The change in phospholipase C-gamma1 expression following balloon injury to the rat carotid artery / 대한내과학회지

BACKGROUND: While inositol phospholipid-specific phospholipase C (PLC) plays a central role in signal transduction pathways, little is known about its role in the vascular response to injury. Recent studies have shown that phospholipase C-gamma1 (PLC-gamma1) is required for PDGF-induced DNA synthesis and angiotensin II signaling. This study was undertaken to determine the potential involvement of PLC-gamma1 in the in vivo response to vascular injury. METHODS: Vascular injury was achieved in the left common carotid artery of six-month-old male Wistar rats. The expression of PLC-gamma1 was evaluated at serial time points by immunohistochemistry and Western blot analysis following balloon de-endothelialization of the rat carotid artery. RESULTS: In the denuded carotid artery at 1 week, the neointima became thicker in a symmetrical manner with respect to the long axis. A strong expression of PLC-gamma1 at one week after injury was seen primarily in the thin layers of neointima. This increased immunoreactivity of PLC-gamma1 persisted at 2-3 weeks after injury, coinciding with the time when neointima gains of its mass. At 4 weeks after injury, staining intensity slightly declined but levels remained elevated. As determined by Western blot analysis, the amount of PLC-gamma1 was about 3-fold higher at 3 weeks after injury compared to uninjured vessels (p<0.01). CONCLUSION: These results suggest that the amplification of traffic within signal transduction pathways involving PLC-gamma1 occurs and may play a significant role in neointima formation following arterial injury.

Expression of tumor necrosis factor receptor superfamily in carotid atheroma

BACKGROUND AND OBJECTIVES: It has been reported that various inflammatory and immune reactions are involved in the development and progression of atherosclerosis. We tried to investigate whether the TNF receptor superfamilies are involved in the development and progression of atherosclerosis. MATERIALS AND METHOD: Thirteen carotid atheroma specimens(frozen sections : 10 cases, paraffin section : 5 cases) were obtained from the patients who underwent carotid endarterectomy at Samsung Medical Center and one normal aortic tissue was obtained from a transplantation donor in brain death. In the carotid endarterectomy specimens and a normal aortic tissue , the expressions of R110(TR1), 139(TR2) and DR3(TR3), members of the TNF receptor superfamilies were evaluated by immunohistochemical staining with monoclonal antibodies. Simultaneously, we evaluated the expressions of foam cells, smooth muscle cells, T-lymphocytes and B-lymphocytes. RESULTS: Immunohistochemical analysis identified a strong expressions of foam cells and smooth muscle cells in all atheroma. But, the expression of T-lymphocytes was minimal and that of B-lymphocytes was rare. The expression of DR3(TR3) was seen in all atheroma as strongly positive. The expression of 139(TR2) was observed well in frozen sections, but not in paraffin sections. Whereas, that of R110(TR1) was observed in paraffin sections as weakly positive, but not in frozen section. The areas where the TNF receptor superfamilies were expressed correlated to the area of foam cell presence. The expression of DR3 also correlated with expression of smooth muscle cells. In normal aortic tissue, the expression of inflammatory cells or TNF receptor superfamilies was not observed except smooth muscle cells which were observed in normal artery. CONCLUSION: Foam cells and smooth muscle cells were abundantly present in atheroma. The TNF receptor superfamilies are expressed in the atheroma and the region of expression was coincident with the presence of foam cells.

Influence of menopause on high density lipoprotein-cholesterol and lipids

It has been generally accepted that high density lipoprotein cholesterol (HDL-C) level decreases with menopause in women. However, recent reports show different results. There is very little data concerning perimenopausal women. To verify these findings, lipids and lipoprotein(a) +AFs-Lp(a)+AF0- levels were compared among pre-, peri- and postmenopausal women of similar mean ages. Postmenopausal women had higher HDL-C levels than premenopausal women (p+ADw-0.001) and there was no difference between peri- and postmenopausal women. LDL-C level in perimenopausal women was lower than in postmenopausal women (p+ADw-0.001) and higher than in premenopausal women with borderline significance (p+AD0-.051). Total cholesterol levels showed stepwise elevation from premenopause to postmenopause. Perimenopausal women had lower Lp(a) levels than postmenopausal women (p+ADw-0.0005) and similar levels to premenopausal women. Lp(a) levels between 0.1 to 10.0 mg/dL were the most prevalent in pre- and perimenopausal women, and those between 10.1 to 20.0 mg/dL in postmenopausal women. In conclusion, menopause itself is associated with the elevation of HDL-C level, and the postmenopausal increase of coronary artery disease is not related to postmenopausal change of HDL-C level. Perimenopausal status, although transient, may favor Lp(a) and lipid profiles for delaying atherosclerosis.

