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Vigna SR, Bowden JJ, McDonald DM, Fisher J, Okamoto A, McVey DC, Payan DG, Bunnett NW. Characterization of antibodies to the rat substance P (NK-1) receptor and to a chimeric substance P receptor expressed in mammalian cells. J Neurosci 1994; 14:834-45. [PMID: 7507985 PMCID: PMC6576831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Antibodies to neuropeptide receptors can be used to localize and characterize the receptors in tissues and cell lines. Two strategies were used to study the rat substance P receptor (SPR, NK-1) by immunological methods. First, a polyclonal antiserum was raised by immunizing rabbits with a peptide corresponding to the 15 amino acid residues (KTMTESSSFYSNMLA, SPR393-407) at the intracellular C-terminus of the rat SPR coupled to bovine thyroglobulin. An antiserum was obtained with a titer for half-maximal binding of 125I-SPR393-407 of 1:70,000. Nonradioactive SPR393-407 inhibited 50% of binding at a concentration of 10 pM. Binding of 125I-SPR393-407 to the antiserum was also displaced in a parallel manner by membrane proteins from tissues expressing high levels of the SPR (brain and submaxillary gland). Second, a chimeric SPR construct of a hydrophilic Flag peptide (DYKDDDDK) genetically engineered in sequence with the extracellular N-terminus of rat SPR was generated by polymerase chain reaction. The Flag-SPR chimera was expressed in rat kidney epithelial cells (KNRK) and judged to be fully functional, assessed by binding of 125I-substance P (apparent Kd of 5.63 nM) and calcium mobilization in response to substance P (EC50 of 0.66 nM). Antibodies to SPR393-407 and the Flag peptide stained the plasma membrane of KNRK cells expressing the native SPR or the Flag-SPR chimera. Staining was abolished by preincubation with SPR393-407 or the Flag peptide. Cells transfected with vector alone were unstained. The SPR antiserum recognized a broad protein band on Western blots of membranes prepared from cells expressing SPR but not from cells transfected with vector alone. The signal was quenched by preincubation of the antiserum with SPR393-407. By immunohistochemistry, the SPR antiserum was found to bind to neurons in the dorsal horn of the rat spinal cord and to ganglion cells in the myenteric plexus of the rat ileum near substance P-immunoreactive nerve fibers. Staining was abolished by preabsorption of the antiserum with SPR393-407. These antibodies can be used to localize the SPR in tissues and cells and to examine the function of the receptor in cell lines.
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Maeta M, Kaibara N, Nakashima K, Kobayashi M, Yoshikawa T, Okamoto A, Sugiyama A. A case-matched control study of intrahepatoarterial chemotherapy in combination with or without regional hyperthermia for treatment of primary and metastatic hepatic tumours. Int J Hyperthermia 1994; 10:51-8. [PMID: 8144988 DOI: 10.3109/02656739409009331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The efficacy of the combined application of intrahepatoarterial (IHA) chemotherapy and regional hyperthermia for the treatment of unresectable hepatic tumours was studied in a case-matched, retrospective control study. Well-matched pairs of patients with the same or similar background factors, who had been treated with IHA chemotherapy plus hyperthermia (group A; n = 32) and with IHA chemotherapy alone (group B; n = 32) were included in this study. In group A, partial responses (PRs) were found in 2 of 8, 4 of 8, and 5 of 16 patients with hepatocellular carcinoma, metastatic gastric cancer, and metastatic colorectal cancer, respectively. In group B, PRs were found in 1 of 8, 3 of 8, and 5 of 16 patients with those diseases, respectively. Overall, PRs were found in 12 (37%) and 9 (28%) of 32 patients in groups A and B, respectively; progressive disease was found in 6 (19%) in group A and in 12 (38%) in group B. These results indicate that this combination therapy is of therapeutic benefit in the treatment of unresectable hepatic tumours.
