1,688 research outputs found

    The role of regulated clinical trials in the development of bacteriophage therapeutics.

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    Antibiotic resistance is now recognized as a major, global threat to human health and the need for the development of novel antibacterial therapies has become urgent. Lytic bacteriophages (phages) targeting individual bacterial pathogens have therapeutic potential as an alternative or adjunct to antibiotic use. Bacteriophage therapy has been used for decades, but clinical trials in this field are rare, leaving many questions unanswered as to its effectiveness for many infectious diseases. As a consequence bacteriophage therapy is not used or accepted in most parts of the world. The increasing need for new antimicrobial therapies is driving the development of bacteriophage therapies for a number of diseases but these require the successful completion of large-scale clinical trials in accordance with US FDA or European EMA guidelines. Bacteriophages are considered as biological agents by regulatory authorities and they are managed by biological medicinal products guidelines for European trials and guidelines of the division of vaccines and related product applications in the USA. Bacteriophage therapy is typically an 'active' treatment requiring multiplication in the bacterial host and therefore the factors that govern its success are different from those of conventional antibiotics. From the pharmacokinetic and pharmacodynamic points of view, time of treatment, dosage depending on the site of infection and the composition of the bacteriophage formulation (single vs multiple strains) need careful consideration when designing clinical trials. Scientific evidence regarding inflammatory effects, potential for gene transfer and phage resistance, need to be evaluated through such trials. However purity, stability and sterility of preparations for human use can be addressed through Good Manufacturing Practises to reduce many potential safety concerns. In this review we discuss the potential for the development of bacteriophage therapy in the context of critical aspects of modern, regulated clinical trials

    Average distances on self-similar sets and higher order average distances of self-similar measures

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    The purpose of this paper is twofold: (1) we study different notions of the average distance between two points of a self-similar subset of ℝ, and (2) we investigate the asymptotic behaviour of higher order average moments of self-similar measures on self-similar subsets of ℝ

    NADPH oxidase and reactive oxygen species contribute to alcohol-induced microglial activation and neurodegeneration

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    <p>Abstract</p> <p>Background</p> <p>Activation of microglia causes the production of proinflammatory factors and upregulation of NADPH oxidase (NOX) that form reactive oxygen species (ROS) that lead to neurodegeneration. Previously, we reported that 10 daily doses of ethanol treatment induced innate immune genes in brain. In the present study, we investigate the effects of chronic ethanol on activation of NOX and release of ROS, and their contribution to ethanol neurotoxicity.</p> <p>Methods</p> <p>Male C57BL/6 and NF-κB enhanced GFP mice were treated intragastrically with water or ethanol (5 g/kg, i.g., 25% ethanol w/v) daily for 10 days. The effects of chronic ethanol on cell death markers (activated caspase-3 and Fluoro-Jade B), microglial morphology, NOX, ROS and NF-κB were examined using real-time PCR, immunohistochemistry and hydroethidine histochemistry. Also, Fluoro-Jade B staining and NOX gp91<sup>phox </sup>immunohistochemistry were performed in the orbitofrontal cortex (OFC) of human postmortem alcoholic brain and human moderate drinking control brain.</p> <p>Results</p> <p>Ethanol treatment of C57BL/6 mice showed increased markers of neuronal death: activated caspase-3 and Fluoro-Jade B positive staining with Neu-N (a neuronal marker) labeling in cortex and dentate gyrus. The OFC of human post-mortem alcoholic brain also showed significantly more Fluoro-Jade B positive cells colocalized with Neu-N, a neuronal marker, compared to the OFC of human moderate drinking control brain, suggesting increased neuronal death in the OFC of human alcoholic brain. Iba1 and GFAP immunohistochemistry showed activated morphology of microglia and astrocytes in ethanol-treated mouse brain. Ethanol treatment increased NF-κB transcription and increased NOX gp91<sup>phox </sup>at 24 hr after the last ethanol treatment that remained elevated at 1 week. The OFC of human postmortem alcoholic brain also had significant increases in the number of gp91<sup>phox </sup>+ immunoreactive (IR) cells that are colocalized with neuronal, microglial and astrocyte markers. In mouse brain ethanol increased gp91<sup>phox </sup>expression coincided with increased production of O<sub>2</sub><sup>- </sup>and O<sub>2</sub><sup>- </sup>- derived oxidants. Diphenyleneiodonium (DPI), a NOX inhibitor, reduced markers of neurodegeneration, ROS and microglial activation.</p> <p>Conclusions</p> <p>Ethanol activation of microglia and astrocytes, induction of NOX and production of ROS contribute to chronic ethanol-induced neurotoxicity. NOX-ROS and NF-κB signaling pathways play important roles in chronic ethanol-induced neuroinflammation and neurodegeneration.</p

