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Biomedical subjects

M Imoto

Publications and source records attributed to M Imoto.

124 records · Page 7Linked to original sources

Analyis of met-form haemoglobins in human erythrocytes of normal adults and of a patient with hereditary methaemoglobinaemia due to deficiency of NADH-cytochrome b5 reductase.

Isoelectric-focusing analysis on an Ampholine/polyacrylamide-gel plate revealed that met-form haemoglobins are present as half-oxidized haemoglobins such as the (alpha 2+ beta 3+)2 and (alpha 3+ beta2+)2 forms rather than as methaemoglobin in the erythrocytes of normal human adults and also of a patient with hereditary methaemoglobinaemia due to deficiency of NADH-cytochrome b5 reductase.

Cytochrome Reductases↗

[Prostaglandins].

Explore the source record for details and available documents.

Endometrium↗

Recent developments in the organic synthesis of lipid A in relation to biologic activities.

For elucidation of a relationship between chemical structure and biologic activity of lipid A, syntheses of 13 derivatives of glucosamine beta (1-6) disaccharide, which were acylated at 3, 4, and 6'-hydroxyl groups and/or phosphorylated at positions 1 and 4', were carried out. The results showed the importance of the presence of the phosphate group at either position 1 or 4' and of the beta-hydroxyl group in acyl function, particularly in N-linked fatty acids, for the exhibition of biologic activities characteristic of lipid A. New evidence on the positions of fatty acids in natural lipid A of Escherichia coli species obtained by means of 2D-H nuclear magnetic resonance was also demonstrated; the findings indicate that the 3'-hydroxyl group is acylated and the 6'-hydroxyl group in the molecule must be free.

Lipid A↗

Endotoxin affects the expansion modes of liver macrophages after partial hepatectomy.

We studied the effect of increased endotoxin levels on the expansion modes of liver macrophages after two-thirds partial hepatectomy using anti-endotoxin polymyxin B. The expansion consists of dual modes: local proliferation and immigration. Local proliferation of mature cells was evaluated by the S-phase proportion measured by flow cytometric DNA analysis. This proportion (11.8 +/- 1.3% before hepatectomy) decreased to 6.0 +/- 1.1% at 12 h and reached a maximum of 21.9 +/- 2.7% on the 5th day after hepatectomy. In polymyxin B treated rats, the proportion reached a maximum of 21.1 +/- 1.6% at 48 h without any preceding decrease. Immigration of macrophage precursors was evaluated by the decreasing proportion of latex beads-containing cells that were marked as resident liver macrophages by injection of latex beads before hepatectomy. This proportion (98.7 +/- 0.2% before hepatectomy) was significantly decreased to 90.5 +/- 1.6% at 48 h. In polymyxin B treated rats, however, the proportion showed no significant decrease within 3 days. These results indicate that endogenous endotoxin, which suppresses the local proliferation and promotes extrahepatic recruitment, regulates the number of liver macrophages in regenerating rat liver.

Animals↗

Clinical evaluation of serum tissue inhibitor of metalloproteinases-1 levels in patients with liver diseases.

Serum levels of the tissue inhibitor of metalloproteinases-1 (TIMP-1) were measured in 268 patients with liver diseases by means of a one-step sandwich enzyme immunoassay. In the cases of acute hepatitis, chronic active hepatitis (CAH), liver cirrhosis (LC) and hepatocellular carcinoma (HCC), the levels of TIMP-1 were higher than those of the control group. Tissue inhibitor of metalloproteinases-1 levels correlated with type III procollagen peptide and with type IV collagen, indicating TIMP-1 as a useful marker for hepatic fibrosis. Levels of TIMP-1 also correlated with aspartate aminotransferase and alanine aminotransferase levels and showed the highest levels in acute hepatitis. Thus, TIMP-1 might also reflect hepatic inflammation. Serum levels of alpha-fetoprotein and TIMP-1 had a significant positive correlation in patients with HCC. A cut-off level of TIMP-1 between LC and HCC was set at 440 ng/mL, having a low sensitivity and a high specificity. These results suggest the usefulness of TIMP-1 as a tumour marker in cases of HCC where alpha-fetoprotein levels are not elevated.

Adolescent↗

High rate of mixed genotypes of hepatitis C virus in patients of an epidemic area in Japan.

