Investigation of the Antiviral Activity of Triterpenoid Compounds Against Retoviruses

The triterpenoid compound glycyrrhizin (GL) is widely used in Japan for the treatment of viral hepatitis. GL, carbenoxolone sodium (CBX), and cicloxolone sodium (CCX) exhibit broad range antiviral activity both in vivo and in vitro. Both in vitro and in vivo anti-HIV activity has also been reported for GL. This thesis investigates the effect of triterpenoid compounds on replication of two retrovirus in tissue cultures; Feline leukaemia virus type A (FeLV-A) and Feline immunodeficiency virus (FIV). Both of these viruses cause AIDS-like immunodeficiency diseases in cats. The anti-retrovirus activity of the triterpenoid compounds is contrasted with the effect of the drugs on the replication of bovine herpesvirus type 1 (BHV-1) in MDBK cells. Triterpenoid compounds are lipophilic and effect the host cell membrane functions. In order to determine drug concentrations in which cytotoxic effect of the drug could be uncoupled from the antiviral activity, cyotoxicity tests were performed. The effect of the drugs on cell culture growth and percentage cell viability were determined by trypan blue dye exclusion. The highest drug concentrations tolerated were; for FeA and CrFK cells 100muM CCX, or 100muM CBX and for MDBK cells 300muM CCX (used for BHV-1 studies). Drug removal experiments have shown that the effect of the drugs was reversible and that two days treatment with 100muM CCX, or 100muM CBX had no effect on the subsequent growth of FeA or CrFK cell cultures. The IC50 concentrations (concentration of the drug inhibiting cellular growth by 50%) determined for both CrFK and FeA cells after 24h or 48h drug treatments were > 300muM and 150muM respectively. Based on the data obtained from cytotoxicity tests, it was concluded that CrFK and FeA cells could be placed within the grouping of CCX-resistant cell lines classified by Galt et al., (1990). In order, to investigate the intracellular location of CCX molecules, an attempt was made to generate an anti-CCX antibody in immunise rabbits. Despite detection of an apparent anti-CCX antibody in an ELISA test, experiments designed to demonstrate the specific antibody tagging of CCX molecules in drug treated cells by immunofluorescence were unsuccessful. Previous studies have shown that CCX treatment impaired the glycosylation of HSV, VSV, and SFV glycoproteins, suggesting that the Golgi apparatus might be a target for triterpenoid compounds. A trans-Golgi specific monoclonal antibody (directed against the p58 protein) was employed to investigate the effect of CCX on the MDBK and CrFK cells Golgi apparatus. While perinuclear (Golgi) immunofluorescence was observed in drugfree cultures, little or no such staining was detected in cells treated with CCX, suggesting that the drug perturb the Golgi apparatus. It was further postulated that up-regulation of Na+/K+ATPase activity (a known effect of triterpenoid compounds) might play a role in the effect of CCX on the Golgi apparatus. To test this hypothesis, ouabain (a specific inhibitor of Na+/K+ATPase activity) was used in Golgi immunofluorescence labelling experiments. The effect of CCX on the Golgi apparatus of MDBK cells was impaired when cells were pre-treated with ouabain, confirming that the CCX-induced perturbation of the trans-Golgi compartment was associated with the up-regulation of Na+/K+ATPase activity. A model that can explain the effect of the triterpenoid compounds on Golgi apparatus has been given. CBX and GL exhibit mild virucidal activity against FeLV-A, FIV, and BHV-1. 300muM CCX treatment of virus particles in suspensions resulted in a 4 fold reduction in FeLV-A, and 10 fold reduction of FIV infectivity. Treatment of BHV-1 particles with 1500muM GL resulted in a 4.2 fold reduction infectivity. FeLV-A infectious virus yield, drug-dose-response experiments in which infected FeA cells were treated with increasing concentrations of CCX, CBX, or GL resulted in extracellular reductions of 155, 101, and 128 fold, when treated with 150muM CCX, 150muM CBX, or 2500muM GL respectively. The kinetics of the dose-response curves obtained for each drug were triphasic; an initial ~ 10 fold reduction in infectivity when cells were treated with 25muM CCX, 25muM CBX, or 500muM GL, followed by a near plateau in the curve up to 100muM CCX, 100muM CBX or 2000muM GL, and a sharp decrease in the curve at 150muM CCX, 150muM CBX, or 2500muM GL. The results suggest that the antiviral activity of triterpenoid compounds may operate by inhibiting two different target functions; the first, a function that enhances but is not essential for virus infectivity and which is sensitive to low drug concentrations, and the second, a function which is probably essential for virus replication and which is only sensitive to high concentrations of the drugs. (Abstract shortened by ProQuest.)

