oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 1 )

2019 ( 55 )

2018 ( 41 )

2017 ( 53 )

Custom range...

Search Results: 1 - 10 of 10228 matches for " Charles Ansong "
All listed articles are free for downloading (OA Articles)
Page 1 /10228
Display every page Item
Nutraceutical with Anti-Inflammatory Activity for the Management of Airway Remodeling in Bronchial Asthma: Kalanchoe integra Var. Crenata (Andr.) Cuf Leaf Extract  [PDF]
Asiedu-Gyekye Isaac Julius, Awortwe Charles, Nyamekye Effah Samuel, Antwi Daniel Ansong, Seidu Mahmood, Adjei Samuel, Banga N’guessan Benoit Kwame, Amoateng Patrick, Nkansah Edwin
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.53032
Abstract:

Background: Kalanchoe integra is widely used in folklore medicine as an antiasthmatic agent. Previous studies have shown the ameliorating effect of Kalanchoe integra leaf extract [KILE] on bronchial hyperesponsiveness and inflammation. Further, the stabilizing effect of Kalanchoe sp on mast cell degranulation, suggests that Kalanchoe species are suitable candidates for allergic asthma therapy. This study is designed to investigate the anti-asthmatic potential of KILE and monitor the accompanying histopathological and immunobiochemical changes that occur in an animal model of bronchial asthma using ovalbumin sensitized guinea pigs. Method: Thirty male guinea pigs were divided into five groups of six animals each. Bronchial asthma was simulated in guinea pigs using ovalbumin. Both low dose (300 mg/kg) and high dose extract (900 mg/kg) were administered daily for 42 days. Prednisolone (2.5 mg/kg) was the standard drug used. Results: Guinea pigs in all KILE treated groups maintained the integrity of their airway structures: bronchial folds and walls, alveoli, alveolar ducts and sacs. KILE and prednisolone caused a reduction in immune parameters (p < 0.001), extent of bronchoconstriction, bronchial wall thickness and goblet cell accumulation in the sensitized guinea pigs. Conclusion: This study demonstrates the anti-asthmatic potential of KILE during prolonged administration by the oral route.

