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Biomedical subjects

K Nemoto

Publications and source records attributed to K Nemoto.

At least 199 records · Page 11Linked to original sources
PubMed1990

[The effects of uneven fractionated irradiation on mouse squamous cell carcinoma and normal tissue].

In uneven fractionated radiotherapy combining large doses and small doses, we studied the influence of the order of their combination on tumors and on normal tissues, using squamous cell carcinoma and skin reaction of mice. The number of fractions was 6, and we used various combinations of 4 small doses and 2 large doses (4 times larger). The antitumor effect was smallest when a large dose was given at the end of treatment, but in skin reactions, there was no difference in effect even when the order of the combination of large and small doses was changed.

Animals↗
PubMed1990

Demyelination and remyelination in spinal cord lesions of human lymphotropic virus type I-associated myelopathy.

We describe postmortem findings in a patient with human T lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM). The patient developed the disease 8 years after blood transfusion and showed good response to corticosteroid treatment but died of cardiac failure. Histologically, chronic, mild meningoencephalomyelitis was noted predominantly involving the bilateral lateral and anterior columns of the middle to lower thoracic segments. The spinal cord lesions showed obvious loss of myelinated nerve fibers and fibrillary gliosis with minimal inflammatory cell infiltration. Electron microscopy of the lesion revealed disintegration of the myelin sheaths, regular separation of the minor dense line of the myelin sheaths, and completely demyelinated axons. In addition, remyelinated fibers with thin central myelin sheaths and disproportionately large axons were seen frequently. These findings indicate that primary demyelination and remyelination by oligodendrocytes occur in the spinal cord lesions of HAM.

Aged↗
PubMed1990

Canine herpesvirus 47 kD and mutated 41 kD glycoproteins are responsible for hemagglutination.

Monoclonal antibodies (MoAbs) were used to identify the hemagglutinin of canine herpesvirus (CHV). The inhibition of viral hemagglutination (HA) activity was observed with MoAbs against 41 kD glycoprotein, while no hemagglutination-inhibition (HI) activity was observed with those against 145/112 kD and 80 kD glycoproteins, suggesting that the 41 kD glycoprotein is the hemagglutinin of plaque-selected virus of CHV YP11 strain used as immunogen for MoAb production. All of the HI MoAbs also showed HI activities against HA antigens which were prepared from cells infected with other CHV strains, namely, F-205 V and Glasgow CHV2 reference strains, eight Japanese isolates, and the original YP11 strain. However, on immunoblotting analysis, a 47 kD protein band was detected in these strains by the HI MoAbs. These data suggest that the 47 kD glycoprotein is the common molecule of the hemagglutinin among CHV strains and the plaque-selected virus of YP11 strain appears to be a mutant whose molecular weight of the hemagglutinin changed into 41 kD.

Animals↗
PubMed1990

Deoxyspergualin therapy in autoimmune MRL/1pr mice suffering advanced lupus-like disease.

The present study was designed to evaluate the therapeutic activity of a novel immunosuppressive agent, deoxyspergualin (DSG, NKT-01) in male MRL/MpJ-lpr/lpr (MRL/lpr) mice suffering advanced systemic lupus erythematosus (SLE)-like lesions. Treatment with DSG in the early phase of the disease at doses of 1.5 and 3 mg/kg strongly suppressed the development of SLE-like lesions. When DSG was administered from week 21 through 29 to MRL/lpr mice in advanced phases of the disease, a daily iv dose of 3 mg/kg (5 days/week) markedly reduced the symptoms, whereas a dose of 1.5 mg/kg did not. Moreover, DSG treatment at a dose of 3mg/kg, started at the time when the blood urea nitrogen levels were over 50 mg/deciliter, significantly prevented deterioration of the hyperuremia. Taking these findings into consideration, DSG was found to be a promising agent for curing such established autoimmune disease.

Animals↗
PubMed1990

Deoxyspergualin directly suppresses antibody formation in vivo and in vitro.

