Search results for: targeting antibodies
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 881

Search results for: targeting antibodies

851 Targeted Delivery of Sustained Release Polymeric Nanoparticles for Cancer Therapy

Authors: Jamboor K. Vishwanatha

Abstract:

Among the potent anti-cancer agents, curcumin has been found to be very efficacious against various cancer cells. Despite multiple medicinal benefits of curcumin, poor water solubility, poor physiochemical properties and low bioavailability continue to pose major challenges in developing a formulation for clinical efficacy. To improve its potential application in the clinical area, we formulated poly lactic-co-glycolic acid (PLGA) nanoparticles. The PLGA nanoparticles were formulated using solid-oil/water emulsion solvent evaporation method and then characterized for percent yield, encapsulation efficiency, surface morphology, particle size, drug distribution within nanoparticles and drug polymer interaction. Our studies showed the successful formation of smooth and spherical curcumin loaded PLGA nanoparticles with a high percent yield of about 92.01±0.13% and an encapsulation efficiency of 90.88±0.14%. The mean particle size of the nanoparticles was found to be 145nm. The in vitro drug release profile showed 55-60% drug release from the nanoparticles over a period of 24 hours with continued sustained release over a period of 8 days. Exposure to curcumin loaded nanoparticles resulted in reduced cell viability of cancer cells compared to normal cells. We used a novel non-covalent insertion of a homo-bifunctional spacer for targeted delivery of curcumin to various cancer cells. Functionalized nanoparticles for antibody/targeting agent conjugation was prepared using a cross-linking ligand, bis(sulfosuccinimidyl) suberate (BS3), which has reactive carboxyl group to conjugate efficiently to the primary amino groups of the targeting agents. In our studies, we demonstrated successful conjugation of antibodies, Annexin A2 or prostate specific membrane antigen (PSMA), to curcumin loaded PLGA nanoparticles for targeting to prostate and breast cancer cells. The percent antibody attachment to PLGA nanoparticles was found to be 92.8%. Efficient intra-cellular uptake of the targeted nanoparticles was observed in the cancer cells. These results have emphasized the potential of our multifunctional curcumin nanoparticles to improve the clinical efficacy of curcumin therapy in patients with cancer.

Keywords: polymeric nanoparticles, cancer therapy, sustained release, curcumin

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850 Demographics Are Not Enough! Targeting and Segmentation of Anti-Obesity Campaigns in Mexico

Authors: Dagmara Wrzecionkowska

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Mass media campaigns against obesity are often designed to impact large audiences. This usually means that their audience is defined based on general demographic characteristics like age, gender, occupation etc., not taking into account psychographics like behavior, motivations, wants, etc. Using psychographics, as the base for the audience segmentation, is a common practice in case of successful campaigns, as it allows developing more relevant messages. It also serves a purpose of identifying key segments, those that generate the best return on investment. For a health campaign, that would be segments that have the best chance of being converted into healthy lifestyle at the lowest cost. This paper presents the limitations of the demographic targeting, based on the findings from the reception study of IMSS anti-obesity TV commercials and proposes mothers as the first level of segmentation, in the process of identifying the key segment for these campaigns.

Keywords: anti-obesity campaigns, mothers, segmentation, targeting

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849 Investigation of Suspected Viral Hepatitis Outbreaks in North India

Authors: Mini P. Singh, Manasi Majumdar, Kapil Goyal, Pvm Lakshmi, Deepak Bhatia, Radha Kanta Ratho

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India is endemic for Hepatitis E virus and frequent water borne outbreaks are reported. The conventional diagnosis rests on the detection of serum anti-HEV IgM antibodies which may take 7-10 days to develop. Early diagnosis in such a situation is desirable for the initiation of prompt control measures. The present study compared three diagnostic methods in 60 samples collected during two suspected HEV outbreaks in the vicinity of Chandigarh, India. The anti-HEV IgM, HEV antigen and HEV-RNA could be detected in serum samples of 52 (86.66%), 16 (26.66%) and 18 (30%) patients respectively. The suitability of saliva samples for antibody detection was also evaluated in 21 paired serum- saliva samples. A total of 15 serum samples showed the presence of anti HEV IgM antibodies, out of which 10 (10/15; 66.6%) were also positive for these antibodies in saliva samples (χ2 = 7.636, p < 0.0057), thus showing a concordance of 76.91%. The positivity of reverse transcriptase PCR and HEV antigen detection was 100% within one week of illness which declined to 5-10% thereafter. The outbreak was attributed to HEV Genotype 1, Subtype 1a and the clinical and environmental strains clustered together. HEV antigen and RNA were found to be an early diagnostic marker with 96.66% concordance. The results indicate that the saliva samples can be used as an alternative to serum samples in an outbreak situation.

Keywords: HEV-antigen, outbreak, phylogenetic analysis, saliva

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848 Development and Evaluation of Novel Diagnostic Methods for Infectious Rhinotracheitis of Cattle

Authors: Wenxiao Liu, Kun Zhang, Yongqing Li

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Bovine herpesvirus 1, a member of the genus Variellovirus of the subfamily Alphaherpesvirinae, has caused severe economic cost to the bovine industry. In this study, BoHV-1 glycerol protein gD was expressed in insect cells, and the purified gD was immunized in the Balb/C mice to generate monoclonal antibodies. Based on hybridoma cell fusion techniques, 20 monoclonal antibodies against Bovine herpesvirus 1 have been obtained. Further, mAb 3F8 with neutralizing activity and gD were applied to develop a blocking enzyme-linked immunosorbent assay (Elisa) for detecting neutralizing antibodies against BoHV-1, which shows a significant correlation between the blocking Elisa and VNT. The sensitivity and specificity of the test were estimated to be 94.59% and 93.42%, respectively. Furthermore, antibody pairing tests revealed that mAb 1B6 conjugated to fluorescence microspheres was used as the capture antibody, and mAb 3F9 was used as the detectable antibody to establish the immunochromatographic assay (ICS). The ICS was conducted to detect BoHV-1 in bovine samples with high sensitivity, specificity, and good stability. Clinical sample testing revealed that the results of ICS and real-time PCR have a coincidence rate of 95.42%. Our research confirmed that the ICS is a rapid and reliable method for the diagnosis of BoHV-1. In conclusion, our results lay a solid foundation for the prevention and control of BoHV-1 infection.

