Characterization of a novel iodocyanopindolol and SM-11044 binding protein, which may mediate relaxation of depolarized rat colon tonus

Studies under blockade of alpha-, beta1-, and beta2-adrenoreceptors revealed a good correlation between the responses of rat colon relaxation of depolarized tonus and of rat adipocyte lipolysis elicited by catecholamines or BRL-37344, a selective beta3-adrenoreceptor agonist, suggesting beta3-adrenoreceptor stimulation. In contrast, SM-11044, a nonselective beta-adrenoreceptor agonist, stimulated colon relaxation more efficiently than lipolysis; its effects were differently antagonized by cyanopindolol with pA2 values of 8.31 in colon and of 7.32 in adipocytes. Binding studies in rat colon smooth muscle membranes using [125I]iodocyanopindolol under blockade of adrenaline and serotonin receptors revealed the existence of a single class of sites (Kd = 11.0 nM, Bmax = 716.7 fmol/mg protein). The specific binding was saturable and reversible and was displaced by SM-11044 but not by BRL-37344, isoproterenol, noradrenaline, adrenaline, serotonin, nor dopamine. This binding site was photoaffinity labeled using [125I]iodocyanopindolol-diazirine. The labeling was prevented by SM-11044 but not by BRL-37344. The amino-terminal amino acid sequences of the high performance liquid chromatography-purified peptides generated by enzymatic and chemical cleavages of the affinity labeled 34-kDa protein confirmed that the novel iodocyanopindolol or SM-11044 binding protein of rat colon smooth muscle membranes is different from known adrenaline, serotonin, or dopamine receptors. Its functional role might include the relaxation of depolarized colon.

Effect of enalapril maleate on cerebral blood flow in patients with chronic heart failure

The effect of enalapril on cerebral blood flow (CBF) was studied in 11 patients with chronic heart failure (NYHA II or III, dilated cardiomyopathy in 6 and old myocardial infarction in 5). CBF was evaluated by analyzing the Patlak-Plot curve obtained from radionuclide angiography with technetium-99m hexamethylpropylene amine oxime (99mTC-HM-PAO). Cardiac index (CI) and stroke volume (SV) were simultaneously measured by impedance cardiography. These measurements were performed before and at four weeks after daily administration of 5 mg enalapril. The stroke volume, cardiac index, and heart rate were not significantly changed after four weeks of enalapril administration. However, CBF was increased by 6.5% from 36.72 +/- 4.66 to 39.13 +/- 5.65 mL/100g/min (P < 0.05). These results suggest that enalapril increased cerebral blood flow, which was not related to increased cardiac output in congestive heart failure. Patlak-Plot analysis of radionuclide angiography using 99mTC-HM-PAO may be available for quantitative assessment of brain perfusion.

Postischemic expression of P-selectin immunoreactivity in rat brain

Change of immunoreactive P-selectin was examined in rat brain after transient middle cerebral artery (MCA) occlusion (O) with anti-P-selectin monoclonal antibody using brain samples of sham control and after ischemia. Temporal, spatial, and cellular changes of immunohistochemical expressions of P-selectin were evaluated with rat brain sections at 2 and 8 h, 1, 3, and 7 days of reperfusion after 1 h of MCAO. Western blot showed a single band at molecular weight of 140 kDa for P-selectin after ischemia. P-selectin immunoreactivity was not normally present in rat brain sections. However, it was expressed mainly in the post-capillary venules of the cerebral cortex and caudate in the MCA territory with a peak at 8 h-1 day. The expression was diminished by 3 days of reperfusion. The present results indicate that P-selectin was expressed from an earlier stage of reperfusion in post-capillary venules, and the expression became maximum at the same time both in the cerebral cortex and caudate.

