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Search Results: 1 - 10 of 512 matches for " Shahram Khademvatan "
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A molecular study on cutaneous leishmaniasis lesions in Khuzestan province (South west of Iran)
Jasem Saki,Shahram Khademvatan
Jundishapur Journal of Microbiology , 2011,
Abstract: Introduction and objective: One of the most likely factors influencing on the clinical manifestations of cutaneous leishmaniasis, is genetic variability of Leishmania parasites that is currently controversial. The aim of this study was to identify the possible correlation between clinical cutaneous lesions and genetic of the causative Leishmania agents in Khuzestan, south west of Iran.Materials and methods: Fourteen samples from patients with different size of cutaneous leishmaniasis (CL) lesions referred to health centers and medical diagnosis laboratories of Ahvaz, Dashteazadegan, Shush, Hendijan and Ramhormoz were collected and studied by mini-exonePCR-RFLP and sequencing methods. The diameter of lesions was measured by a blinded caliper and flexible ruler.Results: Enzyme electrophoretic analysis of different isolates of L. major and L. tropica separated from lesions with different sizes have revealed no heterogeneity in this species, whereas alignment of the mini-exonesequencing isolates revealed 97-99% identity and 2-8 nucleotide substitution. Identity was 99% in isolates obtained from Lesions with near Sizes. Conclusion: This study revealed nucleotides substitutions among sequences of causative agents for different size of lesions. In order to find any correlation between genetic and clinical manifestation in CL, a comprehensive study with more samples from more geographical area is needed. Significance and impact of the study. Information about relationship between the parasite's genetic variability and the clinical form of CL may help us to understand the pathway and a molecular target for devising effective treatment.
Miltefosine induces metacaspase and PARP genes expression in Leishmania infantum
Khademvatan, Shahram;Gharavi, Mohammad Javad;Saki, Jasem;
Brazilian Journal of Infectious Diseases , 2011, DOI: 10.1590/S1413-86702011000500005
Abstract: objectives: apoptosis is the process of programmed cell death (pcd) that occurs in both animal and plant cells. protozoan parasites possess metacaspase and these caspase-related proteases could be involved in the pcd pathways in these organisms. therefore we analyzed the activities of metacaspase and parp genes in leishmania infantum (mcan/ir/96/lon49) treated with miltefosine. materials and methods: anti-leishmania activity of miltefosine was studied by treatment of cultured promastigotes with various concentration of miltefosine. mtt assay and annexin-v fluos staining by using facs flow cytometry methods were used. cytotoxic potential of hepc on the amastigots of l.infantum was evaluated in j774 cell line. in addition, metacaspase and parp genes expression of treated l. infantum were studied. results: miltefosine led to dose-dependent death of l. infantumwith features compatible with apoptosis. over expression of metacaspase and parp was seen 6 hr after treatment. conclusions: our study showed that miltefosine exerts cytotoxic effect on l. infantum via an apoptotic-related mechanism.
Comparison of Traditional Methods and PCR for Diagnosis of Cutaneous
Shahram Khademvatan,Jasem Saki,Sharif Maraghi
Zahedan Journal of Research in Medical Sciences , 2012,
Abstract: Background: The usual method for laboratory diagnosis of cutaneous leishmaniasis was the direct observation of parasites under a light microscope. Although this method has high specificity, it has low sensitivity. The purpose of this study is to compare three methods of direct observation, culture and Mini-exon-PCR to diagnose cutaneous leishmaniasis in Khuzestan province. This study intends to compare sensitivity of PCR approach with sensitivity of the existing traditional methods to diagnose cutaneous leishmaniasis using Mini-exon gene.Materials and Methods: A total 216 skin biopsies prepared from patients with cutaneous leishmaniasis were studied though direct method, culture in NNN, culture in RPMI 1640 and Mini-exon-PCR and the sensitivity of these methods were compared with each other. In this study Mini-exon-PCR was considered as the gold standard method.Results: Results showed that 46.7% with direct method, 35.1% with culture method in RPMI 1640, 57.8% with culture method in NNN and 70.3% with PCR were positive. Sensitivity was obtained 66.4% for microscopic observation, 50% for culture in RPMI1640, and 82.2% for culture in NNN and 100% for PCR.Conclusion: This study showed that PCR on samples stored in normal saline has higher sensitivity and specificity than other traditional methods (p>0.05). Thus, Mini-exon-PCR on samples in normal saline is a reliable method to diagnose cutaneous leishmaniasis, especially in cases where the diagnosis is negative with the other methods.
