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Biomedical subjects

Y Watanabe

Publications and source records attributed to Y Watanabe.

At least 127 records · Page 7Linked to original sources
PubMed2001

Molecular cloning and characterization of a steroid receptor-binding regulator of G-protein signaling protein cDNA.

Steroid hormone receptors are composed of six major functional domains, i.e. the A/B domains as the activation function 1 domain (AF-1), domain C as the DNA-binding domain, domain D as a hinge domain and domain E/F as the ligand-dependent transcriptional domain (AF-2). They regulate gene transcription through interactions with various nuclear factors of their domains, such as AF-1 and AF-2. We have insufficient knowledge of the function of the DNA-binding domain (domain C) except for its DNA-binding function or the hinge domain (domain D). Therefore, we attempted to identify factors interacting with the domains by using a yeast two-hybrid system. Domains C and D of estrogen receptor alpha were used as a bait to isolate cDNA clones from a rat ovary cDNA library. We isolated the cDNA clone of a novel steroid receptor-binding protein bearing the regulator of G-protein signaling (RGS) designated as SRB-RGS. The protein repressed the transcriptional activity of estrogen receptor alpha, suggesting cross-talk of steroid hormones and peptide hormones (or growth factors) for signal transductions mediated by SRB-RGS.

Amino Acid Sequence↗
PubMed2001

Association of arrhythmia and sudden death in macrocephaly-cutis marmorata telangiectatica congenita syndrome.

Macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC) constitutes a distinct entity characterized by prenatal overgrowth, macrosomia, hemihypertrophy, macrocephaly, nonobstructive hydrocephaly, frontal bossing, hypotonia, developmental delay, generalized or facial capillary malformation with upper philtral nevus flammeus and cutis marmorata, joint hypermobility, loose skin, toe syndactyly, and postaxial polydactyly. All but one of the cases reported previously had benign clinical courses without showing an increased risk of early infant death. We describe three additional cases with poor clinical outcomes including severe postnatal growth failure, intractable cardiac arrhythmia in two cases, and sudden infant death in two cases. Arrhythmia has not been described previously as one of the symptoms of M-CMCT. Patients with M-CMTC associated with severe postnatal growth failure and arrhythmia may constitute a distinct clinical subtype of M-CMTC with an increased risk of life-threatening episodes or sudden death. Recognizing this clinical subtype of M-CMTC is important to prevent these serious potential complications.

Abnormalities, Multiple↗
PubMed2001

Oxidative modification of tryptophan 43 in the heme vicinity of the F43W/H64L myoglobin mutant.

The F43W/H64L myoglobin mutant was previously constructed to investigate the effects of electron-rich tryptophan residue in the heme vicinity on the catalysis, where we found that Trp-43 in the mutant was oxidatively modified in the reaction with m-chloroperbenzoic acid (mCPBA). To identify the exact structure of the modified tryptophan in this study, the mCPBA-treated F43W/H64L mutant has been digested stepwise with Lys-C achromobacter and trypsin to isolate two oxidation products by preparative fast protein liquid chromatography. The close examinations of the (1)H NMR spectra of peptide fragments reveal that two forms of the modified tryptophan must have 2,6-disubstituted indole substructures. The (13)C NMR analysis suggests that one of the modified tryptophan bears a unique hydroxyl group in stead of the NH(2) group at the amino-terminal. The results together with mass spectrometry (MS)/MS analysis (30 Da increase in mass of Trp-43) indicate that oxidation products of Trp-43 are 2,6-dihydro-2,6-dioxoindole and 2,6-dihydro-2-imino-6-oxoindole derivatives. Our finding is the first example of the oxidation of aromatic carbons by the myoglobin mutant system.

Catalysis↗
PubMed2001

Activity-dependent neural tissue oxidation emits intrinsic ultraweak photons.

Living organisms have been known to spontaneously emit ultraweak photons in vivo and in vitro. Origin of the photon emission remains unclear, especially in the nervous system. The spontaneous ultraweak photon emission was detected here from cultured rat cerebellar granule neurons using a photomultiplier tube which was highly sensitive to visible light. The photon emission was facilitated by the membrane depolarization of neurons by a high concentration of K+ and was attenuated by application of tetrodotoxin or removal of extracellular Ca2+, indicating the photon emission depending on the neuronal activity and likely on the cellular metabolism. Furthermore, almost all the photon emission was arrested by 2,4-dinitrophenylhydrazine, indicating that the photon emission would be derived from oxidized molecules. Detection of the spontaneous ultraweak photon emission will realize noninvasive and real-time monitoring of the redox state of neural tissue corresponding to the neuronal activity and metabolism.

