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Biomedical subjects

S Sakuma

Publications and source records attributed to S Sakuma.

At least 415 records · Page 23Linked to original sources
PubMed1975

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.

Adrenal Glands↗
PubMed1972

Reovirus replicase-directed synthesis of double-stranded ribonucleic acid.

After the incubation of reovirus replicase reaction mixtures (containing labeled ribonucleoside triphosphates), partially double-stranded ribonucleic acid (pdsRNA) products were isolated by cellulose column chromatography followed by precipitation with 2 m NaCl. The pulse-labeled reaction product contained a significantly large amount of pdsRNA that became complete dsRNA as reaction time increased, indicating that pdsRNA was an intermediate of the replicase reaction. The newly synthesized RNA strand ((3)H-labeled) of the pdsRNA was resistant to ribonuclease digestion, suggesting that single-stranded RNA regions were part of a preexistent unlabeled RNA template. These observations, together with the electrophoretic behavior of the pdsRNA in polyacrylamide gel, are consistent with the hypothesis that dsRNA is synthesized by the elongation of a complementary RNA strand upon a preexistent template of single-stranded RNA (i.e., messenger RNA). The direction of the RNA strand elongation was determined by carrying out the replicase reaction in the presence of (3)H-cytidine triphosphate (or (3)H-uridine triphosphate) and adenine triphosphate-alpha-(32)P followed by a chase with excess unlabeled cytidine triphosphate (or uridine triphosphate). The dsRNA product was digested with T1 ribonuclease and the resulting 3'-terminal fragments were isolated by chromatography on a dihydroxyboryl derivative of cellulose. Examination of the ratio of (3)H to (32)P in these fragments indicated that RNA synthesis proceeded from the 5' to 3' terminus.

Animals↗
PubMed1972

Incorporation of in vitro synthesized reovirus double-stranded ribonucleic acid into virus corelike particles.

When reovirus double-stranded ribonucleic acid (dsRNA) was synthesized in vitro by using a large-particulate fraction (LP-fraction) from reovirus-infected L cells, a significant amount of the (3)H-labeled dsRNA product was incorporated into reovirus corelike particles bound to the LP fraction. These corelike particles were found to be indistinguishable from virus core derived by chymotryptic digestion of virions when compared on the basis of their (i) resistance to chymotryptic digestion, (ii) buoyant density in CsCl, (iii) particle size as determined by agarose chromatography, (iv) elution characteristics from diethylaminoethyl-Sephadex, and (v) resistance of the incorporated (3)H-dsRNA to ribonuclease digestion in 0.01 m NaCl. When the replicase reaction was partially inhibited by NaCl, there was an accumulation of particles that were less dense than the virus core. All of the results indicate that some virus core assembly takes place during the in vitro replicase reaction.

Animals↗