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Tasaki K, Minami T, Ieiri I, Ohtsubo K, Hirakawa Y, Ueda K, Higuchi S. Drug interactions of zonisamide with phenytoin and sodium valproate: serum concentrations and protein binding. Brain Dev 1995; 17:182-5. [PMID: 7573757 DOI: 10.1016/0387-7604(95)00032-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The influence of co-medication with zonisamide (ZNS) on the serum concentration and protein binding of phenytoin (PHT) and sodium valproate (VPA) was studied in 21 pediatric patients. No significant correlation between the daily ZNS dose, and total serum concentrations, free concentrations or free fractions (FF) of PHT or VPA was observed. The patient study showed that changes in the FF of PHT and VPA were correlated more closely with the serum protein and bilirubin levels than changes in the ZNS dosage. An in vitro study revealed that the addition of ZNS caused decreases in the FF of PHT and VPA. However, these decreases were within the range of measurement error and were negligible. In conclusion, no significant effect of ZNS on the serum concentration or protein binding of PHT or VPA was demonstrated.
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Nakamura N, Tasaki K, Tominaga K, Nomizu T, Mulder AH, Abe M, Wakasa H. A case of lymphoblastic lymphoma with aberrant morphologic feature. Fukushima J Med Sci 1994; 40:149-57. [PMID: 7642166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We report a case of 33-year-old Japanese female who had B-cell lymphoblastic lymphoma with Burkitt's lymphoma (BL)-like morphologic feature. Both breasts were involved and the resected tissue showed starry sky macrophages and a proliferation of lymphoblasts containing lipid droplets. The nucleus of the lymphoblast was oval or indented. The neoplastic cells examined expressed TdT, CD10, CD14, CD38, and WH14 (a marker of pre-B cell leukemia/lymphomas). Southern blotting analysis showed a rearrangement of the immunoglobulin heavy chain gene and germline configurations of T-cell receptor gene and c-myc 3rd exon gene. The immunophenotype and genotype of this neoplasm were different from those of previously reported BLs, but identical to those of B-cell lymphoblastic lymphoma. This case, therefore, was regarded as B-cell type lymphoblastic lymphoma containing lipid droplets.
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Abe M, Tasaki K, Matsuda S, Sakuma H, Wakasa H. A single clonal origin of neoplastic B cells in a patient with CD5+B-intermediate lymphocytic lymphoma terminating in plasmacytoid differentiation. Arch Pathol Lab Med 1994; 118:303-7. [PMID: 7510947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To investigate the clonal origin of a case of CD5+B-intermediate lymphocytic lymphoma terminating in plasmacytoid differentiation, we analyzed the immunophenotype and immunoglobulin gene rearrangements in the first and second lymph nodes from which biopsy specimens were taken. Immunohistochemical study revealed that both neoplasms have the same immunoglobulin light chain type (kappa-light chain). Immunoglobulin gene analysis using the Southern blot method revealed the identical immunoglobulin heavy chain and kappa-light chain gene rearrangements in both neoplasms. These findings suggest that both neoplasms are derived from a single clonal B cell. The present case may help a further understanding of CD5+B-lymphocyte differentiation pathway.
