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ABSTRACT: We investigated cardiac and vascular gene profiles in response to immobilization stress (IMO) in rats, an animal model of emotional stress-induced takotsubo cardiomyopathy using microarray analysis, followed by re-confirmation with real-time reverse transcription-polymerase chain reaction. Expression levels of the identified genes were further estimated by pretreatment with an α1-adrenoceptor blocker and/or a β1-adrenoceptor blocker. In response to IMO, expression of 46 genes was significantly altered in the heart and that of 49 genes was significantly altered in the aorta. Pathway analysis with DAVID Bioinformatics Resources indicated that regulation of transcription and response to endogenous stimulation were the top two scoring pathways. Altered expression of cardiac genes was blunted by pretreatment with a β1-adrenoceptor blocker or α1 + β1-adrenoceptor blockers. In contrast, that of aortic genes was blunted by pretreatment with an α1-adrenoceptor blocker or α1 + β1-adrenoceptor blockers. Activation of α1-adrenoceptor in the blood vessels or activation of β1-adrenoceptors in the heart were mainly responsible for emotional stress-induced alteration of cardiac and vascular gene profiles.
Heart and Vessels 12/2010; 26(3):321-37. · 2.05 Impact Factor
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ABSTRACT: Disturbance of the coronary microcirculation and catecholamine intoxication, which may be responsible for the pathogenesis of takotsubo cardiomyopathy, could trigger an oxidative stress response in the heart.
Expression and localization of inducible heme oxygenase-1 (HO-1), which is an oxidative stress-related factor in the heart of immobilization stressed (IMO) rats, an animal model of takotsubo cardiomyopathy, were investigated by real-time reverse transcriptase-polymerase chain reaction and in situ hybridization histochemistry and immunohistochemistry. In response to IMO, the levels of HO-1 mRNA in the heart and in the aorta were slightly increased at 90 min, and increased 3-fold at 3 h compared with control levels. The signals for HO-1 mRNA were expressed on scatted cells in the myocardium and aortic adventitia. Double fluorescence immunohistochemistry showed that HO-1 immunoreactive cells were also ED1 and ED2 positive, indicating that they were macrophages. The numbers of ED1 and ED2 positive cells were constant, whereas the number of HO-1 positive cells was increased 5-fold at 6 h compared with control levels. Blocking of alpha- and beta-adrenoceptors attenuated IMO-induced upregulation of HO-1 mRNA levels in the heart.
Emotional stress and a surge of catecholamine upregulate HO-1 in the cardiac and aortic macrophages.
Circulation Journal 05/2009; 73(6):1141-6. · 3.77 Impact Factor
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ABSTRACT: To investigate the effect of taurine on the sympathetic nervous system, I observed pressor responses of perfused mesenteric arteries by electrical stimulation and baro-reflex sensitivity of spontaneously hypertensive rats (SHR/Izm) and control Wistar-Kyoto rats (WKY/Izm) treated with taurine. Taurine added to the perfusate suppressed norepinephrine (NE) overflow and the pressor response mediated by electrical stimulation of isolated perfused mesenteric arteries. Taurine showed a greater suppressive effect on NE overflow and the pressor response mediated by electrical stimulation in SHR/Izm rats than in WKY/Izm rats. Increment of renal sympathetic nerve activity induced by jet-air stress was suppressed in SHR/Izm rats treated with 3% taurine. The arterial baro-reflex sensitivity was more sensitive in SHR/Izm rats treated with taurine than in those exposed to no taurine. These data suggest that taurine lowers blood pressure directly via the suppression of NE release from the peripheral sympathetic nerve and the improvement of impaired baro-reflex sensitivity.