Systems analysis of multiple regulator perturbations allows discovery of virulence factors in Salmonella
Hyunjin Yoon, Charles Ansong, Jason E McDermott, Marina Gritsenko, Richard D Smith, Fred Heffron, Joshua N Adkins
BMC Systems Biology , 2011, DOI: 10.1186/1752-0509-5-100
Abstract: In this study we present a systems biology approach in which sample-matched multi-omic measurements of fourteen virulence-essential regulator mutants were coupled with computational network analysis to efficiently identify Salmonella virulence factors. Immunoblot experiments verified network-predicted virulence factors and a subset was determined to be secreted into the host cytoplasm, suggesting that they are virulence factors directly interacting with host cellular components. Two of these, SrfN and PagK2, were required for full mouse virulence and were shown to be translocated independent of either of the type III secretion systems in Salmonella or the type III injectisome-related flagellar mechanism.Integrating multi-omic datasets from Salmonella mutants lacking virulence regulators not only identified novel virulence factors but also defined a new class of translocated effectors involved in pathogenesis. The success of this strategy at discovery of known and novel virulence factors suggests that the approach may have applicability for other bacterial pathogens.The interactions between intracellular pathogen and host can be complex involving sophisticated offensive and defensive strategies by both organisms. Developing a systems level understanding of the virulence program of a pathogen, both in terms of the regulatory pathways and the virulence-related proteins that execute this program is important to effectively combat persistent and adapting pathogens [1-3]. Combining high-throughput characterization of proteins and gene transcripts under multiple different conditions relevant to virulence provides a wealth of information that can be mined to provide useful leads for further investigation or used as the basis of predictive models.Salmonella enterica serovar Typhimurium (STM) is a facultative intracellular bacterial pathogen with a broad host range capable of infecting birds, reptiles, mice, humans and other mammals. In humans, it is a leading causative agent
Overweight and hypertension among college of health sciences employees in Ghana
R Aryeetey, J Ansong
African Journal of Food, Agriculture, Nutrition and Development , 2011,
Abstract: Healthcare workers, by virtue of their greater access to information, are expected to have less risk of obesity, hypertension, and other health outcomes often linked to lifestyles. However, there is limited evidence on practices and status of personnel who work in the healthcare setting about hypertension and overweight in Ghana. The current study tests the hypothesis that overweight and hypertension rates, as well as related risk factors among staff and faculty of the College of Health Sciences (CHS), University of Ghana, will be more positive than among the lay public. In June and July 2009, a cross-sectional self-completed survey was administered to 141 male and female faculty and staff of the College of Health Sciences, University of Ghana, in Accra. A representative sample was selected by proportionate random sampling from all seven academic and research units of the CHS. Anthropometry and blood pressure measurements were taken with questionnaire data on lifestyle, dietary history, and socio-demographic variables. Overweight and obesity were diagnosed as BMI >25 and >30 kg/m2, respectively. Abdominal adiposity was estimated as waist hip ratio >0.80 (females) or >0.95 (males). Hypertension was diagnosed as diastolic or systolic blood pressure > 140 or 90 mm Hg, respectively. Mean age of respondents was 40.5 + 10.8 years; 43% were over-weight, including 13% obese. More than one-third of overweight respondents did not report an overweight body image. Abdominal adiposity and hypertension rates were 25% and 34%, respectively. Low rates of regular physical activity (25%) and consumption of fruits and vegetables (40%) were observed. Overweight (OR=3.83; p<0.01) and central adiposity (OR=4.8; p<0.01) were associated with significantly increased risk of hypertension. Being married was a significant predictor of overweight (p<0.05), abdominal adiposity (p<0.05), and hypertension (p<0.05). The study concludes that working in a healthcare environment or being a health worker does not diminish your risk of overweight and hypertension. It is, therefore, recommended that interventions addressing overweight and hypertension should place attention more on environmental modifications rather than awareness creation.
Kinetic studies on the pyrolysis of asphaltenes from different types of kerogens
Ansong Geng,Zewen Liao
Chinese Science Bulletin , 2000, DOI: 10.1007/BF02893785
Abstract: The pyrolysis kinetics of a series of asphaltenes, from different types of kerogens, are studied in this work. The results indicate that the distributions of activation energy are over a wide range for the asphaltenes from type I kerogens. There is still a large potential of hydrocarbon generation in case the activation energy is above 350 kJ ·mol 1. While the distributions of activation energy are comparatively over a narrow range for the asphaltenes from type II and in kerogens, there is a little or almost no potential of hydrocarbon generation with the activation energy above 350 kJ · mol 1 respectively. For the asphaltenes from some specific type of kerogens, the pyrolysis kinetics can be applied to marking their maturity. Furthermore, based on detailed discussions of the kinetics parameter frequency factor, the asphaltenes from type I kerogens are considered to be of great potential to regenerate oils, while the asphaltenes’ potential for oil-to-gas conversion tends to go down in order of primitive kerogen types of III, II and I.
