[The fate of fusarium toxins in the course of the synthesis of bioethanol from contaminated grain]. / Verhalten von Mykotoxinen bei der Ethanolerzeugung aus Getreide.

By means of a modelling experiment we followed the fate of deoxynivalenol (DON) and zearalenone (ZEA) in the production of bioethanol from grain.The experiment has been performed at the 'Versuchs- und Lehranstalt für Brauerei in Berlin e.V.' A total of 33 kg. triticale with a concentration of 3.2 mg/kg DON and 0.035 mg/kg ZEA were treated with water and enzymes which yielded the mash. By adding yeasts the mixture was then brought to formentation. Finally, the alcohol was obtained by destillation.The residue was dried by centrifugation to a content of 25% dry matter and put in silage tubes. In each part of the whole process test samples were taken and the content of DON and ZEA was determined. After three month the silage was scraped out from the tubes and analyzed, too. The mycotoxins were analyzed by HPLC with DAD and HPLC with fluorescence detection, corresponding to VDLUFA-methods.The balance of the mycotoxin contents showed no loss of DON in the process. For ZEA, however, a deficit of about 35% was noted. Because of the mass loss during starch fermentation (33 kg grain yield 8 kg draff) the mycotoxin contents were enhanced by a factor of 2 to 4.DON is well dissolved in water and therefore partially washed out by filtration of the mash. As the whole process is performed in practice as a cycle, the filtrate with DON is permanently recycled in the brewery process. Therefore the mycotoxin concentration in the original grain should not exceed the legal EU boundary values of 1.25 mg/kg DON and 0.1 mg/kg ZEA.

[Investigations of basic feed quality: Mycotoxins on maize for silage 1997-2003]. / Grundfutterqualität in Sachsen: Ergebnisse der mykotoxikologischen Untersuchungen an Silomais der Jahre 1997-2003.

Maize for silage purposes is investigated on Zeralenone (ZEA) and Deoxynivalenol (DON) in Saxony since 1997. About 45 samples from various regions of Saxony are analyzed every year. The occurrence of DON and ZEA was proved for 20 to 90% of all samples. Most of the samples showed both of these toxins. The quantity of the detected toxins was generally very low, even in so called "Fusarium years" only 20% of samples exceeded the lowest border of orientation values for critical dietary concentrations in cattle feed. We observed a higher contamination with DON in samples from the region "Erzgebirge" and clear higher contents of ZEA in the region "Sächsisches Heideland". Correlation between toxin content and other parameters like cultivation, pre-fruit etc. were not observed, probably because of masking these effects by variety and location.

AlgR-binding sites within the algD promoter make up a set of inverted repeats separated by a large intervening segment of DNA.

Activation of algD by AlgR is essential for mucoidy, a virulence factor expressed by Pseudomonas aeruginosa in cystic fibrosis. Two AlgR-binding sites, RB1 and RB2, located far upstream from the algD mRNA start site, are essential for the high-level activity of algD. However, the removal of RB1 and RB2 does not completely abolish inducibility of algD in response to environmental signals. In this work, a third binding site for AlgR, termed RB3, near the algD mRNA start site was characterized. Deletion of RB3 abrogated both the AlgR-binding ability and the residual inducibility of the algD promoter. DNase I footprinting analysis of RB3 resulted in a protection pattern spanning nucleotides -50 to -30. Eight of 10 residues encompassing a continuous region of protection within RB3 (positions -45 to -36) matched in the inverted orientation the conserved core sequence (ACCGTTCGTC) of RB1 and RB2. Quantitative binding measurements of AlgR association with RB1, RB2, and RB3 indicated that AlgR had significantly lower affinity for RB3 than for RB1 and RB2, with differences in the free energy of binding of 1.05 and 0.93 kcal/mol (4.39 and 3.89 kJ/mmol), respectively. Altering the core of RB2 to match the core of RB3 significantly reduced AlgR binding. Conversely, changing the core of RB3 to perfectly match the core of RB2 (mutant site termed RB3*) improved AlgR binding, approximating the affinity of RB2. RB3*, in the absence of the far upstream sites, showed an increase in activity, approaching the levels observed with the full-size algD promoter. Changing 4 nucleotides in two different combinations within the core of RB3 abolished the binding of AlgR to this site and resulted in a significant reduction of promoter activity in the presence of the far upstream sites. Thus, (i) the core sequence is essential for AlgR binding; (ii) the three binding sites, RB1, RB2, and RB3, are organized as an uneven palindrome with symmetrical sequences separated by 341 and 417 bp; and (iii) all three sites participate in algD activation.

