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Saido TC, Kawashima S, Tani E, Yokota M. Up- and down-regulation of calpain inhibitor polypeptide, calpastatin, in postischemic hippocampus. Neurosci Lett 1997; 227:75-8. [PMID: 9180207 DOI: 10.1016/s0304-3940(97)00309-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Based on our previous observation that transient forebrain ischemia induces calpain-catalyzed proteolysis in gerbil hippocampus in a region-specific manner, we examined the effect of ischemia on the quantity and localization of the endogenous calpain-specific inhibitor protein, calpastatin, in the tissue. Brief (5 min) forebrain ischemia followed by reperfusion induced an overall increase of calpastatin immunoreactivity in hippocampus, particularly in pyramidal cells, in 4 h as analyzed by Western blotting and immunohistochemistry. The amount of calpastatin, however, decreased to the preischemic level and lower in 24 h to 7 days due to proteolysis except in CA2 showing continuously elevated calpastatin immunoreactivity. Because calpastatin is not only a potent inhibitor but also a preferred substrate for calpain and because CA2 neurons are less vulnerable to ischemic stress than the adjacent CA1 neurons, these observations imply involvement of calpastatin in calpain regulation as a bait substrate and, possibly, in neuroprotection under ischemic conditions. Calpastatin may participate in the stress responses together with the previously known ischemia-induced stress proteins such as heat shock proteins.
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Goto M, Nagashima M, Baba R, Nagano Y, Yokota M, Nishibata K, Tsuji A. Analysis of heart rate variability demonstrates effects of development on vagal modulation of heart rate in healthy children. J Pediatr 1997; 130:725-9. [PMID: 9152280 DOI: 10.1016/s0022-3476(97)80013-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Analysis of heart rate variability (HRV) has been found to be a useful method of assessing cardiovascular autonomic control, but normal values for standard HRV measures in children have not been established. We analyzed HRV in 60 healthy children aged 3 to 15 years to determine normal values and to assess the effects of development on cardiac autonomic control with the use of ambulatory electrocardiographic monitoring. RESULTS The high-frequency (HF) component, an index of cardiac autonomic tone, increased significantly with age from 3 to 6 years (p < 0.01) and decreased with age from 6 to 15 years (p < 0.01), and the magnitude of HF correlated significantly with the R-R intervals. Thus the changes in cardiac autonomic tone could be described as a simple equation using age and heart rate. CONCLUSIONS We present normal values and changes in the cardiac autonomic system during childhood after HRV analysis, which could lead to a better understanding and treatment of cardiac disease in children.
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Yokota M, Ando N, Ozawa S, Imazu Y, Kitajima M. Enhanced motility of the vagotomized canine stomach by electrical stimulation. J Gastroenterol Hepatol 1997; 12:338-46. [PMID: 9195377 DOI: 10.1111/j.1440-1746.1997.tb00432.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Functional impairment of the vagotomized stomach used as a substitute oesophagus seriously deteriorates the quality of life of patients following oesophageal cancer surgery. We speculated that if the enteric neurons of the reconstructed gastric tube survived functionally, the motility of the gastric tube could be facilitated and the recovery process after operation would improve as a consequence. In the present study we investigated whether direct electrical stimulation was effective for facilitating the motility of the canine vagotomized stomach. Dogs underwent truncal vagotomy by transabdominal approach and, in some cases, arteries to the upper stomach and the oesophagus were also ligated and resected to resemble the blood supply and surgical invasion of the reconstructed gastric tube. Electrical stimulation, a few minutes of positive rectangular current pulses, amplitude 20 V (or 15 mA), duration 0.5 ms and frequency between 0.2 and 7 Hz, was delivered on the greater curvature of the mid corpus. Changes in mechanical contractions were recorded using strain gauge force transducers. Electrical stimulation successfully enhanced the mechanical force of the phasic ring contractions of the vagotomized stomach in a frequency dependent manner. Aboral propagation and periodicity of the contractions, impaired by surgical procedures, were restored during stimulation. These excitatory effects were inhibited by atropine, hexamethonium and tetrodotoxin, suggesting that electrical stimulation acts on intramural cholinergic nerves that have survived functionally. These results suggest that electrical stimulation could be an effective method for improving the motility of the vagotomized stomach.
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Hirato J, Nakazato Y, Iijima M, Yokoo H, Sasaki A, Yokota M, Ono N, Hirato M, Inoue H. An unusual variant of ependymoma with extensive tumor cell vacuolization. Acta Neuropathol 1997; 93:310-6. [PMID: 9083565 DOI: 10.1007/s004010050620] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report a case of ependymoma with unusual vacuolar features arising in the left occipital lobe of a 2-year-old child. The tumor was composed of cells with single or multiple cytoplasmic vacuoles and clear cells. Some cells showed a signet ring-like configuration. Clear cells were compactly arranged and showed an oligodendro-glioma-like appearance. In addition, there were cellular ependymoma-like areas including perivascular pseudorosettes. On immunohistochemistry, glial fibrillary acidic protein and vimentin were mainly detected in cytoplasmic processes, and epithelial membrane antigen (EMA) staining showed granular and small vesicular reactivity. Ultrastructural investigation demonstrated intercellular microrosettes with or without cilia and long zonula adherens-type junctions that are typical of ependymoma. Furthermore, many intracytoplasmic lumina (ICL) were observed. Some ICL had microvilli and some did not. The latter varied in size, and may have fused with each other to develop giant ICL which could correspond to the signet ring-like configuration. Small ICL without microvilli had an appearance similar to that of distended endoplasmic reticula. Serial semithin and ultrathin sections revealed that EMA-positive structures were consistent with ICL containing microvilli and intercellular microrosettes. To determine the presence of unusual vacuolated ependymoma, electron microscopical examination was required. However, light microscopy was useful for detecting EMA-positive microvesicular and granular structures.
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Nakamura M, Kanematsu Y, Yokota M, Takeda J, Nakamura N, Maru M, Furuya K, Noguchi M, Uchida M, Sugimoto Y. [Social support of chronically-ill children and healthy children]. NIHON KANGO KAGAKKAI SHI = JOURNAL OF JAPAN ACADEMY OF NURSING SCIENCE 1997; 17:40-7. [PMID: 9274372 DOI: 10.5630/jans1981.17.1_40] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to describe characteristics of social support of chronically-ill children and to compare social support of chronically-ill children with those of healthy children. Subjects consisted of 204 chronically-ill children aged between 9 and 18 years old and 544 healthy children aged between 10 and 17 years old. Results of this study were as follows: 1. In both chronically-ill children and healthy children, parents' support score and teachers' support score were significantly higher in elementary school children than high school students. In both groups, friends' support score was significantly higher in girls than boys. 2. Chronically-ill children reported significantly higher scores of parents' support, friends' support and teachers' support than those of healthy children. 3. Parents' support score was significantly lower in children with diabetes than those with asthma and cancer. 4. The total score of social support and teachers' support score were significantly lower in children with employed mothers than those with unemployed mothers. 5. The total social support score of children who participated in non-sports extracurricular activities was significantly higher than those of children who did not participate in non-sports activities.
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Machii T, Yokota M, Nagata K, Ishihara H, Iwase M, Sobue T. Effect of dobutamine and OPC-18790 on diastolic chamber stiffness in patients with idiopathic dilated cardiomyopathy. J Cardiovasc Pharmacol 1997; 29:265-72. [PMID: 9057077 DOI: 10.1097/00005344-199702000-00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We investigated the acute effects of the positive inotropic agents (dobutamine and a novel phosphodiesterase inhibitor OPC-18790) on left ventricular diastolic chamber stiffness in patients with idiopathic dilated cardiomyopathy (DCM). We obtained pressure-volume (PV) data before and after drug administration in 17 patients with DCM by using a conductance catheter with a micromanometer tip. Patients were randomly assigned to receive intravenous infusions of dobutamine (2.5-7.5 micrograms/kg body weight per min, n = 8) or OPC-18790 (5-10 micrograms/kg body weight per min, n = 9). The dynamic diastolic chamber stiffness constant was calculated from a steady-state beat. The passive diastolic chamber stiffness constant was determined from the end-diastolic PV relation determined during transient inferior vena caval occlusion. Dobutamine and OPC-18790 similarly improved left ventricular end-systolic elastance (Ees) and left ventricular isovolumic relaxation time constants. The dynamic diastolic chamber stiffness constant decreased significantly in both the dobutamine (0.0934 +/- 0.0271 to 0.0685 +/- 0.0248; p < 0.01) and OPC-18790 (0.0843 +/- 0.0477 to 0.0569 +/- 0.0246; p < 0.05) groups. The passive diastolic chamber stiffness constant decreased significantly in the OPC-18790-treated group (0.0211 +/- 0.0114 to 0.0144 +/- 0.0117; p < 0.005) but not in the dobutamine-treated group (0.0197 +/- 0.0130 to 0.010186 +/- 0.0102; p > 0.05). Thus both dobutamine and OPC-18790 reduced the dynamic diastolic chamber stiffness constant, but only OPC-18790 reduced the passive diastolic chamber stiffness constant. OPC-18790 had a favorable effect on diastolic function in patients with DCM, compared with that of dobutamine. The passive diastolic chamber stiffness obtained from the end-diastolic PV relations represents more likely passive chamber properties than the dynamic diastolic chamber stiffness obtained from traditional single-beat analysis.