Influence of Deicing Salts on the Water-Repellency of Portland Cement Concrete Coated with Polytetrafluoroethylene and Polyetheretherketone

Sustainable super water/ice-repellent pavements are gaining attention as a smart solution for mitigating problems associated with winter pavement maintenance of roadways and airfields. Such smart pavements can facilitate surface drainage and prevent or curb ice formation or snow accumulation. While a conventional method for melting ice and snow is the use of deicing chemicals, such materials can transfer to the surface of nanotechnology-based pavements and influence their water/icerepellency by changing the chemistry of water or ice. This study focused on characterizing the degree of hydrophobicity of Portland cement concrete (PCC) nanocoated with polytetrafluoroethylene/polyetheretherketone (PTFE/PEEK). A layer-bylayer (LBL) spray deposition technique was used for spraying the binding agent and water-repellent materials. The liquid-repellency was characterized by measuring the static liquid contact angles (LCAs) and calculating the works of adhesion (WA). The liquid types used included distilled water and two types of deicing chemicals prepared by dissolving salts in distilled water. Data analysis results revealed that salt contamination improves the water-repellency of nano-coated surfaces

Evaluation of the frequency of the IL-28 polymorphism (rs8099917) in patients with chronic hepatitis C using zip nucleic acid probes, Kerman, Southeast of Iran

Polymorphisms in the region of the interleukin IL-28 gene on chromosome 19 have been related with clearance of hepatitis C virus (HCV), a major human pathogen responsible for chronic hepatitis, cirrhosis and hepatocellular carcinoma. About 3 of the world's population is infected with HCV. The long-term response to therapy is influenced by many host and viral factors, and recent evidence has indicated that some host genetic polymorphisms related to IL-28 are the most powerful predictors of virological response in patients with HCV. This study assessed frequency of the IL-28 polymorphism (rs8099917) in 50 patients (39 men and 11 women ) with chronic hepatitis C using ZNA probe real time PCR new method . All patients were tested for genotype of HCV and the HCV viral load. In parallel, the levels of SGOT, SGPT and ALK enzymes were assessed. Treatment using Peg-interferon alpha with ribavirin was conducted for patients and subsequently samples were collected to detect any change in viral load or liver enzyme rates. The overall frequency of the TT allele is 74, TG allele 20 and GG allele 6 and the percent of patients who had T allele was 84. Clear reduction in viral load and liver enzymes was reported in patients with the T allele. Especially for genotype 1 which is relatively resistant to treatment, these alleles may have a role in this decline. In conclusion, we showed that IL-28 polymorphism rs8099917 strongly predicts virological response in HCV infection and that real-time PCR with Zip nucleic acid probes is a sensitive, specific and rapid detection method for detection of SNPs which will be essential for monitoring patients undergoing antiviral therapy