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MESH Headings
- Aged
- Antigens, CD/analysis
- B-Lymphocytes/pathology
- CD5 Antigens
- Clone Cells
- Female
- Gene Rearrangement, B-Lymphocyte/immunology
- Humans
- Immunophenotyping
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Lymph Nodes/immunology
- Lymph Nodes/pathology
- Lymph Nodes/ultrastructure
- Microscopy, Electron
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Schmidt R, Tasaki K, Brady J. Computer modeling studies of the interaction of water with carbohydrates. J FOOD ENG 1994. [DOI: 10.1016/0260-8774(94)90024-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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55
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Tasaki K, McDonald S, Brady J. Observations concerning the treatment of long-range interactions in molecular dynamics simulations. J Comput Chem 1993. [DOI: 10.1002/jcc.540140304] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Tasaki K, Nakata K, Kato Y, Khan KN, Mitsuoka S, Hamasaki K, Tsuruta S, Nagataki S. A physiological role of epidermal growth factor in cell kinetics of gastric epithelium. Life Sci 1993; 52:1135-9. [PMID: 8450708 DOI: 10.1016/0024-3205(93)90435-6] [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: 01/30/2023]
Abstract
Administration of epidermal growth factor (EGF) stimulates DNA synthesis in gut epithelial cells and inhibits gastric acid secretion. A physiological role of EGF in cell kinetics of gastric epithelium, however, has not been fully understood. In mature male mice, large amounts of EGF are produced in the submandibular glands, and sialoadenectomy (removal of the submandibular glands) causes a marked reduction of plasma EGF levels. For the evaluation of a biophysical function of EGF, sialoadenectomized mice and sham-operated mice were injected with 3H-thymidine to compare the proliferative activity and the cell-turnover of gastric epithelium between the two groups using the autoradiographic analysis. When mice were killed 90 min after a single injection of 3H-thymidine, the percentages of fundic gland mucosal cells radiolabeled in sialoadenectomized and sham-operated mice were 27.3 +/- 5.0% and 26.3 +/- 5.8% (mean +/- SD), respectively. The difference was not significant (p > 0.05). Similarly, the labeling indices of pyloric gland mucosal cells were not different between the two groups (26.7 +/- 4.3% vs 27.8 +/- 3.7%, p > 0.05). In contrast, when mice were given 17 repeated injections of 3H-thymidine at 6 hr intervals and killed 48 hr after the last injection, labeling indices in sialoadenectomized mice were significantly lower than those in sham-operated mice (35.3 +/- 4.3% vs 52.8 +/- 1.1% in the fundic gland area; 41.0 +/- 6.2% vs 55.1 +/- 5.9% in the pyloric gland area, p < 0.001, respectively). Treatment of sialoadenectomized mice with EGF (5 mg/mouse per day) completely restored the percentages of the radiolabeled cells to control levels. These findings suggest that endogenous EGF plays a major role in maintaining biological cell-turnover of the mouse gastric epithelium.
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Hojo H, Morimura Y, Abe M, Tominaga K, Nozawa Y, Nakamura N, Ono N, Tasaki K, Yamaguchi Y, Suzuki S. Protein kinase C isozyme expression in human leukemia-lymphoma cell lines--an immunocytochemical study. Hematol Oncol 1992; 10:295-300. [PMID: 1296930 DOI: 10.1002/hon.2900100602] [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: 12/26/2022]
Abstract
There have been an increasing number of reports describing a pivotal role for phosphorylation in cellular responses for cell differentiation and proliferation. We examined an immunocytochemical expression of protein kinase C(PKC) isozymes (type I, II, and III) in 22 leukemia-lymphoma cell lines. Of these cell lines, 21 expressed type II PKC and 17 showed the co-expression of both types II and III PKC in varying degree. The cell line without PKC activity showed far less [3H]-TdR uptake and no heterotransplantation in nude mice. Types II and III PKC appear to relate to cell proliferation in certain leukemia-lymphoma cell lines.
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Abe M, Tasaki K, Nozawa Y, Tominaga K, Fukuhara S, Ohsato T, Wakasa H. Establishment and characterization of a human T-cell lymphoblastic lymphoma cell line (HT-1) carrying an inversion of chromosome 14. Cancer 1992; 69:1235-40. [PMID: 1310890 DOI: 10.1002/cncr.2820690527] [Citation(s) in RCA: 9] [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
A new human lymphoblastic lymphoma cell line was established (designated HT-1) from the pleural fluid lymphoma cells of a patient with lymphoblastic lymphoma of T-cell type. The HT-1 cells expressed CD1, CD2, CD3, CD4, CD5, CD7, CD8, CD57, and terminal deoxynucleotidyl transferase (TdT) but lacked B-cell-associated antigens and myeloid-associated antigens. In addition, HT-1 cells had rearranged T-cell receptor (TCR) beta-chain gene and gamma-chain gene but retained germlines of immunoglobulin (Ig) heavy chain gene. These findings indicate that HT-1 cell line represents a common thymocyte in the T-cell lineage. Cytogenetic studies revealed that HT-1 cells carry an inversion (inv) of the long arm of chromosome 14. This cell line is the second T-cell line carrying inv(14) chromosome and may be useful for the molecular investigation of the cytogenetic break points of inv(14).
