Biomedical subjects
Publications and source records attributed to N Komatsu.
A simple, fast and reliable isoelectric focusing method for the simultaneous determination of ACP1, ADA and PGM1 is presented, which provides a useful tool for the further study of anthropological and forensic haemogenetics.
The polymorphism of ACP1 was investigated in 749 unrelated Japanese individuals by isoelectric focusing. The allele frequencies were ACP1* A = 0.2083 and ACP1* B = 0.7917, which were almost similar to those reported in other Japanese subpopulations. The isoelectric focusing technique was successfully applied to ACP1 typing in bloodstains; each phenotype was demonstrated at 37 degrees C for up to 4 weeks, at room temperature for up to 10 weeks and at 4 degrees C for over 16 weeks after stain formation. The isoelectric focusing method proved more useful than conventional electrophoretic methods in medicolegal practice.
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Molecular analysis of the beta-globin genes from a patient with a beta-thalassemia phenotype showed that a single nucleotide mutation (CTG-CCG) at codon 110 in one of the genes resulted in a leucine to proline substitution. The same mutation with a similar phenotype, was observed in her mother and sister, by Southern blotting analysis of DNAs digested with Mspl, the recognition site of which was created by this base substitution. This indicates a close relationship between this mutation and the beta-thalassemia phenotype. No anomalous peak of radioactivity was detected by reverse-phase high-performance liquid chromatography (HPLC) in the patient's reticulocytes incubated with isotopically labeled amino acid. The leucine-proline (Leu-Pro) substitution probably disrupts the G-helix and in turn interferes with globin contact points. The uncombined beta-globin chain would be rapidly destroyed and the beta-thalassemia phenotype would follow.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
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Twenty-one patients with refractory acute nonlymphocytic leukemia (ANLL) and myelodysplastic syndrome were treated with low-dose cytosine arabinoside (LDARC). LDARC was administered by subcutaneous injection every 12 hours at a dose of 10 mg/m2 (regimen A) or at a dose of 20 mg/m2 by continuous intravenous infusion (CIV) or continuous subcutaneous injection (CSC) (regimen B). Among 22 courses, two elderly patients with ANLL (M4 and M5) and one M4 patient with myelofibrosis obtained complete remission (CR) and three elderly patients with ANLL (one M1 and two M2) and one patient with ANLL developed from RAEB in transformation obtained partial remission (PR). The overall remission rate (CR + PR) was 31.8%. The CR durations were 2.5, 5 and 2 months, respectively. The plasma concentration of Ara-C determined in regimen B was 8.26 +/- 4.12 ng/ml. There was no difference in the plasma concentration of Ara-C between CIV and CSC. We consider that the major mode of action of LDARC lies in its cytotoxic effect, since all patients who obtained remission exhibited pancytopenia and bone marrow hypoplasia. However, in several patients, we observed transient monocytosis and granulocytosis which were considered to be suggestive evidence of differentiation of leukemia cells.
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Monoclonal antibodies were raised against arachidonate 12-lipoxygenase using a partially purified enzyme from porcine leukocytes as an antigen. Immunohistochemical studies indicated a selective localization of 12-lipoxygenase in the cytosol of polymorphonuclear leukocytes. Two separate species of antibody (lox-1 and lox-2) recognizing different sites of the enzyme protein were utilized to develop a method to determine the amount of 12-lipoxygenase protein rather than the activity of enzyme. Fab fragment of lox-2 was conjugated to horseradish peroxidase, and the conjugate as a label was bound to 12-lipoxygenase. The complex was precipitated with the aid of the other antibody (lox-1) and protein A, and the peroxidase activity in the precipitate was correlated with the amount of 12-lipoxygenase. The immunoenzymometry of 12-lipoxygenase was more convenient and sensitive than the conventional assay to determine the conversion of [1-14C]arachidonic acid. Furthermore, in several porcine tissues this method allowed quantitation of the enzyme, the activity of which was masked due to the presence of certain endogenous inhibitors. A ubiquitous distribution of 12-lipoxygenase in porcine tissues was demonstrated by application of this method.
The findings are described that were determined after a fatal traffic accident. By means of blood and isoenzyme typing, a piece of tissue adhering to the bottom of a car was ascribed to the victim.
