Behavioural and electrophysiological changes caused by inorganic cadmium were investigated in the offspring of female Wistar rats. Dams were given 3.5, 7.0 or 14.0 mg kg(-1) cadmium (cadmium chloride dissolved in distilled water) in three different treatment regimes: days 5-15 of pregnancy; days 5-15 of pregnancy + 4 weeks of lactation; days 5-15 of pregnancy + 4 weeks of lactation followed by the same oral treatment of male rats of the F1 generation for 8 weeks. The behavioural (open-field exploration) and electrophysiological (electrocorticogram, cortical evoked potentials, conduction velocity and refractory periods of a peripheral nerve) parameters of F1 male rats exposed by various treatments were investigated at the age of 12 weeks. It was found that cadmium dose and treatment time dependently altered the spontaneous and evoked electrophysiological functions (e.g. increased the frequency of the electrocorticogram, lengthened the latency and duration of evoked potentials, etc.). Interestingly, only the combination of treatment during prenatal development and the 4-week suckling period resulted in a significant dose-dependent decrease of horizontal and vertical exploratory activity and a significantly lower exploration frequency of the open-field centre. The results showed that low-level pre- and postnatal inorganic cadmium exposure affects the bioelectrical and higher order functions of the nervous system. In the case of human populations, a similar prolonged exposure might be just as harmful.

Administration, Oral↗

PubMedDate not supplied

Behavioral effects of subchronic intoxication with parathion-methyl in male Wistar rats.

The behavioral effects of subchronic exposure of male Wistar rats to the organophosphorus compound parathion-methyl (for 6 weeks 1/50 or 1/100 of LD50, PO) were studied. Open-field (OF) and elevated plus-maze (EPM) tasks were used to decide whether or not the compound can affect behavior. Significant effects were measured in the OF activity during the first minute, on the activity of crossing outer squares, increasing latencies to leave center, start of rearing, grooming, and defecation. EPM parameters showed an increased amount of time spent in the open arms and a clear tendency to enter more frequently open arms. The defecation rate in the EPM was significantly decreased. Results are discussed in terms of effects on emotional behavioral components (arousal) and on physiological functioning of the peripheral nervous system (lengthening of latencies).

Animals↗

PubMedDate not supplied

Improved algorithm for statistical batch-by-batch analysis of corneal topographic data.

PURPOSE: To describe an improved algorithm for topographic batch-by-batch analysis and evaluate the effect of artifact correction on the reproducibility of topographic records. SETTING: University Eye Hospital Vienna, Austria. METHODS: We twice examined 22 eyes of 22 patients (volunteers) using the TMS-1 computer-assisted videokeratoscope (Computed Anatomy, Inc.). Entry criteria were age more than 60 years and lack of corneal pathology. A batch-by-batch analysis of the paired differences was performed. The software consisted of special macro functions for a programmable computer database to eliminate small local artifacts, as well as rotate data, produce mirror images, calculate averaged differences for an entire group, and reduce data to 225 areas in 7 concentric rings. The reduced set of data was used for statistical analysis and correction of defocus artifacts. Reproducibility was evaluated by calculating the absolute deviations between the areas of paired measurements. RESULTS: The absolute deviations were below 0.9 diopter (D) in over 50% of the areas in 90% of the patients with the uncorrected data; after correction for local artifacts, defocus artifacts, and both local and defocus artifacts, these values were 0.9 D, 0.8 D, and 0.5 D, respectively. Absolute deviations were above 1.0 D in 10% of the patients in 66, 40, 29, and 0 of 225 areas, respectively. CONCLUSION: Correction for both local and defocus artifacts yielded a two-fold improvement in the reproducibility of topographic records.

Aged↗

PubMedDate not supplied

Tubular epithelial cells as accessory cells for superantigen-induced T cell activation.

In various inflammatory kidney diseases, tubular epithelial cells (TEC) express major histocompatibility complex class II antigens. To assess whether they might have the capacity to directly activate T cells, human TEC in culture were treated with gamma interferon to induce class II expression. TEC were then cocultivated with staphylococcus enterotoxin and cloned T cells or highly purified peripheral T cells. After 1-2 days, release of interleukin 2 and of gamma interferon was seen; after 3-5 days T cell proliferation occurred. The proliferation could be inhibited by antibodies to class II antigens or by antibodies to ICAM-1; the latter is also expressed on TEC in inflammatory processes and on TEC in culture as well. In conclusion, human TEC might function as accessory cells for T cell activation and might support T cell dependent immune response.

