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Biomedical subjects

M Inagaki

Publications and source records attributed to M Inagaki.

At least 271 records · Page 15Linked to original sources
PubMed1992

Clinical and neuroradiologic findings of congenital hydrocephalus in infant born to mother with HTLV-I-associated myelopathy.

We describe clinical and neuroradiologic findings in a male infant with congenital hydrocephalus born to a mother who developed human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy. Ultrasonography at age 20 days showed multiple cysts in the subependymal germinal matrix and enlarged lateral ventricles. Elevation of serum HTLV-I antibody suggested that his hydrocephalus was probably due to intrauterine HTLV-I infection. HTLV-I may cause neurotropic infection in utero.

Female↗
PubMed1992

Periodic fever compatible with familial Mediterranean fever.

A 55-year-old male presented with a recurrent fever of over 38 degrees C, occurring at irregular intervals 1-6 times a month with chest, back or abdominal pain. After admission to our hospital, we found the following characteristics: 1) the febrile attacks were accompanied by obvious inflammatory findings and pleuritis or peritonitis; 2) the patient's elder sister had a similar periodic fever; and 3) there were no apparent causative factors responsible for his symptoms. Therefore, we diagnosed this as a case compatible with familial Mediterranean fever. The febrile attacks have been completely suppressed by daily colchicine. This is the seventh case of familial Mediterranean fever reported in Japan.

Abdominal Pain↗
PubMed1992

[Correlation between morphological abnormalities of Chiari malformation and evoked potentials].

We studied correlation between morphological abnormalities of Chiari malformation and evoked potentials (short-latency somatosensory evoked potential [SSEP] and auditory brainstem response [ABR]). On SSEP the inter-peak latency prolongation of P3-N1 was revealed in 6 out of 8 cases with Chiari malformations. The feature of positive wave between P3 and N1 was divided into 2 groups. The tendency of the positivity between P3 and N1 was more marked in cases of prolonged P3-N1 latency and correlated with the medullary kink. On ABR the prolongation of III-V inter-peak latency was revealed in one side in 3 patients Chiari malformations with malformed pons and tegmentum.

Adolescent↗
PubMed1992

[Superoxide dismutase activity in the broncho-alveolar lavage fluid in late asthmatic response model in guinea pigs].

In order to investigate the mechanism of the late asthmatic responses (LAR), LAR model in guinea pigs was made by inhalation of a large quantity of egg albumin antigen. Serial changes of inflammatory cells and superoxide dismutase activities in broncho-alveolar lavage fluids obtained from these animals were observed. In this model, increase in inflammatory cells, such as neutrophils, was observed in the broncho-alveolar lavage fluid during the late asthmatic responses of the attack and superoxide dismutase activity increased in the broncho-alveolar lavage fluid in parallel with the increase in inflammatory cells. These results suggest that change in superoxide dismutase activity in the broncho-alveolar lavage fluid may be involved in the onset of the late asthmatic responses.

Animals↗
PubMed1992

[Inhibitory effect of amlexanox on asthmatic attacks in an aspirin sensitive asthmatic].

The anti-allergic action of amlexanox is reported to be associated with inhibition of the release of LTC4, LTD4 and histamine, and with antagonistic activity on leukotrienes. The patient was a 18-year-old female who had suffered from bronchial asthma since the age of fifteen. We diagnosed the case as aspirin sensitive asthma because of development of a severe asthmatic attack with syncope after oral administration of an analgesic for treatment of a common cold at the age of seventeen. She also had sensitivity to toothpaste. Three-minute aerosol inhalation challenge with 0.1, 1 and 10% solution of sulpyrine was performed as a stepwise increment at 20 minutes intervals. This inhalation test was positive and it evoked simultaneous increases of LTC4, LTD4 and histamine in the peripheral blood. Since the commencement of oral administration of 150 mg per day of amlexanox, the patient has had no attacks for about 8 months. In the second inhalation test, premedication with amlexanox elevated the threshold of sulpyrine and inhibited the release of LTC4, LTD4 and histamine. We report that amlexanox was of use to control asthmatic attacks in this aspirin-sensitive asthmatic patient.

Adolescent↗
PubMed1992

[A case of cervical myelopathy due to atlanto-axial subluxation with athetoid cerebral palsy].

We reported cervical myelopathy due to atlanto-axial subluxation of athetoid quadriplegia of cerebral palsy. This lesion was present from upper cervix to lower medulla oblongata, and appeared on MRI. The changes of sSEP was useful to evaluate his spinal function. We think that pediatricians need to understand this pathophysiology, particularly for multihandicapped children.

