Publications by authors named "Won J Choi"

Carcinoma erysipelatoides, also known as inflammatory metastatic carcinoma, is a rare form of cutaneous metastasis. It is most commonly caused by breast carcinoma, but rarely associated with gastric adenocarcinoma. Herein, we report an unusual case of carcinoma erysipelatoides in a 55 year-old female who had been diagnosed with signet ring cell carcinoma of the stomach metastasizing to ovaries.

View Article and Find Full Text PDF

The stereoselective synthesis of truncated 3'-aminocarbanucleosides 4a-d via a stereo- and regioselective conversion of a diol 9 to bromoacetate 11a and their binding affinity towards the human A(3) adenosine receptor are described.

View Article and Find Full Text PDF

A3 adenosine receptor (A3AR) is recognized as a novel therapeutic target for ischemic injury; however, the mechanism underlying anti-ischemic protection by the A3AR agonist remains unclear. Here, we report that 2-chloro-N(6)-(3-iodobenzyl)-5'-N-methylcarbamoyl-4'-thioadenosine (LJ529), a selective A3AR agonist, reduces inflammatory responses that may contribute to ischemic cerebral injury. Postischemic treatment with LJ529 markedly reduced cerebral ischemic injury caused by 1.

View Article and Find Full Text PDF

Background And Objectives: Little data is currently available on the usefulness of peak-standardized uptake value (P-SUV) by positron emission tomography-computed tomography (PET-CT) in gastric cancer. The purpose of the present study was to evaluate the value of PET-CT for the preoperative evaluation of patients with gastric cancer. The aim of this study was to assess the relation of between primary tumor P-SUV, as determined by preoperative PET-CT, and lymph node metastasis in gastric cancer.

View Article and Find Full Text PDF

This article reviews the landmark studies of advertising claims and analyzes the health claims for food products advertised on Korean TV. The present study examined 1,479 food commercials aired on three major television networks from 2005 to 2007. The commercials containing health claims accounted for 29.

View Article and Find Full Text PDF

Purpose: T-tube is a major procedure that prevents complication by biliary decompression, but which is accompanied by complications. Therefore, several procedures such as ENBD, PTBD, and antegrade biliary stent have been attempted, but with controversies as to which procedure is superior. Also, there are no standard procedures after laparoscopic CBD exploration.

View Article and Find Full Text PDF

Background: Despite the beneficial effects of alagebrium (ALA), a putative advanced glycation end-product (AGE) breaker, on diabetic nephropathy, its renoprotective mechanisms are incompletely understood. Since oxidative stress exacerbates diabetic renal injury through interaction with AGE, the present study examined the antioxidative property of ALA in db/db mice, mesangial cells cultured under high glucose or H(2)O(2) and a test tube.

Methods: ALA (2 mg/kg/day) was administered intraperitoneally for 12 weeks to 8-week-old db/m and db/db (D(ALA)E) mice or for 4 weeks to 16-week-old db/db mice (D(ALA)L).

View Article and Find Full Text PDF

Aim: We evaluated the efficacy of uterine artery embolization (UAE) for controlling postpartum hemorrhage (PPH).

Materials And Methods: Between January 2008 and December 2009, 23 women with intractable PPH underwent UAE. Specific diagnoses included uterine atony (n = 10), placenta accreta (n = 8), puerperal hematoma (n = 2) and placental polyp (n = 3).

View Article and Find Full Text PDF

The carrier thermodynamics of InAs self assembled quantum dot (QD) are investigated. The investigated parameters include the dependence of quantum dot photoluminescence on temperature and the photoluminescence (PL) dependence on the excitation power density. Results are discussed on the basis of steady state model.

View Article and Find Full Text PDF

MLN4924 (1), which is in clinical trials as an anticancer agent, was stereoselectively synthesized from d-ribose via a route involving stereoselective reduction, regioselective cleavage of an isopropylidene moiety, and selective displacement of a cyclic sulfate moiety as key steps.

View Article and Find Full Text PDF

Myopericytoma is a benign neoplasm consisting of cells that appear to have a distinct differentiation towards presumed perivascular myoid cells. Amongst myopericytoma, an intravascular variant appears to have been reported only rarely. A 67-year-old man presented with a 15-year history of a painful, slow growing 3 × 3.

View Article and Find Full Text PDF

Background: Although natural orifice extraction is now widely performed, there have been no reports of this procedure following subtotal gastrectomy for gastric cancer. This report describes trans-vaginal specimen extraction in four patients with early gastric cancer.

Methods: The clinical data of four patients with early gastric cancer were reviewed.

View Article and Find Full Text PDF

The X-ray crystal structure of human S-adenosylhomocysteine (AdoHcy) hydrolase was first determined as a tetrameric form bound with the novel mechanism-based inhibitor fluoroneplanocin A (4b). The crystallized enzyme complex showed the closed conformation and turned out to be the intermediate of mechanism-based inhibition. It confirmed that the cofactor depletion by 3'-oxidation of fluoroneplanocin A contributes to the enzyme inhibition along with the irreversible covalent modification of AdoHcy hydrolase.

View Article and Find Full Text PDF

The rapidly expanding market for biodiesel has increased the supply and reduced the cost of glycerol, making it an attractive sustainable feed stock for the fuel and chemical industry. Glycerol-based biorefinery is the microbial fermentation of crude glycerol to produce fuels and chemicals. A major challenge is to obtain microbes tolerant to inhibitors such as salts and organic solvents present in crude glycerol.

