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Biomedical subjects

S K Cho

Publications and source records attributed to S K Cho.

At least 55 records · Page 3Linked to original sources
PubMed1995

Comparative study of efficacy and safety of low-dose diltiazem or betaxolol in combination with digoxin to control ventricular rate in chronic atrial fibrillation: randomized crossover study.

BACKGROUND: The combination therapy of low-dose diltiazem or bexatolol with digoxin can be a useful adjunct for achieving heart rate control with minimal side effects. But there has not been a study including patients with impaired left ventricular function and evaluating whether the beneficial effects of medication will be maintained during a follow-up period. OBJECTIVES: The purpose of this study was three-fold: (1) to compare the efficacy of digoxin with low-dose diltiazem and digoxin with low-dose betaxolol on randomized crossover study; (2) to evaluate whether the beneficial effects of medication will be maintained after 7 months; (3) to evaluate the safety of the combination therapy in patients with impaired left ventricular function. METHODS: We did a prospective randomized crossover study in 35 patients with chronic atrial fibrillation (AF) including 15 patients with left ventricular dysfunction. After enrollment, each patient was evaluated for heart rate, blood pressure, rate-pressure products, maximal exercise tolerance at rest and during symptom-limited treadmill test before medication, at 4 weeks after medication of digoxin (0.125-0.5 mg daily) with diltiazem (90 mg twice daily), and at 4 weeks after digoxin with betaxolol (20 mg once daily). We performed 24-h ambulatory electrocardiogram (ECG) in 15 patients at the end of each phase of treatment. We repeated symptom-limited treadmill test like above method in 15 patients at 7 months of medication. RESULTS: (1) Ventricular rates were significantly reduced in digoxin with low-dose betaxolol therapy at rest and during exercise (67 +/- 3, 135 +/- 5 (mean +/- S.E.M.) beats/min, respectively) in comparison to digoxin with low-dose diltiazem therapy (80 +/- 7, 154 +/- 5) (P < 0.05). (2) Rate-pressure products were significantly less in digoxin with low-dose betaxolol at rest and during exercise (85 +/- 4, 213 +/- 12 x 10(2) mmHg/min) than in digoxin with low-dose diltiazem therapy (105 +/- 6, 269 +/- 12) (P < 0.05). (3) Exercise capacity was significantly improved in digoxin with low-dose betaxolol (9.3 +/- 0.5 METS) or digoxin with low-dose diltiazem (9.7 +/- 0.5) in comparison to control state (8.3 +/- 0.5) (P < 0.05). (4) At 7 months evaluation, there was no significant difference between at 4 weeks and at 7 months. (5) Results on 24-h ambulatory ECG showed the same findings as on treadmill test. (6) Although side effects occurred more frequently in digoxin with low-dose betaxolol therapy, they were minimal and no patient had to withdraw medication. Worsening of left ventricular dysfunction was not observed. CONCLUSION: Our study suggested that (1) combination therapy of low-dose betaxolol with digoxin was more superior to low-dose diltiazem with digoxin in controlling ventricular rate and reducing rate-pressure products; (2) the effects controlling ventricular rate, reducing rate-pressure products and improving exercise capacity have been well maintained even after 7 months of medication with each combination therapy.

Adrenergic beta-Antagonists↗
PubMed1995

Interaction of intravenous heparin and organic nitrates in acute ischemic syndromes.

We evaluated whether a drug interaction between intravenous nitroglycerin or isosorbide dinitrate and heparin exists. Ninety-six patients with a diagnosis of acute myocardial infarction, unstable angina, or other thromboembolic disorders were divided into 3 groups: group I (control group, n = 35) received intravenous heparin alone; group II (n = 31) received combined intravenous nitroglycerin and heparin; and group III (n = 30) received combined intravenous isosorbide dinitrate and heparin. We determined the mean of 2 separate measurements of heparin dosage requirement, antithrombin III activity, and the dose of intravenous nitroglycerin or isosorbide dinitrate at the time that the ratio of activated partial thromboplastin time (aPTT) to baseline aPTT was 1.5 to 2.0. The mean therapeutic heparin dose standardized to total body weight of each group was 13.8, 15.4, and 15.5 U/kg/hour, respectively. At that time, patients were receiving intravenous nitroglycerin at doses of 58.8 +/- 38.6 micrograms/min or intravenous isosorbide dinitrate at doses of 3.7 +/- 2.0 mg/hour. The mean antithrombin III activity of each group was 22.2, 22.8, and 21.3 mg/dl, respectively. The overall results for groups I, II, and III, and results for the subgroup of patients with acute ischemic syndromes in those groups, did not differ significantly. The heparin dose did not show a significant correlation to the dose of intravenous nitroglycerin (r = -0.26, p > 0.05) nor to that of isosorbide dinitrate (r = 0.30, p > 0.05).

