Shahram Ejtemaei Mehr

Tehran University of Medical Sciences, Teheran, Tehrān, Iran

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Publications (8)4.73 Total impact

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    ABSTRACT: Considering the existence of cross-tolerance between clonidine and morphine besides the same interaction between morphine and WIN 55,212-2 persuaded us to verify this fact between WIN 55,212-2 and clonidine in guinea pig ileum, which is a well-known model to examine the mode of action of cannabinoids and α2-adenoceptor agonistsThe rectangular pulses were passed to the 0.5 g stretched ileum segments that were fixed in 20-ml organ bath. PowerLab system and Graphpad Prism were applied to record twitches and analyse the data. Electrically evoked contractions were dose-dependently inhibited by WIN 55,212-2 and clonidine (pD2= 8.56 ± 0.41 and 7.65 ± 0.15, respectively).Tolerance to this effect could be induced by 4-h incubation with WIN 55,212-2 (3 × IC50) (pD2 = 6.36 ± 0.26, degree of tolerance: 159.32) (P < 0.01) but not with clonidine (2 × IC50 and 4 × IC50) for different time courses. Dose–response curve for inhibitory action of WIN 55,212-2 was shifted to the right after 4-h incubation with clonidine (3 × 10−10m) comparing to the untreated tissues (pD2 = 5.26 ± 0.69, degree of tolerance: 2000) (P < 0.001). This observation provides the evidence for the cannabinoid-noradrenergic systems interaction in the enteric nervous system as a simplified representative for central nervous system.
    Autonomic &amp Autacoid Pharmacology 01/2014; 34(1-2).
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    ABSTRACT: OBJECTIVES: To investigate the effect of morphine on the reduced uteroplacental perfusion pressure (RUPP) model of pre-eclampsia in rats. STUDY DESIGN: The abdominal aorta and ovarian arteries of pregnant rats were isolated and clipped on gestational day 14. The chronic morphine treatment group received naltrexone 5mg/kg 1h before each dose of morphine. L-nitromonomethylarginine 2mg/kg was administrated in the same pattern. The control group received saline 10ml/kg. Systolic blood pressure, blood urea nitrogen (BUN), creatinine, creatinine clearance, urinary protein, urinary nitrite/nitrate excretion, and fetal and placental weights were determined. RESULTS: Morphine significantly reduced systolic blood pressure, fetal and placental weights, plasma BUN, creatinine and urinary protein in RUPP rats compared with control rats. Urinary nitrite/nitrate excretion and creatinine clearance were significantly increased in response to morphine treatment. CONCLUSION: Morphine reduced blood pressure and improved renal function in the RUPP model of pre-eclampsia, but this was associated with reduced fetal and placental weights.
    European journal of obstetrics, gynecology, and reproductive biology 02/2013; · 1.97 Impact Factor
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    ABSTRACT: Nicotine, the main pharmacologically active component in tobacco and cigarette, has some toxic effects and also high potential for addiction. In this study, the effect of artichoke (Cynara scolymus L.) and zeolite nano-materials on urinary excretion of nicotine and consequently elimination of systematically absorbed nicotine was investigated. A simple, valid and highly sensitive high performance liquid chromatography method has been developed for determination of nicotine in rat urine according to guidelines for bioanalysis.It was found that nano-zeolites can cause increase in urinary concentration of nicotine due to its high surface adsorption. Artichoke leaf extract can cause increase in urinary excretion of nicotine in longer post administration times. It was observed that co-administration of nanozeolites and the leaf extract has the synergetic effect on increasing the urinary excretion of nicotine.
    Arzneimittel-Forschung 11/2012; · 0.56 Impact Factor
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    ABSTRACT: Nanoemulsions are increasingly being investigated for their fascinating capability of loading both hydrophobic and hydrophilic molecules while their stability is still an issue, being affected by various factors. In this study, to evaluate the dominant factors affecting the stability of nanoemulsions, artificial neural networks (ANNs) were implemented. Nanoemulsions of almond oil in water containing oleic acid-coated superparamagnetic iron oxide nanoparticles were prepared using a mixture of Tween 80 and Span 80 as surfactant system and ethanol as a co-surfactant. The ratio of transparency of the samples at 30 min and 7 days after preparation was taken as an indication of the stability of samples. Four independent variables, namely, concentration of nanoparticle, surfactant, oil, and alcohol were investigated to find their relations with the dependent variable (i.e., transparency ratio). Using ANNs modeling, it was concluded that the stability is affected by all variables, with all variables showing reverse effect on the stability beyond an optimum amount.
    AAPS PharmSciTech 10/2012; · 1.58 Impact Factor
