Search PubMed⌕ Search

Biomedical subjects

S Matsuyama

Publications and source records attributed to S Matsuyama.

At least 19 recordsLinked to original sources
PubMed1995

A novel periplasmic carrier protein involved in the sorting and transport of Escherichia coli lipoproteins destined for the outer membrane.

Lipoproteins are localized in the outer or inner membrane of Escherichia coli, depending on the species of amino acid located next to the N-terminal fatty acylated Cys. The major outer membrane lipoprotein (Lpp) expressed in spheroplasts was, however, retained in the inner membrane as a mature form. A novel protein that is essential for the release of Lpp from the inner membrane was discovered in the periplasm and purified. The partial amino acid sequence of this 20 kDa protein (p20) was determined and used to clone a gene for p20. Sequencing of the gene revealed that p20 is synthesized as a precursor with a signal sequence. p20 formed a soluble complex only with outer membrane-directed lipoproteins such as Lpp, indicating that p20 plays a critical role in the sorting of lipoproteins. Lpp released from the inner membrane in the presence of p20 was specifically assembled into the outer membrane in vitro. These results indicate that p20 is a periplasmic carrier protein involved in the translocation of lipoproteins from the inner to the outer membrane.

Amino Acid Sequence↗
PubMed1995

Bcl-2 oncoprotein expression and apoptosis in neuroblastoma.

Bcl-2 protooncogene, originally discovered at the chromosomal breakpoint of the t(14;18) in follicular lymphoma, is known to regulate the process of programmed cell death or apoptosis. The inhibition of apoptosis is thought to be one of the mechanisms involved in the development of tumors. To investigate the possible association of bcl-2 protooncogene with the tumorigenesis of neuroblastomas, the authors examined bcl-2 expression by immunohistochemistry in 49 neuroblastomas and 7 ganglioneuromas. The distribution of apoptotic cells was also examined by the TUNEL method (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling). Bcl-2 oncoprotein was detected in the cytoplasm in 40 of 49 neuroblastomas (81.6%). There was no correlation between bcl-2 oncoprotein expression and the clinical features of neuroblastoma. The incidence of bcl-2-positive tumors in ganglioneuroma was significantly lower than that in neuroblastoma (28.6%) (P < .01). TUNEL stained the nuclei of tumor cells in 11 of 34 (32.4%) neuroblastomas. TUNEL-positive cells tended to be located around calcifications in neuroblastomas in patients less than 1 year old. Examination of serial sections showed that apoptotic cells were distributed in the area where bcl-2 oncoprotein was not expressed. What we have observed indicates that apoptosis of neuroblastoma cells may be regulated by bcl-2 expression. Our observations suggest that the survival of neuroblastoma cells might be promoted by bcl-2 expression and that bcl-2 might be associated with the tumorigenesis of neuroblastomas.

Adrenal Gland Neoplasms↗
PubMed1995

Retrospective analysis of biological factors in a recurrent IV-S neuroblastoma with intermediate-grade malignancy.

A clinical stage of IV-S neuroblastoma is known to include heterogeneous tumors. The authors report a case of IV-S neuroblastoma that relapsed after regression 4 years and 10 months after diagnosis. Multiagent chemotherapy was necessary to control the disease, and the patient has been doing well with no evidence of disease for more than 5 years. Although Shimada's classification showed favorable characteristics, N-myc protein was positive and DNA ploidy was diploidy in the tumor at diagnosis. Discrepancy in DNA ploidy was observed and aneuploidy was shown in tumor specimens at recurrence. Experience in this case showed the following important clinical features: (1) IV-S neuroblastoma of intermediate-grade malignancy does exist, and patients with such a disease may be cured by aggressive treatment; (2) Identifying IV-S patients with an unfavorable clinical course is possible by examining biological prognostic factors.

Adrenal Gland Neoplasms↗
PubMed1995

Gastrointestinal manometry findings in a case with dilated small bowel and disturbed transit treated successfully with bowel plication.

We report the manometric findings in a case of dilated small bowel and disturbed transit successfully treated with plication of the dilated small bowel. The female newborn infant required total parenteral nutrition following an operation for small bowel atresia. X-ray showed a dilated proximal small bowel. Jejunal manometry showed normal phase 3 migration but persistently low-amplitude contractions in the dilated segment. After plication of the dilated intestine, symptoms of bowel obstruction disappeared. A second manometry two weeks after the operation showed contractions with normal amplitude. These findings indicate that: (1) disturbed transit in the dilated intestine proximal to small intestinal atresia is associated with persistently low contraction amplitude, and (2) the amplitude can be increased by the plication of the dilated loop.

Digestive System↗
PubMed1995

Treatment of a stage I testicular yolk sac tumor with vascular invasion.

