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The Effect of Retinoic Acid on Neutrophil Innate Immune Interactions With Cutaneous Bacterial Pathogens

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Infectious Microbes & Diseases 2024年第2期6卷 65-73页

作者： Alexandra Stream Ross Corriden simon Döhrmann richard L.Gallo Victor Nizet Ericka L.Anderson Division of Host-Microbe Systems and Therapeutics Department of PediatricsUniversity of California San Diego School of MedicineLa JollaCaliforniaUSA Department of Dermatology University of California San Diego School of MedicineLa JollaCaliforniaUSA Skaggs School of Pharmacy and Pharmaceutical Sciences University of California San DiegoLa JollaCaliforniaUSA

Vitamin A and its biologically active derivative,retinoic acid(RA),are important for many immune ***,in particular,is essential for the development of immune cells,including neutrophils,which serve as a front-line defense against *** vitamin A deficiency has been linked to higher susceptibility to infections,the precise role of vitamin A/RA in host-pathogen interactions remains poorly ***,we provided evidence that RA boosts neutrophil killing of methicillin-resistant Staphylococcus aureus(MRSA).RA treatment stimulated primary human neutrophils to produce reactive oxygen species,neutrophil extracellular traps and the antimicrobial peptide cathelicidin(LL-37).Because RA treatment was insufficient to reduce MRSA burden in an in vivo murine model of skin infection,we expanded our analysis to other infectious *** did not affect the growth of a number of common bacterial pathogens,including MRSA,Escherichia coli K1 and Pseudomonas aeruginosa;however,RA directly inhibited the growth of group A Streptococcus(GAS).This antimicrobial effect,likely in combination with RA-mediated neutrophil boosting,resulted in substantial GAS killing in neutrophil killing assays conducted in the presence of ***,in a murine model of GAS skin infection,topical RA treatment showed therapeutic potential by reducing both skin lesion size and bacterial *** findings suggest that RA may hold promise as a therapeutic agent against GAS and perhaps other clinically significant human pathogens.

关键词： retinoic acid neutrophil bacterial infection Staphylococcus aureus group A Streptococcus neutrophil extracellular traps antimicrobial peptide cathelicidin

Advancing Malaria Prediction in Uganda through AI and Geospatial Analysis Models

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Journal of Geographic Information System 2024年第2期16卷 115-135页

作者： Maria Assumpta Komugabe richard Caballero Itamar Shabtai simon Peter Musinguzi Center for Information Systems & Technology Claremont Graduate University Claremont California USA Department of Information Technology Faculty of Business and ICT University of Kisubi Entebbe Uganda Faculty of Health Sciences University of Kisubi Entebbe Uganda Department of Agriculture Production Faculty of Agriculture Kyambogo University Kyambogo Uganda Department of Agriculture and Natural Sciences Faculty of Agriculture Uganda Martyrs University Kampala Uganda

The resurgence of locally acquired malaria cases in the USA and the persistent global challenge of malaria transmission highlight the urgent need for research to prevent this disease. Despite significant eradication efforts, malaria remains a serious threat, particularly in regions like Africa. This study explores how integrating Gregor’s Type IV theory with Geographic Information Systems (GIS) improves our understanding of disease dynamics, especially Malaria transmission patterns in Uganda. By combining data-driven algorithms, artificial intelligence, and geospatial analysis, the research aims to determine the most reliable predictors of Malaria incident rates and assess the impact of different factors on transmission. Using diverse predictive modeling techniques including Linear Regression, K-Nearest Neighbor, Neural Network, and Random Forest, the study found that;Random Forest model outperformed the others, demonstrating superior predictive accuracy with an R2 of approximately 0.88 and a Mean Squared Error (MSE) of 0.0534, Antimalarial treatment was identified as the most influential factor, with mosquito net access associated with a significant reduction in incident rates, while higher temperatures correlated with increased rates. Our study concluded that the Random Forest model was effective in predicting malaria incident rates in Uganda and highlighted the significance of climate factors and preventive measures such as mosquito nets and antimalarial drugs. We recommended that districts with malaria hotspots lacking Indoor Residual Spraying (IRS) coverage prioritize its implementation to mitigate incident rates, while those with high malaria rates in 2020 require immediate attention. By advocating for the use of appropriate predictive models, our research emphasized the importance of evidence-based decision-making in malaria control strategies, aiming to reduce transmission rates and save lives.