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    ABSTRACT: Vincristine (VCR) as a frequently used antimitotic agent which is commonly prescribed for wide spectrum of neoplasm, causes mixed sensorimotor neuropathy. Several evidences show lithium could be a neuroprotective agent, therefore to assess whether a pretreatment and at subtherapeutic dose it could prevent the peripheral neuropathy produced by VCR, rats were treated with VCR 0.1mg/kg i.p. for 3 alternative doses and / or lithium chloride (20mg/kg or 40 mg/kg i.p. daily from the first day to the day of sacrifice). Erythrocyte lithium concentration (ELC) and plasma lithium concentration (PLC) were measured at the seventh day of study and the day of scarification. After seventh day of lithium administration, PLC and ELC reached to a steady state at subtheraputic dose and they did not significantly change at normal housing situation. Hot plate, open field test and nerve conduction velocity were used to evaluate the sensory and motor neuropathy. Only VCR treated rats showed behavioral, electrophysiological and histological evidences of a mixed sensorimotor neuropathy by significant increase in hot plate latencies and a marked decrease in total distance moved and conduction velocities in both sensory and motor nerves. Lithium at the dose of 20mg/kg and specially 40mg/kg robustly reduced the rate of mortality, general toxicity and was able to ameliorate mixed sensorimotor neuropathy induced by VCR. These results suggest that lithium at dose of 20mg/kg and 40 mg/kg, potentially by its effects on cell survival pathways such as inhibition of glycogen synthase kinase-3 (GSK3β), can prevent both motor and sensory components of VCR neuropathy.
    Acta medica Iranica 06/2012; 50(6):373-9.
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    ABSTRACT: Brain ischemia initiates several metabolic events leading to neuronal death. These events mediate large amount of damage that arises after some neurodegenerative disorders as well as transient brain ischemia. Melissa officinalis is considered as a helpful herbal plant in the prevention of various neurological diseases like Alzheimer that is related with oxidative stress. We examined the effect of Melissa officinalis on hypoxia induced neuronal death in a cortical neuronal culture system as in vitro model and transient hippocampal ischemia as in vivo model. Transient hippocampal ischemia was induced in male rats by tow vessel-occlusion for 20 min. After reperfusion, the histopathological changes and the levels inflammation, oxidative stress status, and caspase-3 activity in hippocampus were measured. Cytotoxicity assays showed a significant protection of a 10 μg/ml dose of Melissa against hypoxia in cultured neurons which was confirmed by a conventional staining (P<0.05). Melissa treatment decrease caspase3 activity (P<0.05) and TUNEL-positive cells significantly (P<0.01). Melissa oil has also inhibited malon dialdehyde level and attenuated decrease of Antioxidant Capacity in the hippocampus. Pro-inflammatory cytokines TNF-α, IL-1β and HIF-1α mRNA levels were highly increased after ischemia and treatment with Melissa significantly suppressed HIF-1α gene expression (P<0.05). Results showed that Melissa officinalis could be considered as a protective agent in various neurological diseases associated with ischemic brain injury.
    DARU-JOURNAL OF FACULTY OF PHARMACY 01/2012; 20(1):42. · 0.62 Impact Factor
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    ABSTRACT: Integration is an important educational strategy in medical education. Considering this idea, the goal of the present study was to design and implementation of longitudinal and vertical integrated education of anatomy, physiology, pharmacology, neurology and neuropsychiatry subjects of brain's basal ganglia by a multidisciplinary team. Kern's approach to curriculum development was used. Participants were 20 medical students at basic science level who contribute in a 10 stations of pre-test exam at Medical School's Skill Lab. After the implementation of the module by a multidisciplinary team, post-test were done. A structured questionnaire was designed to assess student opinions about adequacy, usefulness of the module using a Likert scale with 5 categories ranging from "completely agreement" to "completely disagreement". The result of pre and post-test were also compared. Twenty questionnaires were completed, giving a 77.63% satisfaction rate. Seventy-five percent of students found it useful and appropriate at basic science level. About fifty percent of students suggested the implementation of this module for other medical students. The score of post-test was significantly (14.52 ± 0.47 vs 6.32 ± 0.62, P < 0.05) higher than pre-test results. The viewpoints of medical students were positive and they value the module highly. Since it is not easy to change the style we teach, these results suggest necessitate of supporting the faculty member's participation in these modules.
    Acta medica Iranica 11/2011; 49(11):753-9.
  • Journal of Hepatology - J HEPATOL. 01/2011; 54.