Adolescent↗
PubMed1991

Identification of a Gs activator region of the beta 2-adrenergic receptor that is autoregulated via protein kinase A-dependent phosphorylation.

We have localized a G protein activator region of the human beta 2-adrenergic receptor to region beta III-2 (from Arg259 to Lys273). The synthetic beta III-2, corresponding to the C-terminal end of the third cytoplasmic loop, activates Gs at nanomolar concentrations and weakly activates Gi. beta III-2 activates adenylyl cyclase at nanomolar concentrations in wild-type S49 lymphoma membranes, but not in membranes of unc mutant S49 cells, in which Gs is uncoupled from beta-adrenergic stimulation. Phosphorylation of beta III-2 by cAMP-dependent protein kinase A, which is involved in the desensitization of the beta-adrenergic receptor from Gs, drastically reduces the effect of beta III-2 on Gs while potentiating its action on Gi, resulting in a total loss of adenylyl cyclase-stimulating activity. These findings indicate that this receptor sequence is a multipotential G protein activator whose G protein specificity is regulated by protein kinase A.

Adenylyl Cyclases↗
PubMed1991

Inactivation of DNA polymerase beta by in vitro phosphorylation with protein kinase C.

The Mr = 38,300 polypeptide of the purified recombinant rat DNA polymerase beta served as an excellent substrate for protein kinase C (PKC) in vitro but not for the catalytic subunit of cAMP-dependent protein kinase. The phosphorylation by PKC resulted in inactivation of DNA polymerase beta activity, and recovery was achieved by dephosphorylation with alkaline phosphatase. Since the phosphorylated DNA polymerase beta was retained with use of a single-stranded DNA-cellulose column, inactivation might occur at a site different from that for the DNA binding. Amino acid sequence analysis of the phosphopeptides revealed that the phosphorylated sites were 2 serine residues at positions 44 and 55 from the NH2 terminus, either or both of which might be involved in the catalytic activity of DNA polymerase beta. Thus, the inactivation of the DNA repair enzyme, DNA polymerase beta, by PKC may be an important process in the modification of DNA metabolism in the nucleus through signal transduction processes.

Alkaline Phosphatase↗
PubMed1991

Phosphorylation of keratin intermediate filaments by protein kinase C, by calmodulin-dependent protein kinase and by cAMP-dependent protein kinase.

Keratins, constituent proteins of intermediate filaments of epithelial cells, are phosphoproteins containing phosphoserine and phosphothreonine. We examined the in vitro phosphorylation of keratin filaments by cAMP-dependent protein kinase, protein kinase C and Ca2+/calmodulin-dependent protein kinase II. When rat liver keratin filaments reconstituted by type I keratin 18 (molecular mass 47 kDa; acidic type) and type II keratin 8 (molecular mass 55 kDa; basic type) in a 1:1 ratio were used as substrates, all the protein kinases phosphorylated both of the constituent proteins to a significant rate and extent, and disassembly of the keratin filament structure occurred. Kinetic analysis suggested that all these protein kinases preferentially phosphorylate keratin 8, compared to keratin 18. The amino acid residues of keratins 8 and 18 phosphorylated by cAMP-dependent protein kinase or protein kinase C were almost exclusively serine, while those phosphorylated by Ca2+/calmodulin-dependent protein kinase II were serine and threonine. Peptide mapping analysis indicated that these protein kinases phosphorylate keratins 8 and 18 in a different manner. These observations gave the way for in vivo studies of the role of phosphorylation in the reorganization of keratin filaments.

Amino Acids↗
PubMed1991

Evidence that Ser-82 is a unique phosphorylation site on vimentin for Ca2(+)-calmodulin-dependent protein kinase II.

We identified the sites on vimentin that are phosphorylated by Ca2(+)-calmodulin-dependent protein kinase II (CaM-kinase II). Sequential analysis of the purified phosphopeptides demonstrated that the sites are -Thr-Arg-Thr-Tyr-Ser(PO4)38-Leu-Gly-Ser-Ala- and -Val-Arg-Leu-Leu-Gln-Asp-Ser(PO4)82-Val-Asp-, which are located within the amino-terminal head domain of vimentin. For Ser-82 but not Ser-38, the proposed CaM-kinase II recognition amino acid sequence (Arg-X-X-Ser/Thr) was not found. Studies with a series of synthetic peptide analogs corresponding to Ser-82 and its surrounding amino acid sequence indicate that Asp-84 acts as an essential substrate specificity determinant for the Ser-82 phosphorylation by CaM-kinase II. The CaM-kinase II recognition site may be more extensive than heretofore determined.