Advances in experimental medicine and biology 02/2009; 643:57-63. · 1.09 Impact Factor
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ABSTRACT: Emotional stress triggers takotsubo cardiomyopathy in postmenopausal women. Clinical analysis of autonomic nervous function has revealed a transient increase of sympathetic nervous activity and decrease of vagal nervous activity. Immobilization (IMO) stress of rats can reproduce the electrocardiographic and left ventriculographic changes that occur in takotsubo cardiomyopathy, both of which are prevented by combined blockade of alpha- and beta-adrenoceptors. Estrogen supplementation partially attenuated these cardiac changes. It also attenuated the IMO-induced increase of c-Fos immunoreactivity, or c-fos mRNA expression in the lateral septum, medial amygdaloid nucleus, paraventricular hypothalamic nucleus, dorsomedial hypothalamic nucleus, laterodorsal tegmental nucleus, and locus ceruleus; these regions contain central sympathetic neurons and neurons with immunoreactive estrogen receptors. It also downregulated c-fos mRNA expression in the adrenal gland and the heart, suggesting an increase of estrogen attenuated the stress-induced hypothalamo-sympathoadrenal outflow from the central nervous system to the target organs. Estrogen treatment also upregulated the levels of cardioprotective substances, such as atrial natriuretic peptide and heat shock protein 70, in the heart. These data suggest that reduction of estrogen levels following menopause might be involved in the primary cause of takotsubo cardiomyopathy both by indirect action on the nervous system and by direct action on the heart.
Annals of the New York Academy of Sciences 01/2009; 1148:479-85. · 3.15 Impact Factor
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ABSTRACT: Unlike arteriogenesis, little is known about the effects of vasculogenesis and its major effector cells, endothelial progenitor cells (EPCs) on collateral formation. In this study, we investigated whether or not the number and function of EPCs were associated with the development of collateral formation in patients with single-vessel coronary artery disease of chronic total occlusion (CTO).
The subjects were patients (n=35) undergoing coronary angiography (CAG) who had CTO in one major coronary artery. EPCs were isolated from peripheral blood samples and cultured. Their phenotypes were confirmed by uptake of acetylated LDL and binding of fluorescein isothiocyanate (FITC)-labeled Ulex europaeus agglutinin 1 (UEA-1) lectin. The numbers of colony-forming units (CFUs) and the senescent cells, determined by acidic beta-galactosidase staining, were counted. The angiogenic growth factors from the culture medium were also measured by ELISA. Patients with good collaterals (n=22, Rentrop class 2 and 3) exhibited an increased number of CFUs (p=0.023), reduced number of senescent cells (p=0.010), and higher concentration of b-FGF (0.036) in the culture medium, compared with subjects with poor collaterals (n=13, Rentrop class 0 and 1).
Our findings suggested that EPC-mediated angiogenesis might be associated with coronary collateral formation in humans.
Internal Medicine 02/2008; 47(3):127-34. · 0.94 Impact Factor
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Takuzo Hano
Nippon rinsho. Japanese journal of clinical medicine 09/2007; Suppl 4:12-5.
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Takashi Ueyama,
Fuminobu Ishikura,
Akiko Matsuda,
Toshihiko Asanuma,
Kazuki Ueda,
Masao Ichinose,
Ken Kasamatsu, Takuzo Hano,
Takashi Akasaka,
Yoshihiro Tsuruo,
Keiko Morimoto,
Shintaro Beppu
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ABSTRACT: Takotsubo cardiomyopathy is triggered by emotional or physical stress especially in post-menopausal women. A reduction in estrogen levels following menopause might underlie the high incidence of takotsubo cardiomyopathy.
The left ventricular contraction between ovariectomized rats (OVX) and OVX with estrogen supplementation (OVX + E) while subjected to immobilization stress (IMO) was compared. The IMO in combination with general anesthesia impaired the left ventricular contraction in both OVX and OVX + E. Estrogen supplementation tended to improve the IMO-induced cardiac dysfunction and significantly attenuated the increase of blood pressure and heart rate. To understand the protective mechanism of estrogen, the expression of c-fos mRNA, a marker of cellular activation was compared. The mRNA expression of cardioprotective substances in the heart was also investigated. In the OVX + E, the levels of c-fos mRNA were significantly decreased in the paraventricular hypothalamic nucleus, adrenal gland and left ventricle, suggesting that an increase of estrogen attenuates the emotional stress-induced hypothalamo-sympatho-adrenal outflow from the central nervous system to the target organs. An expression of heat shock protein 70 and atrial natriuretic peptide was significantly augmented in the OVX + E.