The effect of deoxyspergualin (DSG, NKT-01) on humoral immunity was investigated both in vitro and in vivo. DSG inhibited the primary and secondary responses to T cell-dependent antigens and the response to T cell-independent antigens in thymic and athymic mice. However, natural antibodies in non-sensitized mice were affected less by the administration of DSG. The agent produced a dose-dependent inhibition of B cell proliferation and antibody production to lipopolysaccharide in vitro. Suppression of secondary antibody response was also shown, whenever antigen stimulation was not given, antibody production was not affected. These results suggest that DSG affects the proliferative stage of B lymphocytes in such a way as to inhibit their growth and antibody production.

Animals↗
PubMed1990

[M-BACOD in advanced case of non-Hodgkin's lymphoma].

A M-BACOD regimen using an increased dose of Adriyamycin has been administered to 18 patients with non-Hodgkin's lymphoma. Sixty-three percent of the patients who had been previously untreated obtained a complete remission and the 2-year survival rate of those who evidenced a complete response reached 71%. The stage of the lymphoma was found to be a prognostic factor for a complete remission, while LDH and tumor response had an influence upon survival.

Adult↗
PubMed1990

Inhibitory effect of an anti-lipoxygenase agent on immunoglobulin G-mediated anaphylactic contraction of single smooth muscle cells.

Intracellular signal transduction during anaphylactic contractions of smooth muscle and the site of signal generation, or antigen-antibody reaction, participating in the appearance of these contractions were studied. The taenia coli was removed from a guinea-pig which had previously been sensitized with anti-egg albumin (EA) rabbit serum or anti-EA rabbit immunoglobulin G (IgG) fraction. Dispersed smooth muscle cells, obtained after enzymatic digestion, were used as the specimen. The dispersed single smooth muscle cells sensitized with anti-EA rabbit IgG fraction showed anaphylactic contractions in response to antigen administration. The method using enzyme-linked antibody revealed binding of IgG by these single muscle cells. Anaphylactic contractions of the single cells were not inhibited by antihistamines or anti-5-hydroxy-tryptamine (5HT) agents, but they were suppressed by Y-19,432 [1-butyl-5-hydroxy-2-methyl-N-[1-(2-phenylethyl)-4-piperidyl] indole-3-carboxamide hydrochloride hydrate], an inhibitor of 5-lipoxygenase. The anaphylactic contractions of the single smooth muscle cells of the guinea-pig taenia coli appear to be initiated in response to IgG binding with the antigen bound to the smooth muscle plasma membrane. For contraction development, the lipoxygenase pathway was shown to participate as a part of the intracellular signal transduction.

Anaphylaxis↗
PubMed1990

[Transmittance of light-cured composite resins. 1. Measurement of transmittance with time].

The factors that influence the change of the transmittance of light-cured composite resins during polymerization were examined. Six experimental composite resins such as used organic composite filler and fourteen commercial composite resins were investigated using the experimental device for measurement of the transmittance. The transmittance of the experimental composite resins were from 25 to 73%. The transmittance of the experimental composite resins changed with time; a group with increasing transmittance (G1), a group giving a maximum transmittance (G2), and a group with decreasing transmittance (G3). These changes of transmittance were influenced by the difference in the refractive indices between matrix resin and filler, but the refractive index that indicated a maximum transmittance of matrix resin during polymerization could not be observed when the refractive index of the matrix resin and filler was same. The light transmitted through the commercial composite resins was less than half of the irradiation light. This change of transmittance could also be classified into the three groups mentioned above. The commercial composite resins belonged to the group with increasing transmittance (G1).

Composite Resins↗
PubMed1990

[Effect of danazol on bone mineral content and bone metabolism in patients with endometriosis].