Amino Acid Sequence↗
PubMed1991

A monoclonal antibody to the phosphorylated form of glial fibrillary acidic protein: application to a non-radioactive method for measuring protein kinase activities.

Monoclonal antibody YC10 showed specificity for the phosphorylated form of human, bovine and porcine glial fibrillary acidic proteins (GFAPs) and negligible reactivity towards the dephosphorylated form of the GFAPs. Analysis of species specificity and of the epitope, determined using synthetic phosphopeptides, indicated that this antibody recognized the local phosphorylation-site sequence Thr-phosphoSer-Ala-Ala-Arg-Arg (residues 7-12 of GFAP). Making use of this antibody we developed a non-radioactive method to measure protein kinase activities. After incubation of a protein kinase with non-radioactive ATP in ninety-six wells coated with the synthetic peptide Arg-Arg-Arg-Val-Thr-Ser-Ala-Ala-Arg-Arg-Ser-Cys (residues 3-13 of GFAP), the phosphorylated product was detected by using this mouse antibody and peroxidase-labeled goat anti-mouse IgG. This method proved to be equally as sensitive as the radioactive method for the measurement of protein kinase activities and was less affected by concentrations of ATP present in the reaction mixture.

Amino Acid Sequence↗
PubMed1991

Specific localization of phosphointermediate filament protein in the constricted area of dividing cells.

We developed antibodies pG1 and pG2 which recognize glial fibrillary acidic protein (GFAP) in its phosphorylated state. Antibodies pG1 and pG2 were produced against two synthetic peptides, Arg-Arg-Arg-Val-Thr-phosphoSer-Ala-Ala-Arg-Arg-phosphoSer (residues 3-13) and Pro-Gly-Pro-Arg-Leu-phosphoSer-Leu-Ala-Arg-Met-Pro (residues 29-39), respectively. The phosphorylation of these serine residues on the intact GFAP induces disassembly of glial filaments in vitro (Inagaki, M., Gonda, Y., Nishizawa, K., Kitamura, S., Sato, C., Ando, S., Tanabe, K., Kikuchi, K., Tsuiki, S., and Nishi, Y. (1990) J. Biol. Chem. 265, 4722-4729). Immunofluorescence and immunoblotting studies demonstrate that both antibodies react specifically with mitotic astroglial cells, thereby supporting the notion that increased phosphorylation during mitosis may directly influence intracellular organization of the glial filaments. The specific distribution pattern of the phosphoGFAP in the mitotic cells reveals that site-specific phosphorylation events may make way for the locally controlled breakdown of glial filaments in the constricted area, before the final separation of daughter cells.

Amino Acid Sequence↗
PubMed1991

Immunosuppressive mechanism of 15-deoxyspergualin on sinusoidal lining cells in swine liver transplantation: suppression of MHC class II antigens and interleukin-1 production.

To elucidate the precise mechanism of action of 15-deoxyspergualin (DSG) in swine liver transplantation, the expression of MHC class II antigens (Ia) on hepatic sinusoidal lining cells (SLC) and their production of interleukin-1 (IL-1) were examined. In our previous study, we isolated sinusoidal endothelial cells (SEC) and Kupffer cells (KC) by enzymatic digestion and centrifugal elutriation, and demonstrated that both SEC and KC present alloantigens effectively and generated IL-1 in response to allogenic or lipopolysaccharide stimulation. Animals were divided into three groups: group 1, nontransplanted normal controls (n = 3); group 2, no immunosuppressive treatment following liver transplantation (n = 5); group 3, DSG (0.8 mg/kg/day) intravenously for 7 days following liver transplantation (n = 5). At 1 week after transplantation, the three liver grafts in groups 2 and 3 were processed for the study of Ia expression and IL-1 production on SEC and KC. The expression of Ia was detected in 21.5 +/- 4.7% of SEC and 24.3 +/- 11.1% of KC in group 1. In group 3, Ia expression was suppressed compared with group 2, being 3.6 +/- 2.8% versus 22.0 +/- 2.8% for SEC (P less than 0.02) and 15.5 +/- 11.3% versus 24.3 +/- 7.1% for KC. IL-1 production by SEC and KC was respectively 11,483 +/- 3311 cpm and 9077 +/- 2161 cpm in group 1. In group 3, IL-1 production was inhibited compared with that in group 2, being 7190 +/- 883 cpm versus 19,297 +/- 5182 cpm for SEC (P less than 0.05) and 16,130 +/- 3769 cpm versus 25,857 +/- 3963 cpm for KC.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