2476
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Wakabayashi K, Kakita A, Hayashi S, Takahashi H. 274 Parkinson's disease with dementia: A quantitative study of cortical lewy bodies and amyloid plaques. Neurobiol Aging 1996. [DOI: 10.1016/s0197-4580(96)80276-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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2477
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Hosoi K, Hashida T, Takahashi H, Yamasaki N, Korenaga T. Low temperature solidification of calcium carbonate through vaterite-calcite wet transformation. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/bf00274614] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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2478
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Kai C, Yamanouchi K, Sakata H, Miyashita N, Takahashi H, Kobune F. Nucleotide sequences of the M gene of prevailing wild measles viruses and a comparison with subacute sclerosing panencephalitis virus. Virus Genes 1996; 12:85-7. [PMID: 8879124 DOI: 10.1007/bf00370004] [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: 02/02/2023]
Abstract
We determined the nucleotide sequences of the coding region for the M gene in seven strains of measles virus (MV) that were isolated in Japan between 1984 and 1993. The mutation found among the seven differed from those of laboratory strains. Many of these mutations were the same as those that are characteristic of SSPE viruses. Thus, we suggest that the mutations that have been considered specific to SSPE virus are in fact consensus among prevailing MV.
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2479
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Gu H, Takahashi H. Towards more practical average bounds on supervised learning. ACTA ACUST UNITED AC 1996; 7:953-68. [PMID: 18263490 DOI: 10.1109/72.508938] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In this paper, we describe a method which enables us to study the average generalization performance of learning directly via hypothesis testing inequalities. The resulting theory provides a unified viewpoint of average-case learning curves of concept learning and regression in realistic learning problems not necessarily within the Bayesian framework. The advantages of the theory are that it alleviates the practical pessimism frequently claimed for the results of the Vapnik-Chervonenkis (VC) theory and its alike, and provides general insights into generalization. Besides, the bounds on learning curves are directly related to the number of adjustable system weights. Although the theory is based on an approximation assumption, and cannot apply to the worst-case learning setting, the precondition of the assumption is mild, and the approximation itself is only a sufficient condition for the validity of the theory. We illustrate the results with numerical simulations, and apply the theory to examining the generalization ability of combination of neural networks.
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2480
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Yamamoto Y, Itoh T, Inoue I, Takahashi H. Expression of p34cdc2 protein kinase and p53 in supraglottic carcinomas. Auris Nasus Larynx 1996; 23:105-10. [PMID: 8809331 DOI: 10.1016/s0385-8146(96)80016-2] [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: 02/02/2023]
Abstract
The clinicopathological significance of the simultaneous expression of the p34cdc2 protein kinase oncogene product and mutant-type p53 oncogene product was studied in 15 supraglottic squamous cell carcinomas. Clinical and histopathological data were recorded from the medical records, and immunohistochemical and DNA cytofluorometric analysis were performed. p34cdc2 was positive in 80% and mutant-type p53 in 53% of the tumors. Their simultaneous expression was seen in 33% of the tumors, but the probability was not statistically significant. Correlations between the expression of p34cdc2 or mutant-type p53 and T, N categories, histological differentiation, and DNA ploidy pattern were not significant. However, when the percentages of p34cdc2 and mutant-type p53-positive cells in the tumor were high, aneuploidy tended to be present and the clinical stage more advanced. It is suggested that the growth and progression of supraglottic carcinomas are associated with the disruption of the regulatory system of the cell cycle.
