Biomedical subjects

J Takeuchi

Publications and source records attributed to J Takeuchi.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Development of Sweet's syndrome during all-trans retinoic acid therapy for acute promyelocytic leukemia].

A 54-year-old woman visited our hospital because of gingival bleeding on May 31, 1998. After hematological and bone marrow examinations, she was diagnosed as having acute promyelocytic leukemia (APL) and given all-trans retinoic acid (ATRA) therapy starting on June 1. Anti-cancer drugs were administered for 5 days from June 12 because of an increase in the number of APL cells. The patient developed fever on June 20, and nodular erythematous eruptions appeared on June 23. Sweet's syndrome was diagnosed from biopsy samples of the eruption. ATRA was therefore discontinued, and prednisolone was started on June 29. The fever and skin eruptions improved rapidly, and complete remission was obtained on July 13. Sweet's syndrome due to ATRA may be a partial form of retinoic acid syndrome, in which the differentiated leukemic neutrophils increase and invade various organs. However, Sweet's syndrome must be considered regardless of the WBC count because in this case the syndrome occurred even when the WBC count was not high.

Female↗

PubMed1999

Distinct roles of thioredoxin in the cytoplasm and in the nucleus. A two-step mechanism of redox regulation of transcription factor NF-kappaB.

Oxidative stresses such as UV irradiation to mammalian cells triggers a variety of oxistress responses including activation of transcription factors. Recently, activation of nuclear factor-kappaB (NF-kappaB) has been shown to be under oxidoreduction (redox) regulation controlled by thioredoxin (TRX), which is one of major endogenous redox-regulating molecules with thiol reducing activity. In order to elucidate where in the cellular compartment TRX participates in NF-kappaB regulation, we investigated the intracellular localization of TRX. UVB irradiation induced translocation of TRX from the cytoplasm into the nucleus. In our in vitro diamide-induced cross-linking study, we showed that TRX can associate directly with NF-kappaB p50. Overexpression of wild-type TRX suppressed induction of luciferase activity under NF-kappaB-binding sites in response to UV irradiation compared with the mock transfectant. In contrast, overexpression of nuclear-targeted TRX enhanced the luciferase activity. Thus, TRX seems to play dual and opposing roles in the regulation of NF-kappaB. In the cytoplasm, it interferes with the signals to IkappaB kinases and blocks the degradation of IkappaB. In the nucleus, however, TRX enhances NF-kappaB transcriptional activities by enhancing its ability to bind DNA. This two-step TRX-dependent regulation of the NF-kappaB complex may be a novel activation mechanism of redox-sensitive transcription factors.

Cell Line, Transformed↗

PubMed1999

Genetic evidence for interaction between components of the yeast 26S proteasome: combination of a mutation in RPN12 (a lid component gene) with mutations in RPT1 (an ATPase gene) causes synthetic lethality.

The 19S regulatory particle of the yeast 26S proteasome consists of six related ATPases (Rpt proteins) and at least 11 non-ATPase proteins (Rpn proteins). RPN12 (formerly NIN1) encodes an Rpn component of the 19S regulatory particle and is essential for growth. To determine which subunit(s) of the 26S proteasome interact(s) with Rpn12, we attempted to screen for mutations that cause synthetic lethality in the presence of the rpn12-1 (formerly nin1-1) mutation. Among the candidates recovered was a new allele of RPT1 (formerly CIM5). This mutant allele was designated rpt1-2; on its own this mutation caused no phenotypic change, whereas the rpn12-1 rpt1-2 double mutant was lethal, suggesting a strong interaction between Rpn12 and Rpt1. The site of the rpt1-2 mutation was determined by DNA sequencing of the RPT1 locus retrieved from the mutant, and a single nucleotide alteration was found. This changes amino acid 446 of the RPT1 product from alanine to valine. The alanine residue is conserved in all Rpt proteins, except Rpt5, but no function has yet been assigned to the region that contains it. We propose that this region is necessary for Rpt1 to interact with Rpn12. The terminal phenotype of the rpn12-1 rpt1-2 double mutant was not cell cycle specific, suggesting that in the double mutant cells the function of the 26S proteasome is completely eliminated, thereby inducing multiple defects in cellular functions.

Adenosine Triphosphatases↗

PubMed1999

Efficient targeting of gene expression in chick embryos by microelectroporation.

