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S Masui

Publications and source records attributed to S Masui.

At least 37 records · Page 2Linked to original sources
PubMed1997

Cytogenetic and molecular genetic analysis of a pediatric pleomorphic sarcoma reveals similarities to adult malignant fibrous histiocytoma.

Cytogenetic and molecular genetic studies were performed on a pleomorphic sarcoma removed from the left atrium of a 15-year-old girl. Histologic analysis was consistent with a storiform-pleomorphic malignant fibrous histiocytoma (MFH). Although MFH is the most common soft-tissue sarcoma of late adulthood. It is extremely rare in childhood and its existence in the pediatric population remains controversial. Cytogenetic analysis revealed several alterations previously associated with adult MFH, including abnormalities of chromosomal bands 11p11 and 19p13. Moreover, the tumor demonstrated homogeneously staining regions (HSR) and double minute chromosomes (dmin) suggestive of gene amplification. We therefore screened the case for amplification of genes localized to chromosomal bands 12q13-14, including the putative protooncogenes MDM2, CDK4, SAS, CHOP, and CLI, which are frequently amplified and overexpressed in adult MFH. Southern and Northern blot analysis confirmed the coamplification of MDM2, CDK4, SAS, and CHOP. To our knowledge, such coamplification studies of the 12q13-14 amplicon have not been previously detected in pediatric MFH. Our results provide cytogenetic and molecular genetic evidence that pediatric and adult MFH are histogenetically related entities.

Adolescent↗
PubMed1997

groE-homologous operon of Wolbachia, an intracellular symbiont of arthropods: a new approach for their phylogeny.

Wolbachia, a member of rickettsia found in the cells of many arthropod species, are cytoplasmically inherited bacteria which interfere with host's sexuality and reproduction. Wolbachia strains have been phylogenetically divided into A and B groups based on the nucleotide sequences of their ftsZ genes. In an attempt to further define the phylogenetical relationship among these endosymbionts, we cloned and sequenced the entire length of the groE operon of a Wolbachia harbored by a cricket. The operon encoded two heat shock proteins, which represented the third and fourth proteins of any Wolbachia ever characterized. Also, 800 bp stretches of the groE operons of several other Wolbachia were sequenced, and a phylogenetic tree was constructed based on the results. The groE tree defined the relationship among A group Wolbachia strains that had not been successfully resolved by the ftsZ tree, and suggested unexpected horizontal transmission of these bacteria.

Amino Acid Sequence↗
PubMed1996

Monoclonal antibody MAT-1 against human tyrosinase can detect melanogenic cells on formalin-fixed paraffin-embedded sections.

Immunohistochemical localization of tyrosinase was examined with a monoclonal antibody (MoAb MAT-1) against human tyrosinase on routine formalin-fixed paraffin-embedded sections of 3 normal skin specimens, 15 melanocytic tumors (6 pigmented nevi, 3 juvenile melanomas and 6 malignant melanomas) and 3 non-melanocytic tumors. In the melanotic melanomas, almost all tumor cells were clearly stained with the antibody. In the nevocytic nevi, the nevus cells in lower epidermis and upper dermis were positive for MoAb MAT-1, but negative in middle and lower dermis. All three juvenile melanomas, one amelanotic melanoma, and three non-melanocytic tumors were entirely negative for MoAb MAT-1. Thus, MoAb MAT-1 could recognize the cells with melanogenic activity on routine formalin-fixed paraffin-embedded sections. However, the staining quality was not adequate for normal epidermal melanocytes, indicating that small technical innovations in the immunostaining process such as formalin fixation after PBS washing are required. Nevertheless, MoAb MAT-1 can be expected to be very useful for identifying melanogenic cells on paraffin-embedded sections, because we have to date no other antibody available for it.

Antibodies, Monoclonal↗
PubMed1996

Detection of mouse tyrosinase with a monoclonal antibody MAT-1 against human tyrosinase.