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Izumisawa M, Yagi M, Fukuta Y, Yokota M, Ohya T, Kudo K, Shouzushima M, Satoh M. The correlation between ultrasonographic imaging and histological features of cervical lymph node metastasis in oral cancer. Int J Oral Maxillofac Surg 1997. [DOI: 10.1016/s0901-5027(97)81516-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Noda A, Okada T, Katsumata K, Yasuma F, Nakashima N, Yokota M. Suppressed cardiac and electroencephalographic arousal on apnea/hypopnea termination in elderly patients with cerebral infarction. J Clin Neurophysiol 1997; 14:68-72. [PMID: 9013361 DOI: 10.1097/00004691-199701000-00006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The goal of the present investigation is to show the clinical significance of arousal response at termination of apnea/hypopnea in patients with sleep apnea syndrome (SAS) after cerebral infarction. We polygraphically assessed "cardiac arousal," which is defined as an abrupt increase in heart rate at a termination of sleep apnea/hypopnea, and electroencephalographic (EEG) arousal. There were six elderly subjects, bedridden after cerebral infarction, with SAS aged 71-87 years (mean 72.3 years) and 11 age-matched patients with SAS aged 61-78 years (mean 62.3 years) as controls. The following sleep parameters were measured: number of apneas per hour (apnea index [AI]), number of hypopneas per hour (hypopnea index [HI]), summation of the two (apnea/hypopnea index [AHI]), and duration in which nocturnal oxygen saturation was decreased below 90% (duration of SaO2 < 90%). We calculated the ratio of apnea/hypopnea per hour with cardiac arousal to total apnea/hypopneas (XI) (% cardiac arousal [XI/AHI x 100]) and the ratio of that with EEG arousal (YI) (% EEG arousal [YI/AHI x 100]). Between the two groups, we found no significant difference in body mass index, the ratio of central apnea to total apnea/hypopnea, AHI, duration of apnea/hypopnea, lowest SaO2, and duration of SaO2 < 90%. Compared with controls, % cardiac and % EEG arousals were significantly lower in patients with cerebral infarction. In contrast, the ratio of HI to AHI was significantly higher in patients with cerebral infarction than in control subjects. Our findings indicate that cardiac and EEG arousals at termination of apnea/hypopnea are significantly suppressed in elderly patients with SAS after cerebral infarction, which may provide useful information on the pathophysiology of SAS in patients with cerebrovascular disease.
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Yamada Y, Yokota M. Effects of protein kinase C activation and inhibition on endothelin-1 release from human aortic and pulmonary artery endothelial cells: comparison with effects on bovine endothelin-1 and human prostaglandin I2 release. Am J Hypertens 1997; 10:32-42. [PMID: 9008246 DOI: 10.1016/s0895-7061(96)00250-6] [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: 02/03/2023] Open
Abstract
Protein kinase C (PKC) has been implicated in the regulation of endothelin-1 production by bovine and porcine endothelial cells. The role of PKC in the synthesis and release of endothelin-1 has not been demonstrated previously in human arterial endothelial cells. The effects of activators and an inhibitor of PKC on endothelin-1 release from cultured human arterial endothelial cells have now been examined. Endothelial monolayers were incubated with the PKC activators phorbol 12-myristate 13-acetate (PMA) or 1-oleoyl 2-acetyl glycerol (OAG) for 30 min to 8 h and the amount of endothelin-1 released into the medium was determined. PMA (0.1 micromol/L) and OAG (0.1 mmol/L) stimulated endothelin-1 release, with maximal increases of 85% and 90%, respectively, apparent at 30 min in aortic endothelial cells, and of 81% and 75%, respectively, apparent at 1 h in pulmonary artery endothelial cells. Endothelin-1 release had returned to control values by 4 h and was approximately one-third to one-half of control values after 8 h of continuous exposure of both cell types to PMA or OAG. Long-term exposure of both types of cells to the PKC inhibitor staurosporine (0.1 micromol/L) reduced both basal endothelin-1 release and the enhancement of release by PMA or OAG. The PKC agonists also stimulated endothelin-1 release by bovine aortic endothelial cells. The maximal effects of PMA and OAG in these cells were apparent at 4 h, at which time endothelin-1 release was increased by 154% and 125%, respectively; after 4 h, endothelin-1 release had decreased, but was still 132% and 120%, respectively, of the control value at 8 h. The PKC activators markedly stimulated prostaglandin I2 (PGI2) release by human pulmonary artery endothelial cells. The enhancement of PGI2 release continued for up to 8 h, at which time 109-fold and threefold increases in PGI2 release were apparent with PMA and OAG, respectively. Therefore, activation of PKC results in a rapid increase in endothelin-1 release by human arterial endothelial cells. The subsequent decrease in endothelin-1 release in the presence of PMA or OAG is presumably attributable to activator-induced downregulation of PKC, which was apparent earlier in human than in nonhuman endothelial cells. The downregulation of endothelin-1 release also occurred much earlier than that of PGI2 release in human pulmonary artery endothelial cells.
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Izawa H, Yokota M, Nagata K, Iwase M, Sobue T. Impaired response of left ventricular relaxation to exercise-induced adrenergic stimulation in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol 1996; 28:1738-45. [PMID: 8962560 DOI: 10.1016/s0735-1097(96)00378-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES We investigated the effect of adrenergic stimulation on left ventricular relaxation in patients with hypertrophic cardiomyopathy. BACKGROUND Exercise-induced decreases in acceleration of left ventricular relaxation have been observed in patients with hypertrophic cardiomyopathy. However, data on sequential changes in left ventricular relaxation during exercise are limited. METHODS We measured right (fluid filled) and left (high fidelity micromanometer) ventricular pressures during moderate supine ergometer exercise and during rapid right atrial pacing in four groups of patients: 9 with severe hypertrophic cardiomyopathy, 9 with moderate hypertrophic cardiomyopathy, 10 with hypertension and moderate hypertrophy and 5 control subjects. RESULTS There was a curvilinear relation between the time constant of relaxation (tau) and heart rate in all groups during exercise. There was no difference in the slope of this relation between the two hypertrophic cardiomyopathy subgroups. Although the slope of this relation between tau and heart rate was steeper in the hypertensive than the moderate hypertrophic cardiomyopathy group (p < 0.001, analysis of covariance), the decrease in tau during right atrial pacing was similar in both groups. There were no significant differences in plasma levels of catecholamines at rest or at peak exercise among groups or in maximal heart rate during pacing. CONCLUSIONS Pacing-induced changes in tau in hypertrophic cardiomyopathy were similar to those in hypertensive hypertrophy, but remarkable decrease in exercise-induced acceleration of tau were observed only in hypertrophic cardiomyopathy. Our results may indicate a depressed left ventricular relaxation response to exercise-induced adrenergic stimulation in hypertrophic cardiomyopathy.
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Baba R, Nagashima M, Goto M, Nagano Y, Yokota M, Tauchi N, Nishibata K. Oxygen uptake efficiency slope: a new index of cardiorespiratory functional reserve derived from the relation between oxygen uptake and minute ventilation during incremental exercise. J Am Coll Cardiol 1996; 28:1567-72. [PMID: 8917273 DOI: 10.1016/s0735-1097(96)00412-3] [Citation(s) in RCA: 303] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVES We investigated the usefulness of a new variable, oxygen uptake efficiency slope (OUES), as a submaximal measure of cardiorespiratory functional reserve. The OUES is derived from the relation between oxygen uptake (Vo2 [ml/min]) and minute ventilation (VE [liters/min]) during incremental exercise and is determined by VO2 = a log VE + b, where a = OUES, which shows the effectiveness of Vo2. BACKGROUND Maximal oxygen uptake (VO2max) is effort dependent. There is no standard submaximal measurement of cardiorespiratory reserve that provides generally acceptable results. METHODS Exercise tests, following a standard Bruce protocol, were performed on a treadmill by 108 patients with heart disease and 36 normal volunteers. Expired gas was continuously analyzed. The OUES was calculated from data of the first 75%, 90% and 100% of exercise duration. We also determined the following submaximal variables: the ventilatory anaerobic threshold (VAT), the slope of the regression line of the minute ventilation-carbon dioxide production relation (VE-VCO2 slope) and the extrapolated maximal oxygen consumption (EMOC). We analyzed the relation of OUES and other submaximal variables against VO2max and examined the effects of submaximal exercise on OUES. RESULTS The correlation coefficient of the logarithmic curve-fitting model was 0.978 +/- 0.016 (mean +/- SD). The OUES and VO2max had a significant correlation (r = 0.941, p < 0.0001). The correlation between VO2max and OUES was stronger than that between VO2max and VAT, the VE-VCO2 slope or EMOC. The OUES values for 100% and 90% of exercise were not different from each other (at an alpha value of 0.05 and treatment effect of 170, the power of the test [1-beta] was 0.90); OUES for 75% of exercise was slightly lower (3.5%). CONCLUSIONS Our results suggest that OUES may provide an objective, effort-independent estimation of cardiorespiratory functional reserve that is related both to pulmonary dead space and to metabolic acidosis.
