Study of the effect of extract of Thymus vulgaris on anxiety in male rats

AbstractThere is some evidence in traditional medicine for the effectiveness of Thymus vulgaris (百里香 bǎi lǐ xiāng) in the treatment of anxiety in humans. The elevated plus-maze (EPM) has broadly been used to investigate anxiolytic and anxiogenic compounds. The present study investigated the effects of extract of T. vulgaris on rat behavior in the EPM. In the present study, the data were obtained from male Wistar rats. Animals were divided into four groups: saline group and T. vulgaris groups (50 mg/kg, 100 mg/kg, and 200 mg/kg infusion for 7 days by feeding). During the test period, the total distance covered by animals, the number of open- and closed-arm entries, and the time spent in open and closed arms of the EPM were recorded. T. vulgaris increased open-arm exploration and open-arm entry in the EPM, whereas extract of this plant has no effects on the total distance covered by animals and the number of closed-arm entries. The results of the present experiment indicate that T. vulgaris may have an anxiolytic profile in rat behavior in the EPM test, which is not influenced by the locomotor activity. Further research is required to determine the mechanisms by which T. vulgaris extract exerts an anxiolytic effect in rats

Viewpoints of Faculty Members and Residents of Kerman University of Medical Sciences, Iran, Regarding the Local Annual Upgrade and Licensure Residency Exams

Background & Objective: In the past, the written exam for the promotion and certification of medical residents was provided nationwide and conducted by the Council of Graduate Medical Education. Changes in the method of performing medical resident’s promotion exams have been continuously discussed by scholars. According to the educational approach in the prestigious universities of the world in the field of specialized clinical residency training, the promotion exam has been transferred to residents training universities. In this study, the viewpoints of faculty members and residents of Kerman University of Medical Sciences, Iran, were evaluated regarding the decentralized promotion and certification residency exam. Methods: This was a cross-sectional study. The study population consisted of all residents and faculty members of Kerman University of Medical Sciences. The data were collected using a self-administered questionnaire including questions about the strengths and weaknesses of the decentralized residency upgrade and certification exam. Data were analyzed using SPSS software. All P-values of ≤ 0.05 were considered significant. Results: The items of “participation of all members of the department in questions preparation” and “more attention to the endemic diseases” (score of 4.06 and 3.55, respectively) obtained the highest scores. The lowest dispersion rate was also related to these two components. The item “decreased quality of questions” with a score of 2.45 had the lowest impact. From the viewpoint of faculty members, “participation of all members of the department in questions preparation" and "different education due to different assessment methods in universities" (3.76 and 3.75, respectively) obtained the highest scores. Moreover, “bias in the ministries regarding enrichment of question banks” and “closure of departments during questions preparation” obtained the lowest scores (2.85). There was no significant difference between the two groups in scoring of the components based on demographic characteristics. Conclusion: Although, in the view of residents and faculty members, the decentralization of this exam has some benefits, there are many deficiencies which must be addressed in order to attain greater effectiveness. Key Words: Faculty members, Clinical residents, Promotion and certification exams, Decentralize

The effects of sildenafil on the hippocampal long-term potentiation in male rats

Introduction: The hippocampal nitric oxide/cGMP signaling pathway plays a crucial role in memory processing. Phosphodiesterase interacts with this signaling pathway. There are controversial reports regarding the effect of sildenafil, a phosphodiesterase inhibitor, on learning and memory. Therefore, the effects of acute administration (intrahippocampal/ intra-dentate gyrus injection) of sildenafil on long-term potentiation (LTP) of rats were investigated. Methods: The rats were anesthetized with urethane and placed in a stereotaxic device for field potential recording. After ensuring a steady-state baseline response, a single intraperitoneal injection of saline or sildenafil (2 and10 µg/kg) was done. The population spike amplitude, the excitatory postsynaptic potentials (EPSPs) slope and paired-pulse stimuli (as an inhibitory interneuron) were compared between groups. Results: The results showed that population spike amplitude and EPSP slope significantly increased after sildenafil administration (10µg/kg) following titanic stimulation compared with the saline group. However, the sildenafil (2µg/kg) and control groups showed no difference regarding population spike amplitude and EPSP slope. Sildenafil had no significant effects on recurrent inhibition. Conclusion: The obtained results indicated that acute administration of sildenafil improved LTP via direct effects on the hippocampus of intact rats. Thus, sildenafil may enhance learning and memory processing by modulating the hippocampal synapse