There is controversy concerning the treatment of stage I yolk sac tumor of the testis, particularly of those with histological factors that indicate a high risk of relapse. Usually orchiectomy alone is sufficient and adjuvant chemotherapy is unnecessary. Retroperitoneal lymphadenectomy is indicated for patients with persistently high alpha-fetoprotein. Once recurred, treatment at that time is thought to be curative. However, postoperative chemotherapy may be necessary for patients with a tumor expressing histological factors that predict possible relapse. In this paper we report on a case of a 2 year old boy whose tumor invaded the testicular veins. The patient suffered from recurrent disease but was successfully treated by chemotherapeutic regimens including cisplatin and retroperitoneal lymphadenectomy. The importance of the histological factors in making a decision on the treatment strategy for stage I testicular yolk sac tumor is discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Molecular cloning of cDNA for equine ovarian inhibin/activin beta A subunit.

cDNAs encoding equine inhibin/activin beta A subunit were isolated from an equine follicle cDNA library and characterized. Using primers based on the rat inhibin/activin beta A subunit cDNA sequence, a RT-PCR was performed to generate the probe for screening. Four positive clones were isolated. Analysis of the nucleotide sequence of these clones revealed that two pairs of identical clones were present, Eq-beta A-1 (0.9 kb) and Eq-beta A-2 (1.5 kb). Eq-beta A-2 clone contained a complete open reading frame encoding 426 amino acids. The deduced amino acid sequence of equine inhibin/activin beta A subunit showed high similarity (> 90%) to those of five other mammalian species. Northern blot analysis revealed that placenta from mare on day 180 of pregnancy contained a 1.5 kb inhibin/activin beta A subunit mRNA.

Activins↗
PubMed1995

Immunoreactive (ir)-transforming growth factor (TGF)-beta in rat corpus luteum: ir-TGF beta is expressed by luteal macrophages.

Western analyses and immunohistochemistry of transforming growth factor beta 1 (TGF beta 1) and TGF beta 2 were performed in rat luteal tissue at either the functional or regressing stage. Anti-TGF beta 1 or TGF beta 2 was localized simultaneously to macrophages within cultured luteal cells and frozen ovarian sections. By Western analysis, an active form of TGF beta (25 kDa) was detected clearly with anti-TGF beta 2 but only faintly with anti-TGF beta 1, and the former band from functional corpora lutea was more intense than that from regressing ones. Treatment with prolactin (PRL), a luteotropic hormone in rodents, also increased the intensity of 25 kDa TGF beta 2 in the corpus luteum. Several specific bands with higher molecular weights than 25 kDa were also recognized with anti-TGF beta 1 or TGF beta 2; they are probably ascribed to latent TGF beta s and/or TGF beta precursor proteins. In cultured luteal cells and frozen ovarian sections, many anti-TGF beta 1 or anti-TGF beta 2 positive cells from functional corpora lutea of pseudopregnant rats were double-stained with anti-macrophage. There were numerous macrophages in structurally regressing corpora lutea of pseudopregnant rats, but most of them were not stained with anti-TGF beta s. These results suggest that the expression of TGF beta, at least for TGF beta 2, is under the influence of PRL in the rat corpora lutea, and that macrophages are responsible for some, if not all, of the immunoreactive-TGF beta in rat luteal tissue.

Animals↗
PubMed1995

[Detection of IgE antibodies to salt-insoluble wheat proteins in sera of patients with atopic dermatitis by ELISA and immunoblotting techniques].

Specific IgE antibodies against salt-insoluble wheat proteins were investigated in sera from 60 patients with atopic dermatitis (AD) positive to wheat specific CAP-RAST. The salt-insoluble wheat protein fraction was prepared from whole protein fraction of wheat flour, which was extracted by PBS containing 6 M urea. IgE antibodies to salt-insoluble proteins were detected in 15 of the sera. IgE-ELISA was applied to these 15 sera, with whole wheat proteins, salt-soluble proteins, and salt-insoluble proteins used as antigens. Wheat specific CAP-RAST values correlated well with the IgE-ELISA titers against salt-soluble proteins (r = 0.918 p < 0.001). On the other hand, IgE-ELISA titers against both the salt-insoluble proteins and the whole wheat proteins correlated least with CAP-RAST values (r = 0.161 and r = 0.113). The inhibition tests indicated that IgE antibodies against salt-insoluble proteins were different from those against salt-soluble ones. Thus, IgE antibodies to salt-insoluble proteins were another antigen target of IgE-mediated allergy manifestation. To determine the molecular weight of antigens reacting with IgE, IgE-immunoblotting was performed. Several polypeptides with molecular weights of 33-45, 84, 90 and 98 KD were detected. However, the antigen patterns of the blots varied depending on the sera used. These findings suggest that salt-insoluble wheat proteins are the major antigens in some wheat-dependent AD, and that IgE detection against salt-insoluble wheat proteins is important for the diagnosis of wheat allergy.