These data suggest that estrogen supplementation partially prevents emotional stress-induced cardiovascular responses both by indirect action on the nervous system and by direct action on the heart.
Circulation Journal 05/2007; 71(4):565-73. · 3.77 Impact Factor
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Takuzo Hano
Nippon rinsho. Japanese journal of clinical medicine 03/2006; 64 Suppl 2:252-6.
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ABSTRACT: Restenosis after stent implantation is caused by endothelial cell damage and subsequent neointimal formation. The objective of this study is to elucidate the relevance of endothelial progenitor cells (EPCs) in the development of in-stent restenosis in patients undergoing stent implantation.
The subjects were 46 patients who underwent coronary stenting. Blood samples were collected at the time of follow-up coronary angiography after coronary stenting. EPCs were isolated from blood samples and cultured. Their phenotypes were confirmed by uptake of acetylated low-density lipoprotein and binding of fluorescein isothiocyanate-labeled Ulex europaeus agglutinin 1 lectin. The number of colony-forming units (CFUs) and the senescent cells, determined by acidic beta-galactosidase staining, was counted. Angiogenic growth factors secreted by EPCs, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (b-FGF), hepatocyte growth factor (HGF), and macrophage chemoattractant protein (MCP-1) from the culture medium were also measured by enzyme-linked immunosorbent assay.
Patients with in-stent restenosis (defined as >40% stenosis, n=16) had a decreased number of CFUs (p<0.05), and increased senescent cells (p<0.05), compared to patients without restenosis (n=30). There was no significant difference of angiogenic growth factors (VEGF, HGF, b-FGF, and MCP-1) secreted by EPCs between the two groups. On multivariate analysis, an increased number of senescent EPCs was the indepen-dent factor associated with in-stent restenosis (OR 1.10, 95% CI 1.01 to 1.20).
These data suggested that EPCs might be involved in the development of in-stent restenosis.
Internal Medicine 01/2006; 45(9):581-7. · 0.94 Impact Factor
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ABSTRACT: Recent studies have revealed an association between coronary risk factors and both the number and function of bone marrow-derived endothelial progenitor cells (EPCs). Although hypertension is an important coronary risk factor, the influence to the EPCs is not fully understood. We investigated the effect of hypertension on EPC senescence.
Experimental study We investigated the number and senescence of EPCs in spontaneously hypertensive rats (SHR/Izm) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. EPCs were isolated from peripheral blood of rats and were characterized. EPC senescence was detected by acidic beta-galactosidase staining. In addition, we measured the telomerase activity using polymerase chain reaction-enzyme-linked immunosorbent assay. CLINICAL STUDY: EPCs were isolated from peripheral blood samples in 37 patients with essential hypertension. After ex-vivo cultivation, we detected senescence and measured the telomerase activity. The total severity index of hypertension-induced organ damage was calculated by the summation of each severity index in the classification of hypertension severity by Tokyo University (1984).
Experimental study The EPC senescence in SHR/Izm and DOCA-salt hypertensive rats was significantly increased compared with that of control rats. The telomerase activities in SHR/Izm and DOCA-salt hypertensive sensitive rats were also significantly lowered compared with those of control rats. Clinical study Compared with the control group, EPCs from hypertensive patients showed accelerated senescence and also showed reduced telomerase activity. In hypertensive patients, the degree of hypertension-induced organ damage was negatively correlated with telomerase activity, and was positively correlated with EPC senescence.
