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Biomedical subjects

Y Ejiri

Publications and source records attributed to Y Ejiri.

15 recordsLinked to original sources
PubMed2006

High-rate nitrification using aerobic granular sludge.

The performance of nitrifying granules, which had been produced in an aerobic upflow fluidised bed (AUFB) reactor, was investigated in various types of ammonia-containing wastewaters. When pure oxygen was supplied to the AUFB reactor with a synthetic wastewater containing a high concentration of ammonia (500 g-N/m3), the ammonia removal rate reached 16.7 kg-N/m3/day with a sustained ammonia removal efficiency of more than 80%. The nitrifying granules possessing a high settling ability could be retained with a high density (approximately 10,000 g-MLSS/m3) in a continuous stirring tank reactor (CSTR) even under a short hydraulic retention time (44 min), which enabled a high-rate and stable nitrification for an inorganic wastewater containing low concentrations of ammonia (50 g-N/m3). Moreover, the nitrifying granules exhibited sufficient performance in the nitrification of real industrial wastewater containing high concentrations of ammonia (1000-1400 g-N/m3) and salinity (1.2-2.2%), which was discharged from metal-refinery processes. When the nitrifying granules were used in cooperation with activated sludge to treat domestic wastewater containing organic pollutants as well as ammonia, they fully contributed to nitrification even though a part of activated sludge adhered onto the granule surfaces to form biofilms. These results show the wide applicability of nitrifying granules to various cases in the nitrification step of wastewater treatment plants.

Ammonia↗
PubMed2004

Formation mechanism of nitrifying granules observed in an aerobic upflow fluidized bed (AUFB) reactor.

The influences of trace metals in the wastewater and shear stress by aeration were particularly examined to clarify the formation mechanism of nitrifying granules in an aerobic upflow fluidized bed (AUFB) reactor. It was found that Fe added as a trace element to the inorganic wastewater accumulated at the central part of the nitrifying granules. Another result obtained was that suitable shear stress by moderate aeration (0.07-0.20 L/min/L-bed) promoted granulation. Furthermore, it was successfully demonstrated that pre-aggregation of seed sludge using hematite promoted core formation, leading to rapid production of nitrifying granules. From these results, a nitrifying granulation mechanism is proposed: 1) as a first step, nitrifying bacteria aggregate along with Fe precipitation, and then the cores of granules are formed; 2) as a second step, the aggregates grow to be spherical or elliptical in form due to multiplication of the nitrifying bacteria and moderate shear stress in the reactor, and then mature nitrifying granules are produced. Fluorescence in situ hybridization (FISH) analysis successfully visualized the change in the spatial distribution of nitrifying bacteria in the granules, which supports the proposed granulation mechanism.

Bacteria↗
PubMed2001

A high molecular weight glutamyl endopeptidase and its endogenous inhibitors from cucumber leaves.

We purified a glutamyl endopeptidase that is a major foliar endopeptidase in cucumber. The endopeptidase had a molecular mass of 400 kDa, consisted of four subunits of 97 kDa, and was inactivated by SH-modifying reagents. Its optimum pH and optimum temperature were 8.0 and 30-37 degrees C, respectively. An internal amino acid sequence of the endopeptidase was highly homologous to a partial sequence of unidentified proteins deduced from genetic information for Arabidopsis thaliana, soybean and rice, but not to the sequences of bacterial glutamyl endopeptidases or animal proteases. Therefore, the unidentified proteins might be glutamyl endopeptidases and be widely distributed only among plant species. The activity of the cucumber glutamyl endopeptidase was inhibited by at least three inhibitors existing in cucumber leaves. One of the inhibitors was a competitive inhibitor of 25 kDa, which did not significantly inhibit commercial endopeptidases derived from animals and microorganisms. This suggests that the cucumber glutamyl endopeptidase might be controlled by endogenous inhibitors in vivo.

Amino Acid Sequence↗
PubMed2001

Purification of an aminopeptidase preferentially releasing N-terminal alanine from cucumber leaves and its identification as a plant aminopeptidase N.

In this study, a highly active foliar aminopeptidase preferentially releasing N-terminal alanine from artificial substrates was purified and characterized from cucumber (Cucumis sativus L. suyo). The enzyme had a molecular mass of 200 kDa consisting of two subunits of 95 kDa. It was a metalloprotease the pH optimum of which was 8 to 9. It cleaved Ala-, Gly-, Met-, Ser-, Leu-, Lys-, and Arg artificial substrates. An internal amino acid sequence was similar to those of aminopeptidase N (clan MA, family M1) of microorganisms, and was very similar to that of a putative aminopeptidase N of Arabidopsis thaliana. From these results, the highly active aminopeptidase in cucumber leaves was identified to be a plant aminopepitdase N.