Adolescent↗
PubMed1994

Potassium and calcium channel involvement in induction of long-lasting synaptic enhancement by calyculin A, a protein phosphatase inhibitor, in rat hippocampal CA1 region.

In the Schaffer collateral-CA1 pathway in rat hippocampal slices, exposure to calyculin A induced a long-lasting potentiation of the extracellular field potentials with a transient increase in glutamate release. The synaptic enhancement produced by calyculin A was blocked by staurosporine and nicardipine, but not by D,L-2-amino-5-phosphonovalerate. In dissociated CA1 pyramidal cells, calyculin A blocked the action-potential repolarization and fast after-hyperpolarization, and increased spike frequency. These results suggest that calyculin A-induced long-lasting potentiation is triggered by the blockade of Ca(2+)-activated K+ channels, the transient increase of glutamate release and the consequent activation of voltage-gated Ca2+ channels, and is maintained by increases in protein kinases activities.

Animals↗
PubMed1994

An unusual presentation of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess: report of a case.

We describe a rare case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing pyogenic liver abscess in a 59-year-old man. The patient was diagnosed as having a hollow viscus perforation based on a sudden onset of acute abdominal pain along with radiological evidence of bilateral subphrenic feee air (pneumoperitoneum), and underwent an emergency laparotomy. Contrary to expectations, the surgery revealed no perforations of the hollow viscus, but instead a ruptured liver abscess at the dome of the right hepatic lobe was identified associated with suppurative peritonitis. To the best of our knowledge, such a case of spontaneous pneumoperitoneum secondary to the rupture of a gas-containing liver abscess is extremely rare.

Abdomen, Acute↗
PubMed1994

A case of hepatocolic fistula after percutaneous drainage for a gas-containing pyogenic liver abscess.

We describe a rare case of gas-containing pyogenic liver abscess which penetrated the adjacent colon, forming a hepatocolic fistula, after percutaneous transhepatic abscess drainage (PTAD) had been performed. To the best of our knowledge, this is the first report of hepatocolic fistula associated with a gas-forming liver abscess in a diabetic patient, with radiological and surgical confirmation of the fistula.

Colonic Diseases↗
PubMed1994

Effect of heat shock on intracellular calcium mobilization in neuroblastoma x glioma hybrid cells.

The effect of heat shock on agonist-stimulated intracellular Ca2+ mobilization and the expression of heat shock protein 72 (hsp72) in neuroblastoma x glioma hybrid cells (NG 108-15 cells) were examined. Hsp72 was expressed at 6 h after heat shock (42.5 degrees C, 2 h), reached a maximum at 12 h, and decreased thereafter. Bradykinin-induced [Ca2+]i rise was attenuated to 28% of control by heat shock at 2 h after heat shock, and reversion to the control level was seen 12 h later. When the cells were treated with quercetin or antisense oligodeoxyribonucleotide against hsp72 cDNA, the synthesis of hsp72 was not induced by heat shock, whereas bradykinin-induced [Ca2+]i rise was abolished and the [Ca2+]i rise was not restored. Recovery from this stressed condition was evident when cells were stimulated by the Ca(2+)-ATPase inhibitor thapsigargin, even in the presence of either quercetin or antisense oligodeoxyribonucleotide. Inositol 1,4,5-trisphosphate (IP3) production was not altered by heat shock at 12 h after heat shock, whereas IP3 receptor binding activity was reduced to 45.3%. In the presence of quercetin or antisense oligodeoxyribonucleotide, IP3 receptor binding activity decreased and reached 27.2% of the control 12 h after heat shock. Our working thesis is that heat shock transiently suppresses the IP3-mediated intracellular Ca2+ signal transduction system and that hsp72 is involved in the recovery of bradykinin-induced [Ca2+]i rise.

Animals↗
PubMed1994

Targeting of the immunoglobulin-binding domain of protein A to the extracellular matrix using a minifibronectin expression vector.

A truncated form of fibronectin consisting of the N-terminal 70-kDa and C-terminal 37-kDa regions, referred to as "minifibronectin," retains the ability to assemble into the extracellular matrix, even though it lacks the central approximately 120-kDa region containing most of the type III modules (Ichihara-Tanaka, K., Titani, K., and Sekiguchi, K., FEBS Lett. 299, 155-158, 1992). Taking advantage of the matrix assembly activity of minifibronectin, we developed a novel method to target non-matrix proteins to the extracellular matrix by inserting them between the N-terminal 70-kDa and the C-terminal 37-kDa regions of minifibronectin. Using the immunoglobulin-binding domain of Staphylococcal protein A as a model, we demonstrated that the bacterial protein expressed in mouse L cells as a chimeric protein with minifibronectin is secreted as disulfide-bonded dimers and successfully deposited onto the extracellular matrix of transfected cells. The chimeric protein retained the immunoglobulin-binding activity not only in solution but also after deposition at the matrix. This targeting strategy we developed will provide a means to manipulate the biological functions of the extracellular matrix through targeting of a wide variety of non-matrix proteins.