A Case of Cardiac Chloroma Complicated by Acute Lymphocytic Leukemia

Chloroma (granulocytic sarcoma) indicates an extramedullary leukemic cell collection. It often develops in the course of, or as a presenting sign of leukemia. Cardiac chloroma is uncommon and rarely detected as a mass. We report the first case of cardiac chloroma in a patient with acute lymphocytic leukemia in Korea. A 73-year-old man was admitted because of exertional dyspnea, orthopnea and generalized weakness. Thrombocytopenia and immature leukocytes were detected in the peripheral blood. An X-ray film of the chest showed mild cardiome-galy and bilateral pleural effusion. Transthoracic and transesophageal echocardiography showed a low echogenic mass at the lateral wall of the right ventricle. The size of the mass was about 6x4 cm. MRI of the chest showed right ventricular mass with slightly increased inhomogeneous signal intensity. Bone marrow aspiration and biopsy confirmed that he had a L3 FAB subtype of acute lymphocytic leukemia. Induction chemotherapy with vincristine, prednisolone, daunorubicin resulted in hematologic complete remission. At 6 weeks after the induction chemotherapy, transesophageal echocardiography demonstrated disappearance of the right ventricular mass which suggested that it was a cardiac chloroma complicating acute lymphocytic leukemia.

Korean multicenter clinical trial of simvastatin ( KS-1 study ) / 대한내과학회지

The aim of this study was to investigate the efficacy of simvastatin to improved lipid profiles in hypercholesterolemic Korean patients. METHODS: From 25 hospitals in Korea, 478 hypercholesterolemic patients were enrolled from November 1996 to April 1998. The inclusion criteria was hypercholesterolemia over 240 mg/dl after diet therapy for 1 month or hypercholesterolemia over 220 mg/dl in patients with definite evidence of ischemic heart disease. Simvastatin 10mg was started and doubled up to 40mg if total cholesterol level remained higher than 200 mg/dl at monthly check. Of 478 subjects, 344 patients in whom study protocol was not violated were analyzed. RESULTS: Male to female ratio was 27:73 and 47% of the subjects were in 6th decade. Hypertension, coronary artery disease, and diabetes mellitus were present in 30, 10, and 4% of the subjects. Baseline lipid profile (mean of total cholesterol-LDL-HDL-triglyceride mg/dl) was 274-185-52-188. The dose of simvastatin for 3 months was 10/10/10mg in 61% of subjects, 10/20/20mg in 21%, 10/10/20mg in 7%, and 10/20/40mg in 12%. The change of total cholesterol level(before-4wk-8wk-12wk-withdrawal 4wk) was 274-209- 205-198-250, and the maximal reduction rate was 27%. The change of LDL-cholesterol was 185-123-116-110-159, with maximal reduction rate 39%. The change of HDL-cholesterol was 52-54-56-55-54, with maximal increase rate 9%. The change of tryglyceride was 188-161- 164-162-189, with maximal reduction rate 15%. The value before/after treatment of ApoA1, ApoB, and Lp(a) was 129/129, 138/83, and 9.3/10.7, respectively. The level of LDL-cholesterol at the end of treatment was below 100mg/dl in 36% of subjects, 100-130 in 45%, 130-160 in 16%, and over 160mg/dl in 4%. The reduction rate of LDL-cholesterol was different between subjects whose LDL decreased below 100 and those whose LDL did not decrease below 130mg/dl, which suggests the existence of the individual difference of responsiveness to simvastatin. There were only 3 subjects (0.9%) who showed increase of liver enzyme over 3 times as the upper normal limit. Conclusion: Simvastatin is effective in improving lipid profiles in hypercholesterolemic Korean patients without serious side effects.

