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Miyajima K, Tamiya S, Oda Y, Adachi T, Konomoto T, Toyoshiba H, Masuda K, Tsuneyoshi M. Relative quantitation of p53 and MDM2 gene expression in leiomyosarcoma; real-time semi-quantitative reverse transcription-polymerase chain reaction. Cancer Lett 2001; 164:177-88. [PMID: 11179833 DOI: 10.1016/s0304-3835(00)00607-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
To investigate the etiology of leiomyosarcoma, we examined abnormalities of p53 and its regulation in 13 cases of leiomyosarcoma using fresh tumor specimens. We estimated p53 and MDM2 mRNA level and MDM2 gene amplification using a real-time semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) based on the TaqMan fluorescence method. We also used immunohistochemistry (IHC) for p53 and MDM2 protein overexpression, polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and direct sequencing to detect p53 mutation. Eight of the 13 cases (62%) showed an overexpression of p53 protein on IHC and eight of 13 cases (62%) had p53 gene point mutations. Five of the 13 cases (38%) showed positive staining for MDM2 protein and only one case (7.7%) demonstrated MDM2 gene amplification. The relative p53 mRNA level of the tumors compared with normal tissue ranged from 1.14 to 12.19 arbitrary units (AU), and the MDM2 mRNA level ranged from 1.06 to 17.17 AU. The mRNA level in the p53-positive cases was higher than in the negative cases (positive: 7.70 AU on average; negative: 3.38 AU on average; P=0.0344). However, there was no significant correlation between the MDM2 mRNA level and other factors, such as p53 IHC, p53 mutation status, p53 mRNA level and MDM2 IHC. Our results indicate that p53 abnormalities are major events and that an increasing level of p53 mRNA is associated with an overexpression of p53 protein in leiomyosarcoma and they may play an important role in the tumorigenesis in this tumor.
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Kameyama K, Takami H, Miyajima K, Mimura T, Hosoda Y, Ito K, Ito K. Papillary carcinoma occurring within an adenomatous goiter of the thyroid gland in Cowden's disease. Endocr Pathol 2001; 12:73-6. [PMID: 11478271 DOI: 10.1385/ep:12:1:73] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cowden's disease is an autosomal dominant disorder characterized by multiple benign and malignant neoplastic lesions involving many organs. The presence of characteristic cutaneous lesions is crucial for the diagnosis. Thyroid disease is a major extracutaneous manifestation of this disease; however, the histologic characteristics have not been described in detail. We report a case of thyroid tumor associated with Cowden's disease. Grossly, the tumor showed a multinodular appearance, like an adenomatous goiter. Microscopically, it consisted of follicular adenomas with a trabecular pattern. Some of the nodules had a second component resembling papillary carcinoma. This was thought to be a unique histological feature not described previously, and might be specific to thyroid tumor associated with Cowden's disease.
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MESH Headings
- Adenoma/chemistry
- Adenoma/complications
- Adenoma/pathology
- Adenoma/surgery
- Adult
- Carcinoma, Papillary/chemistry
- Carcinoma, Papillary/complications
- Carcinoma, Papillary/pathology
- Carcinoma, Papillary/surgery
- Female
- Goiter, Nodular/complications
- Goiter, Nodular/metabolism
- Goiter, Nodular/pathology
- Goiter, Nodular/surgery
- Hamartoma Syndrome, Multiple/complications
- Hamartoma Syndrome, Multiple/metabolism
- Hamartoma Syndrome, Multiple/pathology
- Hamartoma Syndrome, Multiple/surgery
- Humans
- Thyroglobulin/analysis
- Thyroid Neoplasms/chemistry
- Thyroid Neoplasms/complications
- Thyroid Neoplasms/pathology
- Thyroid Neoplasms/surgery
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Yoneyama K, Shima K, Ghi H, Ishizumi T, Ichinose S, Okada S, Nakajima R, Taguchi F, Kito T, Nitadori J, Ishida J, Miyajima K, Kato H. Recent problems in population surveys for lung cancer. Lung Cancer 2000. [DOI: 10.1016/s0169-5002(00)80819-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ochiai H, Horino O, Miyajima K, Kaku H. Genetic Diversity of Xanthomonas oryzae pv. oryzae Strains from Sri Lanka. PHYTOPATHOLOGY 2000; 90:415-421. [PMID: 18944593 DOI: 10.1094/phyto.2000.90.4.415] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT Sixty strains of Xanthomonas oryzae pv. oryzae, collected from 29 locations in Sri Lanka in 1995, were analyzed by restriction fragment length polymorphism using either polymerase chain reaction-amplified 16S and 23S rDNA or the repetitive DNA element IS1112 from X. oryzae pv. oryzae as hybridization probes. Two different ribogroups were observed in the Sri Lankan strains using rDNA probes, whereas