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Biomedical subjects

Aino Nevalainen

Publications and source records attributed to Aino Nevalainen.

At least 19 recordsLinked to original sources
PubMed2005

Effects of microbial cocultivation on inflammatory and cytotoxic potential of spores.

Microbial growth on moisture-damaged building materials is commonly associated with adverse health effects in the occupants. In moisture damage situations, the environmental conditions as well as the dominant microbial species will vary, leading to a diversity of microbes and continual changes in the different microbial populations. Currently, very little is known about the effects of microbial cocultures on the potential harmfulness of the microbial population. In this study we have investigated the effects of cocultivation of certain indoor air microbes on the inflammatory and cytotoxic potential of their spores. We grew various microbial combinations made from strains of Streptomyces californicus, Stachybotrys chartarum, Aspergillus versicolor, and Penicillium spinulosum on wetted plasterboard. After 5 or 10 wk of growth, the spores were collected from the plasterboards, mouse RAW264.7 macrophages were exposed to the spores, and after 24 h the induced inflammatory and cytotoxic responses were analyzed. Among all the tested microbes and their combinations, the spores of Str. californicus proved to be the most potent inducer of cytotoxicity and inflammatory responses. These results indicate also that microbial coculture may support the growth of certain microbes with high immunotoxic potency such as Str.californicus. Furthermore, coculture containing S. chartarum and A. versicolor caused a synergistic increase in cytotoxicity compared to the sum response induced by the pure cultures, but no effect on inflammatory responses was detected. Generally, spore-induced cytotoxicity and production of inflammatory markers increased during the growth period from 5 to 10 wk, suggesting that the immunotoxic potency of spores increases with time.

Air Pollution, Indoor↗
PubMed2004

Viable fungi and bacteria in personal exposure samples in relation to microenvironments.

Personal exposures to viable fungi and bacteria were compared with the concentrations being assessed by stationary samplers in home and workplace microenvironments. A random sample of 81 elementary school teachers in eastern Finland performed two 24-hour measurement periods in wintertime. Concentrations and prevalences of viable fungi and bacteria on the collection filters were determined by cultivation method. The geometric mean concentration was 3-12 cfu m(-3) for total viable fungi, 0.6-3.7 cfu m(-3) for Penicillium and mainly under 1 cfu m(-3) for other fungi. The samples with higher fungal concentrations also had higher diversity of fungi than samples with lower concentrations. The total number of fungal genera recovered was 39 for personal, 34 for home and 23 for work samples. The variation in concentration of Penicillium explained even 25-95% of the variations of total fungal concentration in personal exposure, home and workplace environments. There was an association between personal exposure and home concentration of viable fungi and between personal exposure and home and work concentrations of viable bacteria. Personal exposure and home concentrations of fungi were higher in rural areas than in urban areas. Our results also indicate that presence of a certain fungus in a microenvironment does not necessarily mean similar findings in personal exposure samples.

Air Pollution, Indoor↗
PubMed2004

Amoebae and other protozoa in material samples from moisture-damaged buildings.

Mold growth in buildings has been shown to be associated with adverse health effects. The fungal and bacterial growth on moistened building materials has been studied, but little attention has been paid to the other organisms spawning in the damaged materials. We examined moist building materials for protozoa, concentrating on amoebae. Material samples (n = 124) from moisture-damaged buildings were analyzed for amoebae, fungi, and bacteria. Amoebae were detected in 22% of the samples, and they were found to favor cooccurrence with bacteria and the fungi Acremonium spp., Aspergillus versicolor, Chaetomium spp., and Trichoderma spp. In addition, 11 seriously damaged samples were screened for other protozoa. Ciliates and flagellates were found in almost every sample analyzed. Amoebae are known to host pathogenic bacteria, such as chlamydiae, legionellae, and mycobacteria and they may have a role in the complex of exposure that contributes to the health effects associated with moisture damage in buildings.

Amoeba↗
PubMed2004

Estimating effects of moisture damage repairs on students' health-a long-term intervention study.