Korean multicenter clinical trial of simvastatin ( KS-1 study ) / 대한내과학회지

The aim of this study was to investigate the efficacy of simvastatin to improved lipid profiles in hypercholesterolemic Korean patients. METHODS: From 25 hospitals in Korea, 478 hypercholesterolemic patients were enrolled from November 1996 to April 1998. The inclusion criteria was hypercholesterolemia over 240 mg/dl after diet therapy for 1 month or hypercholesterolemia over 220 mg/dl in patients with definite evidence of ischemic heart disease. Simvastatin 10mg was started and doubled up to 40mg if total cholesterol level remained higher than 200 mg/dl at monthly check. Of 478 subjects, 344 patients in whom study protocol was not violated were analyzed. RESULTS: Male to female ratio was 27:73 and 47% of the subjects were in 6th decade. Hypertension, coronary artery disease, and diabetes mellitus were present in 30, 10, and 4% of the subjects. Baseline lipid profile (mean of total cholesterol-LDL-HDL-triglyceride mg/dl) was 274-185-52-188. The dose of simvastatin for 3 months was 10/10/10mg in 61% of subjects, 10/20/20mg in 21%, 10/10/20mg in 7%, and 10/20/40mg in 12%. The change of total cholesterol level(before-4wk-8wk-12wk-withdrawal 4wk) was 274-209- 205-198-250, and the maximal reduction rate was 27%. The change of LDL-cholesterol was 185-123-116-110-159, with maximal reduction rate 39%. The change of HDL-cholesterol was 52-54-56-55-54, with maximal increase rate 9%. The change of tryglyceride was 188-161- 164-162-189, with maximal reduction rate 15%. The value before/after treatment of ApoA1, ApoB, and Lp(a) was 129/129, 138/83, and 9.3/10.7, respectively. The level of LDL-cholesterol at the end of treatment was below 100mg/dl in 36% of subjects, 100-130 in 45%, 130-160 in 16%, and over 160mg/dl in 4%. The reduction rate of LDL-cholesterol was different between subjects whose LDL decreased below 100 and those whose LDL did not decrease below 130mg/dl, which suggests the existence of the individual difference of responsiveness to simvastatin. There were only 3 subjects (0.9%) who showed increase of liver enzyme over 3 times as the upper normal limit. Conclusion: Simvastatin is effective in improving lipid profiles in hypercholesterolemic Korean patients without serious side effects.

Effects of Angiotensin II on the Growth of Vascular Smooth Muscle Cells

BACKGROUND AND OBJECTIVES: The octapeptide hormone of the renin-angiotensin system, angiotensin ii, regulates a wide variety of physiological responses including salt and water balance, blood pressure, and vascular tone. Contradictory results have been reported regarding the effects of angiotensin ii on vascular smooth mu-scle cell (VSMC) proliferation. The aim of the present study was to investigate the direct effect of angiotensin ii on the growth of VSMC. MATERIALS AND METHOD: Rat aortic smooth muscle cells were obtained by the combined collagenase and elastase methods. Cells between the 4th and 8th passages were used for the experiments. Cultures were treated daily for 3 days with either angiotensin ii alone or angiotensin ii with equimolar concentrations of saralasin. Incorporated radioactivity of [3H]thymidine and [14C]phenylalanine was measured by liquid scintillation spectrometry. RESULTS: Angiotensin ii increased [14C]phenyalanine incor-poration about 20-30%, and saralasin completely blocked the stimulation by angiotensin ii. However, there was no significant increase in [3H]thymidine incorporation by angiotensin ii stimulation in this study. CONCLUSION: These results suggest that angiotensin ii alone induces cellular hypertrophy but has no detectable mitogenic activity in cultured rat aortic VSMC.

ACE Inhibitors and Losartan in the Managerment of Hypertesion

No abstract available.

