290 research outputs found

    Expression patterns in reductive iron assimilation and functional consequences during phagocytosis of lichtheimia corymbifera , an emerging cause of mucormycosis

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    Iron is an essential micronutrient for most organisms and fungi are no exception. Iron uptake by fungi is facilitated by receptor-mediated internalization of siderophores, heme and reductive iron assimilation (RIA). The RIA employs three protein groups: (i) the ferric reductases (Fre5 proteins), (ii) the multicopper ferroxidases (Fet3) and (iii) the high-affinity iron permeases (Ftr1). Phenotyping under different iron concentrations revealed detrimental effects on spore swelling and hyphal formation under iron depletion, but yeast-like morphology under iron excess. Since access to iron is limited during pathogenesis, pathogens are placed under stress due to nutrient limitations. To combat this, gene duplication and differential gene expression of key iron uptake genes are utilized to acquire iron against the deleterious effects of iron depletion. In the genome of the human pathogenic fungus L. corymbifera, three, four and three copies were identified for FRE5, FTR1 and FET3 genes, respectively. As in other fungi, FET3 and FTR1 are syntenic and co-expressed in L. corymbifera. Expression of FRE5, FTR1 and FET3 genes is highly up-regulated during iron limitation (Fe-), but lower during iron excess (Fe+). Fe- dependent upregulation of gene expression takes place in LcFRE5 II and III, LcFTR1 I and II, as well as LcFET3 I and II suggesting a functional role in pathogenesis. The syntenic LcFTR1 I–LcFET3 I gene pair is co-expressed during germination, whereas LcFTR1 IILcFET3 II is co-expressed during hyphal proliferation. LcFTR1 I, II and IV were overexpressed in Saccharomyces cerevisiae to represent high and moderate expression of intracellular transport of Fe3+, respectively. Challenge of macrophages with the yeast mutants revealed no obvious role for LcFTR1 I, but possible functions of LcFTR1 II and IVs in recognition by macrophages. RIA expression pattern was used for a new model of interaction between L. corymbifera and macrophages

    Antidepressant effect of methanol extract of smokeless tobacco and identification of its bioactive components

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    Purpose: To investigate the antidepressant effect of methanol extract of smokeless tobacco and identify its bioactive compounds. Methods: Adult Wistar rats were randomly assigned to five groups of five rats each: normal control group, standard (reference) control group as well as 100, 200 and 500 mg/kg extract group. The extract, standard drug (imipramine) and normal saline were administered via the intraperitoneal (i.p.) route. The rats were subjected to forced swim test (FST) and tail suspension test (TST) to assess the antidepressant effect of methanol extract of smokeless tobacco. Gas chromatography–mass spectrometry (GC-MS) was used to identify the bioactive compounds of the extract. Results: The oral LD50 of the extract was > 2000 mg/kg. Significant decrease in immobility time was observed after single administration of imipramine (p < 0.05). The extract significantly and dosedependently decreased the immobility time, but increased climbing and swimming times, when compared with normal control group (p < 0.05). The immobility time of stressed rats regardless of sex was significantly and dose-dependently lowered, relative to normal control group (p < 0.05). Four major compounds were identified in the extract: nicotine (45.88 %); 1,5-dimethyl-2-pyrrolidinone (23.00 %), nhexadecanoic acid (11.31 %) and vitamin A aldehyde (9.38 %). Conclusion: These results demonstrate that the methanol extract of smokeless tobacco possesses antidepressant and mood-elevating effects in rats. However, its use should be discouraged since it contains a number of hazardous and carcinogenic components such as N-nitroso compounds and benzo(a)pyrene which are categorized as Class-I carcinogens

    Methanol extract of smokeless tobacco alters inflammation and nociception process in animal models

