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Biomedical subjects

S Mizuno

Publications and source records attributed to S Mizuno.

At least 19 recordsLinked to original sources
PubMed1995

The cDNA cloning and transient expression of a chicken gene encoding a 3 beta-hydroxysteroid dehydrogenase/delta 5-->4 isomerase unique to major steroidogenic tissues.

Two cDNA clones, on containing a 2.7-kb and the other a 1.6-kb insert, were obtained from a chicken adrenal gland cDNA library by screening with a partial chicken cDNA fragment generated by PCR. Primers were used that corresponded to conserved regions among several published cDNA sequences of mammalian 3 beta-hydroxysteroid dehydrogenase/delta 5-->4 isomerase (3 beta-HSD). Both clones contained the same open reading frame (ORF) encoding 377 amino acids (aa). The difference in their sizes was due to the use of different polyadenylation sites. The deduced aa sequence showed 54-57% overall identity with those of the human, macaque, bovine, mouse, rat and rainbow trout 3 beta-HSD. A 9-aa stretch (FYYISDDTP) is conserved among the chicken, mammalian and rainbow trout 3 beta-HSD, suggesting that it is essential for enzymatic activity. Northern blot hybridization demonstrated the presence of two types of mRNA, corresponding to the above two cDNA classes, in the adrenal gland, ovary and testis. Transient expression of the chicken ORF in COS-7 cells demonstrated coupled dehydrogenase and isomerase activities of 3 beta-HSD on three different substrates; pregnenolone, 17 alpha-hydroxypregnenolone and dehydroepiandrosterone. Among the Km values determined for the three substrates, that for dehydroepiandrosterone was the lowest, which was different from the case for human 3 beta-HSD.

3-Hydroxysteroid Dehydrogenases↗
PubMed1995

Production of a chimeric fibroin light-chain polypeptide in a fibroin secretion-deficient naked pupa mutant of the silkworm Bombyx mori.

The allelic Nd-s and Nd-sD mutations of the silkworm Bombyx mori are mapped to the same locus as that of the fibroin light (L)-chain gene (Fib-L). The silkworm carrying the homozygous Nd-s or Nd-sD mutation secretes less than 0.3% of the normal level of fibroin and produces a thin cocoon (naked pupa). In this study, cDNA sequences of the Nd-s and Nd-sD L-chains were compared with the cDNA and genomic sequences of the L-chain of the B. mori J-139 strain, a normal-level producer of fibroin. The two mutant cDNA sequences are almost identical except for one base change in the coding region. The N-terminal half of the L-chain encoded by exons I to III is identical between the mutants and J-139, but the rest of the molecule is completely different. The C-terminal half of the Nd-sD mutant L-chain is encoded by two exons, IV' and V', which are brought into proximity with the exon III by recombination between sequences in the third intron and in the far downstream region with concomitant loss of a region containing exons IV to VII. Sequences corresponding to exons IV' and V' are present about 10 kb downstream of the L-chain gene in the J-139 genome. Their homologous sequences have not been found in the DNA and protein databases. The chimeric L-chain molecule of about 27 kDa is present in posterior silk glands of Nd-s and Nd-sD strains without disulfide-bonding to the fibroin heavy (H-) chain, as revealed by Western blotting with the antibody specific to the C-terminal half of the mutant L-chain.

Amino Acid Sequence↗
PubMed1995

Functional expression of Fas antigen (CD95) on hematopoietic progenitor cells.

