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Biomedical subjects

S Kitani

Publications and source records attributed to S Kitani.

At least 37 records · Page 2Linked to original sources
PubMed1993

Isolation and characterization of a major allergenic component (gp55) of Aspergillus fumigatus.

IgE class antibodies specific for antigens in a water-soluble extract of Aspergillus fumigatus (strain NHL-5759) were analyzed by immunoblotting with sera from patients with allergic bronchopulmonary aspergillosis. All the sera tested were reactive with a major 50 to 60 kd protein in the extract. This allergen, designated gp55, was purified by gel filtration and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The antigen was found to be present in the water-soluble extract in the form of a complex composed of approximately eight molecules of gp55. The carbohydrate and phosphate content of the purified antigen were 23.1% and 0.46%, respectively. The molar ratio of mannose to galactose residues was 2.76:1, and the protein was glycosylated predominantly with N-linked oligosaccharides. The serologic activity of the gp55 antigen was abolished by treatment with nonspecific protease (Pronase) but not by treatment with sodium metaperiodate or endoglycosidases. Thus the major antigenic site of the glycoprotein is located within its peptide moiety. The antigen itself displayed no chymotryptic or tryptic activity. The amino acid sequence of the 20 N-terminal residues of the antigen (ATPHEPVFFSWDAGAVTSFP) is different from that of any other protein previously reported.

Amino Acid Sequence↗
PubMed1993

[The role of mast cells and basophils in the pathogenesis of bronchial asthma].

Bronchial asthma has now been recognized as an inflammatory disease. The present study was undertaken to evaluate the role of mast cells and basophils in the pathogenesis of bronchial asthma. Stem cell factor, a growth factor of mast cells, activates rat peritoneal mast cells and human lung mast cells to release histamine. We demonstrated the presence of basophils in lung tissues obtained from fatal asthma cases using immunohistochemical techniques. IL-3, GM-CSF, IL-5 and IGF-I enhanced basophil histamine release. These findings indicate that mast cells and basophils have important roles in the pathogenesis of bronchial asthma.

Animals↗
PubMed1992

Inhibition of IgE-mediated histamine release by myosin light chain kinase inhibitors.

Wortmannin, a specific inhibitor of myosin light chain kinase (MLCK) blocked IgE mediated histamine release from rat basophilic leukemia cell (RBL-2H3) and human basophils dose-dependently. Its IC50 was 20 nM for RBL-2H3 cells and 30 nM for human basophils. There was complete inhibition at the concentration of 1 microM. Wortmannin inhibited partially the A23187 induced histamine release from RBL-2H3 cells (40% inhibition at 1 microM). This inhibition was not accompanied by any significant effect on cytosolic free calcium concentration [( Ca2+]i). KT5926, another MLCK inhibitor, inhibited histamine release comparably with wortmannin and blocked to some degree the increase of [Ca2+]i in RBL-2H3 cells. Thus, the phosphorylation of myosin seems to be involved in signal transduction through Fc epsilon RI.

Alkaloids↗
PubMed1992

Binding of monoclonal antibody AA4 to gangliosides on rat basophilic leukemia cells produces changes similar to those seen with Fc epsilon receptor activation.

The mAb AA4 binds to novel derivatives of the ganglioside Gd1b on rat basophilic leukemia (RBL-2H3) cells. Some of the gangliosides are located close to the high affinity IgE receptor (Fc epsilon RI), and binding of mAb AA4 inhibits Fc epsilon RI-mediated histamine release. In the present study, mAb AA4 was found to bind exclusively to mast cells in all rat tissues examined. In vitro, within 1 min of mAb AA4 binding, the cells underwent striking morphologic changes. They lost their normal spindle shaped appearance, increased their ruffling, and spread over the surface of the culture dish. These changes were accompanied by a redistribution of the cytoskeletal elements, actin, tubulin, and vimentin, but only the actin was associated with the membrane ruffles. Binding of mAb AA4 also induces a rise in intracellular calcium, stimulates phosphatidyl inositol breakdown, and activates PKC. However, the extent of these changes was less than that observed when the cells were stimulated with antigen or antibody directed against the Fc epsilon RI. None of these changes associated with mAb AA4 binding were seen when the cells were exposed to nonspecific IgG, IgE, or four other anti-cell surface antibodies, nor were the changes induced by binding mAb AA4 at 4 degrees C or in the absence of extracellular calcium. Although mAb AA4 does not stimulate histamine release, it enhances the effect of the calcium ionophore A23187 mediated release. The morphological and biochemical effects produced by mAb AA4 are similar to those seen following activation of the cell through the IgE receptor. Therefore, the surface gangliosides which bind mAb AA4 may function in modulating secretory events.

