[Show abstract][Hide abstract] ABSTRACT: Background and objectives:
The diagnosis of ischemic (ICM) and non-ischemic cardiomyopathy (NICM) is conventionally determined by the presence or absence of coronary artery disease (CAD) in the setting of a reduced left systolic function. However the presence of CAD may not always indicate that the actual left ventricular (LV) dysfunction mechanism is ischemia, as other non-ischemic etiologies can be responsible. We investigated patterns of myocardial fibrosis using delayed hyperenhancement (DHE) on cardiac magnetic resonance (CMR) in ICM and NICM.
Subjects and methods:
Patients with systolic heart failure who underwent a CMR were prospectively analyzed. The heart failure diagnosis was based on the modified Framingham criteria and LVEF <35%. LV dysfunction was classified as ICM or NICM based on coronary anatomy.
A total of 101 subjects were analyzed; 34 were classified as ICM and 67 as NICM. The DHE pattern was concordant with the conventional diagnosis in 27 (79.4%) of the patients with ICM and 62 (92.5%) of the patients with NCIM. A discordant NICM DHE pattern was present in 8.8% of patients with ICM, and an ICM pattern was detected 6.0% of the patients with NICM. Furthermore, 11.8% of the patients with ICM and 1.5% of those with NICM demonstrated a mixed pattern.
A subset of patients conventionally diagnosed with ICM or NICM based on coronary anatomy demonstrated a discordant or mixed DHE pattern. CMR-DHE imaging can be helpful to determine the etiology of heart failure in patients with persistent LV systolic dysfunction.
Preview · Article · Jan 2016 · Korean Circulation Journal
[Show abstract][Hide abstract] ABSTRACT: Human telomerase reverse transcriptase (hTERT) contributes to tumor progression as well as maintaining telomere length, however, the mechanism by which hTERT promotes invasiveness is not yet completely understood. This study aims to unravel the precise mechanism through which hTERT promotes cancer invasion. We established an hTERT-overexpressed immortalized cell line (IHOK/hTERT). In orthotopic xenograft models, IHOK/hTERT harbors higher tumorigenicity than IHOK/Control. IHOK/hTERT showed much higher migration and invasion activities compared to IHOK/Control. IHOK/hTERT co-cultured with fibroblasts displayed increased invasion compared to IHOK/hTERT without fibroblasts. We screened for genes that play an important role in intermodulation between cancer cells and fibroblasts using a microarray and identified fibroblast activation protein (FAP). hTERT knockdown showed decreased expression of FAP and early growth response (EGR)-1, one of the transcriptional regulators of FAP in IHOK/hTERT and oral cancer cell line YD10B. Furthermore, EGR-1 knockdown in IHOK/hTERT and YD10B showed reduced invasion and reduced cathepsin D expression compared to Control-siRNA cells. Taken together, this study provides evidence that hTERT overexpression is responsible for the upregulation of the cysteine protease cathepsin D by regulating EGR-1 to activate invasiveness in cancer progression.
[Show abstract][Hide abstract] ABSTRACT: Background Conflict persists regarding whether the presence of early collateral blood flow to the infarct-related artery has an effective role in reducing infarct size and improving myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI). We sought to investigate the impact of the collateral circulation on myocardial salvage and infarct size in STEMI patients. Methods In 306 patients who were diagnosed with STEMI and underwent cardiac magnetic resonance within 1 week after revascularization, initial collateral flow to the infarct-related artery was assessed by coronary angiography. Using cardiac magnetic resonance imaging, myocardial infarct size and salvage were measured. Results Among 247 patients with preprocedural Thrombolysis in Myocardial Infarction flow 0/1, 54 (22%) patients had good collaterals (Rentrop grade ≥2, Collateral Connection Score ≥2). Infarct size and area at risk were significantly smaller in patients with good collaterals than those with poor collaterals (infarct size: 17.1±10.1 %LV vs 21.8±10.5 %LV, P =.003, area at risk: 33.8±16.8 %LV vs 38.8±15.5 %LV, P =.039). There was a significant difference of myocardial salvage index between 2 groups (50.9% ± 15.0% vs 43.8% ± 18.5%, P =.005). Poor collateralization was an independent predictor for large infarct size (odd ratio 2.48 [1.28-4.80], P =.007). Conclusions In patients with STEMI, the presence of well-developed collaterals to occluded coronary artery from the noninfarct vessel and its extent were independently associated with reduced infarct burden and improved myocardial salvage. Our results help explain why MI patients with well-developed collateralization have reduced mortality and morbidity.