Alanine↗
PubMed2000

Effects of sugar concentration on recombinant human alpha(1)-antitrypsin production by genetically engineered rice cell.

Productivity of recombinant human alpha(1)-antitrypsin (rAAT) with a genetically engineered rice cell using an inducible promoter has been studied by batch-wise and continuous production. A simple model explained the effect of proteases released from the disrupted cells on the rAAT degradation. Glucose concentration in the medium significantly affected the rAAT productivity in the continuous production, because the rAAT was induced by sugar depletion. When the fresh medium containing 5mM glucose was supplied to the continuous bioreactor, induction time was long and the productivity was low, indicating that the glucose concentration in the cells was high enough as to repress the promoter. When the glucose concentration in the fresh medium was reduced to 0.5mM, total amount of rAAT produced in 70h cultivation reached 6.7-7.6mg/g-dry cell, which was two times larger than the control medium without glucose.

Journal Article↗
PubMed2000

Focal therapeutic efficacy of transcatheter arterial infusion of styrene maleic acid neocarzinostatin for hepatocellular carcinoma.

We evaluated the focal therapeutic effect of oily carcinostatic agents administered by transcatheter arterial infusion (TAI) as the initial therapy in patients with hepatocellular carcinoma in a randomized controlled clinical trial. Group A (19 patients) received 4 mg of styrene maleic acid neocarzinostatin in 4 ml of Lipiodol, and group B (18 patients) received 100 mg of epirubicin in 4 ml of Lipiodol via the tumor feeding arteries as peripherally as possible. The grade of Lipiodol accumulation and the tumor regression rate were determined 2 weeks after TAI by computerized tomography. Adverse effects within 2 weeks after TAI were evaluated by subjective signs and symptoms such as fever (maximum body temperature) and the frequency of shaking chills and abdominal pain, and by biochemical parameters such as albumin, prothrombin time, and aspartate and alanine aminotransferases. Lipiodol accumulation in the tumor was significantly greater in group A (12/19; 63.2% showing grade IV Lipiodol accumulation) than in group B (3/18; 16.7% showing grade IV) (P<0.05). The tumor regression rate was also significantly greater in group A (8/17; 47.1% showing more than 25% tumor regression) than in group B (1/13; 7.7% showing more than 25% tumor regression) (P<0.05). Although clinically significant elevations of aminotransferases and reductions of cholinesterase, and shaking chills were observed more often in group A than in group B (P<0.0001), these factors had little influence on the clinical outcome. Our results suggest that styrene maleic acid neocarzinostatin in Lipiodol exerts a more favorable focal therapeutic effect than does epirubicin in Lipiodol in the initial treatment of hepatocellular carcinoma.

Antineoplastic Agents↗
PubMed1997

Cancer cell cycle and adoptive immunotherapy using lymphokine-activated killer cells.

The mechanism underlying the lymphokine-activated killer (LAK) cell cytotoxicity to tumor cells in LAK therapy was studied using flow cytometric cell cycle analysis of Daudi cells. It was suggested that the degree of LAK cell cytotoxicity varied depending upon the phase of the cell cycle that the Daudi cells were in: the resting (G0)-phase/preparation for DNA synthesis (G1)-phase, the DNA synthesis (S)-phase or the preparation for mitosis (G2)-phase/mitosis (M)-phase. The levels of expression of intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-3 (LFA-3) and fibronectin (FN), surface antigens playing important roles in LAK cell cytotoxicity, in the different phases of the Daudi cell cycle have been investigated. The level of the expression of ICAM-1 and LFA-3 was significantly higher in S-phase cells and G2/M-phase cells relative to that in G0/G1 phase cells. The level of expression of FN, however, was significantly lower in S-phase cells and G2/M-phase cells in relation to that in G0/G1 phase cells. On the basis of these results, it may be inferred that the degree of LAK cell cytotoxicity is closely related to the cell cycle phase that the Daudi cells are in and the level of expression of surface antigens associated with the cell cycle phase. For Daudi cells treated with cis-diamminedichloroplatinum (II) (CDDP) and mitomycin-c (MMC), the enhancement of the degree of LAK cell cytotoxicity was directly related to the decrease in the proportion of cells in the S-phase. It may be suggested, therefore, that the proportion of cells in the S-phase in a tumor serves as an index of the sensitivity of the tumor cells to LAK cell cytotoxicity, and that designing a therapeutic strategy on the basis of the analysis of tumor cell cycle would help to improve the success of LAK therapy.

