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Biomedical subjects

H Nagano

Publications and source records attributed to H Nagano.

At least 163 records · Page 9Linked to original sources
PubMed1988

Induction of achromosomal cleavage by hydroxyurea in starfish embryo and the reversal by a combination of deoxyadenosine and deoxycytidine: possible involvement of salvage pathway for deoxynucleoside triphosphate biosynthesis in the presence of hydroxyurea.

Effects of hydroxyurea, an inhibitor of ribonucleotide reductase, on cleavage of starfish embryos were studied. In the presence of 1 mM hydroxyurea, fertilized eggs of the starfish, Asterina pectinifera, cleaved up to the 256-cell stage and decomposed before blastulation. Before the 16-cell stage, each blastomere contained a normal nucleus or chromosomes with mitotic apparatus. The cleavage after the 16-cell stage was slow compared to the control embryos, and not all blastomeres contained a nucleus or normal chromosomes. During the fifth cell division (between 16-cell- and 32-cell-stage embryos), chromatin mass unassociated with the mitotic apparatus remained near the cleavage furrow. When hydroxyurea was removed before the 16-cell stage, the embryos developed to normal bipinnalia larvae via normal blastulae. However, the embryos were disintegrated before blastulation when hydroxyurea was removed after the 32-cell stage. DNA synthesis was normally observed before the 16-cell stage but not after the 16-cell stage, but dNTP contents in the embryos remained low throughout development in the presence of hydroxyurea. The achromosomal cleavage observed in the presence of hydroxyurea was reversed by the combination of extracellular dAR and dCR. Therefore, it is assumed that the synthesis of dNTPs required for DNA synthesis in the presence of hydroxyurea occurs via the salvage pathway using deoxynucleosides (dNR) (dNR to dNTP via dNMP and dNDP).

Animals↗
PubMed1988

Detection of antibodies against porcine parvovirus in swine sera by enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) was developed for detection of antibody against porcine parvovirus in swine sera. The antigen used for the assay was partially-purified virus treated with fluorocarbon and shown to contain 7 proteins by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Of these proteins 83-, 64- and 60-K proteins reacted in Western immunoblotting with swine serum after infection with porcine parvovirus. Antibody responses were demonstrated by ELISA in pigs subcutaneously-infected with porcine parvovirus as by hemagglutination-inhibition (HI) test and Western immunoblotting reaction with the 83-, 64- and 60-K viral proteins. The results of ELISA on random swine-serum samples were well-correlated with those of the HI test. These findings indicate the usefulness of the ELISA as a serological tool for porcine parvovirus infection.

Animals↗
PubMed1988

Isolation and characterization of mutant strains of Bordetella bronchiseptica lacking dermonecrotic toxin-producing ability.

Mutant strains of Bordetella bronchiseptica, named B-42, B-76, B-84, and B-119, were obtained after serial passages of a parent strain, L3, on Bordet-Gengou agar plates containing 20% horse blood and 200 micrograms of nalidixic acid per ml (BGN-20 agar plates) at 42 degrees C. Mutant strains completely lacked dermonecrotic toxin-producing ability, and lethal activity of the strains for mice was apparently reduced compared with that of strain L3. Mutant strains were able to grow at 42 degrees C, and the strains were nalidixic acid resistant. The mutant strains showed domed (Dom+) colony morphology with smooth texture (Scs+) and no production of zone of hemolysis (Hly-), but the agglutinability of these strains to antiserum prepared with Dom+ Scs+ Hly+ organisms of strain L3 was the same as that of strain L3. When strain B-42 was inoculated intramuscularly or intranasally into guinea pigs, all the animals survived without manifesting clinical signs and produced a high-level of serum agglutination antibodies against strain L3. These inoculated animals were protected against intranasal challenge with strain L3. These properties of mutant strains are hereditarily stable after 50 subcultures on BGN-20 agar plates or 20 passages in mice. These data suggest that the mutant strains lacking dermonecrotic toxin-producing ability can be used as a live attenuated vaccine against swine atrophic rhinitis.

Animals↗
PubMed1988

Relationship between the relative regional thallium-201 uptake and the regional systolic or diastolic filling function.

Both the resting thallium-201 imaging and resting gated radionuclide ventriculography were conducted in the left anterior oblique view in 35 patients with isolated disease of the left anterior descending coronary artery (LAD), and the corresponding involved region was compared from two differing perspectives, one measuring regional ventricular function and the other regional myocardial perfusion. In the thallium-201 imaging, the thallium activity in the septal or apical region supplied by the LAD was calculated as an activity ratio between the mean value of the normally perfused lateral region and that of the septal or apical region, and was called relative thallium uptake (%T1 uptake). In the gated radionuclide ventriculographic study, a computer program subdivided the image of the left ventricle into 4 regions. The time-activity and first-derivative curves were computed in the septal and apical regions. Significant positive correlations were present between the %T1 uptake and the ejection fraction or peak ejection rate both in the septal and apical regions, indicating that the regional systolic function diminishes progressively as the perfusion abnormality increases. However, positive but poor and scattering correlations were found between the %T1 uptake and the peak filling rate, and there were no significant correlations between the %T1 uptake and the filling period in these affected regions. Thus, we could suppose that the regional systolic function is closely related to the regional %T1 uptake which probably reflects the amount of the residual viable myocardium, but there is the possibility that the regional diastolic filling function may be not so much related to the amount of the viable myocardium as is systolic function or may be modulated by some factors other than the amount of the regional viable myocardium.

