Search results for: cell spreading

Authors: Sahana Selladurai, Christine DeWolf

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Lung surfactant comprises a lipid-protein film that coats the alveolar surface and serves to prevent alveolar collapse upon repeated breathing cycles. Exposure of lung surfactant to high concentrations of airborne pollutants, for example tropospheric ozone in smog, can chemically modify the lipid and protein components. These chemical changes can impact the film functionality by decreasing the film’s collapse pressure (minimum surface tension attainable), altering it is mechanical and flow properties and modifying lipid reservoir formation essential for re-spreading of the film during the inhalation process. In this study, we use Langmuir monolayers spread at the air-water interface as model membranes where the compression and expansion of the film mimics the breathing cycle. The impact of ozone exposure on model lung surfactant films is measured using a Langmuir film balance, Brewster angle microscopy and a pendant drop tensiometer as a function of film and sub-phase composition. The oxidized films are analyzed using mass spectrometry where lipid and protein oxidation products are observed. Oxidation is shown to reduce surface activity, alter line tension (and film morphology) and in some cases visibly reduce the viscoelastic properties of the film when compared to controls. These reductions in functionality of the films are highly dependent on film and sub-phase composition, where for example, the effect of oxidation is more pronounced when using a physiologically relevant buffer as opposed to water as the sub-phase. These findings can lead to a better understanding on the impact of continuous exposure to high levels of ozone on the mechanical process of breathing, as well as understanding the roles of certain lung surfactant components in this process.

Keywords: lung surfactant, oxidation, ozone, viscoelasticity

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Authors: Salma A. El-Marasy, Rehab F. Abdel-Rahman, Reham M. Abd-Elsalam

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The burden of stroke is intensely increasing worldwide. Brain injury following transient or permanent focal cerebral ischemia develops ischemic stroke as a consequence of a complex series of pathophysiological events. The aim of this study is to evaluate the possible neuroprotective effect of a dipeptidyl peptidase-4 inhibitor, vildagliptin, independent on its insulinotropic properties in non-diabetic rats subjected to cerebral ischemia. Anaesthetized Wistar rats were subjected to either left middle cerebral artery occlusion (MCAO) or sham operation followed by reperfusion after 30 min of MCAO. The other three groups were orally administered vildagliptin at 3 dose levels (2.5, 5, 10 mg/kg) for 3 successive weeks before subjected to left focal cerebral ischemia/reperfusion and till the end of the study. Neurological deficit scores and motor activity were assessed 24h following reperfusion. 48h following reperfusion, rats were euthanized and their left brain hemispheres were harvested and used in the biochemical, histopathological, and immunohistochemical investigations. Vildagliptin pretreatment improved neurological score deficit, locomotor activity and motor coordination in MCAO rats. Moreover, vildagliptin reduced malondialdehyde (MDA), elevated reduced glutathione (GSH), phosphotylinosital 3 kinase (PI3K), phosphorylated of protein kinase B (p-AKT), and mechanistic target of rapamycin (mTOR) brain contents in addition to reducing protein expression of caspase-3. Also, vildagliptin showed a dose-dependent attenuation in neuronal cell loss and histopathological alterations in MCAO rats. This study proves that vildagliptin exerted the neuroprotective effect in a dose-dependent manner as shown in amelioration of neuronal cell loss and histopathological damage in MCAO rats, which may be mediated by attenuating neuronal and motor deficits, it’s anti-oxidant property, activation of PI3K/AKT/mTOR pathway and its anti-apoptotic effect.

Keywords: caspase-3, cerebral ischemia, dipeptidyl peptidase-4 inhibitor, oxidative stress, PI3K/AKT/mTOR pathway, rats, vildagliptin

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Authors: Isabela S. Gonçalves, Vitor G. P. Lima, Tiago M. B. Campos, Marcos Jacobovitz, Luana M. R. Vasconcellos, Ivone R. Oliveira

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Periodontitis is an infectious disease of multifactorial origin, which originates from a periodontogenic bacterial biofilm that colonizes the surfaces of the teeth, resulting in an inflammatory reaction to microbial aggression. In the absence of adequate treatment, it can lead to the gradual destruction of the periodontal ligaments, cementum and alveolar bone. In guided tissue/bone regeneration therapy (GTR/GBR), a barrier membrane is placed between the fibrous tissues and the bone defect to prevent unwanted incursions of fibrous tissues into the bone defect, thus allowing the regeneration of quality bone. Currently, there are a significant number of biodegradable barrier membranes available on the market. However, a very common problem is that the membranes are not bioactive/osteogenic, that is, they are incapable of inducing a favorable osteogenic response and integration with the host tissue, resulting in many cases in displacement/expulsion of the membrane, requiring a new surgical procedure and replacement of the implant. Aiming to improve the bioactive and osteogenic properties of the membrane, this work evaluated the production of membranes that integrate the biocompatibility of the hydrophilic synthetic polymer (polyvinyl alcohol - PVA) with the osteogenic effects of chlorinated bioactive glasses (BG58S-Cl), using the electrospinning equipment (AeroSpinner L1.0 from Areka) which allows the execution of spinning by high voltage and/or blowing in solution and with a high production rate, enabling development on an industrial scale. In the formulation of bioactive glasses, the replacement of nitrates by chlorinated molecules has shown to be a promising alternative, since the chloride ion is naturally present in the body and, with its presence in the bioactive glass, the biocompatibility of the material increases. Thus, in this work, chlorinated bioactive glasses were synthesized by the sol-gel route using the compounds tetraethyl orthosilicate (TEOS), calcium chloride dihydrate and monobasic ammonium phosphate with pH adjustments with 37% HCl (1.5 or 2.5) and different calcination temperatures (500, 600 and 700 °C) were evaluated. The BG-58S-Cl powders obtained were characterized by pH, conductivity and zeta potential x time curves and by SEM/FEG, FTIR-ATR and Raman tests. The material produced under the selected conditions was evaluated in relation to the milling procedure, obtaining particles suitable for incorporation into PVA polymer solutions to be electrospun (D50 = 22 µm). Membranes were produced and evaluated regarding the influence of the crosslinking agent content as well as the crosslinking treatment temperature (3, 5 and 10 wt% citric acid) and (130 or 175 oC) and were characterized by SEM/FEG, FTIR, TG and DSC. From the optimization of the crosslinking conditions, membranes were prepared by adding BG58S-Cl powder (5 and 10 wt%) to the PVA solutions and were characterized by SEM-FEG, DSC, bioactivity in SBF and behavior in cell culture (cell viability, total protein content, alkaline phosphatase, mineralization nodules). The micrographs showed homogeneity of the distribution of BG58S-Cl particles throughout the sample, favoring cell differentiation.

Keywords: barrier membranes, chlorinated bioactive glasses, polyvinyl alcohol, tissue regeneration.