In this study we explored the possible application of MAT-1, which has been established as a monoclonal antibody against human tyrosinase, for detection of mouse tyrosinase. The MAT-1 reacted with B16 mouse melanoma cells, but not with tyrosinase-negative NIH-3T3 mouse fibroblasts. In western blot analysis of the large granule fraction (LGF) of B16 cells, MAT-1 detected a single protein of 80 kDa, whose size was close to that of human tyrosinase detected with MAT-1 in extracts of human melanocytes. Furthermore, the 80 kDa band that was detected with MAT-1 in the LGF of B16 cells was also detected by DOPA reaction. In order to confirm that the protein detected with MAT-1 is tyrosinase, a transient expression assay was carried out. When mouse tyrosinase or mouse tyrosinase-related protein-1, which shares high homology with human tyrosinase, was transiently expressed in tyrosinase-negative K1735 mouse melanoma cells by cDNA transfection, MAT-1 reacted only with the cells expressing mouse tyrosinase. These results indicate that MAT-1 specifically reacts with mouse tyrosinase.

Animals↗
PubMed1995

MAT-1, a monoclonal antibody that specifically recognizes human tyrosinase.

There is no available monoclonal antibody which reacts specifically recognizes human tyrosinase. Employing a synthetic peptide, MEKEDYHSLYQSHL, corresponding to the carboxyl terminus of human tyrosinase as an immunogen, we produced a mouse monoclonal antibody MAT-1 of the IgG1 isotype. The epitope for MAT-1 was determined to be EDYH, the sequence of which is not present in human tyrosinase-related protein-1 (TRP-1) or tyrosinase-related protein-2 (TRP-2). By transient expression assays and immunofluorescence technique, we show that MAT-1 reacts specifically with cells expressing human tyrosinase cDNA but not with cells expressing TRP-1 or TRP-2 cDNA. The results of immunohistochemical staining also confirmed that MAT-1 reacts specifically with epidermal melanocytes in human skin sections. MAT-1 should be invaluable for studying the interaction between tyrosinase and TRPs and for detecting the changes in the levels of tyrosinase expression. In addition, MAT-1 should be useful as a sensitive immunohistochemical tool for investigation of various pigmentary disorders and possibly for the diagnosis of melanoma.

Amino Acid Sequence↗
PubMed1994

Astrocytoma with a unique telomere association.

Many primary pediatric brain tumors are characterized by nonrandom cytogenetic abnormalities involving specific structural rearrangements and loss or gain of specific chromosomes. We describe a low-grade cerebellar astrocytoma with telomeric association of chromosomes 18 and 21 in a 7-year old girl. The nonrandom telomeric association of these chromosomes represents a unique cytogenetic finding in this type of pediatric brain tumor.

Astrocytoma↗
PubMed1993

Heredity of muscle fibre composition estimated from a selection experiment in rats.

The extent to which muscle fibre composition was determined by the genes transmitted from parents was estimated by using successive selections of rats. A foundation population (G0) was established to carry out the selections; it consisted of 100 albino rats which were randomly chosen from heterogeneous stock. The heterogeneous stock was produced by random-mating of three strains, Wistar-Imamichi, Fischer 344 and Donryu. Successive selection for a high percentage of slow twitch fibres (% ST) was made from G0 to the fourth generation (G4). The mean values of % ST changed from 50.0% in G0 to 55.6% in G4. The mean value in G4 was significantly higher than that in G0. The realized heritability in G0-G4 was calculated from the regression of selection response on the cumulated selection differential. The regression coefficient was 0.17 (SEM 0.04). The realized heritability was significantly different from 0 at the 0.05 level. We concluded that in rats about 17% of the variation of muscle fibre composition was determined by the genes transmitted from parents.

Animals↗
PubMed1992

Studies on teratological testing using chicken embryos--effects of solvents, injection sites and the age of the embryo.

The purpose of this study was to examine the effects of solvents, injection sites and embryo age when using chicken embryos for teratological testing. The results obtained were as follows: 1) Solvents: distilled water, physiological saline, sesame oil, 25% ethanol, 0.5% carboxymethylcellulose and 0.1% methylcellulose solution were not toxic in Day-4 embryos (eggs incubated for 4 days). 2) With 6-aminonicotinamide, air space injection more effectively induced malformations in chicken embryos. With boric acid, however, yolk sac injection was better. It was shown therefore that the appropriate injection site varied according to the test drug. 3) 6-aminonicotinamide induced characteristic malformations when injected into embryos of various ages ranging from 4 to 13 days of incubation. On the other hand, boric acid was teratogenetic only when injected into Day-3 or Day-4 embryos. It seems, therefore, that the age of the embryo at the time of administration is of critical importance and that the optimum time of administration varies according to the test drug.