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    Purpose: To investigate the inflammatory and nociceptive alterations due to the use of Nicotiana tabacum or smokeless tobacco (MEST) owing to the fact that it is used by some people to relieve dental pain.Methods: Hepatic biochemical indicators and thiobarbituric acid reactive substances assay were used to assess MEST toxicity and pharmacological doses selection. The effects on inflammation of different pharmacological doses (100, 200 and 500 mg/kg i.p.) of MEST were evaluated using xylene-induced ear edema and cotton pellet granuloma tests. Indomethacin (10 mg/kg, i.p.) was used as positive standard drug, whereas the vehicle 0.5 % CMC treated group was considered as negative control. Acetic acid-induced abdominal contraction test and formalin-induced hind paw licking model were utilized to assess the role of MEST in nociception. Indomethacin (10 mg/kg i.p.) and diclofenac sodium (10 mg/kg i.p.) were used as positives standard drugs. The vehicle used was 0.5% CMC which served as the negative control.Results: MEST (50 %, 200 mg/kg) and indomethacin (47.5 %) both elicited a significant (p < 0.001) anti-edematogenic effect on xylene-induced ear edema. MEST also showed a significant (p < 0.001) inhibitory effect on granuloma formation at all administered doses as compared to the untreated groups which was comparable to standard drug indomethacin. The number of acetic acid induced writhings was observed to be significantly increased (p < 0.001) by MEST at all doses, unlike diclofenac that led to significant reduction (p < 0.001) in the number of writhings, when compared to the untreated group. MEST also showed a significant (p < 0.05) dose-dependent reduction of the hind paw licking caused by formalin when compared to the vehicle control.Conclusion: These results signify that administration of MEST induces inflammatory and nociceptive alterations. However, the extract is not recommended for dental pain due to its other toxic effects that have previously been reported.Keywords: Nicotiana tabacum, Smokeless tobacco, Inflammation, Nociceptio

    Hiding data in images using steganography techniques with compression algorithms

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    Steganography is the science and art of secret communication between two sides that attempt to hide the content of the message. It is the science of embedding information into the cover image without causing a loss in the cover image after embedding.Steganography is the art and technology of writing hidden messages in such a manner that no person, apart from the sender and supposed recipient, suspects the lifestyles of the message. It is gaining huge attention these days as it does now not attract attention to its information's existence. In this paper, a comparison of two different techniques is given. The first technique used Least Significant Bit (LSB) with no encryption and no compression. In the second technique, the secret message is encrypted first then LSB technique is applied. Moreover, Discrete Cosine Transform (DCT) is used to transform the image into the frequency domain. The LSB algorithm is implemented in spatial domain in which the payload bits are inserted into the least significant bits of cover image to develop the stego-image while DCT algorithm is implemented in frequency domain in which the stego-image is transformed from spatial domain to the frequency domain and the payload bits are inserted into the frequency components of the cover image.The performance of these two techniques is evaluated on the basis of the parameters MSE and PSNR

    Toxicological Features of Catha edulis (Khat) on Livers and Kidneys of Male and Female Sprague-Dawley Rats: A Subchronic Study

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    Hepato- and nephrotoxicity of Khat consumption (Catha edulis Forskal) have been evoked. Therefore, this study was conducted to evaluate such possible hepatorenal toxicity in female and male Sprague-Dawley rats (SD rats) focusing primarily on liver and kidney. In addition, female and male rats were investigated separately. Accordingly, forty-eight SD-rats (100-120 g) were distributed randomly into four groups of males and female (n = 12). Normal controls (NCs) received distilled water, whereas test groups received 500 mg/kg (low dose (LD)), 1000 mg/kg (medium dose (MD)), or 2000 mg/kg (high dose (HD)) of crude extract of Catha edulis orally for 4 weeks. Then, physical, biochemical, hematological, and histological parameters were analyzed. Results in Khat-fed rats showed hepatic enlargement, abnormal findings in serum aspartate aminotransferase (AST), and alkaline phosphatase (ALP) of male and female SD-rats and serum albumin (A) and serum creatinine (Cr) of female as compared to controls. In addition, histopathological abnormalities confirmed hepatic and renal toxicities of Khat that were related to heavy Khat consumption. In summary, Khat could be associated with hepatic hypertrophy and hepatotoxicity in male and female SD-rats and nephrotoxicity only in female SD-rats. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

