Biomedical subjects

S Shibasaki

Publications and source records attributed to S Shibasaki.

At least 19 recordsLinked to original sources

PubMed2006

Clinical evaluation of magnetic resonance imaging flowmetry of portal and hepatic veins in patients following hepatectomy.

BACKGROUND: Hepatic blood flow was associated with degree of hepatic damage. Measurements of blood flow using ultrasonography (US) may vary due to any observer's and patient's conditions. The utility of magnetic resonance imaging (MRI) flowmetry in portal and hepatic veins was assessed. PATIENTS AND METHODS: Using the phase-contrast method, the mean flow velocity of portal (PVF) and hepatic vein (HVF) were determined by MRI and US in 75 consecutive patients with liver diseases, including 58 patients undergoing hepatectomy. The correlations between these parameters and clinicopathological findings were examined. RESULTS: PVF and HVF measured by MRI flowmetry were 12.8+/-4.5 and 14.7+/-5.3 cm/s, respectively. There was no significant correlation of both flows between MRI and US. PVF correlated significantly with portal pressure (r = -0.722; P < 0.05). There was a negative correlation between HVF and histological activity index score (r = -0.366; P < 0.05). PVF and HVF were lower in patients with cirrhosis and higher staging score (2-4) and PVF was lower in patients with higher grading score (2-3; P < 0.05). PVF and HVF were not significantly associated with postoperative complications. CONCLUSIONS: Our results suggest that MRI flowmetry is a potentially useful tool for measurement of hepatic blood flow and recommend its use for estimation of liver cirrhosis-associated impairment.

Aged↗

PubMed2005

Comparative study of survival of patients with hepatocellular carcinoma predicted by different staging systems using multivariate analysis.

AIMS: In a previous pilot study, we reported the usefulness of the modified the Cancer of the Liver Italian Program (CLIP) score for patients with hepatocellular carcinoma (HCC). To determine the best staging system for predicting the survival of HCC patients, we conducted a comparative analysis of prognosis using multivariate analysis in 210 Japanese HCC patients who underwent hepatic resection. METHODS: We compared the survival as predicted by various staging systems, including tumour node metastasis (TNM) stage of the American Joint Commission on Cancer (AJCC) and the Liver Cancer Study Group of Japan, the Japan Integrated Staging (JIS) score (Japanese TNM and Child-Pugh classification), CLIP score and our modified CLIP score using protein induced by vitamin K absence or antagonist II (PIVKA-II). RESULTS: Univariate analysis showed that discrimination of disease-free survival in the early and advanced stages by the JIS score and modified CLIP score was clearer than by the Japanese or AJCC TNM or the original CLIP score. Discrimination between stages of overall survival by all staging systems was significant. Multivariate analysis showed that the JIS, CLIP and modified CLIP scores were better staging systems for predicting survival than the Japanese and AJCC TNM. The modified CLIP score showed the lowest Akaike information criteria statistical value for disease-free and overall survival, which means the best discrimination ability for patient survival compared with the JIS score and CLIP score. CONCLUSIONS: A staging system that combines tumour factors, sensitive tumour marker(s) and hepatic function is the best predictor of prognosis of HCC patients.

Adult↗

PubMed2004

The Japanese integrated staging score using liver damage grade for hepatocellular carcinoma in patients after hepatectomy.

AIMS: The new Japanese staging system for hepatocellular carcinoma (HCC), the Japan integrated staging (JIS) score, accounts for both Child-Pugh classification and Japan tumour node metastasis (TNM) staging. However, in HCC patients who undergo hepatectomy, liver function is relatively good and a better prognostic classification of hepatic function is necessary. METHODS: The present study was designed to analyse the modified JIS score using liver damage grade by the Liver Cancer Study Group of Japan instead of the Child-Pugh classification (using the category indocyanine green retention rate at 15 min [ICG(R15)] instead of encephalopathy), and to compare the Japan TNM stage in 101 patients who underwent resection of HCC. RESULTS: The liver damage grade showed significantly better discrimination of disease-free and overall survival than did the Child-Pugh classification. The modified JIS score system showed significant differences of disease-free and overall survivals in each score and this system was superior for discriminating survivals compared with the TNM staging. CONCLUSIONS: The combined staging system of hepatic function, particularly ICG(R15), and tumour stage provides a better prediction of prognosis. The JIS score using the liver damage grade was a useful predictor of prognosis of HCC patients who underwent hepatic resection.