Analysis of different signal peptides for the secretory production of Ama r 2 in gram-positive systems (Lactococcus lactis)

Prokaryotic systems have been considered the most affordable and simplest hosts which are being employed to express recombinant proteins such as allergens; nevertheless, without appropriate signal peptide (SP), these systems cannot be used for secretory proteins. Recently, a lot of effort has been put into assessing the potential of gram-positive strains such as lactic acid bacteria for new applications in the production of heterologous proteins. Ama r 2 is a respiratory allergen from Amaranthus retroflexus, whose recombinant production in the probiotic host could be introduced as a specific and effective way to rapid diagnosis and immunotherapy of this allergy. Consequently, the production of this recombinant protein using the prokaryotic system, requires a suitable SP to protect disulfide bonds and to prevent misfolding. This study was designed to predict the best SPs for the expression of Ama r 2 protein in Lactococcus lactis as the host. In this study, 42 signal sequences were selected from SP databases and the most important features of them were evaluated. First, n, h and c regions of the SPs and their probabilities were investigated by signalP software version 4.1. Then, their physicochemical properties were evaluated by Portparam and SOLpro. Moreover, the secretion sorting and sub-cellular localization sites were evaluated by PRED-TAT and ProtcompB software programs. The results revealed that yjgB, entC2 (Entrotoxine type C-2), ent B (Entrotoxine type), blaZ (Beta lactamase), dex (number 21), blm (Beta lactamase 2), dex (Dextranase; number 20) and number 26 were introduced theatrically as the best SPs to express Ama r 2 in Lactococcus lactis

The comparison of omega-3 and flaxseed oil on serum lipids and lipoproteins in hyperlipidemic male rats

Hyperlipidemia affects a significant number of patients despite treatment with cholesterol-lowering drugs. Due to the low efficacy of synthetic drugs, there is a need for new agents with low side effects. Therefore, the effects of flaxseeds oil and animal omega-3 on the hyperlipidemic rats were investigated. Forty male Wistar rats were assigned to four groups (n = 10): 1) control group that was fed with a standard diet (pallets). 2) high-fat diet (HFD) control group that was fed with high-fat food for 42 days, 3) Omega-3 group that received HFD for 21 days, followed by HFD + omega-3 capsule (600 mg/kg; 21 days/gavage), and 4) flaxseed oil group that received HFD for 21 days, followed by HFD + flaxseed oil (10 ml/kg; 21 days/gavage). Blood samples were collected three times and at the stages one to third of the experiment from the rats' tail. The results showed that high levels of fat significantly increased cholesterol, triglyceride (TG), and low-density lipoprotein (LDL) in the flaxseed, HFD control, and omega-3 groups in the second stages of the experiment. Inverse, omega-3 or flaxseed oil supplementation decreased cholesterol, TG, and LDL levels and increased high-density lipoprotein (HDL) level in comparison with the HFD control group in the third stages of the experiment. There was no significant difference in the studied parameters between the flaxseed-and omega-3-treated groups. It can be concluded that flaxseed oil similar to omega-3 is effective in the treatment of hyperlipidemia

Thermal maturity of the Upper Triassic-Middle Jurassic Shemshak Group (Alborz Range, Northern Iran) based on organic petrography, geochemistry and basin modelling: implications for source rock evaluation and petroleum exploration.

