The Role of Selenium Compounds in Cancer Therapy

Experimental evidence is presented that demonstrates the impact of selenium on the effects of a variety of anticancer treatments, including chemotherapy and radiation. Selenium-dependent glutathione peroxidase can detoxify organic peroxides resulting from some of these treatments. Selenium deficiency has also been associated with significant changes in liver enzymes that activate some drugs and contribute to detoxification. Some forms of free selenium have cytotoxicity against a variety of tumor cell lines, both murine and human. Experimental data suggest that catalytic oxidation of cellular glutathione and reduction of molecular oxygen are part of the mechanism of this antitumor activity. This provides provocative possibilities for the inclusion of selenium into cancer therapy regimens.

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Understanding the Redox Biology of Selenium in the Search of Targeted Cancer Therapies

Antioxidants ◽

10.3390/antiox9050420 ◽

2020 ◽

Vol 9 (5) ◽

pp. 420 ◽

Cited By ~ 3

Author(s):

Jeffrey M. Stolwijk ◽

Rohan Garje ◽

Jessica C. Sieren ◽

Garry R. Buettner ◽

Yousef Zakharia

Keyword(s):

Selenium Deficiency ◽

Vital Role ◽

High Dose ◽

Specific Cell ◽

Cancer Therapies ◽

Selenium Compounds ◽

Redox Biology ◽

Selenium Treatment ◽

Prevention Of Cancer

Selenium (Se) is an essential trace nutrient required for optimal human health. It has long been suggested that selenium has anti-cancer properties. However, clinical trials have shown inconclusive results on the potential of Se to prevent cancer. The suggested role of Se in the prevention of cancer is centered around its role as an antioxidant. Recently, the potential of selenium as a drug rather than a supplement has been uncovered. Selenium compounds can generate reactive oxygen species that could enhance the treatment of cancer. Transformed cells have high oxidative distress. As normal cells have a greater capacity to meet oxidative challenges than tumor cells, increasing the flux of oxidants with high dose selenium treatment could result in cancer-specific cell killing. If the availability of Se is limited, supplementation of Se can increase the expression and activities of Se-dependent proteins and enzymes. In cell culture, selenium deficiency is often overlooked. We review the importance of achieving normal selenium biology and how Se deficiency can lead to adverse effects. We examine the vital role of selenium in the prevention and treatment of cancer. Finally, we examine the properties of Se-compounds to better understand how each can be used to address different research questions.

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Arsenate Retention by Epipsammic Biofilms Developed on Streambed Sediments: Influence of Phosphate

BioMed Research International ◽

10.1155/2013/591634 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 6

Author(s):

D. M. Prieto ◽

R. Devesa-Rey ◽

D. A. Rubinos ◽

F. Díaz-Fierros ◽

M. T. Barral

Keyword(s):

Experimental Data ◽

Environmental Quality ◽

Human Activities ◽

Sediment Samples ◽

Average Percentage ◽

Geological Conditions ◽

Streambed Sediments ◽

The Impact

Natural geological conditions together with the impact of human activities could produce environmental problems due to high As concentrations. The aim of this study was to assess the role of epipsammic biofilm-sediment systems onto As (V) sorption and to evaluate the effect of the presence of equimolar P concentrations on As retention. A natural biofilm was grown on sediment samples in the laboratory, using river water as nutrient supplier. Sorption experiments with initial As concentrations 0, 5, 25, 50, 100, 250, and 500 μg L−1were performed. The average percentage of As sorbed was78.9±3.5and96.9±6.6% for the sediment and biofilm-sediment systems, respectively. Phosphate decreased by 25% the As sorption capactity in the sediment devoid of biofilm, whereas no significant effect was observed in the systems with biofilm. Freundlich, Sips, and Toth models were the best to describe experimental data. The maximum As sorption capacity of the sediment and biofilm-sediment systems was, respectively, 6.6 and 6.8 μg g−1and 4.5 and 7.8 μg g−1in the presence of P. In conclusion, epipsammic biofilms play an important role in the environmental quality of river systems, increasing As retention by the system, especially in environments where both As and P occur simultaneously.

