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Biomedical subjects

K Fukuda

Publications and source records attributed to K Fukuda.

At least 1,045 records · Page 58Linked to original sources
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Frequency and significance of tumor thrombi in esophageal varices in hepatocellular carcinoma associated with cirrhosis.

Histological examination of the wall of the stomach and esophagus in patients with hepatocellular carcinoma associated with cirrhosis demonstrated intravariceal tumor thrombi in 13 (23.6%) of 55 cases studied. There were distant hematogenous metastases in 31 of them, of whom 12 (38.7%) had variceal tumor thrombi. Tumor thrombi were of varying sizes, and tumor cells appeared either intact, degenerated or necrotic. In seven cases, there was a firm adhesion of thrombi onto the vascular wall suggesting possible mural infiltration, but no extravascular metastases were noted grossly. These findings suggest a possibility of metastasis of hepatocellular carcinoma to the stomach and esophagus via the portal vein. It is also suggested that the degree of varices is not increased by tumor thrombus formation per se, and that both varices and tumor thrombi are due to extensive hepatofugal collateral circulation. Considering that 12 of 13 cases of intravariceal tumor thrombi had lung metastases, a portal vein-varices-lung route is possible for lung metastasis beside the established route through the hepatic vein in hepatocellular carcinoma.

Adult↗
PubMedDate not supplied

Osmophilic linear plasmids from the salt-tolerant yeast Debaryomyces hansenii.

Three novel linear plasmids, pDHL1 (8.4 kb), pDHL2 (9.2 kb) and pDHL3 (15.0 kb), were discovered in the halophilic (salt-tolerant) yeast Debaryomyces hansenii. Exonuclease treatment indicated that all three plasmids were blocked at their 5' ends, presumably, by analogy with most other eukaryotic linear plasmids which involved protein attachment. The Debaryomyces plasmids were entirely cured simply by growing cells in normal culture medium, but were stably maintained in culture medium containing salts, sorbitol or glycerol at suitable concentrations. This suggested that the pDHL plasmids required an osmotic pressure for stable replication and maintenance. The Debaryomyces yeast secreted a killer toxin against various yeasts species. Toxin activity was demonstrated only in the presence of salts such as NaCl or KCl, but this killer phenotype was not associated with the pDHL plasmids. Analysis of the plasmid-curing pattern suggested that pDHL3 may play a key role in the replication of the Debaryomyces plasmids. Southern hybridization showed that an extensive homology exists between specific regions of pDHL1 and pDHL2, whereas pDHL3 is unique.

Blotting, Southern↗