Adult↗

PubMed2003

Modified CLIP using PIVKA-II for evaluating prognosis after hepatectomy for hepatocellular carcinoma.

AIMS: The new staging system proposed by the Cancer of the Liver Italian Program (CLIP) for hepatocellular carcinoma (HCC) accounts for both liver dysfunction and tumour characteristics. The present study was designed to analyze UICC TNM stage, CLIP and modified CLIP in 91 patients who underwent hepatic resection for HCC. METHODS: In the modified CLIP, scoring of AFP was replaced by that of protein induced by vitamin K absence or antagonist II (PIVKA-II; predictive value, > or = 400 mAU/ml). RESULTS: After hepatic resection, 54 patients developed recurrent tumours. High PIVKA-II was a significant determinant of recurrence (p<0.05). However, a high score of the modified CLIP as well as those other staging systems did not correlate with tumour-recurrence rate. Univariate analysis showed that high TNM score, CLIP score and our modified CLIP score were significant predictors of poor prognosis. Multivariate Cox's analysis revealed that high PIVKA-II and high modified CLIP score were associated with higher risk for disease-free and overall survival as well as high TNM stage. CONCLUSIONS: Compared with the original CLIP, our modified CLIP was a better predictor of prognosis of HCC patients who underwent hepatic resection.

Adult↗

PubMed2002

An arming yeast with the ability to entrap fluorescent 17beta-estradiol on the cell surface.

We constructed a novel surface-engineered yeast displaying the ligand-binding domain of the rat estrogen receptor (ERLBD). ERLBD, display of which on the yeast cell surface was confirmed by immunofluorescence, possessed strong binding activity to fluorescent 17beta-estradiol - an analogue of the natural ligand of the estrogen receptor - that was comparable to the activity of the native receptor. Environmental homeostasis has recently been disturbed by endocrine disruptors, which cause confusion in the hormone secretion system. It is therefore very important to identify chemical compounds with hormone-like activity and remove them from the environment. The present results demonstrate that the new arming yeast displaying ERLBD on its cell surface will be capable of screening, entrapping, and removing estradiol-like compounds from the environment.

Animals↗

PubMed2002

Cell surface-engineered yeast with ability to bind, and self-aggregate in response to, copper ion.

In order to construct a cell surface-engineered yeast Saccharomyces cerevisiae that facilitates adsorption and recovery of heavy metal ions, we endowed it with the ability to self-aggregate in response to binding and accumulation of copper ion. A fusion gene for the expression of GTS1, which encodes a putative zinc-finger transcription factor related to occurrence of cell-aggregation, was constructed under the control of the copper ion-inducible CUP1 promoter from the yeast metallothionein gene. The multicopy plasmid carrying the fusion gene was introduced into a cell surface-engineered yeast displaying histidine hexa-peptide, which can chelate copper ion. This transformant strain aggregated in medium only in the presence of copper ion, with aggregation induced by as little as 1 mM copper ion. The copper ion-induced aggregation did not interfere with the copper ion-adsorbing function of the cell surface-engineered yeast, indicating that this transformant strain has the twin features of enhanced cell surface adsorption of copper ion and self-aggregation in response to environmental copper ion.

Adsorption↗

PubMed2001

Intelligent yeast strains with the ability to self-monitor the concentrations of intra- and extracellular phosphate or ammonium ion by emission of fluorescence from the cell surface.

Saccharomyces cerevisiae strains that respond to environmental changes and transmit the information by emission of fluorescence from the cell surface were constructed. The technique of cell surface engineering enabled the yeast cells to display enhanced cyan blue fluorescent protein (ECFP) or enhanced yellow fluorescent protein (EYFP) on the surface under the control of promoters that sense environmental changes. Two model promoters were examined in this study. For monitoring the intra- and extracellular concentrations of phosphate ion, the PHO5 promoter was chosen to display ECFP. The MEP2 promoter was used to display EYFP to sense the concentrations of ammonium ion. Fluorescence was observed by fluorescence microscopy and immunofluorescence microscopy, and the intensity was measured by a flow cytometer. The relationship between ion concentration inside and outside the cells was evaluated by the change in the rate of fluorescence. This S. cerevisiae system enables environmental changes to be transmitted as intra- and extracellular information using a suitable promoter functioning at real time and in a non-invasive manner.