Actins↗
PubMed1991

A cell surface glycoprotein of rat basophilic leukemia cells close to the high affinity IgE receptor (Fc epsilon RI). Similarity to human melanoma differentiation antigen ME491.

A monoclonal antibody (mAb), AD1, was isolated that recognized a cell surface protein on rat basophilic leukemia cells (RBL-2H3). At high concentration, this antibody inhibited IgE-mediated but not calcium ionophore-induced histamine release (49% inhibition at 100 micrograms/ml). The mAb AD1 did not inhibit the binding of IgE or of several antibodies directed to the high affinity IgE receptor (Fc epsilon RI). Likewise, IgE did not inhibit mAb AD1 binding. However, several anti-Fc epsilon RI antibodies did inhibit mAb AD1 binding as intact molecules but not as Fab fragments. Therefore, the sites on the cell surface to which mAb AD1 binds are close to Fc epsilon RI. The mAb AD1 immunoprecipitated a broad, 50-60-kDa band from 125I-surface-labeled RBL-2H3 cells that upon peptide N-glycosidase F treatment was transformed into a sharp 27-kDa band. A similar 27-kDa protein was immunoprecipitated from surface-radiolabeled cells after culture with tunicamycin. Thus, the protein recognized by mAb AD1 is highly glycosylated with predominantly N-linked oligosaccharides. The N-terminal sequence of 43 amino acids was found to be different from any subunit of Fc epsilon RI but nearly identical to that of the human melanoma-associated antigen ME491. Therefore, mAb AD1 binds to a surface glycoprotein on RBL-2H3 cells sterically close to the Fc epsilon RI but distinct from the recognized subunits of the receptor.

Amino Acid Sequence↗
PubMed1988

Inhibition of allergic reactions with monoclonal antibody to the high affinity IgE receptor.

A mAb that reacts with the high affinity IgE-R on the rat basophilic leukemia cells (RBL-2H3) was used to inhibit allergic reactions. In vitro, the intact mAb BA3 and its Fab fragment inhibited radiolabeled IgE binding to the RBL-2H3 cells. The mAb binds to the IgE-R with a higher affinity than does IgE. Whereas the intact mAb released histamine from the RBL-2H3 cells, the Fab was inactive. The addition of the Fab fragments to RBL-2H3 inhibited the IgE-mediated histamine release reaction. The Fab fragments also inhibited in vivo passive cutaneous reactions in rats when injected intradermally either before or after IgE. The injection of the mAb Fab i.v. before the injection of the IgE into the skin sites also inhibited reactions, although it was less effective. The results demonstrate that anti-R antibodies can be used as a model for inhibiting immediate hypersensitivity reactions.

Animals↗
PubMed1988

Experiments on antidromic evoked potentials of the facial nerve. A possible electroneurodiagnostic examination of intratemporal facial nerve paralysis.

Registering of AEPs of the facial nerve was attempted both in animals and in human subjects. In animal experiments using cats and guinea pigs, electrical stimulus was given to the zygomatic branch. The neural responses registered from the electrode placed on the fallopian canal or on the posterior wall of the external auditory canal were verified to be the AEP. The AEP appeared to be a sensitive and simultaneous indicator of the neural compression damage. In the human experiments, the three major peripheral branches were transcutaneously stimulated, and the AEPs were registered in the depth of the external auditory canal. The marginal mandibular branch was thought to be the most suitable branch of the transcutaneous stimulation for human application. The AEPs registered from a patient with Bell's palsy was demonstrated.

Animals↗
PubMed1986

The earliest form of C-protein expressed during striated muscle development is immunologically the same as cardiac-type C-protein.

A monoclonal antibody (C-315) specific for cardiac-type C-protein was prepared and, in combination with other antibodies specific for fast and slow skeletal muscle C-proteins, it was used to investigate the expression of C-protein isoforms in developing striated muscle cells in vivo and in vitro. During embryonic development of skeletal muscles, a C-protein recognized by C-315 appeared first but only transiently, it being replaced subsequently by two other isoforms recognized by the antibodies to slow and fast skeletal muscle C-proteins in a fiber-type specific manner as previously demonstrated (Obinata et al. (1984) Develop. Biol. 101, 116-124). In contrast, only cardiac-type C-protein was detected in cardiac muscle throughout the developmental stages. When myogenesis in vitro was monitored using the same antibodies, C-315 binding appeared first in multinucleated myotubes as in vivo which was followed by the sequential expression of two other C-protein variants. The reactivity of C-315 as well as that of anti-slow and anti-fast skeletal C-protein antibodies persisted during muscle development in culture. Thus, this study demonstrates that the earliest form of C-protein expressed in striated muscles may either be a cardiac-type isoform or a unique embryonic protein containing an epitope in common with the adult cardiac-type protein, and that transitions of C-protein isoform expression characteristic of each fiber-type occur during muscle development in vivo but not in vitro.

