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Background & Objective: Monitoring the depth of anesthesia is very important to prevent undesirable events during surgery, such as intra operative awareness and overdosing. It is shown that anesthetic agents have direct effects on synaptic activity of brain neurons. So there is a great interest on electroencephalogram analysis as a depth of anesthesia estimator. Due to difficulties in visual explanation of EEG, automatic and computer based signal processing methods have been used to assess the depth of anesthesia. Investigating the relationship between conscious level of patients and electrical activity of brain neurons was the main aim of this study. Materials & Methods: In this study, EEG signals of six patients undergoing aortic valve replacement surgery have been acquired and recorded in a computer. After applying signal processing methods to these data, 3 different measures included temporal, spectral and bispectral parameters have been extracted. Mean values of mentioned parameters in different anesthetic regimens and levels have been analyzed by ANOVA in SPSS software. Results: Extracted temporal parameter is correlated with depth of anesthesia in deep anesthetic levels and spectral one is correlated with depth of anesthesia in moderate and light levels (P<0.05). Bispectral parameter is correlated with the depth of anesthesia only in ICU (P<0.05). Conclusion: Findings of this study confirm the relationship between consciousness and electrical activity of brain neurons and recommend the use of EEG processing techniques to monitor, control and estimate the depth of anesthesia in operating room and ICU ward.

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Background and Objective: Autism is a neurodevelopmental disorder of the brain,which occures in first few years of life, and characterized by symptoms such as qualititative impairments in verbal and non verbal communication, reciprocal social interactions, inability to communicate with others, stereotyped patterns of behavior, loss of eye contact and inappropriate facial expressions. Its prevalence is 2-5 in 10000 children and is greater in boys. Due to retarded language development, differential diagnosis other than those used with communication, behavioral and sensorial deficits should be made with Sensorineural or conductive hearing loss. The aim of this study was to determine whether children with autism have abnormalities affecting the cochlear nerve or auditory pathway in brainstem.

Materials and Methods: In this case – control study, auditory brainstem responses were recorded from 12 autistic children and 12 normal children aged 3-12 years in rehabilitation Zafar central in Tehran – Iran during 2005. Absolute latency values of waves I, III and V and interpeak latencies of I-III, III-V and I-V were compared with the results of 12 normal children as control group.

Results: Wave V could be traced down to 25 dB nHL in both normal and autistic groups. Absolute latency of Wave V and Interpeak latencies of III-V and I-V were significantly prolonged in Autistic children in comparison with control group.

Conclusion: This study showed a slowing in nerve conduction in auditory pathway in brainstem of autism patients. The brainstem lesion may be a part of neurological damage in autistic children that accounts for deviant language, cognition and social development. Prolongation of wave V, III-V and I-V IPLs can be a marker for early diagnosis of autism.

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Background and Objective: The Clostridium botulinum is one of the most important causative of food poisoning. Spores of Clostridium botulinum spread out in the soil, the sea sediments, the marine environments and the marine animals. In recent years use of the marine food products like as fish and cultured fish are elevated. The aim of this study was done to compare between processing and non processing fish infected by predominant type of Clostridium botulinum.

Materials and Methods: This descriptive study was done on the 146 samples of fish in two species of processed and non prosecced that collected from Gilan province in Iran during 2008. These samples included the Liza auratus Fish (45 processed fish and 28 non processed fish) and the Salmo Trutta caspius Fish (34 processing fish and 39 non processing fish). The samples examined according to the APHA2000 and FDA2003 protocols. Data Analyzed with SPSS-13 and Chi-Square test.

Results: 16 (11%) of samples (13% of the processed fish and 7.5% of non processed fish) were confirmed that infected by Clostridium botulinum. Also the dominant type of exotoxin was Type E. The Type E exotoxin was determined from 11 of the samples (6 processed fish and 5 non processed fish).

Conclusion: This study showed that fish are infected by Clostridium botulinum special the type E. also use of fish in bad preparation (half cooking and add material in its stomach) may cause the food poisoning.

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Background and Objective: Alzheimer’s disease is caractrized by brain degenerative alterations with subsequent learning and memory loss. Learning and memory is closely associated with brain colinergic system. Colinergic fibers originated from minent basal nucleus which is extended to cortex and hippocampus. This study was conducted to investigate sensory processing in the barrel cortex neurons of Rat model of Alzheimer’s disease. Materials and Methods: In this experimental study, 14 male Wistar Rats weighing 250-350g randomly divided into control and experimental groups. Alzheimer’s disease in Rats induceted, by infusion of ibotenic acid (5 µg/µl in each site) into nucleus basalis of Meynert (NBM) using Hamilton syringe and stereotaxic apparatus. The control group was non-lesion Rats with vehicle treatment. Two weeks after NBM-lesion, each animal was tested by passive avoidance learning (PAL), then neural response assessed by extracellular recording. Results: In cases, ibotenic acid infusion into NBM, significantly reduced memory (P<0.05). The results evoked by multiple whisker stimulation in extracellular single unit recording showed that in Alzheimer’s disease model of animals excitatory receptive field (RF) of neurons were extended but inhibitory RF was decreased (P<0.05). In addition the magnitude of neural response following principal whisker deflection decreased in cases (P<0.05). Conclusion: This study indicated that in animal model of Alzheimer’s disease possibly reduce sensory processing and contact discrimination.