No preview · Article · Oct 2015 · American Heart Journal
[Show abstract][Hide abstract] ABSTRACT: Hepatocellular carcinoma (HCC) is the fifth most common cancer in Korea. Diverse paraneoplastic syndromes can occur in patients with HCC, but parathyroid hormone-related peptide (PTH-rP)-induced hypercalcemia is uncommon. Hypercalcemia due to PTH or particularly PTH-rP-secreting HCC is associated with poor outcomes. We report a 71-year-old man who presented with symptoms of vague abdominal discomfort, somnolence, lethargy, nausea, vomiting, and weight loss. Imaging studies revealed a large HCC without metastasis. The laboratory findings showed elevated serum calcium level, low intact parathyroid hormone (iPTH) level and elevated PTH-rP level. These results led to a diagnosis of a PTH-rP-secreting HCC and paraneoplastic hypercal-cemia. After emergency management of the hypercalcemia, the patient underwent an extended right hemihepatectomy with cholecystectomy. One year after the surgery, he is alive with normal calcium, PTH-rP, and iPTH levels. This case demonstrates that the rare phenomenon of life-threatening hypercalcemia caused by HCC should not be overlooked. These symptoms offer a good opportunity to diagnose HCC early. Radical tumor resection makes it possible to cure patients with PTH-rP-secreting HCC.
No preview · Article · Aug 2015 · The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi
[Show abstract][Hide abstract] ABSTRACT: In patients with non-ischemic cardiomyopathy (NICM), risk stratification for sudden cardiac death (SCD) and selection of patients who would benefit from prophylactic implantable cardioverter-defibrillators remains challenging. We aim to discuss the evidence of cardiac magnetic resonance (CMR)-derived myocardial scar for the prediction of adverse cardiovascular outcomes in NICM. From the 15 studies analyzed, with a total of 2747 patients, the average prevalence of myocardial scar was 41%. In patients with myocardial scar, the risk for adverse cardiac events was more than 3-fold higher, and risk for arrhythmic events 5-fold higher, as compared to patients without scar. Based on the available observational, single center studies, CMR scar assessment may be a promising new tool for SCD risk stratification, which merits further investigation.
Preview · Article · Jul 2015 · Korean journal of radiology: official journal of the Korean Radiological Society
[Show abstract][Hide abstract] ABSTRACT: Androgen receptor (AR) signaling is important for prostate cancer (PCa) cell proliferation. Here, we showed that proliferation of hormone-sensitive prostate cancer cells such as LNCaP was significantly enhanced by testosterone stimulation whereas hormone-insensitive prostate cancer cells such as PC3 and VCaP did not respond to testosterone stimulation. Blocking of AR using bicalutamide abolished testosterone-induced proliferation of LNCaP cells. In addition, knockdown of AR blocked testosterone-induced proliferation of LNCaP cells. Basal expression of low-density lipoprotein receptor-related protein 6 (LRP6) was elevated in VCaP cells whereas stimulation of testosterone did not affect the expression of LRP6. However, expression of LRP6 in LNCaP cells was increased by testosterone stimulation. In addition, knockdown of LRP6 abrogated testosterone-induced proliferation of LNCaP cells. Given these results, we suggest that androgen-dependent expression of LRP6 plays a crucial role in hormone-sensitive prostate cancer cell proliferation.
Full-text · Article · May 2015 · Korean Journal of Physiology and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Despite technical simplicity and the low cost of brachial-ankle pulse wave velocity (BA-PWV), its use has been hampered by a lack of data supporting its usefulness and reliability. The aim of this study was to evaluate the usefulness of BA-PWV to measure aortic stiffness in comparison to using cardiovascular magnetic resonance (CMR).
A total of 124 participants without cardiovascular risk factors volunteered for this study. BA-PWV was measured using a vascular testing device. On the same day, using CMR, cross-sectional areas for distensibility and average blood flow were measured at four aortic levels: the ascending, upper thoracic descending, lower thoracic descending, and abdominal aorta.
Compared to PWV measured by CMR, BA-PWV values were significantly higher and the differences therein were similar in all age groups (all p<0.001). There was a significant correlation between BA-PWV and PWV by CMR (r=0.697, p<0.001). Both BA-PWV and PWV by CMR were significantly and positively associated with age (r=0.652 and 0.724, p<0.001). The reciprocal of aortic distensibility also demonstrated a statistically significant positive correlation with BA-PWV (r=0.583 to 0.673, all p<0.001).
