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Increased hydrogen peroxide and thiobarbituric acid-reactive products in expired breath condensate of asthmatic patients.

Symptoms of bronchial asthma are a manifestation of airway inflammation. Circulatory leucocytes (predominantly eosinophils, mast cells and neutrophils), release inflammatory mediators, including reactive oxygen species, i.e. superoxide anion which is dismutated to hydrogen peroxide (H2O2). Neutrophils from asthmatics generate greater amounts of these species than those of healthy subjects. Some of the H2O2 and thiobarbituric acid-reactive products (TBARs) can evaporate from alveolar lining fluid, and could be expired from the airways of asthmatics. In this study, therefore, we determined whether asthmatic patients exhale more H2O2 and TBARs than healthy subjects. We examined 10 healthy subjects as a control group and 21 asthmatic subjects. In asthmatic subjects, forced expiratory volume in one second (FEV1), was 68+/-9% of predicted value, peak expiratory flow rate (PEFR) was 65+/-8% pred, and bronchial reversibility was 34+/-5% of prebronchodilated FEV1. The mean H2O2 level measured spectrofluorimetrically in the expired breath condensate of asthmatic subjects was 26 fold higher than that in healthy controls (0.26+/-0.29 vs 0.01+/-0.03 nM; p<0.05). The concentration of TBARs in breath condensate was also higher in asthmatic patients compared with nonasthmatics (0.073+/-0.071 vs 0.004+/-0.009 nM; p<0.05). There was a significant correlation between H2O2 level and concentration of TBARs in asthmatic patients (r=0.74; p<0.01). There was also a strong inverse correlation between H2O2 content of all asthmatics and FEV1% pred (r=-0.63; p<0.005) and PEFR% pred (r=-0.52; p<0.05). We conclude that there are elevated levels of hydrogen peroxide and thiobarbituric acid-reactive products in expired breath condensate of asthmatic patients, and that measurement of these substances in the expired breath condensate could be a simple, noninvasive method that could be used as a biochemical marker of airway inflammation.

Adult↗

Direct computational simulations and experiments for film condensation inside tubes and channels.

This article presents accurate numerical solutions of the full 2D governing equations for steady and unsteady laminar/laminar internal condensing flows of pure vapor (FC-72 and R-113) inside a vertical tube and a channel. The film condensation is on the inside wall of a tube or one of the walls of a channel (the lower wall in case of a downward sloping channel). Both experiments and simulations find that exit condition specifications are important. The computations are able to predict whether or not a steady flow exists with a well-defined and steady natural exit condition. If well-defined natural steady/quasi-steady flows exist-as is shown to be the case for gravity-dominated or strong shear-dominated condensate flows that remain parabolic up to the exit location-the computations are able to predict both the natural exit condition and any point of transition (from stable to unstable or smooth to wavy behavior) that may exist within this zone. Compared to gravity-driven cases, shear-driven cases (zero gravity or horizontal cases) tend to destabilize easily. It is found that only for gravity-driven cases interfacial waves are able to cause a concurrent enhancement in heat transfer rates along with an enhancement in interfacial shear. Also it is found that this enhancement in interfacial wave energy is significant if the condensing surface noise is in resonance with the intrinsic waves.

Journal Article↗

Biphasic effects of acetaldehyde-biogenic amine condensation products on membrane fluidity.

I have studied the effects of four acetaldehyde-biogenic amine condensation products on membrane fluidity of liposomes, consisting of 1-palmitoyl-2-oleoylphosphatidylcholine and cholesterol, by measuring fluorescence polarization using different probes. The condensation products were 1-methyl-1,2,3,4-tetrahydro-beta-carboline (MTBC), 6-hydroxy-1-methyl-1,2,3,4-tetrahydro-beta-carboline (6-OH-MTBC), 3-carboxy-1-methyl-1,2,3,4-tetrahydro-beta-carboline (3-C-MTBC) and 6,7-dihydroxy-1-methyl-1,2,3,4-tetrahydroisoquinoline (salsolinol). They changed the fluidity of the hydrophobic and hydrophilic regions of liposomal membranes at micromolar levels almost corresponding to their antibacterial and antiplatelet concentrations, but their membrane effects varied by structure, concentration and membrane lipid composition. MTBC and salsolinol showed biphasic effects on the inner layers of membranes to enhance the fluidity at 250-1000 microM and reduce the fluidity at 50-100 microM, whereas both of them fluidized the outer layers of the membranes. 3-C-MTBC concentration-dependently fluidized both layers of membranes. 6-OH-MTBC most weakly enhanced and reduced the fluidity of the outer and inner layers, respectively. The membrane effect of MTBC was the greatest of the four condensation products. MTBC (50-1000 nM) significantly reduced the fluidity by exclusively acting on the membrane core, but was less effective in fluidizing the membrane surface. However, the others were not active at low nanomolar levels. The membrane effects may be partly responsible for the antibacterial and antiplatelet actions of the acetaldehyde-biogenic amine condensation products, although they do not appear to be simple membrane fluidizers.