Animals↗
PubMed1985

Sino-orbital aspergillosis associated with total ophthalmoplegia.

Invasive aspergillosis of the paranasal sinuses involving the orbit is termed sino-orbital aspergillosis. Prognosis of sino-orbital aspergillosis, complicated by impaired visual acuity and neurological signs, is disastrous and usually fatal. We herein report two patients with sino-orbital aspergillosis associated with total ophthalmoplegia. One patient was successfully treated with surgical eradication including orbital exenteration. In contrast, the other died of cerebral infarction, probably due to fungal thrombosis of the middle cerebral artery, despite repeated local debridement followed by orbital exenteration and administration of antifungal agents. Experience with these cases strongly indicates the necessity of prompt surgical eradication, including orbital exenteration if necessary, in the treatment of sino-orbital aspergillosis.

Antifungal Agents↗
PubMed1985

IgG, IgA, and IgM antibodies to mite in sera and sputa from asthmatic patients.

In order to examine roles of antibodies to allergens in bronchial secretions, IgG, IgA, and IgM antibodies to mite in sputa from mite-sensitive asthmatics were measured by ELISA and compared with antibodies in sera. IgA antibodies to mite in sputa were significantly higher in mite-sensitive patients than in normal controls or mite-unsensitive asthmatic patients (P less than .01), whereas IgG and IgA antibodies in sera were significantly higher in mite-sensitive patients than in the other two groups (P less than .01). There were no significant differences of serum or sputum IgM antibodies among the three groups. The relative ratio of the level of IgA antibodies: the level of IgG antibodies was higher in sputum than in sera. IgA antibodies in bronchial secretions may play a protective role for asthma when allergens enter into the bronchial trees.

Allergens↗
PubMed1984

Immunochemical analysis of C-protein isoform transitions during the development of chicken skeletal muscle.

Isoforms of C-protein in adult chickens which differ in fast (pectoralis major, PM) and slow (anterior latissimus dorsi, ALD) skeletal muscles can be distinguished immunochemically with monoclonal antibodies (McAbs) specific for the respective fast (MF-1) and slow (ALD-66) protein variants (Reinach et al., 1982 and 1983). The expression of these C-proteins during chick muscle development in vivo has been analyzed by immunoblot and immunofluorescence procedures. Neither MF-1 nor ALD-66 reacted with whole-cell lysates or myofibrils from PM of 12-day-old embryos. However, both McAbs bound to peptides of 145 kDa in PM from late embryonic and young posthatched chickens. All of the myofibers in these muscles reacted with both antibodies, but the binding of the anti-slow McAb (ALD-66) diminished progressively with age and was completely negative with PM by 2 weeks after hatching. In contrast, the ALD muscle from 17 days in ovo thru adulthood only reacted with ALD-66; no binding of MF-1 could be detected at these stages. Since both fast and slow myosin light chains (LC) coexist within embryonic pectoralis and ALD muscles (e.g., G. F. Gauthier, S. Lowey, P. A. Benfield, and A. W. Hobbs, 1982, J. Cell Biol. 92, 471-484) yet segregate to specific fast and slow muscle fibers at different stages of development, the temporal transitions of C-protein and myosin LC were compared during myogenesis. "Slow-type" C-protein appeared after the disappearance of slow myosin light chains, whereas the accumulation of the "fast-type" light chains occurred before the expression of "fast-type" C-protein. The pattern of isoform transitions appears to be far more complex than previously suspected.

Age Factors↗
PubMed1984

Coexistence of fast-type and slow-type C-proteins in neonatal chicken breast muscle.

Two different C-protein variants which selectively react with either monoclonal anti-fast C-protein antibody (MF-1) or monoclonal anti-slow C-protein antibody (ALD-66) were separated from neonatal chicken pectoralis muscle by hydroxylapatite column chromatography. Myofibrils isolated from the neonatal chicken muscle reacted with both monoclonal antibodies as examined by an indirect immunofluorescence method. These observations strongly indicate that both fast-type and slow-type C-proteins are expressed in the neonatal chicken skeletal muscle. Both of them are intermingled and assembled in the same myofibrils.

Aging↗