Adult↗
PubMed1988

[A case of colon cancer with pulmonary metastasis treated effectively by uracil futraful].

A 57-year-old female was admitted for advanced ascending colon cancer with a solitary pulmonary metastasis measuring 1.5 cm in diameter. As laparotomy revealed an absolute noncurable tumor of stage V (H0, p2, s2 n1 (+], palliative right hemicolectomy was performed. A pathological diagnosis of well differentiated adenocarcinoma was made postoperatively. A daily dose of 400 mg of UFT was given orally. After 8 months, plain chest film and tomography revealed a reduction in the size of the pulmonary metastasis to 1.0 cm in diameter. The metastatic lung tumor was controlled for a period of 1 year and 9 months. It was suggested that UFT was rather effective for pulmonary metastasis from colon cancer.

Adenocarcinoma↗
PubMed1988

[The effects of dexamethasone and expansion stress on the osteoblasts in mouse calvarial suture in vitro, with special reference to incorporation of 3H-thymidine and 3H-proline].

Behavior of sutures in response to expansion stress are thought to be in parallel with the response of bone to orthodontic tooth movement. To investigate this relation between psychologic stress and osteoblasts during orthodontic tooth movement, the effects of expansion stress and 10(-7) M dexamethasone on sutural osteoblasts of mouse calvaria were examined in vitro. The model consists of a tensile force applied to the mouse sagittal suture. Expansion stress induced the formation of osteoid in the sutural areas, and incorporation of 3H-thymidine and 3H-proline in sutural osteoblasts were found to be stimulated by expansion stress. Furthermore, labelling index of 3H-thymidine in the osteoblasts was also found to be stimulated. On the other hand, dexamethasone inhibited the incorporation, labelling index and matrix formation. Moreover, these induced stimulations in expansion stress were inhibited by 10(-7) M dexamethasone treatment. As described above, dexamethasone, which is a synthetic glucocorticoid, inhibited the incorporation of 3H-thymidine and 3H-proline, the labelling index of 3H-thymidine, and the matrix formation in sutural osteoblasts that were stimulated by expansion stress. Therefore, also during orthodontic tooth movement, increased secretion of glucocorticoid that is stimulated by psychologic stress may inhibit the proliferation, cell differentiation, and matrix formation of osteoblasts in periodontal ligaments.

Animals↗
PubMed1988

[A case of leukoencephalopathy caused by HCFU].

After a hysterectomy, a bilateral salpingo-oophorectomy, two courses of intra-peritoneal chemotherapy of Cisplatinum, Carmofur (HCFU, 600 mg/day [per os]) were given a patient who had ovarian granulosa cell tumor (malignant, stage Iai). Dizziness and loss of consciousness developed about 60 days after administration of HCFU, and leucoencephalopathy was diagnosed. A CT revealed a diffuse low density area in the white matter of the cerebrum. Myelin Basic Protein in the spinal fluid was found to amount to 9.8 mg/dl, which in norm. person is less than 4.0 mg/dl. Also, it showed parallel changes with the course of the clinical findings. HCFU easily dissolves to fat and changes to 5-FU without enzymes in the liver cell. Further HCFU also passes through Blood Brain Barrier to Produce 5-FU and its derivatives, in which the alpha-Fluoro-beta-Alanine is thought to be the culprit that brings on leucoencephalopathy. Even so, HCFU should be dosed when needed in spite of this risk. Other 5-FU modifiers also have been reported to produce the same effect in several cases.

Adult↗
PubMed1987

Preferential loss of DNA polymerase alpha following suppression of replicative DNA synthesis of guinea pig macrophages by the immunostimulants muramyl dipeptide or lipopolysaccharide.

Oil-induced guinea pig peritoneal exudate macrophages were found to incorporate 3H-thymidine into trichloroacetic acid-insoluble fraction. In pulse-labeling experiments, the incorporated 3H-thymidine was detected in short fragments of DNA, which corresponded to the Okazaki fragments. These results indicate that the observed thymidine incorporation is due to nuclear DNA replication but not DNA repair. The observed DNA synthesis of the macrophages was remarkably suppressed when the cells were cultured in a presence of muramyl dipeptide (MDP) or bacterial lipopolysaccharide (LPS). The significant decrease of DNA polymerase alpha activity was found in the cells treated with MDP or LPS. In contrast, the activity of polymerase beta was not at all affected by the same treatment.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Intracellular localization of argyrophilic proteins in the maturing oocyte, fertilized egg, and spermatozoa of the starfish, Asterina pectinifera.

Changes in intracellular localization of argyrophilic proteins visualized as silver-stained particles by nuclear organizer region (NOR)-silver staining were investigated in starfish oocyte maturation. The silver-stained particles were localized in the germinal vesicle and nucleolus of immature oocytes and dispersed into the cytoplasm at the time of germinal vesicle breakdown (GVBD). In the mature egg cytoplasm, silver-stained particles were distributed on yolk-like granules with diameters of 0.3-1.0 microns. In spermatozoa, silver-stained particles were detected heavily in the acrosome and centrosomes but few were detected in the nucleus, whereas they were present in the male pronucleus of fertilized eggs. The silver-stained particles were removed by pretreatment of eggs with protease but not with nuclease. These results indicate that argyrophilic proteins disperse to the egg cytoplasm during GVBD and might be incorporated to the male pronucleus from the egg cytoplasm in fertilization. The morphological changes from chromosomes through chromosome vesicles to female pronucleus were also observed with light microscopy after NOR-silver staining.

Animals↗