Acute Disease↗
PubMed1995

Transgenic mice overexpressing human copper/zinc-superoxide dismutase (Cu/Zn SOD) are not resistant to endotoxic shock.

Tumor necrosis factor is a key mediator of the septic shock syndrome, and its secretion by monocytes is induced by endotoxin. Increasing evidence exists that the release of oxygen-derived free radicals by polymorphonuclear cells plays a central role in tumor necrosis factor toxicity. Superoxide dismutases scavenge oxygen-derived free radicals and appear to be excellent candidates to provide protection against tumor-necrosis-factor -mediated cytotoxicity. In this study, we have found that transgenic mice overexpressing the human gene for CuZn SOD are not protected against experimentally induced endotoxemia.

Animals↗
PubMed1995

Alterations of CDKN2 (p16) in non-small cell lung cancer.

The cyclin-dependent kinase inhibitor known as p16 (CDK41, CDKN2, INK4A, MTS1) has been proposed as a tumor suppressor gene on chromosome segment 9p21. We have evaluated CDKN2 alterations in 34 non-small cell lung cancers (NSCLCs) with matched normal tissue controls and in 9 NSCLC cell lines by Southern blotting, single-strand conformation polymorphism (SSCP) with the polymerase chain reaction, and direct sequencing. In addition, loss of heterozygosity at chromosome segment 9p21, with the use of the microsatellite marker D9S171, was studied in these samples. Whereas CDKN2 was either deleted or mutated in NSCLC cell lines at a high frequency (6/9, 67%), alterations were much less frequent (7/34, 21%) in primary tumor samples. Only one sample contained a point mutation in exon 1 of CDKN2. In addition, two samples had homozygous deletions of CDKN2 in exon 1; one had a homozygous and three a hemizygous deletion of exon 2. Possibly normal tissue contaminating our tumor samples may have masked homozygous deletions in these cases. Four patient samples had LOH in the region of CDKN2 on chromosome segment 9p21; two of these samples had potentially inactivating alterations of CDKN2; one sample had a mutation of CDKN2, and the other had a homozygous deletion of exon 1. In summary, inactivation of CDKN2 is implicated in the development of about 20% of NSCLC, but the possibility of another tumor suppressor gene on chromosome segment 9p21 important in lung cancer cannot be eliminated.

Base Sequence↗
PubMed1995

Does prevalence of migraine and Raynaud's phenomenon also increase in Korean patients with proven variant angina?

BACKGROUND: The incidence of coronary artery spasm in oriental patients is higher than that in western patients. Oriental patients with variant angina (VA) frequently show normal or insignificant coronary artery stenosis by angiogram, compared with western patients. The prevalence of migraine and Raynaud's phenomenon in oriental patients with VA has not yet reported. OBJECTIVE: We did a prospective study on the prevalence of migraine and Raynaud's phenomenon in patients with proven VA compared with those in two control groups using a radioisotope technique following ice water exposure. Simultaneously, we studied lipid profiles of each group. METHODS AND RESULTS: migraine was diagnosed if the score in part A totalled 7 or more of 26, and Raynaud's phenomenon was diagnosed if the score in part B totalled 4 or more of 11 by Miller et al. Technetium-99m-labeled red blood cells (99mTc-RBC) radionuclide angiography was performed in all patients. Patients were included in a prospective protocol. Patients were grouped as follows: Group I: 20 patients with proven VA; Group II: 30 patients with coronary artery disease; Group III: 31 patients without heart disease. Age and sex of patients were not statistically different among the three groups. Migraine was diagnosed in 8 patients (40.0%) of group I and in 6 patients (20.0%) of group II and in 12 patients (38.7%) of group III. Raynaud's phenomenon was reported in 2 (10.0%) of the patients in group I and in 5 (16.1%) of the patients of group III. The mean index ratio of the digital blood flow of right over left hand on static image was 0.85 +/- 0.07 (mean +/- S.E.M.) of the patients of group I, 0.73 +/- 0.03 of the patients of group II and 0.74 +/- 0.04 of the patients of group III. The mean flow index ratio of right over left hand of the digital blood flow on dynamic study was 0.51 of the patients of group I, 0.43 of the patients of group II and 0.43 of the patients of group III. The score of migraine did not differ significantly among the three groups. The score of Raynaud's phenomenon of patients with variant angina did not differ significantly from that of patients in the non-coronary control group, although it differed significantly from that of patients in the coronary control group. But, the prevalence of migraine and Raynaud's phenomenon (questionnaire and radionuclide angiography) in patients of group I did not differ significantly from that in groups II and III. In the end, more patients with variant angina than coronary or non-coronary control group did not reach the predetermined point level for the diagnosis of migraine and Raynaud's phenomenon. Lipid profiles were not significantly different among three groups. CONCLUSIONS: This result suggests that variant angina may not be a manifestation of a generalized vasospastic disorder in Korean patients.

