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Biomedical subjects

N Kubota

Publications and source records attributed to N Kubota.

At least 145 records · Page 8Linked to original sources
PubMed1989

A crucial effect of splenectomy on prolonging cardiac xenograft survival in combination with cyclosporine.

In this study we investigated the effect of splenectomy in combination with cyclosporine (CsA) on survival of heterotopic cardiac xenografts from hamster to rat. A 12-fold prolongation of mean cardiac xenograft survival, to 41 days, was accomplished with the combined therapy. In both untreated controls and CsA-treated recipients rejection occurred in 3 days. Splenectomy by itself prolonged xenograft function to 5 days. Evidence of humoral-mediated rejection in this cross-species combination was given for the extensive thrombosis and hemorrhage in the subepicardial area, the appearance of lymphocytotoxic titers just before graft function ceased, and the presence of IgM deposits in subepicardial vessels of the xenograft. CsA by itself could not modify this pattern of rejection. Splenectomy decreased antibody formation significantly and rejection became more cellular in nature. The regimen of splenectomy in association with CsA suppressed antibody titers and produced a CsA dose-dependent prolongation of xenograft survival. Thus, a complementary or synergistic effect is the result of the immunosuppressive regimen of splenectomy and CsA in hamster-to-rat cardiac xenografts. In this study the effect of splenectomy in controlling the humoral response in concordant xenografts and its role in future clinical xenografting is emphasized.

Animals↗
PubMed1988

Long-term results after strabismus surgery.

The results of surgery after 4 years' or more postoperative follow-up have been evaluated in a total of 1031 cases (575 esotropia, 456 exotropia). There is a difference in the angle of strabismus 1 month after surgery and 4 years after surgery. Based on these findings, the results of strabismus surgery must be evaluated after a sufficient amount of time has passed. The angle of strabismus to be aimed at, to provide best binocular vision and patient satisfaction, should be in the range of -2 +7 degree for esotropia and +2 -10 degree for exotropia, regardless of the patient's age at surgery.

Age Factors↗
PubMed1988

Repair of potentially mutagenic damage, sensitive to anisotonic treatment, in actively growing Chinese hamster cells.

Using exponentially growing Chinese hamster V79 cells we studied the effect of anisotonic phosphate-buffered saline (PBS) treatment on the frequency of mutation following X-irradiation. Induction of mutants was studied at the hypoxanthine-guanine phosphoribosyl transferase locus (HGPRT). When cells were X-irradiated and immediately followed by 0.5 M NaCl/PBS treatment for 20 min at 37 degrees C, cell survival was significantly decreased and a concomitant increase in the number of mutants was observed, indicating that postirradiation treatment with anisotonic salt solution caused conversions of potentially lethal damage and potentially mutagenic damage to lethal and mutagenic damage, respectively. The repair kinetics of potentially mutagenic damage expressible by 0.5 M NaCl/PBS after 5.86 Gy of X-rays were similar to those of potentially lethal damage. The repair of both types of damage was essentially complete within 40 min after X-irradiation.

Animals↗
PubMed1988

Measurements of active and passive force of horizontal muscles in strabismus.

A precision device was developed for quantitative measurement of the active and passive forces of the horizontal muscles in several different types of strabismus. The device consists of a tension gauge for measuring isometric muscle tension (active force) and passive length-tension (passive force), and a circular-motion guide mechanism. In normal subjects, the active force showed nearly linear changes with the eye position, as was reported in past studies. A similar relationship between the active force and the eye position was observed also in strabismus patients in our study. Normal subjects showed a stronger force in the medial than the lateral rectus muscle. Among strabismus patients, those with normal retinal correspondence (NRC)-intermittent exotropia showed a force closest to that of the normal controls. However, the force of the lateral rectus muscle was significantly greater in those with constant exotropia than in the normal controls. The active force of the medial rectus muscle was significantly smaller in those with dual retinal correspondence (DRC)-intermittent exotropia and constant exotropia. Conversely, the active force of the medial rectus muscle was significantly greater in those with esotropia, compared with the normal group. As for the passive force, there was no significant difference between the temporal passive force and the nasal passive force in the normal and esotropic groups, but the temporal passive force was significantly greater in the esotropic group. The magnitude of the force was greater in both directions when traction was applied against the muscle having the stronger active force. These results suggest that the lateral rectus muscle force is relatively stronger in patients with DRC-intermittent exotropia due to a weakness of the medial rectus muscle force, and that the absolute strength of the lateral rectus muscle force is increased in patients with constant exotropia, but in NRC-intermittent exotropia the muscle forces are almost normal. Those with esotropia are considered to have an absolute increase in the medial rectus muscle force.

