Premature centromere division (PCD) identified in a hucul mare with reproductive difficulties

A hucul mare with reproductive abnormalities was examined during karyotype analysis. The karyotype was analysed based on evaluation of 860 metaphase plates in chromosome preparations. The use of fluorescence in situ hybridization (FISH) with an X chromosome painting probe showed premature X chromosome separation in 9.5% cases of examined chromosome spreads. In this report, we present the first identify premature centromere division (PCD) as a possible cause of abnormal X chromosome morphology in horses and as a probable cause of reproductive difficulties.     

Activity of selected glycosidases and availability of their substrates in bovine placenta during pregnancy and parturition with and without retained foetal membranes

The activity of glycosidases is crucial for the function and biological activity of proteins conjugated with sugar moieties, which play an important role in adhesion of cells during attachment and detachment of the foetal membranes. The aim of study was to describe the ability of bovine placental tissues to break down O-glycosidic bonds in different glycoproteins by the determination of activity of β-galactosidase, α-l-fucosidase, β-N-acetyl-hexosaminidase and sialidase in early–mid-pregnancy as well as at parturition with released and retained foetal membranes. Moreover, the availability of substrates for these glycosidases in placental homogenates was evaluated. Placental samples were collected from pregnant (2–4 months) cows in slaughterhouse (n = 8) as well as during Caesarean section and divided into released foetal membranes (n = 8) and retained foetal membranes (n = 8). Tissue homogenates were subjected to spectrofluorimetric and spectrophotometric determinations of enzyme activities as well as electrophoretic separations. Enzyme activities expressed changes within examined time with significant (p < .05) differences between pregnancy and physiological parturition in β-N-acetyl-hexosaminidase and α-l-fucosidase in foetal part of placenta while in maternal part only in the latter one. Decreasing tendency in enzyme activity was noticed in foetal part of retained samples in comparison with released ones with significant (p < .05) differences in α-l-fucosidase activity. The analysis of staining of sugar moieties attached to selected proteins depicted availability of sugar molecules in examined tissues, but their patterns differed between samples. In conclusion, sugar moieties in conjugated proteins express changes in the course of pregnancy which is reflected by the alterations in activities of placental glycosidases.     

Endotoxin-induced changes in expression of cyclooxygenase isoforms in the lamellar tissue of extracorporeally haemoperfused equine limbs

Angiogenesis and sepsis-related equine laminitis have several features in common. Both events can be induced by endotoxin (lipopolysaccharide— LPS) and both are associated with increased expression of the enzyme cyclooxygenase (COX), of which two isoforms (COX-1 and COX-2) exist. To examine the causal relationship between LPS exposure and COX expression and to investigate the tissue distribution of COX in the LPS-exposed tissue, the technique of extracorporeal haemoperfusion of isolated equine forelimbs was utilized. Perfusion was performed for 10 hr under physiological conditions (control-perfused limbs, n = 5) and with addition of 80 ng/L of endotoxin (LPS-perfused limbs; n = 5). After perfusion, samples of lamellar tissue were collected from the dorsal aspect of the hoof wall. Additional control samples were collected from three non-perfused limbs. Immunohistochemical analysis was performed using antibodies against COX-1 and COX-2, and intensity of immunohistochemical staining was scored for each isoform. In the lamellar tissue of control- and LPS-perfused limbs, there was no significant difference in COX-1 staining intensity and distribution, whereas COX-2 expression was significantly increased in LPS-perfused limbs (especially in endothelial cells, fibroblasts and intravasal leucocytes as well as in epidermal basal cells at the base of the primary epidermal lamellae). These results suggest that COX-2 and its metabolites are involved in the initiation of pathological changes seen in sepsis-associated events such as sepsis-related laminitis. In such cases, COX-2 could therefore be an important therapeutic target; however, early therapy may be required as increase in COX-2 expression occurs within 10 hr after LPS exposure.     

Niedermoore im nordostdeutschen tiefland Einführung

Die Auswirkungen von vier Kippsubstratvarianten des Lausitzer Braunkohlereviers (quartäre, tertiäre asche‐ bzw. kalkmeliorierte sowie quartäre Kippsubstrate über tertiärem Untergrund) auf die Stofffrachten der Sickerwässer aus einer 300 cm mächtigen Bodendecke wurden in den ersten zwei Jahren eines von 1992 bis 1996 laufenden Großlysimeterversuches geprüft. Im Unterschied zu den fast Trinkwasserqualität erreichenden Perkolaten quartärer Kippsubstrate, wiesen die Sickerwässer aus tertiären Substraten vor allem im ersten Versuchsjahr extrem hohe Schadstoffkonzentrationen auf, die bei Ni, Zn, Cr, As und Cd weit über den Grenzwerten für Trinkwasser lagen. Im zweiten Jahr nahmen die Schadstoffkonzentrationen zwar ab (z.B. Zn, As um 56%), lagen aber dennoch deutlich über den Grenzwerten.

Im Vergleich zur Kalkmelioration bewirkte die Aschemelioration der tertiären Kippsubstrate signifikant niedrigere Schwermetall‐, Arsen‐ und Stickstoffausträge sowie im ersten Versuchsjahr z.T. signifikant niedrigere Spezieskonzentrationen.

