Tick-borne encephalitis in pregnant women: A mini narrative review.

Tick-borne encephalitis (TBE) incidence has been increasing in Europe the last decades, but very few cases in pregnant women have been described. We present two cases and describe the serology of both mother and infant at the time of diagnosis and delivery, as well as at months 3, 6, 9, and 12 of follow-up. In both cases, pregnancies and infants developed normally. The mothers had moderate-to severe symptoms of TBE and were positive for IgM and IgG at the time of diagnosis, and throughout the follow up period whilst both infants were PCR- and IgM-negative and positive for IgG during their first months in life. Declining IgG titres were seen in the infants during follow-up until they became negative at the age of nine months. TBE IgG was vertically transmitted in these two cases of infants born to TBE-infected mothers.

Dysphagia and dysphonia among persons with post-polio syndrome - a challenge in neurorehabilitation.

OBJECTIVE: To study the occurrence of dysphagia and dysphonia in persons with post-polio syndrome admitted into the centre for neurological rehabilitation in Finland. MATERIALS AND METHODS: Fifty-one persons with post-polio syndrome who were rehabilitated at Käpylä Rehabilitation Centre, Helsinki, Finland, in 2003-2004 were interviewed on problems with swallowing and voice production. Pulmonary function testing and grip strength measurement were performed. A clinical assessment of oral motor and laryngeal functions was carried out for those who reported daily problems with voice production or swallowing. RESULTS: Fifteen persons (29.4%) reported daily problems with swallowing or voice production. In the clinical assessment, the most commonly observed deficits in swallowing included decreased pharyngeal transit (n = 13) and the food catching in the throat (n = 4). The disturbance of co-ordination of breathing and voice production was seen in 12 persons. There were no significant differences in any of the potential predictors between the groups. CONCLUSIONS: Professionals need to be aware of the routine evaluation of dysphagia and dysphonia in patients with post-polio syndrome.

Field test results of an automated exposure assessment tool, the local positioning system (LPS).

A user-friendly environmental monitoring system that collects real time data has been developed. Flash card memory logs exposure data from multiple sensors along with corresponding times and positions. Optional use of telemetry repeaters and a reference station allows central monitoring of data to assess exposure and to initiate intervention when safe levels are exceeded. A software analysis package allows researchers to identify exposure hot spots and direct control efforts, with the ultimate goal being to reduce injury and disease. Preliminary field test results document position accuracy and system performance in harsh environments.

Estimating historical respirable crystalline silica exposures for Chinese pottery workers and iron/copper, tin, and tungsten miners.

Collaborative studies of Chinese workers, using over four decades of dust monitoring data, are being conducted by the National Institute for Occupational Safety and Health (NIOSH) and Tongji Medical University in China. The goal of these projects is to establish exposure-response relationships for the development of diseases such as silicosis or lung cancer in cohorts of pottery and mine workers. It is necessary to convert Chinese dust measurements to respirable silica measurements in order to make results from the Chinese data comparable to other results in the literature. This article describes the development of conversion factors and estimates of historical respirable crystalline silica exposure for Chinese workers. Ambient total dust concentrations (n>17000) and crystalline silica concentrations (n=347) in bulk dust were first gathered from historical industrial hygiene records. Analysis of the silica content in historical bulk samples revealed no trend from 1950 up to the present. During 1988-1989, side-by-side airborne dust samples (n=143 pairs) were collected using nylon cyclones and traditional Chinese samplers in 20 metal mines and nine pottery factories in China. These data were used to establish conversion factors between respirable crystalline silica concentrations and Chinese total dust concentrations. Based on the analysis of the available evidence, conversion factors derived from the 1988-1989 sampling campaign are assumed to apply to other time periods in this paper. The conversion factors were estimated to be 0.0143 for iron/copper, 0.0355 for pottery factories, 0.0429 for tin mines, and 0.0861 for tungsten mines. Conversion factors for individual facilities within each industry were also calculated. Analysis of variance revealed that mean conversion factors are significantly different among facilities within the iron/copper industry and within the pottery industry. The relative merits of using facility-specific conversion factors, industry-wide conversion factors, or a weighted average of the two are discussed. The exposure matrix of the historical Chinese total dust concentrations was multiplied by these conversion factors to obtain an exposure matrix of historical respirable crystalline silica concentrations.

Augmentative and alternative communication methods in locked-in syndrome.