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2481
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Tsuji S, Okuizumi K, Onodera O, Namba Y, Ikeda K, Yamamoto T, Seki K, Ueki A, Nanko S, Tanaka H, Takahashi H, Oyanagi K, Mizusawa H, Kanazawa I. 598 Genetic risk factors for Alzheimer's disease. Neurobiol Aging 1996. [DOI: 10.1016/s0197-4580(96)80600-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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2482
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Hori N, Okanoue T, Mori T, Kashima K, Nishimura M, Nanbu A, Yoshimura M, Takahashi H. Endogenous nitric oxide production is augmented as the severity advances in patients with liver cirrhosis. Clin Exp Pharmacol Physiol 1996; 23:30-5. [PMID: 8713493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
1. Since endothelium-derived nitric oxide (NO) is a potent vasodilator and degraded into nitrous ions, we measured the serum nitrate ion (NO3-) and the amount of urinary excretions of NO3- as an index for endogenous NO to ascertain whether NO formation is augmented in patients with chronic liver diseases. 2. Using inpatients suffering from chronic liver diseases, serum levels and urinary excretions of NO3- were measured by using high-performance liquid chromatography with an anion exchange column. 3. Among the four patient groups of normal controls, and those with chronic liver diseases such as chronic active hepatitis, compensated cirrhosis, and decompensated cirrhosis the serum level of NO3- showed the highest level in a patient group with decompensated cirrhosis. The amount of urinary excretion of NO3- was significantly increased in both groups of patients with liver cirrhosis compared with the control group and patients with chronic active hepatitis. Patients with chronic active hepatitis did not show any difference between the normal control group. The amount of urinary excretion of NO3- correlated significantly and negatively with the level of serum albumin (P < 0.05) and counts of platelets (P < 0.01) in patients with compensated cirrhosis. 4. These findings suggest that the production of endogenous NO is augmented in patients with liver cirrhosis, particularly in a decompensated subgroup. Increases in the production of endogenous NO correspond to the progress of liver cirrhosis, but not in patients with chronic hepatitis.
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2483
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Yamamoto Y, Inoue I, Takasaki T, Takahashi H. Inhibitory effects of selenium, vitamin A and butylated hydroxytoluene on growth of human maxillary cancer cells in vitro. Auris Nasus Larynx 1996; 23:91-7. [PMID: 8809329 DOI: 10.1016/s0385-8146(96)80014-9] [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: 02/02/2023]
Abstract
The effects of vitamin A, selenium, and butylated hydroxytoluene (BHT) on the growth of a human maxillary cancer cell line were examined in monolayer cell cultures. The colony-forming assay showed a 50% reduction in the survival rate of the cell line at a concentration of 3.6 micrograms/ml of selenium, 28 micrograms/ml of vitamin A, and 74 micrograms/ml of BHT. Flow cytometric analysis with both FITC-labeled bromodeoxyuridine monoclonal antibody and propidium iodide demonstrated an increase of the S-phase fraction in the presence of selenium, an increase of the G0/G1-phase fraction in the presence of vitamin A, and an increase of the G2-M-phase fraction 1 day followed by an increase of G0/G1-phase fraction from the 3rd to 7th day when BHT was added. These results suggest that the mechanisms of inhibition of DNA synthesis by these compounds are different.
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2484
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Mercken M, Takahashi H, Honda T, Sato K, Murayama M, Nakazato Y, Noguchi K, Takashima A. 60 Characterization with monoclonal antibodies of human presenilin 1. Neurobiol Aging 1996. [DOI: 10.1016/s0197-4580(96)80062-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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2485
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Kagawa H, Nomura S, Miyake T, Miyazaki Y, Kido H, Suzuki M, Yanabu M, Fukuhara S, Komiyama Y, Takahashi H. Expression of prothrombinase activity and CD9 antigen on the surface of small vesicles from stimulated human endothelial cells. Thromb Res 1995; 80:451-60. [PMID: 8610273 DOI: 10.1016/0049-3848(95)00200-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We employed flow cytometry and monoclonal antibodies (MoAb) to study the surface membrane protein of shed particles (small vesicles, SV) that were released from vascular endothelial cells (EC) by agonists such as a Ca ionophore (A23187) and thrombin. After stimulation of EC by A23187, CD9 antigens disappeared entirely from the EC surface in a time- and concentration-dependent manner; they subsequently moved onto the SV surface. Von Willebrand factor (vWF) and P-selectin from Weibel-Palade (W-P) bodies were expressed rapidly on the EC surface after thrombin stimulation, but not on the SV surface. P-selectin may have some effect on maintenance of hemostasis on the EC surface. We demonstrated that the surfaces of SV and EC significantly supported prothrombinase activity and confirmed that A23187-induced SV from EC express binding sites for factors IXa and Xa. These results suggest that the SV are an important factor in a novel controlling mechanism of the coagulation system on the EC surface.
