70 research outputs found

    Клещевой энцефалит: иммунологические показатели возможного перехода острой стадии в хроническое течение болезни

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    Several autoimmune diseases with chronic clinical course are characterized by detection of DNA autoantibodies in patients’ serum, while there are no such IgGs in healthy donors’ blood or in patients with acute clinical course with no evidence of chronization. Tick-borne encephalitis has not been considered this way. Several strict criteria have been applied to show that the DNase activity is an intrinsic property of IgGs from the sera of TBE patients but not from healthy donors. The relative activity of IgGs has been shown to vary extensively from patient to patient, but most of the preparations (91%) had detectable levels of the DNase activity. Polyclonal DNase IgGs were not active in the presence of EDTA or after a dialysis against EDTA, but could be activated by several externally added metal ions, with the level of activity decreasing in the order Mn2+ + Ca2+ ≥ Mn2+ + Mg2+ ≥ Mn2+ ≥ ≥ Mg2+ + Ca2+ ≥ Ca2+ ≥ Mg2+ > Ca2+, while K+ , Na+ , Ni2+, Zn2+, and Cu2+ did not stimulate DNA hydrolysis. Affinity chromatography on DNA-cellulose separated the DNase IgGs into many subfractions with various affinities for DNA and very different levels of the relative activity. Possible reasons for catalytic diversity of polyclonal human Abzs are discussed.Ряд аутоиммунных заболеваний с хроническим течением характеризуются обнаружением в крови больных ДНКаутоантител, в то время как их не содержит кровь здоровых доноров или пациентов с острым течением заболеваний, незначительным нарушением иммунного статуса, без определенной склонности к переходу в хронический процесс. Клещевой энцефалит (КЭ) не рассматривался с этих позиций. Предварительно для данной работы проведен поиск достаточно точных критериев обнаружения ДНК-активности антител иммуноглобулина (Ig) G из сыворотки крови больных КЭ и здоровых доноров. Показано, что относительная активность антител IgG значительно варьирует у пациентов, но большинство образцов (91%) имели определяемый уровень ДНКазной активности. Поликлональные ДНКазные антитела IgG не активировались в присутствии ЭДТА или после диализа с ЭДТА, но могли активироваться некоторыми добавленными ионами металлов с уровнем активности, уменьшающимся в ряду Mn2+ + Ca2+ ≥ Mn2+ + Mg2+ ≥ Mn2+ ≥ Mg2+ + Ca2+ ≥ Co2+ ≥ Mg2+ > Ca2+, в то время как K+ , Na+ , Ni2+, Zn2+ и Cu2+ не стимулировали гидролиз ДНК. Аффинная хроматография на ДНК-целлюлозе разделила ДНКазные антитела IgG на множество субфракций с различным сродством к ДНК и очень разными уровнями относительной активности. Возможные причины каталитического разнообразия поликлональных человеческих аутоантител обсуждаются

    A comparison of the radiosensitisation ability of 22 different element metal oxide nanoparticles using clinical megavoltage X-rays

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    Background: A wide range of nanoparticles (NPs), composed of different elements and their compounds, are being developed by several groups as possible radiosensitisers, with some already in clinical trials. However, no systematic experimental survey of the clinical X-ray radiosensitising potential of different element nanoparticles has been made. Here, we directly compare the irradiation-induced (10 Gy of 6-MV X-ray photon) production of hydroxyl radicals, superoxide anion radicals and singlet oxygen in aqueous solutions of the following metal oxide nanoparticles: Al2O3, SiO2, Sc2O3, TiO2, V2O5, Cr2O3, MnO2, Fe3O4, CoO, NiO, CuO, ZnO, ZrO2, MoO3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb4O7, Dy2O3, Er2O3 and HfO2. We also examine DNA damage due to these NPs in unirradiated and irradiated conditions. Results: Without any X-rays, several NPs produced more radicals than water alone. Thus, V2O5 NPs produced around 5-times more hydroxyl radicals and superoxide radicals. MnO2 NPs produced around 10-times more superoxide anions and Tb4O7 produced around 3-times more singlet oxygen. Lanthanides produce fewer hydroxyl radicals than water. Following irradiation, V2O5 NPs produced nearly 10-times more hydroxyl radicals than water. Changes in radical concentrations were determined by subtracting unirradiated values from irradiated values. These were then compared with irradiation-induced changes in water only. Irradiation-specific increases in hydroxyl radical were seen with most NPs, but these were only significantly above the values of water for V2O5, while the Lanthanides showed irradiation-specific decreases in hydroxyl radical, compared to water. Only TiO2 showed a trend of irradiation-specific increase in superoxides, while V2O5, MnO2, CoO, CuO, MoO3 and Tb4O7 all demonstrated significant irradiation-specific decreases in superoxide, compared to water. No irradiation-specific increases in singlet oxygen were seen, but V2O5, NiO, CuO, MoO3 and the lanthanides demonstrated irradiation-specific decreases in singlet oxygen, compared to water. MoO3 and CuO produced DNA damage in the absence of radiation, while the highest irradiation-specific DNA damage was observed with CuO. In contrast, MnO2, Fe3O4 and CoO were slightly protective against irradiation-induced DNA damage. Conclusions: Beyond identifying promising metal oxide NP radiosensitisers and radioprotectors, our broad comparisons reveal unexpected differences that suggest the surface chemistry of NP radiosensitisers is an important criterion for their success

    Calculation of Force Parameters for Powder Material Hydrostatic Compaction

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    Tick-borne encephalitis: immunological indicators of possible transformation of acute process into chronic disease

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    Several autoimmune diseases with chronic clinical course are characterized by detection of DNA autoantibodies in patients’ serum, while there are no such IgGs in healthy donors’ blood or in patients with acute clinical course with no evidence of chronization. Tick-borne encephalitis has not been considered this way. Several strict criteria have been applied to show that the DNase activity is an intrinsic property of IgGs from the sera of TBE patients but not from healthy donors. The relative activity of IgGs has been shown to vary extensively from patient to patient, but most of the preparations (91%) had detectable levels of the DNase activity. Polyclonal DNase IgGs were not active in the presence of EDTA or after a dialysis against EDTA, but could be activated by several externally added metal ions, with the level of activity decreasing in the order Mn2+ + Ca2+ ≥ Mn2+ + Mg2+ ≥ Mn2+ ≥ ≥ Mg2+ + Ca2+ ≥ Ca2+ ≥ Mg2+ > Ca2+, while K+ , Na+ , Ni2+, Zn2+, and Cu2+ did not stimulate DNA hydrolysis. Affinity chromatography on DNA-cellulose separated the DNase IgGs into many subfractions with various affinities for DNA and very different levels of the relative activity. Possible reasons for catalytic diversity of polyclonal human Abzs are discussed
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