Rumen ciliate protozoal fauna of native sheep, friesian cattle and dromedary camel in Libya.

Rumen ciliate species and composition were surveyed on the native sheep, Friesian-cattle and dromedary (one-humped) camels kept in Libya. As a result of survey, 5 genera including 14 species with 5 formae in native sheep, 9 genera including 27 species with 6 formae in Friesian-cattle and 6 genera including 13 species and 7 formae in dromedary camels were identified. All of the ciliate species and their percentage composition detected from the Libyan sheep and cattle in this examination were similar to those found from corresponding animals in the other countries. Libyan camels lacked some peculiar ciliate species found from camels in the other countries, but had many cosmopolitan species common with those in the domestic ruminants, suggesting that ciliate faunae of camel are easily affected by the other domestic ruminants kept together. The ciliate density was estimated as 105/ml in every host species.     

Development of correction formulas for canine and feline urine specific gravity measured using a Japanese refractometer

One of the most important functions of the kidney is to concentrate urine through the reabsorption of water. Urine specific gravity (USG) is used in routine tests of urine concentration and can be estimated using a refractometer. However, as the scale of Japanese refractometer is based on experimental data from healthy Japanese people, and human USG obtained by Japanese refractometers show higher values than that by refractometer produced in Europe or the U.S.A. The purpose of this study was to establish correction formulas for the USG of dogs and cats measured using Japanese refractometers. In this study, we found that Japanese refractometers overestimated USG in both dogs and cats. This study shows that the correlation formulas described in this study are useful for the accurate evaluation of USG.     

Background data of 2-year-old male and female F344 gpt delta rats

Although gpt delta rats, as reporter gene-transgenic rats, were originally developed for in vivo mutation assays, they have also been used to evaluate chemical carcinogenesis and comprehensive toxicity. Therefore, it is necessary to accumulate background data on carcinogenicity and general toxicity in gpt delta rats. Here, we investigated the background data of 110-week-old male and female F344 gpt delta rats and wild-type rats. There was no effect of reporter gene transfection on animal survival rates and body weights during the experiment. The relative weight of male gpt delta rat adrenals was significantly higher than that of wild-type rats, possibly due to the higher incidence of pheochromocytoma. There were no intergenotype differences in the incidence of nonneoplastic lesions in both sexes, including chronic progressive nephropathy and focus of cellular alteration in the liver, which had a higher incidence in both genotypes. Additionally, the significantly higher incidence of adrenal pheochromocytoma in male gpt delta rats than that in wild-type rats was likely incidental because of the lack of differences in the incidences of preneoplastic (male and female) and neoplastic (female) adrenal lesions in both genotypes. Other neoplastic lesions in both sexes showed no intergenotype differences in incidence rates, although large granular lymphocytic leukemia in the spleen and Leydig cell tumors in the testes of males showed higher incidence rates. Overall, there were no effects of reporter gene transfection on the spectrum of spontaneous lesions in F344 gpt delta rats, thus supporting their applicability in evaluating chemical toxicity and carcinogenicity.     

Ectomycorrhizal Association Enhances Al Tolerance by Inducing Citrate Secretion in Pinus densiflora

To investigate the effects of ectomycorrhizal association on the aluminum (Al) tolerance of Pinus densiflora Sieb. & Zucc., seedlings with or without ectomycorrhizal association with the fungus Pisolithus tinctorius (Pers.) Coker & Couch were exposed to 1 mM Al. Association with P. tinctorius alleviated Al-induced inhibition of root elongation and biomass growth in the mycorrhizal seedlings. Secretion of malate and citrate, both low-molecular-weight organic acids that could detoxify Al by the formation of stable complexes, was investigated in P. tinctorius mycelia and in pine roots with and without P. tinctorius association. Citrate secretion from the P. tinctorius mycelia in vitro was stimulated by Al. Citrate secretion from the roots of the ectomycorrhizal seedlings was also stimulated by Al, but was not detected in the non-mycorrhizal seedlings. These results suggest that citrate secreted from the roots of the ectomycorrhizal seedlings was produced in the hyphae of P. tinctorius. Citrate secretion may play a role in enhancing the Al tolerance of host seedlings.     

