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T Demura

Publications and source records attributed to T Demura.

At least 19 recordsLinked to original sources
PubMed2001

Inhibition of proteasome activity by the TED4 protein in extracellular space: a novel mechanism for protection of living cells from injury caused by dying cells.

In maturation process of tracheary element (TE) differentiation, many hydrolases are activated to execute programmed cell death of TEs. Such hydrolases are released from maturing TEs into extracellular space. The release of hydrolases should be harmful to surrounding cells. The TED4 protein, a tentative plant non-specific lipid transfer protein that is expressed preferentially in TE-induced culture of zinnia (Zinnia elegans L.), is secreted into the apoplastic space prior to and associated with morphological changes of TEs. Our studies on the interrelationship between the TED4 protein and proteolytic activities using an in vitro TE differentiation system of zinnia revealed the following facts. (1) Active proteasome is released into medium at maturation stage of TE differentiation. (2) The TED4 protein forms a complex with proteasome in culture medium. (3) The TED4 protein inhibits proteasome activity in the medium and crude extracts of zinnia cells. (4) The depletion of the TED4 protein from culture medium results in an increase in mortality of other living cells. These results strongly suggest that the secreted TED4 protein acts as an inhibitor of proteasome to protect other cells from undesirable injury due to proteolytic activities exudated from dying TEs.

Acetylcysteine↗
PubMed2001

A possible role of glutathione and glutathione disulfide in tracheary element differentiation in the cultured mesophyll cells of Zinnia elegans.

We investigated the relationship between the cellular redox state of GSH or GSSG and tracheary element (TE) differentiation using a Zinnia experimental system, in which isolated mesophyll cells transdifferentiate to TEs. TE differentiation was suppressed by the application of L-buthionine sulfoximine (BSO), a potent inhibitor of GSH biosynthesis, at the early stage of cell culture. Application of GSSG at the early culture stage promoted the differentiation, but that of GSH or GSSG at an advanced period of culture suppressed the differentiation. Application of GSH and GSSG nullified the TE differentiation-suppressing effect of BSO. The results suggest that changes in the redox states of GSH and GSSG have a role in TE differentiation.

Asteraceae↗
PubMed2001

Primary phloem-specific expression of a Zinnia elegans homeobox gene.

Some plant homeobox genes are expressed specifically in vascular cells and are assumed to function in the differentiation of specific types of vascular cells. However, homeobox genes exhibiting primary phloem-specific expression have not been reported. To elucidate the molecular mechanisms of vascular development, we undertook to isolate from Zinnia elegans primary phloem-specific homeobox genes that may function in phloem development. An HD-Zip type homeobox gene, ZeHB3, was isolated. This gene encodes a class I HD-Zip protein, and constitutes a gene subfamily with the Daucus carota gene CHB6, and Arabidopsis thaliana genes Athb-5, Athb-6, and Athb-16. In situ hybridization of 1-, 14- and 50-day-old plants demonstrated that ZeHB3 mRNA accumulation is restricted to a few cells destined to differentiate into phloem cells and to the immature phloem cells surrounding the sieve elements and companion cells. ZeHB3 protein was also localized to immature phloem cells. These findings clearly indicate that ZeHB3 is a novel homeobox gene that marks, and may function in, the early stages of phloem differentiation.

Amino Acid Sequence↗
PubMed2001

Brassinosteroid levels increase drastically prior to morphogenesis of tracheary elements.

As the first step toward understanding the involvement of endogenous brassinosteroids (BRs) in cytodifferentiation, we analyzed biosynthetic activities of BRs in zinnia (Zinnia elegans L. cv Canary Bird) cells differentiating into tracheary elements. The results of feeding experiments suggested that both the early and late C6-oxidation pathways occur during tracheary element differentiation. Gas chromatography-mass spectrometry analysis revealed that five BRs, castasterone, typhasterol, 6-deoxocastasterone, 6-deoxotyphasterol, and 6-deoxoteasterone, actually existed in cultured zinnia cells and culture medium. Quantification of endogenous BRs in each stage of tracheary element differentiation by gas chromatography-mass spectrometry exhibited that they increased dramatically prior to the morphogenesis, which was consistent with the idea that BRs are necessary for the initiation of the final stage of tracheary element differentiation. Moreover, the proportion of each BR in culture medium was quite different from that in cells, suggesting that specific BRs are selectively secreted into medium and may function outside the cells.

