BIOLOGICAL AMMONIA REMOVAL BY SUBMERGED AERATED FILTER FROM HANOI GROUND WATER

Joint Research on Environmental Science and Technology for the Eart

New Bifunctional Chelators Incorporating Dibromomaleimide Groups for Radiolabeling of Antibodies with Positron Emission Tomography Imaging Radioisotopes

Positron Emission Tomography (PET) imaging with antibody-based contrast agents frequently uses the radioisotopes [{64}^Cu]Cu^{2+} and [{89}^Zr]Zr^{4+}. The macrobicyclic chelator commonly known as sarcophagine (sar) is ideal for labeling receptor-targeted biomolecules with [{64}^Cu]Cu^{2+}. The siderophore chelator, desferrioxamine-B (dfo), has been widely used to incorporate [{89}^Zr]Zr^{4+}, respectively, in near quantitative radiochemical yield (>99%). Serum stability studies, in vivo PET imaging, and biodistribution analyses using these radiolabeled immunoconjugates demonstrate that both [{64}^Cu]Cu-sar–dtm–trastuzumab and [{89}^Zr]Zr-dfo–dtm–trastuzumab possess high stability in biological milieu. Dibromomaleimide technology can be easily applied to enable stable, site-specific attachment of radiolabeled chelators, such as sar and dfo, to native interstrand disulfide regions of antibodies, enabling tracking of antibodies with PET imaging

ОПРЕДЕЛЕНИЕ ЭСТОЛИДОВ И ТРИАЦИЛГЛИЦЕРИНОВ МАСЛА СЕМЯН Sapium discolor: СОПОСТАВЛЕНИЕ РАЗДЕЛЕНИЯ ВЕЩЕСТВ В УСЛОВИЯХ ТРАДИЦИОННОЙ И МИКРОКОЛОНОЧНОЙ (МИЛИХРОМ А-02) ХРОМАТОГРАФИИ

Methods for the separation and UV detection of Sapium discolor seed oil estolides and triacylglycerols by traditional analytical as well as by microcolumn reversed-phase high-performance liquid chromatography approaches were developed. For the separation, the columns filled with Kromasil 100-5C18 sorbent were used together with the "propanol-2 – acteonitrile" mobile phase systems. The oil composition was calculated on the basis of the incremental approach. The propositions were confirmed by the mass-spectrometric and the electronic spectra data. The oil was shown to be composed of the traditional α-linolenic, linoleic, oleic, palmitic and stearic acids, and two unusual acids that match the literature data about their structure. Due to the presence of the acid radical with the chromophore O=COR1-CH=CH-CH=CHR2 composition in all estolides, the sensitive and the selective detection of the compounds was possible at the wavelength of 266 nm. This method of detection was a good alternative to the detection at 210 nm, allowing the detection of not only the estolides but also the triacylglycerols, although with approximately threefold reduced sensitivity. The experiment indicated the reduction of the total efficiency (as a number of theoretical plates) in the swap of traditional by microcolumn HPLC, and the subsequent method was proposed to separate the unseparated peaks that occur during this exchange by using the Magicplot student 2.7.2 software. This was achieved with good performance results of the qualitative and quantitative determination of the relative amounts of estolides in the oil.Key words: RP-HPLC, HPLC, microcolumn chromatography, triacylglycerols, estolides, UV detection, deconvolution of complex peaks, Magicplot student 2.7.2.(Russian)DOI: http://dx.doi.org/10.15826/analitika.2018.22.1.003Anh Van Nguyen1, V.I. Deineka1, Long Quoc Pham2, Phuong Lan Doan2,L.А. Deineka1 1Belgorod National Research University, Pobeda str., 85, Belgorod, Russian Federation, 308015.2 Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Viet Nam, 122300Разработаны условия разделения и УФ-детектирования эстолидов (триацилглицерины с одним олигомерным радикалом кислоты) и триацилглицеринов масла семян Sapium discolor в условиях традиционной аналитической и микроколоночной обращенно-фазовой высокоэффективной жидкостной хроматографии. Для разделения использовали колонки, заполненные сорбентом Kromasil 100-5C18, и подвижные фазы системы «пропанол-2 – ацетонитрил». С использованием инкрементного подхода рассчитан и в дальнейшем подтвержден анализом электронных и масс-спектров видовой состав компонентов масла. Показано, что масло содержит радикалы традиционных α-линоленовой, линолевой, олеиновой, пальмитиновой и стеариновой кислот и двух необычных, параметры которых удовлетворяют литературным данным об их строении. Благодаря присутствию во всех эстолидах радикала кислоты с хромофором состава O=COR1-CH=CH-CH=CHR2 возможно чувствительное селективное детектирование эстолидов при длине волны 266 нм. Этот способ детектирования является хорошим дополнением к детектированию при 210 нм, позволяющему обнаруживать не только эстолиды, но и триацилглицерины, хотя и примерно со втрое сниженной чувствительностью. Экспериментально оценено снижение суммарной эффективности (по числу теоретических тарелок) при переходе от колонок с диаметром 4-4.6 мм к микроколоночной ВЭЖХ и предложен способ разделения неразделенных пиков возникающих при этом за счет использования специальной программы Magicplot student 2.7.2, с хорошими характеристиками результатов определения относительных количеств эстолидных компонентов масла.Ключевые слова: обращенно-фазовая ВЭЖХ, микроколоночная ВЭЖХ, триацилглицерины, эстолиды, УФ-детектирование, разделение сложных пиков, Magicplot student 2.7.2.DOI: http://dx.doi.org/10.15826/analitika.2018.22.1.00