Keywords: bovine disease, BoHV-1, ELISA, ICS assay

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847 Capability of a Single Antigen to Induce Both Protective and Disease Enhancing Antibody: An Obstacle in the Creation of Vaccines and Passive Immunotherapies

Authors: Parul Kulshreshtha, Subrata Sinha, Rakesh Bhatnagar

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This study was conducted by taking B. anthracis as a model pathogen. On infecting a host, B. anthracis secretes three proteins, namely, protective antigen (PA, 83kDa), edema factor (EF, 89 kDa) and lethal factor (LF, 90 kDa). These three proteins are the components of two anthrax toxins. PA binds to the cell surface receptors, namely, tumor endothelial marker (TEM) 8 and capillary morphogenesis protein (CMG) 2. TEM8 and CMG2 interact with LDL-receptor related protein (LRP) 6 for endocytosis of EF and LF. On entering the cell, EF acts as a calmodulin-dependent adenylate cyclase that causes a prolonged increase of cytosolic cyclic adenosine monophosphate (cAMP). LF is a metalloprotease that cleaves most isoforms of mitogen-activated protein kinase kinases (MAPKK/MEK) close to their N-terminus. By secreting these two toxins, B.anthracis ascertains death of the host. Once the systemic levels of the toxins rise, antibiotics alone cannot save the host. Therefore, toxin-specific inhibitors have to be developed. In this wake, monoclonal antibodies have been developed for the neutralization of toxic effects of anthrax toxins. We created hybridomas by using spleen of mice that were actively immunized with rLFn (recombinant N-terminal domain of lethal factor of B. anthracis) to obtain anti-toxin antibodies. Later on, separate group of mice were immunized with rLFn to obtain a polyclonal control for passive immunization studies of monoclonal antibodies. This led to the identification of one cohort of rLFn-immunized mice that harboured disease-enhancing polyclonal antibodies. At the same time, the monoclonal antibodies from all the hybridomas were being tested. Two hybridomas secreted monoclonal antibodies (H8 and H10) that were cross-reactive with EF (edema factor) and LF (lethal factor), while the other two hybridomas secreted LF-specific antibodies (H7 and H11). The protective efficacy of H7, H8, H10 and H11 was investigated. H7, H8 and H10 were found to be protective. H11 was found to have disease enhancing characteristics in-vitro and in mouse model of challenge with B. anthracis. In this study the disease enhancing character of H11 monoclonal antibody and anti-rLFn polyclonal sera was investigated. Combination of H11 with protective monoclonal antibodies (H8 and H10) reduced its disease enhancing nature both in-vitro and in-vivo. But combination of H11 with LETscFv (an scFv with VH and VL identical to H10 but lacking Fc region) could not abrogate the disease-enhancing character of H11 mAb. Therefore it was concluded that for suppression of disease enhancement, Fc portion was absolutely essential for interaction of H10 with H11. Our study indicates that the protective potential of an antibody depends equally on its idiotype/ antigen specificity and its isotype. A number of monoclonal and engineered antibodies are being explored as immunotherapeutics but it is absolutely essential to characterize each one for their individual and combined protective potential. Although new in the sphere of toxin-based diseases, it is extremely important to characterize the disease-enhancing nature of polyclonal as well as monoclonal antibodies. This is because several anti-viral therapeutics and vaccines have failed in the face of this phenomenon. The passive –immunotherapy thus needs to be well formulated to avoid any contraindications.

Keywords: immunotherapy, polyclonal, monoclonal, antibody-dependent disease enhancement

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846 Noncovalent Antibody-Nanomaterial Conjugates: A Simple Approach to Produce Targeted Nanomedicines

Authors: Nicholas Fletcher, Zachary Houston, Yongmei Zhao, Christopher Howard, Kristofer Thurecht

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One promising approach to enhance nanomedicine therapeutic efficacy is to include a targeting agent, such as an antibody, to increase accumulation at the tumor site. However, the application of such targeted nanomedicines remains limited, in part due to difficulties involved with biomolecule conjugation to synthetic nanomaterials. One approach recently developed to overcome this has been to engineer bispecific antibodies (BsAbs) with dual specificity, whereby one portion binds to methoxy polyethyleneglycol (mPEG) epitopes present on synthetic nanomedicines, while the other binds to molecular disease markers of interest. In this way, noncovalent complexes of nanomedicine core, comprising a hyperbranched polymer (HBP) of primarily mPEG, decorated with targeting ligands are able to be produced by simple mixing. Further work in this area has now demonstrated such complexes targeting the breast cancer marker epidermal growth factor receptor (EGFR) to show enhanced binding to tumor cells both in vitro and in vivo. Indeed the enhanced accumulation at the tumor site resulted in improved therapeutic outcomes compared to untargeted nanomedicines and free chemotherapeutics. The current work on these BsAb-HBP conjugates focuses on further probing antibody-nanomaterial interactions and demonstrating broad applicability to a range of cancer types. Herein are reported BsAb-HBP materials targeted towards prostate-specific membrane antigen (PSMA) and study of their behavior in vivo using ⁸⁹Zr positron emission tomography (PET) in a dual-tumor prostate cancer xenograft model. In this model mice bearing both PSMA+ and PSMA- tumors allow for PET imaging to discriminate between nonspecific and targeted uptake in tumors, and better quantify the increased accumulation following BsAb conjugation. Also examined is the potential for formation of these targeted complexes in situ following injection of individual components? The aim of this approach being to avoid undesirable clearance of proteinaceous complexes upon injection limiting available therapeutic. Ultimately these results demonstrate BsAb functionalized nanomaterials as a powerful and versatile approach for producing targeted nanomedicines for a variety of cancers.

Keywords: bioengineering, cancer, nanomedicine, polymer chemistry

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845 Comparison of the Effectiveness of Neisseria gonorrhea Crude Protein Injections with Intravenous, Intracutaneous, and Subcutaneous

Authors: Annisa Amalina, Lintang Sekar Sari, Khairunnisa Salsabila, Astya Gema Ramadhan, M. Fatkhi, Andani Eka Putra

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Gonorrhea is one of the sexually transmitted diseases by genito-genital, oro-genital and anogenital. Gonorrhea disease will cause complications if not treated properly. The diagnostic tool that has been used nowadays is microscopic. Thus a rapid diagnostic tool for gonorrhea is required, using polyclonal antibodies. The purpose of this study was to determine the effectiveness of injections of intravenous, subcutaneous and intracutaneous crude protein gonorrhea. The research method used in this research is experimental explorative. This research was conducted in Molecular Microbiology Laboratory of Faculty of Medicine, Andalas University for 3 months from April to June 2017. This study used 3 groups of rabbit with intravenous, subcutaneous, and intracutaneous injections. Each group was treated on days 1, 7, 21, and 28 with crude protein injection. After that, the examination of antibody levels held by using ELISA, followed by the antibody comparative tests contained in all three groups. The results examined by One Way ANOVA test on SPSS 21 and showed that there is no significant difference between intravenous, subcutaneous, and intracutaneous use p=0.69 (p < 0.05). However, there is an increased level (0.047 to 1.171) in antibodies from day 1 to day 14. In addition, subcutaneous use is preferred because it has minimal side effects compared to intravenous and intracutaneous use.

