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Biomedical subjects

H Mikawa

Publications and source records attributed to H Mikawa.

At least 253 records · Page 14Linked to original sources
PubMed1982

Detection of human osteosarcoma-associated antigen(s) by monoclonal antibodies.

Hybrid cell lines have been derived from a fusion between mouse myeloma cells, NS1, and spleen cells from mice immunized with freshly resected osteosarcoma cells from an untreated patient. Of the 276 hybrids obtained, five secreted antibodies which bound to osteosarcoma tissues but not to autologous skin fibroblasts. The antibodies from three of these five hybrids, OST6, OST7, and OST15, reacted with all of five osteosarcoma tissues and with one chondrosarcoma tissue but not with other malignant or benign tumors. Tests of various normal tissues were negative, except for weak binding to a subpopulation of chondrocytes in articular cartilage. The reciprocal binding inhibition test showed that OST6, OST7, and OST15 antibodies were directed against different antigenic determinants.

Animals↗
PubMed1982

Replication of pluripotent stem cells in granulocyte/macrophage colonies developed in methylcellulose culture of mouse bone marrow cells.

The existence of pluripotent hemopoietic stem cells in granulocyte/macrophage colonies was demonstrated in a culture of mouse bone marrow cells in semi-solid methylcellulose with spleen conditioned medium as colony-stimulating activity. When fresh growth medium containing the conditioned medium was supplemented to 1-week culture, the number of cells per colony increased significantly in the next week. The number of pluripotent stem cells also increased by a factor of 12 or more in the second week of the culture. The number of cell divisions in such a culture was calculated as 12-15 in 2 weeks. These results indicate that some of the granulocyte/macrophage colonies are derived from pluripotent stem cells, and that the stem cells can undergo 3-5 self-replications in such semi-solid culture.

Animals↗
PubMed1981

Electroencephalographic and cranial computed tomographic findings in children with hemiplegic cerebral palsy.

The electroencephalographic (EEG) and cranial computed tomographic (CCT) findings of 41 children with hemiplegic cerebral palsy were analyzed. There was a positive correlation between EEG abnormalities and the affected side of the body in 25 (61%), while there was a positive correlation between CCT abnormalities and the affected side of the body in 37 (90%). In 24 cases (59%), there was a positive correlation between EEG and CCT laterality. However, in 13 of the patients with dominant abnormalities in the cerebral hemisphere contralateral to the palsy, EEgs did not show the same laterality as the CCT. In two of these cases, dominant seizure discharges were present on the side opposite to the CCT abnormalities. CCT was more useful than EEG in determining the side of maximal brain damage in hemiplegic cerebral palsy (p less than 0.01).

Adolescent↗
PubMed1981

Idiopathic acute myocarditis with complete atrioventricular block in a baby. Clinicopathological study of the atrioventricular conduction system.

A 17-month-old Japanese girl with an idiopathic acute myocarditis had symptoms of vomiting, slight fever, and liver enlargement, but no edema. Clinical diagnosis of acute myocarditis was not made until she had Stokes-Adams syndrome and electrocardiogram revealed complete atrioventricular block on the day of death. At autopsy, idiopathic acute myocarditis was detected diffusely in the right and left ventricles. Vomiting and liver enlargement were due to congestive heart failure. Serial sections of the atrioventricular conduction system revealed diffuse and severe acute inflammatory changes in the right bundle and the left bundle branches, especially in the terminal portions. Acute inflammation was focally noted in the atrioventricular node and the His bundle. The complete atrioventricular block probably followed the severe acute inflammation of the bundle branches. Our case suggest that idiopathic acute myocarditis may be underdiagnosed in babies, as there is no way to determine whether there is dyspnea and palpitation on exertion, and idiopathic fibrosis of conduction system with or without conduction disturbances in children and adults may be sequelae of healed myocarditis in babies.

Acute Disease↗
PubMed1981

Rosette-increasing factor (RIF) generated in vivo following PHA skin test.

In phytohaemagglutinin (PHA) skin test-positive individuals, rosette-increasing factor (RIF), which augmented active E and EA rosette formation, appeared in the serum following the PHA skin testing. This factor was detectable 6 hr after the application of PHA and reached a peak at 14 hr. The appearance of the factor was closely related to the delayed cutaneous hypersensitivity. When mononuclear (MN) cells derived from individuals exhibiting delayed cutaneous reaction were further cultured without the addition of PHA, a similar property was found in the supernatants. Fractionation of the cells by E rosetting revealed this factor to be the product of T lymphocytes. Moreover, despite a lower percentage in contaminated T lymphocytes, a higher RIF activity was observed in the supernatants of the nylon-wool-retained population. The production of RIF was completely inhibited by cytochalasin B, but was not affected by colchicine. Experiments utilizing cycloheximide revealed that new protein synthesis was only necessary for early activation steps. RIF is a kind of lymphokine synthesized in the active immune process in vivo. Therefore, to assay RIF in vivo may provide a new method for investigating the cellular immune competence of the given patients.

Cells, Cultured↗
PubMed1980

Defective phagocytosis confined to Staphylococcus aureus in a female infant with recurrent infections.