EPC senescence is accelerated in both experimental hypertensive rats and patients with essential hypertension, which may be related to telomerase inactivation. The hypertension-induced EPC senescence may affect the process of vascular remodeling.
Journal of Hypertension 11/2005; 23(10):1831-7. · 4.02 Impact Factor
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ABSTRACT: The functional impairment associated with atherogenic factors, including hypertension, constitutes a limitation to the ability of endothelial progenitor cells (EPCs) to repair. In addition, estrogens have been shown to play a role in reendothelialization after vascular injury. We investigated the effects of estrogens on differentiation and senescence of EPCs derived from bone marrow (BM-EPCs) in spontaneously hypertensive rats (SHR/Izm). Bone marrow (BM) cells were obtained from the tibias and femurs of age-matched, male SHR/Izm and Wistar-Kyoto rats (WKY/Izm). The number of differentiated, adherent BM-EPCs derived from SHR/Izm was significantly smaller than the number derived from WKY/Izm. 17beta-Estradiol (E2) significantly increased the number of adherent BM-EPCs from SHR/Izm, and this effect was significantly attenuated by pharmacological phosphatidylinositol 3-kinase (PI3-K) blockers. Immunoblotting analysis revealed that E2 treatment led to phosphorylation of Akt. Senescence, as assessed by acidic beta-galactosidase staining, occurred at a significantly greater rate in the BM-EPCs from SHR/Izm than in those from WKY/Izm, but E2 treatment dramatically delayed the senescence of BM-EPCs from SHR/Izm. A polymerase chain reaction (PCR)-ELISA based assay revealed that telomerase activity in BM-EPCs from SHR/Izm was significantly lower than in those from WKY/Izm, but that E2 treatment significantly augmented it. Both MTS and colony forming unit assay revealed that E2 treatment significantly augmented the functional activity in BM-endothelial cell (EC)-like cells from SHR/Izm compared to that in control BM-EC-like cells (no treatment). In conclusion, the differentiation of BM-EPCs derived from SHR/Izm was significantly decreased compared with that of BM-EPCs from WKY/Izm. In addition, the rate of senescence was significantly greater in the BM-EPCs from SHR/Izm than in those from WKY/Izm. Estrogen was shown to augment differentiation and delay the onset of senescence in BM-EPCs from SHR/Izm.
Hypertension Research 10/2005; 28(9):763-72. · 2.58 Impact Factor
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ABSTRACT: Recent studies have demonstrated that aging or senescence constitutes a potential limitation to the ability of endothelial progenitor cells (EPCs) to sustain ischemic tissue and repair. Conversely, estrogens have been shown to accelerate recovery of the endothelium after vascular injury.
To investigate whether estrogens are able to prevent senescence of EPCs.
Human EPCs were isolated from peripheral blood and characterized. After ex-vivo cultivation, the cells became senescent as determined by acidic beta-galactosidase staining. 17beta-estradiol dose-dependently inhibited the onset of EPC senescence in culture. Because cellular senescence is critically influenced by telomerase, which elongates telomeres, we measured telomerase activity using a polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (ELISA) technique. 17beta-estradiol significantly increased telomerase activity. Interestingly, reverse transcriptase-PCR analysis demonstrated that 17beta-estradiol dose-dependently increased the catalytic subunit, telomerase reverse transcriptase (TERT) - an effect that was significantly inhibited by pharmacological phosphatidylinositol 3-kinase (PI3-K) blockers (either wortmannin or LY294002). Because the expression of TERT is regulated by the PI3-K/Akt pathway, we examined the effect of 17beta-estradiol on Akt activity in EPCs. Immunoblotting analysis revealed that 17beta-estradiol dose-dependently led to phosphorylation and, thus, to activation of Akt in EPCs. We also examined whether the protective effect of 17beta-estradiol on EPC senescence translates into the augmentation of mitogenic activity in EPCs. A [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) assay demonstrated that the mitogenic potential in EPCs treated with 17beta-estradiol exceeded that in untreated (control) EPCs (P < 0.01). In addition, EPCs released vascular endothelial growth factor (VEGF) protein--an effect that was significantly augmented by 17beta-estradiol. Finally, in a Matrigel assay, EPCs treated with both 17beta-estradiol and VEGF were shown to be more likely to integrate into the network formation than those treated with VEGF alone.