We investigated the expression of an apoptosis-associated antigen (Fas) (CD95) on hematopoietic progenitor cells in the presence or absence of interferon-gamma (IFN-gamma) and/or tumor necrosis factor-alpha (TNF-alpha). CD34+ cells freshly isolated from bone marrow did not express Fas. However, IFN-gamma and/or TNF-alpha induced the expression of both the mRNA of Fas and Fas itself in a dose-dependent fashion on the surface of CD34+ cells after 48 hours of serum-free culture. IFN-gamma and TNF-alpha had a synergistic effect on the induction of Fas, when both cytokines were added to the culture. The TNF-alpha-induced Fas expression is mediated by p55 TNF-alpha receptor. CD34+ cells cultured in medium alone or with stem cell factor (SCF) showed some slight expression of Fas. When anti-Fas antibody (IgM) was added to CD34+ cells after the induction of Fas expression, CD34+ cells underwent apoptosis, as shown by a decrease in the number of viable cells, morphologic changes, the induction of DNA fragmentation, and a decrease in the number of colony-forming cells (CFC) including colony-forming unit granulocytes/macrophages (CFU-GM) and burst-forming unit erythroids (BFU-E). These observations indicate that IFN-gamma and/or TNF-alpha, well known as negative hematopoietic regulators, induce functional Fas on hematopoietic progenitor cells. The suppression of hematopoiesis by negative hematopoietic regulators may be mediated in part by Fas induction.

Antigens, Surface↗
PubMed1995

Flow cytometric analysis of nuclear DNA content in oral leukoplakia: relation to clinicopathologic findings.

DNA ploidy of 50 biopsy specimens of oral leukoplakia was investigated by flow cytometry, and the results were compared with the clinicopathologic appearances. The aneuploidy rate of the leukoplakias was 17/50 (34%), and the mean DNA index (DI) of the aneuploid lesions was 1.22, with a range from 0.70 to 1.84. The incidence of the aneuploidy was significantly (P < 0.01) higher in nonhomogeneous leukoplakias (11/18) than in homogeneous lesions (6/32). The aneuploidy rate of the severely dysplastic leukoplakias (11/17) was significantly higher than those of the mildly dysplastic (4/22; P < 0.01) and the nondysplastic (2/11; P < 0.02) lesions. A significant (P < 0.01) difference in the aneuploidy rate was also observed between tongue (12/23) and gingival (2/18) leukoplakias.

Aneuploidy↗
PubMed1995

A pharmacokinetic and pharmacodynamic analysis of CPT-11 and its active metabolite SN-38.

In the present study, an attempt was made to determine the precise pharmacokinetics of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) and its active metabolite, 7-ethyl-10-hydroxycamptothecin (SN-38). The relationship between pharmacokinetic parameters and pharmacodynamic effects was also investigated to elucidate the cause of interpatient variation in side effects. Thirty-six patients entered the study. CPT-11, 100 mg/m2, was administered by IV infusion over 90 min weekly for four consecutive weeks. The major dose-limiting toxicities were leukopenia and diarrhea. There was a positive correlation between the area under the concentration-time curve (AUC) of CPT-11 and percent decrease of WBC (r = 0.559). On the other hand, episodes of diarrhea had a better correlation with the AUC of SN-38 (r = 0.606) than that of CPT-11 (r = 0.408). Multivariate analysis revealed that the AUC of SN-38, AUC of CPT-11 and indocyanine green retention test were significant variables for the incidence of diarrhea and that both performance status and AUC of CPT-11 were significant variables for percent decrease of WBC. The large interpatient variability of the degree of leukopenia and diarrhea is due to a great plasma pharmacokinetic variation in CPT-11 or SN-38. The AUCs of CPT-11 and SN-38 obtained from the first administration of CPT-11 correlate with toxicities, but it is impossible to predict severe side effects before the administration of CPT-11 at the present time.

Adult↗
PubMed1995

A limited sampling model for estimating pharmacokinetics of CPT-11 and its metabolite SN-38.