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Nozawa Y, Miyazawa M, Tasaki K, Ono N, Abe M, Wakasa H. [CD3-negative natural killer cell leukemia with aggressive clinical course]. [RINSHO KETSUEKI] THE JAPANESE JOURNAL OF CLINICAL HEMATOLOGY 1992; 33:360-4. [PMID: 1533692] [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 authors report an autopsy case of CD3- large granular cell leukemia with an aggressive clinical course. A 15-year-old male was admitted to our hospital with complaint of high fever. Clinical examination revealed cervical lymphadenopathy and hepatosplenomegaly. His white blood cell count was 7,000/microliters with 45% large granular lymphocytes. A biopsy specimen of the cervical lymph node showed diffuse lymphoma, mixed small and large cells (DM). Surface marker analysis by immunohistochemical technique revealed that neoplastic cells expressed CD2, CD38, CD56 and HLA-DR but lacked CD3, CD4 and CD8. Southern blot analysis of immunoglobulin (Ig) and T cell receptor (TCR) genes showed germ line of Ig and TCR. These findings indicate that this case was a large granular cell leukemia with the natural killer cell phenotype. Despite anti-leukemic therapy, he died of hyperkalemia and acidosis. Autopsy showed a marked swelling of the liver (3,122 g) and spleen (2,434 g) with leukemic cell infiltration.
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Abe M, Tasaki K, Tominaga K, Fukuhara S, Imai S, Osato T, Wakasa H. Characterization and comparison of two newly established Epstein-Barr virus (EBV)-negative and EBV-positive Burkitt's lymphoma cell lines. EBV-negative cell line with a low level of expression of ICAM-1 molecule and EBV-positive cell line with a high level of expression of ICAM-1 molecule. Cancer 1992; 69:763-71. [PMID: 1309680 DOI: 10.1002/1097-0142(19920201)69:3<763::aid-cncr2820690325>3.0.co;2-#] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two human Burkitt's lymphoma cell lines (HBL-4 and HBL-5) were established individually from two patients with small noncleaved cell lymphoma (Burkitt's type). The HBL-4 cell line is Epstein-Barr virus (EBV)-negative, and the HBL-5 cell line is EBV-positive. Cytogenetically, both cell lines had the same chromosomal translocation, t(8;14)(q24;q32) as those observed in the primary malignant cells from individual patients. Morphologic, immunophenotypic, cytogenetic, and molecular studies confirmed that both cell lines were derived from the primary lymphoma cells in vivo. HBL-4 cells lacked CD23(H107), CD11a(LFA-1), and latent membrane protein (LMP) but expressed CD54(ICAM-1) at low levels, whereas HBL-5 cells showed the high level of expression of CD54 and faint expression of LMP but lacked CD11a. In addition, the EBV-positive lymphoblastoid cell line (LCL) expressed CD11a, CD23, CD54, and LMP at high levels. Therefore, an HBL-5 phenotype with expression of CD54 and LMP tends toward an LCL phenotype, and the augmentation of CD54 on the HBL-5 cells in comparison with primary lymphoma cells is likely to be upregulated by LMP, probably resulting from the EBV infection. There was little difference in the BrdUrd uptake in vivo and in vitro, doubling time, tumorigenicity, and dynamics of tumor growth in athymic nude mice between both cell lines. These findings indicate that the potentiality of cell growth and tumorigenicity of these two cell lines are unlikely to be related with EBV.
