Epizootic of equine influenza in 1969 in Poland

Epidemiological observations on the course and spread of equine influenza in Poland during the 1969 epizootic were carried out. The dynamics of the spread of the disease in the country are shown graphically by voivodship. The disease incidence and mortality rates for the entire country are also shown. The highest incidence of disease and mortality rates were found to be in November 1969. A/equi-2/Warsaw/69 was identified as the causal virus. It caused the largest epizootic in the country since 1954.     

Dynamics of dissolved ions in the soil of abandoned terraced paddy fields in Sado Island, Japan

We investigated the soil and soil water chemistry in abandoned terraced paddy fields (reed stand) and a thicket of deciduous broad-leaved trees (thicket stand) on the same slope in Sado Island, Japan. The soils gathered from these plots were incubated under different water conditions to examine the dynamics of dissolved ions. The organic carbon pool in the soil in the reed stand at the lower slope position was greater than the thicket stand at the middle slope position. The high concentration of base cations and an almost neutral pH of the soil water at the reed stand corresponded with the high exchangeable cation concentrations and base saturation in the soil. These results reflect the mineral-rich groundwater percolating down the slope, which may be produced by chemical weathering. An in situ sulfate reduction in the reed stand at deeper soil horizons was identified. The different water conditions in the incubated soils affected the soil pH(H₂O), transformation of Fe, and dominant anions (NO₃ ⁻, HCO₃ ⁻, and SO₄ ²⁻). These biogeochemical processes were more conspicuous in the reed stand at the lower slope position where the concentrations of organic matter and base cations were high. When the abandoned terraced paddy field is developed for the conservation of the Japanese crested ibis (Nipponia nippon) habitat in Sado Island, the reductive subsoil at the lower slope position should be kept waterlogged to limit sulfuric acid generation.     

The soil seed bank of the threatened plant <Emphasis Type="Italic">Magnolia stellata</Emphasis> is subordinate to the emergence of current-year seedlings

We studied seed bank formation of the threatened star magnolia, Magnolia stellata, to examine the early stage of regeneration. Forty-five seedling plots (2 × 2 m), each including a soil-sampling quadrat (40 × 40 cm), were established randomly under or around the crowns of mature M. stellata trees. Seeds of M. stellata were collected from each quadrat to a depth of 5 cm. Only four seeds of M. stellata were found (0.56 seeds/m²) and all were located under mature crowns. Current-year seedlings were abundant in water channels, on moss, or under mature crowns, suggesting that the seeds may require wet soil conditions for germination. Magnolia stellata seeds show considerable germination below the crowns of mature trees in the year following masting, while some seeds remain dormant in the soil. Considering the soil seed bank and the current-year seedling bank of M. stellata, a frequent supply of seed is essential for the regeneration of this species. Thus, it is important to maintain mature trees in addition to promoting seed production.     

Protein synthesis measured in the whole body of chick embryos cultured in vitro

1. Whole body protein synthesis was measured in chick embryos cultured in vitro. On day 7 of incubation chick embryos were cultured for 60 min in synthetic serum‐free medium containing 4‐[³H]phenylalanine. Specific radioactivities in free and protein‐bound phenylaline in the whole embryo were measured, starting 2 min after commencement of the culture process.

2. The values for fractional synthesis rate (FSR) estimated in vitro at 20, 30, 45 and 60 min during the embryo culture agreed well, ranging from 35 to 40%/d, suggesting that the method would serve as a useful model for studying the effect of growth promoters in chick embryos.

3. Bovine insulin in the synthetic medium did not affect FSR of protein in chick embryos cultured in vitro.     

Porcine MHC classical class I genes are coordinately expressed in superantigen-activated mononuclear cells

The expression of the major histocompatibility complex (MHC) classical class I genes is important for the adaptive immune response to target virus-infected cells and cancer cells. The up-regulation of the MHC is achieved by hormonal/cytokine signals including IFN-γ-inducible elements. The swine leukocyte antigen (SLA), the MHC class I region of pigs, consists of the duplicated classical class I genes, SLA-1, SLA-2 and SLA-3, but the molecular mechanisms involved in their up-regulation after T cell stimulation have not been fully elucidated. In order to better understand some of the putative regulatory mechanisms of SLA class I gene expression in activated T cells, we examined the coordinated expression of the SLA classical class I, IFN-γ and interferon regulatory factor-1 (IRF-1) genes in the peripheral blood mononuclear cells (PBMCs) of SLA homozygous Clawn miniature swine stimulated for 72h with either IFN-γ or an enterotoxin produced by Staphylococcus aureus. This enterotoxin, toxic shock syndrome-1 (TSST-1), is known to act as a superantigen (sAG) to activate the T cells in various vertebrate species. We showed by using mAbs and flow cytometry that the CD4(+)CD25(+) cell number of swine PBMCs was also increased by TSST-1 and to a lesser degree by IFN-γ. Time course analyses of the expression of the IFN-γ, IRF-1 and the three classical class I genes, SLA-1, SLA-2, and SLA-3, in PBMCs by quantitative real-time PCR revealed a transitory response to TSST-1 or IFN-γ stimulation. The IFN-γ mRNA levels in the PBMCs were continuously up-regulated over the first 48h by TSST-1 or IFN-γ. In contrast, SLA class I expression moderately increased at 24h and then decreased to a baseline level or less at 72h of IFN-γ or TSST-1 stimulation. The three classical SLA class I genes showed similar expression kinetics, although SLA-3 mRNA level was consistently lower than those of SLA-1 and -2. The expression of IRF-1, a modulator of SLA expression, showed similar kinetics to those of the three classical SLA class I genes. The expression profiles detected by flow cytometry of the SLA molecules on the cell surface of PBMCs were maintained at a consistently high level during cell stimulation with either TSST-1 or IFN-γ, which was distinct from the kinetics of mRNA expression. These results showed that miniature swine SLA class I mRNA expression was effectively and equally up-regulated among the three loci and coordinately with IRF-1 gene expression after stimulation of T cell activation by sAG or IFN-γ.     