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Interferon in the Treatment of Multiple Myeloma

Cancer Control ◽

10.1177/107327489800500303 ◽

1998 ◽

Vol 5 (3) ◽

pp. 226-234 ◽

Cited By ~ 10

Author(s):

Chaim Shustik

Keyword(s):

Multiple Myeloma ◽

Antitumor Activity ◽

Randomized Trials ◽

Ex Vivo ◽

Cost Benefit ◽

Reliable Estimate ◽

Medline Search ◽

Ifn Therapy ◽

The Impact

Background The role of interferon (IFN) in the treatment of multiple myeloma has been investigated for nearly two decades. The mechanisms underlying antitumor activity of IFN may be mediated by antiproliferative and immunomodulatory effects. The benefits of treatment remain controversial, and guidelines for the use of IFN in myeloma are needed. This review evaluates available data on the impact of IFN therapy on multiple myeloma. Methods A MEDLINE search of published prospective, randomized trials of IFN in multiple myeloma provided the data included in this review, as well as selected abstracts presented at international meetings. Results IFN has complex and pleiotropic effects on human myeloma lines and ex vivo myeloma cells. An antiproliferative effect with disruption of the IL-6-mediated growth loop may be crucial, but biologic heterogeneity in myeloma may have important clinical implications for response to IFN. IFN has demonstrable antitumor activity in multiple myeloma but appears to have a modest effect on overall survival when combined with chemotherapy during induction or when used as maintenance therapy. Most studies have shown a prolongation of the plateau phase of disease with IFN of variable duration of between four and 12 months. Conclusions A reliable estimate of the benefit of IFN in the overall population of patients with myeloma is difficult to determine with discordant results from different trials. Possible sources of heterogeneity in randomized trials need to be identified, and recognition of subsets of patients who may benefit is important. Cost-benefit analyses with integration of quality-of-life data are essential for developing guidelines for the use of IFN in myeloma.

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The Role of Pre-Conditioning Frequency in the Experimental Characterization of Hyper-Elastic Materials as Models for Soft Tissue Applications

International Journal of Applied Mechanics ◽

10.1142/s1758825116500666 ◽

2016 ◽

Vol 08 (05) ◽

pp. 1650066 ◽

Cited By ~ 4

Author(s):

Serena de Gelidi ◽

Gianluca Tozzi ◽

Andrea Bucchi

Keyword(s):

Experimental Data ◽

Biological Tissues ◽

Experimental Simulation ◽

Elastic Behavior ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Elastic Materials ◽

Hyper Elastic ◽

The Impact

Rubber-like materials as many soft tissues can be described as incompressible and hyper-elastic materials. Their comparable elastic behavior, up to a certain extent, has been exploited to develop and test experimental methodologies to be then applied to soft biological tissues such as aortic wall. Hence, theoretical and experimental simulation of aortic tissue, and more generally blood vessel tissue, has been often conducted using rubbers. Despite all the efforts in characterizing such materials, a clear and comprehensive testing procedure is still missing. In particular, the influence of pre-conditioning in the mechanical response of hyper-elastic materials has been often neglected. In this paper, the importance of pre-conditioning is demonstrated by: (i) exploring the effect of stretching frequency applied before the uniaxial tensile test; (ii) recognizing the role of specimen geometry and strain amplitude; (iii) verifying the impact of experimental data acquisition on finite element predictions. It was found that stress–strain relationship shows a statistical difference between some frequencies of pre-conditioning and its absence. Only certain pre-conditioning frequencies were able to generate repeatable experimental data for strip or dumb-bell shapes. This feature corresponds to a consistent reduction in the scatter of critical pressures obtained by numerical simulations.

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Therapeutic Potential of Selenium and Selenium Compounds in Cervical Cancer

Cancer Control ◽

10.1177/10732748211001808 ◽

2021 ◽

Vol 28 ◽

pp. 107327482110018

Author(s):

Ewa Jablonska ◽

Qi Li ◽

Edyta Reszka ◽

Edyta Wieczorek ◽

Kateryna Tarhonska ◽

...

Keyword(s):

Experimental Data ◽

Cervical Cancer ◽

Genetic Background ◽

Therapeutic Potential ◽

Hpv Infection ◽

Host Immune System ◽

Essential Trace Element ◽

Antitumor Effects ◽

Selenium Compounds

Cervical cancer is a common female cancer. It is strongly associated with human papillomavirus (HPV) infection. However, HPV infection alone is not sufficient to induce cervical cancer because its development is dependent on the coexistence of several factors that enable the virus to overcome the host immune system. These include individual genetic background, environmental factors, or diet, including dietary selenium intake. Selenium is an essential trace element with antiviral properties and has been shown to exert antitumor effects. Surprisingly, the role of selenium in cervical cancer has not been studied as intensively as in other cancers. Here, we have summarized the existing experimental data on selenium and cervical cancer. It may be helpful in evaluating the role of this nutrient in treatment of the mentioned malignancy as well as in planning further studies in this area.

