Modulating effects of ochratoxin A (OTA) and some of its derivatives on viability and oxidative burst activity of porcine monocytes and granulocytes have been studied. The formation of free oxygen radicals by monocytes was suppressed by OTA and ochratoxin C (OTC) at concentrations between 10 and 1000 ng/ml. Intracellular radical formation of granulocytes was in part already significantly reduced at 1 ng/ml of these mycotoxins. Conversely, the intracellular formation of radicals in monocytes of individual pigs was stimulated by the toxins at 1–100 ng/ml. A biologically active fraction of the crude toxin (RE2) which had been identified as OTC had a stronger effect than all other derivatives of ochratoxin A. Whether these modulating effects of OTA and OTC on phagocyte functions are of significance in the pathogenesis of infectious diseases, needs to be studied in more detail. In this context, the occurrence of OTC in food and feeds should be examined more closely.

The immunomodulatory effects of ochratoxin A (OTA) and some of its metabolites on the human monocyte/macrophage line THP-1 are described. Metabolic activity, cell proliferation, cell membrane integrity, cell differentiation, phagocytic behaviour, nitrogen oxide synthesis and cell surface markers were largely suppressed by these mycotoxins at concentrations between 10 and 1000 ng/ml, in individual cases already at 1 ng/ml. After analysis of a crude toxin, a substance designated RE2 could be isolated besides OTA, which was identified as ochratoxin C (OTC). The latter showed a stronger suppressive effect on most functions studied than all other metabolites of OTA. Because of the immunomodulatory effects of OTA and OTC, more attention should be paid to their immunopathogenic importance in addition to their known cytotoxic and genotoxic effects. The occurrence and importance of the mycotoxin OTC should be more closely examined in this context.

The influence of pure OTA and an Aspergillus-ochraceus crude toxin on the intracellular expression and the secretion of tumor necrosis factor (TNF) alpha by the monocytic cell line THP-1 was studied in vitro. After 4 hours exposure, the secretion of TNFalpha was inhibited to 50 % by pure OTA in a concentration of 400 ng/ml and by crude toxin in a concentration of 100 ng/ml. The same concentrations of mycotoxins impaired the mitochondrial activity of THP-1 cells only marginally. The intracellular expression of TNFalpha was not disturbed by pure OTA in the concentrations tested, whereas crude toxin showed an inhibitory effect. The possible reasons for these findings are discussed.

The effect of ochratoxin A (OTA) and C (OTC) on the cytolytic activity of natural killer cells (NK cells) was studied using a fluorescence based bioassay with the cell line NK-92 as effector cell line and K-562 as target cell line. Different OTA and OTC preparations were included in the study. After exposure to very low toxin concentrations (1–10 ng/ml) a slight stimulation of NK cell activity was noted, whereas after addition of higher toxin concentrations (100–1000 ng/ml) NK cell function was suppressed. Preparations containing OTC showed a stronger effect than those containing OTA.

Simulations of urban or natural environments created by graphics computer software are increasingly being utilized in research and applied contexts, and pertinent techniques have become highly sophisticated. However, the quality and utility of such presentation means still need careful validation. This issue was addressed in a series of lab and field studies. In the study reported here, a simulation of a suburban environment was presented to respondents (n=147) in several variations to investigate the effects of lighting (day/sun, day/fog, night), personal shadow (yes/no) and sound (on/off) on perceived simulation quality. The contingencies with related aspects (such as comprehension, recollection and appreciation of the simulated environment) were investigated as well. Based on a comprehensive conceptual framework, a set of scales measuring relevant cognitive and affective aspects was employed. Main results are that simulations were perceived as valid and acceptable, that appraisals differ according to lighting and time-of-day conditions, and that provision of sound enhances the perceived quality of presentations. The findings elucidate which factors are crucial for further improving simulations and clarify the validity of computer simulations for assessing existing and future environments.

To examine the ochratoxin A exposure of the population, 927 blood serum specimens from representative groups of subjects were examined. The resulting share of positive specimens was 98.1%, i.e. 1.9 % of specimens exhibited levels of ( 0,06 ng/mL (detection limit). The foremost part of the specimens concentrated in the 0.11 - 0.30 ng/mL and 0.31 - 0.50 ng/mL ranges (maximum: 2.03 ng/mL; mean: 0.27 ng/mL; median: 0.23 ng/mL; 90th percentile: 0.45 ng/mL). To estimate the possible risk, the daily ochratoxin A intake was calculated from the serum levels and compared to the provisional tolerable daily intake (PTDI) levels available from literature. Although in individual cases, the presence of elevated exposure levels could not be excluded, it has not been possible to derive a risk from ochratoxin A for the majority of the population. The ochratoxin A concentrations found in serum from umbilical cord blood, i.e. in newborns, were comparable to those in maternal sera and the mean value for all subjects examined.