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Shimbo S, Hatai I, Saito T, Yokota M, Imai Y, Watanabe T, Moon CS, Zhang ZW, Ikeda M. Shift in sodium chloride sources in past 10 years of salt reduction campaign in Japan. TOHOKU J EXP MED 1996; 180:249-59. [PMID: 9058509 DOI: 10.1620/tjem.180.249] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Twenty four-hr total food duplicate samples were collected from nonsmoking house-wives (aged mostly 30 to 60 years) twice at a 10-year interval in winter seasons, once in around 1980 and then in around 1990 in 11 prefectures in Japan. In practice, 342 and 472 samples were obtained in the 1980 and 1990 studies, respectively. Sodium chloride (NaCl) intake via each food item was estimated from the weight of the item in the duplicate. The comparison of 1990 results with 1980 results showed that the total NaCl intake (i.e., NaCl intake via all food items) decreased after a 10-year campaign to lower salt intake. The NaCl/energy ratio however stayed essentially unchanged. Whereas NaCl intake via pickles decreased remarkably and that via miso paste [a fermentation product of soy bean, rice (or wheat) and salt] slightly, the decreases were counteracted by a substantial increase in NaCl intake via soy bean sauce. Meaning of this unexpected counteraction was discussed in relation to the difficulties in the campaign to lower salt intake.
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Yokota M, Saido TC, Tani E, Yamaura I, Minami N. Cytotoxic fragment of amyloid precursor protein accumulates in hippocampus after global forebrain ischemia. J Cereb Blood Flow Metab 1996; 16:1219-23. [PMID: 8898694 DOI: 10.1097/00004647-199611000-00016] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We developed an antibody specific to beta-amyloid precursor protein (beta APP) fragments possessing the exact amino terminus of the beta-amyloid peptide and examined its induction in postischemic hippocampus. In control hippocampus, this APP fragment was lightly observed in pyramidal neurons of CA sectors and dentate granule cells. Transient forebrain ischemia enhanced accumulation of the APP fragment in CA1 pyramidal neurons. Seven days after the ischemia, while the APP fragment was still observed in dentate granule cells and CA3 neurons, it disappeared in dead CA1 neurons. While astrocytes did not show in any immunoreactivity throughout the experiment, those in the CA1 sector showed moderate immunoreactivity 7 days after the ischemia. The APP fragment has a cytotoxic effect on cultured neurons. These results suggest that the accumulation of the cytotoxic APP fragment in CA1 neurons may play a role in the development of delayed neuronal death after the ischemic insult.
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Ikeda R, Yokota M, Shinoda T. Serological characterization of Trichosporon cutaneum and related species. Microbiol Immunol 1996; 40:813-9. [PMID: 8985936 DOI: 10.1111/j.1348-0421.1996.tb01146.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recent molecular biological, chemical, physiological and morphological studies indicate that Tri-chosporon cutaneum and related species should be reclassified. In this study, antigenic characteristics of the species were determined. The results of adsorption experiments revealed that there were at least three serological types: I, II and III. Specific factor sera I, II and III were prepared on the basis of adsorption experiments and isolates were serotyped by cell slide agglutination (CSA). Since the CSA test was difficult to read in some strains, the results of the CSA test were compared with the findings from an enzyme-linked immunosorbent assay (ELISA). For the ELISA, crude polysaccharide antigens prepared from the culture supernatant were used as the antigen. The types determined by ELISA correlated well with those determined by the CSA test. These data suggest that T. cutaneum and related species have at least three serological types, and that the typing can be done by either CSA or ELISA.
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Anan H, Tanaka A, Tsuzuki R, Yokota M, Yatsu T, Fujikura T. 4-(3,4-Dihydroxyphenyl)-1,2,3,4-tetrahydroisoquinoline derivatives. II. Their renal vasodilation activity and structure-activity relationship. Chem Pharm Bull (Tokyo) 1996; 44:1865-70. [PMID: 8904813 DOI: 10.1248/cpb.44.1865] [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: 02/02/2023]
Abstract
A series of 4-(3,4-dihydroxyphenyl)-1,2,3,4-tetrahydroisoquinoline derivatives showed potent DA1 agonistic activities. We investigated the structure-activity relationship of the racemic compounds of this series. 4-(3,4-Dihydroxyphenyl)-7-methanesulfonamido-1,2,3,4-tetrahydroiso quinoline (43) was identified as a potent renal vasodilator with activity almost equal to that of YM435 (1).
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Takiwaki H, Yokota M, Ahsan K, Yokota K, Kurokawa Y, Ogawa I. Squamous cell carcinoma associated with verruciform xanthoma of the penis. Am J Dermatopathol 1996; 18:551-4. [PMID: 8902105 DOI: 10.1097/00000372-199610000-00017] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report a case of squamous cell carcinoma of the penis that seemed to arise within a verruciform xanthoma of this organ. A lesion in the prepuce was initially diagnosed as a verruciform xanthoma histopathologically and was removed in part. Six years later, the patient exhibited a well-differentiated squamous cell carcinoma of the penis that contained many clusters of xanthoma cells in the stroma. Although the retrospective examination of biopsy specimens of the initial lesion in this patient showed the features mainly of verruciform xanthoma, significant architectural and cytological atypia was also present in the overlying epidermis. Thus, we must be careful not to overlook the presence of a squamous cell carcinoma arising within a benign reactive lesion such as a verruciform xanthoma.
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Koide M, Akins RE, Harayama H, Yasui K, Yokota M, Tuan RS. Atrial natriuretic peptide accelerates proliferation of chick embryonic cardiomyocytes in vitro. Differentiation 1996; 61:1-11. [PMID: 8921580 DOI: 10.1046/j.1432-0436.1996.6110001.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The developing embryonic heart has been reported to contain significant levels of atrial natriuretic peptide (ANP). In this study, the role of ANP in cardiac development was evaluated using cultured cardiomyocytes isolated from chick embryos. We analyzed the effect of ANP on cell number, DNA synthesis, total RNA level, the expression of cell-cycle-specific and sarcomeric proteins, and levels of lactate dehydrogenase and creatine phosphokinase. ANP increased overall DNA synthesis (measured by BrdU incorporation, P < 0.01) and enhanced cell proliferation. Morphologically, the development of the cardiomyocyte network was distinctly enhanced in the ANP-treated cells. Cellular RNA content was elevated; likewise, myosin and tropomyosin biosynthesis was significantly greater in ANP-treated cells. In addition, expression of G1/S-specific protein increased, whereas G2/M-specific protein remained unchanged by ANP treatment. An antibody against ANP and a specific ANP receptor antagonist, HS-142-1, antagonized and/or attenuated the action of ANP on both cell proliferation and protein biosynthesis. These results indicate that ANP accelerates myocardial cell proliferation by enhancing entry into S phase and by increasing DNA synthesis during S phase specifically through receptor mediated pathway. The in vitro effects of ANP on myocardial cell proliferation, together with the elevated levels of ANP seen in vivo during normal heart formation, suggest a possible autocrine function of ANP in embryonic cardiac development.
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Yamada Y, Yokota M. Production of C-type natriuretic peptide in human aortic endothelial cells induced by activation of protein kinase C. Am J Hypertens 1996; 9:924-9. [PMID: 8879350 DOI: 10.1016/s0895-7061(96)00107-0] [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: 02/02/2023] Open
Abstract
The effects of activators and inhibitors of protein kinase C (PKC) on the production of C-type natriuretic peptide (CNP) by cultured human aortic endothelial cells were examined. The PKC activators phorbol 12-myristate 13-acetate (PMA) and 1-oleoyl 2-acetyl glycerol (OAG) stimulated CNP release; the maximal effects were apparent at 4 h, at which time release was 934 and 205% of the control value, respectively. The PKC inhibitors staurosporine and H-7 did not affect basal CNP release, but each abolished the increase in CNP release induced by PMA or OAG. PKC was activated and translocated from cytosolic to membrane fractions in endothelial cells exposed to PMA or OAG; the maximal effect was apparent at 1 h. PMA and OAG each increased the abundance of CNP mRNA, with the maximal effect at 2 h. These data suggest that activation of PKC by PMA or OAG results in an increase in the abundance of CNP mRNA and subsequent enhancement of CNP production and release in human aortic endothelial cells.