During vertebrate embryonic development, a key to unraveling specific functions of gene products is the capability to manipulate expression of the gene of interest at the desired time and place. For this, we developed a 'microelectroporation' technique by which DNA can be locally introduced into a targeted site of avian embryos, restricting spatial expression of the protein products during development. This technique involved injection of DNA solution in ovo around the target tissue and pinpoint application of an electric field by tungsten electrodes, allowing efficient and reproducible targeted gene transfer, for example, into an optic vesicle, somites, cranial mesoderm and limb mesenchyme. Because of the locality of gene introduction and its expression, survival rates of the embryos were high: approximately 90% of the embryos injected in optic vesicles were alive for at least 1 day after microelectroporation. The instantaneous gene transfer into embryonic cells allowed rapid expression of protein products such as green fluorescence protein within 2.5 h with fluorescence maintained for 3 days of incubation. This improved technique provides a convenient and efficient way to express transgenes in a spatially and temporally restricted manner in chicken embryos.

Animals↗

PubMed1999

Rpn9 is required for efficient assembly of the yeast 26S proteasome.

We have isolated the RPN9 gene by two-hybrid screening with, as bait, RPN10 (formerly SUN1), which encodes a multiubiquitin chain receptor residing in the regulatory particle of the 26S proteasome. Rpn9 is a nonessential subunit of the regulatory particle of the 26S proteasome, but the deletion of this gene results in temperature-sensitive growth. At the restrictive temperature, the Deltarpn9 strain accumulated multiubiquitinated proteins, indicating that the RPN9 function is needed for the 26S proteasome activity at a higher temperature. We analyzed the proteasome fractions separated by glycerol density gradient centrifugation by native polyacrylamide gel electrophoresis and found that a smaller amount of the 26S proteasome was produced in the Deltarpn9 cells and that the 26S proteasome was shifted to lighter fractions than expected. The incomplete proteasome complexes were found to accumulate in the Deltarpn9 cells. Furthermore, Rpn10 was not detected in the fractions containing proteasomes of the Deltarpn9 cells. These results indicate that Rpn9 is needed for incorporating Rpn10 into the 26S proteasome and that Rpn9 participates in the assembly and/or stability of the 26S proteasome.

Adenosine Triphosphate↗

PubMed1999

Lipid microsphere preparation of a lipophilic ceramide derivative suppresses colony formation in a murine experimental pulmonary metastasis model.

Ceramide is a well-known regulator of apoptosis and cell growth. In this study, we synthesized lipophilic ceramide derivatives to incorporate into lipid microspheres (LM) and their activity was evaluated in vivo. Cera 03, a lipophilic ceramide derivative synthesized from membrane-permeable C2-ceramide, caused potent growth inhibition and DNA fragmentation of Meth A-T tumor cells in vitro. Its potency was similar to that of C2-ceramide. Both compounds increased the proportion of apoptotic cells. Cera 02, the diacetylated form of natural ceramide (Cer), also suppressed in vitro cell growth with a similar or higher potency to that of Cer, but both were far less potent than C2-ceramide and Cera 03. LM containing Cera 03 (Lipo-Cera 03) could not totally prevent metastatic incidence of Meth A-T cells, but reduced pulmonary metastatic nodules in number. Intravenous injection of Lipo-Cera 03 (1 mg/kg of Cera 03) produced about 35% inhibition, while Lipo-Cera 02 had no significant effect. In conclusion, Lipo-Cera 03 may have potential as an antimetastatic drug and may also be a useful tool for researching the role of ceramides in vivo.

Animals↗

PubMed1999

[Clinical effects of combination therapy with cefozopran and tobramycin for severe infections in patients with hematologic diseases].

We studied clinical effect of a combination therapy with cefozopran (CZOP) and tobramycin (TOB) for infections in 80 patients with hematologic diseases in 15 institutes. Combined doses with CZOP 2 g and TOB 60-90 mg twice a day had been given intravenously. Of the 80 patients, 61 patients (42 with acute leukemia, 10 with malignant lymphoma, 3 with aplastic anemia, 2 with chronic myeloid leukemia, 2 with multiple myeloma, and 2 with myelodysplastic syndrome) were evaluable. Those consisted of 6 patients with septicemia, 49 with suspected septicemia, 3 with pneumonia, and 3 with other infections. Clinical efficacy by the treatment was excellent in 24, good in 17, fair in 9, and poor in 11 patients, and the overall efficacy rate including excellent and good was 67.2%. Microbiologically, 5 of the 6 patients with septicemia (1 coagulase negative Staphylococcus, 2 S. pneumoniae, 1 S. oralis, and 1 E. coli) were responded. The efficacy rate in patients with severe granulocytopenia showing 100/microliter or lesser neutrophil counts during the drug administration was 57.1% (12/21). Side effects and abnormal changes of clinical laboratory findings were observed in 5 patients, and 16 patients, respectively, but most of them were mild. The findings above suggested that the combination therapy with CZOP and TOB is useful as an empiric therapy for severe infections in patients with hematologic diseases.