Bacterial Proteins↗

PubMed2001

Quantitative evaluation of the enhanced green fluorescent protein displayed on the cell surface of Saccharomyces cerevisiae by fluorometric and confocal laser scanning microscopic analyses.

The number of foreign protein molecules expressed on the cell surface of the budding yeast Saccharomyces cerevisiae by cell surface engineering was quantitatively evaluated using enhanced green fluorescent protein (EGFP). The emission from EGFP on the cell surface was affected by changes in pH. The amount of EGFP on the cell surface, displayed as alpha-agglutinin-fusion protein under control of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter, was determined at the optimum pH of 7.0. The fluorometric analysis and the image analysis by confocal laser scanning microscopy (CLSM) showed a similar number of molecules displayed on the cell surface, demonstrating that 10(4)-10(5) molecules of alpha-agglutinin-fused molecules per cell were expressed. Furthermore, the amount of fluorescent protein expressed on cells harboring a multicopy plasmid was three to four times higher than that on cells harboring the gene integrated into the genome.

Arabidopsis↗

PubMed2001

Creation of cell surface-engineered yeast that display different fluorescent proteins in response to the glucose concentration.

We have successfully created a novel yeast strain able to monitor changes in environmental conditions by displaying either green fluorescent protein (GFP) from Aequorea victoria or blue fluorescent protein (BFP), a variant of GFP, on its cell surface as a visible reporter. For the display of these fluorescent proteins on the cell surface of Saccharomyces cerevisiase, our cell-surface-engineering system was utilized. The GAPDH promoter, which is active in the presence of glucose, and the UPR-ICL promoter from Candida tropicalis, which starts to function in the presence of a reduced level of glucose, were employed simultaneously to express the GFP-encoding gene and the BFP-encoding gene, respectively. This cell-surface-engineered yeast strain emitted green fluorescence from the cell surface when sufficient glucose was present in the medium, and blue fluorescence from the same cell surface when the glucose in the medium was consumed. The fluorescent proteins displayed on the cell surface using the different promoters enabled us to monitor the concentrations of intra- and/or extracellular glucose that regulated activation or inactivation of the promoters. This novel yeast strain could facilitate the computerized control of various bioprocesses measuring emitted fluorescence.

Genetic Engineering↗

PubMed2001

Development of novel whole-cell immunoadsorbents by yeast surface display of the IgG-binding domain.

The ZZ domain derived from Staphylococcus aureus, which binds to the Fc part of immunoglobulin G (IgG), was displayed on the cell surfaces of yeast Saccharomyces cerevisiae by cell-surface engineering using the C-terminal half of alpha-agglutinin under control of the 5'-upstream region of the isocitrate lyase gene from Candida tropicalis (UPR-ICL). Display of ZZ on the cell surface was confirmed by immunofluorescence microscopy. Enzyme-linked immunosorbent assay (ELISA) and sandwich ELISA using the S. cerevisiae cells displaying ZZ detected IgG and antigen (human serum albumin) down to a concentration of 1-10 ng/ml in both cases. The detection range covered by these assay systems was wide and could be varied by adjusting the amount of cells and reaction times with horseradish peroxidase (HRP) substrate. Moreover, yeast cells displaying ZZ were successfully used for repeated affinity purification of IgG from serum. These results indicate that S. cerevisiae displaying ZZ may constitute novel and genetically renewable whole-cell immunoadsorbents widely applicable to immunoassays and affinity purification.

Animals↗

PubMed2001

Cell surface-engineered yeast displaying a histidine oligopeptide (hexa-His) has enhanced adsorption of and tolerance to heavy metal ions.

A histidine oligopeptide (hexa-His) with the ability to chelate divalent heavy metal ions was displayed on the yeast cell surface for the purpose of enhanced adsorption of heavy metal ions. We genetically fused a hexa-His-encoding gene with the gene encoding the C-terminal half of alpha-agglutinin that includes a glycosylphosphatidylinositol anchor attachment signal sequence and attached the hexa-His peptide on the cell wall of Saccharomyces cerevisiae. This surface-engineered yeast adsorbed three to eight times more copper ions than the parent strain and was more resistant to copper (4 mM) than the parent (below 1 mM at pH 7.8). It was possible to recover about a half of the copper ions adsorbed by whole cells with EDTA treatment without disintegrating the cells. Thus, we succeeded in constructing a novel yeast cell with both tolerance to toxic contaminants and enhanced adsorption of metal ions onto the cell surface.