Danazol, which is commonly employed in the treatment of endometriosis creates a low estrogen and high androgen condition by suppressing ovarian steroidogenesis. When a reproductive-aged woman suddenly develops low estrogen, even if it is reversible, it is possible that it can have some effect on her bone mineral content and there is the danger that this might constitute a risk factor in the development of postmenopausal bone metabolism. In 12 cases of endometriosis (average age 42.2) 400 mg/day Danazol was given for 4 months to determine if a low estrogen and high androgen condition actually continued. The effect on the bone metabolism which provides a background to metacarpal bone mineral content was also examined in comparison with before and after seven months' administration. As a result, after Danazol administration, estradiol showed a tendency to decrease and dehydroepiandrosterone showed a tendency to increase although no significant change in the estrogen and androgen level was recognized. There was also no change on the bone mineral content and there was no significant change in bone metabolism, calcitonin excepted. Therefore, from the results of calcitonin evaluation, 400mg/day Danazol administered for 4 months does not seem to be absorbed by bone and at least appears not to have any significance as a bone metabolism risk factor.

Adult↗
PubMed1990

[Bone mineral loss due to premenopausal oophorectomy assessed by dual photon absorptiometry].

Although it has been reported that bone mineral loss due to oophorectomy (OPX) occurs mainly in the axial bone, especially in the trabecular bone, there have been no reports on the use of this method for simultaneous total body calcium measurement. Furthermore, the occurrence of bone mineral loss in regional bone mineral density (BMD) after OPX has not been clarified. We investigated whether there is a decrease in regional BMD after OPX, and whether there are regional differences in bone mineral loss following OPX. The BMD was measured by dual photon absorptiometry in 21 premenopausal oophorectomized subjects (mean age: 46.8 +/- 4.0 yr, mean duration after OPX: 48.0 +/- 40.0 months) and 19 age- and body size-matched females. In OPX subjects, the spinal BMD was significantly lower (corresponding to 87.0 +/- 2.4% of control) than those of the cranium, arms and legs (92.1 +/- 2.6, 97.2 +/- 1.2, 95.4 +/- 1.6% respectively). Furthermore the oophorectomized subjects were divided into three groups according to duration after OPX as follows; within 1 (n = 7), 2-5 (n = 7) and over 6 years (n = 7). The spinal BMD had already tended to decrease in the within 1 year group and significantly decreased in the over-6-year group. On the other hand, there were no differences in the within 1 year group in arm and leg BMD compared with the control. However, in the over-6-year group they were significantly decreased. These results suggest that bone mineral loss in oophorectomized subjects occurs mainly in spinal bone, and the degree of bone mineral loss might be different in regional bone.

Absorptiometry, Photon↗
PubMed1990

[Myelodysplastic syndrome with complex chromosome abnormalities and peculiar fibril formation in granulocytes].

We report a case of myelodysplastic syndrome with peculiar fibril formation in granulocytes shown through electron microscope and complex karyotypic abnormalities including ring chromosomes. The patient, a 76-year-old male, was consulted for mild pancytopenia in February 1987. After 5 month, his hematological findings showed severe pancytopenia getting worse rapidly and presence of blasts in the peripheral blood. He had slightly hypercellular marrow with marked trilineage dysplasia and increased number of blasts (12.6%). Chromosome analysis from the bone marrow cells revealed its various structural abnormalities, especially in No. 3, 4, 5, 7, 11 with translocation on 11q11, and large ring chromosomes derived from unknown one. By electron microscopic study, we observed bizarre structures, which was peculiar fibril formation as bundles of filament resembling actin paracrystals, throughout cytoplasm as well as within nucleus in granulocytes.

Aged↗
PubMed1989

The influence of ventricular extrasystoles and postextrasystoles on cardiovascular dynamics in anesthetized dogs.

