301
|
Akura J, Kaneda S, Ishihara M, Matsuura K. Quarters extraction technique for manual phacofragmentation(1). J Cataract Refract Surg 2000; 26:1281-7. [PMID: 11020612 DOI: 10.1016/s0886-3350(00)00475-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In the quarters extraction technique, the nucleus is manually split and the fragments then removed. A 5.5 to 6.5 mm sclerocorneal single-plane incision is made. After capsulorhexis, hydrodissection, hydrodelineation, and surface cortex aspiration, the edge of the nucleus is prolapsed into the anterior chamber. The front quarter of the nucleus is cut and removed with a nucleus puncher. A corner of the remaining three quarters of nucleus is wedged into the wound and rotated out with a claw vectis. Among the initial 120 cases, there were no posterior capsule ruptures, and the mean endothelial cell loss at 3 months was 8.7% +/- 6.5% (SD). Because there is no need to deeply insert instruments at the time of nuclear fragmentation, this technique can be performed safely and easily in most cases except in eyes with very large nuclei.
Collapse
|
302
|
Kariya Y, Kyogashima M, Suzuki K, Isomura T, Sakamoto T, Horie K, Ishihara M, Takano R, Kamei K, Hara S. Preparation of completely 6-O-desulfated heparin and its ability to enhance activity of basic fibroblast growth factor. J Biol Chem 2000; 275:25949-58. [PMID: 10837484 DOI: 10.1074/jbc.m004140200] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although regioselective removal of 6-O-sulfate groups of heparin has been undertaken by several researchers, complete 6-O-desulfation with little side reaction has not been attained successfully. In this work, a modified method with a certain silylating reagent, N-methyl-N-(trimethylsilyl)trifluoroacetamide, has been established to produce completely 6-O-desulfated heparin with few other chemical changes. The degrees of 6-O-desulfation were estimated by means of chemical disaccharide analyses and/or (13)C NMR spectra. Although the completely 6-O-desulfated heparin lost about 20% of 2-O-sulfate groups, any other chemical changes and depolymerization were not detected. The completely 6-O-desulfated heparin displayed strong inhibition of COS-1 cell adhesion to basic fibroblast growth factor (bFGF)-coated well in a dose-dependent manner, as was clarified by the competitive cell-adhesion assay. Furthermore, the completely 6-O-desulfated heparin was shown to promote in vitro A31 fibroblast proliferation in a dose-dependent manner in the presence of bFGF. These results suggest that signal transduction through bFGF/bFGF receptor in A31 cells occurs in the absence of 6-O-sulfate groups in heparin. The involvement of 6-O-sulfate group(s) of heparin/heparan sulfate in the promotion of bFGF mitogenic activity was reported by several groups. This discrepancy between our results and those of other groups would be due to the differences in molecular size of heparin/heparan sulfate derivatives and/or cell species used for the assay.
Collapse
|
303
|
Ikegaya Y, Itsukaichi-Nishida Y, Ishihara M, Tanaka D, Matsuki N. Distance of target search of isolated rat hippocampal neuron is about 150 microm. Neuroscience 2000; 97:215-7. [PMID: 10799753 DOI: 10.1016/s0306-4522(00)00098-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although the survival of neuronal cells is highly dependent on neural connections with afferents or targets,(10,14,15) little is known about the survival of immature neurons that have not yet encountered the partners. Herein, using cultures of isolated hippocampal neurons of rat embryos, we have attempted to elucidate the contribution of neurite outgrowth to neuron survival and found that neurons died at a certain degree of neurite length with apoptotic characteristics in cases of no contact with other neurons. The threshold was 143.4microm, which was about five times as long as the cell body diameter. It was altered by depolarization or in the presence of basic fibroblast growth factor. Thus, neurons may be designed to kill themselves if they cannot find their targets after exploration within a particular area, the extent of which is variable due to cellular conditions.