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253
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Okamoto A, Demetrick DJ, Spillare EA, Hagiwara K, Hussain SP, Bennett WP, Forrester K, Gerwin B, Greenblatt MS, Serrano M. p16INK4 mutations and altered expression in human tumors and cell lines. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1994; 59:49-57. [PMID: 7587103 DOI: 10.1101/sqb.1994.059.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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254
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Homma T, Hasegawa M, Okamoto A, Yokoyama K, Tamura T. Temporary change of compound action potential amplitude after intense sound exposure. ORL J Otorhinolaryngol Relat Spec 1994; 56:19-23. [PMID: 8121679 DOI: 10.1159/000276602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Intense sound induces a temporary or permanent threshold shift. The aim of this study is to make an experimental model for temporary threshold shift (TTS) using guinea pigs. In this study, two kinds of sound exposure were used for inducing a threshold shift in the guinea pig; one of 110 dB SPL at 10 kHz for 10 min and the other of 120 dB SPL at 10 kHz for 5 min. The former condition produced different levels of reduction in compound action potential (CAP) immediately after sound exposure and different steady levels of CAP amplitude after recovery (within 120 min) in 10 guinea pigs. The latter condition produced a total loss of CAP amplitude immediately after sound exposure in 8 of 9 guinea pigs, and this condition continued for 120 min in 7 of the 9 guinea pigs. Additionally, in 2 of 3 guinea pigs which were exposed the sound of 120 dB SPL at 10 kHz for 5 min, the CAP amplitudes were almost the same as those of control animals 1 day after the exposure. One the basis of these results, we consider the sound of 120 dB SPL at 10 kHz for 5 min to be the optimal intensity and frequency of sound and duration of exposure for producing a TTS in the guinea pig.
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Abstract
AIIKU-HAN activity was initiated by the Imperial Gift Foundation BOSHI-AIIKU-KAI in Japan in 1936 and has been introduced and accepted to community-based maternal and child health development in Indonesia through the international cooperation project conducted by Japan International Cooperation Agency (JICA) in order to encourage community health activities carried out by Indonesian women volunteers. As AIIKU-HAN activity in Japan and Dasa Wisma health activity in Indonesia have much in common, transferring concepts, methods and experiences met less obstacles when Indonesian community health volunteers learned AIIKU-HAN activity. Experience gained while developed countries were less developed can be transferred by shifting the time-scale of history in developed countries.
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256
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Okamoto A, Sekiya K, Fukushima M, Iwaku M. In vivo wear pattern of experimental light-cured hybrid composite resins. Dent Mater J 1993; 12:225-32. [PMID: 8004917 DOI: 10.4012/dmj.12.225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study evaluated the effect of various types of microfiller on the in vivo wear resistance of composite resins. Experimental light-cured composites with two different microfiller systems were prepared: (1) 56 wt % fine quartz filler, 21 wt% organic filler and 3 wt% colloidal silica filler (Hybrid type 1), and (2) 64 wt% fine quartz filler and 21 wt% colloidal silica filler (Hybrid type 2). The resin monomer consisted of 50 wt % Bis-GMA and 50 wt% TEGDMA. These materials were placed in 2 mm diameter cylindrical cavities located in the OCA (occlusal contact area) or the CFA (contact free area) in cast gold-silver-palladium alloy full coverage crowns, which were temporarily set in a volunteer patient's mouth. The crowns were removed at monthly intervals for SEM observation. Hybrid type 1, which contained organic fillers, showed bulk fractures in the OCA, by the second month of the experiment. However, reinforcement of the resin matrix by dispersion of microfiller provided Hybrid type 2 with superior wear resistance for up to two months.