    The role of clathrin in post-golgi trafficking in toxoplasma gondii

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    Apicomplexan parasites are single eukaryotic cells with a highly polarised secretory system that contains unique secretory organelles (micronemes and rhoptries) that are required for host cell invasion. In contrast, the role of the endosomal system is poorly understood in these parasites. With many typical endocytic factors missing, we speculated that endocytosis depends exclusively on a clathrin-mediated mechanism. Intriguingly, in Toxoplasma gondii we were only able to observe the endogenous clathrin heavy chain 1 (CHC1) at the Golgi, but not at the parasite surface. For the functional characterisation of Toxoplasma gondii CHC1 we generated parasite mutants conditionally expressing the dominant negative clathrin Hub fragment and demonstrate that CHC1 is essential for vesicle formation at the trans-Golgi network. Consequently, the functional ablation of CHC1 results in Golgi aberrations, a block in the biogenesis of the unique secretory microneme and rhoptry organelles, and of the pellicle. However, we found no morphological evidence for clathrin mediating endocytosis in these parasites and speculate that they remodelled their vesicular trafficking system to adapt to an intracellular lifestyle

    Metabolic myopathy presenting with polyarteritis nodosa: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>To the best of our knowledge, we describe for the first time a patient in whom an unusual metabolic myopathy was identified after failure to respond to curative therapy for a systemic vasculitis, polyarteritis nodosa. We hope this report will heighten awareness of common metabolic myopathies that may present later in life. It also speculates on the potential relationship between metabolic myopathy and systemic vasculitis.</p> <p>Case presentation</p> <p>A 78-year-old African-American woman with a two-year history of progressive fatigue and exercise intolerance presented to our facility with new skin lesions and profound muscle weakness. Skin and muscle biopsies demonstrated a medium-sized artery vasculitis consistent with polyarteritis nodosa. Biochemical studies of the muscle revealed diminished cytochrome C oxidase activity (0.78 μmol/minute/g tissue; normal range 1.03 to 3.83 μmol/minute/g tissue), elevated acid maltase activity (23.39 μmol/minute/g tissue; normal range 1.74 to 9.98 μmol/minute/g tissue) and elevated neutral maltase activity (35.89 μmol/minute/g tissue; normal range 4.35 to 16.03 μmol/minute/g tissue). Treatment for polyarteritis nodosa with prednisone and cyclophosphamide resulted in minimal symptomatic improvement. Additional management with a diet low in complex carbohydrates and ubiquinone, creatine, carnitine, folic acid, α-lipoic acid and ribose resulted in dramatic clinical improvement.</p> <p>Conclusions</p> <p>Our patient's initial symptoms of fatigue, exercise intolerance and progressive weakness were likely related to her complex metabolic myopathy involving both the mitochondrial respiratory chain and glycogen storage pathways. Management of our patient required treatment of both the polyarteritis nodosa as well as metabolic myopathy. Metabolic myopathies are common and should be considered in any patient with exercise intolerance. Metabolic myopathies may complicate the management of various disease states.</p

    The dose–response relationship between training-load measures and aerobic fitness in elite academy soccer players

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    The aim of the current study is to examine the dose-response relationships between training load (TL) measures and the consequent changes in aerobic fitness. Data were collected over the 6-week pre-season period in elite youth soccer players. Participants completed a lactate threshold test to identify changes in treadmill speed at 2 mmol · l (S2) and 4 mmol · l (S4). Internal TL was quantified with the following training impulse (TRIMP) methods: Banister TRIMP, Edwards TRIMP, Lucia TRIMP, individual TRIMP (iTRIMP) and rate of perceived exertion was also collected. External TL measures were total distance, PlayerLoad, high speed running (14.4-19.8 km · h ), very high-speed running (19.8-25.2 km · h ) and maximal sprint distance (>25.2 km · h ). Individual high-speed distance was derived from each participants treadmill speed at S4. Different Bayesian regression models were run with different likelihood functions. The best-fitting models with both the lowest out-of-sample prediction error and the highest variance explained ( ) were used. iTRIMP had the strongest relationships with changes in S2 (r = 0.93, = 0.90) and S4 (r = 0.88, = 0.82). Explained variance ranged from 10%-69% and 11%-38% for all other internal TL measures and external measures, respectively. In summary, the iTRIMP method demonstrates a dose-response relationship with changes in aerobic fitness in elite youth soccer players

    The Effects of Seed Size on Hybrids Formed between Oilseed Rape (Brassica napus) and Wild Brown Mustard (B. juncea)