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Authors: Okolie Pius Ifeanyi, Emerenini Emilymary Chima

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Aims: The study investigated the diversity and identities of Lactic Acid Bacteria (LAB) isolated from different fresh fruits using Molecular Nested PCR analysis and the efficacy of cell free supernatants from Lactic Acid Bacteria (LAB) isolated from fresh fruits for in vitro control of some tomato pathogens. Study Design: Nested PCR approach was used in this study employing universal 16S rRNA gene primers in the first round PCR and LAB specific Primers in the second round PCR with the view of generating specific Nested PCR products for the LAB diversity present in the samples. The inhibitory potentials of supernatant obtained from LAB isolates of fruits origin that were molecularly characterized were investigated against some tomato phytopathogens using agar-well method with the view to develop biological agents for some tomato disease causing organisms. Methodology: Gram positive, catalase negative strains of LAB were isolated from fresh fruits on Man Rogosa and Sharpe agar (Lab M) using streaking method. Isolates obtained were molecularly characterized by means of genomic DNA extraction kit (Norgen Biotek, Canada) method. Standard methods were used for Nested Polymerase Chain Reaction (PCR) amplification targeting the 16S rRNA gene using universal 16S rRNA gene and LAB specific primers, agarose gel electrophoresis, purification and sequencing of generated Nested PCR products (Macrogen Inc., USA). The partial sequences obtained were identified by blasting in the non-redundant nucleotide database of National Center for Biotechnology Information (NCBI). The antimicrobial activities of characterized LAB against some tomato phytopathogenic bacteria which include (Xanthomonas campestries, Erwinia caratovora, and Pseudomonas syringae) were obtained by using the agar well diffusion method. Results: The partial sequences obtained were deposited in the database of National Centre for Biotechnology Information (NCBI). Isolates were identified based upon the sequences as Weissella cibaria (4, 18.18%), Weissella confusa (3, 13.64%), Leuconostoc paramensenteroides (1, 4.55%), Lactobacillus plantarum (8, 36.36%), Lactobacillus paraplantarum (1, 4.55%) and Lactobacillus pentosus (1, 4.55%). The cell free supernatants of LAB from fresh fruits origin (Weissella cibaria, Weissella confusa, Leuconostoc paramensenteroides, Lactobacillus plantarum, Lactobacillus paraplantarum and Lactobacillus pentosus) can inhibits these bacteria by creating clear zones of inhibition around the wells containing cell free supernatants of the above mentioned strains of lactic acid bacteria. Conclusion: This study shows that potentially LAB can be quickly characterized by molecular methods to specie level by nested PCR analysis of the bacteria isolate genomic DNA using universal 16S rRNA primers and LAB specific primer. Tomato disease causing organisms can be most likely biologically controlled by using extracts from LAB. This finding will reduce the potential hazard from the use of chemical herbicides on plant.

Keywords: nested pcr, molecular characterization, 16s rRNA gene, lactic acid bacteria

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Authors: G. Lambe, D. Mansukhani, A. Shetty, S. Khodaiji, C. Rodrigues, F. Kapadia

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Introduction: Sepsis is known to cause impairment of both innate and adaptive immunity and involves an early uncontrolled inflammatory response, followed by a protracting immunosuppression phase, which includes decreased expression of cell receptors, T cell anergy and exhaustion, impaired cytokine production, which may cause high risk for secondary infections due to reduced response to antigens. Although human cytomegalovirus (CMV) is widely recognized as a serious viral pathogen in sepsis and immunocompromised patients, the incidence of CMV reactivation in patients with sepsis lacking strong evidence of immunosuppression is not well defined. Therefore, it is important to determine an association between CMV reactivation and sepsis-induced immunosuppression. Aim: To determine the association between incidence of CMV reactivation and immune modulation in sepsis-induced immunosuppression with time. Material and Methods: Ten CMV-seropositive adult patients with severe sepsis were included in this study. Blood samples were collected on Day 0, and further weekly up to 21 days. CMV load was quantified by real-time PCR using plasma. The expression of immunosuppression markers, namely, HLA-DR, PD-1, and regulatory T cells, were determined by flow cytometry using whole blood. Results: At Day 0, no CMV reactivation was observed in 6/10 patients. In these patients, the median length for reactivation was 14 days (range, 7-14 days). The remaining four patients, at Day 0, had a mean viral load of 1802+2599 copies/ml, which increased with time. At Day 21, the mean viral load for all 10 patients was 60949+179700 copies/ml, indicating that viremia increased with the length of stay in the hospital. HLA-DR expression on monocytes significantly increased from Day 0 to Day 7 (p = 0.001), following which no significant change was observed until Day 21, for all patients except 3. In these three patients, HLA-DR expression on monocytes showed a decrease at elevated viral load (>5000 copies/ml), indicating immune suppression. However, the other markers, PD-1 and regulatory T cells, did not show any significant changes. Conclusion: These preliminary findings suggest that CMV reactivation can occur in patients with severe sepsis. In fact, the viral load continued to increase with the length of stay in the hospital. Immune suppression, indicated by decreased expression of HLA-DR alone, was observed in three patients with elevated viral load.

Keywords: CMV reactivation, immune suppression, sepsis immune modulation, CMV viral load

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Authors: Mohamed Montassar Ben Slama, Mohamed Fadel Ladeb, Mohamed Ghanmi, Mohamed Ben Youssef, Fouad Zargouni

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The salt province Basin in Northern Tunisia is a complex of late Triassic to Early Cretaceous rift and sag basins which was inverted during the Tertiary folding. The deposition of evaporitic sediments during the Late Triassic times played a major role in the subsequent tectonic evolution of the basin. Within southern tethyan passive marge, the ductile salt mass shown early mobilization, vertical transport and withdrawal of the evaporites. These movements influenced the sedimentation during the late Jurassic and Early Cretaceous. The evaporites also influenced deformation during the inversion of the basin and the development of the Tertiary and Quaternary folding. In the studied area, the biostratigraphic and tectonic map analysis of the region of Jebel el Asoued / Ragoubet el Mahjbia can resolve between the hypotheses of the diapiric intrusion of the Triassic salt and the lateral spreading of the Triassic salt as salt ‘glacier’. Also the variation in thickness and facies of the Aptian sediments demonstrates the existence of continental rise architecture at the Aptian time. The observation in a mappable outcrop of the extension segment of the graben fault of Bou Arada on the one hand confirms the existence of a Cretaceous extensive architecture and the tectonic inversion during the Tertiary time has not filled the main game distension. The extent of our observations of Triassic/Aptian and Triassic/Early Campanian contacts, we propose a composite salt ‘glacier’ model as the structures recorded in the Gulf of Mexico in the subsurface and in the Ouenza east Algeria and in Tunisia within Fedj el Adoum, Touiref-Nebeur and Jebel Ech Cheid in the outcrops.