Expressions of P-selectin- and HSP72-like immunoreactivities in rat brain after transient middle cerebral artery occlusion

The role of an adhesion molecule such as P-selectin may be important in the pathogenesis of stroke. However, temporal, spatial and cellular profiles of the expression of such a protein have not been fully studied. Change of immunoreactive P-selectin was examined in rat brain after transient middle cerebral artery (MCA) occlusion in comparison with that of 72 kDa heat shock protein (HSP72) which is a well known marker of cell injury. Western blot analyses were performed to ensure the selective detection of immunoreactive P-selectin and HSP72 proteins with each antibody using brain samples before and after ischemia. Temporal, spatial and cellular changes of immunohistochemical expressions of P-selectin and HSP72 were evaluated with rat brain sections at 2 and 8 h, and 1, 3 and 7 days of reperfusion after 1 h of MCA occlusion (MCAO). Hematoxylin-eosin (HE) staining was performed to evaluate brain cell damage at 3 and 7 days of reperfusion. Western blot showed a single band at molecular weights of 140 and 72 kDa for P-selectin and HSP72, respectively, only after ischemia. No significant band was observed without primary antibody. P-selectin-like immunoreactivity was not normally present in rat brain sections. However, it was expressed mainly in the post-capillary venules of the cerebral cortex and caudate in the MCA territory with a peak at 8 h to 1 day. The expression was diminished by 3 days of reperfusion. An immunoreactive HSP72 was scarcely present in the cerebral cortex and caudate of the sham control brain. However, the protein was induced in neurons of the MCA territory. The HSP72 induction was gradually intensified from 8 h with peaks at 1 day in the cortex and at 3 days in the caudate. The immunoreactivity decreased by 7 days. Histopathological study with HE staining showed no evident cell damage at 3 and 7 days of reperfusion. The present results indicate that temporal, spatial and cellular differences were present in the expressions of immunoreactive P-selectin and HSP72 proteins. P-selectin was expressed from an earlier stage of reperfusion in post-capillary venules, and the expression became maximum at the same time both in the cerebral cortex and caudate. In contrast, HSP72 induction began later in neurons and reached maximum at a different time between the cortex and caudate.

Leukocyte kinetics in the pulmonary microcirculation: observations using real-time confocal luminescence microscopy coupled with high-speed video analysis

To quantitatively assess blood cell kinetics in the intact pulmonary microcirculation, in which arterioles, venules, and capillaries are exceedingly intricate and densely convoluted, we recently developed a real-time confocal laser luminescence microscope with a high-speed analysis component. The system has the capacity to yield confocal images of rapidly moving cells at a rate of 1000 frames/second and at sufficiently high degrees of magnification. Applying this novel method to isolated perfused rat lungs, we estimated the endothelial distributions of constitutively expressed intercellular adhesion molecule-1 (ICAM-1) and P-selectin and also studied leukocyte hemodynamic behavior in the pulmonary microvasculature under conditions in which ICAM-1, P-selectin, and L-selectin were inhibited, respectively, by 1A29 (monoclonal antibody to rat ICAM-1), ARP2-4 (monoclonal antibody to rat P-selectin), and fucoidin (competitive inhibitor of both P- and L-selectin). The results were compared with those obtained with a nonconfocal microscope using conventional epiluminescence. Intertwined microvessel networks in the lung were clearly distinguishable in confocal images but not in conventional nonconfocal views. ICAM-1 was perceptibly expressed along venular and capillary but not arteriolar endothelium, whereas P-selectin was undetectable in all microvessels examined. Leukocytes were not firmly adhered to venular or arteriolar endothelial cells. Leukocyte rolling was recognized more frequently along arteriolar walls than along venular walls and was suppressed in arterioles by L-selectin inhibition but not by either ICAM-1 or P-selectin inhibition. In capillaries, transient and sustained arrest of leukocytes occurred at physiologic shear rates. Inhibition of ICAM-1 or P-selectin had no remarkable effect upon either transient or sustained entrapment of leukocytes in capillaries. In conclusion, physiologic and biologic characteristics of pulmonary microvessels appear to be quite different from those of the systemic microcirculation.

