Abstracts of Nippon Dojohiryogaku Zasshi

Abstract

The humus composition was analyzed and the humic acid characterized by UV and visible absorption spectroscopy in order to investigate the rotting and maturing process of city refuse compost according to the method of Kumada et al. During the composting process, the following findings were obtained: (1) the HT value was almost constant, but the HE/HT ratio varied somewhat, (2) HA increased with decrease in FA, and the PQ value so increased clearly, (3) the shoulder-like absorption at a wavelength near 270 nm weakened, and (4) the RF value of humic acid increased, whereas the Δ log K value seldom varied.

The IR spectrum of humic acid gradually changed as follows: (1) the absorption band in the 1700-1600 cm^-1 region and in the 1550-1500 cm^-1 region increased slightly, (2) the band in the 1100-1000 cm^-1 region decreased, and (3) the bands at 835 and 710 cm^-1 com pletely disappeared. On the whole, the shape of the IR spectrum of the city refuse compost became featureless. These changes were probably due to the oxidation which occurred in the composting process.     

High incidence of the gullet worm, Gongylonema pulchrum, in a squirrel monkey colony in a zoological garden in Japan

Histological examination revealed the gullet worm (Gongylonema pulchrum) embedded in the lingual mucosa of two of four dead Bolivian squirrel monkeys (Saimiri boliviensis) from a zoological garden in Kyushu, Japan. The zoo had kept the monkeys as a colony of approximately 80-100 individuals in a moated, open ground since 1981. To assess the incidence of G. pulchrum infection in this colony, lingual scraping with disposable plastic sticks was conducted in February during 2 consecutive years (2003 and 2004). The oval, thick-shelled egg containing a larva was found in 15 of 27 arbitrarily-chosen adult monkeys (55.5%) in 2003, and 27 of 106 monkeys (25.5%) in 2004. Infection of other zoo-kept mammals with G. pulchrum was not assessed. Since the gullet worm infects a variety of mammals including primates as natural definitive hosts, and dung beetles and cockroaches as intermediate hosts, the zoological garden may provide an ideal environment for the parasite. Zoo veterinarians should be aware of this disease in kept mammals, and should consider in the case of primates, monthly or bimonthly prophylactic anthelmintic treatment.     

Different effects on the inflammatory lesions in the lacrimal and salivary glands after neonatal thymectomy in IQI/Jic mice, a model for Sjögren's syndrome

Thymectomy on day 3 after birth (D3Tx) is understood to eliminate CD4+CD25+ regulatory T cells (Treg) from the peripheral T cell repertoire in rodents, leading to the activation of autoreactive T cells. Herein, D3Tx was performed in IQI/Jic mice, a model for Sj?gren's syndrome characterized by autoimmune infiltrations into the lacrimal and salivary glands. At the age of 16 weeks, very severe lesions were observed in lacrimal tissues from thymectomized mice, suggesting that Treg preserve their immunoregulatory function in young IQI/Jic mice. In contrast, salivary lesions were comparable in the D3Tx and control groups, raising the possibility that either salivary-specific Treg escaped elimination in thymectomized mice or spontaneous lesions in IQI/Jic mice developed independently of the tolerance through Treg.     

Gain‐of‐function mutation in PTPN11 in histiocytic sarcomas of Bernese Mountain Dogs

Histiocytic sarcoma (HS) is an aggressive malignant neoplasm of dendritic cell origin that is common in certain breeds of dogs. High prevalence of fatal, disseminated HS has been described in Bernese Mountain Dogs (BMDs). Support for genetic predisposition to develop HS has been presented in several studies, but to date, causative genetic events have not been reported. In addition, no driver mutations have been identified in tumours. Recently, E76K gain‐of‐function mutation in SHP2 encoded by the PTPN11 gene has been described in human histiocytic malignancies. In our study, we identified the PTPN11^E76K in HS of BMDs. Amplification of exon 3 of the PTPN11 gene followed by Sanger sequencing was used to detect the mutation and estimate the prevalence in HS from 30 BMDs, 13 Golden Retrievers and 10 other dog breeds. The overall prevalence of PTPN11^E76K in HS of BMDs was 36.67% compared with 8.69% in other breeds. No mutation was identified in normal tissues from 10 BMDs with HS that carried the mutation and 12 control dogs with no neoplastic disease, including 6 BMDs. Increased immunoreactivity for AKT, phosphorylated ERK1/2 and phosphorylated AKT in a small subset of BMDs with PTPN11^E76K suggests that a gain‐of‐function might be mediated by the ERK and AKT pathways. These data suggest PTPN11^E76K as an important driver mutation of HS in BMDs. This information may not only aid in unravelling the tumourigenic events associated with HS in BMDs, but also help in identifying more promising therapeutic strategies.     

Development of an SSR marker set for efficient selection for resistance to black spot disease in pear breeding

Black spot disease, which is caused by Alternaria alternata (Fries) Keissler Japanese pear pathotype, is one of the most harmful diseases in Japanese pear cultivation. Because of the potential harm of fungicides to consumers and the environment, resistant cultivars are desired. In this study, to enable efficient marker-assisted selection in pear breeding, we conducted comprehensive inoculation tests and genotyping with 207 pear cultivars. We identified a marker set (Mdo.chr11.27 and Mdo.chr11.34) suitable for selection for black spot resistance. In most susceptible cultivars, Mdo.chr11.27 amplified a 220-bp band and Mdo.chr11.34 amplified a 259-bp band. The genotype of Mdo.chr11.34 corresponds perfectly to the estimated genotype of Japanese pears susceptible to black spot disease. Using linkage analysis, we identified the positions of the gene for susceptibility to black spot disease in Chinese pear. Mdo.chr11.27 and Mdo.chr11.34 were tightly linked to susceptibility in Chinese pear, and the susceptibility gene was mapped at the top of linkage group 11, similar to that in Japanese pear. This marker set and the accumulation of phenotypic data will enable efficient marker-assisted breeding for black spot resistance in pear breeding.     