Keywords: crude protein, Neisseria gonorrhea, polyclonal antibodies, subcutaneous

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844 Development of pH Responsive Nanoparticles for Colon Targeted Drug Delivery System

Authors: V. Balamuralidhara

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The aim of the present work was to develop Paclitaxel loaded polyacrylamide grafted guar gum nanoparticles as pH responsive nanoparticle systems for targeting colon. The pH sensitive nanoparticles were prepared by modified ionotropic gelation technique. The prepared nanoparticles showed mean diameters in the range of 264±0.676 nm to 726±0.671nm, and a negative net charge 10.8 mV to 35.4mV. Fourier Transformed Infrared Spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC) studies suggested that there was no chemical interaction between drug and polymers. The encapsulation efficiency of the drug was found to be 40.92% to 48.14%. The suitability of the polyacrylamide grafted guar gum ERN’s for the release of Paclitaxel was studied by in vitro release at pH 1.2 and 7.4. It was observed that, there was no significant amount of drug release at gastric pH and 97.63% of drug release at pH 7.4 was obtained for optimized formulation F3 at the end of 12 hrs. In vivo drug targeting performance for the prepared optimized formulation (F3) and pure drug Paclitaxel was evaluated by HPLC. It was observed that the polyacrylamide grafted guar gum can be used to prepare nanoparticles for targeting the drug to the colon. The release performance was greatly affected by the materials used in ERN’s preparation, which allows maximum release at colon’s pH. It may be concluded that polyacrylamide grafted guar gum nanoparticles loaded with paclitaxel have desirable release responsive to specific pH. Hence it is a unique approach for colonic delivery of drug having appropriate site specificity and feasibility and controlled release of drug.

Keywords: colon targeting, polyacrylamide grafted guar gum nanoparticles, paclitaxel, nanoparticles

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843 Determining the Presence of Brucella abortus Antibodies by the Indirect Elisa Method in Bovine Bulk Milk and Risk Factors in the Peri-Urban Zones of Bamenda Cameroon

Authors: Cha-ah C. N., Awah N. J., Mouiche M. M. M.

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Brucellosis is a neglected zoonotic disease of animals and man caused by bacteria of genus Brucella. Though eradicated in some parts of the world, it remains endemic in sub-Saharan Africa including Cameroon. The aim of this study was to contribute to the epidemiology of brucellosis in the North-West region of Cameroon by detecting the presence of anti-Brucella antibodies in bovine bulk milk as this serves as a route of transmission from animals to man. A cross sectional study was conducted to determine the prevalence of Brucella abortus antibodies in bovine bulk milk in the peri-urban zones of Bamenda. One hundred bulk milk samples were collected from 100 herds and tested by milk I-ELISA test. The conducted study revealed the presence of anti-Brucella abortus antibodies in bovine bulk milk. The study revealed that bovine brucellosis is widespread in animal production systems in this area. The animal infection pressure in these systems has remained strong due to movement of livestock in search of pasture, co-existence of animal husbandry, communal sharing of grazing land, concentration of animals around water points, abortions in production systems, locality of production systems and failure to quarantine upon introduction of new animals. The circulation of Brucella abortus antibodies in cattle farms recorded in the study revealed potential public health implication and suggest economic importance of brucellosis to the cattle industry in the Northwest region of Cameroon. The risk for re-emergence and transmission of brucellosis is evident as a result of the co-existence of animal husbandry activities and social-cultural activities that promote brucellosis transmission. Well-designed countrywide, evidence-based studies of brucellosis are needed. These could help to generate reliable frequency and potential impact estimates, to identify Brucella reservoirs, and to propose control strategies of proven efficacy.

Keywords: brucellosis, bulk milk, northwest region Cameroon, prevalence

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842 Faculty and Students Perspectives of E-Learning at the University of Bahrain

Authors: Amira Abdulrazzaq

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This paper is studying the opinion of faculty members and students about the future of education (e-learning) at the University of Bahrain. Through quantitative analysis a distribution of two surveys, one targeting students of IT College, and College of Arts and the other targeting Faculty members of both Colleges. Through the above survey, the paper measures the following factors: awareness and acceptance, satisfaction, usability, and usefulness. Results indicate positive reactions of all above factors.

Keywords: e-learning, education, moodle, WebCT

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841 Leptospira Lipl32-Specific Antibodies: Therapeutic Property, Epitopes Characterization and Molecular Mechanisms of Neutralization

Authors: Santi Maneewatchararangsri, Wanpen Chaicumpa, Patcharin Saengjaruk, Urai Chaisri

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Leptospirosis is a globally neglected disease that continues to be a significant public health and veterinary burden, with millions of cases reported each year. Early and accurate differential diagnosis of leptospirosis from other febrile illnesses and the development of a broad spectrum of leptospirosis vaccines are needed. The LipL32 outer membrane lipoprotein is a member of Leptospira adhesive matrices and has been found to exert hemolytic activity to erythrocytes in vitro. Therefore, LipL32 is regarded as a potential target for diagnosis, broad-spectrum leptospirosis vaccines, and for passive immunotherapy. In this study, we established LipL32-specific mouse monoclonal antibodies, mAbLPF1 and mAbLPF2, and their respective mouse- and humanized-engineered single chain variable fragment (ScFv). Their antibodies’ neutralizing activities against Leptospira-mediated hemolysis in vitro, and the therapeutic efficacy of mAbs against heterologous Leptospira infected hamsters were demonstrated. The epitope peptide of mAb LPF1 was mapped to a non-contiguous carboxy-terminal β-turn and amphipathic α-helix of LipL32 structure contributing to phospholipid/host cell adhesion and membrane insertion. We found that the mAbLPF2 epitope was located on the interacting loop of peptide binding groove of the LipL32 molecule responsible for interactions with host constituents. Epitope sequences are highly conserved among Leptospira spp. and are absent from the LipL32 superfamily of other microorganisms. Both epitopes are surface-exposed, readily accessible by mAbs, and immunogenic. However, they are less dominant when revealed by LipL32-specific immunoglobulins from leptospirosis-patient sera and rabbit hyperimmune serum raised by whole Leptospira. Our study also demonstrated an adhesion inhibitory activity of LipL32 protein to host membrane components and cells mediated by mAbs as well as an anti-hemolytic activity of the respective antibodies. The therapeutic antibodies, particularly the humanized-ScFv, have a potential for further development as non-drug therapeutic agent for human leptospirosis, especially in subjects allergic to antibiotics. The epitope peptides recognized by two therapeutic mAbs have potential use as tools for structure-function studies. Finally, protective peptides may be used as a target for epitope-based vaccines for control of leptospirosis.

Keywords: leptospira lipl32-specific antibodies, therapeutic epitopes, epitopes characterization, immunotherapy

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840 Novel p22-Monoclonal Antibody Based Blocking ELISA for the Detection of African Swine Fever Virus Antibodies in Serum

Authors: Ghebremedhin Tsegay, Weldu Tesfagaber, Yuanmao Zhu, Xijun He, Wan Wang, Zhenjiang Zhang, Encheng Sun, Jinya Zhang, Yuntao Guan, Fang Li, Renqiang Liu, Zhigao Bu, Dongming Zhao*

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African swine fever (ASF) is a highly infectious viral disease of pigs, resulting in significant economic loss worldwide. As there is no approved vaccines and treatments, the control of ASF entirely depends on early diagnosis and culling of infected pigs. Thus, highly specific and sensitive diagnostic assays are required for accurate and early diagnosis of ASF virus (ASFV). Currently, only a few recombinant proteins have been tested and validated for use as reagents in ASF diagnostic assays. The most promising ones for ASFV antibody detection were p72, p30, p54, and pp62. So far, three ELISA kits based on these recombinant proteins have been commercialized. Due to the complex nature of the virus and variety forms of the disease, robust serodiagnostic assays are still required. ASFV p22 protein, encoded by KP177R gene, is located in the inner membrane of viral particle and appeared transiently in the plasma membrane early after virus infection. The p22 protein interacts with numerous cellular proteins, involved in processes of phagocytosis and endocytosis through different cellular pathways. However, p22 does not seem to be involved in virus replication or swine pathogenicity. In this study, E.coli expressed recombinant p22 protein was used to generate a monoclonal antibody (mAb), and its potential use for the development of blocking ELISA (bELISA) was evaluated. A total of 806 pig serum samples were tested to evaluate the bELISA. Acording the ROC (Reciever operating chracteristic) analysis, 100% sensitivity and 98.10% of specificity was recorded when the PI cut-off value was set at 47%. The novel assay was able to detect the antibodies as early as 9 days post infection. Finaly, a highly sensitive, specific and rapid novel p22-mAb based bELISA assay was developed, and optimized for detection of antibodies against genotype I and II ASFVs. It is a promising candidate for an early and acurate detection of the antibodies and is highly expected to have a valuable role in the containment and prevention of ASF.