Evaluation of myocardial viability using sequential dual-isotope single photon emission tomography imaging with rest TI-201/stress Tc-99m tetrofosmin in the prediction of wall motion recovery after revascularization

In patients with coronary artery disease (CAD), differentiation between severely ischemic but potentially viable myocardium and irreversibly infarcted tissue is clinically important, particularly when revascularization procedures are considered. Although thallium (TI) cardiac imaging has been shown to be a good tool for investigating myocardial viability in CAD, this tracer shows physical limitations, such as a low photon energy and long half-life. We assessed the results of a rest TI-201/stress Tc-99m tetrofosmin protocol in subjects with prior anterior myocardial infarction. All of the patients had an akinetic or dyskinetic area and more than 75% stenosis in the left anterior descending artery. All of the patients underwent revascularization after the examination. We evaluated the improvement in wall motion after revascularization using the centerline method with contrast left ventricular angiography. Fourteen patients showed reversible defects with the rest TI-201/stress Tc-99m tetrofosmin protocol or in additional TI-201 24 h redistribution images. All 14 patients showed a significant improvement in wall motion after revascularization. Dual-isotope rest TI-201/stress Tc-99m tetrofosmin single photon emission tomography data, acquired separately, may give fast and complete information about myocardial perfusion during stress and at rest, and on about myocardial viability.

Impaired left ventricular diastolic filling occurs in diabetic patients without atherosclerotic coronary artery disease

Using left ventriculography, left ventricular diastolic function was studied in 24 diabetic patients who had angina pectoris without atherosclerotic large-vessel coronary artery diseases (group A, 14 patients with exercise-induced ischemic ST-T changes as seen during electrocardiogram; group B, 10 patients without such changes). In groups A and B, the global peak filling rate was significantly less than that in control patients without diabetes or cardiac diseases. The ratio of the global time to the peak filling rate to the diastolic time was higher in both groups A and B than in the control groups. However, the total of time differences, defined as the sum of the time differences between global time to the peak filling rate and each of the three regional time to the peak filling rate, was greater in group A than in either group B or the control patients. Total time difference was similar in group B and the controls. Left ventricular diastolic filling was impaired in diabetic patients without large-vessel coronary artery disease. Impaired diastolic filling was present regionally in patients with ischemic ST-T change but globally in those without such change.

[Successful surgical treatment of aortic regurgitation due to annuloaortic ectasia and mitral regurgitation caused by tendon rupture in a case of osteogenesis imperfecta]

A 54-year-old man presented with osteogenesis imperfecta complicated with both aortic regurgitation due to annuloaortic ectasia and mitral regurgitation secondary to tendon rupture. He had spinal and carpal deformities in his childhood, and heart murmurs were identified at the age of 25. He was admitted complaining of dyspnea on effort. His height was 142 cm and his weight was 46 kg. He had kyphosis, scoliosis and carpal deformity. Blue sclera was not observed. Chest radiography showed cardiomegaly and lung congestion. Echocardiography showed annuloaortic ectasia, mild aortic regurgitation, and serious mitral regurgitation due to postero-apical tendon rupture. Bone deformity and his statues were indicative of osteogenesis imperfecta. He received modified Bentall and mitral valve replacements.

Safety and effectiveness of exercise training in patients with silent myocardial ischemia

The effectiveness of exercise training in patients with silent myocardial ischemia was examined. Forty patients with coronary heart disease (mean age 55 +/- 8 years) were recruited for a 12-week exercise training program. All patients underwent treadmill exercise stress testing, exercise thallium-201 single photon emission computed tomography and left heart catheterization. They were divided into three groups based on the symptoms and the results of exercise thallium scintigraphy, i.e., painful myocardial ischemia (PMI group), silent myocardial ischemia (SMI group), and non-myocardial ischemia (NMI group). Normalized treadmill time was longer in the SMI group (108 +/- 24%) than in the PMI group (86 +/- 14%, p < 0.05). All 40 patients, 14 from the PMI group, 16 from the SMI group and 10 from the NMI group, completed the whole exercise training program. A significant prolongation of treadmill time was attained in all three groups after exercise training [PMI group: from 494 +/- 105 to 632 +/- 78 sec (p < 0.05), SMI group: from 609 +/- 147 to 746 +/- 137 sec (p < 0.05), NMI group: from 572 +/- 112 to 739 +/- 13 sec (p < 0.05)]. The improvement of myocardial ischemia following exercise training was similar in the SMI and PMI groups. No adverse effects were detected throughout the program. The exercise training program adopted in this study proved safe and effective in patients with silent myocardial ischemia.