Asteraceae↗
PubMed2000

Isolation of a vascular cell wall-specific monoclonal antibody recognizing a cell polarity by using a phage display subtraction method.

Using a strategy consisting of (i) the isolation of cell walls from synchronously differentiating cells of Zinnia, (ii) the generation of mAbs with an antibody phage display method, and (iii) screening with a subtraction method, we isolated mAbs recognizing vascular development-specific cell wall components without prior antigen identification. One of the isolated mAbs, designated CN 8, recognized a cell wall component contained in the hemicellulosic fraction. Immunohistochemical analyses showed that the CN 8 epitope was localized to the cell wall of immature tracheary elements and xylem parenchyma cells. In immature tracheary elements, the CN 8 epitope had a polarized localization pattern regardless of whether the cells are formed as parts of vessels in situ or as single tracheary elements in vitro, suggesting that cell polarity autonomously formed on the cell wall may function in tracheary element differentiation.

Amino Acid Sequence↗
PubMed2000

The relationship between technical parameters of external beam radiation therapy and complications for localized prostate cancer.

BACKGROUND: This study was performed to review retrospectively the clinical course of chronic rectal bleeding as a complication of external beam radiation therapy for localized prostate cancer and to analyze the relationship between technical parameters of radiation therapy and the complications. METHODS: Seventy-one patients with stages A2, B and C were treated with local-field radiotherapy (total dose 52.5-66 Gy, daily dose 2.0-3.28 Gy, field area 30-81 cm2, number of fields 3-15 ports, planning simulations X-ray or CT-based) between 1989 and 1998 at three institutions. The protocols were consistent during this same period at these institutions. RESULTS: Multivariate analysis revealed pretreatment PSA and Gleason sum to be statistically significant predictors of 5 year prostatic specific antigen (PSA) relapse-free rates in a median follow-up period of 42 months (range 12-119 months). The significant risk factors for higher grading of acute morbidity were a biological equivalent dose, alpha/beta = 10(BED10) > or =65 Gy, dose per fraction > or =3.0 Gy, field area > or =42 cm2, fewer ports and X-ray planning simulation. However, no parameter was associated with higher grading of late morbidity. Eleven patients (15.4%) experienced a late GI complication: grade 1 (4.2%), grade 2 (9.8%), grade 3 (1.4%). The median time to occurrence of rectal bleeding was 12 months after radiotherapy and the mean duration of morbidity was 11 months. CONCLUSIONS: Higher total dose and dose per fraction, larger field area, fewer ports and X-ray simulation increased the grades of acute morbidity. A majority of chronic rectal bleedings were transient and responded to conservative treatment.

Aged↗
PubMed1998

5-fluorouracil and low-dose recombinant interferon-alpha-2a in patients with hormone-refractory adenocarcinoma of the prostate.

BACKGROUND: The effectiveness of a chemotherapy regimen including 5-fluorouracil (5-FU) and recombinant interferon-alpha-2a (rIFN-alpha-2a) was evaluated in hormone-refractory prostate cancer patients. METHODS: Patients received a continuous intravenous infusion of 5-FU at 600 mg/m2/day for 5 days (D1-D5), followed by a bolus injection of 5-FU on D15 and D22. Patients received intramuscular injection of rIFN-alpha-2a at 3 million IU on D1, D3, D5, D15, and D22. This schedule was repeated every 4 weeks. RESULTS: Between 1993 and 1995, 23 patients with hormone refractory prostate cancer were enrolled in this study. Two of five patients with nodal disease exhibited partial responses according to the NPCP criteria. Fourteen of 17 patients with bone disease showed stable disease. Of 21 patients assessible for response, 9 patients had a decrease in the PSA level greater than 50% of baseline. Bone pain disappeared partially or completely in 8 of 14 patients with this symptom at entry. The median overall survival was 18 months. The associate toxicity was well tolerable. CONCLUSIONS: Combination chemotherapy of 5-FU and low dose rIFN-alpha-2a in patients with hormone-refractory prostate cancer proved feasible, and with acceptable toxicity.

Adenocarcinoma↗
PubMed1998

Expression of the Zinnia TED3 promoter in developing tracheary elements of transgenic Arabidopsis.

