences. Also male patients had less flexibility in pelvic and thigh muscles than female patients.Conclusion. Muscular flexibility is decreased in chronic low back pain. Therefore, a necessary treatment in these patients is improvement of flexibility and stretching techniques.