Keywords: Cretaceous rift, salt ‘glassier’, tertiary folding, Tunisia

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Authors: Vijaya Nhaloor, Suja Kumari Leela, Jose Devadasan

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Planning of neighbourhood development strategies in Tier 2 Indian city is highly significant when it has also been selected as a Smart city by the Ministry of Urban Development in India. Smart city mission of India proposes the development of infrastructure in a city in an inclusive way. Thiruvananthapuram, the capital city of Kerala state, India, has been selected as the city to conduct the research. The master plan for the city of Thiruvananthapuram envisions it as a Compact city and proposes densification as a tool for development. Densification may adversely affect the quality of life after a tipping point. This may lead to urban decay which in turn directly or indirectly affects the surrounding neighbourhoods also, thus spreading blight areas in the city. The author thinks that density in urban planning is not a well detailed subject in India, with respect to its varied links on infrastructure, quality of life, transportation, scope of vertical planning, affordability etc. Neighbourhoods are vital tissues of an urban area, and their development directly affects the development of the region. The methodology would involve skimming of proactive neighbourhood planning principles compatible with the Smart city mission in India. United Nations proposes sustainability as a way of planning development of a neighbourhood. After defining various terminologies involved, a framework shall be developed to analyse an existing neighbourhood and prepare planning guidelines in a sustainable manner. The framework shall comply with international and national policy guidelines. The research shall explore and identify a neighbourhood with the potential to meet the housing demand from the investment regions nearby and analyse its potential and weakness as per this framework. Later, a set of indicators shall be enlisted to guide the development of the neighbourhood, leading to recommendations that shall serve as a replicable model for the other neighbourhoods in the Smart city.

Keywords: key indicators, neighbourhood planning, sustainability, smart city

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Authors: Seong Gu Hwang, Young Kyoon Oh, Joseph F. dela Cruz

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Marbling, or intramuscular fat, has been consistently identified as one of the top beef quality problems. Intramuscular adipocytes distribute throughout the perimysial connective tissue of skeletal muscle and are the major site for the deposition of intramuscular fat, which is essential for the eating quality of meat. The stromal vascular fraction of the skeletal muscle contains progenitor cells that can be enhanced to differentiate to adipocytes and increase intramuscular fat. Primary cultures of bovine intramuscular stromal vascular cells were used in this study to elucidate the effects of extracellular calcium and retinoic acid concentration on adipocyte differentiation. Cell viability assay revealed that even at different concentrations of calcium and retinoic acid, there was no significant difference on cell viability. Monitoring of the adipocyte differentiation showed that bovine intramuscular stromal vascular cells cultured in a low concentration of extracellular calcium and retinoic acid had a better degree of fat accumulation. The mRNA and protein expressions of PPARγ, C/EBPα, SREBP-1c and aP2 were analyzed and showed a significant upregulation upon the reduction in the level of extracellular calcium and retinoic acid. The upregulation of these adipogenic related genes means that the decreasing concentration of calcium and retinoic acid is able to stimulate the adipogenic differentiation of bovine intramuscular stromal vascular cells. To further elucidate the effect of calcium, the expression level of calreticulin was measured. Calreticulin which is known to be an inhibitor of PPARγ was down regulated by the decreased level of calcium and retinoic acid in the culture media. The same tendency was observed on retinoic acid receptors RARα and CRABP-II. These receptors are recognized as adipogenic inhibitors, and the downregulation of their expression allowed a better level of differentiation in bovine intramuscular stromal vascular cells. In conclusion, data show that decreasing the level of extracellular calcium and retinoic acid can significantly promote adipogenesis in intramuscular stromal vascular cells of Hanwoo beef cattle. These findings may provide new insights in enhancing intramuscular adipogenesis and marbling in beef cattle.

Keywords: calcium, calreticulin, hanwoo beef, retinoic acid

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Authors: Alaa Abdellatif, Gabrièle Breda

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Background. Advanced therapy medicinal products (ATMPs) are innovative therapies that mainly target orphan diseases and high unmet medical needs. ATMP includes gene therapy medicinal products (GTMP), somatic cell therapy medicinal products (CTMP), and tissue-engineered therapies (TEP). Since legislation opened the way in 2007, 25 ATMPs have been approved in the EU, which is about the same amount as the U.S. Food and Drug Administration. However, not all of the ATMPs that have been approved have successfully reached the market and retained their approval. Objectives. We aim to understand all the factors limiting the market access to very promising therapies in a systemic approach, to be able to overcome these problems, in the future, with scientific, regulatory and commercial innovations. Further to recent reviews that focus either on specific countries, products, or dimensions, we will address all the challenges faced by ATMP development today. Methodology. We used mixed methods and a multi-level approach for data collection. First, we performed an updated academic literature review on ATMP development and their scientific and market access challenges (papers published between 2018 and April 2023). Second, we analyzed industry feedback from cell and gene therapy webinars and white papers published by providers and pharmaceutical industries. Finally, we established a comparative analysis of the regulatory guidelines published by EMA and the FDA for ATMP approval. Results: The main challenges in bringing these therapies to market are the high development costs. Developing ATMPs is expensive due to the need for specialized manufacturing processes. Furthermore, the regulatory pathways for ATMPs are often complex and can vary between countries, making it challenging to obtain approval and ensure compliance with different regulations. As a result of the high costs associated with ATMPs, challenges in obtaining reimbursement from healthcare payers lead to limited patient access to these treatments. ATMPs are often developed for orphan diseases, which means that the patient population is limited for clinical trials which can make it challenging to demonstrate their safety and efficacy. In addition, the complex manufacturing processes required for ATMPs can make it challenging to scale up production to meet demand, which can limit their availability and increase costs. Finally, ATMPs face safety and efficacy challenges: dangerous adverse events of these therapies like toxicity related to the use of viral vectors or cell therapy, starting material and donor-related aspects. Conclusion. As a result of our mixed method analysis, we found that ATMPs face a number of challenges in their development, regulatory approval, and commercialization and that addressing these challenges requires collaboration between industry, regulators, healthcare providers, and patient groups. This first analysis will help us to address, for each challenge, proper and innovative solution(s) in order to increase the number of ATMPs approved and reach the patients

Keywords: advanced therapy medicinal products (ATMPs), product development, market access, innovation

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Authors: Rajashekar Badam, Vedarajan Raman, Noriyoshi Matsumi

