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Biomedical subjects

I Kato

Publications and source records attributed to I Kato.

At least 523 records · Page 29Linked to original sources
PubMed1988

A clear cell pilar sheath tumor of scalp: case report.

A long-standing tumor of scalp is reported characterized histologically by extensive proliferation of pilar epithelium made up exclusively of cells with small round nuclei and clear cytoplasms containing glycogen granules. The tumor epithelium showed no tendency for keratinization and no cytologic atypia. The growth, however, appeared aggressive and replaced the entire thickness of the dermis and extended into the subcutaneous fat tissue.

Epithelium↗
PubMed1988

Changes in binding of staphylococcal leukocidin to HL-60 cells during differentiation induced by dimethyl sulfoxide.

The susceptibility of HL-60 cells to the cytotoxic activity of leukocidin increased depending on the degree of differentiation induced by dimethyl sulfoxide (DMSO). To compare binding characteristics of two components (S and F) of leukocidin to HL-60 and DMSO-treated HL-60 cells, the S and F components were labeled with 125I. Scatchard analysis of the binding curve of the 125I-labeled S component to HL-60 cells showed two classes of binding sites. The binding sites with higher affinity had a dissociation constant of 3.39 nM, and the number of binding sites per cell was 730. The specific binding of the 125I-labeled S component to DMSO-treated cells increased depending on the period of DMSO treatment. Scatchard analysis of the binding curve of cells treated with DMSO for 7 days gave a straight line. The dissociation constant was 1.78 nM, and the number of binding sites per cell was 6,920. The total binding of the 125I-labeled F component to DMSO-treated cells increased about twofold over binding to HL-60 cells. However, in the presence of the unlabeled S component, the increase of binding of the F component to DMSO-treated cells was much greater. These data suggested that the increased susceptibility of DMSO-treated cells to leukocidin was dependent on the changes in the number of high-affinity binding sites of the S component and of the bound F component.

Bacterial Adhesion↗
PubMed1988

Anthropometric relevance on sublabial transseptal transsphenoidal hypophysectomy in the Asiatic type of skull.

In order to preoperatively estimate the width of the operating field during transphenoidal hypophysectomy, we measured the distance between the right and left medial pterygoid plates in 27 normal adults and 11 patients with pituitary adenoma from anteroposterior tomograms. In normal subjects, the mean distance was about 3.2 cm. The distance in patients with acromegaly was not wider than that in normal subjects, but 1 case with giantism showed a much wider distance of 4.1 cm. The measurement of the actual operating field was 2.0 cm in width, about 1.0 cm narrower than the preparative tomogram calculations.

Adenoma↗
PubMed1988

Distribution of retinal ganglion cells projecting into the nucleus of the optic tract in rat.

The present study indicates that visual signals responsible for OKN are conducted through the retinal ganglion cells mainly contralaterally, and only in the ventral region of the retina ipsilateral to the injection site. The retinal ganglion cells projecting into the NOT ipsilateral to the injection site were identified as small- and medium-sized cells in the rat. The density of the ventral ganglion cells of the retina contralateral to the injection site was lower than that in any other regions of the retina except for the dorsal region of the retina, and the density of the ventral ganglion cells ipsilateral to the injection site was about 4 times greater than that on the contralateral side. This finding requires physiological investigation in the future.

Animals↗
PubMed1988

Intracerebral hemorrhage in a Japanese community, Hisayama: incidence, changing pattern during long-term follow-up, and related factors.

The incidence of intracerebral hemorrhage over 13 years is compared between two Hisayama cohorts. Among men aged 40 years or older, the annual incidence declined significantly from 3.1/1,000 in the early cohort (1961-1970) to 1.2/1,000 in the recent cohort (1974-1983). Massive ganglionic hemorrhage decreased, while small or medium-sized intracerebral hemorrhage increased in the recent cohort on pathologic or computed tomographic examination. These trends could be due to the reduced prevalence of hypertension in the Hisayama population. The association of serum total cholesterol with intracerebral hemorrhage is discussed based on the results during a 22-year follow-up period.

Adult↗
PubMed1988

Adoptive transfer of experimental autoimmune hepatitis in mice--cellular interaction between donor and recipient mice.