Der erwartete positive Einfluß der quartären Deckschicht aus Sand über tertiärem Untergrund konnte bisher nicht nachgewiesen werden. Bezogen auf die Schichtmächtigkeit der eingefüllten tertiären Kippsubstrate wurden vor allem im zweiten Jahr nach Abklingen der durch die Bodenumlagerung (Belüftung) verursachten stärkeren Oxidation der Sulfide bei dieser Variante vergleichsweise größere Schadstoffmengen (As, Zn, Ni, Pb) freigesetzt und ausgewaschen. Gleichzeitig nahmen die N_org‐Austräge zu, die wie die hohen NH₄ ⁺‐Frachten auf eine verstärkte oxidative Desaminierung im tertiären Untergrund hinweisen.     

Ein beitrag zur charakterisierung der Bodenveränderungen durch erosion im Jungmoränengebiet

Die Wassererosion, initiiert durch anthropogene Eingriffe durch Bodennutzung, führte zu veränderten Bodenprozessen und einer starken Bodenprofilverkürzung an konvexen und einer Sedimentakkumulation an konkaven Hangbereichen. Die Abtragsbilanz kann durch eine Bodenneubildung nicht annähernd ausgeglichen werden. Der Grad der Veränderung kann durch den Vergleich mit Waldböden der gleichen Genese und Morphologie im Landschaftsausschnitt bestimmt werden, da diese kaum eine Differenzierung zwischen konvexen und konkaven Hangbereichen aufweisen. Der Veränderungsgrad kann durch die Korngrößenzusammensetzung, die Entkalkungstiefe sowie den Gehalt an organischer Bodensubstanz eingeschätzt werden. Die Gehalte an C_org zeigen den Grad der erosionsbedingten Bodendegradierung sehr deutlich. Die Zusammensetzung der leicht abbaubaren OBS differiert viel weniger und wird offenbar durch die aktuelle Nutzung überprägt. An einer weiteren Aufklärung der Veränderung der organischen Bodensubstanz an erosionsbeeinflussten Hängen wird geforscht, weil dieser Parameter als ein wichtiger Indikator für den Zustand und die Degradierung der Böden angesehen werden kann.     

Nitrogen fertilization does not affect micronutrient uptake in grain maize (Zea mays L.)

Abstract

Due to continuous single nitrogen fertilization, we hypothesized a built-up deficiency of micronutrients in crops that would limit plant growth and crop quality. In 2-year field experiments using urea-N fertilized grain maize (Zea mays L.), hybrid KWS 2376 at 0, 120 and 240 kg N ha^?1 crop uptake of Zn, Mn, Cu and Fe was studied at DC 32, DC 61 and in the grain harvested. Micronutrient contents at DC 32 stage – 1st node (aboveground phytomass) and DC 61 – flowering (ear leaf) were all at levels indicative of adequate micronutrient supply to the crop. At both sampling occasions the Fe:Zn and Fe:Mn ratios were adequate implying that Fe did not inhibit the uptake of Zn and Mn. The application of nitrogen increased the Fe content at the 1st sampling in both years; in the second year the same was also the case for the Zn content. Nitrogen nutrition increased the contents of Mn and Fe at the 2nd sampling only in year 2; in the other treatments no changes were observed in the micronutrient contents. Micronutrient correlations in the grain were discovered between Zn and Mn contents and between Fe and Mn contents. In the second year the highest N-rate significantly increased the Fe and Zn content of the grain compared with the lower rates of nitrogen fertilization. Grain yields were not affected by the rate of nitrogen and ranged between 13.65 and 14.34 t ha^?1 (1st year) and between 13.68 and 14.18 t ha^?1 (2nd year). Nitrogen fertilization did not reduce the content of micronutrients in the plant or grain of maize. It is evident that the continuous single use of N fertilization so far has not resulted in a micronutrient deficiency of the plants limiting the nutrient density of the grain or reducing its quality.     

Microbial response of soils with organic and conventional management history to the cultivation of Bacillus thuringiensis (Bt)-maize under climate chamber conditions

An experiment was carried out in a climate chamber to analyse if Bt-maize may cause particular changes in soils with different levels of microbial biomass and activity due to long-term management history. Among the soils selected, the ones managed organically for 30 years exhibited twice the microbial biomass and 2.6 times the dehydrogenase activity (DHA) of the soil from a field with long-term conventional maize monoculture. Soils were cultivated twice in a row with Bt-maize, its near-isogenic line and a conventional breeding line. We tested the hypotheses that (a) soil microbial biomass and activity are affected by the cultivation of Bt-maize and that (b) the influence of Bt-maize depends on the level of soil microbial biomass and activity. Shoot and root yield and shoot C-content of Bt-maize were higher than the ones of the near-isogenic line. DHA under Bt-maize was 6 % higher, and the metabolic quotient for CO₂ (qCO₂) was 9 % lower than under its near-isogenic line, giving some support to hypothesis (a). No significant interactions of the soils and the varieties used were found in this study, thus hypothesis (b) was not confirmed, and soils with different microbial biomass and activity appear to react in a similar way to the cultivation of Bt-maize.