Shahid Beheshti University of Medical Sciences and Health Services

About: Shahid Beheshti University of Medical Sciences and Health Services is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Cancer. The organization has 19456 authors who have published 33659 publications receiving 365676 citations.

Central Nervous System Tuberculosis: An Imaging-Focused Review of a Reemerging Disease

Abstract: Central nervous system (CNS) tuberculosis is a potentially life threatening condition which is curable if the correct diagnosis is made in the early stages. Its clinical and radiologic manifestations may mimic other infectious and noninfectious neurological conditions. Hence, familiarity with the imaging presentations of various forms of CNS tuberculosis is essential in timely diagnosis, and thereby reducing the morbidity and mortality of this disease. In this review, we describe the imaging characteristics of the different forms of CNS tuberculosis, including meningitis, tuberculoma, miliary tuberculosis, abscess, cerebritis, and encephalopathy.

Microbial sensitivity pattern in urinary tract infections in children: a single center experience of 1,177 urine cultures.

Abstract: SUMMARY: Urinary tract infection is one of the most common diseases in children. Early diagnosis and comprehensive treatment can significantly decrease late serious complications. Knowledge of the sensitivity and resistance pattern of uropathogens in specific geographical locations is an important factor for choosing suitable antibacterial treatment. This study was conducted in order to evaluate the antibacterial resistance of urinary pathogens at Mofid Children’s Hospital between March 2000 and August 2001. Positive urine cultures from 1,177 children aged less than 12 years (mean age, 31.7 months; female to male ratio, 2:1) were studied. Cultures were performed on urine samples obtained by sterile urine bags in infants and midstream urine in older children; if samples were contaminated then a suprapubic sample was taken in infants. Sensitivity was measured by the disc diffusion method using the NCCLS protocol. The most prevalent urinary pathogen was Escherichia coli (666 cases, 56.6%). Overall, the lowest resistance rate of microorganisms was that against ciprofloxacin (6.7%) and the highest resistance rate was that against penicillin (83%). A comparison of these data with those of other countries shows that there is considerable geographic variation in bacterial patterns of sensitivity and resistance properties. Therefore, the selection of antibiotics for empiric therapy should be based on the sensitivity and resistance pattern of uropathogens in the respective city.

Astrocyte- neuron interaction as a mechanism responsible for generation of neural synchrony: a study based on modeling and experiments

Abstract: Neural synchronization is considered as an important mechanism for information processing. In addition, based on recent neurophysiologic findings, it is believed that astrocytes regulate the synaptic transmission of neuronal networks. Therefore, the present study focused on determining the functional contribution of astrocytes in neuronal synchrony using both computer simulations and extracellular field potential recordings. For computer simulations, as a first step, a minimal network model is constructed by connecting two Morris-Lecar neuronal models. In this minimal model, astrocyte-neuron interactions are considered in a functional-based procedure. Next, the minimal network is extended and a biologically plausible neuronal population model is developed which considers functional outcome of astrocyte-neuron interactions too. The employed structure is based on the physiological and anatomical network properties of the hippocampal CA1 area. Utilizing these two different levels of modeling, it is demonstrated that astrocytes are able to change the threshold value of transition from synchronous to asynchronous behavior among neurons. In this way, variations in the interaction between astrocytes and neurons lead to the emergence of synchronous/asynchronous patterns in neural responses. Furthermore, population spikes are recorded from CA1 pyramidal neurons in rat hippocampal slices to validate the modeling results. It demonstrates that astrocytes play a primary role in neuronal firing synchronicity and synaptic coordination. These results may offer a new insight into understanding the mechanism by which astrocytes contribute to stabilizing neural activities.