畠山 仁

INTRODUCTION: Spontaneously hyperlipidemic (SHL) mice, a mouse strain derived from an inbred strain of Japanese wild (original)-type mice (KOR; Mus musculus molossinus), show high plasma cholesterol concentrations with disruption of the apolipoprotein E (Apoe) gene. However, the details of the Apoe gene of SHL mice have yet to be described. MATERIAL AND METHODS: The DNA sequence of the Apoe gene of SHL mice was compared to that of control KOR mice in genomic DNA and cDNA analyses. RESULTS: In the DNA analysis, a 4700-bp fragment was found to be inserted into exon 4 of the Apoe gene of SHL mice. The insertion contained two 365-bp repeats at each terminal and was flanked by a 6-bp target duplication at each side. The inserted fragment produced a frameshift of an early stop codon, resulting in a protein product that consisted of 87 amino acids in SHL mice compared to 311 amino acids in control KOR mice. CONCLUSIONS: These findings provide useful information about the molecular basis of SHL mice and related lipid disorders.

Fibroblast growth factor receptor 4 (FGFR4), one of four tyrosine kinase receptors for FGFs, is involved in diverse cellular processes. Activation of FGF19/FGFR4 signaling is closely associated with cancer development and progression. In this study, we examined the expression and roles of FGF19/FGFR4 signaling in human pancreatic ductal adenocarcinoma (PDAC). In human PDAC cases, FGFR4 expression positively correlated with larger primary tumors and more advanced stages. Among eight PDAC cell lines, FGFR4 was expressed at the highest levels in PK-1 cells, in which single-nucleotide polymorphism G388R in FGFR4 was detected. For inhibition of autocrine/paracrine FGF19/FGFR4 signaling, we used BLU9931, a highly selective FGFR4 inhibitor. Inhibition of signal transduction through ERK, AKT, and STAT3 pathways by BLU9931 reduced proliferation in FGF19/FGFR4 signaling-activated PDAC cells. By contrast, BLU9931 did not alter stemness features, including stemness marker expression, anticancer drug resistance, and sphere-forming ability. However, BLU9931 inhibited cell invasion, in part, by downregulating membrane-type matrix metalloproteinase-1 in FGF19/FGFR4 signaling-activated PDAC cells. Furthermore, downregulation of SIRT1 and SIRT6 by BLU9931 contributed to senescence induction, priming these cells for quercetin-induced death, a process termed senolysis. Thus, we propose that BLU9931 is a promising therapeutic agent in FGFR4-positive PDAC, especially when combined with senolysis (195/200).

Abdominal ultrasonographical and computed tomography examinations of a 12-year-old neutered female toy poodle revealed a protruding mass, approximately 2 cm in diameter, at the apex of the bladder. The mass was firm and haemorrhagic with a homogeneously brownish-yellow cut surface. Microscopically, it was unencapsulated and located in the muscle layer with invasion of the extra-muscular layer. It was composed of spindloid to oval neoplastic cells that formed irregular clefts and diffuse sheets that dissected bundles of collagen. Immunohistochemically, the neoplastic cells were positive for vimentin and lymphatic vessel endothelial hyaluronan receptor 1 antigens, but negative for cytokeratin AE1/AE3, factor VIII-related antigen, CD31, CD34, Prox-1, S100, desmin, α-smooth muscle actin and MyoD1. Negative immunolabelling for laminin antigen supported the absence of evidence of a basal lamina on ultrastructural examination. Based on these findings, this tumour was identified as a lymphangiosarcoma. To the best of our knowledge, this case is the first report of lymphangiosarcoma arising from the bladder in a dog.

The Japanese murrelet (Synthliboramphus wumizusume) is an endangered small seabird species in Japan. Molecular sexing using PCR targeting of the gene encoding chromodomain helicase DNA-binding protein 1(CHD1) has been used for sex identification. Specifically, PCR using any of three commonly used primer sets (CHD1F/1R, 2550F/2718R and P2/P8) has permitted sexing in many bird species. CHD1F/1R and 2550F/2718R permitted molecular sexing in Japanese murrelet; however, P2/P8 did not permit. To generate a primer pair that permits efficient molecular sexing in this species, a new primer set, CHD1F1/1R1, was prepared to permit amplification of smaller products from degraded DNA samples. The electrophoretic patterns of PCR products amplified with the new primer set were easily classified as female or male. Additionally, the PCR product indicated the presence of a polymorphism in the fragment from chromosome W. The PCR fragments of long-type (WL) and short-type (WS) polymorphisms were observed only in females. When the distribution of the CHD1 gene on chromosome W of 61 female Japanese murrelet on Biroujima Island in Miyazaki Prefecture, WL and WS were observed in 90.2% and 9.8%. The DNA polymorphism is derived from the number of copies of a 32-bp-repeat unit, with WL and WS corresponding to two and one 32-bp-repeats, respectively.

