Search PubMed⌕ Search

Biomedical subjects

Y Kamata

Publications and source records attributed to Y Kamata.

At least 91 records · Page 5Linked to original sources
PubMed1993

Multiple papillary adenomas of type II pneumocytes found in a 13-year-old boy with von Recklinghausen's disease.

A case of multiple papillary adenomas of type II pneumocytes is reported. A 13-year-old boy with von Recklinghausen's disease had small nodular lesions in both lungs without symptoms. The biopsied lung contained greyish-white nodules ranging in size from 0.5 to 2 mm. Light microscopic examination revealed cuboidal to low columnar cells arranged in a papillary pattern. Elastic fibres were present in the tumour stroma. Electron microscopically, the cells had osmiophilic lamellar bodies in the cytoplasm and short microvilli along the free border. The tumour cells expressed immunoreactivity for epithelial membrane antigen and surfactant apoprotein antibodies. More than 6 years after open lung biopsy, the patient is well but small nodular shadows can still be identified.

Adenoma↗
PubMed1993

Expression in baculovirus vector system of the nucleocapsid protein gene of rinderpest virus.

The rinderpest (RV) nucleocapsid (NP) gene segment was inserted into the genome of Autographa californica nuclear polyhedrosis virus (AcNPV) adjacent to the polyhedrin promoter. The expression of NP protein in Sf9 cells was confirmed by indirect immunofluorescence and by Western blotting analysis with monoclonal antibodies. Recombinant RV-NP protein was purified by ultracentrifugation on a sucrose density gradient, and used as an antigen for an enzyme linked immunosorbent assay to detect anti RV-NP antibody. Both IgM and IgG antibodies against RV-NP were detected in the sera of rabbits infected with the L strain of RV. The pattern of development of IgG anti RV-NP antibody closely correlated with that of virus neutralizing antibody. In rabbits inoculated with recombinant vaccinia virus expressing RV-H gene (RRV-H), anti RV-NP was not detected. The results indicated that the baculovirus vector system can be used for the preparation of the diagnostic antigen of rinderpest as well as to distinguish between natural infection and vaccination with RRV-H.

Animals↗
PubMed1993

An unusual heterotopia of pyloric glands of the stomach with inverted downgrowth.

A rarely reported, large heterotopia of gastric glands in the submucosal layer of the stomach is observed in a 79 year old Japanese man with early gastric cancer. Histologically, it consists of marked hyperplasia of benign foveolar-type epithelia and tubular glands which instead of growing upwards grow downwards into the submucosa. Immunohistochemically, many gastrin-positive G cells are observed within it, indicating the existence of independent pyloric-type glands from the surrounding mucosa with intestinal metaplasia. Muscle actin-positive fascicles, derived from the muscularis mucosae, are demonstrated to branch into it and to encapsulate it. This result suggests that the present lesion may not represent a truly submucosal ectopic location, but an inverted downgrowth of the mucosa into the submucosa, thus resembling an inverted polyp of the colon. An awareness of this unique lesion is important in order that it not be mistaken for a submucosal extension of the primary adenocarcinoma.

Aged↗
PubMed1993

Early stage of development in testicular choriocarcinomas.

Choriocarcinoma is the most malignant among germ cell tumors in the testis. However little is known about the early stage of its development. To understand the development of testicular choriocarcinomas, twenty cases of testicular choriocarcinoma were studied histologically and immunohistochemically. It was found that in the early stage of development, choriocarcinomas imitate the morphologic or functional differentiation of normal trophoblasts. It was also found that some choriocarcinomas regress spontaneously in the early stage. The majority of choriocarcinomas seemed to develop by first going through the embryonal carcinoma phase. However, there were some choriocarcinomas that showed no relationship with embryonal carcinoma.

Choriocarcinoma↗
PubMed1993

Comparison of the pathogenicity of rinderpest virus in different strains of rabbits.

Pathogenicity of the lapinized Nakamura-III (L) strain of rinderpest virus (RPV) was examined in four strains of rabbits consisting of two inbred strains (NW-NIBS and DUY-NIBS) and two outbred strains maintained in closed colony (NW-NIBS and JW-NIBS) using a marmoset lymphoblastoid cell line, B95a cell-passaged virus and tissue homogenates of virus-infected rabbits. The cell culture virus was found to maintain virulence for rabbits of both closed colony and inbred NW-NIBS strain similar to the homogenate virus. Among the strains investigated, inbred NW-NIBS strain showed the highest susceptibility to RPV. Thus experimental model in an inbred rabbit using cell culture virus became useful.