Acetaldehyde↗

Nuclear proteins of the bovine esophageal epithelium. I. Monoclonal antibody W2 specifically reacts with condensed nuclei of differentiated superficial cells.

Cells from three layers of the bovine esophageal epithelium, representing different stages of differentiation, were dissociated and separated by Percoll gradient centrifugation into fractions of small, medium and large sizes. A majority of the large cells possessed condensed nuclei, a characteristic feature of terminal differentiation of the superficial epithelium. The small cells resembled the proliferate cells of the basal layer. In vitro culture of the esophageal epithelial cells resulted in proliferation of the small cells, colony formation, and, in some cases, differentiation into cells with condensed nuclei. Nuclei, or nuclear subfractions derived from cells of the different layers, were used as immunogens for the generation of hybridomas secreting monoclonal antibodies that bound specifically to different regions of the esophageal tissue. One such antibody, designated W2, labeled the condensed nuclei from the superficial layer of stratified esophageal and corneal epithelia in situ, as well as the large cells from esophageal culture in vitro. Thus, the expression of the W2 antigen may be associated with the process of nuclear condensation during epithelial differentiation. Immunoisolation of the target antigen of W2 from extracts of large cells of the bovine esophagus yielded a band of M(r) approximately 33,000 on nonreducing polyacrylamide gels. This band dissociated into two polypeptides, of M(r) approximately 22,000 and approximately 11,000, upon treatment with dithiothreitol. Amino acid sequence analysis of the larger polypeptide showed extensive homology to a group of small calcium-binding proteins, including two helix-turn-helix motifs designated as the EF-hand, characteristic of the configuration of the metal-ion coordinating ligands of the calcium-binding site. Similarly, the sequence at the amino terminus of the polypeptide of approximately 11,000 indicated that it was the light chain counterpart of the same calcium-binding protein complex.

Amino Acid Sequence↗

Phosphorylation of histone H3 is correlated with changes in the maintenance of sister chromatid cohesion during meiosis in maize, rather than the condensation of the chromatin.

Meiotic chromosome condensation is a unique process, characterized by dramatic changes in chromosome morphology that are required for the correct progression of pairing, synapsis, recombination and segregation of sister chromatids. We used an antibody that recognizes a ser 10 phosphoepitope on histone H3 to monitor H3 phosphorylation during meiosis in maize meiocytes. H3 phosphorylation has been reported to be an excellent marker for chromosome condensation during mitotic prophase in animal cells. In this study, we find that on maize mitotic chromosomes only pericentromeric regions are stained; there is little staining on the arms. During meiosis, chromosome condensation from leptotene through diplotene occurs in the absence of H3 phosphorylation. Instead, the changes in H3 phosphorylation at different stages of meiosis correlate with the differences in requirements for sister chromatid cohesion at different stages. Just before nuclear envelope breakdown, histone H3 phosphorylation is seen first in the pericentromeric regions and then extends through the arms at metaphase I; at metaphase II only the pericentromeric regions are stained. In afd1 (absence of first division), a mutant that is defective in many aspects of meiosis including sister chromatid cohesion and has equational separation at metaphase I, staining is restricted to the pericentromeric regions during metaphase I and anaphase I; there is no staining at metaphase II or anaphase II. We conclude that changes in the level of phosphorylation of ser10 in H3 correspond to changes in the cohesion of sister chromatids rather than the extent of chromosome condensation at different stages of meiosis.

Centromere↗

The ultrastructural organization of prematurely condensed chromosomes.