Adult↗

PubMed1998

cDNA cloning and functional analysis of p28 (Nas6p) and p40.5 (Nas7p), two novel regulatory subunits of the 26S proteasome.

We employed cDNA cloning to deduce the complete primary structures of p28 and p40.5, two novel subunits of PA700 (also called 19S complex), a 700 kDa multisubunit regulatory complex of the human 26S proteasome. These polypeptides consisted of 226 and 376 amino acids with calculated molecular masses of 24428 Da and 42945 Da, and isoelectric points of 5. 68 and 5.46, respectively. Intriguingly, p28 contained five conserved motifs known as 'ankyrin repeats', implying that this subunit may contribute to interaction of the 26S proteasome with other protein(s). Computer-assisted homology analysis revealed high sequence similarities of p28 and p40.5 with yeast proteins, termed Nas6p and Nas7p (non-ATPase subunits 6 and 7), respectively, whose functions are as yet unknown. Disruption of these yeast genes, NAS6 and NAS7, had no effect on cell viability, indicating that neither of the two subunits is essential for proliferation of yeast cells. However, the NAS7, but not NAS6, disruptant cells caused high sensitivity to heat stress, being unable to proliferate at 37 degreesC.

Adenosine Triphosphatases↗

PubMed1998

Selective detection of biexponential relaxation in isotropic solutions by mixed coherence filtering NMR.

This is a trial to simplize sequences to get the relaxation function f31(t), which is usually detected by the double- or triple-quantum filtered (DQF or TQF) NMR in an isotropic phase. The results indicate that only two phase cycling is needed to get the f31(t) function, which shows the advantage of S/N (signal-to-noise ratio) in a minimum acquisition time. The filtering of coherence levels in the creation time need not be limited to double- or triple-quantum coherences. An 87Rb signal from a 4% (w/w) agar powder in 500-mM RbCl solution is recorded at 130.9 MHz as a Larmor frequency using a Bruker MSL 400 spectrometer.

Chlorides↗

PubMed1998

Examination of DNA-binding activity of neuronal transcription factors by electrophoretical mobility shift assay.

Electrophoretical mobility shift assay (EMSA) is a simple, rapid, and highly sensitive technique for detection of single- or double-stranded DNA-binding proteins such as transcription factors in crude nuclear extracts (F.M. Ausubel, R. Brent, R.E. Kingston, D. D. Moore, J.G. Seidman, J.A. Smith, K. Struhl (Eds.), Current Protocols in Molecular Biology, Greene Publishing Associates and Wiley-Interscience, 1989, pp. 12.0.1-12.2.10 [1]; J. Carey, Gel Retardation. Methods Enzymol., 208 (1991) 103-117 [2]). By using this technique, it is possible to quantify the abundance, relative affinity and binding specificity of DNA-binding proteins. Since proteins which bind specifically to radiolabeled DNA probes retard the mobility of the probe during electrophoresis (it also called gel retardation assay), discrete bands correspond to the individual DNA-protein complexes. Furthermore, EMSA allows one to determine which member(s) of a certain protein family are included in the DNA-protein complex by means of specific antibodies raised against the DNA-binding protein (supershift assay).

Animals↗

PubMed1998

Purification and characterization of a galactose-rich basic glycoprotein in tobacco.

We found a galactose-rich basic glycoprotein (GBGP) in the cell walls of cultured tobacco (Nicotiana tabacum) cells. GBGP and extensin were isolated as the major components of basic, salt-extracted cell wall glycoproteins. GBGP and extensin were separated by gel filtration in 6 M guanidine hydrochloride as 49- and 90-kD peaks, respectively, and further purified with reverse-phase chromatography. The protein moiety of GBGP constitutes about one-half of the molecule (W/W) and contains lysine (16%), proline (12%), hydroxyproline (10%), tyrosine (4%), alanine (7%), leucine (6%), and cystine (1.4%). Galactose accounted for 72% of the sugar moiety, arabinose content was low (17%), and a significant amount of mannose (7%) was found. No immunological cross-reaction was detected between GBGP and extensin. The antibody against native GBGP with sugar chains reacted with other glycoproteins on the gel blots, whereas the antibodies against deglycosylated GBGP and native extensin were highly specific. Immunolocalization analysis in tobacco stems showed that GBGP is specific to parenchyma tissue and that extensin localizes in the epidermis. This tissue-specific and exclusive distribution suggests important functions of these basic glycoproteins.

