Tehran University Medical Journal

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Background and Aim: Auditory and visual stimuli are the most important factors in communication. It seems during the brain maturation, decrease of visual inputs causes enhancement of somatosensory and auditory cortical responses. In this research latency and amplitude of auditory middle latency responses (AMLR) are studied in blinds and normally sighted subjects.

Materials and Methods: This descriptive-analytical study was performed on 40 congenitally blinds and 40 normally sighted subjects in the range of 14-20 years. All of cases had normal hearing sensitivity and acoustic reflexes without any middle ear disorders. The reason of this age range is the maturation of auditory middle latency responses. Sampling was randomized.

Results: There was significant difference between amplitude of Na, Pa & Nb waves and latency of Na while no significant difference between latency of Pa & Nb in blinds and normally sighted subjects.

Conclusion: Increase of amplitude and decrease of latency of AMLR in blind subjects were due to sensory compensation phenomenon, probably. It seems rate of processing and auditory perception in blinds is better than normally sighted subjects.

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Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: Post-intubation tracheal stenosis is a serious problem and surgical resection is the method of choice in long segment tracheal stenosis treatment. The aim of this study was to review the results of surgical treatment of long segment post intubation tracheal stenosis and the role of bilateral hyoid bone cutting in supra- hyoid release technique.
Methods: Between 2004 to 2008, 14 patients with proximal long segment tracheal stenosis with resection of more than 40% of trachea length were evaluated regarding surgical technique and post-operative results.
Results: The mean age of patients was 22.2±0.4 years. Etiology in all patients were head trauma and prolonged intubation and all patients had tracheostomy at the time of trearment. Average time between surgery and first admission was 4.5±0.5 months. Average length of stenosis and resected segment were 3.6±0.5 and 4.3±0.5cm respectively. Average increased length of trachea after bilateral hyoid bone cutting was 1.1±0.3cm. Postoperative complications occurred in one patient with wound infection, and 4 patients had stenosis recurrence which was treated in 3 patients using multiple dilation. Quality of life 2 years after surgery in 71% of patients were classified in good and excellent group. We didn't have any mortality.
Conclusion: Based on the fact that surgery is the best method of treatment in long and multi segment tracheal stenosis and tension in suture line is a serious problem, we recommend extended releasing technique including bilateral hyoid cutting in surgical treatment of these patients.

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Background: Primary cardiac tumors are rare tumors which should be operated urgently. In this study, cardiac myxoma have been evaluated from diagnosis until dis-charge in a 10 years period and then results including presenting symptoms, approach to the patients were compared with similar study in this center a decade ago. Methods: Patients who underwent operation for myxoma from year 2003 until 2013 in the Shahid Modarres Hospital were included in this study. Results: Eighteen patients included in the study, 11 female and seven male. Patients’ ages were in the range of 13 to 76 years (mean 53 years). Mean time from diagnosis to operation was 5.8 days and mean time from surgery to discharge was 8.6±6.1 days. Most common presenting symptoms were first clinical presentation in four patients. In all patents echocardiography was the main diagnostic modality. In addition to trans thoracic echocardiography (TTE), in five patients TEE was used and in 13 patients coronary angiography was used to rule out concomitant coronary artery disease. 94.4% of all tumors (17 cases) were primary cardiac tumors and only one tumor (5.6%) was recurrent. In 16 patients (88.9%) tumor were found in the Left Atrium (L.A) and in one case, tumor was found in both atria and in another case, tumor was in the ventricle. After tumor excision, atrial septum was repaired primarily in seven cases (38.9%) and with pericardial patch in 9 cases. One patient underwent concomitant coronary artery bypass graft (CABG) and another patient underwent concomitant pulmonary valve repair. 14 patients (77.8%) discharged from hospital without any post operative complication. Heart block occurred in one patient and cerebral emboli with secondary cerebrovascular accident (CVA) developed in two patients. One patient died (5.6%). Conclusion: Comparing results from two similar studies in two consecutive decades revealed that mean time from diagnosis to operation obviously was reduced but ad-vances in diagnostic modalities were unable to change clinical presentation or reduce age of tumor diagnosis or complications or size.

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Background: Poly(amidoamine) (PAMAM) dendrimer derivatives have been investigated for their biological applications, especially for delivery of drugs, including antimicrobial drugs to eukaryotic cells, but their effects on bacterial cells are largely unexplored. Nanotechnology and its application is one of the rapidly developing sciences. As demand of fresh drinking water is increasing, nanotechnology can contribute noticeable development and improvement to water treatment process. This study was aimed to examine synthesis and the antibacterial effect of Nanopolyamidoamine-G7 (NPAMAM-G7) dendrimer on Escherichia Coli (E. Coli), Klebsiella Oxytoca (K. Oxytoca), Pseudomonas Aeruginosa (P. Aeruginosa), Proteus Mirabilis (P. Mirabilis) and Staphylococcus Aureus (S. Aureus) from aqueous solution.
Methods: In this experimental study that has been conducted in August to December 2015 in the laboratory of microbiology of Iran University of Medical Sciences, initially dilution of 103 CFU/ml were prepared from each strain of bacteria. Then different concentrations of dendrimer (0.025, 0.25, 2.5 and 25 µg/ml) in the laboratory temperature (23-25 °C) was added to water. In order to determine the efficiency of dendrimers in removal of bacteria, samples were taken at different times (0, 10, 20, 30, 40, 50 and 60 min) and were cultured on nutrient agar medium. Samples were incubated for 24 hours at 37 °C and then number of colonies were counted.
Results: Antibacterial properties of dendrimers in aqueous solution by increasing the dendrimer concentration and contact time is directly related. At a concentration of 25 μg/ml at 60 minutes all bacteria except S. Aureus, and at 30 minutes, E. Coli and K. Oxytoca bacteria for 100% excluded. The concentration of 2.5 μg/ml at 60 minutes of bacteria, E. Coli, K. Oxytoca and P. Mirabilis are 100% excluded. All concentrations of dendrimers at different times were reduced bacteria in the PAMAM- G7 dendrimer effect on gram-negative bacteria, gram-positive bacteria was better.
Conclusion: The NPAMAM-G7 dendrimer with end amine groups exhibited a positive impact on the removal of standard strains, gram-positive and gram-negative bacteria. Therefore, it is possible to use these nanodendrimers as antibacterial in the future.