Animals↗
PubMed2001

Direct production of an activated matrix metalloproteinase-9 (gelatinase B) from mammalian cells.

Matrix metalloproteinase-9 (MMP-9) is produced by the inactive proform and activated by a proteolytic process. However, it has not been reported to produce the active form directly from cells, which has hindered the research to elicit the physiological roles of this enzyme. In this study, we prepared mutant MMP-9 containing the furin-recognizing sequence in the prodomain and showed that the mutant MMP-9 was secreted as the active form directly from CHO-K1 cells and primary hepatocytes after the gene was transfected. The secreted MMP-9 showed proteolytic activity without further activation and degraded collagen IV in vitro. In addition, the transfection of the gene into the liver resulted in the efficient expression of active MMP-9 in the liver and the serum in vivo.

Animals↗
PubMed2001

Photosynthetic productivity of conical helical tubular photobioreactors incorporating Chlorella sp. under various culture medium flow conditions.

The characteristics of the flow of culture medium significantly affects the photosynthetic productivity of bioreactors incorporating microalgae. Therefore, in order to optimize the performance of a conical helical tubular photobioreactor (CHTP) designed to be useful in practical applications, we characterized the flow pattern of the culture medium through the reactor. The effects of medium flow conditions on the photosynthetic productivity of Chlorella sp. were investigated using several different CHTP units with 0.50-m2 installation areas which were designed to vary the direction and rate of flow driven by airlift. In addition, the performance of two- and four-unit systems constructed by combining individual CHTP units was evaluated. We found that when medium flowed from the bottom to the top of the photostage, it exhibited smoother flow of culture medium than when flowing from top to bottom, which led to higher photosynthetic productivity by the former. Consistent with theoretical calculations, varying the lengths of vertical flow passages caused flow rates to vary, and higher flow rates meant smoother circulation of medium and better photosynthetic performance. Flow of medium through a four-unit CHTP system was similar to that in single units, enabling a photosynthetic productivity of 31.0 g-dry biomass per m2-installation area per day to be achieved, which corresponded to a photosynthetic efficiency of 7.50% (photosynthetically active radiation (PAR; 400-700 nm)). This high photosynthetic performance was possible because smoother medium flow attained in single units was also attained in the four-unit system.

Bioreactors↗
PubMed2001

Elucidation of the differences between the 430- and 455-nm absorbing forms of P450-isocyanide adducts by resonance Raman spectroscopy.

Alkylisocyanide adducts of microsomal P450 exist in two interconvertible forms, each giving the Soret maximum around 430 or 455 nm. This is demonstrated with a rabbit liver P450 2B4. Resonance Raman spectra of the 430- and 455-nm forms were examined for typical P450s of the two types as well as for P450 2B4 because the 430-nm form of P450 2B4 is liable to change into P420. P450cam and P450nor were selected as a model of the 430- and 455-nm forms, respectively. For the n-butyl isocyanide (CNBu) adduct, the Fe(II)-CNBu stretching band was observed for the first time at 480/467 cm(-1) for P450cam and at 471/459 cm(-1) for P450nor with their (12)CNBu/(13)CNBu derivatives. For P450cam, but not P450nor, other (13)C isotope-sensitive bands were observed at 412/402, 844/835, and 940/926 cm(-1). The C-N stretching mode was identified by Fourier transform IR spectroscopy at 2116/2080 cm(-1) for P450cam and at 2148/2108 cm(-1) for P450nor for the (12)C/(13)C derivatives. These findings suggest that the binding geometry of isocyanide differs between the two forms-bent and linear structures for P450cam-CNBu and P450nor-CNBu, respectively. In contrast, in the ferric state, the Raman (13)C isotopic frequency shifts, and the IR C-N stretching frequencies (2213/2170 and 2215/2172 cm(-1)) were similar between P450cam and P450nor, suggesting similar bent structures for both.

Animals↗
PubMed2001

Fractionated administration of irinotecan and cisplatin for treatment of non-small-cell lung cancer: a phase II study of Okayama Lung Cancer Study Group.