关键词： Malaria Predictive Modeling Geospatial Analysis Climate Factors Preventive Measures

A review of the effects of forest fire on soil properties

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Journal of Forestry Research 2022年第5期33卷 1419-1441页

作者： Alex Amerh Agbeshie simon Abugre Thomas Atta-Darkwa richard Awuah Department of Environmental Management University of Energy and Natural Resources(UENR)SunyaniGhana Department of Forest Science University of Energy and Natural Resources(UENR)SunyaniGhana Department of Mechanical and Manufacturing Engineering University of Energy and Natural Resources(UENR)SunyaniGhana

Forest fires are key ecosystem modifiers affecting the biological,chemical,and physical attributes of forest *** extent of soil disturbance by fire is largely dependent on fire intensity,duration and recurrence,fuel load,and soil *** impact on soil properties is intricate,yielding different results based on these *** paper reviews research investigating the effects of wildfire and prescribed fire on the biological and physico-chemical attributes of forest soils and provides a summary of current knowledge associated with the benefits and disadvantages of such ***-intensity fires with ash deposition on soil surfaces cause changes in soil chemistry,including increase in available nutrients and *** intensity fires are noted for the complete combustion of organic matter and result in severe negative impacts on forest *** intensity fires result in nutrient volatilization,the break down in soil aggregate stability,an increase soil bulk density,an increase in the hydrophobicity of soil particles leading to decreased water infiltration with increased erosion and destroy soil *** soil heating(> 120℃) from high-intensity forest fires is detrimental to the soil ecosystem,especially its physical and biological *** this regard,the use of prescribed burning as a management tool to reduce the fuel load is highly recommended due to its low intensity and limited soil ***,the use of prescribed fires to manage fuel loads is critically needed in the light of current global warming as it will help prevent increased wildfire *** review provides information on the impact of forest fires on soil properties,a key feature in the maintenance of healthy *** addition,the review should prompt comprehensive soil and forest management regimes to limit soil disturbance and restore fire-disturbed soil ecosystems.

关键词： Forest fires Low-severity fire Mineralization Soil available nutrients Soil organic matter Volatilization

Influence of interparticle interactions on the kinetics of self-assembly and mechanical strength of nanoparticulate aggregates

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Particuology 2009年第2期7卷 106-113页

作者： Roberto Moreno-Atanasio simon J.Antony richard A.Williams Institute of Particle Science and Engineering University of LeedsLeedsLS2 9JTUnited Kingdom

Computer simulations based on Discrete Element Method have been performed in order to investigate the influence of interparticle interactions on the kinetics of self-assembly and the mechanical strength of nanoparticle aggregates. Three different systems have been considered. In the first system the interaction between particles has been simulated using the JKR （Johnson, Kendall and Roberts） contact theory, while in the second and third systems the interaction between particles has been simulated using van der Waals and electrostatic forces respectively. In order to compare the mechanical behaviour of the three systems, the magnitude of the maximum attractive force between particles has been kept the same in all cases. However, the relationship between force and separation distance differs from case to case and thus, the range of the interparticle force. The results clearly indicate that as the range of the interparticle force increases, the self-assembly process is faster and the work required to produce the mechanical failure of the assemblies increases by more than one order of magnitude.

关键词： Nanoparticles Discrete Element Method (DEM) Self-assembly JKR model van der Waals force

Numerical simulations of water flow and contaminants transport near mining wastes disposed in a fractured rock mass

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International Journal of Mining Science and Technology 2015年第1期25卷 37-45页

作者： Ben Abdelghani Farouk Aubertin Michel simon richard Therrien René Department of Civil Engineering Institut Supérieur de la Construction et de l’Urbanisme Research Institute on Mines and the Environment (RIME) Polytechnique Montreal Department of Geology and Geological Engineering University Laval

A numerical tool, called Hydro-Geosphere, was used to simulate unsaturated water flow and contaminants migration around an open pit filled with mining wastes. Numerical simulations had been carried out to assess the influence of various factors on water flow and solute transport in and around the surface openings including recharge, properties of the waste material and presence of fractures in the surrounding rock mass. The effect of the regional hydraulic gradient was also investigated. The analyses were conducted by simulating various 2D cases using experimentally obtained material properties and controlled boundary conditions. The effects of the hydrogeological properties of the filling material(i.e., water retention curve and hydraulic conductivity function), fracture network characteristics and conductivity of the joints were assessed. The results illustrate that fractures control water flow and contaminants transport around the waste disposal area. A fracture network can desaturate the system and improve the regional gradient effect.

关键词： Hydro-GeosphereNumerical modellingUnsaturated water flowContaminants transportTailingsWaste rocks

Evolving management of metaplasia and dysplasia in Barrett's epithelium

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World Journal of Gastroenterology 2016年第47期22卷 10316-10324页

作者： richard PT Evans Moustafa Mabrouk Mourad simon G Fisher simon R Bramhall Department of Surgery the Wye Valley NHS Trust

Oesophageal cancer affects more than 450000 people worldwide and despite continued medical advancements the incidence of oesophageal cancer is increasing. Oesophageal cancer has a 5 year survival of 15%-25% and now globally attempts are made to more aggressively diagnose and treat Barrett's oesophagus the known precursor to invasive disease. Currently diagnosis the of Barrett's oesophagus is predominantly made after endoscopic visualisation and histopathological confirmation. Minimally invasive techniques are being developed to improve the viability of screening programs. The management of Barrett's oesophagus can vary greatly dependent on the presence and severity of dysplasia. There is no consensus between the major international medical societies to determine and agreed surveillance and intervention pathway. In this review we analysed the current literature to demonstrate the evolving management of metaplasia and dysplasia in Barrett's epithelium.

