Reovirus particles were isolated from adults in laboratory colonies of the housefly, Musca domestica. These particles were spherical in outline, 57–76 nm in diameter, and were found only in hemocyte cytoplasm, where virions have been disclosed by a new technique. Virions were present in large numbers, and viral inclusion bodies were identified. The virus particles had pentagonal and hexagonal shapes resembling a simple icosahedral structure. The virus was shown to be infectious and pathogenic to adult flies through injection or by feeding them suspensions from flies that had died of the virus. Electron micrographs of midgut sections from infected flies showed that the midgut cells were packed with dark undulating threads which were not present in uninfected flies. However, no virus particles or inclusion bodies could be seen in these cells. On the basis of their association with infected flies, and the similarity to results from other studies on reoviruses and insect viruses, it is suggested that these threads are an alternative replicative form of the reovirus. When the virus suspensions from heavily infected flies were dialyzed against weak alkaline solutions, the threads showed an inner component of coiled material, 12 nm in diameter, inside an envelope with a diameter of 50–83 nm, mean 60.3 ± 7.5, composed of subunits 7–8 nm long and 7–8 nm across. 相似文献
Due to its sensitivity, immunohistochemistry (IHC) of abnormal prion protein (PrPsc) is used to study experimental and natural cases of transmissible spongiform encephalopathies (TSEs) such as Creutzfeldt-Jakob disease in humans or scrapie and bovine spongiform encephalopathy (BSE) in animals. The limits of detection are particularly critical when PrPsc IHC is used for diagnostic purposes. In this article, we describe for the first time the use of streptomycin sulfate in IHC, providing a novel original and easy way to amplify specifically PrPsc immunohistochemical detection in natural cases of BSE and scrapie, as well as in experimental TSEs in mice models using two different PrP antibodies. 相似文献
The combined effects of subzero temperature and high pressure on the inactivation of Escherichia coli K12TG1 were investigated. Cells of this bacterial strain were exposed to high pressure (50 to 450 MPa, 10-min holding time) at two temperatures (−20°C without freezing and 25°C) and three water activity levels (aw) (0.850, 0.992, and ca. 1.000) achieved with the addition of glycerol. There was a synergistic interaction between subzero temperature and high pressure in their effects on microbial inactivation. Indeed, to achieve the same inactivation rate, the pressures required at −20°C (in the liquid state) were more than 100 MPa less than those required at 25°C, at pressures in the range of 100 to 300 MPa with an aw of 0.992. However, at pressures greater than 300 MPa, this trend was reversed, and subzero temperature counteracted the inactivation effect of pressure. When the amount of water in the bacterial suspension was increased, the synergistic effect was enhanced. Conversely, when the aw was decreased by the addition of solute to the bacterial suspension, the baroprotective effect of subzero temperature increased sharply. These results support the argument that water compression is involved in the antimicrobial effect of high pressure. From a thermodynamic point of view, the mechanical energy transferred to the cell during the pressure treatment can be characterized by the change in volume of the system. The amount of mechanical energy transferred to the cell system is strongly related to cell compressibility, which depends on the water quantity in the cytoplasm. 相似文献
This study evaluates the antimicrobial effects of ethanolic extract of five herbal plants; Guava (Psidium guajava), Sage (Salvia officinalis), Rhamnus (Ziziphusspina Christi), Mulberry (Morusalba L.), and Olive (Oleaeuropaea L) leaves against several microbial population representing Gram positive, Gram negative and Mollicutes; S. aureus, E. coli, Pasteurella multocida, B. cereus, Salmonella Enteritidis and M. gallisepticum using standard agar disc diffusion technique and minimal inhibitory concentration (MIC). Different extracts reveal variable results against the microorganism under study. All extracts have no antibacterial potency for Mycoplasma gallisepticum except Psidium guajava. The results of minimal inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) of the extracts against the six bacteria ranged from 625 to 5000 μg/ml. The used herbal extract could inhibit the selected microorganism under study with variable minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). 相似文献
Milacemide (2-n-pentylaminoacetamide) is a secondary monoamine that in the brain is converted to glycinamide and glycine. This oxidative reaction was suspected to involve the reaction of monoamine oxidase (MAO). Using mitochondrial preparations from tissues that contain MAO-A and -B (rat brain and liver), MAO-A (human placenta), and MAO-B (human platelet and bovine adrenal chromaffin cell), it has been established that mitochondria containing MAO-B rather than MAO-A oxidize (H2O2 production and glycinamide formation) milacemide. The apparent Km (30-90 microM) for milacemide oxidation by mitochondrial MAO-B preparations is significantly lower than that for milacemide oxidation by mitochondrial MAO-A (approximately 1,300 microM). In vitro MAO-B (l-deprenyl and AGN 1135) rather than MAO-A (clorgyline) selectively inhibited the oxidation of milacemide. These in vitro data are matched by ex vivo experiments where milacemide oxidation was compared to oxidation of serotonin (MAO-A) and beta-phenylethylamine (MAO-B) by brain mitochondria prepared from rats pretreated with clorgyline (0.5-10 mg/kg) and l-deprenyl (0.5-10 mg/kg). Furthermore, in vivo experiment demonstrated that l-deprenyl selectively increased the urinary excretion of [14C]milacemide and the total radioactivity with a concomitant decrease of [14C]glycinamide. Such changes were not observed after clorgyline treatment, but were evident only at doses beyond clorgyline selectivity. The present data therefore demonstrate that milacemide is a substrate for brain MAO-B, and its conversion to glycinamide, further transformed to the inhibitory neurotransmitter, glycine, mediated by this enzyme may contribute to its pharmacological activities. 相似文献
We have previously shown that CD36 is a membrane protein that facilitates long chain fatty acid (FA) transport by muscle tissues.
