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.     

放牧因子与VA菌根的相互作用对鸭茅养分吸收和生长发育的影响

探讨了放牧因子与VA菌根的相互作用对鸭茅(Dactylis glomerataL.)养分吸收和生长发育的影响。菌根效应表现在不施磷肥条件下的鸭茅地上部生育与地上、地下部的磷素营养上,但对地上部生育的效应因刈割次数的增加而降低,对地上、地下部磷素营养的效应因土壤镇压而降低。菌根对鸭茅钙素营养的效应只见于不施磷肥条件下的土壤镇压处理,而在相同条件下菌根却降低了鸭茅的镁含量。说明VA菌根对鸭茅磷素营养和生长发育的效应与土壤磷营养有关,而且因地上部的过度采食和土壤镇压而降低。     

Occurrence of chrysanthemum virescence caused by “<Emphasis Type="Italic">Candidatus</Emphasis> Phytoplasma aurantifolia” in Okinawa

In 1999, a disease of chrysanthemum [Dendranthema grandiflorum (Ramat.) Kitamura], characterized by virescence of flowers, occurred in Okinawa Prefecture. The causal agent was identified as “Candidatus Phytoplasma aurantifolia” based on 16S rDNA sequencing. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession number AB247462.     

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.     

Absolute configuration of arylglycerol-β-aryl ethers obtained by asymmetric reduction of the correspondingα-ketonic compound with intactFusarium solani cells

When (±)--oxo-guaiacylglycerol--(vanillic acid) ether (1) is degraded byFusarium solani M-13-1, the-ketone is initially reduced to giveerythro andthreo guaiacylglycerol--(vanillic acid) ethers (2), arylglycerol--aryl ethers, both of which are enantiomerically pure. The absolute configuration in each2 was determined by Mosher's method; the products were converted to,-di-(R)--methoxy--trifluoromethylphenylacetates (MTPA esters) (3) oferythro (-)- andthreo (+)-veratrylglycerol--(methyl vanillate) ethers (3), whose¹H nuclear magnetic resonance (NMR) spectra were examined and compared with those of four di-(R)-MTPA ester (3) diastereomers from chemically synthesizederythro (±)-3 andthreo (±)-3. To assign the- and-MTPA-OCH₃ peaks, the¹H NMR scans of several compounds that have substructures of 3 and their 3,4,5-trimethoxyphenyl analogues were examined. When a racemic alcohol reacts with (R)-MTPA to give a pair of (R)-MTPA ester diastereomers, the value was defined as the absolute value of the difference in the¹H chemical shifts of the peak between the diastereomers. It was found that the values of-MTPA-OCH₃ were larger than those of-MTPA-OCH₃ owing to a shielding effect of the veratryl ring located on the-MTPA-OCH₃, and that the-MTPA-OCH₃ peaks in the 3,4,5-trimethoxyphenyl compounds shifted downfield relative to those in the veratryl compounds. On the basis of the¹h NMR data of (R)-MTPA esters, the absolute configuration of the four chemically prepared diastereomers (3) were determined. The catabolicerythro 3 [fromerythro (-)-3] andthreo 3 [fromthreo (+)-3] were identical to (R, S, R)-erythro 3 and (R, S, S)- threo 3, respectively. An hydrogen species in the fungal reduction would attack the-ketone fromre-face of both (R)-1 and (S)-1, givingerythro (S, R)-2 andthreo (S, S)-2, respectively.Part of this paper was presented at the 33rd Lignin Symposium, Tsukuba, November 1988     

Sodium bicarbonate protects uranium-induced acute nephrotoxicity through uranium-decorporation by urinary alkalinization in rats

To evaluate the effectiveness of sodium bicarbonate (SB) in removing uranium and protecting animals from uranium toxicity, we intramuscularly administered 1 mg/kg of uranyl nitrate to 8-wk-old male SD rats, and 20 min after administration of uranyl nitrate, the animals were given a single oral administration of SB at 0.1, 0.3 or 1 g/kg. The SB treatment at a dose of 0.3 g/kg or more raised the pH of the rats’ urine until 4 h after treatment, and it significantly reduced the uranium amounts in the kidneys at 1 day after treatment. In another experiment, rats were intramuscularly administered 1 mg/kg of uranyl nitrate, and 20 min later, the animals were treated with sodium bicarbonate (0.1 or 1 g/kg). The rats were autopsied at 1, 3 and 7 days after uranium treatment. High-dose SB resulted in a significant increase in urinary uranium excretion in the first 24 h and a reduction of uranium deposition in the kidneys and femurs, and it also significantly suppressed uranium-induced renal toxicity, as shown by both histopathology and clinical chemistry at 3 days after uranium treatment. Low-dose SB did not show such marked effects. Our findings demonstrated that the uranium decorporation effect of sodium bicarbonate was observed at the dosage showing urine alkalinization in rats and that decorporation effect of sodium bicarbonate might be beneficial if it is administered immediately after incorporation of soluble uranium.     

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.     

Comparative external morphology of cetacean spermatozoa

SUMMARY: To compare size and morphology of spermatozoa in cetaceans, sperm and epididymis samples were collected from 10 species in four families and spermatozoa were observed with phase-contrast and scanning electron microscopes. According to the average total length of the spermatozoa, the 10 species examined were classified into the following four groups in order of increasing size: (i) Baird's beaked (Ziphiidae) and Bryde's whales (Balaenopteridae); (ii) Dall's and finless porpoises (Phocoenidae); (iii) common, bottlenose, and Pacific white-sided dolphins (Delphinidae); and (iv) killer and short-finned pilot whales, and Risso's dolphin (Delphinidae). Spermatozoa head length of Bryde's whale and the finless porpoise were shorter than those of the other species. Spermatozoa head width was widest in the killer whale and thinnest in the Baird's beaked whale. The lateral aspects of sperm heads from the 10 species were characterized as the 'anterior region of the sperm head is thin and flat while the posterior region is thick.' The dorsal aspects of sperm heads were 'paddle-shaped' in Bryde's whales, 'bowling pin-shaped' in Baird's beaked whales, 'Japanese fan-shaped' in killer whales, an 'elongated ellipsoid shape' in Delphinidae except for killer whales, and 'ellipsoid shaped' in Phocoenidae. Size and morphology of the spermatozoa showed interspecific differences among the 10 species examined, which correspond to cetacean taxonomic classification.     

Interaction of grammistins with lipids and their antibacterial activity

ABSTRACT: Grammistins are hemolytic and ichthyotoxic peptides in the skin secretion of soapfishes and are structurally characterized by their abundance in amphiphilic α-helicity. In the present study, their interaction with lipids and lipid vesicles as well as antibacterial activity were examined using four grammistins (Gs 1 and Gs 2 from Grammistes sexlineatus and Pp 1 and Pp 3 from Pogonoperca punctata ). The hemolytic activity of grammistins was inhibited by phospholipids but not by cholesterol. Moreover, grammistins released carboxyfluorescein entrapped within liposomes made of phosphatidylcholine. In contrast, grammistins were found to have antibacterial activity with a broad spectrum against nine species of bacteria, including both Gram-negative and Gram-positive groups. The potency of their antibacterial activity was not related to that of hemolytic activity, suggesting that grammistins bind to membrane phospholipids but lyse erythrocyte and bacterial membranes via different mechanisms. Conclusively, grammistins are new members of the family of cell non-selective membrane-lytic peptides with amphiphilic α-helices, being similar to pardaxins, which are secreted from the skin of soles, and to melittin, which is derived from bee venom.