105 research outputs found

    First mock-up of the CBM STS module based on a new assembly concept

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    A molecular dynamics model has been developed to investigate the effect of the crystallographic orientation on the material deformation behaviors in nano- indentation/scratching of BCC iron. Two cases with different substrate orientations have been simulated. The orientations along x, y and z direction are [001], [100] and [010] for Case I and [111], [-1-12] and [1-10] for Case II, respectively. Case I and Case II exhibit different deformation patterns in the substrate. During indentation, the pile-up can be observed in Case I, but not in Case II. During scratching the pile-up ahead of the movement of the indenter has been enlarged in Case I, while a chip with the disordered atoms is generated in Case II. It has been found that Case I has both higher hardness and larger coefficient of friction. The ratios of the hardness and the coefficient of friction between cases I and II are nearly 2. The reason is attributed to the different crystallographic orientations used in both cases

    Safety and immunogenicity of IMVAMUNE®, a third-generation vaccine based on the modified vaccinia Ankara (MVA) strain

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    In 1980, the World Health Assembly officially declared smallpox eradicated in the world, which allowed developed countries to stop preventive vaccination against this disease. However, circulating and emerging orthopoxviruses along with the lack of herd immunity prompt the need for emergency smallpox vaccines meeting the current requirements for biologicals.The aim of the study was to analyse the safety and efficacy of third-generation smallpox vaccines based on the MVA strain of vaccinia virus compliant with the current (stricter) immunogenicity and safety requirements in healthy subjects and especially in patients with underlying health conditions, considering the lack of herd immunity to orthopoxviruses.The authors analysed the existing experience with smallpox vaccines. The vaccines based on the modified vaccinia Ankara (MVA) strain hold a special place amongst other third-generation vaccines, as this strain is safe and can be used for creating vector vaccines. Bavarian Nordic produces the MVA-based vaccine under three brand names (Imvanex in the EU, Jynneos™ in the USA, and IMVAMUNE® in Canada). According to the results of MVA-based vaccine clinical trials in healthy volunteers and patients with various underlying conditions, the main mild adverse drug reactions (erythema, pain, pruritus, and swelling) were mostly registered at the injection site. The systemic adverse drug reactions included fatigue, headache, myalgia, and chills; several subjects developed upper respiratory tract infections, nausea, and gastroenteritis, which resolved spontaneously within a day. MVA-based vaccines did not cause any cardiac abnormalities, including myo- or pericarditis. Thus, the vaccines may be used in patients with eczema, atopic dermatitis, inflammatory skin conditions, HIV, tuberculosis, cardiac abnormalities, as well as in children, adolescents, and pregnant women. The optimal intradermal immunisation dose was 1×108 TCID50. Two injections at this dose induced a pronounced humoral and cell-mediated immune response comparable to that induced by one administration of a first-generation smallpox vaccine. At this dose, the study vaccine also boosted pre-existing immunity conferred by a first-generation vaccine. The US Centers for Disease Control and Prevention recommend Jynneos™ for preventing monkeypox in adults (18 years of age and older)

    Activity screening of environmental metagenomic libraries reveals novel carboxylesterase families

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    Metagenomics has made accessible an enormous reserve of global biochemical diversity. To tap into this vast resource of novel enzymes, we have screened over one million clones from metagenome DNA libraries derived from sixteen different environments for carboxylesterase activity and identified 714 positive hits. We have validated the esterase activity of 80 selected genes, which belong to 17 different protein families including unknown and cyclase-like proteins. Three metagenomic enzymes exhibited lipase activity, and seven proteins showed polyester depolymerization activity against polylactic acid and polycaprolactone. Detailed biochemical characterization of four new enzymes revealed their substrate preference, whereas their catalytic residues were identified using site-directed mutagenesis. The crystal structure of the metal-ion dependent esterase MGS0169 from the amidohydrolase superfamily revealed a novel active site with a bound unknown ligand. Thus, activity-centered metagenomics has revealed diverse enzymes and novel families of microbial carboxylesterases, whose activity could not have been predicted using bioinformatics tools

    Безопасность и иммуногенность вакцины третьего поколения IMVAMUNE® на основе вируса вакцины, штамм MVA