The inhibition of EPC senescence by estrogen in vitro may improve the functional activity of EPCs in a way that is important for potential cell therapy.
Journal of Hypertension 09/2005; 23(9):1699-706. · 4.02 Impact Factor
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Nippon rinsho. Japanese journal of clinical medicine 04/2005; 63 Suppl 3:533-6.
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Takuzo Hano
Nippon rinsho. Japanese journal of clinical medicine 04/2005; 63 Suppl 3:542-6.
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ABSTRACT: The interaction among estrogen, angiotensin II (Ang II), and oxidative stress in endothelial progenitor cells (EPCs) remains unknown. We therefore investigated the potential effect of estrogen on Ang II-induced EPC oxidative stress and senescence in EPCs. EPCs were isolated from peripheral blood and characterized. Both reverse transcription (RT)-polymerase chain reaction (PCR) and Western blotting were used to assess gp91phox and angiotensin type 1 receptor (AT1R) expression. Immunofluorescence of nitrotyrosine provided evidence of peroxynitrite formation. Our data indicate that Ang II increased the expression of gp91phox mRNA and protein, and these effects were attenuated by 17beta-estradiol (E2). The exposure of cultured EPCs to Ang II (100 nmol/l) significantly accelerated the rate of senescence compared to that in control cells during 14 days in culture as determined by acidic beta-galactosidase staining, and this effect was significantly inhibited by E2 (p < 0.01). Because cellular senescence is critically influenced by telomerase, which elongates telomeres, we measured telomerase activity by using a PCR-ELISA-based assay. Ang II significantly diminished telomerase activity, although the effect was significantly reduced by pre-treatment with E2 (p < 0.01). Because we previously demonstrated that both the up-regulation of gp91phox and the acceleration of cellular senescence in Ang II-stimulated EPCs could be abolished by pre-treatment with the AT1R- specific antagonist, valsartan, we also explored the effect of estrogen on AT1R expression. Ang II increased AT1R mRNA and protein expression, and these increases were prevented by E2, suggesting that AT1R may at least partially mediate the inhibitory effect of E2 on Ang II-induced acceleration of senescence in EPCs. In conclusion, estrogen reduces Ang II-induced acceleration of senescence in EPCs partially through down-regulation of AT1R expression.
Hypertension Research 03/2005; 28(3):263-71. · 2.58 Impact Factor
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ABSTRACT: Recent studies have revealed an association between coronary risk factors and both the number and function of bone marrow-derived endothelial progenitor cell (EPC). We investigated the effect of angiotensin II (Ang II) on EPC senescence, leading to the impairment of proliferative activity.
EPCs were isolated from peripheral blood and characterized. Both reverse transcription (RT)-polymerase chain reaction (PCR) and Western blotting were used to assess gp91phox expression. Immunofluorescence of nitrotyrosine provided evidence of peroxynitrite formation. Our data indicate that Ang II increased the expression of gp91phox mRNA in a dose-dependent manner, which was attenuated by Ang II type 1 (AT1) receptor antagonist valsartan. Similarly, Western blotting revealed that Ang II stimulated an increase in gp91phox, whereas pre-treatment with Valsartan reduced the Ang II-induced expression of gp91phox protein. Valsartan as well as superoxide dismutase (SOD) also inhibited Ang II-induced peroxynitrite formation. The exposure of cultured EPC to Ang II (100 nmol/l) significantly accelerated the rate of senescence compared to a control during 14 days in culture as determined by acidic beta-galactosidase staining. Ang II-induced EPC senescence was significantly inhibited by pre-treatment of either valsartan or SOD (P < 0.01). Because cellular senescence is critically influenced by telomerase, which elongates telomeres, we measured telomerase activity by using PCR-enzyme-linked immunosorbent-based assay. Ang II significantly diminished telomerase activity, although the effect was significantly reduced by pre-treatment with either valsartan or SOD (P < 0.01). We examined whether Ang II-induced EPC senescence translates into an impairment of EPC proliferation. MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenol)-2-(4-sulfophenyl)-2H-tetrazolium] assay disclosed an inhibitory effect of Ang II on EPC proliferation.