INOS and IFN? Gene Expression in Leishmania major-Infected J774 Cells Treated With Miltefosine
Shahram Khademvatan,Mohammad Javad Gharavi,Elham Yousefi,Jasem Saki
International Journal of Pharmacology , 2011,
Abstract: Miltefosine is the new drug of choice for the treatment of leishmaniasis. The aim of this work was to study the molecular mechanisms and immunomudolatory properties of miltefosine in J774 cell line infected with the Leishmania major (MRHO/IR/75/ER) parasite. In this experimental study infected J774 cell line by L. major, treated by miltefosine and incubated for 72 h. Total RNA was extracted and cDNA was synthesis. RT- PCR was used for study of IFN? and iNOS gene expression. IFN? and iNOS proteins were analyzed by Western blotting. Cell culture supernatant was examined by ELISA for of IL12 and IL10 concentration. After 4 h incubation, miltefosine increased iNOS and IFN? gene expression in L. major infected J774 cell line. Western blot analysis of extracted cell proteins showed 130 and 17 kDa of bonds related to iNOS and IFN?, respectively. After 48 h treatment with miltefosine, analysis of cell supernatant with ELISA showed a significant increase of IL12 but no change in IL10 Cytokine. Study showed that miltefosine in addition to its direct effect can improve cellular immunity with rising of IFN? and of iNOS genes expression that are able to activate macrophages.
PCR-Based Molecular Characterization of Toxocara spp. Using Feces of Stray Cats: A Study from Southwest Iran
Shahram Khademvatan, Fakher Rahim, Mahdi Tavalla, Rahman Abdizadeh, Mahmoud Hashemitabar
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065293
Abstract: Feces of stray cat are potential sources of gastrointestinal parasites and play a crucial role in spreading and transmitting parasite eggs, larvae, and oocysts through contamination of soil, food, or water. In this study, we investigated the prevalence of Toxocara spp. infection in stray cats in Ahvaz city, southwest Iran. Eggs of Toxocara spp. in feces of stray cats were detected by the sucrose flotation method, and identification was conducted by polymerase chain reaction (PCR) and DNA sequencing. Of the 140 fecal samples that were randomly collected from public environments during the months of January to May 2012, 45% were found to harbour Toxocara spp. eggs. The highest prevalence of Toxocara spp. eggs was found in the central area of Ahvaz city (28.6%). T. canis eggs were found in 4 (6.34%) of the 63 positive samples. Stray cats are found in parks, playgrounds, and other public places and may be a potential contamination risk. Identification of Toxocara spp. using molecular methods is sufficiently sensitive to detect low levels of parasites and identify the different Toxocara spp. in feces. The relatively high prevalence of Toxocara spp. infection may continue to increase due to lack of effective environmental hygiene control in Iran. Consequently, there is a need to plan adequate programs to detect, identify, and control this infection as well as stray cats in the region.
Investigation of Anti-Toxocara and Anti-Toxoplasma Antibodies in Patients with Schizophrenia Disorder
Shahram Khademvatan,Niloufar Khajeddin,Sakineh Izadi,Elham Yousefi
Schizophrenia Research and Treatment , 2014, DOI: 10.1155/2014/230349
Abstract: Objective. The aim of the present study was to examine the relationship between Toxoplasma gondii and Toxocara spp. infections in patients with schizophrenia disorder. Method. A total of 100 patients with schizophrenia disorder and 95 healthy individuals participated in the study. Participants were tested for the presence of anti-T. gondii and anti-Toxocara spp. antibodies by ELISA and Western blotting. Data were analyzed using Chi-square test and Fisher9s exact test. Results. There were no differences in T. gondii IgG seroprevalence between patients with schizophrenia and healthy individuals ( ), but there were differences in seroprevalence between males and females with schizophrenia ( ). In contrast, Toxocara spp. IgG seroprevalence was greater in patients with schizophrenia disorder than in healthy individuals ( ), but there were no differences in seroprevalence between men and women with schizophrenia ( ). Finally, there were no differences in seroprevalence of T. gondii or Toxocara spp. IgG among different subtypes of schizophrenia, various age groups, residential area, or clinical course of treatment ( ). Conclusion. The present study suggests that patients with schizophrenia disorder are at elevated risk of Toxocara spp. infection. Moreover, contamination with T. gondii is a risk factor for schizophrenia in women. 1. Introduction Schizophrenia is a severe, disabling mental disorder with a devastating impact on patients, their family, and society [1]. Schizophrenia is a heterogeneous disorder characterized by a range of clinical features such as positive and negative symptoms [2], including a reduction in patients’ health-related quality of life [3]. The prevalence of schizophrenia has been reported to be 1% of the adult population [4], developing in late adolescence or early adulthood, and most patients suffer from the disease throughout their lifetime [1]. Toxocariasis is a helminthozoonosis, caused by the Ascaridida nematodes, Toxocara canis and Toxocara cati [5]. Dogs and cats are the definitive hosts of T. canis and T. cati, respectively, although other mammals, such as humans and rodents, can be infected [6]. Humans are infected by ingestion of infectious eggs [6], often as a result of direct contact with pets or consumption of contaminated vegetables or undercooked meat [7]. Toxocara infection is also often transmitted by contact with the soil. Young children, people who live in rural areas, and people with soil-related occupation are at increased risk for toxocariasis [8–10]. The presence of Toxocara spp. larvae in the central nervous
