Concordance between Results of Medium-term Liver Carcinogenesis Bioassays and Long-term Findings for Carcinogenic 2-Nitropropane and Non-carcinogenic1-Nitropropane in F344 Rats

This study was conducted to determine the concordance of results for a pair of structural isomers, 2-nitropropane (2-NP) and 1-nitropropane (1-NP), using the rat medium-term liver carcinogenesis bioassay (Ito test) and previously published long-term carcinogenicity tests. Male F344 rats were given a single intraperitoneal injection of DEN (200 mg/kg b.w.) to initiate hepatocarcinogenesis. After 2 weeks, they received per os 0, 0.8, 4 or 20 mg/kg/day of 2-NP or 1-NP six times a week and were subjected to two-thirds partial hepatectomy at week 3. Non-initiated groups receiving 0 or 20 mg/kg/day were also included. The animals were sacrificed for quantitative analysis of GST-P-positive foci at week 8. With the highest dose of 2-NP, significantly increased numbers and areas of GST-P-positive foci were demonstrated as compared with the respective control but were not noted with 1-NP. In the non-DEN-initiated groups, many small GST-P-positive foci of less than 0.2 mm in diameter were also induced in the rats treated with 2-NP at 20 mg/kg/day but were lacking with 1-NP. These results strongly support that 2-NP is a complete hepatocarcinogen with a potent initiation activity, whereas 1-NP is not.     

Pharmacokinetics and toxicity of zonisamide in cats

With the eventual goal of making zonisamide (ZNS), a relatively new antiepileptic drug, available for the treatment of epilepsy in cats, the pharmacokinetics after a single oral administration at 10mg/kg and the toxicity after 9-week daily administration of 20mg/kg/day of ZNS were studied in healthy cats. Pharmacokinetic parameters obtained with a single administration of ZNS at 10mg/day were as follows: Cmax=13.1microg/ml; Tmax=4.0h; T(1/2)=33.0h; areas under the curves (AUCs)=720.3microg/mlh (values represent the medians). The study with daily administrations revealed that the toxicity of ZNS was comparatively low in cats, suggesting that it may be an available drug for cats. However, half of the cats that were administered 20mg/kg/day daily showed adverse reactions such as anorexia, diarrhoea, vomiting, somnolence and locomotor ataxia.     

Impressions and purchasing intentions of Japanese consumers regarding pork produced by ‘Ecofeed,’ a trademark of food‐waste or food co‐product animal feed certified by the Japanese government

Impressions and purchasing intentions of Japanese consumers regarding pork produced by ‘Ecofeed’, a trademark of food‐waste or co‐product animal feeds certified by the Japanese government, were investigated by a questionnaire on the Internet. ‘Ecofeed’ did not elicit specific impressions as compared to domestic, imported, Kurobuta (in Japan), and specific pathogen‐free (SPF) pork. Purchasing intent for ‘Ecofeed’ pork was the second lowest of the five pork products. Knowledge and purchasing experience regarding ‘Ecofeed’ pork was the lowest of the five pork products. Respondents were classified into four categories according to their impressions of ‘Ecofeed’ pork. The largest category of respondents did not have any specific impression of ‘Ecofeed’ pork and had little knowledge of pork farming. A category that had a positive impression for ‘Ecofeed’ pork had high knowledge of the pork farming system. In order to establish ‘Ecofeed’ pork in Japan, our results suggest that information disclosure and education about ‘Ecofeed’, its certification system, environmental benefits and the current self‐efficiency ratio of animal feed, are needed.     

