Imatinib elicited a favorable response in a dog with a mast cell tumor carrying a c-kit c.1523A>T mutation via suppression of constitutive KIT activation

Target therapy using the tyrosine kinase inhibitor imatinib is one of the new therapeutic approaches for canine mast cell tumors (MCTs). In the present report, we demonstrate a clinical response to imatinib in a dog with MCT carrying a c-kit c.1523A>T mutation. Moreover, the effect of this mutation on the phosphorylation status of KIT and the inhibitory potency of imatinib on the phosphorylation of the mutant KIT were examined in vitro. A dog with a MCT tumor mass on the right forelimb sole with lymph node metastasis and mastocytemia was treated with imatinib. The MCT mass markedly shrank and mastocytemia became undetectable with 2 weeks of treatment. The lymph node enlarged by metastasis became normal in size with 5 weeks of treatment. From the sequencing analysis of c-kit in tumor cells, a substitution mutation c.1523A>T that alters the amino acid composition (p.Asn508Ile) within the extracellular domain of KIT was identified. The mutant KIT expressed on 293 cells showed ligand-independent phosphorylation and imatinib suppressed this phosphorylation in a dose-dependent manner. From these findings, imatinib was considered to elicit a clinical response in a canine case of MCT via inhibition of the constitutively activated KIT caused by a c-kit c.1523A>T mutation.     

Differentiation of uterine natural killer cells in pregnant SCID (scid/scid) mice

To determine whether functional T- and B-cells can affect differentiation and/or proliferation of uterine natural killer (uNK) cells, their numbers in SCID mice (genotype, C.B.-17/Icr-scid/scid) were compared with those of control mice (genotype, C.B.-17/Icr-+/+) on days 8, 12 and 16 of pregnancy. Using biotinylated-Dolichos biflorus agglutinin (DBA) lectin staining, uNK cells can be readily classified into 4 subtypes, I to IV, from immature to mature types. The number of uNK cells was significantly lower in the decidua basalis of SCID mice than in that of control mice on day 8 of pregnancy. Particularly, the number of uNK cells of immature subtype II was significantly lower in SCID mice than in the control mice. By day 12, however, the uNK cell number in the SCID mice reached the same level as that of the control mice. It is likely that uNK cell differentiation in SCID mice was delayed during the early placentation period due to a lack of functional T and B cells.     

Changes in morphological phenotypes and essential oil components in lavandin (Lavandula × intermedia Emeric ex Loisel.) transformed with wild-type strains of Agrobacterium rhizogenes

Hairy roots were induced from leaf-derived calli of lavandin (Lavandula × intermedia Emeric ex Loisel.) by infection with wild-type strains of Agrobacterium rhizogenes, A-5 (MAFF 02-10265) and A-13 (MAFF 02-10266). A-5-inoculated calli formed hairy roots more efficiently than A-13 ones. The transgenic shoots could be obtained from hairy root segments mediated by each Agrobacterium strain. However, different plant growth regulators were required for efficient adventitious shoot formation in each strain. In A-5, the most efficient adventitious shoot formation rate of 23.8% was observed in a medium with 4.4 × 10⁻⁶ M of 6-benzylaminopurine. On the other hand, a significantly higher rate of 13.2% was detected in a medium with 4.0 × 10⁻⁷ M of N-(2-chloro-4-pyridyl)-N′-phenylurea in A-13. Most of the regenerated plants showed dwarfism with closed internodes and extensive lateral branching, which were typical characteristics of ‘hairy root syndrome’. On the other hand, only nine of the 45 regenerated plants formed flower buds in early June, a delay of about one month compared with nontransgenic regenerated plants. The floral stalks and spikes of these plants were very short, resulting in a compacted form. Many regenerants showed a significantly lower productivity of essential oil than nontransgenic regenerants. Moreover, the relative percentage of the linalyl-cation-derived compounds, linalool and linalyl acetate, decreased in most of the regenerated plants. Compact plants with the ability of flower bud formation are assumed to be valuable not only for lavandin breeding, but also for clarifying the interaction between rol genes expression and essential oil production.     

Quantitative study of the optic nerve in buffaloes (Bos bubalis)

The total number, distribution and size of the optic axons of the buffalo (Bos bubalis) were studied in five optic nerves using light and transmission electron microscopes. Semithin sections were cut at 0.40 μm with an ultramicrotome and stained with 0.3% toluidine blue for light microscopic analysis. The ultrathin sections were cut at 70 nm, mounted on copper mesh grids (No. 200) and stained with saturated solution of uranyl acetate dihydrate and examined with the transmission electron microscope. The optic axons were assessed in 10 regions of roughly equal area. The total number of optic fibers was estimated on semithin and ultrathin sections. The measurements of the axonal diameters were made on electron micrographs taken from various regions across the optic nerve. The mean value of the total number of optic axons calculated was 1 397 099 ± 10 995 and 1 584 255 by light and electron microscopes, respectively. There was very little difference in the density of the optic fibers between the 10 regions of the optic nerve. The optic nerve area ranged from 18.2 to 22.4 mm² (mean, 21.3 mm²). The diameters of the optic axons ranged from 0.5 to 12.3 μm (mean, 3.3 μm).     