Animals↗
PubMed1993

[A case of intraocular histiocytosis X].

A solitary massive tumor developed in the left eye of a 61-year-old female who had a history of insulin-independent diabetes mellitus for 20 years and whose left eye had become blind due to repeated anterior uveitis in the recent several years. The eyeball was enucleated and used for further examinations. Intraocular tissues were widely infiltrated by histiocytes, though no extraocular invasion or further metastasis was found. Histological examination including alpha 1-anti-chymotrypsin and S100 staining revealed the features characteristic of histiocytosis X. This is probably a case of intraocular histiocytosis X with no evidence of systemic symptoms.

Eye Diseases↗
PubMed1992

Primary mesenchymal chondrosarcoma of the lung. A case report with immunohistochemical and ultrastructural studies.

A case of primary pulmonary mesenchymal chondrosarcoma is reported. The tumor occurred first in the lower lobe of the right lung of a Japanese female aged 45. Three years after the first operation it metastasized to the upper lobe of the left lung. The tumors were highly cellular and composed of undifferentiated mesenchymal cells and interspersed islands of well-differentiated cartilaginous tissue. Immunohistochemistry failed to detect S-100 and vimentin in the undifferentiated cells. In contrast, Leu-7 and blood coagulation factor XIIIa were positive in these cells. Electron microscopically, undifferentiated mesenchymal cells had narrow cytoplasm with sparsity of organelles, but no intermediate-sized filaments were detected. In the transitional areas between undifferentiated cells and cartilaginous components, thin intracytoplasmic filaments were sometimes observed in the tumor cells. The differentiation toward cartilaginous cells of undifferentiated mesenchymal cells was suggested by immunohistochemistry and electron microscopy. This is the first case of mesenchymal chondrosarcoma occurring in the lung with long-term follow-up.

Chondrosarcoma↗
PubMed1991

Properties of a protease-sensitive acceptor component in mouse brain synaptosomes for Clostridium botulinum type B neurotoxin.

To characterize an acceptor for Clostridium botulinum type B neurotoxin, its binding kinetics were examined with mouse brain synaptosomes treated with various enzymes. The amount of 125I-labelled neurotoxin bound to synaptosomes decreased upon treatment with lysyl endopeptidase, neuraminidase, or phospholipase C. The binding of the neurotoxin was partially recovered by incubation of neuraminidase-treated synaptosomes with ganglioside GT1b or GD1a. Gangliosides incorporated into untreated, lysyl endopeptidase-treated, and phospholipase C-treated synaptosomes had no effect on the binding of the neurotoxin. These results may suggest that type B neurotoxin binds to gangliosides in cooperation with a certain protease-sensitive substance on the neural membranes.

Animals↗
PubMed1991

Nucleotide sequence of cDNA to the rinderpest virus mRNA encoding the nucleocapsid protein.

The full-length cDNA corresponding to the mRNA encoding the nucleocapsid protein (NP) of rinderpest virus (RV) was cloned and its complete nucleotide sequence was determined. The gene of RV-NP was composed of 1683 nucleotides and contained a single large open reading frame, which is capable of encoding a protein of 525 amino acids with a molecular weight of 58,241 Da. The nucleotide sequence and predicted amino acid sequence were compared with those of measles virus (MV) and canine distemper virus (CDV). The nucleotide sequence of the coding region of RV-NP (53-1630) revealed a homology of 68.1% and 63.0% with MV and CDV-NP, respectively. Relatively moderate homologies of 68.7% (MV) and 64.3% (CDV) were found at nucleotides 53-592. The highest homology of 75.3-74.3% was equally present between RV and both MV and CDV in the middle region at nucleotides 593-1312. The homologies of the predicted amino acids in this region were 88.3% (MV) and 86.3% (CDV). Relatively low (MV) or little (CDV) homology was detected in the last 318 nucleotides toward the 3' terminus (1313-1630). The predicted secondary structures of amino acids at the C terminus differed between the three viruses.

Amino Acid Sequence↗
PubMed1991

Immunological characterization of Clostridium butyricum neurotoxin and its trypsin-induced fragment by use of monoclonal antibodies against Clostridium botulinum type E neurotoxin.

