Using IFN-γ as a Biomarker for Detecting Exposure to Viral Pathogens

To determine whether interferon gamma (IFN-γ) can be used as a biomarker of exposure to viral pathogens, 12-week-old BALB/c mice were injected intraperitoneally with coxsackievirus B3 (CVB3) or coxsackievirus B4 (CVB4) diluted in sterilized phosphate-buffered saline (PBS). Control mice were injected with PBS only. Four months after viral infection, mouse spleen cells were harvested and assayed for the release of IFN-γ by memory T cells after in vitro stimulation with viral antigens, phytohemagglutinin (PHA), and PBS, respectively. The level of IFN-γ was examined by an antibody-capture enzyme-linked immunosorbent assay (ELISA). A marked increase in the level of IFN-γ was observed when memory T cells from CVB3-infected mice were incubated with CVB3 virus, but not with CVB4 or PBS. Conversely, memory T cells from mice infected by CVB4 were not stimulated to produce IFN-γ when they were incubated with CVB3 and PBS, but did significantly produce IFN-γ when stimulated with CVB4. T cells from mice injected with PBS did not release IFN-γ after stimulation with CVB3 or CVB4. However, these T cells did release IFN-γ after stimulation with PHA. Our results demonstrated that IFN-γ produced by memory T cells is virus-specific and may have use as a biomarker in viral exposure studies. The results of this study may be extended to the study of infection by pathogens that are capable of inducing cell-mediated immune response in humans. Disclaimer: The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here. It has been subjected to Agency’s administrative review and approved for publication.     

Reply to comments regarding “The Carrageenan Controversy”

Carrageenan has been used in the laboratory for decades because it reliably causes inflammation. Coincident with its use in the laboratory, carrageenan has been used in an ever-increasing list of processed foods, as well as in infant formula, pharmaceuticals, cosmetics, toothpaste, room air deodorizers, and other products. The biological reactivity of carrageenan makes it a useful substance to improve the texture and solubility of ingredients in processed foods. Individuals may consume several grams of carrageenan on a daily basis. However, the potential contribution of carrageenan exposure to chronic human diseases, due to its activation of immune responses and its potent inflammatory properties, must be recognized.     

The Transcription Factor IRF3 Triggers “Defensive Suicide” Necrosis in Response to Viral and Bacterial Pathogens

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Coliform concentrations in Lake Erie — 1966 to 1970

Total coliform concentrations obtained from cruises of Lake Erie, conducted from the Canada Centre for Inland Waters between 1966 and 1970, have been analysed to determine the spatial and temporal distribution of total coliforms in the lake. Although year to year comparisons were made on a qualitative level due to the limitations in the data, some consistent seasonal features of the spatial distribution are evident. The location of zones of higher concentration have been attributed to proximity to large urban areas and lake currents. The contribution of fecal coliforms to the total coliform concentration has been examined with the conclusion that, at the low total coliform concentrations ( 30 per 100 ml) observed in much of the lake, there is no relationship between the two concentrations but, over a broader range, fecal coliforms increase with total coliform concentrations and, at very high total coliform concentrations (1000 per 100 ml), fecal coliforms are always present. The analysis demonstrates 1) the value of examining observed and fitted distributions to compare subsets of a large collection of data and 2) a clustering procedure which is generally applicable to data consisting of counts.     

How Do Changes to the Railroad Causeway in Utah’s Great Salt Lake Affect Water and Salt Flow?

Managing terminal lake elevation and salinity are emerging problems worldwide. We contribute to terminal lake management research by quantitatively assessing water and salt flow for Utah’s Great Salt Lake. In 1959, Union Pacific Railroad constructed a rock-filled causeway across the Great Salt Lake, separating the lake into a north and south arm. Flow between the two arms was limited to two 4.6 meter wide rectangular culverts installed during construction, an 88 meter opening (referred to locally as a breach) installed in 1984, and the semi porous material of the causeway. A salinity gradient developed between the two arms of the lake over time because the south arm receives approximately 95% of the incoming streamflow entering Great Salt Lake. The north arm is often at, or near, salinity saturation, averaging 317 g/L since 1966, while the south is considerably less saline, averaging 142 g/L since 1966. Ecological and industrial uses of the lake are dependent on long-term salinity remaining within physiological and economic thresholds, although optimal salinity varies for the ecosystem and between diverse stakeholders. In 2013, Union Pacific Railroad closed causeway culverts amid structural safety concerns and proposed to replace them with a bridge, offering four different bridge designs. As of summer 2015, no bridge design has been decided upon. We investigated the effect that each of the proposed bridge designs would have on north and south arm Great Salt Lake elevation and salinity by updating and applying US Geological Survey’s Great Salt Lake Fortran Model. Overall, we found that salinity is sensitive to bridge size and depth, with larger designs increasing salinity in the south arm and decreasing salinity in the north arm. This research illustrates that flow modifications within terminal lakes cannot be separated from lake salinity, ecology, management, and economic uses.     

Ranking the importance of alerts for problem determination in large computer systems

The complexity of large computer systems has raised unprecedented challenges for system management. In practice, operators often collect large volume of monitoring data from system components and set up many rules to check data and trigger alerts. However, the alerts from various rules usually have different problem reporting accuracy because their thresholds are often manually set based on operators’ experience and intuition. Meantime, due to system dependencies, a single problem may trigger many alerts at the same time in large systems and the critical question is which alert should be analyzed first in the following problem determination process. In this paper, we propose a novel peer review mechanism to rank the importance of alerts and the top ranked alerts are more likely to be true positives. After comparing a metric value against its threshold to generate alerts, we also compare the value with the equivalent thresholds from many other rules to determine the importance of alerts. Our approach is evaluated with a real test bed system and experimental results are also included to demonstrate its effectiveness.     

How to Preserve Plant Samples for Carbohydrate Analysis? Test of Suitable Methods Applicable in Remote Areas

Nonstructural carbohydrates (NSC) are frequently studied both by ecologists and plant physiologists because they serve as fundamental carbon and energy sources in plant metabolism. Because of the rapid enzymatic hydrolysis of NSC after harvest, plants are usually placed into liquid nitrogen until subsequent analyses in the laboratory. Nevertheless, when the research is performed in poorly accessible regions such as high mountains, tropical forests or deserts, the use of heavy containers containing vaporizing liquid nitrogen is problematic for logistical reasons. These places are particularly interesting as they harbor plant species with interesting physiological adaptations. In our study we aimed to develop a suitable storage method for plants intended for NSC analyses, which would require minimal equipment. These demands resulted in the idea of using the first step in NSC analyses – extraction in ethanol. Samples were extracted in 50 % and 96 % boiling or non-boiling ethanol and then stored for one month; they were compared with samples immediately frozen in liquid nitrogen. We discovered that for samples containing starch, fructans, soluble sugars and sugar alcohols, the best pretreatment for subsequent storage is extraction in 50 % or 96 % boiling ethanol. For total nonstructural carbohydrates (TNC) assessment, only extracting with 50 % ethanol without boiling gave very good results. Finally, we developed a method that could be used in any remote place without bulky laboratory equipment.