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Efficiency of energy converting and storage systems like fuel cells and Li-Air battery principally depended on oxygen reduction reaction (ORR) which occurs at cathode. As the kinetics of the ORR is very slow, it becomes the rate determining step. Exploring carbon substrates for enhancing the dispersion and activity of the metal catalyst and commercially viable simple preparation method is a very crucial area of research in the field of energy materials. Hence, many researchers made large number of carbon-based ORR materials today. But, there are hardly few studies on the effect of interaction between Pt-carbon and carbon-electrolyte on activity. In this work, we have prepared functionalized carbon-based Pt catalyst (Pt-FAB) with enhanced interfacial properties that lead to efficient ORR catalysis. The present work deals with a single-pot method to exfoliate and functionalized acetylene black with enhanced interaction with Pt as well as electrolyte. Acetylene black was functionalized and exfoliated using a facile single pot acid treatment method. The resulted FAB was further decorated with Pt-nano particles (Pt-np). The TEM images of Pt-FAB with uniformly decorated Pt-np of ~3 nm. Further, XPS studies of Pt 4f peak revealed that Pt0 peak was shifted by 0.4 eV in Pt-FAB compared to binding energy of typical Pt⁰ found in Pt/C. The shift can be ascribed to the modulation of electronic state and strong electronic interaction of Pt with carbon. Modulated electronic structure of Pt and strong electronic interaction of Pt with FAB enhances the catalytic activity and durability respectively. To understand the electrode electrolyte interface, electrochemical impedance spectroscopy was carried out. These measurements revealed that the charge transfer resistance of electrode to electrolyte for Pt-FAB is 10 times smaller than that of conventional Pt/C. The interaction with electrolyte helps reduce the interface boundaries, which in turn affects the overall catalytic performance of the electrode. Cyclic voltammetric measurements in 0.1M HClO₄ aq. at a potential scan rate of 50 mVs-1 was employed to evaluate electrochemical surface area (ECSA) of Pt. ECSA of Pt-FAB was found to be as high as 67.2 m²g⁻¹. The three-electrode system showed very high ORR catalytic activity. Mass activity at 0.9 V vs. RHE showed 460 A/g which is much higher than the DOE target values for the year 2020. Further, it showed enhanced performance by showing 723 mW/cm² of highest power density and 1006 mA/cm² of current density at 0.6 V in fuel cell single cell type configuration and 1030 mAhg⁻¹ of rechargeable capacity in Li air battery application. The higher catalytic activity can be ascribed to the improved interaction of FAB with Pt and electrolyte. The aforementioned results evince that Pt-FAB will be a promising cathode material for efficient ORR with significant cyclability for its application in fuel cells and Li-Air batteries. In conclusion, a disordered material was prepared from AB and was systematically characterized. The extremely high ORR activity and ease of preparation make it competent for replacing commercially available ORR materials.

Keywords: functionalized acetylene black, oxygen reduction reaction, fuel cells, Functionalized battery

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Authors: Mohammed Isah Shehu

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This paper examined the context of globalization and Islam and accommodation or containment of one by the other. The paper is born out of the misconception and misunderstanding among many people that globalization is purely Western, anti-Islam and that Islam, globalization and Islam are diametrically opposed as such have no places for accommodating each other. The study used secondary sources to gather data. The study found that from its origin, Islam is in the whole context, a globalized religion and the contemporary globalization is already contained by Islam; that while contemporary globalization is centered on Western world, values and preferences (Western civilization, information and communication technology, free markets, trade and investments); some of the major foundation works that are aiding globalization were originally handiworks of past great Muslims (Islamic civilizations, Order of Algebra, tools of Navigation, Calligraphy, Medicine, Astronomy et cetera) whose major values are not Islamic; with globalization the Muslims have greater opportunities of spreading of Islam and practicing it in a most conducive atmosphere, easy and fast linkage with their fellow Muslim brothers wherever they may be; easier and freer world of trade and have the best opportunities to most things. The study however observed that Western contemporary globalization poses threats to religions such as those of globalization of immorality, injustice, trade with anti-Islamic terms and conditions, internationalized crime et cetera. Muslims would have to avoid or be cautious of many things for Islam is a complete religion that has what is forbidden and allowed (halaal and haramm) based on principles of (Shariah, justice to all, humanity and compassion, obedience to and seeking Allah’s pleasure); to Muslims, Contemporary globalization has to be in conformity with original provisions of Islam. The study recommended that Muslims must rise up in seeking knowledge on Islam and all other fields, further intellectual explorations of works by Muslim scholars/thinkers so that any advancement in globalization would be properly domesticated within Islam for the Muslims to make optimum use of any advancement to the benefit of Islam.

Keywords: accommodation, containment, Islam, globalization

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Authors: J. E. Mendes, T. T. de Barros, O. B. G. de Assis, J. D. C. Pessoa

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Chitosan, a natural polysaccharide of β-1,4-linked glucosamine residues, is a biopolymer obtained primarily from the exoskeletons of crustaceans. Interest in polymeric materials increases year by year. Chitosan is one of the most plentiful biomaterials, with a wide range of pharmaceutical, biomedical, industrial and agricultural applications. Chitosan nanoparticles were synthesized via the ionotropic gelation of chitosan with sodium tripolyphosphate (TPP). Two concentrations of chitosan microparticles (0.1 and 0.2%) were synthesized. In this study, it was possible to synthesize and characterize microparticles of chitosan biomaterial and this will be used for future applications in cell anchorage for 3D bioprinting.

Keywords: chitosan microparticles, biomaterial, scaffold, bioprinting

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Authors: Di Luo, Maria Buchberger, Anja Pickhard

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Objectives: The purpose of this study was to assess and compare the diagnostic accuracy of four common morphological approaches, including sonography, computed tomography (CT), positron emission tomography/computed tomography (PET/CT), and magnetic resonance imaging (MRI) for the evaluation of cervical lymph node metastases in head and neck squamous cell carcinoma (HNSCC) patients. Material and Methods: Included in this retrospective study were 26 patients diagnosed with HNSCC between 2010 and 2011 who all underwent sonography, CT, PET/CT, and MRI imaging before neck dissection. Morphological data were compared to the corresponding histopathological results. Statistical analysis was performed with SPSS statistic software (version 26.0), calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detection of cervical lymph node metastases. Results: The 5-year survival rate of the patient collective was 55.5%.Risk factors for survival included initial primary tumor stage, initial lymph node stage, initial metastasis status, and therapeutic approaches. Cox regression showed initial metastasis status(HR 8.671, 95%CI 1.316-57.123, p=0.025) and therapeutic approaches(HR 6.699, 95%CI 1.746-25.700, p=0.006)to be independent predictive risk factors for survival. Sensitivity was highest for MRI (96% compared to 85% for sonography and 89% for CT and PET/CT). Specificity was comparable with 95 % for CT and 98 % for sonography and PET/CT, but only 68% for MRI. While the MRI showed the least PPV (34%) compared to all other methods (85% for sonography,75% for CT, and 86% for PET/CT), the NPV was comparable in all methods(98-99%). The overall accuracy of cervical lymph node metastases detection was comparable for sonography, CT, and PET/CT with 96%,97%,94%, respectively, while MRI had only 72% accuracy. Conclusion: Since the initial status of metastasis is an independent predictive risk factor for patients’ survival, efficient detection is crucial to plan adequate therapeutic approaches. Sonography, CT, and PET/CT have better diagnostic accuracy than MRI for the evaluation of cervical lymph node metastases in HNSCC patients.

Keywords: cervical lymph node metastases, diagnostic accuracy, head and neck squamous carcinoma, risk factors, survival

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Authors: Hoyeon Park, Kyoung-jae Kim

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The product recommendation is a field of research that has received much attention in the recent information overload phenomenon. The proliferation of the mobile environment and social media cannot help but affect the results of the recommendation depending on how the factors of the user's situation are reflected in the recommendation process. Recently, research has been spreading attention to the context-aware recommender system which is to reflect user's contextual information in the recommendation process. However, until now, most of the context-aware recommender system researches have been limited in that they reflect the passive context of users. It is expected that the user will be able to express his/her contextual information through his/her active behavior and the importance of the context-aware recommender system reflecting this information can be increased. The purpose of this study is to propose a context-aware recommender system that can reflect the user's emotional state as an active context information to recommendation process. The context-aware recommender system is a recommender system that can make more sophisticated recommendations by utilizing the user's contextual information and has an advantage that the user's emotional factor can be considered as compared with the existing recommender systems. In this study, we propose a method to infer the user's emotional state, which is one of the user's context information, by using the user's facial expression data and to reflect it on the recommendation process. This study collects the facial expression data of a user who is looking at a specific product and the user's product preference score. Then, we classify the facial expression data into several categories according to the previous research and construct a model that can predict them. Next, the predicted results are applied to existing collaborative filtering with contextual information. As a result of the study, it was shown that the recommended results of the context-aware recommender system including facial expression information show improved results in terms of recommendation performance. Based on the results of this study, it is expected that future research will be conducted on recommender system reflecting various contextual information.