Ang II increases gp91phox expression in EPC, which may contribute to oxidative stress, as evidenced by peroxynitrite formation. Ang II accelerates the onset of EPC senescence via increased oxidative stress, which may be related to telomerase inactivation. In addition, Ang II-induced EPC senescence leads to the impairment of proliferative activity.
Journal of Hypertension 01/2005; 23(1):97-104. · 4.02 Impact Factor
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ABSTRACT: 1. Recent studies have revealed an association between coronary risk factors and both the number and function of bone marrow-derived endothelial progenitor cells (EPC). We investigated the effect of oxidized low-density lipoprotein (ox-LDL) on the senescence of EPC, leading to cellular dysfunction. 2. Endothelial progenitor cells were isolated from human peripheral blood and characterized. The exposure of cultured EPC to ox-LDL (10 microg/mL) significantly accelerated the rate of senescence compared with control during 20 days in culture as determined by acidic beta-galactosidase staining. Oxidized LDL-induced EPC senescence was significantly inhibited by pretreatment with either lectin-like ox-LDL receptor-1 (LOX-1) antibody (Ab) or atorvastatin (P < 0.01). 3. Because cellular senescence is critically influenced by telomerase, which elongates telomeres, we measured telomerase activity using a polymerase chain reaction-ELISA-based assay. Oxidized LDL significantly diminished telomerase activity to approximately 50%, an effect that was significantly abolished by pretreatment with either LOX-1 Ab or atorvastatin (P < 0.01). 4. We examined whether ox-LDL-induced EPC senescence translates into EPC dysfunction. An MTS assay disclosed an inhibitory effect of ox-LDL on EPC proliferation. In a Matrigel assay, EPC treated with ox-LDL were less likely to participate in network formation compared with controls. 5. In conclusions, ox-LDL accelerates the onset of EPC senescence, which may be related to telomerase inactivation. Oxidized LDL-induced EPC senescence leads to the impairment of proliferative capacity and network formation.
Clinical and Experimental Pharmacology and Physiology 08/2004; 31(7):407-13. · 1.85 Impact Factor
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ABSTRACT: Am J Hypertens (2004) 17, 202A–202A; doi: 10.1016/j.amjhyper.2004.03.536
P-462: Endothelial progenitor cell senescence is related to telomerase activity in patients with hypertension
Chizu Moriwaki1, Toshio Imanishi1, Takuzo Hano1 and Ichiro Nishio11Cardiovascular Medicine, Wakayama Medical University, Wakayama, Japan.
American Journal of Hypertension 04/2004; · 3.18 Impact Factor
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ABSTRACT: Am J Hypertens (2004) 17, 155A–155A; doi: 10.1016/j.amjhyper.2004.03.406
P-331: Angiotensin II potentiates vegf-induced proliferation and network formation of endothelial progenitor cells
Toshio Imanishi1, Takuzo Hano1, Chizu Moriwaki1 and Ichiro Nishio11Cardiovascular Medicine, Wakayama Medical University, Wakayama, Japan.
American Journal of Hypertension 04/2004; · 3.18 Impact Factor
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Nippon rinsho. Japanese journal of clinical medicine 04/2004; 62 Suppl 3:87-91.