A 26-year and 6-month-old male sika deer that was kept at the Showa Park, Tokyo, Japan, collapsed and died of severe disease wasting and severe tabefaction. Grossly, numerous masses, 0.3-1.0 cm diameter, were dispersed throughout the liver. The multiple masses were composed of tumor cells, which had hypochromatic nuclei and abundant faintly eosinophilic cytoplasm, arranged in nests of various sizes. Immunohistochemically, tumor cells were positive for cytokeratin, chromogranin A, synaptophysin and gastrin. Ultrastructurally, the cytoplasm of the tumor cells contained abundant membrane-bound electron-dense granules. A metastatic lesion was observed in the renal, hepatic and pancreatic lymph nodes. On the basis of these findings, this tumor was diagnosed as a neuroendocrine carcinoma with metastases to the lymph nodes.

A 2-year-old neutered female Shiba dog exhibited laboured breathing for 1 month. Computed tomography of the thoracic cavity revealed multiple nodules (2–5 mm diameter) in the lungs. Grossly, the lungs were firm and normal in shape. The nodules were grey–white in colour. Microscopically, the nodules were non-encapsulated and exhibited an irregular shape. They were composed of polygonal or spindle cells with indistinct cell borders arranged in sheets. The cells had large, round, hyperchromatic nuclei and abundant pale eosinophilic cytoplasm with no atypia. Intrapulmonary arterial emboli and infiltration into the bronchioles were observed. Immunohistochemically, the cells were positive for vimentin and negative for cytokeratin, glial fibrillary acidic protein and α-smooth muscle actin. Ultrastructurally, the cells displayed cytoplasmic processes, desmosomes and intermediate filaments. These findings led to a diagnosis of diffuse pulmonary meningotheliomatosis with sarcomatous transformation. To the best of our knowledge, this is the first report of diffuse pulmonary meningotheliomatosis in a dog.

A 35-mo-old spayed female mixed-breed cat with continuous vomiting, emaciation, and abdominal distention for 2 wk was presented to a private veterinary clinic for evaluation. At 71 d after the initial visit, the cat died with anemia, jaundice, and hypoalbuminemia, and was subjected to autopsy. Grossly, numerous firm masses, 0.5-2.5 cm diameter, were randomly located in the left lobe of the pancreas. Histologic examination revealed that the pancreatic mass consisted of 2 tumor cell types: mostly small round cells with a minority of epithelial cells. The small cells were arranged in nests of various sizes, which were separated by thin fibrous stroma, and had small, round, hyperchromatic nuclei, scant cytoplasm containing argyrophilic granules, and often formed rosettes. The epithelial cells formed luminal structures. Metastases were observed in the liver, greater omentum, and pancreatic, gastric, pulmonary, and mediastinal lymph nodes. Immunohistochemical examination revealed that the small cells were positive for vimentin, neuron-specific enolase, chromogranin A, cytokeratin (CK) AE1/AE3, and trypsin, whereas the epithelial cells were positive for AE1/AE3, trypsin, CK19, and nestin. Ultrastructurally, the small cells contained abundant electron-dense granules, ~200 nm diameter, whereas the epithelial cells had apical microvilli and numerous zymogen granules, ~300 nm diameter. These findings indicated that the tumor was a pancreatic neuroendocrine carcinoma with exocrine differentiation and systemic metastases.