Rad51 Interacts with Non-structural 3 Protein of Hepatitis C Virus and Regulates Viral Production

Hepatitis C virus (HCV) is a leading cause of chronic liver disease affecting over 170 million people worldwide. Chronic infection with HCV progresses to liver fibrosis, cirrhosis, and hepatocellular carcinoma. HCV exploits host cellular factors for viral propagation. To investigate the cellular factors required for HCV propagation, we screened a siRNA library targeting human cell cycle genes using cell culture grown HCV-infected cells. In the present study, we selected and characterized a gene encoding Rad51. Rad51, a member of a conserved recombinase family, is an essential factor for homologous recombination and repair of double-strand DNA breaks. We demonstrated that siRNA-mediated knockdown of Rad51 significantly inhibited HCV propagation without affecting HCV RNA replication. Silencing of Rad51 impaired secretion of infectious HCV particles and thus intracellular viruses were accumulated. We showed that HCV NS3 specifically interacted with Rad51 and accumulated Rad51 in the cytosol. Furthermore, Rad51 was coprecipitated with NS3 and HCV RNA. By employing membrane flotation and protease protection assays, we also demonstrated that Rad51 was co-fractionated with HCV NS3 on the lipid raft. These data indicate that Rad51 may be a component of the HCV RNA replication complex. Collectively, these data suggest that HCV may exploit cellular Rad51 to promote viral propagation and thus Rad51 may be a potential therapeutic target for HCV

Evolutionary Pathways to Persistence of Highly Fit and Resistant Hepatitis C Virus Protease Inhibitor Escape Variants