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61
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Mutoh T, Kasai M, Itabashi R, Tamai M, Suzuki H, Tasaki K. [Development of image processing system for fundus video-angiography with non-stroboscopic illumination]. NIPPON GANKA GAKKAI ZASSHI 1991; 95:861-8. [PMID: 1796768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A new recording system for fluorescein video-angiography using a highly sensitive color charge coupled device (CCD) camera was developed. An image processing unit installed in a personal computer made it possible to process video signals from the camera and/or a video tape recorder. Functions of the unit are on-line and/or off-line operations on image data such as smoothing, digital subtraction, differentiation etc. Application of the unit improved the quality of images observed on a monitor screen. This system enabled observation of the ocular fundus with illumination of low intensity, which reduced physical and psychological suffering of patients. In addition continuous and whole sequences of fundus fluorographs were recorded, without using strong stroboscopic lights. Extraction of a clear image from ambiguous records at any moment was possible through off-line processing on the stored data. Furthermore quantification of the blood flow in any blood vessels was possible by subtracting two successive images. With this system, quantitative expression of a slight difference in the color of the fundus could be made through calculation of the ratios among R-, G-, and B-components of signals at any place. Finally, comparative study of images of the fundus with natural color could be made with those of fluorography. These features may provide further information on the physiology and pathology of the fundus.
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62
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Tasaki K, Brady JW. The development of molecular mechanics parameters for carbohydrates. Proteins 1991. [DOI: 10.1007/978-94-010-9063-6_56] [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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63
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Kasai M, Suzuki H, Tamai M, Tasaki K. [Fundus video fluorescein angiography with low steady light]. NIPPON GANKA GAKKAI ZASSHI 1990; 94:637-44. [PMID: 2220501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To decrease both the intensity of the exciting light and the amount of sodium fluorescein, we attached a compact image intensifier incorporating a microchannel plate with a fundus photoscope and tried to record video-fluorescein angiography with low steady light. We preliminarily examined the relationships of exciting and emitted light intensity with various concentrations of sodium fluorescein. The strongest fluorescence was obtained with a concentration of 0.01 mg/ml solution of sodium fluorescein. When the compact image intensifier was attached to the equipment, the exciting light intensity could be decreased to 1/300 with an exciting filter of lambda max of 486 nm. When sodium fluorescein of 0.01 mg/ml solution was injected directly into the heart of Rana catesbeiana, complete video-fluorescein angiography with sufficient brightness and resolution was possible. With the same machine, we recorded video-fluorescein angiography in a normal human subject with injection of 5 ml of 10% sodium fluorescein. The ordinary observing light of the machine was strong enough for video-recording. This exciting light intensity caused no trouble and elicited no complaint from the examinee. These results showed that the use of a compact image intensifier incorporated microchannel plate with a fundus photoscope made it possible to record video-fluorescein angiography and to decrease exciting light intensity and the amount of fluorescein dye. This means that light damage to photoreceptors by exciting light and problems induced by allergic reaction with fluorescein dye might be decreased. These aspects might be very important to obtain information about both retinal circulation and disruption of the blood-retinal barrier and also to perform safe fluorescein angiography examination.