Expression of polymorphonuclear leukocyte adhesion molecules and its clinical significance in patients treated with percutaneous transluminal coronary angioplasty

OBJECTIVES

This study evaluated the role of neutrophil adhesion molecules LFA-1 (CD11a/CD18), Mac-1 (CD11b/CD18) and p150,95 (CD11c/CD18) in patients undergoing percutaneous transluminal coronary angioplasty (PTCA).

BACKGROUND

Several recent studies have suggested that cell adhesion molecules on both neutrophils and vascular endothelial cells play an important role in the process of tissue inflammation.

METHODS

Thirty-eight patients (30 men, 8 women; mean [+/-SE] age 56 +/- 5 years, range 38 to 76) with single-vessel coronary artery disease of the left anterior descending artery underwent coronary angioplasty. Peripheral blood was sampled at baseline before, immediately after and 12, 24, 48 and 144 h after PTCA. The expression of CD18, CD11a, CD11b and CD11c on the surface of polymorphonuclear leukocytes was examined by flow cytometry with monoclonal antibodies.

RESULTS

In patients without subsequent restenosis, there was no change in mean channel fluorescence intensity (MFI) of CD18 at each sampling time. However, in the patients with restenosis, the MFI of CD18 significantly increased at 48 h after PTCA (from 57 +/- 6 to 73 +/- 8, p = 0.0008). The MFI of CD11b increased slightly at 48 h after PTCA in patients without restenosis (from 584 +/- 121 to 735 +/- 114, p = 0.037). In patients with restenosis, the MFI of CD11b was slightly increased at 24 h after PTCA (from 586 +/- 122 to 768 +/- 214, p = 0.018) and significantly increased at 48 h after PTCA (to 1,534 +/- 268, p = 0.0006). The expression of CD11a and CD11c did not change at any sampling points after PTCA in either of the two patient groups. Percent change in the expression of CD18 at 48 h after PTCA (from baseline) and that of CD11b were correlated (r = 0.73, p = 0.0008) in patients with restenosis.

CONCLUSIONS

Inflammatory stimuli within the coronary vessels associated with coronary angioplasty may upregulate Mac-1 expression on the surface of polymorphonuclear leukocytes. This process may be more marked in patients who experience later restenosis. Thus, activation of neutrophil adhesion molecule Mac-1 at 48 h after PTCA may have value as a predictor of subsequent restenosis.

An effective tool to detect lesions causing unstable angina with multivessel disease: iodine-123-betamethyl-p-iodophenyl-pentadecanoic acid single photon emission computed tomography

Radiolabeled fatty acids such as iodine-123-betamethyl-p-iodophenyl-pentadecanoic acid (BMIPP) have unique metabolic properties suggesting potential use as myocardial perfusion tracers. The uptakes of BMIPP and thallium 201 were compared using single photon emission computed tomography (SPECT) in 24 patients displaying unstable angina with multivessel disease at a mean of 3.4 days after admission. Coronary angiography was performed within a week. Uptake was considered normal if the activity was greater than 80% of the normal area, mildly reduced if 50% to 79%, and severely reduced if less than 50%. The regional activities in four quardrants in short-axis slices were measured from basal, mid and apical sets. We attempted to identify the causative lesion on dual SPECT imaging. We planned the following management of each patient based on the results of the dual SPECT study. BMIPP activity imaging found 4 segments (1.4%) with severe decrease, 70 (24.3%) with mild decrease, and 214 (74.3%) with normal uptake. In contrast, T1 activity imaging showed normal uptake in 68 of 74 abnormal BMIPP activity segments. Furthermore, all segments with abnormal BMIPP uptake were matched with locations of coronary artery stenosis by coronary angiography. Accordingly, coronary revascularization (percutaneous transluminal coronary angioplasty, coronary artery bypass grafting) was performed based on BMIPP SPECT. Reductions in BMIPP activity were common in patients with unstable angina with multivessel disease. BMIPP SPECT is an excellent tool for detecting the causative lesion in unstable angina. The subsequent intervention could be performed with less risk based on the strategy of dilating the only causative lesion which was detected by the BMIPP SPECT in patients with multivessel disease displaying unstable angina.