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Shimbo S, Imai Y, Tominaga N, Gotoh T, Yokota M, Inoguchi N, Ikeda Y, Watanabe T, Moon CS, Ikeda M. Insufficient calcium and iron intakes among general female population in Japan, with special reference to inter-regional differences. J Trace Elem Med Biol 1996; 10:133-8. [PMID: 8905555 DOI: 10.1016/s0946-672x(96)80022-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Dietary intakes of calcium (Ca) and iron (Fe) were investigated in 227 women (mostly housewives) in 12 regions in Japan in 1991-1993 by the 24-hour food duplicate method. Nine regions out of 12 had been previously studied in 1977-1982. Utilizing Standard Food Composition database, mean Ca and Fe-intakes in 1991-1993 were estimated to be 602 and 10.4 mg/day, respectively; the former was barely sufficient and the latter was below sufficiency when compared with the Recommended Daily Allowance in Japan for pre-menopausal women. Ca- and Fe-intake did not increase in the 10-year period. Further analysis after classification of the women into three groups of farmers in Okinawa, farmers in Mainland Japan and urban residents showed that Ca and Fe insufficiency was most evident among Okinawa farmers. The leading Ca sources were milk, pulse, vegetables and fish-shellfish, but consumption of milk was generally low, especially among Okinawa farmers. Pulse, vegetables and fish-shellfish were 3 major Fe sources; Okinawa farmers depended more on vegetables and less on fish-shellfish.
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Somei K, Sasaki K, Nara K, Ooe M, Yokota M, Miura H, Somei H. Intracellular mechanism of ATP-induced depolarizing response in the bullfrog sympathetic ganglion cells. METHODS AND FINDINGS IN EXPERIMENTAL AND CLINICAL PHARMACOLOGY 1996; 18:443-8. [PMID: 8900216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Application of adenosine triphosphate (ATP) induced a depolarizing response in bullfrog sympathetic ganglion cells, which was associated with a decrease in membrane conductance. This depolarizing response was also produced by application of ADP, but not by adenosine, cyclic-AMP or cyclic-GMP. Suramin, an antagonist for the P2-purinoceptor, suppressed the response, while caffeine, an antagonist for the P1-purinoceptor, did not. Application of phospholipase C (PLC) inhibitors such as Li+ and 4-bromophenacyl bromide also suppressed the response. In addition, protein kinase C (PKC) inhibitors such as staurosporine and H-7 had a suppressant effect, while ryanodine, an inhibitor of Ca2 release, did not. These results suggest that ATP and ADP may stimulate P2-purinoceptor coupled with PLC, producing diacylglycerol, which activates PKC, resulting in the closing of K+ channel.
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221
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Goto S, Satoh M, Fuse K, Sato K, Yokota M, Muramatsu Y, Takahashi R, Suzuki E, Arakawa M. [Central alveolar hypoventilation syndrome with compression of the medulla oblongata by tortuous and elongated vertebral arteries]. NIHON KYOBU SHIKKAN GAKKAI ZASSHI 1996; 34:1003-8. [PMID: 8937146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A 43-year-old woman was admitted to the hospital with hypoventilation, which developed when she took sedatives because of an operation on an adrenal gland tumor. Central alveolar hypoventilation syndrome was diagnosed after neurophysiological and pulmonary-function tests. Magnetic resonance imaging and vertebral angiography revealed that tortuous and elongated vertebral arteries compressed the ventral sides of the medulla oblongata, which may have caused the hypoventilation. Mechanical ventilation during sleep improved her condition. Home mechanical ventilation was prescribed and she has been well during follow up as an outpatient.
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222
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Ito N, Yokota M, Nagaike C, Morimura Y, Hatake K, Tanaka O, Matsunaga T. Simultaneous expression of keratan sulphate epitope (a sulphated poly-N-acetyllactosamine) and blood group ABH antigens in papillary carcinomas of the human thyroid gland. THE HISTOCHEMICAL JOURNAL 1996; 28:613-23. [PMID: 8910032 DOI: 10.1007/bf02331382] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The monoclonal antibody 5-D-4 recognizes heavily sulphated forms of keratan sulphate epitope. It reacted strongly with the cell surfaces of most thyroid papillary carcinomas from all the individuals examined, independently of the blood group of the patients. Cells of follicular variants of papillary carcinomas were also labelled by 5-D-4. In contrast, no labelling with this antibody was observed in other types of thyroid neoplasms, or in normal tissues. The reactivity of 5-D-4 with papillary carcinomas was markedly reduced or abolished by prior digestion with endo-beta-galactosidase, keratanase II, or N-glycosidase F. Although keratanase digestion had no effect on 5-D-4 labelling, it revealed the binding sites of Griffonia simplicifolia agglutinin II (GSA-II), which recognizes terminal N-acetylglucosamine in a limited number of carcinoma cells from some individuals. Blood group ABH antigens, which are simultaneously expressed together with keratan sulphate epitope in cancer cells, were eliminated by digestion with endo-beta-galactosidase and N-glycosidase F, but were resistant to keratanase and keratanase II treatment. These results indicate that keratan sulphate oligosaccharides are cancer-associated and are probably oncofoetal antigens, as are the blood group antigens in human thyroid glands. The results suggests that poly-N-acetyllactosamine, which is ubiquitously and consistently produced in papillary carcinomas, is modified in two different ways: sulphation on the 6-position of at least some units of either galactose or N-acetylglucosamine or both, and decoration of non-reducing termini with the blood group antigens. Along with the endo-beta-galactosidase-GSA-II labelling procedure, labelling with 5-D-4 may be a useful diagnostic means for distinguishing papillary carcinoma from other types of thyroid neoplasms.
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223
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Kanda H, Yokota M, Ishihara H, Nagata K, Kato R, Sobue T. A novel inotropic vasodilator, OPC-18790, reduces myocardial oxygen consumption and improves mechanical efficiency with congestive heart failure. Am Heart J 1996; 132:361-8. [PMID: 8701899 DOI: 10.1016/s0002-8703(96)90434-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We analyzed the left ventricular (LV) pressure-volume relation and obtained direct measurements of myocardial oxygen consumption (MVO2) before and after drug administration in 21 patients with New York Heart Association functional class II to III congestive heart failure to compare the mechanoenergetic effects of OPC-18790, a novel inotropic agent, and dobutamine. Pressure-volume data were obtained by the conductance method, and MVO2 measurements were obtained with a double-thermistor coronary sinus catheter before and after administration of OPC-18790 and dobutamine. The LV end-diastolic volume index decreased significantly without an increase in the heart rate after administration of OPC-18790, unlike that after administration of dobutamine. Both drugs significantly increased the LV contractility index (Emax) and caused similar improvements in ventricular-arterial coupling. OPC-18790 significantly reduced MVo2, whereas dobutamine increased MVo2. The ratio of the pressure-volume area to myocardial oxygen consumption (PVA/MVo2) remained unchanged after administration of OPC-18790 and decreased after administration of dobutamine. The ratio of external work to the pressure-volume area (EW/PVA) was similarly increased by both drugs, resulting in an improvement in mechanical efficiency (EW/MVo2) with OPC-18790 (p < 0.05) and in a deterioration with dobutamine (p < 0.05). OPC-18790 had an energetic advantage over dobutamine in spite of its positive inotropic effect. Our findings suggest that OPC-18790 may be useful for the treatment of patients with congestive heart failure.
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Tsuji T, Kasamatsu M, Yokota M, Morita A, Schwartz RA. Mucha-Habermann disease and its febrile ulceronecrotic variant. Cutis 1996; 58:123-31. [PMID: 8864599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In 1916 Mucha and in 1925 Habermann reported an acute form of pityriasis lichenoides characterized by the abrupt onset of papulovesicular eruptions and gave the name, pityriasis lichenoides et varioliformis acuta (PLEVA) or Mucha-Habermann disease (MH). In 1966, Degos reported a rare febrile ulceronecrotic variant of MH. MH occurs mainly in young adults, while febrile ulceronecrotic Mucha-Habermann's disease (FUMHD) occurs more frequently in children. The etiology of MH remains obscure, but it may be the result of a hypersensitivity reaction to an infectious agent. Although clinical and histologic features of the disease in children are similar to those of adults, more diseases need to be differentiated in pediatric patients. In addition, a number of effective therapeutic options in adults with MH are unsuitable for use in pediatric patients, to whom beginning with oral antibiotics, usually erythromycin, is recommended. A summary of previously reported fifteen cases with FUMHD, including our case, is listed.