International audienceOrganic petrography and geochemical analyses have been carried out on the shales, carbonaceous shales and coals of the Shemshak Group (Upper Triassic-Middle Jurassic) from fifteen localities along the Alborz Range of Northern Iran. Organic matter (OM) has been investigated using Rock-Eval pyrolysis, elemental analysis of kerogen, vitrinite reflectance (VRr) and Thermal Alteration Index (TAI). Reflectance of autochthonous vitrinite varies from 0.6 to 2.2 % indicating thermally early mature to over mature OM in the Shemshak Group, in agreement with other maturity parameters used. The shales of the Shemshak Group are characterized by poor to moderate residual organic carbon contents (0.25 to 8.5 %) and the presence of hydrogen-depleted OM, predominantly as a consequence of petroleum generation and of oxidation of OM. According to light-reflected microscopy results vitrinite/vitrinite-like macerals are dominant in the kerogens concentrated from the shaly facies. The coals and carbonaceous shales of the Shemshak Group show a wide range in organic carbon concentration (3.5 to 88.6 %) and composition (inertinite- and vitrinite-rich types), and thereby different petroleum potentials. Among the studied sections only the coals and carbonaceous shales of the Hive locality show good residual petroleum potential and may still generate oil. Thermal modelling results suggest that low to moderate paleo-heat flow, ranging from 47 to 79 mW.m-2 (57 mW.m-2 on average), affected the Central-Eastern Alborz. The maximum temperature which induced OM maturation of the Shemshak Group seems to be related to its deep burial rather than to a very strong heat flow related to an uppermost Triassic-Liassic rifting. The interval of petroleum generation in the most deeply buried part of the Shemshak Group (i.e., Tazareh section) corresponds to Late Jurassic-Early Cretaceous times. Exhumation of the Alborz Range during Late Neogene time, especially along the axis of the Central-Eastern Alborz, where maxima of VRr values are recorded, probably destroyed possible petroleum accumulations. However on the northern flank of the Central-Eastern Alborz, preservation of petroleum accumulations may be better. The northern part of the basin therefore seems the best target for petroleum exploration

Effects of pre-training injection of orexin A into dorsal raphe nucleus in passive avoidance acquisition on male rats

AbstractEndogenous orexins, especially orexin A, play an important role in spatial learning and memory. A recent study has shown the effect of orexinergic system in hippocampus on avoidance learning. Orexinergic receptors are distributed in dorsal raphe nucleus (DRN). The aim of this study was to evaluate the role of dorsal raphe orexinergic system in passive avoidance learning (PA). Rats were implanted with the cannula aimed at dorsal raphe nucleus. Orexin A or saline were injected into the DRN prior to avoidance training. Pre-training orexin type 1 receptors activation in DRN impaired passive avoidance acquisition but had no effect on PA retention

Auto Calibration and Optimization of Large-Scale Water Resources Systems

Water resource systems modelling have constantly been a challenge through history for human being. As the innovative methodological development is evolving alongside computer sciences on one hand, researches are likely to confront more complex and larger water resources systems due to new challenges regarding increased water demands, climate change and human interventions, socio-economic concerns, and environment protection and sustainability. In this research, an automatic calibration scheme has been applied on the Gilan's large-scale water resource model using mathematical programming. The water resource model's calibration is developed in order to attune unknown water return flows from demand sites in the complex Sefidroud irrigation network and other related areas. The calibration procedure is validated by comparing several gauged river outflows from the system in the past with model results. The calibration results are pleasantly reasonable presenting a rational insight of the system. Subsequently, the unknown optimized parameters were used in a basin-scale linear optimization model with the ability to evaluate the system's performance against a reduced inflow scenario in future. Results showed an acceptable match between predicted and observed outflows from the system at selected hydrometric stations. Moreover, an efficient operating policy was determined for Sefidroud dam leading to a minimum water shortage in the reduced inflow scenario

Evolution tectonique du nord de l'Iran (Alborz et Kopet-Dagh) depuis le Mésozoïque

A partir d études structurales, de paléocontraintes, subsidence et biostratigraphie, nous proposons un modèle d'évolution tectonique du nord de l'Iran depuis le Trias et l orogenèse éo-cimmérienne (collision blocs cimmériens-Laurasie). Une extension NNE-SSW (failles normales synsédimentaires dans le Shemshak Trias sup.-Jurassique inf.) est liée à la phase de rifting précédant l'ouverture du bassin Sud-Caspien (BSC), contemporaine des formations carbonatées Dalichai et Lar (Bajocien sup.-Néocomien). La formation de Tiz-Kuh (fin Barrémien-Aptien) est discordante (tardi-cimmérien) sur les séries mésozoïques antérieures. Le Crétacé sup. débute par un épisode magmatique alcalin qui se poursuit jusqu au Santonien. Le passage Crétacé-Paléogène est marqué par une discordance régionale liée à une inversion de la marge sud des bassins. Pendant l'Eocène inférieur à moyen, les failles normales synsédimentaires E-W à WNW-ESE sont fréquentes dans le Karaj (bassin d arrière-arc très subsident).PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Sci.Terre recherche (751052114) / SudocFONTAINEBLEAU-MINES ParisTech (771862302) / SudocSudocFranceF