In an effort to understand the arrangement of the basic 30 nm chromatin fibre within metaphase chromosomes, changes in the organization of prematurely condensed chromosomes (PCC) were examined as a function of progression through the cell cycle. The structural features of PCC observed under the light microscope were compared with those obtained by scanning electron microscopy. PCC with varying levels of condensation were obtained by fusing mitotic HeLa cells with interphase cells synchronized at different times in the cell cycle. PCC from G1 cells are composed of rather tightly packed bundles of tortuous chromatin fibres. The density of fibre packing along the longitudinal axis of G1-phase PCC is lower and less uniform than that of metaphase chromosomes. Early G1 PCC exhibit gyres suggesting a despiralized chromonema. The condensed domains in G1 PCC appear to be organized as supercoiled loops; whereas fibre-sparse domains consist of longitudinal fibres running along the chromosome axis. As cells progressed towards S phase, a greater proportion of highly extended regions containing prominent longitudinal fibres became evident in the PCC. The pulverized appearance of S-phase PCC under the light microscope corresponded to the highly condensed, looping fibre domains separated by more extended segments containing longitudinal fibres that are visualized using the scanning electron microscope. Active sites of DNA synthesis are implicated to be localized within extended longitudinal fibres. Post-replicative chromosome maturation extends through the G2 period and appears to involve rearrangement of the extended longitudinal fibres into packed looping-fibre clusters, which then coalesce. These observations support the model for packing DNA into chromosomes proposed in 1980 by Mullinger & Johnson. Briefly, this model suggests that the chromonema of each metaphase chromatid contains regions composed of folded longitudinal chromatin fibres as well as looping fibres that emerge from the axis at distinct foci. The final level of chromatin packing in metaphase chromosomes is attained by spiralization of the chromonema.

Chromatin↗

Phosphorylation of nonhistone proteins during premature chromosome condensation in a temperature-sensitive mutant, tsBN2.

In tsBN2 cells, a temperature-sensitive (ts) mutant of the BHK21 cell line, with a ts-defect in its regulatory system for chromosome condensation, antigens that react with mitotic specific mouse monoclonal antibody MPM-2 were produced when premature chromosome condensation (PCC) was induced by a temperature shift. The polypeptides of antigens recognized by MPM-2 in tsBN2 cells with PCC were identical to those of antigens in mitotic cells. These antigens appeared concomitantly with chromosome condensation, which suggests that these mitotic-specific antigens may be related to chromosome condensation. As the production of mitotic-specific antigens was inhibited by W-7, a specific and potent antagonist of calmodulin, calmodulin may function in the mitotic phosphorylation of nonhistone protein.

Animals↗

Mutagenicity of condensed pyridazines with different substituents.

A total of 24 compounds were prepared by introducing an N-oxide, a hydrazino group, a methoxy group or a chloro group into 3 kinds of condensed pyridazines: pyrido[3,4-d]pyridazines, pyrido[2,3-d]pyridazines and phthalazines. The mutagenicity of these 24 compounds was assessed by the Ames method using two tester strains (Salmonella typhimurium TA98 and TA100). No mutagenic activity was detected with any of the 3 condensed pyridazines without substituents or any of the 5 condensed pyridazines with a methoxy group. The compounds with N-oxide in the pyridazine ring showed no or only very weak mutagenicity. However, when an oxide was introduced into the nitrogen of the pyridine ring, the mutagenicity against strain TA98 was higher than that of any other test compound. All compounds with a hydrazino group were mutagenic against strains TA98 and TA100, irrespective of the presence or absence of S9 mix-induced metabolic activation. 1-Hydrazinophthalazine (hydralazine) which has been clinically used as an antihypertensive agent was weakly mutagenic. The introduction of a chloro group increased the bactericidal effects of the condensed pyridazines, thus hampering the assessment of mutagenicity. A majority of the compounds which were found to be mutagenic in this study required no metabolic activation with S9 mix.

Magnetic Resonance Spectroscopy↗

Facile solid-phase synthesis of sulfated tyrosine-containing peptides: Part II. Total synthesis of human big gastrin-II and its C-terminal glycine-extended peptide (G34-Gly sulfate) by the solid-phase segment condensation approach.

