Search PubMed⌕ Search

Biomedical subjects

Y Kawamoto

Publications and source records attributed to Y Kawamoto.

At least 73 records · Page 4Linked to original sources
PubMed1996

Pancreastatin-like immunoreactivity in globular dystrophic neurites of senile plaques in brains of patients with Alzheimer's disease.

The immunohistochemical localization of pancreastatin (PST) was examined in brains of Alzheimer's disease (AD) and control cases using three different antisera to PST, and was compared with the staining for chromogranin A (CgA), the precursor of PST. In control brains, CgA-like immunoreactivity was observed in the cytoplasm and fibers of certain neuronal populations, which were not immunostained with any of the PST antisera. In AD brains, dystrophic neurites of globular shape located in senile plaques were immunostained with each of the PST antisera, as well as with the CgA antibody. PST-positive and CgA-positive dystrophic neurites showed similar profiles. The present study indicates that CgA is probably cleaved to produce PST in some globular dystrophic neurites in senile plaques.

Aged↗
PubMed1996

Promotion and control of selective adhesion and proliferation of endothelial cells on polymer surface by carbon deposition.

The adhesion and proliferation of endothelial cells can be drastically improved when cultivated on a carbon-deposited polymer surface. When the surface of segmented polyurethane, in which endothelial cells are not capable of proliferating, is modified by carbon deposition, cell adhesion and proliferation occurred selectively on the carbon-deposited region. Carbon deposition to a tissue culture-treated polystyrene surface on which cells are capable of proliferating further promoted cell spreading and proliferation. Cell patterning on carbon-deposited segmented polyurethane was also attempted by controlling the direction or region of cell proliferation. Carbon deposition onto the polymer surface brought about a decrease in the water contact angle of the surface. Precoating fibronectin or laminin on the carbon-deposited polymer surface brought about cell adhesion and proliferation in the carbon-deposited region, but not in the non-carbon-deposited region. Our data suggest that promotion of cell proliferation on a carbon-deposited surface is probably due to selective adhesion of adhesive proteins to the surface.

Animals↗
PubMed1996

Rapid killing of murine lymph node T blasts by intestinal intraepithelial lymphocytes in vitro.

We examined the effect of murine intestinal intraepithelial lymphocytes (IEL) on the proliferation of murine lymph node T cells (LN-T) in vitro. An IEL fraction prevented the proliferation of LN-T stimulated with antigen and X-irradiated spleen cells, or with anti-CD3 monoclonal antibodies (mAb). Concanavalin A-activated LN-T were less sensitive. Such an inhibitory activity was recovered from a CD8-depleted population by panning of bulk IEL using anti-CD8 alpha mAb. This population of BALB/c IEL showed less granzyme A activity, and its surface markers were positive for CD8 (4%), CD3 (80-90%), CD4 (2-6%), alpha-beta TcR (45-70%), and gamma-delta TcR (4-9%). Asialo-GM1 and Thy1.2 were variably expressed, but interleukin-2 (IL-2) receptor-alpha and Fc gamma receptor were not. By contrast, no cytotoxicity against YAC-1 was detected in a CD8-depleted IEL population by a 6-h 51Cr-release assay. Although IEL from severe-combined immunodeficient mice lacking CD4, CD8 and TcR, but expressing IL-2 receptor, showed cytotoxicity against YAC-1, their inhibitory activity against LN-T was almost the same as that by IEL from BALB/c mice. When LN-T blasts (greater than 75% CD4+) activated with anti-CD3 were treated with CD8-depleted IEL, intact cellular DNA of the T blasts disappeared within 1 h with increased amounts of small-sized DNA. These results suggest that CD8- IEL directly and nonspecifically kill lymph node CD4+ T blasts and possibly down-regulate TcR-mediated proliferation of peripheral T cells in the gut epithelium.