five clusters were identified by the IS1112 probe. Bootstrap analysis revealed that the five clusters defined by IS1112 were relatively robust. Our results suggest that the Sri Lankan strains are phylogenetically composed of five different groups. Each cluster was partially associated with climatic conditions (intermediate zone and wet zone) and was related to groups based on ribotyping. Based on virulence analysis using 12 rice cultivars, each containing a single resistance gene, 14 pathotypes were identified among the Sri Lankan strains. All strains were virulent to resistance genes Xa1, Xa2, Xa4, Xa10, Xa11, and Xa14. Only one strain (pathotype 1) was virulent to all major resistance genes including Xa21, while strains of the other pathotypes were all avirulent to Xa21. A partial relationship was found between the determined phylogenetic groups using the IS1112 probe and pathotypes for all but two clusters. The results of this study will facilitate the further understanding of the population structure of X. oryzae pv. oryzae in Sri Lanka.
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Ikeda K, Miyajima K, Shimizu T, Achiwa K. Lipid A and related compounds. XXXVII. Determination of favorable binding linkages of lipid A analog to antigen moiety for synthetic vaccines. Chem Pharm Bull (Tokyo) 2000; 48:32-40. [PMID: 10705471 DOI: 10.1248/cpb.48.32] [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: 11/22/2022]
Abstract
For the determination of favorable binding linkages of lipid A analog as a synthetic immunoadjuvant to the antigen moiety for synthetic vaccines, new N-acylated L-serine-containing D-glucosamine analogs (Type A, B, C) were synthesized and their mitogenicities were examined. Among chemically synthesized compounds (6-15, 30), compound 8 for Type B exhibited the most potent mitogenicity.
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Matsuura S, Fukuya T, Miyajima K, Koga M, Suga N, Seo Y, Fukuda T. Imaging features of pancreatoblastoma: a case report. RADIATION MEDICINE 1999; 17:365-8. [PMID: 10593288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
We present a patient with pancreatoblastoma along with a discussion of various cross-sectional imaging features. The tumor was a large multilocular cystic mass with solid components in the left retroperitoneal space. There were fine internal echoes on ultrasonography, and the signal intensity was high on both T1- and T2-weighted MR images in most of the locules, suggesting the presence of hemorrhagic debris. Among the various retroperitoneal organs displaced by the tumor, only the pancreatic tail was inseparable from the mass, suggesting that the pancreatic tail was the origin of the tumor. Pancreatoblastoma should be included in the differential diagnosis when a large left upper quadrant mass with these imaging features is seen in infants and young children.
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Yoshida M, Miyajima K, Shiraki K, Ando J, Kudoh K, Nakae D, Takahashi M, Maekawa A. Hepatotoxicity and consequently increased cell proliferation are associated with flumequine hepatocarcinogenesis in mice. Cancer Lett 1999; 141:99-107. [PMID: 10454249 DOI: 10.1016/s0304-3835(99)00088-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It has been reported that flumequine (FLU) induces hepatic tumors in mice when given orally for 18 months. We investigated possible underlying mechanisms using a two-stage mouse hepatocarcinogenesis model. After initiation with a single intraperitoneal injection of 100 mg/kg body weight diethylnitrosamine (DEN) or saline, male CD-1 mice were given 4000 ppm FLU in the diet or 500 ppm phenobarbital (PB) in drinking water for 9, 19, 24 or 30 weeks. Toxicity, evidenced by centrilobular swollen and polar hepatocytes with fatty droplets, infiltration of inflammatory cells and increased numbers of mitosis in hepatocytes, was apparent in the livers of mice treated with FLU at all time points, but its severity declined towards the termination. FLU did not induce cytochrome P-450 enzymes such as 1A1, 2B1 and 3A2 as assessed immunohistochemically, while positive expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG) was increased in hepatocytes of both DEN + FLU and FLU groups compared with the relevant controls. In animals given PB, eosinophilic swelling of hepatocytes was prominent, and the hepatocytes showed strongly positive reactions for CYP 1A1 and 3A2. Altered cell foci were induced in the livers of FLU-treated animals both with and without DEN initiation, especially the former, and their development paralleled the degree of hepatic toxicity. These results suggest that FLU hepatocarcinogenicity in mice is dependent on hepatotoxic damage and consequently increased cell proliferation. Oxidative damage to DNA may also be a crucial factor.
