Detection of Borrelia garinii, Borrelia tanukii and Borrelia sp. closely related to Borrelia valaisiana in Ixodes ticks removed from dogs and cats in Japan

Ticks removed from 1136 dogs and 134 cats all over Japan were examined for Borrelia infection by PCR and sequencing. The 5S-23S rDNA intergenic spacer of Borrelia was detected from two Ixodes persulcatus ticks from two dogs and two unidentified Ixodes spp. from another two dogs in Hokkaido, and two Ixodes granulatus ticks from two cats in Okinawa. Additional 2 I. granulatus from the same cats also showed positive. Sequence analysis of the PCR products revealed that the one from Hokkaido was similar to B. garinii, the three from Hokkaido to B. tanukii, and the four from Okinawa to a novel Borrelia sp. closely related to B. valaisiana. The data was confirmed by analysis of the flagellin gene sequence. Infected ticks carried by companion animals can be introduced into the human environment.     

Maxillofacial rhabdomyosarcoma in the canine maxillofacial area

Three dogs had a diagnosis of maxillofacial rhabdomyosarcoma. These dogs were treated with surgery and/or radiotherapy, and had poor clinical responses. The tumor tissues in all three cases were observed around the upper premolar teeth with ulcerative lesions and CT examinations in each case revealed extensive bony involvement into the maxilla. Two cases were subjected to surgical excision of the tissues, followed by an external radiation therapy. The other case was only treated with palliative radiation. Outcomes of the treatment of all the cases were quite poor because of the invasive and refractory nature of the tumor cells, leading to the local recurrence and lung metastasis early in the clinical course. All dogs died within two months of the first admission.     

Expression of the MDR1 gene and P-glycoprotein in canine mast cell tumor cell lines

Cellular drug resistance to antineoplastic drugs is often due to the presence of a drug efflux pump that reduces intracellular drug accumulation and chemosensitivity. P-glycoprotein (P-gp), which is encoded by the MDR1 gene, is considered to function as an ATP-driven membrane drug efflux pump and appears to play an important role in tumor cell resistance. In the present report, we assessed the expression of MDR1 by RT-PCR in three canine mast cell tumor cell lines, TiMC, CoMS and LuMC, originating from a cutaneous tumor, an oral-mucosal tumor and a gastrointestinal tumor, respectively. P-gp expression was also examined by Western blot analysis, while the functional activity of P-gp was assessed by flowcytometric analysis of intracellular rhodamine-123 (Rhd-123) uptake. The results revealed that MDR1 gene and P-gp were both expressed in CoMS and LuMC cells, whereas neither was present in TiMC cells. In CoMS and LuMC cells, intracellular uptake of Rhd-123 increased in the presence of verapamil, a functional modulator of P-gp. In contrast, TiMC cells did not show any changes in the intracellular accumulation of Rhd-123 after the verapamil addition. These findings suggest that the expressions of MDR1 gene and P-gp probably contribute to cellular drug resistance in canine mast cell tumors.     

Comparative analysis of diterpene composition in the bark of the hybrid larch F<Subscript>1</Subscript>, <Emphasis Type="Italic">Larix gmelinii</Emphasis> var. <Emphasis Type="Italic">japonica × L. kaempferi</Emphasis> and their parent trees

The diterpene compositions in the bark of branches were investigated for two families of the F₁ hybrid, Kurile larch (Larix gmelinii var. japonica Pilg.) × Japanese larch [Larix kaempferi (Lamb.) Carr.] (hereafter F₁) and their parents clones. 13-Epimanool, larixol, larixyl acetate, 13-epitorulosyl acetate (not detected in L. gmelinii var. japonica), isopimaric acid, abietic acid, dehydroabietic acid, and neoabietic acid were detected. Larixol and abietic acid represented more than 50% of the diterpene content in L. gmelinii var. japonica and L. kaempferi, respectively. Larixol and abietic acid were the predominant diterpene components in the F₁, and the proportions of these diterpenes were between those of the parental species. Therefore, the diterpene compositions in the F₁ were hereditarily infl uenced by their parents. The ratios of labdane, pimarane, and abietane diterpenes suggested that the main diterpene biosynthesis pathway in L. gmelinii var. japonica was from copalyl diphosphate (CDP) to labdane-type diterpenes, and that in L. kaempferi was from CDP to abietane-type diterpenes via pimarane type. Furthermore, linear discriminant analysis suggested that the diterpene contents are effective indices for the discrimination of the hybrid seedlings. Part of this article was presented at the Annual Meetings of the Japan Society for Bioscience, Biotechnology, and Agrochemistry in Kyoto, March 2006, and in Tokyo, March 2007     

Genetic control of intra-ring wood density variation in hybrid larch (Larix gmelinii var. japonica × L. kaempferi) F1