Osmotic adjustment in sorghum: I. Mechanisms of diurnal osmotic potential changes.

Osmotic adjustment, defined as a lowering of osmotic potential (psi(pi)) due to net solute accumulation in response to water stress, has been considered to be a beneficial drought tolerance mechanism in some crop species. The objective of this experiment was to determine the relative contribution of passive versus active mechanisms involved in diurnal psi(pi) changes in sorghum (Sorghum bicolor L. Moench) leaf tissue in response to water stress. A single sorghum hybrid (cv ATx623 x RTx430) was grown in the field under variable water supplies. Water potential, psi(pi), and relative water content were measured diurnally on expanding and the uppermost fully expanded leaves before flowering and on fully expanded leaves during the grain-filling period. Diurnal changes in total osmotic potential (Deltapsi(pi)) in response to water stress was 1.1 megapascals before flowering and 1.4 megapascals during grain filling in comparison with 0.53 megapascal under well-watered conditions. Under water-stressed conditions, passive concentration of solutes associated with dehydration accounted for 50% (0.55 megapascal) of the diurnal Deltapsi(pi) before flowering and 47% (0.66 megapascal) of the change during grain filling. Net solute accumulation accounted for 42% (0.46 megapascal) of the diurnal Deltapsi(pi) before flowering and 45% (0.63 megapascal) of the change during grain filling in water-stressed leaves. The relative contribution of changes in nonosmotic volume (decreased turgid weight/dry weight) to diurnal Deltapsi(pi) was less than 8% at either growth stages. Water stress did not affect leaf tissue elasticity or partitioning of water between the symplasm and apoplasm.

Osmotic Adjustment in Sorghum: II. Relationship to Gas Exchange Rates.

Lowering of the solute potential by osmotic adjustment (OA) has been proposed to allow maintenance of leaf turgor potential (Psi(p)), stomatal conductance (g), and photosynthesis (A) at low leaf water potential. However, literature concerning the role of OA in the maintenance of g and A under water stress is limited and often contradictory. The objective of this experiment was to examine the association of OA with g and A in grain sorghum (Sorghum bicolor L. Moench). A single sorghum hybrid (cv ATx623 x RTx430) was studied under field conditions using four different water supplies. Diurnal and midday water potential, solute potential, Psi(p), OA, g, and A were measured during preflowering and grain-filling growth stages. A second experiment was conducted under greenhouse conditions. Two sorghum genotypes (BTx623 and BTx378) differing in their g and A responses to plant water stress were compared for their OA capacity during a water deficit cycle imposed from the beginning of panicle initiation through flowering. Under both field and greenhouse conditions, g and A rapidly declined with increased water stress despite the occurrence of OA. Under greenhouse conditions, BTx623 maintained significantly higher g and A than BTx378 during the water stress cycle. However, no significant differences in OA or Psi(p) existed between the two genotypes, indicating that OA was not associated with differences observed in g and A between these genotypes. We conclude that the response of g and A to water stress was not directly associated with OA and certainly was not maintained by OA.

Leaf photosynthetic rate is correlated with biomass and grain production in grain sorghum lines.

Significant genetic variation in leaf photosynthetic rate has been reported in grain sorghum [Sorghum biocolor (L.) Moench]. The relationships between leaf photosynthetic rates and total biomass production and grain yield remain to be established and formed the purpose of this experiment. Twenty two grain sorghum parent lines were tested in the field during the 1988 growing season under well-watered and water-limited conditions. Net carbon assimilation rates were measured at mid-day during the 30 day period from panicle initiation to head exertion on upper-most fully expanded leaves using a portable photosynthesis system (LI-6200). Total biomass and grain production were determined at physiological maturity. The lines exhibited significant genetic variation in leaf photosynthetic rate, total biomass production and grain yield. Significant positive correlations existed between leaf photosynthesis and total biomass and grain production under both well-watered and water-limited conditions. The results suggest that leaf photosynthetic rate measured prior to flowering is a good indicator of productivity in grain sorghum.

Molecular analysis of hemolytic and phospholipase C activities of Pseudomonas cepacia.