A phase II study of fractionated administration of irinotecan (CPT-11) and cisplatin (CDDP) in patients with non-small-cell lung cancer (NSCLC) was conducted. Between January 1996 and January 1998, 44 previously untreated patients with stage IIIB or IV NSCLC were enrolled. CDDP at a dose of 60 mg x m(-2) was given first and followed by CPT-11 at a dose of 50 mg x m(-2). Both drugs were given by 1-hour infusion on days 1 and 8, and repeated every 4 weeks up to 4 cycles. 42 patients were evaluated for response and 44 for survival and toxicity. 20 patients (48%: 95% confidence interval 32-63%) achieved an objective response. The median duration of responses was 8 months, and the median survival time and the 1-year survival rate were 12.5 months and 56.8%, respectively. Major toxicities were neutropenia and diarrhoea. Grade 3 or 4 neutropenia occurred in 70.5% of the patients and one patient died of sepsis. Grade 3 or 4 diarrhoea was experienced in 25.0%, but manageable by conventional therapy. In conclusion, fractionated administration of CPT-11 and CDDP was highly effective for advanced NSCLC with manageable toxicities.

Adult↗
PubMed2001

Expression of thyroid hormone receptor betaA gene assayed by transgenic Xenopus laevis carrying its promoter sequences.

The responsiveness of thyroid hormone responsive element (TRE)-containing promoter sequence to thyroid hormone (TH) was studied utilizing Xenopus laevis carrying a transgene containing 5'-upstream region of TRbetaA1 gene and green fluorescent protein (EGFP) gene. EGFP-expression was seen first in neurulae, which continued to stage 45, then became weak, and again started to increase at the prometamorphic stage, culminating at the metamorphic climax stage. Immunohistochemistry identified eyes, viscera, and muscles as the EGFP-expressing larval tissues. The treatment of premetamorphic tadpoles with TH induced the precocious EGFP-expression. We also showed that the transgenic Xenopus adults were responsive to exogenous TH, a high responsiveness being seen in brain, small intestine, kidney, and bone. TRbeta-expression in the embryo, larva, and adult was verified by Western blotting. Thus, TH not only regulates the metamorphosis, but also might play some biological role(s) in embryos and adults.

Animals↗
PubMed2001

Effect of phosphatidylcholine on skin permeation of indomethacin from gel prepared with liquid paraffin and hydrogenated phospholipid.

The effects of hydrogenated and unhydrogenated phosphatidylcholine (HPC, PC) on the permeation of indomethacin (IM) through hairless rat skin were investigated using liquid paraffin (LP) and a gel prepared with LP and hydrogenated soybean phospholipid (HSL). IM solubility at 95 degrees C increased in proportion to the concentration of HPC or PC, whereas solubility at 37 degrees C did not increase with HPC. IM showed no permeation until 10 h from LP without HPC/PC, but permeated at rates of approximately 5 and 10 microg/cm2 within 10 h from LP with HPC and PC, respectively. The permeation from the gel with various formulations (HSL, 15%; PC/HPC, 0-5%; IM, 0.5-2%) was determined. Permeation rates were 1.7-4.8 microg/cm2 per h and were proportional to the skin concentration. Skin concentration was correlated to the release rate from the gel. We concluded that IM was solubilized by phospholipids, high activity in the vehicle led to high partition of IM in skin, and permeation increased due to a high skin concentration.

Animals↗
PubMed2001

Magnetic resonance imaging system for three-dimensional conformal radiotherapy and its impact on gross tumor volume delineation of central nervous system tumors.

PURPOSE: We developed an MRI system for three-dimensional planning in radiotherapy. Its contribution on gross tumor volume (GTV) delineation of central nervous system (CNS) diseases was evaluated. METHODS AND MATERIALS: The MRI system, with corrected distortion, was registered on computed tomography (CT) by means of fiducial/anatomic landmarks. In 41 consecutive patients with various CNS diseases, GTVs determined by MRI/CT registration (MR/CT-GTV) and CT alone (CT-GTV) were compared. Hard copies of diagnostic MRI were shown to doctors when CT-GTV was determined to simulate a conventional planning situation. Multi-observer volumetric analysis was conducted, assessing interobserver deviations among four radiation oncologists and intermethodological deviations between MR/CT-GTV and CT-GTV. RESULTS: Overall, the mean of geometric distortion was significantly reduced from 1.08 mm to 0.3 mm by distortion correction (p < 0.0001). The contribution of the correction was apparent at >12.0 cm radius from the center of the magnetic field. Interobserver deviation was significantly reduced by MR/CT registration (p = 0.005). The improvement was significant for acoustic neurinoma (p = 0.038), astrocytomas (p = 0.043), and lesions at the cerebellum/brainstem (p = 0.008). The regression coefficient between MR/CT-GTV and CT-GTV was <0.9 for cerebellum/brainstem lesions, suggesting that MRI/CT-GTV was smaller than CT-GTV. CONCLUSIONS: This system is feasible for three-dimensional planning and was shown to reduce interobserver deviations in GTV delineation for CNS diseases.

