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Biomedical subjects

S Shibata

Publications and source records attributed to S Shibata.

At least 199 records · Page 11Linked to original sources
PubMed1998

Internalization of urinary trypsin inhibitor in human uterine fibroblasts.

We have characterized the molecular species and internalization of urinary trypsin inhibitor (UTI) in human uterine fibroblasts. Link protein (LP) has previously been identified as one of the cell-associated UTI binding proteins. The truncated forms of UTI were readily detectable in the cells after incubating the cells with purified UTI. Immunoblotting analysis with a panel of domain-specific antibodies revealed that the UTI species lacked the amino-terminal domain of UTI, but contained the carboxyl-terminal domain. We have examined whether LP is involved in the UTI internalization in the cells. Internalization of 125I-labelled UTI was blocked by the intact UTI, but not by the carboxyl-terminal domain of UTI. Treatment with a polyclonal antibody to the UTI binding domain of LP partially inhibited UTI binding to the cells, but did not significantly prevent UTI internalization. In addition, preincubation of the cells with hyaluronidase reduced the UTI binding to the cells, but had no effect on the rate with which UTI was internalized. These data allow us to conclude that there are at least two different mechanisms for internalization of UTI. The major one is via unknown UTI receptors in a Ca2+, Mg2+-sensitive manner and another is via LP.

Calcium↗
PubMed1998

Characterization of the UL16 gene product of herpes simplex virus type 2.

We have raised rabbit polyclonal antisera against a His-tagged herpes simplex virus type 1 (HSV-1) UL16 fusion protein, one of which very specifically reacted with 40 kDa and 41 kDa proteins in the lysates of HSV-1 and HSV-2-infected cells, respectively. Since its reactivity to the 41 kDa protein was clearly eliminated by pre-adsorption with E. coli lysates expressing the UL16 fusion protein, the antiserum was used to characterize the UL16 products of HSV-2. The HSV-2 UL16 protein was produced at the late phase of infection in a manner highly dependent on viral DNA synthesis and was distributed in both the nuclei and the cytoplasma of infected cells. In immunofluorescence studies, the UL16-specific fluorescence in the nuclei was shown to be detected as small discrete granules. On the other hand, the cytoplasmic fluorescence was diffusely distributed around the nucleus at 8 h postinfection but, at later times of infection, it was mainly detected as a mass at a perinuclear region. The analysis on its association with capsids has revealed that the UL16 protein copurified with C capsids but not B and A capsids, and that the association with C capsids was not tight. Moreover, our experiments have shown that a detectable level of the UL16 protein was not associated with extracellular virions, and that the partially purified UL16 proteins had a DNA-binding activity. These observations are consistent with the hypothesis that the UL16 protein plays a role in capsid maturation including DNA packaging/cleavage. We have also determined the complete nucleotide sequence of the HSV-2 UL16 gene and found that a nonstandard initiation codon may be used for its translation.

Amino Acid Sequence↗
PubMed1998

Correlation between the growth of uterine leiomyomata and estrogen and progesterone receptor content in needle biopsy specimens.

OBJECTIVE: To examine the relationship between estrogen receptor (ER) and progesterone receptor (PR) content in needle biopsy specimens and the growth of uterine leiomyomata after biopsy. DESIGN: Prospective clinical study. SETTING: University teaching hospital. PATIENT(S): Thirty-one women with uterine leiomyomata and a normal menstrual cycle. INTERVENTION(S): Transcervical needle biopsy of uterine leiomyomata. MAIN OUTCOME MEASURE(S): The relationships between histologic features (smooth muscle content, immunohistochemical expression of ER and PR) and the percent increase over a 12-month observation period in the volume of the largest myoma nodule measured by magnetic resonance imaging were analyzed. RESULT(S): Both the density and intensity of immunohistochemical staining of PRs in uterine leiomyoma tissue showed significant positive correlation with leiomyoma growth. CONCLUSION(S): The growth of uterine leiomyomata can be determined by histologic and immunohistochemical analysis of needle biopsy specimens from uterine leiomyomata.

Adult↗
PubMed1998

Thrombomodulin release from umbilical endothelial cells initiated by preeclampsia plasma-induced neutrophil activation.

OBJECTIVE: To assess the capacity of neutrophils to release thrombomodulin from umbilical vein endothelial cells in vitro in response to plasma from normal gravidas and those with preeclampsia. METHODS: We collected venous plasma samples from 66 pregnant women: 18 women with severe preeclampsia, 18 women with mild preeclampsia, and 30 normotensive healthy women with singleton pregnancies in the third trimester. Neutrophils were isolated from venous blood obtained from healthy adult volunteers. Endothelial cells from normal umbilical veins were digested by collagenase and cultured. The effect of preeclampsia plasma on thrombomodulin release from endothelial cells was tested after incubating cultured cells with plasma from severe preeclampsia. Thrombomodulin and elastase levels were measured with specific immunoassays. RESULTS: Plasma thrombomodulin levels (mean +/- standard error of the mean) were elevated in pregnant women with severe preeclampsia (62.5+/-7.9 compared with 40.1+/-3.3 [matched control] ng/mL; P = .02), and elastase levels correlated directly with thrombomodulin (r = .49; P < .05). Both coincubation of endothelial cells and neutrophils with preeclampsia plasma (16.3+/-2.0 compared with 9.4+/-1.2 [normotensive plasma] ng/mL; P < .05) and incubation of endothelial cells with neutrophils pretreated with preeclampsia plasma (13.9+/-1.8 compared with 9.6+/-0.9 [normotensive plasma] ng/mL; P < .05) significantly promoted thrombomodulin release from endothelial cells. Thrombomodulin can be released by the concerted action of preeclampsia plasma-stimulated neutrophils and endothelial cells. CONCLUSION: In patients with severe preeclampsia or eclampsia, neutrophil activation occurs and the activated neutrophils induce vascular endothelial damage.