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Kuwabara S, Nakazawa R, Azuma N, Suzuki M, Miyajima K, Fukutake T, Hattori T. Intravenous methylcobalamin treatment for uremic and diabetic neuropathy in chronic hemodialysis patients. Intern Med 1999; 38:472-5. [PMID: 10411351 DOI: 10.2169/internalmedicine.38.472] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECT To study the effects of the intravenous administration of methylcobalamin, an analogue of vitamin B12, for uremic or uremic-diabetic polyneuropathy in patients who are receiving maintenance hemodialysis. An ultra-high dose of vitamin B12 has been reported to promote peripheral nerve regeneration in experimental neuropathy. METHODS Nine patients received a 500 microg methylcobalamin injection 3 times a week for 6 months. The effects were evaluated using neuropathic pain grading and a nerve conduction study. RESULTS Serum concentrations of vitamin B12 were ultra-high during treatment due to the lack of urinary excretion. After 6 months of treatment, the patients' pain or paresthesia had lessened, and the ulnar motor and median sensory nerve conduction velocities showed significant improvement. There were no side effects. CONCLUSION Intravenous methycobalamin treatment is a safe and potentially beneficial therapy for neuropathy in chronic hemodialysis patients.
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Nakamura S, Miyajima K, Nagahara K, Killiany DM, Tsuchiya T. Cephalometric changes during self-correction of primary anterior crossbite. ASDC JOURNAL OF DENTISTRY FOR CHILDREN 1999; 66:175-9, 154. [PMID: 10476355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Longitudinal growth changes were investigated cephalometrically for sixty-one Japanese girls who had anterior crossbite at the initial visit (ages 3 years and 11 months on an average). Cephalograms were taken annually from the initial visit to the end of the observation period (ages 7 years 6 months on an average). Eleven of them (Group N1) showed self-correction of anterior crossbite during the primary dentition; ten (Group N2) showed self-correction when the permanent incisors erupted and forty (Group R) did not show self-correction. There was no statistical skeletal difference between Groups N1 and N2 during the observation period. Groups N1 and N2 were larger, however, than Group R in A'-Ptm'/Pog'-Go (p < 0.05) and Group N1 was smaller than Group R in Pog'-Go/N-S (p < 0.01) at the end of the observation period. In summary, favorable growth of the maxilla relative to the mandible leads to self-correction of primary crossbite and when mandible size relative to the cranial base is large, primary crossbite does not show self-correction.
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60
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Matsuzaki K, Sugishita K, Miyajima K. Interactions of an antimicrobial peptide, magainin 2, with lipopolysaccharide-containing liposomes as a model for outer membranes of gram-negative bacteria. FEBS Lett 1999; 449:221-4. [PMID: 10338136 DOI: 10.1016/s0014-5793(99)00443-3] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
F12W-magainin 2 preferentially interacted with lipopolysaccharide-containing bilayers, permeabilizing the membranes, compared with lipopolysaccharide-free phosphatidylcholine vesicles. Using this system, we demonstrated for the first time that the magainin peptide forms a helix upon binding to lipopolysaccharide. Incorporation of lipid A into phosphatidylcholine liposomes also enhanced interactions with the peptide. The presence of Mg2+, which nullifies the peptide's antibacterial activity against gram-negative bacteria, again weakened the interactions between the peptide and lipopolysaccharide-doped bilayers. This system seems to be useful for investigating the molecular details of peptide-lipopolysaccharide interactions.
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61
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Ikeda K, Miyajima K, Maruyama Y, Achiwa K. Synthesis of cancer peptide antigen-lipid A analog conjugates for synthetic vaccines. Chem Pharm Bull (Tokyo) 1999; 47:563-8. [PMID: 10319432 DOI: 10.1248/cpb.47.563] [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: 11/22/2022]
Abstract
Conjugates 6 and 7 of cancer peptide antigen with N-tetradecanoyl L-serine-beta-alanine-containing D-glucosamine derivative structurally related to lipid A as an immunoadjuvant were synthesized for the development of totally synthetic vaccines against cancers. The mitogenic activities of compounds 6 and 7 were stronger than that of lipid A analog 3.