The subjects of this study were 151 patients (69 males and 82 females) who underwent examination and liver biopsy owing to liver dysfunction in an epidemic area with hepatitis C. Second generation hepatitis C virus antibody (HCV Ab) was positive in 116 (76.8%) of 151 cases. HCV-RNA was detected in 120 (79.5%) by polymerase chain reaction (PCR). In 7 (4.6%) cases, HCV Ab could not be found, but HCV-RNA was detected. Three (2.0%) cases were positive for HCV Ab but negative for HCV-RNA. On the basis of variation in nucleotide sequence within a restricted region in the putative core gene of HCV, HCV genotypes were classed into four types of I, II, III and IV by PCR. The genotypes were identified in 120 cases. Ninety-eight (81.7%) cases carried one of the four types. Type II was found in 76 (63.3%) cases and type III in 22 (18.3%). The other 22 (18.3%) carried simultaneously two different genotypes (mixed type): 21 (17.5%) cases with type II + III and one (0.8%) case with type II + IV. In comparison with the incidence of HCV mixed types in cases with hepatitis C in a non-epidemic area, carriers of mixed types were found at a significantly higher rate in the epidemic area. Liver biopsy of 120 cases with identified HCV genotypes in the epidemic area showed 93 cases of chronic active hepatitis, nine of chronic lobular hepatitis, 10 of chronic persistent hepatitis and eight of liver cirrhosis. No significant correlation could be detected between liver histology and HCV genotypes.(ABSTRACT TRUNCATED AT 250 WORDS)

Disease Outbreaks↗

Demonstration of noradrenaline-immunoreactive nerve fibres in the liver.

To demonstrate noradrenaline-immunoreactive nerve fibres in liver tissues, we used an antibody to noradrenaline in the immunostaining of liver tissues from rats, guinea-pigs and humans. The tissue specimens were fixed by perfusion or immersion with cacodylate buffer containing sodium metabisulphate and glutaraldehyde, and cryostat sections were prepared. An indirect peroxidase-labelled antibody method was used for staining noradrenaline. Noradrenaline-immunoreactive nerve fibres were localized around blood vessels in the portal area and around the central vein. There were differences between the species in the intralobular distribution of noradrenaline-immunoreactive fibres. Normal guinea-pig and human liver showed intralobular noradrenaline-immunoreactive fibres while rat liver did not. Noradrenaline-immunoreactive fibres were absent from regenerating nodules in a human cirrhotic liver. This method of demonstrating noradrenaline directly using perfusion- or immersion-fixation is appropriate for studying innervation in normal and damaged livers of various species including humans.

Animals↗

Detection of noradrenaline-immunoreactive nerve fibres in rat liver by immunoelectron microscopy.

Noradrenergic innervation of rat liver was studied immunohistochemically using antibody to noradrenaline at the electron-microscopic level. Noradrenaline-immunoreactive nerve fibres were located in the portal tract and some were in close contact with the portal vein and hepatic artery. Noradrenaline-immunoreactive fibres were found to contain many vesicles that were reactive to anti-noradrenaline antibody. This preliminary study suggests that the method for detecting noradrenaline-immunoreactive fibres using the antibody is useful for studies at the electron-microscopic level.

Animals↗

Alcoholic hepatitis with hyperleukocytosis.

We report a fatal case of alcoholic hepatitis with hyperleukocytosis mainly consisting of mature granulocytes in a 43-year-old woman. White blood cell count was increased in parallel with clinical deterioration to 54,800/mm3 with no immature neutrophils on a differential count. The bone marrow aspirate revealed normal maturation and no evidence of hematological malignancy. It has been postulated that severe leukocytosis accompanied by alcoholic hepatitis may be provoked by release of high levels of colony stimulating factor from damaged hepatic cells. However, the present patient showed a normal level of serum granulocyte colony stimulating factor, and could not prove the above assumption.

Adult↗

Bcl-2-independent induction of apoptosis by neuropeptide receptor antagonist in human small cell lung carcinoma cells.

The broad-spectrum antagonist of neuropeptide receptor, [D-Arg1, D-Phe5, D-Trp7,9, Leu11]substance P, induced apoptosis selectively in human small cell lung carcinoma (SCLC) cells, which express gastrin-releasing peptide receptor, but not in other types of tumor cells as well as normal cells. The addition of gastrin-releasing peptide or bombesin and the inhibitor of caspase-3 suppressed [D-Arg1, D-Phe5, D-Trp7,9, Leu11]substance P-induced apoptosis. Moreover, [D-Arg1, D-Phe5, D-Trp7,9, Leu11]substance P-induced apoptosis was not suppressed by Bcl-2 over-expression. Thus, blockage of gastrin-releasing peptide receptor-mediated signaling may provide a novel therapeutic option in SCLC which has become resistant to conventional chemotherapeutic agents.

3T3 Cells↗