The objective of this study was to develop a limited sampling model (LSM) to estimate the area under the curve (AUC) of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) and that of 7-ethyl-10-hydroxycamptothecin (SN-38) as predictive pharmacokinetic variables for leukopenia and episodes of diarrhea induced by CPT-11 administration. The model was developed with a training set consisting of pharmacokinetic studies in 36 patients who received a 90-min i.v. infusion of CPT-11 at a dose of 100 mg/m2. A multiple regression analysis of CPT-11 or SN-38 concentrations observed at each time point in the training set was used to predict the AUC of CPT-11 or SN-38. The final sampling models using only two time points were: AUCCPT-11 = 3.7891*C2.5 + 14.0479*C13.5 + 1.5463 AUCSN-38 = 0.5319*C2.5 + 19.1468*C13.5 + 72.7349 where C2.5 and C13.5 are the plasma concentration of CPT-11 (micrograms/ml) or SN-38 (ng/ml) at 2.5 and 13.5 h after the initiation of CPT-11 infusion, respectively. The models were validated prospectively on a separate test data set of 12 patients receiving the same dose of CPT-11 investigated in a previous study. Validation of the final LSM on the test data set gave values of root mean square error (RMSE) of 12.72% and 5.97% for the AUC of CPT-11 and that of SN-38, respectively. The model can be used to monitor the AUCs of both CPT-11 and SN-38 for the early prediction of toxicities and to establish a pharmacokinetically based dose modification strategy for safe administration of CPT-11.

Adult↗
PubMed1995

Quantitative analysis of AML1/ETO transcripts in peripheral blood stem cell harvests from patients with t(8;21) acute myelogenous leukaemia.

Peripheral blood stem cells (PBSC) have been used increasingly for haemopoietic reconstitution after marrow-ablative chemotherapy in patients with acute leukaemia because of the possibility that there is a lower risk of leukaemic contamination. We have developed a titration assay using a competitive reverse transcriptase polymerase chain reaction (RT-PCR) which is able to estimate the number of AML1/ETO transcripts so that minimal residual disease (MRD) can be monitored quantitatively in patients with t(8;21) acute myelogenous leukaemia (AML). Using a qualitative RT-PCR method, AML1/ETO transcripts could be detected in all samples from 15 first PBSC harvests and 11 second PBSC harvests obtained from 15 patients with t(8;21) AML. With our competitive RT-PCR assay, the number of AML1/ETO transcripts was found to be lower in the second PBSC harvest than that in the first in every individual. Furthermore, MRD in PBSC harvests was less than that in the corresponding bone marrow obtained on the day of PBSC collection in the individual patients studied. In 10 patients who received autologous blood stem cell transplantation (ABSCT), we could not find a relationship between the number of AML1/ETO transcripts in the infused PBSC harvests and the clinical outcome after ABSCT. The present study clearly indicates that although PBSC harvests collected after consolidation chemotherapy are contaminated by leukaemic cells, the degree of leukaemic contamination may decrease as chemotherapy is repeated. The mobilization of PBSC by repeated chemotherapy may provide an advantageous source of haemopoietic stem cells for ABSCT.

Adolescent↗
PubMed1995

Characterization of blasts from a patient with eosinophilic blast crisis of chronic myelogenous leukaemia.

We investigated the biological characteristics of 'eosinophilic' leukaemic blasts from a patient with eosinophilic blast crisis of chronic myelogenous leukaemia (CML). Southern blot analysis of the bcr gene demonstrated the identical single rearranged band in both the leukaemic blasts and mature eosinophils. IL-3, IL-5 and GM-CSF significantly enhanced proliferation and differentiation of these leukaemic blasts, and only eosinophils were generated from in vitro cultures. Those eosinophils expressed the B3A2 chimaeric messenger RNA seen in the leukaemic blasts. These observations indicate that eosinophil progenitors may be involved in the development of eosinophilic blast crisis of CML and that IL-3, IL-5 and GM-CSF act on the leukaemic eosinophil progenitors.

Blast Crisis↗
PubMed1995

[Good response to ganciclovir in a patient of cytomegalovirus (CMV) interstitial pneumonitis and gastric ulcer following allogeneic bone marrow transplantation for acute lymphoblastic leukemia].

