942 research outputs found

    Lipid Peroxidation, Antioxidant Level, and Alpha Naphthyl Acetate Esterase Activity of Peripheral Blood Lymphocytes in the Mallard, Muscovy and Pekin Ducks

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    The aim of this study was to determine blood levels of malondialdehyde (MDA), reduced glutathione (GSH), ceruloplasmin and vitamin C, and the percentages of peripheral blood Tlymphocytes using the alpha-naphthyl acetate esterase (ANAE) method on Mallard (Anas platyrhynchos), Muscovy (Cairina moschata) and Pekin (Anas domestica) ducks. Blood samples were obtained from 8 adult ducks of each breed. The serum levels observed in Mallard, Muscovy and Pekin ducks respectively were 0.8, 1.07 and 1.3 nmol MDA per ml; 77.4, 66.9 and 78.7 mg GSH per 100 ml; 23.9, 26.1 and 24.1 mg ceruloplasmin per 100 ml; and 0.50, 0.52 and 0.70 mg vitamin C per 100 ml. The percentage of the ANAE (+) lymphocytes was 57.9%, 54.8% and 55.1% in Mallard, Muscovy and Pekin ducks, respectively. In this study, blood levels of lipid peroxidation and nonenzymatic antioxidants in the Mallard, Muscovy and Pekin ducks were determined

    Distribution of mast cells in lung tissues of rats exposed to biomass smoke

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    This study was designed to evaluate the distribution of mast cells in the lung tissues of rats exposed to biomass  smoke. Fifty six female Wistar albino adult rats were used. They were divided into two experimental groups  (control and biomass smoke-treated), each containing 28 animals. Control rats were not exposed to the  biomass smoke at any time during the experiment. Rats in the treatment group were exposed daily (one hour)  to biomass smoke for 3, 6 or 9 months. Lung tissues samples were obtained under deep anesthesia from the  randomly selected 7 animals in both groups. Lung tissues were fixed in Mota’s fixative (BLA) for 24 h and  embedded in paraffin. Sections of 6 ÎŒm thickness were cut and stained with 0.5% toluidine blue in 0.5 N  hydrochloric acid at pH 0.5 for 30 min. The numbers of mast cell in lung tissues of the animals exposed to  the biomass for 6 or 9 months were significantly (P<0.05) higher than controls. This study showed that long  term exposure to biomass smoke was associated with the increased number of mast cells in the lung.

    Effect of royal jelly on experimental colitis induced by acetic acid and alteration of mast cell distribution in the colon of rats

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    This study investigated the effects of royal jelly (RJ) on acetic acid-induced colitis in rats. Twenty adult female Wistar albino rats were divided into four treatment groups of 5 animals each, including a control group (Group I); Group II was treated orally with RJ (150 mg kg−1 body weight); Group III had acetic acid-induced colitis; and Group IV had acetic acid-induced colitis treated orally with RJ (150 mg kg−1 body weight) for 4 weeks. Colitis was induced by intracolonic instillation of 4% acetic acid; the control group received physiological saline (10 mL kg−1). Colon samples were obtained under deep anaesthesia from animals in all groups. Tissues were fixed in 10% formalin neutral buffer solution for 24 h and embedded in paraffin. Six-micrometre-thick sections were stained with Mallory’s triple stain and toluidine blue in 1% aqueous solution at pH 1.0 for 5 min (for Mast Cells). RJ was shown to protect the colonic mucosa against the injurious effect of acetic acid. Colitis (colonic damage) was confirmed histomorphometrically as significant increases in the number of mast cells (MC) and colonic erosions in rats with acetic acid-induced colitis. The RJ treatment significantly decreased the number of MC and reduced the area of colonic erosion in the colon of RJ-treated rats compared with rats with untreated colitis. The results suggest that oral treatment with RJ could be used to treat colitis

    Insect oviposition in herbaceous plants attracts egg parasitoids despite fungal phytopathogen infection