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257
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Sekiya K, Okamoto A, Fukushima M, Iwaku M. In vivo wear pattern of experimental composite resins based on different resin monomers. Dent Mater J 1993; 12:145-58. [PMID: 8004909 DOI: 10.4012/dmj.12.145] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study investigated the effects of various monomer systems on composite resin wear in vivo. Experimental light-cured composite resins were prepared employing four different monomer systems: (1) Bis-GMA type, (2) D-2. 6E type, (3) UDMA type, (4) UTMA type. The resin monomers consisted of 70wt% main monomer and 30wt% TEGDMA. These composites contained 80wt% fine quartz. The resins were placed in 2 mm diameter cylindrical cavities located in the occlusal contact area or the contact free area in cast crowns, temporarily set in a mouth. The crowns were removed at monthly intervals, for longitudinal SEM observation. Two months after setting, wear was analyzed, using an electron probe surface roughness analyzer. Microabrasion of the resin matrix and loss of filler particles were observed for all types of monomer systems. The effect of matrix resin systems on occlusal wear was smaller than that of filler systems.
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258
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Usami Y, Sasaki H, Okamoto A, Fukushima M, Kota K, Iwaku M. Pulpal response to a new light-activated fluoride releasing liner. Dent Mater 1993; 9:344-9. [PMID: 7988765 DOI: 10.1016/0109-5641(93)90054-t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The purpose of this study was to investigate the degree of pulp irritation of a newly developed light-activated fluoride-releasing adhesive resin liner using canine teeth compared to the amount caused by a negative control, zinc oxide eugenol cement (ZOE), and a positive control, silicate cement (silicate). In the cases of unexposed pulp, this experimental liner showed none, slight or moderate pulpal changes at 3 d postoperatively. At 30 and 90 d, no pulpal response to the experimental liner was detected in almost all cases. These findings were similar to the ZOE and better than the silicate. There was less evidence of pulpal irritation produced by the experimental liner. This material seems to be safe to the pulp under the conditions of this study.
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259
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Shinomiya K, Okamoto A, Kamikozuru M, Furuya K, Yamaura I. An analysis of failures in primary cervical anterior spinal cord decompression and fusion. JOURNAL OF SPINAL DISORDERS 1993; 6:277-88. [PMID: 8219541 DOI: 10.1097/00002517-199306040-00001] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Recently, postoperative results of cervical spondylosis, disc herniation, and ossification of the posterior longitudinal ligament (OPLL) after anterior cervical surgeries have improved. However, occasional unsatisfactory cases needing a second operation remain. We analyzed and developed strategies for multioperated neck (MON) cases; all patients had two operations. From 1965 to 1988, 443 cervical anterior surgeries were performed in our hospitals; 53 (12.0%) of these patients needed second operations. These MON cases were classified by the following causes: pseudarthrosis, graft fracture, insufficient decompression, misdiagnosis, and adjacent disc problems. These groups were analyzed, and the resulting surgical strategies, including indications and techniques of anterior surgery, are described.
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Takaki H, Haba J, Abe K, Amako K, Arai Y, Arima T, Asano Y, Chiba M, Chiba Y, Daigo M, Fukawa M, Fukushima Y, Hemmi Y, Higuchi M, Hinode F, Hirose T, Homma Y, Hoshi Y, Hosoda N, Ishihara N, Kanatani E, Kanda N, Kanematsu N, Kanzaki J, Kikuchi R, Kondo T, Korhonen TT, Krüger AE, Kurashige H, MacNaughton J, Matsui T, Miyake K, Miura M, Mori S, Nagashima Y, Nakamura T, Nakano I, Odaka S, Ogawa K, Ohama T, Ohsugi T, Ohyama H, Okamoto A, Ono A, Oyama T, Sakamoto H, Sakuda M, Sato M, Sato N, Shioden M, Shirai J, Shirakata M, Sumiyoshi T, Suzuki A, Takada Y, Takasaki F, Takita M, Tamura N, Tobimatsu K, Tsuboyama T, Uehara S, Unno Y, Utsumi M, Watase Y. Particle spectrum in gluon jets produced in e+e- annihilations at sqrt s around 58 GeV. PHYSICAL REVIEW LETTERS 1993; 71:38-41. [PMID: 10054367 DOI: 10.1103/physrevlett.71.38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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261
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Okamoto A, Sekiya K, Fukushima M, Kota K, Iwaku M. Direct observation of in vivo wear of composite resins. Dent Mater J 1993; 12:54-61. [PMID: 8306606 DOI: 10.4012/dmj.12.54] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This study developed a simple method for in vivo evaluation of wear on composite resins and examined the role of filler particles in this process. Experimental light-cured composite resins with two different filler systems were prepared: (1) 81 wt% fine quartz filler (Conventional type) and (2) 73 wt% organic filler (Microfilled type). The resin monomer consisted of 50 wt% Bis-GMA and 50 wt% TEGMA. These materials were placed in cylindrical cavities 2 mm in diameter located in the OCA (occlusal contact area) or the CFA (contact free area) in Au-Pd crowns, temporarily set in a volunteer's mouth. The crowns were removed at monthly intervals for longitudinal SEM observation. Results showed that the newly developed method was useful for observing the in vivo wear-patterns of composite resins. The two experimental composite resins with different filler systems showed quite different wear-patterns.
