Preparation of biopolymer-coated magnetite nanoparticles for magnetic resonance image contrast agent.

The magnetite nanoparticles were synthesized using the sonochemical method with oleic acid as surfactant. The average size of the magnetite particles can be controlled by the ratio R = [H2O]/[surfactant] in the range of 2 to 9 nm. The size of the magnetite nanoparticles prepared by this method shows the narrow distribution. To prepare biopolymer(beta-glucan)-coated magnetite nanoparticles, beta-glucan solution was added to the magnetic colloid suspensions under the ultrasonication at room temperature. The beta-glucan coated magnetite colloidal suspensions of various concentrations did not agglomerate for 15 days, indicating their good stability. The beta-glucan-coated magnetite colloidal suspensions exhibited the enhancement of MRI contrasts in vitro.

Multiple predictors of coronary restenosis after drug-eluting stent implantation in patients with diabetes.

OBJECTIVES: To identify parameters influencing the likelihood of restenosis after implantation of drug-eluting stents (DES) in patients with diabetes. METHODS: Stented patients (n = 840) with DES were retrospectively reviewed for inclusion in the study from the Multicenter PCI Database Registry. From this database, 211 (25.1%) of 840 patients with six-month angiographic follow up had diabetes. Predictors of coronary restenosis were identified with univariate and multivariate logistic regression analyses. RESULTS: Restenosis occurred in 92 of 629 (14.6%) patients without diabetes and in 44 (20.9%) of 211 patients with diabetes (p < 0.001). Multivariate parameters for predicting restenosis in the diabetic group were current smoking (odds ratio (OR) 1.923, 95% confidence interval (CI) 1.055 to 4.725, p = 0.036), higher C reactive protein concentration (OR 1.031, 95% CI 1.011 to 1.075, p = 0.043), use of the paclitaxel-eluting stent (OR 2.638, 95% CI 1.338 to 5.200, p = 0.005), longer stent length (OR 1.065, 95% CI 1.021 to 1.119, p = 0.033), smaller reference diameter before DES implantation (OR 0.501, 95% CI 0.110 to 0.965, p = 0.040), smaller reference diameter (OR 0.455, 95% CI 0.120 to 0.814, p = 0.026) and minimum lumen diameter (OR 0.447, 95% CI 0.068 to 0.876, p = 0.039) after DES implantation. CONCLUSION: Even with the introduction of DES, diabetes remains a significant predictor of coronary restenosis, especially in cases of a small baseline vessel size, small vessel size after percutaneous coronary intervention, longer stent length, use of the paclitaxel-eluting stent, current smoking and high C reactive protein concentration.

A case of successful primary coronary intervention for the total occlusion of left main stem with the aid of abciximab.

A 61-yr-old male patient presented with severe chest pain with cardiogenic shock due to an extensive anterolateral myocardial infarction. Two-dimensional echocardiogram showed severe left ventricular systolic dysfunction (ejection fraction=17%). Emergent coronary angiogram obtained immediately after placing temporary pacing electrode revealed total thrombotic occlusion in the left main stem. We performed direct coronary intervention using kissing balloon technique with the aid of Abciximab (ReoPro) infusion. Residual stenosis with thrombus remained even after high pressure balloon dilatations, therefore we placed two stents, one in the ostia of left anterior descending (LAD) and the other in left circumflex artery (LCX). Coronary angiogram after kissing stents showed improved LAD and LCX flows without residual stenosis. Chest pain resolved and blood pressure normalized after coronary intervention. The whole procedure time was 15 min. Follow-up coronary angiogram taken one week later showed patent previous stented arteries, and echocardiography demonstrated 40% of left ventricular ejection fraction. The clinical course for one-year follow-up was uneventful.

A case of torsade de pointes associated with hypopituitarism due to hemorrhagic fever with renal syndrome.

We describe a 51-yr-old man presenting with syncope due to torsade de pointes. The torsade de pointes was refractory to conventional medical therapy, including infusion of isoproterenol, MgSO4, potassium, lidocaine, and amiodarone. His past history, physical findings, and hormone study confirmed that QT prolongation was caused by anterior hypopituitarism that developed as a sequela of hemorrhagic fever with renal syndrome. The long QT interval with deep inverted T wave was completely normalized 4 weeks after starting steroid and thyroid hormone replacement. Hormonal disorders should be considered as a cause of torsade de pointes, because this life-threatening arrhythmia can be treated by replacing the missing hormone.

