Tehran University Medical Journal

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There are many studies about epidural fibrosis after surgical manipulation of the spine. We have studied formation of the post laminectomy epidural fibrosis after application of two materials (Silicone and Teflon) in this report. This expriment is on two groups of rats. Two separated laminectomies were done in each rat, one serving as control while in the other laminectomy spaces Silicone was used in group A and Teflon in group B. Laminectomy spaces were evaluated with gross dissection and histologic studies after 6 weeks. Silicone decreased intermuscular scar, deep scar, dural adhesion and collagen fiber density in epidural space. Teflon decreased dural adhesion and collagen fiber density but did not decrease intermuscular and deep scar formation in epidural space.

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Background: Constraint-Induced movement therapy (CIMT) is a promising treatment for improving upper limb function in adults after stroke and traumatic brain injury. It involves constraint of the less affected limb and intensive practice with the more affected limb. The purpose of this study on children with hemiplegic cerebral palsy (CP) was to evaluate the effects of CIMT on upper extremity and to make a comparison with conventional treatment. Methods: I a randomized clinical trial twelve children (seven females, five males aged between 48 and 72 months with mean±standard deviation of 59.91±9.15mo) were randomly assigned in two groups. An intensive occupational therapy program including five hours per day for 21 consecutive days was performed for all of them, while less affected limbs were placed in sling for immobilization. Before and after intervention, upper extremity function, spasticity, and motor neuron excitation were evaluated by means of peabody developmental motor scales, modified Ashworth scale, and H reflex and H/M ratio, respectively. Results: The children who received CIMT did not improved their ability to use their hemiplegic hand significantly more than the children in the control group (p>0.05). However, reports of caregivers and clinical observations showed increases in more affected limb frequency of use and quality of movement. Conclusion: Results suggest that the use of CIMT needs to more studies and should be considered experimental in children with hemiplegic CP

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Background: Studying the behavior of a society of neurons, extracting the communication mechanisms of brain with other tissues, finding treatment for some nervous system diseases and designing neuroprosthetic devices, require an algorithm to sort neuralspikes automatically. However, sorting neural spikes is a challenging task because of the low signal to noise ratio (SNR) of the spikes. The main purpose of this study was to design an automatic algorithm for classifying neuronal spikes that are emitted from a specific region of the nervous system.

Methods: The spike sorting process usually consists of three stages: detection, feature extraction and sorting. We initially used signal statistics to detect neural spikes. Then, we chose a limited number of typical spikes as features and finally used them to train a radial basis function (RBF) neural network to sort the spikes. In most spike sorting devices, these signals are not linearly discriminative. In order to solve this problem, the aforesaid RBF neural network was used.

Results: After the learning process, our proposed algorithm classified any arbitrary spike. The obtained results showed that even though the proposed Radial Basis Spike Sorter (RBSS) reached to the same error as the previous methods, however, the computational costs were much lower compared to other algorithms. Moreover, the competitive points of the proposed algorithm were its good speed and low computational complexity.

Conclusion: Regarding the results of this study, the proposed algorithm seems to serve the purpose of procedures that require real-time processing and spike sorting.

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Background: Despite advances in cancer diagnosis and treatment, survival rate of patients suffering from glioblastoma multiform (GBM) has not been significantly improved. Therefore, novel therapeutic adjuncts to routine therapies have been suggested over time. Inhibition of angiogenesis by antiangiogenic drugs is one of the new approaches to inhibit the growth of malignant cells. Microvessel density (MVD) assay is a technique performed by counting immunohistochemically-stained blood vessels. Nowadays, athymic nude mice are widely used for the establishment of xenograft tumor models in cancer research. The aim of this study was to evaluate the MVD of autochthonous xenograft models of GBM isolated from Iranian patients for use in pharmaceutical research on antiangiogenic drugs.Methods: Fresh tumor samples of GBM were obtained from three patients in Cancer Institute of Tehran University of Medical Sciences in Fall of 2010 and Winter of 2011. After preliminary processing, minced tumor samples were implanted heterotopically on flanks of athymic nude mice. Two months later, the animals were sacrificed and the xenograft tumor samples were sent to the pathology laboratory. After establishing the proof of the xenograft tumor type, MVD-CD34, an endothelial cell marker, was assessed by counting hot spot areas in 22 samples.Results: The mean number of microvessels in these xenograft tumor models was 30±2.1. Conclusion: These autochthonous xenograft models of GBM can be used in preclinical settings for research on antiangiogenic drugs regarding a pharmacogenomics-based treatment regimen for the Iranian population. Moreover, such models can be used in future studies for determining the sensitivity or resistance to antiangiogenic drugs in individualized cancer therapy.