We also documented the significant impact of muscle CD36 expression on heart function, skeletal muscle insulin sensitivity as well
as on overall metabolism. To identify a comprehensive set of genes that are differentially regulated by CD36 expression in the
heart, we used two microarray technologies (Affymetrix and Agilent) to compare gene expression in heart tissues from CD36
KnocK-Out (KO-CD36) versus wild type (WT-CD36) mice. The obtained results using the two technologies were similar with
around 35 genes differentially expressed using both technologies. Absence of CD36 led to down-regulation of the expression of
three groups of genes involved in pathways of FA metabolism, angiogenesis/apoptosis and structure. These data are consistent
with the fact that the CD36 protein binds FA and thrombospondin 1 invoved respectively in lipid metabolism and anti-angiogenic
activities. In conclusion, our findings led to validate our data analysis workflow and identify specific pathways, possibly
underlying the phenotypic abnormalities in CD36 Knock -Out hearts. 相似文献
Smooth muscle cells (SMCs) usually express a contractile phenotype in the healthy aorta. However, aortic SMCs have the ability to undergo profound changes in phenotype in response to changes in their extracellular environment, as occurs in ascending thoracic aortic aneurysms (ATAA). Accordingly, there is a pressing need to quantify the mechanobiological effects of these changes at single cell level. To address this need, we applied Traction Force Microscopy (TFM) on 759 cells coming from three primary healthy (AoPrim) human SMC lineages and three primary aneurysmal (AnevPrim) human SMC lineages, from age and gender matched donors. We measured the basal traction forces applied by each of these cells onto compliant hydrogels of different stiffness (4, 8, 12, 25 kPa). Although the range of force generation by SMCs suggested some heterogeneity, we observed that: 1. the traction forces were significantly larger on substrates of larger stiffness; 2. traction forces in AnevPrim were significantly higher than in AoPrim cells. We modelled computationally the dynamic force generation process in SMCs using the motor-clutch model and found that it accounts well for the stiffness-dependent traction forces. The existence of larger traction forces in the AnevPrim SMCs were related to the larger size of cells in these lineages. We conclude that phenotype changes occurring in ATAA, which were previously known to reduce the expression of elongated and contractile SMCs (rendering SMCs less responsive to vasoactive agents), tend also to induce stronger SMCs. Future work aims at understanding the causes of this alteration process in aortic aneurysms.
This study illustrated the immunohistochemical distribution of androgen and vitamin D receptors of epididymis in 20 sexually mature ram (Rahmani breed) with average age ranged from (2_4) years and average weight ranged from (50_65kg). Androgen receptor was localized in the cytoplasm of both ciliated and non ciliated cells of efferent ductules, besides the principal cells via the entire epididymal duct. The principal cells of both corpus and proximal cauda epididymis showed the highest immunoreactivity to androgen receptors. Furthermore, vitamin D receptor was localized in the cytoplasm of all epithelium of the efferent ductules besides principal cells of all epididymal regions, however the immunoreaction was significantly higher in the efferent ductules, distal caput and distal cauda epididymis. In conclusion, these results suggest that the function of ram epididymis is regulated by both androgen and Vitamin D. 相似文献