The cytosolic form of selenium-dependent glutathione peroxidase detoxifies both hydrogen and lipid peroxides and therefore represents a major component of the cellular anti-oxidant defenses. In order to study the biol...The cytosolic form of selenium-dependent glutathione peroxidase detoxifies both hydrogen and lipid peroxides and therefore represents a major component of the cellular anti-oxidant defenses. In order to study the biological role of this enzyme, we generated an expression construct in a retroviral vector, which when introduced into immortalized human T-cells, resulted in significant increases in the activity of this important enzyme. This effect is stable over extended maintenance in culture. The anti-oxidant defenses in these same cells are also shown to be attenuated hy chemically reducing cellular glutathione levels. Collectively, the abllity to both increase and decrease the anti-oxidant defenses in human T cells results in a useful model system for the study of oxidative stress and signaling in this cell type展开更多
Natural products have gained popularity worldwide for promoting healthcare, as well as disease prevention. Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloid...Natural products have gained popularity worldwide for promoting healthcare, as well as disease prevention. Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloids isolated from natural herbs exhibit antiproliferation, antibacterial, antiviral, insecticidal, and antimetastatic effects on various types of cancers both in vitro and in vivo. This paper focuses on the naturally-derived alkaloids such as berberine, matrine, piperine, fritillarine, and rhynchophylline, etc., and summarizes the action mechanisms of these compounds. Based on the information in the literature that is summarized in this paper, the use of alkaloids as drugs is very promising, but more research and clinical trials are necessary before final recommendations on specific alkaloids can be made. Following this, it is hoped that as a result of this review, there will be a greater awareness of the excellent promise that natural alkaloids show for use in the therapy of diseases.展开更多
The concentration distribution of essential and non-essential micro-elements of the tissues of healthy organisms shows significant difference. This fact can be used for clarification of the biological role of hardly k...The concentration distribution of essential and non-essential micro-elements of the tissues of healthy organisms shows significant difference. This fact can be used for clarification of the biological role of hardly known trace elements, as well, proving the essential or non-essential character. In case of essential elements the concentration range is rather narrow, the distribution is normal. In case of non-essential elements the interval is wide, the concentration-distribution is log-normal. Measurements and mathematical calculations were carried out for determination of the concentrations and concentration-distributions of some micro-elements, trying to clarify the essentiality or non-essential character of the investigated elements from point of view of plant physiology. Based on the measurements for radish Li and Ni seem to be non-essential trace elements, however in case of Sr the distribution curve suggests an essential character, because the concentration range is not wide.展开更多
文摘The cytosolic form of selenium-dependent glutathione peroxidase detoxifies both hydrogen and lipid peroxides and therefore represents a major component of the cellular anti-oxidant defenses. In order to study the biological role of this enzyme, we generated an expression construct in a retroviral vector, which when introduced into immortalized human T-cells, resulted in significant increases in the activity of this important enzyme. This effect is stable over extended maintenance in culture. The anti-oxidant defenses in these same cells are also shown to be attenuated hy chemically reducing cellular glutathione levels. Collectively, the abllity to both increase and decrease the anti-oxidant defenses in human T cells results in a useful model system for the study of oxidative stress and signaling in this cell type
基金supported by the grants from the Key Program of Natural Science Foundation of State(Nos.90709019,81173500,81373930,81302905,81102556,81202639)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(Nos.2011BAI03B03,2011BAI03B06,2011BAI03B08)the National Key Subject of Drug Innovation(No.2009ZX09502-005)
文摘Natural products have gained popularity worldwide for promoting healthcare, as well as disease prevention. Alkaloids are important chemical compounds that serve as a rich reservoir for drug discovery. Several alkaloids isolated from natural herbs exhibit antiproliferation, antibacterial, antiviral, insecticidal, and antimetastatic effects on various types of cancers both in vitro and in vivo. This paper focuses on the naturally-derived alkaloids such as berberine, matrine, piperine, fritillarine, and rhynchophylline, etc., and summarizes the action mechanisms of these compounds. Based on the information in the literature that is summarized in this paper, the use of alkaloids as drugs is very promising, but more research and clinical trials are necessary before final recommendations on specific alkaloids can be made. Following this, it is hoped that as a result of this review, there will be a greater awareness of the excellent promise that natural alkaloids show for use in the therapy of diseases.
文摘The concentration distribution of essential and non-essential micro-elements of the tissues of healthy organisms shows significant difference. This fact can be used for clarification of the biological role of hardly known trace elements, as well, proving the essential or non-essential character. In case of essential elements the concentration range is rather narrow, the distribution is normal. In case of non-essential elements the interval is wide, the concentration-distribution is log-normal. Measurements and mathematical calculations were carried out for determination of the concentrations and concentration-distributions of some micro-elements, trying to clarify the essentiality or non-essential character of the investigated elements from point of view of plant physiology. Based on the measurements for radish Li and Ni seem to be non-essential trace elements, however in case of Sr the distribution curve suggests an essential character, because the concentration range is not wide.