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2486
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Takahashi H, Kuramoto A, Hara M, Watanabe F, Aizawa Y, Zeniya M, Toda K. [Intra-hepatic infiltrating T cell clonality analysis in patients with autoimmune hepatitis and the clinical significance]. NIHON RINSHO MEN'EKI GAKKAI KAISHI = JAPANESE JOURNAL OF CLINICAL IMMUNOLOGY 1995; 18:708-712. [PMID: 8963794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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2487
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Gotoh T, Hattori S, Nakamura S, Kitayama H, Noda M, Takai Y, Kaibuchi K, Matsui H, Hatase O, Takahashi H. Identification of Rap1 as a target for the Crk SH3 domain-binding guanine nucleotide-releasing factor C3G. Mol Cell Biol 1995; 15:6746-53. [PMID: 8524240 PMCID: PMC230928 DOI: 10.1128/mcb.15.12.6746] [Citation(s) in RCA: 293] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
C3G, which was identified as a Crk SH3 domain-binding guanine nucleotide-releasing factor, shows sequence similarity to CDC25 and Sos family proteins (S. Tanaka, T. Morishita, Y. Hashimoto, S. Hattori, S. Nakamura, M. Shibuya, K. Matuoka, T. Takenawa, T. Kurata, K. Nagashima, and M. Matsuda, Proc. Natl. Acad. Sci. USA 91:3443-3447, 1994). The substrate specificity of C3G was examined by in vitro and in vivo experiments. C3G markedly stimulated dissociation of bound GDP from Rap1B but marginally affected the same reaction of other Ras family proteins (Ha-Ras, N-Ras, and RalA). C3G also stimulated binding of GTP-gamma S [guanosine 5'-3-O-(thio)triphosphate] to Rap1B. When C3G and Rap1A were expressed in COS7 cells, marked accumulation of the active GTP-bound form of Rap1A was observed, while Sos was not effective in the activation of Rap1A. These results clearly show that C3G is an activator for Rap1. Furthermore, expression of C3G with a membrane localization signal in a v-Ki-ras transformant, DT, induced a reversion of the cells to the flat form, possibly through the activation of endogenous Rap1.
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2488
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Sugahara M, Yahagi N, Takahashi H, Uchida K, Suzuki A, Matsui H, Isokawa K, Toda Y. The influence of scattering on temporo-regional proliferation in the cultured Madin-Darby canine kidney (MDCK) cells. THE JOURNAL OF NIHON UNIVERSITY SCHOOL OF DENTISTRY 1995; 37:201-8. [PMID: 8820339 DOI: 10.2334/josnusd1959.37.201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
An epithelial Madin-Darby canine kidney (MDCK) cell line was grown in two kinds of standard media and a medium conditioned by MRC-5 embryonic lung cells, and temporo-regional differences in cell proliferation were examined by immunohistochemical detection of incorporated bromodeoxyuridine (BrdU). MRC-5-conditioned medium is known to contain scatter factor, which induces scattering of MDCK cells. In a proliferation assay, the BrdU labeling index (percentage ratio of BrdU-positive to total nuclei) was highest in day 2 cultures in the standard media, but on day 3 in the conditioned medium. MDCK cells in the standard media formed multiple epithelial sheets by day 2. In the conditioned medium, however, epithelial sheet formation was retarded and observed only after day 3. Once epithelial sheets had formed, cells close to the edge of the sheet were more proliferative than those distant from the edge in both standard and conditioned media. These findings suggest that proliferation of MDCK cells is suppressed during the scattering induced by the conditioned medium, and that their DNA synthesis becomes most active when cell scattering has ceased and epithelial sheets have begun to form.