Providing beef liver for raw consumption was banned in Japan on July 1, 2012. To lift the ban, the establishment of effective countermeasures for safe raw consumption is necessary. In this study, we examined the effects of high hydrostatic pressure processing on raw beef liver. Beef liver samples subjected to 300MPa of pressure or higher for 10min at 25 degrees C became firmer and showed a paler color and were considered unsuitable for raw consumption. More than 3.0 log reductions of bacteria were seen after treatments at 400 and 500MPa, but the treatment with lower pressure did not show enough microcidal effects for safe consumption. Histological and ultrastructural analysis revealed that high hydrostatic pressure processing increased mitochondrial swelling and reduced rough endoplasmic reticula in hepatocytes, and such changes might be related to the observed changes of texture in the treated raw beef liver.

A 3-y-old male miniature Dachshund was presented with an ~0.8 cm diameter mass in the right mandibular region. Fourteen months later, the mass was 5 × 4 × 3 cm. Grossly, the mass was encapsulated and was homogeneously gray-white on cut surface. Microscopically, the mass was composed of large, round to polygonal tumor cells that were arranged in solid nests and cords separated by a fibrovascular stroma. Tumor cells had large, round, hypochromatic nuclei containing large prominent nucleoli and abundant eosinophilic cytoplasm containing dark blue granules visible with phosphotungstic acid-hematoxylin stain. Metastasis was observed in the mandibular lymph node. Immunohistochemically, tumor cells were positive for CK AE1/AE3, low-molecular-weight CK (CAM5.2), E-cadherin, mitochondria ATPase beta subunit, and S100, but were negative for vimentin, carcinoembryonic antigen, p63, CK14, CD10, and chromogranin A. Ultrastructurally, tumor cells contained numerous mitochondria. Therefore, the tumor was diagnosed as an oncocytic carcinoma of the mandibular gland.

Telomere shortening occurs when cells divide, both in vitro and in vivo. On the other hand, telomerase is able to maintain telomere length in cells by adding TTAGGG repeats to the ends of telomeres. However, the interrelationships existing among telomere length, telomerase activity and growth in vertebrates remain to be clarified. In the present study we measured telomere length (terminal restriction fragment length), telomerase activity and body growth of Oryzias latipes from the embryo stage until senescence. During the rapid growth stage (age 0-7 months), telomeres shortened in parallel with decreasing telomerase activity. Then, during adolescence (age 7 months - 1 year), telomeres lengthened quickly as growth slowed and telomerase activity increased. In the adult stage (age 1-4 years) characterized by little growth, telomerase activity decreased gradually and telomeres shortened. Our data indicate that telomere attrition and restoration are linked to growth and telomerase activity, and suggest that critical loss of telomere homeostasis is associated with mortality in this animal.

A 10-year-old female border collie was presented with a mass (2 cm diameter) in the fifth mammary gland. The mass was located in the subcutis and the cut surface was grey white in colour. Microscopically, the mass was composed of tumour cells arranged in nests of various sizes separated by delicate fibrovascular stroma. The tumour cells had small, round hypochromatic nuclei and abundant cytoplasm. Metastases were observed in the inguinal lymph node. Immunohistochemically, most tumour cells expressed cytokeratin (CK) 20, chromogranin A, neuron-specific enolase, synaptophysin and oestrogen receptor-beta, but not low molecular weight CK (CAM5.2), p63 and insulin. Ultrastructurally, the tumour cells contained a large number of electron-dense granules corresponding to neuroendocrine granules. Based on these findings, this case was diagnosed as a neuroendocrine carcinoma of the mammary gland. (C) 2014 Elsevier Ltd. All rights reserved.

In 2008, several episodes of mortality were recorded in cultured populations of juvenile greater amberjack reared in the southwest region of Japan. Diseased fish had asymmetrical abdominal distention and pale gills. The head kidney, trunk kidney, and spleen of every fish that was examined was enlarged and discolored. The results of all microbiological and molecular biological assays of tissues taken from diseased fish were negative for major known pathogens. Histopathologically, the disease was characterized by proliferative interstitial nephritis and proliferative splenitis associated with minute, round structures within the cytoplasm of proliferating mono-nucleated cells. Transmission trial using the enlarged trunk kidney from a naturally infected fish successfully reproduced the disease. The results indicate that this disease is caused by an infectious microorganism, and the most likely etiological agent is the minute, round structures which are probably a hitherto unknown eukaryotic microorganism. © 2014 The Japanese Society of Fish Pathology.