The polymorphism of EsD was investigated in tissues of various human organs, dental pulps, hair roots, and seminal stains by isoelectric focusing. The method yielded an excellent resolution of the isoenzyme components. The time limits of determination were: in organ tissues 3 weeks, in dental pulps 1 week, and in hair roots several days. The 7-1 type was less stable than the common types. Phenotyping was possible from fresh semen samples, but was unsuccessful from dried seminal stains after storage. The results show that the EsD typing by isoelectric focusing is of practical use for medicolegal individualization of organs, teeth, and hairs.
Two monoclonal antibodies reacted with the Trypanosoma cruzi-specific antigen of an apparent Mr 25,000 from all developmental forms (Tachibana et al. 1986). This T. cruzi-specific antigen was found at the plasma membrane by immunoperoxidase electron microscopy using the monoclonal antibodies TCF48 and TCF87. The TCF48 and TCF87-treated cells showed stain deposits at the plasma membrane clearly distinguishable from those in cells treated with a monoclonal antibody against a surface antigen. This suggests that the epitope(s) of the Mr 25,000 antigen is located on the inner surface or in the matrix of the plasma membrane. TCF48 and TCF87 also reacted with an antigen on the microtubules of the axoneme, but not with the subpellicular microtubules. These results suggest that the T. cruzi-specific Mr 25,000 antigen is common to both the plasma membrane and axoneme but it is not located at the subpellicular microtubules. Its identity and that of the surface antigen, Gp25 (Scharfstein et al. 1983) as well as its role in the pathogenicity of the parasite are discussed.
The polymorphism of alpha-L-fucosidase (Fu) was investigated in a Japanese population from samples of placentae and semen, using isoelectric focusing. The gene frequencies of placental types were Fu1 = 0.748 and Fu2 = 0.252, and those of seminal types were Fu1 = 0.739 and Fu2 = 0.261. The coincidence in the distribution between the placental and seminal types suggests that the Fu types occurring in placentae and in semen are controlled by the same Fu alleles. The Fu typing was possible in seminal stains stored at 4 degrees C for up to 9 weeks, at room temperature for up to 7 weeks and at 37 degrees C for up to 4 weeks. The Fu types were still detectable at semen dilutions of up to 1:4. This polymorphism would provide a useful genetic marker for the medicolegal grouping of seminal stains.
To clarify the mechanism of increased numbers of megakaryocytes in patients with essential thrombocythaemia (ET), we studied in vitro megakaryocytopoiesis in ET and other myeloproliferative disorders, using a megakaryocytic colony assay in methylcellulose containing plasma or serum and medium conditioned by phytohaemagglutinin (PHA) stimulated leucocytes (PHA-LCM). Megakaryocytic colony formation was supported well by heparinized or citrated plasma and citrated serum which was harvested after clot formation of citrated plasma. Whole serum was inhibitory for megakaryocytic colony growth. The addition of platelet releasates and partially purified platelet derived growth factor (PDGF) resulted in a decrease in the number of megakaryocytic colonies. These findings suggested that platelet-derived factor(s) in serum was inhibitory to megakaryocytic colony formation. ET plasma supported the megakaryocytic colony formation by normal or ET bone marrow cells better than normal plasma. Moreover, in ET bone marrow cells, spontaneous megakaryocytic colonies were formed in the absence of PHA-LCM. Increased megakaryocytopoiesis in ET may be ascribed to (i) increased megakaryocyte-colony stimulating activity (Meg-CSA) in plasma and (ii) increased sensitivity to Meg-CSA or autonomous proliferation of megakaryocytic progenitor cells.
In the normal rat kidney, immunohistochemical localization of glutathione peroxidase (GSH-Po) was mainly in the proximal tubules (PTs), where the proximal portions (S1 + S2) were more intensely stained than the distal portion (S3). Immunocytochemically, GSH-Po was localized in cytosol including the core of microvilli and lysosomes of the epithelial cells in the PTs. Since albumin and IgG were not found in cytosol, it is suggested that cytosolic GSH-Po may be generated in situ, but is not derived from the serum.
Using starch gel electrophoresis, a slow variant PGM1 6NGS2-1 (W23-1A) was detected among 749 residents of Yamanashi Prefecture. The isoelectric focusing pattern of this type was demonstrated, which would serve as a reference in further population studies.