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Role of Polar vs Non-polar Configurations in the Decay of 268Sg* Compound Nucleus Within the Skyrme Energy Density Formalism

Journal of Nuclear Physics Material Sciences Radiation and Applications ◽

10.15415/jnp.2021.91011 ◽

2021 ◽

Vol 9 (1) ◽

pp. 61-66

Author(s):

Rajni Mittal ◽

Kirandeep Sandhu ◽

M. K. Sharma

Keyword(s):

Experimental Data ◽

Energy Density ◽

Cross Section ◽

Compound Nucleus ◽

Cross Sections ◽

Fission Cross Section ◽

Cluster Decay ◽

The Impact ◽

Adequate Agreement

The effect of polar and non-polar configurations is investigated in the decay of 268Sg* compound nucleus formed via spherical projectile (30Si) and prolate deformed target (238U) using the dynamical cluster decay model. The SSK and GSkI skyrme forces are used to investigate the impact of polar and nonpolar (equatorial) configurations on the preformation probability P0 and consequently on the fission cross-sections of 268Sg* nucleus. For non-polar configuration some secondary peaks corresponding to magic shells Z=28 and N=50 are observed, whose magnitude is significantly suppressed for the polar counterpart. The effect of polar and non-polar configurations is further analyzed in reference to barrier lowering parameter ΔVB. The calculated fission cross-section find adequate agreement with experimental data for chosen set of skyrme forces.

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Investigations into the Role of Friction for Rigid Penetration into Concrete-Like Material Targets

Materials ◽

10.3390/ma13214733 ◽

2020 ◽

Vol 13 (21) ◽

pp. 4733

Author(s):

Ningjing Jiang ◽

Shufan Wu ◽

Yile Hu ◽

Zhongcheng Mu ◽

Xiaofeng Wu ◽

...

Keyword(s):

Experimental Data ◽

Numerical Simulations ◽

Phase Behavior ◽

Impact Dynamics ◽

Two Phase ◽

Penetration Process ◽

Simulation Results ◽

Penetration Behavior ◽

The Impact

Currently, it appears that there is a lack of understanding related to the role of SSF, in the two-phase behavior of the deceleration history, which is an issue discussed recently in the impact dynamics field. This paper analytically and numerically focuses on the effect of SSF on the projectile deceleration characteristic of concrete-like targets. Firstly, the penetration process according to the two-phase feature of the projectile deceleration is revised, where analytical results indicate that the SSF has a phased feature corresponding to the two-phase behavior of the deceleration history. Furthermore, a series of numerical simulations are conducted to understand the role of SSF more clearly. Simulation results show a similar conclusion to the analyses of the two-phase penetration process; at the range below a certain critical striking velocity, adding friction can reproduce the experimental data; when exceeding the critical striking velocity, the simulated results without considering friction are closest to the experimental data. Hence, it could be gained that the role exchange between the SSF and the dynamic term contributes to the two-phase penetration behavior for concrete-like materials. This indicates that the sensitivity of SSF to the penetration process is one of the factors driving the two-phase feature.

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The Effect of Injunctive Social Norms and Dissent on Budget Reporting Honesty

Journal of International Accounting Research ◽

10.2308/jiar-51744 ◽

2017 ◽

Vol 16 (2) ◽

pp. 9-31 ◽

Cited By ~ 7

Author(s):

Martin Altenburger

Keyword(s):

Experimental Data ◽

Economic Theory ◽

Social Norms ◽

Peer Group ◽

Considerable Influence ◽

Injunctive Norms ◽

The Impact ◽

Budgeting Process ◽

Firm Profit

ABSTRACT Research in budgeting suggests that contextual factors may have a considerable influence on budget reporting honesty. Therefore, the present study investigates managers' honesty in the presence of different social norms. While there are several studies that look at the impact of descriptive social norms (what one actually does) on managerial honesty, injunctive social norms (what one ought to do) have not received a lot of attention in the literature. As concrete actions of peers are rarely observable in the budgeting process, this study focuses on the effect of injunctive norms for honesty/opportunism on budget reporting honesty. Moreover, the role of dissenters from the norm is investigated. The results from a laboratory experiment suggest that injunctive norms can have a considerable influence on managers' budget reporting behavior because many people conform to the preferences of their peer group. However, the effect of injunctive norms decreases substantially when there are minorities that show alternative preferences. With the use of the experimental data, the expected firm profit is calculated under different contracts. As the managers show considerable levels of honesty, a trust contract should be preferred compared to a hurdle contract, which is derived from conventional economic theory. Companies should therefore consider injunctive norms as a possible device to positively affect their managers' honesty and the respective firm profit.

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Intergroup Threat and Outgroup Attitudes

Social Psychology ◽

10.1027/1864-9335/a000127 ◽

2013 ◽

Vol 44 (5) ◽

pp. 311-319 ◽

Cited By ~ 12

Author(s):

Marco Brambilla ◽

David A. Butz

Keyword(s):

Gay Men ◽

Social Group ◽

Welfare Recipients ◽

Intergroup Attitudes ◽

Social Policies ◽

Intergroup Threat ◽

Economic Threat ◽

The Impact ◽

General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

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