We examined the reactivities of Clostridium butyricum neurotoxin to nine monoclonal antibodies against Clostridium botulinum type E neurotoxin which recognize the light chain or the amino-terminal half (H-1 fragment) or the carboxyl-terminal half (H-2 fragment) of the heavy chain of botulinum neurotoxin. Butyricum neurotoxin and its derived chains did not react to two of four monoclonal antibodies recognizing the light chain, one of three recognizing the H-1 fragment, and one of two recognizing the H-2 fragment. The results indicate that the immunological difference between the two neurotoxins is not attributable to a particular portion of the toxin molecule. The fragment of butyricum neurotoxin obtained by prolonged tryptic treatment was found to comprise the light chain and H-1 fragment linked together by a disulfide bond.

Animals↗
PubMed1991

Relationship between the limited proteolysis of glycinin and its conformation.

The relationship between the limited proteolysis and conformation of native glycinin was studied by the following methods: analyses of the proteolytic digestion of chemically modified glycinin, circular dichroism (CD) measurements, a secondary structure prediction from the amino acid sequence and a hydropathy index analysis. The locations of tryptic fragments of glycinin were confirmed from the N-terminal amino acid sequences of the fragments. T fragments and P fragments were located at the N-terminal and central area of the acidic polypeptide chains, respectively. One of the cleavage sites was the Arg residue of around the 100th from the N-terminal side. The regions digested by limited trypsinolysis were presumed to be flexible, hydrophilic and near the surface of the molecule by prediction methods from the amino acid sequence. The other regions were predicted to be compact and beta-sheet in nature, almost 40-50% of the amino acid residues being predicted as beta-sheet from the amino acid sequence and from CD data.

Amino Acid Sequence↗
PubMed1991

Lectins from Triticum vulgaris and Limax flavus are universal antagonists of botulinum neurotoxin and tetanus toxin.

Lectins from Anguilla anguilla, Artocarpus integrifolia, Canavalia ensiformis, Datora stramonium, Glycine max, Limax flavus, Ricinus communis and Triticum vulgaris were tested for their abilities to antagonize the binding of botulinum neurotoxin and tetanus toxin to rat brain membranes and to antagonize the ability of these toxins to block neuromuscular transmission in mouse phrenic nerve-hemidiaphragm preparations. Lectins from Limax flavus and Triticum vulgaris, both of which have affinity for sialic acid, were antagonists of the various serotypes of botulinum neurotoxin and tetanus toxin. When tested against the high affinity binding site for botulinum neurotoxin type B, the lectin from Limax flavus had a Ki of 3.1 x 10(-7) M and the lectin from Triticum vulgaris had a Ki of 3.75 x 10(-7) M. When tested against the high affinity binding site for tetanus toxin, the lectins from Limax flavus and Triticum vulgaris had Ki values of 1.5 x 10(-7) and 1 x 10(-6) M, respectively. In all cases the lectins behaved as competitive antagonists. In reverse experiments, neither botulinum toxin nor tetanus toxin was a very effective antagonist of lectin binding to brain membranes. Studies on isolated neuromuscular preparations showed that the lectin from Triticum vulgaris did not affect transmission at concentrations of 10(-6) to 10(-3) M, but at a concentration of 3 x 10(-5) M the lectin produced highly statistically significant antagonism of the neuromuscular blocking properties of botulinum neurotoxin types A, B, C, D, E and F as well as tetanus toxin. The lectin did not antagonize beta-bungarotoxin.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Tetanus toxin and neuronal membranes: the relationship between binding and toxicity.

Tetanus toxin labeled by the Bolton-Hunter technique possesses high specific activity and retains substantial biological activity. This material can be used to characterize tetanus toxin binding to receptors in brain membrane preparations. In experiments aimed at measuring the absorption of labeled toxin, the displacement of labeled toxin by unlabeled toxin and the on-rate and off-rate constants, the data revealed two binding sites. The high affinity site had a Kd of 0.033 to 0.070 nM and a Bmax of 0.26 to 0.4 pmol/mg of protein; the low affinity site had a Kd of 0.89 to 6.9 nM and a Bmax of 1.55 to 3.0 pmol/mg of protein. The binding of tetanus toxin to brain membranes was enhanced greatly by low pH and ionic strength. Similarly to tetanus toxin, botulinum neurotoxin could be labeled by the Bolton-Hunter technique, and its binding to brain membranes was also enhanced by low pH and ionic strength. In studies with a neutralizing monoclonal antibody against tetanus toxin, the antigen-antibody interaction was not significantly altered by media with low ionic strength and pH. On the other hand, the ability of the antibody to block toxin binding to brain membranes was reduced substantially in nonphysiologic media. In a bioassay aimed at determining the effect of pH and tonicity on tissue association by toxin, low pH and ionic strength did not enhance toxicity. The biological activity of tetanus toxin was unaffected and that of botulinum neurotoxin was greatly diminished. The present findings confirm the widely reported observation that low pH and ionic strength promote tissue association by tetanus toxin, but they challenge the premise that this binding is relevant to the normal process of cell poisoning.