6-Aminonicotinamide↗
PubMed1991

Karyotypic changes associated with loss of prolactin dependency of rat Nb2 node lymphoma cell cultures.

The parent line of cultured "Nb2 node" lymphoma cells is dependent on the hormone prolactin (PRL) for growth and is widely used for the in vitro bioassay of lactogenic hormones. As reported previously, PRL-independent sublines have been developed in vitro from the parental line by lactogen deprivation. The present study describes the G-banded karyotypes of the Noble (Nb) strain of rat (in which the original lymphoma developed), the PRL-dependent cell line (157th generation), and two of its PRL-independent sublines (1220th and 2372nd generations). The karyotype of the Nb rat was determined to be the same as that of Rattus norvegicus. The stemline karyotype of the PRL-dependent cells contains a number of well-defined chromosomal abnormalities. The PRL-independent sublines examined have the same chromosomal abnormalities as the PRL-dependent cells plus a few additional changes indicative of clonal evolution from the PRL-dependent stemline. The development of PRL independence (as seen in the 1220th generation) was associated with only two karyotypic changes, i.e., loss of the Y chromosome and a translocation involving chromosomes 14 and 17. The recently reported mapping of the rat PRL gene and other PRL-related genes to chromosome 17 suggests that rearrangement of chromosome 17 could be involved in the development of the PRL independence. The PRL-dependent and PRL-independent Nb2 cell lines provide a useful system for studying chromosomal and molecular genetic events associated with the malignant progression of polypeptide hormone-dependent cancers.

Aneuploidy↗
PubMed1989

[The genetic architecture of emotionality in rats using Mendelian cross analysis].

Two inbred strains of Tsukuba Emotionality Rat (THE and TLE) and four hybrids derived from them were observed for ambulatory response in a novel environment as a measure of emotionality. The Runway Test (modified "timidity test") was run for successive three days. Mean transformed (square root) scores of ambulation for generation were subjected to Mendelian cross analysis. Total ambulation scores showed significant additive genetic effect, maternal effect and environmental effect. Directional dominance toward low level of response was present only for males. Daily ambulation scores showed changes in the genetic architecture over three days and the difference between males and females. For females, directional dominance occurred toward low level on Day 1, toward high level on Day 3, but no directional dominance was observed on Day 2. Males' directional dominance toward low level, on the other hand, declined with days. These findings on the genetic architecture of emotionality were discussed with reference to evolutionary adaptation.

Affective Symptoms↗
PubMed1986

Chronic incomplete obstruction of the ureter: a new experimental model.

To produce a chronic moderate hydronephrosis in dog, a method of partial ureteral occlusion using a specially designed polypropylene obturator was developed. In 11 of 14 dogs undergoing this procedure, excretory urography constantly revealed a moderate degree of hydronephrosis persisting for 7 weeks. Combination of this method in one ureter with the vaginal-cuff cutaneous ureterostomy, previously reported, in the contralateral ureter is a useful model for split renal function study of unilateral chronic hydronephrosis or obstructive nephropathy analogous to that of clinical case.

Animals↗
PubMed1985

A case of hyperreninemic hypertension with unilateral hydronephrosis.

A patient with unilateral ureteral obstruction by urolithiasis at the ureteropelvic junction was accompanied by hypertension. Plasma renin activity (PRA) was high in peripheral veins and was significantly higher in the renal vein drained from the affected kidney than the contralateral. Infusion of angiotensin II antagonist or an oral administration of captopril, an angiotensin converting enzyme (ACE) inhibitor, resulted in a prompt drop of blood pressure. After pyelolithotomy was successfully performed, both the blood pressure and peripheral PRA completely normalized. It is suggested that the renin-angiotensin system might have played a major role in the mechanism of the accompanied hypertension. Hyperreninemia could have been caused by both renal ischemic vasoconstriction, which might be due to uretero-renal reflex, and increased synthesis of prostaglandins resulting from ureteropelvic obstruction.

1-Sarcosine-8-Isoleucine Angiotensin II↗