BA-PWV was well correlated with central aortic PWV and distensibility, as measured by CMR, regardless of age and sex.
Preview · Article · May 2015 · Yonsei medical journal
[Show abstract][Hide abstract] ABSTRACT: The volume of traveling websites is rapidly increasing. This makes relevant information extraction more challenging. Several fuzzy ontology-based systems have been proposed to decrease the manual work of a full-text query search engine and opinion mining. However, most search engines are keyword-based, and available full-text search engine systems are still imperfect at extracting precise information using different types of user queries. In opinion mining, travelers do not declare their hotel opinions entirely but express individual feature opinions in reviews. Hotel reviews have numerous uncertainties, and most featured opinions are based on complex linguistic wording (small, big, very good and very bad). Available ontology-based systems cannot extract blurred information from reviews to provide better solutions. To solve these problems, this paper proposes a new extraction and opinion mining system based on a type-2 fuzzy ontology called T2FOBOMIE. The system reformulates the user’s full-text query to extract the user requirement and convert it into the format of a proper classical full-text search engine query. The proposed system retrieves targeted hotel reviews and extracts feature opinions from reviews using a fuzzy domain ontology. The fuzzy domain ontology, user information and hotel information are integrated to form a type-2 fuzzy merged ontology for the retrieving of feature polarity and individual hotel polarity. The Protégé OWL-2 (Ontology Web Language) tool is used to develop the type-2 fuzzy ontology. A series of experiments were designed and demonstrated that T2FOBOMIE performance is highly productive for analyzing reviews and accurate opinion mining.
[Show abstract][Hide abstract] ABSTRACT: It is uncertain that atorvastatin pretreatment can reduce myocardial damage in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). The aim of this study was to investigate the effects of atorvastatin pretreatment on infarct size measured by contrast-enhanced magnetic resonance imaging (CE-MRI) in STEMI patients. Patients undergoing primary PCI for STEMI within 12 hr after symptom onset were randomized to an atorvastatin group (n=30, 80 mg before PCI and for 5 days after PCI) or a control group (n=37, 10 mg daily after PCI). The primary end point was infarct size evaluated as the volume of delayed hyperenhancement by CE-MRI within 14 days after the index event. The median infarct size was 19% (IQR 11.1%-31.4%) in the atorvastatin group vs. 16.3% (7.2%-27.2%) in the control group (P=0.27). The myocardial salvage index (37.1% [26.9%-58.7%] vs. 46.9% [39.9-52.4], P=0.46) and area of microvascular obstruction (1.1% [0%-2.0%] vs. 0.7% [0%-1.8%], P=0.37) did not differ significantly between the groups. Frequency of the hemorrhagic and transmural infarctions was not significantly different in the 2 groups. Pretreatment with a high-dose atorvastatin followed by further treatment for 5 days in STEMI patients undergoing primary PCI failed to reduce the extent of myocardial damage or improve myocardial salvage.
Preview · Article · Apr 2015 · Journal of Korean medical science
[Show abstract][Hide abstract] ABSTRACT: In the effects of postconditioning on myocardial reperfusion in patients with ST-segment elevation myocardial infarction (POST) trial, ischemic postconditioning did not improve myocardial reperfusion in 700 patients with STEMI undergoing primary PCI. However, the impact of postconditioning on myocardial salvage and infarct size still needs to be addressed. The aim of this study was to investigate the effect of ischemic postconditioning on myocardial salvage using cardiac magnetic resonance (CMR) in patients with STEMI undergoing primary PCI. For the CMR substudy, a total of 111 patients was analyzed, 56 in the postconditioning group and 55 undergoing conventional primary PCI in the control group. Postconditioning was performed immediately after restoration of coronary flow by four cycles of 1-min balloon occlusion separated by 1 min of deflation. The primary end point was myocardial salvage measured by CMR 3 days after the index event. The myocardial salvage index was not improved by ischemic postconditioning compared with conventional PCI (46.3 ± 18.5 vs. 45.7 ± 20.5 %, p = 0.86). The infarct size was not significantly different between the two groups (18.8 ± 10.3 vs. 20.2 ± 11.0 %, p = 0.52). Moreover, there was no significant difference in the rates of microvascular obstruction or hemorrhagic infarction between the groups. CMR study demonstrated that ischemic postconditioning during primary PCI in STEMI patients did not improve myocardial salvage or reduce infarct size. These findings further support the results of the POST trial which showed no benefit of ischemic postconditioning as an adjunctive treatment of primary PCI.
No preview · Article · Jan 2015 · The International Journal of Cardiovascular Imaging