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64
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Tasaki K, Shima T, Matsumura S, Okada Y, Nishida M, Yamada T, Okita S, Kagawa R. [A case of subdural effusion secondary to dural metastasis of prostatic cancer: case report]. NO SHINKEI GEKA. NEUROLOGICAL SURGERY 1990; 18:539-42. [PMID: 2395513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The authors reported a case of subdural effusion secondary to dural metastasis of prostatic cancer. A 61-year-old man was referred for headache, vomiting and gait disturbance. He had undergone hormonal therapy for prostatic cancer. He showed a mild left hemiparesis and anemia without bleeding. CT-scan disclosed a multilobular crescent shaped low density area in the right hemisphere. Under the diagnosis of chronic subdural hematoma, burr hole irrigation therapy was performed. Xanthochromic fluid was evacuated from the subdural space, in which no tumor cells were shown to exist. CT-scan on the 21st day disclosed a low density area, which was diagnosed as recurrent chronic subdural effusion. Therefore, craniotomy was performed to evacuate the subdural fluid and to explore the dura mater. Removal of the red hemorrhagic tumor at the dura mater and the fluid was performed. The patient died of heart failure in the 16th month despite complete recovery after the second operation. Histopathological examination of the tumor revealed adenocarcinoma at the outer part of the dura mater and the adjacent skull bone, where capillaries were embolized with tumor cells. However, no tumor cells were found in the subdural fluid. The authors could find in the literature 30 cases of subdural hematoma or effusion secondary to dural metastasis of carcinoma. The pathogenesis of the subdural hematoma in this case might be due to circulatory disturbance at the dura mater brought about by the invasion of the tumor or tumor cells emboli in the capillaries.
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65
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Ogasawara T, Tasaki K. Bimodality in the nocturnal behavior of the giant land snail, Achatina fulica. TOHOKU J EXP MED 1990; 161:129-35. [PMID: 2264061 DOI: 10.1620/tjem.161.129] [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: 12/31/2022]
Abstract
Entrainment and phase advance of the circadian locomotor rhythms in the giant land snail, Achatina fulica, were examined by a running wheel method. The mean activity patterns in three light-dark (LD) cycles (LD 14: 10, LD12: 12, LD 10: 14) were characterized by bimodal peaks, namely an initial major peak 1-2 hr after the onset of darkness and a later peak after nearly 6 hr. The activity rhythms were able to follow a 6 hr phase advance shift of the LD 14: 10 cycle with transients, accompanied by shortening or splitting of the activity time. When splitting occurred, the initial component showed phase advancement in the dark and phased to lights-off whereas the later one phased to lights-on, with post-dawn activity being suppressed by light. These results suggest the presence of multioscillator circadian organization which shows monophasic or biphasic entrainment under the LD cycles.
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66
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Horiuchi Y, Itoh Y, Sasaki T, Tasaki K, Iijima K, Uchinishi K. Dorsal dislocation of the D.I.P. joint with fracture of the volar base of the distal phalanx. JOURNAL OF HAND SURGERY (EDINBURGH, SCOTLAND) 1989. [PMID: 2746118 DOI: 10.1016/0266-7681(89)90122-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Between 1978 and 1985, we treated 12 cases of dorsally displaced fracture-dislocation of the I.P. joint of the thumb or of the D.I.P. joint of the finger, with a volar bony fragment. All were treated surgically, active exercise being started three to five weeks later. At the last follow-up, averaging 6.4 years (range 4.3-10 years) after operation, none of the joints was painful but the range of motion was somewhat limited.
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Horiuchi Y, Itoh Y, Sasaki T, Tasaki K, Iijima K, Uchinishi K. Dorsal Dislocation of the D.I.P. Joint with Fracture of the Volar Base of the Distal Phalanx. JOURNAL OF HAND SURGERY 1989; 14:177-82. [PMID: 2746118 DOI: 10.1016/0266-7681_89_90122-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Between 1978 and 1985, we treated 12 cases of dorsally displaced fracture-dislocation of the I.P. joint of the thumb or of the D.I.P. joint of the finger, with a volar bony fragment. All were treated surgically, active exercise being started three to five weeks later. At the last follow-up, averaging 6.4 years (range 4.3–10 years) after operation, none of the joints was painful but the range of motion was somewhat limited.