Role of P-selectin in the early stage of the Arthus reaction

P-selectin is rapidly translocated to the surface of endothelial cells and platelets following exposure to chemical mediators such as histamine, thrombin and complement factors. The Arthus reaction is caused by vascular injury which is initiated by the local deposition of the immune complex followed by the activation of complement and release of chemical mediators. In this report, the role of P-selectin in the early stage of reverse passive Arthus reaction in rat using monoclonal antibodies (mAbs) against rat P-selectin will be investigated. Intravenous administration of the mAb ARP2-4 significantly attenuated paw edema 1 h after challenging it with antigen by 31.5% (1 mg/kg) and 44.7% (3 mg/kg), respectively. Edema formation was also reduced by sulfatide (73.1%, 50 mg/kg) and inositol hexakisphosphate (InsP6) (72.9%, 30 mg/kg), which have been reported to block P-selectin-mediated neutrophil adhesion. Moreover, neutrophil accumulation into the inflammatory site in the Arthus reaction was inhibited by anti-P-selectin mAb. P-selectin expression was detected along vessel walls prior to neutrophil accumulation, as determined by immunohistochemical staining using the antibody. In addition, the expression of P-selectin mRNA was induced 4 h after deposition of immune complex. From these results, we concluded that P-selectin plays an important role in the pathogenesis of the Arthus reaction especially in the early stage by recruiting neutrophils into sites of inflammation.

An impaired carotid sinus distensibility and baroreceptor sensitivity alter autonomic activity in patients with effort angina associated with significant coronary artery disease

Baroreceptor sensitivity and carotid sinus distensibility were lower in patients with angina associated with significant coronary artery disease than in patients with vasospastic angina. Baroreceptor sensitivity was significantly correlated with carotid sinus distensibility in both groups of patients.

Early detection of platelet activation after coronary angioplasty

BACKGROUND

Although platelet activation has been considered an important reaction after percutaneous transluminal coronary angioplasty (PTCA), it is still difficult to detect the activated platelets in vivo directly.

METHODS

To detect platelets activated at an early stage after PTCA, blood samples were take from the coronary sinus and the aorta in 22 patients with coronary artery disease, who underwent PTCA for a lesion of the left anterior descending artery. Ten patients with coronary artery disease, who underwent diagnostic coronary angiography only, were compared with them. The expression of activation-dependent granular protein, CD62P (P-selectin) and CD63, on the platelet membrane surface was analysed using flow cytometry. The plasma thrombomodulin level was also measured.

RESULTS

The percentage of platelets positive for CD62P (0.53 +/- 0.04 to 0.80 +/- 0.11%, P < 0.01) and CD63 (16.0 +/- 1.4 to 19.8 +/- 2.0%, P < 0.05) increased after PTCA in the coronary sinus, although it did not change in the aorta. The plasma thrombomodulin level also increased after PTCA in the coronary sinus (16.7 +/- 1.0 to 20.4 +/- 2.0 mu/ml, P < 0.05). However, these parameters did not change after coronary angiography only. After PTCA, the plasma thrombomodulin level was correlated with the percentage of platelets positive for CD62P (r = 0.88, P < 0.001) and with that for CD63 (r = 0.69, P < 0.001) in the coronary sinus.