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62
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Ishiwata H, Sato SB, Kobayashi S, Oku M, Vertut-Doï A, Miyajima K. Poly(ethylene glycol) derivative of cholesterol reduces binding step of liposome uptake by murine macrophage-like cell line J774 and human hepatoma cell line HepG2. Chem Pharm Bull (Tokyo) 1998; 46:1907-13. [PMID: 9880910 DOI: 10.1248/cpb.46.1907] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Liposome uptake by HepG2 human hepatoma cells was investigated in comparison with the uptake by J774 murine macrophage-like cells. HepG2 cells accumulated liposomes (egg yolk phosphatidylcholine (EPC)/Chol; 75/25, diameter 0.2 micron) at 37 degrees C comparably to J774 macrophage-like cells. Confocal microscopic observations revealed that J774 cells internalized EPC/Chol liposomes efficiently but HepG2 cells kept most of the liposomes bound on their plasma membrane surfaces. Poly(ethylene glycol) (PEG)-coated liposomes (0.2 micron) containing poly(ethylene glycol) cholesteryl ether (PEG-Chol) avoided cellular uptake at 37 degrees C by either cell line. In both cell lines, binding of PEG-coated liposomes was lower than that of EPC/Chol liposomes when incubation was carried out at 4 degrees C. To analyze the binding process at 37 degrees C, surface-bound liposomes were removed from the cells by pronase treatment. A reduction of the amount of bound-liposomes on cell surfaces was observed in the case of PEG-coated liposomes. Therefore, PEG-coating reduces direct binding of liposomes to the cell surfaces. The presence of apolipoprotein E (apoE) increased the uptake to EPC/Chol liposomes via its receptor in both cell lines. In contrast, cellular uptake of PEG-coated liposomes was not enhanced by treatment with apoE. Therefore, while apoE-mediated liposome uptake occurs in the case of EPC/Chol liposomes, it does not occur for PEG-coated liposomes; PEG-coating also inhibits protein-mediated binding to the cells. These results further imply that elusion from liver clearance of PEG-coated liposomes is not only due to the reduction of uptake by Kupffer cells but also by hepatocytes when liposomes are small enough to go through the fenestrates of the endothelial lining.
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63
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Miyajima K, Nekado T, Ikeda K, Achiwa K. Synthesis of Tn, sialyl Tn and HIV-1-derived peptide antigen conjugates having a lipid A analog as an immunoadjuvant for synthetic vaccines. Chem Pharm Bull (Tokyo) 1998; 46:1676-82. [PMID: 9845951 DOI: 10.1248/cpb.46.1676] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Conjugates (3-5) of Tn, sialyl Tn and HIV-1-derived peptide antigen with a N-tetradecanoyl L-serine-beta-alanine-containing D-glucosamine derivative, structurally related to lipid A, as an immunoadjuvant for the development of totally synthetic vaccines against cancers or HIV were synthesized. The mitogenic activity of compounds 3, 4 and 5 was stronger than that of lipid A analogs (1, 2).
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64
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Matsuzaki K, Mitani Y, Akada KY, Murase O, Yoneyama S, Zasloff M, Miyajima K. Mechanism of synergism between antimicrobial peptides magainin 2 and PGLa. Biochemistry 1998; 37:15144-53. [PMID: 9790678 DOI: 10.1021/bi9811617] [Citation(s) in RCA: 179] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The antimicrobial peptides magainin 2 and PGLa, discovered in the skin of the African clawed frog, Xenopus laevis, exhibit marked synergism [Westerhoff, H. V., Zasloff, M., Rosner, J. L., Hendler, R. W., de Waal, A., Vaz Gomes, A., Jongsma, A. P. M., Riethorst, A., and Juretic, D., Eur. J. Biochem. 228, 257-264 (1995)], although the mechanism is not yet clear. They are believed to kill bacteria by permeabilizing membranes. In this study, we examined the interactions of these peptides in lipid bilayers. PGLa, like magainin 2, preferentially interacts with acidic lipids, forming an amphipathic helix. The peptide induces the release of a water-soluble dye, calcein, entrapped within liposomes. The coexistence of magainin 2 enhances membrane permeabilization, which is maximal at a 1:1 molar ratio. Fluorescence experiments using L18W-PGLa revealed that both peptides form a stoichiometric 1:1 complex in the membrane phase with an association free energy of -15 kJ/mol. Single amino acid mutations in magainin 2 significantly altered the synergistic activity, suggesting that precise molecular recognition is involved in complex formation. The complex as well as each component peptide form peptide-lipid supramolecular complex pores, which mediate the mutually coupled transbilayer transport of dye, lipid, and the peptide per se. The rate of pore formation rate is in the order complex >/= PGLa > magainin 2, whereas the pore lifetime is in the order magainin 2 > complex > PGLa. Therefore, the synergism is a consequence of the formation of a potent heterosupramolecular complex, which is characterized by fast pore formation and moderate pore stability.