Huge calcified aneurysm of the sinus of Valsalva.

Aneurysms of the sinus of Valsalva often remain undiagnosed until they rupture. A 61-year-old man had a huge, heavily calcified unruptured aneurysm, originating from the right sinus of Valsalva, detected incidentally on a chest radiograph taken for the diagnosis of cardiomegaly. Two-dimensional echocardiography revealed pericardial effusion with a huge calcified mass compressing the right ventricular outflow tract. The Doppler color-flow echocardiogram showed blood flow from the aortic root into the aneurysm. A chest computed tomographic scan revealed a large thrombosed aneurysm originating from the aortic root and measuring 10x10 cm. After pericardiocentesis, cardiac catheterization was performed, which showed that the right ventricular systolic pressure had elevated to 80 mmHg. Aortic root aortography demonstrated a huge unruptured calcified aneurysm in the sinus of Valsalva arising from the right coronary sinus. The patient underwent surgical correction to prevent aneurysmal rupture and to relieve the right ventricular outflow obstruction.

Clinical characteristics of unexplained sudden cardiac death in Korea.

In Western countries, sudden cardiac death (SCD) is closely related to coronary artery disease, but in Korea the clinical characteristics of SCD are not well determined. Over a 4-year period (June 1995 to May 1999), 186 cases of SCD, ranging in age from 16 to 75 years, were admitted to the Chonnam National University Hospital. In 82 (44.1%) of these, neither symptoms nor evidence of structural heart disease was found and so their clinical characteristics were investigated. There were 66 (80.5%) men and 16 (19.5%) women (male/female ratio = 4.1:1). The mean age was 50 +/- 14 years: 19 (23.2%) were in their 40s, 21 (25.6%) in their 50s, and 17 (20.7%) in their 60s. The time of circulatory collapse witnessed in 68 cases of SCD showed 2 peaks: between midnight and 03.00h (n=16, 23.5%) and between 09.00h and midday (n=15, 22.1%). Unexplained SCD occurred at home in 48 (64.9%) cases and on the street in 12 (16.2%); it occurred during normal daily routine activity in 23 (39.6%) and during sleep in 15 (25.9%). Thirty-three patients (40.2%) experienced various prodromal symptoms, including chest discomfort (n=13, 15.9%) and dyspnea (n=8, 9.8%). The electrocardiogram taken on arrival recorded asystole in 65 (79.3%) and ventricular fibrillation in 17 (20.7%). Idiopathic ventricular fibrillation was diagnosed in 14 (10 men, 4 women; 45 +/- 11 years) of 21 patients who recovered spontaneous circulation. Five (6.1%) patients were discharged alive, and an implantable cardioverter-defibrillator was implanted in 2. Unexplained SCD is common in Korea and develops predominantly in middle-aged males around midnight or in the late morning usually with no prodromal symptoms (59.8%). Idiopathic ventricular fibrillation is thought to be one of the important causes.

Enterobius vermicularis egg positive rates in primary school children in Gangwon-do (province), Korea.

A survey of the infection rate of Enterobius vermicularis among students in 4 primary schools located in Gangwon-do (Province) was done from May to June 2001. Among the 398 examinees, 39 (9.8%) were infected with E. vermicularis demonstrated by the adhesive cellotape anal swab method. The infection rates ranged from 8.3% to 11.8% among the four schools. The infection rate of males and females was 10.7% and 7.7% respectively. The first grade students showed the highest infection rate, 28.7%. The confirmed cases were treated with albendazole three times at an interval of 15 days. We were able to confirm that E. vermicularis infection is still prevalent among students in Gangwon-do, Korea.

Successful management of intractable coronary spasm with a coronary stent.