Keywords: context-aware, emotional state, recommender systems, business analytics

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Authors: Ishtiaq Ahmad Gondal, Mubasher Hussain

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Although the world always has spent a lot to counter the terror, thousands of millions of dollars have been spent in this regard after 9/11 that result to thwart some dangerous plots of terrorists. It is also un-ignorable that the terrorists, keeping the counterterrorist actions in their mind, always planned new ways for their operations, yet there is one thing still common in most terrorists' attacks: to use the label of religion, regardless any specific religion, in any form. The terrorism, in past few years, has also hit state's security, its consistency and coherence for achieving their cultural, political and military objectives. So, if they are not treated harshly for making the people's minds and their society dirty they will continue spreading chaos, anarchy and destruction among the ignorant and innocent people. Australia is doing its best to eliminate terrorism by using different tools such as by educating people and reducing poverty. There is still need to improve the tool of education as it can be used as one of the most effective tools to counter the terrorism. It is, as this paper will highlight, the need of contemporary time for establishing some high level educational centers that can educate people and keep them safe from any kind of terror incident. This study also concluded that common man, to keep himself saved from such activities and incidents, can be educated through public awareness movements and campaigns on media and at social gatherings. There is, according to the study, a need to reorganize the curriculum taught in different educational institutions especially in Islamic Schools (Madāris) that are assumed by some western writers as place of extremists, for the better understanding of moral and social obligations, fundamental rights, religious beliefs as well as cultural and social values to promote social justice and equality. This paper is an attempt to show the role of the Sheikh Zayed Islamic Centre in this regard.

Keywords: social justice, counterterrorism, educational policy, religion, peace, terrorism

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Authors: Momoh Omeiza Sheidu

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Finite element method as a method of providing solutions to problems in computational bio mechanics provides a framework for modeling the function of tissues that integrates structurally from cell to organ system and functionally across the physiological processes that affect tissue mechanics or are regulated by mechanical forces. In this paper, we present an integrative finite element strategy for solution to problems in tissue bio mechanics as a case study.

Keywords: finite element, biomechanics, modeling, computational biomechanics

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Authors: Lise P. Labéjof, Krisnayne S. Ribeiro, Nicolle P. dos Santos

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An unrecorded experiment of use of the smartphone as a tool for practical classes of histology is presented in this article. Behavior, learning of the students of three science courses at the University were analyzed and compared as well as the mode of teaching of this discipline and the appreciation of the students, using either digital photographs taken by phone or drawings for record microscopic observations, analyze and interpret histological sections of human or animal tissues.

Keywords: cell phone, digital micrographies, learning of sciences, teaching practices

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Authors: Rolivhuwa Bishop Ramagoma1*, Lynn Cairncross1, , Saartjie Roux1

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According to the world health organisation, colon cancer is among the most common cancers diagnosed in both men and women. Specifically, it is the second leading cause of cancer related deaths accounting for over 860 000 deaths worldwide in 2018. Currently, chemotherapy has become an essential component of most cancer treatments. Despite progress in cancer drug development over the previous years, traditional chemotherapeutic drugs still have low selectivity for targeting tumour tissues and are frequently constrained by dose-limiting toxicity. The creation of nanoscale delivery vehicles capable of directly directing treatment into cancer cells has recently caught the interest of researchers. Herein, the development of peptide-functionalized polyethylene glycol gold nanoparticles (Peptide-PEG-AuNPs) as a cellular probe and delivery agent is described, with the higher aim to develop a specific diagnostic prototype and assess their specificity not only against cell lines but primary human cells as well. Gold nanoparticles (AuNPs) were synthesized and stabilized through chemical conjugation. The synthesized AuNPs were characterized, stability in physiological solutions was assessed, their cytotoxicity against colon carcinoma and non-carcinoma skin fibroblasts was also studied. Furthermore, genetic effect through real-time polymerase chain reaction (RT-PCR), localization and uptake, peptide specificity were also determined. In this study, different peptide-AuNPs were found to have preferential toxicity at higher concentrations, as revealed by cell viability assays, however, all AuNPs presented immaculate stability for over 3 months following the method of synthesis. The final obtained peptide-PEG-AuNP conjugates showed good biocompatibility in the presence of high ionic solutions and biological media and good cellular uptake. Formulation of colon cancer specific targeting peptide was successful, additionally, the genes/pathways affected by the treatments were determined through RT-PCR. Primary cells study is still on going with promising results thus far.

Keywords: nanotechnology, cancer, diagnosis, therapeutics, gold nanoparticles.

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Authors: Malory Beaujolais

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Chlordecone is an organochlorine pesticide with a bishomocubane structure which led to high stability in organic matter. Microbial fuel cell is a type of electrochemical system that can convert organic matters into electricity thanks to electroactive bacteria. This technique has been used with mangrove swamp from Martinique to try to reduce chlordecone rates. Those experiments led to characterize the behavior of the electroactive biofilm formed at the cathode, without added redox mediator. The designed bioelectrochemical system seems to provide the necessary conditions for chlordecone degradation.

Keywords: bioelectrochemistry, bioremediation, chlordecone, mangrove swamp

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Authors: T. Radu, R. Sreenivas, H. Albuflasa, A. Mustafa Khan, W. Aloqab

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The Kingdom of Bahrain, a small island country in the Gulf region, is experiencing fast economic growth resulting in a sharp increase in population and greater than ever amounts of waste being produced. However, waste management in the country is still very basic, with landfilling being the most popular option. Recycling is still a scarce practice, with small recycling businesses and initiatives emerging in recent years. This scenario is typical for other countries in the region, with similar amounts of per capita waste being produced. In this paper, we are reviewing current waste management practices in Bahrain by collecting data published by the Government and various authors, and by visiting the country’s only landfill site, Askar. In addition, we have performed a survey of the residents to learn more about the awareness and attitudes towards sustainable waste management strategies. A review of the available data on waste management indicates that the Askar landfill site is nearing its capacity. The site uses open tipping as the method of disposal. The highest percentage of disposed waste comes from the building sector (38.4%), followed by domestic (27.5%) and commercial waste (17.9%). Disposal monitoring and recording are often based on estimates of weight and without proper characterization/classification of received waste. Besides, there is a need for assessment of the environmental impact of the site with systematic monitoring of pollutants in the area and their potential spreading to the surrounding land, groundwater, and air. The results of the survey indicate low awareness of what happens with the collected waste in the country. However, the respondents have shown support for future waste reduction and recycling initiatives. This implies that the education of local communities would be very beneficial for such governmental initiatives, securing greater participation. Raising awareness of issues surrounding recycling and waste management and systematic effort to divert waste from landfills are the first steps towards securing sustainable waste management in the Kingdom of Bahrain.