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    In 1980, the World Health Assembly officially declared smallpox eradicated in the world, which allowed developed countries to stop preventive vaccination against this disease. However, circulating and emerging orthopoxviruses along with the lack of herd immunity prompt the need for emergency smallpox vaccines meeting the current requirements for biologicals.The aim of the study was to analyse the safety and efficacy of third-generation smallpox vaccines based on the MVA strain of vaccinia virus compliant with the current (stricter) immunogenicity and safety requirements in healthy subjects and especially in patients with underlying health conditions, considering the lack of herd immunity to orthopoxviruses.The authors analysed the existing experience with smallpox vaccines. The vaccines based on the modified vaccinia Ankara (MVA) strain hold a special place amongst other third-generation vaccines, as this strain is safe and can be used for creating vector vaccines. Bavarian Nordic produces the MVA-based vaccine under three brand names (Imvanex in the EU, Jynneos™ in the USA, and IMVAMUNE® in Canada). According to the results of MVA-based vaccine clinical trials in healthy volunteers and patients with various underlying conditions, the main mild adverse drug reactions (erythema, pain, pruritus, and swelling) were mostly registered at the injection site. The systemic adverse drug reactions included fatigue, headache, myalgia, and chills; several subjects developed upper respiratory tract infections, nausea, and gastroenteritis, which resolved spontaneously within a day. MVA-based vaccines did not cause any cardiac abnormalities, including myo- or pericarditis. Thus, the vaccines may be used in patients with eczema, atopic dermatitis, inflammatory skin conditions, HIV, tuberculosis, cardiac abnormalities, as well as in children, adolescents, and pregnant women. The optimal intradermal immunisation dose was 1×108 TCID50. Two injections at this dose induced a pronounced humoral and cell-mediated immune response comparable to that induced by one administration of a first-generation smallpox vaccine. At this dose, the study vaccine also boosted pre-existing immunity conferred by a first-generation vaccine. The US Centers for Disease Control and Prevention recommend Jynneos™ for preventing monkeypox in adults (18 years of age and older).В 1980 г. Всемирная ассамблея здравоохранения официально провозгласила искоренение натуральной оспы в мире, что позволило в развитых странах отменить профилактическую вакцинацию против этого заболевания. Однако из-за постоянно циркулирующих и вновь возникающих ортопоксвирусов, а также отсутствия популяционного иммунитета необходимо наличие в чрезвычайных ситуациях противооспенных вакцин, отвечающих современным требованиям к иммунобиологическим препаратам.Цель работы — анализ безопасности и эффективности в условиях отсутствия популяционного иммунитета к ортопоксвирусам оспенной вакцины третьего поколения на основе штамма MVA вируса вакцины, отвечающей повышенным требованиям иммуногенности и безопасности, особенно с учетом применения ее для лиц с отклонениями в состоянии здоровья. Проанализирован опыт применения противооспенных вакцин. Среди противооспенных вакцин третьего поколения особое место занимает вакцина на основе вируса вакцины, штамм MVA (modified vaccinia virus Ankara), выпускаемая компанией Bavarian Nordic под тремя названиями (в Европе — Imvanex, в США — Jynneos™, в Канаде — IMVAMUNE®), поскольку он безопасен и может использоваться для конструирования векторных вакцин. Результаты клинических исследований вакцины на основе штамма MVA на здоровых добровольцах и лицах с различными отклонениями в здоровье показали, что основные побочные реакции легкой степени тяжести (эритема, болезненность, зуд, припухлость) в основном регистрировали в месте введения вакцины. Из системных побочных реакций отмечены утомление, головная боль, миалгия, озноб; у незначительной части — инфекция верхних дыхательных путей, тошнота, гастроэнтерит, которые самопроизвольно проходили в течение первых суток. Вакцина не вызывает нарушений сердечной деятельности, включая миоперикардит, может быть применена для лиц с экземой, атопическим дерматитом и воспалительными кожными заболеваниями, ею можно вакцинировать ВИЧ-инфицированных, больных туберкулезом, лиц с нарушениями сердечной деятельности, а также детей младшего возраста, подростков и беременных женщин. Определена оптимальная иммунизирующая доза вакцины при внутрикожном введении, равная 1×108 ЦПД50. Выявлено, что при двукратном введении в данной дозе вакцина индуцирует выраженный гуморальный и клеточный иммунный ответ, сопоставимый по уровню с иммунитетом после однократного введения вакцины первого поколения, а также бустирует иммунитет, ранее сформировавшийся при иммунизации противооспенной вакциной первого поколения. Вакцина Jynneos™ в настоящее время одобрена CDC (США) для профилактики оспы обезьян у взрослых в возрасте 18 лет и старше

    A genome-wide IR-induced RAD51 foci RNAi screen identifies CDC73 involved in chromatin remodeling for DNA repair

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    To identify new regulators of homologous recombination repair, we carried out a genome-wide short-interfering RNA screen combined with ionizing irradiation using RAD51 foci formation as readout. All candidates were confirmed by independent short-interfering RNAs and validated in secondary assays like recombination repair activity and RPA foci formation. Network analysis of the top modifiers identified gene clusters involved in recombination repair as well as components of the ribosome, the proteasome and the spliceosome, which are known to be required for effective DNA repair. We identified and characterized the RNA polymerase II-associated protein CDC73/Parafibromin as a new player in recombination repair and show that it is critical for genomic stability. CDC73 interacts with components of the SCF/Cullin and INO80/NuA4 chromatin-remodeling complexes to promote Histone ubiquitination. Our findings indicate that CDC73 is involved in local chromatin decondensation at sites of DNA damage to promote DNA repair. This function of CDC73 is related to but independent of its role in transcriptional elongation