Collapse
|
304
|
Kujiraoka T, Oka T, Ishihara M, Egashira T, Fujioka T, Saito E, Saito S, Miller NE, Hattori H. A sandwich enzyme-linked immunosorbent assay for human serum paraoxonase concentration. J Lipid Res 2000; 41:1358-63. [PMID: 10946025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Serum paraoxonase (PON) is associated with plasma high density lipoproteins, and prevents the oxidative modification of low density lipoproteins. We have developed a sensitive sandwich enzyme-linked immunosorbent assay (ELISA), using two monoclonal antibodies against PON, to measure serum PON concentration. The concentration of PON in healthy Japanese subjects was 59.3 +/- 1.3 microgram/mL (mean +/- SEM; n = 87). Serum PON concentrations in relation to the PON 192 genetic polymorphism were: 69.5 +/- 2.9 microgram/mL in the QQ genotype; 63.0 +/- 1.9 microgram/mL in the QR genotype; and 52.8 +/- 1.7 microgram/mL in the RR genotype. Concentrations were significantly lower in the RR than in the QQ genotype (P < 0.01). Serum paraoxonase specific activity was higher in RR than in QQ subjects (18.6 +/- 0.40 vs. 2. 56 +/- 0.05 nmol/min/microgram, P < 0.01), but arylesterase specific activity was unrelated to genotype. PON concentration was positively associated (P < 0.001) with both serum arylesterase activity and, after adjusting for the effect of the position 192 polymorphism, with serum paraoxonase activity. Subjects with angiographically verified coronary heart disease had significantly lower PON concentrations than the healthy controls (52.0 +/- 2.3 microgram/mL; n = 35, P < 0.01). This association was independent of the position 192 genotype. Our new ELISA should be of value for epidemiologic and clinical studies of serum PON concentration. immunosorbent assay for human serum paraoxonase concentration.
Collapse
|
305
|
Kujiraoka T, Ishihara M, Fujioka T, Saito E, Saito S, Egashira T, Hattori H. Measurement of paraoxonase (PON) concentrations in coronary heart desease (CHD) subjects by sandwich Elisa. Atherosclerosis 2000. [DOI: 10.1016/s0021-9150(00)80248-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
306
|
Misao H, Yamada M, Ikeda K, Ishihara M. The role and function of the HIV/AIDS coordinator nurse in Japan. J Assoc Nurses AIDS Care 2000; 11:89-96. [PMID: 10911598 DOI: 10.1016/s1055-3290(06)60400-7] [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: 11/29/2022]
Abstract
HIV/AIDS coordinator nurses (CNs) are key professionals in ensuring the provision of quality health care to patients with HIV/AIDS and to their families. Through this case study, the functions of the HIV/AIDS CN in Japan were identified, and an initial model of the HIV/AIDS CN role was developed. Four categories of responsibility were identified: (a) assessment, (b) diagnosis of nursing problems, (c) coordination, and (d) other related nursing activities. The category of other nursing activities included four subcategories. These were (a) consultation, (b) patient education, (c) expansion of the patient's support network, and (d) administrative or office work. These categories and subcategories contribute to an understanding of the role of the HIV/AIDS CN.
Collapse
|
307
|
Ishihara M, Sato H, Tateishi H, Kawagoe T, Shimatani Y, Ueda K, Noma K, Yumoto A, Nishioka K. Beneficial effect of prodromal angina pectoris is lost in elderly patients with acute myocardial infarction. Am Heart J 2000; 139:881-8. [PMID: 10783223 DOI: 10.1016/s0002-8703(00)90021-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Prodromal angina pectoris occurring shortly before the onset of acute myocardial infarction is associated with a favorable outcome by the mechanism of ischemic preconditioning. Recent experiments have reported that the beneficial effect of ischemic preconditioning are reversed in the aged heart. METHODS We studied 990 patients who underwent coronary angiography within 12 hours after the onset of acute myocardial infarction. Patients were divided into 2 groups: those aged <70 years (nonelderly patients, n = 722) and those aged >/=70 years (elderly patients, n = 268). Prodromal angina in the 24 hours before infarction was found in 190 of 722 nonelderly patients and in 66 of 268 elderly patients (26% vs 25%, P =.61). RESULTS In nonelderly patients, prodromal angina was associated with lower peak creatine kinase levels (2438 +/- 1939 IU/L vs 2837 +/- 2341 IU/L, P =.04), lower in-hospital mortality rates (3.7% vs 8.8%, P =.02), and better 5-year survival rates (P =. 007). On the contrary, in elderly patients there was no significant difference in peak creatine kinase levels (2427 +/- 2142 IU/L vs 2256 +/- 1551 IU/L, P =.51), in-hospital mortality rate (21.2% vs 17. 4%, P =.49), and 5-year survival rates (P =.47). A multivariate analysis showed that prodromal angina in the 24 hours before infarction was associated with 5-year survival rate in nonelderly patients (odds ratio 0.49, P =.009) but not in elderly patients (odds ratio l.12, P =.65). CONCLUSIONS In nonelderly patients, prodromal angina in the 24 hours before infarction was associated with a smaller infarct size and better short- and long-term survival, suggesting a relation to ischemic preconditioning. However, such a beneficial effect was not observed in elderly patients.