Adult↗
PubMed1995

sVCAM-1 levels after segmental antigen challenge correlate with eosinophil influx, IL-4 and IL-5 production, and the late phase response.

Evidence from in vitro studies suggests a potential role for vascular cell adhesion molecule-1 (VCAM-1) in eosinophil trafficking. We hypothesized that induction of VCAM-1 occurs in the lung during IgE-mediated airway inflammation in humans. The technique of segmental antigen provocation followed by bronchoalveolar lavage (BAL) at 24 h was used to study 27 ragweed-allergic asthmatics (AA) and 18 atopic nonasthmatics (ANA). Total and differential cell counts were performed, and IL-4, IL-5, and soluble (VCAM) (sVCAM) levels in concentrated BAL fluid were measured by ELISA. A large increase in sVCAM levels after segmental challenge in both AA and ANA (1.79 +/- 0.31 to 139.39 +/- 68.58 ng/ml, p < 0.0005 and 2.85 +/- 0.80 to 98.25 +/- 77.35 ng/ml, p < 0.05, respectively) was observed. BAL IL-4 and IL-5 also increased after challenge (IL-4: 51.7 +/- 17.72 to 150.1 +/- 58.82 pg/ml, 0.05 < p < 0.10, n = 20 for AA, and 36.6 +/- 9.05 to 116.8 +/- 51.5 pg/ml, 0.05 < p < 0.10, n = 15 for ANA; IL-5: 0 to 2.67 +/- 1.62 ng/ml, p < 0.01, n = 16 for AA, and 0 to 2.87 +/- 2.16 ng/ml, 0.05 < p < 0.10, n = 10 for ANA). In both groups, the majority of the increase in sVCAM, IL-4, and IL-5 was accounted for by subjects who displayed a dual phase response after whole-lung antigen inhalation. This fact, plus the strong correlation observed between postchallenge sVCAM, IL-4, and IL-5 levels and eosinophil influx, suggests that VCAM, IL-4, and IL-5 play important roles in the recruitment of eosinophils to the lung of humans after antigen challenge.

Adult↗
PubMed1995

Pulmonary inflammation after segmental ragweed challenge in allergic asthmatic and nonasthmatic subjects.

Inflammatory reactions in the airways are thought to play an important role in asthma pathogenesis. The goal of this work was to test prospectively the hypothesis that the pulmonary inflammatory response to segmental antigen challenge is greater in allergic asthmatic (AA) subjects than in allergic nonasthmatic (ANA) subjects. A total of 46 ragweed-allergic subjects, 27 AA and 19 ANA, took part in these studies. Subjects had normal or nearly normal pulmonary function, were on no chronic medication, and were characterized as to their skin sensitivity to intradermal ragweed injection, their nonspecific responsiveness to methacholine, and the presence (or absence) of a late asthmatic response after whole-lung antigen challenge. Subjects then underwent bronchoscopy, bronchoalveolar lavage (BAL) of a control lung segment, antigen lung challenge of a contralateral lung segment with 5 ml of a concentration of ragweed solution 100-fold higher than that required to produce a positive skin reaction, and finally, BAL of the challenged segment after 24 h. AA did not differ from ANA in any inflammatory parameter measured in BAL fluid (total cells/ml, macrophages/ml, lymphocytes/ml, eosinophils/ml, neutrophils/ml, total protein, albumin, urea, or eosinophil cationic protein) 24 h after challenge. In addition, there was no relationship between nonspecific bronchial responsiveness to methacholine and eosinophils recruited to the lung by segmental antigen challenge. Rather, in both groups a marked inflammatory response was seen only in the subgroup of subjects who demonstrated a late airway reaction after whole-lung antigen challenge, regardless of disease classification.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Association of lipoprotein levels with atherosclerotic changes in patients with coronary artery spasm and insignificant coronary artery stenosis.