Effect of Carvedilol on the Growth of Vascular Smooth Muscle Cells

Background and objectives: Carvedilol is a cardiovascular drug, beta- and alpha1-adrenoceptor antagonist, currently approved for the treatment of hypertension, angina, congestive heart failure by FDA. Carvedilol has been shown to attenuate oxygen free radical-initiated lipid peroxidation and to inhibit neointimal formation of aorta following vascular injury by balloon angioplasty. We have investigated the effect of carvedilol on DNA synthesis of vascular smooth muscle cells (VSMC) stimulated by platelet-derived growth factor (PDGF)-BB. MATERIALS AND METHOD: Rat aortic smooth muscle cells were obtained by the combined collagenase and elastase methods. Cells between the 4th and 8th passages were used for the experiments. Incorporated radioactivity of [3H]-thymidine was measured by liquid scintillation spectrometry. RESULTS: PDGF-BB (1 nM) increased [3H]-thymidine incorporation about 70-100% over basal value in cultured VSMC. PDGF-stimulated increase in DNA synthesis was significantly suppressed by simultaneous administration of carvedilol. In contrast, propranolol did not significantly affect 3[H]-thymidine uptake in rat aortic VSMC. CONCLUSION: The present study demonstrate that carvedilol significantly inhibits the proliferation of vascular smooth muscle cell in our condition. These results indicate that carvedilol may be effective in the treatment of cardiovascular diseases principally associated with abnormal vascular smooth muscle growth.

Risk Factors of Various Cerebrovascular Diseases and Sonographic Findings of Carotid Artery in Cerebral Infarction

BACKGROUND: In Korea, cerebrovascular accident (CVA) is the most significant cause of death among older people, and the incidence of cerebral hemorrhage is much higher than that of developed countries. There have been many investigations about the risk factors for CVA in both Korea as well as developed countries. A few papers reported various risk factors for cerebral hemorrhage in developed countries:however, well-designed studies of risk factors for the various causes of CVA were rare in Korea. Therefore, the purpose of this study was to compare the risk factors for the various causes of CVA and to evaluate the risk factors compared with age- and sex-matched control groups. In addition, duplex sonographic findings of the carotid artery were evaluated in patients with cerebral infarction. METHODS: One hundred and sixty-four patients admitted to the hospital in 1996 were enrolled. The four groups were divided based on the following states: cerebral infarction (n-63), cerebral hemorrhage (n-64), cerebral infarction with atrial fibrillation (n-19), and lacunar infarction (n-18). Major risk factors were compared with age- and sex-matched control groups and among CVA groups. Duplex sonography of the carotid artery was done in 14 patients with cerebral infarction. RESULTS: In multiple logistic regression analysis, patients with cerebral infarction had higher prevalence of diabetes mellitus and lower high density lipoprotein-cholesterol level than the control group, and hypertension showed borderline significance. Patients with cerebral hemorrhage had higher prevalence of hypertension, higher high density lipoprotein-cholesterol level, and more frequent prevalence of smoking compared with the control group. Patients with cerebral infarction showed lower high density lipoprotein-cholesterol, higher low density lipoprotein-cholesterol levels, more frequent diabetes mellitus, lower prevalence of hypertension and older age than patients with cerebral hemorrhage. Patients with cerebral infarction and atrial fibrillation showed only older age than patients with cerebral infarction only. There were no differences in risk factors between patients with cerebral infarction and lacuna infarction. Atheromatous plaque was found in 71% of patients with cerebral infarction. CONCLUSION: Metabolic abnormalities played more important role in the development of cerebral infarction and hemodynamic abnormalities in cerebral infarction. Sonographic examination of the carotid artery may be useful for predicting the occurrence of cerebrovascular accident in high risk patients.

Association of Carotid Artery Intimal-Medial Thickness with Left Ventricular Hypertrophy