Although the long-term survival of patients suffering from coronary spasm is usually excellent, serious complications can develop, such as disabling pain, myocardial infarction, ventricular tachyarrhythmias, atrioventricular block and sudden cardiac death. A 40-year-old man who had intractable chest pain from coronary artery spasm suffered ventricular fibrillation and an acute anterior myocardial infarction upon first admission. The patient underwent a coronary angiogram, which revealed a spontaneous focal spasm at the proximal left anterior descending coronary artery (LAD). He was treated by the combination of nitrate and calcium channel blocker, but continued to complain of severe chest pain despite intensive medical therapy and he had to be treated in the emergency room 5 times during an 8-month follow-up period. An ergonovine coronary angiogram was performed and an intracoronary ultrasound examination, which revealed a focal spasm at the same site of the proximal LAD with a small amount of localized eccentric atheromatous plaque. A coronary artery stent was placed in the proximal LAD and his symptoms resolved. A follow-up coronary angiogram was performed 3 years after stenting and the stent remained patent without any in-stent restenosis or spasm.

A small-scale survey of intestinal parasite infections among children and adolescents in Legaspi city, the Philippines.

To determine the status of infection caused by intestinal parasites among children and adolescents living in Legaspi city, the Philippines, we performed a small survey by fecal examination for helminth ova and protozoan cysts with formalin-ether concentration method. Of the 64 examinees, the infection rate was 78.1%. The infection rates of primary school children, preschool children and adolescents were 95.5%, 64.7% and 87.5%, respectively. The infection rate in urban areas was 56%, and 92.3% in rural areas. The infection rates were 51% with Trichuris trichiura, 40% with Ascaris lumbricoides, 23.4% with hookworm, 15.6% with Iodamoeba butschlii, 14.1% with Endolimax nana, 9.4% with Entamoeba coli and 7.8% with Giardia lamblia. There were 33 cases with multiple infection (51.6%). Mixed infection with more than 3 parasites was observed in 15 cases, all of them being children and adolescents living in rural areas. By this survey, it was conjectured that helminthic infection is prevalent among children and adolescents in Legaspi, Philippines.

Predictive factors for the second restenosis after coronary interventions.

One of the major limitations in coronary intervention is restenosis. This study was aimed to identify clinical, angiographic, and procedural factors that may be related to the second restenosis (SR). We studied 101 patients who underwent more than two follow-up coronary angiograms after two coronary interventions between January 1996 and December 1998 in Chonnam University Hospital (out of 4,092 total coronary interventions in 3,030 patients during the same period). The patients were divided into two groups according to the evidence of SR. Fifty-two patients (group A: 57+/-10 years, M:F = 44:8) who had SR and the other 49 patients (group B: 54+/-9 years, M:F = 44:5) without SR were analyzed. Clinical features, angiographic characteristics, coronary interventional procedures, and other risk factors were compared between two groups by univariate analysis and multivariate stepwise logistic regression analysis was performed for the predictive factors for SR. The clinical variables of age, sex, clinical diagnosis, and risk factors were not different between two groups. The lesion severer than B(2) by AHA/ACC classification were associated with SR (P<0.05). Recurrent angina as an indication for follow-up angiography was associated with SR (P<0.01). Predictive factors associated with SR were patient's subjective symptom and lesion severer than type B(2) according to AHA/ACC classification.

Initial and late results of Freedom coronary stent.

OBJECTIVES: Initial and late results after implantation of Freedom stents, a balloon expandable stainless steel coil stents were evaluated. METHODS: From Jun. 1996 to Nov. 1997, we implanted 123 Freedom stents in 122 lesions in 117 patients and performed follow-up coronary angiograms at 7.0 +/- 3.6 months after stents placement. Clinical courses after stenting and follow-up coronary angiographic findings were evaluated. Comparison of clinical, angiographic, and procedural factors according to the presence or absence of restenosis was performed. RESULTS: In 117 patients who underwent stents implantation, major complications were not observed. Follow-up coronary angiograms were performed in 47 stents in 41 patients (35%). Among 47 stents, angiographic significant restenosis (percent diameter stenosis > 50%) was observed in 13 (28%). Mean age in 41 patients was 59 +/- 9 years, with 27 male patients (66%). Indications for stents implantation were de novo lesions in 18 (38%), suboptimal results after PTCA in 18 (38%), bail-out lesions in 4 (9%) and restenotic lesions in 7 (15%). Lesion types by AHA/ACC classification were A in 1 (1%), B1 in 10 (21%), B2 in 17 (36%), and C in 19 (40%). Average lesion length was 13.7 +/- 9.0 mm, stent diameter 3.0 +/- 0.3 mm, and stent length 24.6 +/- 9.0 mm. There were no significant differences of the clinical, angiographic, and procedural characteristics according to the presence or absence of restenosis. CONCLUSION: Freedom coronary stents implantation is safely performed in various morphology of coronary lesions and no significant predictive factors on restenosis in follow-up coronary angiogram were observed.