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2489
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Honda Y, Kuroki Y, Matsuura E, Nagae H, Takahashi H, Akino T, Abe S. Pulmonary surfactant protein D in sera and bronchoalveolar lavage fluids. Am J Respir Crit Care Med 1995; 152:1860-6. [PMID: 8520747 DOI: 10.1164/ajrccm.152.6.8520747] [Citation(s) in RCA: 214] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Pulmonary surfactant protein D (SP-D) is a hydrophilic glycoprotein with a reduced molecular mass of 43 kDa and a member of the C-type lectin superfamily, along with mannose-binding proteins and surfactant protein A (SP-A). We have recently prepared monoclonal antibodies against human SP-D and developed an enzyme-linked immunosorbent assay (ELISA). In this study, the levels of SP-D in sera and bronchoalveolar lavage (BAL) fluids of patients with lung diseases were determined by ELISA, using human recombinant SP-D as a standard. We demonstrated that the concentrations of SP-D in sera are prominently increased in patients with idiopathic pulmonary fibrosis (IPF), interstitial pneumonia with collagen disease (IPCD), and pulmonary alveolar proteinosis (PAP). Patients with IPF, IPCD, and PAP exhibited levels of serum SP-D 5.1-fold, 7.2-fold, and 7.0-fold, respectively, of those in healthy volunteers; 91.5% of the patients with IPF, 81.3% with IPCD, and 100% with PAP exhibited serum SP-D levels that exceeded the cut-off value (mean + 2 SD of control value). Serum SP-D levels appeared to reflect the disease activity of IPF and IPCD and the disease severity of PAP. High levels of SP-D in BAL fluids were shown in patients with PAP, but not with IPF and IPCD. We conclude that measurement of SP-D in sera can provide an easily identifiable and useful clinical marker for the diagnosis of IPF, IPCD, and PAP, and can predict the disease activity of IPF and IPCD and the disease severity of PAP.
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2490
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Yamamoto Y, Itoh T, Saka T, Sakakura A, Takahashi H. Nucleolar organizer regions in glottic carcinomas: comparison of DNA cytofluorometry and clinicopathological analysis. Eur Arch Otorhinolaryngol 1995; 252:499-503. [PMID: 8719595 DOI: 10.1007/bf02114760] [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: 02/01/2023]
Abstract
The significance of nucleolar organizer regions (NORs) and nuclear DNA content in 73 glottic carcinomas was assessed for proliferative activity and tumor progression. NORs stained with silver colloid were counted, and nuclear DNA content was assayed by cytofluorometry. The cytofluorometric study demonstrated that the percentage of tumors with aneuploidy tended to increase as histological differentiation decreased. Survival rates of patients with diploid and aneuploid tumors were not significantly different. AgNOR staining revealed that mean AgNOR numbers rose as histological differentiation of tumors decreased. Moreover, as T and N categories and stages showed advancing malignancy, mean AgNOR numbers tended to rise. However, there was no significant difference in survival rates between tumors with low and with high AgNOR counts. These studies indicate that while AgNOR staining is better than DNA cytofluorometry for determining histological differentiation of glottic carcinoma, neither is of prognostic value at the present time.
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2491
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Inoue I, Yamamoto Y, Takasaki T, Takahashi H. Inhibitory effects of selenium, vitamin A and butylated hydroxytoluene on in vitro growth of human tongue cancer cells. Eur Arch Otorhinolaryngol 1995; 252:509-12. [PMID: 8719597 DOI: 10.1007/bf02114762] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of vitamin A, selenium and butylated hydroxytoluene (BHT) on the growth of a human tongue cancer cell line were examined in monolayer cell cultures. A colony-forming assay showed a 50% reduction in the survival rate of the cell line at a concentration of 2.6 micrograms/ml selenium, 60 micrograms/ml vitamin A and/or 38 micrograms/ml BHT. Relatively low concentrations of selenium markedly inhibited glucose consumption. Flow cytometric analysis with both fluorescein-isothiocyanate-labelled bromodeoxyuridine monoclonal antibody and propidium iodide demonstrated an increase in S-phase fractions 1 day after the addition of selenium, increased G0/G1 phase fractions in the presence of vitamin A and increased G2-M phase fractions when BHT was added. These results suggest that these compounds inhibit DNA synthesis of in vitro human tongue cancer cells by different mechanisms.