Health symptom questionnaire responses were collected from upper secondary and high school students (n=245) before comprehensive repairs of moisture damage in the school. The questionnaire study was repeated 1 year (n=227), 3 years (n=256), and 5 years (n=233) after the repairs. The data were analyzed both in cross-sectional design including all respondents, and longitudinally including paired observations of those individuals who had responded both before and after the repairs. In addition, the effect of intervention on health symptoms was analyzed using generalized estimating equations (GEEs), taking into account within-subject correlation between repeated measurements. Compared to the situation before the repairs, the situation after the repairs was significantly improved in most of the 20 symptoms studied among the cross-sectional study populations. However, improvement was not so clear in the paired analysis and GEE analysis among the students who responded to three repeated questionnaires. The results indicate that the repairs succeeded in the sense that new cases of symptomatic students were no longer expected. However, the reversibility of symptoms among the group of exposed individuals may need to be considered separately.

Adolescent↗
PubMed2004

Effects of mould remediation on school teachers' health.

The follow-up study of the health of teachers (n = 56) of three mould damage schools were done with self-administered symptom questionnaire before and 1 year after the remediation of school buildings. Technical and microbiological investigations were done parallel at the same time. In the beginning of the study symptoms of allergic rhinitis, sinusitis, conjunctivitis and fatigue were high compared to normal population and 1 year after the intervention a decrease in fatigue (OR = 0.4) and headache (OR = 0.2) was observed. An association between female gender and sinusitis was found before the remediation (OR = 8.1). Age over 40 years was a risk factor for voice problems and more than 10 working years at the same school were associated with increased risk for conjunctivitis (OR = 8.5) and headache (OR = 5.4). Other exposure situations such as mould problems at home and mould exposure during leisure time also have an effect on teachers' health. Significant reduction was found in symptoms of fatigue and headache after the cessation of exposure, while respiratory symptoms need much longer time to relieve after the remediation. Age, female gender, atopy, long-term exposure time and other exposure situations might be the risk factors for prolonged symptoms among mould exposed teachers.

Adult↗
PubMed2004

Potentially pathogenic, slow-growing mycobacteria released into workplace air during the remediation of buildings.

Construction workers' exposure to airborne viable mycobacteria was studied during the remediation of three moldy and two nonmoldy buildings. Furthermore, the concentrations of airborne fungal and actinobacterial spores were determined. The samples for the microbial analyses were collected using a six-stage impactor and an all-glass impinger sampler, and by filter sampling. Specific mycobacteria media and nonselective media were used for the cultures. The samples were cultured for the total numbers of rapidly growing and slow-growing mycobacteria, and the isolates obtained were identified to the genus or species level. Mycobacteria were recovered from the air during the remediation of two of the moldy buildings and one nondamaged building. Concentrations of mycobacteria up to 160 cfu/m3 were detected. A total of 43 mycobacterial isolates was recovered. Most of the isolates were slow-growers, only two rapid-growing strains being detected. The 38 identified isolates belonged to potentially pathogenic species, including Mycobacterium avium complex, M. scrofulaceum, and M. fortuitum, and to saprophytic species, including M. nonchromogenicum and M. terrae. Mycobacteria were the most often detected in samples taken with a six-stage impactor. They were found in buildings with both high and low concentrations of fungi. In conclusion, mycobacteria, both potentially pathogenic and saprophytic species, may be released into the indoor air during the remediation of buildings.

Air Pollution, Indoor↗
PubMed2004

Chlamydia pneumoniae and newly diagnosed asthma: a case-control study in 1 to 6-year-old children.

OBJECTIVE: The aim of the study was to evaluate the association between antibodies to Chlamydia pneumoniae and the onset of asthma in children. METHODOLOGY: In 1996-2000, 122 children aged 1-6 years, who were treated for new asthma as inpatients or outpatients in our hospital, were recruited. For each patient, two controls, matched by age, sex and municipality, were randomly selected from the same population. In 2000, 104 serum samples were available from patients (85%) and 120 from controls (49%) for microimmunofluorescence (MIF) assay for C. pneumoniae and C. trachomatis antibodies, and for enzyme immunoassay (EIA) for C. pneumoniae antibodies. RESULTS: In EIA, the median IgG concentrations were 20 EIU (EIA units) in the patients, and 16 EIU in the controls. IgG was positive (> 30 EIU) in 37 (36%) patients and in 36 (31%) controls. IgA was positive (> 12 EIU) in four (4%) patients and in eight (7%) controls. In MIF, four (4%) patients and seven (6%) controls were IgG positive, and seven were also IgA positive. IgM antibodies were detected in four children by EIA, and in none by MIF. CONCLUSION: IgG antibodies to C. pneumoniae, though common in 1 to 6-year-old children as detected by EIA, did not differ between newly diagnosed asthma patients and controls in this case-control study.