This 35-year-old housewife was initially treated with vincristine, prednisolone and L-asparaginase for acute lymphoblastic leukemia (ALL, L1 by FAB classification) in 1988 and entered into complete remission. Ten months later she underwent bone marrow transplantation (BMT) from her HLA-identical and MLC-negative sister. The conditioning regimens consisted of busulfan 4 mg/kg/day for 4 days orally and cyclophosphamide 60 mg/kg/day for 2 days intravenously followed by cyclosporine and prednisolone for graft-versus-host disease prophylaxis. Fifty days after BMT, she suffered interstitial pneumonitis and a gastric ulcer, and was treated with a high dose of methylprednisolone and cimetidine. She experienced transient improvement, but soon cough, dyspnea and epigastralgia became worse. The specimens obtained by transbronchial alveolar lavage (BAL) and endoscopic gastric biopsy showed many giant cells containing inclusion bodies which were identified as cytomegalovirus (CMV). This time ganciclovir was started in addition to prednisolone. Then she gradually improved and after repeated BAL and the gastric biopsy after treatment showed no inclusion body in the specimen. Although leukocytopenia was significant for this patient, ganciclovir is considered to be useful for controlling CMV infection in both the lungs and stomach.

Adult↗
PubMed1995

[Clinical use of EVAR and OVAR by the dumped rotation test--comparison of normal volunteers and patients with unilateral vestibular nerve section].

Horizontal eye movements in response to either earth vertical axis rotation (EVAR) or off vertical axis rotation (OVAR) by a 10 degree tilted axis were recorded in six normal subjects and three patients with unilateral vestibular nerve section. Both trials consisted of acceleration at approximately 400 deg/sec2 until an angular velocity of 180 deg/sec was reached followed by deceleration at -4 deg/sec2 until rotation ceased. This is the so-called dumped rotation procedure. Total numbers of nystagmic beats and the duration of perrotatory nystagmus in these two different trials were compared. The results were as follows: 1) Total numbers of nystagmic beats in OVAR were significantly larger than in EVAR. 2) The duration of perrotatory nystagmus in OVAR was significantly longer than in EVAR. Only the horizontal semicircular canals were stimulated by angular acceleration in EVAR, whereas both otolith organs and semicircular canals were stimulated on changing the position of the head around the direction of the gravity in OVAR.

Acceleration↗
PubMed1995

[Primary intracranial malignant epidermoid--case report].

Intracranial malignant epidermoid is uncommon. We report a case of a 74-year-old woman with a primary intracranial malignant epidermoid in the parapontine region. The tumor was visualized as two components (a low-density benign prepontine lesion and a malignant enhanced cerebellopontine angle lesion) on CT scan. On MRI, the benign portion demonstrated low-signal intensity on T1 weighted images and markedly increased heterogeneous signal intensity on T2 weighted images, while the malignant portion showed iso-signal intensity on T1 weighted images that was markedly enhanced and heterogeneous signal intensity on T2 weighted images. Lack of contrast enhancement is a typical finding in benign epidermoid, although rim enhancement has been described in a few cases. In our patient, the contrast enhancement on CT scan in the otherwise typical epidermoid cyst suggested malignant degeneration. Using MR imaging, we could distinguish malignant epidermoid from benign epidermoid cyst more precisely.

Aged↗
PubMed1995

Reevaluation of prognostic factors in gastric leiomyosarcoma.

OBJECTIVES: The aim of our study was to reevaluate the prognostic factors in gastric leiomyosarcomas, particularly those under 6 cm, which, because of improved diagnostic techniques, make up a large proportion of this series, in contrast to previously published works. METHODS: The clinicopathological features in 83 patients with gastric leiomyosarcoma were reviewed. Cox's proportional hazards regression analysis was used to determine the prognostic factors. RESULTS: Sixty of 84 leiomyosarcomas (71.4%) were less than 6 cm in diameter. In univariate analysis, the following factors were considered to be unfavorable, with statistical significances: 1) presence of distant metastasis and/or direct invasion of adjacent structures at diagnosis (hazard ratio 36.60), 2) > or = 4 mitoses per 20 high-power fields (25.39), 3) severe nuclear atypia (16.74); 4) presence of ulceration of overlying gastric mucosa (12.57), and 5) diameter > or = 6 cm (5.57). Among these factors, mucosal ulceration has been identified as a new factor associated with poor prognosis. Histologically, the tumors with ulceration showed more severe nuclear atypia (p < 0.05), necrosis (p < 0.01), and a higher incidence of mitosis (p < 0.01), compared with tumors without ulceration. In multivariate analysis, factors 1, 2, and 3 were statistically significant, although neither size nor ulceration was significant. CONCLUSIONS: The presence of distant metastasis and/or direct invasion, high mitotic rate, and severe nuclear atypia were confirmed to be unfavorable prognostic indicators. Mucosal ulceration, indicating high proliferative activity of the tumor, even if small, suggests a poor prognosis, although it was not significant in multivariate analysis.