CONCLUSIONS

PTCA produced activation of circulatory platelets, which might have been caused by balloon-induced vascular endothelial injury. One should take care to avoid needless vascular injury during the PTCA procedure to inhibit the platelet activation.

Acute myocardial infarction during pregnancy

We report a 30-year-old woman who developed an acute myocardial infarction at 24 weeks of gestation. She did not undergo any kind of acute intervention. On the 8th hospital day, premature delivery was performed safely following premature rupture of membrane. Coronary angiogram was normal and no spasm was induced by provocative test with ergometrine maleate. The patient had abnormal values of fibrinogen, thrombin-antithrombin III complex and plasmin-alpha 2-plasmin inhibitor complex. Thus, thrombus formation might have been associated with the onset of acute myocardial infarction. This is the first case of acute myocardial infarction during pregnancy, showing normal coronary angiogram and negative pharmacological provocation of coronary spasm.

Reduction of rat myocardial ischemia and reperfusion injury by sialyl Lewis x oligosaccharide and anti-rat P-selectin antibodies

Polymorphonuclear leukocytes (PMN) are directly involved in development of ischemic myocardial injury. Adhesion of PMN to endothelial cells is an initial step that triggers a sequential process leading to acute inflammatory responses. Interaction between P-selectin and its oligosaccharide ligand, sialyl Lewis x (sLex), plays an important role in the early stage of the adhesion. To examine the role of P-selectin in various animal disease models especially in rats, we have cloned rat E- and P-selectin cDNAs and established monoclonal antibodies against these rat selectins. In this report, we describe the generation and characterization of anti-rat P-selectin antibodies (ARPs). These antibodies detect cell surface P-selectin on thrombin-stimulated rat platelets. More importantly, intravenous administration of ARP2-4 reduced infarction developed after 30 min of ischemia followed by 24 h of reperfusion in a rat myocardial injury model. In addition, similar protective effect was also observed by administration of a sLex-oligosaccharide. These results indicate that cell adhesion mediated via P-selectin is involved in the development of ischemia and reperfusion injury in rat heart.

Tc-99m tetrofosmin myocardial perfusion SPECT after dipyridamole combined with low-level exercise in the diagnosis of coronary artery disease

Tc-99m tetrofosmin is a lipophilic, cationic perfusion imaging agent that changes to Tl-201 in detecting coronary artery disease during exercise testing. The purpose of this study is to evaluate the usefulness of Tc-99m tetrofosmin dipyridamole stress imaging combined with low level exercise for the detection of coronary artery disease. We examined 42 patients and 10 normal volunteers who also underwent coronary angiography. A one-day protocol was used: in the stress study, 296 MBq of tetrofosmin was injected and in the rest study 888 MBq was injected. After intravenous administration of dipyridamole (0.142 mg/kg/min for 4 minutes), the patient was exercised on a bicycle ergometer for 3 min (25 Watts). Tetrofosmin was injected 2 minutes after dipyridamole infusion during the exercise. Single photon emission computed tomographic images were obtained 30 minutes after the tracer injection. Images were interpreted as abnormal in 36 of 42 patients with coronary artery disease, and normal in all of 10 normal volunteers. The overall sensitivity of detection of coronary artery disease was 83.3% and the normalcy rate was 100%. The diagnostic values for the detection of significant stenosis in the three major arteries were: LAD sensitivity 83%, specificity 92%; LCX sensitivity 47%, specificity 91%; RCA sensitivity 75%, specificity 83%. Of the 66 arteries with more than 50% stenosis, 48 arteries were correctly identified. Of the 36 with more than 70% stenosis, 31 were identified. Scintigraphic evidence of multivessel disease was found in only 9 patients (50%). A protocol of Tc-99m tetrofosmin SPECT combined with low level exercise after dipyridamole is therefore useful for the detection of the coronary artery disease.