Locked-in syndrome is a neurological condition due to a brain disease or an injury affecting the brain stem. The symptoms are tetraplegia, double-sided facial paresis, anarthria/dysarthrophonia, dysphagia and reactive involuntary laughing and crying. Vertical eye movements are the only commonly remaining voluntary motor function. Although the linguistic abilities as well as intellectual and emotional functions as a whole remain intact, all the motor abilities of self expression are lost. Seventeen chronic locked-in syndrome patients referred to Käpylä Rehabilitation Centre between 1979-2000 are reported. The multidisciplinary rehabilitation team developed an individual alternative communication method for all patients and trained them to use it by minor movements of e.g. thumb, chin or head. An alternative communication method enabled most of the patients to interact with other people using practical as well as theoretical thinking and decision making.

Estimating factors to convert Chinese 'Total Dust' measurements to ACGIH respirable concentrations in metal mines and pottery industries.

Historical data on the dust exposures of Chinese workers in metal mines (iron/copper, tin, tungsten) and pottery industries are being used in an ongoing joint Chinese/United States epidemiological study to investigate the exposure-response relationship for the development of silicosis, lung cancer, and other diseases. The historical data include 'total dust' concentrations determined by a Chinese method. Information about particle size distribution and the chemical and mineralogical content of airborne particles is generally not available. In addition, the historical Chinese sampling strategy is different from a typical American eight-hour time-weighted average (TWA) sampling strategy, because the Chinese samples were collected for approximately 15 minutes during production so the sample could be compared to their maximum allowable concentration (MAC) standard. Therefore, in order to assess American respirable dust exposure standards in light of the Chinese experience, factors are needed to convert historical Chinese total dust concentrations to respirable dust concentrations. As a part of the joint study to estimate the conversion factors, airborne dust samples were collected in 20 metal mines and 9 pottery factories in China during 1988 and 1989 using three different samplers: 10mm nylon cyclones, multi-stage 'cassette' impactors, and the traditional Chinese total dust samplers. More than 100 samples were collected and analysed for each of the three samplers. The study yielded two different estimates of the conversion factor from the Chinese total dust concentrations (measured during production processes) to respirable dust concentrations. The multivariate analysis of variance (MANOVA) reveals that, with a fixed sampling/analysis method, conversion factors were not statistically different among the different job titles within each industry. It also indicates that conversion factors among the industries were not statistically different. However, the two estimates consistently showed that conversion factors were the lowest in the pottery industry. Average conversion factors were then calculated for each of the estimates across the industries studied. A pooled mean conversion factor, 0.25+/-0.04, was then derived for all the job titles and industries. Respirable dust levels were estimated from the historical 'total dust' concentrations collected between 1952 and 1992 by adopting the American standard.

Perinatal methanol exposure in the rat. I. Blood methanol concentration and neural cell adhesion molecules.

Although the acute toxicity of methanol is well documented, few studies have addressed the consequences of perinatal exposures to the low concentrations that are expected to arise from its proposed use as a component of automobile fuel. This report describes the general research design of a series of studies, the effects of methanol exposures on blood concentrations in dams and neonates, and indices of brain development. Four cohorts of Long-Evans pregnant rats, each cohort consisting of an exposure (n = 12) and a control (n = 12) group, were exposed whole-body to 4500 ppm methanol vapor or air for 6 hr daily beginning on Gestation Day 6. Both dams and pups were then exposed through Postnatal Day 21 (PND 21). Blood methanol concentrations determined by gas chromatography from samples obtained immediately following a 6-hr exposure reached approximately 500-800 micrograms/ml in the dams during gestation and lactation. Average concentrations for pups attained levels about twice those of the dams. Selected offspring from Cohort 4 were exposed for one additional 6-hr session at ages that extended out to PND 52. Regression analyses showed that the blood methanol concentrations of the pups declined until about PND 48, at which time their levels approximated those of their dams. Such pharmacokinetic differences might increase the risks posed to developing organisms. Light-microscopic analysis showed no significant abnormalities in the brains of the methanol-treated animals. However, assays of neural cell adhesion molecules (NCAMs) in brains of pups sacrificed on PND 4 showed staining for both the 140 and the 180 kDa isoforms to be less intense in the cerebellum of exposed animals. NCAM differences were not apparent in animals sacrificed 15 months after their final exposure.

Developmental neurotoxicity of methanol exposure by inhalation in rats.