Application of the fluoren-9-ylmethoxycarbonyl (Fmoc)-based solid-phase segment condensation approach to the preparation of sulfated peptides was investigated through the synthesis of human big gastrin-II, a 34-residue sulfated tyrosine [Tyr(SO3H)]-containing peptide. Highly acid-sensitive 2-chlorotrityl resin (Clt resin) was exclusively employed as an anchor-resin for the preparation of the three peptide segments having the C-terminal Pro residue as well as of the Tyr(SO3H)-containing resin-bound segment. By using the PyBOP-mediated coupling protocol [PyBOP=benzotriazolyloxytris(pyrrolidino)phosphonium hexafluorophosphatel, we successively condensed each segment and constructed the 34-residue peptide-resin without any difficulty. The final acid treatment of the fully protected peptide-resin at low temperature (90% aqueous TFA, 0 degree C for 8 h), which can detach a Tyr(SO3H)-containing peptide from the resin and remove the protecting groups concurrently with minimum deterioration of the sulfate, afforded a crude sulfated peptide. After one-step HPLC purification, a highly homogeneous human big gastrin-II was easily obtained in 14% yield from the protected peptide-resin. The sulfate form of the C-terminal glycine-extended gastrin (G34-Gly sulfate), a posttranslational processing intermediate of gastrin-II, was also successfully prepared with the segment condensation approach (11% yield). These results demonstrated the usefulness of the segment condensation protocol for preparing large Tyr(SO3H)-containing peptides.

Gastrins↗

Inhibitory effects of condensed tannins on angiotensin converting enzyme.

Effects of condensed tannins isolated from Rhei Rhizoma on the activities of angiotensin converting enzyme (ACE) and various proteases were examined in vitro. Among the various condensed tannins tested, procyanidin B-5 3,3'-di-O-gallate and procyanidin C-1 3,3',3"-tri-O-gallate strongly inhibited the activity of ACE. The concentration of procyanidin B-5 3,3'-di-O-gallate required for 50% inhibition of ACE was 1.3 X 10(-6) M. The inhibition of ACE by condensed tannins was reversible and non-competitive, according to dialysis and to Dixon plots. However, over one hundred times the concentration was required to inhibit activities of other proteases such as trypsin, chymotrypsin, leucine aminopeptidase, carboxypeptidase A and urinary kallikrein. These results suggest that the inhibitory effects of condensed tannins on the activities of ACE are specific.

Angiotensin-Converting Enzyme Inhibitors↗

An increased rate of cell-free protein synthesis by condensing wheat-germ extract with ultrafiltration membranes.

Wheat-germ extract for cell-free protein synthesis was condensed with ultrafiltration membranes of which the molecular cut-off values were 10 kDa, 100 kDa, and 300 kDa. Reaction conditions of the cell-free system were optimized for the condensed extracts, which needed a higher concentration of creatine phosphate than the uncondensed one, probably due to the increased activity of degradation of ATP and GTP. By using the condensed extract and optimized reaction conditions, the rate of protein synthesis was increased 2- to 3-fold compared with using an uncondensed extract, and about 10-fold compared with conventional conditions. Condensation of the extract with the 300-kDa membrane showed the highest productivity, which was about 30 micrograms dihydrofolate reductase protein ml-1 h-1. The final amount of synthesized protein was one third of that of a continuous-flow cell-free (CFCF) system reported by Endo et al. [J. Biotechnol., 25, 221-230 (1992)] but the productivity was 5-fold higher than that obtained by the CFCF system.

Adenosine Triphosphate↗

Demonstration and characterization of a detector for minimally destructive detection of Bose condensed atoms in real time.

We present the first detector that is capable of recording high-bandwidth atom number density measurements of a Bose-Einstein condensate, with a readout of the data in real time. It is based on a shot-noise-limited unbalanced Mach-Zehnder interferometer designed for a minimally destructive measurement of the atom column density of a Bose-Einstein condensate. The shot-noise limit is reached by phase modulating the laser in one arm and phase locking the interferometer with a second-color laser. The detector is characterized, and its sensitivity for a fractional change in the column density of a Bose-Einstein condensate is calculated. With this detection system it may be possible to implement feedback to stabilize a Bose-Einstein condensate or an atom laser.

Journal Article↗

8-Isoprostane, a marker of oxidative stress, is increased in the expired breath condensate of patients with pulmonary sarcoidosis.

