Ecology of genus Porphyromonas in canine periodontal disease.

Asaccharolytic pigmented Porphyromonas species, including P. endodontalis, P. gingivalis, P. circumdentaria and unclassified species, were isolated from the plaque of adult dogs, but not from any oral sites of puppies and adolescent dogs. With age-dependency, the proportion of Porphyromonas species in the flora of plaque increased. Isolation of the genus Porphyromonas was clearly associated with the progress of periodontol disease. We suggested that Porphyromonas is the exogenous organism and obligate pathogen for canine periodontal diseases.     

Adsorption behavior of aluminum compounds on pulp fibers at wet-end

Various aluminum compounds were added to pulp suspensions, and the adsorption behavior of their aluminum components on pulp fibers was studied. Aluminum contents in the handsheets were determined using an energy dispersive X-ray analyzer attached to a scanning electron microscope and an X-ray fluorescence analyzer. Although aluminum contents in the handsheets increased with increasing additions of the aluminum compounds, the detailed adsorption patterns varied among the aluminum compounds used. Their chemical structures and the pH values of the pulp suspensions greatly influence the adsorption behavior. When fines are present in the pulp suspensions, the aluminum components are predominantly adsorbed on the fines, probably due to their larger surface areas or the higher carboxyl contents compared to those of coarse fibers. Not only aluminum flocs but also far smaller components such as various aluminum cations seemed to be adsorbed on pulp fibers. Most aluminum flocs, which are formed in pulp suspensions by reacting with OH and entrapped in a fiber matrix by filtration effects, are removable by repeated mechanical agitation of the pulp suspensions.     

First report of white spot syndrome virus in wild crustaceans and mollusks in the Paraíba River,Brazil

The aim of the present study was to investigate the presence of white spot syndrome virus (WSSV) in the Paraíba River, Brazil. Eight sampling sites were established on the bank of the river near water intake areas for the farming of Litopenaeus vannamei. Ten specimens of the shrimp Palaemon pandaliformis and the gastropods Pomacea lineata and Melanoides tuberculatus were collected at each site. Eighty‐one gill fragments from P. pandaliformis, 40 whole individuals of M. tuberculatus and 26 muscle fragments from P. lineata were collected. All samples were stored in microcentrifuge tubes with 95% ethanol (1:10; v:v). Tests were performed at the Potiporã Molecular Analysis Laboratory (state of Rio Grande do Norte, Brazil) for the detection of WSSV using Loop Mediated Isothermal Amplification with the aid of the LAMP WSSV kit (Concepto Azul, Ecuador). Twenty‐nine per cent of P. pandaliformis, 48% of M. tuberculatus and 8% of P. lineata tested positive. The findings demonstrate that WSSV is present in wild crustaceans and mollusks, which may serve as vectors and/or reservoirs of the virus, thereby posing a potential risk to local shrimp farming. This is the first report of WSSV in wild specimens of M. tuberculatus and P. lineata.     

Detection of zearalenone and its metabolites in naturally contaminated porcine follicular fluid by using liquid chromatography-tandem mass spectrometry

Zearalenone (ZEN) and its metabolites are important nonsteroidal estrogenic mycotoxins that cause reproductive disorders in domestic animals, especially pigs. We aimed to simultaneously detect ZEN and its metabolites á-zearalenol (α-ZOL) and β-zearalenol (β-ZOL) in porcine follicular fluid (FF) by liquid chromatography-tandem mass spectrometry. ZEN and α-ZOL, but not β-ZOL, were detected in all pooled FF samples collected from coexisting follicles (diameter ≥ 6 mm) within 10 ovaries. Furthermore, ZEN and α-ZOL were detected in samples pretreated with β-glucuronidase/arylsulfatase, but not in those left untreated, suggesting that the FF samples contained glucuronide-conjugated forms of the mycotoxins that may be less harmful to porcine oocytes due to glucuronidation affecting the receptor binding. Nonetheless, the effects of the glucuronide-conjugated forms should be studied, both in vitro and in vivo.     