Defective chemotaxis and phagocytosis of Staphylococcus aureus was identified in a female infant with marked hepatosplenomegaly and recurrent infections. Neutrophil mobilization from the marrow and marginal pool; random mobility; phagocytosis of yeast particles, latex beads and carbon particles; phagocytosis and intracellular killing capacity of Streptococcus pyogenes and E. coli; and NBT dye reduction were normal. Infiltration of neutrophils was depressed in the skin window test. The complement system and cellular immunity were intact. The patient also had a persistent EB virus infection. Defective phagocytosis limited to Staphylococcus aureus seems to be caused by an intrinsic cellular defect, such as congenital defect in neutrophil receptors for Staphylococcus aureus.

Bacterial Infections↗
PubMed1980

Infarction of the internal capsule in children.

The computed tomographic findings in seven boys and two girls with infarction of the internal capsule are reported. Ages at the time of examination ranged from 8 months to 14 years. The etiology was head injury (concussion) in six and unknown in three. Cerebral angiography carried out in four cases showed narrowing of main arteries in two patients.

Adolescent↗
PubMed1980

Elevated homovanillic acid in cerebrospinal fluid of children with infantile spasms.

To determine the role of noradrenaline, dopamine, and serotonin in the brain of patients with infantile spasms, levels of respective major metabolites in cerebrospinal fluid were examined. Homovanillic acid levels were significantly increased in these patients, while 3-methoxy-4-hydroxyphenylethylene glycol and 5-hydroxyindoleacetic acid were not significantly altered, as compared with controls. In patients with febrile convulsion and status epilepticus who were examined during or within a few hours after convulsions the same phenomenon was evident. The increased level of dopamine metabolite was closely related to the occurrrence of convulsions and is considered to be a secondary phenomenon.

Adrenocorticotropic Hormone↗
PubMed1980

Rosette-increasing factor released by PHA-stimulated mononuclear cells in vitro which augments active E and EA rosette formation.

The supernatants of phytohaemagglutinin (PHA) stimulated mononuclear (MN) cells contained a factor that significantly increased active E and EA (IgG) RFC which belonged to T cells and such was termed 'rosette-increasing factor' (RIF). This factor was demonstrated after as early as 2 hr of cluture and remained stable thereafter. The production of the factor seemed to be independent of macrophages and was mainly by nylon wool-adherent T cells. Cycloheximide and cytochalasin B pretreatment of MN cells prior to the addition of PHA abolished the activity of the supernatants in a dose-dependent manner, whereas mitomycin C and colchicine had no effect. As active E-RFC and Fc (IgG) receptor-positive T cells are considered to be closely correlated with cell-mediated immunity, this factor may play an important role in cellular immune response.

Cells, Cultured↗
PubMed1979

Interaction among IgE-mediated hypersensitivity reaction, PCA reaction and delayed hypersensitivity reaction (at local skin sites of monkeys).

The effect of the IgE-mediated reaction on the passive cutaneous anaphylaxis (PCA) reaction was studied at local skin sites of monkeys, and we found that the IgE-mediated reaction appeared to enhance the PCA reaction. Interactions among IgE-mediated reaction, PCA reaction and delayed hypersensitivity reaction were also determined. Contact dermatitis induced with DNCB was utilized as the delayed hypersensitivity reaction. The IgE-mediated reactior or PCA reaction, as well as simple serum irritation, enhanced the delayed hypersensitivity reaction. It is thus assumed that the IgE-mediated reaction enhances the PCA reaction and that this in turn accelerates the delayed hypersensitivity reaction.

Animals↗
PubMed1979

Suppressive effect of IgA soluble immune complexes on neutrophil chemotaxis.

The effect of IgA and IgG soluble immune complexes (SIC) on neutrophil chemotaxis was investigated. Six types of SIC were prepared from kappa-type IgA and IgG myeloma proteins: IgA-anti-kappa chain antibody SIC in IgA excess, IgA-anti-kappa chain antibody in SIC in anti-kappa chain antibody excess, IgA-anti-alpha chain antibody SIC in IgA excess, IgG-anti-kappa chain antibody SIC in IgG excess, IgG-anti-kappa chain antibody SIC in anti-kappa chain antibody excess, and IgG-anti-gamma chain antibody SIC in IgG excess. Three types of IgA SIC had a marked suppressive effect on neutrophil chemotaxis, while IgG SIC, free IgA, free anti-kappa chain antibody, and free anti-gamma chain antibody showed no inhibitory activity. This suppressive effect on neutrophil chemotaxis caused specifically by polymerized IgA was a cell-directed one and was expressed in a concentration dependent manner.

Antigen-Antibody Complex↗
PubMed1979

Effects of concanavalin A-induced cells on the proliferative response of T cells. Concanavalin A-induced suppressor and amplifier cells to the proliferative response of human T cells to trinitrophenyl-modified autologous lymphocytes.

Effects of Con A-induced human mononuclear cells on the proliferative response of peripheral T cells were examined by using TNP-modified autologous lymphocytes as stimulator cells. Cells induced by incubation with Con A contained both suppressor cells and amplifier cells. The former were induced from nylon wool-nonadherent T cells and these precursor cells were sensitive to mitomycin treatment. On the other hand, amplifier precursor cells were nylon wool-nonadherent T cells and were resistant to mitomycin treatment. Cell proliferation was required for the induction of suppressor cells but not for the induction of amplifier cells. Con A-induced suppressor effector cells were both nylon wool-adherent and nonadherent cells, on the contrary, Con A-induced amplifier effector cells were nonadherent cells. A small number of macrophages enhanced the suppressive activity of nonadherent T cells when added at the induction phase of suppressor T cells.

Cell Adhesion↗