This report extends our previous study on experimental autoimmune hepatitis in C57BL/6(B6) mice. Cellular immunity involved in the induction of liver injury in this model was studied by transfer of primed spleen cells from hepatitis donor mice to syngeneic normal recipient mice. The most prominent liver damage in recipient B6 mice was induced by transfer of nylon wool adherent spleen cells from hepatitis donor mice, and T cells in this fraction were the essential requirement for the liver damage in the recipient mice. Nylon wool adherent spleen cells from hepatitis donor mice after depletion of the suppressor T-cell function by low-dose (300 rad) irradiation induced more severe liver injury compared to the same cells without irradiation. When the recipient mice were depleted of lymphocytes by low or high dose (700 rad) whole body irradiation, transfer of primed spleen cells from hepatitis donor mice did not induce liver lesion in the lymphocyte-depleted mice. This low susceptibility of lymphocyte-depleted recipient mice to primed spleen cells of hepatitis mice was no longer demonstrated after reconstitution with normal spleen cells. In a cell-migration study using 51Cr-labelled spleen cells, it was shown that a considerable number of infiltrating cells in the liver of recipient mice were derived from recipient mice themselves. These results seem to indicate that cell-to-cell interaction between radiosensitive precursor cells of recipient mice and liver-antigen-primed T cells from hepatitis donor mice play an essential role in the induction of liver injury in the recipient mice.

Animals↗
PubMed1988

Non-thiol-activated cytolytic bacterial toxins: current status.

Among non-thiol-activated cytolytic toxins, staphylococcal alpha-toxin, staphylococcal leucocidin, and pseudomonal leucocidin are characterized by their interaction (with susceptible cell membranes) as a biomembrane response modifier. The transmembrane signalling by the receptor-toxin complex follows the activities of membrane-associated enzymes, which lead to changes in membrane ion-permeability.

Animals↗
PubMed1988

[Descriptive epidemiology of cancers in children].

According to the Vital Statistics of Japan, the age-adjusted mortality rate for cancers in children has decreased almost 0.7 times between 1969 and 1986. The decrease was pronounced in cancers of the ovary, testis, stomach, nose & ear and leukemia, and in the age group under 5. Rises in the mean age at death were also observed. From international comparison, Japanese children had a relatively low mortality rate for cancers except leukemia. The international comparison of cancer of incidence suggested that some of risk factors for adult cancers were also involved in the etiology of cancers in children.

Child↗
PubMed1988

Development of artificial mastication system. Construction of one degree of freedom antagonistic muscle model WJ-O.

The authors have determined that there are 2 levels of control systems in mastication; the muscle control system as the lower level system and the mastication control system as the upper level system. And the authors made an experiment of the muscle control system as the first step of an artificial mastication system. The purpose of this paper is to propose the artificial muscle model which uses as DC motor under the control of position, velocity and force feedback.

Humans↗
PubMed1987

Ovoinhibitor introns specify functional domains as in the related and linked ovomucoid gene.

We have isolated cDNA clones and determined the gene structure of chicken ovoinhibitor, a seven domain Kazal serine proteinase inhibitor. Using RNA blot hybridization analysis, the gene was identified initially as a region 9-23 kilobases upstream of the gene for the related inhibitor ovomucoid. Ovoinhibitor RNA appears in oviduct and liver. cDNA clones were identified by screening an oviduct cDNA library with a nick-translated DNA restriction fragment which contained an exon of the gene. The mature protein sequence derived from a cDNa clone is in excellent agreement with that which we obtained from direct sequencing of purified ovoinhibitor. The protein-sequencing strategy is reported. The P1 amino acids of the Kazal domains are consistent with the known broad inhibitory specificity of ovoinhibitor. The gene is about 10.3 kilobases in length and consists of 16 exons. Each Kazal domain is encoded by two exons. Like ovomucoid, introns fall between the coding sequences of the ovoinhibitor domains, an arrangement which may have facilitated domain duplication. The intradomain intron occurs in an identical position in all of the ovoinhibitor and ovomucoid Kazal domains, suggesting that this intron was present in the primordial inhibitor gene. We discuss the location of the intradomain intron in relation to the known structure of four Kazal inhibitors and suggest a scheme for the evolution of the ovoinhibitor gene.

Amino Acid Sequence↗
PubMed1987

Chicken ovomucoid: determination of its amino acid sequence, determination of the trypsin reactive site, and preparation of all three of its domains.