Annual Changes in Some Physiological Properties of Cryptomeria Japonica Leaves from Kanto, Japan

C. japonica leaves were sampled monthly in a heavily damaged area (a-I: Saitama), a slightly damaged area (a-II: plains in Ibaraki), and a healthy area (a-III: mountainous areas in Ibaraki) in Kanto. The leaves were analyzed for apparent cuticular transpiration rates, amounts of epicuticular wax, and contact angles. Sb in aerosols deposited on the leaves was also analyzed. The transpiration rates and the increase in transpiration with leaf aging were higher in a-I than in a-II and a-III. Erosion rates of the wax were higher in a-I and a-II than in a-III. The decrease of contact angles with aging tended to be higher in a-I and a-II than in a-III. Rates of aerosol-Sb deposition on the leaves were in the order a-I ? a-II > a-III. The transpiration rates correlated with the values obtained from a linear binomial function that included the amounts of wax and aerosol-Sb as variables (r = 0.855, P < 0.01). In a-I, the large quantity of aerosols on the leaves (and probably gaseous air pollutants) may have increased the transpiration rates by ca. 50% owing to erosion of the wax and stomatal malfunction, placing C. japonica under chronic water stress.     

Topographic relationship between senile plaques and cerebrovascular amyloidosis in the brain of aged dogs.

The distributions of senile plaques (SP) and cerebrovascular amyloidosis (CA) were studied by employing thioflavin S and modified Bielschowsky stains, and beta-protein immunohistochemistry on serial sections of the brains of aged dogs older than 10 years. Mature and perivascular plaques, both of which contained compact amyloid deposits, always showed a close topographic relationship to CA. In contrast, the majority of diffuse plaques showed no topographic relationship to CA. Cell bodies of neurons and/or glia were almost always involved in the diffuse plaques. In addition, beta-protein immunohistochemistry demonstrated amyloid deposits on the periphery of occasional neurons. These findings suggest that different mechanisms may be involved in the development of the different subtypes of SP in the brains of aged dogs.     

High incidence of rickettsiosis correlated to prevalence of Rickettsia japonica among Haemaphysalis longicornis tick

Endemic spotted fever group rickettsiosis was reported in Shimane Prefecture, Japan. From an analysis of 14 clinical cases found in the endemic area, the infectious agent of spotted fever group rickettsiosis was identified as Rickettsia japonica. In this study, we also found that Rickettsia japonica was highly infected with the vector tick, Haemaphysalis longicornis, in the endemic area. These findings suggest that the high incidence of rickettsiosis in Shimane Prefecture can be explained by the high prevalence of Rickettsia japonica among Haemaphysalis longicornis ticks.     

Novel genomic and EST-derived SSR markers in Japanese chestnuts

A total of 366 novel simple sequence repeat (SSR) markers were developed in Japanese chestnut (Castanea crenata), comprising 220 genomic SSRs derived from enriched genomic libraries and 146 expressed sequence tag (EST)–SSRs obtained from large-scale EST sequencing analysis. Thirty accessions, comprising Japanese, Chinese (C. mollissima), European (Castanea sativa), and American chestnuts (Castanea dentata), were used for evaluation of SSR polymorphism and transferability across species. The EST–SSRs showed less polymorphism than the genomic SSRs and were more transferable. The mean observed heterozygosity (H_O) and the mean expected heterozygosity (H_E) of genomic SSRs in the Japanese chestnuts were 0.63 and 0.68, respectively; those of EST-SSRs were each 0.47. Although about 80% of the genomic SSRs were amplified in all 4 species, more than 95% of the EST–SSRs were transferable across all 4 species. The many novel SSRs developed in this study will be applicable for the construction of genetic linkage maps, QTL analysis of phenotypic traits, high-throughput genotyping of marker-assisted selection, and association genetics.     

Evaluation of the Affinity of Some Toxic Elements to Schwertmannite in Natural Streams Contaminated with Acid Mine Drainage

In order to evaluate fixation potential of schwertmannite for fluvial transport of various toxic elements, we examined bottom precipitates and stream waters collected from the rivers contaminated with acid mine drainage (AMD), which arose from the abandoned Nishinomaki mine (Shimonita, Gunma, Japan). Mineralogical and morphological observations revealed that schwertmannite was the main mineral of the precipitates. The affinity of various toxic ions to schwertmannite was evaluated on the basis of (1) apparent solid?Cliquid partition coefficients (K _d??s) between precipitates and stream waters, (2) coprecipitation behaviors during schwertmannite formation in a laboratory test, and (3) consideration on coprecipitation processes using partial charge model (PCM). As a result, oxyanions of V, As, Mo and Sb, K _d??s of which were relatively large (>10⁴ (ml g^?1)), were considered to be immobilized by schwertmannite precipitates. A laboratory test also demonstrated that these ions except Mo coprecipitated with schwertmannite. In addition, partial charges and average electronegativities predicted on the basis of PCM suggested that the oxyanions of V, As, Mo, and Sb could create stable inner sphere complexes with schwertmannite embryos, which results in their high affinity to schwertmannite. On the other hand, cationic ions of Mn, Cu, Zn, Sr, Cs, and U, K _d??s of which were relatively small (<10⁴ (ml g^?1)), were thought to have a tendency to flow downstream without uptake by schwertmannite precipitates. All these results suggested that schwertmannite has high fixation potential for fluvial transport of various toxic oxyanions in AMD-contaminated rivers.