4,144 research outputs found

    Anti-Trypanosomal Potential Of Momordica Balsamina Linn Fruit Pulp Extract Against Trypanosoma brucei brucei Infection

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    The search for new trypanocides has not been keenly pursued due to high cost of design and development with no promise of financial returns. Momordica balsamina fruit pulp extract was screened for antitrypanosomal activity in experimental Trypanosoma brucei brucei infection in rabbits. The extract was administered prior to parasite inoculation, 24 hours post parasite inoculation and on establishment of infection. The treatment was by oral administration of the extract at 500mg/kg body weight for 14 consecutive days. Parasitaemia was monitored daily while body weight and packed cell volume (PCV) were determined before commencement of studies and subsequently at weekly intervals for 28 days. The result showed a significant (

    Crackling Noise, Power Spectra and Disorder Induced Critical Scaling

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    Crackling noise is observed in many disordered non-equilibrium systems in response to slowly changing external conditions. Examples range from Barkhausen noise in magnets to acoustic emission in martensites to earthquakes. Using the non-equilibrium random field Ising model, we derive universal scaling predictions for the dependence of the associated power spectra on the disorder and field sweep rate, near an underlying disorder-induced non-equilibrium critical point. Our theory applies to certain systems in which the crackling noise results from avalanche-like response to a (slowly) increasing external driving force, and is characterized by a broad power law scaling regime of the power spectra. We compute the critical exponents and discuss the relevance of the results to experiments.Comment: 27 Latex Pages, 14 eps figure

    Proteomic responses reveal the differential effects induced by cadmium in mussels Mytilus galloprovincialis at early life stages

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    Cadmium (Cd) has become an important metal contaminant and posed severe risk on the organisms in the coastal environments of the Bohai Sea. Marine mussel Mytilus galloprovincialis is widely distributed along the Bohai coast and consumed as seafood by local residents. Evidences indicate that the early stages of marine organisms are more sensitive to metal contaminants. In this study, we applied two-dimensional electrophoresis-based proteomics to characterize the biological effects of Cd (50 mu g L-1) in the early life stages (D-shape larval and juvenile) of mussels. The different proteomic responses demonstrated the differential responsive mechanisms to Cd exposure in these two early life stages of mussels. In details, results indicated that Cd mainly induced immune and oxidative stresses in both D-shape larval and juvenile mussels via different pathways. In addition, the significant up-regulation of triosephosphate isomerase and metallothionein confirmed the enhanced energy demand and mobilized detoxification mechanism in D-shape larval mussels exposed to Cd. In juvenile mussels, Cd exposure also induced clear apoptosis. Overall, this work suggests that Cd is a potential immune toxicant to mussel M. galloprovincialis at early life stages. (C) 2016 Elsevier Ltd. All rights reserved

    Celastrol inhibits aminoglycoside-induced ototoxicity via heat shock protein 32

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    Hearing loss is often caused by death of the mechanosensory hair cells of the inner ear. Hair cells are susceptible to death caused by aging, noise trauma, and ototoxic drugs, including the aminoglycoside antibiotics and the antineoplastic agent cisplatin. Ototoxic drugs result in permanent hearing loss for over 500 000 Americans annually. We showed previously that induction of heat shock proteins (HSPs) inhibits both aminoglycoside- and cisplatin-induced hair cell death in whole-organ cultures of utricles from adult mice. In order to begin to translate these findings into a clinical therapy aimed at inhibiting ototoxic drug-induced hearing loss, we have now examined a pharmacological HSP inducer, celastrol. Celastrol induced upregulation of HSPs in utricles, and it provided significant protection against aminoglycoside-induced hair cell death in vitro and in vivo. Moreover, celastrol inhibited hearing loss in mice receiving systemic aminoglycoside treatment. Our data indicate that the major heat shock transcription factor HSF-1 is not required for celastrol-mediated protection. HSP32 (also called heme oxygenase-1, HO-1) is the primary mediator of the protective effect of celastrol. HSP32/HO-1 inhibits pro-apoptotic c-Jun N-terminal kinase (JNK) activation and hair cell death. Taken together, our data indicate that celastrol inhibits aminoglycoside ototoxicity via HSP32/HO-1 induction

