Suppressing effect of neocarrabiose 4-O-sulfate on thermal and freeze denaturation of myosin subfragment-1 and myofibrils

Suppressive effects of neocarrabiose 4-O-sulfate on the thermal and freeze denaturation of myosin subfragment-1 (S-1) and on myofibrils were investigated. The compound strongly suppressed the thermal denaturation of S-1. Its suppressive effect was greater than that of sorbitol and similar to that of maltose. However, it tended to accelerate the denaturation of myofibrils, suggesting a loss of protection by F-actin upon its addition. The compound suppressed the freeze denaturation of myofibrils and S-1. The effect was similar to that of sorbitol or maltose, and completely different from that of Na-sulfate. The compound solubilized myofibrils at concentrations similar to KCl. Therefore, it was concluded that neocarrabiose 4-O-sulfate behaved as an ionic salt in the thermal treatment process, whereas it behaved as a sugar in the frozen storage process.     

Pathogenicity of Bordetella bronchiseptica isolated from apparently healthy rabbits in guinea pig,rat, and mouse

Bordetella bronchiseptica (B. bronchiseptica) is associated with respiratory tract infections in laboratory animals. In our laboratory animal facility, B. bronchiseptica was isolated from 21 of 27 apparently healthy rabbits obtained from a breeding farm contaminated with B. bronchiseptica. Restriction fragment length polymorphism (RFLP) analysis showed that the flagellin genotype of isolates from the laboratory animal facility and breeding farm was type A, which is seen relatively frequently in rabbits in Europe. To examine its pathogenicity, guinea pigs, rats, and mice were inoculated intranasally with a representative strain isolated in the laboratory animal facility. Following inoculation of 10⁷ colony forming unit (cfu), severe inflammation was observed in the lungs of guinea pig and mice, although the inflammation was less severe in rats. The strain was recovered from the trachea and lungs of these species after inoculation with lower dose such as 10³ or 10⁴ cfu. These results suggest that the isolated strain causes respiratory tract infection in guinea pigs, rats, and mice, and that its pathogenicity higher in mice than in rats. This study extends our knowledge of interpreting the microbiologic status of laboratory animals, which will contribute to the development of reliable and reproducible animal experiments.     

Fruit and vegetable consumption and risk of colorectal cancer in Japan: The Miyagi Cohort Study

OBJECTIVE: Adequate fruit and vegetable intake has been suggested to protect against colorectal cancer. However, several recent prospective studies have reported no association. We therefore examined the association between fruit and vegetable intakes and the risk of colorectal cancer in a prospective cohort study in Japan. DESIGN: Between June and August 1990, 47 605 Japanese men and women completed a self-administered questionnaire, including a food-frequency questionnaire. We divided the subjects into quartiles based on their self-reported fruit and vegetable consumption. There were 165 colon cancer and 110 rectal cancer incidences identified during 7 years of follow-up, to the end of December 1997. We used Cox proportional hazards models to estimate the relative risk (RR) of developing colorectal cancer according to the level of fruit and vegetable consumption, applying adjustments for potential confounders. RESULTS: No statistically significant association was observed between fruit and vegetable consumption and the risk of colorectal cancer. The multivariate RR of colon cancer in the highest quartile of fruit and vegetable intake compared with the lowest was 1.13 (95% confidence interval (CI) 0.73-1.75), the RR for vegetables alone was 1.24 (95% CI 0.79-1.95) and that for fruit alone was 1.45 (95% CI 0.85-2.47). The corresponding multivariate RRs for rectal cancer were 1.12 (95% CI 0.67-1.89), 1.14 (95% CI 0.67-1.93) and 1.41 (95% CI 0.73-2.73). CONCLUSIONS: We found no association between the consumption of fruit and vegetables and the risk of colorectal cancer among the Japanese population.     

Modelling the dispersal of larval Japanese sardine, Sardinops melanostictus, by the Kuroshio Current in 1993 and 1994

Acoustic Doppler current profiler (ADCP) data collected during routine monitoring surveys of the distribution and abundance of Japanese sardine larvae ( Sardinops melanostictus ) off the Pacific coast of Japan in February 1993 and 1994 were used to construct stationary average flowfields for three levels in the upper 100 m in each year. No large-scale meanders in the path of the Kuroshio Current were present in either year, but the axis of the current was closer to the coast in 1993 than in 1994. The flowfields were used to drive a particle-tracking model representing the dispersal of sardine eggs and larvae. Particles were released in accordance with the observed distribution of eggs, and their positions tracked for up to 40 days. In 1993, the model indicated that ≈ 50% of the egg production was carried north-eastwards out of the survey area into the area of the NW Pacific referred to as the Kuroshio Extension Zone. In contrast, only 5% of the egg production was exported to the Extension Zone in 1994, the remainder being retained in Japanese coastal waters. The consequences of the different dispersal patterns are discussed in relation to subsequent recruitment to the sardine stock. Based on commercial catch data, survival of the 1993 year class was 15% of that for the 1994 class. Hence, the results indicate that export of larvae to the Kuroshio Extension cannot in itself lead to successful recruitment.     

Effects of antimicrobial peptides derived from the beetle Allomyrina dichotoma defensin on mouse peritoneal macrophages stimulated with lipopolysaccharide

We previously reported that synthetic peptides, RLYLRIGRR-NH2 (peptide A) and RLRLRIGRR-NH2 (peptide B), derived from the beetle Allomyrina dichotoma defensin, showed antimicrobial activity against both Gram-positive and negative bacteria and suppressed lipopolysaccharide (LPS)-induced tumor necrosis factor-alpha (TNF-alpha) mRNA expression in a murine macrophage cell line. In this study, inhibitory effects of these peptides in LPS-induced mouse peritoneal macrophage activation were investigated. The supplement of peptide A to macrophages cultured with LPS resulted in a significant decrease in nitric oxide and TNF-alpha production. Furthermore, NF-kappaB activation was also blocked by addition of peptide A. These results indicated that peptide A blocked macrophage activation induced by LPS.     