Combined Modality Therapy↗
PubMed1995

[The progress of autologous peripheral blood stem cell transplantation].

It has recently become known that sufficient numbers of multi-potent stem cells transiently appear in the peripheral blood at the time of recovery from myelosuppression after chemotherapy for collection for later transfusion (autologous peripheral blood stem cell transplantation; ABSCT). It is also known that cytokines such as G-CSF or GM-CSF enhance the mobilization of stem cells in peripheral blood. It is, therefore, easy to collect a large number of progenitor cells using the apheresis technique. We have also succeeded in developing an easy preservation method using DMSO-HES-ALBUMIN as a cryoprotective agent for simple storage in a -80 degrees C refrigerator. Furthermore, the development of measurement of CD34 positive cells become easy to estimate the contents of progenitor cells in harvested peripheral mononuclear cells. These techniques contribute to the safe and reliable practice of ABSCT. There are high expectations for ABSCT as a new technique in the cure of patients with such diseases as hematological malignancy and chemotherapy sensitive solid tumor, as it makes possible the administration of super-high dose anti-cancer drugs which cause marrow ablation.

Hematopoietic Stem Cell Transplantation↗
PubMed1995

Low incidence of acute GVHD in patients transplanted with marrow from HLA-A,B,DR-compatible unrelated donors among Japanese.

To prevent GVHD in BMT from unrelated donors, the matching of HLA between patient and donor is crucial. The appearance of acute GVHD was studied in 51 patients with hematological malignancies who were transplanted with non-T cell purged marrow from HLA-A,B and DR compatible unrelated donors with the assistance of the Tokai Marrow Donor Bank of Nagoya, Japan. Probability of grade II-IV acute GVHD was 32.0% and of grade III-IV acute GVHD was 17.0%. HLA-class II antigen compatibility showed a good correlation with the occurrence of acute GVHD. When the percentage relative response (RR) of MLC between patient and donor (GVHD vector) was < or = 5, grade II-IV acute GVHD was found in only 7.7% of patients (n = 16) and no severe grade III-IV GVHD occurred. Among patients with 6-10% RR (n = 10), 25.9% showed grade II-IV GVHD and 14.3% grade III-IV GVHD. Among patients with > or = 11% RR (n = 20), however, the incidence of grade II-IV acute GVHD reached 51.8% and that of grade III-IV acute GVHD 36.2%. These reactivities of MLC reflected the compatibility of HLA-DRB1 and DPB1. The fact that the incidence of acute GVHD in BMTs from HLA-A,B,DR compatible Japanese pairs was found to be lower than in the USA may be due to less diversity of the genetic background in Japan.

Adolescent↗
PubMed1994

Conversion of epidermal growth factor (EGF) into a stimulatory ligand for A431-cell growth by herbimycin A by decreasing the level of expression of EGF receptor.

We examined effect of the tyrosine kinase inhibitor herbimycin A on A431 human epidermoid carcinoma cells which over-express epidermal growth factor (EGF) receptor. Herbimycin A inhibited the autophosphorylation of EGF-stimulated receptors in intact cells both time- and dose-dependently. The inhibition was found to be due to a decrease in the level of expression of the receptor amount, because herbimycin A equally decreased the receptor quantity and EGF-stimulated receptor kinase activity in intact cells, but did not exhibit a direct inhibitory effect on EGF receptor kinase activity in vitro. The decrease of the level of EGF receptor was also confirmed by 125I-EGF binding to herbimycin A-treated cells, and Scatchard analysis showed that the decrease in the receptor number occurred in the major population of the low-affinity binding ones, whereas the number with high-affinity binding was unaffected. Interestingly, although the proliferation of A431 cells was inhibited by EGF, herbimycin A converted EGF into a stimulatory ligand for cell growth, as determined by both cell number and DNA synthesis. These findings indicated that herbimycin A decreased the level of expression of EGF receptor by a mechanism other than inactivation of the receptor kinase and reversed the transformed phenotype of A431 cells to a normal one in the proliferative response to EGF.