Keywords: ASFV, blocking ELISA, diagnosis, monoclonal antibodies, sensitivity, specificity

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839 Gluten Intolerance, Celiac Disease, and Neuropsychiatric Disorders: A Translational Perspective

Authors: Jessica A. Hellings, Piyushkumar Jani

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Background: Systemic autoimmune disorders are increasingly implicated in neuropsychiatric illness, especially in the setting of treatment resistance in individuals of all ages. Gluten allergy in fullest extent results in celiac disease, affecting multiple organs including central nervous system (CNS). Clinicians often lack awareness of the association between neuropsychiatric illness and gluten allergy, partly since many such research studies are published in immunology and gastroenterology journals. Methods: Following a Pubmed literature search and online searches on celiac disease websites, 40 articles are critically reviewed in detail. This work reviews celiac disease, gluten intolerance and current evidence of their relationship to neuropsychiatric and systemic illnesses. The review also covers current work-up and diagnosis, as well as dietary interventions, gluten restriction outcomes, and future research directions. Results: Gluten allergy in susceptible individuals damages the small intestine, producing a leaky gut and malabsorption state, as well as allowing antibodies into the bloodstream, which attack major organs. Lack of amino acid precursors for neurotransmitter synthesis together with antibody-associated brain changes and hypoperfusion may result in neuropsychiatric illness. This is well documented; however, studies in neuropsychiatry are often small. In the large CATIE trial, subjects with schizophrenia had significantly increased antibodies to tissue transglutaminase (TTG), and antigliadin antibodies, both significantly greater gluten antibodies than in control subjects. On later follow up, TTG-6 antibodies were identified in these subjects’ brains but not in their intestines. Significant evidence mostly from small studies also exists for gluten allergy and celiac-related depression, anxiety disorders, attention-deficit/hyperactivity disorder, autism spectrum disorders, ataxia, and epilepsy. Dietary restriction of gluten resulted in remission in several published cases, including for treatment-resistant schizophrenia. Conclusions: Ongoing and larger studies are needed of the diagnosis and treatment efficacy of the gluten-free diet in neuropsychiatric illness. Clinicians should ask about the patient history of anemia, hypothyroidism, irritable bowel syndrome and family history of benefit from the gluten-free diet, not limited to but especially in cases of treatment resistance. Obtaining gluten antibodies by a simple blood test, and referral for gastrointestinal work-up in positive cases should be considered.

Keywords: celiac, gluten, neuropsychiatric, translational

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838 Crossing of the Intestinal Barrier Thanks to Targeted Biologics: Nanofitins

Authors: Solene Masloh, Anne Chevrel, Maxime Culot, Leonardo Scapozza, Magali Zeisser-Labouebe

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The limited stability of clinically proven therapeutic antibodies limits their administration by the parenteral route. However, oral administration remains the best alternative as it is the most convenient and less invasive one. Obtaining a targeted treatment based on biologics, which can be orally administered, would, therefore, be an ideal situation to improve patient adherence and compliance. Nevertheless, the delivery of macromolecules through the intestine remains challenging because of their sensitivity to the harsh conditions of the gastrointestinal tract and their low permeability across the intestinal mucosa. To address this challenge, this project aims to demonstrate that targeting receptor-mediated endocytosis followed by transcytosis could maximize the intestinal uptake and transport of large molecules, such as Nanofitins. These affinity proteins of 7 kDa with binding properties similar to antibodies have already demonstrated retained stability in the digestive tract and local efficiency. However, their size does not allow passive diffusion through the intestinal barrier. Nanofitins having a controlled affinity for membrane receptors involved in the transcytosis mechanism used naturally for the transport of large molecules in humans were generated. Proteins were expressed using ribosome display and selected based on affinity to the targeted receptor and other characteristics. Their uptake and transport ex vivo across viable porcine intestines were investigated using an Ussing chambers system. In this paper, we will report the results achieved while addressing the different challenges linked to this study. To validate the ex vivo model, first, we proved the presence of the receptors targeted in humans on the porcine intestine. Then, after the identification of an optimal way of detection of Nanofitins, transport experiments were performed on porcine intestines with viability followed during the time of the experiment. The results, showing that the physiological process of transcytosis is capable of being triggered by the binding of Nanofitins on their target, will be reported here. In conclusion, the results show that Nanofitins can be transported across the intestinal barrier by triggering the receptor-mediated transcytosis and that the ex vivo model is an interesting technique to assess biologics absorption through the intestine.

Keywords: ex-vivo, Nanofitins, oral administration, transcytosis

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837 Production of Camel Nanobodies against of Anti-Morphine-3-Glucuronide for the Development of a Biosensor for Detecting Illicit Drug

Authors: Shirin Jalili, Sadegh Hasannia, Hadi Shirzad, Afshin Khara

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Morphine is one of the most medicinally important analgesics and narcotics. Structurally, it is classified as an alkaloid because of the presence of nitrogen. Its structure is similar to that of codeine, thebaine, and heroin. An immunoassay to accurately discriminate between these analogous alkaloids would be highly beneficial. A key factor for such an assay is specificity with high sensitivity, which is totally dependent on the antibody employed. However, most antibodies against haptens are polyclonal serum antibodies that exhibit significant cross-reactivities with closely related compounds. The camel-derived single-chain antibody fragments (VHH) are the smallest molecules with antigen-binding capacity, possessing unique properties compared to other conventional antibodies. In this study, a library containing the VHH genes of a camel immunized with with morphine conjugated BSA following phage display technology was generated. By screening the camel-derived variable region of the heavy chain cDNA phage display library with the ability to bind the desired hapten, we obtained some nanobodies that recognize this hapten. Phage display expression of the Nbs from this library and pannings against this hapten resulted in a clear enrichment of four distinct Nb-displaying phages with specificity for morphine that could be a potential target site for the development of new strategies for the development of a biosensor for detecting illicit drug.