The first record of sucking louse, Neohaematopinus callosciuri, infesting pallas squirrels in Japan

A species of sucking louse, Neohaematopinus callosciuri, was found for the first time in Japan. The species was found on an invasive species of squirrel, Pallas squirrel, Callosciurus erythraeus, in the Kamakura district, Kanagawa Prefecture, Japan. A total of 52 lice were obtained from 22 of 104 squirrels captured. The lice were about three times more prevalent in male squirrels than in females and were detected most frequently in the winter. As N. callosciuri has never been reported on wild animals in Japan, this species probably was introduced into Japan along with their host, Pallas squirrels.     

Genetic diagnosis of claudin-16 deficiency and sex determination in bovine preimplantation embryos

Renal tubular dysplasia is an autosomal recessively inherited disorder in Japanese black cattle that is due to deletion mutations in the claudin-16 gene and causes chronic renal failure and death of affected animals. Here, we report a multiplex-PCR procedure to determine the genotype for claudin-16 deficiency in preimplantation embryos. The presence or absence of the wild-type and mutant allele(s) was precisely detected with the multiplex-PCR using as little as 5 pg of genomic DNA from leukocytes. When biopsied embryo cells were examined for claudin-16 deficiency, 97.2% of genotypes were consistent with the PCR results obtained for the corresponding embryos. In addition, sexing of embryos by PCR was performed using an aliquot of DNA extracted from biopsied embryo cells, and determination of claudin-16 genotype and sex was successfully achieved with an efficiency of 91.7% for claudin-16 genotyping and 83.3% for sexing. The production of a 100-day fetus that was male and homozygous for claudin-16 deficiency, as expected from the analysis of biopsied embryo cells, gave evidence of the reliability and applicability of this procedure for preventing the transmission of this disease and for enabling advances in animal breeding.     

Estimation Models for the Morbidity of the Horses Infected with Equine Influenza Virus

Estimation formulas for the morbidity of horses infected with equine influenza virus by linear regression, logistic regression and probit transformation were developed, using data from the outbreak at the Sha Tin Racing Track in Hong Kong in 1992. Using these formulas, we estimated the equine influenza virus morbidity rates at training centers belonging to the Japan Racing Association (JRA) in October 1997 and in October 1998. In 1998 JRA started a new vaccination program, and every horse must now be vaccinated twice per year. At that time, the vaccine included two US lineage virus strains, the A/equine/Kentucky/81 strain and the A/equine/La Plata/93 (LP93) strain, against equine type-2 influenza viruses; it did not include any EU lineage virus strains, such as A/equine/Suffolk/89 (SF89). Comparing the geometric mean (GM) values of hemagglutination inhibition (HI) titers between the LP93 strain and the SF89 strain in 1997 and in 1998, they both rose significantly at every age (p<0.05) by Wilcoxon test. Calculations by the simulation models show the morbidity rates for LP93 diminished from 0.439 (linear), 0.423 (logistic) and 0.431 (probit) to 0.276 (linear), 0.265 (logistic) and 0.271 (probit), respectively. On the other hand, the estimated morbidity rates for SF89 diminished only slightly from 0.954 (linear), 0.932 (logistic) and 0.944 (probit) to 0.946 (linear), 0.914 (logistic) and 0.927 (probit), respectively. Our simulation models could estimate the effect of the vaccine on each of the equine virus strains represented by the morbidity of infected horses. Thus, they are useful for vaccine evaluation.     

Virulence characteristics of Yersinia pseudotuberculosis isolated from breeding monkeys in Japan

Between April 2001 and 2007, 18 Yersinia pseudotuberculosis outbreaks occurred in breeding monkeys at 12 zoological gardens in Japan, and 28 monkeys of 8 species died. A total of 18 Y. pseudotuberculosis strains from the dead monkeys, comprising one strain per outbreak, were examined for serotype and the presence of the virulence genes virF, inv, ypm (ypmA, ypmB and ypmC) and irp2. Of the 18 Y. pseudotuberculosis strains, 7 (38.9%) were serotype 4b, 7 (38.9%) were serotype 1b, and there was one each of serotypes 2b, 3, 6 and 7. All the 18 strains examined harbored virF and inv. Sixteen (88.9%) strains, including the strain of serotype 7, harbored ypmA. However, no strain harbored ypmB, ypmC and irp2.

This study demonstrated that among other pathogenic factors, almost all the Y. pseudotuberculosis isolated from the outbreaks had the ypm gene encoding the superantigenic toxin, YPM. As most of the monkeys who died in those outbreaks originated from South America and other regions, where the presence of the ypm gene have not been reported, YPM might be the cause, or at least the most important factor for, the high mortality of the breeding monkeys infected by Y. pseudotuberculosis in Japan. This is also the first report of a fatal case due to Y. pseudotuberculosis serotype 7 infection in the world.     

设施草莓组培快繁研究现状分析

草莓作为多年生小浆果,具有较高的食用价值和经济价值,在巨大的市场需求和设施栽培方式的刺激下,草莓的栽培面积不断扩大,通过草莓组织培养不仅可以为生产上提供大量的脱毒草莓植株,而且对草莓新品种的繁育和草莓种质资源的保存具有重要意义。现从国内外草莓组织培养研究现状、草莓组织培养的主要方式等进行了论述,对草莓组织培养过程中出现的问题及解决方法提出了意见,减少组织培养过程中造成的不必要损失,提高设施草莓种植的经济价值和社会价值。