Benzoquinones↗
PubMed1994

Accelerated degradation of 160 kDa epidermal growth factor (EGF) receptor precursor by the tyrosine kinase inhibitor herbimycin A in the endoplasmic reticulum of A431 human epidermoid carcinoma cells.

The effect of herbimycin A on the biosynthesis of epidermal growth factor (EGF) receptor was examined in human epidermoid carcinoma A431 cells. Cells were pulse-labelled with [35S]methionine, and EGF receptor biosynthesis was quantified by immunoprecipitation using a monoclonal anti-(EGF receptor) antibody. In the presence of herbimycin A, an immature 160 kDa EGF receptor precursor accumulated in 1 h and disappeared completely in 4 h. Pulse-labelled 160 kDa receptor precursor in the absence of herbimycin A, however, was converted normally into a 170 kDa one by chase with herbimycin A. Herbimycin A affected neither the synthesis of the secreted form of EGF receptor devoid of cytoplasmic domain, nor that of the transferrin receptor in A431 cells. The herbimycin A-induced degradation of 160 kDa EGF receptor precursor was not inhibited by an inhibitor of lysosomal enzymes, NH4Cl. Endoglycosidase H digestion of the 160 kDa precursor converted it into the deglycosylated 130 kDa precursor peptide. These results suggested that herbimycin A selectively acted on the EGF receptor precursor during the synthesis of the 160 kDa form, probably on the cytoplasmic domain, to form an aberrant molecule which was subjected to rapid degradation in the endoplasmic reticulum.

Benzoquinones↗
PubMed1994

Molecular genetics for clinical management of colorectal carcinoma. 17p, 18q, and 22q loss of heterozygosity and decreased DCC expression are correlated with the metastatic potential.

BACKGROUND: The molecular genetic changes associated with colorectal carcinoma are among the best understood of any common human cancer. The genetic changes during the late stages of colorectal carcinomas may be useful in clinical management for determining the metastatic potential of the carcinoma. METHODS: Tumor tissues were evaluated by restriction fragment length polymorphism (RFLP) analysis of chromosomes 5q, 17p, 18q, and 22q (n = 98), by reverse transcription-polymerase chain reaction (RT-PCR) analysis of messenger RNA expression of the DCC gene (deleted in colorectal carcinoma) (n = 27) and by immunohistochemical analysis of p53 protein expression (n = 44). RESULTS: Loss of heterozygosity (LOH) on chromosomes 17p, 18q, and 22q, but not on 5q, was much more frequently detected in advanced carcinomas than in intramucosal carcinomas (P < 0.01). 17p LOH was significantly correlated with vascular invasion (P < 0.001), whereas 18q LOH was correlated with lymphatic invasion and hepatic metastasis (P < 0.01), and 22q LOH was correlated with lymph node metastasis (P < 0.05). LOH on 5q did not show a significant correlation with any factors of tumor invasion or metastasis. DCC expression was not observed in any of five hepatic metastasis or in five of seven advanced carcinomas that were accompanied by hepatic metastasis (10 of 12). However, a similar lack of expression was observed in only 5 of 15 carcinomas without hepatic metastasis (P < 0.05). p53 Expression was found to vary in both primary and metastatic carcinomas by immunohistochemistry. CONCLUSIONS: The clinical application of molecular genetics (i.e., RFLP analysis of chromosome 17p, 18q, and 22q and RT-PCR analysis of DCC expression into messenger RNA) can be used to determine the metastatic potential of colorectal carcinomas.

Adult↗