Die Maus-Thymoma-Zellinie EL-4 diente alsin-vitro-T-Zell-Modell für Untersuchungen immunmodulatorischer Effekte von reinem Ochratoxin A (OTA) sowie von einerAspergillus-ochraceaus-Rohtoxinpräparation. Die Zytokinproduktion (IL-2, IL-4, IL-5, IL-6) und die Vitalität PMA-stimulierter EL-4-Zellen wurde unter OTA-Einwirkung untersucht. Rohtoxin wirkte im Vergleich zum reinen OTA bereits bei niedrigeren OTA-Konzentrationen zytotoxisch (IC50-Werte 3 bzw. 11 µg/ml). Steigende Konzentrationen von beiden OTA-Präparationen führten zur Hemmung der Zytokin-Ausschüttung, wobei Rohtoxin wiederum stärker wirkte. Dies deutet auf den Einfluß weiterer noch nicht näher charakterisierter Bestandteile des Rohtoxins hin. Die unterschiedlichen Hemmkonzentrationen von OTA gegenüber den einzelnen Zytokinen machen deutlich, daß auch eine unterschiedliche Empfindlichkeit der betreffenden Regulations-Mechanismen vorliegen könnte. Bei bestimmten Konzentrationen waren bei IL-2 und IL-6 auch stimulierende Effekte beider Toxin-Präparationenen nachweisbar, wogegen diese Konzentrationen bei IL-4 und IL-5 bereits hemmten.

141 Haemophilus (H.) parasuis and 8 H. parasuis-like strains from different farms were serotyped according to MOROZUMI and NICOLET (1986 b) as well as to BAKOS et al. (1952). It was possible to classify 72.8 % of the investigated strains. 7 out of 12 serotypes have been described for the first time. The high specificity in the agargel precipitation test was not reproducible in the more sensitive dot-blot procedure. The dot-blot results point to a participation of non-immunogenic polysaccharides in the detection reaction.The serotypes SV 1, SV 5, SV Jena 6 and SV Jena 10 proved to be highly virulent in SPF pigs, SV 2 and SV 4 were of medium virulence. The other serotypes were found to be nonvirulent. Unencapsulated strains and isolates of serotype SV 5 prevailed in animals with Glassers' disease. 23 H. parasuis and 3 H. parasuis-like strains were examined in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). On the basis of protein profiles of whole-cell lysates, 23 of them could be assigned to 5 groups.Apart from the highly virulent strains of serovar 1, which belonged to PAGE type III, all other highly virulent strains of the serovars SV 5, SV Jena 6 and SV Jena 10 were grouped into PAGE type I. No correlation could be found between PAGE type on the one hand and virulence or origin of isolates on the other hand.

Detailed studies of the surface structures are an important requirement for the development of efficient vaccines against enzootic pneumonia in calves and piglets caused by Pasteurella multocida. Electron microscopical examination after Alcian Blue staining shows capsular material extending far into the surrounding medium. The extent of the capsules depicted by light microscopy did not correlate with virulence and immunogenicity. However, the extent of the capsules was effected by different culture conditions. The immunization with extract material resulted in a good protection against homologous infection. It has been shown that different cultivation conditions can result in heterogeneity of LPS and in altered OMP-profiles.