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2492
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Takahashi H, Tezuka F, Fujita S, Okabe H. Vascular changes in major and lingual minor salivary glands in primary Sjögren's syndrome. Anal Cell Pathol 1995; 9:243-56. [PMID: 8616101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A histological investigation of the vascular changes of three major and lingual minor salivary glands in primary Sjögren's syndrome was carried out on eight autopsied Japanese patients. This study compares vascular lesions in salivary glands between one group of four short-term corticosteroid-treated patients (Cases 1, 3, 4 and 7) and the other group of four long-term corticosteroid-treated patients (Cases 2, 5, 6 and 8). We proposed the following five stages for morphogenesis of arteritis; (1) endothelial swelling, (2) thrombosis, (3) fibrinoid degeneration, (4) necrotizing panarteritis and (5) endarteritis obliterans. Endothelial swelling was seen in small-to-large arteries of major salivary glands and the tongue, and this finding was considered as the initial change of vascular lesion. Thrombosis was observed in the small arteries of both organs. Fibrinoid degeneration and necrotizing panarteritis were predominantly localized in small and middle-sized arteries. Endarteritis obliterans was observed in small and large arteries of major and lingual minor salivary glands in primary Sjögren's syndrome. Vascular lesion of this type was common in the four patients who received corticosteroid for more than 12 months. Corticosteroid therapy appears to accelerate the fibrotic change of the vascular wall. Therefore, we suggest that essential vascular lesions of major and lingual minor salivary glands in primary Sjögren's syndrome may include four types (endothelial swelling, thrombosis, fibrinoid degeneration and necrotizing panarteritis), excluding endarteritis obliterans.
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2493
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Komiyama Y, Murakami T, Masuda M, Egawa H, Takahashi H. [Activated coagulation factors in various thrombotic diseases]. RINSHO BYORI. THE JAPANESE JOURNAL OF CLINICAL PATHOLOGY 1995; 43:1195-200. [PMID: 8569028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Various hemostatic abnormalities have been reported and excess activation of coagulation factors, such as prothrombin, factor VII, factor IX, and factor XI, have been detected in thrombotic diseases states by various assay systems. We recently developed the enzyme-linked differential immunoassay for activated factor XI-alpha 1 antitrypsin complex (FXIa-alpha 1 AT) and applied it with other assays for activated factors such as thrombin-antithrombin III complex (TAT) to detect the hypercoagulable state in clinical samples. In patients with DIC, the FXIa-alpha 1 AT level in plasma increased before onset of DIC. In patients with non-insulin-dependent diabetes mellitus, FXIa-alpha 1AT and TAT levels were increased in the patient plasma. FXIa-alpha 1AT was related to the severity of urinary albumin excretion, whereas TAT was not. Plasma FXIa-alpha 1AT levels were significantly increased in patients with angiographically proven coronary artery disease, and showed a positive correlation with TAT, fibrinogen, and Lp(a). Evaluation of activated coagulation factor provides useful information on the diagnosis of thrombotic disease.
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2494
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Takahashi H, Hara K, Komiyama Y, Masuda M, Murakami T, Nishimura M, Nambu A, Yoshimura M. Mechanism of hypertension induced by chronic inhibition of nitric oxide in rats. Hypertens Res 1995; 18:319-24. [PMID: 8747311 DOI: 10.1291/hypres.18.319] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In order to clarify the mechanism of hypertension induced by a nitric oxide (NO) synthase inhibitor, L-NG-nitro-L-arginine (LNNA), metabolites of NO, catecholamines, and hemodynamic parameters were measured during 7 days of oral administration of LNNA in rats. Control rats received either L-arginine (L-Arg) or the vehicle. systolic blood pressure, measured by the tall-cuff method was elevated throughout the period of LNNA administration, but that in the two control groups was not influenced by treatment. Heart rate decreased on the second day only in LNNA-treated rats. Although L-Arg treatment had no influence, LNNA markedly decreased the plasma level and the urinary excretion of nitrate ions (NO-3). Urinary excretion of noradrenaline was significantly decreased on the second day of LNNA administration and returned to the control level thereafter. When hemodynamic changes were measured by using radioactive microspheres, LNNA was found to increase blood pressure by markedly increasing total peripheral resistance. Cardiac output was decreased by LNNA. L-Arg, again, did not influence the hemodynamic variables as compared with the vehicle control group. The regional vascular resistance index was increased by LNNA in many tissues and organs, except the brain and the heart. Regional blood flow, on the other hand, was significantly decreased only in the liver and skin by LNNA. The marked reduction in NO3- in urine by LNNA-treatments may indicate that the measured NO3- is exclusively of endogenous origin, and that inhibition of NO production causes elevation of blood pressure by constricting peripheral arteries. Sympatholytic responses by the baroreceptor reflex were thereby evident only on the second and the third days, which was indicated by bradycardia and suppression of noradrenaline excretion into urine. These results indicate that the inhibition of NO synthase actually decreases production of endogenous NO, and that the hypertension caused by decreases in NO production is due to elevation of total peripheral vascular resistance.