Short-term effects of thinning intensity on scenic beauty values of different stands

Forest management has significant influences on the preferences of people for forest landscapes. This study attempted to evaluate the effects of thinning on the scenic value of forests. Five typical stands in Nanjing Wuxiangsi National Forest Park were subject to a designed thinning experiment from February to May 2007 with four intensities: unthinned, light-thinning, middle-thinning, and high-thinning. Next, people’s preferences for landscape photographs taken in plots with different thinning intensities were assessed by a scenic beauty estimation (SBE) developed by using normal function theory (N-SBE) 2 years after thinning. In order to resolve shortcomings of N-SBE, another SBE calculation method based on weighted sum theory (W-SBE) was developed in the study, and it was demonstrated to have the same reliability as N-SBE by statistical methods. Then, the difference of W-SBE between different thinning intensities was analyzed by paired samples T test. The results suggested that it was significant, at the 0.01 level, between unthinned plots and all thinned plots, and significant, at the 0.05 level, between high-thinning and light-thinning, and between high-thinning and middle-thinning, while there was no significant difference between middle-thinning and light-thinning. Finally, a stepwise regression model was established between W-SBE as the dependent variable and some possible impact preference factors as independent variables. This indicated that landscape value was diminished with increase of tree density, canopy density, and opening of understory, while the value improved with the increment of average diameter at breast height and tree height, species diversity or uniformity, and also the improvement of accessibility and environment neatness in the forest.     

On the mechanical interaction between cellulose microfibrils and matrix substances in wood cell walls: effects of chemical pretreatment and subsequent repeated dry-and-wet treatment

We investigated the influences of chemical pretreatments and subsequent repeated dry-and-wet (RDW) treatments on the mechanical linkage between cellulose microfibrils (CMFs) and matrix substances (MT) in wood cell wall. Sugi (Cryptomeria japonica D. Don) quarter-sawn specimens were subjected to various types of chemical pretreatments, including ethanol and benzene extraction, delignification, alkali extraction, and hygrothermal treatment, to give substantial damages to principal constituents of wood cell wall, followed by 5 times of RDW treatment. After giving chemical pretreatment, the d-spacing of (200) lattice plane of cellulose I_β (d ₂₀₀), the crystallinity of wood cell wall, and the crystal size of the cellulose were measured at the fiber saturated point, using X-ray diffraction techniques. Thereafter, these were measured again at the absolutely dried condition in the process of subsequent RDW treatments. The d ₂₀₀ in specimens, which were given to light pretreatments, largely expanded by drying at the early stages of RDW treatments, then it decreased and became constant after 5 times of RDW treatments. On the other hand, d ₂₀₀ in specimens, which were given to intensive pretreatments, remained constant at a relatively small level throughout the whole process of RDW treatments. After 5 times of RDW treatments, d ₂₀₀ became similar values between the above two groups. This suggests that RDW treatments have similar effects as intensive pretreatments, which induce substantial damages to the microscopic region in the wood cell wall such as interfacial separation between CMF, MT, and so forth. These defects would weaken mechanical interaction between CMF and MT in the wood cell wall during drying.     

Detection of QTLs to reduce cadmium content in rice grains using LAC23/Koshihikari chromosome segment substitution lines

To advance the identification of quantitative trait loci (QTLs) to reduce Cd content in rice (Oryza sativa L.) grains and breed low-Cd cultivars, we developed a novel population consisting of 46 chromosome segment substitution lines (CSSLs) in which donor segments of LAC23, a cultivar reported to have a low grain Cd content, were substituted into the Koshihikari genetic background. The parental cultivars and 32 CSSLs (the minimum set required for whole-genome coverage) were grown in two fields with different natural levels of soil Cd. QTL mapping by single-marker analysis using ANOVA indicated that eight chromosomal regions were associated with grain Cd content and detected a major QTL (qlGCd3) with a high F-test value in both fields (F = 9.19 and 5.60) on the long arm of chromosome 3. The LAC23 allele at qlGCd3 was associated with reduced grain Cd levels and appeared to reduce Cd transport from the shoots to the grains. Fine substitution mapping delimited qlGCd3 to a 3.5-Mbp region. Our results suggest that the low-Cd trait of LAC23 is controlled by multiple QTLs, and qlGCd3 is a promising candidate QTL to reduce the Cd level of rice grain.