Keywords: phage display, nanobody, Morphine-3, glucuronide, ELISA, biosensor

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836 An Analysis on Aid for Migrants: A Descriptive Analysis on Official Development Assistance During the Migration Crisis

Authors: Elena Masi, Adolfo Morrone

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Migration has recently become a mainstream development sector and is currently at the forefront in institutional and civil society context. However, no consensus exists on how the link between migration and development operates, that is how development is related to migration and how migration can promote development. On one hand, Official Development Assistance is recognized to be one of the levers to development. On the other hand, the debate is focusing on what should be the scope of aid programs targeting migrants groups and in general the migration process. This paper provides a descriptive analysis on how development aid for migration was allocated in the recent past, focusing on the actions that were funded and implemented by the international donor community. In the absence of an internationally shared methodology for defining the boundaries of development aid on migration, the analysis based on lexical hypotheses on the title or on the short description of initiatives funded by several Organization for Economic Co-operation and Development (OECD) countries. Moreover, the research describes and quantifies aid flows for each country according to different criteria. The terms migrant and refugee are used to identify the projects in accordance with the most internationally agreed definitions and only actions in countries of transit or of origin are considered eligible, thus excluding the amount sustained for refugees in donor countries. The results show that the percentage of projects targeting migrants, in terms of amount, has followed a growing trend from 2009 to 2016 in several European countries, and is positively correlated with the flows of migrants. Distinguishing between programs targeting migrants and programs targeting refugees, some specific national features emerge more clearly. A focus is devoted to actions targeting the root causes of migration, showing an inter-sectoral approach in international aid allocation. The analysis gives some tentative solutions to the lack of consensus on language on migration and development aid, and emphasizes the need to internationally agree on a criterion for identifying programs targeting both migrants and refugees, to make action more transparent and in order to develop effective strategies at the global level.

Keywords: migration, official development assistance, ODA, refugees, time series

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835 New Test Algorithm to Detect Acute and Chronic HIV Infection Using a 4th Generation Combo Test

Authors: Barun K. De

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Acquired immunodeficiency syndrome (AIDS) is caused by two types of human immunodeficiency viruses, collectively designated HIV. HIV infection is spreading globally particularly in developing countries. Before an individual is diagnosed with HIV, the disease goes through different phases. First there is an acute early phase that is followed by an established or chronic phase. Subsequently, there is a latency period after which the individual becomes immunodeficient. It is in the acute phase that an individual is highly infectious due to a high viral load. Presently, HIV diagnosis involves use of tests that do not detect the acute phase infection during which both the viral RNA and p24 antigen are expressed. Instead, these less sensitive tests detect antibodies to viral antigens which are typically sero-converted later in the disease process following acute infection. These antibodies are detected in both asymptomatic HIV-infected individuals as well as AIDS patients. Studies indicate that early diagnosis and treatment of HIV infection can reduce medical costs, improve survival, and reduce spreading of infection to new uninfected partners. Newer 4th generation combination antigen/antibody tests are highly sensitive and specific for detection of acute and established HIV infection (HIV1 and HIV2) enabling immediate linkage to care. The CDC (Center of Disease Control, USA) recently recommended an algorithm involving three different tests to screen and diagnose acute and established infections of HIV-1 and HIV-2 in a general population. Initially a 4th generation combo test detects a viral antigen p24 and specific antibodies against HIV -1 and HIV-2 envelope proteins. If the test is positive it is followed by a second test known as a differentiation assay which detects antibodies against specific HIV-1 and HIV-2 envelope proteins confirming established infection of HIV-1 or HIV-2. However if it is negative then another test is performed that measures viral load confirming an acute HIV-1 infection. Screening results of a Phoenix area population detected 0.3% new HIV infections among which 32.4% were acute cases. Studies in the U.S. indicate that this algorithm effectively reduces HIV infection through immediate treatment and education following diagnosis.

Keywords: new algorithm, HIV, diagnosis, infection

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834 Seroprevalence of Toxoplasmosis among Hemato-Oncology Patients in Tertiary Hospital of East Cost Malaysia

Authors: Aisha Khodijah Kholib Jati, Suharni Mohamad, Azlan Husin, Wan Suriana Wan Ab Rahman

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Introduction: Toxoplasmosis is caused by an obligate intracellular parasite, Toxoplasma gondii (T. gondii). It is commonly asymptomatic in normal individual, but it can be fatal to immunocompromised patients as it can lead to severe complications such as encephalitis, chorioetinitis and myocarditis. Objective: The aim of the study was to determine the seroprevalence of toxoplasmosis and its association with socio-demographic and behavioral characteristics among hemato-oncology patients in Hospital USM. Methods: In this cross-sectional study, 56 hemato-oncology patients were screened for immunoglobulin M (IgM) antibodies, immunoglobulin G (IgG) antibodies, and IgG avidity of T. gondii by using ELISA Kit (BioRad, USA). For anti-T. gondii IgG antibody, titer ≥ 9 IU/ml was considered as recent infection, while for IgM, ratio ≥ 1.00 was considered as reactive for the anti-T. gondii IgM antibodies. Low avidity index is considered as recent infection within 20 weeks while high avidity considered as past infection. T. gondii exposure, socio-demographic and behavioral characteristics was assessed by a questionnaire and interview. Results: A total of 28 (50.0%) hemato-oncology patients were seropositive for T. gondii antibodies. Out of that total, 27 (48.21%) patients were IgG+/IgM- and one patient (1.79%) was IgG+/IgM+ with high avidity index. Univariate analysis showed that age, gender, ethnicity, marital status, educational level, employment status, stem cell transplant, blood transfusion, close contact with cats, water supply, and consumption of undercooked meat were not significantly associated with Toxoplasma seropositivity rate. Discussion: The seropositivity rate of IgG anti-T. gondii was high among hemato-oncology patients in Hospital USM. With impaired immune system, these patients might have a severe consequence if the infection reactivated. Therefore, screening for anti-T. gondii may be considered in the future. Moreover, health programme towards healthy food and good hygiene practice need to be implemented.

Keywords: immunocompromised, seroprevalence, socio-demographic, toxoplasmosis

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833 Removal of Aggregates of Monoclonal Antibodies by Ion Exchange Chrmoatography

Authors: Ishan Arora, Anurag Rathore

Abstract:

The primary objective of this work was to study the effect of resin chemistry, pH and molarity of binding and elution buffer on aggregate removal using Cation Exchange Chromatography and find the optimum conditions which can give efficient aggregate removal with minimum loss of yield. Four different resins were used for carrying out the experiments: Fractogel EMD SO3-(S), Fractogel EMD COO-(M), Capto SP ImpRes and S Ceramic HyperD. Runs were carried out on the AKTA Avant system. Design of Experiments (DOE) was used for analysis using the JMP software. The dependence of the yield obtained using different resins on the operating conditions was studied. Success has been achieved in obtaining yield greater than 90% using Capto SP ImpRes and Fractogel EMD COO-(M) resins. It has also been found that a change in the operating conditions generally has different effects on the yields obtained using different resins.