View Article and Find Full Text PDF

Homologated analogues and of potent and selective A adenosine receptor ligands, IB-MECA and dimethyl-IB-MECA were synthesized from commercially available 1--acetyl-2,3,5-tri--benzoyl-β-d-ribofuranose () Co(CO)-catalyzed siloxymethylation as a key step. Unfortunately, homologated analogues and did not show significant binding affinities at three subtypes of adenosine receptors, indicating that free rotation, resulting from homologation, induced unfavorable interactions in the binding site of the receptor maybe due to the presence of many conformations.

View Article and Find Full Text PDF

A 33-year-old male patient with multiple sclerosis (MS) received an emergency laparotomy because of perforated appendicitis. He had been suffering from MS for 2 years and the symptoms of MS were paraplegia and urinary incontinence. Anesthesia was induced with propofol and remifentanil and maintained with nitrous oxide, sevoflurane and remifentanil.

View Article and Find Full Text PDF

Cushing's syndrome (CS) in pregnancy may be confused with a complication of pregnancy, such as pre-eclampsia or gestational diabetes. We managed a case of CS in pregnancy that was considered to be severe pre-eclampsia due to uncontrolled hypertension. The fetus was delivered via emergency cesarean section at 31 weeks' gestation because of severe pre-eclampsia and pulmonary edema.

View Article and Find Full Text PDF

Rocuronium is the anesthetic agent most likely to cause anaphylaxis. Immediately after intravenous rocuronium administration, the authors experienced ventilatory impairment due to unilateral bronchospasm (left lung), which was relieved by emergency treatment. However, 80 minutes after beginning laparoscopic surgery for rectal cancer, the left lung suddenly re-collapsed under pneumoperitoneum in the Trendelenburg position.

View Article and Find Full Text PDF

An 18-year-old male with huge anterior mediastinum mass was scheduled for thoracotomic incisional biopsy under general anesthesia after failed fluoroscopy-guided percutaneous needle biopsy. Under propofol and succinylcholine anesthesia, intubation was successfully achieved using a Univent tube. However, when we changed the patient's position from supine to right lateral decubitus, oxygen saturation declined.

View Article and Find Full Text PDF

We synthesized homologated truncated 4'-thioadenosine analogues 3 in which a methylene (CH(2)) group was inserted in place of the glycosidic bond of a potent and selective A(3) adenosine receptor antagonist 2. The analogues were designed to induce maximum binding interaction in the binding site of the A(3) adenosine receptor. However, all homologated nucleosides were devoid of binding affinity at all subtypes of adenosine receptors, indicating that free rotation through the single bond allowed the compound to adopt an indefinite number of conformations, disrupting the favorable binding interaction essential for receptor recognition.

View Article and Find Full Text PDF

Although writing was the first human process for communication, it may now become the main process in the electronics industry, because in the industry the programmability as an inherent property is a necessary requirement for next-generation electronics. As an effort to open the era of writing electronics, here we show the feasibility of the direct printing of a high-performance inorganic single crystalline semiconductor nanowire (NW) Schottky diode (SD), including Schottky and Ohmic contacts in series, using premetallization and wrapping with metallic nanofoil. To verify the feasibility of our process, SDs made of Al-premetalized ZnO NWs and plain ZnO NWs were compared with each other.

View Article and Find Full Text PDF

Background: Human A(3) adenosine receptor (A(3)AR) plays an essential role in several physiopathological processes. Thus far, A(3)AR-selective ligands have been evaluated as anti-inflammation and anticancer therapeutic agents. Among these ligands, truncated thio-Cl-IB-MECA is a newly reported antagonist, and its function has not been studied.

View Article and Find Full Text PDF

On the basis of potent anti-hepatitis C virus (HCV) activity of 2'-C-hydroxymethyladenosine, 3'-C-substituted-methyl-ribofuranosyl pyrimidine and purine nucleosides were designed and synthesized from D-xylose. Among compounds tested, all adenine analogues, 4a, 4d, and 4g showed significant anti-HCV activity in a replicon-based cell assay irrespective of the substituent (Y=OH, N₃, or F) at the 3'-C-substituted methyl position, among which 4g (Y=N₃) was the most potent, but it is also cytotoxic. This study guarantees the 3'-C-substituted-methyl nucleoside serves as a new template for the development of new anti-HCV agents.

View Article and Find Full Text PDF

Kimura's disease is a rare inflammatory disorder of unknown etiology primarily seen in young Asian males. It is characterized by painless subcutaneous masses, blood and tissue eosinophilia, and markedly elevated serum immunoglobulin E (IgE) levels. Clinically, the subcutaneous nodules occur predominantly in the head and neck.

View Article and Find Full Text PDF

The first synthesis of 4'-selenothymidine (1), a novel DNA building block, and 4'-seleno-AZT (2) was accomplished from 2-deoxy-d-ribose via stereoselective formation of 2-deoxy-4-seleno-d-furanose 17 and a Pummerer-type base condensation as key steps. 4'-Selenothymidine (1) was discovered to adopt the same 2'-endo/3'-exo conformation as thymidine, which is unusual in that 4'-selenouridine has the opposite conformation to that of uridine.

View Article and Find Full Text PDF