STUDY OBJECTIVE: 8-Isoprostane is considered an index of oxidative stress. Measurement of 8-isoprostane in the expired breath condensate, a totally noninvasive method, has not been used to explore the level of inflammation in pulmonary sarcoidosis. Therefore, the aim of our study was to measure the levels of 8-isoprostane in the expired breath condensate of patients with sarcoidosis, and to investigate the relation of 8-isoprostane level to disease activity. PATIENTS: We investigated 30 patients with pulmonary sarcoidosis (active disease, n = 14; nonactive disease, n = 16) and 12 healthy subjects as control group. METHODS: 8-Isoprostane was measured in the expired breath condensate of all subjects, and its levels were compared between the control and sarcoidosis groups as well as between the subgroups of patients with active and nonactive disease. In the group with sarcoidosis, 8-isoprostane levels were further correlated with markers that may reflect disease activity, such as serum angiotensin-converting enzyme (sACE) level, serum calcium level, and pulmonary function test results. RESULTS: The concentration of 8-isoprostane was increased in patients with sarcoidosis compared to control subjects (mean, 64.23 pg/mL; 95% confidence interval [CI], 37.00 to 91.46 pg/mL; vs mean, 20.75 pg/mL; 95% CI, 16.06 to 25.44 pg/mL; p = 0.04). The difference was primarily due to the patients with active disease, who had significantly higher levels of 8-isoprostane (mean, 111.4 pg/mL; 95% CI, 62.56 to 160.30 pg/mL; p < 0.001) compared to patients with nonactive disease (mean, 22.94 pg/mL; 95% CI, 15.89 to 29.99 pg/mL) or healthy subjects. 8-Isoprostane levels in patients with nonactive disease did not differ from those in healthy subjects (p > 0.05). In the patients with sarcoidosis, 8-isoprostane levels were positively correlated with sACE level (p < 0.0001, r = 0.69), but was not correlated with serum calcium level or pulmonary function test values. CONCLUSIONS: Our data suggest that 8-isoprostane levels are increased in the expired breath condensate of patients with sarcoidosis and might serve as an index of disease activity.

Adult↗

Flow cytometric and microscopic evaluation and effect on fertility of abnormal chromatin condensation in bovine sperm nuclei.

The techniques of Feulgen staining, acridine orange staining, and a sperm chromatin structure assay using acridine orange and flow cytometry were compared for selective examination of bovine sperm nuclei. Twenty frozen semen samples were simultaneously analysed by all three methods. The prevalence of abnormally condensed DNA and its relationship to other semen traits were determined in ejaculates from 70 bulbs presented for routine examination for breeding soundness and in frozen semen from 348 bulls evaluated over five years. A breeding trial with 118 beef heifers using semen from six bulls with different degrees of nuclear abnormalities was performed to assess the importance of the defects with respect to fertility. The results indicate that few spermatozoa with abnormal DNA condensation are found in normal semen, but the incidence increases with disturbance of spermatogenesis. However, high numbers of abnormally condensed nuclei were found in the absence of an increase in other defects. This nuclear defect might be at least partially of epididymal origin; it can lower fertility and can be compensated for by increasing the numbers of normal spermatozoa in the insemination dose. The percentage of abnormally condensed sperm nuclei as detected by Feulgen staining was significantly correlated with that detected by microscopy after acridine orange staining and by the sperm chromatin structure assay. We therefore consider the Feulgen technique to be a valuable tool for assessing the nuclear integrity of bovine spermatozoa.

Acridine Orange↗

The effect of a condensed tannin-containing forage on methane emission by goats.

The objective of this study was to compare methane emission by goats consuming the condensed tannin-containing forage sericea lespedeza (Les-pedeza cuneata) or a mixture of crabgrass (Digitaria ischaemum) and Kentucky 31 tall fescue (Festuca arundinacea). Two groups of 12 Angora does (initial average BW = 41.5 +/- 2.7 kg) that previously grazed a pasture of sericea lespedeza or crabgrass/tall fescue for approximately 4 mo were used. After 1 wk of adaptation to metabolism cages, gas exchange was measured for 24 h in an open-circuit respiration calorimetry system with four head boxes. Forage harvested daily from the previously grazed pastures was consumed ad libitum. Crude protein concentration was 10.3 and 13.0%, IVDMD was 64.5 and 75.3%, and the level of condensed tannins was 17.7 and 0.5% for sericea lespedeza and crabgrass/tall fescue, respectively. Dry matter intake (1.11 vs. 0.67 kg/d) and digestible DMI (estimated from IVDMD; 0.71 vs. 0.51 kg/d) were greater (P < 0.01) for sericea lespedeza than for crabgrass/tall fescue. Ruminal ammonia N (3.7 and 9.9 mg/dL; P < 0.001) and plasma urea-N concentrations (16.7 and 20.9 mg/dL; P = 0.07) were lower for sericea lespedeza than for crabgrass/tall fescue. Concentrations of individual and total VFA and the acetate-to-propionate ratio in ruminal fluid did not differ between treatments (P > 0.19). Despite higher DMI by goats fed sericea lespedeza, daily energy expenditure (409 vs. 431 kJ/kg BW(0.75)), heart rate (70 vs. 73 beats/min), and the ratio of energy expenditure to heart rate (5.82 vs. 5.94) did not differ between sericea lespedeza and crabgrass/tall fescue, respectively (P > 0.13). Methane emission expressed as both quantity per day or relative to DMI was lower (P <0.001) for sericea lespedeza than for crabgrass/tall fescue (7.4 vs. 10.6 g/d and 6.9 vs. 16.2 g/kg DMI). Substantial differences between the forages in condensed tannins concentration and methane emission by Angora goats suggest that condensed tannins decreased methane emission.