Keywords: aggregates, cation exchange chromatography, design of experiments, monoclonal antibodies

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832 Removal of Aggregates of Monoclonal Antibodies by Ion Exchange Chromatography

Authors: Ishan Arora, Anurag Rathore

Abstract:

The primary objective of this work was to study the effect of resin chemistry, pH and molarity of binding and elution buffer on aggregate removal using Cation Exchange Chromatography and find the optimum conditions which can give efficient aggregate removal with minimum loss of yield. Four different resins were used for carrying out the experiments: Fractogel EMD SO3-(S), Fractogel EMD COO-(M), Capto SP ImpRes and S Ceramic HyperD. Runs were carried out on the AKTA Avant system. Design of Experiments (DOE) was used for analysis using the JMP software. The dependence of the yield obtained using different resins on the operating conditions was studied. Success has been achieved by obtaining yield greater than 90% using Capto SP ImpRes and Fractogel EMD COO-(M) resins. It has also been found that a change in the operating conditions generally has different effects on the yields obtained using different resins.

Keywords: aggregates, cation exchange chromatography, design of experiments, monoclonal antibodies

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831 Anti-DNA Antibodies from Patients with Schizophrenia Hydrolyze DNA

Authors: Evgeny A. Ermakov, Lyudmila P. Smirnova, Valentina N. Buneva

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Schizophrenia associated with dysregulation of neurotransmitter processes in the central nervous system and disturbances in the humoral immune system resulting in the formation of antibodies (Abs) to the various components of the nervous tissue. Abs to different neuronal receptors and DNA were detected in the blood of patients with schizophrenia. Abs hydrolyzing DNA were detected in pool of polyclonal autoantibodies in autoimmune and infectious diseases, such catalytic Abs were named abzymes. It is believed that DNA-hydrolyzing abzymes are cytotoxic, cause nuclear DNA fragmentation and induce cell death by apoptosis. Abzymes with DNAase activity are interesting because of the mechanism of formation and the possibility of use as diagnostic markers. Therefore, in our work we have set following goals: to determine the level anti-DNA Abs in the serum of patients with schizophrenia and to study DNA-hydrolyzing activity of IgG of patients with schizophrenia. Materials and methods: In our study there were included 41 patients with a verified diagnosis of paranoid or simple schizophrenia and 24 healthy donors. Electrophoretically and immunologically homogeneous IgGs were obtained by sequential affinity chromatography of the serum proteins on protein G-Sepharose and gel filtration. The levels of anti-DNA Abs were determined using ELISA. DNA-hydrolyzing activity was detected as the level of supercoiled pBluescript DNA transition in circular and linear forms, the hydrolysis products were analyzed by agarose electrophoresis followed by ethidium bromide stain. To correspond the registered catalytic activity directly to the antibodies we carried out a number of strict criteria: electrophoretic homogeneity of the antibodies, gel filtration (acid shock analysis) and in situ activity. Statistical analysis was performed in ‘Statistica 9.0’ using the non-parametric Mann-Whitney test. Results: The sera of approximately 30% of schizophrenia patients displayed a higher level of Abs interacting with single-stranded (ssDNA) and double-stranded DNA (dsDNA) compared with healthy donors. The average level of Abs interacting with ssDNA was only 1.1-fold lower than that for interacting with dsDNA. IgG of patient with schizophrenia were shown to possess DNA hydrolyzing activity. Using affinity chromatography, electrophoretic analysis of isolated IgG homogeneity, gel filtration in acid shock conditions and in situ DNAse activity analysis we proved that the observed activity is intrinsic property of studied antibodies. We have shown that the relative DNAase activity of IgG in patients with schizophrenia averaged 55.4±32.5%, IgG of healthy donors showed much lower activity (average of 9.1±6.5%). It should be noted that DNAase activity of IgG in patients with schizophrenia with a negative symptoms was significantly higher (73.3±23.8%), than in patients with positive symptoms (43.3±33.1%). Conclusion: Anti-DNA Abs of patients with schizophrenia not only bind DNA, but quite efficiently hydrolyze the substrate. The data show a correlation with the level of DNase activity and leading symptoms of patients with schizophrenia.

Keywords: anti-DNA antibodies, abzymes, DNA hydrolysis, schizophrenia

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830 Diagnostic Value of Different Noninvasive Criteria of Latent Myocarditis in Comparison with Myocardial Biopsy

Authors: Olga Blagova, Yuliya Osipova, Evgeniya Kogan, Alexander Nedostup

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Purpose: to quantify the value of various clinical, laboratory and instrumental signs in the diagnosis of myocarditis in comparison with morphological studies of the myocardium. Methods: in 100 patients (65 men, 44.7±12.5 years) with «idiopathic» arrhythmias (n = 20) and dilated cardiomyopathy (DCM, n = 80) were performed 71 endomyocardial biopsy (EMB), 13 intraoperative biopsy, 5 study of explanted hearts, 11 autopsy with virus investigation (real-time PCR) of the blood and myocardium. Anti-heart antibodies (AHA) were also measured as well as cardiac CT (n = 45), MRI (n = 25), coronary angiography (n = 47). The comparison group included of 50 patients (25 men, 53.7±11.7 years) with non-inflammatory heart diseases who underwent open heart surgery. Results. Active/borderline myocarditis was diagnosed in 76.0% of the study group and in 21.6% of patients of the comparison group (p < 0.001). The myocardial viral genome was observed more frequently in patients of comparison group than in study group (group (65.0% and 40.2%; p < 0.01. Evaluated the diagnostic value of noninvasive markers of myocarditis. The panel of anti-heart antibodies had the greatest importance to identify myocarditis: sensitivity was 81.5%, positive and negative predictive value was 75.0 and 60.5%. It is defined diagnostic value of non-invasive markers of myocarditis and diagnostic algorithm providing an individual assessment of the likelihood of myocarditis is developed. Conclusion. The greatest significance in the diagnosis of latent myocarditis in patients with 'idiopathic' arrhythmias and DCM have AHA. The use of complex of noninvasive criteria allows estimate the probability of myocarditis and determine the indications for EMB.

Keywords: myocarditis, "idiopathic" arrhythmias, dilated cardiomyopathy, endomyocardial biopsy, viral genome, anti-heart antibodies

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829 Mannosylated Oral Amphotericin B Nanocrystals for Macrophage Targeting: In vitro and Cell Uptake Studies

Authors: Rudra Vaghela, P. K. Kulkarni

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The aim of the present research was to develop oral Amphotericin B (AmB) nanocrystals (Nc) grafted with suitable ligand in order to enhance drug transport across the intestinal epithelial barrier and subsequently, active uptake by macrophages. AmB Nc were prepared by liquid anti-solvent precipitation technique (LAS). Poloxamer 188 was used to stabilize the prepared AmB Nc and grafted with mannose for actively targeting M cells in Peyer’s patches. To prevent shedding of the stabilizer and ligand, N,N’-Dicyclohexylcarbodiimide (DCC) was used as a cross-linker. The prepared AmB Nc were characterized for particle size, PDI, zeta potential, X-ray diffraction (XRD) and surface morphology using scanning electron microscope (SEM) and evaluated for drug content, in vitro drug release and cell uptake studies using caco-2 cells. The particle size of stabilized AmB Nc grafted with WGA was in the range of 287-417 nm with negative zeta potential between -18 to -25 mV. XRD studies revealed crystalline nature of AmB Nc. SEM studies revealed that ungrafted AmB Nc were irregular in shape with rough surface whereas, grafted AmB Nc were found to be rod-shaped with smooth surface. In vitro drug release of AmB Nc was found to be 86% at the end of one hour. Cellular studies revealed higher invasion and uptake of AmB Nc towards caco-2 cell membrane when compared to ungrafted AmB Nc. Our findings emphasize scope on developing oral delivery system for passively targeting M cells in Peyer’s patches.