    Cerebral spectroscopic and oxidative stress studies in patients with schizophrenia who have dangerously violently offended

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to bring together all the results of <it>in vivo </it>studies of ethane excretion and cerebral spectroscopy in patients with schizophrenia who have dangerously seriously violently offended in order to determine the extent to which they shed light on the degree to which the membrane phospholipid hypothesis and the actions of free radicals and other reactive species are associated with cerebral pathophysiological mechanisms in this group of patients.</p> <p>Methods</p> <p>The patients investigated were inpatients from a medium secure unit with a DSM-IV-TR diagnosis of schizophrenia. There was no history of alcohol dependency or any other comorbid psychoactive substance misuse disorder. Expert psychiatric opinion, accepted in court, was that all these patients had violently offended directly as a result of schizophrenia prior to admission. These offences consisted of homicide, attempted murder or wounding with intent to cause grievous bodily harm. Excreted ethane was analyzed and quantified by gas chromatography and mass spectrometry (<it>m</it>/<it>z </it>= 30). 31-phosphorus magnetic resonance spectroscopy data were obtained at a magnetic field strength of 1.5 T using an image-selected <it>in vivo </it>spectroscopy sequence (TR = 10 s; 64 signal averages localized on a 70 Ă— 70 Ă— 70 mm<sup>3 </sup>voxel).</p> <p>Results</p> <p>Compared with age- and sex-matched controls, in the patient group the mean alveolar ethane level was higher (<it>p </it>< 0.0005), the mean cerebral beta-nucleotide triphosphate was lower (<it>p </it>< 0.04) and the mean gamma-nucleotide triphosphate was higher (<it>p </it>< 0.04). There was no significant difference between the two groups in respect of phosphomonoesters, phosphodiesters or broad resonances.</p> <p>Conclusion</p> <p>Our results are not necessarily inconsistent with the membrane phospholipid hypothesis, given that the patients studied suffered predominantly from positive symptoms of schizophrenia. The results suggest that there is increased cerebral mitochondrial oxidative phosphorylation in patients with schizophrenia who have dangerously and seriously violently offended, with an associated increase in oxygen flux and subsequent electron 'leakage' from the electron transport chain leading to the formation of superoxide radicals and other reactive oxygen species. In turn, these reactive species might cause increased lipid peroxidation in neuroglial membranes, thereby accounting for the observation of increased ethane excretion.</p

    Possible Beneficial Effect of Exercise, by Reducing Oxidative Stress, on the Incidence of Preeclampsia

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    We hypothesize that regular exercise enhances antioxidative enzymes in pregnant women, which reduce oxidative stress and, thus, the incidence of preeclampsia. Oxidative stress with enhanced lipid peroxide formation could lead to endothelial dysfunction in preeclampsia. Other conditions, such as increased transferrin saturation and decreased iron-binding capacity, directly and indirectly promote the process of oxidative stress and subsequent endothelial dysfunction. Exercise increases oxidative metabolism and produces a prooxidant environment. This acidic environment during exercise (at or beyond anaerobic threshold) promotes oxygen release from hemoglobin and increases in PO2 in tissues, as well as releases iron from transferrin. When exercise is repeated regularly, the body promptly adjusts so that oxidative stress is eliminated or reduced. The body's adaptations to a regular exercise habit seem to have an antioxidant effect. In humans, training effects have been identified with an enhanced activity of antioxidative enzymes. Another concerted adaptation that regular exercise brings to women's bodies is resistance against production of prooxidants by increasing the number of mitochondria. Equally important is a training effect that decreases susceptibility to lipid peroxidation. Evidence suggests that physically active women are less likely to develop preeclampsia. In theory, intracellular and extracellular conditions resulting from regular exercise should counteract the enhancement of oxidative stress, thus interfering with the process leading to endothelial dysfunction. This position paper describes a hypothesis and includes a brief review of exercise physiology and biochemical research in preeclampsia. Unlike other preventive treatments, such as aspirin or calcium supplements, a regular exercise habit leads to a positive and healthy lifestyle without concern of side effects.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63167/1/152460901317193558.pd

    The Spin Structure of the Nucleon

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    We present an overview of recent experimental and theoretical advances in our understanding of the spin structure of protons and neutrons.Comment: 84 pages, 29 figure
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