Antibodies, Bacterial↗
PubMed2003

Mold-specific immunoglobulin G antibodies in a child population.

The determination of immunoglobulin G (IgG) antibodies to molds has been used as an objective evidence of significant mold exposure. Until present, no data have been published on antibody responses to molds in healthy children living in normal housing conditions. The microbe-specific IgG antibody concentrations of 21 molds and 3 actinobacteria were determined by enzyme-linked immunosorbent assay (ELISA) in 103 1- to 6-year-old children (12.4% of the population of that age), and in 111 7- to 14-year-old school children (12.1%). The international standard sera were available, and the IgG concentrations of the test sera could be expressed in mg/l. On average, IgG concentrations increased in relation to age until the age of 6-7 years. At school age the increase still continued but more slowly. Actinobacteria were the only exceptions; all three tested strains Sreptomyces albus, S. griseus and S. halstedii resulted in rather high concentrations until 3 years of age. If the children lived in a farm, mold-specific IgG concentrations increased at an earlier age than in other children. The results between farmers' children and other children differed significantly before school age for 20 of the 24 microbes tested, the four exceptions being the 3 actinobacteria and the mold Aspergillus versicolor. The reference values must be age related, and separate references are needed for farmers' children before school age.

Actinobacteria↗
PubMed2003

Inflammatory and cytotoxic potential of the airborne particle material assessed by nasal lavage and cell exposure methods.

Exposure to bioaerosols in moisture-damaged indoor environments has been shown to be a potential health risk. The aim of the present study was to evaluate the inflammatory and cytotoxic potential of airborne particle material using both the nasal lavage (NAL) method and a cell exposure study. A 24-h sample collection for airborne particles was performed using personal sampling and microenvironmental measurements in homes and an 8-h sample collection in the working places of the studied subjects. At the end of the sampling period, the production of nitric oxide, tumor necrosis factor alpha, interleukin (IL)-1 beta, IL-4, and IL-6 was analyzed in the NAL samples of the subjects. The same mediators, excluding IL-4, were measured in the cell culture medium of mouse RAW264.7 macrophages, which were exposed to the pooled filter extracts representing personal, home, and workplace exposure of each individual during the 24 h before the NAL. Samplings were repeated after 2 wk. The subjects were divided into groups of "low exposure" and "high exposure" according to the concentrations of viable fungi, viable bacteria, or total microbial amount in the pooled extract. Cytokine levels in the NAL samples of subjects with high microbial exposure were slightly increased compared to the corresponding values of the subjects with low exposure. Filter samples collected from the subjects with high microbial exposure induced a significant increase in the production of cytokines in the RAW264.7 macrophages, as compared to those from the subjects with low exposure. The within-subject variation was low in all of the cytokine measurements, but the correlation between the studied methods was poor. In conclusion, both of the methods discriminate at the group level between subjects with high and low microbial exposure. Sampling of airborne particle material and exposure of the mammalian cells to the obtained samples seems to be highly applicable in the environmental monitoring, whereas examination of the exposed subjects directly, for example by using the NAL method, is essential when association between exposure and health effects is evaluated.

Adult↗
PubMed2003

Nasal lavage method in the monitoring of upper airway inflammation: seasonal and individual variation.

A 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)-1 beta, IL-4, IL-5, IL-6, and tumor necrosis factor alpha (TNF alpha) 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, TNFalpha, IL-1 beta, 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.

Adult↗
PubMed2003

Effect of plasterboard composition on Stachybotrys chartarum growth and biological activity of spores.