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68
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Sugita Y, Suzuki H, Tasaki K. Human rods are acting in the light and cones are inhibited in the dark. TOHOKU J EXP MED 1989; 157:365-72. [PMID: 2741172 DOI: 10.1620/tjem.157.365] [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: 01/02/2023]
Abstract
The light- and color detection thresholds were measured at three different states of retinal adaptation, i.e., light- and dark adapted states and the intermediate state which was obtained just before the Kohlrausch kink in the course of dark adaptation. At 20 degrees from fixation in the nasal visual field, the wavelength function was examined. The color threshold was higher in the dark adapted state than in the state just before the kink, and the amount of increase was more prominent when the wavelength of the stimulus light was closer to the peak wavelength of rod sensitivity. It was concluded that the rod activation interferes with the cone sensitivity, and that the interference effect becomes stronger as a function of the responsiveness of rods. On the other hand, the spectral sensitivity curve determined in the light adapted state could be divided into two parts. The curve for shorter wavelength than 500 nm was well fitted by the scotopic luminosity curve, suggesting that the light threshold for shorter wavelength is determined by the rod system even in the light adapted state.
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Sugita Y, Itabashi R, Tasaki K. Cone activation delaying recovery time of rod sensitivity after flash exposure. TOHOKU J EXP MED 1988; 156:305-10. [PMID: 3266685 DOI: 10.1620/tjem.156.305] [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: 01/05/2023]
Abstract
The recovery time of rods to the fully dark adapted state after flash exposure was psychophysically and electrophysiologically measured. The recovery time increased abruptly once cones were activated. This abrupt increment was not found for the receptor component (P III) of the frog electroretinogram. It was suggested that the cone activation results in inhibitory influence upon the recovery process of the rod sensitivity.
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Abstract
Over the whole course of dark adaptation, light- and color detection thresholds were measured. At 6 degrees in the nasal visual field, the effect of wavelength was examined. After the rod-cone break (Kohlrausch kink), the color threshold began to rise while the light threshold was progressively decreasing. The rise of the color threshold was more remarkable as the test wavelength was more close to the peak wavelength for rod sensitivity. With green test light, the sensitivity difference of retinal position was investigated. The rise of the color threshold was more prominent at the retinal position where rods were more densely packed. Finally, the Stiles-Crawford effect was examined with a green test light at 12 degrees in the nasal visual field. This effect appeared for the color threshold over the whole course of dark adaptation but not for the light threshold even before the rod-cone break. It was concluded that the rod activation interferes with cone sensitivity and the interference effect becomes stronger as rods become progressively more dark adapted, and that the rod system is also acting even before the rod-cone break.
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LeBreton PR, Fetzer S, Tasaki K, Yang X, Yu M, Slutskaya Z, Urano S. UV photoelectron spectroscopy and ab initio characterization of valence orbital structures and conformations of neutral phosphate esters. J Biomol Struct Dyn 1988; 6:199-222. [PMID: 3271519 DOI: 10.1080/07391102.1988.10506491] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The HeI UV photoelectron spectrum of trimethyl phosphate (TMP) has been measured and interpreted with the aid of SCF molecular orbital calculations carried out with STO-3G, STO-3G* and 4-31G basis functions. The photoelectron spectrum of TMP is more accurately reproduced by results from 4-31G calculations than by results from STO-3G or STO-3G* calculations. However, all three basis sets yield results which predict the same assignment of the photoelectron spectrum. Results at the 4-31G level indicate that whether calculations are based on crystallographic bond angles and bond lengths or on STO-3G optimized geometries has little effect on the energetic ordering of the upper occupied orbitals. The energetic ordering of orbitals is also found to be only weakly dependent upon the torsional angle phi, describing rotation of ester groups about P-O bonds and upon the torsional angle psi, describing rotation of methyl groups about C-O bonds. For trimethyl phosphate, with C3 symmetry, the vertical ionization potentials of the upper occupied orbitals are 10.81 eV (8e), 11.4 eV (9a), 11.93 eV (7e), 12.6-12.9 eV (8a and 6e), 14.4 eV (7a) and 15.0-16.0 eV (5e and 6a). Calculations at the 4-31G level indicate that many of the highest occupied orbitals in neutral dimethyl phosphate and methyl phosphate have energies and electron distributions similar to orbitals in TMP. For TMP, a search for optimized values of phi and psi has been carried out at the STO-3G*level. In agreement with previous NMR studies and with classical potential calculations, the STO-3G* results indicate that both the gauche (phi = 53.1 degrees) and anticlinal (phi = 141.9 degrees) conformations are thermally accessible. Also in agreement with the classical potential calculations, the STO-3G* results predict that in the all gauche conformation energy is minimized when the methyl groups assume a staggered geometry (psi = 60 degrees to 80 degrees) and that an energy maximum occurs for an eclipsed geometry (phi = 0 degrees to 20 degrees). A study of the dependence of optimized values of O-P-O ester bond angles on the torsional angles, phi, was carried out at the STO-3G, STO-3G* and 4-31G levels. The results demonstrate that for C3 symmetry, the coupling of O-P-O angles to phi is influence by repulsive steric interactions.
