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Biomedical subjects

M Suenaga

Publications and source records attributed to M Suenaga.

At least 55 records · Page 3Linked to original sources
PubMed1992

Use of strip biopsy in a case of early duodenal cancer.

In a 67-year-old man referred for investigation of an abdominal mass, upper gastrointestinal endoscopy incidentally revealed a polypoid lesion with a central depression in the duodenum. The abdominal mass causing gastric compression was shown by ultrasonography and CT scan to be cyst anterior to the pancreas. Biopsy of the duodenal lesion, however, was suggestive of carcinoma. Strip biopsy was therefore performed. Histological examination showed a tubular adenocarcinoma with invasion limited to the mucosa, and indicated that complete endoscopic resection had been achieved. Follow-up over ten months did not reveal recurrence of the tumor. Strip biopsy would appear to be a safe and efficient method for management of early gastrointestinal tract cancer also in the duodenum.

Adenocarcinoma↗
PubMed1989

Basic amphipathic helical peptides induce destabilization and fusion of acidic and neutral liposomes.

We have studied the fusion of small unilamellar vesicles composed of egg PC and of a mixture of egg PC plus egg PA using various basic amphipathic peptides. Fusion was monitored by carboxyfluorescein leakage assay, light scattering, membrane intermixing assay, contents mixing assay and electron microscopy. Ac-(L-Leu-L-Ala-L-Arg-L-Leu)3-NHCH3 (peptide 4(3] and Ac-(L-Leu-L-Ala-L-Lys-L-Leu)3-NHCH3 (peptide 4'3), which have high hydrophobic moments, caused transformation of small unilamellar vesicles into larger and relatively homogeneous ones. Ac-(L-Leu-L-Leu-L-Ala-L-Arg-L-Leu)2-NHCH3 (5(2], which has medium hydrophobic moment, induced weak but appreciable fusion, while Ac-(L-Ala-L-Arg-L-Leu)3-NHCH3 (3(3] which has no helical structure did not show any fusion. However, peptides 4(3), 4'3 and 5(2) caused massive leakage of the contents from small unilamellar vesicles. These results indicated that interaction of the peptides with artificial membranes caused extensive perturbation of the lipid bilayer, followed by fusion. The fusogenic capacity of model basic peptides was correlated with the hydrophobic moment of each peptide when the peptides adopted an alpha-helical structure in the presence of acidic liposomes. Peptides 4(3) and 4'3 also showed weak fusogenic ability for neutral liposomes, while 5(2) and 3(3) showed no ability, suggesting that highly amphipathic peptides, such as 4(3), interact weakly but distinctly with neutral liposomes to fuse them.

1,2-Dipalmitoylphosphatidylcholine↗