Antibodies↗

PubMedDate not supplied

Biochemical parameters as biomarkers for the early recognition of environmental pollution on Scots pine trees. II. The antioxidative metabolites ascorbic acid, glutathione, alpha-tocopherol and the enzymes superoxide dismutase and glutathione reductase.

Field investigations with Scots pine trees (Pinus sylvestris L.) were performed in eastern Germany, where ambient SO2, NOx and O3 concentrations differed significantly in 1992-99 at three sites, namely Neuglobsow (yearly mean SO2 in 1992: 9 microg m(-3)), Taura (yearly mean SO2 in 1992: 54 microg m(-3)) and Rösa (yearly mean SO2 in 1992: 73 microg m(-3)). To investigate the effects of SO2, NOx and O3 on antioxidants (superoxide dismutase, ascorbic acid, glutathione, glutathione reductase, alpha-tocopherol) and pigments including chlorophyll fluorescence as well as visible damage symptoms in the form of needle yellowing and tip necroses, needles of the 1st and 2nd age class from young and mature trees were collected at the sites every October. Eight years after the start of the field study in 1992, the ambient SO2 concentrations had decreased significantly at Neuglobsow (yearly mean SO2 in 1999: 4 microg m(-3)), Taura (yearly mean SO2 in 1999: 5 microg m(-3)) and Rösa (yearly mean SO2 in 1999: 5 microg m(-3)). NOx and O3 differed less at the three sites and showed no temporal variations. Whole needle glutathione continuously decreased, although concentrations were higher in needles of the 1st and 2nd age class from the polluted sites Taura and Rösa than the unpolluted site Neuglobsow. The activities of glutathione reductase exhibited the same site-related differences and temporal variations and were correlated with concentrations of oxidized glutathione (GSSG). In contrast, the activities of the enzyme superoxide dismutase and the concentrations of whole needle ascorbic acid remained unchanged over the period. Only at the end of the investigation period did the concentrations of oxidized ascorbic acid (dehydroascorbate) increase in six-month-old needles at the polluted sites Taura and Rösa. Despite the clear decreases in SO2, the visible symptoms of needle tip necroses remained unchanged, especially at the polluted sites Taura and Rösa, although the needles contained higher pigment concentrations than needles from the unpolluted sites. The results of measurements with antioxidants as biomarkers for SO2-mediated stress in pine needles show that the adult Scots pine trees at the polluted sites suffered from greater oxidative stress than the needles from the less polluted site.

Ascorbic Acid↗

PubMedDate not supplied

Aerosol bolus dispersion in the respiratory tract of children.

To investigate mechanisms of intrapulmonary convective gas transport, aerosol bolus dispersion was measured in 16 healthy children aged 7-11 years. Subjects inhaled 50-mL aerosol boluses consisting of 0.4-micron droplets of di(2-ethylhexyl) sebacate suspended in air into volumetric lung depths between 95 and 540 mL. Bolus dispersion was quantified by volumetric bolus half-width and by volumetric standard deviation of particle concentrations. Bolus half-width increased from a mean of 160 mL to 360 mL with increasing lung depth, the regression being a power law with an average exponent of 0.48. Standard deviation increased from 68 to 136 mL with the 0.42th power of volumetric penetration. There was no correlation of bolus dispersion with age, body height, or lung function parameters, except for boluses penetrating very deep into the lung where dispersion was weakly related to lung volume. The results obtained in children did not differ from those found in an adult population in an earlier study. It was concluded that airway size per se does not have a strong influence on bolus dispersion. Rather, parameters of airway geometry may be among the dominating factors influencing the fate of inhaled particles.

Aerosols↗

PubMedDate not supplied

Influence of gas composition on convective and diffusive intrapulmonary gas transport.