Collapse
|
308
|
Kusano Y, Oguri K, Nagayasu Y, Munesue S, Ishihara M, Saiki I, Yonekura H, Yamamoto H, Okayama M. Participation of syndecan 2 in the induction of stress fiber formation in cooperation with integrin alpha5beta1: structural characteristics of heparan sulfate chains with avidity to COOH-terminal heparin-binding domain of fibronectin. Exp Cell Res 2000; 256:434-44. [PMID: 10772816 DOI: 10.1006/excr.2000.4802] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study provides direct evidence that syndecan 2 participates selectively in the induction of stress fiber formation in cooperation with integrin alpha5beta1 through specific binding of its heparan sulfate side chains to the fibronectin substrate. Our previous study with Lewis lung carcinoma-derived P29 cells demonstrated that the cell surface heparan sulfate proteoglycan, which binds to fibronectin, is syndecan 2 (N. Itano et al., 1996, Biochem. J. 315, 925-930). We here report that in vitro treatment of the cells by antisense oligonucleotide for syndecan 2 resulted in a failure to form stress fibers on fibronectin substrate in association with specific suppression of its cell surface expression. Instead, localization of actin filaments in the cytoplasmic cortex occurred. A similar response of the cells was observed when the cells were treated to eliminate functions of cell surface heparan sulfates, including exogenous addition of heparin and pretreatment with anti-heparan sulfate antibody, F58-10E4, and with proteinase-free heparitinase I. Size- and structure-defined oligosaccharides prepared from heparin and chemically modified heparins were utilized as competitive inhibitors to examine the structural characteristics of the cell surface heparan sulfates involved in organization of the actin cytoskeleton. Their affinity chromatography on a column linked with a recombinant H-271 peptide containing a C-terminal heparin-binding domain of fibronectin demonstrated that 2-O-sulfated iduronates were essential for the binding. Inhibition studies revealed that a heparin-derived dodecasaccharide sample enriched with an IdoA(2OS)-GlcNS(6OS) disaccharide completely blocked binding of the syndecan 2 ectodomain to immobilized H-271 peptide. Finally, the dodecasaccharide sample was shown to inhibit stress fiber formation, triggered by adhesion of P29 cells to a CH-271 polypeptide consisting of both the RGD cell-binding and the C-terminal heparin-binding domains of fibronectin in a fused form. All these results consistently suggest that syndecan 2 proteoglycan interacts with the C-terminal heparin-binding domain of fibronectin at the highly sulfated cluster(s), such as [IdoA(2OS)-GlcNS(6OS)](6) present in its heparan sulfate chains, to result in the induction of stress fiber formation in cooperation with integrin alpha5beta1.
Collapse
|
309
|
Ishihara M, Ono K, Ishikawa K, Hattori H, Saito Y, Yura H, Akaike T, Ozeki Y, Tanaka S, Mochizuki H, Kurita A. Enhanced ability of heparin-carrying polystyrene (HCPS) to bind to heparin-binding growth factors and to inhibit growth factor-induced endothelial cell growth. J Biochem 2000; 127:797-803. [PMID: 10788788 DOI: 10.1093/oxfordjournals.jbchem.a022672] [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: 11/13/2022] Open
Abstract
Heparin-carrying polystyrene (HCPS) consists of low-molecular-weight heparin chains enriched in trisulfated disaccharide structures linked to a polystyrene core. In this study, the interactions between HCPSs of various molecular weights and heparin-binding growth factors, VEGF(165), FGF-2, and HGF, were compared to the interactions of the same factors with native heparin, periodate-oxidized heparin (IO(4)-heparin) and periodate-oxidized alkaline-degraded heparin (IO(4)-LMW-heparin). The binding of each growth factor to heparin-agarose beads (heparin-beads) was more strongly inhibited by HCPSs in a molecular weight-dependent manner than by native heparin or the modified heparins, indicating a stronger interaction between HCPS and these growth factors. HCPSs also inhibit heparin-binding growth factor-induced endothelial cell growth in a molecular weight-dependent manner much more strongly than the native or modified heparins. However, HCPSs did not inhibit the mitogenic activity of VEGF(121), which has a non-heparin-binding nature. Thus, HCPSs exhibit enhanced abilities to interact with each of the heparin-binding growth factors studied and to inhibit heparin-binding growth factor-induced endothelial cell proliferation in a molecular weight-dependent manner. These effects might be ascribed to the heparin-clustering effect of HCPSs.
