PubMed Health⌕ Search

Biomedical subjects

J C Kang

Publications and source records attributed to J C Kang.

At least 19 recordsLinked to original sources

Fourier-transform infrared-based genome-wide association study identifies candidate genes and variants for sow colostrum composition.

Sows with high prolificacy and better lactation traits are beneficial for weaned piglet number. Because the genetic basis of sow lactation traits remains elusive, genetic improvement for lactation traits lags behind that for litter traits, constraining the full realisation of genetic potential for large litters. Here, we measured 1&#xa0;060 Fourier-transform infrared (FTIR) wavenumbers and five predicted colostrum composition traits from sow colostrum samples. Heritability estimates for both the FTIR spectra and predicted traits ranged from moderate to high. Correlation analysis revealed that lactose percentage was negatively genetically correlated with the other four predicted traits (fat percentage, protein percentage, total solid content, and urea nitrogen content) and with 24&#xa0;h litter weight, which was positively genetically correlated with both protein and total solid content. Genome-wide association studies on the FTIR spectra and predicted traits identified 134 significant single-nucleotide polymorphisms (SNPs) (False discovery rate < 0.05), with most clustering on Sus scrofa chromosomes (SSC) 5 and 7. Among the candidate genes, two expressed in lactating mammary tissue have established roles in milk trait determination: (1) LALBA, which encodes a major colostrum protein and is responsible for lactose synthesis, and (2) BTN1A1, which mediates milk fat secretion. Additionally, the study detected two important candidate variants on SSC7: (1) rs691487382, which was colocalised with the expression quantitative trait locus signal for TRIM26 in the liver, a key metabolic organ supporting lactation, and (2) rs327923027, a missense variant located in a phylogenetically conserved domain of TRIM26, an E3 ubiquitin ligase implicated in liver homeostasis. Taken together, this study identifies, for the first time, candidate genes and variants for sow colostrum, providing genomic markers useful for genetic improvement.

Association analysis↗

The enhancement of nuclear receptor transcriptional activation by a mouse actin-binding protein, alpha actinin 2.

The p160 coactivators, steroid receptor coactivator 1, glucocorticoid receptor interacting protein 1 (GRIP1) and the activator of thyroid and retinoic acid receptor, have two activation domains, AD1 and AD2, which transmit the activation signal from the DNA-bound nuclear receptor to the chromatin and/or transcription machinery. In screening for mammalian proteins that bind the AD2 of GRIP1, we identified a mouse actin-binding protein, alpha actinin 2 (mACTN2). mACTN2 was expressed in the heart, skeletal muscle, lung, brain and testis, but there was no expression in the spleen, liver or kidney. Interestingly, the expression level of mACTN2 in the developing embryo depended on the embryonic stage. We further demonstrated that mACTN2 could enhance two transactivation activities of GRIP1, which in turn could enhance the homodimerization of mACTN2. Importantly, mACTN2 not only served as a primary coactivator for androgen receptor, estrogen receptor and thyroid receptor activities, but also acted synergistically with GRIP1 to enhance these nuclear receptor (NR) functions. However, the NR binding motif, LXXLL, conserved in mACTN2 and other actinin family proteins, might be a dispensable domain for its coactivator roles in NRs. These findings suggested that mACTN2 might play an important role in GRIP1-induced NR coactivator functions.

Actinin↗

Species concepts in the Cylindrocladium floridanum and Cy. spathiphylli complexes (Hypocreaceae) based on multi-allelic sequence data, sexual compatibility and morphology.

