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Biomedical subjects

S Iida

Publications and source records attributed to S Iida.

At least 451 records · Page 25Linked to original sources

Carcinoma of the bifurcation of the hepatic ducts.

Thirty-one patients with carcinoma of the bifurcation of the hepatic ducts were treated during a period of ten years. Sixteen of the 31 patients underwent resection. Left, right, and extended right lobectomy with the resection of the bilateral hepatic ducts, common hepatic and bile ducts were performed on 11, 1, and 3 patients, respectively. In a cirrhotic patient, resection of the left medial segment and bile ducts was carried out. The biliary tract was reconstructed using hepaticojejunostomy or hepatojejunostomy. Four of the 16 patients are still alive for six months, 1 1/2 years, one year and 11 months, and two years and ten months, respectively. The remaining 12 patients died of recurrence at periods ranging from six months to three years and eight months. The treatment is now focused on increasing long-term survival.

Adenocarcinoma↗

Sequence of the site-specific recombinase gene cin and of its substrates serving in the inversion of the C segment of bacteriophage P1.

Inversion of the 4.2-kb C segment flanked by 0.6-kb inverted repeats on the bacteriophage P1 genome is mediated by the P1-encoded site-specific cin recombinase. The cin gene lies adjacent to the C segment and the C inversion cross-over sites cixL and cixR are at the external ends of the inverted repeats. We have sequenced the DNA containing the cin gene and these cix sites. The cin structural gene consists of 561 nucleotides and terminates at the inverted repeat end where the cixL site is located. Only two nucleotides in the cixL region differ from those in the cixR and they are within the cin TAA stop codon. The cin promoter was localized by transposon mutagenesis within a 0.1-kb segment, which contains probable promoter sequences overlapping with a 'pseudo-cix' sequence cixPp. In a particular mutant, integration of an IS1-flanked transposon into the cin control region promoted weak expression of the cin gene. The cin and cix sequences show homology with corresponding, functionally related sequences for H inversion in Salmonella and with cross-over sites for G inversion in phage Mu. Based on a comparison of the DNA sequences and of the gene organizations, a possible evolutionary relationship between these three inversion systems and the possible significance of the cixPp sequence in the cin promoter are discussed.

Base Sequence↗

Genome fusion mediated by the site specific DNA inversion system of bacteriophage P1.

The genome of bacteriophage P1 contains a segment which is invertible by site specific recombination between sequences near the outside ends of the inverted repeats which flank it. Immediately adjacent to this C segment is the coding sequence for cin, the enzyme catalyzing inversion. We show that multicopy plasmids carrying cin and the sequences at which it acts (cix) can form dimers in the absence of the host recA function. Further, such plasmids can be cotransduced with P1 markers at high frequency from recA lysogens, indicating cointegration with the P1 genome. It is thus demonstrated that a system whose primary role is the inversion of a specific DNA segment can also mediate intermolecular recombination.

Bacterial Proteins↗

Effects of intra- and extrahepatic portal systemic shunts on insulin metabolism.

To study the effects of intra- and extrahepatic portal-systemic shunts on insulin degradation, 11 patients with liver cirrhosis and 7 noncirrhotic patients with liver disease were studied with percutaneous transhepatic catheterization. Insulin levels in portal and peripheral blood were measured simultaneously for 1-2 hr after intravenous administration of glucose. The degrees of intra- and extrahepatic portal-systemic shunting were measured with this technique using 131I-macroaggregated albumin and 99mTc-macroaggregated albumin. The amount of insulin secreted and insulin degraded were assessed from the areas under blood concentration curves for portal and peripheral blood. Insulin degradation was significantly reduced in cirrhotics compared to noncirrhotics with liver disease, although there was no difference in the amount of insulin secreted between these two groups. It was also correlated significantly with the degree of intrahepatic shunting but not with the degree of extrahepatic shunting. These results suggest that intrahepatic shunting plays an important role in the reduction of insulin degradation in cirrhosis.

Glucose Tolerance Test↗

Alcohol dehydrogenase (ADH) independent ethanol metabolism in deermice lacking ADH.

To assess the importance of non-ADH ethanol metabolism, ADH-negative (ADH-) and ADH-positive (ADH+) deermice were fed for 2-4 weeks liquid diets containing ethanol or isocaloric carbohydrate. They consumed progressively increasing amounts of ethanol. Blood ethanol clearance (BEC) increased significantly in both strains. It remained almost unchanged at low ethanol concentrations (5-10 mM), but at high levels (40-70 mM) BEC was strikingly increased with significant differences between ethanol-fed and control animals. Kinetics were consistent with the activity of a non-ADH high Km system such as the microsomal ethanol-oxidizing system (MEOS). Naive ADH- had a more active MEOS and more abundant SER than naive ADH+. After ethanol feeding, MEOS was increased 3-4 times in both strains. There was striking proliferation of SER and cytochrome P-450 was enhanced significantly. Expressed per P-450, MEOS activity was higher in ADH- than ADH+. Thus despite absence of ADH, ADH- deermice can consume large amounts of ethanol: this is associated with increased BEC, SER proliferation, enhanced MEOS activity and quantitative and qualitative changes of cytochrome P-450.

Alcohol Dehydrogenase↗

Tissue-specificity of reactivity to concanavalin-A of human cells in culture.

Concanavalin-A (Con-A) reactivity was studied to identify the tissue-specificity of cells established from various normal human tissues. Cells were treated with Con-A-labelled human red blood cells (C-RBC). C-RBC was not absorbed on the cells derived from the bone marrow, skin and liver. Lung-derived fibroblast cells showed weak C-RBC adsorption. Kidney-derived cells showed epithelial morphology and easily adsorbed C-RBC. These suggest that a large number of Con-A receptors exists on the membrane surface of kidney cells.

Adolescent↗

On the origin of the chloramphenicol resistance transposon Tn9.

The widely studied chloramphenicol resistance (Cmr) transposon Tn9 came from phage P1Cm0. This phage, however, had acquired its Cmr marker from the R plasmid pSM14. The analysis of the physical structure of pSM14 has now revealed that this plasmid already carried Tn9 and also the tetracycline resistance transposon Tn10. Physical and functional studies indicated that Tn9 of pSM14, although capable of transposition, probably translocated to the P1 genome by reciprocal recombination processes.

Bacteriophages↗

An experimental study of the influence of sensory nerve fibers on Merkel cell differentiation in the labial mucosa of the rabbits.

The influence of the sensory nerve fibers on the differentiation of the Merkel cell was examined in the denervated labial mucosa of adult rabbits. Part of the lower labial mucosa was excised following mental nerve resection. Twenty-one and 50 days later, the regenerated mucosa was examined by electron microscopy with special reference to the distribution and maturation of Merkel cells, and compared with the normal and the denervated intact mucosa. A number of immature Merkel cells appeared in the denervated and regenerated epithelium by 21st day after the operation. The distribution density of the Merkel cells in a unit area of the mucosa did not change much but the percentage of the mature Merkel cells increased significantly until 50 days after the operation. The mature Merkel cells in the denervated and regenerated mucosa showed a normal ultrastructure, though their orientation and location were not uniform, shifting more superficially than the cells in the normal mucosa. In the controlateral intact epithelium of the denervated labial mucosa, no substantial decrease in the population density of Merkel cells was recognized, though the desquamation of Merkel cells was observed. It was conspicuous that the percentage of immature Merkel cells to the total number of the Merkel cells was significantly increased after the denervation in the intact labial mucosa. This study suggests that Merkel cells differentiate independently of sensory nerve fibers, but the latter are requisite to maintain the former in a uniform, basal disposition in the epithelium.

Animals↗