Genetic parameters for various wood density traits were estimated in 29-year-old trees of 18 full-sib families of hybrid larch (Larix gmelinii var. japonica × Larix kaempferi) F₁. Intra-ring density variation (IDV) was also evaluated using a model that expresses the pattern curve from earlywood to latewood as a power function. A high IDV indicates an abrupt change in wood density from earlywood to latewood. The ring width and wood density traits of individual rings were determined by X-ray densitometry. Overall wood density (RD) was shown to increase with increasing ring number, ranging from 0.42–0.59 g/cm³, whereas IDV of individual rings decreased gradually from pith outwards. Estimates of individual tree narrow-sense heritability of RD and IDV were 0.66 and 0.67, respectively. IDV showed negative genetic and phenotypic correlations with RD (r _g = −0.99, r _p = −0.72). The predicted genetic gains in latewood proportion and IDV were higher than that of RD. These results suggest that the intra-ring density variation is under moderate genetic control equivalent to wood density. The trend of increasing wood density from earlywood to latewood was associated with changes in both tracheid diameter and cell wall thickness.     

Efficiency of planting hybrid larch F1 ( Larix gmelinii var. japonica × L. kaempferi ) at different planting densities and using seedlings or rooted cuttings

The efficiency of planting a hybrid larch F₁ at two planting densities and of using seedlings of hybrid larch F₁ or rooted cuttings of Gream, the registered variety, was investigated. Significantly more time was required to move from one planting spot to the next in plots with 625 seedlings/ha than in plots with 1,333 seedlings/ha, but there was no significant difference between seedlings and rooted cuttings. Approximately 18% more time was needed to plant a single planting stock at the low planting density than at the high density. The need to prune roots or enlarge a planting hole occurred more often for rooted cuttings than for seedlings, and 17% more time was needed to plant rooted cuttings of Gream than seedlings.     

Growth hormone and lactogenic hormones can reduce the leptin mRNA expression in bovine mammary epithelial cells

Leptin mRNA is expressed in not only adipocytes but also mammary epithelial cells and leptin protein is present in milk. Although milk leptin is thought to influence metabolism or the immune system in neonates, there is little information about the regulation of leptin expression in mammary epithelial cells. We examined the effect of growth hormone (GH) and/or lactogenic hormone complex (DIP; dexamethasone, insulin and prolactin) on leptin mRNA expression in mammary epithelial cells. We used a bovine mammary epithelial cell (BMEC) clonal line, which was established from a 26-day pregnant Holstein heifer. We confirmed that the mRNA was expressed in BMECs and the expression was significantly reduced by GH and/or DIP, when the cells were cultured on both plastic plates and cell culture inserts at days 2 and 7 after stimulation with lactogenic hormones. GH and/or DIP significantly increased level of alpha-casein mRNA in BMECs after 7 days on the cell culture inserts, but no mRNA expression was detected at day 2. GH and DIP significantly stimulated the secretion of alpha-casein from BMEC on cell culture inserts at 3.5 and 7 days. However, neither alpha-casein mRNA expression nor secretion was observed in the BMECs cultured on plastic dishes, even in the presence of GH or/and DIP. These results indicate that GH and DIP can directly reduce leptin mRNA expression in both undifferentiated and functionally differentiated bovine mammary epithelial cell.     

Ehrlichia canis infection in two dogs that emigrated from endemic areas

Two dogs, emigrated from Zambia and China to Japan, were diagnosed with Ehrlichia canis infection. Both cases had thrombocytopenia, non-regenerative anemia, and hypergloblinemia with polyclonal gammopathy. Case 1 had ataxia of the hind limbs. Severe meningitis was revealed by magnetic resonance imaging examination. Intracytoplasmic inclusions were observed in mononuclear cells of cerebrospinal fluid. Case 2 had a history of bilateral epistaxis, and severe pancytopenia was noticed in complete blood count. Diagnosis was finally achieved by nested polymerase chain reaction and sequence analysis. Thus, even in non-endemic areas, E. canis infection should be included in the differential diagnosis of clinically ill dogs that emigrated from endemic areas.     

Development of high-grade B-cell lymphoma concurrent with T-cell chronic lymphocytic leukemia in a dog

Second malignancies are frequent complications in human patients with chronic lymphocytic leukemia (CLL). However, the clinical details and outcome of this phenomenon were unclear in their canine counterparts. Here, we report a dog with high-grade lymphoma concurrent with T-cell CLL. A 10-year-old male golden retriever presented with lymphadenopathies. The lymph nodes contained large-sized lymphocytes, raising suspicion of high-grade lymphoma. Meanwhile, small lymphocytic lymphocytosis in the peripheral blood was consistent with CLL. Interestingly, molecular biological analyses revealed that CLL cells were of the T-cell type, whereas lymphoma cells were of the B-cell type. Chemotherapy using the L-VCA short protocol was effective for 155 days, but the dog died on day 194 after diagnosis, despite rescue therapies.