The complete amino acid sequence of chicken ovomucoid (OMCHI) is presented. OMCHI consists of three tandem domains, each homologous to pancreatic secretory trypsin inhibitor (Kazal) and each with an actual or putative reactive site for inhibition of serine proteinases. The major reactive site for bovine beta-trypsin is the Arg89-Ala peptide bond in the second domain. The equilibrium constant for hydrolysis of this peptide bond, K0hyd, is 1.85. The first and third domains of OMCHI are relatively ineffective inhibitors of several serine proteinases against which they were tested. OMCHI is a mixture of two forms: the major form with all of the amino acid residues and a minor form with Val134-Ser135 deleted. This polymorphism is present in all chicken eggs and is the result of ambiguous excision at the 5' end of the F intron. Procedures are given for preparation of modified chicken ovomucoid, OMCHI (in which the Arg89-Ala bond is hydrolyzed), of the first domain, OMCHI1 (residues 1-68), of the second domain, OMCHI2 (residues 65-130), and of the third domain, OMCHI3 (residues 131-186). In the case of the third domain, both the Asn175 glycosylated form, OMCHI3(+), and the carbohydrate-free form, OMCHI3(-), were obtained. These isolated native domains are useful in many studies of ovomucoid behavior.

Amino Acid Sequence↗
PubMed1987

Ovomucoid third domains from 100 avian species: isolation, sequences, and hypervariability of enzyme-inhibitor contact residues.

Ovomucoids were isolated from egg whites of 100 avian species and subjected to limited proteolysis. From each an intact, connecting peptide extended third domain was isolated and purified. These were entirely sequenced by single, continuous runs in a sequencer. Of the 106 sequences we report (five polymorphisms and chicken from the preceding paper [Kato, I., Schrode, J., Kohr, W. J., & Laskowski, M., Jr. (1986) Biochemistry (preceding paper in this issue)]), 65 are unique. In all cases except ostrich (which has Ser45), the third domains are either partially or fully glycosylated at Asn45. The majority of the third domain preparations we isolated are carbohydrate-free. Alignment of the sequences shows that their structurally important residues are strongly conserved. On the other hand, those residues that are in contact with the enzyme in turkey ovomucoid third domain complex with Streptomyces griseus proteinase B [Read, R., Fujinaga, M., Sielecki, A. R., & James, M. N. G. (1983) Biochemistry 22, 4420-4433] are not conserved but instead are by far the most variable residues in the molecule. These findings suggest that ovomucoid third domains may be an exception to the widely accepted generalization that in protein evolution the functionally important residues are strongly conserved. Complete proof will require better understanding of the physiological function of ovomucoid third domains. This large set of variants differing from each other in the enzyme-inhibitor contact area and augmented by several high-resolution structure determinations is useful for the study of our sequence to reactivity (inhibitory activity) algorithm. It is also useful for the study of several other protein properties. In the connecting peptide fragment most phasianoid birds have the dipeptide Val4-Ser5, which is absent in most other orders. This dipeptide is often present in only 70-95% of the molecules and appears to arise from ambiguous excision at the 5' end of the F intron of ovomucoid. Connecting peptides from the ovomucoids of cracid birds contain the analogous Val4-Asn5 peptide. In laughing kookaburra ovomucoid third domain we found (in 91% of the molecules) Gln5A, which we interpret as arising from ambiguous intron excision at the 3' end of the F intron.

Amino Acid Sequence↗
PubMed1987

Suppressor system in murine interstitial nephritis. Analysis of tubular basement membrane (TBM)-specific suppressor T cells and their soluble factor in C57BL/6 mice using a syngeneic system.

We induced typical interstitial nephritis with high titers of anti-tubular basement membrane (TBM) autoantibody in genetically resistant C57BL/6 mice by treating them with sodium aurothiomalate (gold) and immunizing them with syngeneic TBM antigen. When gold was not used, the T-cell fraction of nylon wool adherent splenic cells showed prominent suppressive activity against the proliferative response of nonadherent cells to TBM antigen. However, this suppressive activity was remarkably decreased by the gold treatment. TBM antigen sensitized thymocytes, a thymocyte extract, and a spleen cell extract were transferred to C57BL/6 mice which had been immunized with TBM antigen and treated with gold. This transfer clearly depressed the induction of autoimmune interstitial nephritis in an antigen-specific manner. These results indicate that TBM antigen-specific suppressor T cells and their soluble factor may play an important role in the negative regulation of interstitial nephritis in C57BL/6 mice.

Animals↗