Collapse
|
310
|
Ishihara M, Saito Y, Yura H, Ono K, Ishikawa K, Hattori H, Akaike T, Kurita A. Heparin-carrying polystyrene to mediate cellular attachment and growth via interaction with growth factors. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2000; 50:144-52. [PMID: 10679678 DOI: 10.1002/(sici)1097-4636(200005)50:2<144::aid-jbm8>3.0.co;2-s] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Various sugar-carrying polystyrenes (PSs), which consist of synthetic styrene and sugar moieties, are glycoconjugates that are able to attach to polymeric surfaces. Heparin-carrying PS (HCPS) is especially able to retain the binding of heparin-binding growth factors (GFs) such as vascular endothelial GF 165 (VEGF(165)) or fibroblast GF 2 (FGF-2). Human skin fibroblast cells, human coronary smooth muscle cells, and human coronary endothelial cells have good adherence to the HCPS-coated plate. The growth rate of fibroblast cells on HCPS-coated plates is higher than or comparable to fibronectin-coated, gelatin-coated, or tissue culture treated plates, and the HCPS coating inhibits the growth of smooth muscle cells. On the other hand, the growth rate of endothelial cells on HCPS-coated plates in the presence of either VEGF(165) or FGF-2 is comparable to that on fibronectin-coated, gelatin-coated, and tissue culture treated plates. Endothelial cells grow at a higher rate on HCPS-coated plates retained with either VEGF(165) or FGF-2 than on the other coated plates. These results indicate that growth of various cells can be controlled by the HCPS coating, thereby retaining the bioactivity of molecules such as heparin-binding GFs. Thus, HCPS-coated surfaces control selective growth of various cells.
Collapse
|
311
|
Kitaoka A, Ishihara M. Three elemental illusions determine the Zöllner illusion. PERCEPTION & PSYCHOPHYSICS 2000; 62:569-75. [PMID: 10909247 DOI: 10.3758/bf03212108] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have discovered an apparent contraction illusion of acute angles in a special form of the Zöllner figure at the intersecting angles between 36 degrees and 83 degrees (i.e., a reversal of the Zöllner illusion). The necessary condition for this illusion is that inducing lines are long enough and the induced line (test line) is single. When an illusory line is used as the induced line, the magnitude of contraction increases. Short inducing lines give no illusion or a slight expansion of acute angles at the intersecting angle of 45 degrees. We have ascertained that the source of this expansion is the narrow region in the vicinity of the induced line, whereas the source of the contraction is much broader regions. Furthermore, we have discovered another expansion mechanism, which is generated by the symmetrical configuration of the standard Zöllner figure.