Neuronal Activity in Rat Barrel Cortex Underlying Texture Discrimination

Rats and mice palpate objects with their whiskers to generate tactile sensations. This form of active sensing endows the animals with the capacity for fast and accurate texture discrimination. The present work is aimed at understanding the nature of the underlying cortical signals. We recorded neuronal activity from barrel cortex while rats used their whiskers to discriminate between rough and smooth textures. On whisker contact with either texture, firing rate increased by a factor of two to ten. Average firing rate was significantly higher for rough than for smooth textures, and we therefore propose firing rate as the fundamental coding mechanism. The rat, however, cannot take an average across trials, but must make an immediate decision using the signals generated on each trial. To estimate single-trial signals, we calculated the mutual information between stimulus and firing rate in the time window leading to the rat's observed choice. Activity during the last 75 ms before choice transmitted the most informative signal; in this window, neuronal clusters carried, on average, 0.03 bits of information about the stimulus on trials in which the rat's behavioral response was correct. To understand how cortical activity guides behavior, we examined responses in incorrect trials and found that, in contrast to correct trials, neuronal firing rate was higher for smooth than for rough textures. Analysis of high-speed films suggested that the inappropriate signal on incorrect trials was due, at least in part, to nonoptimal whisker contact. In conclusion, these data suggest that barrel cortex firing rate on each trial leads directly to the animal's judgment of texture

Prevalence and type distribution of human papillomavirus infection using the INNo-Lipa Assay, Kerman, Southeast Iran

The human papilloma virus (HPV) causes skin and mucous membrane infections. It crosses from one person to another by skin-to-skin contact, such as sexual contact. There are more than 100 types of HPV that can influence different parts of the body. Some types of HPV can cause cancer (such as cervical or anal cancer) and others can cause warts (such as genital or plantar warts). HPV infection is one of the most common sexually transmitted infections (STIs) in Iran and around the world. Considerable molecular evidence suggests a role for human papilloma virus (HPV) in the pathogenesis of carcinoma. Epidemiological studies on human papilloma viruses (HPVs) infections in general population are critical for the performing of health policy guidelines for developing the strategies to hinder the primary and secondary different cancer. In different parts of Iran, there is a lack of population-based studies to determine the prevalence of HPV in the general population. The aim of this population-based study was therefore to report the prevalence ratse of HPV types among Iranian patients. To study the risk of human papilloma virus (HPV) infection, we managed a retrospective study in Kerman province, southeast of Iran. For this purpose, 410 patients tested for the presence of HPV DNA using PCR and INNo- Lipa assays. HPV DNA was detected in 108 out of 410 patients (26.34), while it was not detected in any of the control group samples. Patients included 23 (21.1) males and 86 (78.8) females. HPV type 6 was the most common (49) followed by HPV type 16 (10.1), and also HPV type11 (9.2). The prevalence of HPV in Iran is comparable to those reported in other regions of the world. In a similar manner, it seems that HPV types 6, 16 and11 are the most common types in Kerman. Additional studies on larger group of patients, particularly in those with pre-invasive forms of disease, are needed to explain the roles of different HPV types in this location of Iran

Synthesis and Optimization of Reversible Circuits - A Survey

Reversible logic circuits have been historically motivated by theoretical research in low-power electronics as well as practical improvement of bit-manipulation transforms in cryptography and computer graphics. Recently, reversible circuits have attracted interest as components of quantum algorithms, as well as in photonic and nano-computing technologies where some switching devices offer no signal gain. Research in generating reversible logic distinguishes between circuit synthesis, post-synthesis optimization, and technology mapping. In this survey, we review algorithmic paradigms --- search-based, cycle-based, transformation-based, and BDD-based --- as well as specific algorithms for reversible synthesis, both exact and heuristic. We conclude the survey by outlining key open challenges in synthesis of reversible and quantum logic, as well as most common misconceptions.Comment: 34 pages, 15 figures, 2 table

Dermatitis and Aging-Related Barrier Dysfunction in Transgenic Mice Overexpressing an Epidermal-Targeted Claudin 6 Tail Deletion Mutant