BACKGROUND: Atherosclerosis is a diffuse disease process that produce thickening of the vascular wall because of intimal deposition of lipid, fibrous tissue, and calcific material. Nowadays it is possible to evaluate atherosclerotic changes of carotid arteries accurately by developed noninvasive techniques such as ultrasonography. Left ventricular hypertrophy (LVH) is known to be an important risk factor for cardiovascular events in hypertension. The purpose of this study was to establish whether the carotid intimal - medial thickness (IMT) correlates with the severity of LVH. METHOD: We measured intimal-medial thickness (IMT) for 12 sites in carotid arteries (near and far walls in common carotid, bifurcation, and internal carotid arteries of both sides) by B-mode ultrasonography in both 38 normotensive and 72 hypertensive patients. Left ventricular measurements were made according to the recommendations of the American Society of Echocardiography. Left ventricular mass was derived from the formula described by Devereux et al. and each left ventricular mass value was indexed to body surface area. And then we have investigated whether hypertensive patients have significant changes of carotid IMT and IMT correlates with left ventricular mass index (LVMI). RESULTS: (1) Most hypertensive patients had diffuse thickening of the carotid artery and some had focal or multiple plaques. (2) In general, mean IMT was widest in the carotid bifurcation. (3) The mean IMT of all 12 segments increased about 40% in hypertensive patients compared with normal control group. (4) LVMI significantly correlates with IMT of carotid artery, especially bifurcation site and mean all 12 segments. CONCLUSION: The mean IMT may serve as a useful marker of the severity of atherosclerosis in hypertensive patients. The significant association between carotid IMT and LVMI suggests a simultaneous correlation of carotid atherosclerosis with left ventricular hypertrophy in hypertension.

The Effect of Enalapril on the Peak Rates of Left Ventricular Wall Movement in Patients with Dilated Cardiomyopathy / 대한내과학회지

OBJECTIVE: Angiotensin-converting enzyme inhibitors have been shown to improve survival in patients with congestive heart failure. To evaluate the efficacy of enalapril in patients with dilated cardiomyopathy during concurrent treatment with digoxin and diuretics, the peak rates of left ventricular movement were assessed after 6 months of follow-up by digitized echocardiography. METHODS: Using a high quality digitizer, continuous measurement of left ventricular dimension and its rate of change (dD/dt) were obtained throughout the cardiac cycle. Normalized rates of wall movement (dD/dt/D) were used for comparison. RESULTS: 1) Compared with control subjects, patients with dilated cardiomyopathy showed much lower Peak(-) dD/dt and Peak(-) dD/dt/D. 2) Peak(+) dD/dt and Peak(+) dD/dt/D were also depressed in patients. 3) Peak dD/dt improved significantly (p<0.05) in the enalapril group (n=16), but did not change in the conventional treatment group (n=20) after 6 months. Peak dD/dt/D improved approximately (p<0.005) in the enalapril group. 5) There were no deaths in 2 treatment groups during initial 6 months, but 3 patients in the conventional treatment group died suddenly during 1 year of follow-up. CONCLUSION: The present study has shown that left ventrieular Peak dD/dt and Peak dD/dt/D are significantly depressed in patients with dilated cardiomyopathy. Enalapril appears to provide well-tolerated and effective long-term therapy by improving peak rates of left ventricular movement in patients with dilated cardiomyopathy.

Effect of Hormone Replacemcet Therapy on Lipoprotein(a) and Lipids in Postmenopausal Women: Influence of Duration of Medication / 대한내과학회지

OBJECTIVES: Hormone replacement therapy(HRT) in postmenopausal women decreases lipoprotein(a) [Lp(a)]. The influences of progesterone on Lp(a) and lipids, administered with estrogen, are controversial. However, previous studies had variable duration of therapy, and there was no report evaluating the effect of the duration of medication. METHODS: A total 246 postmenopausal women were divided into 4 groups: group A; 0.625mg conjugated equine estrogen(CEE)(n=90), group B; 0.625mg CEE plus 5mg medroxyprogesterone acetate(MPA)(n=35), group C; 0.625mg CEE plus 10mg MPA(n=43), and group D; 2mg estradiol valerate(E2) plus 0.5mg norgestrel(N)(n=76). Lp(a) and lipids levels were measured before, 2, 6 and 12 months after HRT. RESULTS: In total subjects, Lp(a) was decreased with medication for 2 months by 20.7%(p<0,0001). Compared with levels at 2 months after medication, levels at 6 and 12 months revealed further reduction(p<0.001) by 5.3% and 9.0% respectively. Medication for 2 months increased HDL-C in group A, not changed in group B and C, and decreased in group D. After 12 months, HDL-C levels were increased in Group A, B, and C, and not changed in group D, In total subjects, low density lipoprotein-cholesterol(LDL-C) was decreased by 12.2% after 2 months(p<0.001). Compared with levels at 2 months after medication, LDL-C level was decreased by 3.4% after 6 months(p<0.001) and there was no further reduction after 12 months. CONCLUSION: The effect of hormone replacement therapy on Lp(a) and lipids were dependent upon the duration of medication. Inconsistent results in previous studies can be partially explained by the difference in this parameter.