Keywords: landfill, municipal solid waste, survey, waste management

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Authors: Joelle Penniston, E. B. Gueguim-Kana

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Biohydrogen has been identified as a promising alternative to the use of non-renewable fossil reserves, owing to its sustainability and non-polluting nature. pH is considered as a key parameter in fermentative biohydrogen production processes, due to its effect on the hydrogenase activity, metabolic activity as well as substrate hydrolysis. The present study assesses the influence of regulating pH on dark fermentative biohydrogen production. Four experimental hydrogen production schemes were evaluated. Two were implemented using suspended cells under regulated pH growth conditions (Sus_R) and suspended and non-regulated pH (Sus_N). The two others regimes consisted of alginate immobilized cells under pH regulated growth conditions (Imm_R) and immobilized and non-pH regulated conditions (Imm_N). All experiments were carried out at 37.5°C with glucose as sole source of carbon. Sus_R showed a lag time of 5 hours and a peak hydrogen fraction of 36% and a glucose degradation of 37%, compared to Sus_N which showed a peak hydrogen fraction of 44% and complete glucose degradation. Both suspended culture systems showed a higher peak biohydrogen fraction compared to the immobilized cell system. Imm_R experiments showed a lag phase of 8 hours, a peak biohydrogen fraction of 35%, while Imm_N showed a lag phase of 5 hours, a peak biohydrogen fraction of 22%. 100% glucose degradation was observed in both pH regulated and non-regulated processes. This study showed that biohydrogen production in batch mode with suspended cells in a non-regulated pH environment results in a partial degradation of substrate, with lower yield. This scheme has been the culture mode of choice for most reported studies in biohydrogen research. The relatively lower slope in pH trend of the non-regulated pH experiment with immobilized cells (Imm_N) compared to Sus_N revealed that that immobilized systems have a better buffering capacity compared to suspended systems, which allows for the extended production of biohydrogen even under non-regulated pH conditions. However, alginate immobilized cultures in flask systems showed some drawbacks associated to high rate of gas production that leads to increased buoyancy of the immobilization beads. This ultimately impedes the release of gas out of the flask.

Keywords: biohydrogen, sustainability, suspended, immobilized

Procedia PDF Downloads 342

Authors: A. Aslihan Gokaltun, Martin L. Yarmush, Ayse Asatekin, O. Berk Usta

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Poly(dimethylsiloxane) (PDMS) is one of the most widely used materials in the fabrication of microfluidic devices. It is easily patterned and can replicate features down to nanometers. Its flexibility, gas permeability that allows oxygenation, and low cost also drive its wide adoption. However, a major drawback of PDMS is its hydrophobicity and fast hydrophobic recovery after surface hydrophilization. This results in significant non-specific adsorption of proteins as well as small hydrophobic molecules such as therapeutic drugs limiting the utility of PDMS in biomedical microfluidic circuitry. While silicon, glass, and thermoplastics have been used, they come with problems of their own such as rigidity, high cost, and special tooling needs, which limit their use to a smaller user base. Many strategies to alleviate these common problems with PDMS are lack of general practical applicability, or have limited shelf lives in terms of the modifications they achieve. This restricts large scale implementation and adoption by industrial and research communities. Accordingly, we aim to tailor biocompatible PDMS surfaces by developing a simple and one step bulk modification approach with novel smart materials to reduce non-specific molecular adsorption and to stabilize long-term cell analysis with PDMS substrates. Smart polymers that blended with PDMS during device manufacture, spontaneously segregate to surfaces when in contact with aqueous solutions and create a < 1 nm layer that reduces non-specific adsorption of organic and biomolecules. Our methods are fully compatible with existing PDMS device manufacture protocols without any additional processing steps. We have demonstrated that our modified PDMS microfluidic system is effective at blocking the adsorption of proteins while retaining the viability of primary rat hepatocytes and preserving the biocompatibility, oxygen permeability, and transparency of the material. We expect this work will enable the development of fouling-resistant biomedical materials from microfluidics to hospital surfaces and tubing.

Keywords: cell culture, microfluidics, non-specific protein adsorption, PDMS, smart polymers

Procedia PDF Downloads 294

Authors: Sheraz Gul

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The requirements for progressing a compound to clinical trials is well established and relies on the results from in-vitro and in-vivo animal tests to indicate that it is likely to be safe and efficacious when testing in humans. The typical data package required will include demonstrating compound safety, toxicity, bioavailability, pharmacodynamics (potential effects of the compound on body systems) and pharmacokinetics (how the compound is potentially absorbed, distributed, metabolised and eliminated after dosing in humans). If the desired criteria are met and the compound meets the clinical Candidate criteria and is deemed worthy of further development, a submission to regulatory bodies such as the US Food & Drug Administration for an exploratory Investigational New Drug Study can be made. The purpose of this study is to collect data to establish that the compound will not expose humans to unreasonable risks when used in limited, early-stage clinical studies in patients or normal volunteer subjects (Phase I). These studies are also designed to determine the metabolism and pharmacologic actions of the drug in humans, the side effects associated with increasing doses, and, if possible, to gain early evidence on their effectiveness. In order to reach the above goals, we have developed a pre-clinical high throughput Absorption, Distribution, Metabolism and Excretion–Toxicity (ADME–Toxicity) panel of assays to identify compounds that are likely to meet the Lead and Candidate compound acceptance criteria. This panel includes solubility studies in a range of biological fluids, cell viability studies in cancer and primary cell-lines, mitochondrial toxicity, off-target effects (across the kinase, protease, histone deacetylase, phosphodiesterase and GPCR protein families), CYP450 inhibition (5 different CYP450 enzymes), CYP450 induction, cardio-toxicity (hERG) and gene-toxicity. This panel of assays has been applied to multiple compound series developed in a number of projects delivering Lead and clinical Candidates and examples from these will be presented.