Quantitative structure—activity studies of insect growth regulators. XI. Stimulation and inhibition of N-acetylglucosamine incorporation in a cultured integument system by substituted N-tert-butyl-N,N′-dibenzoylhydrazines

The ability to stimulate N-acetylglucosamine (GluNAc) incorporation in-vitro of a number of N-tert-butyl-N,N′-dibenzoylhydrazines having various substituents on both phenyl rings was measured in cultured integument excised from the rice stem borer (Chilo suppressalis Walker). The relationship between in-vitro and larvicidal potency was approximately linear. The substituent effects on variations in the potency were similar between in-vitro and larvicidal activities. An inhibitor of oxidative detoxication, piperonyl butoxide, had no synergistic effects on the in-vitro potency. The ability of some dibenzoylhydrazines to inhibit GluNAc incorporation at exposure periods longer than the optimum for stimulation was also measured in a similar cultured integument system. The relationship between the inhibitory and stimulatory potency indices was linear, indicating that the larvicidal activity of dibenzoylhydrazines is closely related to its ability to stimulate as well as to inhibit GluNAc incorporation into the larval cuticle.     

Relationships among ecology, demography and diseases of European bison (Bison bonasus)

The bison population in the Bialowieza Forest in Poland has now grown to approximately 300, while the herds in the Belarusian part of the forest total about 240 bison. The first signs of a health problem in these herds appeared in 1980, when two cases of balanoposthitis were detected in two bulls (2 and 5 years of age). Since 1980 research has been conducted to explain the cause of diseases, particularly balanoposthitis, and to monitor the health of bison in Bialowieza Forest. A total number of 614 bison (294 male and 320 female) of different ages was eliminated between 1980 and 2000. Not all the culled bison were examined (postmortem analysis, histopathological, bacteriological, virological and toxicological examinations, serological tests, molecular research). Based on the increase in numbers, reproduction in this population for the past 21 years is generally considered successful. Among 182 male bison eliminated during 1990-2000, only 85, or 47%, of the animals had balanoposthitis. Thus, the percentage of balanoposthitis cases went from 100% during the 1980s down to 47% in the past decade. It appears that the culling process has been a major factor leading to this decrease. It can be assumed that a set of factors is involved in the appearance of the disease (Corynebacterium spp., Bacillus sp., Pseudomonas aeruginosa, Escherichia coli, Ureoplasma spp, Fusobacterium necrophorum, Streptoccocus spp., Staphyloccocus spp.) while opportunistic infections including nematodes (Onchocerca spp.) are responsible for the occurrence of secondary lesions.     

Age trends in the genetic parameters of wood density and the relationship with growth rates in hybrid larch (Larix gmelinii var. japonica × L. kaempferi) F1

Age trends in variance components and heritability of overall wood density, earlywood and latewood density, and latewood proportion were investigated in 29-year-old trees of 19 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F₁. The age–age correlation and optimum selection age for these traits were also estimated and genetic and phenotypic correlations between wood density and radial growth rate were calculated for each growth ring. Intraring wood density data were obtained using X-ray densitometry. The coefficient of additive genetic variance was stable over all ages, whereas the coefficient of environmental variances gradually decreased with increasing age, resulting in increases in heritability estimates with age for overall density. The latewood proportion had the highest heritability estimates at all ages, ranging from 0.44 to 0.66. Overall density and its various components at 28 years of age showed strong genetic correlations with their respective traits at all younger ages. Optimum selection ages for the wood density traits ranged from 8 to 14 years, at which point maximum gain efficiencies per year were obtained. There were negative correlations between wood density and radial growth rate at early ages, although these relationships tended to be weaker with increasing age. These results suggest that selection at a young age is effective for wood density, but particular care must be taken in selecting trees with an improved radial growth rate because rapid growth will result in a low-density wood product, especially in the early growth period.     

Anemia amelioration by lactose infusion during trypanosomosis could be associated with erythrocytes membrane de-galactosylation

African trypanosomosis is a potentially fatal disease that is caused by extracellular parasitic protists known as African trypanosomes. These parasites inhabit the blood stream of their mammalian hosts and produce a number of pathological features, amongst which is anemia. Etiology of the anemia has been partly attributed to an autoimmunity-like mediated erythrophagocytosis of de-sialylated red blood cells (dsRBCs) by macrophages. Lactose infusion to infected animals has proven effective at delaying progression of the anemia. However, the mechanism of this anemia prevention is yet to be well characterized. Here, the hypothesis of a likely induced further modification of the dsRBCs was investigated. RBC membrane galactose (RBC m-GAL) and packed cell volume (PCV) were measured during the course of experimental trypanosomosis in mice infected with Trypanosoma congolense (stb 212). Intriguingly, while the membrane galactose on the RBCs of infected and lactose-treated mice (group D) decreased as a function of parasitemia, that of the lactose-untreated infected group (group C) remained relatively constant, as was recorded for the uninfected lactose-treated control (group B) animals. At the peak of infection, the respective cumulative percent decrease in PCV and membrane galactose were 30 and 185 for group D, and 84 and 13 for group C. From this observed inverse relationship between RBCs membrane galactose and PCV, it is logical to rationalize that the delay of anemia progression during trypanosomosis produced by lactose might have resulted from an induction of galactose depletion from dsRBCs, thereby preventing their recognition by the macrophages.