Effect of dietary Schizochytrium microalga oil and fish oil on plasma cholesterol level in rats

The purpose of the study was to test the hypothesis that the dietary oils with different content of n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) affect plasma lipid level in rats in a different degree. The diets with 6% of fish oil (FO) and Schizochytrium microalga oil (SchO; EPA+DHA content in the diets 9.5 + 12.3 and 2.6 + 29.5% of the sum of total fatty acids, respectively) were used; the diet with 6% of safflower oil (high content of n‐6 PUFA linoleic acid, 65.5%; EPA+DHA content 0.7 + 0.9%) was used as a control. The difference between FO and SchO was established only in the case of plasma triacylglycerol (TAG) level: plasma TAG of the FO‐fed rats did not differ from the control rats (p > 0.05), while SchO decreased (p < 0.05) plasma TAG to 46% of the control. On the other hand, FO and SchO decreased (p < 0.05) total plasma cholesterol (TC) in rats in the same extent, to 73% of the control. Regarding the underlying mechanisms for the TC decrease, both SchO and FO up‐regulated hepatic Insig‐1 gene (181 and 133% of the control; p < 0.05), which tended (p = 0.15 and p = 0.19 respectively) to decrease the amount of hepatic nSREBP‐2 protein (61 and 66% of the control). However, neither SchO nor FO influenced hepatic 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase gene expression (p > 0.05); SchO (but not FO) increased (p < 0.05) low‐density lipoprotein receptor mRNA in the liver. It was concluded that the decrease of total plasma cholesterol might be caused by an increased cholesterol uptake from plasma into the cells (in the case of SchO), but also by other (in the present study not tested) mechanisms.     

The effect of Lumbricus rubellus and Lumbricus terrestris on zinc distribution and availability in artificial soil columns

This study investigated the impact of epigeic and (epi)anecic earthworms on the distribution and availability of zinc in the soil profile. Experiments were carried out with Lumbricus rubellus and Lumbricus terrestris in perspex columns (Ø 10 cm), filled with 20 to 23 cm non-polluted soil [organic matter 2%, clay 2.9%, pH 6.4 (0.01 M CaCl₂)], that was covered by a 3- to 5-cm layer of aged zinc-spiked soil (500 mg Zn/kg dry soil) and another 2 cm non-polluted soil on top. After 80 days, columns were sacrificed and sampled in a depth profile. Earthworm casts, deposited on top of the soil, were collected. Each sample was analyzed for total and 0.01 M CaCl₂-exchangeable zinc concentrations. L. rubellus did not go deeper than 3 cm into the soil and therefore no effect on zinc distribution in the soil could be detected. For L. terrestris, total zinc concentrations in the non-polluted layers were slightly but significantly higher in columns with earthworms, and so were the CaCl₂-exchangeable zinc concentrations in the polluted layers of these columns. Casts of L. terrestris collected from the soil surface showed higher total zinc concentrations than those from non-polluted soil. Casts were mainly placed on top of the soil. This study showed that these epigeic and (epi)anecic species have only a slight effect on zinc availability, and that deep burrowing species, like L. terrestris, are able to transport polluted soil from deeper layers to the soil surface.     

The effect of two endogeic earthworm species on zinc distribution and availability in artificial soil columns

The objective of this study was to determine the impact of earthworm bioturbation on the distribution and availability of zinc in the soil profile.Experiments were carried out with Allolobophora chlorotica and Aporrectodea caliginosa in 24 perspex columns (∅ 10 cm), filled with 20-23 cm non-polluted soil (OM 2%, clay 2.9%, pH 0.01 M CaCl₂ 6.4), that was covered by a 3-5 cm layer of aged zinc spiked soil (500 mg Zn/kg dry soil) and another 2 cm non-polluted soil on top. After 80 and 175 days, columns were sacrificed and each cm from the top down to a depth of 15 cm was sampled. Earthworm casts, placed on top of the soil, were collected. Each sample was analyzed for total and CaCl₂-exchangeable zinc concentrations.Effects of earthworm bioturbation were most pronounced after 175 days. For A. chlorotica, total and CaCl₂-exchangeable zinc concentrations in the polluted layers were lower with than without earthworms. Total zinc concentrations in the non-polluted layers were higher in columns with earthworms. Casts of A. chlorotica collected on the soil surface showed slightly higher total zinc concentrations than non-polluted soil. Casts were found throughout the whole column. For A. caliginosa there were no differences in total zinc concentration between columns with and without earthworms. CaCl₂-exchangeable zinc concentrations in the polluted layers were lower for columns with earthworms. Casts were mainly placed on top of the soil and contained total zinc concentrations intermediate between those in non-polluted and polluted soil layers.This study shows that different endogeic earthworm species have different effects on zinc distribution and availability in soils. A. chlorotica transfers soil throughout the whole column, effectively mixing it, while A. caliginosa decreases metal availability and transfers polluted soil to the soil surface.     

Species-specific earthworm population responses in relation to flooding dynamics in a Dutch floodplain soil

Earthworms dominate the animal biomass in moist floodplain soils. They are known to survive long periods in aerated water, but little is known about earthworm population dynamics in floodplain systems with changing inundation frequencies. This study determined earthworm population dynamics in a floodplain system, in relation to frequency and duration of flooding events. From October 2000 to May 2003 earthworms were hand sorted in the ‘Afferdensche en Deestsche Waarden’, a floodplain on the south bank of the river Rhine, near Druten, The Netherlands. Earthworm numbers and biomasses per age class (adult, subadult, juvenile) were recorded. Numbers and biomasses tend to decrease during flooding. Lumbricus terrestris was found in high numbers (>10/m²) only at the end of a flooding period. Allolobophora chlorotica was hardly affected by flooding; their biomass remained stable during the year. Aporrectodea caliginosa showed fluctuating numbers and biomasses during the sampling period that did not correlate with flooding frequency. Numbers and biomasses of Lumbricus rubellus were strongly reduced at the end of each flooding event, but their population densities fully recovered until next flooding event. Earthworm populations in floodplains fluctuate in time, depending on the season and on the time, duration and frequency of flooding. Different earthworm species react differently towards these flooding dynamics.     