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65
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Iida M, Nakagaki H, Kato K, Chu S, Kojima S, Igo J, Miyajima K, Goto S. Fluoride release from a light-cured bonding material in openbite orthodontic patients. ASDC JOURNAL OF DENTISTRY FOR CHILDREN 1998; 65:330-4, 355. [PMID: 9795737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
This study was undertaken to clarify whether the salivary fluoride concentration on the anterior and premolar teeth, released from an orthodontic bonding material, differed between openbite and non-openbite patients. Using fluoride-releasing bonding materials, brackets were bonded to the teeth in openbite and in non-openbite patients. Saliva films on the tooth surfaces near the brackets were collected with filter paper and fluoride concentrations in the saliva were determined by using a fluoride electrode technique. Saliva was collected and analyzed at different periods after the bonding. Fluoride concentrations in the saliva increased sharply immediately after bonding, decreased gradually thereafter, then leveled off. Fluoride concentrations in the saliva on the tooth surfaces were higher in openbite patients for one day to as long as one week. The results of the two-way analysis (ANOVA) showed that the differences in the overbite factor (openbite, non-openbite) contributed to the variances the most (p < 0.001; contribution, 59.50 percent after one day and p < 0.01; contribution, 49.63 percent after 3 days). In conclusion, the fluoride released from the bonding materials on the tooth surfaces was retained more in openbite than in non-openbite patients, suggesting their lower flow rate of saliva.
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Kumagai S, Tabuchi T, Tainaka H, Miyajima K, Matsunaga I, Kosaka H, Andoh K, Seo A. [Load on the low back of teachers in kindergartens]. SANGYO EISEIGAKU ZASSHI = JOURNAL OF OCCUPATIONAL HEALTH 1998; 40:204-11. [PMID: 9836331 DOI: 10.1539/sangyoeisei.kj00001990619] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In order to evaluate the load on the low back of teachers in kindergartens, basic activity and working posture were analyzed for four teachers by means of video recording. The trunk inclination angle (TIA) was also measured continuously during full workshifts for 12 kindergarten teachers by means of an inclination monitor. The kindergarten teachers spent 67% of the workshift on activities in contact with children, "indoor group childcare", "indoor free playing", "outdoor childcare", "preparation and clearing away" and "help and care", and did not take a recess during the workshift. They spent 36% of the workshift in three working postures with the load on the low back, "standing bent forward", "squatting" and "kneeling". Cumulative time at a TIA of 20 degrees or more represented 43% of the workshift. The frequency of trunk-lifting from severe bending forward (TIA > 45 degrees) was 95 times/hr on average. A comparison of the kindergarten teachers and nursery teachers in 4-5 year age classes showed that the time distributions of basic activities were generally similar to each other. Although the time distributions of working postures were also similar, time spent "standing bent forward", "squatting" and "kneeling" was longer in the kindergarten teachers than in the nursery teachers. Cumulative time at a TIA of 45 degrees or more was significantly longer in the kindergarten teachers. Although the frequency of trunklifting was not significantly different, the kindergarten teachers tended to lift their trunk more frequently. The present study found that the load on the low back was considerably great in the kindergarten teachers.
