First Report of <Emphasis Type="Italic">Pepper mottle virus</Emphasis> on <Emphasis Type="Italic">Capsicum annuum</Emphasis> in Japan

Pepper mottle virus, genus Potyvirus, was first identified in Japan based on particle morphology, host range, aphid transmission, and molecular classification using the nucleotide sequence of the coat protein gene and 3-untranslated region.     

Anthracnose of Sansevieria trifasciata caused by Colletotrichum sansevieriae sp. nov.

A Colletotrichum sp. was isolated from water-soaked lesions on sansevieria (Sansevieria trifasciata Prain cv. Laurentii) in Japan. Classifying the species only from the morphology of the fungus was difficult; therefore, host range was tested and the ribosomal DNA ITS2 region was phylogenetically analyzed. The fungus was pathogenic only on sansevieria among 20 test plants belonging to 11 families. In a phylogenetic analysis with the neighbor-joining method, the two isolates used formed a single-isolate clade. The fungus is thus proposed to be a new species, Colletotrichum sansevieriae. This report is the first of anthracnose on sansevieria.     

The Activity Ratio of the Cytosolic MDH/LDH and the Isoenzyme Pattern of LDH in the Peripheral Leukocytes of Dogs,Cats and Rabbits

The activities of malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) and the pattern of the isoenzymes of LDH were determined in the peripheral blood leukocytes of dogs, rabbits and cats. Rabbits had significantly higher plasma glucose concentrations than dogs or cats. Feline leukocytes showed higher LDH and lower MDH activities than canine or rabbit leukocytes. The M/L ratio, defined as the MDH activity divided by the LDH activity in cytosolic fractions, was considered to be a good indicator with which to evaluate the metabolic state in animal tissues. The M/L ratio was highest in canine and lowest in feline leukocytes. LDH-2 and LDH-3 isoenzymes were dominant in canine leukocytes. LDH-1 and LDH-2 were dominant in rabbit leukocytes, whereas LDH-5 was dominant in feline leukocytes. It was evident that there were significant differences in energy metabolism between the leukocytes of dogs, rabbits and cats.     

Expression of desmosomal proteins in rat keratinocytes during in vitro differentiation

The keratinocyte, the major component of the epidermis, expresses several proteins that characterize the keratinization during the differentiation. Proliferation and differentiation of cultured human keratinocytes are known to be regulated by the Ca2+ concentration in the culture medium. However, informations about the rat keratinocyte are relatively limited and their physiology is still an open question. To elucidate the characteristics of the rat keratinocyte, we established rat keratinocyte culture system and examined effects of extracellular calcium concentration on the expression of differentiation-related proteins. Keratinocytes were isolated from the newborn rat skin with 0.25% trypsin, followed by separation with a Percoll density gradient. The separated cells were grown in MCDB 153 medium containing several growth factors and Ca(2+)-free fetal bovine serum, then stimulated with Ca2+. Immunoblotting demonstrated strong expression of beta1 integrin in unstimulated cells, suggesting that the primary culture of rat keratinocytes was successfully established. Expression of desmoglein and transglutaminase was increased by Ca2+ stimulation, whereas beta1 integrin expression was decreased in response to increasing concentrations of Ca2+. These observations indicate that cultured rat keratinocytes maintain the ability to differentiate in vitro, which is similar to that of the basal keratinocytes in the epidermis.     

Changes in hepatic enzyme activities in transgenic mice carrying human prototype c-Ha-ras gene treated with diethylnitrosamine

Activities of malate dehydrogenase (MDH) and aspartate aminotransferase in the malate-aspartate shuttle were significantly increased in the cytosolic fractions of livers with early neoplastic symptoms such as swelling and discoloration in transgenic mice carrying the prototype human c-Ha-ras gene, Tg-rasH2 mice, which were administered with diethylnitrosamine (DEN) as a carcinogenic chemical at a dose of 200 mg/kg body weight. Cytosolic MDH/LDH (lactate dehydrogenase) (ML) ratio increased significantly and was considered to be a useful marker to characterize the energy metabolism at early neoplastic stage in livers of the Tg-rasH2 mice.     