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262
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Hwang L, Leichter R, Okamoto A, Payan D, Collins SM, Bunnett NW. Downregulation of neutral endopeptidase (EC 3.4.24.11) in the inflamed rat intestine. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 264:G735-43. [PMID: 8476057 DOI: 10.1152/ajpgi.1993.264.4.g735] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Intestinal inflammation induced by the nematode Trichinella spiralis is accompanied by increased intestinal concentrations of substance P, a mediator of inflammation and a stimulant of smooth muscle contraction, and by intestinal hypermotility. The expression of neutral endopeptidase (NEP), a cell surface enzyme that degrades substance P in the extracellular fluid, was examined in the inflamed intestine. NEP enzymatic activity, measured by a fluorometric assay, was reduced by 84-fold in jejunal mucosa-circular muscle and by 12-fold in jejunal longitudinal muscle-myenteric plexus within 6 days after infection with T. spiralis. The downregulation was unaffected by treatment with betamethasone and was still observed in athymic animals. NEP protein levels, examined by Western blotting, confirmed the loss of NEP from inflamed tissue. The specific activity for degradation of substance P was reduced by sixfold in jejunal mucosa-circular muscle and by twofold in jejunal longitudinal muscle-myenteric plexus of rats infected with T. spiralis compared with uninfected controls. Thus the downregulation of NEP resulted in reduced substance P degradation, which may contribute to functional abnormalities of the inflamed intestine.
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Okamoto A, Okabe M, Gomi K. Analysis of DNA fragmentation in human uterine cervix carcinoma HeLa S3 cells treated with duocarmycins or other antitumor agents by pulse field gel electrophoresis. Jpn J Cancer Res 1993; 84:93-8. [PMID: 8449832 PMCID: PMC5919028 DOI: 10.1111/j.1349-7006.1993.tb02789.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Pulse field gel electrophoresis using a contour-clamped homogeneous electric field was applied for the analysis of DNA-fragmenting activity of antitumor agents towards human uterine cervix carcinoma HeLa S3 cells. Duocarmycins (DUMs), novel antitumor antibiotics with ultrapotent cell growth-inhibitory activities, caused DNA fragmentation at 10 times their IC50 values at 2 h exposure. At 100 times their IC50 values, the size of the smallest fragments was about 245 kilobase pairs (kbp). DUMA, DUMB1 and DUMB2 exhibited similar DNA fragmentation patterns, suggesting similar action mechanisms. DNA fragmentation was also detected in cells treated with radical producers, intercalators and topoisomerase inhibitors. Two bands of about 1800 and 1500 kbp were commonly detected in the cells treated with DUMs and these agents. In addition, fragments of about 900 kbp were detected in the cells treated with a topoisomerase inhibitor, 4'-(9-acridinylamino)methane-sulfon-m-anisidine, and fragments in the broad size range between 700 and 245 kbp in the cells treated with radical producers, bleomycin and neocarzinostatin. DUMs showed a characteristic DNA fragmentation pattern, since both types of fragments induced by the topoisomerase inhibitor and the radical producers were simultaneously detected, suggesting a novel mode of interaction with DNA. DNA-crosslinking agents and mitotic inhibitors did not induce DNA fragmentation under these conditions. The pulse field gel electrophoresis is potentially useful for characterizing DNA-cleaving activity of various antitumor agents at the cellular level.