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Matsuzaki K, Sugishita K, Ishibe N, Ueha M, Nakata S, Miyajima K, Epand RM. Relationship of membrane curvature to the formation of pores by magainin 2. Biochemistry 1998; 37:11856-63. [PMID: 9718308 DOI: 10.1021/bi980539y] [Citation(s) in RCA: 346] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Magainin 2, an antimicrobial peptide from the Xenopus skin, kills bacteria by permeabilizing the cell membranes. We have proposed that the peptide preferentially interacts with acidic phospholipids to form a peptide-lipid supramolecular complex pore, which allows mutually coupled transbilayer traffic of ions, lipids, and peptides, thus simultaneously dissipating transmembrane potential and lipid asymmetry [Matsuzaki, K., Murase, O., Fujii, N., and Miyajima, K. (1996) Biochemistry 35, 11361-11368]. In this paper, we examined the effect of membrane curvature strain on pore formation. Magainin effectively forms the pore only in phosphatidylglycerol bilayers at low peptide-to-lipid ratios, well below 1/100. In contrast, the permeabilization of phosphatidylserine, phosphatidic acid, or cardiolipin bilayers occurred at much higher peptide-to-lipid ratios (1/50 to 1/10) with some morphological change of the vesicles. The latter three classes of phospholipids are known to form hexagonal II structures under conditions of reduced interlipid electrostatic repulsions. Incorporation of phosphatidylethanolamine also inhibited the magainin-induced pore formation in the inhibitory order of dioleoylphosphatidylethanolamine > dielaidoylphosphatidylethanolamine. Addition of a small amount of palmitoyllysophosphatidylcholine enhanced the peptide-induced permeabilization of phosphatidylglycerol bilayers. Magainin greatly raised the bilayer to hexagonal II phase transition temperature of dipalmitoleoylphosphatidylethanolamine. These results suggest that the peptide imposes positive curvature strain, facilitating the formation of a torus-type pore, and that the presence of negative curvature-inducing lipids inhibits pore formation.
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Nishiyama K, Ando-Lu J, Nishimura S, Takahashi M, Yoshida M, Sasahara K, Miyajima K, Maekawa A. Initiating and promoting effects of concurrent oral administration of ethylenethiourea and sodium nitrite on uterine endometrial adenocarcinoma development in Donryu rats. In Vivo 1998; 12:363-8. [PMID: 9706485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The effects of oral administration of ethylenethiourea (ETU) and sodium nitrite on endometrial adenocarcinoma development was investigated in female Donryu rats. At 10 week of age, groups 1 and 3 received a single dose of polyethylene glycol (PEG) into the uterine cavity, while groups 2 and 4 were given N-ethyl-N-nitrosourea (ENU) (15 mg/kg) solution, dissolved in PEG, in the same manner. ETU (80 mg/kg) and sodium nitrite (56 mg/kg) dissolved in distilled water were orally given to animals in groups 3 and 4 once a week from 11 to 51 weeks of age. Groups 1 and 2 received the vehicle alone. At termination (52 weeks of age), endometrial adenocarcinomas were observed in 29, 13 and 57% of rats in groups 2, 3 and 4, respectively, but not in group 1. Persistent estrus appeared earlier in groups 3 and 4 than in group 1. In groups 3 and 4, hyperplastic and neoplastic lesions of the digestive tract, especially the forestomach, were also observed. The results indicate that N-nitroso ETU formed in the stomach by concurrent oral administration of ETU and sodium nitrite, itself induces endometrial adenocarcinomas by its mutagenic action, as well as promoting their development after ENU-initiation, presumably by influencing the hormonal balance.
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Miyajima K, Tanaka F, Takeuchi T, Kuninaga S. Streptomyces turgidiscabies sp. nov. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1998; 48 Pt 2:495-502. [PMID: 9731290 DOI: 10.1099/00207713-48-2-495] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A new bacterial species is described, for which the name Streptomyces turgidiscabies is proposed. This organism causes potato (Solanum tuberosum) scab in eastern Hokkaido, Japan; the lesions caused are distinctly erumpent. In culture, S. turgidiscabies is distinct from other scab-causing Streptomyces species, having flexuous spore chains and grey mass colour. The spores of this organism are cylindrical and smooth. Its cell walls contain the LL-diaminopimelic acid isomer, and its DNA G + C content is 71 mol%. S. turgidiscabies does not produce melanin or other diffusible pigments, does not grow on agar media at pH 4.0 or 37 degrees C, is positive for utilization of raffinose and inulin as a carbon source, and is sensitive to streptomycin (20 micrograms ml-1), penicillin G (10 IU ml-1), polymyxin B (15 micrograms ml-1), and thallium acetate (10 micrograms ml-1). The levels of DNA relatedness within S. turgidiscabies strains are high but relatedness between strains of this species and strains of S. acidiscabies, S. scabies, S. caviscabies, S. griseus, S. setonii and S. tendae are low. The type strain is SY9113T (= ATCC 700248T = IFO 16080T).
