Effects of Prenatal Dexamethasone on Hipopcampal Serotonin 1A Receptors in Adult Male Rats

The main activation route for the stress response is the hypothalamo-pituitaryadrenal axis (HPA) and the sympatho-adrenomedullary system. The HPA axis is a neuroendocrine feedback loop mediated by an array of tissue specific hormones, receptors and neurotransmitters that regulate glucocorticoid (GC) release. GCs are steroidal hormones produced by the adrenal glands and are key players in a negativefeedback loop controlling HPA activity. They influence the HPA axis through glucocorticoid receptors in the hypothalamus and pituitary and through both glucocorticoid (GR) and mineralcorticoid receptors (MR) that are co-localized in the hippocampus. Repeated or chronic stress exerts a negative influence on these HPA axis regulatory sites and contributes to potentially pathological conditions, especially during early development. For example, chronic stress promotes increased maternal adrenal gland secretion of glucocortiocoid, leading to abnormally high concentrations of GC inthe fetal environment. The timing and maturation of the HPA axis relative to birth is highly species specific and is closely linked to landmarks in fetal development. In rats this development of the HPA axis takes place in utero and continues even shortly after birth. It is likely that the maternal endocrine environment will affect fetal development during this critical time point and may alter the overall set point for the expression ofgenes and their protein products that mediate fetal HPA axis function. Dexamethasone (DEX) is a synthetic glucocorticoid (sGC) and is a consensus treatment in preterm pregnancies used to expedite fetal lung development. However it has been shown that DEX causes long term physiological and behavioral disorders in prenatally-exposed laboratory animals. Previous studies have also shown that it alters the MR: GR receptor ratio in the hippocampus. Taking into consideration corticosteroid regulation of serotonin receptors, especially 5HT1A receptors and their putative interaction with glucocorticoid receptors in the hippocampus, we hypothesized that prenatal DEX exposure would lead to changes in the expression and function of 5HT1A receptors in the hippocampus. We administered DEX to rat dams during the last trimester of gestation and investigated the changes in these receptors in the adult rat offspring. Radioligand receptor binding assays were used to study hippocampal 5HT1A receptor binding affinity and number. Our results demonstrate that hippocampal 5HT1A receptors are increased in the DEX animalscompared with controls by 36%, with no change in binding affinity. The efficiency of ligand-induced receptor signal transduction via G-protein activation was also studied using [35S]GTPγS incorporation assay. Using this technique, we showed that there was no significant difference in the maximum ligand mediated stimulation (Emax) of 5HT1Areceptors between control and dex exposed animals. However, the intracellular signalling efficiency of hippocampal 5HT1A receptors was diminished, since a significant increase in EC50 values was obtained with the dex exposed group showing a value 51% higherEC50 than controls. Taken together these data illustrate a considerable change in the 5HT1A component of the serotonergic system following prenatal DEX exposure

Stress Techniques and Management : A Review paper

The term stress means an imbalance between the mental and emotional levels of an individual. Stress reason out due to various external and internal factors, makes a periphery around a persona. In recent times it is observed that the stress levels are gaining the momentum in the organizational working frame. Researchers are keen to derive out the various parameters resulting in creating stress among the employees of the organization and parallel to this they are also seeking various techniques to minimize the stress levels so as to enhance productivity. The present paper is an attempt to gather and present the reviews of the various researchers, so far has worked on the stress techniques and management .The paper is descriptive in nature and based on secondary data gathered from various published and online sources. The study will be able to give a glimpse of the various factors responsible for the stress creation and the techniques used to minimize it. Keywords: Stress, Imbalance, Productivit

Synthesis and antimicrobial activities of novel 1,4-benzothiazine derivatives

AbstractA series of 2H,4H-2-[3,5-dimethyl-4-(substituted) phenyl azo pyrazol-1-yl] carbonyl methyl-3-oxo-1,4-benzothiazine derivatives have been synthesized by the reaction of 2H,4H-2-hydrazino carbonyl methyl-3-oxo-1,4-benzothiazine with acetyl acetone derivatives using ultrasound in lesser time with higher yields. All the synthesized compounds were investigated for their antibacterial activities. The result indicated that the compounds show convincing activities against Gram-positive bacteria (Bacillus subtilis and Streptococcus lactis) when compared with standard drug (ampicillin trihydrate). These compounds were also synthesized by conventional method and their structures have been elucidated on the basis of spectral analyses and chemical reactions