Comparison of the characters of the plaque-purified viruses from foot-and-mouth disease virus O/JPN/2000

At least two biotypes were observed at the 2nd passage stage after the isolation of Foot-and-mouth disease Virus (FMDV) O/JPN/2000 strain. These 2 types of viruses differed from their plaque phenotypes and were distinguishable by using a monoclonal antibody (MAb) 64G8 that was made for the FMDV O/JPN/2000 strain. One of these 2 biotypes formed small plaque (SP) and with immuno staining showed a positive reaction to MAb 64G8, while the other formed clear large plaque (LP) and did not react with MAb 64G8. The amino acid sequences of the capsid coding region (VP1-VP4) of the SP virus (SPV) and the LP virus (LPV) revealed two substitutions on the 133rd amino acid in VP2, and the 56th amino acid in VP3. These amino acid changes of SPV and LPV are Asn to Asp, Arg to His, respectively. The Arg of the 56th amino acid in VP3 that have been known as critical position of cell culture adapted virus. Only LPV showed high pathogenicity in suckling mice, and its LD(50) was calculated to be about 10(2) TCID(50)/0.1 ml. These results showed that the SPV that existed at the 2nd passage stage from isolation was a low virulence virus, which may suggest why the pathogenicity of O/JPN/2000 did not show clear symptoms in infected cattle.     

Hemorrhagic necrotizing splenitis in a slaughter pig infected with Arcanobacterium species

A 6-month-old barrow presented with lethargy, inappetence and dysstasia. At necropsy, multiple coalescing hemorrhagic foci were detected in the margins of the spleen. Gram-positive bacilli were isolated from the spleen, kidney, muscle and liver. Comparative 16S rDNA gene sequencing analysis of the isolates (TO16177) revealed that they would be the same species of unpublished Arcanobacterium species strain HJ57-14E (accession no. gi 18873551) (99.7% similarity based on a comparison of 675 bp). Histologic examination of the splenic tissue sections revealed extensive necrosis and inflammation, and gram-positive bacilli were discernible. Multifocal necrosis was also detected in the liver. Immunohistochemically, the isolates were cross-reacted with polyclonal antibodies against Arcanobacterium pyogenes and Actinomyces naeslundii, and the reaction was strong for the latter. Similar reactions were found in the suppurative lesions of the tonsil, and occasionally in the spleen and lymph nodes. The present results indicate that the unpublished Arcanobacterium species induced multiple organ failure accompanied by acute hemorrhagic necrotizing splenitis in this growing-finishing pig.     

Changes in oxidative status in periparturient dairy cows in hot conditions

We investigated the changes in the plasma concentrations of oxidative stress markers in periparturient dairy cows in hot conditions. This study was performed on 10 cows from day ?5 to day 10 after parturition. The experimental duration was divided into three periods: period 1 (5 days before parturition); period 2 (5 days after parturition); and period 3 (from day 6 to day 10 after parturition). The average rectal temperature in the cows during the experimental period was more than 39°C. Plasma aspartate aminotransferase activities in periods 2 and 3 were higher than that in period 1 (P < 0.05). Blood urea nitrogen concentration in period 3 was lower than those in periods 1 and 2 (P < 0.05). The total ascorbic acid concentration in the plasma in period 2 was greater than those in periods 1 and 3 (P < 0.05). Thiobarbituric acid reactive substances (TBARS) concentrations in periods 2 and 3 were greater than that in period 1 (P < 0.05). TBARS concentration was positively correlated with aspartate aminotransferase activity (P < 0.05). These results suggested that oxidative stress increased in cows after parturition under hot climatic conditions.     

Suppurative meningoencephalitis and perineuritis caused by Streptococcus gallolyticus in a Japanese Black calf

A 179-day-old calf, which was weak and stunted, showed neurological signs and was euthanized. Postmortem examination revealed extensive and severe cloudy area in the meninges, and pleural pneumonia. Gram-positive cocci were isolated from systemic organs. Biochemical and 16S rRNA gene sequence analyses identified the isolate as Streptococcus gallolyticus, and its subspecies was suggested to be gallolyticus (SGG). The isolate was classified as a novel sequence type (ST115) by the multilocus sequence typing scheme for SGG and showed susceptibility to penicillin, ampicillin, amoxicillin, florfenicol, sulfamethoxazole-trimethoprim, and chloramphenicol. Histopathologically, suppurative meningoencephalitis and perineuritis were detected. As SGG has been isolated solely from a cow with mastitis in Japan, this is the first SGG infection in a calf with suppurative meningoencephalitis and perineuritis in this country.     