Amino Acid Sequence↗

PubMed1998

Correlation of wing-leg identity in ectopic FGF-induced chimeric limbs with the differential expression of chick Tbx5 and Tbx4.

It has been reported that members of the fibroblast growth factor (FGF) family can induce additional limb formation in the flank of chick embryos. The phenotype of the ectopic limb depends on the somite level at which it forms: limbs in the anterior flank resemble wings, whereas those in the posterior flank resemble legs. Ectopic limbs located in the mid-flank appear chimeric, possessing characteristics of both wings and legs; feather buds are present in the anterior halves with scales and claws in the posterior halves. To study the mechanisms underlying the chimerism of these additional limbs, we cloned chick Tbx5 and Tbx4 to use as forelimb and hindlimb markers and examined their expression patterns in FGF-induced limb buds. We found that Tbx5 and Tbx4 were differentially expressed in the anterior and posterior halves of additional limb buds in the mid-flank, respectively, consistent with the chimeric patterns of the integument. A boundary of Tbx5/Tbx4 exists in all ectopic limbs, indicating that the additional limbs are essentially chimeric, although the degree of chimerism is dependent on the position. The boundary of Tbx5/Tbx4 expression is not fixed at a specific position within the interlimb region, but dependent upon where FGF was applied. Since the ectopic expression patterns of Tbx5/Tbx4 in the additional limbs are closely correlated with the patterns of their chimeric phenotypes, it is likely that Tbx5 and Tbx4 expression in the limb bud is involved in determination of the forelimb and hindlimb identities, respectively, in vertebrates.

Amino Acid Sequence↗

PubMed1998

The role of Alx-4 in the establishment of anteroposterior polarity during vertebrate limb development.

We have determined that Strong's Luxoid (lstJ) [corrected] mice have a 16 bp deletion in the homeobox region of the Alx-4 gene. This deletion, which leads to a frame shift and a truncation of the Alx-4 protein, could cause the polydactyly phenotype observed in lstJ [corrected] mice. We have cloned the chick homologue of Alx-4 and investigated its expression during limb outgrowth. Chick Alx-4 displays an expression pattern complementary to that of shh, a mediator of polarizing activity in the limb bud. Local application of Sonic hedgehog (Shh) and Fibroblast Growth Factor (FGF), in addition to ectodermal apical ridge removal experiments suggest the existence of a negative feedback loop between Alx-4 and Shh during limb outgrowth. Analysis of polydactylous mutants indicate that the interaction between Alx-4 and Shh is independent of Gli3, a negative regulator of Shh in the limb. Our data suggest the existence of a negative feedback loop between Alx-4 and Shh during vertebrate limb outgrowth.

Amino Acid Sequence↗

PubMed1998

Pineal dermoid cyst developing 18 years after gross total removal of a pineal mature teratoma.

A 21-year-old male presented with a pineal dermoid cyst manifesting as headache and diplopia. He had undergone gross total removal of a pineal mature teratoma 18 years before and had done well until recently. Diffusion-weighted magnetic resonance imaging showed a region of high signal intensity due to a round mass in the pineal region and extending into the trigone of the right lateral ventricle. Subtotal excision of the tumor was achieved. Histological examination showed an epidermoid cyst consisting of keratinized stratified squamous epithelium and connective tissue. Intraoperative observation had detected black hairs, so the diagnosis was dermoid cyst. The dermoid cyst may have arisen from a microscopic remnant of the cyst wall of the original pineal mature teratoma. The regrowth of a dermoid cyst 18 years after gross total removal of a mature cystic teratoma in the pineal region is exceptional. However, careful follow-up of patients who undergo gross total removal of a pineal teratoma is recommended for a period more than that of the patient's age at surgery plus 9 months.

Adolescent↗

PubMed1998

[Pulmonary function at the early stage after bone marrow transplantation].