Adsorption↗

PubMed2001

Measurement of serum hyaluronic acid level during the perioperative period of liver resection for evaluation of functional liver reserve.

BACKGROUND AND AIM: The serum hyaluronic acid (HA) concentrations reflect the degree of hepatic fibrosis and sinusoidal endothelial cell damage. The HA concentrations were examined to evaluate liver damage during the perioperative period of hepatectomy. METHODS: The HA level of serum samples from 79 patients who underwent a hepatectomy was measured, and the results were compared to conventional liver function tests, the degree of fibrosis, liver regeneration and complications. RESULTS: Hyaluronic acid concentrations correlated with the severe fibrosis or histological activity index, and also correlated with liver function tests including transaminase level, platelet counts, prothrombin time activity, indocyanine green retention rate at 15 min (ICG R15), liver activity at 15 min by technetium-99m galactosyl human serum albumin scintigraphy (LHL 15), and portal pressure. The HA level postoperatively correlated with liver function, especially with total bilirubin. Hyaluronic acid levels at day 28 postoperatively correlated with ICG R15 and LHL 15. The hyaluronic acid level before surgery and at day 28 postoperatively correlated with the regeneration of remnant liver in major hepatectomy. The HA levels were significantly higher in patients with hepatic failure or prolonged ascites. CONCLUSION: Our results indicate that the measurement of the HA level is useful for monitoring liver damage or predicting complications associated with liver surgery.

Adult↗

PubMed2001

High prevalence of asthma in five remote indigenous communities in Australia.

Data on the prevalence of asthma in children residing in remote indigenous communities in Australia are sparse, despite the many reports of high prevalence in nonindigenous children of this country. Two previous Australian studies have had poor participation rates, limiting interpretation of their results. A study of children in the Torres Strait and Northern Peninsula Area of Australia was conducted to document the prevalence of asthma symptoms. Five indigenous communities were randomly selected and trained interviewers, who were local indigenous health workers, recruited participants using a house-by-house approach. Information was collected by a structured face-to-face interview based on a standardized questionnaire constructed from the protocol International Study of Asthma and Allergy in Childhood; 1,650 children were included in the study with a 98% response rate. Overall, the prevalence of self-reported ever wheezing was 21%; 12% reported wheezing in the previous year; and 16% reported ever having asthma. There was significant variation in the prevalence of asthma symptoms between communities. It is concluded that there are significant intercommunity variations in the prevalence of asthma symptoms in remote communities and that the prevalence in these communities is as high as in nonindigenous groups.

Adolescent↗

PubMed2000

Cytochemical evaluation of localization and secretion of a heterologous enzyme displayed on yeast cell surface.

A starch-utilizing Saccharomyces cerevisiae strain was constructed by cell surface engineering. Distribution of the heterologous glucoamylase-alpha-agglutinin fusion protein on the yeast cell was analyzed by indirect fluorescence microscopy using an anti-glucoamylase antibody. Most of the intense fluorescence was first localized in the small bud, then observed on the entire cell wall of the daughter and mother cells. Fluorescence also accumulated at the neck region. These observations suggest that the display of the heterologous protein on the cell surface is carried with other cell wall components to the areas in which the cell wall is newly synthesized; the distribution is controlled by the cell cycle. Then, the heterologous protein-encoding gene was expressed in a sec1 mutant, in which secretory vesicles accumulate under restrictive temperature, and the produced protein was detected by immunoelectron microscopy. Most of the gold particles that reacted with the fusion protein were not localized in vesicles but in expanding endoplasmic reticulum. This phenomenon may be due to overproduction of the heterologous protein which was designed to be displayed on the cell wall. Artificial production of heterologous protein may have caused a relative shortage of glycosyl phosphatidylinositol anchors.

Agglutinins↗

PubMed2000

Construction of an engineered yeast with glucose-inducible emission of green fluorescence from the cell surface.