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225
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Yokota M, Nitta K. Purification and some properties of hemagglutinin from the Myxomycete, Physarum polycephalum. EXPERIENTIA 1996; 52:544-8. [PMID: 8698086 DOI: 10.1007/bf01969725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A new hemagglutinin was isolated from the plasmodium of Physarum polycephalum by salting out with ammonium sulphate followed by chromatography on DE-32, DEAE-Toyopearl and hydroxyapatite. This hemagglutinin, named physarumin, was purified 1000-fold over crude extracts. The molecular weight of physarumin was determined to be 22,000 by size exclusion chromatography on Bio-Gel P-60 and 8,700 by SDS-polyacrylamide gel electrophoresis. Physarumin agglutinated rabbit, guinea pig, horse and human erythrocytes. Physarumin-induced hemagglutination was inhibited by fetuin and alpha 1-acid glycoprotein, but not by commercially available mono- and disaccharides. Hemagglutinating activity was blocked by EDTA, and was restored by adding Ca2+ but not by Mg2+.
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226
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Koide M, Harayama H, Iio A, Obata K, Matsuda N, Ono T, Yokota M, Tuan RS. Major risk factors for atherosclerosis are manifested in experimental Ca-deficiency. Hypertens Res 1996; 19 Suppl 1:S35-40. [PMID: 9240762 DOI: 10.1291/hypres.19.supplementi_s35] [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: 02/04/2023]
Abstract
The eggshell is the major source of Ca required during growth of chick embryos. Therefore, chick embryos placed ex ovo for long-term (SL) are rendered severe systemic calcium deficiency. We report here that SL chick embryos express Ca-deficiency related atherogenic disorders, and that in vitro Ca-deficiency induces dedifferentiation, i.e. loss of cell-type specific features and accelerated proliferative activities, in the various types of cultured cells. Systemic blood pressure is significantly higher and an accelerated weight gain of the heart is noted in SL compared to normal embryos (NL) at the incubation Day-14. Plasma cholesterol was lower, while triglyceride and glucose were higher in SL. Varying Ca in the culture medium (FCa, 1.8 mM; HCa, 2.8 mM; Ca/2, 0.9 mM) clearly affected the phenotype of the cultured cardiomyocytes and vascular cells isolated from the chick embryos. The cell number and total DNA were significantly larger and the level of LDH and proliferating cell nuclear antigen (PCNA) was elevated in Ca/2 compared to FCa. On the contrary, the level of CPK and contractile proteins were lowered in Ca/2. Thus, it is indicated that Ca-deficiency induces atherogenic disorders in vivo, and accelerates cell proliferation and decelerates sarcomeric protein expression in vitro. Taken together, it is suggested that the atherogenic, developmental disorders in SL may be the integrated result of the phenotype alteration in the various cell types directly induced by Ca-deficiency.
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227
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Kato R, Yokota M, Ishihara H, Sobue T. Correlation between left ventricular contractility and relaxation in patients with idiopathic dilated cardiomyopathy. Clin Cardiol 1996; 19:413-8. [PMID: 8723602 DOI: 10.1002/clc.4960190516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND AND HYPOTHESIS It is not fully understood whether alterations in left ventricular (LV) relaxation in patients with idiopathic dilated cardiomyopathy (DCM) precede or follow alterations in LV systolic function. Accordingly, we investigated the relationship between LV systole and diastolic relaxation in patients with DCM using LV pressure-volume analysis. METHODS Hemodynamic data were collected for 38 consecutive patients with DCM in normal sinus rhythm and in the resting steady state (New York Heart Association functional class II to III). Continuous simultaneous pressure-volume relationships were obtained by conductance catheter. Left ventricular end-systolic elastance (Ees) was determined during transient occlusion of the inferior vena cava. RESULTS Left ventricular ejection fraction, peak negative dP/dt, and peak positive dP/dt were depressed (31 +/- 11%, -1242 +/- 351 mmHg/s, and 1118 +/- 253 mmHg/s, respectively). The LV end-diastolic volume index, the time constants of isovolumic LV pressure decay TL and TD were increased (141 +/- 38 ml/m2, 54 +/- 14 ms, and 69 +/- 17 ms, respectively). Ees was markedly depressed (0.9 +/- 0.5 mmHg/ml) and was not correlated with established systolic or diastolic indices except for peak positive dP/dt. Our results showed that abnormalities of relaxation were not correlated with contractile dysfunction in patients with DCM in the resting steady state; however, most patients (79%) had both prolonged relaxation and extremely depressed contractility. Abnormal relaxation may have been transient or compensated in some patients (21%) with DCM who had preserved relaxation despite severely depressed contractility.
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228
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Yamada Y, Yokota M. Enhancement of barrier function of human aortic endothelial cells by activators of protein kinase C. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1996; 39:69-76. [PMID: 8799329 DOI: 10.1080/15216549600201071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We investigated the role of protein kinase C (PKC) in regulating the permeability of human and bovine aortic endothelial cells (AECs) cultured on micropore filters. AECs cultured in the upper chamber were incubated with medium containing a PKC agonist, phorbol 12-myristate 13-acetate (PMA) or 1-oleoyl-2-acetyl-glycerol (OAG) for 15 min to 8 h, after which the cells were incubated with albumin for 1 h. The amount of albumin that had transferred through AECs was determined. Activation of PKC by exposure to PMA or OAG inhibited albumin permeability in human AECs, but increased it in bovine AECs. While the PKC inhibitor, staurosporine, did not itself influence endothelial permeability, it reduced the decrease or increase in permeability induced by exposure to PMA or OAG in human and bovine AECs, respectively. Activation of PKC thus enhanced the barrier function of human AECs, but reduced it in bovine AECs.
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229
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Yamada Y, Yokota M. Direct interactions of plasminogen activators with human aortic and pulmonary artery endothelial cells in vitro: implications for thrombolytic therapy. J Cardiovasc Pharmacol 1996; 27:629-35. [PMID: 8859931 DOI: 10.1097/00005344-199605000-00003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Direct interactions of plasminogen activators with arterial endothelial cells are important in the pathogenesis of vascular complications associated with thrombolytic therapy. We investigated the direct effects of various plasminogen activators on human aortic and pulmonary artery endothelial cell functions in vitro. The effects of plasminogen activators on endothelial cells were not caused by generation of plasmin, as shown by the absence of plasminogen and alpha(2)-plasmin inhibitor-plasmin complex both before and after addition of plasminogen activators to endothelial cells. High concentrations of plasminogen activators increased the permeability of aortic endothelial cells to albumin. Alteplase (50 x 10(3) IU/ml), a recombinant tissue-type plasminogen activator (t-PA), increased prostaglandin I(2) (PGI(2)) production by aortic endothelial cells from 175.5 +/- 13.8 to 870.8 +/- 131.0 pg/mg cellular protein during a 2-h incubation; other plasminogen activators increased PGI(2) production to a lesser extent. Alteplase (100 x 10(3) IU/ml) also increased PGI(2) production from 152.0 +/- 16.2 to 1,080 +/- 95.1 pg/mg cellular protein in human pulmonary artery endothelial cells. High concentrations of urokinases decreased the amount of endothelin-1 in the medium of aortic or pulmonary artery endothelial cells by as much as 93%; part of this decrease was attributable to degradation of endothelin-l by urokinases. Other plasminogen activators either had no effect on or slightly increased the production of endothelin-1. These changes in the function of human arterial endothelial cells induced by plasminogen activators may affect regional vascular tone, endothelial permeability, and platelet aggregability, all of which are important in the efficacy of thrombolysis and in the pathogenesis of such vascular complications as rethrombosis and hemorrhage.
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230
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Yokota M, Uchibori S, Hayashi H, Koyama R, Kosakai K, Wakabayashi S, Tomiyama T. Azulene derivatives as TXA2/PGH2 receptor antagonists--II. Synthesis and biological activity of 6-mono- and 6-dihydroxylated-isopropylazulenes. Bioorg Med Chem 1996; 4:575-91. [PMID: 8735846 DOI: 10.1016/0968-0896(96)00038-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In order to examine the correlation between activity and hydrophilicity of the side chain of sodium 3-[4-(4-chlorobenzenesulfonylamino)butyl]-6-isopropylazulene -1-sulfonate (KT2-962), a non-prostanoid TXA2/PGH2 receptor antagonist, one or two hydroxyl groups were introduced into the isopropyl moiety. A series of 6-hydroxylated-isopropylazulenes were synthesized by regioselective oxidation of 6-isopropylazulenes and their in vitro and in vivo antagonistic activities were studied. Both the primary and tertiary alcohols, monohydroxylated derivatives, exhibited potent biological activities comparable to unmodified 6-isopropylazulenes both in vitro and in vivo. In contrast, the activities of 1,2- and 1,3-diols of 6-substituted derivatives, markedly decreased, but recovered by O-isopropylidenation of the dihydroxyl moiety. These findings indicate that the moderate hydrophobicity of substituent at the 6-position of the azulene ring might be required for the activity and the size of the substituent at this position, not so rigid for keeping potent biological activity.
