The activation of Statl by the interferon-gamma （IFN-γ） receptor complex is responsible for the transcription of a significant portion of IFN-γ induced genes. Many of these genes are responsible for the induction ...The activation of Statl by the interferon-gamma （IFN-γ） receptor complex is responsible for the transcription of a significant portion of IFN-γ induced genes. Many of these genes are responsible for the induction of an apoptotic state in response to IFN-γ. In the absence of Stat 1 activation, IFN-γ instead induces a proliferative response. Modifying Stat 1 activation by IFN-γ may have pharmacological benefits. We report that the rate of activation of Statl can be altered in HeLa cells by overexpressing either the IFN-γ R1 chain or the IFN-γ R2 chain. These alterations occur in hematopoietic cell lines： Raji cells and monocytic cell lines, which have average and above-average IFN-γ R2 surface expression, activate Statl similarly to HeLa cells and HeLa cells overexpressing IFNγR2, respectively. The rapid Statl activation seen in HeLa cells can be inhibited by overexpressing a chimeric IFN-γR2 chain that does not bind Jak2 or （when high concentrations of IFN-γ are used） by overexpressing IFN-γR1. These data are consistent with a model in which the recruitment of additional Jak2 activity to a signaling complex accelerates the rate of Statl activation. We conclude that the rate of activation of Statl in cells by IFN-γ can be modified by regulating either receptor chain and speculate that pharmacological agents which modify receptor chain expression may alter IFN-γ receptor signal transduction.展开更多
The operation of a complicated radiators structure creating a required field in a given area is disturbed often due to different external actions. As an example, the impact of metallic objects approaching off to an an...The operation of a complicated radiators structure creating a required field in a given area is disturbed often due to different external actions. As an example, the impact of metallic objects approaching off to an antenna system with minimal irradiation on user＇s body is analyzed. In this case, the zone itself, where the area of a weak field （a dark spot） is created, is generally not approachable for sensors installation. In order to counteract the disturbance of the system operation due to presence of different metallic objects in close proximity to the radiators, two methods based on two information sources are studied. These information sources are antennas driving currents and fields at a predetermined point outside the given area. As an example, the antenna system used in the compensation method for reducing human＇s body irradiation, to which a metal object approaches, is analyzed. The conditions of severe external actions are considered： a great metal body and a small distance from this body to the dark spot. It is shown that under these conditions of severe external actions the second method based on the field values measuring demonstrates a higher efficiency. A block scheme for structure of an automatic adjustment is suggested. The considered problem is a common one, and developers of radio circuits are faced with them constantly.展开更多
文摘The activation of Statl by the interferon-gamma （IFN-γ） receptor complex is responsible for the transcription of a significant portion of IFN-γ induced genes. Many of these genes are responsible for the induction of an apoptotic state in response to IFN-γ. In the absence of Stat 1 activation, IFN-γ instead induces a proliferative response. Modifying Stat 1 activation by IFN-γ may have pharmacological benefits. We report that the rate of activation of Statl can be altered in HeLa cells by overexpressing either the IFN-γ R1 chain or the IFN-γ R2 chain. These alterations occur in hematopoietic cell lines： Raji cells and monocytic cell lines, which have average and above-average IFN-γ R2 surface expression, activate Statl similarly to HeLa cells and HeLa cells overexpressing IFNγR2, respectively. The rapid Statl activation seen in HeLa cells can be inhibited by overexpressing a chimeric IFN-γR2 chain that does not bind Jak2 or （when high concentrations of IFN-γ are used） by overexpressing IFN-γR1. These data are consistent with a model in which the recruitment of additional Jak2 activity to a signaling complex accelerates the rate of Statl activation. We conclude that the rate of activation of Statl in cells by IFN-γ can be modified by regulating either receptor chain and speculate that pharmacological agents which modify receptor chain expression may alter IFN-γ receptor signal transduction.
文摘The operation of a complicated radiators structure creating a required field in a given area is disturbed often due to different external actions. As an example, the impact of metallic objects approaching off to an antenna system with minimal irradiation on user＇s body is analyzed. In this case, the zone itself, where the area of a weak field （a dark spot） is created, is generally not approachable for sensors installation. In order to counteract the disturbance of the system operation due to presence of different metallic objects in close proximity to the radiators, two methods based on two information sources are studied. These information sources are antennas driving currents and fields at a predetermined point outside the given area. As an example, the antenna system used in the compensation method for reducing human＇s body irradiation, to which a metal object approaches, is analyzed. The conditions of severe external actions are considered： a great metal body and a small distance from this body to the dark spot. It is shown that under these conditions of severe external actions the second method based on the field values measuring demonstrates a higher efficiency. A block scheme for structure of an automatic adjustment is suggested. The considered problem is a common one, and developers of radio circuits are faced with them constantly.