Much attention has recently been devoted to the delimitation of species units in Cylindrocladium (Cy.). In this regard the present study focuses on the taxa within the unresolved Cy. floridanum and Cy. spathiphylli species complexes. Maximum parsimony analyses of DNA sequences of ITS, beta-tubulin and histone regions of rRNA genes, and mating experiments revealed a geographically isolated species of Cylindrocladium in the Cy. spathiphylli (teleomorph: Calonectria spathiphylli) species complex. Cy. pseudospathiphylli sp. nov. (teleomorph: Ca. pseudospathiphylli sp. nov.) is described as a new phylogenetic, biological and morphological species. It is distinguished from Cy. spathiphylli by being homothallic, having smaller macroconidia, and distinct DNA sequences of beta-tubulin and histone genes. Similarly, parsimony analysis of a combined data set also indicated several phylogenetic species to exist within Cy. floridanum (teleomorph: Ca. kyotensis). Based on differences in vesicle morphology and conidium dimensions, the Canadian population of Cy. floridanum, formerly known as Cy. floridanum Group 2, is described as Cy. canadense sp. nov., while a further collection from Hawaii is described as Cy. pacificum sp. nov.

Alleles↗

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.

Adolescent↗

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.

Aortic Aneurysm↗

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.

Hemorrhagic Fever with Renal Syndrome↗

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.

Abciximab↗

Melatonin ameliorates autoimmune encephalomyelitis through suppression of intercellular adhesion molecule-1.

Melatonin (N-acetyl-5-methoxytryptamine), a pineal neurohormone, is a hydroxyl radical scavenger and antioxidant, and plays an important role in the immune system. We studied the effect of exogenous melatonin on the pathogenesis of experimental autoimmune encephalomyelitis (EAE). EAE was induced in Lewis rats by immunization with rat spinal cord homogenates. Subsequent oral administration of melatonin at 5 mg/kg significantly reduced the clinical severity of EAE paralysis compared with administration of the vehicle alone (p<0.01). Infiltration of ED1+ macrophages and CD4+ T cells into spinal cords occurred both in the absence and presence of melatonin treatment, but melatonin-treated rats had less spinal cord infiltration of inflammatory cells than did the control group. ICAM-1 immunoreactivity in the blood vessels of EAE lesions was decreased in melatonin-treated rats compared to vehicle-treated rats. These findings suggest that exogenous melatonin ameliorates EAE via a mechanism involving reduced expression of ICAM-1 and lymphocyte function associated antigen-1a in autoimmune target organs.

Animals↗

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.

Aged↗

Premedication with dextromethorphan provides posthemorrhoidectomy pain relief.

PURPOSE: Previous studies have shown that N-methyl-D-aspartate receptor antagonists provide a preemptive analgesic effect in humans. This study was designed to examine whether premedication with dextromethorphan, an N-methyl-D-aspartate antagonist, also provided a preemptive analgesic effect that improved postoperative pain management. METHODS: Sixty patients who were American Society of Anesthesiologists status I and II scheduled for hemorrhoidectomy (modified Whitehead procedure) were included in the study. Patients were randomly assigned to the control and study groups. For the control group patients received chlorpheniramine maleate (20 mg), a component of the injection form of dextromethorphan, intramuscular injection 30 minutes before skin incision. In the study group dextromethorphan 40 mg containing 20 mg chlorpheniramine maleate (intramuscular) was given as premedication 30 minutes before skin incision. Pethidine (1 mg/kg, intramuscular) was given for pain relief as required postoperatively. The time to first pethidine injection, total pethidine consumption, worst pain score, and pethidine-related side effects were recorded for 48 hours postoperatively. RESULTS: The times to first pethidine injection (mean +/- standard error of the mean) were 5.2 +/- 3 and 19.6 +/- 6 hours in the control and study groups, respectively. Total pethidine consumption was 140 +/- 11.3 and 63.5 +/- 11.8 mg in the control and study groups. The worst visual analog scale pain scores were 7.4 +/- 0.2 and 5.6 +/- 0.3 in the control and study groups during the two-day observation. The numbers of patients who required pethidine injection were 29 and 20 in the control and study groups, respectively. Two patients suffered pethidine-related side effects, such as nausea, vomiting, dizziness, and headache, in the control group, and no patient complained of any side effect in the study group. CONCLUSION: We found that dextromethorphan premedication provided a preemptive analgesic effect, thus producing reduced postoperative pain and pethidine requirement and improved recovery from hemorrhoidectomy.

Adult↗

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.

Adult↗

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.

Aged↗

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.

Animals↗

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.

Adult↗

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.

Abciximab↗

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.

Adipose Tissue↗