Protease inhibitors (PIs) are important components of treatment regimens for patients with chronic hepatitis C virus (HCV) infection. However, emergence and persistence of antiviral resistance could reduce their efficacy. Thus, defining resistance determinants is highly relevant for efforts to control HCV. Here, we investigated patterns of PI resistance–associated substitutions (RASs) for the major HCV genotypes and viral determinants for persistence of key RASs. We identified protease position 156 as a RAS hotspot for genotype 1‐4, but not 5 and 6, escape variants by resistance profiling using PIs grazoprevir and paritaprevir in infectious cell culture systems. However, except for genotype 3, engineered 156‐RASs were not maintained. For genotypes 1 and 2, persistence of 156‐RASs depended on genome‐wide substitution networks, co‐selected under continued PI treatment and identified by next‐generation sequencing with substitution linkage and haplotype reconstruction. Persistence of A156T for genotype 1 relied on compensatory substitutions increasing replication and assembly. For genotype 2, initial selection of A156V facilitated transition to 156L, persisting without compensatory substitutions. The developed genotype 1, 2, and 3 variants with persistent 156‐RASs had exceptionally high fitness and resistance to grazoprevir, paritaprevir, glecaprevir, and voxilaprevir. A156T dominated in genotype 1 glecaprevir and voxilaprevir escape variants, and pre‐existing A156T facilitated genotype 1 escape from clinically relevant combination treatments with grazoprevir/elbasvir and glecaprevir/pibrentasvir. In genotype 1 infected patients with treatment failure and 156‐RASs, we observed genome‐wide selection of substitutions under treatment. Conclusion : Comprehensive PI resistance profiling for HCV genotypes 1‐6 revealed 156‐RASs as key determinants of high‐level resistance across clinically relevant PIs. We obtained in vitro proof of concept for persistence of highly fit genotype 1‐3 156‐variants, which might pose a threat to clinically relevant combination treatments

Determination of Sapium discolor seed oil estolides and triacylglycerines: comparison of the substances separation by conventional and microcolumn (Milichrome A-02) chromatography

Methods for the separation and UV detection of Sapium discolor seed oil estolides and triacylglycerols by traditional analytical as well as by microcolumn reversed-phase high-performance liquid chromatography approaches were developed. For the separation, the columns filled with Kromasil 100-5C18 sorbent were used together with the "propanol-2 - acteonitrile" mobile phase systems. The oil composition was calculated on the basis of the incremental approach. The propositions were confirmed by the mass-spectrometric and the electronic spectra data. The oil was shown to be composed of the traditional ?-linolenic, linoleic, oleic, palmitic and stearic acids, and two unusual acids that match the literature data about their structure. Due to the presence of the acid radical with the chromophore O=COR1-CH=CH-CH=CHR2 composition in all estolides, the sensitive and the selective detection of the compounds was possible at the wavelength of 266 nm. This method of detection was a good alternative to the detection at 210 nm, allowing the detection of not only the estolides but also the triacylglycerols, although with approximately threefold reduced sensitivity. The experiment indicated the reduction of the total efficiency (as a number of theoretical plates) in the swap of traditional by microcolumn HPLC, and the subsequent method was proposed to separate the unseparated peaks that occur during this exchange by using the Magicplot student 2.7.2 software. This was achieved with good performance results of the qualitative and quantitative determination of the relative amounts of estolides in the oil.Разработаны условия разделения и УФ-детектирования эстолидов (триацилглицерины с одним олигомерным радикалом кислоты) и триацилглицеринов масла семян Sapium discolor в условиях традиционной аналитической и микроколоночной обращенно-фазовой высокоэффективной жидкостной хроматографии. Для разделения использовали колонки, заполненные сорбентом Kromasil 100-5C18, и подвижные фазы системы «пропанол-2 - ацетонитрил». С использованием инкрементного подхода рассчитан и в дальнейшем подтвержден анализом электронных и масс-спектров видовой состав компонентов масла. Показано, что масло содержит радикалы традиционных ?-линоленовой, линолевой, олеиновой, пальмитиновой и стеариновой кислот и двух необычных, параметры которых удовлетворяют литературным данным об их строении. Благодаря присутствию во всех эстолидах радикала кислоты с хромофором состава O=COR1-CH=CH-CH=CHR2 возможно чувствительное селективное детектирование эстолидов при длине волны 266 нм. Этот способ детектирования является хорошим дополнением к детектированию при 210 нм, позволяющему обнаруживать не только эстолиды, но и триацилглицерины, хотя и примерно со втрое сниженной чувствительностью. Экспериментально оценено снижение суммарной эффективности (по числу теоретических тарелок) при переходе от колонок с диаметром 4-4.6 мм к микроколоночной ВЭЖХ и предложен способ разделения неразделенных пиков возникающих при этом за счет использования специальной программы Magicplot student 2.7.2, с хорошими характеристиками результатов определения относительных количеств эстолидных компонентов масла