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72
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Urano S, Fetzer S, Harvey RG, Tasaki K, LeBreton PR. Influences of 7-alkyl substitution on the reversible binding of the proximate carcinogen trans-3,4-dihydroxy-3,4-dihydrobenz[a]anthracene to DNA. Biochem Biophys Res Commun 1988; 154:789-95. [PMID: 3401236 DOI: 10.1016/0006-291x(88)90209-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effects of 7-alkyl substitution on the reversible intercalation of the proximate carcinogen trans-3,4-dihydroxy-3,4-dihydrobenz[a]anthracene (BAD) to calf thymus DNA have been examined using time-resolved fluorescence spectroscopy. The results indicate that in 10(-3) M sodium cacodylate the binding constant of BAD is 1.8 x 10(3) M-1. 7-Ethyl substitution decreases the binding constant 1.6 times, while 7-methyl substitution increases the binding constant 1.7 times. UV Photoelectron data and results from ab initio molecular orbital calculations suggest that an increase in polarizability contributes to the increased binding accompanying methyl substitution. The decreased binding accompanying ethyl substitution arises from steric inhibition. The physical binding data correlates with the decrease in carcinogenic activity which occurs with 7-ethyl substitution of benz[a]anthracene metabolites.
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Wada K, Muramatsu Y, Tasaki K, Satou T, Ozaki K, Takano M, Arakawa M. [An infection route of meningococcal meningitis and eradication of carriers]. KANSENSHOGAKU ZASSHI. THE JOURNAL OF THE JAPANESE ASSOCIATION FOR INFECTIOUS DISEASES 1988; 62:194-9. [PMID: 3147299 DOI: 10.11150/kansenshogakuzasshi1970.62.194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Abstract
In the retinal periphery, rod and cone thresholds to the same green light were measured. After the rod-cone break in the course of dark adaptation, cone sensitivity decreases gradually as rod sensitivity progressively increases. Cone sensitivity, however, increases when rod sensitivity is decreased by blue light. The emergence of the facilitatory effect of rod activation requires at least a few hundred msec after rod stimulation. It is concluded that rod activation plays a major role in sensitivity regulation of the cone system, i.e., in human color vision.
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75
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Uekama K, Otagiri M, Uemura Y, Fujinaga T, Arimori K, Matsuo N, Tasaki K, Sugii A. Improvement of oral bioavailability of prednisolone by beta-cyclodextrin complexation in humans. JOURNAL OF PHARMACOBIO-DYNAMICS 1983; 6:124-7. [PMID: 6864436 DOI: 10.1248/bpb1978.6.124] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Inclusion complex of prednisolone with beta-cyclodextrin (beta-CyD) in 1:2 molar ratio was prepared and its dissolution, membrane permeation and oral absorption behaviors were examined. The rates of dissolution and permeation through a cellophane membrane in water were significantly increased by beta-CyD complexation. A crossover bioavailability study was performed using human subjects with lower doses of prednisolone tablets, where the plasma levels of the drug were determined by radioimmunoassay. The enhanced bioavailability of prednisolone by beta-CyD complexation suggested the possibility of smaller doses and fewer side effects in prednisolone therapy.
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