Collapse
|
312
|
Ishihara M, Sato H, Kawagoe T, Shimatani Y, Kurisu S, Noma K, Yumoto A, Nishioka K. [Long-term prognosis after reperfusion therapy for acute myocardial infarction in elderly patients]. Nihon Ronen Igakkai Zasshi 2000; 37:278-82. [PMID: 10917023 DOI: 10.3143/geriatrics.37.278] [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: 11/11/2022]
Abstract
Although it has been well demonstrated that TIMI grade 3 flow is associated with improved survival after acute myocardial infarction in non-elderly patients, its implication in elderly patients has not been clarified. To assess this issue, 1,115 patients with acute myocardial infarction who underwent coronary angiography within 24 hours after the onset of chest pain were studied: there were 131 elderly patients (age > or = 75 years) and 984 non-elderly patients (age < 75 years). Follow-up was achieved for 1,092 patients (98%). Elderly patients were associated with more female, Killip class > or = 2, 3 vessel disease and non-smokers. Although modality of reperfusion therapy was not different, final TIMI flow grade was less frequently obtained in elderly patients (53% vs 65%, p = 0.005). Elderly patients were associated with higher in-hospital mortality (25% vs 9%, p < 0.001) and lower 10 years cardiac death free rate (p < 0.001). Cox proportional hazards model showed that final TIMI flow grade 3 was an independent predictor of 10 years cardiac death free in elderly patients (odds ratio (OR) = 0.39, 95% confidence interval (CI) = 0.20-0.74, p = 0.004) as well as non-elderly patients (OR = 0.41, 95% CI = 0.29-0.58, p < 0.001). In conclusion, our data suggest that final TIMI grade 3 flow is an important determinant to improve short- and long-term survival after acute myocardial infarction in elderly patients as well as in non-elderly patients.
Collapse
|
313
|
Ishihara M, Itoh M, Miyamoto K, Suna S, Takeuchi Y, Takenaka I, Jitsunari F. Spermatogenic disturbance induced by di-(2-ethylhexyl) phthalate is significantly prevented by treatment with antioxidant vitamins in the rat. INTERNATIONAL JOURNAL OF ANDROLOGY 2000; 23:85-94. [PMID: 10762434 DOI: 10.1046/j.1365-2605.2000.00212.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phthalate esters, now regarded as endocrine disruptors, are widely used in the plastics industry. In particular, di-(2-ethylhexyl) phthalate (DEHP) is produced in large quantities, and is used in blood storage bags, catheters and haemodialysis instruments. Previous studies have demonstrated that treatment of rats with DEHP induces testicular atrophy with liver enlargement, although the precise nature and mechanism of the action of DEHP on these organs remains unclear. In the present study, we produced an experimental model of DEHP-induced spermatogenic disturbance in rats by feeding them a DEHP-containing diet. Liver enlargement occurred in rats fed either a 1 or 2% DEHP-containing diet. However, testicular atrophy accompanied by aspermatogenesis was induced by feeding with the 2% but not with the 1% DEHP-containing diet. This suggests that the critical DEHP dose for gonadotoxicity is higher than that for hepatotoxicity. Using the 2% DEHP-dose, the effect of simultaneous administration of antioxidant vitamins (= vitamins C and E) was next examined. It was found that the vitamin supplementation significantly prevented the testicular injury. The results suggest that antioxidant vitamins can protect the testes from DEHP-toxicity.
Collapse
|
314
|
Ito M, Ban A, Ishihara M. Anti-ulcer effects of chitin and chitosan, healthy foods, in rats. JAPANESE JOURNAL OF PHARMACOLOGY 2000; 82:218-25. [PMID: 10887952 DOI: 10.1254/jjp.82.218] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this study, we compared the effects of low molecular weight (LMW) chitosan (MW: 25,000-50,000), high molecular weight (HMW) chitosan (MW: 500,000-1000,000) and chitin on ethanol-induced gastric mucosal injury and on the healing of acetic acid-induced gastric ulcers in rats. Oral administration of LMW chitosan (250, 500 and 1000 mg/kg) dose-dependently prevented ethanol-induced gastric mucosal injury. Repeated oral administration of LMW chitosan (100, 200 and 400 mg/kg twice daily) also dose-dependently accelerated the gastric ulcer healing. However, the effects of HMW chitosan and chitin on the gastric mucosal injury formation and the gastric ulcer healing were less potent than those of LMW chitosan. LMW chitosan (250 and 500 mg/kg, orally) was ineffective in inhibiting gastric acid secretion in pylorus-ligated rats, although it had a weak acid-neutralizing action. LMW-chitosan (250, 500 and 1000 mg/kg orally) dose-dependently prevented the decrease in gastric mucus content induced by ethanol. These results indicate that of the three compounds, LMW chitosan has the most potent gastric cytoprotective and ulcer healing-promoting actions. In addition, gastric mucus-increasing action of LMW-chitosan may be, at least in part, related to the anti-ulcer effect of this compound.