Adolescent↗
PubMed1987

Molecular cloning and characterization of cDNA for human myeloperoxidase.

Partial amino acid sequence of human myeloperoxidase was determined, and a 41-base oligonucleotide containing deoxyinosines at four positions was chemically synthesized. By using the oligonucleotide as a probe, cDNA clones for human myeloperoxidase were isolated from a cDNA library constructed with mRNA from human promyelocytic leukemia HL-60 cells. One of the clones containing a 2.6-kilobase insert was subjected to nucleotide sequence analysis. The sequence was found to contain an open reading frame, 2,235 nucleotides coding for a protein of 745 amino acids with a calculated Mr of 83,868. The heavy chain of myeloperoxidase, consisting of 467 amino acids, was located on the COOH terminus half of the protein. The RNA specified by the cDNA was prepared using SP6 RNA polymerase and translated in rabbit reticulocyte lysates, and the product was identified as human myeloperoxidase by immunoprecipitation with rabbit anti-human myeloperoxidase antibody. By Northern hybridization analysis of RNA from leukemic cells, it was shown that myeloperoxidase mRNA is abundantly expressed in human promyelocytic HL-60 and mouse myeloid leukemia NFS-60 cells. Furthermore, the results of Southern hybridization analysis of human genomic DNA suggest that there are one or two genes for myeloperoxidase in the human haploid genome.

Amino Acid Sequence↗
PubMed1987

Induction of neutrophilic granulocytosis in mice by administration of purified human native granulocyte colony-stimulating factor (G-CSF).

Mice were subcutaneously (sc) injected once a day for up to 15 days with a purified human native G-CSF sample at a dose of 2.5 micrograms/injection or with control samples with or without added endotoxin. In the G-CSF-treated mice, blood neutrophil counts began to rise as early as 2 hours after the first injection, reached a level 8 times above the preinjection level after 15 days of injections with marked elevation of all progenitor cell levels in spleen, and returned to normal within 48 hours after cessation of the injections. Such neutrophilia was observed even when endotoxin-resistant C3H/HeJ mice were used, but not in control mice. It is possible that repeated G-CSF injections after administration of cyclophosphamide (CY) in mice could accelerate recovery of granulopoiesis with a rather transient rise in blood neutrophil counts.

Animals↗
PubMed1987

Comparison of two strains of avian infectious bronchitis virus for their interferon induction, viral growth and development of virus-neutralizing antibody in experimentally-infected chickens.

Two field strains of avian infectious bronchitis virus were tested in specific pathogen-free chickens for interferon induction, growth and stimulation of virus-neutralizing antibody. Both strains induced interferon in lungs and trachea and neither strain induced it in kidneys. Strain Kagoshima-34, isolated from the kidneys of a chicken that had died of nephrosis/nephritis, induced interferon earlier than Strain Tottori-2, which was isolated from the trachea of a chicken with respiratory disease. Virus growth was generally more prolonged with Kagoshima-34, especially in the kidneys, but Tottori-2 persisted longer in the lungs.

Animals↗
PubMed1987

Prolonged survival of hamster-to-rat liver xenografts using splenectomy and cyclosporine administration.

The immunosuppressive effect of splenectomy, alone or in combination with cyclosporine (CsA), was examined in hamster-to-rat orthotopic liver xenografts. The mean survival time was 7.3 +/- 0.5 days in untreated controls, 7.6 +/- 0.8 days with 40 mg/kg/day CsA, 7.2 +/- 0.4 days with splenectomy alone, and 17.6 +/- 5.6 days with splenectomy combined with 30 mg/kg/day CsA (P less than 0.01). The longest survival time was 27 days in this group. Marked enlargement of the spleen and high lymphocytotoxic antibody titer were characteristic of the unmodified recipients and those treated with CsA alone. Splenectomy by itself decreased the antibody formation without improvement of graft survival. In animals treated with the combined regimen, the lymphocytotoxic antibody titer was significantly suppressed, and the PMN and round cell infiltration were greatly reduced. Therefore, a synergistic effect was postulated between cyclosporine and splenectomy in this liver xenograft system.

Animals↗
PubMed1987

Isolation of influenza A viruses from migratory waterfowls in San-in District, Western Japan, in the winter of 1982-1983.

From November 1982 to March 1983, winter migratory waterfowls of some species staying in San-in District, Western Japan, were surveyed for influenza virus at five stations. A total of eight influenza A viruses were isolated from 354 faeces samples of whistling swans; in contrast, no virus was isolated from any sample of 261 black-tailed gulls, of 113 pintails and of 10 mallards. Five of eight isolates belonged to human pandemic subtype H2N2, two isolates belonged to fowl plague subtype H7N7, and the remaining one to subtype H4N6.

Animals↗