Cognitive Congestion Control for Data Portals with Variable Link Capacity  [PDF]
Ershad Sharifahmadian, Shahram Latifi
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2012, DOI: 10.4236/ijcns.2012.58058
Abstract: Network congestion, one of the challenging tasks in communication networks, leads to queuing delays, packet loss, or the blocking of new connections. In this study, a data portal is considered as an application-based network, and a cognitive method is proposed to deal with congestion in this kind of network. Unlike previous methods for congestion control, the proposed method is an effective approach for congestion control when the link capacity and information inquiries are unknown or variable. Using sufficient training samples and the current value of the network parameters, available bandwidth is adjusted to distribute the bandwidth among the active flows. The proposed cognitive method was tested under such situations as unexpected variations in link capacity and oscillatory behavior of the bandwidth. Based on simulation results, the proposed method is capable of adjusting the available bandwidth by tuning the queue length, and provides a stable queue in the network.
Decentralization of a Multi Data Source Distributed Processing System Using a Distributed Hash Table  [PDF]
Grzegorz Chmaj, Shahram Latifi
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2013, DOI: 10.4236/ijcns.2013.610047
Abstract: A distributed processing system (DPS) contains many autonomous nodes, which contribute their own computing power. DPS is considered a unified logical structure, operating in a distributed manner; the processing tasks are divided into fragments and assigned to various nodes for processing. That type of operation requires and involves a great deal of communication. We propose to use the decentralized approach, based on a distributed hash table, to reduce the communication overhead and remove the server unit, thus avoiding having a single point of failure in the system. This paper proposes a mathematical model and algorithms that are implemented in a dedicated experimental system. Using the decentralized approach, this study demonstrates the efficient operation of a decentralized system which results in a reduced energy emission.
On Point-Based Haptic Rendering  [PDF]
Shi Wen, Shahram Payandeh
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.55A003
Abstract: Haptic rendering is referred to as an approach for complementing graphical model of the virtual object with mechanics- based properties. As a result, when the user interacts with the virtual object through a haptic device, the object can graphically deflect or deform following laws of mechanics. In addition, the user is able to feel the resulting interaction force when interacting with the virtual object. This paper presents a study of defining the levels-of-detail (LOD) in point-based computational mechanics for haptic rendering of objects. The approach uses the description of object as a set of sampled points. In comparison with the finite element method (FEM), point-based approach does not rely on any predefined mesh representation and depends on the point representation of the volume of the object. Different from solving the governing equations of motion representing the entire object based on pre-defined mesh representation which is used in FEM, in point-based modeling approach, the number of points involved in the computation of displacement/deformation can be adaptively defined during the solution cycle. This frame work can offer the implementation of the notion for levels-of-detail techniques for which can be used to tune the haptic rendering environment for in- creased realism and computational efficiency. This paper presents some initial experimental studies in implementing LOD in such environment.

Preana: Game Theory Based Prediction with Reinforcement Learning  [PDF]
Zahra Eftekhari, Shahram Rahimi
Natural Science (NS) , 2014, DOI: 10.4236/ns.2014.613099
Abstract:

In this article, we have developed a game theory based prediction tool, named Preana, based on a promising model developed by Professor Bruce Beuno de Mesquita. The first part of this work is dedicated to exploration of the specifics of Mesquita’s algorithm and reproduction of the factors and features that have not been revealed in literature. In addition, we have developed a learning mechanism to model the players’ reasoning ability when it comes to taking risks. Preana can predict the outcome of any issue with multiple steak-holders who have conflicting interests in economic, business, and political sciences. We have utilized game theory, expected utility theory, Median voter theory, probability distribution and reinforcement learning. We were able to reproduce Mesquita’s reported results and have included two case studies from his publications and compared his results to that of Preana. We have also applied Preana on Irans 2013 presidential election to verify the accuracy of the prediction made by Preana.

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