Brain Neoplasms↗
PubMed2001

The fission yeast meiotic regulator Mei2p undergoes nucleocytoplasmic shuttling.

Schizosaccharomyces pombe Mei2p is an RNA-binding protein that switches the cell cycle from mitotic to meiotic. Mei2p forms a unique dot in the nucleus prior to meiosis I, aided by a non-coding RNA molecule termed meiRNA. Here we show that Mei2p intrinsically undergoes nucleocytoplasmic shuttling. Artificial acceleration of nuclear migration of Mei2p advances nuclear dot formation, but meiRNA does not appear to promote the dot formation by modulating the migration rate of Mei2p into the nucleus. Rather, this RNA is likely to facilitate the assembly of Mei2p into a dot structure and trap the protein as such in the nucleus.

Active Transport, Cell Nucleus↗
PubMed2001

Characterization of imidazolate-bridged dinuclear and mononuclear hydroperoxo complexes.

Dinucleating ligands having two metal-binding sites bridged by an imidazolate moiety, Hbdpi, HMe(2)bdpi, and HMe(4)bdpi (Hbdpi = 4,5-bis(di(2-pyridylmethyl)aminomethyl)imidazole, HMe(2)bdpi = 4,5-bis((6-methyl-2-pyridylmethyl)(2-pyridylmethyl)aminomethyl)imidazole, HMe(4)bdpi = 4,5-bis(di(6-methyl-2-pyridylmethyl)aminomethyl)imidazole), have been designed and synthesized as model ligands for copper-zinc superoxide dismutase (Cu,Zn-SOD). The corresponding mononucleating ligands, MeIm(Py)(2), MeIm(Me)(1), and MeIm(Me)(2) (MeIm(Py)(2) = (1-methyl-4-imidazolylmethyl)bis(2-pyridylmethyl)amine, MeIm(Me)(1) = (1-methyl-4-imidazolylmethyl)(6-methyl-2-pyridylmethyl)(2-pyridylmethyl)amine, MeIm(Me)(2) = (1-methyl-4-imidazolyl-methyl)bis(6-methyl-2-pyridylmethyl)amine), have also been synthesized for comparison. The imidazolate-bridged Cu(II)-Cu(II) homodinuclear complexes represented as [Cu(2)(bdpi)(CH(3)CN)(2)](ClO(4))(3).CH(3)CN.3H(2)O (1), [Cu(2)(Me(2)bdpi)(CH(3)CN)(2)](ClO(4))(3) (2), [Cu(2)(Me(4)bdpi)(H(2)O)(2)](ClO(4))(3).4H(2)O (3), a Cu(II)-Zn(II) heterodinuclear complex of the type of [CuZn(bdpi)(CH(3)CN)(2)](ClO(4))(3).2CH(3)CN (4), Cu(II) mononuclear complexes of [Cu(MeIm(Py)(2))(CH(3)CN)](ClO(4))(2).CH(3)CN (5), [Cu(MeIm(Me)(1))(CH(3)CN)](ClO(4))(2)( )()(6), and [Cu(MeIm(Me)(2))(CH(3)CN)](ClO(4))(2)( )()(7) have been synthesized and the structures of complexes 5-7 determined by X-ray crystallography. The complexes 1-7 have a pentacoordinate structure at each metal ion with the imidazolate or 1-methylimidazole nitrogen, two pyridine nitrogens, the tertiary amine nitrogen, and a solvent (CH(3)CN or H(2)O) which can be readily replaced by a substrate. The reactions between complexes 1-7 and hydrogen peroxide (H(2)O(2)) in the presence of a base at -80 degrees C yield green solutions which exhibit intense bands at 360-380 nm, consistent with the generation of hydroperoxo Cu(II) species in all cases. The resonance Raman spectra of all hydroperoxo intermediates at -80 degrees C exhibit a strong resonance-enhanced Raman band at 834-851 cm(-1), which shifts to 788-803 cm(-1) (Deltanu = 46 cm(-1)) when (18)O-labeled H(2)O(2) was used, which are assigned to the O-O stretching frequency of a hydroperoxo ion. The resonance Raman spectra of hydroperoxo adducts of complexes 2 and 6 show two Raman bands at 848 (802) and 834 (788), 851 (805), and 835 (789) cm(-1) (in the case of H(2)(18)O(2), Deltanu = 46 cm(-1)), respectively. The ESR spectra of all hydroperoxo complexes are quite close to those of the parent Cu(II) complexes except 6. The spectrum of 6 exhibits a mixture signal of trigonal-bipyramid and square-pyramid which is consistent with the results of resonance Raman spectrum.