The influence of gas composition on convective and diffusive gas transport in the lungs was assessed by studying the dispersion of combined particle and argon (Ar) boluses induced by the passage through the lungs filled with three different gas mixtures. Particles, as a "nondiffusing gas," served as a tracer for convective gas transport, while the significance of diffusive gas transport was inferred from the difference in the behavior of Ar and particles. The lungs of six anesthetized and mechanically ventilated beagle dogs were equilibrated with air or either of the test atmospheres, He-O2 or SF6-O2, where nitrogen was replaced by helium (He) or sulfur hexafluoride (SF6). Due to differences in gas density and gas viscosity Reynolds numbers varied by a factor of twelve and Ar diffusivity by a factor of four between He-O2 and SF6-O2, suggesting that both kinds of intrapulmonary gas transport, convection and diffusion, should be affected. Combined particle and Ar boluses were inhaled into various lung depths and the extent of gas transport was inferred from changes in bolus shape induced by the passage through the lungs. In air, convective bulk gas transport generally followed the symmetric first-in, last-out principle and acted at all tested lung depths. Within the conducting airways, gas transport to the lung periphery was primarily due to convection but beyond these airways diffusion became rapidly significant. Breathing test atmospheres affects intrapulmonary gas transport only slightly. The extent of convective mixing was increased by 4% in SF6-O2 (p < .01) and reduced by 5% in He-O2 (p < .01) as compared to air. The symmetry of convective lung filling and emptying was slightly disturbed. In SF6-O2 the mean of the exhaled bolus was shifted by 8% toward the lung periphery. In He-O2 it was shifted by 4% toward the airway opening. In both test atmospheres exhaled Ar boluses were similar, suggesting that diffusive gas transport overwhelms the small changes in convective gas transport. Hence, factors other than gas composition-related flow characteristics, e.g., nonreversibility of in- and expiratory flow profiles or features of lung geometry, are the major determinants of gas transport in the lungs.

Animals↗

PubMedDate not supplied

Influence of intrinsic particle properties on the assessment of convective gas transport by aerosol bolus technique.

Aerosol bolus measurements are increasingly being used in patients and healthy subjects to assess convective gas transport and mixing in the lungs. To investigate the extent to which intrinsic particle properties confound parameters derived for the assessment of intrapulmonary transport, bolus inhalation experiments were performed in six anesthetized, intubated, and mechanically ventilated beagle dogs using DEHS particles of 0.5, 1, or 2 microns diameter. Therefore, particle displacement by diffusion varied by a factor of two, settling velocity by a factor of 13, and particle inertia as inferred from the stopping distance by a factor of 16. By using a standardized breathing maneuver 6-mL boluses were inhaled into lung depths between 75 and 475 mL. Mode, half-width, and intrapulmonary particle deposition along with mean, standard deviation, and skewness of the particle concentration distributions in the expired air were determined. For all particle sizes studied particle deposition increased with increasing lung depth not exceeding 25% for 0.5-micron particles, but being 80% in deep lung regions for 2-micron particles. Whereas half-width and standard deviation exhibited only small differences between particle sizes (less than 20%), mode and mean of the exhaled bolus were clearly dependent on particle size, in particular for particles inhaled deep into the lung. No significant effects were detectable for the skewness. Hence, convective mixing assessed by half-width or standard deviation is only slightly dependent on particle size, but the estimate of convective bulk transport as inferred from the mean volume from which the bolus is exhaled is highly dependent on particle size. Yet, the intrinsic mobility of unit-density 0.5-micron particles was found to be small enough to consider these particles as ideal tracers for probing convective gas transport in the lungs.

Administration, Inhalation↗

PubMedDate not supplied

[1-Year follow-up of inpatient treatment in a psychosomatic rehabilitation clinic with either a psychoanalytic or behavior therapy oriented treatment].

In a naturalistic setting, we studied the long-term effects of an inpatient treatment program at a psychosomatic rehabilitation clinic, where patients were assigned to a department with either a psychoanalytic or behavior therapeutic orientated treatment after one week of comprehensive diagnosis. The study is based on a self-developed questionnaire which gathers retrospective information in a broad spectrum of problem areas at the point of admittance and release (t0 and t1) as well as current assessments one year following treatment (t2). Additionally, a symptom checklist (Giessener Beschwerdebogen) and a questionnaire assessing depression (Allgemeine Depressionsskala) were prospectively employed at t0 and t2. We asked a consecutive sample of 376 patients to participate, of which 56% answered at t2. Despite limitations of the internal and external validity of the study, we were able to show that substantial improvements are maintained following treatment for both therapies at one-year follow-up, whereas only small difference are found between the outcomes of the two different schools implemented in the clinic.

Adult↗