Ultrastructural Changes of the Aorta in Spontaneously Hypertensive Rats and the Effect of High Cholesterol Diet

BACKGROUND: Vascular lesions are the major cause of morbidity and mortality in hypertensive patients. However, the pathologic characteristics of gradually evolving, chronic hypertension have not been adequately studied and the mechanism by which hypertension accelerates atherosclerosis is still uncertain. This study was undertaken to invertigate the ultrastructural changes of the aorta and the effect of high cholesterol diet in spontaneously hypertensive rats(SHR). METHODS: Spontaneously hypertensive rats (n=80, male, 5 weeks old) and Wistar rats (n=40, male, 5 week old) were used. Forty SHR were fed with 2% cholestrol diete, while the remainder with control diet. Systolic blood pressure was measured weekly until 16 weeks after birth, and then biweekly until 40 weeks after birth. Transmission and scanning electron microscopy were used to evaluate ultrastrucural changes of the aorta. RESULTS: 1) The blood pressure of SHR rose stedily and progressively from the 5 weeks after birth and reached nearly 190mmHG at the 16 weeks after birth. 2) In SHR, the subendothelial component contained finely granular substances, abundant fibrillar collagen and elastin. Infiltration of the mononuclear blood leukocytes into the intima was frequently seen. 3) Endothelium from cholestrol-fed SHR did exhibit numerous pinocytotic vesicles and contained many cytoplasmic filaments. There were a number of large mononuclear lipid-filled cells in the intimal lesions. Blistering of the endothelial plasma membrane was also observed in high cholesterol diet-fed SHR. Later on, adhesion of platelets, febrin, and white blood cells as well as damage of intima shown as multiple small holes were more marked. 4) There was no significant difference in systoloic blood pressure between high cholesterol diet-fed and control diet-fed SHR. CONCLUSION: In the aorta of SHR, the most prominent change was an expansion of the subendothelial space and infiltration of the mononuclear leukocytes into the intima. The present study showed that the SHR was indeed a reliable model for the essential hypertension. In some SHR, high cholesterol diet could induce more pronounced vascular lesions, which were enhanced by hypertension.

Effect of Hormone Replacement Therapy on Lipoprotein(a) and Lipids in Postmenopausal Women : Influence of Androgenic Activity of Progesterone

BACKGROUND: Many reports have shown that hormone replacement therapy(HRT) in postmenopausal women decreases lipoprotein(a)[Lp(a)]. However these had small numbers of subjects, short duration of therapy, or comparisons of only a few regimens. The influences of progesterone on Lp(a) and lipids, administered with estrogen, are controversial. METHODS: Five hundred and fifty-one postmenopausal women were divided into 4 groups : group A ; 0.625mg conjugated equine estrogen(CEE)(m=140), group B ; 0.625mg CEE plus 5mg medroxyprogesterone acetate(MPA)(m=97), group C ; 0.625mg CEE plus 10mg MPA(n=109), and group D ; 2mg estradiol valerate(E2) plus 0.5mg norgestrel(N)(n=134) and group E ; control(n=71). Lp(a) and lipids levels were measured before and 12 months after HRT. RESULTS: Estrogen replacement therapy(ERT) for 12 months lowered Lp(a) level by 37.1%. The addition of progesterone attenuated the Lp(a)-lowering effect of estrogen and decreased by 27.7%, 29.6%, and 30.3% in groups B(p<0.05), C(p<0.05), and D(p<0.0001) respectively. High density lipoprotein cholesterol(HDL-C) was increased markedly in group A(16.5%), increased moderately in groups B(10.8%) and C(11.3%), and not changed in group D. Low density lipoprotein cholesterol was decreased by 10.9%, 13.7%, 11.3%, and 17.6% in groups A, B, C, and D respectively. CONCLUSIONS: Reduction of Lp(a) with estrogen replacement therapy may be one of mechanisms for cardioprotective effect in postmenopausal women. The combined therapy of estrogen and progesterone may reveal different effects on heart due to adverse actions of progesterone on Lp(a) and HDL-C. The variations in the androgenic potency of progesterone may explaine inconsistent results on HDL-C in previous studies.