An engineered yeast with emission of fluorescence from the cell surface was constructed. Cell surface engineering was applied to display a visible reporter molecule, green fluorescent protein (GFP). A glucose-inducible promoter GAPDH as a model promoter was selected to control the expression of the reporter gene in response to environmental changes. The GFP gene was fused with the gene encoding the C-terminal half of alpha-agglutinin of Saccharomyces cerevisiae having a glycosylphosphatidylinositol anchor attachment signal sequence. A secretion signal sequence of the fungal glucoamylase precursor protein was connected to the N-terminal of GFP. This designed gene was integrated into the TRP1 locus of the chromosome of S. cerevisiae with homologous recombination. Fluorescence microscopy demonstrated that the transformant cells emitted green fluorescence derived from functionally expressed GFP involved in the fusion molecule. The surface display of GFP was further verified by immunofluorescence labeling with a polyclonal antibody (raised in rabbits) against GFP as the first antibody and Rhodamine Red-X-conjugated goat anti-rabbit IgG as the second antibody which cannot penetrate into the cell membrane. The display of GFP on the cell surface was confirmed using a confocal laser scanning microscope and by measuring fluorescence in each cell fraction obtained after the subcellular fractionation. As GFP was proved to be displayed as an active form on the cell surface, selection of promoters will endow yeast cells with abilities to respond to changes in environmental conditions, including nutrient concentrations in the media, through the emission of fluorescence.

Base Sequence↗

PubMed1999

A long-term survival case of thymic squamous cell carcinoma, performed complete extirpation with vascular reconstruction of the superior vena cava.

A 59-year-old woman who complained of anterior chest pain exhibited an abnormal shadow on chest X ray and was admitted to our hospital. The chest X ray showed a demarcated tumor at the anterosuperior mediastinum and she was diagnosed as having a mediastinal tumor. After the midsternotomy was performed, the mediastinal tumor derived from the thymic tissues was discovered to have invaded the right upper lung, pericardium and superior vena cava. After excising the tumor, anastomosis between the right brachiocephalic vein and superior vena cava, followed by that between the left brachiocephalic vein and right cardiac auricle was performed using expanded polytetrafluoroethylene-ringed vascular grafts (phi 10 mm) for reconstruction. The tumor was diagnosed as a thymic carcinoma (squamous cell carcinoma) pathologically. After surgery, she was treated by cobalt irradiation. One month and again 3 months after the operation, venography showed patency. The patient has not demonstrated recurrence for 9 years and 6 months.

Blood Vessel Prosthesis Implantation↗

PubMed1999

Proliferation of hepatic metastases of colorectal carcinoma: relationship to primary tumours and prognosis after hepatic resection.

In this study, we determined the proliferation indices of liver metastatic tumours originating from colorectal carcinomas using Ki67 and argyrophil nucleolar organizer region associated proteins (AgNOR) stain. We examined the primary and metastatic tumours in 27 patients with liver metastasis and eight cases with non-metastatic colorectal carcinoma as a control.The number of AgNOR dots in metastatic tumours was significantly higher than in the respective primary tumours of the metastasis group or in non-metastatic colorectal carcinomas. The Ki67 labelling index was similar in all groups. The Ki67 labelling index and AgNOR counts did not correlate with each other. There was no significant relationship between proliferation indices and the duration of the disease-free period following hepatic resection for metastases or with prognosis after hepatectomy. We conclude that Ki67 and AgNOR are not useful indicators of prognosis in patients who undergo operation for liver metastasis of colorectal carcinomas.

Adult↗

PubMed1999

[Treatment with 5-FU modulated by low-dose CDDP for advanced cancers and recurrent cases of metastasis].

Advanced gastric, colon and esophageal cancers (n = 21) were treated with 5-FU (250 mg) modulated by CDDP (5 mg). The reductive ratio of tumor was 6/21 (28.6%). Six cases of partial response (PR) were limited with no surgical treatment and exploratory laparotomy of all cases, and the effectiveness rate was 54.5% (6/11). Few side effects, such as dysfunction of bone marrow and kidney, were noted. Even if side effects occurred, they were mild. We concluded that excellent treatment with 5-FU modulated by CDDP has markedly improved the efficacy.

Adult↗