AbstractA noninvasive and reliable method is needed to investigate causal relationship between exposure to bioaerosols in occupational and indoor environments and adverse health effects. As an essential part of the method development, the individual variation as well as seasonal and gender differences in the concentrations of inflammatory mediators in nasal lavage (NAL) fluid were studied. NAL was performed in 10 healthy volunteers every other week for a year. Concentrations of nitric oxide, assessed as nitrite, interleukin (IL)-1β, IL-4, IL-5, IL-6, and tumor necrosis factor alpha (TNFα) in NAL fluid were measured. The NAL sampling was minimally invasive and well tolerated and no side effects were observed among the studied subjects. Low concentrations of nitrite, TNFα, IL-1β, IL-4, and IL-6 were detected in the NAL samples of the studied subjects. Within-subject variation in the concentrations of inflammatory mediators in the NAL fluid was at its lowest during the wintertime. Moreover, differences between individuals and genders were statistically significant. In summary, the individual variation in the basal levels of measured inflammatory markers is low, whereas differences between individuals are considerable. Thus, in the studies evaluating upper airway effects of occupational or environmental exposure, the method is most suitable in settings where comparison can be made using test subjects as their own controls.
<b><i>Background:</i></b> Exposure to microbes and their components may affect the maturation of the immune system.<b> </b>We examined the association of house dust microbial content with cytokine-producing capacity at birth and at the age of 1 year. <b><i>Methods:</i></b> Production of TNF-α, IFN-γ, IL-5, IL-8 and IL-10 at birth (n = 228) and at the age of 1 year (n = 200) following 24- and 48-hour whole-blood stimulation with staphylococcal enterotoxin B (SEB), lipopolysaccharide and the combination of phorbol ester and ionomycin was measured. Concentrations of ergosterol (marker for fungal biomass), muramic acid (marker for Gram-positive bacteria) and 3-hydroxy fatty acids with a carbon chain length from 10 to 14 (marker for Gram-negative bacteria) in living room floor dust were analyzed using gas chromatography-tandem mass spectrometry. Five single microbial species or groups were determined using a quantitative polymerase chain reaction method. <b><i>Results:</i></b> A high total level of the studied Gram-positive bacteria in general or <i>Mycobacterium </i>spp. in house dust was associated with decreased SEB-stimulated IFN-γ production, especially at the age of 1 year. The total level of indoor fungi analyzed <i>(Penicillium</i> spp<i>., Aspergillus </i>spp<i>. </i>and<i> Paecilomyces variotii</i> group, <i>Trichoderma viride/atroviride/koningii,</i><i>Wallemia sebi)</i> was also inversely associated with IFN-γ production at the age of 1 year, but this association did not remain significant after adjustment for potential confounders. A few associations were found between microbial exposures and other measured cytokines. <b><i>Conclusions:</i></b> High indoor microbial exposures may affect immune development in early life by reducing T helper type 1 cytokine secretion capacity. The observed hyporesponsiveness may reflect the adaptation of the immune system to environmental antigens. In future, more attention should be paid especially to the immunomodulatory role of exposures to Gram-positive bacteria.
Moisture and mold problems in buildings contaminate also the furniture and other movable property. If cleaning of the contaminated furniture is neglected, it may continue to cause problems to the occupants even after the moisture-damage repairs. The aim of this study was to determine the effectiveness of high-efficiency ozone treatment in cleaning of the furniture from moisture-damaged buildings. In addition, the effectiveness of two cleaning methods was compared. Samples were vacuumed from the padded areas before and after the treatment. The microbial flora and concentrations in the dust sample were determined by quantitative cultivation and QPCR-methods. The immunotoxic potential of the dust samples was analyzed by measuring effects on cell viability and production of inflammatory mediators in vitro. Concentrations of viable microbes decreased significantly in most of the samples after cleaning. Cleaning with combined steam wash and ozonisation was more effective method than ozonising alone, but the difference was not statistically significant. Detection of fungal species with PCR showed a slight but nonsignificant decrease in concentrations after the cleaning. The immunotoxic potential of the collected dust decreased significantly in most of the samples. However, in a small subgroup of samples, increased concentrations of microbes and immunotoxicological activity were detected. This study shows that a transportable cleaning unit with high-efficiency ozonising is in most cases effective in decreasing the concentrations of viable microbes and immunotoxicological activity of the furniture dust. However, the method does not destroy or remove all fungal material present in the dust, as detected with QPCR analysis, and in some cases the cleaning procedure may increase the microbial concentrations and immunotoxicity of the dust.
Aiming to identify factors causing the adverse health effects associated with moisture-damaged indoor environments, we analyzed immunotoxicological potential of settled dust from moisture-damaged and reference schools in relation to their microbiological composition. Mouse RAW264.7 macrophages were exposed to settled dust samples (n = 25) collected from moisture-damaged and reference schools in Spain, the Netherlands, and Finland. After exposure, we analyzed production of inflammatory markers [nitric oxide (NO), tumor necrosis factor-α (TNF-)α, interleukin (IL)-6, and macrophage inflammatory protein (MIP)2] as well as mitochondrial activity, viability, apoptosis, and cell cycle arrest. Furthermore, particle counts, concentration of selected microbial groups as well as chemical markers such as ergosterol, 3-hydroxy fatty acids, muramic acid, endotoxins, and glucans were measured as markers of exposure. Dust from moisture-damaged schools in Spain and the Netherlands induced stronger immunotoxicological responses compared to samples from reference schools; the responses to Finnish samples were generally lower with no difference between the schools. In multivariate analysis, IL-6 and apoptosis responses were most strongly associated with moisture status of the school. The measured responses correlated with several microbial markers and numbers of particles, but the most important predictor of the immunotoxicological potential of settled dust was muramic acid concentration, a marker of Gram-positive bacteria.
To study the production and interrelations of maternal and neonatal cytokines (IL-6 and TNF-alpha) during labor, after vaginal delivery and at three months after delivery.The unstimulated concentrations of cytokines in the supernatants of whole-blood cultures and concentrations after PMA (phorbol 12-myristate 13-acetate) and concanavalin (conA) stimulation were determined by enzyme-linked immunosorbent assays (ELISAs). The blood samples were from the peripheral veins of 27 healthy women during term labor and immediately after delivery and three months after delivery. Neonatal samples were taken at birth (cord blood) and three months after delivery.IL-6 responses to stimulation were increased in the parturients and in umbilical cord blood at delivery compared with maternal and neonatal samples obtained 3 months postpartum. In contrast, the production of maternal TNF-alpha in peripheral blood was down-regulated at delivery compared with values 3 months postpartum. After an IL-6 and TNF-alpha burst in umbilical cord samples, neonatal cytokine production was at a low level three months after delivery. IL-6 production tended to be higher in both umbilical cord blood as well as in maternal samples after delivery in women who were younger. In addition, TNF-alpha production in umbilical cord blood was significantly higher in those women who were younger.The production of IL-6 was up-regulated in both the maternal and in umbilical cord blood at delivery. The production of TNF-alpha was up-regulated in umbilical cord blood compared with neonatal values 3 months after birth. Maternal age had effects on IL-6 and TNF-alpha production at delivery.
