Cumulation of mycotoxins in maize cobs infected with<Emphasis Type="Italic">Fusarium gramihearum</Emphasis>

Maize cobs withFusarium ear rot were collected at 1986 season and five infected byFusarium graminearum were analyzed for presence of triohothecenes and zearalenone. Collected material was subsampled forFusarium damaged kernels and corresponding axial stems and healthy looking kernels. All investigated cobs contained deoxynivalenol (DON) (range 18.0–131.5 mg/kg) and zearalenone (ZEA) (range 0.38–2.17 mg/kg), in four cobs 15-acetyl-deoxynivalenol (15-AcDON) (range 5.2–6.2 mg/kg) was present and two cobs besides three all metabolites contained 3-acetyl-deoxynivalenol (3-AcD0N) (range 0.5–0.8 mg/kg).The average of individual toxins amount in axial stems: in mg/kg was equal to: DON — 110.36, ZEA — 4.57, 15-AcD0N — 16.66, and 3-AcD0N — 1.32.Fusarium damaged kernels contained in average the following amount (mg/kg) of: DON 77.00, ZEA 0.98, 15-AcD0N 3.78 and 3-AcD0N 0.06. Healthy looking kernels contained DON 1.96 mg/kg and ZEA 0.07 mg/kg only. Cooccurrence of 3-AcDON and 15-AcDON in two samples was an interesting finding. The amount of DON in total cob was highly correlated (r = 0.94) with percentage ofFusarium damaged kernels in given ear.     

Antibiotic Y: biosynthesis by Fusarium avenaceum (Corda ex Fries) Sacc., isolation, and some physicochemical and biological properties

A compound very similar to the mycotoxin citrinin was observed on thin-layer chromatographic plates during the screening analysis of grain extracts. This compound was produced by 22 of the tested Fusarium avenaceum (Corda ex Fries) Sacc. strains isolated from wheat, triticale, barley, corn, and potatoes. A chemical test confirmed the presence of an unknown compound, which was given the preliminary name of antibiotic Y (indicating yellow fluorescence). The following properties of the new metabolite are described: spectroscopic (UV, infrared, proton nuclear magnetic resonance, fluorescence, and mass spectrometry), phytotoxic, antibiotic (inhibitory effect of bacterial growth), and toxic (toxicity to Artemia salina, chicken embryos, and mouse fibroblasts). Elemental analysis of the compound showed that it had the general formula C15H10O8, in agreement with the mass spectrometric finding that the molecular ion had a molecular weight of 318. The structure of the compound is presently under study.     

Conformation and structure of 2-amino-8-(β-d-ribofuranosyl)imidazo [1,2-a]-s-triazin-4-one (5-aza-7-deaza guanosine), a potent antiviral nucleoside

The crystal and molecular structure of one imidazo[1,2-a]-s-triazine nucleoside and its antiviral activity are described. The crystal structure of 2-amino-8-(β-d-ribofuranosyl)imidazo-[1,2-a]-s-triazin-4-one monohydrate (C₁₀H₁₃N₅O₅·H₂O) was solved by X-ray counter data. The compound crystallizes in the monoclinic space group P2₁ with cell dimensions a = 7.353 (1), b = 6.465 (1), c = 13.701 (1) Å, β = 104.64 (1)°. The structure was solved by direct methods and refined by full matrix least-squares technique to a final value of the conventional R-factor of 0.049 using 1998 observed intensities. The orientation of the base relative to the sugar ring defined in terms of rotation about the C(1′)-N(8) glycosyl bond is anti (47.8°). The ribose moiety exhibits C(2′)-endo, ²E conformation. The conformation around C(4′)-C(5′) is gauche^?. Molecular packing is dominated by hydrogen bonds. Base stacking occurs long the b axis. 5-Aza-7-deazaguanosine has shown a marked antiviral activity in vitro against herpes simplex virus despite the fact that N(3) is effective as the hydrogen acceptor only.     