Collapse
|
315
|
Ishihara M, Ito H, Morris M, Sakurai T, Toyoda M, Wada Y. Obituary: takekiyo matsuo (1943-1999). JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:111-113. [PMID: 10679970 DOI: 10.1002/(sici)1096-9888(200002)35:2<111::aid-jms919>3.0.co;2-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
316
|
Ishihara M, Nakano T, Ohama E, Kawai Y. Postischemic reperfusion in the eyes of young and aged rats. THE JAPANESE JOURNAL OF PHYSIOLOGY 2000; 50:125-32. [PMID: 10866704 DOI: 10.2170/jjphysiol.50.125] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The hemodynamic changes during postischemic reperfusion were investigated in the eyes of young (4 months) and aged (more than 18 months) rats using laser Doppler flowmetry, and histological changes in the retina were examined 6 h after the cessation of ischemia. During exposure to 80 mmHg of intraocular pressure, choroidal blood flow (ChBF) decreased to 40-50% of the baseline value. Marked hyperperfusion (186 +/- 9%) was observed 1 min after cessation of 30-min ischemia in young rats. The hyperperfusion was less (111 +/- 3%) after 120-min ischemia. Delayed hypoperfusion was not observed during 6 h of reperfusion after 120-min ischemia. In aged rats, the hyperperfusion after 30-min ischemia was less (130 +/- 17%) than that in young rats, and the ChBF decreased to 80% of the baseline value during 6 h of reperfusion after 120-min ischemia. Histological examination of the retina showed that exposure to 120-min ischemia caused microvacuolation in the inner and outer plexiform layers and vacuolar changes in the cytoplasms in the inner nuclear layer of both young and aged rats, suggesting edema formation in the retina. The thickness of the outer layers of the retina tended to increase after 120-min ischemia in young rats, whereas it decreased significantly in aged rats. These results suggest that 120-min ischemia with 40-50% of normal choroidal blood flow causes more severe damage than 30-min ischemia, and that the hemodynamic changes during reperfusion in aged rats are different from those in young rats.
Collapse
|
317
|
Ono K, Saito Y, Yura H, Ishikawa K, Kurita A, Akaike T, Ishihara M. Photocrosslinkable chitosan as a biological adhesive. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2000; 49:289-95. [PMID: 10571917 DOI: 10.1002/(sici)1097-4636(200002)49:2<289::aid-jbm18>3.0.co;2-m] [Citation(s) in RCA: 297] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A photocrosslinkable chitosan to which both azide and lactose moieties were introduced (Az-CH-LA) was prepared as a biological adhesive for soft tissues and its effectiveness was compared with that of fibrin glue. Introduction of the lactose moieties resulted in a much more water-soluble chitosan at neutral pH. Application of ultraviolet light (UV) irradiation to photocrosslinkable Az-CH-LA produced an insoluble hydrogel within 60 s. This hydrogel firmly adhered two pieces of sliced ham with each other, depending upon the Az-CH-LA concentration. The binding strength of the chitosan hydrogel prepared from 30-50 mg/mL of Az-CH-LA was similar to that of fibrin glue. Compared to the fibrin glue, the chitosan hydrogel more effectively sealed air leakage from pinholes on isolated small intestine and aorta and from incisions on isolated trachea. Neither Az-CH-LA nor its hydrogel showed any cytotoxicity in cell culture tests of human skin fibroblasts, coronary endothelial cells, and smooth muscle cells. Furthermore, all mice studied survived for at least 1 month after implantation of 200 microL of photocrosslinked chitosan gel and intraperitoneal administration of up to 1 mL of 30 mg/mL of Az-CH-LA solution. These results suggest that the photocrosslinkable chitosan developed here has the potential of serving as a new tissue adhesive in medical use.
Collapse
|
318
|
Toyoda M, Ishihara M, Yamaguchi S, Ito H, Matsuo T, Roll R, Rosenbauer H. Construction of a new multi-turn time-of-flight mass spectrometer. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:163-167. [PMID: 10679976 DOI: 10.1002/(sici)1096-9888(200002)35:2<163::aid-jms924>3.0.co;2-g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new type of multi-turn time-of-flight mass spectrometer was constructed, consisting of four cylindrical electric sectors and 28 electric quadrupole lenses, the size of the vacuum chamber being 60 x 70 x 20 cm. It was demonstrated that the mass resolution can be increased according to the number of cycles of the ions through the ion optical system.