Animals↗
PubMed1994

SecF stabilizes SecD and SecY, components of the protein translocation machinery of the Escherichia coli cytoplasmic membrane.

The effect of the overproduction of SecF encoded by the tac-secF gene on a plasmid on the synthesis of other Sec proteins was studied in Escherichia coli. SecF overproduction resulted in the simultaneous overproduction of SecD encoded by the tac-secD gene on a plasmid. Deletion of the orf6 gene, located downstream of the secF gene, had no effect on SecD overproduction. A pulse-chase experiment revealed that the overproduction was due to stabilization of SecD with SecF. SecF overproduction also resulted in the overproduction of SecY encoded by the tac-secY gene on a plasmid as well. SecF overproduction also enhanced the level of SecY expressed by the chromosomal secY gene. This SecF effect was not due to its effect on SecD or SecE, since SecF overproduction did not affect the levels of SecD and SecE expressed by the chromosomal secD and secE genes, respectively. SecE-dependent overproduction of SecY has already been demonstrated. It is suggested that SecF interacts with both SecD and SecY. SecE-SecY interaction has been demonstrated. It is likely, therefore, that all Sec proteins in the cytoplasmic membrane interact with each other.

Bacterial Proteins↗
PubMed1994

[Effects of aging on urinary secretion of 3-hydroxyproline and its importance for cancer screening in the elderly with ROC analysis].

OBJECTIVE: to observe the influence of aging on urinary secretion of 3-hydroxyproline (3-Hyp) in normal subjects and in cancer patients and study the effects of aging on the accuracy of urinary 3-Hyp as a general-purpose cancer screening test. DESIGN: We reanalyzed, from the aspect of gerontology, the amounts of 3-Hyp in the urine samples of the 211 healthy persons and 94 patients with cancer reported earlier. The two groups were divided in 3 age subgroups: adult, 30 to 44 years, middle-aged, 45 to 64 years, and aged, 65 years and older. The cancer stage was separated into 3 categories: stage 1, the early stage without any invasion, stage 2, locally invasive with no distant metastasis, and stage 3, advanced cancer. The correlation of age and urinary 3-Hyp was analyzed in normal subjects and cancer patients. Sensitivity and specificity were calculated for different cutoff points in the diverse groups to construct the receiver operating characteristic (ROC) curves. MAIN RESULTS: We observed that aging decreases the urinary secretion of 3-Hyp in normal subjects, with a correlation coefficient of -0.250 (p < 0.001). The mean levels of urinary 3-Hyp in patients with cancer were significantly higher than in the normal subjects, p = 0.005. The correlation coefficient of urinary 3-Hyp and age was not significant (0.100) in cancer patients. The cutoff points of 0.800 mg/g creatinine of urinary 3-Hyp for persons under 65 years of age and 0.600 mg/g creatinine for persons 65 years or older were the best thresholds for cancer screening. In the ROC analyses, we observed that 3-Hyp has higher accuracy for cancer screening in the aged group for all stages together and in the aged and middle-aged for early stages of cancer. CONCLUSIONS: The urinary 3-Hyp test was more effective for cancer screening in old persons (65 years or older), where cancer is more frequent and more difficult to discover. The authors stress the necessity and importance of verifying the effectiveness of urinary 3-Hyp for general cancer screening in a larger population and in a community set.

Adult↗
PubMed1994

Changes in endogenous growth hormone secretion and onset of puberty in transgenic rats expressing human growth hormone gene.

A chimeric gene comprising murine whey acidic protein (mWAP) and human growth hormone (hGH) was used to produce transgenic rats that express hGH and secrete it into the blood. Two lines of transgenic rats carrying the mWAP/hGH construct were established: Line 1 was characterized by relatively high levels of serum hGH, and Line 2 had relatively low levels. The secretory profiles of rat GH (rGH) as well as hGH, the transgene product, were obtained in transgenic males and females of Line 2; both hGH and rGH serum levels were flattened with no episodic fluctuations, and the overall mean concentration of rGH was significantly lower than in normal littermates. Although the animals of Line 1 showed an accelerated increase in growth rate, those of Line 2 did not. Nevertheless, the onset of puberty in females, as assessed by vaginal opening and occurrence of first ovulation, advanced by 7-8 days in both Lines of animals. Accordingly, the body weight at puberty of Line 2 transgenic females was much lower than that of normal littermates, indicating that continuous hGH expression could induce precocious puberty without enhancing the growth rate.

Age Factors↗