    Mechanisms of Gastroprotective Effects of Ethanolic Leaf Extract of Jasminum sambac against HCl/Ethanol-Induced Gastric Mucosal Injury in Rats

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    Jasminum sambac is used in folk medicine as the treatment of many diseases. The aim of the present investigation is to evaluate the gastroprotective effects of ethanolic extracts of J. sambac leaves against acidified ethanol-induced gastric ulcers in rats. Seven groups of rats were orally pre-treated with carboxymethylcellulose (CMC) as normal group, CMC as ulcer group, 20 mg/kg of omeprazole as positive group, 62.5, 125, 250, and 500 mg/kg of extract as the experimental groups, respectively. An hour later, CMC was given orally to normal group and acidified ethanol solution was given orally to the ulcer control, positive control, and the experimental groups. The rats were sacrificed after an hour later. Acidity of gastric content, the gastric wall mucus, ulcer areas, and histology and immunohistochemistry of the gastric wall were assessed. Gastric homogenates were determined for prostaglandin E2 (PGE2), superoxide dismutase (SOD), andmalondialdehyde (MDA) content. Ulcer group exhibited significantly severe mucosal injury as compared with omeprazole or extract which shows significant protection towards gastric mucosal injury the plant promotes ulcer protection as it shows significant reduction of ulcer area grossly, and histology showed marked reduction of edema and leucocytes infiltration of submucosal layer compared with ulcer group. Immunohistochemistry showed overexpression of Hsp70 protein and downexpression of Bax protein in rats pretreated with extract. Significant increased in the pH, mucus of gastric content and high levels of PGE2, SOD and reduced amount of MDA was observed

    Cosmological dynamics of exponential gravity

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    We present a detailed investigation of the cosmological dynamics based on exp(R/Λ)\exp (-R/{\Lambda}) gravity. We apply the dynamical system approach to both the vacuum and matter cases and obtain exact solutions and their stability in the finite and asymptotic regimes. The results show that cosmic histories exist which admit a double de-Sitter phase which could be useful for describing the early and the late-time accelerating universe.Comment: 17 pages LaTeX, 3 figure

    Isolation of Flow and Nonflow Correlations by Two- and Four-Particle Cumulant Measurements of Azimuthal Harmonics in √\u3csup\u3es\u3c/sup\u3eNN=200 GeV Au+Au collisions

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    A data-driven method was applied to Au+Au collisions at √sNN = 200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance Δη-dependent and Δη-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a Δη-independent component of the correlation, which is dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η within the measured range of pseudorapidity |η| \u3c 1. In 20–30% central Au+Au colli- sions, the relative flow fluctuation was found to be 34% ± 2%(stat.) ± 3%(sys.) for particles with transverse momentum PT less than 2 GeV/c. The Δη-dependent part, attributed to nonflow correlations, is found to be 5% ± 2%(sys.) relative to the flow of the measured second harmonic cumulant at |Δη| \u3e 0.7

    Isolation of Flow and Nonflow Correlations by Two and Four Particle Cumulant Measurements of Azimuthal Harmonics in √Sɴɴ = GeV Au+Au Collisions

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    A data-driven method was applied to Au+Au collisions at √Sɴɴ = 200 GeV made with the STAR detector at RHIC to isolate pseudorapidity distance Δ η-dependent and Δ η-independent correlations by using two- and four-particle azimuthal cumulant measurements. We identified a Δ η-independent component of the correlation, which is dominated by anisotropic flow and flow fluctuations. It was also found to be independent of η within the measured range of pseudorapidity | η | \u3c 1. In 20-30% central Au+Au collisions, the relative flow fluctuation was found to be 34% ± 2%(stat.) ± 3%(sys.) for particles with transverse momentum pT less than 2 GeV/c. The Δ η-dependent part, attributed to nonflow correlations, is found to be 5% ± 2%(sys.) relative to the flow of the measured second harmonic cumulant at | Δ η | \u3e 0.7
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