The effects of plasterboard composition on the growth and sporulation of Stachybotrys chartarum as well as on the inflammatory potential of the spores were studied. S. chartarum was grown on 13 modified plasterboards under saturated humidity conditions. The biomass was estimated by measuring the ergosterol content of the S. chartarum culture while the spore-induced cytotoxicity and production of nitric oxide (NO), tumor necrosis factor alpha (TNF-alpha), and interleukin-6 in mouse macrophages was used to illustrate the bioactivity of spores. The ergosterol content of S. chartarum correlated with the number of spores collected from plasterboards. The growth and sporulation decreased compared to that of the reference board in those cases where (i) the liner was treated with biocide, (ii) starch was removed from the plasterboard, or (iii) desulfurization gypsum was used in the core. Spores collected from all the plasterboards were toxic to the macrophages. The biocide added to the core did not reduce the growth; in fact, the spores collected from that board evoked the highest cytotoxicity. The conventional additives used in the core had inhibitory effects on growth. Recycled plasterboards used in the core and the board lacking the starch triggered spore-induced TNF-alpha production in macrophages. In summary, this study shows that the growth of a strain of S. chartarum on plasterboard and the subsequent bioactivity of spores were affected by minor changes to the composition of the core or liners, but it could not be totally prevented without resorting to the use of biocides. However, incomplete prevention of microbial growth by biocides even increased the cytotoxic potential of the spores.

Animals↗
PubMed2003

Production of proinflammatory mediators by indoor air bacteria and fungal spores in mouse and human cell lines.

We compared the inflammatory and cytotoxic responses caused by household mold and bacteria in human and mouse cell lines. We studied the fungi Aspergillus versicolor, Penicillium spinulosum, and Stachybotrys chartarum and the bacteria Bacillus cereus, Pseudomonas fluorescens, and Streptomyces californicus for their cytotoxicity and ability to stimulate the production of inflammatory mediators in mouse RAW264.7 and human 28SC macrophage cell lines and in the human A549 lung epithelial cell line in 24-hr exposure to 10(5), 10(6), and 10(7) microbes/mL. We studied time dependency by terminating the exposure to 10(6) microbes/mL after 3, 6, 12, 24, and 48 hr. We analyzed production of the cytokines tumor necrosis factor-alpha and interleukins 6 and 1ss (TNF-alpha, IL-6, IL-1ss, respectively) and measured nitric oxide production using the Griess method, expression of inducible NO-synthase with Western Blot analysis, and cytotoxicity with the MTT-test. All bacteria strongly induced the production of TNF-alpha, IL-6 and, to a lesser extent, the formation of IL-1ss in mouse macrophages. Only the spores of Str. californicus induced the production of NO and IL-6 in both human and mouse cells. In contrast, exposure to fungal strains did not markedly increase the production of NO or any cytokine in the studied cell lines except for Sta. chartarum, which increased IL-6 production somewhat in human lung epithelial cells. These microbes were less cytotoxic to human cells than to mouse cells. On the basis of equivalent numbers of bacteria and spores of fungi added to cell cultures, the overall potency to stimulate the production of proinflammatory mediators decreased in the order Ps. fluorescens > Str. californicus > B. cereus > Sta. chartarum > A. versicolor > P. spinulosum. These data suggest that bacteria in water-damaged buildings should also be considered as causative agents of adverse inflammatory effects.

Air Pollution, Indoor↗
PubMed2003

Mould specific IgG antibodies connected with sinusitis in teachers of mould damaged school: a two-year follow-up study.

OBJECTIVES: The aim of this study was to describe the relationship between mould exposure induced by moisture damage and mould specific immunoglobulin G antibodies to 20 common mould species and their association with respiratory diseases. MATERIALS AND METHODS: Mould specific immunoglobulin G (IgG) antibodies were monitored in teachers in a follow-up after an extensive mould remediation process in school buildings. IgG antibodies to 20 different microbes were determined from the sera of 26 teachers (19 exposed and 7 references) by enzyme-linked immunosorbent assay (ELISA). The serum samples were drawn twice, firstly at the completion of the remediation in the spring of 1997 and secondly, two years later in the spring of 1999. Health data was collected with self-administered questionnaires. RESULTS: No statistical differences were found in the overall concentrations of 20 mould-specific IgG-antibodies between the study and control groups at the beginning of the study. An association between sinusitis and elevated mould-specific IgG-levels forAspergillus fumigatus, Aspergillus versicolor, Aureobasidium pullulans, Chaetomium globosum, Cladosporium cladosporioides, Phialophora bubakii, Rhodotorula glutinis, Sporobolomyces salmonicolor, Stachybotrys atra, and Tritirachium roseum was found in the study group. CONCLUSIONS: In a two-year follow-up the total concentration of the IgG antibodies for Tr. toseum was lower at the end than at the beginning of the follow-up and this remained significant for the group of teachers with sinusitis. The decrease in mould specific IgG to Cl. cladosporioides, Geotrichum candidum, Ph. bubakii and Rhizopus nigricans was associated with bronchitis. According to our knowledge, this is the first study in which the association between elevated mould specific IgG antibodies and sinusitis was found in the school environment.