By using a gene-specific fragment from the hemolytic phospholipase C (PLC) gene of Pseudomonas aeruginosa as a probe and data from Southern hybridizations under reduced stringency conditions, we cloned a 4.2-kb restriction fragment from a beta-hemolytic Pseudomonas cepacia strain which expressed hemolytic and PLC activities in Escherichia coli under the control of the lac promoter. It was found, by using a T7 phage promoter-directed expression system, that this DNA fragment carries at least two genes. One gene which shares significant DNA homology with both PLC genes from P. aeruginosa encodes a 72-kDa protein, while the other gene encodes a 22-kDa protein. When both genes on the 4.2-kb fragment were expressed from the T7 promoter in the same cell, hemolytic and PLC activities could be detected in the cell lysate. In contrast, when each individual gene was expressed in different cells or when lysates containing the translated products of each separate gene were mixed, neither hemolytic activity nor PLC activity could be detected. Clinical and environmental isolates of P. cepacia were examined for beta-hemolytic activity, PLC activity, sphingomyelinase activity, and reactivity in Southern hybridizations with a probe from P. cepacia which is specific for the larger gene which encodes the 72-kDa protein. There were considerable differences in the ability of the different strains to express hemolytic and PLC activities, and the results of Southern DNA-DNA hybridizations of the genomic DNAs of these strains revealed considerable differences in the probe-reactive fragments between high- and medium-stringency conditions as well as remarkable variation in size and number of probe-reactive fragments among different strains. Analysis of the genomic DNAs from hemolytic and nonhemolytic variants of an individual strain (PC-69) by agarose gel electrophoresis. Southern hybridization, and transverse alternating pulsed field gel electrophoresis suggests that the conversion of the hemolytic phenotype to the nonhemolytic phenotype is associated with either the loss of a large plasmid (greater than 200 kb) or a large deletion of the chromosome of P. cepacia PC-69.

Genetic variation for gas exchange rates in grain sorghum.

Carbon assimilation rate (A) and stomatal conductance (g) are highly correlated. However, the slope of the A versus g relationship differs among species and environments resulting in differences in gas exchange efficiency which should reflect water use efficiency. The objective of this research was to determine the genetic variation for A and g in grain sorghum (Sorghum bicolor [L.] Moench.). Field experiments were conducted using 30 sorghum hybrids with four water supply treatments. A, g, and leaf water potential (Psi(w)) of individual leaves were monitored every 15 to 20 days. Significant genetic variation existed among the hybrids for A and g. Plant age and water supply also affected A and g as expected. When A was regressed on g for each hybrid, large and significant differences existed among the slopes, implying differences in intrinsic gas exchange efficiency. The regression analysis of A and g versus Psi(w) suggested that A was more sensitive than g to increasing water stress. Genetic differences in the rate of change in A as water stress increased were observed. Regression analysis was used to evaluate the individual hybrid response relative to other hybrids. Twofold difference in slopes existed for A. These results provide evidence for genetic variation in gas exchange rates which might directly contribute to whole plant water use efficiency and productivity.

Resistance of mucoid Pseudomonas aeruginosa to nonopsonic phagocytosis by alveolar macrophages in vitro.

A unique, recently described rat alveolar macrophage cell line (NR8383) was used to study the interaction of the pulmonary immune system with a mucoid cystic fibrosis isolate of Pseudomonas aeruginosa (SRM-3), its nonmucoid revertant (SRM-3R), and a non-cystic fibrosis isolate (PAO-1). Strain SRM-3 was cultivated in a chemostat system to allow maintenance of an entirely mucoid population. The alveolar macrophage response to the mucoid and nonmucoid strains of P. aeruginosa was determined by visually quantitating phagocytosis in acridine orange-stained monolayers and measuring the induction of an oxidative burst as indicated by chemiluminescence and H2O2 production. In all experiments, fewer than 2% of the NR8383 cells engulfed the mucoid SRM-3 isolate, while SRM-3R and PAO-1 were phagocytized by 15 and 41%, respectively. Opsonization by normal serum (complement) provided minimal phagocytic enhancement of these strains, whereas specific anti-P. aeruginosa antibody slightly elevated phagocytic responses to strains with nonmucoid phenotypes while providing a sevenfold increase in uptake of SRM-3. Chemiluminescent and H2O2 responses were comparable with the levels of phagocytosis observed, with very little or no response to the mucoid strain SRM-3. The data indicate that the strains with mucoid phenotypes are refractile to ingestion and that studies which describe ingestion of mucoid strains were likely measuring ingestion of revertants. Alginic acid (2 mg/ml) was found to inhibit stimulation of macrophage response to the opsonized and unopsonized nonmucoid strain PAO-1.

Phosphorylcholine stimulates capsule formation of phosphate-limited mucoid Pseudomonas aeruginosa.

