Glomerulopathy with IgA deposition in the dog.

In 100 dogs autopsied, glomerular IgA deposition was examined by the immunofluorescence technique and the histopathological features of glomeruli with IgA deposition were examined by light and electron microscopy. The incidence of the IgA deposition was age-related but there were no sex and breed predisposition. Deposition of IgA was observed mainly in mesangial areas in approximately a half (47%) of dogs examined. IgG, IgM and C3 often co-deposited. Histopathology of the glomeruli with IgA deposition indicated increase of mesangial cells, crescent formation, hemispherical deposits in paramesangial areas and glomerular sclerosis. Ultrastructurally electron dense substances positive for IgA deposited in mesangial and paramesangial areas. The examination to know the relation between the severity of IgA deposition and the number of mesangial cells or percent of the cells to total glomerular cells indicated that mesangial cells increased at the early stage of the disease and subsequently epithelial and endothelial cells proliferated as the increasing amount of IgA. Dogs suffering from enteritis or liver diseases showed high incidence of glomerular IgA deposition.     

Investigation of the short-term effect of chemonucleolysis with chondroitinase ABC.

Chondroitinase ABC (C-ABC) is expected to be a novel agent for chemonucleolysis. The effect of C-ABC was investigated by magnetic resonance (MR) and radiograph. C-ABC was administered into the lumbar intervertebral disks on the clinically normal beagles (n=5), in a dose of 50 microl (12.5 units as C-ABC). MR scans were performed pre-dose, and 1, 3, 7, 14 and 28 days after administration of C-ABC, and the signal intensity (SI) of the nucleus pulposus was measured. Radiographs were taken pre-dose, and 1, 2, 3, 4, 5, 6, 7, 14 and 28 days post-dose, to evaluate narrowing of the disk space in terms of height index (HI). In addition, the quantity of the chondroitin sulfate (CS) and the hyaluronic acid (HA) in the nucleus pulposus were measured by high performance liquid chromatography on day 28 after dosing. SI and HI continuously decreased, following the injection to 37.1% and 78.9% of the pre-dose values, respectively. Statistically significant differences (p<0.01) were observed between the C-ABC group and the control group in the respects on day 1 post-dose. CS and HA contents of the nucleus pulposus were noted to be significantly decreased on day 28 (p<0.01) in the treated group. This agent proved to degenerate proteoglycans in the nucleus pulposus, thus progressively reducing the interdiskal pressure from day 1 post-dose onwards. It is concluded that C-ABC is expected to afford its efficacy from early in the course of chemonucleolysis.     

Purification and characterization of lysozyme from purple washington clam Saxidomus purpurata

ABSTRACT:   Lysozyme was purified from purple washington clam Saxidomus purpurata by sequential procedures using Chitopearl Basic BL-01 affinity and TSKgel ODS-120T column chromatographies. Molecular mass of the purified enzyme was estimated to be 12 kDa by SDS-PAGE. Optimum pH of the enzyme was 5.2 toward Micrococcus lysodeikticus cells. The optimum temperature was 50°C. The enzyme was stable in the range of pH 4.8–6.8 and 20–90°C. Further, the N-terminal amino acid sequence of the enzyme showed similarity to lysozymes from invertebrates. However, the specific activity of the enzyme toward M. lysodeikticus cells and p -nitrophenyl penta- N -acetyl- β -chitopentaoside was 143 times and 12 times higher than that of hen egg white lysozyme, respectively.     

Leaching behaviour of benzalkonium chloride homologues in soil and water solutions

Experiments were carried out to determine the leaching mechanism of benzalkonium chloride (BAC) from treated wood in soil. Wood specimens were treated with C12, C14 and C16 BAC homologues and exposed to soil or aqueous solutions containing oxalic acid, sodium oxalate, hydrochloric acid, sodium chloride or sodium humate. The leaching rates of the homologues in soil were close to each other and all higher than in distilled water. The order of the rates in soil (C12 ≈ C14 ≈ C16) was different from that in distilled water (C12 > C14 > C16). The leaching rates of the homologues in the acidic solutions and their salts solution were also higher than in distilled water, and the order of the rates was the same as in distilled water. The aqueous solution of sodium humate also accelerated homologue leaching but resulted in an order of C16 > C14 > C12. The BAC leaching acceleration mechanism by humate was thought to be different from the mechanisms of acids and their salts and plays an important role in the leaching behaviour of BAC in soil.     