The barrier function of the skin protects the mammalian body against infection, dehydration, UV irradiation and temperature fluctuation. Barrier function is reduced with the skin's intrinsic aging process, however the molecular mechanisms involved are unknown. We previously demonstrated that Claudin (Cldn)-containing tight junctions (TJs) are essential in the development of the epidermis and that transgenic mice overexpressing Cldn6 in the suprabasal layers of the epidermis undergo a perturbed terminal differentiation program characterized in part by reduced barrier function. To dissect further the mechanisms by which Cldn6 acts during epithelial differentiation, we overexpressed a Cldn6 cytoplasmic tail deletion mutant in the suprabasal compartment of the transgenic mouse epidermis. Although there were no gross phenotypic abnormalities at birth, subtle epidermal anomalies were present that disappeared by one month of age, indicative of a robust injury response. However, with aging, epidermal changes with eventual chronic dermatitis appeared with a concomitant barrier dysfunction manifested in increased trans-epidermal water loss. Immunohistochemical analysis revealed aberrant suprabasal Cldn localization with marked down-regulation of Cldn1. Both the proliferative and terminal differentiation compartments were perturbed as evidenced by mislocalization of multiple epidermal markers. These results suggest that the normally robust injury response mechanism of the epidermis is lost in the aging Involucrin-Cldn6-CΔ196 transgenic epidermis, and provide a model for evaluation of aging-related skin changes

RNAi and miRNA in viral infections and cancers

Since the first report of RNA interference (RNAi) less than a decade ago, this type of molecular intervention has been introduced to repress gene expression in vitro and also for in vivo studies in mammals. Understanding the mechanisms of action of synthetic small interfering RNAs (siRNAs) underlies use as therapeutic agents in the areas of cancer and viral infection. Recent studies have also promoted different theories about cell-specific targeting of siRNAs. Design and delivery strategies for successful treatment of human diseases are becomingmore established and relationships between miRNA and RNAi pathways have been revealed as virus-host cell interactions. Although both are well conserved in plants, invertebrates and mammals, there is also variabilityand a more complete understanding of differences will be needed for optimal application. RNA interference (RNAi) is rapid, cheap and selective in complex biological systems and has created new insight sin fields of cancer research, genetic disorders, virology and drug design. Our knowledge about the role of miRNAs and siRNAs pathways in virus-host cell interactions in virus infected cells is incomplete. There are different viral diseases but few antiviral drugs are available. For example, acyclovir for herpes viruses, alpha-interferon for hepatitis C and B viruses and anti-retroviral for HIV are accessible. Also cancer is obviously an important target for siRNA-based therapies, but the main problem in cancer therapy is targeting metastatic cells which spread from the original tumor. There are also other possible reservations and problems that might delay or even hinder siRNA-based therapies for the treatment of certain conditions; however, this remains the most promising approach for a wide range of diseases. Clearly, more studies must be done to allow efficient delivery and better understanding of unwanted side effects of siRNA-based therapies. In this review miRNA and RNAi biology, experimental design, anti-viral and anti-cancer effects are discussed

Psychometric Curve and Behavioral Strategies for Whisker-Based Texture Discrimination in Rats

The rodent whisker system is a major model for understanding neural mechanisms for tactile sensation of surface texture (roughness). Rats discriminate surface texture using the whiskers, and several theories exist for how texture information is physically sensed by the long, moveable macrovibrissae and encoded in spiking of neurons in somatosensory cortex. However, evaluating these theories requires a psychometric curve for texture discrimination, which is lacking. Here we trained rats to discriminate rough vs. fine sandpapers and grooved vs. smooth surfaces. Rats intermixed trials at macrovibrissa contact distance (nose >2 mm from surface) with trials at shorter distance (nose <2 mm from surface). Macrovibrissae were required for distant contact trials, while microvibrissae and non-whisker tactile cues were used for short distance trials. A psychometric curve was measured for macrovibrissa-based sandpaper texture discrimination. Rats discriminated rough P150 from smoother P180, P280, and P400 sandpaper (100, 82, 52, and 35 µm mean grit size, respectively). Use of olfactory, visual, and auditory cues was ruled out. This is the highest reported resolution for rodent texture discrimination, and constrains models of neural coding of texture information