Journal Article↗
PubMed2001

The impact of traumatic brain injury on family members living with patients: a preliminary study in Japan and the UK.

PURPOSE: To ascertain the views of families living with TBI patients about the nature of the problems experienced as a result of TBI, and to compare the views of Japanese family members (J-FM) and British family members (B-FM) in order to find out whether there were cultural differences in family response to TBI. METHODS: Family members involved in providing care were identified by the patients. Face to face interviews were conducted with all 18 carers in B-FM and four carers in J-FM. The remaining eight carers in J-FM participated in the postal questionnaire. Questionnaires were developed to explore the nature of problems and the involvement of family such as social embarrassment. RESULTS: Problems arising in families were almost the same reported from both groups. However families in B-FM were likely to know more about how to cope with these problems. Family members in J-FM reported more statistically significant increases in social embarrassment than those in B-FM. CONCLUSION: The preliminary results showed that family members living with TBI patients in both groups had experienced problems. Appropriate rehabilitation services should be developed to help families as well as TBI patients in Japan.

Adaptation, Psychological↗
PubMed2001

Protein kinase C-catalyzed phosphorylation of an inhibitory phosphoprotein of myosin phosphatase is involved in human platelet secretion.

Protein kinase C (PKC)-potentiated inhibitory phosphoprotein of myosin phosphatase (CPI) was detected in human platelets. Like smooth muscle CPI-17, in vitro phosphorylation of platelet CPI by PKC inhibited the activity of myosin phosphatase containing the PP1delta catalytic subunit and the 130-kd myosin-binding subunit (MBS). Treatment of intact platelets with thrombin or the stable thromboxane A(2) analog STA(2) resulted in increased phosphorylation of both CPI and MBS at Thr-696, whereas phorbol myristate acetate (PMA) and the Ca(++) ionophore ionomycin only induced CPI phosphorylation. PMA induced slow adenosine triphosphate (ATP) secretion of fura 2-loaded platelets with no change in cytosolic Ca(++). The PMA-induced increase in CPI phosphorylation preceded phosphorylation of 20-kd myosin light chain (MLC(20)) at Ser-19 and ATP secretion. The PKC inhibitor, GF109203X, inhibited PMA-induced phosphorylation of CPI and MLC(20) with similar IC(50) values. These findings suggest that the activation of PKC by PMA induces MLC(20) phosphorylation by inhibiting myosin phosphatase through phosphorylation of CPI. STA(2)-induced MLC(20) phosphorylation was also diminished but not abolished by GF109203X, even at high concentrations that completely inhibited STA(2)-induced CPI phosphorylation. A combination of the Rho-kinase inhibitor Y-27632 and GF109203X led to a further decrease in STA(2)-induced MLC(20) phosphorylation, mainly because of a significant inhibition of MBS phosphorylation at Thr-696. Inhibition of STA(2)-induced ATP release by Y-27632, GF109203X, or both appeared to correlate with the extent of MLC(20) phosphorylation. Thus, CPI phosphorylation by PKC may participate in inhibiting myosin phosphatase, in addition to the Rho-kinase-mediated regulation of myosin phosphatase, during agonist-induced platelet secretion. (Blood. 2001;97:3798-3805)

Adenosine Triphosphate↗
PubMed2001

Protein conformation change of myoglobin upon ligand binding probed by ultraviolet resonance Raman spectroscopy.

Conformational change of myoglobin (Mb) accompanied by binding of a ligand was investigated with 244 nm excited ultraviolet resonance Raman Spectroscopy (UVRR). The UVRR spectra of native sperm whale (sw) and horse (h) Mbs and W7F and W14F swMb mutants for the deoxy and CO-bound states enabled us to reveal the UVRR spectra of Trp7, Trp14, and Tyr151 residues, separately. The difference spectra between the deoxy and CO-bound states reflected the environmental or structural changes of Trp and Tyr residues upon CO binding. The W3 band of Trp7 near the N-terminus exhibited a change upon CO binding, while Trp14 did not. Tyr151 in the C-terminus also exhibited a definite change upon CO binding, but Tyr103 and Tyr146 did not. The spectral change of Tyr residues was characterized through solvent effects of a model compound. The corresponding spectral differences between CO- and n-butyl isocyanide-bound forms were much smaller than those between the deoxy and CO-bound forms, suggesting that the conformation change in the C- and N-terminal regions is induced by the proximal side of the heme through the movement of iron. Although the swinging up of His64 upon binding of a bulky ligand is noted by X-ray crystallographic analysis, UVRR spectra of His for the n-butyl isocyanide-bound form did not detect the exposure of His64 to solvent.

Animals↗