Urinary lipid production profile in canine patients with splenic mass

Polyunsaturated fatty acids (PUFAs), including arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), are metabolized to various lipid mediators. The profile of these lipid metabolites excreted into the urine reflects inflammatory state of the body and disease conditions. In this study, we quantified 156 types of lipids in urine samples of dogs with splenic mass, using liquid chromatography-tandem mass spectrometry. We found that metabolites of prostaglandin (PG) E₂, F_2α, and D₂, 8-iso-PGF_3α, lyso-platelet activating factor, and 14,15-leukotrien C₄ significantly increased in urine samples of dogs with splenic mass compared to that of healthy dogs. These observations may reflect general inflammatory responses and will help better understanding of the canine splenic mass.     

High susceptibility to zymbal gland and intestinal carcinogenesis in diabetic Otsuka long-evans Tokushima Fatty rats

Diabetes mellitus (DM) and obesity are believed to be risk factors for colorectal cancer in humans. In experiment 1, male nondiabetic Long-Evans Tokushima Otsuka (LETO) rats and Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model animal of type 2 DM, were whole-body X-irradiated (4 Gy) at 6 and 8 weeks of age and euthanized at 78 weeks of age (n=15, respectively). The incidences of small intestine adenocarcinoma in LETO and OLETF rats were 0% and 30%, respectively. In experiment 2, male LETO and OLETF rats (n=24, respectively) were given s.c. injections of 15 mg/kg azoxymethane (AOM) once weekly for 3 weeks and euthanized at 36 weeks of age. The incidences of Zymbal gland tumors in LETO and OLETF rats were 0% and 67%, respectively (P<0.001), whereas those of small intestine adenocarcinoma were 0% and 43% (P<0.001) and those of cecum/colon adenocarcinoma were 46% and 79% (P<0.05), respectively. Fatty change of hepatocytes was common in OLETF rats (63%) but not in LETO rats. Serum triglyceride and free fatty acid levels in OLETF rats were significantly higher than in LETO rats at sacrifice, whereas serum insulin levels in OLETF rats were very diverse. These data suggest that hyperlipidemia plays a significant role in high susceptibility to lower intestinal tract carcinogenesis in OLETF rats; this strain is susceptible to AOM-induced Zymbal gland carcinogenesis.     

Dynamic properties of three types of wood-based composites

This study used a vibration test method to show that grain angles of face veneer have substantial effects on sound velocities and dynamic Youngs moduli of three types of wood-based composites. The sound velocity at 0° grain angle of face veneer was the highest, and it decreased with increasing grain angle in the range of 0° to 90°. This tendency was similar to that for dynamic Youngs modulus. The relationship between the grain angle of face veneer and the sound velocity of three types of wood-based composites can be expressed in the form of Hankinsons equation or a second-order parabolic equation. This study also showed that the application of orthotropic elasticity theory was valid for the three types of wood-based composites. The relationship between the grain angle of the face veneer and the Youngs modulus of three types of wood-based composites can be expressed in the form of the Jenkin equation, Hankinsons equation, or a second-order parabolic equation. Rule of mixture can also be used to predict the Youngs modulus of wood-based composite from the Youngs moduli of the two elements.Part of this study was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, Japan, March 2003 and the 15th Annual Meeting of Chugoku Shikoku Branch of the Japan Wood Research Society, Higashi-Hiroshima, Japan, September 2003     

Temporal water deficit and wood formation in Cryptomeria japonica

Cell behavior in the cambium and developing xylem of 3-year-old Japanese cedar (Cryptomeria japonica D. Don.) trees, during and after an 11-day suspension of irrigation, was analyzed. Leaf xylem pressure potential and tangential strain of the stem surface were monitored throughout the experiment. Anatomical features and numbers of developing tracheids and cambial cells were observed in four trees, sampled on Days 0, 4, 8 and 11 after irrigation was suspended. Daytime xylem pressure potential decreased to -1.9 MPa on Day 7 and remained the same until irrigation was resumed on Day 11. The transverse dimensions of the tracheids, which began to form secondary walls, began to decrease on Day 4. The number of cells in the cambial zone and cell expansion zone decreased abruptly on Day 8. Tangentially aligned developing tracheids with collapsed cell walls were observed in samples harvested on Days 8 and 11. Secondary wall formation was recognized in these tracheids. After the resumption of irrigation, xylem pressure potential recovered rapidly to the same value as before the suspension of irrigation. Tangential strain increased within 30 min after the resumption of irrigation, and continued to increase until the onset of light the next day. Eighteen days after the resumption of irrigation, anatomical features of cells in the cambium and cell-expansion zone were similar to those observed before suspension of irrigation.     

Piezoelectric behavior of wood under combined compression and vibration stresses I: Relation between piezoelectric voltage and microscopic deformation of a Sitka spruce (Picea sitchensis Carr.)