Keywords: absorption, distribution, metabolism and excretion–toxicity , drug discovery, food and drug administration , pharmacodynamics

Procedia PDF Downloads 174

Authors: Sahar Nasr, Lin Li, Edwin Wang

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Bladder cancer (BLCA) is known as the 13th cause of death among cancer patients worldwide, and ~575,000 new BLCA cases are diagnosed each year. Urothelial carcinoma (UC) is the most prevalent subtype among BLCA patients, which can be categorized into muscle-invasive bladder cancer (MIBC) and non-muscle-invasive bladder cancer (NMIBC). Currently, various therapeutic options are available for UC patients, including (1) transurethral resection followed by intravesical instillation of chemotherapeutics or Bacillus Calmette-Guérin for NMIBC patients, (2) neoadjuvant platinum-based chemotherapy (NAC) plus radical cystectomy is the standard of care for localized MIBC patients, and (3) systematic chemotherapy for metastatic UC. However, conventional treatments may lead to several challenges for treating patients. As an illustration, some patients may suffer from recurrence of the disease after the first line of treatment. Recently, immune checkpoint therapy (ICT) has been introduced as an alternative treatment strategy for the first or second line of treatment in advanced or metastatic BLCA patients. Although ICT showed lucrative results for a fraction of BLCA patients, ~80% of patients were not responsive to it. Therefore, novel treatment methods are required to augment the ICI response rate within BLCA patients. It has been shown that the infiltration of T-cells into the tumor microenvironment (TME) is positively correlated with the response to ICT within cancerous patients. Therefore, the goal of this study is to enhance the infiltration of cytotoxic T-cells into TME through the identification of target genes within the tumor that are responsible for the non-T-cell inflamed TME and their inhibition. BLCA bulk RNA-sequencing data from The Cancer Genome Atlas (TCGA) and immune score for TCGA samples were used to determine the Pearson correlation score between the expression of different genes and immune score for each sample. The genes with strong negative correlations were selected (r < -0.2). Thereafter, the correlation between the expression of each gene and survival in BLCA patients was calculated using the TCGA data and Cox regression method. The genes that are common in both selected gene lists were chosen for further analysis. Afterward, BLCA bulk and single-cell RNA-sequencing data were ranked based on the expression of each selected gene and the top and bottom 25% samples were used for pathway enrichment analysis. If the pathways related to the T-cell infiltration (e.g., antigen presentation, interferon, or chemokine pathways) were enriched within the low-expression group, the gene was included for downstream analysis. Finally, the selected genes will be used to calculate the correlation between their expression and the infiltration rate of the activated CD+8 T-cells, natural killer cells and the activated dendric cells. A list of potential target genes has been identified and ranked based on the above-mentioned analysis and criteria. SUN-1 got the highest score within the gene list and other identified genes in the literature as benchmarks. In conclusion, inhibition of SUN1 may increase the tumor-infiltrating lymphocytes and the efficacy of ICI in BLCA patients. BLCA tumor cells with and without SUN-1 CRISPR/Cas9 knockout will be injected into the syngeneic mouse model to validate the predicted SUN-1 effect on increasing tumor-infiltrating lymphocytes.

Keywords: data analysis, gene expression analysis, gene identification, immunoinformatic, functional genomics, transcriptomics

Procedia PDF Downloads 157

Authors: George N. Prodromidis, Frank A. Coutelieris

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Biogas can be currently considered as an alternative option for electricity production, mainly due to its high energy content (hydrocarbon-rich source), its renewable status and its relatively low utilization cost. Solid Oxide Fuel Cell (SOFC) stacks convert fuel’s chemical energy to electricity with high efficiencies and reveal significant advantages on fuel flexibility combined with lower emissions rate, especially when utilize biogas. Electricity production by biogas constitutes a composite problem which incorporates an extensive parametric analysis on numerous dynamic variables. The main scope of the presented study is to propose a detailed thermodynamic model on the optimization of SOFC-based power plants’ operation based on fundamental thermodynamics, energy and exergy balances. This model named THERMAS (THERmodynamic MAthematical Simulation model) incorporates each individual process, during electricity production, mathematically simulated for different case studies that represent real life operational conditions. Also, THERMAS offers the opportunity to choose a great variety of different values for each operational parameter individually, thus allowing for studies within unexplored and experimentally impossible operational ranges. Finally, THERMAS innovatively incorporates a specific criterion concluded by the extensive energy analysis to identify the most optimal scenario per simulated system in exergy terms. Therefore, several dynamical parameters as well as several biogas mixture compositions have been taken into account, to cover all the possible incidents. Towards the optimization process in terms of an innovative OPF (OPtimization Factor), presented here, this research study reveals that systems supplied by low methane fuels can be comparable to these supplied by pure methane. To conclude, such an innovative simulation model indicates a perspective on the optimal design of a SOFC stack based system, in the direction of the commercialization of systems utilizing biogas.

Keywords: biogas, exergy, efficiency, optimization

Procedia PDF Downloads 371

Authors: Wenjun Zhang, Thao Thi Le, Dongyup Shin, Jong Min Kim

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Electrochemical hydrogen peroxide (H₂O₂) synthesis holds significant promise for decentralized environmental remediation through the electro-Fenton process. However, challenges persist, such as the absence of robust electrocatalysts for the selective two-electron oxygen reduction reaction (2e⁻ ORR) and the high cost and sluggish kinetics of conventional electro-Fenton systems in treating highly concentrated wastewater. This study introduces an efficient water treatment system for removing substantial quantities of organic pollutants using an advanced electro-Fenton system coupled with a high-valent NiO catalyst. By employing a precipitation method involving crystal facet and cation vacancy engineering, a trivalent Ni (Ni³⁺)-rich NiO catalyst with a (111)-domain-exposed crystal facet, named {111}-NivO, was synthesized. This catalyst exhibited a remarkable 96% selectivity and a high mass activity of 59 A g⁻¹ for H₂O₂ production, outperforming all previously reported Ni-based catalysts. Furthermore, an advanced electro-Fenton system, integrated with a flow cell for electrochemical H₂O₂ production, was utilized to achieve 100% removal of 50 ppm bisphenol A (BPA) in 200 mL of wastewater under heavy-duty conditions, reaching a superior rapid degradation rate (4 min, k = 1.125 min⁻¹), approximately 102 times faster than the conventional electro-Fenton system. The hyper-efficiency is attributed to the continuous and appropriate supply of H₂O₂, the provision of O₂, and the timely recycling of the electrolyte under high current density operation. This catalyst also demonstrated a 93% removal of total organic carbon after 2 hours of operation and can be applied for efficient removal of highly concentrated phenol pollutants from aqueous systems, which opens new avenues for wastewater treatment.

Keywords: hydrogen peroxide production, nickel oxides, crystal facet and cation vacancy engineering, wastewater treatment, flow cell, electro-Fenton

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Authors: Varvara Roubtsova, Mohamed Chekired

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Recent studies on the numerical simulation of geotechnical problems show the importance of considering the soil micro-structure. At this scale, soil is a discrete particle medium where the particles can interact with each other and with water flow under external forces, structure loads or natural events. This paper presents research conducted in a virtual laboratory named SiGran, developed at IREQ (Institut de recherche d’Hydro-Quebec) for the purpose of investigating a broad range of problems encountered in geotechnics. Using Discrete Element Method (DEM), SiGran simulated granular materials directly by applying Newton’s laws to each particle. The water flow was simulated by using Marker and Cell method (MAC) to solve the full form of Navier-Stokes’s equation for non-compressible viscous liquid. In this paper, examples of numerical simulation and their comparisons with real experiments have been selected to show the complexity of geotechnical research at the micro level. These examples describe transient flows into a porous medium, interaction of particles in a viscous flow, compacting of saturated and unsaturated soils and the phenomenon of liquefaction under seismic load. They also provide an opportunity to present SiGran’s capacity to compute the distribution and evolution of energy by type (particle kinetic energy, particle internal elastic energy, energy dissipated by friction or as a result of viscous interaction into flow, and so on). This work also includes the first attempts to apply micro discrete results on a macro continuum level where the Smoothed Particle Hydrodynamics (SPH) method was used to resolve the system of governing equations. The material behavior equation is based on the results of simulations carried out at a micro level. The possibility of combining three methods (DEM, MAC and SPH) is discussed.