Collapse
|
319
|
Hayashi N, Ishihara M, Tanaka A, Yoshida T. Impeding O(2) unloading in muscle delays oxygen uptake response to exercise onset in humans. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:R1274-81. [PMID: 10564197 DOI: 10.1152/ajpregu.1999.277.5.r1274] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested whether the leftward shift of the oxygen dissociation curve of hemoglobin with hyperpnea delays the oxygen uptake (VO(2)) response to the onset of exercise. Six male subjects performed cycle ergometer exercise at a work rate corresponding to 80% of the ventilatory threshold (VT) VO(2) of each individual after 3 min of 20-W cycling under eupnea [control (Con) trial]. A hyperpnea procedure (minute ventilation = 60 l/min) was undertaken for 2 min before and during 80% VT exercise in hypocapnia (Hypo) and normocapnia (Normo) trials. In the Normo trial, the inspired CO(2) fraction was 3% to prevent hypocapnia. The subjects completed two repetitions of each trial. To determine the kinetic variables of VO(2) and heart rate (HR) at the onset of exercise, a nonlinear least-squares fitting was applied to the data averaged from two repetitions by a monoexponential model. The end-tidal CO(2) partial pressure before the onset of exercise was significantly lower in the Hypo trial than in the Con and Normo trials (22 +/- 1 vs. 38 +/- 3 and 36 +/- 1 mmHg, respectively, P < 0.05). The time constant of VO(2) and HR was significantly longer in the Normo trial (28 +/- 7 and 39 +/- 18 s, respectively) than in the Con trial (21 +/- 7, 34 +/- 16 s, respectively, P < 0.05). The VO(2) time constant of the Hypo trial (37 +/- 12 s) was significantly longer than that of the Normo trial, although no significant difference in the HR time constant was seen (Hypo, 41 +/- 28 s). These findings suggested that respiratory alkalosis delayed the kinetics of oxygen diffusion in active muscle as a result of the leftward shift of the oxygen dissociation curve of hemoglobin. This supports an important role for hemoglobin-O(2) offloading in setting the VO(2) kinetics at exercise onset.
Collapse
|
320
|
Amano Y, Hayashi H, Ishihara M, Kumazaki T. Coronary flow reserve estimated with fast cine phase-contrast magnetic resonance imaging in 4 patients with syndrome X: technical note. Can Assoc Radiol J 1999; 50:298-300. [PMID: 10555501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
|
321
|
Higashiura Y, Ishihara M, Schaefer PW. Sex ratio distortion and severe inbreeding depression in the gypsy moth Lymantria dispar L. in Hokkaido, Japan. Heredity (Edinb) 1999; 83 ( Pt 3):290-7. [PMID: 10504426 DOI: 10.1038/sj.hdy.6885590] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
An abnormal female producing only female progeny was found in Lymantria dispar in Hokkaido, Japan, in July 1996. Similarly, its progeny produced only females. Egg hatch rates were near 50% in all-female matrilines. Therefore, a certain cytoplasmic factor was thought to kill males in eggs differentially, resulting in only female hosts. In the next generation, the field population was estimated to contain 9.1% abnormal females. Severe inbreeding depression was also observed in egg hatch rates during confirmation of maternal inheritance. The cost of inbreeding was estimated at 0. 395, which is one of the highest in insects. Inbreeding avoidance by their host has been cited as one of the advantages of a male-killing factor, but we suggest that this is not applicable in this moth.
Collapse
|
322
|
Satoh K, Ida Y, Ishihara M, Sakagami H. Interaction between sodium ascorbate and polyphenols. Anticancer Res 1999; 19:4177-86. [PMID: 10628372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The interaction between sodium ascorbate and polyphenols was investigated by two different parameters: radical intensity and cytotoxicity induction. ESR spectroscopy shows that sodium ascorbate, lignins (alkali-lignin, lignin sulfonate, pine cone-derived lignin) and tannins (gallic acid, epigallocatechin gallate (EGCg), tannic acid) all produced radicals with different intensities under alkaline conditions. All lignin samples significantly enhanced the radical intensity and cytotoxic activity of sodium ascorbate, whereas all tannin samples slightly reduced the radical intensity of sodium ascorbate. Sodium ascorbate efficiently scavenged the radical and cytotoxic activity of gallic acid, as expected by the ionization potential and heat of reaction by the PM3 semiempirical method. EGCg and tannic acid slightly reduced the cytotoxic activity of sodium ascorbate. The present study demonstrates that lignins and tannins modify the radical intensity and cytotoxic activity of sodium ascorbate in different manners, and suggests the applicability of ESR spectroscopy for the screening of drug to drug interaction.