The possibility of widespread methanol exposure via inhalation stemming from its adoption as an automotive fuel or fuel component arouses concerns about the potential vulnerability of the fetal brain. This project was designed to help address such concerns by studying the behavior of neonate and adult rats following perinatal exposure to methanol vapor. Four cohorts of pregnant Long-Evans hooded rats, each cohort consisting of an exposure and a control group, were exposed to 0 parts per million (ppm) (control) or 4,500 ppm methanol vapor for six hours daily beginning on gestation day (GD) 6 with dams and pups then being exposed postnatal day (PND) 21. Exposures took place in 2-m3 Rochester-type inhalation chambers while the animals remained in their plastic breeder cages. Prenatal and postnatal blood methanol concentrations were determined by gas chromatography. Blood methanol concentrations of the dams, measured immediately following a six-hour exposure, were approximately 500 to 800 micrograms/mL throughout gestation and lactation. Average blood methanol concentrations of the pups were about twice those of the dams. Because such results appeared consistently across the other cohorts, we decided to obtain additional data with Cohort 4. Once it had undergone the standard exposure protocol, we selected sets of extra pups from those that had not been assigned previously to the adult phase of behavioral testing. Each set was exposed once, at ages that extended out to PND 52, for one additional six-hour session of exposure to 4,500 ppm methanol. The blood methanol concentrations of these pups declined until about PND 48, at which time they approximated those of the dams. These findings might be accounted for by a process of metabolic maturation in the pups that remains to be identified.

Role of the alveolar macrophage in lung injury: studies with ultrafine particles.

We conducted a series of experiments with ultrafine particles (approximately 20 nm) and larger particles (less than 200 nm) of "nuisance" dusts to evaluate the involvement of alveolar macrophages (AM) in particle-induced lung injury and particle translocation in rats. After intratracheal instillation of both ultrafine particles and larger particles of TiO2, we found a highly increased interstitial access of the ultrafine particles combined with a large acute inflammatory reaction as determined by lung lavage parameters. An additional experiment revealed that intratracheal instillation of phagocytized ultrafine TiO2 particles (inside AM) prevented both the pulmonary inflammatory reaction and the interstitial access of the ultrafine particles. Another experiment showed that the influx of polymorphonuclear cells (PMN) into the alveolar space unexpectedly decreased with higher doses of ultrafine particles, whereas alveolar epithelial permeability (protein leakage) increased. The divergence between PMN influx into the alveolar space and changes in alveolar epithelial permeability implies that they are separate events. Pulmonary inflammatory parameters determined by lung lavage analysis correlated best with the surface area of the retained particles rather than with their mass, volume, or numbers. Because higher doses resulted in an increased interstitialized fraction of particles, we suggest that inflammatory events induced by particles in the interstitial space can modify the inflammation in the alveolar space detectable by lung lavage. Our results demonstrate the dual role of AM for modifying particle-induced lung injury, i.e., both preventing such injury and contributing to it. We conclude that the increased pulmonary toxicity of ultrafine particles is related to their larger surface area and to their increased interstitial access.(ABSTRACT TRUNCATED AT 250 WORDS)

Thermal degradation events as health hazards: particle vs gas phase effects, mechanistic studies with particles.

Exposure to thermal degradation products arising from fire or smoke could be a major concern for manned space missions. Severe acute lung damage has been reported in people after accidental exposure to fumes from plastic materials, and animal studies revealed the extremely high toxicity of freshly generated fumes whereas a decrease in toxicity of aged fumes has been found. This and the fact that toxicity of the freshly generated fumes can be prevented with filters raises the question whether the toxicity may be due to the particulate rather than the gas phase components of the thermodegradation products. Indeed, results from recent studies implicate ultrafine particles (particle diameter in the nm range) as potential severe pulmonary toxicants. We have conducted a number of in vivo (inhalation and instillation studies in rats) and in vitro studies to test the hypothesis that ultrafine particles possess an increased potential to injure the lung compared to larger-sized particles. We used as surrogate particles ultrafine TiO2 particles (12 and 20 nm diameter). Results in exposed rats showed that the ultrafine TiO2 particles not only induce a greater acute inflammatory reaction in the lung than larger-sized TiO2 particles, but can also lead to persistent chronic effects, as indicated by an adverse effect on alveolar macrophage mediated clearance function of particles. Release of mediators from alveolar macrophages during phagocytosis of the ultrafine particles and an increased access of the ultrafine particles to the pulmonary interstitium are likely factors contributing to their pulmonary toxicity. In vitro studies with lung cells (alveolar macrophages) showed, in addition, that ultrafine TiO2 particles have a greater potential to induce cytokines than larger-sized particles. We conclude from our present studies that ultrafine particles have a significant potential to injure the lung and that their occurrence in thermal degradation events can play a major role in the highly acute toxicity of fumes. Future studies will include adsorption of typical gas phase components (HCl, HF) on surrogate particles to differentiate between gas and particle phase effects and to perform mechanistic studies aimed at introducing therapeutic/preventive measures. These studies will be complemented by a comparison with actual thermal degradation products.