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MESH Headings
- 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/chemistry
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Azulenes
- Benzenesulfonates/chemistry
- Benzenesulfonates/metabolism
- Benzenesulfonates/pharmacology
- Cycloheptanes/chemistry
- Cycloheptanes/metabolism
- Cycloheptanes/pharmacology
- Death, Sudden/etiology
- Humans
- Male
- Mice
- Prostaglandin Endoperoxides, Synthetic/pharmacology
- Prostaglandins H/metabolism
- Rabbits
- Rats
- Rats, Wistar
- Receptors, Prostaglandin/antagonists & inhibitors
- Receptors, Prostaglandin/metabolism
- Receptors, Thromboxane/antagonists & inhibitors
- Receptors, Thromboxane/metabolism
- Receptors, Thromboxane A2, Prostaglandin H2
- Structure-Activity Relationship
- Thromboxane A2/analogs & derivatives
- Thromboxane A2/pharmacology
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231
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Matsumoto T, Ueda J, Yokota M, Kaba K, Maeda Y, Tani E, Nishigami T. Gliomatosis cerebri: a case report. NOSHUYO BYORI = BRAIN TUMOR PATHOLOGY 1996; 13:67-71. [PMID: 8916129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Gliomatosis cerebri is a rare disease that thus far was usually diagnosed at the time of autopsy. In this communication we report the case of a young woman with gliomatosis cerebri. Diagnosis was established on the basis of characteristic imaging findings and typical histopathological features of surgical specimens obtained by craniotomy.
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Baba R, Nagashima M, Goto M, Nagano Y, Yokota M, Tauchi N, Nishibata K. Oxygen intake efficiency slope: a new index of cardiorespiratory functional reserve derived from the relationship between oxygen consumption and minute ventilation during incremental exercise. NAGOYA JOURNAL OF MEDICAL SCIENCE 1996; 59:55-62. [PMID: 8725489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We investigated the usefulness of the oxygen intake efficiency slope (OIES) as a submaximal measure of cardiorespiratory functional reserve. OIES was derived from the relationship between oxygen consumption (VO2; ml/min) and minute ventilation (VE; l/min) during incremental exercise, which was determined by the following equation: VO2 = a logVE + b, where "a" represents OIES, which shows the effectiveness of ventilation. Maximal oxygen consumption (VO2max) is effort-dependent. There is no standard submaximal measurement of cardiorespiratory reserve that provides generally acceptable results. Exercise tests were performed by 17 normal volunteers on an ergometer using a symptom-limited Ramp protocol. Expired gas was continuously analyzed. OIES was calculated using the first 75%, 90%, and 100% of exercise data. We also determined the following submaximal parameters: the ventilatory anaerobic threshold (VAT), the slope of the minute ventilation-carbon dioxide production relationship (VE-VCO2 slope), and the extrapolated maximal oxygen consumption (EMOC). We analyzed the relationship between OIES, other submaximal parameters and VO2max, and examined the effects of submaximal exercise on OIES. The correlation coefficient of the logarithmic curve-fitting model was 0.991 +/- 0.006. OIES and VO2max were significantly correlated (r = 0.966, p < 0.0001). The correlation between OIES and VO2max was stronger than the correlation between VO2max and VAT, the VE-VCO2 slope and EMOC. OIES values for 100% and 90% of exercise were identical; OIES for 75% of exercise was slightly lower (3%). Our results suggested that OIES may provide an objective, effort-independent estimation of cardiorespiratory functional reserve.
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233
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Yokota M. [Pulmonary vein stenosis, common pulmonary vein atresia]. RYOIKIBETSU SHOKOGUN SHIRIZU 1996:301-4. [PMID: 9117633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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234
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Saido T, Iwatsubo T, Yokota M, Kawashima S. 795 Post-secretory catabolism of ß-amyloid in brain. Neurobiol Aging 1996. [DOI: 10.1016/s0197-4580(96)80797-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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235
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Ito N, Yokota M, Nagaike C, Morimura Y, Hatake K, Matsunaga T. Histochemical demonstration and analysis of poly-N-acetyllactosamine structures in normal and malignant human tissues. Histol Histopathol 1996; 11:203-14. [PMID: 8720464] [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
Poly-N-acetyllactosaminyl structures carry a variety of physiologically and pathologically important carbohydrate antigens and are presumed to have essential roles in the process of cellular recognition, differentiation, malignant transformation and cancer metastasis. Monoclonal antibodies, lectins and endo-beta-galactosidase are useful histochemical tools for detecting and analyzing poly-N-acetyllactosamines in tissue sections. I (branched structure) and i (linear structure) antigens recognized by monoclonal antibodies have been shown to be differentiation antigens in mouse embryo and mouse and human teratocarcinoma cells as well as in human erythrocytes. They are also oncofoetal antigens and are expressed in carcinoma cells in several tissues and organs. Immobilized lectins specific to poly-N-acetyllactosamine structures have been successfully applied for fractioning glycoproteins with poly-N-acetyllactosamine, but histochemical use of these lectins has been restricted to some animal tissues. Among them, pokeweed mitogen agglutinin was used to detect branched poly-N-acetyllactosamine in normal and malignant human colon, demonstrating that it has a highly selective affinity for colorectal carcinomas. Griffonia simplicifolia agglutinin-II staining following endo-beta-galactosidase digestion procedure revealed the presence of poly-N-acetyllactosamine structures with or without blood group-specificities in several normal human tissues. By using this procedure, it was demonstrated that the blood group-related antigens oncofoetally expressed in thyroid carcinoma cells are carried by poly-N-acetyllactosamines containing a domain susceptible to the enzyme digestion. Staining with lectins specific to poly-N-acetyllactosamine in combination with endo-beta-galactosidase digestion demonstrated that poly-N-acetyllactosaminyl structures ubiquitously and consistently produced in thyroid papillary carcinomas are highly heterogeneous in their chain length and branching status and quite different from those produced in other thyroid neoplasms. Staining with monoclonal antibodies or lectins combined with endo-beta-galactosidase digestion procedures have been proven to be powerful tools for localizing and analyzing different types of poly-N-acetyllactosamine structures in normal and malignant tissues.
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Yokota M. [Peripheral pulmonary artery stenosis]. RYOIKIBETSU SHOKOGUN SHIRIZU 1996:340-3. [PMID: 9117647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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237
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Yokota M. [Pulmonary atresia with intact ventricular septum]. RYOIKIBETSU SHOKOGUN SHIRIZU 1996:136-9. [PMID: 9117582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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238
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Takenaka A, Iwase M, Sobue T, Yokota M. The discrepancy between echocardiography, cineventriculography and thermodilution. Evaluation of left ventricular volume and ejection fraction. INTERNATIONAL JOURNAL OF CARDIAC IMAGING 1995; 11:255-62. [PMID: 8596064 DOI: 10.1007/bf01145194] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have often experienced disagreement in left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) between cineventriculography and echocardiography not performed simultaneously, and unnaturally hyperdynamic left ventricular wall motion. We determined EDV, ESV, stroke volume, and EF (with modified Simpson's rule) in 65 consecutive patients using 2-dimensional echocardiography with a 2.5 MHz, 128-element phased-array transducer within three days of cardiac catheterization and compared our results with those obtained by the thermodilution technique and biplane cineventriculography. Heart rate and stroke volume were significantly different among the three techniques: cineventriculography yielded the highest values. These findings suggest that patients may have been in a hyperadrenergic state caused by anxiety experienced during invasive cineventriculography and thermodilution examinations. Inter- and intraobserver variabilities for echocardiography differed little from the variability in cineventriculography. Although there were good correlations between echocardiographic and cineventriculographic findings for EDV (r = 0.67), ESV (r = 0.80), and EF (r = 0.78) by two independent observers, there was a lack of agreement for EDV, ESV, and EF. Echocardiographic EDV values were significantly lower than cineventriculographic values. When left ventricular function is good, the left ventricle tends to be hyperadrenergic and in a more hyperdynamic state with smaller ESV than echocardiographic values during cineventriculography. When left ventricular function is poor, the left ventricle tends to be influenced by the effect of the contrast medium and stress during the invasive examinations and in a more hypodynamic state with larger ESV than echocardiographic values during cineventriculography. The echocardiography is highly reproducible and may provide information that is not available from cineventriculography and thermodilution. Cineventriculography may provide another manifestation of cardiac reserve. In conclusion, we must take into account each peculiar property of the echocardiography, the cineventriculography, or the thermodilution technique when patients are examined with cardiac conditions by different methods at different days.
