Structural unit of xylans from sugi (<Emphasis Type="Italic">Cryptomeria japonica</Emphasis>) and hinoki (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>)

Arabinoglucuronoxylans (AGXs) isolated from the holocellulose of sugi (Cryptomeria japonica) and hinoki (Chamaecyparis obtusa) contained one 4-O-methyl-d-glucopyranosyluronic acid (4-O-Me-d-GlcAp) residue per 6.2 d-xylopyranose (d-Xylp) residues and one 4-O-Me-d-GlcAp residue per 3.8 d-Xylp residues. These AGXs were subjected to partial acid hydrolysis. Analyses by size exclusion chromatography and electrospray-ionization mass spectroscopy of the neutral sugar fractions in the hydrolysates showed the presence of xylooligosaccharides having a degree of polymerization of 2-8 in addition to d-Xyl, suggesting that the AGXs from sugi and hinoki contained unsubstituted chains consisting of at least eight d-Xyl residues. The acidic sugars in the hydrolysates were separated into two series of aldouronic acids composed of 4-O-Me-d-GlcAp and d-Xylp by ion-exchange chromatography. The first series included aldouronic acids from aldobiouronic acid (4-O-Me-d-GlcAp-Xyl) to aldopentaouronic acids (4-O-Me-d-GlcAp-Xyl₄). The second series were aldouronic acids composed of two 4-O-Me-d-GlcAp residues and 2-4 d-Xyl residues. In these acidic sugars, the uronic acid side chains were located on two contiguous d-Xyl residues. These facts indicated that AGXs from sugi and hinoki had a structural unit containing two 4-O-Me-d-GlcAp residues on two contiguous d-Xyl residues as well as AGXs from spruce and larch.     

Foundation and progress of Japanese society of toxicologic pathology*

The Japanese Society of Toxicologic Pathology (JSTP) has a differing conceptual framework from the Japanese Society of Pathology (JSP) and Japanese Society of Toxicology (JST) and was founded in 1985 by the leadership of late Dr. Yasukazu Nishiyama with the cooperation of several founding members and the support of JSP. The aim of the JSTP is to improve the human and animal health using an interdisciplinary scientific approach based on pathology and toxicology. In its development as a professional society, the JSTP has established society rules and activities. The JSTP has grown in terms of membership and financial aspects and is now recognized not only domestically but also internationally as a well-organized scientific society. To maintain the high professional standard and visibility of JSTP, we here provide the historical background of the society as a basis for current members to contribute to the continued improvement of our scientific organization.     

Effects of whey protein hydrolysate on growth promotion and immunomodulation in mouse pups in artificial rearing system

This study aimed to investigate the effects of whey protein hydrolysate (WPH) on the growth and immunity of mouse pups in artificial rearing (AR) system. Mouse pups were reared in the AR system with artificial milk including 5% WPH (AR with WPH) or not (AR without WPH), and the remaining pups were reared by their mother (dam) for 14 days after birth. The body weight change and body weight gain rates in the AR with WPH group were significantly higher than those observed in the AR without WPH group and similar to those in the dam group. Moreover the feed and protein efficiencies in the AR with WPH group were significantly higher than those of the AR without WPH group. In addition, the supplement of WPH in the AR system was shown to significantly elevate the number of CD3⁺CD8⁺, B220⁺CD19⁺, IA/IE⁺CD11c⁺, and CD11b⁺ in the thymocyte and/or splenocyte, and the thymus weight. Furthermore, MALDI‐TOF/MS analysis identified the amino acid sequences corresponding to some peptides, and indicated that VRTPEVDDE had the highest relative intensity among the peptides from tested WPH. Therefore, WPH would be required to not only promote growth, but also exert immunomodulatory activities in mouse pups in AR system.     