Seed and pollen transmission of <Emphasis Type="Italic">Apple latent spherical virus</Emphasis> in apple

To examine whether Apple latent spherical virus (ALSV) has spread among apple trees in an orchard, we surveyed 21 apple trees surrounding two ALSV-infected trees for virus infection using a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). None of the 21 trees were infected, indicating that ALSV has not spread from the infected trees to the neighboring apple trees since it was first detected in 1984. We analyzed seed embryos and seedlings derived from infected trees and detected ALSV in 10 of 223 seed embryos (4.5%) and 10 of 227 seedlings (4.4%). From these results, we conclude that ALSV is seed-transmitted at a rate of ca. 4.5% in apple. We also analyzed seed embryos and seedlings from uninfected apple trees that were hand-pollinated with pollen from infected trees. We detected ALSV in only 1 of 260 seed embryos and in none of the 227 apple seedlings. This result indicated that the seed transmission rate via infected pollen is only 0–0.38%. In situ hybridization analysis of ALSV-infected apple flower buds showed that ALSV was present inside almost all pollen grains and in all ovary and ovule tissues, including the embryo sac and inner integument.     

Amino-terminal amino Acid sequence of the silkworm prothoracicotropic hormone: homology with insulin

Three molecular forms of prothoracicotropic hormone were isolated from the head of the adult silkworm, Bombyx mori, and the amino acid sequence of 19 amino acid residues in the amino terminus of these prothoracicotropic hormones was determined. These residues exhibit significant homology with insulin and insulin-like growth factors.     

Solid-state13C-NMR analysis of size components in handsheets prepared by fatty acid soap size-alum systems

The mechanism of paper sizing in fatty acid soap size-alum systems was studied by structural analyses of the size components in handsheets prepared with¹³C-labeled fatty acid soap size. Patterns of sizing performance and aluminum content of the handsheets were similar to those for the rosin soap size-alum sizing systems, although the patterns of calcium content were different. Solid-state¹³C-nuclear magnetic resonance analysis of the handsheets revealed that fatty acid calcium salt was the predominant size component in the handsheets prepared using tap water. This calcium salt is formed from the fatty acid soap size (fatty acid potassium salt) by ion exchange with calcium ion in pulp suspensions and retained on pulp fibers through aluminum compounds originating from alum added. On the other hand, when deionized water was used, free fatty acid was the major component in the handsheets. Fatty acid aluminum salt was present as a minor component in the handsheets prepared in both tap water and deionized water systems. Therefore, all size components (i.e., fatty acid calcium salt, free fatty acid, fatty acid aluminum salt) seem to contribute to the appearance of sizing features.This research was presented in part at the 64th Pulp and Paper Research Conference of Japan TAPPI, Tokyo, June 1997     

Cloning and characterization of the glutamate dehydrogenase gene in Streptococcus bovis

Streptococcus bovis, an etiologic agent of rumen acidosis in cattle, is a rumen bacterium that can grow in a chemically defined medium containing ammonia as a sole source of nitrogen. To understand its ability to assimilate inorganic ammonia, we focused on the function of glutamate dehydrogenase. In order to identify the gene encoding this enzyme, we first amplified an internal region of the gene by using degenerate primers corresponding to hexameric family I and NAD(P)⁺ binding motifs. Subsequently, inverse PCR was used to identify the whole gene, comprising an open reading frame of 1350 bp that encodes 449 amino acid residues that appear to have the substrate binding site of glutamate dehydrogenase observed in other organisms. Upon introduction of a recombinant plasmid harboring the gene into an Escherichia coli glutamate auxotroph lacking glutamate dehydrogenase and glutamate synthase, the transformants gained the ability to grow on minimal medium without glutamate supplementation. When cell extracts of the transformant were resolved by blue native polyacrylamide gel electrophoresis followed by activity staining, a single protein band appeared that corresponded to the size of S. bovis glutamate dehydrogenase. Based on these results, we concluded that the gene obtained encodes glutamate dehydrogenase in S. bovis.