Collapse
|
323
|
Hiramatsu S, Ishihara M, Fujie M, Usami S, Yamada T. Expression of a chitinase gene and lysis of the host cell wall during Chlorella virus CVK2 infection. Virology 1999; 260:308-15. [PMID: 10417265 DOI: 10.1006/viro.1999.9824] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A chitinase gene (vChti-1) encoded by the Chlorella virus CVK2 was cloned and characterized. The vChti-1 open reading frame consisted of 2508 bp corresponding to 836 amino acid residues. The predicted amino acid sequence contained two sets of a family 18 catalytic domain that is responsible for chitinase activity. Northern blot analysis revealed that the vChti-1 gene was expressed in virus-infected Chlorella cells late in infection, when a single transcript of about 2.5 kb appeared at 120 min postinfection. This result was confirmed by Western blotting with a specific anti-vChti-1 protein antibody; a protein of about 94 kDa was detected specifically beginning at 240 min postinfection and was present until cell lysis. The protein was not incorporated into viral particles but remained in the medium after cell lysis. The vChti-1 protein produced in virus-infected cells showed chitinase activity on zymogram assays.
Collapse
|
324
|
Ono K, Hattori H, Takeshita S, Kurita A, Ishihara M. Structural features in heparin that interact with VEGF165 and modulate its biological activity. Glycobiology 1999; 9:705-11. [PMID: 10362840 DOI: 10.1093/glycob/9.7.705] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The 165 amino acid form of vascular endothelial growth factor (VEGF165) is a heparin-binding growth factor with mitogenic activity for vascular endothelial cells. We examined activities of various heparin derivatives toward their interactions with VEGF165 using an enzyme-linked immunosorbent assay and elucidated the structural features in heparin for the interactions. Native heparin interacted with VEGF165, whereas N-desulfated, N-acetylated (N-DS, N-Ac-) heparin, and 6-O-desulfated (6-O-DS-) heparin did not. The 2-O-desulfated (2-O-DS-) heparin retained the ability for the interaction with VEGF165. In contrast, the 2-O-DS-heparin exhibited no ability for the interaction with FGF-2 and HGF. Thus, structural requirements in heparin for the specific interaction with VEGF165 are distinct from those with FGF-2 and HGF which require a high content of 2-O-sulfate groups. In a cell proliferation assay, native heparin and 2-O-DS-heparin exhibited inhibitory abilities for VEGF165-induced proliferation of human umbilical vein endothelial cells (HUVECs) with their high concentrations (more than 64 microg/ml), while only native heparin could enhance the proliferation of the chlorate-treated cells. These results suggested that a high content of 2-O-sulfate groups is not required for the specific interaction with VEGF165alone, although it is essential for the mitogenic activity of the growth factor.
Collapse
|
325
|
Hayashi H, Ishihara M, Takahama K, Nakajo H, Inoue K, Kumazaki T. [Composition of vascular tree using moving-table MR angiography: development and preliminary clinical experience with a semi-automated program combining stacks of MR angiographic images]. NIHON IGAKU HOSHASEN GAKKAI ZASSHI. NIPPON ACTA RADIOLOGICA 1999; 59:409-11. [PMID: 10459286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Moving-table MR angiography, combining a contrast enhanced MRA approach with table movement, has recently become available. This technique allows imaging of long, longitudinal anatomical regions of vasculature. We have developed a semi-automated program combining stacks of MRA images obtained from different image stations, and applied it to the reconstruction of vascular trees in twenty-five patients with peripheral arterial occlusive disease. Using this program, continuous vascular trees, extending from the abdominal aorta to lower leg (up to 124 cm), were semi-automatically reconstructed within two minutes from six different projection angles. Extensive vascular lesions were recognized three-dimensionally by moving image display mode.
Collapse
|