A novel canine tumor cell line designated as the CMS-C cell line was established from pleomorphic rhabdomyosarcoma (RMS) raised in the prostate gland of a 14-year-old intact male mixed-breed dog. CMS-C cells displayed the same immunohistochemical characteristics (positive for vimentin and desmin and negative for cytokeratin and smooth muscle actin) as the original tumor cells and express myoD1 and UCP3, known as striated muscle-specific molecules, as shown by RT-PCR assay. Therefore, the established CMS-C cell line appears to be of rhabdomyoblast cell origin. The CMS-C cell line established from pleomorphic RMS will be a useful tool for further studies about canine RMS.

We developed a long-term culture system for Japanese flounder Paralichthys olivaceus leukocytes supported by JFF07-1 feeder cells established from Japanese flounder fin tissue. Kidney leukocytes were seeded onto a monolayer of the feeder cells in enriched RDF medium supplemented with 20% fetal bovine serum and 2.5% flounder serum. Several colonies adhered to the feeder cells after 7 days of cultivation, demonstrating leukocyte proliferation. Increasing numbers of floating cells, which signified colony growth, were observed as the length of the culture period increased. The optimum culture conditions consisted of an incubation temperature of 25°C, the addition of 2.5% flounder serum to the medium and the inoculation of kidney leukocytes at a density of 2 × 10 6 cells/mL. The proliferated cells were grouped into three types based on May-Grünwald Giemsa staining: basophilic cytoplasmic cells (65%), neutrophilic cytoplasmic cells (30%) and large cells containing many vacuoles (5%). The cells showed acid-phosphatase activity (90%), peroxidase activity (31%) and non-specific esterase activity (57%). Electron microscopy revealed that many of the cells contained endoplasmic reticula and mitochondria, but not specific granules with the fibrillar structure that characterizes flounder granulocytes. A monocyte lineage thus appeared to be the dominant population among the proliferated cells in the culture system. The composition of growing cells was also kept after 20 passages.

The chemokine (C-X-C) receptor 1 (CXCR1) expressed on the neutrophil surfaces interacts primarily with interleukin-8 (IL-8) and has an important role in immune response. Two interesting single nucleotide polymorphisms (SNPs), SNP CXCR1+777G>C and SNP CXCR1-1768T>A, that exhibit an association with subclinical mastitis and milk quality in dairy cattle, respectively, have been reported in the bovine CXCR1 gene. The aim of this study was to demonstrate the presence of the two SNPs in the CXCR1 gene of Japanese Black cattle and examine the association between the SNPs and clinical diseases including intestinal and respiratory diseases in calves. Genotyping of the SNPs in healthy Japanese Black cattle showed that the SNPs were also present in Japanese Black cattle with gene frequencies of 0.37 and 0.15 for the C-type allele in SNP CXCR1+777 and for the A-type allele in SNP CXCR1-1768, respectively. Statistical analysis of the genotype distribution of the SNPs in the bovine CXCR1 gene in healthy and clinical intestinal or respiratory diseased Japanese Black cattle indicated no significant association of the SNPs with clinical diseases in the calves. However, a significant correlation of the number of A alleles in SNP CXCR1-1768 with white blood cell (WBC) and platelet counts was found in the disease group. It is possible that the SNP in the bovine CXCR1 gene plays a role in modulating the hematological profile of WBC and platelet counts.

Previous studies of telomeres and telomerase have focused mostly on mammals, and data for other vertebrates are limited. We analyzed both telomere length (terminal restriction fragment length) and telomerase activity in a small freshwater teleost fish, the medaka (Oryzias latipes), and found that the telomeres shorten during ageing despite the fact that a considerable amount of telomerase activity is ubiquitously detectable throughout the life of the fish. Since the telomere attrition rate during development was greater than that in adulthood, telomere length is inversely correlated with the increase in body length. The difference in telomere length among medaka individuals was similar to that in humans, and the individual specific differences were evident even at the earliest embryonic stage. Telomerase activity was ubiquitously detectable not only in the body of the embryo but also in the systemic organs of mature individuals throughout their entire life span. These data suggest that telomere attrition during ageing in medaka, which is similar to that in humans, may be a major factor determining their mortality, and that telomere maintenance through strong telomerase activity may be required for the characteristic lifelong continuous growth of this fish.

