Histopathology of feline panleukopenia in domestic cats.

Histopathological observations were carried out on 17 domestic cats naturally affected with feline panleukopenia. Principal lesions were found in the intestine, bone marrow, and lymphoid organs. Intestinal lesions were characterized by degenerative changes accompanied by the appearance of intranuclear inclusion bodies in the epithelial cells of the crypts. In contrast to the crypts, the villi were seldom involved. Hypoplasia, parenchymal degeneration, and activation of the reticuloendothelial system were observed in the bone marrow and lymphoid organs. Intranuclear inclusion bodies were found occasionally also in the reticular and parenchymal cells of the bone marrow, lymphoid organs, liver, adrenals, and pancreas. Most of the inclusion bodies were amphophilic when stained with hematoxylin and eosin and occupied the whole area of the nucleus without producing any zone of clear halo. While cells bearing inclusion bodies underwent degenerative changes constantly in the intestinal crypts, the formation of inclusion body was not accompanied by the degeneration of corresponding cells in any other organ. Pathological changes as mentioned above were considered to be closely related to the systemic infection of feline panleukopenia virus.     

Abiotrophia defectiva adhere to saliva-coated hydroxyapatite beads via interactions between salivary proline-rich-proteins and bacterial glyceraldehyde-3-phosphate dehydrogenase

Abiotrophia defectiva is a species of nutritionally variant streptococci that is found in human saliva and dental plaques and that has been associated with infective endocarditis. In our previous study, it was found that A. defectiva could bind specifically to saliva-coated hydroxyapatite beads (SHA). This study identified a cell surface component of A. defectiva that promotes adherence to SHA beads. The binding of A. defectiva to SHA was reduced in the presence of antibodies against human proline-rich protein (PRP); these results suggested that PRP may be a critical component mediating interactions between A. defectiva and the salivary pellicle. Two-dimensional gel electrophoresis of whole A. defectiva cells followed by Far-Western blotting was conducted by probing with synthetic peptides analogous to the binding region of PRP known as PRP-C. The results indicate that an A. defectiva protein of 37 kDa interacts with PRP-C. The results of amino-terminal sequencing of the adhesive A. defectiva protein revealed significant similarity to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Recombinant GAPDH bound to immobilized PRP-C in a dose-dependent manner and binding of A. defectiva to SHA or to PRP was reduced in the presence of anti-GAPDH antiserum. Western blotting or electron immunomicroscopic observations with anti-GAPDH antiserum revealed that this protein was expressed in both cytosolic and cell wall fractions. These results suggest that A. defectiva could specifically bind to PRP via interactions with cell surface GAPDH; the findings suggest a mechanism underlying A. defectiva-mediated adherence to saliva-coated tooth surfaces.     

Characteristics of Bupleurum falcatum plants propagated through somatic embryogenesis of callus cultures

Various characteristics including the saponin content in the root of Bupleurum falcatum plants propagated in vitro through somatic embryogenesis of callus cultures were compared with those of the plants propagated by seeds. The asexually propagated plants had an aerial part of more uniform characteristics than those of sexually propagated ones. However, both the mean and variance of root weight of the former were significantly larger than those of the latter. As for the saponin content of the root on a dry weight basis, there was little difference between the two groups. The amounts of saikosaponins c and d in a root were significantly larger in the asexually propagated plants than in the sexually propagated ones.