The prevalence and risk factors of hoarseness among pupils in elementary schools in the South of Finland.

Purpose: Hoarseness and voice problems are one of the chronic conditions experienced by children. The aim of this study was to investigate the prevalence of hoarseness, possible risk factors and effects of the remediation of school buildings to the prevalence of hoarseness among school children.Methods: The material was gathered from all the schools in a large city in the south of Finland and the collection method used was an e-mail survey sent to the parents of the pupils and a simultaneous survey sent to the personnel in the schools.Results: All 51 schools participated, and 5889 pupils returned the questionnaire (39%). The exposure data was obtained from two building experts who knew the repair history of the schools. A subjective estimation of the quality of the indoor air was obtained from teachers and the parents. The overall prevalence of hoarseness among pupils was 6.3%; prevalence being higher in unrepaired school buildings than in schools in a good condition or buildings with a thorough remediation. Hoarseness was associated with asthma and allergies, several respiratory symptoms, and respiratory infections. Exposure to tobacco smoke increased the risk, and consumption of caffeine containing drinks seemed to reduce the risk. Noise, stuffiness of the indoor air and microbial smells correlated strongly with the occurrence of hoarseness in a logistic regression model when controlled for age, gender, asthma, passive smoking, and caffeine consumption.Conclusions: We recommend renovations in school buildings with the aim of providing better acoustics, sufficient ventilation, and a reduction in exposure to moisture damage microbes.

Hoarseness Among Young Children in Day-Care Centers.

BACKGROUND: Chronic respiratory symptoms among toddlers are assumed to be due to allergies and common respiratory infections. Because symptoms and respiratory disease in this age group often continue on to school age and later life, it is important to know the possible risk factors for prevention of the chronic hoarseness. AIM: We aimed to determine the current prevalence of hoarseness and other chronic respiratory symptoms among toddlers and young children. Another aim was to examine the risk factors for hoarseness in the building environments of day-care centers (DCC). MATERIAL: An electronic symptom survey was sent to all parents of children in day-care centers of a large city in southern Finland. In all, 3721 individuals completed the questionnaire (38%), 53.4% were the parents of boys and 46.6% girls. RESULTS: The prevalence of hoarseness was 5.6%. The boy's parents reported hoarseness more often than the girls, but no significant difference was observed. Risk factors for hoarseness in a built environment in this age group were noise, visible dust and dirt, mold and a cellar like odor, a sewer smell, other unpleasant smells, stuffiness of the indoor air, a too high or too low temperatures, a cold floor, insufficient ventilation, the age of the DCC building, and wood as the bearing construction of the building. The lifestyle factors that correlated with the prevalence of hoarseness were the amount of time spent outdoors; however, passive smoking, the number of siblings and pets at home did not correlate with hoarseness. Hoarseness was significantly correlated with other chronic respiratory symptoms such as rhinitis, coughs, eye irritation, tiredness, headaches, and stomach problems and also with the regular or periodic use of medication. Hoarseness was also significantly correlated with asthma and allergic rhinitis and also with repeated infections, such as a common cold, cold with a fever, laryngitis, otitis media and acute bronchitis, but not with tonsillitis or pneumonia. When potential confounders had been controlled for with a logistic regression model, the following risk factors in the built environment remained statistically significant: noise, high room temperature, insufficient ventilation and the stuffiness of the indoor air, a solvent odor, wood as the bearing construction and the age of the building. CONCLUSIONS: We conclude that in day-care centers, buildings should be maintained, cleaned and ventilated properly. Concrete and brick used in the construction were protective compared with wood. The acoustic environment should be planned to reduce noise indoors and solvent based chemicals should be avoided. Neither having pets at home or the number of siblings were risk factors, but they were also not found to be protective in this material. All measures that reduce the occurrence of respiratory infections probably also reduce chronic voice problems.

Impact of cyanogen iodide in killing of Escherichia coli by the lactoperoxidase-hydrogen peroxide-(pseudo)halide system.

In the presence of hydrogen peroxide, the heme protein lactoperoxidase is able to oxidize thiocyanate and iodide to hypothiocyanite, reactive iodine species, and the inter(pseudo)halogen cyanogen iodide. The killing efficiency of these oxidants and of the lactoperoxidase-H2O2-SCN-/I- system was investigated on the bioluminescent Escherichia coli K12 strain that allows time-resolved determination of cell viability. Among the tested oxidants, cyanogen iodide was most efficient in killing E. coli, followed by reactive iodine species and hypothiocyanite. Thereby, the killing activity of the LPO-H2O2-SCN-/I- system was greatly enhanced in comparison to the sole application of iodide when I- was applied in two- to twenty-fold excess over SCN-. Further evidence for the contribution of cyanogen iodide in killing of E. coli was obtained by applying methionine. This amino acid disturbed the killing of E. coli mediated by reactive iodine species (partial inhibition) and cyanogen iodide (total inhibition), but not by hypothiocyanite. Changes in luminescence of E. coli cells correlate with measurements of colony forming units after incubation of cells with the LPO-H2O2-SCN-/I- system or with cyanogen iodide. Taken together, these results are important for the future optimization of the use of lactoperoxidase in biotechnological applications.

Resistance to oxidative damage but not immunosuppression by organic tin compounds in natural populations of Daubenton's bats (Myotis daubentonii).

The acute toxicity of organic tin compounds (OTCs) has been studied in detail. However, due to their complex nature, very little is known about species-specific methods of accumulation and consequences for food-webs. Chironomids, on which e.g. Daubenton's bats feed, may act as vectors for the transport of organic tin compounds from aquatic to terrestrial ecosystems. Bats are prone to environmental toxins because of their longevity and their ecological role as top predators. Organic tin compounds are associated with increased formation of reactive oxygen species and associated oxidative damage as well as suppression of immune function. The present paper investigates whether the OTC, tributyltin (TBT) and its metabolite, dibutyltin (DBT), accumulate in natural populations of Daubenton's bats and whether TBT-associated effects are seen in general body condition, redox balance, redox enzyme activities, associated oxidative damage of red blood cells and complement function. We discovered the concentration of bat fur DBT correlated with local marine sediment TBT concentrations. However, we did not find a correlation between the explanatory factors, bat fur DBT and marine sediment TBT concentrations, and several physiological and physical response variables apart from complement activity. Higher DBT concentrations resulted in weaker complement activity and thus a weaker immune response. Although the observed physiological effects in the present study were not strongly correlated to butyltin concentrations in fur or sediment, the result is unique for natural populations so far and raises interesting questions for future ecotoxicological studies.

The real-time-based assessment of the microbial killing by the antimicrobial compounds of neutrophils.

A recombinant Escherichia coli K-12 strain, transformed with a modified bacterial luciferase gene (luxABCDE) from Photorhabdus luminescens, was constructed in order to monitor the activity of various antimicrobial agents on a real-time basis. This E. coli-lux emitted, without any addition of substrate, constitutive bioluminescence (BL), which correlated to the number of viable bacterial cells. The decrease in BL signal correlated to the number of killed bacterial cells. Antimicrobial activity of hydrogen peroxide (H(2)O(2)) and myeloperoxidase (MPO) was assessed. In high concentrations, H(2)O(2) alone had a bacteriocidic function and MPO enhanced this killing by forming hypochlorous acid (HOCl). Taurine, the known HOCl scavenger, blocked the killing by MPO. When E. coli-lux was incubated with neutrophils, similar killing kinetics was recorded as in H(2)O(2)/MPO experiments. The opsonization of bacteria enhanced the killing, and the maximum rate of the MPO release from lysosomes coincided with the onset of the killing.