Liver alteration and hematological and serum biochemical responses of common carp,Cyprinus carpio Linnaeus, 1758, following long‐term feeding of pistachio (Pistacia vera) green hull extract as a source of natural phenol

This study was conducted to investigate the effect of pistachio green hull extract (PGHE) on hematological and serum biochemical changes in common carp, Cyprinus carpio. Three hundred common carp (11.65 ± 1.65 g) were fed one of five different dietary treatments (with three replications) containing 0, 0.5, 1.5, 4.5 or 9 g PGHE kg^?1diet for ten continuous weeks. Each tank had a 90‐L capacity and water flow rate of about 500 ml min^_1.Total phenolic compounds of the different diets differed significantly (P < 0.001) according to the amount of PGHE. At the end of experiment, six fish were removed randomly from each treatment. Blood samples were taken for hematological and serum biochemical analyses at room temperature. Liver tissue samples were processed for histology and stained by H&E. The results indicated that all doses of tested PGHE induced no significant changes in hematocrit, hemoglobin, or erythrocytes, nor alkaline phosphatase, alanine transaminase, lactate dehydrogenase, total protein, albumin, globulin, triglycerides, low‐density lipoprotein, high‐density lipoprotein, glucose or cholesterol in the serum. Leukocytes were higher (P < 0.01) in fish fed a 1.5, 4.5, or 9 g PGHE kg^?1 diet when compared to the 0.5 g PGHE kg^?1 diet group or the control. Serum aspartate transaminase in treatments containing a 4.5 or 9 g PGHE kg^?1 diet was significantly (P < 0.001) higher in comparison with the control. Liver histology showed focal necrosis, cytoplasm degeneration, lateral nuclei and an increase in Kupffer cells following PGHE administrations. The results of this trial indicated that although there were no significant changes in most hematological and biochemical parameters, PGHE could induce some adverse pathological effects on liver tissue.     

The role of selected tree species in industrial sewage sludge/flotation tailing management

The aim of the study was to estimate the ability of ten tree and bush species to tolerate and accumulate Cd, Cu, Pb, Zn, and As species [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg^?1) in a pot experiment. The premise being that it will then be possible to select the most promising tree/bush species, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested tree species were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg^?1 DW), where the dominant As species was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected tree species that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters.     

2-(Bipiperidin-1-yl)-5-(nitroaryl)-1,3,4-thiadiazoles: Synthesis,evaluation of in vitro leishmanicidal activity,and mechanism of action

The development of novel leishmanicidal agents that are capable of being replaced by the available therapeutic options has become a priority. In the present study, the synthesis and leishmanicidal activity of a series of 5-(nitroheteroaryl-2-yl)-1,3,4-thiadiazole derivatives are described. All compounds appeared to be potent anti-leishmanial agents against both promastigote and amastigote forms of Leishmania major (L. major). Amongst the synthesized compounds, 2-([1,4′-bipiperidin]-1′-yl)-5-(5-nitrofuran-2-yl)-1,3,4-thiadiazole (IIa) and 1-(5-(1-methyl-5-nitro-1H-imidazole-2-yl)-1,3,4-thiadiazol-2-yl)-4-(piperidine-1-yl) piperidine (IIc) are the most effective. Infection index was statistically declined in the presence of all compounds. The analysis of redox-related factors revealed that exposure of L. major cells to IIa and IIc led to an increase in reactive oxygen species (ROS). Furthermore, two compounds were able to increase ROS and NO levels in infected macrophages in a dose-independent manner. In addition, we showed that these compounds induced cell death in promastigotes. Altogether, our results indicated the anti-leishmanial potential of IIa and IIc is mediated by apoptosis through an imbalance in the redox system resulting in the elevation of ROS. This new class of compound seems to hold great promise for the development of new and useful anti-leishmanial agents.     

Impact of the ESR gene on litter size and production traits in Czech Large White pigs

To evaluate the effect of the PvuII polymorphism of the oestrogen receptor gene on litter size and production traits in Czech Large White swine, data from 1250 sows and 3600 litters were analysed with two four-trait animal models. The traits in the first model were number of piglets born alive in a sow's first litter, number of piglets born alive in second and subsequent litters, lifetime daily gain and lean meat percentage. The second model included number of piglets born, number of piglets born alive, number of piglets weaned and litter weight at weaning from first and subsequent litters. The oestrogen receptor (ESR) locus significantly affected prolicacy in the first parity and averaged over all parities (P < 0.05), with allele A superior to allele B. In the first parity, AA sows produced approximately 0.5 more live piglets per litter than BB sows. Averaged over all parities, this difference was c. 0.25 piglets. Results for total number of piglets born and number of piglets weaned were similar to results for numbers born alive. No significant dominance effect was found for prolificacy traits. For litter weight at weaning, no significant additive effect was observed at the ESR locus, but a significant negative dominance effect (-1.5 kg) was estimated averaged across parities (litters of AB sows were similar to litters of BB sows for this trait). No pleiotropic effect of the ESR polymorphism on average daily gain or lean meat percentage was found.     