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264
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Gu ZF, Menozzi D, Okamoto A, Maton PN, Bunnett NW. Neutral endopeptidase (EC 3.4.24.11) modulates the contractile effects of neuropeptides on muscle cells from the guinea-pig stomach. Exp Physiol 1993; 78:35-48. [PMID: 8448012 DOI: 10.1113/expphysiol.1993.sp003669] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The objectives of this investigation were to characterize neuropeptide-degrading enzymes on the surface of gastric muscle cells and to determine their physiological function. Neutral endopeptidase (NEP, EC 3.4.24.11) activity was measured using the fluorogenic substrate glutaryl-Ala-Ala-Phe-4-methoxy-2-naphthylamine. The NEP inhibitors phosphoramidon and DL-thiorphan (1 microM) inhibited degradation of the substrate by gastric muscle membranes by 100% and by freshly dispersed gastric muscle cells by 55-60%. The phosphoramidon or DL-thiorphan-inhibitable activity, attributed to NEP, of membranes was 112 +/- 4.0 pmol h-1 (micrograms protein)-1 and of cells was 4.2 +/- 0.8 nmol h-1 (10(6) cells)-1. This activity was associated with membranes prepared from cells and was not detected in the cytoplasm or in the cell incubation solution. Gastric muscle membranes were fractionated by electrophoresis and analysed by Western blotting using two NEP antisera. Both antisera recognized a protein in membranes with an electrophoretic mobility identical to that of recombinant human NEP and an apparent molecular mass of approximately 95 kDa. Neuropeptides were degraded by membranes with specific activities in the order of [Leu5]enkephalin > [Met5]enkephalin > gastrin-releasing peptide-10 (GRP-10) > [D-Ala2][Leu5]enkephalin > somatostatin-14. Phosphoramidon and DL-thiorphan similarly inhibited the degradation of GRP-10 (mean of 35% inhibition), somatostatin-14 (57%) and the aminopeptidase-resistant analogue, [D-Ala2][Leu5]enkephalin (75%). When aminopeptidases were inhibited with amastatin (10 microM) phosphoramidon inhibited degradation of [Leu5]enkephalin (54%) and [Met5]enkephalin (100%). Phosphoramidon increased the potency of the contractile effects of neuropeptides on muscle cells by > 280-fold for somatostatin-14, 17-fold for GRP-10, 18-fold for [Met5]enkephalin and 14-fold for [Leu5]enkephalin. The results show that an NEP-like enzyme on the surface of gastric muscle cells degrades and inactivates enkephalins, GRP-10 and somatostatin-14 and acts in a manner analogous to that of acetylcholinesterase in the neuromuscular junction of skeletal muscle.
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265
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Okamoto A, Hayashi D, Hashimoto N. [A case report of the fallopian tubal carcinoma successfully treated with intraperitoneal chemotherapy using a subcutaneously implanted reservoir]. NIHON SANKA FUJINKA GAKKAI ZASSHI 1992; 44:1451-4. [PMID: 1281206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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266
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Okamoto A. Effects of metallothionein on mutagenicity and oxidation of quercetin. OSAKA CITY MEDICAL JOURNAL 1992; 38:127-36. [PMID: 1488255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effects of four types of Zn/Cd-metallothioneins on the mutagenicity of quercetin in Salmonella typhimurium TA98 were studied. The four types of Zn/Cd-metallothionein used in this experiment were metallothionein I, metallothionein I/II and metallothionein II from rabbit liver and metallothionein I/II from horse kidney. All four of the metallothioneins enhanced the mutagenicity of quercetin. Metallothionein II from rabbit liver, in which Zn content was the highest of the four metallothioneins, enhanced the mutagenicity of quercetin most effectively. Metallothioneins as well as Zn/Cu-SOD prevented quercetin oxidation under aerobic conditions. The action of these metallothioneins, which enhances the mutagenicity of quercetin, was fairly proportional to the activity which prevents quercetin from being oxidized. Reduced glutathione did not enhance the mutagenicity of quercetin although it did inhibit the quercetin oxidation. These results suggest that metallothioneins have superoxide (O2-) scavenging ability and act as "SOD-like" proteins in vivo. A simple and reliable system to detect biological substances which have antioxidant activity for the superoxide (O2-) was devised.