BACKGROUND: Coronary artery spasm readily occurs at sites of atheromatous plaque. Some lipid profiles are related to the genesis of coronary artery spasm. In Korean patients, it is frequently observed in grossly normal coronary arteries, in contrast to the situation in western patients, who frequently have coronary artery spasm superimposed on significant coronary artery stenosis. Intravascular ultrasound examination has shown that mild or diffuse atherosclerotic changes in patients with focal vasospasm, even in the absence of angiographic coronary disease. OBJECTIVES: We studied prospectively 104 patients in order to find out which lipid profiles were associated with atherosclerotic changes in patients with coronary artery spasm. METHODS: Patients were grouped as follows: group I, control, 50 patients (34 men, 16 women); group II, 35 patients (26 men, 9 women) with significant coronary artery disease; group III, 19 patients (13 men, six women) with significant coronary artery spasm and either no coronary artery stenosis or insignificant stenosis. There was no significant difference in age (group I 55 +/- 1 years, group II 56 +/- 2 years, group III 54 +/- 2 years) or sex among the groups. The following parameters were evaluated: hypertension, cigarette smoking, diabetes mellitus, and lipid profile. RESULTS: The incidence of hypertension in group II patients was higher than in group I or III (P < 0.05). No significant difference was found in the percentage of cigarette smokers and patients with diabetes mellitus among three groups. The lipid profiles of each group were analysed. Group II patients had higher lipoprotein (a) levels (39 +/- 6 mg/dl) than those in group I (21 +/- 3 mg/dl) or group III (13 +/- 3 mg/dl) (P < 0.05). Other lipid profiles were not significantly different among the groups. CONCLUSION: Our results indicate that the atherosclerotic changes in the coronary arteries of group III patients were not associated with lipid profiles, including lipoprotein (a).

Constriction, Pathologic↗
PubMed1994

Eosinophils recruited to the lung by segmental antigen challenge show a reduced chemotactic response to leukotriene B4.

Inflammatory cells, particularly eosinophils, are thought to be important in allergic airway disease. However, the mechanisms responsible for their recruitment to the lung have not been well established in humans, in vivo. In this report we demonstrate that eosinophils recruited to the lung of ragweed allergic volunteers by segmental antigen challenge have a decreased chemotactic response to leukotriene (LT) B4 ex vivo, in comparison with eosinophils isolated from peripheral blood (80% inhibition at 10(-8) M LTB4, the optimal concentration, p < 0.01). Their chemotactic response to formyl-methionyl-leucyl-phenylalanine (FMLP) was normal. Although the response to platelet activating factor also appeared to be reduced, this reduction was not statistically significant. These data suggest that lung eosinophils were exposed to LTB4 in vivo and are consistent with the hypothesis that LTB4 is important in the recruitment of eosinophils to the lung during IgE-mediated reactions in the lung in humans.

Allergens↗
PubMed1994

Isolated left main coronary ostial stenosis: intraoperative transesophageal echocardiography during surgical angioplasty.

OBJECTIVE: We hypothesized that transesophageal echocardiography could be used to image the repair of a left ostium or main coronary artery following surgical angioplasty. METHODS AND RESULTS: Six patients, all women, were found to have isolated left main coronary ostial stenosis. We performed preoperative transesophageal echocardiography (TEE) in three and intraoperative TEE in four of six patients. Their mean age was 48 years. They presented with severe angina (Class III or IV) with a short duration (6.8 +/- 7.8 months). They had a low incidence of risk factors while histopathologic examinations showed typical atherosclerosis in all four patients. Preoperative two-dimensional echocardiography demonstrated left main coronary ostial stenosis in three patients. We clearly observed the patency of the pericardial or saphenous venous patch with basal short-axis scan on two-dimensional and color Doppler echocardiography in all four patients after weaning them from cardiopulmonary bypass and finished operation without complications. CONCLUSIONS: Our study shows that TEE can be used to image the repair of a left ostium or main coronary artery following surgical angioplasty and provide the surgeon with the required information about the adequacy of the repair.

Coronary Disease↗
PubMed1994

Adenosine deaminase and carcinoembryonic antigen in pericardial effusion diagnosis, especially in suspected tuberculous pericarditis.