Production of both alginic acid and lipopolysaccharide by a mucoid strain of Pseudomonas aeruginosa, SRM-3, was studied in a chemostat system during growth under nutrient-limiting conditions chosen to reflect the chronic growth conditions in the lungs of cystic fibrosis patients. Since mucoid strains have been shown to elaborate extracellular proteases and phospholipase C, nitrogen and phosphate limitation were selected for analysis. A modified alginate-promoting medium containing either 1 mM glutamate or 0.05 mM K2HPO4 as limiting nutrient and doubling times of 1.6 to 15.7 h were used. Under nitrogen limitation, strain SRM-3 produced 1.4 mg of uronic acid per mg (dry weight) of cells at all doubling times studied. However, phosphate limitation resulted in the synthesis of only 0.4 mg of uronic acid per mg (dry weight) of cells. The role of phosphate in alginic acid polysaccharide production was further investigated by using phosphorylcholine, a product of phospholipase C activity on phosphatidylcholine, the major lung surfactant. No only were mucoid cells capable of utilizing phosphorylcholine for growth, but a highly specific interaction occurred among phosphorylcholine, alginate, and whole cells, resulting in greatly enhanced culture viscosity. Electron micrographs showed the gradual formation of a capsule during growth on phosphorylcholine, indicating that the mucoid strain has the ability to utilize surfactant not only as a nutrient source but also for constructing a capsule with greatly enhanced adhesive properties.

Aeration selects for mucoid phenotype of Pseudomonas aeruginosa.

A mucoid strain of Pseudomonas aeruginosa isolated from a patient with cystic fibrosis and its nonmucoid revertant were grown in a chemically defined alginate-promoting medium under batch and continuous culture conditions. Selection for the mucoid and nonmucoid phenotype was accomplished by varying the levels of air available to the culture. The addition of air at a rate of 0.5 liters/min to the nonmucoid revertant growing under batch or continuous culture conditions resulted in a greater than 50% decrease in viability over a 10-h incubation period. In contrast, aeration of the mucoid culture maintained a totally mucoid population and there was no decrease in viability over a 55-h incubation. Aeration of a mixed population of the mucoid and nonmucoid phenotype (1:1) resulted in selection for the mucoid phenotype within the first 20 h of cocultivation. The correlation between the mucoid phenotype and alginic acid was demonstrated by the production of 580 micrograms of uronic acid per mg (dry weight) of cells by the mucoid phenotype and less than 1 microgram of uronic acid per mg (dry weight) of cells by the nonmucoid revertant. These results suggest that nonmucoid revertants may have an unusual sensitivity to aeration, which may indicate a mechanism for natural selection of the mucoid phenotype in vivo.

[Multicenter study of the results of the extraction of transvenously implanted heart-pacemaker electrodes using continuous traction]. / Multizentrische Studie zu Ergebnissen der Extraktion transvenös implantierter Herzschrittmacherelektroden mittels Dauerzuges.

The continuous traction of firmly grown-in collar electrodes from the right ventricle is a simple technique poor in complications with a high success rate, which can be recommended taking into consideration the indications in the failure of the immediate manual extraction and which can be performed in every centre for cardiac pacemakers. Apart from the consideration of adequate informations in literature this evidence above all depends on the evaluation of data of 29 cases from 10 centres for cardiac pacemakers.

Photosynthetic rate control in cotton : stomatal and nonstomatal factors.

The relationship between single leaf photosynthesis and conductance was examined in cotton (Gossypium hirsutum L.) across a range of environmental conditions. The purpose of this research was to separate and define the degree of stomatal and nonstomatal limitations in the photosynthetic process of field-grown cotton.Photosynthetic rates were related to leaf conductance of upper canopy leaves in a curvilinear manner. Increases in leaf conductance of CO(2) in excess of 0.3 to 0.4 mole per square meter per second did not result in significant increases in gross or net photosynthetic rates. No tight coupling between environmental influences on photosynthetic rates and those affecting conductance levels was evident, since photosynthesis per unit leaf conductance did not remain constant. Slowly developing water stress caused greater reductions in photosynthesis than in leaf conductance, indicating nonstomatal limitations of photosynthesis.Increases in external CO(2) concentration to levels above ambient did not produce proportional increases in photosynthesis even though substomatal or intercellular CO(2) concentration increased. The lack of a linear increase in photosynthetic rate in response to increases in leaf conductance and in response to increases in external CO(2) concentration demonstrated that nonstomatal factors are major photosynthetic rate determinants of cotton under field conditions.

Photosynthetic rate control in cotton : photorespiration.