Ammonia↗

Effect of smoke condensate on the physiological integrity and morphology of organ cultured rat lenses.

Smoke, either from cigarette smoking or from burning of organic fuels, has been proposed to be a major environmental risk factor for a variety of human diseases. Recently, smoke was implicated in cataract, an eye lens opacification which is a major cause of blindness. We have undertaken a study to investigate the effect of wood smoke condensate on the physiological integrity and morphology of organ cultured lenses. Lenses in organ culture are metabolically active and have functional defense systems, thus they provide an appropriate model for studying effects of smoke condensate. Our present study indicates that metabolites of wood smoke condensate accumulate in the lens. The ability of the lenses to accumulate rubidium-86 (mimic of potassium) and choline from the medium is compromised by exposure to smoke condensate. Rubidium efflux studies suggest that the damage is primarily at the uptake level and does not involve an overall increase in membrane permeability. Protein leakage experiments corroborate this suggestion. Histological data show distinct morphological changes such as hyperplasia, hypertrophy and multilayering of epithelial cells.

Animals↗

Influence of eggshell condensation on eggshell penetration and whole egg contamination with Salmonella enterica serovar enteritidis.

Shells of agar-filled and whole eggs were inoculated with 10(3) to 10(4) CFU of Salmonella enterica serovar Enteritidis per eggshell. The agar-filled eggs were used to study bacterial eggshell penetration, and the whole egg results were used to characterize contamination of the egg contents. In each group, half of the eggs were stored for 21 days at 20 degrees C and 60% relative humidity (RH), and the other half was stored for 24 h at 6 degrees C and then for 20 days at 20 degrees C. The latter conditions resulted in condensation on the eggshell for 30 min from the moment the eggs were placed in the 20 degrees C chamber. Taking into account the ages at which hens were studied (39, 53, and 67 weeks), an average of 62% of the eggshells with condensate were penetrated compared with 43% for the control group; this difference was significant (P < 0.01). No significant difference in whole egg contamination was found; 18% of the control eggs were contaminated compared with 22% of the condensate eggs. Whole egg contamination was significantly higher for eggs from the hens at an older age (67 weeks). This difference probably was not due to a higher penetration potential because differences were not observed for the corresponding agar-filled eggs. Condensation on the eggshell seemed to encourage bacterial penetration of the eggshell but had a smaller impact on whole egg contamination.

Age Factors↗

[Genotoxicity of stack gas condensates of Bavarian waste incineration plants. III. Emission monitoring with a simple UDS assay using the human lung cell lines NCI-H 322 and 358].

For the validation of the genotoxicity testing on stack gas condensates from waste incineration plants using bacterial short time tests (15), a modified UDS assay with the lung cell lines NCI-H 322 and 358 was developed. The UDS assay is more sensitive than the SOS chromotest and discriminates better between the negative or weakly positive and the clearly positive samples. It has a high sensitive and specificity and also accuracy, is practicable in a comparatively simple, speedy and reasonably priced manner and is therefore appropriate for an emission monitoring similar to simple bacterial short time tests. Especially in strongly concentrated crude and clean gas condensates, maximal induction factors were seen in the range of strong UDS inducers. From 55 samples on 16 incineration plants tested in the years 1992 to 1995, in 48 we found weak to strong UDS inductions in at least one of the two test cell lines. From three plants examined continuously in this period only two emitted stack gases with constantly low genotoxicity at the end of sampling. 5 clean gas condensates, that were taken in random samples from 3 other plants in the period 1994 to 1995, proved to be non-genotoxic in the UDS assay. However, one of these plants emitted stack gases with high cytotoxicity, which might have masked UDS-inducing single substances. It is not possible to make a statement on the human toxicological relevance. However, a clearly positive development towards more harmless stack gas condensates was established. A definite correlation could not be shown between the chemical analysis of the detected cancerogenic organic single substances of the samples and the detected UDS inductions. Further investigations for finding strong UDS inducers from the substance spectrum of municipal stack gas emissions are necessary.

Air Pollutants↗