This study investigated the relation between piezoelectric behavior and the deformation of trachieds in real time under combined compression and vibration stresses. Scanning electron microscope images were recorded directly into a video recorder. Two types of microscopic destruction were observed in the specimens. With the first type, although a small uprush around the boundary of the annual ring was observed, the specimens were broken only by shearing fracture in the 45° direction. With the second type, the specimens were finally broken by shearing fracture after repeated buckling. In these cases the piezoelectric voltage increased almost linearly in the elastic region, proceeded to the maximal point, and then decreased gradually. Finally a clear peak appeared in the buckling and shearing fracture. There is a curved relation between the specific gravity and the piezoelectric parameter when the influence of voids is considered, and there is a linear relation between the dynamic Young's modulus and the piezoelectric parameter when the stress is considered.Part of this paper was presented at the 46th annual meeting of the Japan Wood Research Society in Kumamoto, April 1996     

Effects of the lateral growth rate on wood quality parameters of Eucalyptus grandis from different latitudes in Brazil and Argentina

Climate change resulting from increased atmospheric carbon dioxide (CO₂) and shortages of fossil fuels such as petroleum are major problems worldwide. Under these conditions, demand for woody biomass resources is increasing. We investigated the feasibility of using fast-growing Eucalyptus grandis for material production. Samples of E. grandis were collected from four plantations in different latitude divisions, including tropical and subtropical Brazil and subtropical Argentina. Various xylem qualities were measured and related to the lateral growth rate. Lateral growth rate did not significantly affect the longitudinal released strain of the surface growth stresses or the xylem density at any of the sampling sites. Higher lateral growth rate, higher values of xylem density, and lower absolute values of the released strain were observed in plantations closer to the equator. Higher growth rates in tropical climate promote longer fiber length. In subtropical plantations, smaller diameter trees will produce tension wood with smaller microfibril angles. Planting E. grandis closer to the equator thus produces higher quality wood than in plantations at lower latitudes.     

Characterization of monoclonal antibodies against Actinobacillus pleuropneumoniae serotype 5.

Two monoclonal antibodies against Actinobacillus pleuropneumoniae serotype 5, designated as 5MAb-1 and 5MAb-6, were characterized. Enzyme-linked immunosorbent assay-inhibition tests with whole-cell antigens obtained from strains of serotype 1 through 12 of A pleuropneumoniae revealed that 5 MAb-1 bound to only serotype-5 strains. The epitope recognized by 5MAb-1 was a carbohydrate that was sensitive to periodate oxidation and resided on the structure of beta-1,6-linked D-galactose in an O-antigen polysaccharide of serotype-5 lipopolysaccharide. Analysis of these results revealed that the O-antigen polysaccharide of lipopolysaccharide was 1 of the antigenic determinants responsible for the serotype specificity of A pleuropneumoniae. On the other hand, 5MAb-6 reacted with strains of serotype 1 through 10 in varying degrees and its epitope was located on polypeptides sensitive to proteinase K. In an immunoblotting analysis, 5MAb-6 reacted with 2 polypeptide bands, with molecular weights of approximately 41,500 and 28,000, in the outer membrane protein-rich fraction obtained from strains of serotype 1 through 10. These results indicated that outer membrane proteins from several serotype strains of A pleuropneumoniae possessed common antigenic determinants.     

In vitro infection of fractionated chicken lymphocytes by infectious bursal disease virus

Lymphocytes from bursa of Fabricius and thymus of chickens were purified and separated into the three cell subsets--T, B, and null cells--by the techniques of nylon fiber columns and cytotoxicity tests. The in vitro susceptibility of the fractionated lymphocytes to a virulent strain of infectious bursal disease virus (IBDV) was studied by using immunofluorescence as the infection criterion. B cells were highly susceptible. By contrast, T cells and null cells were insusceptible to infection by IBDV. The relationship between the target cells for virus infection and those B cells that possessed surface immunoglobulin (SIg) was tested. B cells were further divided into SIg(M)- and SIg(G)-bearing cells by immunoadsorbent columns employing anti-immunoglobulin M(IgM) (mu-specific) or anti-IgG (gamma-specific) sera coated with Sephadex. The SIg(M)-bearing cells were highly susceptible. These results suggest strongly that SIg(M)-bearing B cells were the target cells for infection by IBDV.     

Sequential changes in the number of surface immunoglobulin-bearing B lymphocytes in infectious bursal disease virus-infected chickens

Variations of B lymphocytes bearing surface immunoglobulin (SIg) M [SIg(M)] and G [SIg(G)] were studied in the spleen and peripheral blood of chickens infected with infectious bursal disease virus (IBDV). The proportion of SIg-bearing B lymphocytes and SIg(M)- and SIg(G)-bearing B cells in chickens infected at one day of age decreased from 1 week postinfection (p.i.) onward and was significantly lower at 8 weeks p.i. In chickens infected at 4 weeks, the percentage of SIg-bearing B cells decreased severely during the first 2 weeks p.i. The decrease of SIg(M)-bearing B cells preceded that of SIg (G)-bearing B cells: the lowest percentage of SIg(M)-bearing B cells has observed 2 to 3 days p.i., and that of SIg(G)-bearing B cells was seen 4 days p.i. The results suggest that SIg(M)-bearing B cells are the major target for IBDV infection.