A mechanism of ischemic preconditioning during percutaneous transluminal coronary angioplasty

Manifestation of ischemic preconditioning and its mechanisms during percutaneous transluminal coronary angioplasty (PTCA) was evaluated. Twenty-two patients with angina pectoris, who had one-vessel coronary artery disease of the proximal left anterior descending artery but without visual collateral circulation, underwent elective PTCA performed by balloon inflations of 90 s, repeated three times or more. Changes in standard 12-lead electrocardiogram, hemodynamics and oxygen saturation of the great cardiac vein by a fiber-optic catheter were analyzed. Anginal chest pain occurred in 21 patients (95%) during the first balloon inflation, and in only 9 patients (41%) during the third inflation. In comparison with the first inflation, the third produced less shifts in ST junction (p < 0.01) and peak T (p < 0.01), which were measured and averaged by 4 chest leads from V2 to V5. The heart rate-blood pressure product during the third inflation was equivalent to that during the first. The great cardiac vein oxygen saturation decreased equally during the first and third inflations. However, the ratio of the saturation at reactive hyperemia after balloon deflation to baseline was higher (p < 0.01) in the third than in the first inflation. The adenosine content of the great cardiac vein measured in 11 patients just prior to balloon deflation was also higher (p < 0.05) in the third inflation than the value in the first. Repeated coronary artery occlusion during PTCA could cause ischemic preconditioning, which may be derived from mechanisms common to accelerated reactive hyperemia, for example an increase in intrinsic adenosine levels.

Relationship between regional abnormality of left ventricular rapid filling and coronary microcirculation disturbance in hypertrophic cardiomyopathy

BACKGROUND AND HYPOTHESIS

To investigate the mechanism of regional left ventricular diastolic filling disturbance in hypertrophic cardiomyopathy (HCM), we assessed the relationship between abnormalities of regional ventricular rapid filling and regional coronary microcirculation using radionuclide ventriculography and exercise 201thallium (201TI) myocardial scintigraphy with sector analysis.

METHODS

Thirty patients with HCM and 14 patients with atypical chest pain syndrome (controls) were studied. Left ventricular images (left anterior oblique view) were obtained by electrocardiogram-gated 99mtechnetium radionuclide angiography and were divided into three sectors radiating from the geometric center. The time-activity curves and their first derivative curves were analyzed, and the peak filling rate (PFR), the ratio of the time-to-peak filling rate per diastolic interval (TPFR/T) were calculated for the global left ventricle and for the lateral and septal sectors. Exercise stress 201TI myocardial scintigraphy was also performed, and early and delayed images were obtained. The regional washout rate (WR) was then evaluated for the lateral and septal sectors.

RESULTS

In HCM patients, the regional PFR in the septal sector (corresponding to the region of hypertrophic myocardium) was 285 +/- 76%/s, and was significantly lower than that in the controls (398 +/- 90%/s, p < 0.01). The regional TPFR/T in the septal sector (32 +/- 10%) was prolonged compared with the value of 21 +/- 5% in the controls (p < 0.05). The regional WR in the septal sector was 21 +/- 9%, and was significantly lower than that in the controls (43 +/- 5%, p < 0.01). Moreover, regional WR correlated positively with regional PFR (r = 0.5, p < 0.05) and showed a weak negative relationship with regional TPFR/T (r = -0.4, p < 0.07) in the septal sector.

CONCLUSIONS

These results suggest that regional impairment of rapid filling might be related to a disturbance of the coronary microcirculation in HCM.

Relationship of thallium-201 clearance on exercise stress myocardial scintigraphy to coronary flow reserve in patients with coronary artery disease

OBJECTIVE

We evaluated thallium-201 (201Th) clearance measurement during exercise myocardial scintigraphy in patients with coronary artery disease, for the assessment of coronary circulatory function and diagnosis.

DESIGN

The clearance rate of 201Th was compared with the coronary flow reserve measured by Doppler coronary flow velocimetry.