Influence of melatonin on immunotoxicity of cadmium.

The results suggested that immunotoxicity induced by Cd was significantly restored or prevented by MLT. MLT (10 or 50 mg/kg) was orally administered to ICR mice daily for 28 consecutive days, and cadmium (Cd, as [Cd(AC)(2)]) was also administered at 25 mg/kg by the same route 2 h after the administration of MLT, and the normal mice were given vehicle. Within the Cd plus MLT-treated group, the body weight gains and relative thymus weights were significantly increased when compared with the treatment of Cd alone. The relative spleen and liver weights were increased by treatment of Cd alone, then restored to normal value by MLT treatment. Hemagglutination (HA) titer, primary IgM antibody response to SRBC, and secondary IgG antibody response to BSA was significantly increased with the Cd plus MLT-treated mice, as opposed to when compared with treatment of Cd alone. The NK cell and phagocytic activity used for evaluation of non-specific immunocompetence was significantly increased in Cd plus MLT-treated mice when compared with the treatment of Cd alone. The number of peripheral leukocytes was significantly increased in Cd plus MLT-treated mice when compared with treatment of Cd alone.

A case of prominent epicardial fat mimicking a tumor on echocardiography.

Epicardial fat may anteriorly produce an echo-free space that can be mistaken for pericardial fluid. We recently experienced a 67-year-old woman with prominent epicardial fat which was presented as an echogenic tumor-like mass. She underwent open pericardiostomy to relieve large amount of pericardial effusion. Operative findings revealed only prominent epicardial fat. Biopsy of the pericardial and fat tissues revealed an inflammation and normal fat cells without any malignant cell infiltration.

Preventive effects of the heparin-coated stent on restenosis in the porcine model.

The coronary stent reduces acute coronary arterial occlusion and late restenosis during and after coronary intervention. However, stent thrombosis and restenosis are still major limitations in the widespread use of the coronary stent. Local drug delivery using the heparin-coated stent may be a new approach, which reduces the incidence of stent thrombosis and restenosis. In order to evaluate the effects of the heparin-coated stent on stent restenosis, heparin-coated stents were compared with control stents in a porcine coronary stent restenosis model. Stent overdilation injury (stent:artery = 1.3:1.0) was performed with bare Wiktor stents (group I, n = 10) and heparin-coated Wiktor stents (group II, n = 20; HEPAMED, Medtronics) in porcine coronary arteries. Follow-up quantitative coronary angiography (QCA) was performed at 4 weeks after stenting, and histo-pathologic assessments of stented porcine coronary arteries were compared in both groups. On QCA, percent diameter stenosis was significantly higher in group I than in group II (16.3% +/- 6.62% vs. 9.6% +/- 5.06%, P < 0.05). The injury score of stented porcine coronary arteries was the same in both groups (1. 26 +/- 0.23 vs. 1.20 +/- 0.22). The area of pathologic stenosis of the stented arteries was higher in group I than in group II (41.6% +/- 12.5% vs. 27.1% +/- 9.9%, P < 0.005). The neointimal area was higher in group I than in group II (4.58 +/- 1.41 mm(2) vs. 2.57 +/- 1.07 mm(2), P < 0.05). By immunohistochemistry, the proliferating cell nuclear antigen (PCNA) index was higher in group I compared with group II (11.2% +/- 6.75% vs. 6.3% +/- 4.14%, P < 0.05). The heparin-coated stent is effective in the prevention of late coronary stent restenosis in a porcine coronary stent restenosis model. This may be related to the inhibition of neointimal cell proliferation.

Production and characterization of monoclonal antibodies to porcine brain pyridoxal kinase.