Adult↗
PubMed2003

Microbial exposure and mold-specific serum IgG levels among children with respiratory symptoms in 2 school buildings.

In this study, the authors determined the association between serum mold-specific immunoglobulin G (IgG) levels in primary school children (N = 181) with asthma, wheezing, or cough symptoms and exposure to indoor mold in 2 schools, with and without mold damage. Microbial exposure was determined with environmental sampling. Serum IgG antibody concentrations against 24 microbial strains were determined with enzyme-linked immunosorbent assay. Children's microbe-specific IgG levels were often higher in the reference school. There was an association between elevated serum IgG antibody levels to Penicillium notatum and moisture damage in the school. In addition, moisture damage both in school and at home was associated with Penicillium notatum and Eurotium amstelodami IgG levels. These observations comported with microbial findings in the index school. No other positive associations between IgG antibodies and microbial findings for the school buildings were observed. IgG levels in sera of school children did not provide a specific means for assessing the microbial exposure associated with moisture and microbial problems in the school buildings. Thus, IgG analysis cannot be readily suggested as a routine method for the evaluation of these exposures.

Air Pollution, Indoor↗
PubMed2002

Validity of detection of microbial growth in buildings by trained dogs.

Microbial growth in buildings may evoke respiratory and other symptoms in the occupants and promote decay of construction materials. The decay in wood is usually caused by dry-rot fungus, leading to the decomposition of cellulose and lignin. There are also some mold fungi and bacteria that can use wood as a nutrient. In this study, two trained dogs were used to detect microbial growth present in buildings. The rot fungi Serpula lacrymans, Coniophora puteana and Antrodia sinuosa were used in the training. In addition to decay samples, pieces of healthy birch, pine and imbued wood were used as controls. Another experiment was made using bacteria (Streptomyces sp.). In these experiments, a total of 100 decay, 75 control and 25 bacteria samples were used. The dogs detected 75% of the decay and 60% of the bacteria samples. Some (0-24%) control samples were also expressed as positive. Since the dogs identified also the bacteria samples without any specific training, a new test with some mold strains (Cladosporium, Botrytis, Trichoderma, Penicillium, Aspergillus) was carried out. The dogs found all the decay, mold and bacteria samples but only one sample of healthy wood. The use of dogs to detect mold or decay damage appears to have high specificity and high positive predictive value, but low sensitivity.

Animals↗
PubMed2002

Media for cultivation of indoor streptomycetes.

The growth of 10 indoor Streptomyces spp. isolates on nutritionally complex and selective 26 media revealed that the mycelium production had a tendency to increase in order: starch-casein < glycerol-arginine < glucose-tryptone, and NH(4)NO(3) < Na-caseinate-asparagine. Yeast extract increased mycelium biosynthesis, but not always the growth rate. The strains belonging to streptomycetes most common environmental isolates produced visible mycelium in 5 days on all media.

Air Pollution, Indoor↗
PubMed2002

Mould-specific immunoglobulin G antibodies in students from moisture- and mould-damaged schools: a 3-year follow-up study.

Immunoglobulin G (IgG) antibodies to moulds have been used as biomarkers of mould exposure, though their role reflecting exposure is not confirmed. The purpose of the present study was to evaluate the changes in mould-specific IgG antibodies in children during a 3-year follow-up in relation to changes in exposure, and to allergic and respiratory morbidity. In 1996, 212 primary school students with asthma, wheezing or prolonged cough participated in a clinical study, including clinical examination, skin-prick tests to 12 moulds and mould-specific IgG determinations to 24 moulds. In 1999, 144 students of the same cohort participated in an identical follow-up study; among them, mould-specific IgG was measured in 121 students. No association was found between IgG antibodies to moulds and exposure to moisture or moulds in schools. Likewise, changes in mould-specific antibodies were only weakly associated with changes in exposure. Mould-specific IgG antibodies had no significant association with asthma, wheezing or cough episodes. IgG antibodies to moulds seem to be poor markers of exposure among children exposed to moisture or moulds at school.

Adolescent↗