ZusammenfassungAuf der Grundlage der Bestimmung des GC‐Gehaltes und der Untersuchungsergebnisse zur DNA: DNA‐Hybridisation wurden verschiedene Actinobacillus‐Referenzstämme sowie ein Haemophilus‐pleuropneumoniae‐Wildstamm mit Bakterienstämmen genotypisch verglichen, die in der DDR und in der Schweiz aus hämorrhagisch‐nekrotisierenden Pleuropneumonie‐Herden des Schweines isoliert wurden, aber eindeutig von H. pleuropneumoniae vor allem in den kulturmorphologischen Merkmalen abwichen. Diese Stämme waren zunächst wegen der fehlenden V‐Faktor‐Abhängigkeit, der ausgeprägten Urease‐ und Hämolysebildung als Pasteurella‐haemolytica‐like‐Organismen bzw. als Actinobacillus taxonomisch zugeordnet worden. Wir konnten nachweisen, daß diese Bakterienstämme aus spontanen Pleuropneumonien des Schweines in der Schweiz und DDR identisch sind und enge verwandtschaftliche Beziehungen zu H. pleuropneumoniae und den Actinobacillus‐Arten aufweisen. Auf der Grundlage des DNA: DNA‐Hybridisationsgrades und der beschriebenen phänotypischen und biochemischen Merkmale der Stämme möchten wir die von uns isolierten Bakterien als Actinobacillus sp. bezeichnen.SummaryGenotypical studies on the agents of haemorrhagic‐necrotizing pleuropneumonia of pigsOn the basis of determination of the GC‐content and studies of DNA: DNA hybridization, various Actinobacillus reference strains as well as a Huemophilus pleuropneumoniae wild strain were genotypically compared using strains isolated in the DDR and in Switzerland, but particularly with H. pleuropneumoniae differing especially in respect of its cultural and morphological characters. These strains were first, on account of their relationship to lack of V‐factor, marked urease and hemolysin formation, classified as Pasteurella‐like organisms or as Actinobacillus.It was shown that these strains from spontaneous pleuropneumonia in Switzerland and the DDR are identical and are closely related to H. pleuropneumoniae and to Actinobacillus species. On the basis of the degree of DNA: DNA hybridization and the described phenotypic and biochemical features the strains isolated by the authors are to be designated as Actinobacillus species.RésuméRecherches génotypiques sur des agents de pleuropneumonie hémorragique et nécrosante du porcSur la base de la détermination du taux GC et des résultats de recherche sur l'hybridation DNA: DNA, différentes souches de référence d'Actinobacillus et une souche sauvage d'Haemophilus pleuropneumoniae ont été comparées génotypiquement. Ces souches avaient été isolées en DDR et en Suisse à partir de foyers de pleuropneumonie hémorragique et nécrosante du porc mais se différenciaient nettement du point de vue morphologique en culture de H. pleuropneumoniae. Ces souches ont été tout d'abord classées taxonomiquement sur la base de l'absence de dépendance du facteur V, de l'uréase positive et de l'hémolyse comme Pasteurella haemolytica‐like‐organism et comme Actonobacillus.Il a pu être rnontré que ces souches bactériennes isolées de pleuropneumonies spontanées du porc en Suisse et en DDR sont identiques et étroitement apparentées à H. pleuropneumoniae et à des espèces d'Actinobacillus. On aimerait désigner les bactèries isolèes par nos soins comme Actinobacillus sp. sur la base du degré d'hybridation DNA: DNA et des caractères phénotypiques et biochimiques décrits des souches.ResumenEstudios genotípicos en gérmenes de la pleuropneumonía hemorrágico‐necrotizante del cerdoSobre la base de valoración del contenido de GC y de los resultados de investigación sobre la hibridación DNA: DNA, se compararon genotípicamente varias estirpes de referencia Actinobacillus y una cepa selvática o silvestre de Haemophilus pleuropneumoniae con bacterias aisladas en la RDA y en Suiza de explotaciones porcinas con pleuropneumonías hemorrágico‐necrotizantes, pero que divergían de manera inequívoca de H. pleuropneumoniae sobre todo en las características morfológicoculturales. Estas cepas se encuadraron taxonómicamente en un principio a causa de la dependica ausente del factor V, de la formación acusada de ureasa y hemólisis como organismos similares a Pasteurella haemolytica resp. como Actinobacillus. Pudimos poner en evidencia que estas estirpes bacterianas de pleuropneumonías porcinas espontáneas ubicadas en Suiza y la RDA son idénticas, teniendo relaciones estrechas de parentesco con H. pleuropneumoniae y las especies Actinobacillus. Sobre la base del grado de hibridación DNA: DNA y de las características fenotípicas y bioquímicas descritas de las cepas, quisiéramos designar las bacterias aisladas por nosotros como Actinobacillus sp.

A social psychological questionnair has been developed to study the effects of environmental noise and was applied to 636 people living in 19 different areas of Hamburg. The theoretical foundations and the statistical means employed in its development are described. Four main reactions to noise are isolated statistically, and it is determined that these are moderated by several intervening variables, chief of which are coping capacity for noise, the perceived dangerousness of the noise souce, other daily loads and the individual's liability.

Pasteurella multocida and P. haemolytica strains contain between 1.5 and three per cent phosphorus, between nine and 14 per cent nitrogen, between two and four per cent DNA, and between five and 18 per cent RNA, the precise figures depending on culturing conditions. High-molecular DNA may be isolated by means of bacteriolysis, using deoxycholate or dodecylsulphate and the usual steps of purification, with yield and purity differing by strains. DNA with sufficient purity can be obtained from Sepharose 2 B by gel chromatography. The isolated DNA yields were characterised, base values being between 37 and 38 per cent GC for P. haemolytica and between 41 and 48 per cent GC for P. multocida. Highly suitable precursors to DNA synthesis for tritium labelling are 3H-thymidine, which is incorporated in excess of 3H-thymine by a factor of 255, as well as 3H-uracil, with its activity being recovered also from the pyrimidine bases of DNA via pyrimidine biosynthesis.