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Arimoto I, Saito H, Kawashima Y, Miyajima K, Handa T. Effects of sphingomyelin and cholesterol on lipoprotein lipase-mediated lipolysis in lipid emulsions. J Lipid Res 1998; 39:143-51. [PMID: 9469593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Lipoprotein lipase (LPL) hydrolyzes triacylglycerol (TG) of TG-rich lipoproteins. We investigated the effects of sphingomyelin (SM) and cholesterol (Chol) on the lipolysis of lipid emulsions by LPL using human apolipoprotein C-II (apoC-II) or plasma as an activator. Kinetic studies of the lipolysis rates clearly demonstrated that the primary effect of the activator on the LPL reaction was not to increase the affinity of LPL for the emulsion surface, but to enhance LPL catalytic activity. Incorporation of SM into the emulsion surface caused increases in Km(app) and decreases in Vmax(app), indicating that SM inhibited lipolysis by decreasing both affinity for substrates and catalytic activity of LPL. SM was also found to affect possible factors related to the lipolysis rates; that is, SM increased TG solubility in surface layers and decreased apoC-II binding to the emulsion surface. Interestingly, Chol did not affect the lipolysis rates even though it decreased TG solubility and apoC-II binding. These results indicated that neither TG solubility nor amount of apoC-II binding were determinate factors in LPL-mediated lipolysis under physiological conditions. Our results suggest that the content of SM in the lipoprotein surface plays an important role by controlling lipoprotein lipase-mediated lipolysis, and that cholesterol enrichment in the lipoprotein surface has no influence on lipolysis, but may affect other metabolic processes such as uptake by the liver through the selectivity of apolipoprotein binding.
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Ishiwata H, Sato SB, Vertut-Doï A, Hamashima Y, Miyajima K. Cholesterol derivative of poly(ethylene glycol) inhibits clathrin-independent, but not clathrin-dependent endocytosis. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1359:123-35. [PMID: 9409809 DOI: 10.1016/s0167-4889(97)00061-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The effect of poly(ethylene glycol) cholesteryl ethers (PEG(n)-Chols) with two different numbers of units (n = 50 and 200) in the hydrophilic PEG moiety on cellular endocytic activity was studied on HT-1080 cells. The amphipathic molecules were soluble in aqueous solution. When fluorescein derivatives of PEG-Chols (one fluorescein at the distal end of PEG) were incubated with the cells in culture, the cellular fluorescence was localized at the plasma membrane level and in intracellular vesicles. Fluorescence quantification indicated that for the same external concentration, twice more FPEG(50)-Chol than FPEG(200)-Chol was associated with the cells under the same conditions. Regardless of the length of PEG moiety, PEG-Chols' interaction with cells reduced the endocytic internalization of a fluid phase marker, horseradish peroxidase (HRP) depending on the cell-associated amount. In contrast, internalization of 125I-labeled epidermal growth factor (EGF) through receptor-mediated endocytosis did not change upon incubation with PEG(50)-Chol. The effect of PEG(200)-Chol was also small, since EGF internalization showed a reduction of 10-20%, while at the same concentration as much as 80% of HRP uptake was inhibited. PEG(50)-Chol did not influence the internalization of a larger ligand, 125I-transferrin (Tfn). However, in the presence of PEG(200)-Chol, the uptake of 125I-Tfn decreased remarkably, and yet, PEG(200)-Chol has no influence on the binding and internalization of a monoclonal antibody directed toward the ectodomain of the Tfn-receptor. These results suggested that incorporation of PEG-Chols in the outer monolayer of the plasma membrane specifically inhibited clathrin-independent, but not clathrin-dependent endocytosis.