Keywords: discrete element method, marker and cell method, numerical simulation, multi-scale simulations, smoothed particle hydrodynamics

Procedia PDF Downloads 302

Authors: Vitor Rafael Regiani, Carlos Henrique Viesi Do Nascimento Filho, Patricia Matos Biselli-Chicote, Claudia Aparecida Rainho, Luiz Sergio Raposo, José Victor Maniglia, Eny Maria Goloni-Bertollo, Erika Cristina Pavarino

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Promoter hypermethylation of tumor-related genes has been associated with prognosis in early-stage head-and-neck cancers, providing strong evidence that these hypermethylated genes are valuable biomarkers for prognostic evaluation. Hence, we selected the MGMT and RASSF1A genes to examine the methylation status in head and neck squamous cell carcinomas (HNSCC) samples matched with non-tumor tissues (tumor-surrounding tissues or peripheral blood samples). DNA methylation analysis was based on Methylation-Sensitive High Resolution Melting, and the methylation status was correlated with clinic-pathological characteristics of the patients. RASSF1A and MGMT promoter methylation was detected in 43.24% (16/37) and in 44.44% (16/36) of the tumors, respectively. RASSF1A and MGMT methylation was significantly more frequent in tumor tissue than non-tumor tissues, as well as, simultaneous methylation of RASSF1A and MGMT also was higher in tumor tissue than non-tumor tissues. In relation to anatomic site, larynx cancer presented significant methylation of MGMT gene compared to tumor-surrounding tissue. The frequency of RASSF1A and MGMT promoter methylated was higher in tumor tissues in relation to peripheral blood from the same patient. No association was found between methylation and the variables analyzed, including gender, age, smoking or alcohol drinking habits. Clinic-pathological characteristics also showed no association in the presence of methylation. The Kaplan–Meier's method showed no association of methylation and both disease-free and overall survival. In conclusion, the presence of epigenetic abnormalities in normal-appearing tissue corroborates the hypothesis of the ‘field cancerization', or it can reflect preneoplastic and/or preinvasive. Moreover, MGMT methylation may serve as an important laryngeal cancer biomarker because it showed significant difference between laryngeal cancer and surrounding tumor tissues.

Keywords: head and neck cancer, DNA methylation, MGMT promoter methylation, RASSF1A promoter methylation

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Authors: Nefzi Ahlem, Aydi Ben Abdallah Rania, Jabnoun-Khiareddine Hayfa, Ammar Nawaim, Mejda Daami-Remadi

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Fusarium Crown and Root Rot (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici (FORL) is a serious tomato (Solanum lycopersicum L.) disease in Tunisia. Its management is very difficult due to the long survival of its resting structures and to the luck of genetic resistance. In this work, we explored the wild Solanaceae species Withania somnifera, growing in the Tunisian Centre-East, as a potential source of biocontrol agents effective in FCRR suppression and tomato growth promotion. Seven fungal isolates were shown able to colonize tomato roots, crowns, and stems. Used as conidial suspensions or cell-free culture filtrates, all tested fungal treatments significantly enhanced tomato growth parameters by 21.5-90.3% over FORL-free control and by 27.6-93.5% over pathogen-inoculated control. All treatments significantly decreased the leaf and root damage index by 28.5-92.8 and the vascular browning extent 9.7-86.4% over FORL-inoculated and untreated control. The highest disease suppression ability (decrease by 86.4-92.8% in FCRR severity) over pathogen-inoculated control and by 81.3-88.8 over hymexazol-treated control) was expressed by I6 based treatments. This endophytic fungus was morphologically characterized and identified using rDNA sequencing gene as Fusarium sp. I6 (MG835371). This fungus was shown able to reduce FORL radial growth by 58.5–83.2% using its conidial suspension or cell-free culture filtrate. Fusarium sp. I6 showed chitinolytic, proteolytic and amylase activities. The current study clearly demonstrated that Fusarium sp. (I6) is a promising biocontrol candidate for suppressing FCRR severity and promoting tomato growth. Further investigations are required for elucidating its mechanism of action involved in disease suppression and plant growth promotion.

Keywords: antifungal activity, associated fungi, Fusarium oxysporum f. sp. radicis-lycopersici, Withania somnifera, tomato growth

Procedia PDF Downloads 146

Authors: Chevonne Reynolds, Res Altwegg, Andrew Balmford, Claire N. Spottiswoode

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Modern agriculture has revolutionised the planet’s capacity to support humans, yet has simultaneously had a greater negative impact on biodiversity than any other human activity. Balancing the demand for food with the conservation of biodiversity is one of the most pressing issues of our time. Biodiversity-friendly farming (‘land sharing’), or alternatively, separation of conservation and production activities (‘land sparing’), are proposed as two strategies for mediating the trade-off between agriculture and biodiversity. However, there is much debate regarding the efficacy of each strategy, as this trade-off has typically been addressed by short term studies at fine spatial scales. These studies ignore processes that are relevant to biodiversity at larger scales, such as meta-population dynamics and landscape connectivity. Therefore, to better understand species response to agricultural land-use and provide evidence to underpin the planning of better production landscapes, we need to determine the merits of each strategy at larger scales. In South Africa, a remarkable citizen science project - the South African Bird Atlas Project 2 (SABAP2) – collates an extensive dataset describing the occurrence of birds at a 5-min by 5-min grid cell resolution. We use these data, along with fine-resolution data on agricultural land-use, to determine which strategy optimises the agriculture-biodiversity trade-off in a southern African context, and at a spatial scale never considered before. To empirically test this trade-off, we model bird species population density, derived for each 5-min grid cell by Royle-Nicols single-species occupancy modelling, against both the amount and configuration of different types of agricultural production in the same 5-min grid cell. In using both production amount and configuration, we can show not only how species population densities react to changes in yield, but also describe the production landscape patterns most conducive to conservation. Furthermore, the extent of both the SABAP2 and land-cover datasets allows us to test this trade-off across multiple regions to determine if bird populations respond in a consistent way and whether results can be extrapolated to other landscapes. We tested the land sparing/sharing trade-off for 281 bird species across three different biomes in South Africa. Overall, a higher proportion of species are classified as losers, and would benefit from land sparing. However, this proportion of loser-sparers is not consistent and varies across biomes and the different types of agricultural production. This is most likely because of differences in the intensity of agricultural land-use and the interactions between the differing types of natural vegetation and agriculture. Interestingly, we observe a higher number of species that benefit from agriculture than anticipated, suggesting that agriculture is a legitimate resource for certain bird species. Our results support those seen at smaller scales and across vastly different agricultural systems, that land sparing benefits the most species. However, our analysis suggests that land sparing needs to be implemented at spatial scales much larger than previously considered. Species persistence in agricultural landscapes will require the conservation of large tracts of land, and is an important consideration in developing countries, which are undergoing rapid agricultural development.

Keywords: agriculture, birds, land sharing, land sparing

Procedia PDF Downloads 209