Einfluß von Epicoccum nigrum,Alternaria alternata,Mucor racemosus und Ulocladium chartarum auf die Protozoenpopulation im Pansen des Rindes (in vitro)

The influence of moulded hay (Alternaria alternata, Epicoccum nigrum, Mucor racemosus, Ulocladium chartarum) and the efficiency of Vitamin B1 substitution to cope these effects on rumen protozoa was investigated using the longterm rumen simulation technique (RUSITEC) for about 25 days. Moulded hay affected medium-sized protozoa to a different extent (Alternaria alternata: ?16 %, Epicoccum nigrum: ?27 %, Mucor racemosus: ?9 %, Ulocladium chartarum: +2 %). The vitamin B1 substitution had positive effects during the feeding of Mucor racemosus and Ulocladium chartarum.     

Moniliformin,deoxynivalenol, 3Acetyldeoxynivalenol and zearalenone — Mycotoxins associated with corn cob fusariosis in Poland

An isolated rat liver was perfused with deoxynivalenol (DON) at a dose of 3 mg in a recirculating perfusion system. To identify glucuronide conjugates equal amounts of bile samples, perfusate and liver homogenates were incubated with and without (control) a β-glucuronidase preparation and analyzed by thin layer chromatography and capillary gas liquid chromatography — chemical ionization mass spectrometry. A total of 40.4% of the administered dose of DON was found to be conjugated with glucuronic acid (perfusate 20.4%, bile 19.2%, liver 0.8%), while only 1.3% of the parent DON (perfusate 1.1%, bile 0.2%) was detected. The cleavage of DON-glucuronide was demonstrated by incubating DON-glucuronide containing bile samples with intestine contents under anaerobic conditions.     

Differential Postnatal Development of Monoamine Oxidases A and B in the Blood-Brain Barrier of the Rat

Abstract: We studied the monoamine metabolizing mitochondrial enzyme, monoamine oxidase (MAO), in cerebral microvessels obtained from postnatally developing rats by measuring the specific binding of [³H]pargyline, an irreversible inhibitor of MAO, and the rate of oxidation of three known MAO substrates: benzylamine, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and tryptamine. MAO activity increased postnatally, with the greatest increase occurring in the second week and reaching a peak at 3 weeks of age. A concomitant increase in MAO of the cerebral cortex also occurred, but was several-fold less than that of cerebral microvessels. Using clorgyline and deprenyl, relatively specific inhibitors of MAO-A and MAO-B, we showed that cerebral microvessels contain both forms of MAO at all ages, but there was a major preponderance in the postnatal development of MAO-B. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analyses of rat microvessels after [³H]pargyline binding also showed two distinct bands of radioactivity at all ages. These two bands corresponded to molecular weights of ∼6.5,000 for MAO-A and -60,000 for MAO-B. SDS-PAGE resuits of brain microvessels obtained from 1-, 14-, and 42-day-old rats confirm the differential postnatal development of MAO-B in rat brain microvessels.     

Evidence for a sex pheromone metabolizing cytochrome P-450 mono-oxygenase in the housefly

Direct evidence is presented for the role of a cytochrome P-450 monooxygenase (called mixed-function oxidase, or polysubstrate mono-oxygenase, PSMO) in the metabolism of the sex pheromone (Z)-9-tricosene to its corresponding epoxide and ketone in the housefly. A secondary alcohol, most likely an intermediate in the conversion of the alkene to the ketone, was also tentatively identified. The results of in vivo and in vitro experiments showed that the PSMO inhibitors, piperonyl butoxide (PB) and carbon monoxide, markedly inhibited the formation of epoxide and ketone from (9,10-³H) (Z)-9-tricosene. An examination of the relative rates of (Z)-9-tricosene metabolism showed that males exhibited a higher rate of metabolism than females with the antennae of males showing the highest activity of any tissue/organ examined. The major product from all tissues/organs was the epoxide. Data from experiments with subcellular fractions showed that the microsomal fraction had the majority of enzyme activity, which was strongly inhibited by PB and CO and required NADPH and O₂ for activity. A carbon monoxide difference spectrum with reduced cytochrome showed maximal absorbance at 450 nm and allowed quantification of the cytochrome P-450 in the microsomal fraction of 0.410-nmol cytochrome P-450 mg^?1 protein. Interaction of (Z)-9-tricosene with the cytochrome P-450 resulted in a type I spectrum, indicating that the pheromone binds to a hydrophobic site adjacent to the heme moiety of the oxidized cytochrome P-450.     

Morphology and Taxonomy of <Emphasis Type="Italic">Apristurus longicephahis</Emphasis> (Lamniformes,Seyliorhinidae)

Data on the individual variation and changes with growth in proportions and morphology are presented for the poorly known Apristurus longicephalus, and compared with those of other species. A. longicephalus is concluded to be a distinct species without synonyms, characterized by its long snout, widely separate nostrils, long caudal fin, short abdomen, very sparse teeth, and low number of monospondylous vertebrae. It is a species of small size, maturing at about 42 cm in total length.     

Scale Growth and Squamation Chronology for the Laboratory-Reared Hermaphroditic Fish <Emphasis Type="Italic">Rivulus marmoratus</Emphasis> (Cyprinodontidae)

Scale morphology, growth and the squarnation chronology are described for the hermaphroditic fish Rivulus marmoratus reared in the laboratory. The scales are round or oval shaped cycloid type, and their sizes are about 0.3–1.0 mm in diameter. The number of ridges increases more rapidly relative to the body growth of the fish in early stages, but this increase is proportionate to growth subsequently. Three loci of scale development have been identified. The scales first appeared on the center of the parietal region at 8 days after hatching. The second locus of scale formation was on the lateral line of the posterior end of the caudal peduncle. A third locus was later observed on the lower right corner of the operculum: The final squamation was completed at 6 weeks after hatching.     

Cultural characteristics and zearalenone production by strains of<Emphasis Type="Underline">Fusarium</Emphasis> from wheat

Conidia of the speciesFusarium culmorum /W.G.Sm./ Sacc. andFusarium graminearum Schwabe are characterized by variability in zearalenone production and dimensions depending on the substrate. The sporulation of isolates from some wheat eultivars have been deprived in vivo and in vitro in the first passage, but not their pathogenicity and toxic metabolites production. Nonsporulating strains produced lower quantités of zearalenone than sporulating ones. Liquid filtrates of such nonsporulating strains had a high phytotoxic effect on wheat caryopses. The crystalline toxin DAS /0,25 ug/ml/ had low phytotoxic effect on wheat caryopses.