Evaluation of bioluminescence as a measure of bacterial cell density in porous media

Salicylate-induced, lux gene dependent bioluminescence was measured using a cooled charge-coupled device (CCD) camera to evaluate its potential as a quantitative measurement of cell density of Pseudomonas fluorescens HK44 in porous media. The CCD camera was able to detect bioluminescence from cell densities between 1x10⁶ and 1x10⁸ cells/ml in both liquid suspensions and saturated sand, and between 5x10⁶ and 8.5x10⁸ cells/ml in unsaturated sand at 7.0% (cm³/cm³) volumetric water content. After lux gene induction by 100 mg/L salicylate, light emission increased with the square of time and linearly with increasing cell density. A model was developed to relate light emission with cell density. Similar values were determined for the rate of increase in light emission, B', [12 (± 0.2) x 10⁻¹⁰ light units/(cell-min²)] for suspensions of cells in aqueous media and in saturated or unsaturated sand. Growth phase of HK44 significantly influenced the first detectable time (FDT) of bioluminescence response with log and stationary phase cells expressing FDT values of 2.5 and 1.8 hours, respectively, after induction. The effect of growth phase was eliminated by the addition of 10 to 250 mg/L glucose and salicylate simultaneously. Oxygen availability limited the upper cell density limit (1x10⁸ cells/ml) that could be measured by bioluminescence with the CCD camera. While each camera system and bioluminescent organism combination will require calibration, a CCD camera system has the potential to quantify bacterial bioluminescence as a means to study microbial growth and dynamics non-destructively in two-dimensional porous media

Perceptions of the Environment and Health Among Members of the Confederated Tribes of the Umatilla Indian Reservation

Indigenous cultures perceive the natural environment as an essential link between traditional cultural practices, social connectedness, identity, and health. Many tribal communities face substantial health disparities related to exposure to environmental hazards. Our study used qualitative methods to better understand the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) members’ perspectives about their environment and its connections with their health including views on environmental health hazards. Three 90-minute focus group sessions with a total of 27 participants were held to elicit opinions on meanings of health and how the environment interacts with health. A systematic text analysis was used to derive themes across focus groups. Participants expressed a holistic view of health that included environmental, physical, mental, spiritual, and social components. A healthy natural environment was identified as an essential component of a healthy individual and a healthy community. Participants also described many environmental health concerns including second-hand smoke, outdoor smoke, diesel exhaust, mold, pesticides, contaminated natural foods, and toxic wastes from the Hanford nuclear site and methamphetamine labs. Many believe the identified environmental hazards contribute to diseases in their community. The natural environment is an important resource to CTUIR members and plays an integral role in achieving and maintaining health. Knowledge about the values and concerns of the community are useful to the tribal and federal governments, health professionals, environmental health practitioners, and community members who seek to achieve sustainable and healthy rural Native communities

Multivitamin/Multimineral Supplementation Prevents or Reverses Decline in Vitamin Biomarkers and Cellular Energy Metabolism in Healthy Older Men: A Randomized, Double-Blind, Placebo-Controlled Study

Despite the reported prevalence of micronutrient deficiencies in older adults, it is not yet established whether multivitamin/multimineral (MV/MM) supplements improve blood micronutrient status in individuals over the age of 65. Therefore, a cohort of 35 healthy men (>67 years) was recruited for an MV/MM supplementation trial. The primary endpoint was, as an indicator of micronutrient status, changes in blood micronutrient biomarkers from baseline to at least six months of supplementation with MV/MM or placebo. The secondary endpoint was basal O2 consumption in monocytes as an indicator of cellular metabolism. MV/MM supplementation improved blood concentrations of pyridoxal phosphate, calcifediol, α-tocopherol, and β-carotene concentrations throughout the cohort. By contrast, those in the placebo group generally showed declines in blood vitamin concentrations and an increased prevalence of suboptimal vitamin status during the study period. On the other hand, MV/MM supplementation did not significantly affect blood mineral concentrations, i.e., calcium, copper, iron, magnesium, and zinc. Interestingly, MV/MM supplementation prevented the decline in monocyte O2 consumption rate. Overall, MV/MM use improves or prevents declines in vitamin, but not mineral, status and limits declines in cellular O2 consumption, which may have important implications for metabolism and immune health in healthy older men

The Effect of a Multivitamin and Mineral Supplement on Immune Function in Healthy Older Adults: A Double-Blind, Randomized, Controlled Trial

Older adults are at increased risk for vitamin and mineral deficiencies that contribute to age-related immune system decline. Several lines of evidence suggest that taking a multi-vitamin and mineral supplement (MVM) could improve immune function in individuals 55 and older. To test this hypothesis, we provided healthy older adults with either an MVM supplement formulated to improve immune function (Redoxon® VI, Singapore) or an identical, inactive placebo control to take daily for 12 weeks. Prior to and after treatment, we measured (1) their blood mineral and vitamin status (i.e., vitamin C, zinc and vitamin D); (2) immune function (i.e., whole blood bacterial killing activity, neutrophil phagocytic activity, and reactive oxygen species production); (3) immune status (salivary IgA and plasma cytokine/chemokine levels); and (4) self-reported health status. MVM supplementation improved vitamin C and zinc status in blood and self-reported health-status without altering measures of immune function or status or vitamin D levels, suggesting that healthy older adults may benefit from MVM supplementation. Further development of functional assays and larger study populations should improve detection of specific changes in immune function after supplementation in healthy older adults. Clinical Trials Registration: ClinicalTrials.gov #NCT02876315