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    Egg parasitoids are important natural enemies of several insect pests. The ability to kill the pest before it can inflict damage to the plant makes egg parasitoids ideal candidates for biological control. Several studies have shown that egg parasitoids exploit oviposition-induced plant volatiles (OIPVs) to locate host eggs laid on plant organs. Yet such studies have often overlooked that, in nature, plants frequently suffer concurrent attack by insect herbivores and phytopathogens. These dual attacks can modify the emission of induced plant volatiles, which may potentially interfere with the host location abilities of egg parasitoids. We investigated this research question using the following study organisms: the broad bean Vicia faba, the plant pathogen Stemphylium sp., the southern green stink bug Nezara viridula and its associated egg parasitoid Trissolcus basalis. We showed that T. basalis is able to exploit OPIVs in order to locate N. viridula egg masses even when V. faba plants were previously infected by Stemphylium sp. Chemical analyses indicate that the egg parasitoid ability to exploit OIPVs persists despite significant alterations of the volatile blends emitted by plants suffering multiple biotic stresses. This study highlights the importance of incorporating the complexity of multiple biotic stresses when studying parasitoid foraging behavior, in order to comprehend how to enhance the effectiveness of natural enemies in crop protection

    Microvascular dysfunction as a link between obesity, insulin resistance and hypertension

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    Impaired microvascular dilatation from any cause and impaired insulin-mediated capillary recruitment in particular result in suboptimal delivery of glucose and insulin to skeletal muscle, and subsequently impairment of glucose disposal (insulin resistance). In addition, microvascular dysfunction, through functional and/or structural arteriolar and capillary drop-out, and arteriolar constriction, increases peripheral resistance and thus blood pressure. Microvascular dysfunction may thus constitute a pathway that links insulin resistance and hypertension. Overweight and obesity may be an important cause of microvascular dysfunction. Mechanisms linking overweight and obesity to microvascular dysfunction include changes in the secretion of adipokines leading to increased levels of free fatty acids and inflammatory mediators, and decreased levels of adiponectin all of which may impair endothelial insulin signaling. Microvascular dysfunction may thus constitute a new treatment target in the prevention of type 2 diabetes mellitus and hypertension

    Deficiency of Sphingosine-1-phosphate Lyase Impairs Lysosomal Metabolism of the Amyloid Precursor Protein

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    Progressive accumulation of the amyloid ÎČ protein in extracellular plaques is a neuropathological hallmark of Alzheimer disease. Amyloid ÎČ is generated during sequential cleavage of the amyloid precursor protein (APP) by ÎČ- and Îł-secretases. In addition to the proteolytic processing by secretases, APP is also metabolized by lysosomal proteases. Here, we show that accumulation of intracellular sphingosine-1-phosphate (S1P) impairs the metabolism of APP. Cells lacking functional S1P-lyase, which degrades intracellular S1P, strongly accumulate full-length APP and its potentially amyloidogenic C-terminal fragments (CTFs) as compared with cells expressing the functional enzyme. By cell biological and biochemical methods, we demonstrate that intracellular inhibition of S1P-lyase impairs the degradation of APP and CTFs in lysosomal compartments and also decreases the activity of Îł-secretase. Interestingly, the strong accumulation of APP and CTFs in S1P-lyase-deficient cells was reversed by selective mobilization of Ca(2+) from the endoplasmic reticulum or lysosomes. Intracellular accumulation of S1P also impairs maturation of cathepsin D and degradation of Lamp-2, indicating a general impairment of lysosomal activity. Together, these data demonstrate that S1P-lyase plays a critical role in the regulation of lysosomal activity and the metabolism of APP

    Transient deSUMOylation of IRF2BP proteins controls early transcription in EGFR signaling

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    Molecular switches are essential modules in signaling networksand transcriptional reprogramming. Here, we describe a role forsmall ubiquitin-related modifier SUMO as a molecular switch inepidermal growth factor receptor (EGFR) signaling. Using quantita-tive mass spectrometry, we compare the endogenous SUMOproteomes of HeLa cells before and after EGF stimulation. Thereby,we identify a small group of transcriptional coregulators includingIRF2BP1, IRF2BP2, and IRF2BPL as novel players in EGFR signaling.Comparison of cells expressing wild type or SUMOylation-deficientIRF2BP1indicates that transient deSUMOylation of IRF2BP proteinsis important for appropriate expression of immediate early genesincludingdual specificity phosphatase1(DUSP1, MKP-1) and thetranscription factor ATF3. We find that IRF2BP1is a repressor,whose transient deSUMOylation on the DUSP1promoter allows—and whose timely reSUMOylation restricts—DUSP1transcription.Our work thus provides a paradigm how comparative SUMOproteome analyses serve to reveal novel regulators in signal trans-duction and transcription
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