MAVS expressed by hematopoietic cells is critical for control of West Nile virus infection and pathogenesis

West Nile virus (WNV) is the most important cause of epidemic encephalitis in North America. Innate immune responses, which are critical for control of WNV infection, are initiated by signaling through pathogen recognition receptors, RIG-I and MDA5, and their downstream adaptor molecule, MAVS. Here, we show that a deficiency of MAVS in hematopoietic cells resulted in increased mortality and delayed WNV clearance from the brain. In Mavs(−/−) mice, a dysregulated immune response was detected, characterized by a massive influx of macrophages and virus-specific T cells into the infected brain. These T cells were polyfunctional and lysed peptide-pulsed target cells in vitro. However, virus-specific T cells in the brains of infected Mavs(−/−) mice exhibited lower functional avidity than those in wild-type animals, and even virus-specific memory T cells generated by prior immunization could not protect Mavs(−/−) mice from WNV-induced lethal disease. Concomitant with ineffective virus clearance, macrophage numbers were increased in the Mavs(−/−) brain, and both macrophages and microglia exhibited an activated phenotype. Microarray analyses of leukocytes in the infected Mavs(−/−) brain showed a preferential expression of genes associated with activation and inflammation. Together, these results demonstrate a critical role for MAVS in hematopoietic cells in augmenting the kinetics of WNV clearance and thereby preventing a dysregulated and pathogenic immune response. IMPORTANCE West Nile virus (WNV) is the most important cause of mosquito-transmitted encephalitis in the United States. The innate immune response is known to be critical for protection in infected mice. Here, we show that expression of MAVS, a key adaptor molecule in the RIG-I-like receptor RNA-sensing pathway, in hematopoietic cells is critical for protection from lethal WNV infection. In the absence of MAVS, there is a massive infiltration of myeloid cells and virus-specific T cells into the brain and overexuberant production of proinflammatory cytokines. These results demonstrate the important role that MAVS expression in hematopoietic cells has in regulating the inflammatory response in the WNV-infected brain

Agent-Based Simulation Disaster Evacuation Awareness on Night Situation in Aceh

In 2004 at least 230,000 people were victims of the Aceh tsunami disaster. To prevent the recurrence of many victims, the Aceh government held an evacuation exercise in 2008. To improve effectiveness dan reduce the cost reduction during evacuations drills, simulation is the best option. Agent-Based Modeling is a simulation program that was employed for tsunami evacuation in Aceh. This study on tsunami evacuation using agent-based modelling presented and evaluated the different control parameters that affect the evacuation rate. Evacuation scenario during day or night has different environmental, agent base, road modelling, and population approach. The Road Network Model has explained that to analyze the effect of agents in the evacuation process, resident agents are presumed to know the direction and shortest path to the nearest evacuation points. This simulation designed in Netlogo is also able to assess the congestion possibility on the road network. The road network emphasized the different scenarios to discover the possibility of congestion points. Nighttime is proven to be the best scenario for performing the evacuation in the simulation. The key reason to select the night scenario is to maximize the effects of an evaluation of the road network. In addition, simulation using night scenarios is also expected to raise people’s awareness

Visual Servoing of a UGV from a UAV using Differential Flatness

In this paper the problem of controlling the motion of a nonholonomic vehicle along a desired trajectory using observations from an overhead camera is considered. The control problem is formulated in the image plane. We show that the system in the image plane is differentially flat and use this property to generate effective control strategies using only visual feedback. Simulation results illustrate the methodology and show robustness to errors in the camera calibration parameters

Calibrating an Air-Ground Control System from Motion Correspondences

In this paper we consider the problem of controlling the motion of a vehicle moving on a ground plane based on aerial imagery. In the course of this work we propose a novel analysis of the relationship between the velocity of the vehicle on the ground plane and the velocity of its projection in the image. We show that this relationship provides information about a subset of the parameters of the homography relating the ground plane to the aerial image plane and describe how we can recover this relationship from available measurements