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Miyajima K, McNamara JA, Sana M, Murata S. An estimation of craniofacial growth in the untreated Class III female with anterior crossbite. Am J Orthod Dentofacial Orthop 1997; 112:425-34. [PMID: 9345155 DOI: 10.1016/s0889-5406(97)70051-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The literature has little to say regarding the normal growth and development of untreated individuals with Class III malocclusion or anterior crossbite. In part, this paucity of information is because of the relatively low prevalence of these characteristics in European-American populations and the need, recognized by the lay public and health professionals, for treatment of these conditions. Given the absence of true longitudinal data, this study attempts to estimate the growth of the untreated individual with Class III malocclusion and anterior crossbite by evaluating large samples of untreated subjects at distinct developmental stages. Initially the morphologic characteristics of 2074 Japanese female patients who had anterior crossbite were evaluated cephalometrically before treatment. On the basis of the cephalometric analysis, all subjects who did not have a Class III molar relationship were excluded from further analysis, leaving a sample of 1376. The subjects then were classified into seven groups (120-256 subjects per group) according to Hellman's stages of dental development. Descriptive statistics for 28 measurements were calculated. The results of this study imply that the maxilla in Japanese females maintains a retruded relationship to the cranial base and does not become less retrusive with time. In contrast, the mandible is protrusive even in the late deciduous dentition and becomes more protrusive with time, making the discrepancy between the upper and lower jaws progressively more severe. Dental compensations in both arches become increasingly evident as development progresses, and the underlying skeletal and dentoalveolar imbalances also are reflected in the soft tissue profile.
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Miyajima K, Nekado T, Ikeda K, Achiwa K. Synthesis of Tn and sialyl Tn antigen-lipid A analog conjugates for synthetic vaccines. Chem Pharm Bull (Tokyo) 1997; 45:1544-6. [PMID: 9332007 DOI: 10.1248/cpb.45.1544] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Conjugates of Tn and sialyl Tn antigen with N-teradecanoyl L-seryl-beta-alanine-containing D-glucosamine derivatives structurally related to lipid A as an immunoadjuvant were synthesized for the development of totally synthetic vaccines against cancers or HIV.
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Miyajima K, Yoshimoto J, Murata S, Kanomi R. Uprighting the mandibular molars stimulates mandibular growth during treatment of class II malocclusion. ASDC JOURNAL OF DENTISTRY FOR CHILDREN 1997; 64:340-3. [PMID: 9391711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We hypothesized that uprighting of the mandibular molars creates a counter-clockwise rotation of the mandible and stimulates mandibular forward growth during the treatment of a Class II malocclusion. This investigation used 33 longitudinal lateral cephalometric radiographs of Class II, Division 1 female patients. All cases were treated with non-extraction. Treatment was started in early adolescence with .018 slot edgewise Alexander appliances. High-pull head-gear and Class II elastics were used. Seventeen cases that showed more than 5 degrees of uprighting of the mandibular first molars were selected as the uprighted group. Cases that showed less than 5 degrees of uprighting of the mandibular first molars were selected as the non-uprighted group. There was a significant correlation coefficient between the uprighted degree of the mandibular first molars and the degree of clockwise rotation of the mandibular plane to FH.
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Matsuzaki K, Yoneyama S, Fujii N, Miyajima K, Yamada K, Kirino Y, Anzai K. Membrane permeabilization mechanisms of a cyclic antimicrobial peptide, tachyplesin I, and its linear analog. Biochemistry 1997; 36:9799-806. [PMID: 9245412 DOI: 10.1021/bi970588v] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tachyplesin I (T-SS), an antimicrobial peptide from Tachypleus tridentatus, has a cyclic antiparallel beta-sheet structure maintained by two disulfide bridges. The peptide effectively permeabilizes both bacterial and artificial lipid membranes. T-Acm, a linear analog peptide with the four SH groups protected by acetamidomethyl groups, exhibits a much weaker membrane-permeabilizing activity in spite of a greater disruption of the lipid organization [Matsuzaki, K., Nakayama, M., Fukui, M., Otaka, A., Funakoshi, S., Fujii, N., Bessho, K., & Miyajima, K. (1993) Biochemistry 32, 11704-11710]. To clarify the efficient permeabilization mechanism of T-SS, we studied the interactions of both peptides with liposomes and planar lipid bilayers. The cyclic peptide capable of spanning the bilayer (ca. 3 nm length) was found to form an anion-selective pore and translocate across the bilayer coupled with the pore formation. A cis-negative transmembrane potential facilitated the pore formation compared with the cis-positive potential. In contrast, the linear peptide failed to translocate. Instead, it impaired the membrane barrier by disrupting the lipid organization with morphological changes in the vesicles.
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