关键词： Barrett’s Oesophagus Dysplasia Metaplasia Oesophageal cancer

Corrosion of magnesium and magnesium–calcium alloy in biologically-simulated environment

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Progress in Natural Science:Materials International 2014年第5期24卷 539-546页

作者： richard Harrison Diana Maradze simon Lyons Yufeng Zheng Yang Liu Wolfson Centre for Stem Cells Tissue Engineering and Modelling (STEM) Centre for Biomolecular Sciences University of Nottingham College of Engineering Peking University Wolfson School of Mechanical and Manufacturing Engineering Loughborough University Loughborough

A study of biocompatibility and corrosion of both metallic magnesium(Mg) and a magnesium alloy containing 1% calcium(Mg–Ca) were investigated in in vitro culture conditions with and without the presence of bone marrow derived human mesenchymal stem cells(h MSCs).Chemical analysis of the degraded samples was performed using XRD and FEGSEM. The results from the XRD analysis strongly suggested that crystalline phase of magnesium carbonate was present on the surface of both the Mg and Mg–Ca samples. Flame absorption spectrometry was used to analyse the release of magnesium and calcium ions into the cell culture medium. Magnesium concentration was kept consistently at a level ranging from 40 to 80 m M for both Mg and Mg–Ca samples. No cell growth was observed when in direct contact with the metals apart from a few cells observed at the bottom of culture plate containing Mg–Ca alloy. In general, in vitro study of corrosion of Mg–Ca in a biologicallysimulated environment using cell culture medium with the presence of h MSCs demonstrated close resemblances to in vivo corrosion. Although in vitro corrosion of Mg–Ca revealed slow corrosion rate and no immediate cytotoxicity effects to h MSCs, its corrosion rate was still too high to achieve normal stem cell growth when cells and alloys were cultured in vitro in direct contact.

关键词： Magnesium Biometal Corrosion Biocompatibility Stem cells In vitro

Pancreatitis: Preventing catastrophic haemorrhage

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World Journal of Gastroenterology 2017年第30期23卷 5460-5468页

作者： richard PT Evans Moustafa Mabrouk Mourad Gunraj Pall simon G Fisher simon R Bramhall Russel’s Hall Hospital Department of Surgery the Wye Valley NHS Trust

Pancreatitis represents nearly 3% of acute admissions to general surgery in United Kingdom hospitals and has a mortality of around 1%-7% which increases to around 10%-18% in patients with severe pancreatitis. Patients at greatest risk were those identified to have infected pancreatic necrosis and/or organ failure. This review seeks to highlight the potential vascular complications associated with pancreatitis that despite being relatively uncommon are associated with mortality in the region of 34%-52%. We examine the current evidence base to determine the most appropriate method by which to image and treat pseudo-aneurysms that arise as the result of acute and chronic inflammation of pancreas. We identify how early recognition of the presence of a pseudo-aneurysm can facilitate expedited care in an expert centre of a complex pathology that may require angiographic, percutaneous, endoscopic or surgical intervention to prevent catastrophic haemorrhage.

关键词： Complication of pancreatitis Splenicartery Pancreatitis Haemorrhage Pseudoaneurysm

Can palliative radiotherapy influence prostate-specific antigen response in patients with castrate-resistant prostate cancer treated with systemic therapy(chemotherapy or abiraterone)?——a report of three cases

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Cancer Biology & Medicine 2015年第1期12卷 60-63页

作者： Mohan Hingorani Sanjay Dixit Pattu Pugazhenthi simon Hawkyard Andrew Robertson richard Khafagy Department of Clinical Oncology Castle Hill HospitalHull and East YorkshireNHS TrustCottinghamEast Riding of YorkshireHU16 5JQUK Department of Urology Scarborough District General Hospital

Palliative radiotherapy(pRT) is primarily employed for palliation of bone pain in patients with castrate-resistant prostate cancer(CRPC). However, evidence that p RT influences prostate-specific antigen response in patients with CRPC on systemic therapy is lacking. We describe three cases of CRPC progressing after treatment with docetaxel(n=2) and abiraterone(n=1), who responded unusually after p RT for bone pain with the development of a significant biochemical response and restoration of response to systemic therapy. The possibility of p RT influencing metastatic disease in CRPC has not been previously reported, and raises the possibility of radiation-induced modulation of anti-tumor immune response mechanisms that may play a role in the restoration of response to systemic treatment.

关键词： Prostate cancer palliative radiotherapy chemotherapy