Animals↗
PubMed1996

Laser Spectroscopy of the CCO Radical in the 0.77-μm Region: Analysis of the A(020)kappa3Pi and A3Pii(001) States

The A(020)kappa3Pi-X3Sigma-(000) and A3Pii(001)-X3Sigma-(000) bands of the CCO radical have been investigated by laser spectroscopy with two types of tunable laser system. An analysis was made simultaneously for both the bands to establish line assignments and determine molecular constants for both the A(020) and A(001) states. A coupling constant between these two states was also determined by assuming the interaction to be of Fermi type.

Journal Article↗
PubMed1996

Phylogenetic relationship among all living species of the genus Bubalus based on DNA sequences of the cytochrome b gene.

The cytochrome b genes of all living species of Bubalus, including the river type and the swamp type of domestic buffaloes (Bubalus bubalis), were sequenced to clarify their phylogenetic relationships. These sequences were compared together with the African buffalo (Syncerus caffer) and banteng (Bos javanicus) sequences as an outgroup. Phylogenetic trees of Bubalus species based on the DNA sequences of the cytochrome b gene demonstrated that the tamaraw (Bubalus mindorensis), endemic to the Philippines, could be classified into the subgenus Bubalus, not the subgenus Anoa. The divergence time between the lowland anoa (B. depressicornis) and the mountain anoa (B. quarlesi) was estimated at approximately 2.0 million years (Myr), which is almost the same as the coalescence time for the Bubalus sequences. This large genetic distance supports the idea that the lowland anoa and the mountain anoa are different species. An unexpectedly large genetic distance between the river and the swamp type of domestic buffaloes suggests a divergence time of about 1.7 Myr, while the swamp type was noticed to have the closest relationship with the tamaraw (1.5 Myr). This result implies that the two types of domestic buffaloes have differentiated at the full species level.

Animals↗
PubMed1996

Immunohistochemical localization of brain-derived neurotrophic factor in adult rat brain.

To investigate the role of brain-derived neurotrophic factor in the central nervous system, we produced an anti-peptide antibody that specifically recognized brain-derived neurotrophic factor and performed immunohistochemistry for brain-derived neurotrophic factor-like immunoreactivity in normal adult rat brain. A synthetic peptide (EKVPVSKGQL), derived from mature brain-derived neurotrophic factor, was conjugated to bovine thyroglobulin at a ratio of 1:3 and used as an immunogen to produce a high-titre anti-brain-derived neurotrophic factor polyclonal antibody in Japanese white rabbits. Dot blotting demonstrated that the antiserum could detect 3.91 pmol of synthetic peptide, and Western blotting showed that the antiserum recognized one band with a molecular weight consistent with that of brain-derived neurotrophic factor. In immunohistochemistry, brain-derived neurotrophic factor-like immunoreactivity was widespread in adult rat brain, including cerebral cortex, hippocampus, basal forebrain, striatum, hypothalamus, brainstem and cerebellum. Not only neuronal somata but also nerve fibres showed positive staining. Our data suggest that brain-derived neurotrophic factor is transported through axons in a subpopulation of neurons in adult rat brain, and that brain-derived neurotrophic factor influences a great variety of neurons and acts as a neurotrophic factor in the central nervous system.

Animals↗
PubMed1996

"Obtundation status (Dravet)" caused by complex partial status epilepticus in a patient with severe myoclonic epilepsy in infancy.

PURPOSE: We report a 1-year 7-month-old boy with severe myoclonic epilepsy in infancy (SME) who exhibited complex partial status epilepticus (CPSE), which was confirmed by ictal video-EEG analysis. This boy first had a hemiconvulsion in a hot bath at age 3 months. Thereafter, he exhibited both partial and generalized seizures that were extremely intractable. At age 9 months, he had a prolonged episode of impaired consciousness that fit the "obtundation status in SME" defined by Dravet et al. METHODS AND RESULTS: Ictal EEG revealed persisting irregular spike-and-wave complexes over the left hemisphere, predominantly in the occipitotemporal area, and confirmed CPSE. The EEG abnormalities with decreased level of the consciousness continued approximately 6 h after onset of the symptoms even with AED administration. CONCLUSIONS: Because SME features both generalized and focal seizures, both types of nonconvulsive status may be seen in SME. Although Dravet et al. already reported long-lasting atypical absences in patients with SME as "obtundation status," we demonstrated CPSE in an infant with SME who exhibited a prolonged stuporous state.