    Pressure adaptation is linked to thermal adaptation in salt-saturated marine habitats

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    The present study provides a deeper view of protein functionality as a function of temperature, salt and pressure in deep-sea habitats. A set of eight different enzymes from five distinct deep-sea (3040–4908 m depth), moderately warm (14.0–16.5°C) biotopes, characterized by a wide range of salinities (39–348 practical salinity units), were investigated for this purpose. An enzyme from a ‘superficial’ marine hydrothermal habitat (65°C) was isolated and characterized for comparative purposes. We report here the first experimental evidence suggesting that in saltsaturated deep-sea habitats, the adaptation to high pressure is linked to high thermal resistance (P value = 0.0036). Salinity might therefore increase the temperature window for enzyme activity, and possibly microbial growth, in deep-sea habitats. As an example, Lake Medee, the largest hypersaline deepsea anoxic lake of the Eastern Mediterranean Sea, where the water temperature is never higher than 16°C, was shown to contain halopiezophilic-like enzymes that are most active at 70°C and with denaturing temperatures of 71.4°C. The determination of the crystal structures of five proteins revealed unknown molecular mechanisms involved in protein adaptation to poly-extremes as well as distinct active site architectures and substrate preferences relative to other structurally characterized enzymes.European Community project MAMBA (FP7-KBBE-2008-226977). This grant BIO2011-25012 from the Spanish Ministry of Economy and Competitiveness (formerly MICINN). European Commission for ‘MicroB3’ grant (FP7-OCEAN.2011-2 (contract Nr 287589)). Government of Canada through Genome Canada and the Ontario Genomics Institute (grant 2009-OGI-ABC-1405) and U.S. National Institutes of Health (grants GM074942 and GM094585). Midwest Center for Structural Genomics).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1462-2920hb2016Biochemistr

    Preclinical pharmacokinetics and metabolism of a novel prototype DNA-PK inhibitor NU7026

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    In this study we investigated the in vitro time dependence of radiosensitisation, pharmacokinetics and metabolism of NU7026, a novel inhibitor of the DNA repair enzyme DNA-dependent protein kinase (DNA-PK). At a dose of 10 μM, which is nontoxic to cells per se, a minimum NU7026 exposure of 4 h in combination with 3 Gy radiation is required for a significant radiosensitisation effect in CH1 human ovarian cancer cells. Following intravenous administration to mice at 5 mg kg−1, NU7026 underwent rapid plasma clearance (0.108 l h−1) and this was largely attributed to extensive metabolism. Bioavailability following interperitoneal (i.p.) and p.o. administration at 20 mg kg−1 was 20 and 15%, respectively. Investigation of NU7026 metabolism profiles in plasma and urine indicated that the compound undergoes multiple hydroxylations. A glucuronide conjugate of a bis-hydroxylated metabolite represented the major excretion product in urine. Identification of the major oxidation site as C-2 of the morpholine ring was confirmed by the fact that the plasma clearance of NU7107 (an analogue of NU7026 methylated at C-2 and C-6 of the morpholine ring) was four-fold slower than that of NU7026. The pharmacokinetic simulations performed predict that NU7026 will have to be administered four times per day at 100 mg kg−1 i.p. in order to obtain the drug exposure required for radiosensitisation

    The proteasome inhibitor MG-132 sensitizes PC-3 prostate cancer cells to ionizing radiation by a DNA-PK-independent mechanism

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    BACKGROUND: By modulating the expression levels of specific signal transduction molecules, the 26S proteasome plays a central role in determining cell cycle progression or arrest and cell survival or death in response to stress stimuli, including ionizing radiation. Inhibition of proteasome function by specific drugs results in cell cycle arrest, apoptosis and radiosensitization of many cancer cell lines. This study investigates whether there is also a concomitant increase in cellular radiosensitivity if proteasome inhibition occurs only transiently before radiation. Further, since proteasome inhibition has been shown to activate caspase-3, which is involved in apoptosis, and caspase-3 can cleave DNA-PKcs, which is involved in DNA-double strand repair, the hypothesis was tested that caspase-3 activation was essential for both apoptosis and radiosensitization following proteasome inhibition. METHODS: Prostate carcinoma PC-3 cells were treated with the reversible proteasome inhibitor MG-132. Cell cycle distribution, apoptosis, caspase-3 activity, DNA-PKcs protein levels and DNA-PK activity were monitored. Radiosensitivity was assessed using a clonogenic assay. RESULTS: Inhibition of proteasome function caused cell cycle arrest and apoptosis but this did not involve early activation of caspase-3. Short-time inhibition of proteasome function also caused radiosensitization but this did not involve a decrease in DNA-PKcs protein levels or DNA-PK activity. CONCLUSION: We conclude that caspase-dependent cleavage of DNA-PKcs during apoptosis does not contribute to the radiosensitizing effects of MG-132
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