Pyrogenic activity of air to characterize bioaerosol exposure in public buildings: a pilot study.

AIMS: The aim of our study was to investigate indoor air quality (IAQ) by comparing pyrogen concentration and microbiological contamination in offices in public buildings. METHODS AND RESULTS: Air samples were collected during cold and warm seasons in 39 offices in four European cities. Pyrogens were measured by the in vitro pyrogen test (IPT), moulds and bacteria by classical microbiology. In 92% of the investigated offices, pyrogen and microbial contaminations were below 150 EEU m(-3) and 10(3) CFU m(-3), respectively, whilst in 75%, moulds did not exceed 10(2) CFU m(-3). CONCLUSIONS: The IPT is a rapid, reliable tool for measuring pyrogens that could be used as an 'early warning' indicator of IAQ. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study on pyrogenic compound detection in offices using IPT, which could serve for developing future indoor air guidelines.

Determination of aerial microbiological contamination in scholastic sports environments.

AIMS: To assess the microbiological indoor air quality (IAQ) of high school and college gyms during physical training lessons and to evaluate the effective microbiological exposure of students. METHODS AND RESULTS: Air samples from 11 high school and college gyms of Pavia, Italy were collected. Total bacterial counts, total fungal counts and characterization of fungal taxa were determined. Air quality was evaluated using three microbiological contamination indices: the global index of microbiological contamination per m3 (GIMC per m3), the index of mesophilic bacterial contamination (IMC) and the amplification index (AI). CONCLUSIONS: This work testifies that air contamination in indoor gyms is always superior to that of the outdoor environment. Nevertheless, students are exposed to relatively low concentrations of airborne micro-organisms. The highest values of fungal counts and GIMC per m3 (>14,661) were observed between April and October when the central heating systems were switched off. The lowest fungal counts were detected in modern buildings equipped with forced ventilation systems. From qualitative aeromycological studies, 45 fungal taxa were identified, and different potentially allergenic species were isolated. SIGNIFICANCE AND IMPACT OF THE STUDY: The standardization of air sampling methods and the correct evaluation of aeromicrobiological results allow the classification of indoor air healthiness. The proposed microbiological contamination indices together with the characterization of airborne fungal taxa are useful tools for detailed description of IAQ.

The epizootiology of sarcoptic mange in chamois, Rupicapra rupicapra, from the Italian eastern Alps.

Sarcoptic mange is the most severe infection in chamois in the Eastern Alps. This study analyses and discusses data from two mange foci in the Foresta Demaniale di Tarvisio (NE Italy). The first impact of mange on naive host populations was dramatic, with mortality rates of over 80%. The chamois herds were decimated, but they recovered quite fast and two later epizootics were observed to have a far less severe impact on the chamois population. Intervals between successive waves lasted 10 to 15 years. No sign of low reproductive performance nor evidence of a poor physical condition of the animals was observed in the years preceding the new epizootic waves. Mortality rates were only slightly influenced by the density of the host population. In a long lasting focus of disease, adult males appeared more vulnerable to mange than other sex and age classes. Cases of mange were also more frequent in winter and spring. This seasonal trend may be explained by the interaction between the dynamics of mites, ethological patterns-rut activity-and the poorer physical condition of the host during this period.

Doppler velocimetry: critical analysis of umbilical, cerebral and aortic reference values.

Cross-sectional reference standards of the umbilical flow velocity waveforms were investigated from 18 to 38 weeks of gestation on 482 normal pregnancies. A significant decrease in the pulsatility index (PI) and systolic/diastolic (SD) ratio was observed during gestation. This phenomenon was confirmed in a longitudinal study on 150 patients of the same population. The two slopes of cross-sectional and longitudinal data were not significantly different. A bimodal distribution of PI and S/D ratio was observed. Six per cent of data fell above the vast majority of cases. The dimension of the population studied allowed us to consider these findings not as outliers but as an interesting transient phenomenon of very low end-diastolic velocities which can occur in normal fetuses, without concomitant variations on the thoracic aorta and middle cerebral artery. Cross-sectional reference ranges were studied for these vessels on the same population from 26 to 38 weeks of gestation. A significant decrease in the PI of the middle cerebral artery was observed versus a significant increase in the PI of the thoracic aorta. These latter indices could be used to obtain indirect information on the normal redistribution of blood flow in the human fetus in the third trimester of gestation. However, the great variability observed should warn against the risks of a simplistic clinical use of these observations.

Power spectral analysis of the heart rate of the human fetus at 26 and 36 weeks of gestation.

The fetal electrocardiogram (ECG) was recorded from the maternal abdomen together with sonographic detection of fetal states in four pregnant patients at 26 and 36 weeks of gestation. Computerised algorithms obtained a good recognition of maternal ECG and fetal ECG. The corresponding power spectral density (PSD) was estimated during epochs of quiet or breathing movements for 256 consecutive heart beats. At 36 weeks of gestation the PSD analysis showed heart rate variability components similar to an adult heart. A low frequency component was observed together with a high frequency component in the range of fetal breathing movements. This high frequency component (0.6 - 0.9 Hz) disappeared from the PSD analysis during epochs of apnea. To our knowledge this is the first demonstration of such a mechanism in the human fetus in utero. At 26 weeks no respiratory component was observed in the PSD analysis. The maturation of control mechanisms could be responsible for this difference.