Animals↗
PubMed1990

ADP-ribosylation of the rho/rac proteins induces growth inhibition, neurite outgrowth and acetylcholine esterase in cultured PC-12 cells.

Botulinum ADP-ribosyltransferase C3 (C3 exoenzyme) was purified to homogeneity and added to cultured rat pheochromocytoma PC-12 cells. Incubation with this exoenzyme caused inhibition of cell growth and induced neurites as well as acetylcholine esterase in these cells. These changes were dependent on the amount of the enzyme added to the culture, which correlated with the in situ ADP-ribosylation of the rho/rac proteins in the cells. Preincubation with a specific anti-C3 exoenzyme monoclonal antibody inhibited both the ADP-ribosyltransferase activity and the neurite-inducing activity of the enzyme preparation. These results suggest that C3 exoenzyme affected the cellular function of the rho/rac proteins by ADP-ribosylation to induce these changes in the cells.

Acetylcholinesterase↗
PubMed1990

Distinct characters of Clostridium botulinum type A strains and their toxin associated with infant botulism in Japan.

Four strains of Clostridium botulinum type A having been associated with infant botulism in Japan, and another strain isolated from honey not associated with infant botulism, were found to be hemagglutinin (HA) negative. These strains do not produce L (Mr 500 kDa) nor LL toxin (Mr 900 kDa) but M toxin (Mr 300 kDa) only. No marked difference was found between the HA-positive and HA-negative strains in other biochemical properties, but the HA-negative strains tended to colonize more easily in the intestines of infant mice than did HA-positive strains. The toxin of HA-positive strains and that of HA-negative strains differed in the antigenicity of part of the toxic component and that of the nontoxic component, and in the molecular size of the toxic component.

Botulinum Toxins↗
PubMed1990

Immunochemical identification of the ADP-ribosyltransferase in botulinum C1 neurotoxin as C3 exoenzyme-like molecule.

Botulinum C1 neurotoxin and C3 exoenzyme were purified to apparent homogeneity from the culture filtrate of Clostridium botulinum type C strain 003-9. Both preparations catalyzed ADP-ribosylation of the same substrate, the Mr 22,000 rho gene product (Gb). When the light and heavy chains of C1 toxin were separated, ADP-ribosyltransferase activity in the toxin was quantitatively recovered in the light chain fraction. Anti-C1 toxin antiserum precipitated the ADP-ribosyltransferase activity and the neurotoxicity of C1 toxin in parallel, whereas it had no effect on C3 exoenzyme. On the other hand, anti-C3 exoenzyme antiserum precipitated the ADP-ribosyltransferase activities of both C3 exoenzyme and C1 toxin. This antibody, however, did not precipitate the neurotoxicity of C1 toxin. The ADP-ribosyltransferase in C1 toxin was quantitatively adsorbed onto the anti-C3 antibody column and separated from the majority of C1 toxin protein. The enzyme was then eluted with acidic urea and Western blotting analysis of this eluate revealed the appearance of a protein band positively stained with anti-C3 antibody at a position similar to that of C3 exoenzyme. Quantitative determination by enzyme-linked immunosorbent assay showed that the C3-like immunoreactivity is present in the C1 toxin molecules at the molecular ratio of 1 to 1,000. These results suggest that the ADP-ribosyltransferase activity in C1 toxin is expressed by a C3-like molecule which is present in a small amount in the toxin preparation and appears to bind to the toxin component(s). The above results also indicate that the ADP-ribosyltransferase in C1 toxin is not related to its neurotoxin action.

Antibodies, Bacterial↗
PubMed1990

Histiocytosis X: successful treatment with recombinant interferon-alpha A.

Two patients with disseminated histiocytosis X were treated with intramuscular injections of recombinant interferon alpha A. The bone, skin and visceral lesions of these patients diminished rapidly. Significant sclerosis and recalcification of bone were observed. From our limited but positive experience, it would be justified to consider the use of interferon in patients with disseminated histiocytosis X.

Histiocytosis, Langerhans-Cell↗