BACKGROUND: Adenosine deaminase (ADA) and carcinoembryonic antigen (CEA) have been measured in pleural fluid to help distinguish malignant from benign effusions, especially in tuberculous pleurisy. We investigated ADA and CEA levels in patients with moderate to large pericardial effusions of different etiologies. METHODS AND RESULTS: We performed diagnostic and therapeutic pericardiostomy with drainage and biopsy. We measured ADA and CEA levels in the pericardial fluid in 26 patients with moderate to large pericardial effusion and 19 control patients. Patients were included in a prospective protocol from August 1991 to August 1993. Patients were grouped as follows: group 1, 9 patients with tuberculous pericarditis (TP) confirmed by bacteriologic culture or histology of pericardial biopsy; group 2, 5 patients with clinically strongly suspected TP; group 3, 12 patients with malignancy (8) and acute pericarditis (4); group 4, 19 control patients without pericardial disease. We treated patients with TP with isoniazid, rifampin, and either streptomycin or ethambutol for 12 months and pyrazinamide for 2 months. We observed for symptoms and signs of recurrent pericarditis or constrictive pericarditis on follow-up. In group 1 the ADA activity was significantly higher (101 +/- 14 U/L) than that in group 3 (22 +/- 5 U/L) or that in group 4 (17 +/- 2 U/L) (P < .05). There was no significant difference between ADA activity in group 1 (101 +/- 14 U/L) and that in group 2 (100 +/- 26 U/L). With a cutoff value for ADA activity of 40 U/L, sensitivity was 93% and specificity 97% in the diagnosis of TP. In benign diseases, the CEA level was significantly lower (1.0 +/- 0.3 ng/mL) than that in malignant diseases (135.1 +/- 79.7 ng/mL) (P < .05). With a cutoff value for CEA level of 5 ng/mL, sensitivity was 75% and specificity 100% in the diagnosis of malignant pericarditis. Follow-up study (mean, 12.9, 19.8, and 11.8 months in groups 1, 2, and 3, respectively, showed no symptoms or signs of constrictive pericarditis, except for 1 patient. CONCLUSIONS: Pericardial fluid ADA and CEA are useful for the differential diagnosis of pericardial effusion of various causes. They also have great value in early diagnosis of TP, particularly when the results of other clinical and laboratory tests are negative.

Adenosine Deaminase↗
PubMed1994

Variant angina complicating ergot therapy of migraine.

A 55-year-old man demonstrated typical reflux esophagitis, not esophageal spasm, by esophageal manometry, although he demonstrated classic migraine, positive Raynaud's scan, and proven coronary artery spasm. He suffered from severe chest pain by medication of ergotamine tartrate. Ergot alkaloids should be avoided in patients with symptomatic coronary artery spasm.

Angina Pectoris, Variant↗
PubMed1993

Coronary vasospasm, multiple coronary thrombosis, unstable angina and essential thrombocytosis.

Rarely, essential thrombocythemia has led to coronary artery occlusion. Only one patient has been described, in whom coronary angiography demonstrated multiple coronary thrombosis. We report a case of coronary vasospasm, multiple coronary thrombosis involving right and left coronary artery and possibly leading to myocardial infarction and unstable angina pectoris in a woman with migraine, Raynaud's phenomenon, and essential thrombocytosis.

Angina, Unstable↗
PubMed1993

Isolated left main coronary ostial stenosis in Oriental people: operative, histopathologic and clinical findings in six patients.

OBJECTIVES: This study was performed to determine whether there are differences in the operative, histopathologic, angiographic and clinical findings of isolated ostial stenosis between Oriental and western patients. BACKGROUND: Angiographic, clinical and histologic findings in isolated ostial stenosis have been reported in western but not in Oriental patients. METHODS: Six patients, all women (0.88% of a total of 684 patients who underwent coronary angiography between March 1989 and July 1991), were found to have isolated left main coronary ostial stenosis. We performed surgical ostial angioplasty with the autologous pericardial or saphenous venous patch and biopsy at the aortic arteriotomy site in four of the six patients. RESULTS: All six patients presented with severe angina (angina class III or IV) of short duration (mean +/- SD 6.2 +/- 6.2 months) and had a very low incidence of risk factors, although histopathologic examination showed typical atherosclerosis in four of the six patients. They were young to middle-aged women (mean 45 +/- 3 years) except for Patient 6 (62 years). Exercise duration was short and ST segment depression, accompanied by typical angina, was observed in many leads in the warm-up period or stage I. Despite the crucial location of the lesion, most patients had well preserved left ventricular function and normal wall motion. There was no angiographically definable collateral circulation from either ipsilateral or contralateral vessels except for grade I collateral circulation in Patient 5. Operative findings demonstrated mostly yellow atheroma in the aortic wall and left coronary ostium. Coronary angiography showed only ostial stenosis of the left coronary artery in all six patients, but operative findings documented atheromatous change in the left main coronary artery in two of the six. CONCLUSIONS: The clinical, angiographic, histopathologic and operative findings of Oriental patients were similar to those reported in western patients, but the incidence of isolated left main coronary ostial stenosis was higher in the Oriental group. Angiographically definable isolated coronary ostial stenosis may often not be true isolated ostial stenosis.

Cardiac Catheterization↗