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    Background : Seed size has significant implications in ecology, because of its effects on plant fitness. The hybrid seeds that result from crosses between crops and their wild relatives are often small, and the consequences of this have been poorly investigated. Here we report on plant performance of hybrid and its parental transgenic oilseed rape (Brassica napus) and wild B. juncea, all grown from seeds sorted into three seed-size categories.[br/] Methodology/Principal Findings : Three seed-size categories were sorted by seed diameter for transgenic B. napus, wild B. juncea and their transgenic and non-transgenic hybrids. The seeds were sown in a field at various plant densities. Globally, small-seeded plants had delayed flowering, lower biomass, fewer flowers and seeds, and a lower thousand-seed weight. The seed-size effect varied among plant types but was not affected by plant density. There was no negative effect of seed size in hybrids, but it was correlated with reduced growth for both parents.[br/] Conclusions : Our results imply that the risk of further gene flow would probably not be mitigated by the small size of transgenic hybrid seeds. No fitness cost was detected to be associated with the Bt-transgene in this study

    Reduced levels of intracellular calcium releasing in spermatozoa from asthenozoospermic patients

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    <p>Abstract</p> <p>Background</p> <p>Asthenozoospermia is one of the most common findings present in infertile males characterized by reduced or absent sperm motility, but its aetiology remains unknown in most cases. In addition, calcium is one of the most important ions regulating sperm motility. In this study we have investigated the progesterone-evoked intracellular calcium signal in ejaculated spermatozoa from men with normospermia or asthenozoospermia.</p> <p>Methods</p> <p>Human ejaculates were obtained from healthy volunteers and asthenospermic men by masturbation after 4–5 days of abstinence. For determination of cytosolic free calcium concentration, spermatozoa were loaded with the fluorescent ratiometric calcium indicator Fura-2.</p> <p>Results</p> <p>Treatment of spermatozoa from normospermic men with 20 micromolar progesterone plus 1 micromolar thapsigargin in a calcium free medium induced a typical transient increase in cytosolic free calcium concentration due to calcium release from internal stores. Similar results were obtained when spermatozoa were stimulated with progesterone alone. Subsequent addition of calcium to the external medium evoked a sustained elevation in cytosolic free calcium concentration indicative of capacitative calcium entry. However, when progesterone plus thapsigargin were administered to spermatozoa from patients with asthenozoospermia, calcium signal and subsequent calcium entry was much smaller compared to normospermic patients. As expected, pretreatment of normospermic spermatozoa with both the anti-progesterone receptor c262 antibody and with progesterone receptor antagonist RU-38486 decreased the calcium release induced by progesterone. Treatment of spermatozoa with cytochalasin D or jasplakinolide decreased the calcium entry evoked by depletion of internal calcium stores in normospermic patients, whereas these treatments proved to be ineffective at modifying the calcium entry in patients with asthenozoospermia.</p> <p>Conclusion</p> <p>Our results suggest that spermatozoa from asthenozoospermic patients present a reduced responsiveness to progesterone.</p

    Monitoring trends in socioeconomic health inequalities: it matters how you measure

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    <p>Abstract</p> <p>Background</p> <p>Odds ratio (OR), a relative measure for health inequality, has frequently been used in prior studies for presenting inequality trends in health and health behaviors. Since OR is not a good approximation of prevalence ratio (PR) when the outcome prevalence is quite high, an important problem may arise when OR trends are used in data in which the outcome variable (e.g., smoking or ill-health) is of relatively high prevalence and varies significantly over time. This study is to compare time trends of odds ratio (OR) and prevalence ratio (PR) for examining time trends in socioeconomic inequality in smoking.</p> <p>Methods</p> <p>A total of 147,805 subjects (71,793 men and 76,017 women) aged 25–64 from three Social Statistics Surveys of Korea from 1999 to 2006 were analyzed. Socioeconomic position indicators were occupational class and education.</p> <p>Results</p> <p>While there were no significant p values for trend in ORs of occupational class among men, trends for PRs were significant. In women, p values for OR trends were similar to those for PR trends. In males, RII by log-binomial regression showed a significant increasing tendency while RII by logistic regression was stable between years. In females, trends of RIIs by logistic regression and log-binomial regression produced a similar level of p values.</p> <p>Conclusion</p> <p>Different methods of measuring trends in socioeconomic health inequalities may lead to different conclusions about whether relative inequalities are increasing or decreasing. Trends in ORs may overstate or understate trends in relative inequality in health when the outcome is of relatively high prevalence and that prevalence varies significantly with time.</p
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