Antineoplastic Agents↗
PubMed1996

Enhancement of lymphokine-activated killer cell cytotoxicity implicated in the increased expression of surface adhesion molecules on tumor cells treated with anticancer agents.

We investigated mechanisms underlying lymphokine-activated killer (LAK) cell cytotoxicity in terms of intensity of expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte-function-associated antigen-3 (LFA-3) on Daudi and KATO-III cells treated with cis-diamminedichloroplatinum (II) (CDDP) and mitomycin-C (MMC). Enhancement (mean, 49.8%) of ICAM-1 or LFA-3 in mRNA and protein expression on treated tumor cells was found by flow cytometry, slot-blot RNA analysis, and reverse transcription-polymerase chain reaction (RT-PCR). Increases in adhesion and cytotoxicity of LAK cells to treated tumor cells were 10.1% and 17.7%, respectively. Results suggested that increased ICAM-1 or LFA-3 expression by low-dose CDDP or MMC binds LAK cells to tumor cells, helping to kill tumor cells. Thus, LAK cell therapy with anticancer agent pretreatment could be useful for treatment of cancer patients.

Antibodies, Monoclonal↗
PubMed1995

Clinical effectiveness of lansoprazole in patients with gastric ulcers: evaluation of quality of ulcer healing based on endoscopic ultrasonographic findings.

The effects of lansoprazole (30 mg/day) in 18 patients with gastric ulcers and the quality of ulcer healing were studied using endoscopy (including dye endoscopy) and endoscopic ultrasonography (EUS). The results showed an 8-week endoscopic healing rate of 94.4% and an S2-stage shift rate of 11.1%. In dye endoscopic findings of 11 S1-stage patients, S1b healing with regenerated mucosa close to S2 was seen in 63.6%. In a study of EUS findings, E0 with few relapses and high quality of healing accounted for 44.4%. When E0 rates were compared with the scarring images seen in endoscopic findings, the rates were 100% for S2, 66.7% for S1b, and 33.3% for S1a. These results indicate that a high degree of ulcer healing was achieved with lansoprazole, as good contraction of the ulcer tissue and early maturation of regenerated epithelium were observed.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1994

A case of Behçet's disease with occlusion of both caval veins and "downhill" esophageal varices.

A case of Behçet's disease (BD) with occlusion of both caval veins and "downhill" esophageal varices is reported. A 59-year-old male patient had esophageal varices, established as the "downhill" type by endoscopy, venography, and contrast-enhanced computed tomography (CE-CT) scan. Venography via both jugular veins did not lead to the visualization of the superior vena cava (SVC), but revealed numerous collateral veins, which formed esophageal varices en route. Venography via both femoral veins did not lead to the visualization of the inferior vena cava (IVC), but revealed numerous collateral veins, which flowed into the portal vein together with the jugular flow. CE-CT scan revealed the disappearance of the SVC and the lower part of the IVC, below the hepatic vein. The patient was diagnosed as having BD, based on his history of recurrent oral and skin lesions over the past 26 years.

Behcet Syndrome↗
PubMed1993

An autopsy case of ulcerative colitis associated with Takayasu's disease with a review of 13 Japanese cases.

An autopsy was performed on a 42-year-old Japanese female who had been suffering from both ulcerative colitis (UC) and Takayasu's disease. Her UC started at age 27 with bloody stool, and Takayasu's disease was diagnosed at age 30 on the basis of absence of pulse in her left arm. After more than ten years she died of multiple cerebral infarction. An autopsy study revealed the scarring stage of UC in the entire colon and aortitis in the aortic arch and its major branches and pulmonary arteries. Her HLA type was positive for HLA-A2, 24, Bw52 and 61. Clinical features of a total of 13 Japanese cases that had both UC and Takayasu's disease have been reviewed in the Japanese and Western literature.

Adult↗
PubMedDate not supplied

Utilization of an alternative carbon source for efficient production of human alpha(1)-antitrypsin by genetically engineered rice cell culture.

Human alpha(1)-antitrypsin was produced by genetically engineered rice cells using promoter and signal peptide of a rice alpha-amylase isozyme. Batch and continuous cultures were employed to investigate the effects of alternative carbon sources on the alpha(1)-antitrypsin production. While this expression system is inducible by sugar depletion, we have found that the productivity of alpha(1)-antitrypsin increased 2.4- to 3.4-fold, compared with the control medium without carbon source, in medium containing an alternative carbon source, such as pyruvic acid and glyoxylic acid. The accumulated alpha(1)-antitrypsin in the medium containing pyruvic acid reached 18.2-24.2 mg/g-dry cell in 50-70 h by batch culture.

Carbon↗