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Background: Vertebrobasilar dolichoectasia is defined as a prominent elongation, dilatation and tortuosity of the vertebral and basilar arteries. Ectatic basilar arteries may cause different neurological symptoms by several mechanisms including compressive effects and embolic or ischemic events.

Case presentation: In this report we present a 58-year old female patient who was admitted in Dr. Shariati General Hospital in Tehran, Iran with complaints of dysarthria, vertigo, ataxia and nausea. Neuro-imaging procedures (brain CT scan, CT angiography, and an MRI study of the blood vessels or MRA) were performed. Dilation and elongation, as well as tortuosity of the vertebral and basilar arteries revealed the diagnosis of vertebrobasilar dolichoectasia. The patient was discharged from the hospital following the control of underlying diseases and neurological symptoms related to dolichoectasia without undergoing any invasive procedures.

Conclusion: Paying attention to any minor or major neurological symptoms, as well as underlying medical conditions along with the conservative control of symptoms can be most helpful. Invasive interventions in a chronically ill patient can be very risky, therefore, medical management including control of associated or underlying diseases is recommended as the first line of treatment.

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Background: Intracranial lipomas are rare benign neoplasms that comprise 1% of all primary brain tumors. Generally, occur in midline structure and usually identified incidentally on CT scans or in autopsies. The incidence of intracranial lipomas is about 0.08 to 0.46% on autopsies. These benign lesions are slow-growing, usually asymptomatic and rarely require surgery.

Case Presentation: We report a 20 years old male who complained of headache since two years ago. On CT examination, a quadrigeminal cistern lipoma without any pressure effect on neural structures demonstrated. His headache remitted with conservative measures. Here, we have a review on the literature and explain CT scan and MRI findings.

Conclusion: According to the literature and present case, it seems that direct surgical excision of tumor is not justified in the majority of cases and symptoms of patients greatly respond to conservative measures and, at most, in cases of hydrocephalus, CSF shunting relieves their symptoms.

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Glioma is the most common type of brain tumor and according to the 2016 WHO classification, based on invasion level, it is divided into four categories. The most severe and invasive type is grade IV glioma or glioblastoma (GBM), which has a very poor prognosis and a survival rate of only 15 months. However, the molecular pathway of invasion in malignant glioma tumors has not yet been clearly elucidated. Like other cancers, brain tumors are thought to migrate and metastasize to other tissues via epithelial-to-mesenchymal transition (EMT). EMT is a process by which epithelial cells lose their cell polarity and cell-cell adhesion, and gain migratory and invasive properties to become mesenchymal stem cells. Studies have shown that EMT and angiogenesis can help brain tumors to migrate to other parts of the brain as well as surrounding tissues. Thus they can induce metastasis. EMT is controlled by three gene families, including SNAIL, TWIST, and ZEB. During EMT, the expression of epithelial-related genes is silenced, and, conversely, the expression of mesenchymal-related genes is increased. In this way, the cells acquire the mesenchymal tissue’s features and can be prepared for invasion and metastasis. On the other hand, only about 1% of the genome can take its role in the translation of functional proteins, and the large remaining part of the genome is made up of non-coding sequences. Therefore, much attention has recently been paid to the role of such noncoding transcripts, at the top of them, long non-coding RNAs (lncRNAs), in regulating the expression of genes involved in important molecular pathways such as apoptosis, proliferation, invasion, and migration in cancer progression and metastasis. Any interference in regulating the expression of genes involved in each of these molecular pathways leads to cancer in different ways. Understanding and identifying lncRNAs involved in tumorigenesis and invasion of brain tumors, while helping to better identify the molecular mechanisms of metastasis in glioma, can also be effective as biomarkers in the diagnosis, prognosis, treatment, and drug resistance of glioma. Therefore, in this review study, the most important lncRNAs involved in EMT in glioma have been investigated.