Histological Characterization of Defective Spermatogenesis in Mice Lacking the Basigin Gene

Basigin is a transmembrane protein belonging to the immunoglobulin superfamily. In the light of the fact that knockout mice lacking the basigin gene (Bsg) are azoospermic, the phenotype in the male reproductive system was extensively examined in this study. Spermatogenesis in Bsg (-/-) mice was found to be disrupted, and arrested at the metaphase of the first meiotic division. A few germ cells differentiated into young spermatids, but they were exfoliated. The lumens of the male reproductive system were filled with round degenerated cells. Using the TUNEL method and electron microscopy, some of the degenerated cells in the testis and epididymal head were shown to be apoptotic. Crystalloids of fine tubules and unusual ectoplasmic specializations were also observed in the Sertoli cells of Bsg (-/-) mice. These specializations displayed unusual 'circular' structures. Furthermore, unusual ectoplasmic specializations covering the spermatocytes rather than the mature spermatids were found. These structures were formed as a result of the lack of mature spermatids in the Bsg (-/-) testis. Results from analyses of azoospermia in the Bsg (-/-) mice suggest that basigin, through the interactions between germ cells and Sertoli cells, is an essential factor in the growth and/or survival of spermatids.     

Imogolite of Imogo-Layers in Kyushu

A distinct, brownish yellow soil layer often intervenes between dark colored layers in the profiles of Ando soil in Kyushu, particularly in central east and southern Kyushu. The layer is called “imogo” in the Hitoyoshi district and “akahoya” in the Miyazaki district. The soil is characterized by a very low bulk density such as 0.4, and bears glassy particles in abundance, which are colorless and shard-shaped. It often displays exchange-neutrality or exchange-alkalinity. Plant roots are very few in the layer, and most roots are observed to make a bend along the layer surface, from perpendicular to horizontal. It seems that the plant root has trouble intruding the layer, probably because of its special structure (1, 2).     

Strain-softening behavior of wood under tension perpendicular to the grain

Three softwood samples and one hardwood sample were tested under a tension load applied along the radial direction using small clear specimens and the local tension strain was measured using the digital image correlation method. We successfully obtained a stress-strain curve with a strain-softening branch by calculating the stress using the strain distributions in the vicinity where the specimen ruptured. The continuous digital imaging of the specimen proved to be very effective for measuring the strain in quasi-brittle materials such as wood under tension. The nonlinearity of the stress-strain curve was quantified using two parameters representing the deviation from linear elasticity, and the formula of the stress-strain curve was deduced from the interrelation between these parameters. This formula is expressed quite simply by using the modulus of elasticity along the radial direction and another constant that is unique to the material. Part of this article was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, Japan, August 2006     

Effects of alkyl chain length and the mixing of homologues with different alkyl chains on the leaching characteristics of benzalkonium chloride

Benzalkonium chloride (BAC) is the active ingredient of ACQ-1, one of the most widely used wood preservatives in Japan. BAC in ACQ-1 comprises homologues with different alkyl chains: C12 comprises 74%; C14 26%; and C16 < 1%. To clarify the leaching characteristics and the factors affecting the leaching of BAC homologues, wood specimens treated individually with the C12, C14, and C16 homologues were used in a leaching experiment with distilled water (DW) and artificial sea water (SW). The leaching rates of the BAC homologues were accelerated by the SW, and the order of the leaching rate in both DW and SW was C12 > C14 > C16. When the specimens were treated with a mixture of two of the three homologues, the leaching rates of the C14 and C16 homologues from specimens treated with a solution containing C14 and C16 were lower than that from specimens treated with a solution containing the C14 or C16 homologue together with C12. From the adsorption isotherm of the homologues it is assumed that the formation of BAC aggregates on the treated wood is related to their leaching. BACs consisting of mainly C14 and C16 are thought to be suitable for reducing leaching, particularly in marine usage.     

长沙东郊第四纪红土红壤粘土矿物组成X射线衍射法分析

通过X射线衍射分析湖南长沙东郊第四纪红色粘土发育的红壤,结果表明:该地红壤粘土矿物成分以水云母,高岭石,蛭石、蛭石-蒙脱石1.4×10~(-9)m 过渡矿物等3种粘土矿物群为主.