Ischemic Preconditioning in Isolated Rabbit Heart : Effect on Left Ventricular Function, Infarct Size, and Protein Kinase C*

BACKGROUND: It has been demonstrated that ischemic preconditioning(IP, repetitive brief period of ischemia and reperfusion) enhances recovery of post-ischemic contractile dysfunction and reduces incidences of reperfusion-arrhythmia and infarct size after a prolonged ischemia. A lot of mechanisms have been proposed, however, controversies still remain. Recent studies suggested that IP could activate protein kinase C(PKC). Therefore, we measured left ventricular function, myocardial creatinin and PKC activities, and infarct size to assess whether IPs cardioprotective effect is related to PKC activation using isolated rabbit hearts. METHODS AND RESULTS: Hearts isolated from New Zealand White rabbits(1.5-2.0kg body weight) were perfused with Tyrode solution by Langendorff technique. After stabilization of baseline hemodynamics, the hearts were subjected to 60-min ischemia followed by 120-min reperfusion with IP(IP group, n=15) or without IP(control group, n=14), IP was induced by 4 cycles of 5-min global ischemia and 5-min reperfusion. Left ventricular function including developed pressure(LVEDP), dp/dt, heart rate(HR), and coronary flow(CF) was measured to determine the recovery of LVEDP, RPP(rate-pressure product, HRXLVEDP) and CF to baseline measurement. Frequency of arrhythmia was counted on reperfusion. Myocardial CK-MB, myocardial cytosolic and membrance PKC were measured and the infarct size was determined by staining with tetrazolium salt and planimetry. Data were analyzed by one-way ANOVA, Tukey's post-hoc test and t-test. There was no significant differences in the recovery of LVEDP, dp/dt, RPP, and CF and frequency of arrhythmia during reperfusion between the control and the IP groups. In comparison with the control groups, however, CK-MB was significantly lowered in the IP group(P < 0.05). Cytosolic PKC was significantly decreased but membrance PKC was increased(p < 0.05). These findings indicate that PKC was translocated and activated by IP. Furthermore infarct size was smaller and limited to the antero-lateral or posterior wall and papillary muscle in the IP group(p < 0.05). CONCLUSION: These results indicate that IP dose not improve post-ischemic contractile dysfunction after a prolonged ischemia of 60 minutes but has an infarct-limiting effect. This cardioprotective effect of IP may be related to PKC activation.

Fibrinogen as Risk Factors for the Coronary Artery Disease

BACKGROUND: This prospective and cross-sectional study was conducted to assess the risk factors for coronary artery disease in the selected Korean Pateints. METHOD: We analyzed clinical parameters and biochemical parameters in 158 subjects; 98 subjects with significant coronary artery disease as proven by coronary angiography(stable angina pectoris : 55, unstable angina pectoris : 30, post-myocardial infarction angina pectoris : 13) and 58 normal subjects as proven by coronary angiography, from November 1993 to April 1994 in Seoul National University Hospital. RESULTS: 1) Old age, male gender, history of diabetes and smoking, high low density lipoprotein cholesterol level, high lipoprotein (a) level and high fibrinogen level were identified and risk factors for coronary artery disease on simple logistic regression analysis. 2) Lp(a) was positively related to fibrinogen(r=0.23), cholesterol(r=0.23) and low density lipoprotein cholesterol(r=0.28). 3) High fibrinogen level, old age, and male gender were independent risk factors of significant coronary artery disease in the selected Korean Population on multiple stepwise logistic regression analysis. CONCLUSION: High fibrinogen level, old age, and male gender six were independent risk factors of significant coronary artery disease in the selected Korean Population of multiple stepwise logistic regression analysis. These findings could not deny the role of cholesterol in coronary artery disease, but suggested that factors related to thrombosis and fibrinolysis, may play more important role in Korean patients coronary artery disease.