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2495
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Yamamoto M, Takahashi H. Tensile fatigue strength of light cure composite resins for posterior teeth. Dent Mater J 1995; 14:175-84. [PMID: 8940556 DOI: 10.4012/dmj.14.175] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The fatigue property of the composite resin has recently been a subject of research. In this study, the fatigue strength and the tensile strength of composite resins stored in water were investigated. Two types of light cure composite resins were used: a Hybrid type and am MFR type. Dumbbell-shaped specimens were prepared. After storage at 37 +/- 0.5 degrees C for 24 hours, 1 month, 3 months, 6 months and 12 months, the fatigue test and the direct tensile test were performed. The staircase method was employed to analyze the fatigue strength under a 10(5) cyclic load. The fatigue strength of the Hybrid type at 24h ours was 54.7 MPa; that of the MFR type was 28.1 MPa. Both fatigue strengths decreased during water storage. Otherwise, the tensile strength of the Hybrid type was 77.0 MPa; that of the MFR type was 53.5 MPa. After 12 months of storage, the tensile strength of the Hybrid type remained unchanged during water storage; however, that of the MFR type decreased.
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2496
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Nishimura M, Nanbu A, Sakamoto M, Nakanishi T, Takahashi H, Yoshimura M. Role of cerebral ATP-sensitive K+ channels in arterial pressure regulation during acute cerebral ischaemia in SHR and WKY rats. CLINICAL AND EXPERIMENTAL PHARMACOLOGY & PHYSIOLOGY. SUPPLEMENT 1995; 22:S70-2. [PMID: 9072449 DOI: 10.1111/j.1440-1681.1995.tb02975.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
1. ATP-sensitive K+ channels (KATP) are activated either by decreased intracellular ATP content or ATP/ADP ratio during ischaemia. We examined the role of a cerebral KATP in arterial pressure regulation during acute cerebral ischaemia using SHR and WKY rats. Thirteen week old male SHR or WKY rats were anaesthetized with urethane, and arterial pressure and heart rate were recorded under an artificial ventilation. 2. Intracerebroventricular (i.c.v.) injections of glibenclamide, a specific inhibitor of KATP, elicited dose-dependent vasopressor responses in WKY with bilateral ligation of carotid arteries, whereas it caused smaller vasopressor responses in SHR than WKY. 3. Systemic administration of AVP V1 receptor antagonist, OPC-21268, abolished the vasopressor responses of i.c.v. injections of glibenclamide in WKY but not in SHR. 4. Intracerebroventricular injections of glibenclamide caused both the increase in plasma concentration of AVP and the decrease in pituitary AVP content in WKY with bilateral ligation of carotid arteries, whereas it elicited no significant change in plasma and pituitary concentration of AVP in SHR with bilateral ligation of carotid arteries. 5. Cerebral KATP may play a role in the protection of excess hypertension by inhibiting AVP release from the pituitary glands during acute ischaemia in WKY, but this mechanism might not work in SHR during acute cerebral ischaemia.
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2497
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Kishi M, Zheng YH, Bahmani MK, Tokunaga K, Takahashi H, Kakinuma M, Lai PK, Nonoyama M, Luftig RB, Ikuta K. Naturally occurring accessory gene mutations lead to persistent human immunodeficiency virus type 1 infection of CD4-positive T cells. J Virol 1995; 69:7507-18. [PMID: 7494257 PMCID: PMC189689 DOI: 10.1128/jvi.69.12.7507-7518.1995] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Proviral DNA from cells surviving severe but transient cytopathic effects, mediated by infection with recombinant human immunodeficiency virus type 1 (HIV-1) carrying a single gene mutation at vif, vpr, or vpu, was characterized by use of HIV-1-specific primer pairs in a two-step PCR. Deletion mutations were detected in a region that spanned the vif and vpr open reading frames. Cloning and sequencing of the amplified DNA from this region revealed frequent large deletions in a limited number of nucleotide positions. Analyses of the deletions suggested that (i) genetic recombination, (ii) template-primer slippage, and (iii) misalignment of the growing point during reverse transcription of the HIV-1 genome might be the mechanisms that generated the mutations. Apart from the large deletions, smaller deletions that gave frameshift mutations in vif and/or vpr prevailed. In addition, cells infected with a triple mutant defective in vif, vpr, and vpu did not show any cytopathic effect. Thus, mutations generating multiple accessory gene defects during HIV-1 replication correlate with viral persistence and loss of cytopathogenicity.