Coma↗
PubMed1995

Nucleotide diversity of mitochondrial DNAs between the swamp and the river types of domestic water buffaloes, Bubalus bubalis, based on restriction endonuclease cleavage patterns.

Cleavage patterns of mitochondrial DNAs (mtDNAs) by 15 restriction endonucleases were analyzed for 10 swamp and 13 river types of domestic water buffaloes. Digestions with nine enzymes exhibited polymorphisms giving two or three kinds of cleavage patterns. Five mtDNA types were identified, three types in the swamp buffaloes of the Philippines, Vietnam, and Indonesia (S-types) and two types in the river buffaloes of Bangladesh and Pakistan (R-types). Nucleotide diversities ranged from 0.2 to 0.6% within the S- and R-types and from 1.9 to 2.4% between the R-types and the S-types. These values indicated that R-type and S-type mtDNAs differentiated at the subspecific level of other mammalian species reported. The possibility of polyphyletic domestication in different places is discussed for the origin of two distinct types of domestic water buffaloes.

Animals↗
PubMed1995

Clinicopathologic growth factors of acoustic neuromas.

BACKGROUND Understanding the tumor growth rate is very important when considering strategies for the treatment of an acoustic neuroma, although the natural course of acoustic neuromas has not been reviewed in detail. METHODS The clinicopathologic features and the postoperative growth of tumors were evaluated in 32 patients with acoustic neuromas. This study was undertaken to assess the variability of the growth potential of cells within an acoustic tumor and to determine the relationships between the growth rate and the clinicopathologic characteristics of the patients with acoustic neuromas, including age at surgery, gender, tumor location and preoperative size, the duration of the symptoms, the presence of cystic regions, the presence of Antoni type A and B cells, the tumor cell density, tumor vascularity, mitotic rate, the presence of hyaline degeneration and hemosiderin deposition, nucleolar organizer regions (NORs), and the level of proliferating cell nuclear antigen (PCNA). RESULTS The growth patterns of the tumors were divided into three groups according to their growth rate: a regression group, a "no-growth" group (growth rates from 0-0.11 cm/year) and a progression group (growth rates from 0.19-1.72 cm/year). An additional operation was required in all patients whose growth rate was more than 0.38 cm/year. A statistical study on the factors associated with an increased growth rate showed that the three histopathologic factors most significantly associated with a postoperative growth rate were hyaline degeneration (p < 0.05), cell density (p < 0.005), and PCNA labeling index (p < 0.005). CONCLUSIONS These results strongly suggest that acoustic tumors can be subdivided into several groups, based upon different biologic activities and tumor growth rates.

Adult↗
PubMed1995

In vitro evaluation of antithrombogenicity of hybrid-type vascular vessel models based on analysis of the mechanism of blood coagulation.

In vitro evaluation of antithrombogenicity of materials of artificial vascular vessels was carried out based on an analysis of the coagulation mechanism of blood. Coagulation of blood in tubes coated with endothelial cells (ECs) or segmented polyurethane (SPU) was measured by a rheological technique. Coagulation of blood in hybrid-type vascular vessel model tubes consisting of cultured ECs proliferated on carbon-deposited SPU was also examined. Coagulation of blood in these tubes occurred within 40 min, and appears to be due to the interaction between erythrocytes and a coagulant factor in plasma. From the in vitro evaluation test, when the time of onset of the coagulation of blood in contact with a surface of the artificial materials is longer than 20-39 min, the materials can be considered to provide an inert surface against thrombus formation and blood coagulation.

Adult↗
PubMed1995

Complex partial status epilepticus in childhood.