Effects of flooding on downstream processes of glycolysis and fermentation in roots of Melaleuca cajuputi seedlings

We investigated the energy metabolism in roots of flooded Melaleuca cajuputi Powell, a tropical flood-tolerant tree species, by measuring adenylate concentrations and activities of glycolytic and fermentative enzymes under flooded conditions. Adenylate energy charge (AEC) decreased slightly to 0.72 on the second day of flooding and recovered to around 0.8 by the fourth day of flooding. Activities of pyruvate decarboxylase (EC 4.1.1.1) and alcohol dehydrogenase (EC 1.1.1.1) increased initially and then decreased to the control level after 14 days of flooding. On the other hand, activities of pyruvate kinase (EC 2.7.1.40), phosphoenolpyruvate phosphatase (EC 3.1.3.2), and a series of phosphoenolpyruvate carboxylase (EC 4.1.1.31), malate dehydrogenase (EC 1.1.1.37), and NADP dependent malic enzyme (EC 1.1.1.40), which can convert PEP into pyruvate, were not induced in flooded roots throughout the experiment. These results suggest that neither the downstream reactions of glycolysis nor ATP production via glycolysis was enhanced by flooding, whereas alcohol fermentation was enhanced. With the low ATP yield of the glycolysis–alcohol fermentation pathway and no induction of glycolytic enzymes, the glycolysis–alcohol fermentation pathway itself contributes little to ATP production in flooded roots of M. cajuputi. These physiological responses of M. cajuputi to flooding may have the advantages of surviving flooded conditions because they can avoid exhaustion of sugar and accumulation of ethanol, a toxic end product of alcohol fermentation.     

The effects of various lignocelluloses and lignins on physiological responses of a lower termite, <Emphasis Type="Italic">Coptotermes formosanus</Emphasis>

We investigated the physiological responses of a lower termite, Coptotermes formosanus, fed on various lignocelluloses and purified lignins (milled-wood lignins, MWLs) from Japanese cedar (softwood), Japanese beech (hardwood), and rice (grass). Termite survival, body mass, and the changes of the symbiotic protists in the hindgut of workers were observed for 4 weeks. The survival, body mass and presence of both Pseudotrichonympha grassii and Holomastigotoides hartmanni in the hindgut of workers fed on rice lignocellulose at the 4th week of observation were significantly lower than those of the workers fed on Japanese cedar and Japanese beech lignocellulose samples, whereas there was no significant difference in Spirotrichonympha leidyi among all the diets. The three purified MWLs, regardless of their structural differences, did not show any significant differences for the termites’ survival or body mass or the survival of all the three protists. The three MWL diets resulted in significantly lower termite survival compared to starvation, although these diets showed no significant effects on body mass or the protist profiles. Overall, lignins are hardly utilized as a nutrient source by C. formosanus workers and are even rather detrimental to termites when fed on solely.     

Effect of element type on the internal bond quality of wood-based panels determined by three methods

Three mechanical tests with different loading modes were conducted to evaluate the effect of element type on the internal bond quality of wood-based panels. In addition to the internal bond test, which is commonly used for mat-formed panels, interlaminar and edgewise shear tests were used to test oriented strandboard (OSB), particleboard, medium-density fiberboard (MDF) of two thicknesses, and plywood. The following results were obtained. Epoxy resin proved to be suitable for determining the interlaminar shear modulus instead of hot-melt glue. There was a linear relation between panel density and interlaminar shear modulus and a linear correlation between the interlaminar shear strength and internal bond (IB) strength for the mat-formed panels tested. OSB had the highest edgewise shear modulus, and MDFs had the highest edgewise shear strength in this study. The modulus/strength ratio also depended on both panel type and loading mode. The relation between the shear moduli determined from the edgewise and interlaminar tests indicated the characteristics of the shear properties of panels made of different elements.Part of this paper was presented at the Fourth International Wood Science Symposium, Serpong, Indonesia, September 2002     

Detection of telomere length and oxidative stress in Chondrichthyes

Telomeres, repeating TTAGGG sequences at the ends of eukaryotic chromosomes, increase genomic stability. Telomere shortening occurs not only during DNA replication associated with cell division but also under oxidative stress, where reactive oxygen species damage DNA. Therefore, changes in telomere length can be used to evaluate chronic cost or stress responses incurred by individuals. The phylogenetically unique Chondrichthyes are among the least-studied groups of marine vertebrates. Telomere data are limited and have only been reported in a few Chondrichthyes species. In this study, we measured telomere length and quantified oxidative stress and antioxidant power in 17 Chondrichthyes species whose telomere length has not been measured before. The presence of telomere sequences?>?30 bp and lower values of oxidative stress were confirmed in most species. Average telomere length was not correlated with oxidative stress and antioxidant power in 15 species for which both measurements were available. It would be desirable in the future to elucidate the nature of telomeres in Chondrichthyes, and their direct relationship with reactive oxygen species.