Biological control of trichostrongyles in calves by the fungus Duddingtonia flagrans fed to animals under natural grazing conditions

The present study was conducted in the 1993 grazing season with yearling calves exposed to a pasture with a natural mixed trichostrongyle larval infection. It was shown that daily feeding with the microfungus Duddingtonia flagrans during the first 2 months of the season led to a lowered herbage infectivity and a reduced acquisition of Ostertagia sp. and Cooperia sp. later in the season. In addition, the procedure delayed the onset of clinical disease. This was due to the nematode-destroying effects of the fungi in the dung excreted by the fungus-treated calves, as evidenced by results from a parallel in vitro assay on faecal larval cultures. The paper discusses future research needs before practical biological control can be implemented.     

ULTRASONIC DIAGNOSIS OF OVARIAN CYSTS IN TEN GUINEA PIGS

Ten guinea pigs with an ovarian cyst had clinical signs of anorexia, alopecia, or depression. Ultrasonographic features of the 2- to 3-cm diameter fluid-filled cysts included compartmentalization and connection to the ovary. In two animals, a unilateral cyst was present, and in two others, the cysts were bilateral. Diagnosis of the disease by plain radiography is difficult because of the similar opacity of ovarian cysts, abdominal neoplasms, and trichobezoars.     

Transplantation of CD6-depleted peripheral blood stem cells after DLA-haploidentical bone marrow transplantation contributes to engraftment and tolerance in a preclinical model of stem cell transplantation

Human leukocyte antigen (HLA)-haploidentical stem cell transplantation is an opportunity for nearly all patients lacking an HLA matched stem cell donor. However, graft rejection and graft-versus-host disease (GvHD) as well as infectious complications still result in high treatment-related mortality. Here, we used the dog as a preclinical model for the study of tolerance induction with the aim to optimize and to improve a clinical protocol of haploidentical stem cell transplantation. For this purpose CD6-depleted peripheral blood stem cells (PBSCs) were transfused 6d after transplantation of unmodified bone marrow from dog leukocyte antigen (DLA)-haploidentical littermate donors in order to induce immune tolerance. Besides hematopoietic stem cells CD6-depleted PBSC contain, NK cells and a minority of suppressive CD8-positive cells that may suppress activated T lymphocytes. Recipients were conditioned with, cyclophosphamide and antithymocyte globulin (ATG) preceded by a transfusion of donor buffy coat and either 1, 2 or 3 × 3.3 Gy total body irradiation (TBI). Postgrafting immunosuppression was limited to 30 d of cyclosporine and methotrexate. The additional administration of CD6-depleted PBSCs after unmodified marrow could not prevent GvHD, but it may improve engraftment and chimerism after conditioning with 2 × 3.3 Gy TBI. Reasons for incomplete suppression and possible improvements for clinical applications are discussed.     

Predacious activity of the nematode-trapping fungus Duddingtonia flagrans against cyathostome larvae in faeces after passage through the gastrointestinal tract of horses

This study was undertaken to examine the potential of the nematode-trapping microfungus Duddingtonia flagrans to survive passage through the gastrointestinal tract of horses and subsequently to destroy free-living stages of cyathostomes in faecal cultures. Three different oral dose levels were tested, two horses being used for each level. Faeces were collected twice daily and the number of parasite eggs per gram of faeces were determined. The numbers of infective third stage larvae which developed in faecal cultures were determined after the cultures had been incubated for 2 weeks at 24°C. Results showed a positive relationship between dose level and reduction in the number of infective larvae. Fungi were recovered in faeces at times which corresponded to high larval reduction.     

Untersuchungen zur Charakterisierung des pflanzenverfügbaren Phosphats in Thüringer Carbonatböden

Investigations on the characterization of plant available phosphate in Thuringian calcareous soils Phosphate availability in Thuringian calcareous soils and its characterization by CAL‒, NaHCO₃-, H₂O- and CaCl₂-soil tests was investigated in laboratory and pot experiments. Soil CaCO₃ contents > 10% increase the pH value of CAL solution and thus decrease phosphate extractability. The increase of pH also causes an inadequate assessment of plant available phosphate by H₂O- and CaCl₂-soil tests. The CAL soluble P content of the soil corrected by the pH value of the extraction solution was most suitable for the forecast of P uptake of corn in a pot trial. From both parameters P availability indices for calcareous soils can be calculated which are comparable with those in soils containing < 5% CaCO₃. The equation, which still has to be verified in field experiments, reads as CAL-P_corrected = CAL-P_measured · (1 + 0.83·〈pH-value_{CAL solution} — 4.1〉).     

Structure-specific detection of plant cuticle bound residues of chlorothalonil by ELISA

Monoclonal antibodies (mAb) against the main photo-addition products of chlorothalonil with olefinic compounds of plant cuticles were produced. An indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of free and bound chlorothalonil and its derivatives. For the characterization of the binding properties of the mAb, derivatives of chlorothalonil (simulating structures of cuticle bound residues) were synthesized. The cross-reactivities of these products were determined by ELISA. The test system was employed to detect bound residues of chlorothalonil in enzymatically isolated tomato cuticles, which had been spiked with methanolic solutions of the compound, irradiated by simulated sunlight and extracted. The use of isolated cuticles allows work to be carried out with authentic material without disturbance by metabolic processes. © 1999 Society of Chemical Industry