Twenty-one patients, aged 16-41 years, were prospectively followed for pulmonary function prior to and up to nine months after bone marrow transplantation (BMT). All patients had normal radiographs and no clinical signs of pulmonary disease. The FEV1.0%, V25, and of V50/V25 were within the normal ranges for all patients. Percent vital capacity (%VC) and percent diffusing capacity of lung for CO (% DLco) dropped progressively in most of the patients up to 9 months following BMT. Pulmonary function decreased earlier in patients with GVHD as well as patients who received total body irradiation either at a high dose rate (10 cGy/min) or a high lung dose (12 Gy). These asymptomatic declines in pulmonary function were measured by frequent tests of lung function.

Adolescent↗

PubMed1997

Induction of apoptosis in multi-drug resistant (MDR) human glioblastoma cells by SN-38, a metabolite of the camptothecin derivative CPT-11.

The overexpression of the multidrug resistance (mdr1) gene and its product, P-glycoprotein (P-gp), is thought to limit the successful chemotherapy of human tumors. Recent studies demonstrate that SN-38, a metabolite of the camptothecin (CPT) derivative CPT-11, has antitumor effects on several tumors, but the mechanisms responsible for its cytotoxicity remain unclear. We therefore determined whether SN-38 has cytotoxic effects on MDR human glioblastoma GB-1 cells and non-MDR human glioblastoma U87-MG cells. Furthermore, we determined what role SN-38 plays in the induction of cytotoxicity in these tumor cells. In this study, we demonstrated that SN-38 had significantly stronger antitumor effects on GB-1 and U-87MG cells than did CPT (P < 0.01 and P < 0.05, respectively). In addition, findings obtained using a DNA fragmentation assay, Hoechst 33258 staining, in situ end-labeling and cell cycle analysis demonstrated that SN-38 induced apoptosis in these tumors. Our results suggest that SN-38 has a stronger antitumor effect on malignant glioma cells regardless of MDR expression than does CPT, and therefore can be considered a new chemotherapeutic agent potentially effective in the treatment of human primary or recurrent malignant gliomas resistant to chemotherapy.

Antineoplastic Agents, Phytogenic↗

PubMed1997

Quadrupolar nutation NMR on a compound semiconductor gallium-arsenide.

Lattice defects in a compound semiconductor, gallium-arsenide are evaluated by two-dimensional nutation nuclear magnetic resonance. Especially in the case of indium doped gallium-arsenide, analysis of the nutation patterns indicates that the electric field gradient exists in the whole crystal. Asymmetry parameters and quadrupolar coupling constants are determined as approximately 1.0 and 93 kHz, respectively. These results suggest that the whole crystal is under slight strain. Through this work, it is demonstrated that a two-dimensional nutation nuclear magnetic resonance is the useful method to investigate the lattice defects in gallium-arsenide.

Arsenicals↗

PubMed1997

Immunohistochemical localization of extracellular matrix components in human breast tumours with special reference to PG-M/versican.

Immunohistochemical localization of the large proteoglycan, PG-M/versican, was studied in 36 breast tumours, including infiltrating ductal carcinomas, benign tumours and fibrocystic diseases. The relation between the proteoglycan and the other extracellular matrix components was also investigated. In the carcinoma tissues, the interstitial elements of the 'specific stroma', consisting of fibroblastic cells and fine fibrils, were reactive to antibody 2B1, which specifically recognizes the large proteoglycan, PG-M/versican. In the peripheral invasive areas of infiltrating ductal carcinoma, the most intense 2B1-positive reaction was visualized in mesenchymal tissues between carcinoma cells clumps and the surrounding tissues, where hyaluronic acid could be demonstrated histochemically. The 2B1-positive elements were not reactive to antibody 6B6, which specifically recognizes small proteoglycan. In the central sclerotic areas, where antibody 6B6 was reactive, a 2B1-positive reaction was detected only in elastosis masses, which also bound antibodies to type IV collagen and laminin, and to some extent antibody raised against chondroitin 6-sulphate proteoglycan. Elastic tissues of blood vessel walls and perivascular elements became reactive to antibody 2B1 when they were involved in carcinoma invasion. The present results have shown that PG-M/versican was localized in the proliferating interstitial tissues, in particular in hyaluronic acid-rich portions, in association with carcinoma cell growth, and also that PG-M/versican accumulated in vascular and perivascular elastic tissues involved in carcinoma invasion. The biological significance of PG-M/versican was briefly discussed.

Breast Neoplasms↗