Inhibition of appressorial adhesion of Pyricularia oryzae to barley leaves by fungicides

The effects of rice blast fungicides known to inhibit melanisation or penetration on the adhesion of Pyricularia oryzae to the leaf surface of barley were investigated. Adhering appressoria were counted after shaking inoculated leaves vigorously with water. On untreated leaves, appressoria began to adhere at the time when appressorial melanisation was initiated. The number of adhering appressoria then increased gradually, and most were melanised. On chlobenthiazone-treated leaves, appressoria were not melanised and were easily detached from the surface. Similar results were obtained with tricyclazole. However, after treatment with tetrachlorophthalide or pentachlorobenzyl alcohol, which are also known to prevent penetration of P. oryzae, melanised appressoria still remained after shaking in water. It is suggested that appressorial melanisation in P. oryzae is involved in appressorial adhesion. The antipenetrant action of the melanin biosynthesis inhibitors chlobenthiazone and tricyclazole may be ascribed to the lack of adhesive intensity necessary to support the mechanical shearing of the cuticle of rice plants.     

Plasma glucose,mannose, and non-esterified fatty acid concentrations in layer-type chickens

1. The oral administration of glucose or dietary glucose reduces fasting plasma mannose concentrations in mammals. On the other hand, there have been no reports on plasma mannose levels in birds. We have analysed chicken plasma mannose and glucose by an original high-performance liquid chromatography (HPLC) method, together with plasma non-esterified fatty acid (NEFA) concentrations in chickens.

2. Plasma glucose concentrations of chickens did not differ among three different age groups (0, 18 and 150 d). However, the plasma mannose concentrations of chicks at the age of 0 d were higher than those of chickens at the ages of 18 and 150 d.

3. At the age of 18 and 150 d, plasma glucose concentrations were elevated and plasma mannose and NEFA concentrations were decreased after regular feeding, compared to fasting levels.     

Simultaneous determination of serum mannose and glucose concentrations in dog serum using high performance liquid chromatography

Serum mannose and glucose concentrations in dogs before and after eating a meal were determined simultaneously with a recently established HPLC method combined with a UV and fluorescence detection system of p-aminobenzoic acid ethyl ester (ABEE)-derivatized monosaccharides. In this newly established HPLC method, detection limits were 0.09 micromol/L for mannose and 0.04 mmol/L for glucose. Linearity of peak areas vs. amounts of mannose and glucose in the range of 0.27-320 micromol/L and 0.13-64 mmol/L were observed, respectively. The value of the glucose content measured by the HPLC method was in good agreement with that of the commonly used enzymatic method (control). Serum glucose concentrations in dogs 90 min after the meal were almost the same as those before the meal, whereas serum mannose concentrations decreased significantly after the meal. This HPLC method may be useful for determination of monosaccharides in animal blood.     

Improving production systems of timber-processing plants IV: Application of genetic algorithms for appropriate positioning of processing machines

The development of a layout plan for a new plant with the aid of genetic algorithms was studied to place the machines so that the plant floor was effectively utilized and the operation would not be impeded. Genetic algorithms are search algorithms based on the mechanics of natural evolution and natural genetics to solve problems in engineering fields. Simulation with the aid of genetic algorithms was undertaken step by step. The first seven hundred strings (chromosomes) were generated at random to organize an initial population. Each string consisted of 40 bits (genes), which represented characteristics of machines (x- andy-coordinates and inlet and outlet formations of materials on machines) in the binary coding. Then the simulation was undertaken by repeating selection, crossover, reproduction, and mutation of strings until all strings were saturated with the highest evaluation (fitness of chromosomes to environments in the case of creatures). Under some limitations, an acceptable layout plan of the modeled plant involving four wood-processing machines was obtained according to evaluation indices.Part III of this series appeared inMokuzai Gakkaishi 37: 702–710, 1991.Part of this report was presented at the 47^th annual meeting of the Japan Wood Research Society, Kocht, April 1997     

Thermal constants of wood during the heating process measured with the laser flash method

The thermal diffusivity, specific heat, and thermal conductivity of 13 species of wood were measured by means of the laser flash method to investigate the thermal properties of wood during the heating process. The temperature ranged from room temperature to 270°C in air or under vacuum. The thermal diffusivity varied little during the heating process up to 240°C. The values in air were larger than those under vacuum. There was a linear relation between the specific heat and the ambient temperature, and the specific heat under vacuum was larger than that in air at high temperature. The thermal conductivity increased with density and the ambient temperature. To discuss the effects of the atmospheric conditions on the thermal constants of wood, a theoretical model of thermal conductivity was proposed and its validity examined, where the wood was assumed to be a uniformly distributed material composed of cell walls and air.Part of this paper was presented at the 47th annual meeting of Japan Wood Research Society at Kochi, April 1997