Asphaltenes in oil reservior recovery
Zewen Liao,Ansong Geng
Chinese Science Bulletin , 2000, DOI: 10.1007/BF02886171
Abstract: Asphaltene is one of the important compositions in oil reservoirs, while it is also a major factor that causes difficulties in oil recovery and oil post-processings. Up to date, study on asphaltenes in oil recovery is still a bottleneck problem. In this paper, the advances of studies on asphaltenes are reviewed, and some directions for further studying are suggested. What is reviewed in the paper includes the precipitation studies of asphaltenes, the degradation studies of asphaltenes and the applications of asphaltene’s studying in oil recovery; furthermore, it is regarded as a promising direction to study the possible applications of asphaltene’s selectively decomposing by chemical reagents in oil recovery.
Determination of carbon isotopic composition of individual light hydrocarbons evolved from pyrolysis of source rocks by using GC-IRMS
Ansong Geng,Yongqiang Xiong
Chinese Science Bulletin , 2000, DOI: 10.1007/BF02893777
Abstract: The carbon isotopic composition of individual light hydrocarbons generated from source rocks that had been pyrolysed in vacuum glass tube were determined by using the GC-IRMS techniques. The results indicate that abundant CO2 in the pyrolysates has a remarkable effect on the determination of CH4δ13C. Running cryogenically with an initial temperature of 40°C can effectively eliminate the effect. In addition, it conduces to measuring the δ13C of C2+ hydrocarbons by increasing the injection volume and/or absorbing CO2 with the solution of sodium hydroxide. The above measures will help to get the carbon isotopic composition of C1–C7 components, which is of great significance for gas/source rock correlation and for study on the genesis of natural gas.
Are Weeds Hitchhiking a Ride on Your Car? A Systematic Review of Seed Dispersal on Cars
Michael Ansong, Catherine Pickering
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080275
Abstract: When traveling in cars, we can unintentionally carry and disperse weed seed; but which species, and where are they a problem? To answer these questions, we systematically searched the scientific literature to identify all original research studies that assess seed transported by cars and listed the species with seed on/in cars. From the 13 studies that fit these criteria, we found 626 species from 75 families that have seed that can be dispersed by cars. Of these, 599 are listed as weeds in some part of the world, with 439 listed as invasive or naturalized alien species in one or more European countries, 248 are invasive/noxious weeds in North America, 370 are naturalized alien species in Australia, 167 are alien species in India, 77 are invasive species in China and 23 are declared weeds/invaders in South Africa. One hundred and one are classified as internationally important environmental weeds. Although most (487) were only recorded once, some species such as Chenopodium album, Poa pratensis and Trifolium repens were common among studies. Perennial graminoids seem to be favoured over annual graminoids while annual forbs are favoured over perennial forbs. Species characteristics including seed size and morphology and where the plants grew affected the probability that their seed was transported by cars. Seeds can be found in many different places on cars including under the chassis, front and rear bumpers, wheel wells and rims, front and back mudguards, wheel arches, tyres and on interior floor mats. With increasing numbers of cars and expanding road networks in many regions, these results highlight the importance of cars as a dispersal mechanism, and how it may favour invasions by some species over others. Strategies to reduce the risk of seed dispersal by cars include reducing seed on cars by mowing road verges and cleaning cars.
Global Systems-Level Analysis of Hfq and SmpB Deletion Mutants in Salmonella: Implications for Virulence and Global Protein Translation
Charles Ansong, Hyunjin Yoon, Steffen Porwollik, Heather Mottaz-Brewer, Brianne O. Petritis, Navdeep Jaitly, Joshua N. Adkins, Michael McClelland, Fred Heffron, Richard D. Smith
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0004809
Abstract: Using sample-matched transcriptomics and proteomics measurements it is now possible to begin to understand the impact of post-transcriptional regulatory programs in Enterobacteria. In bacteria post-transcriptional regulation is mediated by relatively few identified RNA-binding protein factors including CsrA, Hfq and SmpB. A mutation in any one of these three genes, csrA, hfq, and smpB, in Salmonella is attenuated for mouse virulence and unable to survive in macrophages. CsrA has a clearly defined specificity based on binding to a specific mRNA sequence to inhibit translation. However, the proteins regulated by Hfq and SmpB are not as clearly defined. Previous work identified proteins regulated by hfq using purification of the RNA-protein complex with direct sequencing of the bound RNAs and found binding to a surprisingly large number of transcripts. In this report we have used global proteomics to directly identify proteins regulated by Hfq or SmpB by comparing protein abundance in the parent and isogenic hfq or smpB mutant. From these same samples we also prepared RNA for microarray analysis to