Six monoclonal antibodies that recognize porcine brain pyridoxal kinase have been selected and designated as PK67, PK86, PK91, PK144, PK252 and PK275. A total of six monoclonal antibodies recognizing different epitopes of the enzyme were obtained, of which four inhibited the enzyme activity. When total proteins of porcine brain homogenate separated by SDS-PAGE were subjected to monoclonal antibodies, a single reactive protein band of molecular weight 39 kDa which comigrated with purified porcine pyridoxal kinase was detected. Using the anti-pyridoxal kinase antibodies as probes, the cross reactivities of brain pyridoxal kinase from human and other mammalian tissues and from avian sources were also investigated. Among human and all animal tissues tested, immunoreactive bands on Western blots appeared to have the same molecular mass of 39 kDa. These results indicate that mammalian brains contain only one major type of immunologically similar pyridoxal kinase, although some properties of the enzymes reported previously differed from one another.

Myocardial infarction with Moyamoya disease and pituitary gigantism in a young female patient.

Myocardial infarction is very rare in young female patients with systemic vascular disorders. Moyamoya disease is a cerebrovascular disease associated with an abnormal vascular network. This report presents a 19-year-old female patient who suffered from chest pain and exertional dyspnea for 2 months prior to admission. She had a history of Moyamoya disease and pituitary gigantism since childhood. Her ejection fraction on echocardiogram was 20% and a perfusion defect with partial reversibility in the anterior wall was demonstrated on stress single photon emission computed tomography (SPECT). Diagnostic coronary angiogram revealed critical stenosis in the middle left anterior descending artery, which was treated by coronary stenting. Her subjective symptoms were relieved and the perfusion defect seen on SPECT decreased after coronary intervention.

Morphological variations of the peripapillary circle of Zinn-Haller by flat section.

AIMS: To evaluate the morphometric and morphological variations of the circle of Zinn-Haller (CZH) in the human eye. METHODS: 42 human enucleated eyes were used in this study. After transverse flat thick sections were cut through the optic nerve and adjacent sclera, tissue sections were stained with haematoxylin and eosin or examined immediately by wet preparation under a light microscope. The average vessel diameter of the arterial circle and the average distance between the optic nerve head (ONH) and the arterial circle were determined. Various branching patterns of the CZH were also evaluated. RESULTS: The vessel diameter of the arterial circle was 123 (SD 75) microm (range 20-230 microm). The distance of the CZH from the ONH margin was 403 (352) microm (0-1050 microm). The CZH gave off branches to the optic nerve and to the peripapillary choroid (PPC) with various branching patterns especially at the entry point of paraoptic short posterior ciliary artery. CONCLUSIONS: The CZH exists within a variable distance from the ONH and its average diameter is similar to that of the central retinal vessels though it shows marked variation even in the same circle. The CZH also shows variable configurations in branching patterns. These variations may act as contributing factors that are responsible for the individual susceptibility of the anterior optic nerve and the PPC to circulatory disturbances.

The effects of antiplatelet agents in the prevention of ventricular tachyarrhythmias during acute myocardial ischemia in rats.

Experiments were performed in rat models to study the effectiveness of various antiplatelet agents in the prevention of ventricular tachyarrhythmias during acute myocardial ischemia. The time to the onset of ST-segment elevation and initiating ventricular arrhythmias, frequency and incidence of ventricular arrhythmias, and mortality rates were observed during acute myocardial ischemia (20 minutes) induced by ligation of the proximal left anterior descending coronary artery (LAD) in anesthetized rats. Four groups were studied: Control group (n = 10, not pretreated); Aspirin pretreated group (n = 10, 300 mg/kg p.o. for 1 wk); Ticlopidine pretreated group (n = 10, 200 mg/kg p.o. for 1 wk); and Abciximab (Platelet glycoprotein IIb/IIIa receptor antagonist) pretreated group (n = 10, 2 mg/kg i.v. 10-20 minutes before an experiment). No significant difference was observed in the time to the onset of ST-segment elevation and ventricular arrhythmias between the groups. The incidence of ventricular tachycardia (VT) in the abciximab group was significantly lower than in the control group (p < 0.05) and ventricular fibrillation (VF) in the aspirin and ticlopidine group was significantly lower than in the control group (p < 0.05). The mortality rate in the ticlopidine group was significantly lower than in the control group (p < 0.01). This study suggests aspirin, ticlopidine, and abciximab can effectively prevent VT or VF during acute myocardial ischemia induced by nonthrombotic occlusion and its antiarrhythmic effect may lead to prolonged survival.