Hydration behavior and compressive strength of cement mixed with exploded wood fiber strand obtained by the water-vapor explosion process

Poor compatibility was found between exploded wood fiber strand (WFS) and cement due to the excessive presence of water-soluble degraded polysaccharides in extractives of exploded WFS obtained from weathered wood waste treated by the water-vapor explosion process (WVEP). This study presents some comparative results from a continuing investigation on the compressive strengths of exploded WFS–cement mixtures. Based on results previously obtained with the hydration test, the relation between hydration behavior and compressive strength of the mixture was explored. In addition, the effect of the curing age on compressive strength development of the mixture with selected additive chemicals was examined. The results supported the results of early studies with hydration tests indicating that adding MgCl₂ to the mixtures of exploded WFS mixed with quick-curing cement or ordinary Portland cement and a composite of MgCl₂ + CaO added to the mixture of exploded WFS and furnace-slag cement effectively improved the hydration behaviors; it greatly enhanced the compressive strengths of mixtures as well. Compressive strengths were strongly correlated to maximum hydration temperatures (T_max) of wood–cement mixtures influenced by the cement type, wood wastes (treated or not with WVEP), additive chemicals, and their content levels. The results also indicated that adding selected chemicals had no significant effect on compressive strength among the mixtures of exploded WFS mixed, respectively, with three types of cement at a curing age of 180 days. X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy were used to identify the hydration products and to probe the element distribution of the mixture in the wood–cement interface zone from a fractured surface.Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002     

Effects of contact with wood on blood pressure and subjective evaluation

This study examined the effects of contact with wood on the living human body using a physiological index and subjective evaluation. Consecutive blood pressure measurements were used as the physiological index, and sensory evaluation using the semantic differential (SD) method was used for subjective evaluation. Consideration was also given to cases in which materials were cooled and heated as well as kept at room temperature, to eliminate the effects of heat flux due to differences in thermal conductivity between wood and other materials. It was found that contact with wood produced coarse/natural sensations, with no associated increase in systolic blood pressure. Contact with cold wood created subjectively dangerous/uncomfortable but still coarse/natural sensations, also with no associated increase in blood pressure; therefore, there was no correspondence between subjective evaluation and physiological responses. Contact with aluminum kept at room temperature and cold acrylic plastic created flat/artificial and dangerous/uncomfortable sensations, with an associated significant increase in blood pressure; thus, there was a close correlation between subjective evaluation and physiological responses. It was therefore concluded that contact with wood, unlike artificial materials such as aluminum, induces no physiological stress even when kept at room temperature or cooled. Part of this report was presented at the 48th Annual Meeting of the Japan Wood Research Society in Shizuoka, April 1998     

At5g54160 gene encodes <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> 5-hydroxyconiferaldehyde <Emphasis Type="Italic">O</Emphasis>-methyltransferase

The function of an Arabidopsis thaliana gene, At5g54160 annotated as a caffeic acid O-methyltransferase CAOMT gene was characterized. The recombinant enzyme of this gene (AtOMT1) catalyzed the O-methylation of phenylpropanoid and flavonoid substrates. The specificity constants (k _cat/K _m) for 5-hydroxyconiferaldehyde (5-HCAld) and quercetin were both 0.11 μM⁻¹·min⁻¹. On the other hand, lignins of At5g54160-knockout Arabidopsis mutants lacked syringyl units. In addition, we showed that the gene silencing also resulted in significant accumulation of caffeyl alcohol (CaAlc). These results strongly suggested that At5g54160 gene is involved in syringyl lignin synthesis for the methylation of both 5-hydroxyconiferaldehyde and 3,4-dihydroxyphenyl compound(s). Part of this work was presented at the Annual Meeting of Japan Society for Bioscience, Biotechnology, and Agrochemistry, March 24–27, 2007