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267
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Okamoto A, Hirotsu K. [Protein engineering. I: X-ray crystallographic study of aspartate aminotransferase and its mutant enzymes]. TANPAKUSHITSU KAKUSAN KOSO. PROTEIN, NUCLEIC ACID, ENZYME 1992; 37:2231-42. [PMID: 1410511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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268
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Okamoto A, Yokoyama S, Terashima Y. [Genetic alterations in the genesis and development of ovarian cancer]. Gan To Kagaku Ryoho 1992; 19:1971-6. [PMID: 1358031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Genetic alterations of various cancers have been clarified by recent development of molecular biology. Multiple genetic alterations occur through the development of cancer. Both activation of proto-oncogenes and inactivation of tumor suppressor genes are important for the development of cancer. Alterations of oncogenes such as K-ras, c-erbB-2/HER-2/neu and c-myc, and those of tumor suppressor genes such as p53, RB and DCC have been reported in ovarian cancer. Allelic losses of the specific chromosomes, which suggest the existence of tumor suppressor genes on those chromosomes, also have been reported in ovarian cancer. Further studies on genetic alterations of ovarian cancer will clarify the mechanisms for the development of ovarian cancer and also will develop new methods for prevention, diagnosis and treatment in clinical.
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Maruyama K, Yuda T, Okamoto A, Kojima S, Suginaka A, Iwatsuru M. Prolonged circulation time in vivo of large unilamellar liposomes composed of distearoyl phosphatidylcholine and cholesterol containing amphipathic poly(ethylene glycol). BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1128:44-9. [PMID: 1390877 DOI: 10.1016/0005-2760(92)90255-t] [Citation(s) in RCA: 173] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effect of poly(ethylene glycol) (PEG) on the circulation time of liposomes in mice was examined by employing amphipathic PEGs (phosphatidylethanolamine (PE) derivatives of PEG) with average molecular weights of 1000, 2000, 5000 and 12,000. The activity of dioleoyl phosphatidylethanolamine-PEG (DOPE-PEG) in prolonging the circulation time of egg phosphatidylcholine/cholesterol large unilamellar liposomes (ePC/CH LUVs) (200 nm) was proportional to the molecular weight of PEG, i.e., 12000 = 5000 greater than 2000 greater than 1000. On the other hand, inclusion of distearoylphosphatidylethanolamine-PEG (DSPE-PEG) or dipalmitoyl-phosphatidylethanolamine-PEG (DPPE-PEG) of low molecular weight such as 1000 and 2000 in distearoylphosphatidylcholine (DSPC)/CH LUVs or dipalmitoyl phosphatidylcholine (DPPC)/CH LUVs effectively increased their blood circulation time. At least 3 mol% of amphipathic PEG in liposomes was required for activity. Addition of CH, which has a bilayer-tightening effect, to DSPC/CH/DSPE-PEG2000 LUVs further increased the blood residence time. A size of less than 300 nm was essential for prolonging the residence time of amphipathic PEG-containing liposomes in blood. DSPC/CH/DSPE-PEG2000 LUVs (1:1:0.13, m/m) containing 6 mol% of PEG and 200 nm in diameter remained in the circulation for over 24 h after injection and may be clinically useful for sustained release of an entrapped drug in the bloodstream and for drug accumulation in solid tumors.