Keywords: leishmaniasis, amphotericin b nanocrystals, macrophage targeting, LAS technique

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828 Seroprevalence of Cytomegalovirus among Pregnant Women in Islamabad, Pakistan

Authors: Hassan Waseem

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Cytomegalovirus (CMV) is ubiquitously distributed viral agent responsible for different clinical manifestations that may vary according to the immunologic status of the patient. CMV can cause morbidity and mortality among fetuses and patients with compromised immune system. A cross-sectional study was carried out in Islamabad to investigate the prevalence and risk factors associated with CMV infection among pregnant women. Blood samples of 172 pregnant women visiting Mother and Child Healthcare, Pakistan Institute of Medical Sciences (PIMS) Islamabad were taken. In present study, serum samples of the women were checked for CMV-specific IgG and IgM antibodies by enzyme linked immunosorbent assay (ELISA). Clinical, obstetrical and socio-demographical characteristics of the women were collected by using structured questionnaires. Out of 172 pregnant women included in the study, 171 (99.4%) were CMV specific IgG positive and 30 (17.4%) were found positive for CMV-IgM antibodies. The CMV has taken an endemic form in Pakistan so, routine screening of CMV among pregnant women is recommended.

Keywords: Cytomegalovirus, blood transfusion, ELISA, seroprevalence

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827 Rheumatoid Arthritis, Periodontitis and the Subgingival Microbiome: A Circular Relationship

Authors: Isabel Lopez-Oliva, Akshay Paropkari, Shweta Saraswat, Stefan Serban, Paola de Pablo, Karim Raza, Andrew Filer, Iain Chapple, Thomas Dietrich, Melissa Grant, Purnima Kumar

Abstract:

Objective: We aimed to explicate the role of the subgingival microbiome in the causal link between rheumatoid arthritis (RA) and periodontitis (PD). Methods: Subjects with/without RA and with/without PD were randomized for treatment with scaling and root planing (SRP) or oral hygiene instructions. Subgingival biofilm, gingival crevicular fluid, and serum were collected at baseline and at 3- and 6-months post-operatively. Correlations were generated between 72 million 16S rDNA sequences, immuno-inflammatory mediators, circulating antibodies to oral microbial antigens, serum inflammatory molecules, and clinical metrics of RA. The dynamics of inter-microbial and host-microbial interactions were modeled using differential network analysis. Results: RA superseded periodontitis as a determinant of microbial composition, and DAS28 score superseded the severity of periodontitis as a driver of microbial assemblages (p=0.001, ANOSIM). RA subjects evidenced higher serum anti-PPAD (p=0.0013), anti-Pg-enolase (p=0.0031), anti-RPP3, anti- Pg-OMP and anti- Pi-OMP (p=0.001) antibodies than non-RA controls (with and without periodontitis). Following SRP, bacterial networks anchored by IL-1b, IL-4, IL-6, IL-10, IL-13, MIP-1b, and PDGF-b underwent ≥5-fold higher rewiring; and serum antibodies to microbial antigens decreased significantly. Conclusions: Our data suggest a circular relationship between RA and PD, beginning with an RA-influenced dysbiosis within the healthy subgingival microbiome that leads to exaggerated local inflammation in periodontitis and circulating antibodies to periodontal pathogens and positive correlation between severity of periodontitis and RA activity. Periodontal therapy restores host-microbial homeostasis, reduces local inflammation, and decreases circulating microbial antigens. Our data highlights the importance of integrating periodontal care into the management of RA patients.

Keywords: rheumatoid arthritis, periodontal, subgingival, DNA sequence analysis, oral microbiome

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826 Functionalized Titanium Dioxide Nanoparticles for Targeting and Disrupting Amyloid Fibrils

Authors: Elad Arad, Raz Jelinek, Hanna Rapaport

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Amyloidoses are a family of diseases characterized by abnormal protein folding that leads to aggregation. They accumulate to form fibrillar plaques which are implicated in the pathogenesis of Alzheimer, prion, diabetes type II and other diseases. To the best of our knowledge, despite extensive research efforts devoted to plaque aggregates inhibition, there is yet no cure for this phenomenon. Titanium and its alloys are found in growing interest for biomedical applications. Variety of surface modifications enable porous, adhesive, bioactive coatings for its surface. Titanium oxides (titania) are also being developed for photothermal and photodynamic treatments. Inspired by this, we set to explore the effect of functionalized titania nanoparticles in combination with external stimuli, as potential photothermal ablating agents against amyloids. Titania nanoparticles were coated with bi-functional catechol derivatives (dihydroxy-phenylalanine propanoic acid, noted DPA) to gain targeting properties. In conjunction with UV-radiation, these nanoparticles may selectively destroy the vicinity of their target. Titania modified 5 nm nanoparticles coated with DPA were further conjugated to the amyloid-targeting Congo Red (CR). These Titania-DPA-CR nanoparticles were found to target mature amyloid fibril of both amyloid-β (Aβ 1-42 a.a). Moreover, irradiation of the peptides in presence of the modified nanoparticles decreased the aggregate content and oligomer fraction. This work provides insights into the use of modified titania nanoparticles for amyloid plaque targeting and photothermal destruction. It may shed light on future modifications and functionalization of titania nanoparticles for different applications.

Keywords: titanium dioxide, amyloids, photothermal treatment, catechol, Congo-red

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825 Biosensor for Determination of Immunoglobulin A, E, G and M

Authors: Umut Kokbas, Mustafa Nisari

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Immunoglobulins, also known as antibodies, are glycoprotein molecules produced by activated B cells that transform into plasma cells and result in them. Antibodies are critical molecules of the immune response to fight, which help the immune system specifically recognize and destroy antigens such as bacteria, viruses, and toxins. Immunoglobulin classes differ in their biological properties, structures, targets, functions, and distributions. Five major classes of antibodies have been identified in mammals: IgA, IgD, IgE, IgG, and IgM. Evaluation of the immunoglobulin isotype can provide a useful insight into the complex humoral immune response. Evaluation and knowledge of immunoglobulin structure and classes are also important for the selection and preparation of antibodies for immunoassays and other detection applications. The immunoglobulin test measures the level of certain immunoglobulins in the blood. IgA, IgG, and IgM are usually measured together. In this way, they can provide doctors with important information, especially regarding immune deficiency diseases. Hypogammaglobulinemia (HGG) is one of the main groups of primary immunodeficiency disorders. HGG is caused by various defects in B cell lineage or function that result in low levels of immunoglobulins in the bloodstream. This affects the body's immune response, causing a wide range of clinical features, from asymptomatic diseases to severe and recurrent infections, chronic inflammation and autoimmunity Transient infant hypogammaglobulinemia (THGI), IgM deficiency (IgMD), Bruton agammaglobulinemia, IgA deficiency (SIgAD) HGG samples are a few. Most patients can continue their normal lives by taking prophylactic antibiotics. However, patients with severe infections require intravenous immune serum globulin (IVIG) therapy. The IgE level may rise to fight off parasitic infections, as well as a sign that the body is overreacting to allergens. Also, since the immune response can vary with different antigens, measuring specific antibody levels also aids in the interpretation of the immune response after immunization or vaccination. Immune deficiencies usually occur in childhood. In Immunology and Allergy clinics, apart from the classical methods, it will be more useful in terms of diagnosis and follow-up of diseases, if it is fast, reliable and especially in childhood hypogammaglobulinemia, sampling from children with a method that is more convenient and uncomplicated. The antibodies were attached to the electrode surface via the poly hydroxyethyl methacrylamide cysteine nanopolymer. It was used to evaluate the anodic peak results obtained in the electrochemical study. According to the data obtained, immunoglobulin determination can be made with a biosensor. However, in further studies, it will be useful to develop a medical diagnostic kit with biomedical engineering and to increase its sensitivity.