The purpose of this research was to determine the magnitude of photorespiration in field-grown cotton (Gossypium hirsutum L.) as a function of environmental and plant-related factors. Photorespiration rates were estimated as the difference between measured gross and net photosynthetic rates.A linear increase in photorespiration was observed as air temperature increased from 22 to 40 degrees C at saturating photon flux density. At 22 degrees C, photorespiration was less than 15 per cent of net photosynthesis and very comparable to the dark respiration rate. At 40 degrees C, photorespiration represented about 50 per cent of net photosynthesis. Gross photosynthesis had a temperature optimum of 32 to 34 degrees C. Water stress, as indicated by Psi(L), did not alter the ratio of gross photosynthesis to net photosynthesis when the confounding effects of leaf temperature differences were accounted for in the data analyses. A reduction in both gross and net photosynthesis was apparent as Psi(L) declined from -2.0 megapascals indicating direct effects of water stress on the photosynthetic process. Photorespiration expressed as a proportion of net photosynthesis increased as water stress intensified.Cotton cultivars possessing a fruit load had significantly higher gross and net photosynthetic rates and lower photorespiration rates than did photoperiod-sensitive cotton strains without a fruit load. Within the fruiting types, which were genetically very similar, only minor differences were observed in the photorespiration:net photosynthesis ratios. However, in the photoperiod-sensitive strains, considerable genetic variability existed when photorespiration was expressed as a proportion of net photosynthesis. These results suggest that the kinetics of ribulose-1,5-bisphosphate carboxylase:oxygenase may be different and, thus, the possibility of genetically reducing photorespiration exists.

Relative sensitivity of photosynthetic assimilation and translocation of carbon to water stress.

The relationship between photosynthesis and translocation rate changes as affected by water stress intensity and stage of plant development was evaluated in cotton and sorghum, representing a C(3) and a C(4) photosynthetic type, respectively. Photosynthetic rates were reduced as midday leaf water potentials declined from -14 to -27 bars in both species. Sorghum maintained higher photosynthesis and translocation rates compared to cotton at comparable leaf water potentials; however, the rate of change per bar decline in water potential was greater in sorghum than in cotton. Photosynthetic rates were reduced with increasing water stress prior to any significant change in translocation rates suggesting that photosynthesis is the more sensitive of the two processes. Severe water stress, corresponding to leaf water potentials of -27 bars, did not completely inhibit either photosynthesis or translocation.

Stomatal and nonstomatal regulation of water use in cotton, corn, and sorghum.

Stomata of corn (Zea mays L.) and sorghum (Sorghum bicolor L.) responded to changes in leaf water potential during the vegetative growth phase. During reproductive growth, leaf resistances were minimal and stomata were no longer sensitive to bulk leaf water status even when leaf water potentials approached -27 bars. Stomata of corn, cotton (Gossypium hirsutum L.), and sorghum appear to respond to changes in the humidity deficit between the leaf and air and in this manner, regulated transpirational flux to some degree. Distinct differences in water transport efficiency were observed in the three species. Under nonlimiting soil water conditions, sorghum exhibited the greatest efficiency of water transport while under limiting soil moisture conditions, cotton appeared most efficient. Corn was the least efficient with respect to nonstomatal regulation of water use. Differences in drought tolerance among the three species are partially dependent on stomatal regulation of water loss, but efficiency of the water transport system may be more related to drought adaptation. This is particularly important since stomata of all three species did not respond to bulk leaf water status during a large portion of the growing season.

Prognosis of chronic hepatitis.

The morbidity by viral hepatitis within the municipal and rural district of Eisenhüttenstadt with 66 211 inhabitants from 1960 t0 1970 amounts to 19.45 +/- 1.06%. The transition into chronic hepatitis appears in 5.5 per cent in 1 283 controlled cases of illness. Contrary to the acute viral hepatitis the numbers of illness by chronic hepatitis are increasing with proceeding age (0.3 per cent up to 14 per cent). The prognosis of viral hepatitis is altogether favorable. 84.1 per cent are healing completely primarily without any subsequences and 4.4 per cent are followed by defective states. The chronic persisting hepatitis heals in more than the half of the cases, mostly after a duration of two till five years of illness. The tendency to heal is significantly stronger in children and adolescents than in adults. The chronic aggressive hepatitis has an unfavorable prognosis. In the development of the cirrhosis of the liver (0.5 per cent) additional noxes are playing a role. The alcohol shows an unfavorable influence on the course of the illness (0.7 per cent). A hyperbilirubinemia does not appear essentially more frequently than in the normal population. The prospective character of the study in not selected patients imparts to these findings a real epidemiological sentential power.