To determine the regulatory mechanism of gene expression in the early stages of tracheary element (TE) differentiation, we isolated and characterized a genomic fragment of TED3 whose mRNA is expressed preferentially in differentiating TEs 12-24 h before morphological changes in the in vitro Zinnia system. Transgenic Arabidopsis plants with a chimeric gene of the 537 bp TED3 promoter and the beta-glucuronidase (GUS) reporter gene indicated the strong expression of the GUS gene by the TED3 promoter in TEs, in particular in immature TEs as well as stipules and trichomes. GUS expression driven by the promoter was also induced in callus, in which GUS activity was localized in immature TEs and slender cells around TEs that may be TE precursor cells. The TED3 promoter was not significantly activated by wounding. This pattern of expression differed clearly from that of other vascular tissue-related genes such as PAL, 4CL, and GRP1.8. The nature of TED3 promoter enables us to use it to monitor TE differentiation in tissue and to introduce foreign genes preferentially into immature TE.

Amino Acid Sequence↗
PubMed1998

Treatment of metastatic nonseminomatous germ cell tumors of the testis: significance of the international consensus prognostic classification as a prognostic factor-based staging system.

BACKGROUND: We reviewed treatment results in patients with metastatic nonseminomatous germ cell tumors of the testis and examined the significance of the International Consensus Prognostic Classification to make appropriate risk-based decisions concerning induction chemotherapy. METHODS: We divided 37 patients treated with platinum-based combination chemotherapy into good, intermediate, and poor prognostic groups utilizing the International Consensus Prognostic Classification. The data was analyzed for both overall survival and progression-free survival among the 3 prognostic groups. RESULTS: Among the 37 patients, 10 died (8 of progressive disease, 1 of pneumonia during induction chemotherapy and 1 of cyclophosphamide-induced hemorrhagic cardiomyolitis during salvage chemotherapy). The survivors were followed for 6 to 1 84 months from the beginning of induction chemotherapy (median, 80 months). Five of the 37 patients (14%) were classified as having a good prognosis, 1 8 (48%) as intermediate, and 14 (38%) as having a poor prognosis. The patients in the poor prognostic group had a 5-year overall survival of only 40%, while those in the good and intermediate groups had 5-year overall survivals of 100% and 94%, respectively. When we applied the International Consensus Prognostic Classification to patients with advanced disease classified by the Indiana University Staging System, these patients could be clearly divided into good-risk and poor-risk groups. CONCLUSIONS: The International Consensus Prognostic Classification is easily applicable and accurate for risk assessment in patients with metastatic nonseminomatous germ cell tumors of the testis. This classification will now be widely used in general oncology practices and for clinical trials in these patients.

Adolescent↗
PubMed1998

[Application and limitation of neoadjuvant hormonal therapy for prostate cancer].

Of 156 patients, 111 (clinical stage T1a-b; 21, T1c; 17, T2a-b; 36, T2c; 27, T3; 10) immediately underwent radical prostatectomy (surgery group), and 45 (clinical stage T1a-b; 8, T1c; 4, T2a-b; 10, T2c; 9, T3; 14) received neoadjuvant hormonal therapy (NHT group). NHT offered probability of increasing organ-confined cancer(OCC; pathological stage pT2 or lower N0M0) in the following group, which contains (a) patients who had moderately differentiated adenocarcinoma in the biopsy specimen and T2b or lower diseases, and (b) those who had well differentiated adenocarcinoma, T2c diseases and PSA levels of 10 ng/ml or higher, referred to as "OCC suitable criteria". Of 156 patients, 51 (33%) met OCC suitable criteria. In those cases, the proportion of OCC in NHT group was significantly higher than that in surgery group (11/12 (92%) vs. 16/39 (41%), p = 0.002). NHT is useful for increasing OCC in patients who meet OCC suitable criteria.

Adenocarcinoma↗
PubMed1997

Brassinosteroids induce entry into the final stage of tracheary element differentiation in cultured Zinnia cells.

To elucidate the involvement of brassinosteroids in the progression of tracheary element differentiation in cultured Zinnia cells, we analyzed the effects of uniconazole, an inhibitor of brassinosteroid synthesis, and brassinolide, a biologically active brassinosteroid, on the accumulation of mRNAs for various genes that were expressed in different stages of differentiation. Uniconazole specifically suppressed the accumulation of transcripts for genes that were induced in the final stage of differentiation in association with secondary wall formation and cell death. This suppression was recovered with the addition of brassinolide. These results strongly suggest that endogenous brassinosteroids induce entry into the final stage of differentiation.

Brassinosteroids↗