We report 5 pediatric patients (2 male, 3 female; age range: 4-8 years) with complex partial status epilepticus (CPSE). Four patients had previous illnesses and mild motor or mental retardation. In 2 patients, CPSE was induced by inappropriate management or selection of antiepileptic drugs. Clinical features varied and automatisms were observed in 3 patients. In 1 patient, decreased physical tone with syncope and impaired consciousness with amaurosis were observed. The episodes of CPSE were continuous in 3 patients and recurrent in 2 patients. In 4 patients, ictal electroencephalographic (EEG) findings, including video-EEG analyses of 3 patients, demonstrated persistent focal epileptic features. Intravenous diazepam abolished CPSE in 3 patients with brief periods of definite EEG localizations remaining. In 4 patients, seizure prognoses were favorable after appropriate treatments; in 1 patient, seizures were intractable even after antiepileptic drug administration.

Anticonvulsants↗
PubMed1995

Natural killer (NK)-like cytotoxicity of murine intraepithelial lymphocytes in the small intestine (iIEL) and the effect of the serine proteases.

The natural killer (NK)-like cytotoxicity of murine intraepithelial lymphocytes in the small intestine (iIEL) and the participation of serine proteases in it were investigated. We monitored the cytotoxicity of iIEL with a sensitive cytotoxic assay using laser flow cytometry. iIEL exhibited NK-like cytotoxicity on YAC-1 target cells. Benzamidine, a serine protease inhibitor, inhibited significantly both Na-CBZ-L-lysine thiobenzyl ester (BLT)-specific serine protease activity and iIEL-mediated NK-like cytotoxicity. These results suggest that BLT-specific serine proteases may participate in NK-like cytotoxicity of murine iIEL.

Amino Acid Sequence↗
PubMed1994

Phylogenetic relationships among Homo sapiens and related species based on restriction site variations in rDNA spacers.

A rapid method, using 12 restriction enzymes, was employed to analyze variations in ribosomal DNA (rDNA) spacers in a study of phylogenetic relationships between Homo sapiens and related species. We mapped restriction sites in the external and internal spacer regions and compared the arrangements of sites. The estimated sequence divergence between Homo sapiens and Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus, Hylobates lar, H. agilis, and Macaca fuscata was 2.7, 2.3, 3.8, 7.3, 6.8, 7.8, and 14.1%, respectively. The genetic relationships inferred from these distances generally correspond to those inferred from analyses of other molecular markers in the literature. The divergence between H. lar and H. agilis and between H. lar and H. syndactylus was 0.34 and 2.4%, respectively.

Animals↗
PubMed1993

Polymorphism of transferrin found in the laboratory rat and wild rats in Japan.

Polymorphism of the transferrin locus (Tf) was found in the laboratory rat and wild rats in Japan by polyacrylamide gel electrophoresis. Two phenotypes, "a" and "b," were distinguished in homozygotes. It is suggested that these are controlled by autosomal codominant alleles. In 10 laboratory strains, only the IS strain showed the a type. This allele found in the IS strain was broadly distributed in Japanese wild rats. It is considered to be derived from a wild rat in Japan. Linkage relationship between Tf and Alp-1 was not established.

Animals↗
PubMed1993

[Prognostic factors in primary lymphoma of the thyroid--a review of 74 cases].

Prognoses and prognostic factors in 74 patients with primary lymphoma of the thyroid gland were analyzed. From 1968 to 1991, 74 patients with non-Hodgkin's lymphoma originating in the thyroid gland were treated at Noguchi Thyroid Clinic Hospital. Patients consisted of 53 females and 21 males, with a median age of 64.5 years. Survival curves were calculated by the Kaplan-Meier method and significance was tested by generalized Wilcoxon test. The overall 5-year and 10-year survival rates were 81.8% and 62.5%, respectively. The survival rate in stage II disease was significantly (P = 0.004) lower than that in stage I. By the LSG classification, there was no significant difference in survival curves between follicular lymphoma and diffuse lymphoma. Using the Working Formulation, there was no significant difference in survival curves between cases with low and intermediate grade histology. Histologic subtype of the tumor did not appear to be a significant determinant of prognosis. Patients with vocal cord paralysis had poorer survival rates than others (P = 0.001). Extrathyroidal spread of the tumor by direct soft tissue invasion had a distinctly adverse effect on prognosis.

Adult↗