Fibrinogen as Risk Factors for the Coronary Artery Disease

BACKGROUND: This prospective and cross-sectional study was conducted to assess the risk factors for coronary artery disease in the selected Korean Pateints. METHOD: We analyzed clinical parameters and biochemical parameters in 158 subjects; 98 subjects with significant coronary artery disease as proven by coronary angiography(stable angina pectoris : 55, unstable angina pectoris : 30, post-myocardial infarction angina pectoris : 13) and 58 normal subjects as proven by coronary angiography, from November 1993 to April 1994 in Seoul National University Hospital. RESULTS: 1) Old age, male gender, history of diabetes and smoking, high low density lipoprotein cholesterol level, high lipoprotein (a) level and high fibrinogen level were identified and risk factors for coronary artery disease on simple logistic regression analysis. 2) Lp(a) was positively related to fibrinogen(r=0.23), cholesterol(r=0.23) and low density lipoprotein cholesterol(r=0.28). 3) High fibrinogen level, old age, and male gender were independent risk factors of significant coronary artery disease in the selected Korean Population on multiple stepwise logistic regression analysis. CONCLUSION: High fibrinogen level, old age, and male gender six were independent risk factors of significant coronary artery disease in the selected Korean Population of multiple stepwise logistic regression analysis. These findings could not deny the role of cholesterol in coronary artery disease, but suggested that factors related to thrombosis and fibrinolysis, may play more important role in Korean patients coronary artery disease.

Heart Rate Adjustment of ST Segment Depression as a Myocardial Ischemia Index of Coronary Artery Disease

BACKGROUND: Exercise testing is an importnat diagnostic and prognostic procedure in the assessment of patients with ischemic heart disease. But standard ST-segment depression criteria was not high enough to estimate coronary srtery disease. Recently, the heart rate adjustment of ST segment depression, ST segment/heart rate slope and index, have been proposed as a more accurate criteria for diagnosing significant coronary artery disease. The objective of this study was to compare the discriminating power of proposed ST segment/heart rate slope and index with that of a standard method of assessing exercise-induced ST segment depression for estimating coronary artery disease. METHODS: Sixty nine patients with ischemic heart disease were studied with exercise treadmill testing and coronary angiography. Computer-measured ST-segment amplitudes were obtained and analysis of the heart rate-adjusted ST segment depression(ST/HR slope and big up tri, Delta ST/HR index) was done. The sensitivity, specificity, and extent of coronary artery disease on each criteria were compared. RESULTS: 1) The sensitivity of big up tri, Delta ST/HR index partition of 1.6uV/beats/min was slightly higher(83%) and the specificity of ST/HR slope partition of 2.4uV/beats/min was higher(87%) than the standard exercise electrocardiographic criteria. 2) Early onset of ischemic ST-segment depression, profound ST-segment depression(> or =2mm), and downsloping ST-segment were associated with more extensive coronary artery disease. 3) On ST/HR slope, no CAD was 1.7+/-0.26uV/beats/min, one vessel disease was 2.6+/-0.34 uV/beats/min, two vessel disease was 2.7+/-1.36uV/beats/min, one vessel disease was 2.8+/-0.35uV/beats/min, and on big up tri, Delta ST/HR index, no CAD was 1.8+/-0.38uV/beats/min, one vessel disease was 2.8+/-1.36uV/beats/min, two vessel disease 3.4+/-1.44uV/beats/min, and three vessel disease was 3.7+/-2.95uV/beats/min. The increment of ST/HR slope and big up tri, Delta ST/HR index were associated with the coronary artery disease and its severity, but the correlations were not high enough. CONCLUSION: The heart rate adjustment of ST segment depression was not high enough for improved detection of coronary artery disease, compared with standard ST-segment depression criteria. But these indexes can be improved the clinical usefulness of the treadmill exercise test for coronary aretry disease.

The correlation between 24-hour ambulatory blood pressure and echocardiographic LVH in hypertension / 대한내과학회지

No abstract available.