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270
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Tomisawa H, Hayashi M, Uda F, Okamoto A, Hattori K, Ozawa N, Tateishi M. Purification and characterization of 3-mercaptolactic acid S-conjugate oxidases. Biochem Pharmacol 1992; 44:703-14. [PMID: 1510716 DOI: 10.1016/0006-2952(92)90406-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two enzymes catalysing the oxidative formation of 3-mercaptopyruvic acid S-conjugates from L-3-mercaptolactic acid S-conjugates were purified to apparent homogeneity from rat liver cytosol. The two enzymes, tentatively designated MLO-I and MLO-II, showed a molecular mass of 160 and 250 kDa and were composed of four and six subunits of 41 and 39 kDa, respectively. Both enzymes possessed flavin mononucleotide as prosthetic group and oxidized several aromatic and aliphatic S-substituted L-3-mercaptolactic acids as well as alpha-hydroxy acids such as L-3-phenyllactic acid and L-2-hydroxyisocaproic acid. Glycolic acid and 3-(4-hydroxyphenyl)-lactic acid were the specific substrates for MLO-I and MLO-II, respectively. Neither of the enzymes oxidized beta- and gamma-hydroxy acids such as 3- and 4-hydroxybutyric acid. 2-Hydroxyisobutyric acid, ethyl-2-hydroxybutyrate, malic acid, 1-butanol, benzyl alcohol and L-leucine did not act as substrates for the enzymes. MLO-I and MLO-II exerted their maximum activities around pH 5.5 with Km of 0.5 and 0.25 mM and Vmax of 0.9 and 0.2 mumol/min/mg, respectively, when S-(4-bromophenyl)-3-thiolactic acid was used as substrate. MLO-I was inhibited by sulphydryl-modifying agents, while MLO-II was not. Both enzymes were strongly inhibited by divalent metal ions. These results indicate that MLO-I and MLO-II are different from L-amino acid oxidase (EC 1.4.3.2), malate oxidase (EC 1.1.3.3), L-alpha-hydroxy acid oxidase (EC 1.1.3.15) and glycolate oxidase (EC 1.1.3.1). The present enzymes are likely to be involved in the formation of cysteine conjugates from L-3-mercaptolactic acid S-conjugates in conjunction with cysteine conjugate aminotransferases.
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Abstract
Neutral endopeptidase (NEP) and aminopeptidase M (APM) were identified in the pancreas by enzymatic assays and Western blotting. The NEP activity, assessed by the phosphoramidon- and DL-thiorphan-inhibitable degradation of glutaryl-Ala-Ala-Phe-4-methoxy-2-naphthylamine, was 28.8 pmol/h/micrograms of pancreatic membrane protein and 124 pmol/h/10(6) pancreatic acinar cells. The APM enzymatic activity, assessed by the actinonin- and amastatin-inhibitable degradation of Ala-4-methoxy-2-naphthylamine, was 633 pmol/h/micrograms pancreatic membrane protein and 17.4 nmol/h/10(6) pancreatic acinar cells. Proteins corresponding to NEP (95 kDa) and APM (140 kDa) were identified in membranes by Western blotting. Both NEP and APM on acinar cells may degrade neuropeptides and regulate their effects on exocrine secretion.
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272
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Han L, Okamoto A, Iwaku M. The effects of various clinical factors on marginal enamel micro-cracks produced around composite restoration. Dent Mater J 1992; 11:26-37. [PMID: 1395484 DOI: 10.4012/dmj.11.26] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this study, enamel micro-cracks produced around composite restorations were observed on surfaces and vertical sections, using a stereomicroscope and a scanning electron microscope (SEM). The effects of various clinical factors, i.e. the curing system, the marginal form and the polishing period after filling, on the incidence of marginal enamel micro-cracks were examined. Enamel micro-cracks were observed on all of the class 1 and 5 composite restorations when the cavity had no marginal bevel and the restorations were polished immediately after filling. Enamel micro-cracks distributed approximately parallel to the cavity margin and located 0.01-0.3 mm from the restored cavity margin. The occurrence of enamel micro-cracks was higher in light-cured composite resin restorations than in chemical-cured ones, for non-beveled cavities when polished 10 min or 24 hours after filling. The occurrence of micro-cracks was reduced by marginal beveling and delayed polishing.