The influence of ventricular extrasystoles and postextrasystoles on cardiovascular dynamics were assessed in terms of maximum rate of rise of left ventricular pressure (max dP/dt), ascending aortic flow, left ventricular stroke volume, and left ventricular end-diastolic transverse dimension in anesthetized dogs. A single ventricular extrasystole, two and three consecutive ventricular extrasystoles (couplet and triplet) were induced by applying mechanical stimulation to the surface of the right ventricule. In any of these ventricular extrasystoles, max dP/dt, stroke volume and end-diastolic transverse dimension were decreased, compared with those in preceding sinus beats, i.e., pre-extrasystoles. Over the several postextrasystoles, max dP/dt was increased and gradually returned to its control level. This increase in max dP/dt, i.e., postextrasystolic potentiation paralleled an increase in ascending aortic peak flow but did not always bring about an increase in stroke volume, even when a left ventricular contraction was initiated by a significantly greater end-diastolic transverse dimension. The postextrasystolic potentiation seems to be associated with the Frank-Starling mechanism and does not compensate for the decreased in stroke volume elicited by the ventricular extrasystoles. In conclusion, not only ventricular extrasystoles per se but also postextrasystoles exert the adverse influence on cardiovascular dynamics consecutively.

Journal Article↗
PubMed1989

Ultrastructure of multinucleated giant myeloma cells: report of one case.

The ultrastructure of multinucleated giant myeloma cells obtained from an IgA kappa myeloma patient was investigated. The characteristic findings were marked nucleocytoplasmic asynchrony, irregular nuclear indentation, branched mitochondria, and Golgi apparatus surrounded by nuclei. The patient died of renal failure only 6 months after diagnosis.

Bone Marrow↗
PubMed1989

Giant cavernous hemangioma of the liver and multiple primary malignant tumors in a patient with suspected familial inhibition of natural killer cell activity--a case report.

A woman was operated on for a nonepithelial malignant tumor of the left leg and subsequently, for an epithelial carcinoma of the right breast and a borderline malignant tumor of the right ovary. She also developed a giant cavernous hemangioma that caused disseminated intravascular coagulation syndrome, which necessitated a left trisegmentectomy of the liver. Her family history suggested a hereditary predisposition to diverse malignant neoplasms, and also to giant cavernous hemangioma of the liver. Immunological evaluation disclosed selective inhibition of natural killer cell activity. Hormonal and hereditary factors are discussed in relation to the development of multiple primary tumors and giant cavernous hemangioma of the liver.

Breast Neoplasms↗
PubMed1989

Isolation and characterization of s-myc, a member of the rat myc gene family.

A 9-kilobase-pair clone containing a myc-related gene that we have designated s-myc was isolated from a rat genomic library. The entire nucleotide sequence of the cloned DNA was determined, showing that the s-myc gene contains an open reading frame consisting of 1287 base pairs without introns. In vitro transcription-translation analysis of s-myc indicated that this gene produces a protein of approximately 50 kDa. The amino acid sequence predicted from the DNA sequence showed that the s-Myc protein is closely related to the murine N-Myc protein but lacks an acidic amino acid-rich sequence commonly present in the Myc-family proteins. Studies on transfection of s-myc into rat RT4-AC tumor cells revealed that the gene produces a polyadenylylated transcript of approximately 4.7 kilobases and that its high-level expression suppresses the tumor-igenicity of RT4-AC tumor cells in nude mice.

Amino Acid Sequence↗
PubMed1989

Pena-Shokeir I syndrome: a comparative pathological study.

A case of Pena-Shokeir I syndrome in a female neonate is reported. The baby died of respiratory insufficiency shortly after birth. Postmortem examination revealed marked pulmonary hypoplasia and microscopic abnormalities of the hypoglossal nucleus and anterior horn cells in spinal cord. A comparative study with respect to hypoglossal nucleus disclosed the possibility of hypoplasia of the hypoglossal nucleus as part of this syndrome. This finding led us to propose that hypoplasia of the nucleus is one of the causes of polyhydramnios, based on the lack of swallowing activity. Moreover, ectopic cross-striated muscle fibers and an increase of muscle spindles were noted in tongue. The findings, particularly the neuropathologic one, provide further insight into the pathogenesis of the syndrome.

Abnormalities, Multiple↗