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Ando A, Yokota M, Sobue T, Nishinaka Y, Iwase M, Hayashi H, Saito H. Correlation between the exercise-induced increase in left ventricular filling pressure and the extent of ischemic or infarcted myocardium. JAPANESE CIRCULATION JOURNAL 1995; 59:705-14. [PMID: 8747760 DOI: 10.1253/jcj.59.705] [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
We investigated the correlation between left ventricular filling pressure and the extent of ischemic or infarcted myocardium in 39 patients with coronary artery disease: 25 with angina pectoris (group A) and 14 with old myocardial infarction but without overt transient myocardial ischemia (group B). Hemodynamic parameters were measured at rest and during exercise. The extent and severity scores of ischemia or infarct were calculated using thallium-201 (201Tl) myocardial single-photon emission computed tomography. In group A, the extent and severity scores of ischemia were strongly correlated with pulmonary artery wedge pressure at peak exercise (r = 0.71, p < 0.001, r = 0.62, p < 0.01, respectively). In group B, the extent and severity scores of the infarct were significantly correlated with left ventricular ejection fraction (r = -0.81, p < 0.001, r = -0.77, p < 0.01, respectively), but were not correlated with pulmonary artery wedge pressure. Since no relationship was found between the extent of infarct and left ventricular filling pressure, dynamic exercise appears to elicit a different compensatory mechanisms in nonischemic myocardium for exercise-induced transient ischemia and in noninfarcted myocardium for old infarction. The compensatory mechanism in patients with old myocardial infarction may be affected by ventricular remodeling.
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Yokota M, Saido TC, Tani E, Kawashima S, Suzuki K. Three distinct phases of fodrin proteolysis induced in postischemic hippocampus. Involvement of calpain and unidentified protease. Stroke 1995; 26:1901-7. [PMID: 7570746 DOI: 10.1161/01.str.26.10.1901] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND PURPOSE Fodrin, a neuronal cytoskeleton protein, is proteolyzed by calpain after ischemic insult. We examined proteolysis of fodrin induced by global forebrain ischemia in gerbil hippocampus in spatial terms by using the antibody specific to the calpain-proteolyzed form of fodrin. METHODS In gerbils, a 10-minute forebrain ischemia was produced by occlusion of both carotid arteries. After recirculation, the hippocampus was processed for immunohistochemical and immunoblot study with the antibody against the calpain-proteolyzed form of fodrin. Additionally, short-term ischemia was studied to find the threshold of fodrin proteolysis. RESULTS Three phases of fodrin proteolysis distinct in chronology and distribution arose: (1) an early predegeneration phase in the molecular layer and stratum oriens of the CA1 and CA3 sectors within the first 15 minutes, which lasted up to 4 hours; (2) a late predegeneration phase in the whole CA1 sector, except for the pyramidal cells, between 12 hours and 2 days; and (3) a postdegeneration phase in the cytoplasm of the CA1 neurons, which arose in 3 to 7 days. A 4-minute (not a 3-minute) forebrain ischemia induced the late predegeneration phase of fodrin proteolysis and delayed neuronal death in CA1. Immunoblotting showed that the primary product of calpain action was further proteolyzed by an unidentified protease. CONCLUSIONS Calpain induced proteolysis of fodrin in ischemic hippocampus, and the late predegeneration phase of the proteolysis was closely associated with the delayed neuronal death in the CA1 sector. Calpain and another protease may play a role in the development of neuronal death after transient forebrain ischemia.
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Noda A, Okada T, Yasuma F, Yamada Y, Nakashima N, Yokota M. Effect of aging on cardiac and electroencephalographic arousal in sleep apnea/hypopnea syndrome. J Am Geriatr Soc 1995; 43:1070-1. [PMID: 7657932 DOI: 10.1111/j.1532-5415.1995.tb05585.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Yokota M, Yane K, Tanaka O, Miyahara H, Matsunaga T, Ito N. [Evaluation of blood-group-related carbohydrate antigens in thyroid neoplasms]. NIHON JIBIINKOKA GAKKAI KAIHO 1995; 98:1381-6. [PMID: 8523166 DOI: 10.3950/jibiinkoka.98.1381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
An immunohistochemical study using a panel of monoclonal antibodies (mAbs) against blood group A, B, H and Lewis antigens Le(a), Le(b), Le(x) and Le(y) and lectins, such as PNA, VVA-B4 and UEA -1, was carried out to investigate the aberrant expression of carbohydrate antigens in formalin-fixed, paraffin-embedded tissue sections of thyroid neoplasms. The tissues examined consisted of 26 papillary carcinomas, seven follicular adenomas, seven follicular carcinomas, one anaplastic carcinoma and one medullary carcinoma. MAbs against A, B and H antigens reacted strongly with papillary carcinomas from most of the individuals studied (22 of 26 individuals) and their reactivity corresponded well to the blood groups of individuals. In follicular adenomas and carcinomas, these mAbs reacted weakly with a small number of neoplastic cells from two of seven, and four of seven individuals, respectively. Positive staining with mAbs against Le(a) and Le(b) antigens was found in almost all papillary carcinomas. On the contrary, these mAbs rarely reacted with cells from follicular adenomas and carcinomas. T and Tn antigens which were recognized by PNA and VVA-B4, respectively, were only weakly expressed in a limited number of cells from the thyroid neoplasms. Normal cells adjacent to malignant cells were not stained by any of the stains used in this study. These results are discussed in light of our recent findings that polylactosamine structures produced in papillary carcinomas are quite different from those expressed in other types of neoplasms.
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Ito N, Yokota M, Kawahara S, Nagaike C, Morimura Y, Hirota T, Matsunaga T. Histochemical demonstration of different types of poly-N-acetyllactosamine structures in human thyroid neoplasms using lectins and endo-beta-galactosidase digestion. THE HISTOCHEMICAL JOURNAL 1995; 27:620-9. [PMID: 8550383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Blood-group-related antigens expressed in papillary carcinomas and other types of neoplasm of the human thyroid glands have been shown to be carried by poly-N-acetyllactosamines containing a linear domain susceptible to endo-beta-galactosidase digestion. To make clear more precisely the backbone poly-N-acetyllactosamine structures, labelled lectins specific to different types of these structures and specific to core structures with beta 1-6GlcNAc branching of N- and O-linked glycoproteins were employed in conjunction with prior endo-beta-galactosidase digestion on formalin-fixed, paraffin-embedded neoplasms of the human thyroid glands. In papillary carcinomas, Datura stramonium agglutinin (DSA) and succinyl wheat germ agglutinin (Suc-WGA) reacted most consistently and frequently with papillary carcinomas from all the individuals examined. Pokeweed mitogen (PWM) likewise stained the cells of papillary carcinomas from all the individuals examined, but in some individuals the number of lectin-reactive cells were very small. Lycoperscion esculentum aggultinin (LEA), Solanum tuberosum agglutinin (STA), Phaseolus vulgaris agglutinin L (PHA-L) and Artocarpus integrifolia agglutinin (jacalin) similarly bound to the cancer cells from most of the individuals, and in these cases the number of reactive cells was usually much more restricted than was the case with DSA or PWM. In adenoma and other types of carcinoma, such as follicular carcinomas, these lectins specific to poly-N-acetyllactosamine exhibited slight or no reactivity with the cells, whereas PHA-L and jacalin similarly bound to the cells of adenomas and carcinomas from most of the individuals examined. Prior digestion with endo-beta-galactosidase completely eliminated or markedly reduced the reactivity with PWM and LEA in papillary carcinomas. Reactivity with DSA, Suc-WGA, STA, PHA-L and jacalin was slightly reduced or not at all affected by enzyme digestion. These results confirmed that poly-N-acetyllactosamine species found in papillary carcinomas are quite different from those in other types of thyroid neoplasm, suggesting that at least three different types of poly-N-acetyllactosamine, that is, linear unbranched short and long sequences and highly branched ones are produced in these cells.
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Noda A, Okada T, Yasuma F, Nakashima N, Yokota M. Cardiac hypertrophy in obstructive sleep apnea syndrome. Chest 1995; 107:1538-44. [PMID: 7781343 DOI: 10.1378/chest.107.6.1538] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Fifty-one middle-aged male patients with obstructive sleep apnea syndrome (OSAS) were evaluated using two-dimensional echocardiography, 24-h blood pressure measurements, polysomnography, and plasma norepinephrine (NE) measurements. Among these patients, left ventricular hypertrophy (LVH) (left ventricular posterior wall thickness [LVPWT] or interventricular septal thickness [IVST] > or = 12 mm) and right ventricular hypertrophy (RVH) (right ventricular wall thickness [RVT] > or = 5 mm) were present in 41.2% (21/51) and 11.8% (6/51). LVH was present in 50.0% of group 2 patients (apnea index > or = 20) and in 30.5% of group 1 patients (apnea index < 20). All patients with LVH had hypertension. RVH was present in 21.4% of group 2 patients and none of the group 1 patients. IVST, LVPWT, LV mass, LV mass/body surface area (BSA), and obesity index were significantly greater in group 2 than in group 1. Apnea index and the duration in which nocturnal oxygen saturation was decreased under 90% (duration of SaO2 < 90%), were significantly correlated with LV mass/BSA and 24-h mean blood pressure. Apnea index, number of apneas, duration of nocturnal oxygen saturation less than 90%, weight, and obesity index were significantly greater in patients with both LVH and RVH than in patients without LVH and RVH, or those with only LVH. Plasma NE after waking significantly increased compared with that before sleep (p < 0.05). The ratio of plasma NE levels after waking to those before sleep was significantly correlated with the duration of SaO2 < 90% (r = 0.83, p < 0.05), but not with apnea index. These results suggest that frequent episodes of oxygen desaturation and/or arousal responses caused by apnea may contribute to the complication of LVH and RVH in the long term, and apnea-induced cyclical increases in blood pressure and the resulting sustained elevation in blood pressure associated with the increase in afterload and sympathetic activity may play a role in the development of LVH.