METHODS

We selected 20 patients who had chronic stable angina with single-vessel coronary artery disease of the left anterior descending artery (LAD) and underwent percutaneous transluminal coronary angioplasty (PTCA). Ten control patients had atypical chest pain but no detectable heart disease. Regional net clearance of 201Th was measured from the early and delayed bull's-eye images of 201Th exercise stress single photon emission tomography (SPECT). Using a Doppler catheter, we also measured coronary flow reserve of the LAD, which was obtained by the intracoronary administration of papaverine.

RESULTS

The net 201Th clearance in the anterior wall myocardium in the patients with coronary artery disease before PTCA was significantly less than that in the controls. At follow-up angiography after successful PTCA, it increased. The coronary flow reserve before PTCA was also lower than that in the controls. It was increased immediately after PTCA, and was more markedly increased at the follow-up angiography. Before PTCA, regional net clearance in the anterior myocardium was correlated with the coronary flow reserve of the LAD. The ratio for the net clearance of the anterior myocardium at follow-up angiography to that before PTCA was also correlated with the ratio for coronary flow reserve.

CONCLUSIONS

In patients with coronary artery disease, the regional 201Th clearance in the ischaemic area measured by exercise 201Th SPECT is correlated with the coronary flow reserve of the affected artery. Moreover, the increase in the clearance rate after PTCA is also correlated with that in the coronary flow reserve. Thus the measurement of regional 201Th clearance might be a useful non-invasive method of estimating of the coronary flow reserve.

Cross-linking of the ninth consensus repeat domain of P-selectin (GMP-140, CD62P) with a monoclonal antibody enhanced leukocyte adhesive activity

P-selectin (GMP-140, CD62P) is a member of the selectin family of cell adhesion molecules expressed on the cell surface of platelets and endothelial cells, which mediates leukocyte adhesion via carbohydrate ligands. We now report that a monoclonal antibody (mAb), recognizing the ninth consensus repeat domain of the human P-selectin molecule, enhanced the adhesion activity of neutrophils to platelets, whereas the monovalent Fab fragment of the mAb did not exert this effect. The enhancement by the mAb was thought to result from cross-linking of the P-selectin molecules. The results indicated that cross-linking adjacent to the transmembrane domain of P-selectin enhanced the cell adhesion activity.

Effect of SM-12502 on disseminated intravascular coagulation (DIC) in tumor-bearing rats

To investigate the role of PAF in tumor-associated disseminated intravascular coagulation (DIC), we have established the tumor-induced DIC model in rats and examined the effect of PAF-antagonist as compared with commonly used anti-DIC drugs. Four days after the intraperitoneal inoculation of rat ascites hepatoma AH-130, DIC-like hematological parameter changes such as decrease in platelet count, prolongation of PTT and increase in FDP were observed. In addition, serum levels of GOT and GPT were increased, indicating that liver injury was provoked. PAF-antagonist SM-12502 inhibited the development of DIC (PT, PTT and FDP) and liver injury. These results indicate that PAF plays an important role in tumor-associated DIC as well as accompanying organ failure.

Lipoteichoic acid-induced neutrophil adhesion via E-selectin to human umbilical vein endothelial cells (HUVECs)

We investigated whether lipoteichoic acid (LTA) induces the expression of E-selectin and neutrophil adhesion to human umbilical vein endothelial cells (HUVECs). LTA (0.01-30 micrograms/ml) induced the expression of E-selectin in a concentration-dependent manner with maximal response at 10 micrograms/ml. The expression level of E-selectin increased from 2 h after stimulation by LTA with the maximal level at 4-8 h. Neutrophil adhesion to LTA-treated HUVECs correlated with the levels of E-selectin expression. In addition, the adhesion was clearly inhibited by anti-human E-selectin monoclonal antibody CY-1787 as well as a sialyl Lewis X (SLeX) oligosaccharide. LTA-induced expression of E-selectin was inhibited by protein kinase C inhibitors, H-7 and staurosporine. These results indicate that LTA induced the expression of E-selectin and neutrophils adhered to HUVECs via E-selectin.