Dosage Window of Selenium on Human Natural Killer Cytotoxicity and Neutrophilmediated Chemiluminescence

Few studies have been conducted on the effect of in vitro selenium (Se) supplementation on cellular immunity. In the present study, the effects of in vitro incubation with sodium selenite on natural killer (NK)-mediated cytotoxicity and phagocyte chemiluminescence (CL) were examined. NK-mediated cytotoxicity and phagocyte CL were observed to be affected by added selenite. These changes generally included augmentation and suppression of both neutrophil CL and NK-mediated cytotoxicity. All dosages of selenite used were shown to be capable of causing augmentation of neutrophil CL. However, 1.0 /xg/ml selenite was also observed to occasionally cause depression of neutrophil CL. When Se supplementation enhanced NK cytotoxicity, the effect was always observed at 0.1 /xg/ml selenite dosage. Higher dosages of selenite induced both enhancement and depression of activity. The existence of a narrow dosage-window is evident. The activity of the selenoenzyme glutathione peroxidase (GSH-Px) was also determined in NK cells and phagocytes following selenite supplementation. Dose-dependent augmentation of phagocytic activity by selenite supplementation was accompanied by a corresponding increase in phagocyte GSH-Px activity. The effect of Se treatment on non-adherent cell GSH-Px activity did not correlate with NK cytotoxicity

Diseased Thyrocytes Have Aberrant Communication and TNF Receptor Secretion

Autoimmune diseases are a world-wide health concern and are an intense area of investigation. However, one area of research has been largely ignored. This involves the contribution of the target tissue to the disease process. We hypothesized that cell-cell communication is disrupted by lymphocytic infiltration and advancing fibrosis and this disruption results in altered target cell responses to immune components produced at the site of inflammation, including Tumor Necrosis Factor-alpha (TNF- α). We have used thyroiditis as our model of autoimmunity and have documented the development of spontaneous thyroiditis in MRL-lpr/lpr mice. We have found aberrant connexin expression in thyroid tissue from these mice. The abnormal gap junction assembly persisted when the cells were removed from the inflammation site and cultured in vitro. Primary thyrocyte cultures from these mice were also functionally uncoupled, as indicated by decreased Lucifer Yellow dye transfer. This indicated that mechanisms other than physical disruption were influencing intercellular communication in diseased thyrocytes. Protein kinase C (pKC) decreases connexin 43-mediated communication and regulates numerous cellular properties. We found increased pKC activity in diseased thyrocytes. This enhanced pKC activity was found to be responsible for their decreased cell-cell communication. Furthermore, pKC also decreased T4 release from murine thyrocytes and this decrease was partially mediated through the effect of pKC on intercellular communication. TNF- α did not cause cytotoxic damage to the diseased thyrocytes. We did find, however, that the enhanced pKC activity in the diseased thyrocytes caused an increase in soluble TNF- α receptor production. The production of soluble TNF- α receptors was not the result of proteolytic cleavage of the cell-surface receptor. Instead, the diseased thyrocytes may be secreting soluble receptors. We are the first to report this mode of production for soluble TNF- α receptors

Integrating Wiki Technology into Middle School Literature Circles

This action research study used a quasi-experimental pre/post-test design to investigate the effects of integrating technology into middle school literature circles. The intervention group used wiki technology to support their literature circle preparations, while the control group used role sheets. Data sources included a comprehension curriculum based measure, a reading motivation survey, and a researcher log. The intervention group earned larger mean gain scores on both quantitative measures, but this score difference was not statistically significant based on the results of independent t-tests. Qualitative data suggested positives to using the intervention over traditional methods, and highlighted areas for further research

Integrating Wiki Technology into Middle School Literature Circles

This action research study used a quasi-experimental pre/post-test design to investigate the effects of integrating technology into middle school literature circles. The intervention group used wiki technology to support their literature circle preparations, while the control group used role sheets. Data sources included a comprehension curriculum based measure, a reading motivation survey, and a researcher log. The intervention group earned larger mean gain scores on both quantitative measures, but this score difference was not statistically significant based on the results of independent t-tests. Qualitative data suggested positives to using the intervention over traditional methods, and highlighted areas for further research

Alternate energy sources for the future.

This project examines the renewable alternatives of fossil fuels in view of their projected depletion. We concentrated on nuclear energy and examined its potential dangers and ways to improve its safety. Special attention was paid to protection from terrorist attacks, storage and disposal of byproduct. We conclude that nuclear energy is a viable energy source to replace fossil fuels in the near future

Alternate energy sources for the future.

This project examines the renewable alternatives of fossil fuels in view of their projected depletion. We concentrated on nuclear energy and examined its potential dangers and ways to improve its safety. Special attention was paid to protection from terrorist attacks, storage and disposal of byproduct. We conclude that nuclear energy is a viable energy source to replace fossil fuels in the near future

Crayfish (Orconectes virilis) as Bioindicators of Polycyclic Aromatic Hydrocarbon Contamination in the Blackstone River Valley

The use of crayfish as bioindicators of polycyclic aromatic hydrocarbons (PAHs), specifically benzo[a]pyrene, was investigated. These contaminants have been identified by the EPA as potential human carcinogens, and are common in industrial areas like the Blackstone region of Massachusetts. Crayfish blood, hepatopancreas, and muscle, along with water, and sediment samples from the Blackstone River were analyzed using gas chromatography to determine benzo[a]pyrene concentrations. Results show the potential of crayfish to act as bioindicators of PAHs, while creating a base for future research