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Møller AR, Jho HD, Yokota M, Jannetta PJ. Contribution from crossed and uncrossed brainstem structures to the brainstem auditory evoked potentials: a study in humans. Laryngoscope 1995; 105:596-605. [PMID: 7769942 DOI: 10.1288/00005537-199506000-00007] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The neural generators of the brainstem auditory evoked potentials (BAEPs) in humans are not completely known. Attempts to identify the anatomical location of the neural generators of the human BAEP based on the results of studies in animals commonly used in auditory experimentation have been difficult because of the considerable anatomical differences between the ascending auditory pathways in humans and animals. The authors of this study compared recordings obtained from different locations on the lateral side of the brainstem in six patients undergoing microvascular decompression surgery for a cranial nerve disorder affecting the fifth cranial nerve (i.e., trigeminal neuralgia). Ipsilateral click stimulation evoked prominent responses from the caudal aspect of the pons up to the junction between the pons and the midbrain, but all components of the responses with latencies shorter than 8 msec had smaller amplitudes when recorded at more rostral locations. Components with latencies in the range of peak V elicited by contralateral click stimulation had their largest amplitudes when recorded from the lateral brainstem at the level of the fourth cranial nerve (thus, close to the inferior colliculus). Earlier components of the contralateral responses (latencies in the range of the latency of peak III) had their largest amplitudes when recorded from the caudal lateral brainstem. The results of this study indicate that the part of the uncrossed auditory pathway that is located rostral to the cochlear nucleus contributes little to the farfield potentials (i.e., BAEP), and it is doubtful whether the contralateral response that can be recorded at the level of the cochlear nucleus contributes noticeably to the BAEP.
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Yokota M, Peterson JW, Kaoutzanis MC, Yamakawa K, Sibilia R, Zervas NT. Protein kinase C and diacylglycerol content in basilar arteries during experimental cerebral vasospasm in the dog. J Neurosurg 1995; 82:834-40. [PMID: 7714610 DOI: 10.3171/jns.1995.82.5.0834] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Sixteen dogs were entered into a study of the double subarachnoid hemorrhage (SAH) model of cerebral vasospasm. Six animals were sacrificed 72 hours after the first experimental SAH, and the remaining 10 animals were killed 72 hours after the second experimental SAH; ten additional animals served as controls. Basilar arteries were rapidly excised from the dogs and frozen. Multiple segments of the frozen arteries were analyzed independently for total protein and 1,2-diacylglycerol (DAG) content, which averaged 3.17 (+/- 0.27 standard error of the mean; SEM) pmol DAG/microgram protein for all 25 arteries analyzed. A slight decreasing trend in DAG content relative to that of control vessels was found in vessels chronically constricted in situ by subarachnoid blood clot; however, this trend did not attain statistical significance. Two segments of the same vessels were assayed independently for protein kinase C (PKC) activity, which averaged 1.21 (+/- 0.08 SEM) pmol phosphate incorporation per minute per microgram protein for all 24 arteries analyzed. A small decrease in PKC content was noted in vessels that experienced a single SAH; however, PKC returned to near control value in vessels subjected to double SAH. The ratio of particulate (membrane bound) to soluble PKC activity, an indicator of PKC translocation to the membrane and hence PKC activation, showed a small but statistically significant trend to increase with experimental SAH.
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Nagata T, Yokota M, Nishikawa S, Ishida H, Wakano Y. Osteopontin expression in clonal dental pulp cells. Ann N Y Acad Sci 1995; 760:342-5. [PMID: 7785912 DOI: 10.1111/j.1749-6632.1995.tb44652.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Meyer MW, Witt AR, Krishnan LK, Yokota M, Roszkowski MJ, Rudney JD, Herzberg MC. Therapeutic advantage of recombinant human plasminogen activator in endocarditis: evidence from experiments in rabbits. Thromb Haemost 1995; 73:680-2. [PMID: 7495078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In infective endocarditis vegetations are stabilized by fibrin. To learn if fibrin digestion would be therapeutic, experimental endocarditis was induced in rabbits by inoculation with a platelet-aggregating strain (Agg+) of Streptococcus sanguis and treated with recombinant tissue plasminogen activator (rt-PA), rt-PA with penicillin, or penicillin alone. Control rabbits were inoculated with saline. All treatments of Agg+ endocarditis reduced the mass of valvular vegetations and clinical signs of endocarditis, including the frequency of left axis deviation and heart ischemia. rt-PA with penicillin was more effective than penicillin or rt-PA alone, reducing the mass of vegetations and clinical signs to that of saline controls. Within 50 min, rt-PA cleared 5-fold more 111Indium-labelled platelets from the heart than untreated rabbits and 1.4-fold more after 3 days. Combined with penicillin, thrombolytic therapy for human endocarditis should be reconsidered.
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Ukai M, Nishinaka Y, Sobue T, Miyahara T, Yokota M. Improvement in exercise-induced left ventricular dysfunction by infusion of alpha-human atrial natriuretic peptide in coronary artery disease. Am J Cardiol 1995; 75:449-54. [PMID: 7863987 DOI: 10.1016/s0002-9149(99)80579-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The effects of recombinant alpha-human atrial natriuretic peptide (alpha-hANP) infusion an acute left ventricular dysfunction provoked by exercise were examined in 14 men with coronary artery disease. Patients performed symptom-limited, graded exercise on a supine bicycle ergometer. Plasma alpha-hANP and guanosine 3',5'-monophosphate (cyclic GMP) concentrations as well as hemodynamic variables were measured at rest, during and after exercise. In 14 patients whose pulmonary artery wedge pressure was > 20 mm Hg at peak exercise, the same exercise protocol was repeated at 30 minutes after starting intravenous alpha-hANP infusion (0.05 microgram.kg-1.min-1). In 8 of these patients, a Webster thermodilution catheter was advanced into the coronary sinus for measurement of coronary sinus blood flow. From the control exercise test, plasma alpha-hANP concentration increased from 86 +/- 20 pg/ml at rest to 188 +/- 32 pg/ml at peak exercise (p < 0.001), and plasma cyclic GMP concentration increased from 4.8 +/- 1.9 pmol/ml at rest to 7.2 +/- 2.9 pmol/ml at peak exercise (p < 0.001). Both plasma alpha-hANP and cyclic GMP concentrations showed a significant positive correlation with pulmonary artery wedge pressure during control exercise. With alpha-hANP infusion, systolic and diastolic pulmonary artery pressures and pulmonary artery wedge pressure were significantly decreased at all time points during exercise testing. Heart rate was increased and systolic blood pressure was significantly decreased at rest and at 3 minutes of exercise. Diastolic blood pressure, systemic vascular resistance, and pulmonary vascular resistance were significantly decreased at rest.(ABSTRACT TRUNCATED AT 250 WORDS)
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Matsubara K, Yokota M, Miyahara T, Sobue T, Iwase M, Saito H. Left ventricular performance during exercise testing in patients with silent and symptomatic myocardial ischemia. Am Heart J 1995; 129:459-64. [PMID: 7872171 DOI: 10.1016/0002-8703(95)90268-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We compared cardiohemodynamic response to dynamic exercise in 32 patients with exercise-induced silent or symptomatic myocardial ischemia. All patients had coronary artery disease without prior myocardial infarction and left ventricular hypertrophy. Patients underwent supine leg-exercise testing and received right heart catheterization. All patients exhibited ischemic ST-segment depression on electrocardiogram during exercise testing. They were classified retrospectively into two groups according to the absence (n = 10, group 1) or presence (n = 22, group 2) of chest pain induced by exercise. There was no significant difference between groups in the magnitude of peak ST-segment depression. Pulmonary artery wedge pressure at peak exercise was significantly lower (p < 0.01), and the cardiac index was significantly higher (p < 0.01), in group 1 versus group 2. Our results indicate that exercise-induced left ventricular dysfunction is less severe in patients with silent myocardial ischemia than in those with symptomatic ischemia.
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