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273
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Kukita T, Yamaguchi A, Okamoto A, Nemoto M. Interaction between polyethylene films and bromhexine HCl in solid dosage form. IV. Prevention of the sorption by addition of magnesium aluminum silicate. Chem Pharm Bull (Tokyo) 1992; 40:1257-60. [PMID: 1394643 DOI: 10.1248/cpb.40.1257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of magnesium aluminum silicate (MAS) addition on the sorption of bromhexine HCl to polyethylene film in tablets were studied. The addition of MAS prevented the sorption of bromhexine HCl to polyethylene film. In order to investigate the mechanism, the interaction between bromhexine HCl and MAS was studied by the powder X-ray diffraction method. It was observed that bromhexine HCl was preferentially adsorbed to the surface of MAS rather than to polyethylene film. The adsorption was accelerated at high temperature and reduced pressure conditions. The sorption of bromhexine base and bromhexine HCl to packaging material were compared using tablet dosage forms. The sorption of bromhexine base to polyethylene film was greater than that of bromhexine HCl.
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274
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Kihira K, Mikami T, Ikawa S, Okamoto A, Yoshii M, Miki S, Mosbach EH, Hoshita T. Synthesis of sulfonate analogs of bile acids. Steroids 1992; 57:193-8. [PMID: 1519263 DOI: 10.1016/0039-128x(92)90008-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sulfonate analogs of C23 and C24 bile acids were synthesized from norcholic, norchenodeoxycholic, norursodeoxycholic, nordeoxycholic, norhyodeoxycholic, cholic, deoxycholic, hyodeoxycholic, and lithocholic acids. The principal reactions used were (1) reduction of the bile acids with NaBH4 to the corresponding bile alcohols, (2) selective tosylation of the terminal hydroxyl group, (3) iodination of the tosyl esters with NaI, and (4) treatment of the iodides with Na2SO3 to form the sulfonate analogs of the bile acids. The sulfonate analogs showed polarity similar to that of taurine-conjugated bile acids on thin-layer chromatography. The carbon 13 nuclear magnetic resonance spectral data for the sulfonate analogs were tabulated.
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275
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Okamoto A, Hasegawa M, Tamura T, Homma T, Komatsuzaki A. Effects of frequency and intensity of sound on cochlear blood flow. Acta Otolaryngol 1992; 112:59-64. [PMID: 1575038 DOI: 10.3109/00016489209100783] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Laser Doppler flowmetry demonstrates that loud sound induces a decrease of blood flow in the cochlea of the guinea pig. In this experiment, we observed the effects of frequency and intensity of sound on cochlear blood flow using 15 guinea pigs. In the first 5 guinea pigs, a Doppler probe was attached to the basal turn of the cochlea and sounds of 6, 7, 8, 9 and 10 kHz were delivered to the ear serially from lower to higher frequency, i.e. from 6 kHz to 10 kHz. In the next 5 guinea pigs, the sound was delivered from higher to lower frequency, i.e. from 10 kHz to 6 kHz. The sound intensity delivered to the ear was changed from lower to higher intensity (80 to 120 dB SPL by 10 dB width) at each frequency. In the last 5 guinea pigs, the blood flow in the basal, second, third, and fourth turns of the cochlea was measured at 120 dB SPL of 10 kHz. No change of blood flow was seen in the cochlear basal turn at 6 and 7 kHz up to 120 dB SPL, but a decrease of blood flow was found at 110 and 120 dB SPL at 8, 9, and 10 kHz. On the other hand, the sound of 120 dB SPL at 10 kHz induced a decrease of blood flow only in the basal turn of the cochlea. Our results suggest that there is a corresponding blood flow area which is sensitive to specific frequency in the cochlea.
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