determine if alteration of protein expression was mediated post-transcriptionally. Samples were analyzed from bacteria grown under four different conditions; two laboratory conditions and two that are thought to mimic the intracellular environment. We show that mutants of hfq and smpB directly or indirectly modulate at least 20% and 4% of all possible Salmonella proteins, respectively, with limited correlation between transcription and protein expression. These proteins represent a broad spectrum of Salmonella proteins required for many biological processes including host cell invasion, motility, central metabolism, LPS biosynthesis, two-component regulatory systems, and fatty acid metabolism. Our results represent one of the first global analyses of post-transcriptional regulons in any organism and suggest that regulation at the translational level is widespread and plays an important role in virulence regulation and environmental adaptation for Salmonella.
An experimentally-supported genome-scale metabolic network reconstruction for Yersinia pestis CO92
Pep Charusanti, Sadhana Chauhan, Kathleen McAteer, Joshua A Lerman, Daniel R Hyduke, Vladimir L Motin, Charles Ansong, Joshua N Adkins, Bernhard O Palsson
BMC Systems Biology , 2011, DOI: 10.1186/1752-0509-5-163
Abstract: Here we report a genome-scale reconstruction and mathematical model of metabolism for Y. pestis CO92 and supporting experimental growth and metabolite measurements. The model contains 815 genes, 678 proteins, 963 unique metabolites and 1678 reactions, accurately simulates growth on a range of carbon sources both qualitatively and quantitatively, and identifies gaps in several key biosynthetic pathways and suggests how those gaps might be filled. Furthermore, our model presents hypotheses to explain certain known nutritional requirements characteristic of this strain.Y. pestis continues to be a dangerous threat to human health during modern times. The Y. pestis genome-scale metabolic reconstruction presented here, which has been benchmarked against experimental data and correctly reproduces known phenotypes, provides an in silico platform with which to investigate the metabolism of this important human pathogen.Yersinia pestis is a gram-negative bacterium within the family Enterobacteriaceae that, along with Yersinia pseudotuberculosis and Yersinia enterocolitica, is one of three members of its genus that can cause disease in humans. Y. pestis diverged from Y. pseudotuberculosis only 1,500 - 20,000 years ago, but Y. pestis and Y. pseudotuberculosis diverged from Y. enterocolitica in the more distant past [1]. Despite their close evolutionary relationship, the diseases they cause differ markedly. Whereas Y. pseudotuberculosis and Y. enterocolitica are primarily gastrointestinal pathogens in humans, Y. pestis infections lead to a systemic disease known as plague that can become fatal rapidly. In the last 2000 years, there have been three distinct outbreaks of plague that have led to a large number of fatalities: the Justinian plague between the 5th and 7th centuries, the Black Death in Europe between the 13th and 15th centuries, and the modern plague from the latter half of the 1800s to the present. These outbreaks of fatal infections that continue to occur [2,3], the
HAM-5 Functions As a MAP Kinase Scaffold during Cell Fusion in Neurospora crassa
Wilfried Jonkers,Abigail C. Leeder,Charles Ansong,Yuexi Wang,Feng Yang,Trevor L. Starr,David G. Camp II,Richard D. Smith,N. Louise Glass
PLOS Genetics , 2014, DOI: doi/10.1371/journal.pgen.1004783
Abstract: Cell fusion in genetically identical Neurospora crassa germlings and in hyphae is a highly regulated process involving the activation of a conserved MAP kinase cascade that includes NRC-1, MEK-2 and MAK-2. During chemotrophic growth in germlings, the MAP kinase cascade members localize to conidial anastomosis tube (CAT) tips every ~8 minutes, perfectly out of phase with another protein that is recruited to the tip: SOFT, a recently identified scaffold for the MAK-1 MAP kinase pathway in Sordaria macrospora. How the MAK-2 oscillation process is initiated, maintained and what proteins regulate the MAP kinase cascade is currently unclear. A global phosphoproteomics approach using an allele of mak-2 (mak-2Q100G) that can be specifically inhibited by the ATP analog 1NM-PP1 was utilized to identify MAK-2 kinase targets in germlings that were potentially involved in this process. One such putative target was HAM-5, a protein of unknown biochemical function. Previously, Δham-5 mutants were shown to be deficient for hyphal fusion. Here we show that HAM-5-GFP co-localized with NRC-1, MEK-2 and MAK-2 and oscillated with identical dynamics from the cytoplasm to CAT tips during chemotropic interactions. In the Δmak-2 strain, HAM-5-GFP localized to punctate complexes that did not oscillate, but still localized to the germling tip, suggesting that MAK-2 activity influences HAM-5 function/localization. However, MAK-2-GFP showed cytoplasmic and nuclear localization in a Δham-5 strain and did not localize to puncta. Via co-immunoprecipitation experiments, HAM-5 was shown to physically interact with NRC-1, MEK-2 and MAK-2, suggesting that it functions as a scaffold/transport hub for the MAP kinase cascade members for oscillation and chemotropic interactions during germling and hyphal fusion in N. crassa. The identification of HAM-5 as a scaffold-like protein will help to link the activation of MAK-2 cascade to upstream factors and proteins involved in this intriguing process of fungal communication.
Page 1 /10228
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.