Glycation and phosphorylation of beta-lactoglobulin by dry-heating: effect on protein structure and some properties

Beta-lactoglobulin (beta-Lg) was glycated with maltopentaose and subsequently phosphorylated by dry-heating in the presence of pyrophosphate to investigate the structural and functional properties of phosphorylated beta-Lg. The circular dichroism spectra showed that the change of the secondary structure in the beta-Lg molecule by glycation and subsequent phosphorylation was small. The differential scanning calorimetry thermograms of beta-Lg showed that the denaturation temperature of the most stable domain was only slightly affected, whereas the retinol-binding activity of beta-Lg was somewhat reduced by glycation and subsequent phosphorylation. These results indicated that the conformational changes of the beta-Lg molecule by glycation and subsequent phosphorylation were mild. The anti-beta-Lg antibody response was somewhat reduced by glycation, but significant changes were not observed by phosphorylation. Although the stability of beta-Lg against heat-induced insolubility was improved by glycation alone, it was further enhanced by phosphorylation. The calcium phosphate solubilizing ability of beta-Lg was enhanced by phosphorylation following glycation.     

Nine cases of granular cell tumors in B6C3F1 mice

The histological characteristics of 9 cases of granular cell tumors (GCTs) observed in B6C3F1 mice were examined to determine their cellular origin. Seven of the 9 cases were found in the uterus and other 2 cases were in the subcutaneous tissue. Tumor cells had abundant granules in the cytoplasm which were stained with PAS and were resistant to diastase treatment. Ultrastructurally, the granules were identified as lysosomes. The cell surface had cytoplasmic processus showing interdigitation with adjacent cells. A character feature of the tumor cells was the presence of a desmosome-like structure on their cell surface but no basal lamina was demonstrated. Although GCTs have been considered to be derived from Schwann cells on the basis of their ultrastructural features and S-100 protein-immunopositive findings, the absence of basal lamina in the present cases may raise a controversy as to their origin.     

Combined hepatocellular and cholangiocellular carcinoma in a dog

A transitional type of combined hepatocellular and cholangiocellular carcinoma developed in a 12-year-old male Yorkshire terrier dog. The tumor was histologically composed of both hepatocellular carcinoma and cholangiocellular carcinoma components, and both elements were closely intermingled. Intraluminal mucin accumulation in cytokeratin-positive tubular/glandular structures was observed within the cholangiocellular carcinoma components and this feature was useful histological marker for a differential diagnosis between combined hepatocellular and cholangiocellular carcinoma and a pseudoglandular type of hepatocellular carcinoma. This primary hepatic tumor is extremely rare in dogs.     

A morphological study off a thyroid carcinoma in a medaka, Oryzias latipes (Temminck & Schlegel)

A large mass protruding beyond the left operculum was found in an adult male medaka, Oryzias latipes (Temminck & Schlegel). Histologically, the mass was mainly composed of thyroid follicles measuring up to 292 μm in diameter. The follicular epithelium consisted of cuboidal or squamous cells. The follicles lacked colloidal material in the lumen. The thyroid tissue infiltrated into the kidney. Electron microscopically, the tumour cells were characterized by dilation and vesiculation of rough endoplasmic reticulum, which extended throughout the cytoplasm, and an irregular outline of the nucleus. Mitotic figures and partly degenerate cells were frequently observed. Based on the above features, the tumour was diagnosed as a follicular carcinoma of the thyroid, the first reported case in the medaka.     

Cesium-137 discharge into the freshwater fishery ground of grazing fish, ayu Plecoglossus altivelis after the March 2011 Fukushima nuclear accident

The Fukushima nuclear accident led to deposition of radionuclides into the freshwater fishery ground of ayu Plecoglossus altivelis. For the purpose of more comprehensive understanding of the radioactive contamination, cesium-137 (¹³⁷Cs) was analyzed in running water, muddy sediment, attached algae, and ayu using samples from three river systems with different levels of contamination within Fukushima Prefecture in summer and autumn 2011. The amount of ¹³⁷Cs contained in water as well as in sediment declined over an interval of two months, although the concentration in sediment samples was up to 10,000-fold higher than that in water samples. The changes in ¹³⁷Cs concentration of algae showed different courses among the three river systems, the concentration being greater in autumn in the river systems with high and moderate radioactive contamination. ¹³⁷Cs detected within a single stock of ayu appeared to be excreted rather rapidly with a calculated half-life of approximately 39 days, while the concentration ratio ranged from 10³ to 10⁴ l/kg, attaining higher levels than previously reported. These findings indicate that the most important pathway of ¹³⁷Cs into ayu is via intake of algae as food but that the retention time of ¹³⁷Cs inside ayu is relatively short.