Explicit reformulations of time-dependent solution for a Michaelis-Menten enzyme reaction model

The exact closed-form solution to the Michaelis-Menten equation is expressed in terms of the Lambert W(x) function. However, the utility of this solution is limited because the W(x) function is not widely available in curve-fitting software. Based on various approximations to the W(x) function, different explicit equations expressed in terms of the elementary functions are proposed here as useful shortcuts to fit time depletion of substrate concentration directly to progress curves using commonly available nonlinear regression computer programs. The results are compared with those obtained by fitting other algebraic equations that have been proposed previously in the literature.     

Survival and Competitiveness of Bradyrhizobium japonicum Strains 20 Years after Introduction into Field Locations in Poland

It was previously demonstrated that there are no indigenous strains of Bradyrhizobium japonicum forming nitrogen-fixing root nodule symbioses with soybean plants in arable field soils in Poland. However, bacteria currently classified within this species are present (together with Bradyrhizobium canariense) as indigenous populations of strains specific for nodulation of legumes in the Genisteae tribe. These rhizobia, infecting legumes such as lupins, are well established in Polish soils. The studies described here were based on soybean nodulation field experiments, established at the Poznań University of Life Sciences Experiment Station in Gorzyń, Poland, and initiated in the spring of 1994. Long-term research was then conducted in order to study the relation between B. japonicum USDA 110 and USDA 123, introduced together into the same location, where no soybean rhizobia were earlier detected, and nodulation and competitive success were followed over time. Here we report the extra-long-term saprophytic survival of B. japonicum strains nodulating soybeans that were introduced as inoculants 20 years earlier and where soybeans were not grown for the next 17 years. The strains remained viable and symbiotically competent, and molecular and immunochemical methods showed that the strains were undistinguishable from the original inoculum strains USDA 110 and USDA 123. We also show that the strains had balanced numbers and their mobility in soil was low. To our knowledge, this is the first report showing the extra-long-term persistence of soybean-nodulating strains introduced into Polish soils and the first analyzing the long-term competitive relations of USDA 110 and USDA 123 after the two strains, neither of which was native, were introduced into the environment almost 2 decades ago.     

Insecticidal potential of natural zeolite and diatomaceous earth formulations against rice weevil (Coleoptera: Curculionidae) and red flour beetle (Coleoptera: Tenebrionidae)

Insecticidal potential of natural zeolites and diatomaceous earths originating from Serbia against Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) was evaluated. Two natural zeolite formulations (NZ and NZ Modified) were applied to wheat at rates of 0.50, 0.75, and 1.0 g/kg, while two diatomaceous earth (DE) formulations (DE S-1 and DE S-2) were applied at rates of 0.25, 0.50, 0.75, and 1.0 g/kg. A bioassay was conducted under laboratory conditions: temperature of 24 +/- 1 degrees C, relative humidity in the range 50-55%, in tests with natural zeolites, and 60-65%, in tests with DEs, and in all combinations for progeny production. Mortality was assessed after 7, 14, and 21 d of insect contact with treated wheat, and the total mortality after an additional 7-d recovery on untreated broken wheat. Progeny production was also assessed after 8 wk for S. oryzae and 12 wk for T. castaneum. The highest mortality for S. oryzae and T. castaneum was found after the longest exposure period and 7 d of recovery, on wheat treated with NZ at the highest rate and DEs at rates of 0.50 -1.0 g/kg. Progeny reduction higher than 90% was achieved after 14 and 21 d of contact of both beetle pests with wheat treated with DE S-1 at 0.50-1.0 g/kg and DE S-2 at 0.75-1.0 g/kg, while the same level of reduction was achieved only for T. castaneum after its contact with the highest rate of NZ formulation. NZ Modified, applied even at the highest rate, revealed much lower insecticidal potential.