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2498
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Takemori N, Hirai K, Onodera R, Saito N, Yokota K, Kinouchi M, Takahashi H, Iizuka H. Satisfactory remission achieved by PUVA therapy in a case of crisis-type adult T-cell leukaemia/lymphoma with generalized cutaneous leukaemic cell infiltration. Br J Dermatol 1995; 133:955-60. [PMID: 8547051 DOI: 10.1111/j.1365-2133.1995.tb06933.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We used PUVA therapy in a patient with crisis-type adult T-cell leukaemia/lymphoma and generalized cutaneous leukaemic cell infiltration. PUVA proved very effective in reducing leukaemic cells and in clearing the eruption. To understand the way in which PUVA produced a reduction in the number of leukaemic cells, we examined peripheral blood cells by light and electron microscopy. Light microscopy was of little help, but electron microscopy revealed that PUVA induced apoptosis-like changes in circulating leukaemic cells. This suggests that apoptosis-like changes in leukaemic cells might be the reason for the success of this treatment.
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Takahashi H. Space-flight experiments for the study of gravimorphogenesis in cucumber seedlings. UCHU SEIBUTSU KAGAKU 1995; 9:345-7. [PMID: 11541896 DOI: 10.2187/bss.9.345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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2500
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Takahashi H, Kobayashi H, Hashimoto Y, Matsuo S, Iizuka H. Interferon-gamma-dependent stimulation of Fas antigen in SV40-transformed human keratinocytes: modulation of the apoptotic process by protein kinase C. J Invest Dermatol 1995; 105:810-5. [PMID: 7490476 DOI: 10.1111/1523-1747.ep12326577] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Fas antigen is a cell membrane protein that has been suggested to mediate apoptosis. Using SV40-transformed human keratinocytes, we investigated the Fas-antigen-dependent apoptotic process. The expression of Fas antigen mRNA was markedly induced by interferon-gamma (IFN-gamma) treatment (500 U/ml). After IFN-gamma treatment in the presence of anti-Fas monoclonal antibody, apoptosis was induced, as detected by the formation of nucleosome-sized fragments of DNA and morphologically by apoptotic cells with round homogeneous nuclear beads detected by acridine orange staining. The apoptotic SV40-transformed keratinocytes were analyzed quantitatively by enzyme-linked immunosorbent assay using antihistone and peroxidase-conjugated anti-DNA antibodies to detect cell death. The IFN-gamma- and anti-Fas antibody-dependent apoptotis was observed by 3 h, and the maximal response was observed by 12 h. The induction of apoptosis was significantly augmented by treatment with 10 ng/ml 12-o-tetradecanoyl-phorbol-13-acetate (TPA). TPA alone had no effect on either Fas antigen expression or on the apoptotic process. Other protein kinase C activators (1-oleoyl-2-acetylglycerol and mezerein) also stimulated IFN-gamma-dependent apoptosis, whereas 4-o-methyl phorbol myristate acetate, a very weak protein kinase C activator, had only a slight effect. The TPA-induced augmentation of apoptosis was inhibited by the protein kinase C inhibitor, 1-(5-isoquinoline-sulfonyl)-2-methyl piperazine dihydrochloride (H-7). However, H-7 inhibited only the TPA-induced augmentation of apoptosis; the basal IFN-gamma- and anti-Fas-dependent apoptosis remained in the presence of H-7. Northern blot analysis revealed that c-jun mRNA was induced by IFN-gamma plus anti-Fas antibody treatment as well as by TPA treatment; the addition of IFN-gamma alone to the incubation medium had no effect on the expression of c-jun mRNA. These results indicate that IFN-gamma induces a Fas-antigen-dependent apoptotic process in SV40-transformed keratinocytes and that TPA augments the process through the activation of protein kinase C.
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