メスが群を出る野生のチンパンジーの場合、養育環境が変わるため、母と子の養育態度を直接比較することは難しい。一方、飼育下の場合、メスが生まれ育った環境で出産、育児を行う場合もあるため、母と娘の養育態度を一定の範囲内で比較することが可能になる。<br>多摩動物公園で六頭の子育てをし たパイン（1963～2002）の三女チェリー（第４子 1990～）は2005年10月に第一子、ボンボン（オス）を出産。パインが二男トム（1996～）と四女ベリー （1999.12～）を出産、子育てを傍らで見ている。ベリーが幼い頃は、母親と共にベリーと過ごす時間が多く（柿沼他2003a）、パインの死後、ベリーの親代わりをしていた。<br>今回、パインがベリーを養育していた時の記録と、チェリーの養育の比較を行った。パインの特徴としては、群の他の個体に比べ子どもを肌身離さず抱いている傾向があり（柿沼 他2003b）、１８ヶ月時でも子どもを近くに置こうとしていた（柿沼他2004）。また、放飼場内をうろうろする、おおげさに子どもをなだめるなど、不安傾向の高い様子が伺えた（柿沼他2005）。チェリーも落ち着き無く移動する傾向は見られたが、子どもを肌身離さずというよりは、腕を持ちながら体から離すなど、ペコ（1961～）のスタイルに似ている部分も見られた。また子どもの活動内容もベリーに比べ多く、５ヶ月時に母親の近くでロープにぶら下がって遊ぶなど、活発に動いている。活動内容はどちらかというとペコの子どもモコ（2001.4～）に似ている（柿沼他2003a）。<br>今後はチェリーの養育態度、ボンボンの活動内容の変化を他個体のデータと比較検討することで、養育態度の世代間伝達の可能性について検討する。

Invasion of chicken embryo fibroblast (CEF) cells by the virulent encapsulated Pasteurella multocida strains P-1059 (serovar A:3) and X-73 (serovar A:1) and an avirulent noncapsulated derivative P-1059B (serovar -:3) was investigated. The number of intracellular bacteria increased for all the strains after 2, 4 and 6 h post-inoculation to CEF cells. By 6 h post-inoculation, the number of invaded bacteria of encapsulated strains was significantly higher than noncapsulated strain and reached 150- and 112-fold for strains P-1059 and X-73, respectively, while it was 9-fold for strain P-1059B as compared to the number of invaded bacteria recovered after 2 h post-inoculation. Electron microscopy of invasion by encapsulated strains showed that the bacteria were adhering to CEF cells membrane after 1 h of inoculation. By 4-h, one or two bacteria were detected within membrane-bound vacuoles of the intracellular space. The number of intracellular bacteria markedly increased at 14 h post-inoculation. Invasion of all strains was inhibited significantly when the monolayers were treated with periodic acid (P<0.001) or trypsin (P<0.05). The treatment of bacteria with hyaluronidase did not affect invasion. The present results indicate that avian P. multocida capsular type A strains are invasive and that the receptor on CEF cell surface might be glycoprotein.

The role of a 39kDa protein of avian Pasteurella multocida in pathogenesis of fowl cholera was investigated using monoclonal antibodies (Mabs). Mabs were prepared by immunization of BALB/c mice with a crude capsular extract (CCE) of P. multocida strain P-1059 (serovar A:3). Totally eight hybridomas producing Mab were obtained. Immunoblot analysis of the hybridomas revealed that all the Mabs recognized a 39kDa protein of CCE. Treatment of CCE antigen with proteinase K or periodic acid indicated that the epitope recognized was proteinaceous. The Mabs reacted with a major 39kDa protein of CCE from encapsulated strains but not with any protein of non-capsulated strains indicating that a direct correlation between encapsulation and the 39kDa protein. Immunoelectron microscopy on strain P-1059 and the non-capsulated derivative P-1059B (serovar -:3) reacting with the Mabs and gold-labeled anti-mouse IgG indicated that the protein is associated with the capsule. The Mabs significantly inhibited the adherence of encapsulated P. multocida strains to chicken embryo fibroblast cells, but only slightly that of non-capsulated strains. Mice passively immunized with the Mabs were protected from lethal challenge with virulent strains P-1059 and X-73 (serovar A:1). Thus the capsular 39kDa protein was determined to be an adherence factor and a cross-protective antigen of avian P. multocida type A strains.