Adult↗
PubMed1998

Nuclear factor kappa B dependent induction of gamma glutamylcysteine synthetase by ionizing radiation in T98G human glioblastoma cells.

Glioblastoma is one of the most malignant of all neoplasms, and often shows resistance to chemotherapy and radiation therapy. Ionizing radiation activates transcriptional factors, such as nuclear factor kappa-B (NF-kappa B). Previously we found that glutathione (GSH) synthesis is induced by cytokines mediated by NF-kappa B (Urata et al. J. Biol. Chem., 1996). Here, we present direct evidence that NF-kappa B activated by ionizing radiation induces the expression of gamma-glutamylcysteine synthetase (gamma-GCS), the rate limiting enzyme of GSH synthesis, using T98G human glioblastoma cells. T98G cells have approximately 14-times the level of intracellular GSH of NB9 cells, radiation-sensitive neuroblastoma cells. In T98G cells, 30-Gy of ionizing radiation was required for the activation of NF-kappa B on an electrophoretic mobility shift assay and the induction of gamma-GCS mRNA on Northern blots and a nuclear run-on assay. However, when T98G cells were treated with buthionine sulfoximine, 3-Gy of ionizing radiation stimulated the DNA-binding activity of NF-kappa B and the expression of gamma-GCS. We constructed chimeric genes containing various regions of gamma-GCS promoter gene and the coding region for Luciferase. T98G cells transiently transfected with a plasmid containing the gamma-GCS promoter-luciferase construct showed increased luciferase activity when treated with ionizing radiation. The luciferase activity stimulated by ionizing radiation was found in the gamma-GCS promoter containing the NF-kappa B binding site, whereas not in that containing its mutated site. These results suggest that GSH synthesis is upregulated by ionizing radiation mediated by NF-kappa B and a high concentration of GSH in T98G cells causes downregulation of the NF-kappa B-DNA binding activity in response to ionizing radiation. The irresponsiveness of the intracellular signal transduction cascade to irradiation may be a factor in the resistance of T98G cells to radiation therapy.

Acetylcysteine↗
PubMed1998

Increase in the peripheral lymphocyte populations expressing CD54 (ICAM-1) after hyperthermic isolated limb perfusion in patients with malignant melanoma: an analysis of four cases.

The lymphocytes isolated from perfused or non-perfused circulations before, during, and after hyperthermic isolated limb perfusion (HILP) in the four patients with malignant melanoma were analysed for the expression of CD54 (ICAM-1), CD58 (LFA-3), CD4, CD8, HLA class I and class II in order to investigate the mechanism(s) of the activation of such immunocompetent cells as natural killer (NK)-cells or T-lymphocytes by HILP. It was thus found that the lymphocyte populations expressing CD54 increased significantly 1 day after HILP in the four patients examined. The lymphocyte populations expressing CD58 apparently increased. It was also found that the NK-cell and T-lymphocyte activities increased during or after HILP in the present four cases as observed previously in the other melanoma patients. These results indicate that our HILP system may augment the immunological activities through the mechanisms of the induction of CD54 or CD58 expression in the peripheral lymphocytes of the melanoma patients who receive HILP.

Adult↗
PubMed1998

Protective role of glutathione synthesis on radiation-induced DNA damage in rabbit brain.

1. Radiotherapy has attracted increasing interest in recent years. It is known that ionizing radiation induces oxygen radical injury, whereas oxidative stress by the radiation can cause cellular responses to defense cellular injury. In this study, the metabolism of antioxidants in response to ionizing radiation to the brain was studied in the brain using experimental rabbits. 2. Ionizing radiation to the hemicerebrum caused an increase in the levels of glutathione (GSH) and the activity of a GSH synthesizing enzyme, gamma-glutamylcysteine synthetase (gamma-GCS), and Cu,Zn-superoxide dismutase (Cu,Zn-SOD). Ionizing radiation also induced DNA-damage estimated by the formation of 8-hydroxydeoxyguanosine. These changes were dependent on the radiation dose. 3. Previous intrathecal-administration of buthionine sulfoximine (100 microM), a specific inhibitor of gamma-GCS, increased DNA damage by radiation in the radiated hemicerebrum. That of S-methyl GSH, on the other hand, resulted in a significant reduction of DNA damage by radiation. 4. These results suggest that synthesis of GSH and Cu,Zn-SOD is responsive to ionizing radiation and this induction of antioxidants may play a role in reducing tissue damage in radiotherapy.

Animals↗
PubMed1998

Development of a health promotion system for the elderly: Committee of Health Evaluation for Elderly Persons Council of Japan AMHTS Institutions.

A new health promotion approach for elderly persons is required which maintains not only their physical health but also their quality of life. We are developing a health promotion system which makes use of questionnaires dealing with physical conditions and quality of life, and makes health reports. Health evaluation is carried out in three steps. First, detailed information about the physical health of each client is collected. Second, quality of life is evaluated according to five health indicators. Last, health recommendations are generated. An artificial intelligence (AI) program produces detailed questions to collect necessary information for the evaluation of a client's health. The information related to quality of life is converted into five health indicators and presented as a radar-chart in documents and displays. The knowledge-based AI program automatically generates the health recommendation documents. This information is available for physicians and nurses for health counseling.

Aged↗