Keywords: biosensor, immunosensor, immunoglobulin, infection

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824 Double Functionalization of Magnetic Colloids with Electroactive Molecules and Antibody for Platelet Detection and Separation

Authors: Feixiong Chen, Naoufel Haddour, Marie Frenea-Robin, Yves MéRieux, Yann Chevolot, Virginie Monnier

Abstract:

Neonatal thrombopenia occurs when the mother generates antibodies against her baby’s platelet antigens. It is particularly critical for newborns because it can cause coagulation troubles leading to intracranial hemorrhage. In this case, diagnosis must be done quickly to make platelets transfusion immediately after birth. Before transfusion, platelet antigens must be tested carefully to avoid rejection. The majority of thrombopenia (95 %) are caused by antibodies directed against Human Platelet Antigen 1a (HPA-1a) or 5b (HPA-5b). The common method for antigen platelets detection is polymerase chain reaction allowing for identification of gene sequence. However, it is expensive, time-consuming and requires significant blood volume which is not suitable for newborns. We propose to develop a point-of-care device based on double functionalized magnetic colloids with 1) antibodies specific to antigen platelets and 2) highly sensitive electroactive molecules in order to be detected by an electrochemical microsensor. These magnetic colloids will be used first to isolate platelets from other blood components, then to capture specifically platelets bearing HPA-1a and HPA-5b antigens and finally to attract them close to sensor working electrode for improved electrochemical signal. The expected advantages are an assay time lower than 20 min starting from blood volume smaller than 100 µL. Our functionalization procedure based on amine dendrimers and NHS-ester modification of initial carboxyl colloids will be presented. Functionalization efficiency was evaluated by colorimetric titration of surface chemical groups, zeta potential measurements, infrared spectroscopy, fluorescence scanning and cyclic voltammetry. Our results showed that electroactive molecules and antibodies can be immobilized successfully onto magnetic colloids. Application of a magnetic field onto working electrode increased the detected electrochemical signal. Magnetic colloids were able to capture specific purified antigens extracted from platelets.

Keywords: Magnetic Nanoparticles , Electroactive Molecules, Antibody, Platelet

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823 Electrochemical Modification of Boron Doped Carbon Nanowall Electrodes for Biosensing Purposes

Authors: M. Kowalski, M. Brodowski, K. Dziabowska, E. Czaczyk, W. Bialobrzeska, N. Malinowska, S. Zoledowska, R. Bogdanowicz, D. Nidzworski

Abstract:

Boron-doped-carbon nanowall (BCNW) electrodes are recently in much interest among scientists. BCNWs are good candidates for biosensor purposes as they possess interesting electrochemical characteristics like a wide potential range and the low difference between redox peaks. Moreover, from technical parameters, they are mechanically resistant and very tough. The production process of the microwave plasma-enhanced chemical vapor deposition (MPECVD) allows boron to build into the structure of the diamond being formed. The effect is the formation of flat, long structures with sharp ends. The potential of these electrodes was checked in the biosensing field. The procedure of simple carbon electrodes modification by antibodies was adopted to BCNW for specific antigen recognition. Surface protein D deriving from H. influenzae pathogenic bacteria was chosen as a target analyte. The electrode was first modified with the aminobenzoic acid diazonium salt by electrografting (electrochemical reduction), next anti-protein D antibodies were linked via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) chemistry, and free sites were blocked by BSA. Cyclic voltammetry measurements confirmed the proper electrode modification. Electrochemical impedance spectroscopy records indicated protein detection. The sensor was proven to detect protein D in femtograms. This work was supported by the National Centre for Research and Development (NCBR) TECHMATSTRATEG 1/347324/12/NCBR/ 2017.

Keywords: anti-protein D antibodies, boron-doped carbon nanowall, impedance spectroscopy, Haemophilus influenzae.

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822 Quercetin and INT3 Inhibits Endocrine Therapy Resistance and Epithelial to Mesenchymal Transition in MCF7 Breast Cancer Cells

Authors: S. Pradhan, D. Pradhan, G. Tripathy

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Anti-estrogen treatment resistant is a noteworthy reason for disease relapse and mortality in estrogen receptor alpha (ERα)- positive breast cancers. Tamoxifen or estrogen withdrawal increases the dependance of breast malignancy cells on INT3 signaling. Here, we researched the contribution of Quercetin and INT3 signaling in endocrine resistant breast cancer cells. Methods: We utilized two models of endocrine therapies resistant (ETR-) breast cancer: tamoxifen-resistant (TamR) and long term estrogen-deprived (LTED) MCF7 cells. We assessed the migratory and invasive limit of these cells by Transwell assay. Expression of epithelial to mesenchymal transition (EMT) controllers and in addition INT3 receptors and targets were assessed by real-time PCR and western blot analysis. Besides, we tried in vitro anti-Quercetin monoclonal antibodies (mAbs) and gamma secretase inhibitors (GSIs) as potential EMT reversal therapeutic agents. At last, we created stable Quercetin over expessing MCF7 cells and assessed their EMT features and response to tamoxifen. Results:We found that ETR cells acquired an epithelial to mesenchymal transition (EMT) phenotype and showed expanded levels of Quercetin and INT3 targets. Interestingly, we detected higher level of INT3 however lower levels of INT31 and INT32 proposing a switch to targeting through distinctive INT3 receptors after obtaining of resistance. Anti-Quercetin monoclonal antibodies and the GSI PF03084014 were effective in obstructing the Quercetin/INT3 axis and in part inhibiting the EMT process. As a consequence of this, cell migration and invasion were weakened and the stem cell like population was considerably decreased. Genetic hushing of Quercetin and INT3 prompted proportionate impacts. Finally, stable overexpression of Quercetin was adequate to make MCF7 lethargic to tamoxifen by INT3 activation. Conclusions: ETR cells express abnormal amounts of Quercetin and INT3, whose actuation eventually drives invasive conduct. Anti-Quercetin mAbs and GSI PF03084014 lessen expression of EMT molecules decreasing cellular invasiveness. Quercetin overexpression instigates tamoxifen resistance connected to obtaining of EMT phenotype. Our discovering propose that focusing on Quercetin and/or INT3 warrants further clinical assessment as substantial therapeutic methodologies in endocrine-resistant breast cancer.

Keywords: quercetin, INT3, mesenchymal transition, MCF7 breast cancer cells

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